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c906108c SS |
1 | /* Read a symbol table in MIPS' format (Third-Eye). |
2 | Copyright 1986, 87, 89, 90, 91, 92, 93, 94, 95, 96, 1998 | |
3 | Free Software Foundation, Inc. | |
4 | Contributed by Alessandro Forin (af@cs.cmu.edu) at CMU. Major work | |
5 | by Per Bothner, John Gilmore and Ian Lance Taylor at Cygnus Support. | |
6 | ||
c5aa993b | 7 | This file is part of GDB. |
c906108c | 8 | |
c5aa993b JM |
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 2 of the License, or | |
12 | (at your option) any later version. | |
c906108c | 13 | |
c5aa993b JM |
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. | |
c906108c | 18 | |
c5aa993b JM |
19 | You should have received a copy of the GNU General Public License |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
23 | |
24 | /* Read symbols from an ECOFF file. Most of the work is done in | |
25 | mdebugread.c. */ | |
26 | ||
27 | #include "defs.h" | |
28 | #include "gdb_string.h" | |
29 | #include "bfd.h" | |
30 | #include "symtab.h" | |
31 | #include "symfile.h" | |
32 | #include "objfiles.h" | |
33 | #include "buildsym.h" | |
34 | #include "stabsread.h" | |
35 | #include "gdb-stabs.h" | |
36 | ||
37 | #include "coff/sym.h" | |
38 | #include "coff/internal.h" | |
39 | #include "coff/ecoff.h" | |
40 | #include "libcoff.h" /* Private BFD COFF information. */ | |
41 | #include "libecoff.h" /* Private BFD ECOFF information. */ | |
42 | #include "elf/common.h" | |
43 | #include "elf/mips.h" | |
44 | ||
392a587b JM |
45 | extern void _initialize_mipsread PARAMS ((void)); |
46 | ||
c906108c SS |
47 | static void |
48 | mipscoff_new_init PARAMS ((struct objfile *)); | |
49 | ||
50 | static void | |
51 | mipscoff_symfile_init PARAMS ((struct objfile *)); | |
52 | ||
53 | static void | |
54 | mipscoff_symfile_read PARAMS ((struct objfile *, struct section_offsets *, | |
55 | int)); | |
56 | ||
57 | static void | |
58 | mipscoff_symfile_finish PARAMS ((struct objfile *)); | |
59 | ||
60 | static void | |
61 | read_alphacoff_dynamic_symtab PARAMS ((struct section_offsets *, | |
c5aa993b | 62 | struct objfile * objfile)); |
c906108c SS |
63 | |
64 | /* Initialize anything that needs initializing when a completely new | |
65 | symbol file is specified (not just adding some symbols from another | |
66 | file, e.g. a shared library). */ | |
67 | ||
68 | extern CORE_ADDR sigtramp_address; | |
69 | ||
70 | static void | |
71 | mipscoff_new_init (ignore) | |
72 | struct objfile *ignore; | |
73 | { | |
74 | sigtramp_address = 0; | |
75 | stabsread_new_init (); | |
76 | buildsym_new_init (); | |
77 | } | |
78 | ||
79 | /* Initialize to read a symbol file (nothing to do). */ | |
80 | ||
81 | static void | |
82 | mipscoff_symfile_init (objfile) | |
83 | struct objfile *objfile; | |
84 | { | |
85 | } | |
86 | ||
87 | /* Read a symbol file from a file. */ | |
88 | ||
89 | static void | |
90 | mipscoff_symfile_read (objfile, section_offsets, mainline) | |
91 | struct objfile *objfile; | |
92 | struct section_offsets *section_offsets; | |
93 | int mainline; | |
94 | { | |
95 | bfd *abfd = objfile->obfd; | |
c5aa993b | 96 | struct cleanup *back_to; |
c906108c SS |
97 | |
98 | init_minimal_symbol_collection (); | |
99 | back_to = make_cleanup ((make_cleanup_func) discard_minimal_symbols, 0); | |
100 | ||
101 | /* Now that the executable file is positioned at symbol table, | |
