/* dw2gencfi.c - Support for generating Dwarf2 CFI information. Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Contributed by Michal Ludvig <mludvig@suse.cz> This file is part of GAS, the GNU Assembler. GAS 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. GAS 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 GAS; see the file COPYING. If not, write to the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ #include "as.h" #include "dw2gencfi.h" #include "subsegs.h" #include "dwarf2dbg.h" #ifdef TARGET_USE_CFIPOP /* By default, use difference expressions if DIFF_EXPR_OK is defined. */ #ifndef CFI_DIFF_EXPR_OK # ifdef DIFF_EXPR_OK # define CFI_DIFF_EXPR_OK 1 # else # define CFI_DIFF_EXPR_OK 0 # endif #endif #ifndef CFI_DIFF_LSDA_OK # define CFI_DIFF_LSDA_OK CFI_DIFF_EXPR_OK #endif #if CFI_DIFF_EXPR_OK == 1 && CFI_DIFF_LSDA_OK == 0 # error "CFI_DIFF_EXPR_OK should imply CFI_DIFF_LSDA_OK" #endif /* We re-use DWARF2_LINE_MIN_INSN_LENGTH for the code alignment field of the CIE. Default to 1 if not otherwise specified. */ #ifndef DWARF2_LINE_MIN_INSN_LENGTH # define DWARF2_LINE_MIN_INSN_LENGTH 1 #endif /* By default, use 32-bit relocations from .eh_frame into .text. */ #ifndef DWARF2_FDE_RELOC_SIZE # define DWARF2_FDE_RELOC_SIZE 4 #endif /* By default, use a read-only .eh_frame section. */ #ifndef DWARF2_EH_FRAME_READ_ONLY # define DWARF2_EH_FRAME_READ_ONLY SEC_READONLY #endif #ifndef EH_FRAME_ALIGNMENT # define EH_FRAME_ALIGNMENT (bfd_get_arch_size (stdoutput) == 64 ? 3 : 2) #endif #ifndef tc_cfi_frame_initial_instructions # define tc_cfi_frame_initial_instructions() ((void)0) #endif #ifndef DWARF2_FORMAT # define DWARF2_FORMAT(SEC) dwarf2_format_32bit #endif #ifndef DWARF2_ADDR_SIZE # define DWARF2_ADDR_SIZE(bfd) (bfd_arch_bits_per_address (bfd) / 8) #endif /* ??? Share this with dwarf2cfg.c. */ #ifndef TC_DWARF2_EMIT_OFFSET #define TC_DWARF2_EMIT_OFFSET generic_dwarf2_emit_offset /* Create an offset to .dwarf2_*. */ static void generic_dwarf2_emit_offset (symbolS *symbol, unsigned int size) { expressionS exp; exp.X_op = O_symbol; exp.X_add_symbol = symbol; exp.X_add_number = 0; emit_expr (&exp, size); } #endif struct cfi_escape_data { struct cfi_escape_data *next; expressionS exp; }; struct cfi_insn_data { struct cfi_insn_data *next; int insn; union { struct { unsigned reg; offsetT offset; } ri; struct { unsigned reg1; unsigned reg2; } rr; unsigned r; offsetT i; struct { symbolS *lab1; symbolS *lab2; } ll; struct cfi_escape_data *esc; struct { unsigned reg, encoding; expressionS exp; } ea; } u; }; struct fde_entry { struct fde_entry *next; symbolS *start_address; symbolS *end_address; struct cfi_insn_data *data; struct cfi_insn_data **last; unsigned char per_encoding; unsigned char lsda_encoding; expressionS personality; expressionS lsda; unsigned int return_column; unsigned int signal_frame; }; struct cie_entry { struct cie_entry *next; symbolS *start_address; unsigned int return_column; unsigned int signal_frame; unsigned char per_encoding; unsigned char lsda_encoding; expressionS personality; struct cfi_insn_data *first, *last; }; /* List of FDE entries. */ static struct fde_entry *all_fde_data; static struct fde_entry **last_fde_data = &all_fde_data; /* List of CIEs so that they could be reused. */ static struct cie_entry *cie_root; /* Stack of old CFI data, for save/restore. */ struct cfa_save_data { struct cfa_save_data *next; offsetT cfa_offset; }; /* Current open FDE entry. */ struct frch_cfi_data { struct fde_entry *cur_fde_data; symbolS *last_address; offsetT cur_cfa_offset; struct cfa_save_data *cfa_save_stack; }; /* Construct a new FDE structure and add it to the end of the fde list. */ static struct fde_entry * alloc_fde_entry (void) { struct fde_entry *fde = (struct fde_entry *) xcalloc (1, sizeof (struct fde_entry)); frchain_now->frch_cfi_data = (struct frch_cfi_data *) xcalloc (1, sizeof (struct frch_cfi_data)); frchain_now->frch_cfi_data->cur_fde_data = fde; *last_fde_data = fde; last_fde_data = &fde->next; fde->last = &fde->data; fde->return_column = DWARF2_DEFAULT_RETURN_COLUMN; fde->per_encoding = DW_EH_PE_omit; fde->lsda_encoding = DW_EH_PE_omit; return fde; } /* The following functions are available for a backend to construct its own unwind information, usually from legacy unwind directives. */ /* Construct a new INSN structure and add it to the end of the insn list for the currently active FDE. */ static struct cfi_insn_data * alloc_cfi_insn_data (void) { struct cfi_insn_data *insn = (struct cfi_insn_data *) xcalloc (1, sizeof (struct cfi_insn_data)); struct