/* write.c - emit .o file Copyright (C) 1986, 1987, 1990, 1991, 1992, 1993 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, 675 Mass Ave, Cambridge, MA 02139, 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" /* The NOP_OPCODE is for the alignment fill value. Fill it with a nop instruction so that the disassembler does not choke on it. */ #ifndef NOP_OPCODE #define NOP_OPCODE 0x00 #endif #ifndef WORKING_DOT_WORD extern CONST int md_short_jump_size; extern CONST int md_long_jump_size; #endif #ifndef BFD_ASSEMBLER #ifndef MANY_SEGMENTS struct frag *text_frag_root; struct frag *data_frag_root; struct frag *bss_frag_root; struct frag *text_last_frag; /* Last frag in segment. */ struct frag *data_last_frag; /* Last frag in segment. */ static struct frag *bss_last_frag; /* Last frag in segment. */ #endif #if ! defined (BFD_ASSEMBLER) && ! defined (BFD) static object_headers headers; static char *the_object_file; #endif long string_byte_count; char *next_object_file_charP; /* Tracks object file bytes. */ #ifndef OBJ_VMS int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE; #endif #endif /* BFD_ASSEMBLER */ #ifdef BFD_ASSEMBLER static fixS *fix_new_internal PARAMS ((fragS *, int where, int size, symbolS *add, symbolS *sub, offsetT offset, int pcrel, bfd_reloc_code_real_type r_type)); #else static fixS *fix_new_internal PARAMS ((fragS *, int where, int size, symbolS *add, symbolS *sub, offsetT offset, int pcrel, int r_type)); #endif #if defined (BFD_ASSEMBLER) || !defined (BFD) static long fixup_segment PARAMS ((fixS * fixP, segT this_segment_type)); #endif static relax_addressT relax_align PARAMS ((relax_addressT addr, int align)); /* * fix_new() * * Create a fixS in obstack 'notes'. */ static fixS * fix_new_internal (frag, where, size, add_symbol, sub_symbol, offset, pcrel, r_type) 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. */ #ifdef BFD_ASSEMBLER bfd_reloc_code_real_type r_type; /* Relocation type */ #else int r_type; /* Relocation type */ #endif { fixS *fixP; fixP = (fixS *) obstack_alloc (¬es, sizeof (fixS)); fixP->fx_frag = frag; fixP->fx_where = where; fixP->fx_size = size; fixP->fx_addsy = add_symbol; fixP->fx_subsy = sub_symbol; fixP->fx_offset = offset; fixP->fx_pcrel = pcrel; #if defined(NEED_FX_R_TYPE) || defined (BFD_ASSEMBLER) fixP->fx_r_type = r_type; #endif fixP->fx_im_disp = 0; fixP->fx_pcrel_adjust = 0; fixP->fx_bit_fixP = 0; fixP->fx_addnumber = 0; fixP->tc_fix_data = NULL; #ifdef TC_something fixP->fx_bsr = 0; #endif #ifdef TC_I960 fixP->fx_callj = 0; #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. */ { #ifdef BFD_ASSEMBLER fixS **seg_fix_rootP = & (seg_info (now_seg)->fix_root); fixS **seg_fix_tailP = & (seg_info (now_seg)->fix_tail); #endif #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 (frag, where, size, add_symbol, offset, pcrel, r_type) fragS *frag; /* Which frag? */ int where; /* Where in that frag? */ short 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. */ #ifdef BFD_ASSEMBLER bfd_reloc_code_real_type r_type; /* Relocation type */ #else int r_type; /* Relocation type */ #endif { 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 (frag, where, size, exp, pcrel, r_type) fragS *frag; /* Which frag? */ int where; /* Where in that frag? */ short int size; /* 1, 2, or 4 usually. */ expressionS *exp; /* Expression. */ int pcrel; /* TRUE if PC-relative relocation. */ #ifdef BFD_ASSEMBLER bfd_reloc_code_real_type r_type; /* Relocation type */ #else int r_type; /* Relocation type */ #endif { symbolS *add = NULL; symbolS *sub = NULL; offsetT off = 0; switch (exp->X_op) { case O_absent: 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: as_bad ("expression too complex for fixup"); } return fix_new_internal (frag, where, size, add, sub, off, pcrel, r_type); } /* Append a string onto another string, bumping the pointer along. */ void append (charPP, fromP, length) char **charPP; char *fromP; unsigned long length; { /* Don't trust memcpy() of 0 chars. */ if (length == 0) return; memcpy (*charPP, fromP, length); *charPP += length; } #ifndef BFD_ASSEMBLER int section_alignment[SEG_MAXIMUM_ORDINAL]; #endif /* * 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 (seg, align) /* 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; { #ifdef BFD_ASSEMBLER if (align > bfd_get_section_alignment (stdoutput, seg)) bfd_set_section_alignment (stdoutput, seg, align); #else if (align > section_alignment[(int) seg]) section_alignment[(int) seg] = align; #endif } #if defined (BFD_ASSEMBLER) || ! defined (BFD) static fragS * chain_frchains_together_1 (section, frchp) segT section; struct frchain *frchp; { fragS dummy, *prev_frag = &dummy; for (; frchp && frchp->frch_seg == section; frchp = frchp->frch_next) { prev_frag->fr_next = frchp->frch_root; prev_frag = frchp->frch_last; } prev_frag->fr_next = 0; return prev_frag; } #endif #ifdef BFD_ASSEMBLER static void chain_frchains_together (abfd, section, xxx) bfd *abfd; /* unused */ segT section; char *xxx; /* 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) chain_frchains_together_1 (section, info->frchainP); } #endif #if !defined (BFD) && !defined (BFD_ASSEMBLER) void remove_subsegs (head, seg, root, last) frchainS *head; int seg; fragS **root; fragS **last; { *root = head->frch_root; *last = chain_frchains_together_1 (seg, head); } #endif /* BFD */ #if defined (BFD_ASSEMBLER) || !defined (BFD) #ifdef BFD_ASSEMBLER static void cvt_frag_to_fill (sec, fragP) segT sec; fragS *fragP; #else static void cvt_frag_to_fill (headers, fragP) object_headers *headers; fragS *fragP; #endif { switch (fragP->fr_type) { case rs_align: case rs_org: #ifdef HANDLE_ALIGN HANDLE_ALIGN (fragP); #endif fragP->fr_type = rs_fill; know (fragP->fr_var == 1); know (fragP->fr_next != NULL); fragP->fr_offset = (fragP->fr_next->fr_address - fragP->fr_address - fragP->fr_fix); break; case rs_fill: break; case rs_machine_dependent: #ifdef BFD_ASSEMBLER md_convert_frag (stdoutput, sec, fragP); #else md_convert_frag (headers, fragP); #endif assert (fragP->fr_next == NULL || (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; } } #endif /* defined (BFD_ASSEMBLER) || !defined (BFD) */ #ifdef BFD_ASSEMBLER static void relax_and_size_seg (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { flagword flags; fragS *fragp; segment_info_type *seginfo; int x; valueT size, newsize; flags = bfd_get_section_flags (abfd, sec); seginfo = (segment_info_type *) bfd_get_section_userdata (abfd, sec); if (seginfo && seginfo->frchainP) { relax_segment (seginfo->frchainP->frch_root, sec); 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; if (size > 0) { flags |= SEC_HAS_CONTENTS; /* @@ This is just an approximation. */ if (seginfo->fix_root) flags |= SEC_RELOC; else flags &= ~SEC_RELOC; x = bfd_set_section_flags (abfd, sec, flags); assert (x == true); } newsize = md_section_align (sec, size); x = bfd_set_section_size (abfd, sec, newsize); assert (x == true); /* 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; fragp->fr_offset += newsize - size; } #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 (abfd, sec, stream_) bfd *abfd; asection *sec; char *stream_; { FILE *stream = (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; if (s) fprintf (stream, " %08x: %s(%s+%x)+%x\n", fixp, S_GET_NAME (s), s->bsym->section->name, S_GET_VALUE (s), fixp->fx_offset); else fprintf (stream, " %08x: type %d no sym\n", fixp, fixp->fx_r_type); fixp = fixp->fx_next; } } #else #define dump_section_relocs(ABFD,SEC,STREAM) (void)(ABFD,SEC,STREAM) #endif static void adjust_reloc_syms (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { 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_addsy) { symbolS *sym = fixp->fx_addsy; asection *symsec = sym->bsym->section; segment_info_type *symseginfo = seg_info (symsec); /* If it's one of these sections, assume the symbol is definitely going to be output. */ if (symsec == &bfd_und_section || symsec == &bfd_abs_section || bfd_is_com_section (symsec)) { fixp->fx_addsy->sy_used_in_reloc = 1; continue; } /* Since we're reducing to section symbols, don't attempt to reduce anything that's already using one. */ if (sym->bsym == symsec->symbol) { fixp->fx_addsy->sy_used_in_reloc = 1; continue; } /* Is there some other reason we can't adjust this one? (E.g., call/bal links in i960-bout symbols.) */ #ifdef obj_fix_adjustable if (! obj_fix_adjustable (fixp)) { fixp->fx_addsy->sy_used_in_reloc = 1; continue; } #endif /* 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)) { fixp->fx_addsy->sy_used_in_reloc = 1; continue; } #endif /* If the section symbol isn't going to be output, the relocs at least should still work. If not, figure out what to do when we run into that case. */ fixp->fx_offset += S_GET_VALUE (sym); if (sym->sy_frag) fixp->fx_offset += sym->sy_frag->fr_address; if (symseginfo->sym) fixp->fx_addsy = symseginfo->sym; else { fixp->fx_addsy = symbol_find (symsec->name); if (!fixp->fx_addsy) { fixp->fx_addsy = symbol_make (symsec->name); fixp->fx_addsy->bsym = symsec->symbol; } symseginfo->sym = fixp->fx_addsy; } fixp->fx_addsy->sy_used_in_reloc = 1; } dump_section_relocs (abfd, sec, stderr); } static void write_relocs (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { segment_info_type *seginfo = seg_info (sec); int i; unsigned int n; arelent **relocs; fixS *fixp; /* If seginfo is NULL, we did not create this section; don't do anything with it. */ if (seginfo == NULL) return; fixup_segment (seginfo->fix_root, sec); n = 