102 | process it and define symbols accordingly. */ | |
103 | ||
104 | if (!((*ecoff_backend (abfd)->debug_swap.read_debug_info) | |
105 | (abfd, (asection *) NULL, &ecoff_data (abfd)->debug_info))) | |
106 | error ("Error reading symbol table: %s", bfd_errmsg (bfd_get_error ())); | |
107 | ||
108 | mdebug_build_psymtabs (objfile, &ecoff_backend (abfd)->debug_swap, | |
109 | &ecoff_data (abfd)->debug_info, section_offsets); | |
110 | ||
111 | /* Add alpha coff dynamic symbols. */ | |
112 | ||
113 | read_alphacoff_dynamic_symtab (section_offsets, objfile); | |
114 | ||
115 | /* Install any minimal symbols that have been collected as the current | |
116 | minimal symbols for this objfile. */ | |
117 | ||
118 | install_minimal_symbols (objfile); | |
119 | ||
120 | /* If the entry_file bounds are still unknown after processing the | |
121 | partial symbols, then try to set them from the minimal symbols | |
122 | surrounding the entry_point. */ | |
123 | ||
124 | if (mainline | |
125 | && objfile->ei.entry_point != INVALID_ENTRY_POINT | |
126 | && objfile->ei.entry_file_lowpc == INVALID_ENTRY_LOWPC) | |
127 | { | |
128 | struct minimal_symbol *m; | |
129 | ||
130 | m = lookup_minimal_symbol_by_pc (objfile->ei.entry_point); | |
131 | if (m && SYMBOL_NAME (m + 1)) | |
132 | { | |
133 | objfile->ei.entry_file_lowpc = SYMBOL_VALUE_ADDRESS (m); | |
134 | objfile->ei.entry_file_highpc = SYMBOL_VALUE_ADDRESS (m + 1); | |
135 | } | |
136 | } | |
137 | ||
138 | do_cleanups (back_to); | |
139 | } | |
140 | ||
141 | /* Perform any local cleanups required when we are done with a | |
142 | particular objfile. */ | |
143 | ||
144 | static void | |
145 | mipscoff_symfile_finish (objfile) | |
146 | struct objfile *objfile; | |
147 | { | |
148 | } | |
149 | ||
150 | /* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a | |
151 | standard coff section. The ELF format for the symbols differs from | |
152 | the format defined in elf/external.h. It seems that a normal ELF 32 bit | |
153 | format is used, and the representation only changes because longs are | |
154 | 64 bit on the alpha. In addition, the handling of text/data section | |
155 | indices for symbols is different from the ELF ABI. | |
156 | As the BFD linker currently does not support dynamic linking on the alpha, | |
157 | there seems to be no reason to pollute BFD with another mixture of object | |
158 | file formats for now. */ | |
159 | ||
160 | /* Format of an alpha external ELF symbol. */ | |
161 | ||
c5aa993b JM |
162 | typedef struct |
163 | { | |
164 | unsigned char st_name[4]; /* Symbol name, index in string tbl */ | |
165 | unsigned char st_pad[4]; /* Pad to long word boundary */ | |
166 | unsigned char st_value[8]; /* Value of the symbol */ | |
167 | unsigned char st_size[4]; /* Associated symbol size */ | |
168 | unsigned char st_info[1]; /* Type and binding attributes */ | |
169 | unsigned char st_other[1]; /* No defined meaning, 0 */ | |
170 | unsigned char st_shndx[2]; /* Associated section index */ | |
171 | } | |
172 | Elfalpha_External_Sym; | |
c906108c SS |
173 | |
174 | /* Format of an alpha external ELF dynamic info structure. */ | |
175 | ||
c5aa993b JM |
176 | typedef struct |
177 | { | |
178 | unsigned char d_tag[4]; /* Tag */ | |
179 | unsigned char d_pad[4]; /* Pad to long word boundary */ | |
180 | union | |
181 | { | |
