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[/] [openrisc/] [trunk/] [gnu-old/] [binutils-2.18.50/] [gas/] [write.c] - Rev 38
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/* write.c - emit .o file Copyright 1986, 1987, 1990, 1991, 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 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. */ /* This thing should be set up to do byteordering correctly. But... */ #include "as.h" #include "subsegs.h" #include "obstack.h" #include "output-file.h" #include "dwarf2dbg.h" #include "libbfd.h" #ifndef TC_ADJUST_RELOC_COUNT #define TC_ADJUST_RELOC_COUNT(FIX, COUNT) #endif #ifndef TC_FORCE_RELOCATION #define TC_FORCE_RELOCATION(FIX) \ (generic_force_reloc (FIX)) #endif #ifndef TC_FORCE_RELOCATION_ABS #define TC_FORCE_RELOCATION_ABS(FIX) \ (TC_FORCE_RELOCATION (FIX)) #endif #ifndef TC_FORCE_RELOCATION_LOCAL #define TC_FORCE_RELOCATION_LOCAL(FIX) \ (!(FIX)->fx_pcrel \ || TC_FORCE_RELOCATION (FIX)) #endif #ifndef TC_FORCE_RELOCATION_SUB_SAME #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG) \ (! SEG_NORMAL (SEG)) #endif #ifndef TC_FORCE_RELOCATION_SUB_ABS #define TC_FORCE_RELOCATION_SUB_ABS(FIX) 0 #endif #ifndef TC_FORCE_RELOCATION_SUB_LOCAL #ifdef DIFF_EXPR_OK #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX) 0 #else #define TC_FORCE_RELOCATION_SUB_LOCAL(FIX) 1 #endif #endif #ifndef TC_VALIDATE_FIX_SUB #ifdef UNDEFINED_DIFFERENCE_OK /* The PA needs this for PIC code generation. */ #define TC_VALIDATE_FIX_SUB(FIX) 1 #else #define TC_VALIDATE_FIX_SUB(FIX) \ ((FIX)->fx_r_type == BFD_RELOC_GPREL32 \ || (FIX)->fx_r_type == BFD_RELOC_GPREL16) #endif #endif #ifndef TC_LINKRELAX_FIXUP #define TC_LINKRELAX_FIXUP(SEG) 1 #endif #ifndef MD_APPLY_SYM_VALUE #define MD_APPLY_SYM_VALUE(FIX) 1 #endif #ifndef TC_FINALIZE_SYMS_BEFORE_SIZE_SEG #define TC_FINALIZE_SYMS_BEFORE_SIZE_SEG 1 #endif #ifndef MD_PCREL_FROM_SECTION #define MD_PCREL_FROM_SECTION(FIX, SEC) md_pcrel_from (FIX) #endif #ifndef TC_FAKE_LABEL #define TC_FAKE_LABEL(NAME) (strcmp ((NAME), FAKE_LABEL_NAME) == 0) #endif /* Positive values of TC_FX_SIZE_SLACK allow a target to define fixups that far past the end of a frag. Having such fixups is of course most most likely a bug in setting fx_size correctly. A negative value disables the fixup check entirely, which is appropriate for something like the Renesas / SuperH SH_COUNT reloc. */ #ifndef TC_FX_SIZE_SLACK #define TC_FX_SIZE_SLACK(FIX) 0 #endif /* Used to control final evaluation of expressions. */ int finalize_syms = 0; int symbol_table_frozen; symbolS *abs_section_sym; /* Remember the value of dot when parsing expressions. */ addressT dot_value; /* Relocs generated by ".reloc" pseudo. */ struct reloc_list* reloc_list; void print_fixup (fixS *); /* We generally attach relocs to frag chains. However, after we have chained these all together into a segment, any relocs we add after that must be attached to a segment. This will include relocs added in md_estimate_size_for_relax, for example. */ static int frags_chained = 0; static int n_fixups; #define RELOC_ENUM enum bfd_reloc_code_real /* Create a fixS in obstack 'notes'. */ static fixS * fix_new_internal (fragS *frag, /* Which frag? */ int where, /* Where in that frag? */ int size, /* 1, 2, or 4 usually. */ symbolS *add_symbol, /* X_add_symbol. */ symbolS *sub_symbol, /* X_op_symbol. */ offsetT offset, /* X_add_number. */ int pcrel, /* TRUE if PC-relative relocation. */ RELOC_ENUM r_type ATTRIBUTE_UNUSED /* Relocation type. */) { fixS *fixP; n_fixups++; fixP = obstack_alloc (¬es, sizeof (fixS)); fixP->fx_frag = frag; fixP->fx_where = where; fixP->fx_size = size; /* We've made fx_size a narrow field; check that it's wide enough. */ if (fixP->fx_size != size) { as_bad (_("field fx_size too small to hold %d"), size); abort (); } fixP->fx_addsy = add_symbol; fixP->fx_subsy = sub_symbol; fixP->fx_offset = offset; fixP->fx_dot_value = dot_value; fixP->fx_pcrel = pcrel; fixP->fx_r_type = r_type; fixP->fx_im_disp = 0; fixP->fx_pcrel_adjust = 0; fixP->fx_bit_fixP = 0; fixP->fx_addnumber = 0; fixP->fx_tcbit = 0; fixP->fx_tcbit2 = 0; fixP->fx_done = 0; fixP->fx_no_overflow = 0; fixP->fx_signed = 0; #ifdef USING_CGEN fixP->fx_cgen.insn = NULL; fixP->fx_cgen.opinfo = 0; #endif #ifdef TC_FIX_TYPE TC_INIT_FIX_DATA (fixP); #endif as_where (&fixP->fx_file, &fixP->fx_line); /* Usually, we want relocs sorted numerically, but while comparing to older versions of gas that have relocs reverse sorted, it is convenient to have this compile time option. xoxorich. */ { fixS **seg_fix_rootP = (frags_chained ? &seg_info (now_seg)->fix_root : &frchain_now->fix_root); fixS **seg_fix_tailP = (frags_chained ? &seg_info (now_seg)->fix_tail : &frchain_now->fix_tail); #ifdef REVERSE_SORT_RELOCS fixP->fx_next = *seg_fix_rootP; *seg_fix_rootP = fixP; #else /* REVERSE_SORT_RELOCS */ fixP->fx_next = NULL; if (*seg_fix_tailP) (*seg_fix_tailP)->fx_next = fixP; else *seg_fix_rootP = fixP; *seg_fix_tailP = fixP; #endif /* REVERSE_SORT_RELOCS */ } return fixP; } /* Create a fixup relative to a symbol (plus a constant). */ fixS * fix_new (fragS *frag, /* Which frag? */ int where, /* Where in that frag? */ int size, /* 1, 2, or 4 usually. */ symbolS *add_symbol, /* X_add_symbol. */ offsetT offset, /* X_add_number. */ int pcrel, /* TRUE if PC-relative relocation. */ RELOC_ENUM r_type /* Relocation type. */) { return fix_new_internal (frag, where, size, add_symbol, (symbolS *) NULL, offset, pcrel, r_type); } /* Create a fixup for an expression. Currently we only support fixups for difference expressions. That is itself more than most object file formats support anyhow. */ fixS * fix_new_exp (fragS *frag, /* Which frag? */ int where, /* Where in that frag? */ int size, /* 1, 2, or 4 usually. */ expressionS *exp, /* Expression. */ int pcrel, /* TRUE if PC-relative relocation. */ RELOC_ENUM r_type /* Relocation type. */) { symbolS *add = NULL; symbolS *sub = NULL; offsetT off = 0; switch (exp->X_op) { case O_absent: break; case O_register: as_bad (_("register value used as expression")); break; case O_add: /* This comes up when _GLOBAL_OFFSET_TABLE_+(.-L0) is read, if the difference expression cannot immediately be reduced. */ { symbolS *stmp = make_expr_symbol (exp); exp->X_op = O_symbol; exp->X_op_symbol = 0; exp->X_add_symbol = stmp; exp->X_add_number = 0; return fix_new_exp (frag, where, size, exp, pcrel, r_type); } case O_symbol_rva: add = exp->X_add_symbol; off = exp->X_add_number; r_type = BFD_RELOC_RVA; break; case O_uminus: sub = exp->X_add_symbol; off = exp->X_add_number; break; case O_subtract: sub = exp->X_op_symbol; /* Fall through. */ case O_symbol: add = exp->X_add_symbol; /* Fall through. */ case O_constant: off = exp->X_add_number; break; default: add = make_expr_symbol (exp); break; } return fix_new_internal (frag, where, size, add, sub, off, pcrel, r_type); } /* Generic function to determine whether a fixup requires a relocation. */ int generic_force_reloc (fixS *fix) { if (fix->fx_r_type == BFD_RELOC_VTABLE_INHERIT || fix->fx_r_type == BFD_RELOC_VTABLE_ENTRY) return 1; if (fix->fx_addsy == NULL) return 0; return S_FORCE_RELOC (fix->fx_addsy, fix->fx_subsy == NULL); } /* Append a string onto another string, bumping the pointer along. */ void append (char **charPP, char *fromP, unsigned long length) { /* Don't trust memcpy() of 0 chars. */ if (length == 0) return; memcpy (*charPP, fromP, length); *charPP += length; } /* This routine records the largest alignment seen for each segment. If the beginning of the segment is aligned on the worst-case boundary, all of the other alignments within it will work. At least one object format really uses this info. */ void record_alignment (/* Segment to which alignment pertains. */ segT seg, /* Alignment, as a power of 2 (e.g., 1 => 2-byte boundary, 2 => 4-byte boundary, etc.) */ int align) { if (seg == absolute_section) return; if ((unsigned int) align > bfd_get_section_alignment (stdoutput, seg)) bfd_set_section_alignment (stdoutput, seg, align); } int get_recorded_alignment (segT seg) { if (seg == absolute_section) return 0; return bfd_get_section_alignment (stdoutput, seg); } /* Reset the section indices after removing the gas created sections. */ static void renumber_sections (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *countparg) { int *countp = (int *) countparg; sec->index = *countp; ++*countp; } static fragS * chain_frchains_together_1 (segT section, struct frchain *frchp) { fragS dummy, *prev_frag = &dummy; fixS fix_dummy, *prev_fix = &fix_dummy; for (; frchp; frchp = frchp->frch_next) { prev_frag->fr_next = frchp->frch_root; prev_frag = frchp->frch_last; assert (prev_frag->fr_type != 0); if (frchp->fix_root != (fixS *) NULL) { if (seg_info (section)->fix_root == (fixS *) NULL) seg_info (section)->fix_root = frchp->fix_root; prev_fix->fx_next = frchp->fix_root; seg_info (section)->fix_tail = frchp->fix_tail; prev_fix = frchp->fix_tail; } } assert (prev_frag->fr_type != 0); assert (prev_frag != &dummy); prev_frag->fr_next = 0; return prev_frag; } static void chain_frchains_together (bfd *abfd ATTRIBUTE_UNUSED, segT section, void *xxx ATTRIBUTE_UNUSED) { segment_info_type *info; /* BFD may have introduced its own sections without using subseg_new, so it is possible that seg_info is NULL. */ info = seg_info (section); if (info != (segment_info_type *) NULL) info->frchainP->frch_last = chain_frchains_together_1 (section, info->frchainP); /* Now that we've chained the frags together, we must add new fixups to the segment, not to the frag chain. */ frags_chained = 1; } static void cvt_frag_to_fill (segT sec ATTRIBUTE_UNUSED, fragS *fragP) { switch (fragP->fr_type) { case rs_align: case rs_align_code: case rs_align_test: case rs_org: case rs_space: #ifdef HANDLE_ALIGN HANDLE_ALIGN (fragP); #endif know (fragP->fr_next != NULL); fragP->fr_offset = (fragP->fr_next->fr_address - fragP->fr_address - fragP->fr_fix) / fragP->fr_var; if (fragP->fr_offset < 0) { as_bad_where (fragP->fr_file, fragP->fr_line, _("attempt to .org/.space backwards? (%ld)"), (long) fragP->fr_offset); fragP->fr_offset = 0; } fragP->fr_type = rs_fill; break; case rs_fill: break; case rs_leb128: { valueT value = S_GET_VALUE (fragP->fr_symbol); int size; size = output_leb128 (fragP->fr_literal + fragP->fr_fix, value, fragP->fr_subtype); fragP->fr_fix += size; fragP->fr_type = rs_fill; fragP->fr_var = 0; fragP->fr_offset = 0; fragP->fr_symbol = NULL; } break; case rs_cfa: eh_frame_convert_frag (fragP); break; case rs_dwarf2dbg: dwarf2dbg_convert_frag (fragP); break; case rs_machine_dependent: md_convert_frag (stdoutput, sec, fragP); assert (fragP->fr_next == NULL || ((offsetT) (fragP->fr_next->fr_address - fragP->fr_address) == fragP->fr_fix)); /* After md_convert_frag, we make the frag into a ".space 0". md_convert_frag() should set up any fixSs and constants required. */ frag_wane (fragP); break; #ifndef WORKING_DOT_WORD case rs_broken_word: { struct broken_word *lie; if (fragP->fr_subtype) { fragP->fr_fix += md_short_jump_size; for (lie = (struct broken_word *) (fragP->fr_symbol); lie && lie->dispfrag == fragP; lie = lie->next_broken_word) if (lie->added == 1) fragP->fr_fix += md_long_jump_size; } frag_wane (fragP); } break; #endif default: BAD_CASE (fragP->fr_type); break; } #ifdef md_frag_check md_frag_check (fragP); #endif } struct relax_seg_info { int pass; int changed; }; static void relax_seg (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx) { segment_info_type *seginfo = seg_info (sec); struct relax_seg_info *info = (struct relax_seg_info *) xxx; if (seginfo && seginfo->frchainP && relax_segment (seginfo->frchainP->frch_root, sec, info->pass)) info->changed = 1; } static void size_seg (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED) { flagword flags; fragS *fragp; segment_info_type *seginfo; int x; valueT size, newsize; subseg_change (sec, 0); seginfo = seg_info (sec); if (seginfo && seginfo->frchainP) { for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next) cvt_frag_to_fill (sec, fragp); for (fragp = seginfo->frchainP->frch_root; fragp->fr_next; fragp = fragp->fr_next) /* Walk to last elt. */ ; size = fragp->fr_address + fragp->fr_fix; } else size = 0; flags = bfd_get_section_flags (abfd, sec); if (size > 0 && ! seginfo->bss) flags |= SEC_HAS_CONTENTS; flags &= ~SEC_RELOC; x = bfd_set_section_flags (abfd, sec, flags); assert (x); newsize = md_section_align (sec, size); x = bfd_set_section_size (abfd, sec, newsize); assert (x); /* If the size had to be rounded up, add some padding in the last non-empty frag. */ assert (newsize >= size); if (size != newsize) { fragS *last = seginfo->frchainP->frch_last; fragp = seginfo->frchainP->frch_root; while (fragp->fr_next != last) fragp = fragp->fr_next; last->fr_address = size; if ((newsize - size) % fragp->fr_var == 0) fragp->fr_offset += (newsize - size) / fragp->fr_var; else /* If we hit this abort, it's likely due to subsegs_finish not providing sufficient alignment on the last frag, and the machine dependent code using alignment frags with fr_var greater than 1. */ abort (); } #ifdef tc_frob_section tc_frob_section (sec); #endif #ifdef obj_frob_section obj_frob_section (sec); #endif } #ifdef DEBUG2 static void dump_section_relocs (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, FILE *stream) { segment_info_type *seginfo = seg_info (sec); fixS *fixp = seginfo->fix_root; if (!fixp) return; fprintf (stream, "sec %s relocs:\n", sec->name); while (fixp) { symbolS *s = fixp->fx_addsy; fprintf (stream, " %08lx: type %d ", (unsigned long) fixp, (int) fixp->fx_r_type); if (s == NULL) fprintf (stream, "no sym\n"); else { print_symbol_value_1 (stream, s); fprintf (stream, "\n"); } fixp = fixp->fx_next; } } #else #define dump_section_relocs(ABFD,SEC,STREAM) ((void) 0) #endif #ifndef EMIT_SECTION_SYMBOLS #define EMIT_SECTION_SYMBOLS 1 #endif /* Resolve U.A.OFFSET_SYM and U.A.SYM fields of RELOC_LIST entries, and check for validity. Convert RELOC_LIST from using U.A fields to U.B fields. */ static void resolve_reloc_expr_symbols (void) { struct reloc_list *r; for (r = reloc_list; r; r = r->next) { expressionS *symval; symbolS *sym; bfd_vma offset, addend; asection *sec; reloc_howto_type *howto; resolve_symbol_value (r->u.a.offset_sym); symval = symbol_get_value_expression (r->u.a.offset_sym); offset = 0; sym = NULL; if (symval->X_op == O_constant) sym = r->u.a.offset_sym; else if (symval->X_op == O_symbol) { sym = symval->X_add_symbol; offset = symval->X_add_number; symval = symbol_get_value_expression (symval->X_add_symbol); } if (sym == NULL || symval->X_op != O_constant || (sec = S_GET_SEGMENT (sym)) == NULL || !SEG_NORMAL (sec)) { as_bad_where (r->file, r->line, _("invalid offset expression")); sec = NULL; } else offset += S_GET_VALUE (sym); sym = NULL; addend = r->u.a.addend; if (r->u.a.sym != NULL) { resolve_symbol_value (r->u.a.sym); symval = symbol_get_value_expression (r->u.a.sym); if (symval->X_op == O_constant) sym = r->u.a.sym; else if (symval->X_op == O_symbol) { sym = symval->X_add_symbol; addend += symval->X_add_number; symval = symbol_get_value_expression (symval->X_add_symbol); } if (symval->X_op != O_constant) { as_bad_where (r->file, r->line, _("invalid reloc expression")); sec = NULL; } else if (sym != NULL) symbol_mark_used_in_reloc (sym); } if (sym == NULL) { if (abs_section_sym == NULL) abs_section_sym = section_symbol (absolute_section); sym = abs_section_sym; } howto = r->u.a.howto; r->u.b.sec = sec; r->u.b.s = symbol_get_bfdsym (sym); r->u.b.r.sym_ptr_ptr = &r->u.b.s; r->u.b.r.address = offset; r->u.b.r.addend = addend; r->u.b.r.howto = howto; } } /* This pass over fixups decides whether symbols can be replaced with section symbols. */ static void adjust_reloc_syms (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx ATTRIBUTE_UNUSED) { segment_info_type *seginfo = seg_info (sec); fixS *fixp; if (seginfo == NULL) return; dump_section_relocs (abfd, sec, stderr); for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next) if (fixp->fx_done) /* Ignore it. */ ; else if (fixp->fx_addsy) { symbolS *sym; asection *symsec; #ifdef DEBUG5 fprintf (stderr, "\n\nadjusting fixup:\n"); print_fixup (fixp); #endif sym = fixp->fx_addsy; /* All symbols should have already been resolved at this point. It is possible to see unresolved expression symbols, though, since they are not in the regular symbol table. */ resolve_symbol_value (sym); if (fixp->fx_subsy != NULL) resolve_symbol_value (fixp->fx_subsy); /* If this symbol is equated to an undefined or common symbol, convert the fixup to being against that symbol. */ while (symbol_equated_reloc_p (sym) || S_IS_WEAKREFR (sym)) { symbolS *newsym = symbol_get_value_expression (sym)->X_add_symbol; if (sym == newsym) break; fixp->fx_offset += symbol_get_value_expression (sym)->X_add_number; fixp->fx_addsy = newsym; sym = newsym; } if (symbol_mri_common_p (sym)) { fixp->fx_offset += S_GET_VALUE (sym); fixp->fx_addsy = symbol_get_value_expression (sym)->X_add_symbol; continue; } /* If the symbol is undefined, common, weak, or global (ELF shared libs), we can't replace it with the section symbol. */ if (S_FORCE_RELOC (fixp->fx_addsy, 1)) continue; /* Is there some other (target cpu dependent) reason we can't adjust this one? (E.g. relocations involving function addresses on the PA. */ #ifdef tc_fix_adjustable if (! tc_fix_adjustable (fixp)) continue; #endif /* Since we're reducing to section symbols, don't attempt to reduce anything that's already using one. */ if (symbol_section_p (sym)) continue; symsec = S_GET_SEGMENT (sym); if (symsec == NULL) abort (); if (bfd_is_abs_section (symsec)) { /* The fixup_segment routine normally will not use this symbol in a relocation. */ continue; } /* Don't try to reduce relocs which refer to non-local symbols in .linkonce sections. It can lead to confusion when a debugging section refers to a .linkonce section. I hope this will always be correct. */ if (symsec != sec && ! S_IS_LOCAL (sym)) { if ((symsec->flags & SEC_LINK_ONCE) != 0 || (IS_ELF /* The GNU toolchain uses an extension for ELF: a section beginning with the magic string .gnu.linkonce is a linkonce section. */ && strncmp (segment_name (symsec), ".gnu.linkonce", sizeof ".gnu.linkonce" - 1) == 0)) continue; } /* Never adjust a reloc against local symbol in a merge section with non-zero addend. */ if ((symsec->flags & SEC_MERGE) != 0 && (fixp->fx_offset != 0 || fixp->fx_subsy != NULL)) continue; /* Never adjust a reloc against TLS local symbol. */ if ((symsec->flags & SEC_THREAD_LOCAL) != 0) continue; /* We refetch the segment when calling section_symbol, rather than using symsec, because S_GET_VALUE may wind up changing the section when it calls resolve_symbol_value. */ fixp->fx_offset += S_GET_VALUE (sym); fixp->fx_addsy = section_symbol (S_GET_SEGMENT (sym)); #ifdef DEBUG5 fprintf (stderr, "\nadjusted fixup:\n"); print_fixup (fixp); #endif } dump_section_relocs (abfd, sec, stderr); } /* fixup_segment() Go through all the fixS's in a segment and see which ones can be handled now. (These consist of fixS where we have since discovered the value of a symbol, or the address of the frag involved.) For each one, call md_apply_fix to put the fix into the frag data. Result is a count of how many relocation structs will be needed to handle the remaining fixS's that we couldn't completely handle here. These will be output later by emit_relocations(). */ static long fixup_segment (fixS *fixP, segT this_segment) { long seg_reloc_count = 0; valueT add_number; fragS *fragP; segT add_symbol_segment = absolute_section; if (fixP != NULL && abs_section_sym == NULL) abs_section_sym = section_symbol (absolute_section); /* If the linker is doing the relaxing, we must not do any fixups. Well, strictly speaking that's not true -- we could do any that are PC-relative and don't cross regions that could change size. And for the i960 we might be able to turn callx/callj into bal anyways in cases where we know the maximum displacement. */ if (linkrelax && TC_LINKRELAX_FIXUP (this_segment)) { for (; fixP; fixP = fixP->fx_next) if (!fixP->fx_done) { if (fixP->fx_addsy == NULL) { /* There was no symbol required by this relocation. However, BFD doesn't really handle relocations without symbols well. So fake up a local symbol in the absolute section. */ fixP->fx_addsy = abs_section_sym; } symbol_mark_used_in_reloc (fixP->fx_addsy); if (fixP->fx_subsy != NULL) symbol_mark_used_in_reloc (fixP->fx_subsy); seg_reloc_count++; } TC_ADJUST_RELOC_COUNT (fixP, seg_reloc_count); return seg_reloc_count; } for (; fixP; fixP = fixP->fx_next) { #ifdef DEBUG5 fprintf (stderr, "\nprocessing fixup:\n"); print_fixup (fixP); #endif fragP = fixP->fx_frag; know (fragP); #ifdef TC_VALIDATE_FIX TC_VALIDATE_FIX (fixP, this_segment, skip); #endif add_number = fixP->fx_offset; if (fixP->fx_addsy != NULL) add_symbol_segment = S_GET_SEGMENT (fixP->fx_addsy); if (fixP->fx_subsy != NULL) { segT sub_symbol_segment; resolve_symbol_value (fixP->fx_subsy); sub_symbol_segment = S_GET_SEGMENT (fixP->fx_subsy); if (fixP->fx_addsy != NULL && sub_symbol_segment == add_symbol_segment && !TC_FORCE_RELOCATION_SUB_SAME (fixP, add_symbol_segment)) { add_number += S_GET_VALUE (fixP->fx_addsy); add_number -= S_GET_VALUE (fixP->fx_subsy); fixP->fx_offset = add_number; fixP->fx_addsy = NULL; fixP->fx_subsy = NULL; #ifdef TC_M68K /* See the comment below about 68k weirdness. */ fixP->fx_pcrel = 0; #endif } else if (sub_symbol_segment == absolute_section && !TC_FORCE_RELOCATION_SUB_ABS (fixP)) { add_number -= S_GET_VALUE (fixP->fx_subsy); fixP->fx_offset = add_number; fixP->fx_subsy = NULL; } else if (sub_symbol_segment == this_segment && !TC_FORCE_RELOCATION_SUB_LOCAL (fixP)) { add_number -= S_GET_VALUE (fixP->fx_subsy); fixP->fx_offset = (add_number + fixP->fx_dot_value + fixP->fx_frag->fr_address); /* Make it pc-relative. If the back-end code has not selected a pc-relative reloc, cancel the adjustment we do later on all pc-relative relocs. */ if (0 #ifdef TC_M68K /* Do this for m68k even if it's already described as pc-relative. On the m68k, an operand of "pc@(foo-.