0; for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next) n++; #ifndef RELOC_EXPANSION_POSSIBLE /* Set up reloc information as well. */ relocs = (arelent **) bfd_alloc_by_size_t (stdoutput, n * sizeof (arelent *)); memset ((char*)relocs, 0, n * sizeof (arelent*)); i = 0; for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next) { arelent *reloc; char *data; bfd_reloc_status_type s; if (fixp->fx_addsy == 0) { /* @@ Need some other flag to indicate which have already been performed... */ n--; continue; } reloc = tc_gen_reloc (sec, fixp); if (!reloc) { n--; continue; } data = fixp->fx_frag->fr_literal + fixp->fx_where; /* @@ Assumes max size of reloc is 4. */ if (fixp->fx_where + 4 > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset) abort (); /* Pass bogus address so that when bfd_perform_relocation adds `address' back in, it'll come up with `data', which is where we want it to operate. */ if (reloc->howto->partial_inplace == false && reloc->howto->pcrel_offset == true && reloc->howto->pc_relative == true) { /* bfd_perform_relocation screws this up */ reloc->addend += reloc->address; } s = bfd_perform_relocation (stdoutput, reloc, data - reloc->address, sec, stdoutput); switch (s) { case bfd_reloc_ok: break; default: as_fatal ("bad return from bfd_perform_relocation"); } relocs[i++] = reloc; } #else n = n * MAX_RELOC_EXPANSION; /* Set up reloc information as well. */ relocs = (arelent **) bfd_alloc_by_size_t (stdoutput, n * sizeof (arelent *)); i = 0; for (fixp = seginfo->fix_root; fixp != (fixS *) NULL; fixp = fixp->fx_next) { arelent **reloc; char *data; bfd_reloc_status_type s; int j; if (fixp->fx_addsy == 0) { /* @@ Need some other flag to indicate which have already been performed... */ n--; continue; } reloc = tc_gen_reloc (sec, fixp); for (j = 0; reloc[j]; j++) { relocs[i++] = reloc[j]; assert(i <= n); } data = fixp->fx_frag->fr_literal + fixp->fx_where; if (fixp->fx_where + 4 > fixp->fx_frag->fr_fix + fixp->fx_frag->fr_offset) abort (); for (j = 0; reloc[j]; j++) { s = bfd_perform_relocation (stdoutput, reloc[j], data - reloc[j]->address, sec, stdoutput); switch (s) { case bfd_reloc_ok: break; default: as_fatal ("bad return from bfd_perform_relocation"); } } } n = i; #endif if (n) bfd_set_reloc (stdoutput, sec, relocs, n); else bfd_set_section_flags (abfd, sec, (bfd_get_section_flags (abfd, sec) & (flagword) ~SEC_RELOC)); #ifdef DEBUG2 { 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 @%08x off %4x : sym %-10s addend %x\n", i, r, r->address, s->name, r->addend); } } #endif } static void write_contents (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { segment_info_type *seginfo = seg_info (sec); unsigned long 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; unsigned long fill_size; char *fill_literal; long 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); assert (x == true); 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) while (count--) { x = bfd_set_section_contents (stdoutput, sec, fill_literal, (file_ptr) offset, (bfd_size_type) fill_size); assert (x == true); offset += fill_size; } } } #endif #if defined(BFD_ASSEMBLER) || (!defined (BFD) && !defined(OBJ_AOUT)) static void merge_data_into_text () { #if defined(BFD_ASSEMBLER) || defined(MANY_SEGMENTS) 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; #else fixS *tmp; text_last_frag->fr_next = data_frag_root; text_last_frag = data_last_frag; data_last_frag = NULL; data_frag_root = NULL; if (text_fix_root) { for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next);; tmp->fx_next = data_fix_root; text_fix_tail = data_fix_tail; } else text_fix_root = data_fix_root; data_fix_root = NULL; #endif } #endif /* BFD_ASSEMBLER || (! BFD && ! OBJ_AOUT) */ #if !defined (BFD_ASSEMBLER) && !defined (BFD) static void relax_and_size_all_segments () { fragS *fragP; relax_segment (text_frag_root, SEG_TEXT); relax_segment (data_frag_root, SEG_DATA); relax_segment (bss_frag_root, SEG_BSS); /* * Now the addresses of frags are correct within the segment. */ know (text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0); H_SET_TEXT_SIZE (&headers, text_last_frag->fr_address); text_last_frag->fr_address = H_GET_TEXT_SIZE (&headers); /* * Join the 2 segments into 1 huge segment. * To do this, re-compute every rn_address in the SEG_DATA frags. * Then join the data frags after the text frags. * * Determine a_data [length of data segment]. */ if (data_frag_root) { register relax_addressT slide; know ((text_last_frag->fr_type == rs_fill) && (text_last_frag->fr_offset == 0)); H_SET_DATA_SIZE (&headers, data_last_frag->fr_address); data_last_frag->fr_address = H_GET_DATA_SIZE (&headers); slide = H_GET_TEXT_SIZE (&headers); /* & in file of the data segment. */ #ifdef OBJ_BOUT #define RoundUp(N,S) (((N)+(S)-1)&-(S)) /* For b.out: If