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Diffstat (limited to 'gas/write.c')
| -rw-r--r-- | gas/write.c | 1162 |
1 files changed, 1162 insertions, 0 deletions
diff --git a/gas/write.c b/gas/write.c new file mode 100644 index 0000000..a0b36c3 --- /dev/null +++ b/gas/write.c @@ -0,0 +1,1162 @@ +/* write.c - emit .o file + Copyright (C) 1986, 1987, 1990, 1991 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 1, 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. */ + +/* static const char rcsid[] = "$Id$"; */ + +/* + + This thing should be set up to do byteordering correctly. But... + + In order to cross-assemble the target machine must have an a.out header + similar to the one in a.out.h on THIS machine. Byteorder doesn't matter, + we take special care of it, but the numbers must be the same SIZE (# of + bytes) and in the same PLACE. If this is not true, you will have some + trouble. + */ + +#include "as.h" + +#include "subsegs.h" +#include "obstack.h" +#include "output-file.h" + +/* Hook for machine dependent relocation information output routine. + If not defined, the variable is allocated in BSS (Fortran common model). + If some other module defines it, we will see their value. */ + +void (*md_emit_relocations)(); + +/* + * In: length of relocation (or of address) in chars: 1, 2 or 4. + * Out: GNU LD relocation length code: 0, 1, or 2. + */ + +unsigned char +nbytes_r_length [] = { + 42, 0, 1, 42, 2 + }; + + +static struct frag *text_frag_root; +static struct frag *data_frag_root; + +static struct frag *text_last_frag; /* Last frag in segment. */ +static struct frag *data_last_frag; /* Last frag in segment. */ + +static object_headers headers; + +long string_byte_count; + +static char *the_object_file; + +char *next_object_file_charP; /* Tracks object file bytes. */ + +int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE; + +/* static long length; JF unused */ /* String length, including trailing '\0'. */ + + +#ifdef __STDC__ + +static int is_dnrange(struct frag *f1, struct frag *f2); +static long fixup_segment(fixS *fixP, segT this_segment_type); +static relax_addressT relax_align(relax_addressT address, long alignment); +static void relax_segment(struct frag *segment_frag_root, segT segment_type); + +#else + +static int is_dnrange(); +static long fixup_segment(); +static relax_addressT relax_align(); +static void relax_segment(); + +#endif /* __STDC__ */ + +/* + * fix_new() + * + * Create a fixS in obstack 'notes'. + */ +fixS *fix_new(frag, where, size, add_symbol, sub_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. */ +symbolS *sub_symbol; /* X_subtract_symbol. */ +long offset; /* X_add_number. */ +int pcrel; /* TRUE if PC-relative relocation. */ +enum reloc_type r_type; /* Relocation type */ +{ + register 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; + fixP->fx_r_type = r_type; + fixP->fx_next = NULL; + + /* JF these 'cuz of the NS32K stuff */ + fixP->fx_im_disp = 0; + fixP->fx_pcrel_adjust = 0; + fixP->fx_bsr = 0; + fixP->fx_bit_fixP = 0; + + if (*seg_fix_tailP) + (*seg_fix_tailP)->fx_next = fixP; + else + *seg_fix_rootP = fixP; + *seg_fix_tailP = fixP; + fixP->fx_callj = 0; + return fixP; +} + +void write_object_file() { + register struct frchain * frchainP; /* Track along all frchains. */ + register fragS * fragP; /* Track along all frags. */ + register struct frchain * next_frchainP; + register fragS * * prev_fragPP; +/* register char * name; */ +/* symbolS *symbolP; */ +/* register symbolS ** symbolPP; */ + /* register fixS * fixP; JF unused */ + unsigned int data_siz; + +#ifdef DONTDEF + void gdb_emit(); + void gdb_end(); +#endif + long object_file_size; + +#ifdef 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. + */ +#define SUB_SEGMENT_ALIGN (2) + for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next) { +#ifdef VMS + /* + * Under VAX/VMS, the linker (and PSECT specifications) + * take care of correctly aligning the segments. + * Doing the alignment here (on initialized data) can + * mess up the calculation of global data PSECT sizes. + */ +#undef SUB_SEGMENT_ALIGN +#define SUB_SEGMENT_ALIGN ((frchainP->frch_seg != SEG_DATA) ? 