1 /* Generic stabs parsing for gas.
2 Copyright (C) 1989-2018 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 3,
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 License
17 along with GAS; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
22 #include "filenames.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, const char *, const char *);
38 static void generate_asm_file (int, const char *);
40 /* Allow backends to override the names used for the stab sections. */
41 #ifndef STAB_SECTION_NAME
42 #define STAB_SECTION_NAME ".stab"
45 #ifndef STAB_STRING_SECTION_NAME
46 #define STAB_STRING_SECTION_NAME ".stabstr"
49 /* True 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 bfd_boolean in_dot_func_p = FALSE;
55 /* Label at start of current function if in_dot_func_p != FALSE. */
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
83 get_stab_string_offset (const char *string, const char *stabstr_secname)
92 if (! SEPARATE_STAB_SECTIONS)
95 length = strlen (string);
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;
106 /* Make sure the first string is empty. */
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);
116 { /* Ordinary case. */
117 p = frag_more (length + 1);
120 seg_info (seg)->stabu.stab_string_size += length + 1;
125 subseg_set (save_seg, save_subseg);
131 #ifndef OBJ_PROCESS_STAB
132 #define OBJ_PROCESS_STAB(SEG,W,S,T,O,D) aout_process_stab(W,S,T,O,D)
135 /* Here instead of obj-aout.c because other formats use it too. */
137 aout_process_stab (int what, const char *string, int type, int other, int desc)
139 /* Put the stab information in the symbol table. */
142 /* Create the symbol now, but only insert it into the symbol chain
143 after any symbols mentioned in the value expression get into the
144 symbol chain. This is to avoid "continuation symbols" (where one
145 ends in "\" and the debug info is continued in the next .stabs
146 directive) from being separated by other random symbols. */
147 symbol = symbol_create (string, undefined_section, 0,
149 if (what == 's' || what == 'n')
151 /* Pick up the value from the input line. */
156 /* .stabd sets the name to NULL. Why? */
157 S_SET_NAME (symbol, NULL);
158 symbol_set_frag (symbol, frag_now);
159 S_SET_VALUE (symbol, (valueT) frag_now_fix ());
162 symbol_append (symbol, symbol_lastP, &symbol_rootP, &symbol_lastP);
164 symbol_get_bfdsym (symbol)->flags |= BSF_DEBUGGING;
166 S_SET_TYPE (symbol, type);
167 S_SET_OTHER (symbol, other);
168 S_SET_DESC (symbol, desc);
172 /* This can handle different kinds of stabs (s,n,d) and different
173 kinds of stab sections. */
176 s_stab_generic (int what,
177 const char * stab_secname,
178 const char * stabstr_secname)
182 char *saved_string_obstack_end;
187 /* The general format is:
188 .stabs "STRING",TYPE,OTHER,DESC,VALUE
189 .stabn TYPE,OTHER,DESC,VALUE
190 .stabd TYPE,OTHER,DESC
191 At this point input_line_pointer points after the pseudo-op and
192 any trailing whitespace. The argument what is one of 's', 'n' or
193 'd' indicating which type of .stab this is. */
198 saved_string_obstack_end = 0;
204 string = demand_copy_C_string (&length);
207 as_warn (_(".stab%c: missing string"), what);
208 ignore_rest_of_line ();
211 /* FIXME: We should probably find some other temporary storage
212 for string, rather than leaking memory if someone else
213 happens to use the notes obstack. */
214 saved_string_obstack_end = notes.next_free;
216 if (*input_line_pointer == ',')
217 input_line_pointer++;
220 as_warn (_(".stab%c: missing comma"), what);
221 ignore_rest_of_line ();
226 if (get_absolute_expression_and_terminator (&longint) != ',')
228 as_warn (_(".stab%c: missing comma"), what);
229 ignore_rest_of_line ();
234 if (get_absolute_expression_and_terminator (&longint) != ',')
236 as_warn (_(".stab%c: missing comma"), what);
237 ignore_rest_of_line ();
242 desc = get_absolute_expression ();
244 if ((desc > 0xffff) || (desc < -0x8000))
245 /* This could happen for example with a source file with a huge
246 number of lines. The only cure is to use a different debug
247 format, probably DWARF. */
248 as_warn (_(".stab%c: description field '%x' too big, try a different debug format"),
251 if (what == 's' || what == 'n')
253 if (*input_line_pointer != ',')
255 as_warn (_(".stab%c: missing comma"), what);
256 ignore_rest_of_line ();
259 input_line_pointer++;