the data section has a strict alignment requirement, its load address in the .o file will be rounded up from the size of the text section. These two values are *not* the same! Similarly for the bss section.... */ slide = RoundUp (slide, 1 << section_alignment[SEG_DATA]); #endif for (fragP = data_frag_root; fragP; fragP = fragP->fr_next) { fragP->fr_address += slide; } /* for each data frag */ know (text_last_frag != 0); text_last_frag->fr_next = data_frag_root; } else { H_SET_DATA_SIZE (&headers, 0); } #ifdef OBJ_BOUT /* See above comments on b.out data section address. */ { long bss_vma; if (data_last_frag == 0) bss_vma = H_GET_TEXT_SIZE (&headers); else bss_vma = data_last_frag->fr_address; bss_vma = RoundUp (bss_vma, 1 << section_alignment[SEG_BSS]); bss_address_frag.fr_address = bss_vma; } #else /* ! OBJ_BOUT */ bss_address_frag.fr_address = (H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers)); #endif /* ! OBJ_BOUT */ /* Slide all the frags */ if (bss_frag_root) { relax_addressT slide = bss_address_frag.fr_address; for (fragP = bss_frag_root; fragP; fragP = fragP->fr_next) { fragP->fr_address += slide; } /* for each bss frag */ } if (bss_last_frag) H_SET_BSS_SIZE (&headers, bss_last_frag->fr_address - bss_frag_root->fr_address); else H_SET_BSS_SIZE (&headers, 0); } #endif /* ! BFD_ASSEMBLER && ! BFD */ #if defined (BFD_ASSEMBLER) || !defined (BFD) void write_object_file () { register struct frchain *frchainP; /* Track along all frchains. */ #if ! defined (BFD_ASSEMBLER) || ! defined (WORKING_DOT_WORD) register fragS *fragP; /* Track along all frags. */ #endif #if !defined (BFD_ASSEMBLER) && !defined (OBJ_VMS) long object_file_size; #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 (flagseen['Z']) { if (n_warns || n_errs) as_warn ("%d error%s, %d warning%s, generating bad object file.\n", 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", 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 /* VMS */ /* 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. @@ Is this really necessary?? */ #ifndef SUB_SEGMENT_ALIGN #ifdef BFD_ASSEMBLER #define SUB_SEGMENT_ALIGN(SEG) (0) #else #define SUB_SEGMENT_ALIGN(SEG) (2) #endif #endif for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next) { subseg_set (frchainP->frch_seg, frchainP->frch_subseg); frag_align (SUB_SEGMENT_ALIGN (now_seg), NOP_OPCODE); /* 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); } /* From now on, we don't care about sub-segments. Build one frag chain for each segment. Linked thru fr_next. */ #ifdef BFD_ASSEMBLER /* Remove the sections created by gas for its own purposes. */ { asection **seclist, *sec; seclist = &stdoutput->sections; while (seclist && *seclist) { sec = *seclist; while (sec == reg_section || sec == expr_section) { sec = sec->next; *seclist = sec; stdoutput->section_count--; if (!sec) break; } if (*seclist) seclist = &(*seclist)->next; } } bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0); #else remove_subsegs (frchain_root, SEG_TEXT, &text_frag_root, &text_last_frag); remove_subsegs (data0_frchainP, SEG_DATA, &data_frag_root, &data_last_frag); remove_subsegs (bss0_frchainP, SEG_BSS, &bss_frag_root, &bss_last_frag); #endif /* 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 !defined (OBJ_AOUT) || defined (BFD_ASSEMBLER) if (flagseen['R']) { merge_data_into_text (); } #endif #ifdef BFD_ASSEMBLER bfd_map_over_sections (stdoutput, relax_and_size_seg, (char *) 0); #else relax_and_size_all_segments (); #endif /* BFD_ASSEMBLER */ #ifndef BFD_ASSEMBLER /* * * Crawl the symbol chain. * * For each symbol whose value depends on a frag, take the address of * that frag and subsume it into the value of the symbol. * After this, there is just one way to lookup a symbol value. * Values are left in their final state for object file emission. * We adjust the values of 'L' local symbols, even if we do * not intend to emit them to the object file, because their values * are needed for fix-ups. * * Unless we saw a -L flag, remove all symbols that begin with 'L' * from the symbol chain. (They are still pointed to by the fixes.) * * Count the remaining symbols. * Assign a symbol number to each symbol. * Count the number of string-table chars we will emit. * Put this info into the headers as appropriate. * */ know (zero_address_frag.fr_address == 0); string_byte_count = sizeof (string_byte_count); obj_crawl_symbol_chain (&headers); if (string_byte_count == sizeof (string_byte_count)) string_byte_count = 0; H_SET_STRING_SIZE (&headers, string_byte_count); /* * Addresses of frags now reflect addresses we use in the object file. * Symbol values are correct. * Scan the frags, converting any ".org"s and ".align"s to ".fill"s. * Also converting any machine-dependent frags using md_convert_frag(); */ subseg_change (SEG_TEXT, 0); for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) { cvt_frag_to_fill (&headers, fragP); /* Some assert macros don't work with # directives mixed in. */ #ifndef NDEBUG if (!