xref: /dragonfly/contrib/gdb-7/gdb/coff-pe-read.c (revision 9348a738)
1 /* Read the export table symbols from a portable executable and
2    convert to internal format, for GDB. Used as a last resort if no
3    debugging symbols recognized.
4 
5    Copyright (C) 2003-2013 Free Software Foundation, Inc.
6 
7    This file is part of GDB.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 
22    Contributed by Raoul M. Gough (RaoulGough@yahoo.co.uk).  */
23 
24 #include "defs.h"
25 
26 #include "coff-pe-read.h"
27 
28 #include "bfd.h"
29 #include "gdbtypes.h"
30 
31 #include "command.h"
32 #include "gdbcmd.h"
33 #include "symtab.h"
34 #include "symfile.h"
35 #include "objfiles.h"
36 #include "common/common-utils.h"
37 #include "coff/internal.h"
38 
39 #include <ctype.h>
40 
41 /* Internal section information */
42 
43 /* Coff PE read debugging flag:
44    default value is 0,
45    value 1 outputs problems encountered while parsing PE file,
46    value above 1 also lists all generated minimal symbols.  */
47 static unsigned int debug_coff_pe_read;
48 
49 struct read_pe_section_data
50 {
51   CORE_ADDR vma_offset;		/* Offset to loaded address of section.  */
52   unsigned long rva_start;	/* Start offset within the pe.  */
53   unsigned long rva_end;	/* End offset within the pe.  */
54   enum minimal_symbol_type ms_type;	/* Type to assign symbols in
55 					   section.  */
56   char *section_name;		/* Recorded section name.  */
57 };
58 
59 #define IMAGE_SCN_CNT_CODE 0x20
60 #define IMAGE_SCN_CNT_INITIALIZED_DATA 0x40
61 #define IMAGE_SCN_CNT_UNINITIALIZED_DATA 0x80
62 #define PE_SECTION_INDEX_TEXT     0
63 #define PE_SECTION_INDEX_DATA     1
64 #define PE_SECTION_INDEX_BSS      2
65 #define PE_SECTION_TABLE_SIZE     3
66 #define PE_SECTION_INDEX_INVALID -1
67 
68 /* Get the index of the named section in our own array, which contains
69    text, data and bss in that order.  Return PE_SECTION_INDEX_INVALID
70    if passed an unrecognised section name.  */
71 
72 static int
73 read_pe_section_index (const char *section_name)
74 {
75   if (strcmp (section_name, ".text") == 0)
76     {
77       return PE_SECTION_INDEX_TEXT;
78     }
79 
80   else if (strcmp (section_name, ".data") == 0)
81     {
82       return PE_SECTION_INDEX_DATA;
83     }
84 
85   else if (strcmp (section_name, ".bss") == 0)
86     {
87       return PE_SECTION_INDEX_BSS;
88     }
89 
90   else
91     {
92       return PE_SECTION_INDEX_INVALID;
93     }
94 }
95 
96 /* Get the index of the named section in our own full arrayi.
97    text, data and bss in that order.  Return PE_SECTION_INDEX_INVALID
98    if passed an unrecognised section name.  */
99 
100 static int
101 get_pe_section_index (const char *section_name,
102 		      struct read_pe_section_data *sections,
103 		      int nb_sections)
104 {
105   int i;
106 
107   for (i = 0; i < nb_sections; i++)
108     if (strcmp (sections[i].section_name, section_name) == 0)
109       return i;
110   return PE_SECTION_INDEX_INVALID;
111 }
112 
113 /* Structure used by get_section_vmas function below
114    to access section_data array and the size of the array
115    stored in nb_sections field.  */
116 struct pe_sections_info
117 {
118   int nb_sections;
119   struct read_pe_section_data *sections;
120 };
121 
122 /* Record the virtual memory address of a section.  */
123 
124 static void
125 get_section_vmas (bfd *abfd, asection *sectp, void *context)
126 {
127   struct pe_sections_info *data = context;
128   struct read_pe_section_data *sections = data->sections;
129   int sectix = get_pe_section_index (sectp->name, sections,
130 				     data->nb_sections);
131 
132   if (sectix != PE_SECTION_INDEX_INVALID)
133     {
134       /* Data within the section start at rva_start in the pe and at
135          bfd_get_section_vma() within memory.  Store the offset.  */
136 
137       sections[sectix].vma_offset
138 	= bfd_get_section_vma (abfd, sectp) - sections[sectix].rva_start;
139     }
140 }
141 
142 /* Create a minimal symbol entry for an exported symbol.
