1 /* Generic stabs parsing for gas.
2 Copyright (C) 1989-2017 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);
205 /* FIXME: We should probably find some other temporary storage
206 for string, rather than leaking memory if someone else
207 happens to use the notes obstack. */
208 saved_string_obstack_end = notes.next_free;
210 if (*input_line_pointer == ',')
211 input_line_pointer++;
214 as_warn (_(".stab%c: missing comma"), what);
215 ignore_rest_of_line ();
220 if (get_absolute_expression_and_terminator (&longint) != ',')
222 as_warn (_(".stab%c: missing comma"), what);
223 ignore_rest_of_line ();
228 if (get_absolute_expression_and_terminator (&longint) != ',')
230 as_warn (_(".stab%c: missing comma"), what);
231 ignore_rest_of_line ();
236 desc = get_absolute_expression ();
238 if ((desc > 0xffff) || (desc < -0x8000))
239 /* This could happen for example with a source file with a huge
240 number of lines. The only cure is to use a different debug
241 format, probably DWARF. */
242 as_warn (_(".stab%c: description field '%x' too big, try a different debug format"),
245 if (what == 's' || what == 'n')
247 if (*input_line_pointer != ',')
249 as_warn (_(".stab%c: missing comma"), what);
250 ignore_rest_of_line ();
253 input_line_pointer++;
259 /* Solaris on PowerPC has decided that .stabd can take 4 arguments, so if we were
260 given 4 arguments, make it a .stabn */
261 else if (what == 'd')
263 char *save_location = input_line_pointer;
266 if (*input_line_pointer == ',')
268 input_line_pointer++;
272 input_line_pointer = save_location;
283 listing_source_line ((unsigned int) desc);
287 listing_source_file (string);
291 #endif /* ! NO_LISTING */
293 /* We have now gathered the type, other, and desc information. For
294 .stabs or .stabn, input_line_pointer is now pointing at the
297 if (SEPARATE_STAB_SECTIONS)
298 /* Output the stab information in a separate section. This is used
299 at least for COFF and ELF. */
301 segT saved_seg = now_seg;
302 subsegT saved_subseg = now_subseg;
303 fragS *saved_frag = frag_now;
309 static segT cached_sec;
310 static char *cached_secname;
312 dot = frag_now_fix ();
314 #ifdef md_flush_pending_output
315 md_flush_pending_output ();
318 if (cached_secname && !strcmp (cached_secname, stab_secname))
325 seg = subseg_new (stab_secname, 0);
327 free (cached_secname);
328 cached_secname = xstrdup (stab_secname);
332 if (! seg_info (seg)->hadone)
334 bfd_set_section_flags (stdoutput, seg,
335 SEC_READONLY | SEC_RELOC | SEC_DEBUGGING);
336 #ifdef INIT_STAB_SECTION
337 INIT_STAB_SECTION (seg);
339 seg_info (seg)->hadone = 1;
342 stroff = get_stab_string_offset (string, stabstr_secname);
345 /* Release the string, if nobody else has used the obstack. */
346 if (saved_string_obstack_end == notes.next_free)
347 obstack_free (¬es, string);
350 /* At least for now, stabs in a special stab section are always
351 output as 12 byte blocks of information. */
353 md_number_to_chars (p, (valueT) stroff, 4);
354 md_number_to_chars (p + 4, (valueT) type, 1);
355 md_number_to_chars (p + 5, (valueT) other, 1);
356 md_number_to_chars (p + 6, (valueT) desc, 2);
358 if (what == 's' || what == 'n')
360 /* Pick up the value from the input line. */
362 input_line_pointer--;
369 /* Arrange for a value representing the current location. */
370 symbol = symbol_temp_new (saved_seg, dot, saved_frag);
373 exp.X_add_symbol = symbol;
374 exp.X_add_number = 0;
379 #ifdef OBJ_PROCESS_STAB
380 OBJ_PROCESS_STAB (seg, what, string, type, other, desc);
383 subseg_set (saved_seg, saved_subseg);
387 #ifdef OBJ_PROCESS_STAB
388 OBJ_PROCESS_STAB (0, what, string, type, other, desc);
394 demand_empty_rest_of_line ();
397 /* Regular stab directive. */
402 s_stab_generic (what, STAB_SECTION_NAME, STAB_STRING_SECTION_NAME);
405 /* "Extended stabs", used in Solaris only now. */
411 char *stab_secname, *stabstr_secname;
412 static char *saved_secname, *saved_strsecname;
414 /* @@ MEMORY LEAK: This allocates a copy of the string, but in most
415 cases it will be the same string, so we could release the storage
416 back to the obstack it came from. */
417 stab_secname = demand_copy_C_string (&length);
419 if (*input_line_pointer == ',')
420 input_line_pointer++;
423 as_bad (_("comma missing in .xstabs"));
424 ignore_rest_of_line ();
428 /* To get the name of the stab string section, simply add "str" to
429 the stab section name. */
430 if (saved_secname == 0 || strcmp (saved_secname, stab_secname))
432 stabstr_secname = concat (stab_secname, "str", (char *) NULL);
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);
446 /* Frob invented at RMS' request. Set the n_desc of a symbol. */
