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[deliverable/binutils-gdb.git] / gdb / mipsread.c
CommitLineData
c906108c 1/* Read a symbol table in MIPS' format (Third-Eye).
303d2914 2
197e01b6 3 Copyright (C) 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4c38e0a4 4 1998, 1999, 2000, 2001, 2003, 2004, 2007, 2008, 2009, 2010
9b254dd1 5 Free Software Foundation, Inc.
303d2914 6
c906108c
SS
7 Contributed by Alessandro Forin (af@cs.cmu.edu) at CMU. Major work
8 by Per Bothner, John Gilmore and Ian Lance Taylor at Cygnus Support.
9
c5aa993b 10 This file is part of GDB.
c906108c 11
c5aa993b
JM
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
a9762ec7 14 the Free Software Foundation; either version 3 of the License, or
c5aa993b 15 (at your option) any later version.
c906108c 16
c5aa993b
JM
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
c906108c 21
c5aa993b 22 You should have received a copy of the GNU General Public License
a9762ec7 23 along with this program. If not, see <http://www.gnu.org/licenses/>. */
c906108c
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24
25/* Read symbols from an ECOFF file. Most of the work is done in
26 mdebugread.c. */
27
28#include "defs.h"
29#include "gdb_string.h"
30#include "bfd.h"
31#include "symtab.h"
c906108c
SS
32#include "objfiles.h"
33#include "buildsym.h"
34#include "stabsread.h"
c906108c
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35
36#include "coff/sym.h"
37#include "coff/internal.h"
38#include "coff/ecoff.h"
39#include "libcoff.h" /* Private BFD COFF information. */
40#include "libecoff.h" /* Private BFD ECOFF information. */
41#include "elf/common.h"
4fbb74a6 42#include "elf/internal.h"
c906108c
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43#include "elf/mips.h"
44
ccefe4c4
TT
45#include "psymtab.h"
46
c906108c 47static void
a14ed312
KB
48read_alphacoff_dynamic_symtab (struct section_offsets *,
49 struct objfile *objfile);
c906108c
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50
51/* Initialize anything that needs initializing when a completely new
52 symbol file is specified (not just adding some symbols from another
53 file, e.g. a shared library). */
54
c906108c 55static void
fba45db2 56mipscoff_new_init (struct objfile *ignore)
c906108c 57{
c906108c
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58 stabsread_new_init ();
59 buildsym_new_init ();
60}
61
62/* Initialize to read a symbol file (nothing to do). */
63
64static void
fba45db2 65mipscoff_symfile_init (struct objfile *objfile)
c906108c
SS
66{
67}
68
69/* Read a symbol file from a file. */
70
71static void
f4352531 72mipscoff_symfile_read (struct objfile *objfile, int symfile_flags)
c906108c
SS
73{
74 bfd *abfd = objfile->obfd;
c5aa993b 75 struct cleanup *back_to;
c906108c
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76
77 init_minimal_symbol_collection ();
56e290f4 78 back_to = make_cleanup_discard_minimal_symbols ();
c906108c
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79
80 /* Now that the executable file is positioned at symbol table,
81 process it and define symbols accordingly. */
82
83 if (!((*ecoff_backend (abfd)->debug_swap.read_debug_info)
84 (abfd, (asection *) NULL, &ecoff_data (abfd)->debug_info)))
8a3fe4f8 85 error (_("Error reading symbol table: %s"), bfd_errmsg (bfd_get_error ()));
c906108c
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86
87 mdebug_build_psymtabs (objfile, &ecoff_backend (abfd)->debug_swap,
d4f3574e 88 &ecoff_data (abfd)->debug_info);
c906108c
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89
90 /* Add alpha coff dynamic symbols. */
91
96baa820 92 read_alphacoff_dynamic_symtab (objfile->section_offsets, objfile);
c906108c
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93
94 /* Install any minimal symbols that have been collected as the current
95 minimal symbols for this objfile. */
96
97 install_minimal_symbols (objfile);
c906108c
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98 do_cleanups (back_to);
99}
100
101/* Perform any local cleanups required when we are done with a
102 particular objfile. */
103
104static void
fba45db2 105mipscoff_symfile_finish (struct objfile *objfile)
c906108c
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106{
107}
108
