/* ELF object file format Copyright (C) 1992, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc. 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 2, 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define OBJ_HEADER "obj-elf.h" #include "as.h" #include "subsegs.h" #include "obstack.h" #ifndef ECOFF_DEBUGGING #define ECOFF_DEBUGGING 0 #else #define NEED_ECOFF_DEBUG #endif #ifdef NEED_ECOFF_DEBUG #include "ecoff.h" #endif #ifdef TC_ALPHA #include "elf/alpha.h" #endif #ifdef TC_MIPS #include "elf/mips.h" #endif #ifdef TC_PPC #include "elf/ppc.h" #endif #ifdef TC_I370 #include "elf/i370.h" #endif static bfd_vma elf_s_get_size PARAMS ((symbolS *)); static void elf_s_set_size PARAMS ((symbolS *, bfd_vma)); static bfd_vma elf_s_get_align PARAMS ((symbolS *)); static void elf_s_set_align PARAMS ((symbolS *, bfd_vma)); static void elf_copy_symbol_attributes PARAMS ((symbolS *, symbolS *)); static int elf_sec_sym_ok_for_reloc PARAMS ((asection *)); static void adjust_stab_sections PARAMS ((bfd *, asection *, PTR)); #ifdef NEED_ECOFF_DEBUG static boolean elf_get_extr PARAMS ((asymbol *, EXTR *)); static void elf_set_index PARAMS ((asymbol *, bfd_size_type)); #endif static void obj_elf_line PARAMS ((int)); void obj_elf_version PARAMS ((int)); static void obj_elf_size PARAMS ((int)); static void obj_elf_type PARAMS ((int)); static void obj_elf_ident PARAMS ((int)); static void obj_elf_weak PARAMS ((int)); static void obj_elf_local PARAMS ((int)); static void obj_elf_visibility PARAMS ((int)); static void obj_elf_symver PARAMS ((int)); static void obj_elf_vtable_inherit PARAMS ((int)); static void obj_elf_vtable_entry PARAMS ((int)); static void obj_elf_subsection PARAMS ((int)); static void obj_elf_popsection PARAMS ((int)); static const pseudo_typeS elf_pseudo_table[] = { {"comm", obj_elf_common, 0}, {"common", obj_elf_common, 1}, {"ident", obj_elf_ident, 0}, {"local", obj_elf_local, 0}, {"previous", obj_elf_previous, 0}, {"section", obj_elf_section, 0}, {"section.s", obj_elf_section, 0}, {"sect", obj_elf_section, 0}, {"sect.s", obj_elf_section, 0}, {"pushsection", obj_elf_section, 1}, {"popsection", obj_elf_popsection, 0}, {"size", obj_elf_size, 0}, {"type", obj_elf_type, 0}, {"version", obj_elf_version, 0}, {"weak", obj_elf_weak, 0}, /* These define symbol visibility. */ {"internal", obj_elf_visibility, STV_INTERNAL}, {"hidden", obj_elf_visibility, STV_HIDDEN}, {"protected", obj_elf_visibility, STV_PROTECTED}, /* These are used for stabs-in-elf configurations. */ {"line", obj_elf_line, 0}, /* This is a GNU extension to handle symbol versions. */ {"symver", obj_elf_symver, 0}, /* A GNU extension to change subsection only. */ {"subsection", obj_elf_subsection, 0}, /* These are GNU extensions to aid in garbage collecting C++ vtables. */ {"vtable_inherit", obj_elf_vtable_inherit, 0}, {"vtable_entry", obj_elf_vtable_entry, 0}, /* These are used for dwarf. */ {"2byte", cons, 2}, {"4byte", cons, 4}, {"8byte", cons, 8}, /* We need to trap the section changing calls to handle .previous. */ {"data", obj_elf_data, 0}, {"text", obj_elf_text, 0}, /* End sentinel. */ {NULL, NULL, 0}, }; static const pseudo_typeS ecoff_debug_pseudo_table[] = { #ifdef NEED_ECOFF_DEBUG /* COFF style debugging information for ECOFF. .ln is not used; .loc is used instead. */ { "def", ecoff_directive_def, 0 }, { "dim", ecoff_directive_dim, 0 }, { "endef", ecoff_directive_endef, 0 }, { "file", ecoff_directive_file, 0 }, { "scl", ecoff_directive_scl, 0 }, { "tag", ecoff_directive_tag, 0 }, { "val", ecoff_directive_val, 0 }, /* COFF debugging requires pseudo-ops .size and .type, but ELF already has meanings for those. We use .esize and .etype instead. These are only generated by gcc anyhow. */ { "esize", ecoff_directive_size, 0 }, { "etype", ecoff_directive_type, 0 }, /* ECOFF specific debugging information. */ { "begin", ecoff_directive_begin, 0 }, { "bend", ecoff_directive_bend, 0 }, { "end", ecoff_directive_end, 0 }, { "ent", ecoff_directive_ent, 0 }, { "fmask", ecoff_directive_fmask, 0 }, { "frame", ecoff_directive_frame, 0 }, { "loc", ecoff_directive_loc, 0 }, { "mask", ecoff_directive_mask, 0 }, /* Other ECOFF directives. */ { "extern", ecoff_directive_extern, 0 }, /* These are used on Irix. I don't know how to implement them. */ { "alias", s_ignore, 0 }, { "bgnb", s_ignore, 0 }, { "endb", s_ignore, 0 }, { "lab", s_ignore, 0 }, { "noalias", s_ignore, 0 }, { "verstamp", s_ignore, 0 }, { "vreg", s_ignore, 0 }, #endif {NULL, NULL, 0} /* end sentinel */ }; #undef NO_RELOC #include "aout/aout64.h" /* This is called when the assembler starts. */ void elf_begin () { /* Add symbols for the known sections to the symbol table. */ symbol_table_insert (section_symbol (bfd_get_section_by_name (stdoutput, TEXT_SECTION_NAME))); symbol_table_insert (section_symbol (bfd_get_section_by_name (stdoutput, DATA_SECTION_NAME))); symbol_table_insert (section_symbol (bfd_get_section_by_name (stdoutput, BSS_SECTION_NAME))); } void elf_pop_insert () { pop_insert (elf_pseudo_table); if (ECOFF_DEBUGGING) pop_insert (ecoff_debug_pseudo_table); } static bfd_vma elf_s_get_size (sym) symbolS *sym; { return S_GET_SIZE (sym); } static void elf_s_set_size (sym, sz) symbolS *sym; bfd_vma sz; { S_SET_SIZE (sym, sz); } static bfd_vma elf_s_get_align (sym) symbolS *sym; { return S_GET_ALIGN (sym); } static void elf_s_set_align (sym, align) symbolS *sym; bfd_vma align; { S_SET_ALIGN (sym, align); } int elf_s_get_other (sym) symbolS *sym; { return elf_symbol (symbol_get_bfdsym (sym))->internal_elf_sym.st_other; } static void elf_copy_symbol_attributes (dest, src) symbolS *dest, *src; { OBJ_COPY_SYMBOL_ATTRIBUTES (dest, src); } static int elf_sec_sym_ok_for_reloc (sec) asection *sec; { return obj_sec_sym_ok_for_reloc (sec); } void elf_file_symbol (s) char *s; { symbolS *sym; sym = symbol_new (s, absolute_section, (valueT) 0, (struct frag *) 0); symbol_set_frag (sym, &zero_address_frag); symbol_get_bfdsym (sym)->flags |= BSF_FILE; if (symbol_rootP != sym) { symbol_remove (sym, &symbol_rootP, &symbol_lastP); symbol_insert (sym, symbol_rootP, &symbol_rootP, &symbol_lastP); #ifdef DEBUG verify_symbol_chain (symbol_rootP, symbol_lastP); #endif } #ifdef NEED_ECOFF_DEBUG ecoff_new_file (s); #endif } void obj_elf_common (is_common) int is_common; { char *name; char c; char *p; int temp, size; symbolS *symbolP; int have_align; if (flag_mri && is_common) { s_mri_common (0); return; } name = input_line_pointer; c = get_symbol_end (); /* just after name is now '\0' */ p = input_line_pointer; *p = c; SKIP_WHITESPACE (); if (*input_line_pointer != ',') { as_bad (_("Expected comma after symbol-name")); ignore_rest_of_line (); return; } input_line_pointer++; /* skip ',' */ if ((temp = get_absolute_expression ()) < 0) { as_bad (_(".COMMon length (%d.) <0! Ignored."), temp); ignore_rest_of_line (); return; } size = temp; *p = 0; symbolP = symbol_find_or_make (name); *p = c; if (S_IS_DEFINED (symbolP) && ! S_IS_COMMON (symbolP)) { as_bad (_("Ignoring attempt to re-define symbol")); ignore_rest_of_line (); return; } if (S_GET_VALUE (symbolP) != 0) { if (S_GET_VALUE (symbolP) != (valueT) size) { as_warn (_("Length of .comm \"%s\" is already %ld. Not changed to %d."), S_GET_NAME (symbolP), (long) S_GET_VALUE (symbolP), size); } } know (symbolP->sy_frag == &zero_address_frag); if (*input_line_pointer != ',') have_align = 0; else { have_align = 1; input_line_pointer++; SKIP_WHITESPACE (); } if (! have_align || *input_line_pointer != '"') { if (! have_align) temp = 0; else { temp = get_absolute_expression (); if (temp < 0) { temp = 0; as_warn (_("Common alignment negative; 0 assumed")); } } if (symbol_get_obj (symbolP)->local) { segT old_sec; int old_subsec; char *pfrag; int align; /* allocate_bss: */ old_sec = now_seg; old_subsec = now_subseg; if (temp) { /* convert to a power of 2 alignment */ for (align = 0; (temp & 1) == 0; temp >>= 1, ++align); if (temp != 1) { as_bad (_("Common alignment not a power of 2")); ignore_rest_of_line (); return; } } else align = 0; record_alignment (bss_section, align); subseg_set (bss_section, 0); if (align) frag_align (align, 0, 0); if (S_GET_SEGMENT (symbolP) == bss_section) symbol_get_frag (symbolP)->fr_symbol = 0; symbol_set_frag (symbolP, frag_now); pfrag = frag_var (rs_org, 1, 1, (relax_substateT) 0, symbolP, (offsetT) size, (char *) 0); *pfrag = 0; S_SET_SIZE (symbolP, size); S_SET_SEGMENT (symbolP, bss_section); S_CLEAR_EXTERNAL (symbolP); subseg_set (old_sec, old_subsec); } else { allocate_common: S_SET_VALUE (symbolP, (valueT) size); S_SET_ALIGN (symbolP, temp); S_SET_EXTERNAL (symbolP); S_SET_SEGMENT (symbolP, bfd_com_section_ptr); } } else { input_line_pointer++; /* @@ Some use the dot, some don't. Can we get some consistency?? */ if (*input_line_pointer == '.') input_line_pointer++; /* @@ Some say data, some say bss. */ if (strncmp (input_line_pointer, "bss\"", 4) && strncmp (input_line_pointer, "data\"", 5)) { while (*--input_line_pointer != '"') ; input_line_pointer--; goto bad_common_segment; } while (*input_line_pointer++ != '"') ; goto allocate_common; } symbol_get_bfdsym (symbolP)->flags |= BSF_OBJECT; demand_empty_rest_of_line (); return; { bad_common_segment: p = input_line_pointer; while (*p && *p != '\n') p++; c = *p; *p = '\0'; as_bad (_("bad .common segment %s"), input_line_pointer + 1); *p = c; input_line_pointer = p; ignore_rest_of_line (); return; } } static void obj_elf_local (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; int c; symbolS *symbolP; do { name = input_line_pointer; c = get_symbol_end (); symbolP = symbol_find_or_make (name); *input_line_pointer = c; SKIP_WHITESPACE (); S_CLEAR_EXTERNAL (symbolP); symbol_get_obj (symbolP)->local = 1; if (c == ',') { input_line_pointer++; SKIP_WHITESPACE (); if (*input_line_pointer == '\n') c = '\n'; } } while (c == ','); demand_empty_rest_of_line (); } static void obj_elf_weak (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; int c; symbolS *symbolP; do { name = input_line_pointer; c = get_symbol_end (); symbolP = symbol_find_or_make (name); *input_line_pointer = c; SKIP_WHITESPACE (); S_SET_WEAK (symbolP); symbol_get_obj (symbolP)->local = 1; if (c == ',') { input_line_pointer++; SKIP_WHITESPACE (); if (*input_line_pointer == '\n') c = '\n'; } } while (c == ','); demand_empty_rest_of_line (); } static void obj_elf_visibility (visibility) int visibility; { char *name; int c; symbolS *symbolP; asymbol *bfdsym; elf_symbol_type *elfsym; do { name = input_line_pointer; c = get_symbol_end (); symbolP = symbol_find_or_make (name); *input_line_pointer = c; SKIP_WHITESPACE (); bfdsym = symbol_get_bfdsym (symbolP); elfsym = elf_symbol_from (bfd_asymbol_bfd (bfdsym), bfdsym); assert (elfsym); elfsym->internal_elf_sym.st_other = visibility; if (c == ',') { input_line_pointer ++; SKIP_WHITESPACE (); if (*input_line_pointer == '\n') c = '\n'; } } while (c == ','); demand_empty_rest_of_line (); } static segT previous_section; static int previous_subsection; struct section_stack { struct section_stack *next; segT seg, prev_seg; int subseg, prev_subseg; }; static struct section_stack *section_stack; /* Handle the .section pseudo-op. This code supports two different syntaxes. The first is found on Solaris, and looks like .section ".sec1",#alloc,#execinstr,#write Here the names after '#' are the SHF_* flags to turn on for the section. I'm not sure how it determines the SHT_* type (BFD doesn't really give us control over the type, anyhow). The second format is found on UnixWare, and probably most SVR4 machines, and looks like .section .sec1,"a",@progbits The quoted string may contain any combination of a, w, x, and represents the SHF_* flags to turn on for the section. The string beginning with '@' can be progbits or nobits. There should be other possibilities, but I don't know what they are. In any case, BFD doesn't really let us set the section type. */ /* Certain named sections have particular defined types, listed on p. 4-19 of the ABI. */ struct special_section { const char *name; int type; int attributes; }; static struct special_section const special_sections[] = { { ".bss", SHT_NOBITS, SHF_ALLOC + SHF_WRITE }, { ".comment", SHT_PROGBITS, 0 }, { ".data", SHT_PROGBITS, SHF_ALLOC + SHF_WRITE }, { ".data1", SHT_PROGBITS, SHF_ALLOC + SHF_WRITE }, { ".debug", SHT_PROGBITS, 0 }, { ".fini", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, { ".init", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, { ".line", SHT_PROGBITS, 0 }, { ".note", SHT_NOTE, 0 }, { ".rodata", SHT_PROGBITS, SHF_ALLOC }, { ".rodata1", SHT_PROGBITS, SHF_ALLOC }, { ".text", SHT_PROGBITS, SHF_ALLOC + SHF_EXECINSTR }, #ifdef ELF_TC_SPECIAL_SECTIONS ELF_TC_SPECIAL_SECTIONS #endif #if 0 /* The following section names are special, but they can not reasonably appear in assembler code. Some of the attributes are processor dependent. */ { ".dynamic", SHT_DYNAMIC, SHF_ALLOC /* + SHF_WRITE */ }, { ".dynstr", SHT_STRTAB, SHF_ALLOC }, { ".dynsym", SHT_DYNSYM, SHF_ALLOC }, { ".got", SHT_PROGBITS, 0 }, { ".hash", SHT_HASH, SHF_ALLOC }, { ".interp", SHT_PROGBITS, /* SHF_ALLOC */ }, { ".plt", SHT_PROGBITS, 0 }, { ".shstrtab",SHT_STRTAB, 0 }, { ".strtab", SHT_STRTAB, /* SHF_ALLOC */ }, { ".symtab", SHT_SYMTAB, /* SHF_ALLOC */ }, #endif { NULL, 0, 0 } }; void obj_elf_change_section (name, type, attr, push) char *name; int type, attr, push; { asection *old_sec; segT sec; flagword flags; int i; #ifdef md_flush_pending_output md_flush_pending_output (); #endif /* Switch to the section, creating it if necessary. */ if (push) { struct section_stack *elt; elt = xmalloc (sizeof (struct section_stack)); elt->next = section_stack; elt->seg = now_seg; elt->prev_seg = previous_section; elt->subseg = now_subseg; elt->prev_subseg = previous_subsection; section_stack = elt; } previous_section = now_seg; previous_subsection = now_subseg; old_sec = bfd_get_section_by_name (stdoutput, name); sec = subseg_new (name, 0); /* See if this is one of the special sections. */ for (i = 0; special_sections[i].name != NULL; i++) if (strcmp (name, special_sections[i].name) == 0) { if (type == SHT_NULL) type = special_sections[i].type; else if (type != special_sections[i].type) { if (old_sec == NULL) { as_warn (_("Setting incorrect section type for %s"), name); } else { as_warn (_("Ignoring incorrect section type for %s"), name); type = special_sections[i].type; } } if ((attr &~ special_sections[i].attributes) != 0 && old_sec == NULL) { /* As a GNU extension, we permit a .note section to be allocatable. If the linker sees an allocateable .note section, it will create a PT_NOTE segment in the output file. */ if (strcmp (name, ".note") != 0 || attr != SHF_ALLOC) as_warn (_("Setting incorrect section attributes for %s"), name); } attr |= special_sections[i].attributes; break; } /* Convert ELF type and flags to BFD flags. */ flags = (SEC_RELOC | ((attr & SHF_WRITE) ? 0 : SEC_READONLY) | ((attr & SHF_ALLOC) ? SEC_ALLOC : 0) | (((attr & SHF_ALLOC) && type != SHT_NOBITS) ? SEC_LOAD : 0) | ((attr & SHF_EXECINSTR) ? SEC_CODE : 0)); #ifdef md_elf_section_flags flags = md_elf_section_flags (flags, attr, type); #endif if (old_sec == NULL) { symbolS *secsym; /* Prevent SEC_HAS_CONTENTS from being inadvertently set. */ if (type == SHT_NOBITS) seg_info (sec)->bss = 1; bfd_set_section_flags (stdoutput, sec, flags); /* Add a symbol for this section to the symbol table. */ secsym = symbol_find (name); if (secsym != NULL) symbol_set_bfdsym (secsym, sec->symbol); else symbol_table_insert (section_symbol (sec)); } else if (attr != 0) { /* If section attributes are specified the second time we see a particular section, then check that they are the same as we saw the first time. */ if ((old_sec->flags ^ flags) & (SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_EXCLUDE | SEC_SORT_ENTRIES)) as_warn (_("Ignoring changed section attributes for %s"), name); } #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } int obj_elf_parse_section_letters (str, len) char *str; size_t len; { int attr = 0; while (len > 0) { switch (*str) { case 'a': attr |= SHF_ALLOC; break; case 'w': attr |= SHF_WRITE; break; case 'x': attr |= SHF_EXECINSTR; break; default: { char *bad_msg = _("Unrecognized .section attribute: want a,w,x"); #ifdef md_elf_section_letter int md_attr = md_elf_section_letter (*str, &bad_msg); if (md_attr >= 0) attr |= md_attr; else #endif { as_warn ("%s", bad_msg); attr = -1; } } break; } str++, len--; } return attr; } int obj_elf_section_word (str, len) char *str; size_t len; { if (len == 5 && strncmp (str, "write", 5) == 0) return SHF_WRITE; if (len == 5 && strncmp (str, "alloc", 5) == 0) return SHF_ALLOC; if (len == 9 && strncmp (str, "execinstr", 9) == 0) return SHF_EXECINSTR; #ifdef md_elf_section_word { int md_attr = md_elf_section_word (str, len); if (md_attr >= 0) return md_attr; } #endif as_warn (_("Unrecognized section attribute")); return 0; } int obj_elf_section_type (str, len) char *str; size_t len; { if (len == 8 && strncmp (str, "progbits", 8) == 0) return SHT_PROGBITS; if (len == 6 && strncmp (str, "nobits", 6) == 0) return SHT_NOBITS; #ifdef md_elf_section_type { int md_type = md_elf_section_type (str, len); if (md_type >= 0) return md_type; } #endif as_warn (_("Unrecognized section type")); return 0; } void obj_elf_section (push) int push; { char *name, *beg, *end; int type, attr, dummy; #ifndef TC_I370 if (flag_mri) { char mri_type; #ifdef md_flush_pending_output md_flush_pending_output (); #endif previous_section = now_seg; previous_subsection = now_subseg; s_mri_sect (&mri_type); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif return; } #endif /* ! defined (TC_I370) */ /* Get name of section. */ SKIP_WHITESPACE (); if (*input_line_pointer == '"') { name = demand_copy_C_string (&dummy); if (name == NULL) { ignore_rest_of_line (); return; } } else { end = input_line_pointer; while (0 == strchr ("\n\t,; ", *end)) end++; if (end == input_line_pointer) { as_warn (_("Missing section name")); ignore_rest_of_line (); return; } name = xmalloc (end - input_line_pointer + 1); memcpy (name, input_line_pointer, end - input_line_pointer); name[end - input_line_pointer] = '\0'; input_line_pointer = end; } SKIP_WHITESPACE (); type = SHT_NULL; attr = 0; if (*input_line_pointer == ',') { /* Skip the comma. */ ++input_line_pointer; SKIP_WHITESPACE (); if (*input_line_pointer == '"') { beg = demand_copy_C_string (&dummy); if (beg == NULL) { ignore_rest_of_line (); return; } attr |= obj_elf_parse_section_letters (beg, strlen (beg)); SKIP_WHITESPACE (); if (*input_line_pointer == ',') { char c; ++input_line_pointer; SKIP_WHITESPACE (); c = *input_line_pointer; if (c == '"') { beg = demand_copy_C_string (&dummy); if (beg == NULL) { ignore_rest_of_line (); return; } type = obj_elf_section_type (beg, strlen (beg)); } else if (c == '@' || c == '%') { beg = ++input_line_pointer; c = get_symbol_end (); *input_line_pointer = c; type = obj_elf_section_type (beg, input_line_pointer - beg); } } } else { do { char c; SKIP_WHITESPACE (); if (*input_line_pointer != '#') { as_warn (_("Bad .section directive - character following name is not '#'")); ignore_rest_of_line (); return; } beg = ++input_line_pointer; c = get_symbol_end (); *input_line_pointer = c; attr |= obj_elf_section_word (beg, input_line_pointer - beg); SKIP_WHITESPACE (); } while (*input_line_pointer++ == ','); --input_line_pointer; } } demand_empty_rest_of_line (); obj_elf_change_section (name, type, attr, push); } /* Change to the .data section. */ void obj_elf_data (i) int i; { #ifdef md_flush_pending_output md_flush_pending_output (); #endif previous_section = now_seg; previous_subsection = now_subseg; s_data (i); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } /* Change to the .text section. */ void obj_elf_text (i) int i; { #ifdef md_flush_pending_output md_flush_pending_output (); #endif previous_section = now_seg; previous_subsection = now_subseg; s_text (i); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } static void obj_elf_subsection (ignore) int ignore ATTRIBUTE_UNUSED; { register int temp; #ifdef md_flush_pending_output md_flush_pending_output (); #endif previous_section = now_seg; previous_subsection = now_subseg; temp = get_absolute_expression (); subseg_set (now_seg, (subsegT) temp); demand_empty_rest_of_line (); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } /* This can be called from the processor backends if they change sections. */ void obj_elf_section_change_hook () { previous_section = now_seg; previous_subsection = now_subseg; } void obj_elf_previous (ignore) int ignore ATTRIBUTE_UNUSED; { segT new_section; int new_subsection; if (previous_section == 0) { as_bad (_(".previous without corresponding .section; ignored")); return; } #ifdef md_flush_pending_output md_flush_pending_output (); #endif new_section = previous_section; new_subsection = previous_subsection; previous_section = now_seg; previous_subsection = now_subseg; subseg_set (new_section, new_subsection); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } static void obj_elf_popsection (xxx) int xxx ATTRIBUTE_UNUSED; { struct section_stack *top = section_stack; if (top == NULL) { as_bad (_(".popsection without corresponding .pushsection; ignored")); return; } #ifdef md_flush_pending_output md_flush_pending_output (); #endif section_stack = top->next; previous_section = top->prev_seg; previous_subsection = top->prev_subseg; subseg_set (top->seg, top->subseg); free (top); #ifdef md_elf_section_change_hook md_elf_section_change_hook (); #endif } static void obj_elf_line (ignore) int ignore ATTRIBUTE_UNUSED; { /* Assume delimiter is part of expression. BSD4.2 as fails with delightful bug, so we are not being incompatible here. */ new_logical_line ((char *) NULL, (int) (get_absolute_expression ())); demand_empty_rest_of_line (); } /* This handles the .symver pseudo-op, which is used to specify a symbol version. The syntax is ``.symver NAME,SYMVERNAME''. SYMVERNAME may contain ELF_VER_CHR ('@') characters. This pseudo-op causes the assembler to emit a symbol named SYMVERNAME with the same value as the symbol NAME. */ static void obj_elf_symver (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; char c; symbolS *sym; name = input_line_pointer; c = get_symbol_end (); sym = symbol_find_or_make (name); *input_line_pointer = c; if (symbol_get_obj (sym)->versioned_name != NULL) { as_bad (_("multiple .symver directives for symbol `%s'"), S_GET_NAME (sym)); ignore_rest_of_line (); return; } SKIP_WHITESPACE (); if (*input_line_pointer != ',') { as_bad (_("expected comma after name in .symver")); ignore_rest_of_line (); return; } ++input_line_pointer; name = input_line_pointer; while (1) { c = get_symbol_end (); if (c != ELF_VER_CHR) break; *input_line_pointer++ = c; } symbol_get_obj (sym)->versioned_name = xstrdup (name); *input_line_pointer = c; if (strchr (symbol_get_obj (sym)->versioned_name, ELF_VER_CHR) == NULL) { as_bad (_("missing version name in `%s' for symbol `%s'"), symbol_get_obj (sym)->versioned_name, S_GET_NAME (sym)); ignore_rest_of_line (); return; } demand_empty_rest_of_line (); } /* This handles the .vtable_inherit pseudo-op, which is used to indicate to the linker the hierarchy in which a particular table resides. The syntax is ".vtable_inherit CHILDNAME, PARENTNAME". */ static void obj_elf_vtable_inherit (ignore) int ignore ATTRIBUTE_UNUSED; { char *cname, *pname; symbolS *csym, *psym; char c, bad = 0; if (*input_line_pointer == '#') ++input_line_pointer; cname = input_line_pointer; c = get_symbol_end (); csym = symbol_find (cname); /* GCFIXME: should check that we don't have two .vtable_inherits for the same child symbol. Also, we can currently only do this if the child symbol is already exists and is placed in a fragment. */ if (csym == NULL || symbol_get_frag (csym) == NULL) { as_bad ("expected `%s' to have already been set for .vtable_inherit", cname); bad = 1; } *input_line_pointer = c; SKIP_WHITESPACE (); if (*input_line_pointer != ',') { as_bad ("expected comma after name in .vtable_inherit"); ignore_rest_of_line (); return; } ++input_line_pointer; SKIP_WHITESPACE (); if (*input_line_pointer == '#') ++input_line_pointer; if (input_line_pointer[0] == '0' && (input_line_pointer[1] == '\0' || isspace ((unsigned char) input_line_pointer[1]))) { psym = section_symbol (absolute_section); ++input_line_pointer; } else { pname = input_line_pointer; c = get_symbol_end (); psym = symbol_find_or_make (pname); *input_line_pointer = c; } demand_empty_rest_of_line (); if (bad) return; assert (symbol_get_value_expression (csym)->X_op == O_constant); fix_new (symbol_get_frag (csym), symbol_get_value_expression (csym)->X_add_number, 0, psym, 0, 0, BFD_RELOC_VTABLE_INHERIT); } /* This handles the .vtable_entry pseudo-op, which is used to indicate to the linker that a vtable slot was used. The syntax is ".vtable_entry tablename, offset". */ static void obj_elf_vtable_entry (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; symbolS *sym; offsetT offset; char c; if (*input_line_pointer == '#') ++input_line_pointer; name = input_line_pointer; c = get_symbol_end (); sym = symbol_find_or_make (name); *input_line_pointer = c; SKIP_WHITESPACE (); if (*input_line_pointer != ',') { as_bad ("expected comma after name in .vtable_entry"); ignore_rest_of_line (); return; } ++input_line_pointer; if (*input_line_pointer == '#') ++input_line_pointer; offset = get_absolute_expression (); fix_new (frag_now, frag_now_fix (), 0, sym, offset, 0, BFD_RELOC_VTABLE_ENTRY); demand_empty_rest_of_line (); } void elf_obj_read_begin_hook () { #ifdef NEED_ECOFF_DEBUG if (ECOFF_DEBUGGING) ecoff_read_begin_hook (); #endif } void elf_obj_symbol_new_hook (symbolP) symbolS *symbolP; { struct elf_obj_sy *sy_obj; sy_obj = symbol_get_obj (symbolP); sy_obj->size = NULL; sy_obj->versioned_name = NULL; #ifdef NEED_ECOFF_DEBUG if (ECOFF_DEBUGGING) ecoff_symbol_new_hook (symbolP); #endif } void obj_elf_version (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; unsigned int c; char ch; char *p; asection *seg = now_seg; subsegT subseg = now_subseg; Elf_Internal_Note i_note; Elf_External_Note e_note; asection *note_secp = (asection *) NULL; int