1 /* b.out object file format
2 Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as
8 published by the Free Software Foundation; either version 2,
9 or (at your option) any later version.
11 GAS is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 the GNU General Public License for more details.
16 You should have received a copy of the GNU General Public
17 License along with GAS; see the file COPYING. If not, write
18 to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
24 #include "aout/stab_gnu.h"
25 #endif /* NO_LISTING */
27 const short /* in: segT out: N_TYPE bits */
37 N_UNDF, /* bignum/flonum */
38 N_UNDF, /* difference */
39 N_REGISTER, /* register */
42 const segT N_TYPE_seg[N_TYPE+2] = { /* N_TYPE == 0x1E = 32-2 */
43 SEG_UNKNOWN, /* N_UNDF == 0 */
45 SEG_ABSOLUTE, /* N_ABS == 2 */
47 SEG_TEXT, /* N_TEXT == 4 */
49 SEG_DATA, /* N_DATA == 6 */
51 SEG_BSS, /* N_BSS == 8 */
53 SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
54 SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
55 SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
56 SEG_REGISTER, /* dummy N_REGISTER for regs = 30 */
61 static void obj_bout_stab(int what);
62 static void obj_bout_line(void);
63 static void obj_bout_desc(void);
64 #else /* not __STDC__ */
65 static void obj_bout_desc();
66 static void obj_bout_stab();
67 static void obj_bout_line();
68 #endif /* not __STDC__ */
70 const pseudo_typeS obj_pseudo_table[] = {
71 /* stabs (aka a.out aka b.out directives for debug symbols) */
72 { "desc", obj_bout_desc, 0 }, /* def */
73 { "line", obj_bout_line, 0 }, /* source code line number */
74 { "stabd", obj_bout_stab, 'd' }, /* stabs */
75 { "stabn", obj_bout_stab, 'n' }, /* stabs */
76 { "stabs", obj_bout_stab, 's' }, /* stabs */
78 /* coff debugging directives. Currently ignored silently */
79 { "def", s_ignore, 0 },
80 { "dim", s_ignore, 0 },
81 { "endef", s_ignore, 0 },
82 { "ln", s_ignore, 0 },
83 { "scl", s_ignore, 0 },
84 { "size", s_ignore, 0 },
85 { "tag", s_ignore, 0 },
86 { "type", s_ignore, 0 },
87 { "val", s_ignore, 0 },
89 /* other stuff we don't handle */
90 { "ABORT", s_ignore, 0 },
91 { "ident", s_ignore, 0 },
93 { NULL} /* end sentinel */
94 }; /* obj_pseudo_table */
101 * Crawl along a fixS chain. Emit the segment's relocations.
103 void obj_emit_relocations(where, fixP, segment_address_in_file)
105 fixS *fixP; /* Fixup chain for this segment. */
106 relax_addressT segment_address_in_file;
108 for (; fixP; fixP = fixP->fx_next) {
109 if (fixP->fx_addsy != NULL) {
110 tc_bout_fix_to_chars(*where, fixP, segment_address_in_file);
111 *where += sizeof(struct relocation_info);
112 } /* if there's a symbol */
113 } /* for each fixup */
115 } /* emit_relocations() */
117 /* Aout file generation & utilities */
119 /* Convert a lvalue to machine dependent data */
120 void obj_header_append(where, headers)
122 object_headers *headers;
124 /* Always leave in host byte order */
126 headers->header.a_talign = section_alignment[SEG_TEXT];
128 if (headers->header.a_talign < 2){
129 headers->header.a_talign = 2;
130 } /* force to at least 2 */
132 headers->header.a_dalign = section_alignment[SEG_DATA];
133 headers->header.a_balign = section_alignment[SEG_BSS];
135 headers->header.a_tload = 0;
136 headers->header.a_dload = md_section_align(SEG_DATA, H_GET_TEXT_SIZE(headers));
138 append(where, (char *) &headers->header, sizeof(headers->header));
139 } /* a_header_append() */
141 void obj_symbol_to_chars(where, symbolP)
145 /* leave in host byte order */
146 append(where, (char *)&symbolP->sy_symbol, sizeof(obj_symbol_type));
147 } /* obj_symbol_to_chars() */
149 void obj_emit_symbols(where, symbol_rootP)
151 symbolS *symbol_rootP;
156 * Emit all symbols left in the symbol chain.