109/* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a
303d2914
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110 standard COFF section. The ELF format for the symbols differs from
111 the format defined in elf/external.h. It seems that a normal ELF
112 32-bit format is used, and the representation only changes because
113 longs are 64-bit on the alpha. In addition, the handling of
114 text/data section indices for symbols is different from the ELF
115 ABI. As the BFD linker currently does not support dynamic linking
116 on the alpha, there seems to be no reason to pollute BFD with
117 another mixture of object file formats for now. */
c906108c
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118
119/* Format of an alpha external ELF symbol. */
120
c5aa993b
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121typedef struct
122{
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123 unsigned char st_name[4]; /* Symbol name, index in string table. */
124 unsigned char st_pad[4]; /* Pad to long word boundary. */
125 unsigned char st_value[8]; /* Value of the symbol. */
126 unsigned char st_size[4]; /* Associated symbol size. */
127 unsigned char st_info[1]; /* Type and binding attributes. */
128 unsigned char st_other[1]; /* No defined meaning, 0. */
129 unsigned char st_shndx[2]; /* Associated section index. */
130} Elfalpha_External_Sym;
c906108c
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131
132/* Format of an alpha external ELF dynamic info structure. */
133
c5aa993b 134typedef struct
303d2914
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135{
136 unsigned char d_tag[4]; /* Tag. */
137 unsigned char d_pad[4]; /* Pad to long word boundary. */
138 union
c5aa993b 139 {
303d2914
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140 unsigned char d_ptr[8]; /* Pointer value. */
141 unsigned char d_val[4]; /* Integer value. */
c5aa993b 142 }
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143 d_un;
144} Elfalpha_External_Dyn;
c906108c
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145
146/* Struct to obtain the section pointers for alpha dynamic symbol info. */
147
c5aa993b 148struct alphacoff_dynsecinfo
303d2914
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149{
150 asection *sym_sect; /* Section pointer for .dynsym section. */
151 asection *str_sect; /* Section pointer for .dynstr section. */
152 asection *dyninfo_sect; /* Section pointer for .dynamic section. */
153 asection *got_sect; /* Section pointer for .got section. */
154};
c906108c 155
c906108c 156/* We are called once per section from read_alphacoff_dynamic_symtab.
303d2914
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157 We need to examine each section we are passed, check to see if it
158 is something we are interested in processing, and if so, stash away
159 some access information for the section. */
c906108c
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160
161static void
12b9c64f 162alphacoff_locate_sections (bfd *ignore_abfd, asection *sectp, void *sip)
c906108c 163{
52f0bd74 164 struct alphacoff_dynsecinfo *si;
c906108c
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165
166 si = (struct alphacoff_dynsecinfo *) sip;
167
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168 if (strcmp (sectp->name, ".dynsym") == 0)
169 si->sym_sect = sectp;
170 else if (strcmp (sectp->name, ".dynstr") == 0)
171 si->str_sect = sectp;
172 else if (strcmp (sectp->name, ".dynamic") == 0)
173 si->dyninfo_sect = sectp;
174 else if (strcmp (sectp->name, ".got") == 0)
c906108c 175 si->got_sect = sectp;
c906108c
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176}
177
303d2914
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178/* Scan an alpha dynamic symbol table for symbols of interest and add
179 them to the minimal symbol table. */
c906108c
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180
181static void
fba45db2
KB
182read_alphacoff_dynamic_symtab (struct section_offsets *section_offsets,
183 struct objfile *objfile)
c906108c
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184{
185 bfd *abfd = objfile->obfd;
186 struct alphacoff_dynsecinfo si;
187 char *sym_secptr;
188 char *str_secptr;
189 char *dyninfo_secptr;
190 char *got_secptr;
191 bfd_size_type sym_secsize;