(fragP->fr_next == NULL #ifdef OBJ_BOUT || fragP->fr_next == data_frag_root #endif || ((fragP->fr_next->fr_address - fragP->fr_address) == (fragP->fr_fix + fragP->fr_offset * fragP->fr_var)))) abort (); #endif } #endif /* ! BFD_ASSEMBLER */ #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; exp.X_op = O_subtract; exp.X_add_symbol = lie->add; exp.X_op_symbol = lie->sub; exp.X_add_number = lie->addnum; #ifdef BFD_ASSEMBLER fix_new_exp (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp, 0, BFD_RELOC_NONE); #else #if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE) fix_new_exp (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp, 0, NO_RELOC); #else #ifdef TC_NS32K fix_new_ns32k_exp (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp, 0, 0, 2, 0, 0); #else fix_new_exp (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, &exp, 0, 0); #endif /* TC_NS32K */ #endif /* TC_SPARC|TC_A29K|NEED_FX_R_TYPE */ #endif /* BFD_ASSEMBLER */ *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; 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); 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 */ #ifndef BFD_ASSEMBLER #ifndef OBJ_VMS { /* not vms */ /* * Scan every FixS performing fixups. We had to wait until now to do * this because md_convert_frag() may have made some fixSs. */ int trsize, drsize; subseg_change (SEG_TEXT, 0); trsize = md_reloc_size * fixup_segment (text_fix_root, SEG_TEXT); subseg_change (SEG_DATA, 0); drsize = md_reloc_size * fixup_segment (data_fix_root, SEG_DATA); H_SET_RELOCATION_SIZE (&headers, trsize, drsize); /* FIXME move this stuff into the pre-write-hook */ H_SET_MAGIC_NUMBER (&headers, magic_number_for_object_file); H_SET_ENTRY_POINT (&headers, 0); obj_pre_write_hook (&headers); /* extra coff stuff */ object_file_size = H_GET_FILE_SIZE (&headers); next_object_file_charP = the_object_file = xmalloc (object_file_size); output_file_create (out_file_name); obj_header_append (&next_object_file_charP, &headers); know ((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE (&headers)); /* * Emit code. */ for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) { register long count; register char *fill_literal; register long fill_size; know (fragP->fr_type == rs_fill); append (&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix); fill_literal = fragP->fr_literal + fragP->fr_fix; fill_size = fragP->fr_var; know (fragP->fr_offset >= 0); for (count = fragP->fr_offset; count; count--) { append (&next_object_file_charP, fill_literal, (unsigned long) fill_size); } /* for each */ } /* for each code frag. */ know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers))); /* * Emit relocations. */ obj_emit_relocations (&next_object_file_charP, text_fix_root, (relax_addressT) 0); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers))); #ifdef TC_I960 /* Make addresses in data relocation directives relative to beginning of * first data fragment, not end of last text fragment: alignment of the * start of the data segment may place a gap between the segments. */ obj_emit_relocations (&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address); #else /* TC_I960 */ obj_emit_relocations (&next_object_file_charP, data_fix_root, text_last_frag->fr_address); #endif /* TC_I960 */ know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers))); /* * Emit line number entries. */ OBJ_EMIT_LINENO (&next_object_file_charP, lineno_rootP, the_object_file); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers))); /* * Emit symbols. */ obj_emit_symbols (&next_object_file_charP, symbol_rootP); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers) + H_GET_SYMBOL_TABLE_SIZE (&headers))); /* * Emit strings. */ if (string_byte_count > 0) { obj_emit_strings (&next_object_file_charP); } /* only if we have a string table */ #ifdef BFD_HEADERS bfd_seek (stdoutput, 0, 0); bfd_write (the_object_file, 1, object_file_size, stdoutput); #else /* Write the data to the file */ output_file_append (the_object_file, object_file_size, out_file_name); #endif output_file_close (out_file_name); } /* non vms output */ #else /* VMS */ /* * Now do the VMS-dependent part of writing the object file */ VMS_write_object_file (H_GET_TEXT_SIZE (&headers), H_GET_DATA_SIZE (&headers), H_GET_BSS_SIZE (&headers), text_frag_root, data_frag_root); #endif /* VMS */ #else /* BFD_ASSEMBLER */ #ifdef obj_check_file_symbols obj_check_file_symbols (); #endif bfd_map_over_sections (stdoutput, adjust_reloc_syms, (char *)0); /* Set up symbol table, and write it out. */ if (symbol_rootP) { unsigned int i = 0; unsigned int n; symbolS *symp; for (symp = symbol_rootP; symp; symp = symbol_next (symp)) { if (! symp->sy_resolved) { if (symp->sy_value.X_op == O_constant) { /* This is the normal case; skip the call. */ S_SET_VALUE (symp, (S_GET_VALUE (symp) + symp->sy_frag->fr_address)); symp->sy_resolved = 1; } else resolve_symbol_value (symp); } /* So far, common symbols have been treated like undefined symbols. Put them in the common section now. */ if (S_IS_DEFINED (symp) == 0 && S_GET_VALUE (symp) != 0) S_SET_SEGMENT (symp, &bfd_com_section); #if 0 printf ("symbol `%s'\n\t@%x: value=%d flags=%x seg=%s\n", S_GET_NAME (symp), symp, S_GET_VALUE (symp), symp->bsym->flags, segment_name (symp->bsym->section)); #endif if (! symp->sy_used_in_reloc) { #ifdef obj_frob_symbol { int punt = 0; obj_frob_symbol (symp, punt); if (punt) goto punt_it; } #endif #ifdef tc_frob_symbol { int punt = 0; tc_frob_symbol (symp, punt); if (punt) goto punt_it; } #endif } /* If we don't want to keep this symbol, splice it out of the chain now. */ if (! symp->sy_used_in_reloc && S_IS_LOCAL (symp)) { symbolS *prev, *next; #if defined (obj_frob_symbol) || defined (tc_frob_symbol) punt_it: #endif prev = symbol_previous (symp); next = symbol_next (symp); #ifdef DEBUG_SYMS verify_symbol_chain_2 (symp); #endif if (prev) { symbol_next (prev) = next; symp = prev; } else if (symp == symbol_rootP) symbol_rootP = next; else abort (); if (next) symbol_previous (next) = prev; else symbol_lastP = prev; #ifdef DEBUG_SYMS if (prev) verify_symbol_chain_2 (prev); else if (next) verify_symbol_chain_2 (next); #endif continue; } /* Make sure we really got a value for the symbol. */ if (! symp->sy_resolved) { as_bad ("can't resolve value for symbol \"%s\"", S_GET_NAME (symp)); symp->sy_resolved = 1; } /* Set the value into the BFD symbol. Up til now the value has only been kept in the gas symbolS struct. */ symp->bsym->value = S_GET_VALUE (symp); i++; } n = i; if (n) { asymbol **asympp; boolean result; extern PTR bfd_alloc PARAMS ((bfd *, size_t)); asympp = (asymbol **) bfd_alloc (stdoutput, n * sizeof (asymbol *)); symp = symbol_rootP; for (i = 0; i < n; i++, symp = symbol_next (symp)) { asympp[i] = symp->bsym; symp->written = 1; } result = bfd_set_symtab (stdoutput, asympp, n); assert (result == true); } } #ifdef obj_frob_file /* If obj_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 {obj,tc}_frob_symbol. */ obj_frob_file (); #endif /* Now that all the sizes are known, and contents correct, we can start writing the file. */ bfd_map_over_sections (stdoutput, write_relocs, (char *) 0); bfd_map_over_sections (stdoutput, write_contents, (char *) 0); output_file_close (out_file_name); #endif /* BFD_ASSEMBLER */ } #endif /* ! BFD */ /* * relax_segment() * * 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. */ /* Subroutines of relax_segment. */ static int is_dnrange (f1, f2) struct frag *f1; struct frag *f2; { for (; f1; f1 = f1->fr_next) if (f1->fr_next == f2) return 1; return 0; } /* 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 (address, alignment) 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); 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); return (new_address - address); } void relax_segment (segment_frag_root, segment) struct frag *segment_frag_root; segT segment; { register struct frag *fragP; register relax_addressT address; #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know (segment == SEG_DATA || segment == SEG_TEXT || segment == SEG_BSS); #endif /* 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 (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) { 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: address += relax_align (address, (int) fragP->fr_offset); break; case rs_org: /* Assume .org is nugatory. It will grow with 1st relax. */ break; case rs_machine_dependent: 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 default: BAD_CASE (fragP->fr_type); break; } /* switch(fr_type) */ } /* for each frag in the segment */ /* Do relax(). */ { long stretch; /* May be any size, 0 or negative. */ /* Cumulative number of addresses we have */ /* relaxed this pass. */ /* We may have relaxed more than one address. */ long stretched; /* Have we stretched on this pass? */ /* This is 'cuz stretch may be zero, when, in fact some piece of code grew, and another shrank. If a branch instruction doesn't fit anymore, we could be scrod. */ do { stretch = stretched = 0; for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) { long growth = 0; unsigned long was_address; long offset; symbolS *symbolP; long target; long after; 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 = (lie->add->sy_frag->fr_address + S_GET_VALUE (lie->add) + lie->addnum - (lie->sub->sy_frag->fr_address + S_GET_VALUE (lie->sub))); if (offset <= -32768 || offset >= 32767) { if (flagseen['K']) { char buf[50]; sprint_value (buf, (addressT) lie->addnum); as_warn (".