265 /* Solaris on PowerPC has decided that .stabd can take 4 arguments, so if we were
266 given 4 arguments, make it a .stabn */
267 else if (what == 'd')
269 char *save_location = input_line_pointer;
272 if (*input_line_pointer == ',')
274 input_line_pointer++;
278 input_line_pointer = save_location;
289 listing_source_line ((unsigned int) desc);
293 listing_source_file (string);
297 #endif /* ! NO_LISTING */
299 /* We have now gathered the type, other, and desc information. For
300 .stabs or .stabn, input_line_pointer is now pointing at the
303 if (SEPARATE_STAB_SECTIONS)
304 /* Output the stab information in a separate section. This is used
305 at least for COFF and ELF. */
307 segT saved_seg = now_seg;
308 subsegT saved_subseg = now_subseg;
309 fragS *saved_frag = frag_now;
315 static segT cached_sec;
316 static char *cached_secname;
318 dot = frag_now_fix ();
320 #ifdef md_flush_pending_output
321 md_flush_pending_output ();
324 if (cached_secname && !strcmp (cached_secname, stab_secname))
331 seg = subseg_new (stab_secname, 0);
333 free (cached_secname);
334 cached_secname = xstrdup (stab_secname);
338 if (! seg_info (seg)->hadone)
340 bfd_set_section_flags (stdoutput, seg,
341 SEC_READONLY | SEC_RELOC | SEC_DEBUGGING);
342 #ifdef INIT_STAB_SECTION
343 INIT_STAB_SECTION (seg);
345 seg_info (seg)->hadone = 1;
348 stroff = get_stab_string_offset (string, stabstr_secname);
351 /* Release the string, if nobody else has used the obstack. */
352 if (saved_string_obstack_end == notes.next_free)
353 obstack_free (¬es, string);
356 /* At least for now, stabs in a special stab section are always
357 output as 12 byte blocks of information. */
359 md_number_to_chars (p, (valueT) stroff, 4);
360 md_number_to_chars (p + 4, (valueT) type, 1);
361 md_number_to_chars (p + 5, (valueT) other, 1);
362 md_number_to_chars (p + 6, (valueT) desc, 2);
364 if (what == 's' || what == 'n')
366 /* Pick up the value from the input line. */
368 input_line_pointer--;
375 /* Arrange for a value representing the current location. */
376 symbol = symbol_temp_new (saved_seg, dot, saved_frag);
379 exp.X_add_symbol = symbol;
380 exp.X_add_number = 0;
385 #ifdef OBJ_PROCESS_STAB
386 OBJ_PROCESS_STAB (seg, what, string, type, other, desc);
389 subseg_set (saved_seg, saved_subseg);
393 #ifdef OBJ_PROCESS_STAB
394 OBJ_PROCESS_STAB (0, what, string, type, other, desc);
400 demand_empty_rest_of_line ();
403 /* Regular stab directive. */
408 s_stab_generic (what, STAB_SECTION_NAME, STAB_STRING_SECTION_NAME);
411 /* "Extended stabs", used in Solaris only now. */
417 char *stab_secname, *stabstr_secname;
418 static char *saved_secname, *saved_strsecname;
420 /* @@ MEMORY LEAK: This allocates a copy of the string, but in most
421 cases it will be the same string, so we could release the storage
422 back to the obstack it came from. */
423 stab_secname = demand_copy_C_string (&length);
425 if (*input_line_pointer == ',')
426 input_line_pointer++;
429 as_bad (_("comma missing in .xstabs"));
430 ignore_rest_of_line ();
434 /* To get the name of the stab string section, simply add "str" to
435 the stab section name. */
436 if (saved_secname == 0 || strcmp (saved_secname, stab_secname))
438 stabstr_secname = concat (stab_secname, "str", (char *) NULL);
441 free (saved_secname);
442 free (saved_strsecname);
444 saved_secname = stab_secname;
445 saved_strsecname = stabstr_secname;
447 s_stab_generic (what, saved_secname, saved_strsecname);
452 /* Frob invented at RMS' request. Set the n_desc of a symbol. */
455 s_desc (int ignore ATTRIBUTE_UNUSED)
463 c = get_symbol_name (&name);
464 p = input_line_pointer;
466 SKIP_WHITESPACE_AFTER_NAME ();
467 if (*input_line_pointer != ',')
470 as_bad (_("expected comma after \"%s\""), name);
472 ignore_rest_of_line ();
476 input_line_pointer++;
477 temp = get_absolute_expression ();
479 symbolP = symbol_find_or_make (name);
481 S_SET_DESC (symbolP, temp);
483 demand_empty_rest_of_line ();
486 #endif /* defined (S_SET_DESC) */
488 /* Generate stabs debugging information to denote the main source file. */
491 stabs_generate_asm_file (void)
496 file = as_where (&lineno);
497 if (use_gnu_debug_info_extensions)
502 dir = remap_debug_filename (getpwd ());
503 dir2 = concat (dir, "/", NULL);
504 generate_asm_file (N_SO, dir2);
506 xfree ((char *) dir);
508 generate_asm_file (N_SO, file);
511 /* Generate stabs debugging information to denote the source file.