i, len; SKIP_WHITESPACE (); if (*input_line_pointer == '\"') { ++input_line_pointer; /* -> 1st char of string. */ name = input_line_pointer; while (is_a_char (c = next_char_of_string ())) ; c = *input_line_pointer; *input_line_pointer = '\0'; *(input_line_pointer - 1) = '\0'; *input_line_pointer = c; /* create the .note section */ note_secp = subseg_new (".note", 0); bfd_set_section_flags (stdoutput, note_secp, SEC_HAS_CONTENTS | SEC_READONLY); /* process the version string */ len = strlen (name); i_note.namesz = ((len + 1) + 3) & ~3; /* round this to word boundary */ i_note.descsz = 0; /* no description */ i_note.type = NT_VERSION; p = frag_more (sizeof (e_note.namesz)); md_number_to_chars (p, (valueT) i_note.namesz, 4); p = frag_more (sizeof (e_note.descsz)); md_number_to_chars (p, (valueT) i_note.descsz, 4); p = frag_more (sizeof (e_note.type)); md_number_to_chars (p, (valueT) i_note.type, 4); for (i = 0; i < len; i++) { ch = *(name + i); { FRAG_APPEND_1_CHAR (ch); } } frag_align (2, 0, 0); subseg_set (seg, subseg); } else { as_bad (_("Expected quoted string")); } demand_empty_rest_of_line (); } static void obj_elf_size (ignore) int ignore ATTRIBUTE_UNUSED; { char *name = input_line_pointer; char c = get_symbol_end (); char *p; expressionS exp; symbolS *sym; p = input_line_pointer; *p = c; SKIP_WHITESPACE (); if (*input_line_pointer != ',') { *p = 0; as_bad (_("expected comma after name `%s' in .size directive"), name); *p = c; ignore_rest_of_line (); return; } input_line_pointer++; expression (&exp); if (exp.X_op == O_absent) { as_bad (_("missing expression in .size directive")); exp.X_op = O_constant; exp.X_add_number = 0; } *p = 0; sym = symbol_find_or_make (name); *p = c; if (exp.X_op == O_constant) S_SET_SIZE (sym, exp.X_add_number); else { symbol_get_obj (sym)->size = (expressionS *) xmalloc (sizeof (expressionS)); *symbol_get_obj (sym)->size = exp; } demand_empty_rest_of_line (); } /* Handle the ELF .type pseudo-op. This sets the type of a symbol. There are four syntaxes: The first (used on Solaris) is .type SYM,#function The second (used on UnixWare) is .type SYM,@function The third (reportedly to be used on Irix 6.0) is .type SYM STT_FUNC The fourth (used on NetBSD/Arm and Linux/ARM) is .type SYM,%function */ static void obj_elf_type (ignore) int ignore ATTRIBUTE_UNUSED; { char *name; char c; int type; const char *typename; symbolS *sym; name = input_line_pointer; c = get_symbol_end (); sym = symbol_find_or_make (name); *input_line_pointer = c; SKIP_WHITESPACE (); if (*input_line_pointer == ',') ++input_line_pointer; SKIP_WHITESPACE (); if ( *input_line_pointer == '#' || *input_line_pointer == '@' || *input_line_pointer == '%') ++input_line_pointer; typename = input_line_pointer; c = get_symbol_end (); type = 0; if (strcmp (typename, "function") == 0 || strcmp (typename, "STT_FUNC") == 0) type = BSF_FUNCTION; else if (strcmp (typename, "object") == 0 || strcmp (typename, "STT_OBJECT") == 0) type = BSF_OBJECT; else as_bad (_("ignoring unrecognized symbol type \"%s\""), typename); *input_line_pointer = c; symbol_get_bfdsym (sym)->flags |= type; demand_empty_rest_of_line (); } static void obj_elf_ident (ignore) int ignore ATTRIBUTE_UNUSED; { static segT comment_section; segT old_section = now_seg; int old_subsection = now_subseg; #ifdef md_flush_pending_output md_flush_pending_output (); #endif if (!comment_section) { char *p; comment_section = subseg_new (".comment", 0); bfd_set_section_flags (stdoutput, comment_section, SEC_READONLY | SEC_HAS_CONTENTS); p = frag_more (1); *p = 0; } else subseg_set (comment_section, 0); stringer (1); subseg_set (old_section, old_subsection); } #ifdef INIT_STAB_SECTION /* The first entry in a .stabs section is special. */ void obj_elf_init_stab_section (seg) segT seg; { char *file; char *p; char *stabstr_name; unsigned int stroff; /* Force the section to align to a longword boundary. Without this, UnixWare ar crashes. */ bfd_set_section_alignment (stdoutput, seg, 2); /* Make space for this first symbol. */ p = frag_more (12); /* Zero it out. */ memset (p, 0, 12); as_where (&file, (unsigned int *) NULL); stabstr_name = (char *) alloca (strlen (segment_name (seg)) + 4); strcpy (stabstr_name, segment_name (seg)); strcat (stabstr_name, "str"); stroff = get_stab_string_offset (file, stabstr_name); know (stroff == 1); md_number_to_chars (p, stroff, 4); seg_info (seg)->stabu.p = p; } #endif /* Fill in the counts in the first entry in a .stabs section. */ static void adjust_stab_sections (abfd, sec, xxx) bfd *abfd; asection *sec; PTR xxx ATTRIBUTE_UNUSED; { char *name; asection *strsec; char *p; int strsz, nsyms; if (strncmp (".stab", sec->name, 5)) return; if (!strcmp ("str", sec->name + strlen (sec->name) - 3)) return; name = (char *) alloca (strlen (sec->name) + 4); strcpy (name, sec->name); strcat (name, "str"); strsec = bfd_get_section_by_name (abfd, name); if (strsec) strsz = bfd_section_size (abfd, strsec); else strsz = 0; nsyms = bfd_section_size (abfd, sec) / 12 - 1; p = seg_info (sec)->stabu.p; assert (p != 0); bfd_h_put_16 (abfd, (bfd_vma) nsyms, (bfd_byte *) p + 6); bfd_h_put_32 (abfd, (bfd_vma) strsz, (bfd_byte *) p + 8); } #ifdef NEED_ECOFF_DEBUG /* This function is called by the ECOFF code. It is