/* Output variables, constants and external declarations, for GNU compiler. Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see . */ /* This file handles generation of all the assembler code *except* the instructions of a function. This includes declarations of variables and their initial values. We also output the assembler code for constants stored in memory and are responsible for combining constants with the same value. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "tree.h" #include "flags.h" #include "function.h" #include "expr.h" #include "hard-reg-set.h" #include "regs.h" #include "real.h" #include "output.h" #include "toplev.h" #include "hashtab.h" #include "c-pragma.h" #include "ggc.h" #include "langhooks.h" #include "tm_p.h" #include "debug.h" #include "target.h" #include "tree-mudflap.h" #include "cgraph.h" #include "cfglayout.h" #include "basic-block.h" #include "tree-iterator.h" #ifdef XCOFF_DEBUGGING_INFO #include "xcoffout.h" /* Needed for external data declarations for e.g. AIX 4.x. */ #endif /* The (assembler) name of the first globally-visible object output. */ extern GTY(()) const char *first_global_object_name; extern GTY(()) const char *weak_global_object_name; const char *first_global_object_name; const char *weak_global_object_name; struct addr_const; struct constant_descriptor_rtx; struct rtx_constant_pool; struct varasm_status GTY(()) { /* If we're using a per-function constant pool, this is it. */ struct rtx_constant_pool *pool; /* Number of tree-constants deferred during the expansion of this function. */ unsigned int deferred_constants; }; #define n_deferred_constants (cfun->varasm->deferred_constants) /* Number for making the label on the next constant that is stored in memory. */ static GTY(()) int const_labelno; /* Carry information from ASM_DECLARE_OBJECT_NAME to ASM_FINISH_DECLARE_OBJECT. */ int size_directive_output; /* The last decl for which assemble_variable was called, if it did ASM_DECLARE_OBJECT_NAME. If the last call to assemble_variable didn't do that, this holds 0. */ tree last_assemble_variable_decl; /* The following global variable indicates if the first basic block in a function belongs to the cold partition or not. */ bool first_function_block_is_cold; /* We give all constants their own alias set. Perhaps redundant with MEM_READONLY_P, but pre-dates it. */ static alias_set_type const_alias_set; static const char *strip_reg_name (const char *); static int contains_pointers_p (tree); #ifdef ASM_OUTPUT_EXTERNAL static bool incorporeal_function_p (tree); #endif static void decode_addr_const (tree, struct addr_const *); static hashval_t const_desc_hash (const void *); static int const_desc_eq (const void *, const void *); static hashval_t const_hash_1 (const tree); static int compare_constant (const tree, const tree); static tree copy_constant (tree); static void output_constant_def_contents (rtx); static void output_addressed_constants (tree); static unsigned HOST_WIDE_INT array_size_for_constructor (tree); static unsigned min_align (unsigned, unsigned); static void output_constructor (tree, unsigned HOST_WIDE_INT, unsigned int); static void globalize_decl (tree); #ifdef BSS_SECTION_ASM_OP #ifdef ASM_OUTPUT_BSS static void asm_output_bss (FILE *, tree, const char *, unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT); #endif #ifdef ASM_OUTPUT_ALIGNED_BSS static void asm_output_aligned_bss (FILE *, tree, const char *, unsigned HOST_WIDE_INT, int) ATTRIBUTE_UNUSED; #endif #endif /* BSS_SECTION_ASM_OP */ static void mark_weak (tree); static void output_constant_pool (const char *, tree); /* Well-known sections, each one associated with some sort of *_ASM_OP. */ section *text_section; section *data_section; section *readonly_data_section; section *sdata_section; section *ctors_section; section *dtors_section; section *bss_section; section *sbss_section; /* Various forms of common section. All are guaranteed to be nonnull. */ section *tls_comm_section; section *comm_section; section *lcomm_section; /* A SECTION_NOSWITCH section used for declaring global BSS variables. May be null. */ section *bss_noswitch_section; /* The section that holds the main exception table, when known. The section is set either by the target's init_sections hook or by the first call to switch_to_exception_section. */ section *exception_section; /* The section that holds the DWARF2 frame unwind information, when known. The section is set either by the target's init_sections hook or by the first call to switch_to_eh_frame_section. */ section *eh_frame_section; /* asm_out_file's current section. This is NULL if no section has yet been selected or if we lose track of what the current section is. */ section *in_section; /* True if code for the current function is currently being directed at the cold section. */ bool in_cold_section_p; /* A linked list of all the unnamed sections. */ static GTY(()) section *unnamed_sections; /* Return a nonzero value if DECL has a section attribute. */ #ifndef IN_NAMED_SECTION #define IN_NAMED_SECTION(DECL) \ ((TREE_CODE (DECL) == FUNCTION_DECL || TREE_CODE (DECL) == VAR_DECL) \ && DECL_SECTION_NAME (DECL) != NULL_TREE) #endif /* Hash table of named sections. */ static GTY((param_is (section))) htab_t section_htab; /* A table of object_blocks, indexed by section. */ static GTY((param_is (struct object_block))) htab_t object_block_htab; /* The next number to use for internal anchor labels. */ static GTY(()) int anchor_labelno; /* A pool of constants that can be shared between functions. */ static GTY(()) struct rtx_constant_pool *shared_constant_pool; /* TLS emulation. */ static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map))) htab_t emutls_htab; static GTY (()) tree emutls_object_type; #ifndef NO_DOT_IN_LABEL # define EMUTLS_VAR_PREFIX "__emutls_v." # define EMUTLS_TMPL_PREFIX "__emutls_t." #elif !defined NO_DOLLAR_IN_LABEL # define EMUTLS_VAR_PREFIX "__emutls_v$" # define EMUTLS_TMPL_PREFIX "__emutls_t$" #else # define EMUTLS_VAR_PREFIX "__emutls_v_" # define EMUTLS_TMPL_PREFIX "__emutls_t_" #endif /* Create an identifier for the struct __emutls_object, given an identifier of the DECL_ASSEMBLY_NAME of the original object. */ static tree get_emutls_object_name (tree name) { char *toname = alloca (strlen (IDENTIFIER_POINTER (name)) + sizeof (EMUTLS_VAR_PREFIX)); strcpy (toname, EMUTLS_VAR_PREFIX); strcpy (toname + sizeof (EMUTLS_VAR_PREFIX) - 1, IDENTIFIER_POINTER (name)); return get_identifier (toname); } /* Create the structure for struct __emutls_object. This should match the structure at the top of emutls.c, modulo the union there. */ static tree get_emutls_object_type (void) { tree type, type_name, field, next_field, word_type_node; type = emutls_object_type; if (type) return type; emutls_object_type = type = lang_hooks.types.make_type (RECORD_TYPE); type_name = get_identifier ("__emutls_object"); type_name = build_decl (TYPE_DECL, type_name, type); TYPE_NAME (type) = type_name; field = build_decl (FIELD_DECL, get_identifier ("__templ"), ptr_type_node); DECL_CONTEXT (field) = type; next_field = field; field = build_decl (FIELD_DECL, get_identifier ("__offset"), ptr_type_node); DECL_CONTEXT (field) = type; TREE_CHAIN (field) = next_field; next_field = field; word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); field = build_decl (FIELD_DECL, get_identifier ("__align"), word_type_node); DECL_CONTEXT (field) = type; TREE_CHAIN (field) = next_field; next_field = field; field = build_decl (FIELD_DECL, get_identifier ("__size"), word_type_node); DECL_CONTEXT (field) = type; TREE_CHAIN (field) = next_field; TYPE_FIELDS (type) = field; layout_type (type); return type; } /* Create a read-only variable like DECL, with the same DECL_INITIAL. This will be used for initializing the emulated tls data area. */ static tree get_emutls_init_templ_addr (tree decl) { tree name, to; char *toname; if (!DECL_INITIAL (decl)) return null_pointer_node; name = DECL_ASSEMBLER_NAME (decl); toname = alloca (strlen (IDENTIFIER_POINTER (name)) + sizeof (EMUTLS_TMPL_PREFIX)); strcpy (toname, EMUTLS_TMPL_PREFIX); strcpy (toname + sizeof (EMUTLS_TMPL_PREFIX) - 1, IDENTIFIER_POINTER (name)); name = get_identifier (toname); to = build_decl (VAR_DECL, name, TREE_TYPE (decl)); SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to)); DECL_ARTIFICIAL (to) = 1; TREE_USED (to) = TREE_USED (decl); TREE_READONLY (to) = 1; DECL_IGNORED_P (to) = 1; DECL_CONTEXT (to) = DECL_CONTEXT (decl); DECL_WEAK (to) = DECL_WEAK (decl); if (DECL_ONE_ONLY (decl)) { make_decl_one_only (to); TREE_STATIC (to) = TREE_STATIC (decl); TREE_PUBLIC (to) = TREE_PUBLIC (decl); DECL_VISIBILITY (to) = DECL_VISIBILITY (decl); } else TREE_STATIC (to) = 1; DECL_INITIAL (to) = DECL_INITIAL (decl); DECL_INITIAL (decl) = NULL; varpool_finalize_decl (to); return build_fold_addr_expr (to); } /* When emulating tls, we use a control structure for use by the runtime. Create and return this structure. */ tree emutls_decl (tree decl) { tree name, to; struct tree_map *h, in; void **loc; if (targetm.have_tls || decl == NULL || decl == error_mark_node || TREE_CODE (decl) != VAR_DECL || ! DECL_THREAD_LOCAL_P (decl)) return decl; /* Look up the object in the hash; return the control structure if it has already been created. */ if (! emutls_htab) emutls_htab = htab_create_ggc (512, tree_map_hash, tree_map_eq, 0); name = DECL_ASSEMBLER_NAME (decl); /* Note that we use the hash of the decl's name, rather than a hash of the decl's pointer. In emutls_finish we iterate through the hash table, and we want this traversal to be predictable. */ in.hash = htab_hash_string (IDENTIFIER_POINTER (name)); in.base.from = decl; loc = htab_find_slot_with_hash (emutls_htab, &in, in.hash, INSERT); h = *loc; if (h != NULL) to = h->to; else { to = build_decl (VAR_DECL, get_emutls_object_name (name), get_emutls_object_type ()); h = ggc_alloc (sizeof (struct tree_map)); h->hash = in.hash; h->base.from = decl; h->to = to; *(struct tree_map **) loc = h; DECL_ARTIFICIAL (to) = 1; DECL_IGNORED_P (to) = 1; TREE_READONLY (to) = 0; SET_DECL_ASSEMBLER_NAME (to, DECL_NAME (to)); if (DECL_ONE_ONLY (decl)) make_decl_one_only (to); DECL_CONTEXT (to) = DECL_CONTEXT (decl); } /* Note that these fields may need to be updated from time to time from the original decl. Consider: extern __thread int i; int foo() { return i; } __thread int i = 1; in which I goes from external to locally defined and initialized. */ TREE_STATIC (to) = TREE_STATIC (decl); TREE_USED (to) = TREE_USED (decl); TREE_PUBLIC (to) = TREE_PUBLIC (decl); DECL_EXTERNAL (to) = DECL_EXTERNAL (decl); DECL_COMMON (to) = DECL_COMMON (decl); DECL_WEAK (to) = DECL_WEAK (decl); DECL_VISIBILITY (to) = DECL_VISIBILITY (decl); return to; } static int emutls_common_1 (void **loc, void *xstmts) { struct tree_map *h = *(struct tree_map **) loc; tree args, x, *pstmts = (tree *) xstmts; tree word_type_node; if (! DECL_COMMON (h->base.from) || (DECL_INITIAL (h->base.from) && DECL_INITIAL (h->base.from) != error_mark_node)) return 1; word_type_node = lang_hooks.types.type_for_mode (word_mode, 1); /* The idea was to call get_emutls_init_templ_addr here, but if we do this and there is an initializer, -fanchor_section loses, because it would be too late to ensure the template is output. */ x = null_pointer_node; args = tree_cons (NULL, x, NULL); x = build_int_cst (word_type_node, DECL_ALIGN_UNIT (h->base.from)); args = tree_cons (NULL, x, args); x = fold_convert (word_type_node, DECL_SIZE_UNIT (h->base.from)); args = tree_cons (NULL, x, args); x = build_fold_addr_expr (h->to); args = tree_cons (NULL, x, args); x = built_in_decls[BUILT_IN_EMUTLS_REGISTER_COMMON]; x = build_function_call_expr (x, args); append_to_statement_list (x, pstmts); return 1; } void emutls_finish (void) { tree body = NULL_TREE; if (emutls_htab == NULL) return; htab_traverse_noresize (emutls_htab, emutls_common_1, &body); if (body == NULL_TREE) return; cgraph_build_static_cdtor ('I', body, DEFAULT_INIT_PRIORITY); } /* Helper routines for maintaining section_htab. */ static int section_entry_eq (const void *p1, const void *p2) { const section *old = p1; const char *new = p2; return strcmp (old->named.name, new) == 0; } static hashval_t section_entry_hash (const void *p) { const section *old = p; return htab_hash_string (old->named.name); } /* Return a hash value for section SECT. */ static hashval_t hash_section (section *sect) { if (sect->common.flags & SECTION_NAMED) return htab_hash_string (sect->named.name); return sect->common.flags; } /* Helper routines for maintaining object_block_htab. */ static int object_block_entry_eq (const void *p1, const void *p2) { const struct object_block *old = p1; const section *new = p2; return old->sect == new; } static hashval_t object_block_entry_hash (const void *p) { const struct object_block *old = p; return hash_section (old->sect); } /* Return a new unnamed section with the given fields. */ section * get_unnamed_section (unsigned int flags, void (*callback) (const void *), const void *data) { section *sect; sect = ggc_alloc (sizeof (struct unnamed_section)); sect->unnamed.common.flags = flags | SECTION_UNNAMED; sect->unnamed.callback = callback; sect->unnamed.data = data; sect->unnamed.next = unnamed_sections; unnamed_sections = sect; return sect; } /* Return a SECTION_NOSWITCH section with the given fields. */ static section * get_noswitch_section (unsigned int flags, noswitch_section_callback callback) { section *sect; sect = ggc_alloc (sizeof (struct unnamed_section)); sect->noswitch.common.flags = flags | SECTION_NOSWITCH; sect->noswitch.callback = callback; return sect; } /* Return the named section structure associated with NAME. Create a new section with the given fields if no such structure exists. */ section * get_section (const char *name, unsigned int flags, tree decl) { section *sect, **slot; slot = (section **) htab_find_slot_with_hash (section_htab, name, htab_hash_string (name), INSERT); flags |= SECTION_NAMED; if (*slot == NULL) { sect = ggc_alloc (sizeof (struct named_section)); sect->named.common.flags = flags; sect->named.name = ggc_strdup (name); sect->named.decl = decl; *slot = sect; } else { sect = *slot; if ((sect->common.flags & ~SECTION_DECLARED) != flags && ((sect->common.flags | flags) & SECTION_OVERRIDE) == 0) { /* Sanity check user variables for flag changes. */ if (decl == 0) decl = sect->named.decl; gcc_assert (decl); error ("%+D causes a section type conflict", decl); } } return sect; } /* Return true if the current compilation mode benefits from having objects grouped into blocks. */ static bool use_object_blocks_p (void) { return flag_section_anchors; } /* Return the object_block structure for section SECT. Create a new structure if we haven't created one already. Return null if SECT itself is null. */ static struct object_block * get_block_for_section (section *sect) { struct object_block *block; void **slot; if (sect == NULL) return NULL; slot = htab_find_slot_with_hash (object_block_htab, sect, hash_section (sect), INSERT); block = (struct object_block *) *slot; if (block == NULL) { block = (struct object_block *) ggc_alloc_cleared (sizeof (struct object_block)); block->sect = sect; *slot = block; } return block; } /* Create a symbol with label LABEL and place it at byte offset OFFSET in BLOCK. OFFSET can be negative if the symbol's offset is not yet known. LABEL must be a garbage-collected string. */ static rtx create_block_symbol (const char *label, struct object_block *block, HOST_WIDE_INT offset) { rtx symbol; unsigned int size; /* Create the extended SYMBOL_REF. */ size = RTX_HDR_SIZE + sizeof (struct block_symbol); symbol = ggc_alloc_zone (size, &rtl_zone); /* Initialize the normal SYMBOL_REF fields. */ memset (symbol, 0, size); PUT_CODE (symbol, SYMBOL_REF); PUT_MODE (symbol, Pmode); XSTR (symbol, 0) = label; SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_HAS_BLOCK_INFO; /* Initialize the block_symbol stuff. */ SYMBOL_REF_BLOCK (symbol) = block; SYMBOL_REF_BLOCK_OFFSET (symbol) = offset; return symbol; } static void initialize_cold_section_name (void) { const char *stripped_name; char *name, *buffer; tree dsn; gcc_assert (cfun && current_function_decl); if (cfun->unlikely_text_section_name) return; dsn = DECL_SECTION_NAME (current_function_decl); if (flag_function_sections && dsn) { name = alloca (TREE_STRING_LENGTH (dsn) + 1); memcpy (name, TREE_STRING_POINTER (dsn), TREE_STRING_LENGTH (dsn) + 1); stripped_name = targetm.strip_name_encoding (name); buffer = ACONCAT ((stripped_name, "_unlikely", NULL)); cfun->unlikely_text_section_name = ggc_strdup (buffer); } else cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME; } /* Tell assembler to switch to unlikely-to-be-executed text section. */ section * unlikely_text_section (void) { if (cfun) { if (!cfun->unlikely_text_section_name) initialize_cold_section_name (); return get_named_section (NULL, cfun->unlikely_text_section_name, 0); } else return get_named_section (NULL, UNLIKELY_EXECUTED_TEXT_SECTION_NAME, 0); } /* When called within a function context, return true if the function has been assigned a cold text section and if SECT is that section. When called outside a function context, return true if SECT is the default cold section. */ bool unlikely_text_section_p (section *sect) { const char *name; if (cfun) name = cfun->unlikely_text_section_name; else name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME; return (name && sect && SECTION_STYLE (sect) == SECTION_NAMED && strcmp (name, sect->named.name) == 0); } /* Return a section with a particular name and with whatever SECTION_* flags section_type_flags deems appropriate. The name of the section is taken from NAME if nonnull, otherwise it is taken from DECL's DECL_SECTION_NAME. DECL is the decl associated with the section (see the section comment for details) and RELOC is as for section_type_flags. */ section * get_named_section (tree decl, const char *name, int reloc) { unsigned int flags; gcc_assert (!decl || DECL_P (decl)); if (name == NULL) name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl)); flags = targetm.section_type_flags (decl, name, reloc); return get_section (name, flags, decl); } /* If required, set DECL_SECTION_NAME to a unique name. */ void resolve_unique_section (tree decl, int reloc ATTRIBUTE_UNUSED, int flag_function_or_data_sections) { if (DECL_SECTION_NAME (decl) == NULL_TREE && targetm.have_named_sections && (flag_function_or_data_sections || DECL_ONE_ONLY (decl))) targetm.asm_out.unique_section (decl, reloc); } #ifdef BSS_SECTION_ASM_OP #ifdef ASM_OUTPUT_BSS /* Utility function for ASM_OUTPUT_BSS for targets to use if they don't support alignments in .bss. ??? It is believed that this function will work in most cases so such support is localized here. */ static void asm_output_bss (FILE *file, tree decl ATTRIBUTE_UNUSED, const char *name, unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT rounded) { gcc_assert (strcmp (XSTR (XEXP (DECL_RTL (decl), 0), 0), name) == 0); targetm.asm_out.globalize_decl_name (file, decl); switch_to_section (bss_section); #ifdef ASM_DECLARE_OBJECT_NAME last_assemble_variable_decl = decl; ASM_DECLARE_OBJECT_NAME (file, name, decl); #else /* Standard thing is just output label for the object. */ ASM_OUTPUT_LABEL (file, name); #endif /* ASM_DECLARE_OBJECT_NAME */ ASM_OUTPUT_SKIP (file, rounded ? rounded : 1); } #endif #ifdef ASM_OUTPUT_ALIGNED_BSS /* Utility function for targets to use in implementing ASM_OUTPUT_ALIGNED_BSS. ??? It is believed that this function will work in most cases so such support is localized here. */ static void asm_output_aligned_bss (FILE *file, tree decl ATTRIBUTE_UNUSED, const char *name, unsigned HOST_WIDE_INT size, int align) { switch_to_section (bss_section); ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT)); #ifdef ASM_DECLARE_OBJECT_NAME last_assemble_variable_decl = decl; ASM_DECLARE_OBJECT_NAME (file, name, decl); #else /* Standard thing is just output label for the object. */ ASM_OUTPUT_LABEL (file, name); #endif /* ASM_DECLARE_OBJECT_NAME */ ASM_OUTPUT_SKIP (file, size ? size : 1); } #endif #endif /* BSS_SECTION_ASM_OP */ #ifndef USE_SELECT_SECTION_FOR_FUNCTIONS /* Return the hot section for function DECL. Return text_section for null DECLs. */ static section * hot_function_section (tree decl) { if (decl != NULL_TREE && DECL_SECTION_NAME (decl) != NULL_TREE && targetm.have_named_sections) return get_named_section (decl, NULL, 0); else return text_section; } #endif /* Return the section for function DECL. If DECL is NULL_TREE, return the text section. We can be passed NULL_TREE under some circumstances by dbxout.c at least. */ section * function_section (tree decl) { int reloc = 0; if (first_function_block_is_cold) reloc = 1; #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS if (decl != NULL_TREE && DECL_SECTION_NAME (decl) != NULL_TREE) return reloc ? unlikely_text_section () : get_named_section (decl, NULL, 0); else return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl)); #else return reloc ? unlikely_text_section () : hot_function_section (decl); #endif } section * current_function_section (void) { #ifdef USE_SELECT_SECTION_FOR_FUNCTIONS if (current_function_decl != NULL_TREE && DECL_SECTION_NAME (current_function_decl) != NULL_TREE) return in_cold_section_p ? unlikely_text_section () : get_named_section (current_function_decl, NULL, 0); else return targetm.asm_out.select_section (current_function_decl, in_cold_section_p, DECL_ALIGN (current_function_decl)); #else return (in_cold_section_p ? unlikely_text_section () : hot_function_section (current_function_decl)); #endif } /* Return the read-only data section associated with function DECL. */ section * default_function_rodata_section (tree decl) { if (decl != NULL_TREE && DECL_SECTION_NAME (decl)) { const char *name = TREE_STRING_POINTER (DECL_SECTION_NAME (decl)); if (DECL_ONE_ONLY (decl) && HAVE_COMDAT_GROUP) { size_t len = strlen (name) + 3; char* rname = alloca (len); strcpy (rname, ".rodata"); strcat (rname, name + 5); return get_section (rname, SECTION_LINKONCE, decl); } /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */ else if (DECL_ONE_ONLY (decl) && strncmp (name, ".gnu.linkonce.t.", 16) == 0) { size_t len = strlen (name) + 1; char *rname = alloca (len); memcpy (rname, name, len); rname[14] = 'r'; return get_section (rname, SECTION_LINKONCE, decl); } /* For .text.foo we want to use .rodata.foo. */ else if (flag_function_sections && flag_data_sections && strncmp (name, ".text.", 6) == 0) { size_t len = strlen (name) + 1; char *rname = alloca (len + 2); memcpy (rname, ".rodata", 7); memcpy (rname + 7, name + 5, len - 5); return get_section (rname, 0, decl); } } return readonly_data_section; } /* Return the read-only data section associated with function DECL for targets where that section should be always the single readonly data section. */ section * default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED) { return readonly_data_section; } /* Return the section to use for string merging. */ static section * mergeable_string_section (tree decl ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED, unsigned int flags ATTRIBUTE_UNUSED) { HOST_WIDE_INT len; if (HAVE_GAS_SHF_MERGE && flag_merge_constants && TREE_CODE (decl) == STRING_CST && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE && align <= 256 && (len = int_size_in_bytes (TREE_TYPE (decl))) > 0 && TREE_STRING_LENGTH (decl) >= len) { enum machine_mode mode; unsigned int modesize; const char *str; HOST_WIDE_INT i; int j, unit; char name[30]; mode = TYPE_MODE (TREE_TYPE (TREE_TYPE (decl))); modesize = GET_MODE_BITSIZE (mode); if (modesize >= 8 && modesize <= 256 && (modesize & (modesize - 1)) == 0) { if (align < modesize) align = modesize; str = TREE_STRING_POINTER (decl); unit = GET_MODE_SIZE (mode); /* Check for embedded NUL characters. */ for (i = 0; i < len; i += unit) { for (j = 0; j < unit; j++) if (str[i + j] != '\0') break; if (j == unit) break; } if (i == len - unit) { sprintf (name, ".rodata.str%d.