158 for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
159 /* Used to save the offset of the name. It is used to point
160 to the string in memory but must be a file offset. */
163 temp = S_GET_NAME(symbolP);
164 S_SET_OFFSET(symbolP, symbolP->sy_name_offset);
166 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
167 if (!S_IS_DEBUG(symbolP) && !S_IS_DEFINED(symbolP)) S_SET_EXTERNAL(symbolP);
169 obj_symbol_to_chars(where, symbolP);
170 S_SET_NAME(symbolP,temp);
172 } /* emit_symbols() */
174 void obj_symbol_new_hook(symbolP)
177 S_SET_OTHER(symbolP, 0);
178 S_SET_DESC(symbolP, 0);
180 } /* obj_symbol_new_hook() */
182 static void obj_bout_line() {
183 /* Assume delimiter is part of expression. */
184 /* BSD4.2 as fails with delightful bug, so we */
185 /* are not being incompatible here. */
186 new_logical_line ((char *)NULL, (int)(get_absolute_expression ()));
187 demand_empty_rest_of_line();
188 } /* obj_bout_line() */
193 * Handle .stabX directives, which used to be open-coded.
194 * So much creeping featurism overloaded the semantics that we decided
195 * to put all .stabX thinking in one place. Here.
197 * We try to make any .stabX directive legal. Other people's AS will often
198 * do assembly-time consistency checks: eg assigning meaning to n_type bits
199 * and "protecting" you from setting them to certain values. (They also zero
200 * certain bits before emitting symbols. Tut tut.)
202 * If an expression is not absolute we either gripe or use the relocation
203 * information. Other people's assemblers silently forget information they
204 * don't need and invent information they need that you didn't supply.
206 * .stabX directives always make a symbol table entry. It may be junk if
207 * the rest of your .stabX directive is malformed.
209 static void obj_bout_stab(what)
212 register symbolS * symbolP = 0;
213 register char * string;
216 int goof; /* TRUE if we have aborted. */
220 * Enter with input_line_pointer pointing past .stabX and any following
223 goof = 0; /* JF who forgot this?? */
225 string = demand_copy_C_string(& length);
227 if (*input_line_pointer == ',')
228 input_line_pointer ++;
230 as_bad("I need a comma after symbol's name");
237 * Input_line_pointer->after ','. String->symbol name.
240 symbolP = symbol_new(string,
246 S_SET_NAME(symbolP,NULL); /* .stabd feature. */
247 S_SET_VALUE(symbolP,obstack_next_free(&frags) -
248 frag_now->fr_literal);
249 symbolP->sy_frag = frag_now;
253 symbolP->sy_frag = &zero_address_frag;
257 symbolP->sy_frag = & zero_address_frag;
264 if (get_absolute_expression_and_terminator(& longint) == ',')
265 symbolP->sy_symbol.n_type = saved_type = longint;
267 as_bad("I want a comma after the n_type expression");
269 input_line_pointer--; /* Backup over a non-',' char. */
273 if (get_absolute_expression_and_terminator (& longint) == ',')
274 S_SET_OTHER(symbolP,longint);
276 as_bad("I want a comma after the n_other expression");
278 input_line_pointer--; /* Backup over a non-',' char. */
282 S_SET_DESC(symbolP, get_absolute_expression ());
283 if (what == 's' || what == 'n') {
284 if (* input_line_pointer != ',') {
285 as_bad("I want a comma after the n_desc expression");
288 input_line_pointer ++;
292 if ((!goof) && (what == 's' || what == 'n')) {
294 symbolP->sy_symbol.n_type = saved_type;
300 if (listing && !goof) {
301 if (symbolP->sy_symbol.n_type == N_SLINE) {
303 listing_source_line(symbolP->sy_symbol.n_desc);
304 } else if (symbolP->sy_symbol.n_type == N_SO
305 || symbolP->sy_symbol.n_type == N_SOL) {
306 listing_source_file(string);
314 ignore_rest_of_line ();
316 demand_empty_rest_of_line ();
317 } /* obj_bout_stab() */
319 static void obj_bout_desc() {
323 register symbolS * symbolP;
327 * Frob invented at RMS' request. Set the n_desc of a symbol.