-2)" should address "foo" in a pc-relative mode. */ || 1 #endif || !fixP->fx_pcrel) add_number += MD_PCREL_FROM_SECTION (fixP, this_segment); fixP->fx_subsy = NULL; fixP->fx_pcrel = 1; } else if (!TC_VALIDATE_FIX_SUB (fixP)) { as_bad_where (fixP->fx_file, fixP->fx_line, _("can't resolve `%s' {%s section} - `%s' {%s section}"), fixP->fx_addsy ? S_GET_NAME (fixP->fx_addsy) : "0", segment_name (add_symbol_segment), S_GET_NAME (fixP->fx_subsy), segment_name (sub_symbol_segment)); } } if (fixP->fx_addsy) { if (add_symbol_segment == this_segment && !TC_FORCE_RELOCATION_LOCAL (fixP)) { /* This fixup was made when the symbol's segment was SEG_UNKNOWN, but it is now in the local segment. So we know how to do the address without relocation. */ add_number += S_GET_VALUE (fixP->fx_addsy); fixP->fx_offset = add_number; if (fixP->fx_pcrel) add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment); fixP->fx_addsy = NULL; fixP->fx_pcrel = 0; } else if (add_symbol_segment == absolute_section && !TC_FORCE_RELOCATION_ABS (fixP)) { add_number += S_GET_VALUE (fixP->fx_addsy); fixP->fx_offset = add_number; fixP->fx_addsy = NULL; } else if (add_symbol_segment != undefined_section && ! bfd_is_com_section (add_symbol_segment) && MD_APPLY_SYM_VALUE (fixP)) add_number += S_GET_VALUE (fixP->fx_addsy); } if (fixP->fx_pcrel) { add_number -= MD_PCREL_FROM_SECTION (fixP, this_segment); if (!fixP->fx_done && fixP->fx_addsy == NULL) { /* There was no symbol required by this relocation. However, BFD doesn't really handle relocations without symbols well. So fake up a local symbol in the absolute section. */ fixP->fx_addsy = abs_section_sym; } } if (!fixP->fx_done) md_apply_fix (fixP, &add_number, this_segment); if (!fixP->fx_done) { ++seg_reloc_count; if (fixP->fx_addsy == NULL) fixP->fx_addsy = abs_section_sym; symbol_mark_used_in_reloc (fixP->fx_addsy); if (fixP->fx_subsy != NULL) symbol_mark_used_in_reloc (fixP->fx_subsy); } if (!fixP->fx_bit_fixP && !fixP->fx_no_overflow && fixP->fx_size != 0) { if (fixP->fx_size < sizeof (valueT)) { valueT mask; mask = 0; mask--; /* Set all bits to one. */ mask <<= fixP->fx_size * 8 - (fixP->fx_signed ? 1 : 0); if ((add_number & mask) != 0 && (add_number & mask) != mask) { char buf[50], buf2[50]; sprint_value (buf, fragP->fr_address + fixP->fx_where); if (add_number > 1000) sprint_value (buf2, add_number); else sprintf (buf2, "%ld", (long) add_number); as_bad_where (fixP->fx_file, fixP->fx_line, _("value of %s too large for field of %d bytes at %s"), buf2, fixP->fx_size, buf); } /* Generic error checking. */ } #ifdef WARN_SIGNED_OVERFLOW_WORD /* Warn if a .word value is too large when treated as a signed number. We already know it is not too negative. This is to catch over-large switches generated by gcc on the 68k. */ if (!flag_signed_overflow_ok && fixP->fx_size == 2 && add_number > 0x7fff) as_bad_where (fixP->fx_file, fixP->fx_line, _("signed .word overflow; switch may be too large; %ld at 0x%lx"), (long) add_number, (long) (fragP->fr_address + fixP->fx_where)); #endif } /* Not a bit fix. */ #ifdef TC_VALIDATE_FIX skip: ATTRIBUTE_UNUSED_LABEL ; #endif #ifdef DEBUG5 fprintf (stderr, "result:\n"); print_fixup (fixP); #endif } /* For each fixS in this segment. */ TC_ADJUST_RELOC_COUNT (fixP, seg_reloc_count); return seg_reloc_count; } static void fix_segment (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx ATTRIBUTE_UNUSED) { segment_info_type *seginfo = seg_info (sec); fixup_segment (seginfo->fix_root, sec); } static void install_reloc (asection *sec, arelent *reloc, fragS *fragp, char *file, unsigned int line) { char *err; bfd_reloc_status_type s; s = bfd_install_relocation (stdoutput, reloc, fragp->fr_literal, fragp->fr_address, sec, &err); switch (s) { case bfd_reloc_ok: break; case bfd_reloc_overflow: as_bad_where (file, line, _("relocation overflow")); break; case bfd_reloc_outofrange: as_bad_where (file, line, _("relocation out of range")); break; default: as_fatal (_("%s:%u: bad return from bfd_install_relocation: %x"), file, line, s); } } static void write_relocs (bfd *abfd, asection *sec, void *xxx ATTRIBUTE_UNUSED) { segment_info_type *seginfo = seg_info (sec); unsigned int i; unsigned int n; struct reloc_list *my_reloc_list, **rp, *r; arelent **relocs; fixS *fixp; /* If seginfo is NULL, we did not create this section; don't do anything with it. */ if (seginfo == NULL) return; n = 0; for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next) if (!fixp->fx_done) n++; #ifdef RELOC_EXPANSION_POSSIBLE n *= MAX_RELOC_EXPANSION; #endif /* Extract relocs for this section from reloc_list. */ rp = &reloc_list; my_reloc_list = NULL; while ((r = *rp) != NULL) { if (r->u.b.sec == sec) { *rp = r->next; r->next = my_reloc_list; my_reloc_list = r; n++; } else rp = &r->next; } relocs = xcalloc (n, sizeof (arelent *)); i = 0; for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next) { int j; int fx_size, slack; offsetT loc; if (fixp->fx_done) continue; fx_size = fixp->fx_size; slack = TC_FX_SIZE_SLACK (fixp); if (slack > 0) fx_size = fx_size > slack ? fx_size - slack : 0; loc = fixp->fx_where + fx_size; if (slack >= 0 && loc > fixp->fx_frag->fr_fix) as_bad_where (fixp->fx_file, fixp->fx_line, _("internal error: fixup not contained within frag")); #ifndef RELOC_EXPANSION_POSSIBLE { arelent *reloc = tc_gen_reloc (sec, fixp); if (!reloc) continue; relocs[i++] = reloc; j = 1; } #else { arelent **reloc = tc_gen_reloc (sec, fixp); for (j = 0; reloc[j]; j++) relocs[i++] = reloc[j]; } #endif for ( ; j != 0; --j) install_reloc (sec, relocs[i - j], fixp->fx_frag, fixp->fx_file, fixp->fx_line); } n = i; #ifdef DEBUG4 { unsigned int i, j, nsyms; asymbol **sympp; sympp = bfd_get_outsymbols (stdoutput); nsyms = bfd_get_symcount (stdoutput); for (i = 0; i < n; i++) if (((*relocs[i]->sym_ptr_ptr)->flags & BSF_SECTION_SYM) == 0) { for (j = 0; j < nsyms; j++) if (sympp[j] == *relocs[i]->sym_ptr_ptr) break; if (j == nsyms) abort (); } } #endif for (r = my_reloc_list; r != NULL; r = r->next) { fragS *f; for (f = seginfo->frchainP->frch_root; f; f = f->fr_next) if (f->fr_address <= r->u.b.r.address && r->u.b.r.address < f->fr_address + f->fr_fix) break; if (f == NULL) as_bad_where (r->file, r->line, _("reloc not within (fixed part of) section")); else { relocs[n++] = &r->u.b.r; install_reloc (sec, &r->u.b.r, f, r->file, r->line); } } if (n) { flagword flags = bfd_get_section_flags (abfd, sec); flags |= SEC_RELOC; bfd_set_section_flags (abfd, sec, flags); bfd_set_reloc (stdoutput, sec, relocs, n); } #ifdef SET_SECTION_RELOCS SET_SECTION_RELOCS (sec, relocs, n); #endif #ifdef DEBUG3 { unsigned int i; arelent *r; asymbol *s; fprintf (stderr, "relocs for sec %s\n", sec->name); for (i = 0; i < n; i++) { r = relocs[i]; s = *r->sym_ptr_ptr; fprintf (stderr, " reloc %2d @%p off %4lx : sym %-10s addend %lx\n", i, r, (unsigned long)r->address, s->name, (unsigned long)r->addend); } } #endif } static void write_contents (bfd *abfd ATTRIBUTE_UNUSED, asection *sec, void *xxx ATTRIBUTE_UNUSED) { segment_info_type *seginfo = seg_info (sec); addressT offset = 0; fragS *f; /* Write out the frags. */ if (seginfo == NULL || !