143    SYM_NAME contains the exported name or NULL if exported by ordinal,
144    FUNC_RVA contains the Relative Virtual Address of the symbol,
145    ORDINAL is the ordinal index value of the symbol,
146    SECTION_DATA contains information about the section in which the
147    symbol is declared,
148    DLL_NAME is the internal name of the DLL file,
149    OBJFILE is the objfile struct of DLL_NAME.  */
150 
151 static void
152 add_pe_exported_sym (const char *sym_name,
153 		     unsigned long func_rva,
154 		     int ordinal,
155 		     const struct read_pe_section_data *section_data,
156 		     const char *dll_name, struct objfile *objfile)
157 {
158   char *qualified_name, *bare_name;
159   /* Add the stored offset to get the loaded address of the symbol.  */
160   CORE_ADDR vma = func_rva + section_data->vma_offset;
161   int dll_name_len = strlen (dll_name);
162 
163   /* Generate a (hopefully unique) qualified name using the first part
164      of the dll name, e.g. KERNEL32!AddAtomA.  This matches the style
165      used by windbg from the "Microsoft Debugging Tools for Windows".  */
166 
167   if (sym_name == NULL || *sym_name == '\0')
168     bare_name = xstrprintf ("#%d", ordinal);
169   else
170     bare_name = xstrdup (sym_name);
171 
172   qualified_name = xstrprintf ("%s!%s", dll_name, bare_name);
173 
174   if ((section_data->ms_type == mst_unknown) && debug_coff_pe_read)
175     fprintf_unfiltered (gdb_stdlog , _("Unknown section type for \"%s\""
176 			" for entry \"%s\" in dll \"%s\"\n"),
177 			section_data->section_name, sym_name, dll_name);
178 
179   prim_record_minimal_symbol (qualified_name, vma,
180 			      section_data->ms_type, objfile);
181 
182   /* Enter the plain name as well, which might not be unique.  */
183   prim_record_minimal_symbol (bare_name, vma, section_data->ms_type, objfile);
184   if (debug_coff_pe_read > 1)
185     fprintf_unfiltered (gdb_stdlog, _("Adding exported symbol \"%s\""
186 			" in dll \"%s\"\n"), sym_name, dll_name);
187   xfree (qualified_name);
188   xfree (bare_name);
189 }
190 
191 /* Create a minimal symbol entry for an exported forward symbol.