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 ((untruth->add->sy_frag == lie->add->sy_frag) && 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: growth = (relax_align ((relax_addressT) (address + fragP->fr_fix), (int) offset) - relax_align ((relax_addressT) (was_address + fragP->fr_fix), (int) offset)); break; case rs_org: target = offset; if (symbolP) { #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT (symbolP) == SEG_DATA) || (S_GET_SEGMENT (symbolP) == SEG_TEXT) || S_GET_SEGMENT (symbolP) == SEG_BSS); know (symbolP->sy_frag); know (!(S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (symbolP->sy_frag == &zero_address_frag)); #endif target += S_GET_VALUE (symbolP) + symbolP->sy_frag->fr_address; } /* if we have a symbol */ know (fragP->fr_next); after = fragP->fr_next->fr_address; growth = ((target - after) > 0) ? (target - after) : 0; /* Growth may be negative, but variable part of frag cannot have fewer than 0 chars. That is, we can't .org backwards. */ growth -= stretch; /* This is an absolute growth factor */ break; case rs_machine_dependent: { const relax_typeS *this_type; const relax_typeS *start_type; relax_substateT next_state; relax_substateT this_state; long aim; this_state = fragP->fr_subtype; start_type = this_type = md_relax_table + this_state; target = offset; if (symbolP) { #ifndef DIFF_EXPR_OK #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT (symbolP) == SEG_DATA) || (S_GET_SEGMENT (symbolP) == SEG_BSS) || (S_GET_SEGMENT (symbolP) == SEG_TEXT)); #endif know (symbolP->sy_frag); #endif know (!(S_GET_SEGMENT (symbolP) == absolute_section) || symbolP->sy_frag == &zero_address_frag); target += S_GET_VALUE (symbolP) + symbolP->sy_frag->fr_address; /* 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. Beware zero-length frags. There should be a faster way to do this. */ if (symbolP->sy_frag->fr_address >= was_address && is_dnrange (fragP, symbolP->sy_frag)) { target += stretch; } } aim = target - address - fragP->fr_fix; /* The displacement is affected by the instruction size for the 32k architecture. I think we ought to be able to add fragP->fr_pcrel_adjust in all cases (it should be zero if not used), but just in case it breaks something else we'll put this inside #ifdef NS32K ... #endif */ #ifndef TC_NS32K if (fragP->fr_pcrel_adjust) abort (); #endif aim += fragP->fr_pcrel_adjust; 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 = md_relax_table + this_state; next_state = this_type->rlx_more; } } else { #ifdef M68K_AIM_KLUDGE M68K_AIM_KLUDGE (aim, this_state, this_type); #endif /* 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 = md_relax_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; } break; default: BAD_CASE (fragP->fr_type); break; } if (growth) { stretch += growth; stretched++; } } /* For each frag in the segment. */ } while (stretched); /* Until nothing further to relax. */ } /* do_relax */ /* * We now have valid fr_address'es for each frag. */ /* * All fr_address's are correct, relative to their own segment. * We have made all the fixS we will ever make. */ } /* relax_segment() */ #if defined (BFD_ASSEMBLER) || !defined (BFD) /* 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 (fixP, this_segment_type) register fixS *fixP; segT this_segment_type; /* N_TYPE bits for segment. */ { register long seg_reloc_count; register symbolS *add_symbolP; register symbolS *sub_symbolP; valueT add_number; register int size; register char *place; register long where; register char pcrel; register fragS *fragP; register segT add_symbol_segment = absolute_section; seg_reloc_count = 0; /* 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 (the only machine for which we've got a relaxing linker right now), we might be able to turn callx/callj into bal in cases where we know the maximum displacement. */ if (linkrelax) for (; fixP; fixP = fixP->fx_next) seg_reloc_count++; else for (; fixP; fixP = fixP->fx_next) { fragP = fixP->fx_frag; know (fragP); where = fixP->fx_where; place = fragP->fr_literal + where; size = fixP->fx_size; add_symbolP = fixP->fx_addsy; #ifdef TC_I960 if (fixP->fx_callj && TC_S_IS_CALLNAME (add_symbolP)) { /* Relocation should be done via the associated 'bal' entry point symbol. */ if (!TC_S_IS_BALNAME (tc_get_bal_of_call (add_symbolP))) { as_bad ("No 'bal' entry point for leafproc %s", S_GET_NAME (add_symbolP)); continue; } fixP->fx_addsy = add_symbolP = tc_get_bal_of_call (add_symbolP); } #endif sub_symbolP = fixP->fx_subsy; add_number = fixP->fx_offset; pcrel = fixP->fx_pcrel; if (add_symbolP) add_symbol_segment = S_GET_SEGMENT (add_symbolP); if (sub_symbolP) { if (!add_symbolP) { /* Its just -sym */ /* @@ Should try converting to pcrel ref to fixed addr. */ if (S_GET_SEGMENT (sub_symbolP) != absolute_section) as_bad ("Negative of non-absolute symbol %s", S_GET_NAME (sub_symbolP)); add_number -= S_GET_VALUE (sub_symbolP); } else if ((S_GET_SEGMENT (sub_symbolP) == add_symbol_segment) && (SEG_NORMAL (add_symbol_segment) || (add_symbol_segment == absolute_section))) { /* Difference of 2 symbols from same segment. Can't make difference of 2 undefineds: 'value' means something different for N_UNDF. */ #ifdef TC_I960 /* Makes no sense to use the difference of 2 arbitrary symbols as the target of a call instruction. */ if (fixP->fx_callj) { as_bad ("callj to difference of 2 symbols"); } #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP) - S_GET_VALUE (sub_symbolP); add_symbolP = NULL; fixP->fx_addsy = NULL; } #if !defined(SEG_DIFF_ALLOWED) && !defined (GLOBAL_DIFF_ALLOWED) else { /* Different segments in subtraction. */ know (!(S_IS_EXTERNAL (sub_symbolP) && (S_GET_SEGMENT (sub_symbolP) == absolute_section))); if ((S_GET_SEGMENT (sub_symbolP) == absolute_section)) { add_number -= S_GET_VALUE (sub_symbolP); } #ifdef DIFF_EXPR_OK else if (!pcrel && S_GET_SEGMENT (sub_symbolP) == this_segment_type) { /* Make it pc-relative. */ add_number += (md_pcrel_from (fixP) - S_GET_VALUE (sub_symbolP)); pcrel = 1; fixP->fx_pcrel = 1; sub_symbolP = 0; fixP->fx_subsy = 0; } #endif else { char buf[50]; sprint_value (buf, fragP->fr_address + where); as_bad ("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %s.", segment_name (S_GET_SEGMENT (sub_symbolP)), S_GET_NAME (sub_symbolP), buf); } } #else else { seg_reloc_count++; fixP->fx_addnumber = add_number; /* Remember value for emit_reloc */ continue; } /* if absolute */ #endif } if (add_symbolP) { if (add_symbol_segment == this_segment_type && pcrel) { /* * 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. */ #ifdef TC_I960 /* reloc_callj() may replace a 'call' with a 'calls' or a 'bal', in which cases it modifies *fixP as appropriate. In the case of a 'calls', no further work is required, and *fixP has been set up to make the rest of the code below a no-op. */ reloc_callj (fixP); #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP); add_number -= md_pcrel_from (fixP); pcrel = 0; /* Lie. Don't want further pcrel processing. */ #ifndef TC_HPPA fixP->fx_addsy = NULL; /* No relocations please. */ #endif } else { if (add_symbol_segment == absolute_section) { #ifdef TC_I960 /* See comment about reloc_callj() above. */ reloc_callj (fixP); #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP); fixP->fx_addsy = NULL; add_symbolP = NULL; } else if (add_symbol_segment == undefined_section #ifdef BFD_ASSEMBLER || bfd_is_com_section (add_symbol_segment) #endif ) { #ifdef TC_I960 if ((int) fixP->fx_bit_fixP == 13) { /* This is a COBR instruction. They have only a * 13-bit displacement and are only to be used * for local branches: flag as error, don't generate * relocation. */ as_bad ("can't use COBR format with external label"); fixP->fx_addsy = NULL; /* No relocations please. */ continue; } /* COBR */ #endif /* TC_I960 */ #ifdef OBJ_COFF #ifdef TE_I386AIX if (S_IS_COMMON (add_symbolP)) add_number += S_GET_VALUE (add_symbolP); #endif /* TE_I386AIX */ #endif /* OBJ_COFF */ ++seg_reloc_count; } else { seg_reloc_count++; add_number += S_GET_VALUE (add_symbolP); } } } if (pcrel) { add_number -= md_pcrel_from (fixP); if (add_symbolP == 0) { fixP->fx_addsy = &abs_symbol; ++seg_reloc_count; } /* if there's an add_symbol */ } /* if pcrel */ if (!fixP->fx_bit_fixP) { valueT mask = 0; /* set all bits to one */ mask--; /* Technically speaking, combining these produces an undefined result if size is sizeof (valueT), though I think these two half-way operations should both be defined. */ mask <<= size * 4; mask <<= size * 4; if ((add_number & mask) != 0 && (add_number & mask) != mask) { char buf[50], buf2[50]; sprint_value (buf, fragP->fr_address + 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, 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 (!flagseen['J'] && 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, (unsigned long) (fragP->fr_address + where)); #endif } /* not a bit fix */ #ifdef BFD_ASSEMBLER md_apply_fix (fixP, &add_number); #else md_apply_fix (fixP, add_number); #endif } /* For each fixS in this segment. */ #if defined (OBJ_COFF) && defined (TC_I960) { fixS *topP = fixP; /* two relocs per callj under coff. */ for (fixP = topP; fixP; fixP = fixP->fx_next) if (fixP->fx_callj && fixP->fx_addsy != 0) ++seg_reloc_count; } #endif /* OBJ_COFF && TC_I960 */ return (seg_reloc_count); } #endif /* defined (BFD_ASSEMBLER) || !defined (BFD) */ /* end of write.c */