182 | unsigned char d_ptr[8]; /* Pointer value */ | |
183 | unsigned char d_val[4]; /* Integer value */ | |
184 | } | |
185 | d_un; | |
186 | } | |
187 | Elfalpha_External_Dyn; | |
c906108c SS |
188 | |
189 | /* Struct to obtain the section pointers for alpha dynamic symbol info. */ | |
190 | ||
c5aa993b JM |
191 | struct alphacoff_dynsecinfo |
192 | { | |
193 | asection *sym_sect; /* Section pointer for .dynsym section */ | |
194 | asection *str_sect; /* Section pointer for .dynstr section */ | |
195 | asection *dyninfo_sect; /* Section pointer for .dynamic section */ | |
196 | asection *got_sect; /* Section pointer for .got section */ | |
197 | }; | |
c906108c SS |
198 | |
199 | static void | |
200 | alphacoff_locate_sections PARAMS ((bfd *, asection *, void *)); | |
201 | ||
202 | /* We are called once per section from read_alphacoff_dynamic_symtab. | |
203 | We need to examine each section we are passed, check to see | |
204 | if it is something we are interested in processing, and | |
205 | if so, stash away some access information for the section. */ | |
206 | ||
207 | static void | |
208 | alphacoff_locate_sections (ignore_abfd, sectp, sip) | |
209 | bfd *ignore_abfd; | |
210 | asection *sectp; | |
211 | PTR sip; | |
212 | { | |
213 | register struct alphacoff_dynsecinfo *si; | |
214 | ||
215 | si = (struct alphacoff_dynsecinfo *) sip; | |
216 | ||
217 | if (STREQ (sectp->name, ".dynsym")) | |
218 | { | |
219 | si->sym_sect = sectp; | |
220 | } | |
221 | else if (STREQ (sectp->name, ".dynstr")) | |
222 | { | |
223 | si->str_sect = sectp; | |
224 | } | |
225 | else if (STREQ (sectp->name, ".dynamic")) | |
226 | { | |
227 | si->dyninfo_sect = sectp; | |
228 | } | |
229 | else if (STREQ (sectp->name, ".got")) | |
230 | { | |
231 | si->got_sect = sectp; | |
232 | } | |
233 | } | |
234 | ||
235 | /* Scan an alpha dynamic symbol table for symbols of interest and | |
236 | add them to the minimal symbol table. */ | |
237 | ||
238 | static void | |
239 | read_alphacoff_dynamic_symtab (section_offsets, objfile) | |
240 | struct section_offsets *section_offsets; | |
241 | struct objfile *objfile; | |
242 | { | |
243 | bfd *abfd = objfile->obfd; | |
244 | struct alphacoff_dynsecinfo si; | |
245 | char *sym_secptr; | |
246 | char *str_secptr; | |
247 | char *dyninfo_secptr; | |
248 | char *got_secptr; | |
249 | bfd_size_type sym_secsize; | |
250 | bfd_size_type str_secsize; | |
251 | bfd_size_type dyninfo_secsize; | |
252 | bfd_size_type got_secsize; | |
253 | int sym_count; | |
254 | int i; | |
255 | int stripped; | |
256 | Elfalpha_External_Sym *x_symp; | |
257 | char *dyninfo_p; | |
258 | char *dyninfo_end; | |
259 | int got_entry_size = 8; | |
260 | int dt_mips_local_gotno = -1; | |
261 | int dt_mips_gotsym = -1; | |
262 | ||
263 | ||
264 | /* We currently only know how to handle alpha dynamic symbols. */ | |
265 | if (bfd_get_arch (abfd) != bfd_arch_alpha) | |
266 | return; | |
267 | ||
268 | /* Locate the dynamic symbols sections and read them in. */ | |
269 | memset ((char *) &si, 0, sizeof (si)); | |
c5aa993b | 270 | bfd_map_over_sections (abfd, alphacoff_locate_sections, (PTR) & si); |
c906108c SS |
271 | if (si.sym_sect == NULL |
272 | || si.str_sect == NULL | |
273 | || si.dyninfo_sect == NULL | |
274 | || si.got_sect == NULL) | |
275 | return; | |
276 | ||
277 | sym_secsize = bfd_get_section_size_before_reloc (si.sym_sect); | |
