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[binutils.git] / gas / stabs.c
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1 /* Generic stabs parsing for gas.
2 Copyright 1989, 1990, 1991, 1993, 1995, 1996, 1997, 1998, 2000, 2001
3 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 2,
10 or (at your option) any later version.
12 GAS is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 the GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GAS; see the file COPYING. If not, write to the Free
19 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
20 02110-1301, USA. */
22 #include "as.h"
23 #include "obstack.h"
24 #include "subsegs.h"
25 #include "ecoff.h"
27 /* We need this, despite the apparent object format dependency, since
28 it defines stab types, which all object formats can use now. */
30 #include "aout/stab_gnu.h"
32 /* Holds whether the assembler is generating stabs line debugging
33 information or not. Potentially used by md_cleanup function. */
35 int outputting_stabs_line_debug = 0;
37 static void s_stab_generic (int, char *, char *);
38 static void generate_asm_file (int, char *);
40 /* Allow backends to override the names used for the stab sections. */
41 #ifndef STAB_SECTION_NAME
42 #define STAB_SECTION_NAME ".stab"
43 #endif
45 #ifndef STAB_STRING_SECTION_NAME
46 #define STAB_STRING_SECTION_NAME ".stabstr"
47 #endif
49 /* Non-zero if we're in the middle of a .func function, in which case
50 stabs_generate_asm_lineno emits function relative line number stabs.
51 Otherwise it emits line number stabs with absolute addresses. Note that
52 both cases only apply to assembler code assembled with -gstabs. */
53 static int in_dot_func_p;
55 /* Label at start of current function if in_dot_func_p != 0. */
56 static const char *current_function_label;
59 * Handle .stabX directives, which used to be open-coded.
60 * So much creeping featurism overloaded the semantics that we decided
61 * to put all .stabX thinking in one place. Here.
63 * We try to make any .stabX directive legal. Other people's AS will often
64 * do assembly-time consistency checks: eg assigning meaning to n_type bits
65 * and "protecting" you from setting them to certain values. (They also zero
66 * certain bits before emitting symbols. Tut tut.)
68 * If an expression is not absolute we either gripe or use the relocation
69 * information. Other people's assemblers silently forget information they
70 * don't need and invent information they need that you didn't supply.
74 * Build a string dictionary entry for a .stabX symbol.
75 * The symbol is added to the .<secname>str section.
78 #ifndef SEPARATE_STAB_SECTIONS
79 #define SEPARATE_STAB_SECTIONS 0
80 #endif
82 unsigned int
83 get_stab_string_offset (const char *string, const char *stabstr_secname)
85 unsigned int length;
86 unsigned int retval;
87 segT save_seg;
88 subsegT save_subseg;
89 segT seg;
90 char *p;
92 if (! SEPARATE_STAB_SECTIONS)
93 abort ();
95 length = strlen (string);
97 save_seg = now_seg;
98 save_subseg = now_subseg;
100 /* Create the stab string section. */
101 seg = subseg_new (stabstr_secname, 0);
103 retval = seg_info (seg)->stabu.stab_string_size;
104 if (retval <= 0)
106 /* Make sure the first string is empty. */
107 p = frag_more (1);
108 *p = 0;
109 retval = seg_info (seg)->stabu.stab_string_size = 1;
110 bfd_set_section_flags (stdoutput, seg, SEC_READONLY | SEC_DEBUGGING);
111 if (seg->name == stabstr_secname)
112 seg->name = xstrdup (stabstr_secname);
115 if (length > 0)