192    Return 1 if the forwarded function was found 0 otherwise.
193    SYM_NAME contains the exported name or NULL if exported by ordinal,
194    FORWARD_DLL_NAME is the name of the DLL in which the target symobl resides,
195    FORWARD_FUNC_NAME is the name of the target symbol in that DLL,
196    ORDINAL is the ordinal index value of the symbol,
197    DLL_NAME is the internal name of the DLL file,
198    OBJFILE is the objfile struct of DLL_NAME.  */
199 
200 static int
201 add_pe_forwarded_sym (const char *sym_name, const char *forward_dll_name,
202 		      const char *forward_func_name, int ordinal,
203 		      const char *dll_name, struct objfile *objfile)
204 {
205   CORE_ADDR vma;
206   struct objfile *forward_objfile;
207   struct minimal_symbol *msymbol;
208   short section;
209   enum minimal_symbol_type msymtype;
210   int dll_name_len = strlen (dll_name);
211   char *qualified_name, *bare_name;
212   int forward_dll_name_len = strlen (forward_dll_name);
213   int forward_func_name_len = strlen (forward_func_name);
214   int forward_len = forward_dll_name_len + forward_func_name_len + 2;
215   char *forward_qualified_name = alloca (forward_len);
216 
217   xsnprintf (forward_qualified_name, forward_len, "%s!%s", forward_dll_name,
218 	     forward_func_name);
219 
220 
221   msymbol = lookup_minimal_symbol_and_objfile (forward_qualified_name,
222 					       &forward_objfile);
223 
224   if (!msymbol)
225     {
226       int i;
227 
228       for (i = 0; i < forward_dll_name_len; i++)
229 	forward_qualified_name[i] = tolower (forward_qualified_name[i]);
230       msymbol = lookup_minimal_symbol_and_objfile (forward_qualified_name,
231 						   &forward_objfile);
232     }
233 
234   if (!msymbol)
235     {
236       if (debug_coff_pe_read)
237 	fprintf_unfiltered (gdb_stdlog, _("Unable to find function \"%s\" in"
238 			    " dll \"%s\", forward of \"%s\" in dll \"%s\"\n"),
239 			    forward_func_name, forward_dll_name, sym_name,
240 			    dll_name);
241       return 0;
242     }
243 
244   if (debug_coff_pe_read > 1)
245     fprintf_unfiltered (gdb_stdlog, _("Adding forwarded exported symbol"
246 			" \"%s\" in dll \"%s\", pointing to \"%s\"\n"),
247 			sym_name, dll_name, forward_qualified_name);
248 
249   vma = SYMBOL_VALUE_ADDRESS (msymbol);
250   section = SYMBOL_SECTION (msymbol);
251   msymtype = MSYMBOL_TYPE (msymbol);
252 
253   /* Generate a (hopefully unique) qualified name using the first part
254      of the dll name, e.g. KERNEL32!AddAtomA.  This matches the style
255      used by windbg from the "Microsoft Debugging Tools for Windows".  */
256 
257   if (sym_name == NULL || *sym_name == '\0')
258     bare_name = xstrprintf ("#%d", ordinal);
259   else
260     bare_name = xstrdup (sym_name);
261 
262   qualified_name = xstrprintf ("%s!%s", dll_name, bare_name);
263 
264   prim_record_minimal_symbol (qualified_name, vma, msymtype, objfile);
265 
266   /* Enter the plain name as well, which might not be unique.  */
267   prim_record_minimal_symbol (bare_name, vma, msymtype, objfile);
268   xfree (qualified_name);
269   xfree (bare_name);
270 
271   return 1;
272 }
273 
274 /* Truncate a dll_name at the last dot character.  */
275 
276 static void
277 read_pe_truncate_name (char *dll_name)
278 {
279   char *last_point = strrchr (dll_name, '.');
280 
281   if (last_point != NULL)
282     *last_point = '\0';
283 }
284 
285 /* Low-level support functions, direct from the ld module pe-dll.c.  */
286 static unsigned int
287 pe_get16 (bfd *abfd, int where)
288 {
289   unsigned char b[2];
290 
291   bfd_seek (abfd, (file_ptr) where, SEEK_SET);
292   bfd_bread (b, (bfd_size_type) 2, abfd);
293   return b[0] + (b[1] << 8);
294 }
295 
296 static unsigned int
297 pe_get32 (bfd *abfd, int where)
298 {
299   unsigned char b[4];