192 bfd_size_type str_secsize;
193 bfd_size_type dyninfo_secsize;
194 bfd_size_type got_secsize;
195 int sym_count;
196 int i;
197 int stripped;
198 Elfalpha_External_Sym *x_symp;
199 char *dyninfo_p;
200 char *dyninfo_end;
201 int got_entry_size = 8;
202 int dt_mips_local_gotno = -1;
203 int dt_mips_gotsym = -1;
4b2e4867 204 struct cleanup *cleanups;
c906108c 205
c906108c
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206 /* We currently only know how to handle alpha dynamic symbols. */
207 if (bfd_get_arch (abfd) != bfd_arch_alpha)
208 return;
209
210 /* Locate the dynamic symbols sections and read them in. */
211 memset ((char *) &si, 0, sizeof (si));
12b9c64f 212 bfd_map_over_sections (abfd, alphacoff_locate_sections, (void *) & si);
303d2914
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213 if (si.sym_sect == NULL || si.str_sect == NULL
214 || si.dyninfo_sect == NULL || si.got_sect == NULL)
c906108c
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215 return;
216
2c500098
AM
217 sym_secsize = bfd_get_section_size (si.sym_sect);
218 str_secsize = bfd_get_section_size (si.str_sect);
219 dyninfo_secsize = bfd_get_section_size (si.dyninfo_sect);
220 got_secsize = bfd_get_section_size (si.got_sect);
4b2e4867 221 sym_secptr = xmalloc (sym_secsize);
6c761d9c 222 cleanups = make_cleanup (xfree, sym_secptr);
4b2e4867 223 str_secptr = xmalloc (str_secsize);
6c761d9c 224 make_cleanup (xfree, str_secptr);
4b2e4867 225 dyninfo_secptr = xmalloc (dyninfo_secsize);
6c761d9c 226 make_cleanup (xfree, dyninfo_secptr);
4b2e4867 227 got_secptr = xmalloc (got_secsize);
6c761d9c 228 make_cleanup (xfree, got_secptr);
c906108c
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229
230 if (!bfd_get_section_contents (abfd, si.sym_sect, sym_secptr,
c5aa993b 231 (file_ptr) 0, sym_secsize))
c906108c
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232 return;
233 if (!bfd_get_section_contents (abfd, si.str_sect, str_secptr,
c5aa993b 234 (file_ptr) 0, str_secsize))
c906108c
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235 return;
236 if (!bfd_get_section_contents (abfd, si.dyninfo_sect, dyninfo_secptr,
c5aa993b 237 (file_ptr) 0, dyninfo_secsize))
c906108c
SS
238 return;
239 if (!bfd_get_section_contents (abfd, si.got_sect, got_secptr,
c5aa993b 240 (file_ptr) 0, got_secsize))
c906108c
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241 return;
242
303d2914
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243 /* Find the number of local GOT entries and the index for the the
244 first dynamic symbol in the GOT. */
c906108c
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245 for (dyninfo_p = dyninfo_secptr, dyninfo_end = dyninfo_p + dyninfo_secsize;
246 dyninfo_p < dyninfo_end;
247 dyninfo_p += sizeof (Elfalpha_External_Dyn))
248 {
c5aa993b 249 Elfalpha_External_Dyn *x_dynp = (Elfalpha_External_Dyn *) dyninfo_p;
c906108c
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250 long dyn_tag;
251
252 dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_tag);
253 if (dyn_tag == DT_NULL)
254 break;
255 else if (dyn_tag == DT_MIPS_LOCAL_GOTNO)
256 {
257 if (dt_mips_local_gotno < 0)
258 dt_mips_local_gotno
259 = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_un.d_val);
260 }
261 else if (dyn_tag == DT_MIPS_GOTSYM)
262 {
263 if (dt_mips_gotsym < 0)
264 dt_mips_gotsym
265 = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_un.d_val);
266 }
267 }
268 if (dt_mips_local_gotno < 0 || dt_mips_gotsym < 0)
269 return;
270
303d2914
MK
271 /* Scan all dynamic symbols and enter them into the minimal symbol
272 table if appropriate. */
c906108c
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273 sym_count = sym_secsize / sizeof (Elfalpha_External_Sym);
274 stripped = (bfd_get_symcount (abfd) == 0);
275
276 /* Skip first symbol, which is a null dummy. */
277 for (i = 1, x_symp = (Elfalpha_External_Sym *) sym_secptr + 1;
278 i < sym_count;
279 i++, x_symp++)
280 {
281 unsigned long strx;
282 char *name;
283 bfd_vma sym_value;
284 unsigned char sym_info;
285 unsigned int sym_shndx;
286 int isglobal;
287 enum minimal_symbol_type ms_type;
288
289 strx = bfd_h_get_32 (abfd, (bfd_byte *) x_symp->st_name);
290 if (strx >= str_secsize)
291 continue;
292 name = str_secptr + strx;
293 if (*name == '\0' || *name == '.')