2 : 0) +#endif /* VMS */ + subseg_new (frchainP->frch_seg, frchainP->frch_subseg); + frag_align (SUB_SEGMENT_ALIGN, 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 ); + /* know( frags . obstack_c_base == frags . obstack_c_next_free ); */ + /* Above shows we haven't left a half-completed object on obstack. */ + } /* walk the frag chain */ + + /* + * From now on, we don't care about sub-segments. + * Build one frag chain for each segment. Linked thru fr_next. + * We know that there is at least 1 text frchain & at least 1 data frchain. + */ + prev_fragPP = &text_frag_root; + for (frchainP = frchain_root; frchainP; frchainP = next_frchainP) { + know( frchainP->frch_root ); + * prev_fragPP = frchainP->frch_root; + prev_fragPP = & frchainP->frch_last->fr_next; + + if (((next_frchainP = frchainP->frch_next) == NULL) + || next_frchainP == data0_frchainP) { + prev_fragPP = & data_frag_root; + if (next_frchainP) { + text_last_frag = frchainP->frch_last; + } else { + data_last_frag = frchainP->frch_last; + } + } + } /* walk the frag chain */ + + /* + * 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 (flagseen[ 'R' ]) { + 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; + } else + text_fix_root=data_fix_root; + data_fix_root=NULL; + } + + relax_segment(text_frag_root, SEG_TEXT); + relax_segment(data_frag_root, SEG_DATA); + /* + * 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. */ + + for (fragP = data_frag_root; + fragP; + fragP = fragP->fr_next) + { + fragP->fr_address += slide; + } + know( text_last_frag ); + text_last_frag->fr_next = data_frag_root; + } else { + H_SET_DATA_SIZE(&headers,0); + data_siz = 0; + } + + bss_address_frag.fr_address = H_GET_TEXT_SIZE(&headers) + + H_GET_DATA_SIZE(&headers); + + H_SET_BSS_SIZE(&headers,local_bss_counter); + + /* + * + * 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; + } /* if no strings, then no count. */ + + 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) { + switch (fragP->fr_type) { + case rs_align: + case rs_org: + fragP->fr_type = rs_fill; + know( fragP->fr_var == 1 ); + know( fragP->fr_next ); + fragP->fr_offset + = fragP->fr_next->fr_address + - fragP->fr_address + - fragP->fr_fix; + break; + + case rs_fill: + break; + + case rs_machine_dependent: + md_convert_frag (fragP); + /* + * 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; + extern md_short_jump_size; + extern md_long_jump_size; + + 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; + } /* switch (fr_type) */ + } /* for each frag. */ + +#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) { +#ifdef TC_NS32K + fix_new_ns32k(lie->frag, + lie->word_goes_here - lie->frag->fr_literal, + 2, + lie->add, + lie->sub, + lie->addnum, + 0, 0, 2, 0, 0); +#else /* TC_NS32K */ + fix_new( lie->frag, lie->word_goes_here - lie->frag->fr_literal, + 2, lie->add, + lie->sub, lie->addnum, + 0, NO_RELOC); +#endif /* TC_NS32K */ + /* md_number_to_chars(lie->word_goes_here, + S_GET_VALUE(lie->add) + + lie->addnum + - S_GET_VALUE(lie->sub), + 2); */ + *prevP=lie->next_broken_word; + } else + prevP= &(lie->next_broken_word); + + for (lie=broken_words;lie;) { + struct broken_word *untruth; + char *table_ptr; + long table_addr; + long from_addr, + to_addr; + int n, + m; + + extern md_short_jump_size; + extern md_long_jump_size; + + 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 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. + */ + H_SET_RELOCATION_SIZE(&headers, + md_reloc_size * fixup_segment(text_fix_root, SEG_TEXT), + md_reloc_size * fixup_segment(data_fix_root, SEG_DATA)); + + /* 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); + +#ifdef EXEC_MACHINE_TYPE + H_SET_MACHINE_TYPE(&headers,EXEC_MACHINE_TYPE); +#endif +#ifdef EXEC_VERSION + H_SET_VERSION(&headers,EXEC_VERSION); +#endif + + obj_pre_write_hook(&headers); /* extra coff stuff */ + + if ((had_warnings() && flagseen['Z']) + || had_errors() > 0) { + if (flagseen['Z']) { + as_warn("%d error%s, %d warning%s, generating bad object file.