(bfd_get_section_flags (abfd, sec) & SEC_HAS_CONTENTS)) return; for (f = seginfo->frchainP->frch_root; f; f = f->fr_next) { int x; addressT fill_size; char *fill_literal; offsetT count; assert (f->fr_type == rs_fill); if (f->fr_fix) { x = bfd_set_section_contents (stdoutput, sec, f->fr_literal, (file_ptr) offset, (bfd_size_type) f->fr_fix); if (!x) as_fatal (_("can't write %s: %s"), stdoutput->filename, bfd_errmsg (bfd_get_error ())); offset += f->fr_fix; } fill_literal = f->fr_literal + f->fr_fix; fill_size = f->fr_var; count = f->fr_offset; assert (count >= 0); if (fill_size && count) { char buf[256]; if (fill_size > sizeof (buf)) { /* Do it the old way. Can this ever happen? */ while (count--) { x = bfd_set_section_contents (stdoutput, sec, fill_literal, (file_ptr) offset, (bfd_size_type) fill_size); if (!x) as_fatal (_("can't write %s: %s"), stdoutput->filename, bfd_errmsg (bfd_get_error ())); offset += fill_size; } } else { /* Build a buffer full of fill objects and output it as often as necessary. This saves on the overhead of potentially lots of bfd_set_section_contents calls. */ int n_per_buf, i; if (fill_size == 1) { n_per_buf = sizeof (buf); memset (buf, *fill_literal, n_per_buf); } else { char *bufp; n_per_buf = sizeof (buf) / fill_size; for (i = n_per_buf, bufp = buf; i; i--, bufp += fill_size) memcpy (bufp, fill_literal, fill_size); } for (; count > 0; count -= n_per_buf) { n_per_buf = n_per_buf > count ? count : n_per_buf; x = bfd_set_section_contents (stdoutput, sec, buf, (file_ptr) offset, (bfd_size_type) n_per_buf * fill_size); if (!x) as_fatal (_("cannot write to output file")); offset += n_per_buf * fill_size; } } } } } static void merge_data_into_text (void) { seg_info (text_section)->frchainP->frch_last->fr_next = seg_info (data_section)->frchainP->frch_root; seg_info (text_section)->frchainP->frch_last = seg_info (data_section)->frchainP->frch_last; seg_info (data_section)->frchainP = 0; } static void set_symtab (void) { int nsyms; asymbol **asympp; symbolS *symp; bfd_boolean result; /* Count symbols. We can't rely on a count made by the loop in write_object_file, because *_frob_file may add a new symbol or two. */ nsyms = 0; for (symp = symbol_rootP; symp; symp = symbol_next (symp)) nsyms++; if (nsyms) { int i; bfd_size_type amt = (bfd_size_type) nsyms * sizeof (asymbol *); asympp = bfd_alloc (stdoutput, amt); symp = symbol_rootP; for (i = 0; i < nsyms; i++, symp = symbol_next (symp)) { asympp[i] = symbol_get_bfdsym (symp); symbol_mark_written (symp); } } else asympp = 0; result = bfd_set_symtab (stdoutput, asympp, nsyms); assert (result); symbol_table_frozen = 1; } /* Finish the subsegments. After every sub-segment, we fake an ".align ...". This conforms to BSD4.2 brane-damage. We then fake ".fill 0" because that is the kind of frag that requires least thought. ".align" frags like to have a following frag since that makes calculating their intended length trivial. */ #ifndef SUB_SEGMENT_ALIGN #ifdef HANDLE_ALIGN /* The last subsegment gets an alignment corresponding to the alignment of the section. This allows proper nop-filling at the end of code-bearing sections. */ #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) \ (!(FRCHAIN)->frch_next ? get_recorded_alignment (SEG) : 0) #else #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0 #endif #endif void subsegs_finish (void) { struct frchain *frchainP; asection *s; for (s = stdoutput->sections; s; s = s->next) { segment_info_type *seginfo = seg_info (s); if (!seginfo) continue; for (frchainP = seginfo->frchainP; frchainP != NULL; frchainP = frchainP->frch_next) { int alignment = 0; subseg_set (s, frchainP->frch_subseg); /* This now gets called even if we had errors. In that case, any alignment is meaningless, and, moreover, will look weird if we are generating a listing. */ if (!had_errors ()) { alignment = SUB_SEGMENT_ALIGN (now_seg, frchainP); if ((bfd_get_section_flags (now_seg->owner, now_seg) & SEC_MERGE) && now_seg->entsize) { unsigned int entsize = now_seg->entsize; int entalign = 0; while ((entsize & 1) == 0) { ++entalign; entsize >>= 1; } if (entalign > alignment) alignment = entalign; } } if (subseg_text_p (now_seg)) frag_align_code (alignment, 0); else frag_align (alignment, 0, 0); /* frag_align will have left a new frag. Use this last frag for an empty ".fill". For this segment ... Create a last frag. Do not leave a "being filled in frag". */ frag_wane (frag_now); frag_now->fr_fix = 0; know (frag_now->fr_next == NULL); } } } /* Write the object file. */ void write_object_file (void) { struct relax_seg_info rsi; #ifndef WORKING_DOT_WORD fragS *fragP; /* Track along all frags. */ #endif /* Do we really want to write it? */ { int n_warns, n_errs; n_warns = had_warnings (); n_errs = had_errors (); /* The -Z flag indicates that an object file should be generated, regardless of warnings and errors. */ if (flag_always_generate_output) { if (n_warns || n_errs) as_warn (_("%d error%s, %d warning%s, generating bad object file"), n_errs, n_errs == 1 ? "" : "s", n_warns, n_warns == 1 ? "" : "s"); } else { if (n_errs) as_fatal (_("%d error%s, %d warning%s, no object file generated"), n_errs, n_errs == 1 ? "" : "s", n_warns, n_warns == 1 ? "" : "s"); } } #ifdef OBJ_VMS /* Under VMS we try to be compatible with VAX-11 "C". Thus, we call a routine to check for the definition of the procedure "_main", and if so -- fix it up so that it can be program entry point. */ vms_check_for_main (); #endif /* OBJ_VMS */ /* From now on, we don't care about sub-segments. Build one frag chain for each segment. Linked thru fr_next. */ /* Remove the sections created by gas for its own purposes. */ { int i; bfd_section_list_remove (stdoutput, reg_section); bfd_section_list_remove (stdoutput, expr_section); stdoutput->section_count -= 2; i = 0; bfd_map_over_sections (stdoutput, renumber_sections, &i); } bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0); /* We have two segments. If user gave -R flag, then we must put the data frags into the text segment. Do this before relaxing so we know to take advantage of -R and make shorter addresses. */ if (flag_readonly_data_in_text) { merge_data_into_text (); } rsi.pass = 0; while (1) { #ifndef WORKING_DOT_WORD /* We need to reset the markers in the broken word list and associated frags between calls to relax_segment (via relax_seg). Since the broken word list is global, we do it once per round, rather than locally in relax_segment for each segment. */ struct broken_word *brokp; for (brokp = broken_words; brokp != (struct broken_word *) NULL; brokp = brokp->next_broken_word) { brokp->added = 0; if (brokp->dispfrag != (fragS *) NULL && brokp->dispfrag->fr_type == rs_broken_word) brokp->dispfrag->fr_subtype = 0; } #endif rsi.changed = 0; bfd_map_over_sections (stdoutput, relax_seg, &rsi); rsi.pass++; if (!rsi.changed) break; } /* Note - Most ports will use the default value of TC_FINALIZE_SYMS_BEFORE_SIZE_SEG, which 1. This will force local symbols to be resolved, removing their frag information. Some ports however, will not have finished relaxing all of their frags and will still need the local symbol frag information. These ports can set TC_FINALIZE_SYMS_BEFORE_SIZE_SEG to 0. */ finalize_syms = TC_FINALIZE_SYMS_BEFORE_SIZE_SEG; bfd_map_over_sections (stdoutput, size_seg, (char *) 0); /* Relaxation has completed. Freeze all syms. */ finalize_syms = 1; #ifdef md_post_relax_hook md_post_relax_hook; #endif #ifndef WORKING_DOT_WORD { struct broken_word *lie; struct broken_word **prevP; prevP = &broken_words; for (lie = broken_words; lie; lie = lie->next_broken_word) if (!lie->added) { expressionS exp; subseg_change (lie->seg, lie->subseg); exp.X_op = O_subtract; exp.X_add_symbol = lie->add; exp.X_op_symbol = lie->sub; exp.X_add_number = lie->addnum; #ifdef