%d", modesize / 8, (int) (align / 8)); flags |= (modesize / 8) | SECTION_MERGE | SECTION_STRINGS; return get_section (name, flags, NULL); } } } return readonly_data_section; } /* Return the section to use for constant merging. */ section * mergeable_constant_section (enum machine_mode mode ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED, unsigned int flags ATTRIBUTE_UNUSED) { unsigned int modesize = GET_MODE_BITSIZE (mode); if (HAVE_GAS_SHF_MERGE && flag_merge_constants && mode != VOIDmode && mode != BLKmode && modesize <= align && align >= 8 && align <= 256 && (align & (align - 1)) == 0) { char name[24]; sprintf (name, ".rodata.cst%d", (int) (align / 8)); flags |= (align / 8) | SECTION_MERGE; return get_section (name, flags, NULL); } return readonly_data_section; } /* Given NAME, a putative register name, discard any customary prefixes. */ static const char * strip_reg_name (const char *name) { #ifdef REGISTER_PREFIX if (!strncmp (name, REGISTER_PREFIX, strlen (REGISTER_PREFIX))) name += strlen (REGISTER_PREFIX); #endif if (name[0] == '%' || name[0] == '#') name++; return name; } /* The user has asked for a DECL to have a particular name. Set (or change) it in such a way that we don't prefix an underscore to it. */ void set_user_assembler_name (tree decl, const char *name) { char *starred = alloca (strlen (name) + 2); starred[0] = '*'; strcpy (starred + 1, name); change_decl_assembler_name (decl, get_identifier (starred)); SET_DECL_RTL (decl, NULL_RTX); } /* Decode an `asm' spec for a declaration as a register name. Return the register number, or -1 if nothing specified, or -2 if the ASMSPEC is not `cc' or `memory' and is not recognized, or -3 if ASMSPEC is `cc' and is not recognized, or -4 if ASMSPEC is `memory' and is not recognized. Accept an exact spelling or a decimal number. Prefixes such as % are optional. */ int decode_reg_name (const char *asmspec) { if (asmspec != 0) { int i; /* Get rid of confusing prefixes. */ asmspec = strip_reg_name (asmspec); /* Allow a decimal number as a "register name". */ for (i = strlen (asmspec) - 1; i >= 0; i--) if (! ISDIGIT (asmspec[i])) break; if (asmspec[0] != 0 && i < 0) { i = atoi (asmspec); if (i < FIRST_PSEUDO_REGISTER && i >= 0) return i; else return -2; } for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) if (reg_names[i][0] && ! strcmp (asmspec, strip_reg_name (reg_names[i]))) return i; #ifdef ADDITIONAL_REGISTER_NAMES { static const struct { const char *const name; const int number; } table[] = ADDITIONAL_REGISTER_NAMES; for (i = 0; i < (int) ARRAY_SIZE (table); i++) if (table[i].name[0] && ! strcmp (asmspec, table[i].name)) return table[i].number; } #endif /* ADDITIONAL_REGISTER_NAMES */ if (!strcmp (asmspec, "memory")) return -4; if (!strcmp (asmspec, "cc")) return -3; return -2; } return -1; } /* Return true if DECL's initializer is suitable for a BSS section. */ static bool bss_initializer_p (const_tree decl) { return (DECL_INITIAL (decl) == NULL || DECL_INITIAL (decl) == error_mark_node || (flag_zero_initialized_in_bss /* Leave constant zeroes in .rodata so they can be shared. */ && !TREE_READONLY (decl) && initializer_zerop (DECL_INITIAL (decl)))); } /* Compute the alignment of variable specified by DECL. DONT_OUTPUT_DATA is from assemble_variable. */ void align_variable (tree decl, bool dont_output_data) { unsigned int align = DECL_ALIGN (decl); /* In the case for initialing an array whose length isn't specified, where we have not yet been able to do the layout, figure out the proper alignment now. */ if (dont_output_data && DECL_SIZE (decl) == 0 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE) align = MAX (align, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl)))); /* Some object file formats have a maximum alignment which they support. In particular, a.out format supports a maximum alignment of 4. */ if (align > MAX_OFILE_ALIGNMENT) { warning (0, "alignment of %q+D is greater than maximum object " "file alignment. Using %d", decl, MAX_OFILE_ALIGNMENT/BITS_PER_UNIT); align = MAX_OFILE_ALIGNMENT; } /* On some machines, it is good to increase alignment sometimes. */ if (! DECL_USER_ALIGN (decl)) { #ifdef DATA_ALIGNMENT unsigned int data_align = DATA_ALIGNMENT (TREE_TYPE (decl), align); /* Don't increase alignment too much for TLS variables - TLS space is too precious. */ if (! DECL_THREAD_LOCAL_P (decl) || data_align <= BITS_PER_WORD) align = data_align; #endif #ifdef CONSTANT_ALIGNMENT if (DECL_INITIAL (decl) != 0 && DECL_INITIAL (decl) != error_mark_node) { unsigned int const_align = CONSTANT_ALIGNMENT (DECL_INITIAL (decl), align); /* Don't increase alignment too much for TLS variables - TLS space is too precious. */ if (! DECL_THREAD_LOCAL_P (decl) || const_align <= BITS_PER_WORD) align = const_align; } #endif } /* Reset the alignment in case we have made it tighter, so we can benefit from it in get_pointer_alignment. */ DECL_ALIGN (decl) = align; } /* Return the section into which the given VAR_DECL or CONST_DECL should be placed. PREFER_NOSWITCH_P is true if a noswitch section should be used wherever possible. */ static section * get_variable_section (tree decl, bool prefer_noswitch_p) { int reloc; /* If the decl has been given an explicit section name, then it isn't common, and shouldn't be handled as such. */ if (DECL_COMMON (decl) && DECL_SECTION_NAME (decl) == NULL) { if (DECL_THREAD_LOCAL_P (decl)) return tls_comm_section; if (TREE_PUBLIC (decl) && bss_initializer_p (decl)) return comm_section; } if (DECL_INITIAL (decl) == error_mark_node) reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0; else if (DECL_INITIAL (decl)) reloc = compute_reloc_for_constant (DECL_INITIAL (decl)); else reloc = 0; resolve_unique_section (decl, reloc, flag_data_sections); if (IN_NAMED_SECTION (decl)) return get_named_section (decl, NULL, reloc); if (!DECL_THREAD_LOCAL_P (decl) && !(prefer_noswitch_p && targetm.have_switchable_bss_sections) && bss_initializer_p (decl)) { if (!TREE_PUBLIC (decl)) return lcomm_section; if (bss_noswitch_section) return bss_noswitch_section; } return targetm.asm_out.select_section (decl, reloc, DECL_ALIGN (decl)); } /* Return the block into which object_block DECL should be placed. */ static struct object_block * get_block_for_decl (tree decl) { section *sect; if (TREE_CODE (decl) == VAR_DECL) { /* The object must be defined in this translation unit. */ if (DECL_EXTERNAL (decl)) return NULL; /* There's no point using object blocks for something that is isolated by definition. */ if (DECL_ONE_ONLY (decl)) return NULL; } /* We can only calculate block offsets if the decl has a known constant size. */ if (DECL_SIZE_UNIT (decl) == NULL) return NULL; if (!host_integerp (DECL_SIZE_UNIT (decl), 1)) return NULL; /* Find out which section should contain DECL. We cannot put it into an object block if it requires a standalone definition. */ if (TREE_CODE (decl) == VAR_DECL) align_variable (decl, 0); sect = get_variable_section (decl, true); if (SECTION_STYLE (sect) == SECTION_NOSWITCH) return NULL; return get_block_for_section (sect); } /* Make sure block symbol SYMBOL is in block BLOCK. */ static void change_symbol_block (rtx symbol, struct object_block *block) { if (block != SYMBOL_REF_BLOCK (symbol)) { gcc_assert (SYMBOL_REF_BLOCK_OFFSET (symbol) < 0); SYMBOL_REF_BLOCK (symbol) = block; } } /* Return true if it is possible to put DECL in an object_block. */ static bool use_blocks_for_decl_p (tree decl) { /* Only data DECLs can be placed into object blocks. */ if (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != CONST_DECL) return false; /* Detect decls created by dw2_force_const_mem. Such decls are special because DECL_INITIAL doesn't specify the decl's true value. dw2_output_indirect_constants will instead call assemble_variable with dont_output_data set to 1 and then print the contents itself. */ if (DECL_INITIAL (decl) == decl) return false; /* If this decl is an alias, then we don't want to emit a definition. */ if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl))) return false; return true; } /* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should have static storage duration. In other words, it should not be an automatic variable, including PARM_DECLs. There is, however, one exception: this function handles variables explicitly placed in a particular register by the user. This is never called for PARM_DECL nodes. */ void make_decl_rtl (tree decl) { const char *name = 0; int reg_number; rtx x; /* Check that we are not being given an automatic variable. */ gcc_assert (TREE_CODE (decl) != PARM_DECL && TREE_CODE (decl) != RESULT_DECL); /* A weak alias has TREE_PUBLIC set but not the other bits. */ gcc_assert (TREE_CODE (decl) != VAR_DECL || TREE_STATIC (decl) || TREE_PUBLIC (decl) || DECL_EXTERNAL (decl) || DECL_REGISTER (decl)); /* And that we were not given a type or a label. */ gcc_assert (TREE_CODE (decl) != TYPE_DECL && TREE_CODE (decl) != LABEL_DECL); /* For a duplicate declaration, we can be called twice on the same DECL node. Don't discard the RTL already made. */ if (DECL_RTL_SET_P (decl)) { /* If the old RTL had the wrong mode, fix the mode. */ x = DECL_RTL (decl); if (GET_MODE (x) != DECL_MODE (decl)) SET_DECL_RTL (decl, adjust_address_nv (x, DECL_MODE (decl), 0)); if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl)) return; /* ??? Another way to do this would be to maintain a hashed table of such critters. Instead of adding stuff to a DECL to give certain attributes to it, we could use an external hash map from DECL to set of attributes. */ /* Let the target reassign the RTL if it wants. This is necessary, for example, when one machine specific decl attribute overrides another. */ targetm.encode_section_info (decl, DECL_RTL (decl), false); /* If the symbol has a SYMBOL_REF_BLOCK field, update it based on the new decl information. */ if (MEM_P (x) && GET_CODE (XEXP (x, 0)) == SYMBOL_REF && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (x, 0))) change_symbol_block (XEXP (x, 0), get_block_for_decl (decl)); /* Make this function static known to the mudflap runtime. */ if (flag_mudflap && TREE_CODE (decl) == VAR_DECL) mudflap_enqueue_decl (decl); return; } name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); if (name[0] != '*' && TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl)) { error ("register name not specified for %q+D", decl); } else if (TREE_CODE (decl) != FUNCTION_DECL && DECL_REGISTER (decl)) { const char *asmspec = name+1; reg_number = decode_reg_name (asmspec); /* First detect errors in declaring global registers. */ if (reg_number == -1) error ("register name not specified for %q+D", decl); else if (reg_number < 0) error ("invalid register name for %q+D", decl); else if (TYPE_MODE (TREE_TYPE (decl)) == BLKmode) error ("data type of %q+D isn%'t suitable for a register", decl); else if (! HARD_REGNO_MODE_OK (reg_number, TYPE_MODE (TREE_TYPE (decl)))) error ("register specified for %q+D isn%'t suitable for data type", decl); /* Now handle properly declared static register variables. */ else { int nregs; if (DECL_INITIAL (decl) != 0 && TREE_STATIC (decl)) { DECL_INITIAL (decl) = 0; error ("global register variable has initial value"); } if (TREE_THIS_VOLATILE (decl)) warning (OPT_Wvolatile_register_var, "optimization may eliminate reads and/or " "writes to register variables"); /* If the user specified one of the eliminables registers here, e.g., FRAME_POINTER_REGNUM, we don't want to get this variable confused with that register and be eliminated. This usage is somewhat suspect... */ SET_DECL_RTL (decl, gen_rtx_raw_REG (DECL_MODE (decl), reg_number)); ORIGINAL_REGNO (DECL_RTL (decl)) = reg_number; REG_USERVAR_P (DECL_RTL (decl)) = 1; if (TREE_STATIC (decl)) { /* Make this register global, so not usable for anything else. */ #ifdef ASM_DECLARE_REGISTER_GLOBAL name = IDENTIFIER_POINTER (DECL_NAME (decl)); ASM_DECLARE_REGISTER_GLOBAL (asm_out_file, decl, reg_number, name); #endif nregs = hard_regno_nregs[reg_number][DECL_MODE (decl)]; while (nregs > 0) globalize_reg (reg_number + --nregs); } /* As a register variable, it has no section. */ return; } } /* Now handle ordinary static variables and functions (in memory). Also handle vars declared register invalidly. */ else if (name[0] == '*') { #ifdef REGISTER_PREFIX if (strlen (REGISTER_PREFIX) != 0) { reg_number = decode_reg_name (name); if (reg_number >= 0 || reg_number == -3) error ("register name given for non-register variable %q+D", decl); } #endif } /* Specifying a section attribute on a variable forces it into a non-.bss section, and thus it cannot be common. */ if (TREE_CODE (decl) == VAR_DECL && DECL_SECTION_NAME (decl) != NULL_TREE && DECL_INITIAL (decl) == NULL_TREE && DECL_COMMON (decl)) DECL_COMMON (decl) = 0; /* Variables can't be both common and weak. */ if (TREE_CODE (decl) == VAR_DECL && DECL_WEAK (decl)) DECL_COMMON (decl) = 0; if (use_object_blocks_p () && use_blocks_for_decl_p (decl)) x = create_block_symbol (name, get_block_for_decl (decl), -1); else x = gen_rtx_SYMBOL_REF (Pmode, name); SYMBOL_REF_WEAK (x) = DECL_WEAK (decl); SET_SYMBOL_REF_DECL (x, decl); x = gen_rtx_MEM (DECL_MODE (decl), x); if (TREE_CODE (decl) != FUNCTION_DECL) set_mem_attributes (x, decl, 1); SET_DECL_RTL (decl, x); /* Optionally set flags or add text to the name to record information such as that it is a function name. If the name is changed, the macro ASM_OUTPUT_LABELREF will have to know how to strip this information. */ targetm.encode_section_info (decl, DECL_RTL (decl), true); /* Make this function static known to the mudflap runtime. */ if (flag_mudflap && TREE_CODE (decl) == VAR_DECL) mudflap_enqueue_decl (decl); } /* Output a string of literal assembler code for an `asm' keyword used between functions. */ void assemble_asm (tree string) { app_enable (); if (TREE_CODE (string) == ADDR_EXPR) string = TREE_OPERAND (string, 0); fprintf (asm_out_file, "\t%s\n", TREE_STRING_POINTER (string)); } /* Record an element in the table of global destructors. SYMBOL is a SYMBOL_REF of the function to be called; PRIORITY is a number between 0 and MAX_INIT_PRIORITY. */ void default_stabs_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED, int priority ATTRIBUTE_UNUSED) { #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO /* Tell GNU LD that this is part of the static destructor set. This will work for any system that uses stabs, most usefully aout systems. */ dbxout_begin_simple_stabs ("___DTOR_LIST__", 22 /* N_SETT */); dbxout_stab_value_label (XSTR (symbol, 0)); #else sorry ("global destructors not supported on this target"); #endif } /* Write the address of the entity given by SYMBOL to SEC. */ void assemble_addr_to_section (rtx symbol, section *sec) { switch_to_section (sec); assemble_align (POINTER_SIZE); assemble_integer (symbol, POINTER_SIZE / BITS_PER_UNIT, POINTER_SIZE, 1); } /* Return the numbered .ctors.N (if CONSTRUCTOR_P) or .dtors.N (if not) section for PRIORITY. */ section * get_cdtor_priority_section (int priority, bool constructor_p) { char buf[16]; /* ??? This only works reliably with the GNU linker. */ sprintf (buf, "%s.%.5u", constructor_p ? ".ctors" : ".dtors", /* Invert the numbering so the linker puts us in the proper order; constructors are run from right to left, and the linker sorts in increasing order. */ MAX_INIT_PRIORITY - priority); return get_section (buf, SECTION_WRITE, NULL); } void default_named_section_asm_out_destructor (rtx symbol, int priority) { section *sec; if (priority != DEFAULT_INIT_PRIORITY) sec = get_cdtor_priority_section (priority, /*constructor_p=*/false); else sec = get_section (".dtors", SECTION_WRITE, NULL); assemble_addr_to_section (symbol, sec); } #ifdef DTORS_SECTION_ASM_OP void default_dtor_section_asm_out_destructor (rtx symbol, int priority ATTRIBUTE_UNUSED) { assemble_addr_to_section (symbol, dtors_section); } #endif /* Likewise for global constructors. */ void default_stabs_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED, int priority ATTRIBUTE_UNUSED) { #if defined DBX_DEBUGGING_INFO || defined XCOFF_DEBUGGING_INFO /* Tell GNU LD that this is part of the static destructor set. This will work for any system that uses stabs, most usefully aout systems. */ dbxout_begin_simple_stabs ("___CTOR_LIST__", 22 /* N_SETT */); dbxout_stab_value_label (XSTR (symbol, 0)); #else sorry ("global constructors not supported on this target"); #endif } void default_named_section_asm_out_constructor (rtx symbol, int priority) { section *sec; if (priority != DEFAULT_INIT_PRIORITY) sec = get_cdtor_priority_section (priority, /*constructor_p=*/true); else sec = get_section (".ctors", SECTION_WRITE, NULL); assemble_addr_to_section (symbol, sec); } #ifdef CTORS_SECTION_ASM_OP void default_ctor_section_asm_out_constructor (rtx symbol, int priority ATTRIBUTE_UNUSED) { assemble_addr_to_section (symbol, ctors_section); } #endif /* CONSTANT_POOL_BEFORE_FUNCTION may be defined as an expression with a nonzero value if the constant pool should be output before the start of the function, or a zero value if the pool should output after the end of the function. The default is to put it before the start. */ #ifndef CONSTANT_POOL_BEFORE_FUNCTION #define CONSTANT_POOL_BEFORE_FUNCTION 1 #endif /* DECL is an object (either VAR_DECL or FUNCTION_DECL) which is going to be output to assembler. Set first_global_object_name and weak_global_object_name as appropriate. */ void notice_global_symbol (tree decl) { const char **type = &first_global_object_name; if (first_global_object_name || !TREE_PUBLIC (decl) || DECL_EXTERNAL (decl) || !DECL_NAME (decl) || (TREE_CODE (decl) != FUNCTION_DECL && (TREE_CODE (decl) != VAR_DECL || (DECL_COMMON (decl) && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node)))) || !MEM_P (DECL_RTL (decl))) return; /* We win when global object is found, but it is useful to know about weak symbol as well so we can produce nicer unique names. */ if (DECL_WEAK (decl) || DECL_ONE_ONLY (decl) || flag_shlib) type = &weak_global_object_name; if (!