\n", + had_errors(), had_errors() == 1 ? "" : "s", + had_warnings(), had_warnings() == 1 ? "" : "s"); + } else { + as_fatal("%d error%s, %d warning%s, no object file generated.\n", + had_errors(), had_errors() == 1 ? "" : "s", + had_warnings(), had_warnings() == 1 ? "" : "s"); + } /* on want output */ + } /* on error condition */ + + 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); + + /* + * 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 code frag. */ + + /* + * Emit relocations. + */ + obj_emit_relocations(&next_object_file_charP, text_fix_root, (relax_addressT)0); + +#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 */ + + /* + * Emit line number entries. + */ + OBJ_EMIT_LINENO(&next_object_file_charP, lineno_rootP, the_object_file); + + /* + * Emit symbols. + */ + obj_emit_symbols(&next_object_file_charP, symbol_rootP); + + /* + * Emit strings. + */ + + if (string_byte_count > 0) { + obj_emit_strings(&next_object_file_charP); + } /* only if we have a string table */ + + know(next_object_file_charP == the_object_file + object_file_size); + /* Write the data to the file */ + output_file_append(the_object_file,object_file_size,out_file_name); + +#ifdef DONTDEF + if (flagseen['G']) /* GDB symbol file to be appended? */ + { + gdb_emit (out_file_name); + gdb_end (); + } +#endif /* DONTDEF */ + + 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(text_siz, data_siz, text_frag_root, data_frag_root); +#endif /* VMS */ +} /* write_object_file() */ + +/* + * 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. + */ +#ifndef VMS +static +#endif /* not VMS */ +void relax_segment(segment_frag_root, segment_type) + struct frag * segment_frag_root; + segT segment_type; /* SEG_DATA or SEG_TEXT */ +{ + register struct frag * fragP; + register relax_addressT address; + /* register relax_addressT old_address; JF unused */ + /* register relax_addressT new_address; JF unused */ + + know( segment_type == SEG_DATA || segment_type == SEG_TEXT ); + + /* In case md_estimate_size_before_relax() wants to make fixSs. */ + subseg_change(segment_type, 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, 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_type); + 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(). + */ + { + register 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. */ + register 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) + { + register long growth = 0; + register unsigned long was_address; + /* register long var; */ + register long offset; + register symbolS *symbolP; + register long target; + register long after; + register long aim; + + was_address = fragP->fr_address; + address = fragP->fr_address += stretch; + symbolP = fragP->fr_symbol; + offset = fragP->fr_offset; + /* var = fragP->fr_var; */ + 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; + extern int md_short_jump_size; + extern int md_long_jump_size; + + /* 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']) + as_warn(".word %s-%s+%ld didn't fit", + S_GET_NAME(lie->add), + S_GET_NAME(lie->sub), + lie->addnum); + 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; +#endif + case rs_align: + growth = relax_align ((relax_addressT)(address + fragP->fr_fix), offset) + - relax_align ((relax_addressT)(was_address + fragP->fr_fix), offset); + break; + + case rs_org: + target = offset; + if (symbolP) + { + know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || + (S_GET_SEGMENT(symbolP) == SEG_DATA) || + (S_GET_SEGMENT(symbolP) == SEG_TEXT)); + know(symbolP->sy_frag); + know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || + symbolP->sy_frag==&zero_address_frag ); + target += + S_GET_VALUE(symbolP) + + symbolP->sy_frag->fr_address; + } + know( fragP->fr_next ); + after = fragP->fr_next->fr_address; + growth = ((target - after ) > 0) ? (target - after) : 0; + /* Growth may be -ve, but variable part */ + /* of frag cannot have < 0 chars. */ + /* That is, we can't .org backwards. */ + + growth -= stretch; /* This is an absolute growth factor */ + break; + + case rs_machine_dependent: + { + register const relax_typeS * this_type; + register const relax_typeS * start_type; + register relax_substateT next_state; + register relax_substateT this_state; + + start_type = this_type + = md_relax_table + (this_state = fragP->fr_subtype); + target = offset; + if (symbolP) + { + know((S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || + (S_GET_SEGMENT(symbolP) == SEG_DATA) || + (S_GET_SEGMENT(symbolP) == SEG_TEXT)); + know(symbolP->sy_frag); + know(!(S_GET_SEGMENT(symbolP) == SEG_ABSOLUTE) || + 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. */ + + /* JF was just address */ + /* JF also added is_dnrange hack */ + /* There's gotta be a better/faster/etc way + to do this. . . */ + /* gnu@cygnus.com: I changed this from > to >= + because I ran into a zero-length frag (fr_fix=0) + which was created when the obstack needed a new + chunk JUST AFTER the opcode of a branch. Since + fr_fix is zero, fr_address of this frag is the same + as fr_address of the next frag. This + zero-length frag was variable and jumped to .+2 + (in the next frag), but since the > comparison + below failed (the two were =, not >), "stretch" + was not added to the target. Stretch was 178, so + the offset appeared to be .-176 instead, which did + not fit into a byte branch, so the assembler + relaxed the branch to a word. This didn't compare + with what happened when the same source file was + assembled on other machines, which is how I found it. + You might want to think about what other places have + trouble with zero length frags... */ + + 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 + */ +#ifdef TC_NS32K + aim += fragP->fr_pcrel_adjust; +#endif /* TC_NS32K */ + + 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_type = md_relax_table + (this_state = next_state); + next_state = this_type->rlx_more; + } + } + } + else + { +#ifdef DONTDEF +/* JF these next few lines of code are for the mc68020 which can't handle short + offsets of zero in branch instructions. What a kludge! */ + if (aim==0 && this_state==(1<<2+0)) { /* FOO hard encoded from m.c */ + aim=this_type->rlx_forward+1; /* Force relaxation into word mode */ + } +#endif +/* JF end of 68020 code */ + /* 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_type = md_relax_table + (this_state = next_state); + next_state = this_type->rlx_more; + } + } + } + if ((growth = this_type->rlx_length - start_type->rlx_length) != 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. */ + } + + /* + * 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() */ + +/* + * Relax_align. Advance location counter to next address that has 'alignment' + * lowest order bits all 0s. + */ + + /* How many addresses does the .align take? */ +static relax_addressT relax_align(address, alignment) +register relax_addressT address; /* Address now. */ +register long alignment; /* Alignment (binary). */ +{ + relax_addressT mask; + relax_addressT new_address; + + mask = ~ ( (~0) << alignment ); + new_address = (address + mask) & (~ mask); + return (new_address - address); +} /* relax_align() */ + +/* 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; + register long add_number; + register int size; + register char *place; + register long where; + register char pcrel; + register fragS *fragP; + register segT add_symbol_segment = SEG_ABSOLUTE; + fixS *topP = fixP; + + + seg_reloc_count = 0; + + 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); + } /* callj relocation */ +#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 there is an addend */ + + if (sub_symbolP) { + if (!add_symbolP) { + /* Its just -sym */ + if (S_GET_SEGMENT(sub_symbolP) != SEG_ABSOLUTE) { + as_bad("Negative of non-absolute symbol %s", S_GET_NAME(sub_symbolP)); + } /* not absolute */ + + add_number -= S_GET_VALUE(sub_symbolP); + + /* if sub_symbol is in the same segment that add_symbol + and add_symbol is either in DATA, TEXT, BSS or ABSOLUTE */ + } else if ((S_GET_SEGMENT(sub_symbolP) == add_symbol_segment) + && ((add_symbol_segment == SEG_DATA) + || (add_symbol_segment == SEG_TEXT) + || (add_symbol_segment == SEG_BSS) + || (add_symbol_segment == SEG_ABSOLUTE))) { + /* 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; + } else { + /* Different segments in subtraction. */ + know(!(S_IS_EXTERNAL(sub_symbolP) && (S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE))); + + if ((S_GET_SEGMENT(sub_symbolP) == SEG_ABSOLUTE)) { + add_number -= S_GET_VALUE(sub_symbolP); + } else { + as_bad("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %d.", + segment_name(S_GET_SEGMENT(sub_symbolP)), + S_GET_NAME(sub_symbolP), fragP->fr_address + where); + } /* if absolute */ + } + } /* if sub_symbolP */ + + 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. */ + fixP->fx_addsy = NULL; /* No relocations please. */ + } else { + switch (add_symbol_segment) { + case SEG_ABSOLUTE: +#ifdef TC_I960 + reloc_callj(fixP); /* See comment about reloc_callj() above*/ +#endif /* TC_I960 */ + add_number += S_GET_VALUE(add_symbolP); + fixP->fx_addsy = NULL; + add_symbolP = NULL; + break; + + case SEG_BSS: + case SEG_DATA: + case SEG_TEXT: + seg_reloc_count ++; + add_number += S_GET_VALUE(add_symbolP); + break; + + case SEG_UNKNOWN: +#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 */ + /* FIXME-SOON: I think this is trash, but I'm not sure. xoxorich. */ +#ifdef comment +#ifdef OBJ_COFF + if (S_IS_COMMON(add_symbolP)) + add_number += S_GET_VALUE(add_symbolP); +#endif /* OBJ_COFF */ +#endif /* comment */ + + ++seg_reloc_count; + break; + + default: + BAD_CASE(add_symbol_segment); + break; + } /* switch on symbol seg */ + } /* if not in local seg */ + } /* if there was a + symbol */ + + 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) { + if ((size==1 && + (add_number& ~0xFF) && (add_number&~0xFF!=(-1&~0xFF))) || + (size==2 && + (add_number& ~0xFFFF) && (add_number&~0xFFFF!=(-1&~0xFFFF)))) { + as_bad("Value of %d too large for field of %d bytes at 0x%x", + add_number, size, fragP->fr_address + where); + } /* generic error checking */ + } /* not a bit fix */ + + md_apply_fix(fixP, add_number); + } /* For each fixS in this segment. */ + +#ifdef OBJ_COFF +#ifdef TC_I960 + /* 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; + } /* if callj and not already fixed. */ + } /* for each fix */ +#endif /* TC_I960 */ +#endif /* OBJ_COFF */ + return(seg_reloc_count); +} /* fixup_segment() */ + + +static int is_dnrange(f1,f2) +struct frag *f1; +struct frag *f2; +{ + while (f1) { + if (f1->fr_next==f2) + return 1; + f1=f1->fr_next; + } + return 0; +} /* is_dnrange() */ + +/* Append a string onto another string, bumping the pointer along. */ +void +append (charPP, fromP, length) +char **charPP; +char *fromP; +unsigned long length; +{ + if (length) { /* Don't trust bcopy() of 0 chars. */ + bcopy(fromP, *charPP, (int) length); + *charPP += length; + } +} + +int section_alignment[SEG_MAXIMUM_ORDINAL]; + +/* + * 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) +segT seg; /* Segment to which alignment pertains */ +int align; /* Alignment, as a power of 2 + * (e.g., 1 => 2-byte boundary, 2 => 4-byte boundary, etc.) + */ +{ + + if ( align > section_alignment[(int) seg] ){ + section_alignment[(int) seg] = align; + } /* if highest yet */ + + return; +} /* record_alignment() */ + +/* + * Local Variables: + * comment-column: 0 + * fill-column: 131 + * End: + */ + +/* end of write.c */ |