116 { /* Ordinary case. */
117 p = frag_more (length + 1);
118 strcpy (p, string);
120 seg_info (seg)->stabu.stab_string_size += length + 1;
122 else
123 retval = 0;
125 subseg_set (save_seg, save_subseg);
127 return retval;
130 #ifdef AOUT_STABS
131 #ifndef OBJ_PROCESS_STAB
132 #define OBJ_PROCESS_STAB(SEG,W,S,T,O,D) aout_process_stab(W,S,T,O,D)
133 #endif
135 /* Here instead of obj-aout.c because other formats use it too. */
136 void
137 aout_process_stab (what, string, type, other, desc)
138 int what;
139 const char *string;
140 int type, other, desc;
142 /* Put the stab information in the symbol table. */
143 symbolS *symbol;
145 /* Create the symbol now, but only insert it into the symbol chain
146 after any symbols mentioned in the value expression get into the
147 symbol chain. This is to avoid "continuation symbols" (where one
148 ends in "\" and the debug info is continued in the next .stabs
149 directive) from being separated by other random symbols. */
150 symbol = symbol_create (string, undefined_section, 0,
151 &zero_address_frag);
152 if (what == 's' || what == 'n')
154 /* Pick up the value from the input line. */
155 pseudo_set (symbol);
157 else
159 /* .stabd sets the name to NULL. Why? */
160 S_SET_NAME (symbol, NULL);
161 symbol_set_frag (symbol, frag_now);
162 S_SET_VALUE (symbol, (valueT) frag_now_fix ());
165 symbol_append (symbol, symbol_lastP, &symbol_rootP, &symbol_lastP);
167 S_SET_TYPE (symbol, type);
168 S_SET_OTHER (symbol, other);
169 S_SET_DESC (symbol, desc);
171 #endif
173 /* This can handle different kinds of stabs (s,n,d) and different
174 kinds of stab sections. */
176 static void
177 s_stab_generic (int what, char *stab_secname, char *stabstr_secname)
179 long longint;
180 char *string, *saved_string_obstack_end;
181 int type;
182 int other;
183 int desc;
185 /* The general format is:
186 .stabs "STRING",TYPE,OTHER,DESC,VALUE
187 .stabn TYPE,OTHER,DESC,VALUE
188 .stabd TYPE,OTHER,DESC
189 At this point input_line_pointer points after the pseudo-op and
190 any trailing whitespace. The argument what is one of 's', 'n' or
191 'd' indicating which type of .stab this is. */
193 if (what != 's')
195 string = "";
196 saved_string_obstack_end = 0;
198 else
200 int length;
202 string = demand_copy_C_string (&length);
203 /* FIXME: We should probably find some other temporary storage
204 for string, rather than leaking memory if someone else
205 happens to use the notes obstack. */
206 saved_string_obstack_end = notes.next_free;
207 SKIP_WHITESPACE ();
208 if (*input_line_pointer == ',')
209 input_line_pointer++;
210 else
212 as_warn (_(".stab%c: missing comma"), what);
213 ignore_rest_of_line ();
214 return;
218 if (get_absolute_expression_and_terminator (&longint) != ',')
220 as_warn (_(".stab%c: missing comma"), what);
221 ignore_rest_of_line ();
222 return;
224 type = longint;
226 if (get_absolute_expression_and_terminator (&longint) != ',')
228 as_warn (_(".stab%c: missing comma"), what);
229 ignore_rest_of_line ();
230 return;
232 other = longint;
234 desc = get_absolute_expression ();
236 if ((desc > 0xffff) || (desc < -0x8000))
237 /* This could happen for example with a source file with a huge
238 number of lines. The only cure is to use a different debug
239 format, probably DWARF. */
240 as_warn (_(".stab%c: description field '%x' too big, try a different debug format"),
241 what, desc);
243 if (what == 's' || what == 'n')
245 if (*input_line_pointer != ',')
247 as_warn (_(".stab%c: missing comma"), what);