329 name = input_line_pointer;
330 c = get_symbol_end();
331 p = input_line_pointer;
334 if (*input_line_pointer != ',') {
336 as_bad("Expected comma after name \"%s\"", name);
338 ignore_rest_of_line();
340 input_line_pointer ++;
341 temp = get_absolute_expression ();
343 symbolP = symbol_find_or_make(name);
345 S_SET_DESC(symbolP,temp);
347 demand_empty_rest_of_line();
348 } /* obj_bout_desc() */
350 void obj_read_begin_hook() {
352 } /* obj_read_begin_hook() */
354 void obj_crawl_symbol_chain(headers)
355 object_headers *headers;
359 int symbol_number = 0;
361 /* JF deal with forward references first... */
362 for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
363 if (symbolP->sy_forward) {
364 S_SET_VALUE(symbolP, S_GET_VALUE(symbolP)
365 + S_GET_VALUE(symbolP->sy_forward)
366 + symbolP->sy_forward->sy_frag->fr_address);
368 symbolP->sy_forward=0;
369 } /* if it has a forward reference */
370 } /* walk the symbol chain */
372 tc_crawl_symbol_chain(headers);
374 symbolPP = & symbol_rootP; /*->last symbol chain link. */
375 while ((symbolP = *symbolPP) != NULL) {
376 if (flagseen['R'] && (S_GET_SEGMENT(symbolP) == SEG_DATA)) {
377 S_SET_SEGMENT(symbolP, SEG_TEXT);
378 } /* if pusing data into text */
380 S_SET_VALUE(symbolP, S_GET_VALUE(symbolP) + symbolP->sy_frag->fr_address);
382 /* OK, here is how we decide which symbols go out into the
383 brave new symtab. Symbols that do are:
385 * symbols with no name (stabd's?)
386 * symbols with debug info in their N_TYPE
388 Symbols that don't are:
389 * symbols that are registers
390 * symbols with \1 as their 3rd character (numeric labels)
391 * "local labels" as defined by S_LOCAL_NAME(name)
392 if the -L switch was passed to gas.
394 All other symbols are output. We complain if a deleted
395 symbol was marked external. */
399 && !S_IS_REGISTER(symbolP)
400 && (!S_GET_NAME(symbolP)
401 || S_IS_DEBUG(symbolP)
403 /* FIXME-SOON this ifdef seems highly dubious to me. xoxorich. */
404 || !S_IS_DEFINED(symbolP)
405 || S_IS_EXTERNAL(symbolP)
407 || (S_GET_NAME(symbolP)[0] != '\001' && (flagseen['L'] || ! S_LOCAL_NAME(symbolP))))) {
408 symbolP->sy_number = symbol_number++;
410 /* The + 1 after strlen account for the \0 at the
411 end of each string */
412 if (!S_IS_STABD(symbolP)) {
414 symbolP->sy_name_offset = string_byte_count;
415 string_byte_count += strlen(S_GET_NAME(symbolP)) + 1;
417 else /* .Stabd case. */
418 symbolP->sy_name_offset = 0;
419 symbolPP = &(symbol_next(symbolP));
421 if (S_IS_EXTERNAL(symbolP) || !S_IS_DEFINED(symbolP)) {
422 as_bad("Local symbol %s never defined", S_GET_NAME(symbolP));
425 /* Unhook it from the chain */
426 *symbolPP = symbol_next(symbolP);
427 } /* if this symbol should be in the output */
428 } /* for each symbol */
430 H_SET_SYMBOL_TABLE_SIZE(headers, symbol_number);
433 } /* obj_crawl_symbol_chain() */
436 * Find strings by crawling along symbol table chain.
439 void obj_emit_strings(where)
445 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
446 md_number_to_chars(*where, string_byte_count, sizeof(string_byte_count));
447 *where += sizeof(string_byte_count);
448 #else /* CROSS_COMPILE */
449 append(where, (char *) &string_byte_count, (unsigned long) sizeof(string_byte_count));
450 #endif /* CROSS_COMPILE */
452 for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next(symbolP)) {
453 if (S_GET_NAME(symbolP))
454 append(where, S_GET_NAME(symbolP), (unsigned long)(strlen (S_GET_NAME(symbolP)) + 1));
455 } /* walk symbol chain */
458 } /* obj_emit_strings() */
460 void obj_pre_write_hook(headers)
461 object_headers *headers;
463 H_SET_MAGIC_NUMBER(headers, BMAGIC);
464 H_SET_ENTRY_POINT(headers, 0);
467 } /* obj_pre_write_hook() */
476 /* end of obj-bout.c */