TC_CONS_FIX_NEW TC_CONS_FIX_NEW (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp); #else fix_new_exp (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp, 0, BFD_RELOC_16); #endif *prevP = lie->next_broken_word; } else prevP = &(lie->next_broken_word); for (lie = broken_words; lie;) { struct broken_word *untruth; char *table_ptr; addressT table_addr; addressT from_addr, to_addr; int n, m; subseg_change (lie->seg, lie->subseg); fragP = lie->dispfrag; /* Find out how many broken_words go here. */ n = 0; for (untruth = lie; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word) if (untruth->added == 1) n++; table_ptr = lie->dispfrag->fr_opcode; table_addr = (lie->dispfrag->fr_address + (table_ptr - lie->dispfrag->fr_literal)); /* Create the jump around the long jumps. This is a short jump from table_ptr+0 to table_ptr+n*long_jump_size. */ from_addr = table_addr; to_addr = table_addr + md_short_jump_size + n * md_long_jump_size; md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add); table_ptr += md_short_jump_size; table_addr += md_short_jump_size; for (m = 0; lie && lie->dispfrag == fragP; m++, lie = lie->next_broken_word) { if (lie->added == 2) continue; /* Patch the jump table. */ /* This is the offset from ??? to table_ptr+0. */ to_addr = table_addr - S_GET_VALUE (lie->sub); #ifdef TC_CHECK_ADJUSTED_BROKEN_DOT_WORD TC_CHECK_ADJUSTED_BROKEN_DOT_WORD (to_addr, lie); #endif md_number_to_chars (lie->word_goes_here, to_addr, 2); for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word) { if (untruth->use_jump == lie) md_number_to_chars (untruth->word_goes_here, to_addr, 2); } /* Install the long jump. */ /* This is a long jump from table_ptr+0 to the final target. */ from_addr = table_addr; to_addr = S_GET_VALUE (lie->add) + lie->addnum; md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add); table_ptr += md_long_jump_size; table_addr += md_long_jump_size; } } } #endif /* not WORKING_DOT_WORD */ /* Resolve symbol values. This needs to be done before processing the relocations. */ if (symbol_rootP) { symbolS *symp; for (symp = symbol_rootP; symp; symp = symbol_next (symp)) resolve_symbol_value (symp); } resolve_local_symbol_values (); resolve_reloc_expr_symbols (); PROGRESS (1); #ifdef tc_frob_file_before_adjust tc_frob_file_before_adjust (); #endif #ifdef obj_frob_file_before_adjust obj_frob_file_before_adjust (); #endif bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *) 0); #ifdef tc_frob_file_before_fix tc_frob_file_before_fix (); #endif #ifdef obj_frob_file_before_fix obj_frob_file_before_fix (); #endif bfd_map_over_sections (stdoutput, fix_segment, (char *) 0); /* Set up symbol table, and write it out. */ if (symbol_rootP) { symbolS *symp; bfd_boolean skip_next_symbol = FALSE; for (symp = symbol_rootP; symp; symp = symbol_next (symp)) { int punt = 0; const char *name; if (skip_next_symbol) { /* Don't do anything besides moving the value of the symbol from the GAS value-field to the BFD value-field. */ symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp); skip_next_symbol = FALSE; continue; } if (symbol_mri_common_p (symp)) { if (S_IS_EXTERNAL (symp)) as_bad (_("%s: global symbols not supported in common sections"), S_GET_NAME (symp)); symbol_remove (symp, &symbol_rootP, &symbol_lastP); continue; } name = S_GET_NAME (symp); if (name) { const char *name2 = decode_local_label_name ((char *) S_GET_NAME (symp)); /* They only differ if `name' is a fb or dollar local label name. */ if (name2 != name && ! S_IS_DEFINED (symp)) as_bad (_("local label `%s' is not defined"), name2); } /* Do it again, because adjust_reloc_syms might introduce more symbols. They'll probably only be section symbols, but they'll still need to have the values computed. */ resolve_symbol_value (symp); /* Skip symbols which were equated to undefined or common symbols. */ if (symbol_equated_reloc_p (symp) || S_IS_WEAKREFR (symp)) { const char *name = S_GET_NAME (symp); if (S_IS_COMMON (symp) && !TC_FAKE_LABEL (name) && !S_IS_WEAKREFR (symp) && (!S_IS_EXTERNAL (symp) || S_IS_LOCAL (symp))) { expressionS *e = symbol_get_value_expression (symp); as_bad (_("Local symbol `%s' can't be equated to common symbol `%s'"), name, S_GET_NAME (e->X_add_symbol)); } if (S_GET_SEGMENT (symp) == reg_section) { /* Report error only if we know the symbol name. */ if (S_GET_NAME (symp) != reg_section->name) as_bad (_("can't make global register symbol `%s'"), name); } symbol_remove (symp, &symbol_rootP, &symbol_lastP); continue; } #ifdef obj_frob_symbol obj_frob_symbol (symp, punt); #endif #ifdef tc_frob_symbol if (! punt || symbol_used_in_reloc_p (symp)) tc_frob_symbol (symp, punt); #endif /* If we don't want to keep this symbol, splice it out of the chain now. If EMIT_SECTION_SYMBOLS is 0, we never want section symbols. Otherwise, we skip local symbols and symbols that the frob_symbol macros told us to punt, but we keep such symbols if they are used in relocs. */ if (symp == abs_section_sym || (! EMIT_SECTION_SYMBOLS && symbol_section_p (symp)) /* Note that S_IS_EXTERNAL and S_IS_LOCAL are not always opposites. Sometimes the former checks flags and the latter examines the name... */ || (!S_IS_EXTERNAL (symp) && (punt || S_IS_LOCAL (symp) || (S_IS_WEAKREFD (symp) && ! symbol_used_p (symp))) && ! symbol_used_in_reloc_p (symp))) { symbol_remove (symp, &symbol_rootP, &symbol_lastP); /* After symbol_remove, symbol_next(symp) still returns the one that came after it in the chain. So we don't need to do any extra cleanup work here. */ continue; } /* Make sure we really got a value for the symbol. */ if (! symbol_resolved_p (symp)) { as_bad (_("can't resolve value for symbol `%s'"), S_GET_NAME (symp)); symbol_mark_resolved (symp); } /* Set the value into the BFD symbol. Up til now the value has only been kept in the gas symbolS struct. */ symbol_get_bfdsym (symp)->value = S_GET_VALUE (symp); /* A warning construct is a warning symbol followed by the symbol warned about. Don't let anything object-format or target-specific muck with it; it's ready for output. */ if (symbol_get_bfdsym (symp)->flags & BSF_WARNING) skip_next_symbol = TRUE; } } PROGRESS (1); /* Now do any format-specific adjustments to the symbol table, such as adding file symbols. */ #ifdef tc_adjust_symtab tc_adjust_symtab (); #endif #ifdef obj_adjust_symtab obj_adjust_symtab (); #endif /* Stop if there is an error. */ if (had_errors ()) return; /* Now that all the sizes are known, and contents correct, we can start writing to the file. */ set_symtab (); /* If *_frob_file changes the symbol value at this point, it is responsible for moving the changed value into symp->bsym->value as well. Hopefully all symbol value changing can be done in *_frob_symbol. */ #ifdef tc_frob_file tc_frob_file (); #endif #ifdef obj_frob_file obj_frob_file (); #endif bfd_map_over_sections (stdoutput, write_relocs, (char *) 0); #ifdef tc_frob_file_after_relocs tc_frob_file_after_relocs (); #endif #ifdef obj_frob_file_after_relocs obj_frob_file_after_relocs (); #endif bfd_map_over_sections (stdoutput, write_contents, (char *) 0); } #ifdef TC_GENERIC_RELAX_TABLE /* Relax a fragment by scanning TC_GENERIC_RELAX_TABLE. */ long relax_frag (segT segment, fragS *fragP, long stretch) { const relax_typeS *this_type; const relax_typeS *start_type; relax_substateT next_state; relax_substateT this_state; offsetT growth; offsetT aim; addressT target; addressT address; symbolS *symbolP; const relax_typeS *table; target = fragP->fr_offset; address = fragP->fr_address; table = TC_GENERIC_RELAX_TABLE; this_state = fragP->fr_subtype; start_type = this_type = table + this_state; symbolP = fragP->fr_symbol; if (symbolP) { fragS *sym_frag; sym_frag = symbol_get_frag (symbolP); #ifndef DIFF_EXPR_OK know (sym_frag != NULL); #endif know (S_GET_SEGMENT (symbolP) != absolute_section || sym_frag == &zero_address_frag); target += S_GET_VALUE (symbolP); /* If frag has yet to be reached on this pass, assume it will move by STRETCH just as we did. If this is not so, it will be because some frag between grows, and that will force another pass. */ if (stretch != 0 && sym_frag->relax_marker != fragP->relax_marker && S_GET_SEGMENT (symbolP) == segment) { target += stretch; } } aim = target - address - fragP->fr_fix; #ifdef TC_PCREL_ADJUST /* Currently only the ns32k family needs this. */ aim += TC_PCREL_ADJUST (fragP); #endif #ifdef md_prepare_relax_scan /* Formerly called M68K_AIM_KLUDGE. */ md_prepare_relax_scan (fragP, address, aim, this_state, this_type); #endif if (aim < 0) { /* Look backwards. */ for (next_state = this_type->rlx_more; next_state;) if (aim >= this_type->rlx_backward) next_state = 0; else { /* Grow to next state. */ this_state = next_state; this_type = table + this_state; next_state = this_type->rlx_more; } } else { /* Look forwards. */ for (next_state = this_type->rlx_more; next_state;) if (aim <= this_type->rlx_forward) next_state = 0; else { /* Grow to next state. */ this_state = next_state; this_type = table + this_state; next_state = this_type->rlx_more; } } growth = this_type->rlx_length - start_type->rlx_length; if (growth != 0) fragP->fr_subtype = this_state; return growth; } #endif /* defined (TC_GENERIC_RELAX_TABLE) */ /* Relax_align. Advance location counter to next address that has 'alignment' lowest order bits all 0s, return size of adjustment made. */ static relax_addressT relax_align (register relax_addressT address, /* Address now. */ register int alignment /* Alignment (binary). */) { relax_addressT mask; relax_addressT new_address; mask = ~((~0) << alignment); new_address = (address + mask) & (~mask); #ifdef LINKER_RELAXING_SHRINKS_ONLY if (linkrelax) /* We must provide lots of padding, so the linker can discard it when needed. The linker will not add extra space, ever. */ new_address += (1 << alignment); #endif return (new_address - address); } /* Now we have a segment, not a crowd of sub-segments, we can make fr_address values. Relax the frags. After this, all frags in this segment have addresses that are correct within the segment. Since segments live in different file addresses, these frag addresses may not be the same as final object-file addresses. */ int relax_segment (struct frag *segment_frag_root, segT segment, int pass) { unsigned long frag_count; struct frag *fragP; relax_addressT address; int ret; /* In case md_estimate_size_before_relax() wants to make fixSs. */ subseg_change (segment, 0); /* For each frag in segment: count and store (a 1st guess of) fr_address. */ address = 0; for (frag_count = 0, fragP = segment_frag_root; fragP; fragP = fragP->fr_next, frag_count ++) { fragP->relax_marker = 0; fragP->fr_address = address; address += fragP->fr_fix; switch (fragP->fr_type) { case rs_fill: address += fragP->fr_offset * fragP->fr_var; break; case rs_align: case rs_align_code: case rs_align_test: { addressT offset = relax_align (address, (int) fragP->fr_offset); if (fragP->fr_subtype != 0 && offset > fragP->fr_subtype) offset = 0; if (offset % fragP->fr_var != 0) { as_bad_where (fragP->fr_file, fragP->fr_line, _("alignment padding (%lu bytes) not a multiple of %ld"), (unsigned long) offset, (long) fragP->fr_var); offset -= (offset % fragP->fr_var); } address += offset; } break; case rs_org: case rs_space: /* Assume .org is nugatory. It will grow with 1st relax. */ break; case rs_machine_dependent: /* If fr_symbol is an expression, this call to resolve_symbol_value sets up the correct segment, which will likely be needed in md_estimate_size_before_relax. */ if (fragP->fr_symbol) resolve_symbol_value (fragP->fr_symbol); address += md_estimate_size_before_relax (fragP, segment); break; #ifndef WORKING_DOT_WORD /* Broken words don't concern us yet. */ case rs_broken_word: break; #endif case rs_leb128: /* Initial guess is always 1; doing otherwise can result in stable solutions that are larger than the minimum. */ address += fragP->fr_offset = 1; break; case rs_cfa: address += eh_frame_estimate_size_before_relax (fragP); break; case rs_dwarf2dbg: address += dwarf2dbg_estimate_size_before_relax (fragP); break; default: BAD_CASE (fragP->fr_type); break; } } /* Do relax(). */ { unsigned long max_iterations; /* Cumulative address adjustment. */ offsetT stretch; /* Have we made any adjustment this pass? We can't just test stretch because one piece of code may have grown and another shrank. */ int stretched; /* Most horrible, but gcc may give us some exception data that is impossible to assemble, of the form .align 4 .byte 0, 0 .uleb128 end - start start: .space 128*128 - 1 .align 4 end: If the leb128 is two bytes in size, then end-start is 128*128, which requires a three byte leb128. If the leb128 is three bytes in size, then end-start is 128*128-1, which requires a two byte leb128. We work around this dilemma by inserting an extra 4 bytes of alignment just after the .align. This works because the data after the align is accessed relative to the end label. This counter is used in a tiny state machine to detect whether a leb128 followed by an align is impossible to relax. */ int rs_leb128_fudge = 0; /* We want to prevent going into an infinite loop where one frag grows depending upon the location of a symbol which is in turn moved by the growing frag. eg: foo = . .org foo+16 foo = . So we dictate that this algorithm can be at most O2. */ max_iterations = frag_count * frag_count; /* Check for overflow. */ if (max_iterations < frag_count) max_iterations = frag_count; ret = 0; do { stretch = 0; stretched = 0; for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) { offsetT growth = 0; addressT was_address; offsetT offset; symbolS *symbolP; fragP->relax_marker ^= 1; was_address = fragP->fr_address; address = fragP->fr_address += stretch; symbolP = fragP->fr_symbol; offset = fragP->fr_offset; switch (fragP->fr_type) { case rs_fill: /* .fill never relaxes. */ growth = 0; break; #ifndef WORKING_DOT_WORD /* JF: This is RMS's idea. I do *NOT* want to be blamed for it I do not want to write it. I do not want to have anything to do with it. This is not the proper way to implement this misfeature. */ case rs_broken_word: { struct broken_word *lie; struct broken_word *untruth; /* Yes this is ugly (storing the broken_word pointer in the symbol slot). Still, this whole chunk of code is ugly, and I don't feel like doing anything about it. Think of it as stubbornness in action. */ growth = 0; for (lie = (struct broken_word *) (fragP->fr_symbol); lie && lie->dispfrag == fragP; lie = lie->next_broken_word) { if (lie->added) continue; offset = (S_GET_VALUE (lie->add) + lie->addnum - S_GET_VALUE (lie->sub)); if (offset <= -32768 || offset >= 32767) { if (flag_warn_displacement) { char buf[50]; sprint_value (buf, (addressT) lie->addnum); as_warn_where (fragP->fr_file, fragP->fr_line, _(".word %s-%s+%s didn't fit"), S_GET_NAME (lie->add), S_GET_NAME (lie->sub), buf); } lie->added = 1; if (fragP->fr_subtype == 0) { fragP->fr_subtype++; growth += md_short_jump_size; } for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == lie->dispfrag; untruth = untruth->next_broken_word) if ((symbol_get_frag (untruth->add) == symbol_get_frag (lie->add)) && (S_GET_VALUE (untruth->add) == S_GET_VALUE (lie->add))) { untruth->added = 2; untruth->use_jump = lie; } growth += md_long_jump_size; } } break; } /* case rs_broken_word */ #endif case rs_align: case rs_align_code: case rs_align_test: { addressT oldoff, newoff; oldoff = relax_align (was_address + fragP->fr_fix, (int) offset); newoff = relax_align (address + fragP->fr_fix, (int) offset); if (fragP->fr_subtype != 0) { if (oldoff > fragP->fr_subtype) oldoff = 0; if (newoff > fragP->fr_subtype) newoff = 0; } growth = newoff - oldoff; /* If this align happens to follow a leb128 and we have determined that the leb128 is bouncing in size, then break the cycle by inserting an extra alignment. */ if (growth < 0 && (rs_leb128_fudge & 16) != 0 && (rs_leb128_fudge & 15) >= 2) { segment_info_type *seginfo = seg_info (segment); struct obstack *ob = &seginfo->frchainP->frch_obstack; struct frag *newf; newf = frag_alloc (ob); obstack_blank_fast (ob, fragP->fr_var); obstack_finish (ob); memcpy (newf, fragP, SIZEOF_STRUCT_FRAG); memcpy (newf->fr_literal, fragP->fr_literal + fragP->fr_fix, fragP->fr_var); newf->fr_type = rs_fill; newf->fr_fix = 0; newf->fr_offset = (((offsetT) 1 << fragP->fr_offset) / fragP->fr_var); if (newf->fr_offset * newf->fr_var != (offsetT) 1 << fragP->fr_offset) { newf->fr_offset = (offsetT) 1 << fragP->fr_offset; newf->fr_var = 1; } /* Include growth of new frag, because rs_fill frags don't normally grow. */ growth += newf->fr_offset * newf->fr_var; /* The new frag address is newoff. Adjust this for the amount we'll add when we process the new frag. */ newf->fr_address = newoff - stretch - growth; newf->relax_marker ^= 1; fragP->fr_next = newf; #ifdef DEBUG as_warn (_("padding added")); #endif } } break; case rs_org: { addressT target = offset; addressT after; if (symbolP) { /* Convert from an actual address to an octet offset into the section. Here it is assumed that the section's VMA is zero, and can omit subtracting it from the symbol's value to get the address offset. */ know (S_GET_SEGMENT (symbolP)->vma == 0); target += S_GET_VALUE (symbolP) * OCTETS_PER_BYTE; } know (fragP->fr_next); after = fragP->fr_next->fr_address; growth = target - after; if (growth < 0) { growth = 0; /* Don't error on first few frag relax passes. The symbol might be an expression involving symbol values from other sections. If those sections have not yet been processed their frags will all have zero addresses, so we will calculate incorrect values for them. The number of passes we allow before giving an error is somewhat arbitrary. It should be at least one, with larger values requiring increasingly contrived dependencies between frags to trigger a false error. */ if (pass < 2) { /* Force another pass. */ ret = 1; break; } /* Growth may be negative, but variable part of frag cannot have fewer than 0 chars. That is, we can't .org backwards. */ as_bad_where (fragP->fr_file, fragP->fr_line, _("attempt to move .org backwards")); /* We've issued an error message. Change the frag to avoid cascading errors. */ fragP->fr_type = rs_align; fragP->fr_subtype = 0; fragP->fr_offset = 0; fragP->fr_fix = after - was_address; break; } /* This is an absolute growth factor */ growth -= stretch; break; } case rs_space: growth = 0; if (symbolP) { offsetT amount; amount = S_GET_VALUE (symbolP); if (S_GET_SEGMENT (symbolP) != absolute_section || S_IS_COMMON (symbolP) || ! S_IS_DEFINED (symbolP)) { as_bad_where (fragP->fr_file, fragP->fr_line, _(".space specifies non-absolute value")); /* Prevent repeat of this error message. */ fragP->fr_symbol = 0; } else if (amount < 0) { /* Don't error on first few frag relax passes. See rs_org comment for a longer explanation. */ if (pass < 2) { ret = 1; break; } as_warn_where (fragP->fr_file, fragP->fr_line, _(".space or .fill with negative value, ignored")); fragP->fr_symbol = 0; } else growth = (was_address + fragP->fr_fix + amount - fragP->fr_next->fr_address); } break; case rs_machine_dependent: #ifdef md_relax_frag growth = md_relax_frag (segment, fragP, stretch); #else #ifdef TC_GENERIC_RELAX_TABLE /* The default way to relax a frag is to look through TC_GENERIC_RELAX_TABLE. */ growth = relax_frag (segment, fragP, stretch); #endif /* TC_GENERIC_RELAX_TABLE */ #endif break; case rs_leb128: { valueT value; offsetT size; value = resolve_symbol_value (fragP->fr_symbol); size = sizeof_leb128 (value, fragP->fr_subtype); growth = size - fragP->fr_offset; fragP->fr_offset = size; } break; case rs_cfa: growth = eh_frame_relax_frag (fragP); break; case rs_dwarf2dbg: growth = dwarf2dbg_relax_frag (fragP); break; default: BAD_CASE (fragP->fr_type); break; } if (growth) { stretch += growth; stretched = 1; if (fragP->fr_type == rs_leb128) rs_leb128_fudge += 16; else if (fragP->fr_type == rs_align && (rs_leb128_fudge & 16) != 0 && stretch == 0) rs_leb128_fudge += 16; else rs_leb128_fudge = 0; } } if (stretch == 0 && (rs_leb128_fudge & 16) == 0 && (rs_leb128_fudge & -16) != 0) rs_leb128_fudge += 1; else rs_leb128_fudge = 0; } /* Until nothing further to relax. */ while (stretched && -- max_iterations); if (stretched) as_fatal (_("Infinite loop encountered whilst attempting to compute the addresses of symbols in section %s"), segment_name (segment)); } for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) if (fragP->last_fr_address != fragP->fr_address) { fragP->last_fr_address = fragP->fr_address; ret = 1; } return ret; } void number_to_chars_bigendian (char *buf, valueT val, int n) { if (n <= 0) abort (); while (n--) { buf[n] = val & 0xff; val >>= 8; } } void number_to_chars_littleendian (char *buf, valueT val, int n) { if (n <= 0) abort (); while (n--) { *buf++ = val & 0xff; val >>= 8; } } void write_print_statistics (FILE *file) { fprintf (file, "fixups: %d\n", n_fixups); } /* For debugging. */ extern int indent_level; void print_fixup (fixS *fixp) { indent_level = 1; fprintf (stderr, "fix "); fprintf_vma (stderr, (bfd_vma)((bfd_hostptr_t) fixp)); fprintf (stderr, " %s:%d",fixp->fx_file, fixp->fx_line); if (fixp->fx_pcrel) fprintf (stderr, " pcrel"); if (fixp->fx_pcrel_adjust) fprintf (stderr, " pcrel_adjust=%d", fixp->fx_pcrel_adjust); if (fixp->fx_im_disp) { #ifdef TC_NS32K fprintf (stderr, " im_disp=%d", fixp->fx_im_disp); #else fprintf (stderr, " im_disp"); #endif } if (fixp->fx_tcbit) fprintf (stderr, " tcbit"); if (fixp->fx_done) fprintf (stderr, " done"); fprintf (stderr, "\n size=%d frag=", fixp->fx_size); fprintf_vma (stderr, (bfd_vma) ((bfd_hostptr_t) fixp->fx_frag)); fprintf (stderr, " where=%ld offset=%lx addnumber=%lx", (long) fixp->fx_where, (long) fixp->fx_offset, (long) fixp->fx_addnumber); fprintf (stderr, "\n %s (%d)", bfd_get_reloc_code_name (fixp->fx_r_type), fixp->fx_r_type); if (fixp->fx_addsy) { fprintf (stderr, "\n +<"); print_symbol_value_1 (stderr, fixp->fx_addsy); fprintf (stderr, ">"); } if (fixp->fx_subsy) { fprintf (stderr, "\n -<"); print_symbol_value_1 (stderr, fixp->fx_subsy); fprintf (stderr, ">"); } fprintf (stderr, "\n"); #ifdef TC_FIX_DATA_PRINT TC_FIX_DATA_PRINT (stderr, fixp); #endif }
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