512 TYPE is one of N_SO, N_SOL. */
515 generate_asm_file (int type, const char *file)
517 static char *last_file;
518 static int label_count;
521 const char *tmp = file;
522 const char *file_endp = file + strlen (file);
525 if (last_file != NULL
526 && filename_cmp (last_file, file) == 0)
529 /* Rather than try to do this in some efficient fashion, we just
530 generate a string and then parse it again. That lets us use the
531 existing stabs hook, which expect to see a string, rather than
532 inventing new ones. */
533 sprintf (sym, "%sF%d", FAKE_LABEL_NAME, label_count);
536 /* Allocate enough space for the file name (possibly extended with
537 doubled up backslashes), the symbol name, and the other characters
538 that make up a stabs file directive. */
539 bufp = buf = XNEWVEC (char, 2 * strlen (file) + strlen (sym) + 12);
543 while (tmp < file_endp)
545 const char *bslash = strchr (tmp, '\\');
546 size_t len = bslash != NULL ? bslash - tmp + 1 : file_endp - tmp;
548 /* Double all backslashes, since demand_copy_C_string (used by
549 s_stab to extract the part in quotes) will try to replace them as
550 escape sequences. backslash may appear in a filespec. */
551 memcpy (bufp, tmp, len);
560 sprintf (bufp, "\",%d,0,0,%s\n", type, sym);
568 if (last_file != NULL)
570 last_file = xstrdup (file);
575 /* Generate stabs debugging information for the current line. This is
576 used to produce debugging information for an assembler file. */
579 stabs_generate_asm_lineno (void)
581 static int label_count;
586 /* Remember the last file/line and avoid duplicates. */
587 static unsigned int prev_lineno = -1;
588 static char *prev_file = NULL;
590 /* Rather than try to do this in some efficient fashion, we just
591 generate a string and then parse it again. That lets us use the
592 existing stabs hook, which expect to see a string, rather than
593 inventing new ones. */
595 file = as_where (&lineno);
597 /* Don't emit sequences of stabs for the same line. */
598 if (prev_file == NULL)
600 /* First time through. */
601 prev_file = xstrdup (file);
602 prev_lineno = lineno;
604 else if (lineno == prev_lineno
605 && filename_cmp (file, prev_file) == 0)
607 /* Same file/line as last time. */
612 /* Remember file/line for next time. */
613 prev_lineno = lineno;
614 if (filename_cmp (file, prev_file) != 0)
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);
632 buf = XNEWVEC (char, 100 + strlen (current_function_label));
633 sprintf (buf, "%d,0,%d,%s-%s\n", N_SLINE, lineno,
634 sym, current_function_label);
638 buf = XNEWVEC (char, 100);
639 sprintf (buf, "%d,0,%d,%s\n", N_SLINE, lineno, sym);
648 outputting_stabs_line_debug = 0;
652 /* Emit a function stab.
653 All assembler functions are assumed to have return type `void'. */
656 stabs_generate_asm_func (const char *funcname, const char *startlabname)
658 static bfd_boolean void_emitted_p = FALSE;
662 if (! void_emitted_p)
664 temp_ilp ((char *) "\"void:t1=1\",128,0,0,0");
667 void_emitted_p = TRUE;
671 if (asprintf (&buf, "\"%s:F1\",%d,0,%d,%s",
672 funcname, N_FUN, lineno + 1, startlabname) == -1)
673 as_fatal ("%s", xstrerror (errno));
680 current_function_label = xstrdup (startlabname);
681 in_dot_func_p = TRUE;
684 /* Emit a stab to record the end of a function. */
687 stabs_generate_asm_endfunc (const char *funcname ATTRIBUTE_UNUSED,
688 const char *startlabname)
690 static int label_count;
694 sprintf (sym, "%sendfunc%d", FAKE_LABEL_NAME, label_count);
698 if (asprintf (&buf, "\"\",%d,0,0,%s-%s", N_FUN, sym, startlabname) == -1)
699 as_fatal ("%s", xstrerror (errno));
706 in_dot_func_p = FALSE;
707 current_function_label = NULL;