278 | str_secsize = bfd_get_section_size_before_reloc (si.str_sect); | |
279 | dyninfo_secsize = bfd_get_section_size_before_reloc (si.dyninfo_sect); | |
280 | got_secsize = bfd_get_section_size_before_reloc (si.got_sect); | |
281 | sym_secptr = alloca (sym_secsize); | |
282 | str_secptr = alloca (str_secsize); | |
283 | dyninfo_secptr = alloca (dyninfo_secsize); | |
284 | got_secptr = alloca (got_secsize); | |
285 | ||
286 | if (!bfd_get_section_contents (abfd, si.sym_sect, sym_secptr, | |
c5aa993b | 287 | (file_ptr) 0, sym_secsize)) |
c906108c SS |
288 | return; |
289 | if (!bfd_get_section_contents (abfd, si.str_sect, str_secptr, | |
c5aa993b | 290 | (file_ptr) 0, str_secsize)) |
c906108c SS |
291 | return; |
292 | if (!bfd_get_section_contents (abfd, si.dyninfo_sect, dyninfo_secptr, | |
c5aa993b | 293 | (file_ptr) 0, dyninfo_secsize)) |
c906108c SS |
294 | return; |
295 | if (!bfd_get_section_contents (abfd, si.got_sect, got_secptr, | |
c5aa993b | 296 | (file_ptr) 0, got_secsize)) |
c906108c SS |
297 | return; |
298 | ||
299 | /* Find the number of local GOT entries and the index for the | |
300 | the first dynamic symbol in the GOT. */ | |
301 | for (dyninfo_p = dyninfo_secptr, dyninfo_end = dyninfo_p + dyninfo_secsize; | |
302 | dyninfo_p < dyninfo_end; | |
303 | dyninfo_p += sizeof (Elfalpha_External_Dyn)) | |
304 | { | |
c5aa993b | 305 | Elfalpha_External_Dyn *x_dynp = (Elfalpha_External_Dyn *) dyninfo_p; |
c906108c SS |
306 | long dyn_tag; |
307 | ||
308 | dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_tag); | |
309 | if (dyn_tag == DT_NULL) | |
310 | break; | |
311 | else if (dyn_tag == DT_MIPS_LOCAL_GOTNO) | |
312 | { | |
313 | if (dt_mips_local_gotno < 0) | |
314 | dt_mips_local_gotno | |
315 | = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_un.d_val); | |
316 | } | |
317 | else if (dyn_tag == DT_MIPS_GOTSYM) | |
318 | { | |
319 | if (dt_mips_gotsym < 0) | |
320 | dt_mips_gotsym | |
321 | = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp->d_un.d_val); | |
322 | } | |
323 | } | |
324 | if (dt_mips_local_gotno < 0 || dt_mips_gotsym < 0) | |
325 | return; | |
326 | ||
327 | /* Scan all dynamic symbols and enter them into the minimal symbol table | |
328 | if appropriate. */ | |
329 | sym_count = sym_secsize / sizeof (Elfalpha_External_Sym); | |
330 | stripped = (bfd_get_symcount (abfd) == 0); | |
331 | ||
332 | /* Skip first symbol, which is a null dummy. */ | |
333 | for (i = 1, x_symp = (Elfalpha_External_Sym *) sym_secptr + 1; | |
334 | i < sym_count; | |
335 | i++, x_symp++) | |
336 | { | |
337 | unsigned long strx; | |
338 | char *name; | |
339 | bfd_vma sym_value; | |
340 | unsigned char sym_info; | |
341 | unsigned int sym_shndx; | |
342 | int isglobal; | |
343 | enum minimal_symbol_type ms_type; | |
344 | ||
345 | strx = bfd_h_get_32 (abfd, (bfd_byte *) x_symp->st_name); | |
346 | if (strx >= str_secsize) | |
347 | continue; | |
348 | name = str_secptr + strx; | |
349 | if (*name == '\0' || *name == '.') | |
350 | continue; | |
351 | ||
352 | sym_value = bfd_h_get_64 (abfd, (bfd_byte *) x_symp->st_value); | |
353 | sym_info = bfd_h_get_8 (abfd, (bfd_byte *) x_symp->st_info); | |
354 | sym_shndx = bfd_h_get_16 (abfd, (bfd_byte *) x_symp->st_shndx); | |
355 | isglobal = (ELF_ST_BIND (sym_info) == STB_GLOBAL); | |
356 | ||
357 | if (sym_shndx == SHN_UNDEF) | |
358 | { | |