supposed to record the external symbol information so that the backend can write it out correctly. The ELF backend doesn't actually handle this at the moment, so we do it ourselves. We save the information in the symbol. */ void elf_ecoff_set_ext (sym, ext) symbolS *sym; struct ecoff_extr *ext; { symbol_get_bfdsym (sym)->udata.p = (PTR) ext; } /* This function is called by bfd_ecoff_debug_externals. It is supposed to *EXT to the external symbol information, and return whether the symbol should be used at all. */ static boolean elf_get_extr (sym, ext) asymbol *sym; EXTR *ext; { if (sym->udata.p == NULL) return false; *ext = *(EXTR *) sym->udata.p; return true; } /* This function is called by bfd_ecoff_debug_externals. It has nothing to do for ELF. */ /*ARGSUSED*/ static void elf_set_index (sym, indx) asymbol *sym ATTRIBUTE_UNUSED; bfd_size_type indx ATTRIBUTE_UNUSED; { } #endif /* NEED_ECOFF_DEBUG */ void elf_frob_symbol (symp, puntp) symbolS *symp; int *puntp; { struct elf_obj_sy *sy_obj; #ifdef NEED_ECOFF_DEBUG if (ECOFF_DEBUGGING) ecoff_frob_symbol (symp); #endif sy_obj = symbol_get_obj (symp); if (sy_obj->size != NULL) { switch (sy_obj->size->X_op) { case O_subtract: S_SET_SIZE (symp, (S_GET_VALUE (sy_obj->size->X_add_symbol) + sy_obj->size->X_add_number - S_GET_VALUE (sy_obj->size->X_op_symbol))); break; case O_constant: S_SET_SIZE (symp, (S_GET_VALUE (sy_obj->size->X_add_symbol) + sy_obj->size->X_add_number)); break; default: as_bad (_(".size expression too complicated to fix up")); break; } free (sy_obj->size); sy_obj->size = NULL; } if (sy_obj->versioned_name != NULL) { /* This symbol was given a new name with the .symver directive. If this is an external reference, just rename the symbol to include the version string. This will make the relocs be against the correct versioned symbol. If this is a definition, add an alias. FIXME: Using an alias will permit the debugging information to refer to the right symbol. However, it's not clear whether it is the best approach. */ if (! S_IS_DEFINED (symp)) { char *p; /* Verify that the name isn't using the @@ syntax--this is reserved for definitions of the default version to link against. */ p = strchr (sy_obj->versioned_name, ELF_VER_CHR); know (p != NULL); if (p[1] == ELF_VER_CHR) { as_bad (_("invalid attempt to declare external version name as default in symbol `%s'"), sy_obj->versioned_name); *puntp = true; } S_SET_NAME (symp, sy_obj->versioned_name); } else { symbolS *symp2; /* FIXME: Creating a new symbol here is risky. We're in the final loop over the symbol table. We can get away with it only because the symbol goes to the end of the list, where the loop will still see it. It would probably be better to do this in obj_frob_file_before_adjust. */ symp2 = symbol_find_or_make (sy_obj->versioned_name); /* Now we act as though we saw symp2 = sym. */ S_SET_SEGMENT (symp2, S_GET_SEGMENT (symp)); /* Subtracting out the frag address here is a hack because we are in the middle of the final loop. */ S_SET_VALUE (symp2, (S_GET_VALUE (symp) - symbol_get_frag (symp)->fr_address)); symbol_set_frag (symp2, symbol_get_frag (symp)); /* This will copy over the size information. */ copy_symbol_attributes (symp2, symp); if (S_IS_WEAK (symp)) S_SET_WEAK (symp2); if (S_IS_EXTERNAL (symp)) S_SET_EXTERNAL (symp2); } } /* Double check weak symbols. */ if (S_IS_WEAK (symp)) { if (S_IS_COMMON (symp)) as_bad (_("Symbol `%s' can not be both weak and common"), S_GET_NAME (symp)); } #ifdef TC_MIPS /* The Irix 5 and 6 assemblers set the type of any common symbol and any undefined non-function symbol to STT_OBJECT. We try to be compatible, since newer Irix 5 and 6 linkers care. However, we only set undefined symbols to be STT_OBJECT if we are on Irix, because that is the only time gcc will generate the necessary .global directives to mark functions. */ if (S_IS_COMMON (symp)) symbol_get_bfdsym (symp)->flags |= BSF_OBJECT; if (strstr (TARGET_OS, "irix") != NULL && ! S_IS_DEFINED (symp) && (symbol_get_bfdsym (symp)->flags & BSF_FUNCTION) == 0) symbol_get_bfdsym (symp)->flags |= BSF_OBJECT; #endif #if 0 /* TC_PPC */ /* If TC_PPC is defined, we used to force the type of a symbol to be BSF_OBJECT if it was otherwise unset. This was required by some version of VxWorks. Thomas de Lellis says that this is no longer needed, so it is now commented out. */ if ((symbol_get_bfdsym (symp)->flags & (BSF_FUNCTION | BSF_FILE | BSF_SECTION_SYM)) == 0 && S_IS_DEFINED (symp)) symbol_get_bfdsym (symp)->flags |= BSF_OBJECT; #endif } void elf_frob_file () { bfd_map_over_sections (stdoutput, adjust_stab_sections, (PTR) 0); #ifdef elf_tc_final_processing elf_tc_final_processing (); #endif } /* It is required that we let write_relocs have the opportunity to optimize away fixups before output has begun, since it is possible to eliminate all fixups for a section and thus we never should have generated the relocation section. */ void elf_frob_file_after_relocs () { #ifdef NEED_ECOFF_DEBUG if (ECOFF_DEBUGGING) /* Generate the ECOFF debugging information. */ { const struct ecoff_debug_swap *debug_swap; struct ecoff_debug_info debug; char *buf; asection *sec; debug_swap = get_elf_backend_data (stdoutput)->elf_backend_ecoff_debug_swap; know (debug_swap != (const