*type) { const char *p; const char *name; rtx decl_rtl = DECL_RTL (decl); p = targetm.strip_name_encoding (XSTR (XEXP (decl_rtl, 0), 0)); name = ggc_strdup (p); *type = name; } } /* Output assembler code for the constant pool of a function and associated with defining the name of the function. DECL describes the function. NAME is the function's name. For the constant pool, we use the current constant pool data. */ void assemble_start_function (tree decl, const char *fnname) { int align; char tmp_label[100]; bool hot_label_written = false; cfun->unlikely_text_section_name = NULL; first_function_block_is_cold = false; if (flag_reorder_blocks_and_partition) { ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno); cfun->hot_section_label = ggc_strdup (tmp_label); ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDB", const_labelno); cfun->cold_section_label = ggc_strdup (tmp_label); ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTE", const_labelno); cfun->hot_section_end_label = ggc_strdup (tmp_label); ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LCOLDE", const_labelno); cfun->cold_section_end_label = ggc_strdup (tmp_label); const_labelno++; } else { cfun->hot_section_label = NULL; cfun->cold_section_label = NULL; cfun->hot_section_end_label = NULL; cfun->cold_section_end_label = NULL; } /* The following code does not need preprocessing in the assembler. */ app_disable (); if (CONSTANT_POOL_BEFORE_FUNCTION) output_constant_pool (fnname, decl); resolve_unique_section (decl, 0, flag_function_sections); /* Make sure the not and cold text (code) sections are properly aligned. This is necessary here in the case where the function has both hot and cold sections, because we don't want to re-set the alignment when the section switch happens mid-function. */ if (flag_reorder_blocks_and_partition) { switch_to_section (unlikely_text_section ()); assemble_align (DECL_ALIGN (decl)); ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_label); /* When the function starts with a cold section, we need to explicitly align the hot section and write out the hot section label. But if the current function is a thunk, we do not have a CFG. */ if (!current_function_is_thunk && BB_PARTITION (ENTRY_BLOCK_PTR->next_bb) == BB_COLD_PARTITION) { switch_to_section (text_section); assemble_align (DECL_ALIGN (decl)); ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label); hot_label_written = true; first_function_block_is_cold = true; } } else if (DECL_SECTION_NAME (decl)) { /* Calls to function_section rely on first_function_block_is_cold being accurate. The first block may be cold even if we aren't doing partitioning, if the entire function was decided by choose_function_section (predict.c) to be cold. */ initialize_cold_section_name (); if (cfun->unlikely_text_section_name && strcmp (TREE_STRING_POINTER (DECL_SECTION_NAME (decl)), cfun->unlikely_text_section_name) == 0) first_function_block_is_cold = true; } in_cold_section_p = first_function_block_is_cold; /* Switch to the correct text section for the start of the function. */ switch_to_section (function_section (decl)); if (flag_reorder_blocks_and_partition && !hot_label_written) ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_label); /* Tell assembler to move to target machine's alignment for functions. */ align = floor_log2 (DECL_ALIGN (decl) / BITS_PER_UNIT); if (align > 0) { ASM_OUTPUT_ALIGN (asm_out_file, align); } /* Handle a user-specified function alignment. Note that we still need to align to DECL_ALIGN, as above, because ASM_OUTPUT_MAX_SKIP_ALIGN might not do any alignment at all. */ if (! DECL_USER_ALIGN (decl) && align_functions_log > align && cfun->function_frequency != FUNCTION_FREQUENCY_UNLIKELY_EXECUTED) { #ifdef ASM_OUTPUT_MAX_SKIP_ALIGN ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file, align_functions_log, align_functions - 1); #else ASM_OUTPUT_ALIGN (asm_out_file, align_functions_log); #endif } #ifdef ASM_OUTPUT_FUNCTION_PREFIX ASM_OUTPUT_FUNCTION_PREFIX (asm_out_file, fnname); #endif (*debug_hooks->begin_function) (decl); /* Make function name accessible from other files, if appropriate. */ if (TREE_PUBLIC (decl)) { notice_global_symbol (decl); globalize_decl (decl); maybe_assemble_visibility (decl); } if (DECL_PRESERVE_P (decl)) targetm.asm_out.mark_decl_preserved (fnname); /* Do any machine/system dependent processing of the function name. */ #ifdef ASM_DECLARE_FUNCTION_NAME ASM_DECLARE_FUNCTION_NAME (asm_out_file, fnname, current_function_decl); #else /* Standard thing is just output label for the function. */ ASM_OUTPUT_LABEL (asm_out_file, fnname); #endif /* ASM_DECLARE_FUNCTION_NAME */ } /* Output assembler code associated with defining the size of the function. DECL describes the function. NAME is the function's name. */ void assemble_end_function (tree decl, const char *fnname ATTRIBUTE_UNUSED) { #ifdef ASM_DECLARE_FUNCTION_SIZE /* We could have switched section in the middle of the function. */ if (flag_reorder_blocks_and_partition) switch_to_section (function_section (decl)); ASM_DECLARE_FUNCTION_SIZE (asm_out_file, fnname, decl); #endif if (! CONSTANT_POOL_BEFORE_FUNCTION) { output_constant_pool (fnname, decl); switch_to_section (function_section (decl)); /* need to switch back */ } /* Output labels for end of hot/cold text sections (to be used by debug info.) */ if (flag_reorder_blocks_and_partition) { section *save_text_section; save_text_section = in_section; switch_to_section (unlikely_text_section ()); ASM_OUTPUT_LABEL (asm_out_file, cfun->cold_section_end_label); if (first_function_block_is_cold) switch_to_section (text_section); else switch_to_section (function_section (decl)); ASM_OUTPUT_LABEL (asm_out_file, cfun->hot_section_end_label); switch_to_section (save_text_section); } } /* Assemble code to leave SIZE bytes of zeros. */ void assemble_zeros (unsigned HOST_WIDE_INT size) { /* Do no output if -fsyntax-only. */ if (flag_syntax_only) return; #ifdef ASM_NO_SKIP_IN_TEXT /* The `space' pseudo in the text section outputs nop insns rather than 0s, so we must output 0s explicitly in the text section. */ if (ASM_NO_SKIP_IN_TEXT && (in_section->common.flags & SECTION_CODE) != 0) { unsigned HOST_WIDE_INT i; for (i = 0; i < size; i++) assemble_integer (const0_rtx, 1, BITS_PER_UNIT, 1); } else #endif if (size > 0) ASM_OUTPUT_SKIP (asm_out_file, size); } /* Assemble an alignment pseudo op for an ALIGN-bit boundary. */ void assemble_align (int align) { if (align > BITS_PER_UNIT) { ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); } } /* Assemble a string constant with the specified C string as contents. */ void assemble_string (const char *p, int size) { int pos = 0; int maximum = 2000; /* If the string is very long, split it up. */ while (pos < size) { int thissize = size - pos; if (thissize > maximum) thissize = maximum; ASM_OUTPUT_ASCII (asm_out_file, p, thissize); pos += thissize; p += thissize; } } /* A noswitch_section_callback for lcomm_section. */ static bool emit_local (tree decl ATTRIBUTE_UNUSED, const char *name ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) { #if defined ASM_OUTPUT_ALIGNED_DECL_LOCAL ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, decl, name, size, DECL_ALIGN (decl)); return true; #elif defined ASM_OUTPUT_ALIGNED_LOCAL ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, DECL_ALIGN (decl)); return true; #else ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); return false; #endif } /* A noswitch_section_callback for bss_noswitch_section. */ #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS static bool emit_bss (tree decl ATTRIBUTE_UNUSED, const char *name ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) { #if defined ASM_OUTPUT_ALIGNED_BSS ASM_OUTPUT_ALIGNED_BSS (asm_out_file, decl, name, size, DECL_ALIGN (decl)); return true; #else ASM_OUTPUT_BSS (asm_out_file, decl, name, size, rounded); return false; #endif } #endif /* A noswitch_section_callback for comm_section. */ static bool emit_common (tree decl ATTRIBUTE_UNUSED, const char *name ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) { #if defined ASM_OUTPUT_ALIGNED_DECL_COMMON ASM_OUTPUT_ALIGNED_DECL_COMMON (asm_out_file, decl, name, size, DECL_ALIGN (decl)); return true; #elif defined ASM_OUTPUT_ALIGNED_COMMON ASM_OUTPUT_ALIGNED_COMMON (asm_out_file, name, size, DECL_ALIGN (decl)); return true; #else ASM_OUTPUT_COMMON (asm_out_file, name, size, rounded); return false; #endif } /* A noswitch_section_callback for tls_comm_section. */ static bool emit_tls_common (tree decl ATTRIBUTE_UNUSED, const char *name ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT size ATTRIBUTE_UNUSED, unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED) { #ifdef ASM_OUTPUT_TLS_COMMON ASM_OUTPUT_TLS_COMMON (asm_out_file, decl, name, size); return true; #else sorry ("thread-local COMMON data not implemented"); return true; #endif } /* Assemble DECL given that it belongs in SECTION_NOSWITCH section SECT. NAME is the name of DECL's SYMBOL_REF. */ static void assemble_noswitch_variable (tree decl, const char *name, section *sect) { unsigned HOST_WIDE_INT size, rounded; size = tree_low_cst (DECL_SIZE_UNIT (decl), 1); rounded = size; /* Don't allocate zero bytes of common, since that means "undefined external" in the linker. */ if (size == 0) rounded = 1; /* Round size up to multiple of BIGGEST_ALIGNMENT bits so that each uninitialized object starts on such a boundary. */ rounded += (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1; rounded = (rounded / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); if (!sect->noswitch.callback (decl, name, size, rounded) && (unsigned HOST_WIDE_INT) DECL_ALIGN_UNIT (decl) > rounded) warning (0, "requested alignment for %q+D is greater than " "implemented alignment of %wu", decl, rounded); } /* A subroutine of assemble_variable. Output the label and contents of DECL, whose address is a SYMBOL_REF with name NAME. DONT_OUTPUT_DATA is as for assemble_variable. */ static void assemble_variable_contents (tree decl, const char *name, bool dont_output_data) { /* Do any machine/system dependent processing of the object. */ #ifdef ASM_DECLARE_OBJECT_NAME last_assemble_variable_decl = decl; ASM_DECLARE_OBJECT_NAME (asm_out_file, name, decl); #else /* Standard thing is just output label for the object. */ ASM_OUTPUT_LABEL (asm_out_file, name); #endif /* ASM_DECLARE_OBJECT_NAME */ if (!dont_output_data) { if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node && !initializer_zerop (DECL_INITIAL (decl))) /* Output the actual data. */ output_constant (DECL_INITIAL (decl), tree_low_cst (DECL_SIZE_UNIT (decl), 1), DECL_ALIGN (decl)); else /* Leave space for it. */ assemble_zeros (tree_low_cst (DECL_SIZE_UNIT (decl), 1)); } } /* Assemble everything that is needed for a variable or function declaration. Not used for automatic variables, and not used for function definitions. Should not be called for variables of incomplete structure type. TOP_LEVEL is nonzero if this variable has file scope. AT_END is nonzero if this is the special handling, at end of compilation, to define things that have had only tentative definitions. DONT_OUTPUT_DATA if nonzero means don't actually output the initial value (that will be done by the caller). */ void assemble_variable (tree decl, int top_level ATTRIBUTE_UNUSED, int at_end ATTRIBUTE_UNUSED, int dont_output_data) { const char *name; rtx decl_rtl, symbol; section *sect; if (! targetm.have_tls && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) { tree to = emutls_decl (decl); /* If this variable is defined locally, then we need to initialize the control structure with size and alignment information. We do this at the last moment because tentative definitions can take a locally defined but uninitialized variable and initialize it later, which would result in incorrect contents. */ if (! DECL_EXTERNAL (to) && (! DECL_COMMON (to) || (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node))) { VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, 4); constructor_elt *elt; tree type = TREE_TYPE (to); tree field = TYPE_FIELDS (type); elt = VEC_quick_push (constructor_elt, v, NULL); elt->index = field; elt->value = fold_convert (TREE_TYPE (field), DECL_SIZE_UNIT (decl)); elt = VEC_quick_push (constructor_elt, v, NULL); field = TREE_CHAIN (field); elt->index = field; elt->value = build_int_cst (TREE_TYPE (field), DECL_ALIGN_UNIT (decl)); elt = VEC_quick_push (constructor_elt, v, NULL); field = TREE_CHAIN (field); elt->index = field; elt->value = null_pointer_node; elt = VEC_quick_push (constructor_elt, v, NULL); field = TREE_CHAIN (field); elt->index = field; elt->value = get_emutls_init_templ_addr (decl); DECL_INITIAL (to) = build_constructor (type, v); /* Make sure the template is marked as needed early enough. Without this, if the variable is placed in a section-anchored block, the template will only be marked when it's too late. */ record_references_in_initializer (to); } decl = to; } last_assemble_variable_decl = 0; /* Normally no need to say anything here for external references, since assemble_external is called by the language-specific code when a declaration is first seen. */ if (DECL_EXTERNAL (decl)) return; /* Output no assembler code for a function declaration. Only definitions of functions output anything. */ if (TREE_CODE (decl) == FUNCTION_DECL) return; /* Do nothing for global register variables. */ if (DECL_RTL_SET_P (decl) && REG_P (DECL_RTL (decl))) { TREE_ASM_WRITTEN (decl) = 1; return; } /* If type was incomplete when the variable was declared, see if it is complete now. */ if (DECL_SIZE (decl) == 0) layout_decl (decl, 0); /* Still incomplete => don't allocate it; treat the tentative defn (which is what it must have been) as an `extern' reference. */ if (!dont_output_data && DECL_SIZE (decl) == 0) { error ("storage size of %q+D isn%'t known", decl); TREE_ASM_WRITTEN (decl) = 1; return; } /* The first declaration of a variable that comes through this function decides whether it is global (in C, has external linkage) or local (in C, has internal linkage). So do nothing more if this function has already run. */ if (TREE_ASM_WRITTEN (decl)) return; /* Make sure targetm.encode_section_info is invoked before we set ASM_WRITTEN. */ decl_rtl = DECL_RTL (decl); TREE_ASM_WRITTEN (decl) = 1; /* Do no output if -fsyntax-only. */ if (flag_syntax_only) return; app_disable (); if (! dont_output_data && ! host_integerp (DECL_SIZE_UNIT (decl), 1)) { error ("size of variable %q+D is too large", decl); return; } gcc_assert (MEM_P (decl_rtl)); gcc_assert (GET_CODE (XEXP (decl_rtl, 0)) == SYMBOL_REF); symbol = XEXP (decl_rtl, 0); name = XSTR (symbol, 0); if (TREE_PUBLIC (decl) && DECL_NAME (decl)) notice_global_symbol (decl); /* Compute the alignment of this data. */ align_variable (decl, dont_output_data); set_mem_align (decl_rtl, DECL_ALIGN (decl)); if (TREE_PUBLIC (decl)) maybe_assemble_visibility (decl); if (DECL_PRESERVE_P (decl)) targetm.asm_out.mark_decl_preserved (name); /* First make the assembler name(s) global if appropriate. */ sect = get_variable_section (decl, false); if (TREE_PUBLIC (decl) && DECL_NAME (decl) && (sect->common.flags & SECTION_COMMON) == 0) globalize_decl (decl); /* Output any data that we will need to use the address of. */ if (DECL_INITIAL (decl) && DECL_INITIAL (decl) != error_mark_node) output_addressed_constants (DECL_INITIAL (decl)); /* dbxout.c needs to know this. */ if (sect && (sect->common.flags & SECTION_CODE) != 0) DECL_IN_TEXT_SECTION (decl) = 1; /* If the decl is part of an object_block, make sure that the decl has been positioned within its block, but do not write out its definition yet. output_object_blocks will do that later. */ if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) { gcc_assert (!dont_output_data); place_block_symbol (symbol); } else if (SECTION_STYLE (sect) == SECTION_NOSWITCH) assemble_noswitch_variable (decl, name, sect); else { switch_to_section (sect); if (DECL_ALIGN (decl) > BITS_PER_UNIT) ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (DECL_ALIGN_UNIT (decl))); assemble_variable_contents (decl, name, dont_output_data); } } /* Return 1 if type TYPE contains any pointers. */ static int contains_pointers_p (tree type) { switch (TREE_CODE (type)) { case POINTER_TYPE: case REFERENCE_TYPE: /* I'm not sure whether OFFSET_TYPE needs this treatment, so I'll play safe and return 1. */ case OFFSET_TYPE: return 1; case RECORD_TYPE: case UNION_TYPE: case QUAL_UNION_TYPE: { tree fields; /* For a type that has fields, see if the fields have pointers. */ for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) if (TREE_CODE (fields) == FIELD_DECL && contains_pointers_p (TREE_TYPE (fields))) return 1; return 0; } case ARRAY_TYPE: /* An array type contains pointers if its element type does. */ return contains_pointers_p (TREE_TYPE (type)); default: return 0; } } /* In unit-at-a-time mode, we delay assemble_external processing until the compilation unit is finalized. This is the best we can do for right now (i.e. stage 3 of GCC 4.0) - the right thing is to delay it all the way to final. See PR 17982 for further discussion. */ static GTY(()) tree pending_assemble_externals; #ifdef ASM_OUTPUT_EXTERNAL /* True if DECL is a function decl for which no out-of-line copy exists. It is assumed that DECL's assembler name has been set. */ static bool incorporeal_function_p (tree decl) { if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) { const char *name; if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL && DECL_FUNCTION_CODE (decl) == BUILT_IN_ALLOCA) return true; name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); if (strncmp (name, "__builtin_", strlen ("__builtin_")) == 0) return true; } return false; } /* Actually do the tests to determine if this is necessary, and invoke ASM_OUTPUT_EXTERNAL. */ static void assemble_external_real (tree decl) { rtx rtl = DECL_RTL (decl); if (MEM_P (rtl) && GET_CODE (XEXP (rtl, 0)) == SYMBOL_REF && !SYMBOL_REF_USED (XEXP (rtl, 0)) && !incorporeal_function_p (decl)) { /* Some systems do require some output. */ SYMBOL_REF_USED (XEXP (rtl, 0)) = 1; ASM_OUTPUT_EXTERNAL (asm_out_file, decl, XSTR (XEXP (rtl, 0), 0)); } } #endif void process_pending_assemble_externals (void) { #ifdef ASM_OUTPUT_EXTERNAL tree list; for (list = pending_assemble_externals; list; list = TREE_CHAIN (list)) assemble_external_real (TREE_VALUE (list)); pending_assemble_externals = 0; #endif } /* Output something to declare an external symbol to the assembler. (Most assemblers don't need this, so we normally output nothing.) Do nothing if DECL is not external. */ void assemble_external (tree decl ATTRIBUTE_UNUSED) { /* Because most platforms do not define ASM_OUTPUT_EXTERNAL, the main body of this code is only rarely exercised. To provide some testing, on all platforms, we make sure that the ASM_OUT_FILE is open. If it's not, we should not be calling this function. */ gcc_assert (asm_out_file); #ifdef ASM_OUTPUT_EXTERNAL if (!DECL_P (decl) || !DECL_EXTERNAL (decl) || !TREE_PUBLIC (decl)) return; /* We want to output external symbols at very last to check if they are references or not. */ pending_assemble_externals = tree_cons (0, decl, pending_assemble_externals); #endif } /* Similar, for calling a library function FUN. */ void assemble_external_libcall (rtx fun) { /* Declare library function name external when first used, if nec. */ if (! SYMBOL_REF_USED (fun)) { SYMBOL_REF_USED (fun) = 1; targetm.asm_out.external_libcall (fun); } } /* Assemble a label named NAME. */ void assemble_label (const char *name) { ASM_OUTPUT_LABEL (asm_out_file, name); } /* Set the symbol_referenced flag for ID. */ void mark_referenced (tree id) { TREE_SYMBOL_REFERENCED (id) = 1; } /* Set the symbol_referenced flag for DECL and notify callgraph. */ void mark_decl_referenced (tree decl) { if (TREE_CODE (decl) == FUNCTION_DECL) { /* Extern inline functions don't become needed when referenced. If we know a method will be emitted in other TU and no new functions can be marked reachable, just use the external definition. */ struct cgraph_node *node = cgraph_node (decl); if (!DECL_EXTERNAL (decl) && (!node->local.vtable_method || !cgraph_global_info_ready || !node->local.finalized)) cgraph_mark_needed_node (node); } else if (TREE_CODE (decl) == VAR_DECL) { struct varpool_node *node = varpool_node (decl); varpool_mark_needed_node (node); /* C++ frontend use mark_decl_references to force COMDAT variables to be output that might appear dead otherwise. */ node->force_output = true; } /* else do nothing - we can get various sorts of CST nodes here, which do not need to be marked. */ } /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at *ALIAS until we find an identifier that is not itself a transparent alias. Modify the alias passed to it by reference (and all aliases on the way to the ultimate target), such that they do not have to be followed again, and return the ultimate target of the alias chain. */ static inline tree ultimate_transparent_alias_target (tree *alias) { tree target = *alias; if (IDENTIFIER_TRANSPARENT_ALIAS (target)) { gcc_assert (TREE_CHAIN (target)); target = ultimate_transparent_alias_target (&TREE_CHAIN (target)); gcc_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target) && ! TREE_CHAIN (target)); *alias = target; } return target; } /* Output to FILE (an assembly file) a reference to NAME. If NAME starts with a *, the rest of NAME is output verbatim. Otherwise NAME is transformed in a target-specific way (usually by the addition of an underscore). */ void assemble_name_raw (FILE *file, const char *name) { if (name[0] == '*') fputs (&name[1], file); else ASM_OUTPUT_LABELREF (file, name); } /* Like assemble_name_raw, but should be used when NAME might refer to an entity that is also represented as a tree (like a function or variable). If NAME does refer to such an entity, that entity will be marked as referenced. */ void assemble_name (FILE *file, const char *name) { const char *real_name; tree id; real_name = targetm.strip_name_encoding (name); id = maybe_get_identifier (real_name); if (id) { tree id_orig = id; mark_referenced (id); ultimate_transparent_alias_target (&id); if (id != id_orig) name = IDENTIFIER_POINTER (id); gcc_assert (! TREE_CHAIN (id)); } assemble_name_raw (file, name); } /* Allocate SIZE bytes writable static space with a gensym name and return an RTX to refer to its address. */ rtx assemble_static_space (unsigned HOST_WIDE_INT size) { char name[12]; const char *namestring; rtx x; ASM_GENERATE_INTERNAL_LABEL (name, "LF", const_labelno); ++const_labelno; namestring = ggc_strdup (name); x = gen_rtx_SYMBOL_REF (Pmode, namestring); SYMBOL_REF_FLAGS (x) = SYMBOL_FLAG_LOCAL; #ifdef ASM_OUTPUT_ALIGNED_DECL_LOCAL ASM_OUTPUT_ALIGNED_DECL_LOCAL (asm_out_file, NULL_TREE, name, size, BIGGEST_ALIGNMENT); #else #ifdef ASM_OUTPUT_ALIGNED_LOCAL ASM_OUTPUT_ALIGNED_LOCAL (asm_out_file, name, size, BIGGEST_ALIGNMENT); #else { /* Round size up to multiple of BIGGEST_ALIGNMENT bits so that each uninitialized object starts on such a boundary. */ /* Variable `rounded' might or might not be used in ASM_OUTPUT_LOCAL. */ unsigned HOST_WIDE_INT rounded ATTRIBUTE_UNUSED = ((size + (BIGGEST_ALIGNMENT / BITS_PER_UNIT) - 1) / (BIGGEST_ALIGNMENT / BITS_PER_UNIT) * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); ASM_OUTPUT_LOCAL (asm_out_file, name, size, rounded); } #endif #endif return x; } /* Assemble the static constant template for function entry trampolines. This is done at most once per compilation. Returns an RTX for the address of the template. */ static GTY(()) rtx initial_trampoline; #ifdef TRAMPOLINE_TEMPLATE rtx assemble_trampoline_template (void) { char label[256]; const char *name; int align; rtx symbol; if (initial_trampoline) return initial_trampoline; /* By default, put trampoline templates in read-only data section. */ #ifdef TRAMPOLINE_SECTION switch_to_section (TRAMPOLINE_SECTION); #else switch_to_section (readonly_data_section); #endif /* Write the assembler code to define one. */ align = floor_log2 (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT); if (align > 0) { ASM_OUTPUT_ALIGN (asm_out_file, align); } targetm.asm_out.internal_label (asm_out_file, "LTRAMP", 0); TRAMPOLINE_TEMPLATE (asm_out_file); /* Record the rtl to refer to it. */ ASM_GENERATE_INTERNAL_LABEL (label, "LTRAMP", 0); name = ggc_strdup (label); symbol = gen_rtx_SYMBOL_REF (Pmode, name); SYMBOL_REF_FLAGS (symbol) = SYMBOL_FLAG_LOCAL; initial_trampoline = gen_rtx_MEM (BLKmode, symbol); set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT); return initial_trampoline; } #endif /* A and B are either alignments or offsets. Return the minimum alignment that may be assumed after adding the two together. */ static inline unsigned min_align (unsigned int a, unsigned int b) { return (a | b) & -(a | b); } /* Return the assembler directive for creating a given kind of integer object. SIZE is the number of bytes in the object and ALIGNED_P indicates whether it is known to be aligned. Return NULL if the assembly dialect has no such directive. The returned string should be printed at the start of a new line and be followed immediately by the object's initial value. */ const char * integer_asm_op (int size, int aligned_p) { struct asm_int_op *ops; if (aligned_p) ops = &targetm.asm_out.aligned_op; else ops = &targetm.asm_out.unaligned_op; switch (size) { case 1: return targetm.asm_out.byte_op; case 2: return ops->hi; case 4: return ops->si; case 8: return ops->di; case 16: return ops->ti; default: return NULL; } } /* Use directive OP to assemble an integer object X. Print OP at the start of the line, followed immediately by the value of X. */ void assemble_integer_with_op (const char *op, rtx x) { fputs (op, asm_out_file); output_addr_const (asm_out_file, x); fputc ('\n', asm_out_file); } /* The default implementation of the asm_out.integer target hook. */ bool default_assemble_integer (rtx x ATTRIBUTE_UNUSED, unsigned int size ATTRIBUTE_UNUSED, int aligned_p ATTRIBUTE_UNUSED) { const char *op = integer_asm_op (size, aligned_p); /* Avoid GAS bugs for large values. Specifically negative values whose absolute value fits in a bfd_vma, but not in a bfd_signed_vma. */ if (size > UNITS_PER_WORD && size > POINTER_SIZE / BITS_PER_UNIT) return false; return op && (assemble_integer_with_op (op, x), true); } /* Assemble the integer constant X into an object of SIZE bytes. ALIGN is the alignment of the integer in bits. Return 1 if we were able to output the constant, otherwise 0. We must be able to output the constant, if FORCE is nonzero. */ bool assemble_integer (rtx x, unsigned int size, unsigned int align, int force) { int aligned_p; aligned_p = (align >= MIN (size * BITS_PER_UNIT, BIGGEST_ALIGNMENT)); /* See if the target hook can handle this kind of object. */ if (targetm.asm_out.integer (x, size, aligned_p)) return true; /* If the object is a multi-byte one, try splitting it up. Split it into words it if is multi-word, otherwise split it into bytes. */ if (size > 1) { enum machine_mode omode, imode; unsigned int subalign; unsigned int subsize, i; unsigned char mclass; subsize = size > UNITS_PER_WORD? UNITS_PER_WORD : 1; subalign = MIN (align, subsize * BITS_PER_UNIT); if (GET_CODE (x) == CONST_FIXED) mclass = GET_MODE_CLASS (GET_MODE (x)); else mclass = MODE_INT; omode = mode_for_size (subsize * BITS_PER_UNIT, mclass, 0); imode = mode_for_size (size * BITS_PER_UNIT, mclass, 0); for (i = 0; i < size; i += subsize) { rtx partial = simplify_subreg (omode, x, imode, i); if (!partial || !assemble_integer (partial, subsize, subalign, 0)) break; } if (i == size) return true; /* If we've printed some of it, but not all of it, there's no going back now. */ gcc_assert (!i); } gcc_assert (!force); return false; } void assemble_real (REAL_VALUE_TYPE d, enum machine_mode mode, unsigned int align) { long data[4] = {0, 0, 0, 0}; int i; int bitsize, nelts, nunits, units_per; /* This is hairy. We have a quantity of known size. real_to_target will put it into an array of *host* longs, 32 bits per element (even if long is more than 32 bits). We need to determine the number of array elements that are occupied (nelts) and the number of *target* min-addressable units that will be occupied in the object file (nunits). We cannot assume that 32 divides the mode's bitsize (size * BITS_PER_UNIT) evenly. size * BITS_PER_UNIT is used here to make sure that padding bits (which might appear at either end of the value; real_to_target will include the padding bits in its output array) are included. */ nunits = GET_MODE_SIZE (mode); bitsize = nunits * BITS_PER_UNIT; nelts = CEIL (bitsize, 32); units_per = 32 / BITS_PER_UNIT; real_to_target (data, &d, mode); /* Put out the first word with the specified alignment. */ assemble_integer (GEN_INT (data[0]), MIN (nunits, units_per), align, 1); nunits -= units_per; /* Subsequent words need only 32-bit alignment. */ align = min_align (align, 32); for (i = 1; i < nelts; i++) { assemble_integer (GEN_INT (data[i]), MIN (nunits, units_per), align, 1); nunits -= units_per; } } /* Given an expression EXP with a constant value, reduce it to the sum of an assembler symbol and an integer. Store them both in the structure *VALUE. EXP must be reducible. */ struct addr_const GTY(()) { rtx base; HOST_WIDE_INT offset; }; static void decode_addr_const (tree exp, struct addr_const *value) { tree target = TREE_OPERAND (exp, 0); int offset = 0; rtx x; while (1) { if (TREE_CODE (target) == COMPONENT_REF && host_integerp (byte_position (TREE_OPERAND (target, 1)), 0)) { offset += int_byte_position (TREE_OPERAND (target, 1)); target = TREE_OPERAND (target, 0); } else if (TREE_CODE (target) == ARRAY_REF || TREE_CODE (target) == ARRAY_RANGE_REF) { offset += (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (target)), 1) * tree_low_cst (TREE_OPERAND (target, 1), 0)); target = TREE_OPERAND (target, 0); } else break; } switch (TREE_CODE (target)) { case VAR_DECL: case FUNCTION_DECL: x = DECL_RTL (target); break; case LABEL_DECL: x = gen_rtx_MEM (FUNCTION_MODE, gen_rtx_LABEL_REF (Pmode, force_label_rtx (target))); break; case REAL_CST: case FIXED_CST: case STRING_CST: case COMPLEX_CST: case CONSTRUCTOR: case INTEGER_CST: x = output_constant_def (target, 1); break; default: gcc_unreachable (); } gcc_assert (MEM_P (x)); x = XEXP (x, 0); value->base = x; value->offset = offset; } /* Uniquize all constants that appear in memory. Each constant in memory thus far output is recorded in `const_desc_table'. */ struct constant_descriptor_tree GTY(()) { /* A MEM for the constant. */ rtx rtl; /* The value of the constant. */ tree value; /* Hash of value. Computing the hash from value each time hashfn is called can't work properly, as that means recursive use of the hash table during hash table expansion. */ hashval_t hash; }; static GTY((param_is (struct constant_descriptor_tree))) htab_t const_desc_htab; static struct constant_descriptor_tree * build_constant_desc (tree); static void maybe_output_constant_def_contents (struct constant_descriptor_tree *, int); /* Compute a hash code for a constant expression. */ static hashval_t const_desc_hash (const void *ptr) { return ((const struct constant_descriptor_tree *)ptr)->hash; } static hashval_t const_hash_1 (const tree exp) { const char *p; hashval_t hi; int len, i; enum tree_code code = TREE_CODE (exp); /* Either set P and LEN to the address and len of something to hash and exit the switch or return a value. */ switch (code) { case INTEGER_CST: p = (char *) &TREE_INT_CST (exp); len = sizeof TREE_INT_CST (exp); break; case REAL_CST: return real_hash (TREE_REAL_CST_PTR (exp)); case FIXED_CST: return fixed_hash (TREE_FIXED_CST_PTR (exp)); case STRING_CST: p = TREE_STRING_POINTER (exp); len = TREE_STRING_LENGTH (exp); break; case COMPLEX_CST: return (const_hash_1 (TREE_REALPART (exp)) * 5 + const_hash_1 (TREE_IMAGPART (exp))); case CONSTRUCTOR: { unsigned HOST_WIDE_INT idx; tree value; hi = 5 + int_size_in_bytes (TREE_TYPE (exp)); FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, value) if (value) hi = hi * 603 + const_hash_1 (value); return hi; } case ADDR_EXPR: case FDESC_EXPR: { struct addr_const value; decode_addr_const (exp, &value); switch (GET_CODE (value.base)) { case SYMBOL_REF: /* Don't hash the address of the SYMBOL_REF; only use the offset and the symbol name. */ hi = value.offset; p = XSTR (value.base, 0); for (i = 0; p[i] != 0; i++) hi = ((hi * 613) + (unsigned) (p[i])); break; case LABEL_REF: hi = value.offset + CODE_LABEL_NUMBER (XEXP (value.base, 0)) * 13; break; default: gcc_unreachable (); } } return hi; case PLUS_EXPR: case POINTER_PLUS_EXPR: case MINUS_EXPR: return (const_hash_1 (TREE_OPERAND (exp, 0)) * 9 + const_hash_1 (TREE_OPERAND (exp, 1))); case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: return const_hash_1 (TREE_OPERAND (exp, 0)) * 7 + 2; default: /* A language specific constant. Just hash the code. */ return code; } /* Compute hashing function. */ hi = len; for (i = 0; i < len; i++) hi = ((hi * 613) + (unsigned) (p[i])); return hi; } /* Wrapper of compare_constant, for the htab interface. */ static int const_desc_eq (const void *p1, const void *p2) { const struct constant_descriptor_tree *c1 = p1; const struct constant_descriptor_tree *c2 = p2; if (c1->hash != c2->hash) return 0; return compare_constant (c1->value, c2->value); } /* Compare t1 and t2, and return 1 only if they are known to result in the same bit pattern on output. */ static int compare_constant (const tree t1, const tree t2) { enum tree_code typecode; if (t1 == NULL_TREE) return t2 == NULL_TREE; if (t2 == NULL_TREE) return 0; if (TREE_CODE (t1) != TREE_CODE (t2)) return 0; switch (TREE_CODE (t1)) { case INTEGER_CST: /* Integer constants are the same only if the same width of type. */ if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) return 0; if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) return 0; return tree_int_cst_equal (t1, t2); case REAL_CST: /* Real constants are the same only if the same width of type. */ if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) return 0; return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); case FIXED_CST: /* Fixed constants are the same only if the same width of type. */ if (TYPE_PRECISION (TREE_TYPE (t1)) != TYPE_PRECISION (TREE_TYPE (t2))) return 0; return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2)); case STRING_CST: if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2))) return 0; return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2), TREE_STRING_LENGTH (t1))); case COMPLEX_CST: return (compare_constant (TREE_REALPART (t1), TREE_REALPART (t2)) && compare_constant (TREE_IMAGPART (t1), TREE_IMAGPART (t2))); case CONSTRUCTOR: { VEC(constructor_elt, gc) *v1, *v2; unsigned HOST_WIDE_INT idx; typecode = TREE_CODE (TREE_TYPE (t1)); if (typecode != TREE_CODE (TREE_TYPE (t2))) return 0; if (typecode == ARRAY_TYPE) { HOST_WIDE_INT size_1 = int_size_in_bytes (TREE_TYPE (t1)); /* For arrays, check that the sizes all match. */ if (TYPE_MODE (TREE_TYPE (t1)) != TYPE_MODE (TREE_TYPE (t2)) || size_1 == -1 || size_1 != int_size_in_bytes (TREE_TYPE (t2))) return 0; } else { /* For record and union constructors, require exact type equality. */ if (TREE_TYPE (t1) != TREE_TYPE (t2)) return 0; } v1 = CONSTRUCTOR_ELTS (t1); v2 = CONSTRUCTOR_ELTS (t2); if (VEC_length (constructor_elt, v1) != VEC_length (constructor_elt, v2)) return 0; for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx) { constructor_elt *c1 = VEC_index (constructor_elt, v1, idx); constructor_elt *c2 = VEC_index (constructor_elt, v2, idx); /* Check that each value is the same... */ if (!compare_constant (c1->value, c2->value)) return 0; /* ... and that they apply to the same fields! */ if (typecode == ARRAY_TYPE) { if (!compare_constant (c1->index, c2->index)) return 0; } else { if (c1->index != c2->index) return 0; } } return 1; } case ADDR_EXPR: case FDESC_EXPR: { struct addr_const value1, value2; decode_addr_const (t1, &value1); decode_addr_const (t2, &value2); return (value1.offset == value2.offset && strcmp (XSTR (value1.base, 0), XSTR (value2.base, 0)) == 0); } case PLUS_EXPR: case POINTER_PLUS_EXPR: case MINUS_EXPR: case RANGE_EXPR: return (compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)) && compare_constant(TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1))); case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: case VIEW_CONVERT_EXPR: return compare_constant (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); default: return 0; } gcc_unreachable (); } /* Make a copy of the whole tree structure for a constant. This handles the same types of nodes that compare_constant handles. */ static tree copy_constant (tree exp) { switch (TREE_CODE (exp)) { case ADDR_EXPR: /* For ADDR_EXPR, we do not want to copy the decl whose address is requested. We do want to copy constants though. */ if (CONSTANT_CLASS_P (TREE_OPERAND (exp, 0))) return build1 (TREE_CODE (exp), TREE_TYPE (exp), copy_constant (TREE_OPERAND (exp, 0))); else return copy_node (exp); case INTEGER_CST: case REAL_CST: case FIXED_CST: case STRING_CST: return copy_node (exp); case COMPLEX_CST: return build_complex (TREE_TYPE (exp), copy_constant (TREE_REALPART (exp)), copy_constant (TREE_IMAGPART (exp))); case PLUS_EXPR: case POINTER_PLUS_EXPR: case MINUS_EXPR: return build2 (TREE_CODE (exp), TREE_TYPE (exp), copy_constant (TREE_OPERAND (exp, 0)), copy_constant (TREE_OPERAND (exp, 1))); case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: case VIEW_CONVERT_EXPR: return build1 (TREE_CODE (exp), TREE_TYPE (exp), copy_constant (TREE_OPERAND (exp, 0))); case CONSTRUCTOR: { tree copy = copy_node (exp); VEC(constructor_elt, gc) *v; unsigned HOST_WIDE_INT idx; tree purpose, value; v = VEC_alloc(constructor_elt, gc, VEC_length(constructor_elt, CONSTRUCTOR_ELTS (exp))); FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (exp), idx, purpose, value) { constructor_elt *ce = VEC_quick_push (constructor_elt, v, NULL); ce->index = purpose; ce->value = copy_constant (value); } CONSTRUCTOR_ELTS (copy) = v; return copy; } default: gcc_unreachable (); } } /* Return the alignment of constant EXP in bits. */ static unsigned int get_constant_alignment (tree exp) { unsigned int align; align = TYPE_ALIGN (TREE_TYPE (exp)); #ifdef CONSTANT_ALIGNMENT align = CONSTANT_ALIGNMENT (exp, align); #endif return align; } /* Return the section into which constant EXP should be placed. */ static section * get_constant_section (tree exp) { if (IN_NAMED_SECTION (exp)) return get_named_section (exp, NULL, compute_reloc_for_constant (exp)); else return targetm.asm_out.select_section (exp, compute_reloc_for_constant (exp), get_constant_alignment (exp)); } /* Return the size of constant EXP in bytes. */ static HOST_WIDE_INT get_constant_size (tree exp) { HOST_WIDE_INT size; size = int_size_in_bytes (TREE_TYPE (exp)); if (TREE_CODE (exp) == STRING_CST) size = MAX (TREE_STRING_LENGTH (exp), size); return size; } /* Subroutine of output_constant_def: No constant equal to EXP is known to have been output. Make a constant descriptor to enter EXP in the hash table. Assign the label number and construct RTL to refer to the constant's location in memory. Caller is responsible for updating the hash table. */ static struct constant_descriptor_tree * build_constant_desc (tree exp) { rtx symbol; rtx rtl; char label[256]; int labelno; struct constant_descriptor_tree *desc; desc = ggc_alloc (sizeof (*desc)); desc->value = copy_constant (exp); /* Propagate marked-ness to copied constant. */ if (flag_mudflap && mf_marked_p (exp)) mf_mark (desc->value); /* Create a string containing the label name, in LABEL. */ labelno = const_labelno++; ASM_GENERATE_INTERNAL_LABEL (label, "LC", labelno); /* We have a symbol name; construct the SYMBOL_REF and the MEM. */ if (use_object_blocks_p ()) { section *sect = get_constant_section (exp); symbol = create_block_symbol (ggc_strdup (label), get_block_for_section (sect), -1); } else symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; SET_SYMBOL_REF_DECL (symbol, desc->value); TREE_CONSTANT_POOL_ADDRESS_P (symbol) = 1; rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), symbol); set_mem_attributes (rtl, exp, 1); set_mem_alias_set (rtl, 0); set_mem_alias_set (rtl, const_alias_set); /* Set flags or add text to the name to record information, such as that it is a local symbol. If the name is changed, the macro ASM_OUTPUT_LABELREF will have to know how to strip this information. This call might invalidate our local variable SYMBOL; we can't use it afterward. */ targetm.encode_section_info (exp, rtl, true); desc->rtl = rtl; return desc; } /* Return an rtx representing a reference to constant data in memory for the constant expression EXP. If assembler code for such a constant has already been output, return an rtx to refer to it. Otherwise, output such a constant in memory and generate an rtx for it. If DEFER is nonzero, this constant can be deferred and output only if referenced in the function after all optimizations. `const_desc_table' records which constants already have label strings. */ rtx output_constant_def (tree exp, int defer) { struct constant_descriptor_tree *desc; struct constant_descriptor_tree key; void **loc; /* Look up EXP in the table of constant descriptors. If we didn't find it, create a new one. */ key.value = exp; key.hash = const_hash_1 (exp); loc = htab_find_slot_with_hash (const_desc_htab, &key, key.hash, INSERT); desc = *loc; if (desc == 0) { desc = build_constant_desc (exp); desc->hash = key.hash; *loc = desc; } maybe_output_constant_def_contents (desc, defer); return desc->rtl; } /* Subroutine of output_constant_def: Decide whether or not we need to output the constant DESC now, and if so, do it. */ static void maybe_output_constant_def_contents (struct constant_descriptor_tree *desc, int defer) { rtx symbol = XEXP (desc->rtl, 0); tree exp = desc->value; if (flag_syntax_only) return; if (TREE_ASM_WRITTEN (exp)) /* Already output; don't do it again. */ return; /* We can always defer constants as long as the context allows doing so. */ if (defer) { /* Increment n_deferred_constants if it exists. It needs to be at least as large as the number of constants actually referred to by the function. If it's too small we'll stop looking too early and fail to emit constants; if it's too large we'll only look through the entire function when we could have stopped earlier. */ if (cfun) n_deferred_constants++; return; } output_constant_def_contents (symbol); } /* Subroutine of output_constant_def_contents. Output the definition of constant EXP, which is pointed to by label LABEL. ALIGN is the constant's alignment in bits. */ static void assemble_constant_contents (tree exp, const char *label, unsigned int align) { HOST_WIDE_INT size; size = get_constant_size (exp); /* Do any machine/system dependent processing of the constant. */ #ifdef ASM_DECLARE_CONSTANT_NAME ASM_DECLARE_CONSTANT_NAME (asm_out_file, label, exp, size); #else /* Standard thing is just output label for the constant. */ ASM_OUTPUT_LABEL (asm_out_file, label); #endif /* ASM_DECLARE_CONSTANT_NAME */ /* Output the value of EXP. */ output_constant (exp, size, align); } /* We must output the constant data referred to by SYMBOL; do so. */ static void output_constant_def_contents (rtx symbol) { tree exp = SYMBOL_REF_DECL (symbol); unsigned int align; /* Make sure any other constants whose addresses appear in EXP are assigned label numbers. */ output_addressed_constants (exp); /* We are no longer deferring this constant. */ TREE_ASM_WRITTEN (exp) = 1; /* If the constant is part of an object block, make sure that the decl has been positioned within its block, but do not write out its definition yet. output_object_blocks will do that later. */ if (SYMBOL_REF_HAS_BLOCK_INFO_P (symbol) && SYMBOL_REF_BLOCK (symbol)) place_block_symbol (symbol); else { switch_to_section (get_constant_section (exp)); align = get_constant_alignment (exp); if (align > BITS_PER_UNIT) ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT)); assemble_constant_contents (exp, XSTR (symbol, 0), align); } if (flag_mudflap) mudflap_enqueue_constant (exp); } /* Look up EXP in the table of constant descriptors. Return the rtl if it has been emitted, else null. */ rtx lookup_constant_def (tree exp) { struct constant_descriptor_tree *desc; struct constant_descriptor_tree key; key.value = exp; key.hash = const_hash_1 (exp); desc = htab_find_with_hash (const_desc_htab, &key, key.hash); return (desc ? desc->rtl : NULL_RTX); } /* Used in the hash tables to avoid outputting the same constant twice. Unlike 'struct constant_descriptor_tree', RTX constants are output once per function, not once per file. */ /* ??? Only a few targets need per-function constant pools. Most can use one per-file pool. Should add a targetm bit to tell the difference. */ struct rtx_constant_pool GTY(()) { /* Pointers to first and last constant in pool, as ordered by offset. */ struct constant_descriptor_rtx *first; struct constant_descriptor_rtx *last; /* Hash facility for making memory-constants from constant rtl-expressions. It is used on RISC machines where immediate integer arguments and constant addresses are restricted so that such constants must be stored in memory. */ htab_t GTY((param_is (struct constant_descriptor_rtx))) const_rtx_htab; /* Current offset in constant pool (does not include any machine-specific header). */ HOST_WIDE_INT offset; }; struct constant_descriptor_rtx GTY((chain_next ("%h.next"))) { struct constant_descriptor_rtx *next; rtx mem; rtx sym; rtx constant; HOST_WIDE_INT offset; hashval_t hash; enum machine_mode mode; unsigned int align; int labelno; int mark; }; /* Hash and compare functions for const_rtx_htab. */ static hashval_t const_desc_rtx_hash (const void *ptr) { const struct constant_descriptor_rtx *desc = ptr; return desc->hash; } static int const_desc_rtx_eq (const void *a, const void *b) { const struct constant_descriptor_rtx *x = a; const struct constant_descriptor_rtx *y = b; if (x->mode != y->mode) return 0; return rtx_equal_p (x->constant, y->constant); } /* This is the worker function for const_rtx_hash, called via for_each_rtx. */ static int const_rtx_hash_1 (rtx *xp, void *data) { unsigned HOST_WIDE_INT hwi; enum machine_mode mode; enum rtx_code code; hashval_t h, *hp; rtx x; x = *xp; code = GET_CODE (x); mode = GET_MODE (x); h = (hashval_t) code * 1048573 + mode; switch (code) { case CONST_INT: hwi = INTVAL (x); fold_hwi: { const int shift = sizeof (hashval_t) * CHAR_BIT; const int n = sizeof (HOST_WIDE_INT) / sizeof (hashval_t); int i; h ^= (hashval_t) hwi; for (i = 1; i < n; ++i) { hwi >>= shift; h ^= (hashval_t) hwi; } } break; case CONST_DOUBLE: if (mode == VOIDmode) { hwi = CONST_DOUBLE_LOW (x) ^ CONST_DOUBLE_HIGH (x); goto fold_hwi; } else h ^= real_hash (CONST_DOUBLE_REAL_VALUE (x)); break; case CONST_FIXED: h ^= fixed_hash (CONST_FIXED_VALUE (x)); break; case CONST_VECTOR: { int i; for (i = XVECLEN (x, 0); i-- > 0; ) h = h * 251 + const_rtx_hash_1 (&XVECEXP (x, 0, i), data); } break; case SYMBOL_REF: h ^= htab_hash_string (XSTR (x, 0)); break; case LABEL_REF: h = h * 251 + CODE_LABEL_NUMBER (XEXP (x, 0)); break; case UNSPEC: case UNSPEC_VOLATILE: h = h * 251 + XINT (x, 1); break; default: break; } hp = data; *hp = *hp * 509 + h; return 0; } /* Compute a hash value for X, which should be a constant. */ static hashval_t const_rtx_hash (rtx x) { hashval_t h = 0; for_each_rtx (&x, const_rtx_hash_1, &h); return h; } /* Create and return a new rtx constant pool. */ static struct rtx_constant_pool * create_constant_pool (void) { struct rtx_constant_pool *pool; pool = ggc_alloc (sizeof (struct rtx_constant_pool)); pool->const_rtx_htab = htab_create_ggc (31, const_desc_rtx_hash, const_desc_rtx_eq, NULL); pool->first = NULL; pool->last = NULL; pool->offset = 0; return pool; } /* Initialize constant pool hashing for a new function. */ void init_varasm_status (struct function *f) { struct varasm_status *p; p = ggc_alloc (sizeof (struct varasm_status)); f->varasm = p; p->pool = create_constant_pool (); p->deferred_constants = 0; } /* Given a MINUS expression, simplify it if both sides include the same symbol. */ rtx simplify_subtraction (rtx x) { rtx r = simplify_rtx (x); return r ? r : x; } /* Given a constant rtx X, make (or find) a memory constant for its value and return a MEM rtx to refer to it in memory. */ rtx force_const_mem (enum machine_mode mode, rtx x) { struct constant_descriptor_rtx *desc, tmp; struct rtx_constant_pool *pool; char label[256]; rtx def, symbol; hashval_t hash; unsigned int align; void **slot; /* If we're not allowed to drop X into the constant pool, don't. */ if (targetm.cannot_force_const_mem (x)) return NULL_RTX; /* Record that this function has used a constant pool entry. */ current_function_uses_const_pool = 1; /* Decide which pool to use. */ pool = (targetm.use_blocks_for_constant_p (mode, x) ? shared_constant_pool : cfun->varasm->pool); /* Lookup the value in the hashtable. */ tmp.constant = x; tmp.mode = mode; hash = const_rtx_hash (x); slot = htab_find_slot_with_hash (pool->const_rtx_htab, &tmp, hash, INSERT); desc = *slot; /* If the constant was already present, return its memory. */ if (desc) return copy_rtx (desc->mem); /* Otherwise, create a new descriptor. */ desc = ggc_alloc (sizeof (*desc)); *slot = desc; /* Align the location counter as required by EXP's data type. */ align = GET_MODE_ALIGNMENT (mode == VOIDmode ? word_mode : mode); #ifdef CONSTANT_ALIGNMENT { tree type = lang_hooks.types.type_for_mode (mode, 0); if (type != NULL_TREE) align = CONSTANT_ALIGNMENT (make_tree (type, x), align); } #endif pool->offset += (align / BITS_PER_UNIT) - 1; pool->offset &= ~ ((align / BITS_PER_UNIT) - 1); desc->next = NULL; desc->constant = tmp.constant; desc->offset = pool->offset; desc->hash = hash; desc->mode = mode; desc->align = align; desc->labelno = const_labelno; desc->mark = 0; pool->offset += GET_MODE_SIZE (mode); if (pool->last) pool->last->next = desc; else pool->first = pool->last = desc; pool->last = desc; /* Create a string containing the label name, in LABEL. */ ASM_GENERATE_INTERNAL_LABEL (label, "LC", const_labelno); ++const_labelno; /* Construct the SYMBOL_REF. Make sure to mark it as belonging to the constants pool. */ if (use_object_blocks_p () && targetm.use_blocks_for_constant_p (mode, x)) { section *sect = targetm.asm_out.select_rtx_section (mode, x, align); symbol = create_block_symbol (ggc_strdup (label), get_block_for_section (sect), -1); } else symbol = gen_rtx_SYMBOL_REF (Pmode, ggc_strdup (label)); desc->sym = symbol; SYMBOL_REF_FLAGS (symbol) |= SYMBOL_FLAG_LOCAL; CONSTANT_POOL_ADDRESS_P (symbol) = 1; SET_SYMBOL_REF_CONSTANT (symbol, desc); /* Construct the MEM. */ desc->mem = def = gen_const_mem (mode, symbol); set_mem_attributes (def, lang_hooks.types.type_for_mode (mode, 0), 1); set_mem_align (def, align); /* If we're dropping a label to the constant pool, make sure we don't delete it. */ if (GET_CODE (x) == LABEL_REF) LABEL_PRESERVE_P (XEXP (x, 0)) = 1; return copy_rtx (def); } /* Given a constant pool SYMBOL_REF, return the corresponding constant. */ rtx get_pool_constant (rtx addr) { return SYMBOL_REF_CONSTANT (addr)->constant; } /* Given a constant pool SYMBOL_REF, return the corresponding constant and whether it has been output or not. */ rtx get_pool_constant_mark (rtx addr, bool *pmarked) { struct constant_descriptor_rtx *desc; desc = SYMBOL_REF_CONSTANT (addr); *pmarked = (desc->mark != 0); return desc->constant; } /* Similar, return the mode. */ enum machine_mode get_pool_mode (const_rtx addr) { return SYMBOL_REF_CONSTANT (addr)->mode; } /* Return the size of the constant pool. */ int get_pool_size (void) { return cfun->varasm->pool->offset; } /* Worker function for output_constant_pool_1. Emit assembly for X in MODE with known alignment ALIGN. */ static void output_constant_pool_2 (enum machine_mode mode, rtx x, unsigned int align) { switch (GET_MODE_CLASS (mode)) { case MODE_FLOAT: case MODE_DECIMAL_FLOAT: { REAL_VALUE_TYPE r; gcc_assert (GET_CODE (x) == CONST_DOUBLE); REAL_VALUE_FROM_CONST_DOUBLE (r, x); assemble_real (r, mode, align); break; } case MODE_INT: case MODE_PARTIAL_INT: case MODE_FRACT: case MODE_UFRACT: case MODE_ACCUM: case MODE_UACCUM: assemble_integer (x, GET_MODE_SIZE (mode), align, 1); break; case MODE_VECTOR_FLOAT: case MODE_VECTOR_INT: case MODE_VECTOR_FRACT: case MODE_VECTOR_UFRACT: case MODE_VECTOR_ACCUM: case MODE_VECTOR_UACCUM: { int i, units; enum machine_mode submode = GET_MODE_INNER (mode); unsigned int subalign = MIN (align, GET_MODE_BITSIZE (submode)); gcc_assert (GET_CODE (x) == CONST_VECTOR); units = CONST_VECTOR_NUNITS (x); for (i = 0; i < units; i++) { rtx elt = CONST_VECTOR_ELT (x, i); output_constant_pool_2 (submode, elt, i ? subalign : align); } } break; default: gcc_unreachable (); } } /* Worker function for output_constant_pool. Emit constant DESC, giving it ALIGN bits of alignment. */ static void output_constant_pool_1 (struct constant_descriptor_rtx *desc, unsigned int align) { rtx x, tmp; x = desc->constant; /* See if X is a LABEL_REF (or a CONST referring to a LABEL_REF) whose CODE_LABEL has been deleted. This can occur if a jump table is eliminated by optimization. If so, write a constant of zero instead. Note that this can also happen by turning the CODE_LABEL into a NOTE. */ /* ??? This seems completely and utterly wrong. Certainly it's not true for NOTE_INSN_DELETED_LABEL, but I disbelieve proper functioning even with INSN_DELETED_P and friends. */ tmp = x; switch (GET_CODE (x)) { case CONST: if (GET_CODE (XEXP (x, 0)) != PLUS || GET_CODE (XEXP (XEXP (x, 0), 0)) != LABEL_REF) break; tmp = XEXP (XEXP (x, 0), 0); /* FALLTHRU */ case LABEL_REF: tmp = XEXP (x, 0); gcc_assert (!INSN_DELETED_P (tmp)); gcc_assert (!NOTE_P (tmp) || NOTE_KIND (tmp) != NOTE_INSN_DELETED); break; default: break; } #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY ASM_OUTPUT_SPECIAL_POOL_ENTRY (asm_out_file, x, desc->mode, align, desc->labelno, done); #endif assemble_align (align); /* Output the label. */ targetm.asm_out.internal_label (asm_out_file, "LC", desc->labelno); /* Output the data. */ output_constant_pool_2 (desc->mode, x, align); /* Make sure all constants in SECTION_MERGE and not SECTION_STRINGS sections have proper size. */ if (align > GET_MODE_BITSIZE (desc->mode) && in_section && (in_section->common.flags & SECTION_MERGE)) assemble_align (align); #ifdef ASM_OUTPUT_SPECIAL_POOL_ENTRY done: #endif return; } /* Given a SYMBOL_REF CURRENT_RTX, mark it and all constants it refers to as used. Emit referenced deferred strings. This function can be used with for_each_rtx to mark all SYMBOL_REFs in an rtx. */ static int mark_constant (rtx *current_rtx, void *data ATTRIBUTE_UNUSED) { rtx x = *current_rtx; if (x == NULL_RTX || GET_CODE (x) != SYMBOL_REF) return 0; if (CONSTANT_POOL_ADDRESS_P (x)) { struct constant_descriptor_rtx *desc = SYMBOL_REF_CONSTANT (x); if (desc->mark == 0) { desc->mark = 1; for_each_rtx (&desc->constant, mark_constant, NULL); } } else if (TREE_CONSTANT_POOL_ADDRESS_P (x)) { tree exp = SYMBOL_REF_DECL (x); if (!TREE_ASM_WRITTEN (exp)) { n_deferred_constants--; output_constant_def_contents (x); } } return -1; } /* Look through appropriate parts of INSN, marking all entries in the constant pool which are actually being used. Entries that are only referenced by other constants are also marked as used. Emit deferred strings that are used. */ static void mark_constants (rtx insn) { if (!INSN_P (insn)) return; /* Insns may appear inside a SEQUENCE. Only check the patterns of insns, not any notes that may be attached. We don't want to mark a constant just because it happens to appear in a REG_EQUIV note. */ if (GET_CODE (PATTERN (insn)) == SEQUENCE) { rtx seq = PATTERN (insn); int i, n = XVECLEN (seq, 0); for (i = 0; i < n; ++i) { rtx subinsn = XVECEXP (seq, 0, i); if (INSN_P (subinsn)) for_each_rtx (&PATTERN (subinsn), mark_constant, NULL); } } else for_each_rtx (&PATTERN (insn), mark_constant, NULL); } /* Look through the instructions for this function, and mark all the entries in POOL which are actually being used. Emit deferred constants which have indeed been used. */ static void mark_constant_pool (void) { rtx insn, link; if (!current_function_uses_const_pool && n_deferred_constants == 0) return; for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) mark_constants (insn); for (link = current_function_epilogue_delay_list; link; link = XEXP (link, 1)) mark_constants (XEXP (link, 0)); } /* Write all the constants in POOL. */ static void output_constant_pool_contents (struct rtx_constant_pool *pool) { struct constant_descriptor_rtx *desc; for (desc = pool->first; desc ; desc = desc->next) if (desc->mark) { /* If the constant is part of an object_block, make sure that the constant has been positioned within its block, but do not write out its definition yet. output_object_blocks will do that later. */ if (SYMBOL_REF_HAS_BLOCK_INFO_P (desc->sym) && SYMBOL_REF_BLOCK (desc->sym)) place_block_symbol (desc->sym); else { switch_to_section (targetm.asm_out.select_rtx_section (desc->mode, desc->constant, desc->align)); output_constant_pool_1 (desc, desc->align); } } } /* Mark all constants that are used in the current function, then write out the function's private constant pool. */ static void output_constant_pool (const char *fnname ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED) { struct rtx_constant_pool *pool = cfun->varasm->pool; /* It is possible for gcc to call force_const_mem and then to later discard the instructions which refer to the constant. In such a case we do not need to output the constant. */ mark_constant_pool (); #ifdef ASM_OUTPUT_POOL_PROLOGUE ASM_OUTPUT_POOL_PROLOGUE (asm_out_file, fnname, fndecl, pool->offset); #endif output_constant_pool_contents (pool); #ifdef ASM_OUTPUT_POOL_EPILOGUE ASM_OUTPUT_POOL_EPILOGUE (asm_out_file, fnname, fndecl, pool->offset); #endif } /* Write the contents of the shared constant pool. */ void output_shared_constant_pool (void) { output_constant_pool_contents (shared_constant_pool); } /* Determine what kind of relocations EXP may need. */ int compute_reloc_for_constant (tree exp) { int reloc = 0, reloc2; tree tem; switch (TREE_CODE (exp)) { case ADDR_EXPR: case FDESC_EXPR: /* Go inside any operations that get_inner_reference can handle and see if what's inside is a constant: no need to do anything here for addresses of variables or functions. */ for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); tem = TREE_OPERAND (tem, 0)) ; if (TREE_PUBLIC (tem)) reloc |= 2; else reloc |= 1; break; case PLUS_EXPR: case POINTER_PLUS_EXPR: reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); reloc |= compute_reloc_for_constant (TREE_OPERAND (exp, 1)); break; case MINUS_EXPR: reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); reloc2 = compute_reloc_for_constant (TREE_OPERAND (exp, 1)); /* The difference of two local labels is computable at link time. */ if (reloc == 1 && reloc2 == 1) reloc = 0; else reloc |= reloc2; break; case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: case VIEW_CONVERT_EXPR: reloc = compute_reloc_for_constant (TREE_OPERAND (exp, 0)); break; case CONSTRUCTOR: { unsigned HOST_WIDE_INT idx; FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) if (tem != 0) reloc |= compute_reloc_for_constant (tem); } break; default: break; } return reloc; } /* Find all the constants whose addresses are referenced inside of EXP, and make sure assembler code with a label has been output for each one. Indicate whether an ADDR_EXPR has been encountered. */ static void output_addressed_constants (tree exp) { tree tem; switch (TREE_CODE (exp)) { case ADDR_EXPR: case FDESC_EXPR: /* Go inside any operations that get_inner_reference can handle and see if what's inside is a constant: no need to do anything here for addresses of variables or functions. */ for (tem = TREE_OPERAND (exp, 0); handled_component_p (tem); tem = TREE_OPERAND (tem, 0)) ; /* If we have an initialized CONST_DECL, retrieve the initializer. */ if (TREE_CODE (tem) == CONST_DECL && DECL_INITIAL (tem)) tem = DECL_INITIAL (tem); if (CONSTANT_CLASS_P (tem) || TREE_CODE (tem) == CONSTRUCTOR) output_constant_def (tem, 0); break; case PLUS_EXPR: case POINTER_PLUS_EXPR: case MINUS_EXPR: output_addressed_constants (TREE_OPERAND (exp, 1)); /* Fall through. */ case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: case VIEW_CONVERT_EXPR: output_addressed_constants (TREE_OPERAND (exp, 0)); break; case CONSTRUCTOR: { unsigned HOST_WIDE_INT idx; FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (exp), idx, tem) if (tem != 0) output_addressed_constants (tem); } break; default: break; } } /* Whether a constructor CTOR is a valid static constant initializer if all its elements are. This used to be internal to initializer_constant_valid_p and has been exposed to let other functions like categorize_ctor_elements evaluate the property while walking a constructor for other purposes. */ bool constructor_static_from_elts_p (const_tree ctor) { return (TREE_CONSTANT (ctor) && (TREE_CODE (TREE_TYPE (ctor)) == UNION_TYPE || TREE_CODE (TREE_TYPE (ctor)) == RECORD_TYPE) && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (ctor))); } /* Return nonzero if VALUE is a valid constant-valued expression for use in initializing a static variable; one that can be an element of a "constant" initializer. Return null_pointer_node if the value is absolute; if it is relocatable, return the variable that determines the relocation. We assume that VALUE has been folded as much as possible; therefore, we do not need to check for such things as arithmetic-combinations of integers. */ tree initializer_constant_valid_p (tree value, tree endtype) { switch (TREE_CODE (value)) { case CONSTRUCTOR: if (constructor_static_from_elts_p (value)) { unsigned HOST_WIDE_INT idx; tree elt; bool absolute = true; FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (value), idx, elt) { tree reloc; reloc = initializer_constant_valid_p (elt, TREE_TYPE (elt)); if (!reloc) return NULL_TREE; if (reloc != null_pointer_node) absolute = false; } /* For a non-absolute relocation, there is no single variable that can be "the variable that determines the relocation." */ return absolute ? null_pointer_node : error_mark_node; } return TREE_STATIC (value) ? null_pointer_node : NULL_TREE; case INTEGER_CST: case VECTOR_CST: case REAL_CST: case FIXED_CST: case STRING_CST: case COMPLEX_CST: return null_pointer_node; case ADDR_EXPR: case FDESC_EXPR: value = staticp (TREE_OPERAND (value, 0)); if (value) { /* "&(*a).f" is like unto pointer arithmetic. If "a" turns out to be a constant, this is old-skool offsetof-like nonsense. */ if (TREE_CODE (value) == INDIRECT_REF && TREE_CONSTANT (TREE_OPERAND (value, 0))) return null_pointer_node; /* Taking the address of a nested function involves a trampoline. */ if (TREE_CODE (value) == FUNCTION_DECL && decl_function_context (value) && !DECL_NO_STATIC_CHAIN (value)) return NULL_TREE; /* "&{...