248 ignore_rest_of_line ();
249 return;
251 input_line_pointer++;
252 SKIP_WHITESPACE ();
255 #ifdef TC_PPC
256 #ifdef OBJ_ELF
257 /* Solaris on PowerPC has decided that .stabd can take 4 arguments, so if we were
258 given 4 arguments, make it a .stabn */
259 else if (what == 'd')
261 char *save_location = input_line_pointer;
263 SKIP_WHITESPACE ();
264 if (*input_line_pointer == ',')
266 input_line_pointer++;
267 what = 'n';
269 else
270 input_line_pointer = save_location;
272 #endif /* OBJ_ELF */
273 #endif /* TC_PPC */
275 #ifndef NO_LISTING
276 if (listing)
278 switch (type)
280 case N_SLINE:
281 listing_source_line ((unsigned int) desc);
282 break;
283 case N_SO:
284 case N_SOL:
285 listing_source_file (string);
286 break;
289 #endif /* ! NO_LISTING */
291 /* We have now gathered the type, other, and desc information. For
292 .stabs or .stabn, input_line_pointer is now pointing at the
293 value. */
295 if (SEPARATE_STAB_SECTIONS)
296 /* Output the stab information in a separate section. This is used
297 at least for COFF and ELF. */
299 segT saved_seg = now_seg;
300 subsegT saved_subseg = now_subseg;
301 fragS *saved_frag = frag_now;
302 valueT dot;
303 segT seg;
304 unsigned int stroff;
305 char *p;
307 static segT cached_sec;
308 static char *cached_secname;
310 dot = frag_now_fix ();
312 #ifdef md_flush_pending_output
313 md_flush_pending_output ();
314 #endif
316 if (cached_secname && !strcmp (cached_secname, stab_secname))
318 seg = cached_sec;
319 subseg_set (seg, 0);
321 else
323 seg = subseg_new (stab_secname, 0);
324 if (cached_secname)
325 free (cached_secname);
326 cached_secname = xstrdup (stab_secname);
327 cached_sec = seg;
330 if (! seg_info (seg)->hadone)
332 bfd_set_section_flags (stdoutput, seg,
333 SEC_READONLY | SEC_RELOC | SEC_DEBUGGING);
334 #ifdef INIT_STAB_SECTION
335 INIT_STAB_SECTION (seg);
336 #endif
337 seg_info (seg)->hadone = 1;
340 stroff = get_stab_string_offset (string, stabstr_secname);
341 if (what == 's')
343 /* Release the string, if nobody else has used the obstack. */
344 if (saved_string_obstack_end == notes.next_free)
345 obstack_free (&notes, string);
348 /* At least for now, stabs in a special stab section are always
349 output as 12 byte blocks of information. */
350 p = frag_more (8);
351 md_number_to_chars (p, (valueT) stroff, 4);
352 md_number_to_chars (p + 4, (valueT) type, 1);
353 md_number_to_chars (p + 5, (valueT) other, 1);
354 md_number_to_chars (p + 6, (valueT) desc, 2);
356 if (what == 's' || what == 'n')
358 /* Pick up the value from the input line. */
359 cons (4);
360 input_line_pointer--;
362 else
364 symbolS *symbol;
365 expressionS exp;
367 /* Arrange for a value representing the current location. */
368 symbol = symbol_temp_new (saved_seg, dot, saved_frag);
370 exp.X_op = O_symbol;
371 exp.X_add_symbol = symbol;
372 exp.X_add_number = 0;
374 emit_expr (&exp, 4);
377 #ifdef OBJ_PROCESS_STAB
378 OBJ_PROCESS_STAB (seg, what, string, type, other, desc);
379 #endif
381 subseg_set (saved_seg, saved_subseg);
383 else
385 #ifdef OBJ_PROCESS_STAB
386 OBJ_PROCESS_STAB (0, what, string, type, other, desc);
387 #else
388 abort ();
389 #endif
392 demand_empty_rest_of_line ();
395 /* Regular stab directive. */
397 void
398 s_stab (int what)
400 s_stab_generic (what, STAB_SECTION_NAME, STAB_STRING_SECTION_NAME);
403 /* "Extended stabs", used in Solaris only now. */
405 void
406 s_xstab (int what)
408 int length;
409 char *stab_secname, *stabstr_secname;
410 static char *saved_secname, *saved_strsecname;