300 
301   bfd_seek (abfd, (file_ptr) where, SEEK_SET);
302   bfd_bread (b, (bfd_size_type) 4, abfd);
303   return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24);
304 }
305 
306 static unsigned int
307 pe_as16 (void *ptr)
308 {
309   unsigned char *b = ptr;
310 
311   return b[0] + (b[1] << 8);
312 }
313 
314 static unsigned int
315 pe_as32 (void *ptr)
316 {
317   unsigned char *b = ptr;
318 
319   return b[0] + (b[1] << 8) + (b[2] << 16) + (b[3] << 24);
320 }
321 
322 /* Read the (non-debug) export symbol table from a portable
323    executable.  Code originally lifted from the ld function
324    pe_implied_import_dll in pe-dll.c.  */
325 
326 void
327 read_pe_exported_syms (struct objfile *objfile)
328 {
329   bfd *dll = objfile->obfd;
330   unsigned long nbnormal, nbforward;
331   unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
332   unsigned long export_opthdrrva, export_opthdrsize;
333   unsigned long export_rva, export_size, nsections, secptr, expptr;
334   unsigned long exp_funcbase;
335   unsigned char *expdata, *erva;
336   unsigned long name_rvas, ordinals, nexp, ordbase;
337   char *dll_name = (char *) dll->filename;
338   int otherix = PE_SECTION_TABLE_SIZE;
339   int exportix = -1;
340   int is_pe64 = 0;
341   int is_pe32 = 0;
342 
343   /* Array elements are for text, data and bss in that order
344      Initialization with RVA_START > RVA_END guarantees that
345      unused sections won't be matched.  */
346   struct read_pe_section_data *section_data;
347   struct pe_sections_info pe_sections_info;
348 
349   struct cleanup *back_to = make_cleanup (null_cleanup, 0);
350 
351   char const *target = bfd_get_target (objfile->obfd);
352 
353   section_data = xzalloc (PE_SECTION_TABLE_SIZE
354 			 * sizeof (struct read_pe_section_data));
355 
356   make_cleanup (free_current_contents, &section_data);
357 
358   for (i=0; i < PE_SECTION_TABLE_SIZE; i++)
359     {
360       section_data[i].vma_offset = 0;
361       section_data[i].rva_start = 1;
362       section_data[i].rva_end = 0;
363     };
364   section_data[PE_SECTION_INDEX_TEXT].ms_type = mst_text;
365   section_data[PE_SECTION_INDEX_TEXT].section_name = ".text";
366   section_data[PE_SECTION_INDEX_DATA].ms_type = mst_data;
367   section_data[PE_SECTION_INDEX_DATA].section_name = ".data";
368   section_data[PE_SECTION_INDEX_BSS].ms_type = mst_bss;
369   section_data[PE_SECTION_INDEX_BSS].section_name = ".bss";
370 
371   is_pe64 = (strcmp (target, "pe-x86-64") == 0
372 	     || strcmp (target, "pei-x86-64") == 0);
373   is_pe32 = (strcmp (target, "pe-i386") == 0
374 	     || strcmp (target, "pei-i386") == 0
375 	     || strcmp (target, "pe-arm-wince-little") == 0
376 	     || strcmp (target, "pei-arm-wince-little") == 0);
377   if (!is_pe32 && !is_pe64)
378     {
379       /* This is not a recognized PE format file.  Abort now, because
380 	 the code is untested on anything else.  *FIXME* test on
381 	 further architectures and loosen or remove this test.  */
382       do_cleanups (back_to);
383       return;
384     }
385 
386   /* Get pe_header, optional header and numbers of export entries.  */
387   pe_header_offset = pe_get32 (dll, 0x3c);
388   opthdr_ofs = pe_header_offset + 4 + 20;
389   if (is_pe64)
390     num_entries = pe_get32 (dll, opthdr_ofs + 108);
391   else
392     num_entries = pe_get32 (dll, opthdr_ofs + 92);
393 
394   if (num_entries < 1)		/* No exports.  */
395     {
396       do_cleanups (back_to);
397       return;
398     }
399   if (is_pe64)
400     {
401       export_opthdrrva = pe_get32 (dll, opthdr_ofs + 112);
402       export_opthdrsize = pe_get32 (dll, opthdr_ofs + 116);
403     }
404   else
405     {
406       export_opthdrrva = pe_get32 (dll, opthdr_ofs + 96);
407       export_opthdrsize = pe_get32 (dll, opthdr_ofs + 100);
408     }