}" requires a temporary to hold the constructed object. */ if (TREE_CODE (value) == CONSTRUCTOR) return NULL_TREE; } return value; case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR: return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype); case CONVERT_EXPR: case NOP_EXPR: { tree src; tree src_type; tree dest_type; src = TREE_OPERAND (value, 0); src_type = TREE_TYPE (src); dest_type = TREE_TYPE (value); /* Allow conversions between pointer types, floating-point types, and offset types. */ if ((POINTER_TYPE_P (dest_type) && POINTER_TYPE_P (src_type)) || (FLOAT_TYPE_P (dest_type) && FLOAT_TYPE_P (src_type)) || (TREE_CODE (dest_type) == OFFSET_TYPE && TREE_CODE (src_type) == OFFSET_TYPE)) return initializer_constant_valid_p (src, endtype); /* Allow length-preserving conversions between integer types. */ if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type) && (TYPE_PRECISION (dest_type) == TYPE_PRECISION (src_type))) return initializer_constant_valid_p (src, endtype); /* Allow conversions between other integer types only if explicit value. */ if (INTEGRAL_TYPE_P (dest_type) && INTEGRAL_TYPE_P (src_type)) { tree inner = initializer_constant_valid_p (src, endtype); if (inner == null_pointer_node) return null_pointer_node; break; } /* Allow (int) &foo provided int is as wide as a pointer. */ if (INTEGRAL_TYPE_P (dest_type) && POINTER_TYPE_P (src_type) && (TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type))) return initializer_constant_valid_p (src, endtype); /* Likewise conversions from int to pointers, but also allow conversions from 0. */ if ((POINTER_TYPE_P (dest_type) || TREE_CODE (dest_type) == OFFSET_TYPE) && INTEGRAL_TYPE_P (src_type)) { if (TREE_CODE (src) == INTEGER_CST && TYPE_PRECISION (dest_type) >= TYPE_PRECISION (src_type)) return null_pointer_node; if (integer_zerop (src)) return null_pointer_node; else if (TYPE_PRECISION (dest_type) <= TYPE_PRECISION (src_type)) return initializer_constant_valid_p (src, endtype); } /* Allow conversions to struct or union types if the value inside is okay. */ if (TREE_CODE (dest_type) == RECORD_TYPE || TREE_CODE (dest_type) == UNION_TYPE) return initializer_constant_valid_p (src, endtype); } break; case POINTER_PLUS_EXPR: case PLUS_EXPR: if (! INTEGRAL_TYPE_P (endtype) || TYPE_PRECISION (endtype) >= POINTER_SIZE) { tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype); tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), endtype); /* If either term is absolute, use the other term's relocation. */ if (valid0 == null_pointer_node) return valid1; if (valid1 == null_pointer_node) return valid0; } break; case MINUS_EXPR: if (! INTEGRAL_TYPE_P (endtype) || TYPE_PRECISION (endtype) >= POINTER_SIZE) { tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype); tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1), endtype); /* Win if second argument is absolute. */ if (valid1 == null_pointer_node) return valid0; /* Win if both arguments have the same relocation. Then the value is absolute. */ if (valid0 == valid1 && valid0 != 0) return null_pointer_node; /* Since GCC guarantees that string constants are unique in the generated code, a subtraction between two copies of the same constant string is absolute. */ if (valid0 && TREE_CODE (valid0) == STRING_CST && valid1 && TREE_CODE (valid1) == STRING_CST && operand_equal_p (valid0, valid1, 1)) return null_pointer_node; } /* Support narrowing differences. */ if (INTEGRAL_TYPE_P (endtype)) { tree op0, op1; op0 = TREE_OPERAND (value, 0); op1 = TREE_OPERAND (value, 1); /* Like STRIP_NOPS except allow the operand mode to widen. This works around a feature of fold that simplifies (int)(p1 - p2) to ((int)p1 - (int)p2) under the theory that the narrower operation is cheaper. */ while (TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR || TREE_CODE (op0) == NON_LVALUE_EXPR) { tree inner = TREE_OPERAND (op0, 0); if (inner == error_mark_node || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))) > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) break; op0 = inner; } while (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR || TREE_CODE (op1) == NON_LVALUE_EXPR) { tree inner = TREE_OPERAND (op1, 0); if (inner == error_mark_node || ! INTEGRAL_MODE_P (TYPE_MODE (TREE_TYPE (inner))) || (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op1))) > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (inner))))) break; op1 = inner; } op0 = initializer_constant_valid_p (op0, endtype); op1 = initializer_constant_valid_p (op1, endtype); /* Both initializers must be known. */ if (op0 && op1) { if (op0 == op1) return null_pointer_node; /* Support differences between labels. */ if (TREE_CODE (op0) == LABEL_DECL && TREE_CODE (op1) == LABEL_DECL) return null_pointer_node; if (TREE_CODE (op0) == STRING_CST && TREE_CODE (op1) == STRING_CST && operand_equal_p (op0, op1, 1)) return null_pointer_node; } } break; default: break; } return 0; } /* Output assembler code for constant EXP to FILE, with no label. This includes the pseudo-op such as ".int" or ".byte", and a newline. Assumes output_addressed_constants has been done on EXP already. Generate exactly SIZE bytes of assembler data, padding at the end with zeros if necessary. SIZE must always be specified. SIZE is important for structure constructors, since trailing members may have been omitted from the constructor. It is also important for initialization of arrays from string constants since the full length of the string constant might not be wanted. It is also needed for initialization of unions, where the initializer's type is just one member, and that may not be as long as the union. There a case in which we would fail to output exactly SIZE bytes: for a structure constructor that wants to produce more than SIZE bytes. But such constructors will never be generated for any possible input. ALIGN is the alignment of the data in bits. */ void output_constant (tree exp, unsigned HOST_WIDE_INT size, unsigned int align) { enum tree_code code; unsigned HOST_WIDE_INT thissize; if (size == 0 || flag_syntax_only) return; /* See if we're trying to initialize a pointer in a non-default mode to the address of some declaration somewhere. If the target says the mode is valid for pointers, assume the target has a way of resolving it. */ if (TREE_CODE (exp) == NOP_EXPR && POINTER_TYPE_P (TREE_TYPE (exp)) && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) { tree saved_type = TREE_TYPE (exp); /* Peel off any intermediate conversions-to-pointer for valid pointer modes. */ while (TREE_CODE (exp) == NOP_EXPR && POINTER_TYPE_P (TREE_TYPE (exp)) && targetm.valid_pointer_mode (TYPE_MODE (TREE_TYPE (exp)))) exp = TREE_OPERAND (exp, 0); /* If what we're left with is the address of something, we can convert the address to the final type and output it that way. */ if (TREE_CODE (exp) == ADDR_EXPR) exp = build1 (ADDR_EXPR, saved_type, TREE_OPERAND (exp, 0)); /* Likewise for constant ints. */ else if (TREE_CODE (exp) == INTEGER_CST) exp = build_int_cst_wide (saved_type, TREE_INT_CST_LOW (exp), TREE_INT_CST_HIGH (exp)); } /* Eliminate any conversions since we'll be outputting the underlying constant. */ while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR || TREE_CODE (exp) == NON_LVALUE_EXPR || TREE_CODE (exp) == VIEW_CONVERT_EXPR) { HOST_WIDE_INT type_size = int_size_in_bytes (TREE_TYPE (exp)); HOST_WIDE_INT op_size = int_size_in_bytes (TREE_TYPE (TREE_OPERAND (exp, 0))); /* Make sure eliminating the conversion is really a no-op, except with VIEW_CONVERT_EXPRs to allow for wild Ada unchecked conversions and union types to allow for Ada unchecked unions. */ if (type_size > op_size && TREE_CODE (exp) != VIEW_CONVERT_EXPR && TREE_CODE (TREE_TYPE (exp)) != UNION_TYPE) /* Keep the conversion. */ break; else exp = TREE_OPERAND (exp, 0); } code = TREE_CODE (TREE_TYPE (exp)); thissize = int_size_in_bytes (TREE_TYPE (exp)); /* Allow a constructor with no elements for any data type. This means to fill the space with zeros. */ if (TREE_CODE (exp) == CONSTRUCTOR && VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (exp))) { assemble_zeros (size); return; } if (TREE_CODE (exp) == FDESC_EXPR) { #ifdef ASM_OUTPUT_FDESC HOST_WIDE_INT part = tree_low_cst (TREE_OPERAND (exp, 1), 0); tree decl = TREE_OPERAND (exp, 0); ASM_OUTPUT_FDESC (asm_out_file, decl, part); #else gcc_unreachable (); #endif return; } /* Now output the underlying data. If we've handling the padding, return. Otherwise, break and ensure SIZE is the size written. */ switch (code) { case BOOLEAN_TYPE: case INTEGER_TYPE: case ENUMERAL_TYPE: case POINTER_TYPE: case REFERENCE_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE: if (! assemble_integer (expand_expr (exp, NULL_RTX, VOIDmode, EXPAND_INITIALIZER), MIN (size, thissize), align, 0)) error ("initializer for integer/fixed-point value is too complicated"); break; case REAL_TYPE: if (TREE_CODE (exp) != REAL_CST) error ("initializer for floating value is not a floating constant"); assemble_real (TREE_REAL_CST (exp), TYPE_MODE (TREE_TYPE (exp)), align); break; case COMPLEX_TYPE: output_constant (TREE_REALPART (exp), thissize / 2, align); output_constant (TREE_IMAGPART (exp), thissize / 2, min_align (align, BITS_PER_UNIT * (thissize / 2))); break; case ARRAY_TYPE: case VECTOR_TYPE: switch (TREE_CODE (exp)) { case CONSTRUCTOR: output_constructor (exp, size, align); return; case STRING_CST: thissize = MIN ((unsigned HOST_WIDE_INT)TREE_STRING_LENGTH (exp), size); assemble_string (TREE_STRING_POINTER (exp), thissize); break; case VECTOR_CST: { int elt_size; tree link; unsigned int nalign; enum machine_mode inner; inner = TYPE_MODE (TREE_TYPE (TREE_TYPE (exp))); nalign = MIN (align, GET_MODE_ALIGNMENT (inner)); elt_size = GET_MODE_SIZE (inner); link = TREE_VECTOR_CST_ELTS (exp); output_constant (TREE_VALUE (link), elt_size, align); thissize = elt_size; while ((link = TREE_CHAIN (link)) != NULL) { output_constant (TREE_VALUE (link), elt_size, nalign); thissize += elt_size; } break; } default: gcc_unreachable (); } break; case RECORD_TYPE: case UNION_TYPE: gcc_assert (TREE_CODE (exp) == CONSTRUCTOR); output_constructor (exp, size, align); return; case ERROR_MARK: return; default: gcc_unreachable (); } if (size > thissize) assemble_zeros (size - thissize); } /* Subroutine of output_constructor, used for computing the size of arrays of unspecified length. VAL must be a CONSTRUCTOR of an array type with an unspecified upper bound. */ static unsigned HOST_WIDE_INT array_size_for_constructor (tree val) { tree max_index, i; unsigned HOST_WIDE_INT cnt; tree index, value, tmp; /* This code used to attempt to handle string constants that are not arrays of single-bytes, but nothing else does, so there's no point in doing it here. */ if (TREE_CODE (val) == STRING_CST) return TREE_STRING_LENGTH (val); max_index = NULL_TREE; FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (val), cnt, index, value) { if (TREE_CODE (index) == RANGE_EXPR) index = TREE_OPERAND (index, 1); if (max_index == NULL_TREE || tree_int_cst_lt (max_index, index)) max_index = index; } if (max_index == NULL_TREE) return 0; /* Compute the total number of array elements. */ tmp = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (val))); i = size_binop (MINUS_EXPR, fold_convert (sizetype, max_index), fold_convert (sizetype, tmp)); i = size_binop (PLUS_EXPR, i, build_int_cst (sizetype, 1)); /* Multiply by the array element unit size to find number of bytes. */ i = size_binop (MULT_EXPR, i, TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (val)))); return tree_low_cst (i, 1); } /* Subroutine of output_constant, used for CONSTRUCTORs (aggregate constants). Generate at least SIZE bytes, padding if necessary. */ static void output_constructor (tree exp, unsigned HOST_WIDE_INT size, unsigned int align) { tree type = TREE_TYPE (exp); tree field = 0; tree min_index = 0; /* Number of bytes output or skipped so far. In other words, current position within the constructor. */ HOST_WIDE_INT total_bytes = 0; /* Nonzero means BYTE contains part of a byte, to be output. */ int byte_buffer_in_use = 0; int byte = 0; unsigned HOST_WIDE_INT cnt; constructor_elt *ce; gcc_assert (HOST_BITS_PER_WIDE_INT >= BITS_PER_UNIT); if (TREE_CODE (type) == RECORD_TYPE) field = TYPE_FIELDS (type); if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) != 0) min_index = TYPE_MIN_VALUE (TYPE_DOMAIN (type)); /* As LINK goes through the elements of the constant, FIELD goes through the structure fields, if the constant is a structure. if the constant is a union, then we override this, by getting the field from the TREE_LIST element. But the constant could also be an array. Then FIELD is zero. There is always a maximum of one element in the chain LINK for unions (even if the initializer in a source program incorrectly contains more one). */ for (cnt = 0; VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (exp), cnt, ce); cnt++, field = field ? TREE_CHAIN (field) : 0) { tree val = ce->value; tree index = 0; /* The element in a union constructor specifies the proper field or index. */ if ((TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == QUAL_UNION_TYPE) && ce->index != 0) field = ce->index; else if (TREE_CODE (type) == ARRAY_TYPE) index = ce->index; #ifdef ASM_COMMENT_START if (field && flag_verbose_asm) fprintf (asm_out_file, "%s %s:\n", ASM_COMMENT_START, DECL_NAME (field) ? IDENTIFIER_POINTER (DECL_NAME (field)) : ""); #endif /* Eliminate the marker that makes a cast not be an lvalue. */ if (val != 0) STRIP_NOPS (val); if (index && TREE_CODE (index) == RANGE_EXPR) { unsigned HOST_WIDE_INT fieldsize = int_size_in_bytes (TREE_TYPE (type)); HOST_WIDE_INT lo_index = tree_low_cst (TREE_OPERAND (index, 0), 0); HOST_WIDE_INT hi_index = tree_low_cst (TREE_OPERAND (index, 1), 0); HOST_WIDE_INT index; unsigned int align2 = min_align (align, fieldsize * BITS_PER_UNIT); for (index = lo_index; index <= hi_index; index++) { /* Output the element's initial value. */ if (val == 0) assemble_zeros (fieldsize); else output_constant (val, fieldsize, align2); /* Count its size. */ total_bytes += fieldsize; } } else if (field == 0 || !DECL_BIT_FIELD (field)) { /* An element that is not a bit-field. */ unsigned HOST_WIDE_INT fieldsize; /* Since this structure is static, we know the positions are constant. */ HOST_WIDE_INT pos = field ? int_byte_position (field) : 0; unsigned int align2; if (index != 0) pos = (tree_low_cst (TYPE_SIZE_UNIT (TREE_TYPE (val)), 1) * (tree_low_cst (index, 0) - tree_low_cst (min_index, 0))); /* Output any buffered-up bit-fields preceding this element. */ if (byte_buffer_in_use) { assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); total_bytes++; byte_buffer_in_use = 0; } /* Advance to offset of this element. Note no alignment needed in an array, since that is guaranteed if each element has the proper size. */ if ((field != 0 || index != 0) && pos != total_bytes) { gcc_assert (pos >= total_bytes); assemble_zeros (pos - total_bytes); total_bytes = pos; } /* Find the alignment of this element. */ align2 = min_align (align, BITS_PER_UNIT * pos); /* Determine size this element should occupy. */ if (field) { fieldsize = 0; /* If this is an array with an unspecified upper bound, the initializer determines the size. */ /* ??? This ought to only checked if DECL_SIZE_UNIT is NULL, but we cannot do this until the deprecated support for initializing zero-length array members is removed. */ if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE && TYPE_DOMAIN (TREE_TYPE (field)) && ! TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (field)))) { fieldsize = array_size_for_constructor (val); /* Given a non-empty initialization, this field had better be last. */ gcc_assert (!fieldsize || !TREE_CHAIN (field)); } else if (DECL_SIZE_UNIT (field)) { /* ??? This can't be right. If the decl size overflows a host integer we will silently emit no data. */ if (host_integerp (DECL_SIZE_UNIT (field), 1)) fieldsize = tree_low_cst (DECL_SIZE_UNIT (field), 1); } } else fieldsize = int_size_in_bytes (TREE_TYPE (type)); /* Output the element's initial value. */ if (val == 0) assemble_zeros (fieldsize); else output_constant (val, fieldsize, align2); /* Count its size. */ total_bytes += fieldsize; } else if (val != 0 && TREE_CODE (val) != INTEGER_CST) error ("invalid initial value for member %qs", IDENTIFIER_POINTER (DECL_NAME (field))); else { /* Element that is a bit-field. */ HOST_WIDE_INT next_offset = int_bit_position (field); HOST_WIDE_INT end_offset = (next_offset + tree_low_cst (DECL_SIZE (field), 1)); if (val == 0) val = integer_zero_node; /* If this field does not start in this (or, next) byte, skip some bytes. */ if (next_offset / BITS_PER_UNIT != total_bytes) { /* Output remnant of any bit field in previous bytes. */ if (byte_buffer_in_use) { assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); total_bytes++; byte_buffer_in_use = 0; } /* If still not at proper byte, advance to there. */ if (next_offset / BITS_PER_UNIT != total_bytes) { gcc_assert (next_offset / BITS_PER_UNIT >= total_bytes); assemble_zeros (next_offset / BITS_PER_UNIT - total_bytes); total_bytes = next_offset / BITS_PER_UNIT; } } if (! byte_buffer_in_use) byte = 0; /* We must split the element into pieces that fall within separate bytes, and combine each byte with previous or following bit-fields. */ /* next_offset is the offset n fbits from the beginning of the structure to the next bit of this element to be processed. end_offset is the offset of the first bit past the end of this element. */ while (next_offset < end_offset) { int this_time; int shift; HOST_WIDE_INT value; HOST_WIDE_INT next_byte = next_offset / BITS_PER_UNIT; HOST_WIDE_INT next_bit = next_offset % BITS_PER_UNIT; /* Advance from byte to byte within this element when necessary. */ while (next_byte != total_bytes) { assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); total_bytes++; byte = 0; } /* Number of bits we can process at once (all part of the same byte). */ this_time = MIN (end_offset - next_offset, BITS_PER_UNIT - next_bit); if (BYTES_BIG_ENDIAN) { /* On big-endian machine, take the most significant bits first (of the bits that are significant) and put them into bytes from the most significant end. */ shift = end_offset - next_offset - this_time; /* Don't try to take a bunch of bits that cross the word boundary in the INTEGER_CST. We can only select bits from the LOW or HIGH part not from both. */ if (shift < HOST_BITS_PER_WIDE_INT && shift + this_time > HOST_BITS_PER_WIDE_INT) { this_time = shift + this_time - HOST_BITS_PER_WIDE_INT; shift = HOST_BITS_PER_WIDE_INT; } /* Now get the bits from the appropriate constant word. */ if (shift < HOST_BITS_PER_WIDE_INT) value = TREE_INT_CST_LOW (val); else { gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); value = TREE_INT_CST_HIGH (val); shift -= HOST_BITS_PER_WIDE_INT; } /* Get the result. This works only when: 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ byte |= (((value >> shift) & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) << (BITS_PER_UNIT - this_time - next_bit)); } else { /* On little-endian machines, take first the least significant bits of the value and pack them starting at the least significant bits of the bytes. */ shift = next_offset - int_bit_position (field); /* Don't try to take a bunch of bits that cross the word boundary in the INTEGER_CST. We can only select bits from the LOW or HIGH part not from both. */ if (shift < HOST_BITS_PER_WIDE_INT && shift + this_time > HOST_BITS_PER_WIDE_INT) this_time = (HOST_BITS_PER_WIDE_INT - shift); /* Now get the bits from the appropriate constant word. */ if (shift < HOST_BITS_PER_WIDE_INT) value = TREE_INT_CST_LOW (val); else { gcc_assert (shift < 2 * HOST_BITS_PER_WIDE_INT); value = TREE_INT_CST_HIGH (val); shift -= HOST_BITS_PER_WIDE_INT; } /* Get the result. This works only when: 1 <= this_time <= HOST_BITS_PER_WIDE_INT. */ byte |= (((value >> shift) & (((HOST_WIDE_INT) 2 << (this_time - 1)) - 1)) << next_bit); } next_offset += this_time; byte_buffer_in_use = 1; } } } if (byte_buffer_in_use) { assemble_integer (GEN_INT (byte), 1, BITS_PER_UNIT, 1); total_bytes++; } if ((unsigned HOST_WIDE_INT)total_bytes < size) assemble_zeros (size - total_bytes); } /* This TREE_LIST contains any weak symbol declarations waiting to be emitted. */ static GTY(()) tree weak_decls; /* Mark DECL as weak. */ static void mark_weak (tree decl) { DECL_WEAK (decl) = 1; if (DECL_RTL_SET_P (decl) && MEM_P (DECL_RTL (decl)) && XEXP (DECL_RTL (decl), 0) && GET_CODE (XEXP (DECL_RTL (decl), 0)) == SYMBOL_REF) SYMBOL_REF_WEAK (XEXP (DECL_RTL (decl), 0)) = 1; } /* Merge weak status between NEWDECL and OLDDECL. */ void merge_weak (tree newdecl, tree olddecl) { if (DECL_WEAK (newdecl) == DECL_WEAK (olddecl)) { if (DECL_WEAK (newdecl) && SUPPORTS_WEAK) { tree *pwd; /* We put the NEWDECL on the weak_decls list at some point and OLDDECL as well. Keep just OLDDECL on the list. */ for (pwd = &weak_decls; *pwd; pwd = &TREE_CHAIN (*pwd)) if (TREE_VALUE (*pwd) == newdecl) { *pwd = TREE_CHAIN (*pwd); break; } } return; } if (DECL_WEAK (newdecl)) { tree wd; /* NEWDECL is weak, but OLDDECL is not. */ /* If we already output the OLDDECL, we're in trouble; we can't go back and make it weak. This error cannot caught in declare_weak because the NEWDECL and OLDDECL was not yet been merged; therefore, TREE_ASM_WRITTEN was not set. */ if (TREE_ASM_WRITTEN (olddecl)) error ("weak declaration of %q+D must precede definition", newdecl); /* If we've already generated rtl referencing OLDDECL, we may have done so in a way that will not function properly with a weak symbol. */ else if (TREE_USED (olddecl) && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (olddecl))) warning (0, "weak declaration of %q+D after first use results " "in unspecified behavior", newdecl); if (SUPPORTS_WEAK) { /* We put the NEWDECL on the weak_decls list at some point. Replace it with the OLDDECL. */ for (wd = weak_decls; wd; wd = TREE_CHAIN (wd)) if (TREE_VALUE (wd) == newdecl) { TREE_VALUE (wd) = olddecl; break; } /* We may not find the entry on the list. If NEWDECL is a weak alias, then we will have already called globalize_decl to remove the entry; in that case, we do not need to do anything. */ } /* Make the OLDDECL weak; it's OLDDECL that we'll be keeping. */ mark_weak (olddecl); } else /* OLDDECL was weak, but NEWDECL was not explicitly marked as weak. Just update NEWDECL to indicate that it's weak too. */ mark_weak (newdecl); } /* Declare DECL to be a weak symbol. */ void declare_weak (tree decl) { if (! TREE_PUBLIC (decl)) error ("weak declaration of %q+D must be public", decl); else if (TREE_CODE (decl) == FUNCTION_DECL && TREE_ASM_WRITTEN (decl)) error ("weak declaration of %q+D must precede definition", decl); else if (SUPPORTS_WEAK) { if (! DECL_WEAK (decl)) weak_decls = tree_cons (NULL, decl, weak_decls); } else warning (0, "weak declaration of %q+D not supported", decl); mark_weak (decl); } static void weak_finish_1 (tree decl) { #if defined (ASM_WEAKEN_DECL) || defined (ASM_WEAKEN_LABEL) const char *const name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); #endif if (! TREE_USED (decl)) return; #ifdef ASM_WEAKEN_DECL ASM_WEAKEN_DECL (asm_out_file, decl, name, NULL); #else #ifdef ASM_WEAKEN_LABEL ASM_WEAKEN_LABEL (asm_out_file, name); #else #ifdef ASM_OUTPUT_WEAK_ALIAS { static bool warn_once = 0; if (! warn_once) { warning (0, "only weak aliases are supported in this configuration"); warn_once = 1; } return; } #endif #endif #endif } /* This TREE_LIST contains weakref targets. */ static GTY(()) tree weakref_targets; /* Forward declaration. */ static tree find_decl_and_mark_needed (tree decl, tree target); /* Emit any pending weak declarations. */ void weak_finish (void) { tree t; for (t = weakref_targets; t; t = TREE_CHAIN (t)) { tree alias_decl = TREE_PURPOSE (t); tree target = ultimate_transparent_alias_target (&TREE_VALUE (t)); if (! TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (alias_decl))) /* Remove alias_decl from the weak list, but leave entries for the target alone. */ target = NULL_TREE; #ifndef ASM_OUTPUT_WEAKREF else if (! TREE_SYMBOL_REFERENCED (target)) { /* Use ASM_WEAKEN_LABEL only if ASM_WEAKEN_DECL is not defined, otherwise we and weak_finish_1 would use a different macros. */ # if defined ASM_WEAKEN_LABEL && ! defined ASM_WEAKEN_DECL ASM_WEAKEN_LABEL (asm_out_file, IDENTIFIER_POINTER (target)); # else tree decl = find_decl_and_mark_needed (alias_decl, target); if (! decl) { decl = build_decl (TREE_CODE (alias_decl), target, TREE_TYPE (alias_decl)); DECL_EXTERNAL (decl) = 1; TREE_PUBLIC (decl) = 1; DECL_ARTIFICIAL (decl) = 1; TREE_NOTHROW (decl) = TREE_NOTHROW (alias_decl); TREE_USED (decl) = 1; } weak_finish_1 (decl); # endif } #endif { tree *p; tree t2; /* Remove the alias and the target from the pending weak list so that we do not emit any .weak directives for the former, nor multiple .weak directives for the latter. */ for (p = &weak_decls; (t2 = *p) ; ) { if (TREE_VALUE (t2) == alias_decl || target == DECL_ASSEMBLER_NAME (TREE_VALUE (t2))) *p = TREE_CHAIN (t2); else p = &TREE_CHAIN (t2); } /* Remove other weakrefs to the same target, to speed things up. */ for (p = &TREE_CHAIN (t); (t2 = *p) ; ) { if (target == ultimate_transparent_alias_target (&TREE_VALUE (t2))) *p = TREE_CHAIN (t2); else p = &TREE_CHAIN (t2); } } } for (t = weak_decls; t; t = TREE_CHAIN (t)) { tree decl = TREE_VALUE (t); weak_finish_1 (decl); } } /* Emit the assembly bits to indicate that DECL is globally visible. */ static void globalize_decl (tree decl) { #if defined (ASM_WEAKEN_LABEL) || defined (ASM_WEAKEN_DECL) if (DECL_WEAK (decl)) { const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0); tree *p, t; #ifdef ASM_WEAKEN_DECL ASM_WEAKEN_DECL (asm_out_file, decl, name, 0); #else ASM_WEAKEN_LABEL (asm_out_file, name); #endif /* Remove this function from the pending weak list so that we do not emit multiple .weak directives for it. */ for (p = &weak_decls; (t = *p) ; ) { if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) *p = TREE_CHAIN (t); else p = &TREE_CHAIN (t); } /* Remove weakrefs to the same target from the pending weakref list, for the same reason. */ for (p = &weakref_targets; (t = *p) ; ) { if (DECL_ASSEMBLER_NAME (decl) == ultimate_transparent_alias_target (&TREE_VALUE (t))) *p = TREE_CHAIN (t); else p = &TREE_CHAIN (t); } return; } #endif targetm.asm_out.globalize_decl_name (asm_out_file, decl); } /* We have to be able to tell cgraph about the needed-ness of the target of an alias. This requires that the decl have been defined. Aliases that precede their definition have to be queued for later processing. */ typedef struct alias_pair GTY(()) { tree decl; tree target; } alias_pair; /* Define gc'd vector type. */ DEF_VEC_O(alias_pair); DEF_VEC_ALLOC_O(alias_pair,gc); static GTY(()) VEC(alias_pair,gc) *alias_pairs; /* Given an assembly name, find the decl it is associated with. At the same time, mark it needed for cgraph. */ static tree find_decl_and_mark_needed (tree decl, tree target) { struct cgraph_node *fnode = NULL; struct varpool_node *vnode = NULL; if (TREE_CODE (decl) == FUNCTION_DECL) { fnode = cgraph_node_for_asm (target); if (fnode == NULL) vnode = varpool_node_for_asm (target); } else { vnode = varpool_node_for_asm (target); if (vnode == NULL) fnode = cgraph_node_for_asm (target); } if (fnode) { /* We can't mark function nodes as used after cgraph global info is finished. This wouldn't generally be necessary, but C++ virtual table thunks are introduced late in the game and might seem like they need marking, although in fact they don't. */ if (! cgraph_global_info_ready) cgraph_mark_needed_node (fnode); return fnode->decl; } else if (vnode) { varpool_mark_needed_node (vnode); return vnode->decl; } else return NULL_TREE; } /* Output the assembler code for a define (equate) using ASM_OUTPUT_DEF or ASM_OUTPUT_DEF_FROM_DECLS. The function defines the symbol whose tree node is DECL to have the value of the tree node TARGET. */ static void do_assemble_alias (tree decl, tree target) { if (TREE_ASM_WRITTEN (decl)) return; TREE_ASM_WRITTEN (decl) = 1; TREE_ASM_WRITTEN (DECL_ASSEMBLER_NAME (decl)) = 1; if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) { ultimate_transparent_alias_target (&target); if (!targetm.have_tls && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) { decl = emutls_decl (decl); target = get_emutls_object_name (target); } if (!TREE_SYMBOL_REFERENCED (target)) weakref_targets = tree_cons (decl, target, weakref_targets); #ifdef ASM_OUTPUT_WEAKREF ASM_OUTPUT_WEAKREF (asm_out_file, decl, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), IDENTIFIER_POINTER (target)); #else if (!SUPPORTS_WEAK) { error ("%Jweakref is not supported in this configuration", decl); return; } #endif return; } if (!targetm.have_tls && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) { decl = emutls_decl (decl); target = get_emutls_object_name (target); } #ifdef ASM_OUTPUT_DEF /* Make name accessible from other files, if appropriate. */ if (TREE_PUBLIC (decl)) { globalize_decl (decl); maybe_assemble_visibility (decl); } # ifdef ASM_OUTPUT_DEF_FROM_DECLS ASM_OUTPUT_DEF_FROM_DECLS (asm_out_file, decl, target); # else ASM_OUTPUT_DEF (asm_out_file, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)), IDENTIFIER_POINTER (target)); # endif #elif defined (ASM_OUTPUT_WEAK_ALIAS) || defined (ASM_WEAKEN_DECL) { const char *name; tree *p, t; name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); # ifdef ASM_WEAKEN_DECL ASM_WEAKEN_DECL (asm_out_file, decl, name, IDENTIFIER_POINTER (target)); # else ASM_OUTPUT_WEAK_ALIAS (asm_out_file, name, IDENTIFIER_POINTER (target)); # endif /* Remove this function from the pending weak list so that we do not emit multiple .weak directives for it. */ for (p = &weak_decls; (t = *p) ; ) if (DECL_ASSEMBLER_NAME (decl) == DECL_ASSEMBLER_NAME (TREE_VALUE (t))) *p = TREE_CHAIN (t); else p = &TREE_CHAIN (t); /* Remove weakrefs to the same target from the pending weakref list, for the same reason. */ for (p = &weakref_targets; (t = *p) ; ) { if (DECL_ASSEMBLER_NAME (decl) == ultimate_transparent_alias_target (&TREE_VALUE (t))) *p = TREE_CHAIN (t); else p = &TREE_CHAIN (t); } } #endif } /* First pass of completing pending aliases. Make sure that cgraph knows which symbols will be required. */ void finish_aliases_1 (void) { unsigned i; alias_pair *p; for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) { tree target_decl; target_decl = find_decl_and_mark_needed (p->decl, p->target); if (target_decl == NULL) { if (! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) error ("%q+D aliased to undefined symbol %qs", p->decl, IDENTIFIER_POINTER (p->target)); } else if (DECL_EXTERNAL (target_decl) && ! lookup_attribute ("weakref", DECL_ATTRIBUTES (p->decl))) error ("%q+D aliased to external symbol %qs", p->decl, IDENTIFIER_POINTER (p->target)); } } /* Second pass of completing pending aliases. Emit the actual assembly. This happens at the end of compilation and thus it is assured that the target symbol has been emitted. */ void finish_aliases_2 (void) { unsigned i; alias_pair *p; for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++) do_assemble_alias (p->decl, p->target); VEC_truncate (alias_pair, alias_pairs, 0); } /* Emit an assembler directive to make the symbol for DECL an alias to the symbol for TARGET. */ void assemble_alias (tree decl, tree target) { tree target_decl; bool is_weakref = false; if (lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) { tree alias = DECL_ASSEMBLER_NAME (decl); is_weakref = true; ultimate_transparent_alias_target (&target); if (alias == target) error ("weakref %q+D ultimately targets itself", decl); else { #ifndef ASM_OUTPUT_WEAKREF IDENTIFIER_TRANSPARENT_ALIAS (alias) = 1; TREE_CHAIN (alias) = target; #endif } if (TREE_PUBLIC (decl)) error ("weakref %q+D must have static linkage", decl); } else { #if !defined (ASM_OUTPUT_DEF) # if !defined(ASM_OUTPUT_WEAK_ALIAS) && !defined (ASM_WEAKEN_DECL) error ("%Jalias definitions not supported in this configuration", decl); return; # else if (!DECL_WEAK (decl)) { error ("%Jonly weak aliases are supported in this configuration", decl); return; } # endif #endif } /* We must force creation of DECL_RTL for debug info generation, even though we don't use it here. */ make_decl_rtl (decl); TREE_USED (decl) = 1; /* A quirk of the initial implementation of aliases required that the user add "extern" to all of them. Which is silly, but now historical. Do note that the symbol is in fact locally defined. */ if (! is_weakref) DECL_EXTERNAL (decl) = 0; /* Allow aliases to aliases. */ if (TREE_CODE (decl) == FUNCTION_DECL) cgraph_node (decl)->alias = true; else varpool_node (decl)->alias = true; /* If the target has already been emitted, we don't have to queue the alias. This saves a tad o memory. */ target_decl = find_decl_and_mark_needed (decl, target); if (target_decl && TREE_ASM_WRITTEN (target_decl)) do_assemble_alias (decl, target); else { alias_pair *p = VEC_safe_push (alias_pair, gc, alias_pairs, NULL); p->decl = decl; p->target = target; } } /* Emit an assembler directive to set symbol for DECL visibility to the visibility type VIS, which must not be VISIBILITY_DEFAULT. */ void default_assemble_visibility (tree decl, int vis) { static const char * const visibility_types[] = { NULL, "protected", "hidden", "internal" }; const char *name, *type; name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); type = visibility_types[vis]; #ifdef HAVE_GAS_HIDDEN fprintf (asm_out_file, "\t.%s\t", type); assemble_name (asm_out_file, name); fprintf (asm_out_file, "\n"); #else warning (OPT_Wattributes, "visibility attribute not supported " "in this configuration; ignored"); #endif } /* A helper function to call assemble_visibility when needed for a decl. */ int maybe_assemble_visibility (tree decl) { enum symbol_visibility vis = DECL_VISIBILITY (decl); if (vis != VISIBILITY_DEFAULT) { targetm.asm_out.visibility (decl, vis); return 1; } else return 0; } /* Returns 1 if the target configuration supports defining public symbols so that one of them will be chosen at link time instead of generating a multiply-defined symbol error, whether through the use of weak symbols or a target-specific mechanism for having duplicates discarded. */ int supports_one_only (void) { if (SUPPORTS_ONE_ONLY) return 1; return SUPPORTS_WEAK; } /* Set up DECL as a public symbol that can be defined in multiple translation units without generating a linker error. */ void make_decl_one_only (tree decl) { gcc_assert (TREE_CODE (decl) == VAR_DECL || TREE_CODE (decl) == FUNCTION_DECL); TREE_PUBLIC (decl) = 1; if (SUPPORTS_ONE_ONLY) { #ifdef MAKE_DECL_ONE_ONLY MAKE_DECL_ONE_ONLY (decl); #endif DECL_ONE_ONLY (decl) = 1; } else if (TREE_CODE (decl) == VAR_DECL && (DECL_INITIAL (decl) == 0 || DECL_INITIAL (decl) == error_mark_node)) DECL_COMMON (decl) = 1; else { gcc_assert (SUPPORTS_WEAK); DECL_WEAK (decl) = 1; } } void init_varasm_once (void) { section_htab = htab_create_ggc (31, section_entry_hash, section_entry_eq, NULL); object_block_htab = htab_create_ggc (31, object_block_entry_hash, object_block_entry_eq, NULL); const_desc_htab = htab_create_ggc (1009, const_desc_hash, const_desc_eq, NULL); const_alias_set = new_alias_set (); shared_constant_pool = create_constant_pool (); #ifdef TEXT_SECTION_ASM_OP text_section = get_unnamed_section (SECTION_CODE, output_section_asm_op, TEXT_SECTION_ASM_OP); #endif #ifdef DATA_SECTION_ASM_OP data_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, DATA_SECTION_ASM_OP); #endif #ifdef SDATA_SECTION_ASM_OP sdata_section = get_unnamed_section (SECTION_WRITE, output_section_asm_op, SDATA_SECTION_ASM_OP); #endif #ifdef READONLY_DATA_SECTION_ASM_OP readonly_data_section = get_unnamed_section (0, output_section_asm_op, READONLY_DATA_SECTION_ASM_OP); #endif #ifdef CTORS_SECTION_ASM_OP ctors_section = get_unnamed_section (0, output_section_asm_op, CTORS_SECTION_ASM_OP); #endif #ifdef DTORS_SECTION_ASM_OP dtors_section = get_unnamed_section (0, output_section_asm_op, DTORS_SECTION_ASM_OP); #endif #ifdef BSS_SECTION_ASM_OP bss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, output_section_asm_op, BSS_SECTION_ASM_OP); #endif #ifdef SBSS_SECTION_ASM_OP sbss_section = get_unnamed_section (SECTION_WRITE | SECTION_BSS, output_section_asm_op, SBSS_SECTION_ASM_OP); #endif tls_comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS | SECTION_COMMON, emit_tls_common); lcomm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS | SECTION_COMMON, emit_local); comm_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS | SECTION_COMMON, emit_common); #if defined ASM_OUTPUT_ALIGNED_BSS || defined ASM_OUTPUT_BSS bss_noswitch_section = get_noswitch_section (SECTION_WRITE | SECTION_BSS, emit_bss); #endif targetm.asm_out.init_sections (); if (readonly_data_section == NULL) readonly_data_section = text_section; } enum tls_model decl_default_tls_model (const_tree decl) { enum tls_model kind; bool is_local; is_local = targetm.binds_local_p (decl); if (!flag_shlib) { if (is_local) kind = TLS_MODEL_LOCAL_EXEC; else kind = TLS_MODEL_INITIAL_EXEC; } /* Local dynamic is inefficient when we're not combining the parts of the address. */ else if (optimize && is_local) kind = TLS_MODEL_LOCAL_DYNAMIC; else kind = TLS_MODEL_GLOBAL_DYNAMIC; if (kind < flag_tls_default) kind = flag_tls_default; return kind; } /* Select a set of attributes for section NAME based on the properties of DECL and whether or not RELOC indicates that DECL's initializer might contain runtime relocations. We make the section read-only and executable for a function decl, read-only for a const data decl, and writable for a non-const data decl. */ unsigned int default_section_type_flags (tree decl, const char *name, int reloc) { unsigned int flags; if (decl && TREE_CODE (decl) == FUNCTION_DECL) flags = SECTION_CODE; else if (decl && decl_readonly_section (decl, reloc)) flags = 0; else if (current_function_decl && cfun && cfun->unlikely_text_section_name && strcmp (name, cfun->unlikely_text_section_name) == 0) flags = SECTION_CODE; else if (!decl && (!current_function_decl || !cfun) && strcmp (name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0) flags = SECTION_CODE; else flags = SECTION_WRITE; if (decl && DECL_ONE_ONLY (decl)) flags |= SECTION_LINKONCE; if (decl && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) flags |= SECTION_TLS | SECTION_WRITE; if (strcmp (name, ".bss") == 0 || strncmp (name, ".bss.", 5) == 0 || strncmp (name, ".gnu.linkonce.b.", 16) == 0 || strcmp (name, ".sbss") == 0 || strncmp (name, ".sbss.", 6) == 0 || strncmp (name, ".gnu.linkonce.sb.", 17) == 0) flags |= SECTION_BSS; if (strcmp (name, ".tdata") == 0 || strncmp (name, ".tdata.", 7) == 0 || strncmp (name, ".gnu.linkonce.td.", 17) == 0) flags |= SECTION_TLS; if (strcmp (name, ".tbss") == 0 || strncmp (name, ".tbss.", 6) == 0 || strncmp (name, ".gnu.linkonce.tb.", 17) == 0) flags |= SECTION_TLS | SECTION_BSS; /* These three sections have special ELF types. They are neither SHT_PROGBITS nor SHT_NOBITS, so when changing sections we don't want to print a section type (@progbits or @nobits). If someone is silly enough to emit code or TLS variables to one of these sections, then don't handle them specially. */ if (!(flags & (SECTION_CODE | SECTION_BSS | SECTION_TLS)) && (strcmp (name, ".init_array") == 0 || strcmp (name, ".fini_array") == 0 || strcmp (name, ".preinit_array") == 0)) flags |= SECTION_NOTYPE; return flags; } /* Return true if the target supports some form of global BSS, either through bss_noswitch_section, or by selecting a BSS section in TARGET_ASM_SELECT_SECTION. */ bool have_global_bss_p (void) { return bss_noswitch_section || targetm.have_switchable_bss_sections; } /* Output assembly to switch to section NAME with attribute FLAGS. Four variants for common object file formats. */ void default_no_named_section (const char *name ATTRIBUTE_UNUSED, unsigned int flags ATTRIBUTE_UNUSED, tree decl ATTRIBUTE_UNUSED) { /* Some object formats don't support named sections at all. The front-end should already have flagged this as an error. */ gcc_unreachable (); } void default_elf_asm_named_section (const char *name, unsigned int flags, tree decl ATTRIBUTE_UNUSED) { char flagchars[10], *f = flagchars; /* If we have already declared this section, we can use an abbreviated form to switch back to it -- unless this section is part of a COMDAT groups, in which case GAS requires the full declaration every time. */ if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) && (flags & SECTION_DECLARED)) { fprintf (asm_out_file, "\t.section\t%s\n", name); return; } if (!(flags & SECTION_DEBUG)) *f++ = 'a'; if (flags & SECTION_WRITE) *f++ = 'w'; if (flags & SECTION_CODE) *f++ = 'x'; if (flags & SECTION_SMALL) *f++ = 's'; if (flags & SECTION_MERGE) *f++ = 'M'; if (flags & SECTION_STRINGS) *f++ = 'S'; if (flags & SECTION_TLS) *f++ = 'T'; if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) *f++ = 'G'; *f = '\0'; fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars); if (!(flags & SECTION_NOTYPE)) { const char *type; const char *format; if (flags & SECTION_BSS) type = "nobits"; else type = "progbits"; format = ",@%s"; #ifdef ASM_COMMENT_START /* On platforms that use "@" as the assembly comment character, use "%" instead. */ if (strcmp (ASM_COMMENT_START, "@") == 0) format = ",%%%s"; #endif fprintf (asm_out_file, format, type); if (flags & SECTION_ENTSIZE) fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE); if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE)) fprintf (asm_out_file, ",%s,comdat", lang_hooks.decls.comdat_group (decl)); } putc ('\n', asm_out_file); } void default_coff_asm_named_section (const char *name, unsigned int flags, tree decl ATTRIBUTE_UNUSED) { char flagchars[8], *f = flagchars; if (flags & SECTION_WRITE) *f++ = 'w'; if (flags & SECTION_CODE) *f++ = 'x'; *f = '\0'; fprintf (asm_out_file, "\t.section\t%s,\"%s\"\n", name, flagchars); } void default_pe_asm_named_section (const char *name, unsigned int flags, tree decl) { default_coff_asm_named_section (name, flags, decl); if (flags & SECTION_LINKONCE) { /* Functions may have been compiled at various levels of optimization so we can't use `same_size' here. Instead, have the linker pick one. */ fprintf (asm_out_file, "\t.linkonce %s\n", (flags & SECTION_CODE ? "discard" : "same_size")); } } /* The lame default section selector. */ section * default_select_section (tree decl, int reloc, unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) { if (DECL_P (decl)) { if (decl_readonly_section (decl, reloc)) return readonly_data_section; } else if (TREE_CODE (decl) == CONSTRUCTOR) { if (! ((flag_pic && reloc) || !TREE_READONLY (decl) || TREE_SIDE_EFFECTS (decl) || !TREE_CONSTANT (decl))) return readonly_data_section; } else if (TREE_CODE (decl) == STRING_CST) return readonly_data_section; else if (! (flag_pic && reloc)) return readonly_data_section; return data_section; } enum section_category categorize_decl_for_section (const_tree decl, int reloc) { enum section_category ret; if (TREE_CODE (decl) == FUNCTION_DECL) return SECCAT_TEXT; else if (TREE_CODE (decl) == STRING_CST) { if (flag_mudflap) /* or !flag_merge_constants */ return SECCAT_RODATA; else return SECCAT_RODATA_MERGE_STR; } else if (TREE_CODE (decl) == VAR_DECL) { if (bss_initializer_p (decl)) ret = SECCAT_BSS; else if (! TREE_READONLY (decl) || TREE_SIDE_EFFECTS (decl) || ! TREE_CONSTANT (DECL_INITIAL (decl))) { /* Here the reloc_rw_mask is not testing whether the section should be read-only or not, but whether the dynamic link will have to do something. If so, we wish to segregate the data in order to minimize cache misses inside the dynamic linker. */ if (reloc & targetm.asm_out.reloc_rw_mask ()) ret = reloc == 1 ? SECCAT_DATA_REL_LOCAL : SECCAT_DATA_REL; else ret = SECCAT_DATA; } else if (reloc & targetm.asm_out.reloc_rw_mask ()) ret = reloc == 1 ? SECCAT_DATA_REL_RO_LOCAL : SECCAT_DATA_REL_RO; else if (reloc || flag_merge_constants < 2) /* C and C++ don't allow different variables to share the same location. -fmerge-all-constants allows even that (at the expense of not conforming). */ ret = SECCAT_RODATA; else if (TREE_CODE (DECL_INITIAL (decl)) == STRING_CST) ret = SECCAT_RODATA_MERGE_STR_INIT; else ret = SECCAT_RODATA_MERGE_CONST; } else if (TREE_CODE (decl) == CONSTRUCTOR) { if ((reloc & targetm.asm_out.reloc_rw_mask ()) || TREE_SIDE_EFFECTS (decl) || ! TREE_CONSTANT (decl)) ret = SECCAT_DATA; else ret = SECCAT_RODATA; } else ret = SECCAT_RODATA; /* There are no read-only thread-local sections. */ if (TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) { /* Note that this would be *just* SECCAT_BSS, except that there's no concept of a read-only thread-local-data section. */ if (ret == SECCAT_BSS || (flag_zero_initialized_in_bss && initializer_zerop (DECL_INITIAL (decl)))) ret = SECCAT_TBSS; else ret = SECCAT_TDATA; } /* If the target uses small data sections, select it. */ else if (targetm.in_small_data_p (decl)) { if (ret == SECCAT_BSS) ret = SECCAT_SBSS; else if (targetm.have_srodata_section && ret == SECCAT_RODATA) ret = SECCAT_SRODATA; else ret = SECCAT_SDATA; } return ret; } bool decl_readonly_section (const_tree decl, int reloc) { switch (categorize_decl_for_section (decl, reloc)) { case SECCAT_RODATA: case SECCAT_RODATA_MERGE_STR: case SECCAT_RODATA_MERGE_STR_INIT: case SECCAT_RODATA_MERGE_CONST: case SECCAT_SRODATA: return true; break; default: return false; break; } } /* Select a section based on the above categorization. */ section * default_elf_select_section (tree decl, int reloc, unsigned HOST_WIDE_INT align) { const char *sname; switch (categorize_decl_for_section (decl, reloc)) { case SECCAT_TEXT: /* We're not supposed to be called on FUNCTION_DECLs. */ gcc_unreachable (); case SECCAT_RODATA: return readonly_data_section; case SECCAT_RODATA_MERGE_STR: return mergeable_string_section (decl, align, 0); case SECCAT_RODATA_MERGE_STR_INIT: return mergeable_string_section (DECL_INITIAL (decl), align, 0); case SECCAT_RODATA_MERGE_CONST: return mergeable_constant_section (DECL_MODE (decl), align, 0); case SECCAT_SRODATA: sname = ".sdata2"; break; case SECCAT_DATA: return data_section; case SECCAT_DATA_REL: sname = ".data.rel"; break; case SECCAT_DATA_REL_LOCAL: sname = ".data.rel.local"; break; case SECCAT_DATA_REL_RO: sname = ".data.rel.ro"; break; case SECCAT_DATA_REL_RO_LOCAL: sname = ".data.rel.ro.local"; break; case SECCAT_SDATA: sname = ".sdata"; break; case SECCAT_TDATA: sname = ".tdata"; break; case SECCAT_BSS: if (bss_section) return bss_section; sname = ".bss"; break; case SECCAT_SBSS: sname = ".sbss"; break; case SECCAT_TBSS: sname = ".tbss"; break; default: gcc_unreachable (); } if (!DECL_P (decl)) decl = NULL_TREE; return get_named_section (decl, sname, reloc); } /* Construct a unique section name based on the decl name and the categorization performed above. */ void default_unique_section (tree decl, int reloc) { /* We only need to use .gnu.linkonce if we don't have COMDAT groups. */ bool one_only = DECL_ONE_ONLY (decl) && !HAVE_COMDAT_GROUP; const char *prefix, *name; size_t nlen, plen; char *string; switch (categorize_decl_for_section (decl, reloc)) { case SECCAT_TEXT: prefix = one_only ? ".gnu.linkonce.t." : ".text."; break; case SECCAT_RODATA: case SECCAT_RODATA_MERGE_STR: case SECCAT_RODATA_MERGE_STR_INIT: case SECCAT_RODATA_MERGE_CONST: prefix = one_only ? ".gnu.linkonce.r." : ".rodata."; break; case SECCAT_SRODATA: prefix = one_only ? ".gnu.linkonce.s2." : ".sdata2."; break; case SECCAT_DATA: prefix = one_only ? ".gnu.linkonce.d." : ".data."; break; case SECCAT_DATA_REL: prefix = one_only ? ".gnu.linkonce.d.rel." : ".data.rel."; break; case SECCAT_DATA_REL_LOCAL: prefix = one_only ? ".gnu.linkonce.d.rel.local." : ".data.rel.local."; break; case SECCAT_DATA_REL_RO: prefix = one_only ? ".gnu.linkonce.d.rel.ro." : ".data.rel.ro."; break; case SECCAT_DATA_REL_RO_LOCAL: prefix = one_only ? ".gnu.linkonce.d.rel.ro.local." : ".data.rel.ro.local."; break; case SECCAT_SDATA: prefix = one_only ? ".gnu.linkonce.s." : ".sdata."; break; case SECCAT_BSS: prefix = one_only ? ".gnu.linkonce.b." : ".bss."; break; case SECCAT_SBSS: prefix = one_only ? ".gnu.linkonce.sb." : ".sbss."; break; case SECCAT_TDATA: prefix = one_only ? ".gnu.linkonce.td." : ".tdata."; break; case SECCAT_TBSS: prefix = one_only ? ".gnu.linkonce.tb." : ".tbss."; break; default: gcc_unreachable (); } plen = strlen (prefix); name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)); name = targetm.strip_name_encoding (name); nlen = strlen (name); string = alloca (nlen + plen + 1); memcpy (string, prefix, plen); memcpy (string + plen, name, nlen + 1); DECL_SECTION_NAME (decl) = build_string (nlen + plen, string); } /* Like compute_reloc_for_constant, except for an RTX. The return value is a mask for which bit 1 indicates a global relocation, and bit 0 indicates a local relocation. */ static int compute_reloc_for_rtx_1 (rtx *xp, void *data) { int *preloc = data; rtx x = *xp; switch (GET_CODE (x)) { case SYMBOL_REF: *preloc |= SYMBOL_REF_LOCAL_P (x) ? 1 : 2; break; case LABEL_REF: *preloc |= 1; break; default: break; } return 0; } static int compute_reloc_for_rtx (rtx x) { int reloc; switch (GET_CODE (x)) { case CONST: case SYMBOL_REF: case LABEL_REF: reloc = 0; for_each_rtx (&x, compute_reloc_for_rtx_1, &reloc); return reloc; default: return 0; } } section * default_select_rtx_section (enum machine_mode mode ATTRIBUTE_UNUSED, rtx x, unsigned HOST_WIDE_INT align ATTRIBUTE_UNUSED) { if (compute_reloc_for_rtx (x) & targetm.asm_out.reloc_rw_mask ()) return data_section; else return readonly_data_section; } section * default_elf_select_rtx_section (enum machine_mode mode, rtx x, unsigned HOST_WIDE_INT align) { int reloc = compute_reloc_for_rtx (x); /* ??? Handle small data here somehow. */ if (reloc & targetm.asm_out.reloc_rw_mask ()) { if (reloc == 1) return get_named_section (NULL, ".data.rel.ro.local", 1); else return get_named_section (NULL, ".data.rel.ro", 3); } return mergeable_constant_section (mode, align, 0); } /* Set the generally applicable flags on the SYMBOL_REF for EXP. */ void default_encode_section_info (tree decl, rtx rtl, int first ATTRIBUTE_UNUSED) { rtx symbol; int flags; /* Careful not to prod global register variables. */ if (!MEM_P (rtl)) return; symbol = XEXP (rtl, 0); if (GET_CODE (symbol) != SYMBOL_REF) return; flags = SYMBOL_REF_FLAGS (symbol) & SYMBOL_FLAG_HAS_BLOCK_INFO; if (TREE_CODE (decl) == FUNCTION_DECL) flags |= SYMBOL_FLAG_FUNCTION; if (targetm.binds_local_p (decl)) flags |= SYMBOL_FLAG_LOCAL; if (targetm.have_tls && TREE_CODE (decl) == VAR_DECL && DECL_THREAD_LOCAL_P (decl)) flags |= DECL_TLS_MODEL (decl) << SYMBOL_FLAG_TLS_SHIFT; else if (targetm.in_small_data_p (decl)) flags |= SYMBOL_FLAG_SMALL; /* ??? Why is DECL_EXTERNAL ever set for non-PUBLIC names? Without being PUBLIC, the thing *must* be defined in this translation unit. Prevent this buglet from being propagated into rtl code as well. */ if (DECL_P (decl) && DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)) flags |= SYMBOL_FLAG_EXTERNAL; SYMBOL_REF_FLAGS (symbol) = flags; } /* By default, we do nothing for encode_section_info, so we need not do anything but discard the '*' marker. */ const char * default_strip_name_encoding (const char *str) { return str + (*str == '*'); } #ifdef ASM_OUTPUT_DEF /* The default implementation of TARGET_ASM_OUTPUT_ANCHOR. Define the anchor relative to ".", the current section position. */ void default_asm_output_anchor (rtx symbol) { char buffer[100]; sprintf (buffer, "*. + " HOST_WIDE_INT_PRINT_DEC, SYMBOL_REF_BLOCK_OFFSET (symbol)); ASM_OUTPUT_DEF (asm_out_file, XSTR (symbol, 0), buffer); } #endif /* The default implementation of TARGET_USE_ANCHORS_FOR_SYMBOL_P. */ bool default_use_anchors_for_symbol_p (const_rtx symbol) { section *sect; tree decl; /* Don't use anchors for mergeable sections. The linker might move the objects around. */ sect = SYMBOL_REF_BLOCK (symbol)->sect; if (sect->common.flags & SECTION_MERGE) return false; /* Don't use anchors for small data sections. The small data register acts as an anchor for such sections. */ if (sect->common.flags & SECTION_SMALL) return false; decl = SYMBOL_REF_DECL (symbol); if (decl && DECL_P (decl)) { /* Don't use section anchors for decls that might be defined by other modules. */ if (!targetm.binds_local_p (decl)) return false; /* Don't use section anchors for decls that will be placed in a small data section. */ /* ??? Ideally, this check would be redundant with the SECTION_SMALL one above. The problem is that we only use SECTION_SMALL for sections that should be marked as small in the section directive. */ if (targetm.in_small_data_p (decl)) return false; } return true; } /* Assume ELF-ish defaults, since that's pretty much the most liberal wrt cross-module name binding. */ bool default_binds_local_p (const_tree exp) { return default_binds_local_p_1 (exp, flag_shlib); } bool default_binds_local_p_1 (const_tree exp, int shlib) { bool local_p; /* A non-decl is an entry in the constant pool. */ if (!DECL_P (exp)) local_p = true; /* Weakrefs may not bind locally, even though the weakref itself is always static and therefore local. */ else if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp))) local_p = false; /* Static variables are always local. */ else if (! TREE_PUBLIC (exp)) local_p = true; /* A variable is local if the user has said explicitly that it will be. */ else if (DECL_VISIBILITY_SPECIFIED (exp) && DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) local_p = true; /* Variables defined outside this object might not be local. */ else if (DECL_EXTERNAL (exp)) local_p = false; /* If defined in this object and visibility is not default, must be local. */ else if (DECL_VISIBILITY (exp) != VISIBILITY_DEFAULT) local_p = true; /* Default visibility weak data can be overridden by a strong symbol in another module and so are not local. */ else if (DECL_WEAK (exp)) local_p = false; /* If PIC, then assume that any global name can be overridden by symbols resolved from other modules, unless we are compiling with -fwhole-program, which assumes that names are local. */ else if (shlib) local_p = flag_whole_program; /* Uninitialized COMMON variable may be unified with symbols resolved from other modules. */ else if (DECL_COMMON (exp) && (DECL_INITIAL (exp) == NULL || DECL_INITIAL (exp) == error_mark_node)) local_p = false; /* Otherwise we're left with initialized (or non-common) global data which is of necessity defined locally. */ else local_p = true; return local_p; } /* Determine whether or not a pointer mode is valid. Assume defaults of ptr_mode or Pmode - can be overridden. */ bool default_valid_pointer_mode (enum machine_mode mode) { return (mode == ptr_mode || mode == Pmode); } /* Default function to output code that will globalize a label. A target must define GLOBAL_ASM_OP or provide its own function to globalize a label. */ #ifdef GLOBAL_ASM_OP void default_globalize_label (FILE * stream, const char *name) { fputs (GLOBAL_ASM_OP, stream); assemble_name (stream, name); putc ('\n', stream); } #endif /* GLOBAL_ASM_OP */ /* Default function to output code that will globalize a declaration. */ void default_globalize_decl_name (FILE * stream, tree decl) { const char *name = XSTR (XEXP (DECL_RTL (decl), 0), 0); targetm.asm_out.globalize_label (stream, name); } /* Default function to output a label for unwind information. The default is to do nothing. A target that needs nonlocal labels for unwind information must provide its own function to do this. */ void default_emit_unwind_label (FILE * stream ATTRIBUTE_UNUSED, tree decl ATTRIBUTE_UNUSED, int for_eh ATTRIBUTE_UNUSED, int empty ATTRIBUTE_UNUSED) { } /* Default function to output a label to divide up the exception table. The default is to do nothing. A target that needs/wants to divide up the table must provide it's own function to do this. */ void default_emit_except_table_label (FILE * stream ATTRIBUTE_UNUSED) { } /* This is how to output an internal numbered label where PREFIX is the class of label and LABELNO is the number within the class. */ void default_internal_label (FILE *stream, const char *prefix, unsigned long labelno) { char *const buf = alloca (40 + strlen (prefix)); ASM_GENERATE_INTERNAL_LABEL (buf, prefix, labelno); ASM_OUTPUT_INTERNAL_LABEL (stream, buf); } /* This is the default behavior at the beginning of a file. It's controlled by two other target-hook toggles. */ void default_file_start (void) { if (targetm.file_start_app_off && !flag_verbose_asm) fputs (ASM_APP_OFF, asm_out_file); if (targetm.file_start_file_directive) output_file_directive (asm_out_file, main_input_filename); } /* This is a generic routine suitable for use as TARGET_ASM_FILE_END which emits a special section directive used to indicate whether or not this object file needs an executable stack. This is primarily a GNU extension to ELF but could be used on other targets. */ int trampolines_created; void file_end_indicate_exec_stack (void) { unsigned int flags = SECTION_DEBUG; if (trampolines_created) flags |= SECTION_CODE; switch_to_section (get_section (".note.GNU-stack", flags, NULL)); } /* Output DIRECTIVE (a C string) followed by a newline. This is used as a get_unnamed_section callback. */ void output_section_asm_op (const void *directive) { fprintf (asm_out_file, "%s\n", (const char *) directive); } /* Emit assembly code to switch to section NEW_SECTION. Do nothing if the current section is NEW_SECTION. */ void switch_to_section (section *new_section) { if (in_section == new_section) return; if (new_section->common.flags & SECTION_FORGET) in_section = NULL; else in_section = new_section; switch (SECTION_STYLE (new_section)) { case SECTION_NAMED: if (cfun && !cfun->unlikely_text_section_name && strcmp (new_section->named.name, UNLIKELY_EXECUTED_TEXT_SECTION_NAME) == 0) cfun->unlikely_text_section_name = UNLIKELY_EXECUTED_TEXT_SECTION_NAME; targetm.asm_out.named_section (new_section->named.name, new_section->named.common.flags, new_section->named.decl); break; case SECTION_UNNAMED: new_section->unnamed.callback (new_section->unnamed.data); break; case SECTION_NOSWITCH: gcc_unreachable (); break; } new_section->common.flags |= SECTION_DECLARED; } /* If block symbol SYMBOL has not yet been assigned an offset, place it at the end of its block. */ void place_block_symbol (rtx symbol) { unsigned HOST_WIDE_INT size, mask, offset; struct constant_descriptor_rtx *desc; unsigned int alignment; struct object_block *block; tree decl; gcc_assert (SYMBOL_REF_BLOCK (symbol)); if (SYMBOL_REF_BLOCK_OFFSET (symbol) >= 0) return; /* Work out the symbol's size and alignment. */ if (CONSTANT_POOL_ADDRESS_P (symbol)) { desc = SYMBOL_REF_CONSTANT (symbol); alignment = desc->align; size = GET_MODE_SIZE (desc->mode); } else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol)) { decl = SYMBOL_REF_DECL (symbol); alignment = get_constant_alignment (decl); size = get_constant_size (decl); } else { decl = SYMBOL_REF_DECL (symbol); alignment = DECL_ALIGN (decl); size = tree_low_cst (DECL_SIZE_UNIT (decl), 1); } /* Calculate the object's offset from the start of the block. */ block = SYMBOL_REF_BLOCK (symbol); mask = alignment / BITS_PER_UNIT - 1; offset = (block->size + mask) & ~mask; SYMBOL_REF_BLOCK_OFFSET (symbol) = offset; /* Record the block's new alignment and size. */ block->alignment = MAX (block->alignment, alignment); block->size = offset + size; VEC_safe_push (rtx, gc, block->objects, symbol); } /* Return the anchor that should be used to address byte offset OFFSET from the first object in BLOCK. MODEL is the TLS model used to access it. */ rtx get_section_anchor (struct object_block *block, HOST_WIDE_INT offset, enum tls_model model) { char label[100]; unsigned int begin, middle, end; unsigned HOST_WIDE_INT min_offset, max_offset, range, bias, delta; rtx anchor; /* Work out the anchor's offset. Use an offset of 0 for the first anchor so that we don't pessimize the case where we take the address of a variable at the beginning of the block. This is particularly useful when a block has only one variable assigned to it. We try to place anchors RANGE bytes apart, so there can then be anchors at +/-RANGE, +/-2 * RANGE, and so on, up to the limits of a ptr_mode offset. With some target settings, the lowest such anchor might be out of range for the lowest ptr_mode offset; likewise the highest anchor for the highest offset. Use anchors at the extreme ends of the ptr_mode range in such cases. All arithmetic uses unsigned integers in order to avoid signed overflow. */ max_offset = (unsigned HOST_WIDE_INT) targetm.max_anchor_offset; min_offset = (unsigned HOST_WIDE_INT) targetm.min_anchor_offset; range = max_offset - min_offset + 1; if (range == 0) offset = 0; else { bias = 1 << (GET_MODE_BITSIZE (ptr_mode) - 1); if (offset < 0) { delta = -(unsigned HOST_WIDE_INT) offset + max_offset; delta -= delta % range; if (delta > bias) delta = bias; offset = (HOST_WIDE_INT) (-delta); } else { delta = (unsigned HOST_WIDE_INT) offset - min_offset; delta -= delta % range; if (delta > bias - 1) delta = bias - 1; offset = (HOST_WIDE_INT) delta; } } /* Do a binary search to see if there's already an anchor we can use. Set BEGIN to the new anchor's index if not. */ begin = 0; end = VEC_length (rtx, block->anchors); while (begin != end) { middle = (end + begin) / 2; anchor = VEC_index (rtx, block->anchors, middle); if (SYMBOL_REF_BLOCK_OFFSET (anchor) > offset) end = middle; else if (SYMBOL_REF_BLOCK_OFFSET (anchor) < offset) begin = middle + 1; else if (SYMBOL_REF_TLS_MODEL (anchor) > model) end = middle; else if (SYMBOL_REF_TLS_MODEL (anchor) < model) begin = middle + 1; else return anchor; } /* Create a new anchor with a unique label. */ ASM_GENERATE_INTERNAL_LABEL (label, "LANCHOR", anchor_labelno++); anchor = create_block_symbol (ggc_strdup (label), block, offset); SYMBOL_REF_FLAGS (anchor) |= SYMBOL_FLAG_LOCAL | SYMBOL_FLAG_ANCHOR; SYMBOL_REF_FLAGS (anchor) |= model << SYMBOL_FLAG_TLS_SHIFT; /* Insert it at index BEGIN. */ VEC_safe_insert (rtx, gc, block->anchors, begin, anchor); return anchor; } /* Output the objects in BLOCK. */ static void output_object_block (struct object_block *block) { struct constant_descriptor_rtx *desc; unsigned int i; HOST_WIDE_INT offset; tree decl; rtx symbol; if (block->objects == NULL) return; /* Switch to the section and make sure that the first byte is suitably aligned. */ switch_to_section (block->sect); assemble_align (block->alignment); /* Define the values of all anchors relative to the current section position. */ for (i = 0; VEC_iterate (rtx, block->anchors, i, symbol); i++) targetm.asm_out.output_anchor (symbol); /* Output the objects themselves. */ offset = 0; for (i = 0; VEC_iterate (rtx, block->objects, i, symbol); i++) { /* Move to the object's offset, padding with zeros if necessary. */ assemble_zeros (SYMBOL_REF_BLOCK_OFFSET (symbol) - offset); offset = SYMBOL_REF_BLOCK_OFFSET (symbol); if (CONSTANT_POOL_ADDRESS_P (symbol)) { desc = SYMBOL_REF_CONSTANT (symbol); output_constant_pool_1 (desc, 1); offset += GET_MODE_SIZE (desc->mode); } else if (TREE_CONSTANT_POOL_ADDRESS_P (symbol)) { decl = SYMBOL_REF_DECL (symbol); assemble_constant_contents (decl, XSTR (symbol, 0), get_constant_alignment (decl)); offset += get_constant_size (decl); } else { decl = SYMBOL_REF_DECL (symbol); assemble_variable_contents (decl, XSTR (symbol, 0), false); offset += tree_low_cst (DECL_SIZE_UNIT (decl), 1); } } } /* A htab_traverse callback used to call output_object_block for each member of object_block_htab. */ static int output_object_block_htab (void **slot, void *data ATTRIBUTE_UNUSED) { output_object_block ((struct object_block *) (*slot)); return 1; } /* Output the definitions of all object_blocks. */ void output_object_blocks (void) { htab_traverse (object_block_htab, output_object_block_htab, NULL); } /* This function provides a possible implementation of the TARGET_ASM_RECORD_GCC_SWITCHES target hook for ELF targets. When triggered by -frecord-gcc-switches it creates a new mergeable, string section in the assembler output file called TARGET_ASM_RECORD_GCC_SWITCHES_SECTION which contains the switches in ASCII format. FIXME: This code does not correctly handle double quote characters that appear inside strings, (it strips them rather than preserving them). FIXME: ASM_OUTPUT_ASCII, as defined in config/elfos.h will not emit NUL characters - instead it treats them as sub-string separators. Since we want to emit NUL strings terminators into the object file we have to use ASM_OUTPUT_SKIP. */ int elf_record_gcc_switches (print_switch_type type, const char * name) { static char buffer[1024]; /* This variable is used as part of a simplistic heuristic to detect command line switches which take an argument: "If a command line option does not start with a dash then it is an argument for the previous command line option." This fails in the case of the command line option which is the name of the file to compile, but otherwise it is pretty reasonable. */ static bool previous_name_held_back = FALSE; switch (type) { case SWITCH_TYPE_PASSED: if (* name != '-') { if (previous_name_held_back) { unsigned int len = strlen (buffer); snprintf (buffer + len, sizeof buffer - len, " %s", name); ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer)); ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1); previous_name_held_back = FALSE; } else { strncpy (buffer, name, sizeof buffer); ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer)); ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1); } } else { if (previous_name_held_back) { ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer)); ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1); } strncpy (buffer, name, sizeof buffer); previous_name_held_back = TRUE; } break; case SWITCH_TYPE_DESCRIPTIVE: if (name == NULL) { /* Distinguish between invocations where name is NULL. */ static bool started = false; if (started) { if (previous_name_held_back) { ASM_OUTPUT_ASCII (asm_out_file, buffer, strlen (buffer)); ASM_OUTPUT_SKIP (asm_out_file, (unsigned HOST_WIDE_INT) 1); } } else { section * sec; sec = get_section (targetm.asm_out.record_gcc_switches_section, SECTION_DEBUG | SECTION_MERGE | SECTION_STRINGS | (SECTION_ENTSIZE & 1), NULL); switch_to_section (sec); started = true; } } default: break; } /* The return value is currently ignored by the caller, but must be 0. For -fverbose-asm the return value would be the number of characters emitted into the assembler file. */ return 0; } /* Emit text to declare externally defined symbols. It is needed to properly support non-default visibility. */ void default_elf_asm_output_external (FILE *file ATTRIBUTE_UNUSED, tree decl, const char *name ATTRIBUTE_UNUSED) { /* We output the name if and only if TREE_SYMBOL_REFERENCED is set in order to avoid putting out names that are never really used. */ if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl)) && targetm.binds_local_p (decl)) maybe_assemble_visibility (decl); } #include "gt-varasm.h"