fde_entry *cur_fde_data = frchain_now->frch_cfi_data->cur_fde_data; *cur_fde_data->last = insn; cur_fde_data->last = &insn->next; return insn; } /* Construct a new FDE structure that begins at LABEL. */ void cfi_new_fde (symbolS *label) { struct fde_entry *fde = alloc_fde_entry (); fde->start_address = label; frchain_now->frch_cfi_data->last_address = label; } /* End the currently open FDE. */ void cfi_end_fde (symbolS *label) { frchain_now->frch_cfi_data->cur_fde_data->end_address = label; free (frchain_now->frch_cfi_data); frchain_now->frch_cfi_data = NULL; } /* Set the return column for the current FDE. */ void cfi_set_return_column (unsigned regno) { frchain_now->frch_cfi_data->cur_fde_data->return_column = regno; } /* Universal functions to store new instructions. */ static void cfi_add_CFA_insn(int insn) { struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = insn; } static void cfi_add_CFA_insn_reg (int insn, unsigned regno) { struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = insn; insn_ptr->u.r = regno; } static void cfi_add_CFA_insn_offset (int insn, offsetT offset) { struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = insn; insn_ptr->u.i = offset; } static void cfi_add_CFA_insn_reg_reg (int insn, unsigned reg1, unsigned reg2) { struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = insn; insn_ptr->u.rr.reg1 = reg1; insn_ptr->u.rr.reg2 = reg2; } static void cfi_add_CFA_insn_reg_offset (int insn, unsigned regno, offsetT offset) { struct cfi_insn_data *insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = insn; insn_ptr->u.ri.reg = regno; insn_ptr->u.ri.offset = offset; } /* Add a CFI insn to advance the PC from the last address to LABEL. */ void cfi_add_advance_loc (symbolS *label) { struct cfi_insn_data *insn = alloc_cfi_insn_data (); insn->insn = DW_CFA_advance_loc; insn->u.ll.lab1 = frchain_now->frch_cfi_data->last_address; insn->u.ll.lab2 = label; frchain_now->frch_cfi_data->last_address = label; } /* Add a DW_CFA_offset record to the CFI data. */ void cfi_add_CFA_offset (unsigned regno, offsetT offset) { unsigned int abs_data_align; gas_assert (DWARF2_CIE_DATA_ALIGNMENT != 0); cfi_add_CFA_insn_reg_offset (DW_CFA_offset, regno, offset); abs_data_align = (DWARF2_CIE_DATA_ALIGNMENT < 0 ? -DWARF2_CIE_DATA_ALIGNMENT : DWARF2_CIE_DATA_ALIGNMENT); if (offset % abs_data_align) as_bad (_("register save offset not a multiple of %u"), abs_data_align); } /* Add a DW_CFA_def_cfa record to the CFI data. */ void cfi_add_CFA_def_cfa (unsigned regno, offsetT offset) { cfi_add_CFA_insn_reg_offset (DW_CFA_def_cfa, regno, offset); frchain_now->frch_cfi_data->cur_cfa_offset = offset; } /* Add a DW_CFA_register record to the CFI data. */ void cfi_add_CFA_register (unsigned reg1, unsigned reg2) { cfi_add_CFA_insn_reg_reg (DW_CFA_register, reg1, reg2); } /* Add a DW_CFA_def_cfa_register record to the CFI data. */ void cfi_add_CFA_def_cfa_register (unsigned regno) { cfi_add_CFA_insn_reg (DW_CFA_def_cfa_register, regno); } /* Add a DW_CFA_def_cfa_offset record to the CFI data. */ void cfi_add_CFA_def_cfa_offset (offsetT offset) { cfi_add_CFA_insn_offset (DW_CFA_def_cfa_offset, offset); frchain_now->frch_cfi_data->cur_cfa_offset = offset; } void cfi_add_CFA_restore (unsigned regno) { cfi_add_CFA_insn_reg (DW_CFA_restore, regno); } void cfi_add_CFA_undefined (unsigned regno) { cfi_add_CFA_insn_reg (DW_CFA_undefined, regno); } void cfi_add_CFA_same_value (unsigned regno) { cfi_add_CFA_insn_reg (DW_CFA_same_value, regno); } void cfi_add_CFA_remember_state (void) { struct cfa_save_data *p; cfi_add_CFA_insn (DW_CFA_remember_state); p = (struct cfa_save_data *) xmalloc (sizeof (*p)); p->cfa_offset = frchain_now->frch_cfi_data->cur_cfa_offset; p->next = frchain_now->frch_cfi_data->cfa_save_stack; frchain_now->frch_cfi_data->cfa_save_stack = p; } void cfi_add_CFA_restore_state (void) { struct cfa_save_data *p; cfi_add_CFA_insn (DW_CFA_restore_state); p = frchain_now->frch_cfi_data->cfa_save_stack; if (p) { frchain_now->frch_cfi_data->cur_cfa_offset = p->cfa_offset; frchain_now->frch_cfi_data->cfa_save_stack = p->next; free (p); } else as_bad (_("CFI state restore without previous remember")); } /* Parse CFI assembler directives. */ static void dot_cfi (int); static void dot_cfi_escape (int); static void dot_cfi_sections (int); static void dot_cfi_startproc (int); static void dot_cfi_endproc (int); static void dot_cfi_personality (int); static void dot_cfi_lsda (int); static void dot_cfi_val_encoded_addr (int); /* Fake CFI type; outside the byte range of any real CFI insn. */ #define