409   nsections = pe_get16 (dll, pe_header_offset + 4 + 2);
410   secptr = (pe_header_offset + 4 + 20 +
411 	    pe_get16 (dll, pe_header_offset + 4 + 16));
412   expptr = 0;
413   export_size = 0;
414 
415   /* Get the rva and size of the export section.  */
416   for (i = 0; i < nsections; i++)
417     {
418       char sname[8];
419       unsigned long secptr1 = secptr + 40 * i;
420       unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
421       unsigned long vsize = pe_get32 (dll, secptr1 + 16);
422       unsigned long fptr = pe_get32 (dll, secptr1 + 20);
423 
424       bfd_seek (dll, (file_ptr) secptr1, SEEK_SET);
425       bfd_bread (sname, (bfd_size_type) sizeof (sname), dll);
426 
427       if ((strcmp (sname, ".edata") == 0)
428 	  || (vaddr <= export_opthdrrva && export_opthdrrva < vaddr + vsize))
429 	{
430 	  if (strcmp (sname, ".edata") != 0)
431 	    {
432 	      if (debug_coff_pe_read)
433 		fprintf_unfiltered (gdb_stdlog, _("Export RVA for dll "
434 				    "\"%s\" is in section \"%s\"\n"),
435 				    dll_name, sname);
436 	    }
437 	  else if (export_opthdrrva != vaddr && debug_coff_pe_read)
438 	    fprintf_unfiltered (gdb_stdlog, _("Wrong value of export RVA"
439 				" for dll \"%s\": 0x%lx instead of 0x%lx\n"),
440 				dll_name, export_opthdrrva, vaddr);
441 	  expptr = fptr + (export_opthdrrva - vaddr);
442 	  exportix = i;
443 	  break;
444 	}
445     }
446 
447   export_rva = export_opthdrrva;
448   export_size = export_opthdrsize;
449 
450   if (export_size == 0)
451     {
452       /* Empty export table.  */
453       do_cleanups (back_to);
454       return;
455     }
456 
457   /* Scan sections and store the base and size of the relevant
458      sections.  */
459   for (i = 0; i < nsections; i++)
460     {
461       unsigned long secptr1 = secptr + 40 * i;
462       unsigned long vsize = pe_get32 (dll, secptr1 + 8);
463       unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
464       unsigned long characteristics = pe_get32 (dll, secptr1 + 36);
465       char sec_name[SCNNMLEN + 1];
466       int sectix;
467 
468       bfd_seek (dll, (file_ptr) secptr1 + 0, SEEK_SET);
469       bfd_bread (sec_name, (bfd_size_type) SCNNMLEN, dll);
470       sec_name[SCNNMLEN] = '\0';
471 
472       sectix = read_pe_section_index (sec_name);
473 
474       if (sectix != PE_SECTION_INDEX_INVALID)
475 	{
476 	  section_data[sectix].rva_start = vaddr;
477 	  section_data[sectix].rva_end = vaddr + vsize;
478 	}
479       else
480 	{
481 	  char *name;
482 
483 	  section_data = xrealloc (section_data, (otherix + 1)
484 				   * sizeof (struct read_pe_section_data));
485 	  name = xstrdup (sec_name);
486 	  section_data[otherix].section_name = name;
487 	  make_cleanup (xfree, name);
488 	  section_data[otherix].rva_start = vaddr;
489 	  section_data[otherix].rva_end = vaddr + vsize;
490 	  section_data[otherix].vma_offset = 0;
491 	  if (characteristics & IMAGE_SCN_CNT_CODE)
492 	    section_data[otherix].ms_type = mst_text;
493 	  else if (characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA)
494 	    section_data[otherix].ms_type = mst_data;
495 	  else if (characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
496 	    section_data[otherix].ms_type = mst_bss;
497 	  else
498 	    section_data[otherix].ms_type = mst_unknown;
499 	  otherix++;
500 	}
501     }
502 
503   expdata = (unsigned char *) xmalloc (export_size);
504   make_cleanup (xfree, expdata);
505 
506   bfd_seek (dll, (file_ptr) expptr, SEEK_SET);
507   bfd_bread (expdata, (bfd_size_type) export_size, dll);
508   erva = expdata - export_rva;
509 
510   nexp = pe_as32 (expdata + 24);
511   name_rvas = pe_as32 (expdata + 32);
512   ordinals = pe_as32 (expdata + 36);
513   ordbase = pe_as32 (expdata + 16);
514   exp_funcbase = pe_as32 (expdata + 28);