412 /* @@ MEMORY LEAK: This allocates a copy of the string, but in most
413 cases it will be the same string, so we could release the storage
414 back to the obstack it came from. */
415 stab_secname = demand_copy_C_string (&length);
416 SKIP_WHITESPACE ();
417 if (*input_line_pointer == ',')
418 input_line_pointer++;
419 else
421 as_bad (_("comma missing in .xstabs"));
422 ignore_rest_of_line ();
423 return;
426 /* To get the name of the stab string section, simply add "str" to
427 the stab section name. */
428 if (saved_secname == 0 || strcmp (saved_secname, stab_secname))
430 stabstr_secname = (char *) xmalloc (strlen (stab_secname) + 4);
431 strcpy (stabstr_secname, stab_secname);
432 strcat (stabstr_secname, "str");
433 if (saved_secname)
435 free (saved_secname);
436 free (saved_strsecname);
438 saved_secname = stab_secname;
439 saved_strsecname = stabstr_secname;
441 s_stab_generic (what, saved_secname, saved_strsecname);
444 #ifdef S_SET_DESC
446 /* Frob invented at RMS' request. Set the n_desc of a symbol. */
448 void
449 s_desc (ignore)
450 int ignore ATTRIBUTE_UNUSED;
452 char *name;
453 char c;
454 char *p;
455 symbolS *symbolP;
456 int temp;
458 name = input_line_pointer;
459 c = get_symbol_end ();
460 p = input_line_pointer;
461 *p = c;
462 SKIP_WHITESPACE ();
463 if (*input_line_pointer != ',')
465 *p = 0;
466 as_bad (_("expected comma after \"%s\""), name);
467 *p = c;
468 ignore_rest_of_line ();
470 else
472 input_line_pointer++;
473 temp = get_absolute_expression ();
474 *p = 0;
475 symbolP = symbol_find_or_make (name);
476 *p = c;
477 S_SET_DESC (symbolP, temp);
479 demand_empty_rest_of_line ();
480 } /* s_desc() */
482 #endif /* defined (S_SET_DESC) */
484 /* Generate stabs debugging information to denote the main source file. */
486 void
487 stabs_generate_asm_file (void)
489 char *file;
490 unsigned int lineno;
492 as_where (&file, &lineno);
493 if (use_gnu_debug_info_extensions)
495 char *dir, *dir2;
497 dir = getpwd ();
498 dir2 = alloca (strlen (dir) + 2);
499 sprintf (dir2, "%s%s", dir, "/");
500 generate_asm_file (N_SO, dir2);
502 generate_asm_file (N_SO, file);
505 /* Generate stabs debugging information to denote the source file.
506 TYPE is one of N_SO, N_SOL. */
508 static void
509 generate_asm_file (int type, char *file)
511 static char *last_file;
512 static int label_count;
513 char *hold;
514 char sym[30];
515 char *buf;
516 char *tmp = file;
517 char *endp = file + strlen (file);
518 char *bufp;
520 if (last_file != NULL
521 && strcmp (last_file, file) == 0)
522 return;
524 /* Rather than try to do this in some efficient fashion, we just
525 generate a string and then parse it again. That lets us use the
526 existing stabs hook, which expect to see a string, rather than
527 inventing new ones. */
528 hold = input_line_pointer;
530 sprintf (sym, "%sF%d", FAKE_LABEL_NAME, label_count);
531 ++label_count;
533 /* Allocate enough space for the file name (possibly extended with
534 doubled up backslashes), the symbol name, and the other characters
535 that make up a stabs file directive. */
536 bufp = buf = xmalloc (2 * strlen (file) + strlen (sym) + 12);
538 *bufp++ = '"';
540 while (tmp < endp)
542 char *bslash = strchr (tmp, '\\');
543 size_t len = (bslash) ? (size_t) (bslash - tmp + 1) : strlen (tmp);
545 /* Double all backslashes, since demand_copy_C_string (used by
546 s_stab to extract the part in quotes) will try to replace them as
547 escape sequences. backslash may appear in a filespec. */
548 strncpy (bufp, tmp, len);