CFI_adjust_cfa_offset 0x100 #define CFI_return_column 0x101 #define CFI_rel_offset 0x102 #define CFI_escape 0x103 #define CFI_signal_frame 0x104 #define CFI_val_encoded_addr 0x105 const pseudo_typeS cfi_pseudo_table[] = { { "cfi_sections", dot_cfi_sections, 0 }, { "cfi_startproc", dot_cfi_startproc, 0 }, { "cfi_endproc", dot_cfi_endproc, 0 }, { "cfi_def_cfa", dot_cfi, DW_CFA_def_cfa }, { "cfi_def_cfa_register", dot_cfi, DW_CFA_def_cfa_register }, { "cfi_def_cfa_offset", dot_cfi, DW_CFA_def_cfa_offset }, { "cfi_adjust_cfa_offset", dot_cfi, CFI_adjust_cfa_offset }, { "cfi_offset", dot_cfi, DW_CFA_offset }, { "cfi_rel_offset", dot_cfi, CFI_rel_offset }, { "cfi_register", dot_cfi, DW_CFA_register }, { "cfi_return_column", dot_cfi, CFI_return_column }, { "cfi_restore", dot_cfi, DW_CFA_restore }, { "cfi_undefined", dot_cfi, DW_CFA_undefined }, { "cfi_same_value", dot_cfi, DW_CFA_same_value }, { "cfi_remember_state", dot_cfi, DW_CFA_remember_state }, { "cfi_restore_state", dot_cfi, DW_CFA_restore_state }, { "cfi_window_save", dot_cfi, DW_CFA_GNU_window_save }, { "cfi_escape", dot_cfi_escape, 0 }, { "cfi_signal_frame", dot_cfi, CFI_signal_frame }, { "cfi_personality", dot_cfi_personality, 0 }, { "cfi_lsda", dot_cfi_lsda, 0 }, { "cfi_val_encoded_addr", dot_cfi_val_encoded_addr, 0 }, { NULL, NULL, 0 } }; static void cfi_parse_separator (void) { SKIP_WHITESPACE (); if (*input_line_pointer == ',') input_line_pointer++; else as_bad (_("missing separator")); } #ifndef tc_parse_to_dw2regnum static void tc_parse_to_dw2regnum(expressionS *exp) { # ifdef tc_regname_to_dw2regnum SKIP_WHITESPACE (); if (is_name_beginner (*input_line_pointer) || (*input_line_pointer == '%' && is_name_beginner (*++input_line_pointer))) { char *name, c; name = input_line_pointer; c = get_symbol_end (); exp->X_op = O_constant; exp->X_add_number = tc_regname_to_dw2regnum (name); *input_line_pointer = c; } else # endif expression_and_evaluate (exp); } #endif static unsigned cfi_parse_reg (void) { int regno; expressionS exp; tc_parse_to_dw2regnum (&exp); switch (exp.X_op) { case O_register: case O_constant: regno = exp.X_add_number; break; default: regno = -1; break; } if (regno < 0) { as_bad (_("bad register expression")); regno = 0; } return regno; } static offsetT cfi_parse_const (void) { return get_absolute_expression (); } static void dot_cfi (int arg) { offsetT offset; unsigned reg1, reg2; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } /* If the last address was not at the current PC, advance to current. */ if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now || S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ()) cfi_add_advance_loc (symbol_temp_new_now ()); switch (arg) { case DW_CFA_offset: reg1 = cfi_parse_reg (); cfi_parse_separator (); offset = cfi_parse_const (); cfi_add_CFA_offset (reg1, offset); break; case CFI_rel_offset: reg1 = cfi_parse_reg (); cfi_parse_separator (); offset = cfi_parse_const (); cfi_add_CFA_offset (reg1, offset - frchain_now->frch_cfi_data->cur_cfa_offset); break; case DW_CFA_def_cfa: reg1 = cfi_parse_reg (); cfi_parse_separator (); offset = cfi_parse_const (); cfi_add_CFA_def_cfa (reg1, offset); break; case DW_CFA_register: reg1 = cfi_parse_reg (); cfi_parse_separator (); reg2 = cfi_parse_reg (); cfi_add_CFA_register (reg1, reg2); break; case DW_CFA_def_cfa_register: reg1 = cfi_parse_reg (); cfi_add_CFA_def_cfa_register (reg1); break; case DW_CFA_def_cfa_offset: offset = cfi_parse_const (); cfi_add_CFA_def_cfa_offset (offset); break; case CFI_adjust_cfa_offset: offset = cfi_parse_const (); cfi_add_CFA_def_cfa_offset (frchain_now->frch_cfi_data->cur_cfa_offset + offset); break; case DW_CFA_restore: for (;;) { reg1 = cfi_parse_reg (); cfi_add_CFA_restore (reg1); SKIP_WHITESPACE (); if (*input_line_pointer != ',') break; ++input_line_pointer; } break; case DW_CFA_undefined: for (;;) { reg1 = cfi_parse_reg (); cfi_add_CFA_undefined (reg1); SKIP_WHITESPACE (); if (*input_line_pointer != ',') break; ++input_line_pointer; } break; case DW_CFA_same_value: reg1 = cfi_parse_reg (); cfi_add_CFA_same_value (reg1); break; case CFI_return_column: reg1 = cfi_parse_reg (); cfi_set_return_column (reg1); break; case DW_CFA_remember_state: cfi_add_CFA_remember_state (); break; case DW_CFA_restore_state: cfi_add_CFA_restore_state (); break; case DW_CFA_GNU_window_save: cfi_add_CFA_insn (DW_CFA_GNU_window_save); break; case CFI_signal_frame: frchain_now->frch_cfi_data->cur_fde_data->signal_frame = 1; break; default: abort (); } demand_empty_rest_of_line (); } static void dot_cfi_escape (int ignored