515 
516   /* Use internal dll name instead of full pathname.  */
517   dll_name = pe_as32 (expdata + 12) + erva;
518 
519   pe_sections_info.nb_sections = otherix;
520   pe_sections_info.sections = section_data;
521 
522   bfd_map_over_sections (dll, get_section_vmas, &pe_sections_info);
523 
524   /* Adjust the vma_offsets in case this PE got relocated. This
525      assumes that *all* sections share the same relocation offset
526      as the text section.  */
527   for (i = 0; i < otherix; i++)
528     {
529       section_data[i].vma_offset
530 	+= ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
531     }
532 
533   /* Truncate name at first dot. Should maybe also convert to all
534      lower case for convenience on Windows.  */
535   read_pe_truncate_name (dll_name);
536 
537   if (debug_coff_pe_read)
538     fprintf_unfiltered (gdb_stdlog, _("DLL \"%s\" has %ld export entries,"
539 			" base=%ld\n"), dll_name, nexp, ordbase);
540   nbforward = 0;
541   nbnormal = 0;
542   /* Iterate through the list of symbols.  */
543   for (i = 0; i < nexp; i++)
544     {
545       /* Pointer to the names vector.  */
546       unsigned long name_rva = pe_as32 (erva + name_rvas + i * 4);
547       /* Retrieve ordinal value.  */
548 
549       unsigned long ordinal = pe_as16 (erva + ordinals + i * 2);
550 
551 
552       /* Pointer to the function address vector.  */
553       /* This is relatived to ordinal value. */
554       unsigned long func_rva = pe_as32 (erva + exp_funcbase +
555                                         ordinal * 4);
556 
557       /* Find this symbol's section in our own array.  */
558       int sectix = 0;
559       int section_found = 0;
560 
561       /* First handle forward cases.  */
562       if (func_rva >= export_rva && func_rva < export_rva + export_size)
563 	{
564 	  char *forward_name = (char *) (erva + func_rva);
565 	  char *funcname = (char *) (erva + name_rva);
566 	  char *forward_dll_name = forward_name;
567 	  char *forward_func_name = forward_name;
568 	  char *sep = strrchr (forward_name, '.');
569 
570 	  if (sep)
571 	    {
572 	      int len = (int) (sep - forward_name);
573 
574 	      forward_dll_name = alloca (len + 1);
575 	      strncpy (forward_dll_name, forward_name, len);
576 	      forward_dll_name[len] = '\0';
577 	      forward_func_name = ++sep;
578 	    }
579 	  if (add_pe_forwarded_sym (funcname, forward_dll_name,
580 				    forward_func_name, ordinal,
581 				    dll_name, objfile) != 0)
582 	    ++nbforward;
583 	  continue;
584 	}
585 
586       for (sectix = 0; sectix < otherix; ++sectix)
587 	{
588 	  if ((func_rva >= section_data[sectix].rva_start)
589 	      && (func_rva < section_data[sectix].rva_end))
590 	    {
591 	      section_found = 1;
592 	      add_pe_exported_sym (erva + name_rva,
593 				   func_rva, ordinal,
594 				   section_data + sectix, dll_name, objfile);
595 	      ++nbnormal;
596 	      break;
597 	    }
598 	}
599       if (!section_found)
600 	{
601 	  char *funcname = (char *) (erva + name_rva);
602 
603 	  if (name_rva == 0)
604 	    {
605 	      add_pe_exported_sym (NULL, func_rva, ordinal,
606 				   section_data, dll_name, objfile);
607 	      ++nbnormal;
608 	    }
609 	  else if (debug_coff_pe_read)
610 	    fprintf_unfiltered (gdb_stdlog, _("Export name \"%s\" ord. %lu,"
611 				" RVA 0x%lx in dll \"%s\" not handled\n"),
612 				funcname, ordinal, func_rva, dll_name);
613 	}
614     }
615 
616   if (debug_coff_pe_read)
617     fprintf_unfiltered (gdb_stdlog, _("Finished reading \"%s\", exports %ld,"
618 			" forwards %ld, total %ld/%ld.\n"), dll_name, nbnormal,
619 			nbforward, nbnormal + nbforward, nexp);
620   /* Discard expdata and section_data.  */
621   do_cleanups (back_to);
622 }
623 
624 /* Extract from ABFD the offset of the .text section.