449 s_desc (int ignore ATTRIBUTE_UNUSED)
457 c = get_symbol_name (&name);
458 p = input_line_pointer;
460 SKIP_WHITESPACE_AFTER_NAME ();
461 if (*input_line_pointer != ',')
464 as_bad (_("expected comma after \"%s\""), name);
466 ignore_rest_of_line ();
470 input_line_pointer++;
471 temp = get_absolute_expression ();
473 symbolP = symbol_find_or_make (name);
475 S_SET_DESC (symbolP, temp);
477 demand_empty_rest_of_line ();
480 #endif /* defined (S_SET_DESC) */
482 /* Generate stabs debugging information to denote the main source file. */
485 stabs_generate_asm_file (void)
490 file = as_where (&lineno);
491 if (use_gnu_debug_info_extensions)
496 dir = remap_debug_filename (getpwd ());
497 dir2 = concat (dir, "/", NULL);
498 generate_asm_file (N_SO, dir2);
500 xfree ((char *) dir);
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. */
509 generate_asm_file (int type, const char *file)
511 static char *last_file;
512 static int label_count;
515 const char *tmp = file;
516 const char *file_endp = file + strlen (file);
519 if (last_file != NULL
520 && filename_cmp (last_file, file) == 0)
523 /* Rather than try to do this in some efficient fashion, we just
524 generate a string and then parse it again. That lets us use the
525 existing stabs hook, which expect to see a string, rather than
526 inventing new ones. */
527 sprintf (sym, "%sF%d", FAKE_LABEL_NAME, label_count);
530 /* Allocate enough space for the file name (possibly extended with
531 doubled up backslashes), the symbol name, and the other characters
532 that make up a stabs file directive. */
533 bufp = buf = XNEWVEC (char, 2 * strlen (file) + strlen (sym) + 12);
537 while (tmp < file_endp)
539 const char *bslash = strchr (tmp, '\\');
540 size_t len = (bslash) ? (size_t) (bslash - tmp + 1) : strlen (tmp);
542 /* Double all backslashes, since demand_copy_C_string (used by
543 s_stab to extract the part in quotes) will try to replace them as
544 escape sequences. backslash may appear in a filespec. */
545 strncpy (bufp, tmp, len);
554 sprintf (bufp, "\",%d,0,0,%s\n", type, sym);
562 if (last_file != NULL)
564 last_file = xstrdup (file);
569 /* Generate stabs debugging information for the current line. This is
570 used to produce debugging information for an assembler file. */
573 stabs_generate_asm_lineno (void)
575 static int label_count;
580 /* Remember the last file/line and avoid duplicates. */
581 static unsigned int prev_lineno = -1;
582 static char *prev_file = NULL;
584 /* Rather than try to do this in some efficient fashion, we just
585 generate a string and then parse it again. That lets us use the
586 existing stabs hook, which expect to see a string, rather than
587 inventing new ones. */
589 file = as_where (&lineno);
591 /* Don't emit sequences of stabs for the same line. */
592 if (prev_file == NULL)
594 /* First time through. */
595 prev_file = xstrdup (file);
596 prev_lineno = lineno;
598 else if (lineno == prev_lineno
599 && filename_cmp (file, prev_file) == 0)
601 /* Same file/line as last time. */
606 /* Remember file/line for next time. */
607 prev_lineno = lineno;
608 if (filename_cmp (file, prev_file) != 0)
611 prev_file = xstrdup (file);
615 /* Let the world know that we are in the middle of generating a
616 piece of stabs line debugging information. */
617 outputting_stabs_line_debug = 1;
619 generate_asm_file (N_SOL, file);
621 sprintf (sym, "%sL%d", FAKE_LABEL_NAME, label_count);
626 buf = XNEWVEC (char, 100 + strlen (current_function_label));
627 sprintf (buf, "%d,0,%d,%s-%s\n", N_SLINE, lineno,
628 sym, current_function_label);
632 buf = XNEWVEC (char, 100);
633 sprintf (buf, "%d,0,%d,%s\n", N_SLINE, lineno, sym);
642 outputting_stabs_line_debug = 0;
646 /* Emit a function stab.
647 All assembler functions are assumed to have return type `void'. */
650 stabs_generate_asm_func (const char *funcname, const char *startlabname)
652 static bfd_boolean void_emitted_p = FALSE;
656 if (! void_emitted_p)
658 temp_ilp ((char *) "\"void:t1=1\",128,0,0,0");
661 void_emitted_p = TRUE;
665 if (asprintf (&buf, "\"%s:F1\",%d,0,%d,%s",
666 funcname, N_FUN, lineno + 1, startlabname) == -1)
667 as_fatal ("%s", xstrerror (errno));
674 current_function_label = xstrdup (startlabname);
675 in_dot_func_p = TRUE;
678 /* Emit a stab to record the end of a function. */
681 stabs_generate_asm_endfunc (const char *funcname ATTRIBUTE_UNUSED,
682 const char *startlabname)
684 static int label_count;
688 sprintf (sym, "%sendfunc%d", FAKE_LABEL_NAME, label_count);
692 if (asprintf (&buf, "\"\",%d,0,0,%s-%s", N_FUN, sym, startlabname) == -1)
693 as_fatal ("%s", xstrerror (errno));
700 in_dot_func_p = FALSE;
701 current_function_label = NULL;