ATTRIBUTE_UNUSED) { struct cfi_escape_data *head, **tail, *e; struct cfi_insn_data *insn; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } /* If the last address was not at the current PC, advance to current. */ if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now || S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ()) cfi_add_advance_loc (symbol_temp_new_now ()); tail = &head; do { e = (struct cfi_escape_data *) xmalloc (sizeof (*e)); do_parse_cons_expression (&e->exp, 1); *tail = e; tail = &e->next; } while (*input_line_pointer++ == ','); *tail = NULL; insn = alloc_cfi_insn_data (); insn->insn = CFI_escape; insn->u.esc = head; --input_line_pointer; demand_empty_rest_of_line (); } static void dot_cfi_personality (int ignored ATTRIBUTE_UNUSED) { struct fde_entry *fde; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } fde = frchain_now->frch_cfi_data->cur_fde_data; encoding = cfi_parse_const (); if (encoding == DW_EH_PE_omit) { demand_empty_rest_of_line (); fde->per_encoding = encoding; return; } if ((encoding & 0xff) != encoding || ((encoding & 0x70) != 0 #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) { as_bad (_("invalid or unsupported encoding in .cfi_personality")); ignore_rest_of_line (); return; } if (*input_line_pointer++ != ',') { as_bad (_(".cfi_personality requires encoding and symbol arguments")); ignore_rest_of_line (); return; } expression_and_evaluate (&fde->personality); switch (fde->personality.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) == DW_EH_PE_pcrel) encoding = DW_EH_PE_omit; break; default: encoding = DW_EH_PE_omit; break; } fde->per_encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong second argument to .cfi_personality")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } static void dot_cfi_lsda (int ignored ATTRIBUTE_UNUSED) { struct fde_entry *fde; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } fde = frchain_now->frch_cfi_data->cur_fde_data; encoding = cfi_parse_const (); if (encoding == DW_EH_PE_omit) { demand_empty_rest_of_line (); fde->lsda_encoding = encoding; return; } if ((encoding & 0xff) != encoding || ((encoding & 0x70) != 0 #if CFI_DIFF_LSDA_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) { as_bad (_("invalid or unsupported encoding in .cfi_lsda")); ignore_rest_of_line (); return; } if (*input_line_pointer++ != ',') { as_bad (_(".cfi_lsda requires encoding and symbol arguments")); ignore_rest_of_line (); return; } fde->lsda_encoding = encoding; expression_and_evaluate (&fde->lsda); switch (fde->lsda.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) == DW_EH_PE_pcrel) encoding = DW_EH_PE_omit; break; default: encoding = DW_EH_PE_omit; break; } fde->lsda_encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong second argument to .cfi_lsda")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } static void dot_cfi_val_encoded_addr (int ignored ATTRIBUTE_UNUSED) { struct cfi_insn_data *insn_ptr; offsetT encoding; if (frchain_now->frch_cfi_data == NULL) { as_bad (_("CFI instruction used without previous .cfi_startproc")); ignore_rest_of_line (); return; } /* If the last address was not at the current PC, advance to current. */ if (symbol_get_frag (frchain_now->frch_cfi_data->last_address) != frag_now || S_GET_VALUE (frchain_now->frch_cfi_data->last_address) != frag_now_fix ()) cfi_add_advance_loc (symbol_temp_new_now ()); insn_ptr = alloc_cfi_insn_data (); insn_ptr->insn = CFI_val_encoded_addr; insn_ptr->u.ea.reg = cfi_parse_reg (); cfi_parse_separator (); encoding = cfi_parse_const (); if ((encoding & 0xff) != encoding || ((encoding & 0x70) != 0 #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr && (encoding & 0x70) != DW_EH_PE_pcrel #endif ) /* leb128 can be handled, but does something actually need it? */ || (encoding & 7) == DW_EH_PE_uleb128 || (encoding & 7) > DW_EH_PE_udata8) { as_bad (_("invalid or unsupported encoding in .cfi_lsda")); encoding = DW_EH_PE_omit; } cfi_parse_separator (); expression_and_evaluate (&insn_ptr->u.ea.exp); switch (insn_ptr->u.ea.exp.X_op) { case O_symbol: break; case O_constant: if ((encoding & 0x70) != DW_EH_PE_pcrel) break; default: encoding = DW_EH_PE_omit; break; } insn_ptr->u.ea.encoding = encoding; if (encoding == DW_EH_PE_omit) { as_bad (_("wrong third argument to .cfi_val_encoded_addr")); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } /* By default emit .eh_frame only, not .debug_frame. */ #define CFI_EMIT_eh_frame (1 << 0) #define CFI_EMIT_debug_frame (1 << 1) static int cfi_sections = CFI_EMIT_eh_frame; static void dot_cfi_sections (int ignored