294 continue;
295
296 sym_value = bfd_h_get_64 (abfd, (bfd_byte *) x_symp->st_value);
297 sym_info = bfd_h_get_8 (abfd, (bfd_byte *) x_symp->st_info);
298 sym_shndx = bfd_h_get_16 (abfd, (bfd_byte *) x_symp->st_shndx);
4fbb74a6
AM
299 if (sym_shndx >= (SHN_LORESERVE & 0xffff))
300 sym_shndx += SHN_LORESERVE - (SHN_LORESERVE & 0xffff);
c906108c
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301 isglobal = (ELF_ST_BIND (sym_info) == STB_GLOBAL);
302
303 if (sym_shndx == SHN_UNDEF)
304 {
305 /* Handle undefined functions which are defined in a shared
306 library. */
307 if (ELF_ST_TYPE (sym_info) != STT_FUNC
308 || ELF_ST_BIND (sym_info) != STB_GLOBAL)
309 continue;
310
311 ms_type = mst_solib_trampoline;
312
313 /* If sym_value is nonzero, it points to the shared library
314 trampoline entry, which is what we are looking for.
315
316 If sym_value is zero, then we have to get the GOT entry
317 for the symbol.
c906108c 318
303d2914
MK
319 If the GOT entry is nonzero, it represents the quickstart
320 address of the function and we use that as the symbol
321 value.
322
323 If the GOT entry is zero, the function address has to be
324 resolved by the runtime loader before the executable is
325 started. We are unable to find any meaningful address
326 for these functions in the executable file, so we skip
327 them. */
c906108c
SS
328 if (sym_value == 0)
329 {
330 int got_entry_offset =
303d2914 331 (i - dt_mips_gotsym + dt_mips_local_gotno) * got_entry_size;
c906108c
SS
332
333 if (got_entry_offset < 0 || got_entry_offset >= got_secsize)
334 continue;
335 sym_value =
336 bfd_h_get_64 (abfd,
337 (bfd_byte *) (got_secptr + got_entry_offset));
338 if (sym_value == 0)
339 continue;
340 }
341 }
342 else
343 {
303d2914
MK
344 /* Symbols defined in the executable itself. We only care
345 about them if this is a stripped executable, otherwise
346 they have been retrieved from the normal symbol table
347 already. */
c906108c
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348 if (!stripped)
349 continue;
350
351 if (sym_shndx == SHN_MIPS_TEXT)
352 {
353 if (isglobal)
354 ms_type = mst_text;
355 else
356 ms_type = mst_file_text;
b8fbeb18 357 sym_value += ANOFFSET (section_offsets, SECT_OFF_TEXT (objfile));
c906108c
SS
358 }
359 else if (sym_shndx == SHN_MIPS_DATA)
360 {
361 if (isglobal)
362 ms_type = mst_data;
363 else
364 ms_type = mst_file_data;
b8fbeb18 365 sym_value += ANOFFSET (section_offsets, SECT_OFF_DATA (objfile));
c906108c
SS
366 }
367 else if (sym_shndx == SHN_MIPS_ACOMMON)
368 {
369 if (isglobal)
370 ms_type = mst_bss;
371 else
372 ms_type = mst_file_bss;
b8fbeb18 373 sym_value += ANOFFSET (section_offsets, SECT_OFF_BSS (objfile));
c906108c
SS
374 }
375 else if (sym_shndx == SHN_ABS)
376 {
377 ms_type = mst_abs;
378 }
379 else
380 {
381 continue;
382 }
383 }
384
385 prim_record_minimal_symbol (name, sym_value, ms_type, objfile);
386 }
4b2e4867
PS
387
388 do_cleanups (cleanups);
c906108c
SS
389}
390
303d2914 391/* Initialization. */
c906108c 392
00b5771c 393static const struct sym_fns ecoff_sym_fns =
c906108c
SS
394{
395 bfd_target_ecoff_flavour,
396 mipscoff_new_init, /* sym_new_init: init anything gbl to entire symtab */
397 mipscoff_symfile_init, /* sym_init: read initial info, setup for sym_read() */
398 mipscoff_symfile_read, /* sym_read: read a symbol file into symtab */
399 mipscoff_symfile_finish, /* sym_finish: finished with file, cleanup */
400 default_symfile_offsets, /* sym_offsets: dummy FIXME til implem sym reloc */
31d99776
DJ
401 default_symfile_segments, /* sym_segments: Get segment information from
402 a file. */
c295b2e5 403 NULL, /* sym_read_linetable */
ac8035ab 404 default_symfile_relocate, /* sym_relocate: Relocate a debug section. */
00b5771c 405 &psym_functions
c906108c
SS
406};
407
303d2914
MK
408/* Provide a prototype to silence -Wmissing-prototypes. */
409void _initialize_mipsread (void);
410
c906108c 411void
fba45db2 412_initialize_mipsread (void)
c906108c
SS
413{
414 add_symtab_fns (&ecoff_sym_fns);
415}
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