359 | /* Handle undefined functions which are defined in a shared | |
360 | library. */ | |
361 | if (ELF_ST_TYPE (sym_info) != STT_FUNC | |
362 | || ELF_ST_BIND (sym_info) != STB_GLOBAL) | |
363 | continue; | |
364 | ||
365 | ms_type = mst_solib_trampoline; | |
366 | ||
367 | /* If sym_value is nonzero, it points to the shared library | |
368 | trampoline entry, which is what we are looking for. | |
369 | ||
370 | If sym_value is zero, then we have to get the GOT entry | |
371 | for the symbol. | |
372 | If the GOT entry is nonzero, it represents the quickstart | |
373 | address of the function and we use that as the symbol value. | |
374 | ||
375 | If the GOT entry is zero, the function address has to be resolved | |
376 | by the runtime loader before the executable is started. | |
377 | We are unable to find any meaningful address for these | |
378 | functions in the executable file, so we skip them. */ | |
379 | if (sym_value == 0) | |
380 | { | |
381 | int got_entry_offset = | |
c5aa993b | 382 | (i - dt_mips_gotsym + dt_mips_local_gotno) * got_entry_size; |
c906108c SS |
383 | |
384 | if (got_entry_offset < 0 || got_entry_offset >= got_secsize) | |
385 | continue; | |
386 | sym_value = | |
387 | bfd_h_get_64 (abfd, | |
388 | (bfd_byte *) (got_secptr + got_entry_offset)); | |
389 | if (sym_value == 0) | |
390 | continue; | |
391 | } | |
392 | } | |
393 | else | |
394 | { | |
395 | /* Symbols defined in the executable itself. We only care about | |
396 | them if this is a stripped executable, otherwise they have | |
397 | been retrieved from the normal symbol table already. */ | |
398 | if (!stripped) | |
399 | continue; | |
400 | ||
401 | if (sym_shndx == SHN_MIPS_TEXT) | |
402 | { | |
403 | if (isglobal) | |
404 | ms_type = mst_text; | |
405 | else | |
406 | ms_type = mst_file_text; | |
407 | sym_value += ANOFFSET (section_offsets, SECT_OFF_TEXT); | |
408 | } | |
409 | else if (sym_shndx == SHN_MIPS_DATA) | |
410 | { | |
411 | if (isglobal) | |
412 | ms_type = mst_data; | |
413 | else | |
414 | ms_type = mst_file_data; | |
415 | sym_value += ANOFFSET (section_offsets, SECT_OFF_DATA); | |
416 | } | |
417 | else if (sym_shndx == SHN_MIPS_ACOMMON) | |
418 | { | |
419 | if (isglobal) | |
420 | ms_type = mst_bss; | |
421 | else | |
422 | ms_type = mst_file_bss; | |
423 | sym_value += ANOFFSET (section_offsets, SECT_OFF_BSS); | |
424 | } | |
425 | else if (sym_shndx == SHN_ABS) | |
426 | { | |
427 | ms_type = mst_abs; | |
428 | } | |
429 | else | |
430 | { | |
431 | continue; | |
432 | } | |
433 | } | |
434 | ||
435 | prim_record_minimal_symbol (name, sym_value, ms_type, objfile); | |
436 | } | |
437 | } | |
438 | ||
439 | /* Initialization */ | |
440 | ||
441 | static struct sym_fns ecoff_sym_fns = | |
442 | { | |
443 | bfd_target_ecoff_flavour, | |
444 | mipscoff_new_init, /* sym_new_init: init anything gbl to entire symtab */ | |
445 | mipscoff_symfile_init, /* sym_init: read initial info, setup for sym_read() */ | |
446 | mipscoff_symfile_read, /* sym_read: read a symbol file into symtab */ | |
447 | mipscoff_symfile_finish, /* sym_finish: finished with file, cleanup */ | |
448 | default_symfile_offsets, /* sym_offsets: dummy FIXME til implem sym reloc */ | |
449 | NULL /* next: pointer to next struct sym_fns */ | |
450 | }; | |
451 | ||
452 | void | |
453 | _initialize_mipsread () | |
454 | { | |
455 | add_symtab_fns (&ecoff_sym_fns); | |
456 | } |