ATTRIBUTE_UNUSED) { int sections = 0; SKIP_WHITESPACE (); if (is_name_beginner (*input_line_pointer)) while (1) { char *name, c; name = input_line_pointer; c = get_symbol_end (); if (strcmp (name, ".eh_frame") == 0) sections |= CFI_EMIT_eh_frame; else if (strcmp (name, ".debug_frame") == 0) sections |= CFI_EMIT_debug_frame; else { *input_line_pointer = c; input_line_pointer = name; break; } *input_line_pointer = c; SKIP_WHITESPACE (); if (*input_line_pointer == ',') { name = input_line_pointer++; SKIP_WHITESPACE (); if (!is_name_beginner (*input_line_pointer)) { input_line_pointer = name; break; } } else if (is_name_beginner (*input_line_pointer)) break; } demand_empty_rest_of_line (); cfi_sections = sections; } static void dot_cfi_startproc (int ignored ATTRIBUTE_UNUSED) { int simple = 0; if (frchain_now->frch_cfi_data != NULL) { as_bad (_("previous CFI entry not closed (missing .cfi_endproc)")); ignore_rest_of_line (); return; } cfi_new_fde (symbol_temp_new_now ()); SKIP_WHITESPACE (); if (is_name_beginner (*input_line_pointer)) { char *name, c; name = input_line_pointer; c = get_symbol_end (); if (strcmp (name, "simple") == 0) { simple = 1; *input_line_pointer = c; } else input_line_pointer = name; } demand_empty_rest_of_line (); frchain_now->frch_cfi_data->cur_cfa_offset = 0; if (!simple) tc_cfi_frame_initial_instructions (); } static void dot_cfi_endproc (int ignored ATTRIBUTE_UNUSED) { if (frchain_now->frch_cfi_data == NULL) { as_bad (_(".cfi_endproc without corresponding .cfi_startproc")); ignore_rest_of_line (); return; } cfi_end_fde (symbol_temp_new_now ()); demand_empty_rest_of_line (); } /* Emit a single byte into the current segment. */ static inline void out_one (int byte) { FRAG_APPEND_1_CHAR (byte); } /* Emit a two-byte word into the current segment. */ static inline void out_two (int data) { md_number_to_chars (frag_more (2), data, 2); } /* Emit a four byte word into the current segment. */ static inline void out_four (int data) { md_number_to_chars (frag_more (4), data, 4); } /* Emit an unsigned "little-endian base 128" number. */ static void out_uleb128 (addressT value) { output_leb128 (frag_more (sizeof_leb128 (value, 0)), value, 0); } /* Emit an unsigned "little-endian base 128" number. */ static void out_sleb128 (offsetT value) { output_leb128 (frag_more (sizeof_leb128 (value, 1)), value, 1); } static void output_cfi_insn (struct cfi_insn_data *insn) { offsetT offset; unsigned int regno; switch (insn->insn) { case DW_CFA_advance_loc: { symbolS *from = insn->u.ll.lab1; symbolS *to = insn->u.ll.lab2; if (symbol_get_frag (to) == symbol_get_frag (from)) { addressT delta = S_GET_VALUE (to) - S_GET_VALUE (from); addressT scaled = delta / DWARF2_LINE_MIN_INSN_LENGTH; if (scaled <= 0x3F) out_one (DW_CFA_advance_loc + scaled); else if (scaled <= 0xFF) { out_one (DW_CFA_advance_loc1); out_one (scaled); } else if (scaled <= 0xFFFF) { out_one (DW_CFA_advance_loc2); out_two (scaled); } else { out_one (DW_CFA_advance_loc4); out_four (scaled); } } else { expressionS exp; exp.X_op = O_subtract; exp.X_add_symbol = to; exp.X_op_symbol = from; exp.X_add_number = 0; /* The code in ehopt.c expects that one byte of the encoding is already allocated to the frag. This comes from the way that it scans the .eh_frame section looking first for the .byte DW_CFA_advance_loc4. */ *frag_more (1) = DW_CFA_advance_loc4; frag_var (rs_cfa, 4, 0, DWARF2_LINE_MIN_INSN_LENGTH << 3, make_expr_symbol (&exp), frag_now_fix () - 1, (char *) frag_now); } } break; case DW_CFA_def_cfa: offset = insn->u.ri.offset; if (offset < 0) { out_one (DW_CFA_def_cfa_sf); out_uleb128 (insn->u.ri.reg); out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT); } else { out_one (DW_CFA_def_cfa); out_uleb128 (insn->u.ri.reg); out_uleb128 (offset); } break; case DW_CFA_def_cfa_register: case DW_CFA_undefined: case DW_CFA_same_value: out_one (insn->insn); out_uleb128 (insn->u.r); break; case DW_CFA_def_cfa_offset: offset = insn->u.i; if (offset < 0) { out_one (DW_CFA_def_cfa_offset_sf); out_sleb128 (offset / DWARF2_CIE_DATA_ALIGNMENT); } else { out_one (DW_CFA_def_cfa_offset); out_uleb128 (offset); } break; case DW_CFA_restore: regno = insn->u.r; if (regno <= 0x3F) { out_one (DW_CFA_restore + regno); } else { out_one (DW_CFA_restore_extended); out_uleb128 (regno); } break; case DW_CFA_offset: regno = insn->u.ri.reg; offset = insn->u.ri.offset / DWARF2_CIE_DATA_ALIGNMENT; if (offset < 0) { out_one (DW_CFA_offset_extended_sf); out_uleb128 (regno); out_sleb128 (offset); } else if (regno <= 0x3F) { out_one (DW_CFA_offset + regno); out_uleb128 (offset); } else { out_one (DW_CFA_offset_extended); out_uleb128 (regno); out_uleb128 (offset); } break; case DW_CFA_register: out_one (DW_CFA_register); out_uleb128 (insn->u.rr.reg1); out_uleb128 (insn->u.rr.reg2); break; case DW_CFA_remember_state: case DW_CFA_restore_state: out_one (insn->insn); break; case DW_CFA_GNU_window_save: out_one (DW_CFA_GNU_window_save); break; case CFI_escape: { struct cfi_escape_data *e; for (e = insn->u.esc; e ; e = e->next) emit_expr (&e->exp, 1); break; } case CFI_val_encoded_addr: { unsigned encoding = insn->u.ea.encoding; offsetT encoding_size; if (encoding == DW_EH_PE_omit) break; out_one (DW_CFA_val_expression); out_uleb128 (insn->u.ea.reg); switch (encoding & 0x7) { case DW_EH_PE_absptr: encoding_size = DWARF2_ADDR_SIZE (stdoutput); break; case DW_EH_PE_udata2: encoding_size = 2; break; case DW_EH_PE_udata4: encoding_size = 4; break; case DW_EH_PE_udata8: encoding_size = 8; break; default: abort (); } /* If the user has requested absolute encoding, then use the smaller DW_OP_addr encoding. */ if (insn->u.ea.encoding == DW_EH_PE_absptr) { out_uleb128 (1 + encoding_size); out_one (DW_OP_addr); } else { out_uleb128 (1 + 1 + encoding_size); out_one (DW_OP_GNU_encoded_addr); out_one (encoding); if ((encoding & 0x70) == DW_EH_PE_pcrel) { #if CFI_DIFF_EXPR_OK insn->u.ea.exp.X_op = O_subtract; insn->u.ea.exp.X_op_symbol = symbol_temp_new_now (); #elif defined (tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (&insn->u.ea.exp, encoding_size); break; #else abort (); #endif } } emit_expr (&insn->u.ea.exp, encoding_size); } break; default: abort (); } } static offsetT encoding_size (unsigned char encoding) { if (encoding == DW_EH_PE_omit) return 0; switch (encoding & 0x7) { case 0: return bfd_get_arch_size (stdoutput) == 64 ? 8 : 4; case DW_EH_PE_udata2: return 2; case DW_EH_PE_udata4: return 4; case DW_EH_PE_udata8: return 8; default: abort (); } } static void output_cie (struct cie_entry *cie, bfd_boolean eh_frame, int align) { symbolS *after_size_address, *end_address; expressionS exp; struct cfi_insn_data *i; offsetT augmentation_size; int enc; enum dwarf2_format fmt = DWARF2_FORMAT (now_seg); cie->start_address = symbol_temp_new_now (); after_size_address = symbol_temp_make (); end_address = symbol_temp_make (); exp.X_op = O_subtract; exp.X_add_symbol = end_address; exp.X_op_symbol = after_size_address; exp.X_add_number = 0; if (eh_frame || fmt == dwarf2_format_32bit) emit_expr (&exp, 4); /* Length. */ else { if (fmt == dwarf2_format_64bit) out_four (-1); emit_expr (&exp, 8); /* Length. */ } symbol_set_value_now (after_size_address); if (eh_frame) out_four (0); /* CIE id. */ else { out_four (-1); /* CIE id. */ if (fmt != dwarf2_format_32bit) out_four (-1); } out_one (DW_CIE_VERSION); /* Version. */ if (eh_frame) { out_one ('z'); /* Augmentation. */ if (cie->per_encoding != DW_EH_PE_omit) out_one ('P'); if (cie->lsda_encoding != DW_EH_PE_omit) out_one ('L'); out_one ('R'); } if (cie->signal_frame) out_one ('S'); out_one (0); out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */ out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */ if (DW_CIE_VERSION == 1) /* Return column. */ out_one (cie->return_column); else out_uleb128 (cie->return_column); if (eh_frame) { augmentation_size = 1 + (cie->lsda_encoding != DW_EH_PE_omit); if (cie->per_encoding != DW_EH_PE_omit) augmentation_size += 1 + encoding_size (cie->per_encoding); out_uleb128 (augmentation_size); /* Augmentation size. */ if (cie->per_encoding != DW_EH_PE_omit) { offsetT size = encoding_size (cie->per_encoding); out_one (cie->per_encoding); exp = cie->personality; if ((cie->per_encoding & 0x70) == DW_EH_PE_pcrel) { #if CFI_DIFF_EXPR_OK exp.X_op = O_subtract; exp.X_op_symbol = symbol_temp_new_now (); emit_expr (&exp, size); #elif defined (tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (&exp, size); #else abort (); #endif } else emit_expr (&exp, size); } if (cie->lsda_encoding != DW_EH_PE_omit) out_one (cie->lsda_encoding); } switch (DWARF2_FDE_RELOC_SIZE) { case 2: enc = DW_EH_PE_sdata2; break; case 4: enc = DW_EH_PE_sdata4; break; case 8: enc = DW_EH_PE_sdata8; break; default: abort (); } #if CFI_DIFF_EXPR_OK || defined tc_cfi_emit_pcrel_expr enc |= DW_EH_PE_pcrel; #endif if (eh_frame) out_one (enc); if (cie->first) for (i = cie->first; i != cie->last; i = i->next) output_cfi_insn (i); frag_align (align, DW_CFA_nop, 0); symbol_set_value_now (end_address); } static void output_fde (struct fde_entry *fde, struct cie_entry *cie, bfd_boolean eh_frame, struct cfi_insn_data *first, int align) { symbolS *after_size_address, *end_address; expressionS exp; offsetT augmentation_size; enum dwarf2_format fmt = DWARF2_FORMAT (now_seg); int offset_size; int addr_size; after_size_address = symbol_temp_make (); end_address = symbol_temp_make (); exp.X_op = O_subtract; exp.X_add_symbol = end_address; exp.X_op_symbol = after_size_address; exp.X_add_number = 0; if (eh_frame || fmt == dwarf2_format_32bit) offset_size = 4; else { if (fmt == dwarf2_format_64bit) out_four (-1); offset_size = 8; } emit_expr (&exp, offset_size); /* Length. */ symbol_set_value_now (after_size_address); if (eh_frame) { exp.X_op = O_subtract; exp.X_add_symbol = after_size_address; exp.X_op_symbol = cie->start_address; exp.X_add_number = 0; emit_expr (&exp, offset_size); /* CIE offset. */ } else { TC_DWARF2_EMIT_OFFSET (cie->start_address, offset_size); } if (eh_frame) { exp.X_op = O_subtract; exp.X_add_number = 0; #if CFI_DIFF_EXPR_OK exp.X_add_symbol = fde->start_address; exp.X_op_symbol = symbol_temp_new_now (); emit_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */ #else exp.X_op = O_symbol; exp.X_add_symbol = fde->start_address; #ifdef tc_cfi_emit_pcrel_expr tc_cfi_emit_pcrel_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */ #else emit_expr (&exp, DWARF2_FDE_RELOC_SIZE); /* Code offset. */ #endif #endif addr_size = DWARF2_FDE_RELOC_SIZE; } else { exp.X_op = O_symbol; exp.X_add_symbol = fde->start_address; exp.X_add_number = 0; addr_size = DWARF2_ADDR_SIZE (stdoutput); emit_expr (&exp, addr_size); } exp.X_op = O_subtract; exp.X_add_symbol = fde->end_address; exp.X_op_symbol = fde->start_address; /* Code length. */ exp.X_add_number = 0; emit_expr (&exp, addr_size); augmentation_size = encoding_size (fde->lsda_encoding); if (eh_frame) out_uleb128 (augmentation_size); /* Augmentation size. */ if (fde->lsda_encoding != DW_EH_PE_omit) { exp = fde->lsda; if ((fde->lsda_encoding & 0x70) == DW_EH_PE_pcrel) { #if CFI_DIFF_LSDA_OK exp.X_op = O_subtract; exp.X_op_symbol = symbol_temp_new_now (); emit_expr (&exp, augmentation_size); #elif defined (tc_cfi_emit_pcrel_expr) tc_cfi_emit_pcrel_expr (&exp, augmentation_size); #else abort (); #endif } else emit_expr (&exp, augmentation_size); } for (; first; first = first->next) output_cfi_insn (first); frag_align (align, DW_CFA_nop, 0); symbol_set_value_now (end_address); } static struct cie_entry * select_cie_for_fde (struct fde_entry *fde, bfd_boolean eh_frame, struct cfi_insn_data **pfirst, int align) { struct cfi_insn_data *i, *j; struct cie_entry *cie; for (cie = cie_root; cie; cie = cie->next) { if (cie->return_column != fde->return_column || cie->signal_frame != fde->signal_frame || cie->per_encoding != fde->per_encoding || cie->lsda_encoding != fde->lsda_encoding) continue; if (cie->per_encoding != DW_EH_PE_omit) { if (cie->personality.X_op != fde->personality.X_op || cie->personality.X_add_number != fde->personality.X_add_number) continue; switch (cie->personality.X_op) { case O_constant: if (cie->personality.X_unsigned != fde->personality.X_unsigned) continue; break; case O_symbol: if (cie->personality.X_add_symbol != fde->personality.X_add_symbol) continue; break; default: abort (); } } for (i = cie->first, j = fde->data; i != cie->last && j != NULL; i = i->next, j = j->next) { if (i->insn != j->insn) goto fail; switch (i->insn) { case DW_CFA_advance_loc: case DW_CFA_remember_state: /* We reached the first advance/remember in the FDE, but did not reach the end of the CIE list. */ goto fail; case DW_CFA_offset: case DW_CFA_def_cfa: if (i->u.ri.reg != j->u.ri.reg) goto fail; if (i->u.ri.offset != j->u.ri.offset) goto fail; break; case DW_CFA_register: if (i->u.rr.reg1 != j->u.rr.reg1) goto fail; if (i->u.rr.reg2 != j->u.rr.reg2) goto fail; break; case DW_CFA_def_cfa_register: case DW_CFA_restore: case DW_CFA_undefined: case DW_CFA_same_value: if (i->u.r != j->u.r) goto fail; break; case DW_CFA_def_cfa_offset: if (i->u.i != j->u.i) goto fail; break; case CFI_escape: case CFI_val_encoded_addr: /* Don't bother matching these for now. */ goto fail; default: abort (); } } /* Success if we reached the end of the CIE list, and we've either run out of FDE entries or we've encountered an advance, remember, or escape. */ if (i == cie->last && (!j || j->insn == DW_CFA_advance_loc || j->insn == DW_CFA_remember_state || j->insn == CFI_escape || j->insn == CFI_val_encoded_addr)) { *pfirst = j; return cie; } fail:; } cie = (struct cie_entry *) xmalloc (sizeof (struct cie_entry)); cie->next = cie_root; cie_root = cie; cie->return_column = fde->return_column; cie->signal_frame = fde->signal_frame; cie->per_encoding = fde->per_encoding; cie->lsda_encoding = fde->lsda_encoding; cie->personality = fde->personality; cie->first = fde->data; for (i = cie->first; i ; i = i->next) if (i->insn == DW_CFA_advance_loc || i->insn == DW_CFA_remember_state || i->insn == CFI_escape || i->insn == CFI_val_encoded_addr) break; cie->last = i; *pfirst = i; output_cie (cie, eh_frame, align); return cie; } #ifdef md_reg_eh_frame_to_debug_frame static void cfi_change_reg_numbers (struct cfi_insn_data *insn) { for (; insn; insn = insn->next) switch (insn->insn) { case DW_CFA_advance_loc: case DW_CFA_def_cfa_offset: case DW_CFA_remember_state: case DW_CFA_restore_state: case DW_CFA_GNU_window_save: case CFI_escape: break; case DW_CFA_def_cfa: case DW_CFA_offset: insn->u.ri.reg = md_reg_eh_frame_to_debug_frame (insn->u.ri.reg); break; case DW_CFA_def_cfa_register: case DW_CFA_undefined: case DW_CFA_same_value: case DW_CFA_restore: insn->u.r = md_reg_eh_frame_to_debug_frame (insn->u.r); break; case DW_CFA_register: insn->u.rr.reg1 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg1); insn->u.rr.reg2 = md_reg_eh_frame_to_debug_frame (insn->u.rr.reg2); break; case CFI_val_encoded_addr: insn->u.ea.reg = md_reg_eh_frame_to_debug_frame (insn->u.ea.reg); break; default: abort (); } } #else #define cfi_change_reg_numbers(insn) do { } while (0) #endif void cfi_finish (void) { segT cfi_seg; struct fde_entry *fde; int save_flag_traditional_format; if (all_fde_data == 0) return; if ((cfi_sections & CFI_EMIT_eh_frame) != 0) { /* Open .eh_frame section. */ cfi_seg = subseg_new (".eh_frame", 0); bfd_set_section_flags (stdoutput, cfi_seg, SEC_ALLOC | SEC_LOAD | SEC_DATA | DWARF2_EH_FRAME_READ_ONLY); subseg_set (cfi_seg, 0); record_alignment (cfi_seg, EH_FRAME_ALIGNMENT); #ifdef md_fix_up_eh_frame md_fix_up_eh_frame (cfi_seg); #endif /* Make sure check_eh_frame doesn't do anything with our output. */ save_flag_traditional_format = flag_traditional_format; flag_traditional_format = 1; for (fde = all_fde_data; fde ; fde = fde->next) { struct cfi_insn_data *first; struct cie_entry *cie; if (fde->end_address == NULL) { as_bad (_("open CFI at the end of file; missing .cfi_endproc directive")); fde->end_address = fde->start_address; } cie = select_cie_for_fde (fde, TRUE, &first, 2); output_fde (fde, cie, TRUE, first, fde->next == NULL ? EH_FRAME_ALIGNMENT : 2); } flag_traditional_format = save_flag_traditional_format; } if ((cfi_sections & CFI_EMIT_debug_frame) != 0) { struct cie_entry *cie, *cie_next; int alignment = ffs (DWARF2_ADDR_SIZE (stdoutput)) - 1; for (cie = cie_root; cie; cie = cie_next) { cie_next = cie->next; free ((void *) cie); } cie_root = NULL; /* Open .debug_frame section. */ cfi_seg = subseg_new (".debug_frame", 0); bfd_set_section_flags (stdoutput, cfi_seg, SEC_READONLY | SEC_DEBUGGING); subseg_set (cfi_seg, 0); record_alignment (cfi_seg, alignment); for (fde = all_fde_data; fde ; fde = fde->next) { struct cfi_insn_data *first; if (fde->end_address == NULL) { as_bad (_("open CFI at the end of file; missing .cfi_endproc directive")); fde->end_address = fde->start_address; } fde->per_encoding = DW_EH_PE_omit; fde->lsda_encoding = DW_EH_PE_omit; cfi_change_reg_numbers (fde->data); cie = select_cie_for_fde (fde, FALSE, &first, alignment); output_fde (fde, cie, FALSE, first, alignment); } } } #else /* TARGET_USE_CFIPOP */ /* Emit an intelligible error message for missing support. */ static void dot_cfi_dummy (int ignored ATTRIBUTE_UNUSED) { as_bad (_("CFI is not supported for this target")); ignore_rest_of_line (); } const pseudo_typeS cfi_pseudo_table[] = { { "cfi_sections", dot_cfi_dummy, 0 }, { "cfi_startproc", dot_cfi_dummy, 0 }, { "cfi_endproc", dot_cfi_dummy, 0 }, { "cfi_def_cfa", dot_cfi_dummy, 0 }, { "cfi_def_cfa_register", dot_cfi_dummy, 0 }, { "cfi_def_cfa_offset", dot_cfi_dummy, 0 }, { "cfi_adjust_cfa_offset", dot_cfi_dummy, 0 }, { "cfi_offset", dot_cfi_dummy, 0 }, { "cfi_rel_offset", dot_cfi_dummy, 0 }, { "cfi_register", dot_cfi_dummy, 0 }, { "cfi_return_column", dot_cfi_dummy, 0 }, { "cfi_restore", dot_cfi_dummy, 0 }, { "cfi_undefined", dot_cfi_dummy, 0 }, { "cfi_same_value", dot_cfi_dummy, 0 }, { "cfi_remember_state", dot_cfi_dummy, 0 }, { "cfi_restore_state", dot_cfi_dummy, 0 }, { "cfi_window_save", dot_cfi_dummy, 0 }, { "cfi_escape", dot_cfi_dummy, 0 }, { "cfi_signal_frame", dot_cfi_dummy, 0 }, { "cfi_personality", dot_cfi_dummy, 0 }, { "cfi_lsda", dot_cfi_dummy, 0 }, { "cfi_val_encoded_addr", dot_cfi_dummy, 0 }, { NULL, NULL, 0 } }; void cfi_finish (void) { } #endif /* TARGET_USE_CFIPOP */