625    This offset is mainly related to the offset within the file.
626    The value was previously expected to be 0x1000 for all files,
627    but some Windows OS core DLLs seem to use 0x10000 section alignement
628    which modified the return value of that function.
629    Still return default 0x1000 value if ABFD is NULL or
630    if '.text' section is not found, but that should not happen...  */
631 
632 #define DEFAULT_COFF_PE_TEXT_SECTION_OFFSET 0x1000
633 
634 CORE_ADDR
635 pe_text_section_offset (struct bfd *abfd)
636 
637 {
638   unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
639   unsigned long export_rva, export_size, nsections, secptr, expptr;
640   unsigned long exp_funcbase;
641   unsigned char *expdata, *erva;
642   unsigned long name_rvas, ordinals, nexp, ordbase;
643   char *dll_name;
644   int is_pe64 = 0;
645   int is_pe32 = 0;
646   char const *target;
647 
648   if (!abfd)
649     return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
650 
651   target = bfd_get_target (abfd);
652 
653   is_pe64 = (strcmp (target, "pe-x86-64") == 0
654 	     || strcmp (target, "pei-x86-64") == 0);
655   is_pe32 = (strcmp (target, "pe-i386") == 0
656 	     || strcmp (target, "pei-i386") == 0
657 	     || strcmp (target, "pe-arm-wince-little") == 0
658 	     || strcmp (target, "pei-arm-wince-little") == 0);
659 
660   if (!is_pe32 && !is_pe64)
661     {
662       /* This is not a recognized PE format file.  Abort now, because
663 	 the code is untested on anything else.  *FIXME* test on
664 	 further architectures and loosen or remove this test.  */
665       return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
666     }
667 
668   /* Get pe_header, optional header and numbers of sections.  */
669   pe_header_offset = pe_get32 (abfd, 0x3c);
670   opthdr_ofs = pe_header_offset + 4 + 20;
671   nsections = pe_get16 (abfd, pe_header_offset + 4 + 2);
672   secptr = (pe_header_offset + 4 + 20 +
673 	    pe_get16 (abfd, pe_header_offset + 4 + 16));
674 
675   /* Get the rva and size of the export section.  */
676   for (i = 0; i < nsections; i++)
677     {
678       char sname[SCNNMLEN + 1];
679       unsigned long secptr1 = secptr + 40 * i;
680       unsigned long vaddr = pe_get32 (abfd, secptr1 + 12);
681 
682       bfd_seek (abfd, (file_ptr) secptr1, SEEK_SET);
683       bfd_bread (sname, (bfd_size_type) SCNNMLEN, abfd);
684       sname[SCNNMLEN] = '\0';
685       if (strcmp (sname, ".text") == 0)
686 	return vaddr;
687     }
688 
689   return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
690 }
691 
692 /* Implements "show debug coff_pe_read" command.  */
693 
694 static void
695 show_debug_coff_pe_read (struct ui_file *file, int from_tty,
696 			 struct cmd_list_element *c, const char *value)
697 {
698   fprintf_filtered (file, _("Coff PE read debugging is %s.\n"), value);
699 }
700 
701 /* Provide a prototype to silence -Wmissing-prototypes.  */
702 
703 void _initialize_coff_pe_read (void);
704 
705 /* Adds "Set/show debug coff_pe_read" commands.  */
706 
707 void
708 _initialize_coff_pe_read (void)
709 {
710   add_setshow_zuinteger_cmd ("coff-pe-read", class_maintenance,
711 			     &debug_coff_pe_read,
712 			     _("Set coff PE read debugging."),
713 			     _("Show coff PE read debugging."),
714 			     _("When set, debugging messages for coff reading "
715 			       "of exported symbols are displayed."),
716 			     NULL, show_debug_coff_pe_read,
717 			     &setdebuglist, &showdebuglist);
718 }
719