550 tmp += len;
551 bufp += len;
553 if (bslash != NULL)
554 *bufp++ = '\\';
557 sprintf (bufp, "\",%d,0,0,%s\n", type, sym);
559 input_line_pointer = buf;
560 s_stab ('s');
561 colon (sym);
563 if (last_file != NULL)
564 free (last_file);
565 last_file = xstrdup (file);
567 free (buf);
569 input_line_pointer = hold;
572 /* Generate stabs debugging information for the current line. This is
573 used to produce debugging information for an assembler file. */
575 void
576 stabs_generate_asm_lineno (void)
578 static int label_count;
579 char *hold;
580 char *file;
581 unsigned int lineno;
582 char *buf;
583 char sym[30];
584 /* Remember the last file/line and avoid duplicates. */
585 static unsigned int prev_lineno = -1;
586 static char *prev_file = NULL;
588 /* Rather than try to do this in some efficient fashion, we just
589 generate a string and then parse it again. That lets us use the
590 existing stabs hook, which expect to see a string, rather than
591 inventing new ones. */
593 hold = input_line_pointer;
595 as_where (&file, &lineno);
597 /* Don't emit sequences of stabs for the same line. */
598 if (prev_file == NULL)
600 /* First time thru. */
601 prev_file = xstrdup (file);
602 prev_lineno = lineno;
604 else if (lineno == prev_lineno
605 && strcmp (file, prev_file) == 0)
607 /* Same file/line as last time. */
608 return;
610 else
612 /* Remember file/line for next time. */
613 prev_lineno = lineno;
614 if (strcmp (file, prev_file) != 0)
616 free (prev_file);
617 prev_file = xstrdup (file);
621 /* Let the world know that we are in the middle of generating a
622 piece of stabs line debugging information. */
623 outputting_stabs_line_debug = 1;
625 generate_asm_file (N_SOL, file);
627 sprintf (sym, "%sL%d", FAKE_LABEL_NAME, label_count);
628 ++label_count;
630 if (in_dot_func_p)
632 buf = (char *) alloca (100 + strlen (current_function_label));
633 sprintf (buf, "%d,0,%d,%s-%s\n", N_SLINE, lineno,
634 sym, current_function_label);
636 else
638 buf = (char *) alloca (100);
639 sprintf (buf, "%d,0,%d,%s\n", N_SLINE, lineno, sym);
641 input_line_pointer = buf;
642 s_stab ('n');
643 colon (sym);
645 input_line_pointer = hold;
646 outputting_stabs_line_debug = 0;
649 /* Emit a function stab.
650 All assembler functions are assumed to have return type `void'. */
652 void
653 stabs_generate_asm_func (const char *funcname, const char *startlabname)
655 static int void_emitted_p;
656 char *hold = input_line_pointer;
657 char *buf;
658 char *file;
659 unsigned int lineno;
661 if (! void_emitted_p)
663 input_line_pointer = "\"void:t1=1\",128,0,0,0";
664 s_stab ('s');
665 void_emitted_p = 1;
668 as_where (&file, &lineno);
669 asprintf (&buf, "\"%s:F1\",%d,0,%d,%s",
670 funcname, N_FUN, lineno + 1, startlabname);
671 input_line_pointer = buf;
672 s_stab ('s');
673 free (buf);
675 input_line_pointer = hold;
676 current_function_label = xstrdup (startlabname);
677 in_dot_func_p = 1;
680 /* Emit a stab to record the end of a function. */
682 void
683 stabs_generate_asm_endfunc (const char *funcname ATTRIBUTE_UNUSED,
684 const char *startlabname)
686 static int label_count;
687 char *hold = input_line_pointer;
688 char *buf;
689 char sym[30];
691 sprintf (sym, "%sendfunc%d", FAKE_LABEL_NAME, label_count);
692 ++label_count;
693 colon (sym);
695 asprintf (&buf, "\"\",%d,0,0,%s-%s", N_FUN, sym, startlabname);
696 input_line_pointer = buf;
697 s_stab ('s');
698 free (buf);
700 input_line_pointer = hold;
701 in_dot_func_p = 0;
702 current_function_label = NULL;