struct ecoff_debug_swap *) NULL); ecoff_build_debug (&debug.symbolic_header, &buf, debug_swap); /* Set up the pointers in debug. */ #define SET(ptr, offset, type) \ debug.ptr = (type) (buf + debug.symbolic_header.offset) SET (line, cbLineOffset, unsigned char *); SET (external_dnr, cbDnOffset, PTR); SET (external_pdr, cbPdOffset, PTR); SET (external_sym, cbSymOffset, PTR); SET (external_opt, cbOptOffset, PTR); SET (external_aux, cbAuxOffset, union aux_ext *); SET (ss, cbSsOffset, char *); SET (external_fdr, cbFdOffset, PTR); SET (external_rfd, cbRfdOffset, PTR); /* ssext and external_ext are set up just below. */ #undef SET /* Set up the external symbols. */ debug.ssext = debug.ssext_end = NULL; debug.external_ext = debug.external_ext_end = NULL; if (! bfd_ecoff_debug_externals (stdoutput, &debug, debug_swap, true, elf_get_extr, elf_set_index)) as_fatal (_("Failed to set up debugging information: %s"), bfd_errmsg (bfd_get_error ())); sec = bfd_get_section_by_name (stdoutput, ".mdebug"); assert (sec != NULL); know (stdoutput->output_has_begun == false); /* We set the size of the section, call bfd_set_section_contents to force the ELF backend to allocate a file position, and then write out the data. FIXME: Is this really the best way to do this? */ sec->_raw_size = bfd_ecoff_debug_size (stdoutput, &debug, debug_swap); /* Pass BUF to bfd_set_section_contents because this will eventually become a call to fwrite, and ISO C prohibits passing a NULL pointer to a stdio function even if the pointer will not be used. */ if (! bfd_set_section_contents (stdoutput, sec, (PTR) buf, (file_ptr) 0, (bfd_size_type) 0)) as_fatal (_("Can't start writing .mdebug section: %s"), bfd_errmsg (bfd_get_error ())); know (stdoutput->output_has_begun == true); know (sec->filepos != 0); if (! bfd_ecoff_write_debug (stdoutput, &debug, debug_swap, sec->filepos)) as_fatal (_("Could not write .mdebug section: %s"), bfd_errmsg (bfd_get_error ())); } #endif /* NEED_ECOFF_DEBUG */ } #ifdef SCO_ELF /* Heavily plagarized from obj_elf_version. The idea is to emit the SCO specific identifier in the .notes section to satisfy the SCO linker. This looks more complicated than it really is. As opposed to the "obvious" solution, this should handle the cross dev cases correctly. (i.e, hosting on a 64 bit big endian processor, but generating SCO Elf code) Efficiency isn't a concern, as there should be exactly one of these sections per object module. SCO OpenServer 5 identifies it's ELF modules with a standard ELF .note section. int_32 namesz = 4 ; Name size int_32 descsz = 12 ; Descriptive information int_32 type = 1 ; char name[4] = "SCO" ; Originator name ALWAYS SCO + NULL int_32 version = (major ver # << 16) | version of tools ; int_32 source = (tool_id << 16 ) | 1 ; int_32 info = 0 ; These are set by the SCO tools, but we don't know enough about the source environment to set them. SCO ld currently ignores them, and recommends we set them to zero. */ #define SCO_MAJOR_VERSION 0x1 #define SCO_MINOR_VERSION 0x1 void sco_id () { char *name; unsigned int c; char ch; char *p; asection *seg = now_seg; subsegT subseg = now_subseg; Elf_Internal_Note i_note; Elf_External_Note e_note; asection *note_secp = (asection *) NULL; int i, len; /* create the .note section */ note_secp = subseg_new (".note", 0); bfd_set_section_flags (stdoutput, note_secp, SEC_HAS_CONTENTS | SEC_READONLY); /* process the version string */ i_note.namesz = 4; i_note.descsz = 12; /* 12 descriptive bytes */ i_note.type = NT_VERSION; /* Contains a version string */ p = frag_more (sizeof (i_note.namesz)); md_number_to_chars (p, (valueT) i_note.namesz, 4); p = frag_more (sizeof (i_note.descsz)); md_number_to_chars (p, (valueT) i_note.descsz, 4); p = frag_more (sizeof (i_note.type)); md_number_to_chars (p, (valueT) i_note.type, 4); p = frag_more (4); strcpy (p, "SCO"); /* Note: this is the version number of the ELF we're representing */ p = frag_more (4); md_number_to_chars (p, (SCO_MAJOR_VERSION << 16) | (SCO_MINOR_VERSION), 4); /* Here, we pick a magic number for ourselves (yes, I "registered" it with SCO. The bottom bit shows that we are compat with the SCO ABI. */ p = frag_more (4); md_number_to_chars (p, 0x4c520000 | 0x0001, 4); /* If we knew (or cared) what the source language options were, we'd fill them in here. SCO has given us permission to ignore these and just set them to zero. */ p = frag_more (4); md_number_to_chars (p, 0x0000, 4); frag_align (2, 0, 0); /* We probably can't restore the current segment, for there likely isn't one yet... */ if (seg && subseg) subseg_set (seg, subseg); } #endif /* SCO_ELF */ const struct format_ops elf_format_ops = { bfd_target_elf_flavour, 0, /* dfl_leading_underscore */ 1, /* emit_section_symbols */ elf_frob_symbol, elf_frob_file, elf_frob_file_after_relocs, elf_s_get_size, elf_s_set_size, elf_s_get_align, elf_s_set_align, elf_s_get_other, 0, /* s_get_desc */ elf_copy_symbol_attributes, #ifdef NEED_ECOFF_DEBUG ecoff_generate_asm_lineno, ecoff_stab, #else 0, /* generate_asm_lineno */ 0, /* process_stab */ #endif elf_sec_sym_ok_for_reloc, elf_pop_insert, #ifdef NEED_ECOFF_DEBUG elf_ecoff_set_ext, #else 0, /* ecoff_set_ext */ #endif elf_obj_read_begin_hook, elf_obj_symbol_new_hook, };