1 /* Read a symbol table in MIPS' format (Third-Eye).
2 Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
3 1998, 1999, 2000, 2001, 2003, 2004
4 Free Software Foundation, Inc.
5 Contributed by Alessandro Forin (af@cs.cmu.edu) at CMU. Major work
6 by Per Bothner, John Gilmore and Ian Lance Taylor at Cygnus Support.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 59 Temple Place - Suite 330,
23 Boston, MA 02111-1307, USA. */
25 /* Read symbols from an ECOFF file. Most of the work is done in
29 #include "gdb_string.h"
34 #include "stabsread.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"
44 extern void _initialize_mipsread (void);
46 static void mipscoff_new_init (struct objfile
*);
48 static void mipscoff_symfile_init (struct objfile
*);
50 static void mipscoff_symfile_read (struct objfile
*, int);
52 static void mipscoff_symfile_finish (struct objfile
*);
55 read_alphacoff_dynamic_symtab (struct section_offsets
*,
56 struct objfile
*objfile
);
58 /* Initialize anything that needs initializing when a completely new
59 symbol file is specified (not just adding some symbols from another
60 file, e.g. a shared library). */
62 extern CORE_ADDR sigtramp_address
;
65 mipscoff_new_init (struct objfile
*ignore
)
68 stabsread_new_init ();
72 /* Initialize to read a symbol file (nothing to do). */
75 mipscoff_symfile_init (struct objfile
*objfile
)
79 /* Read a symbol file from a file. */
82 mipscoff_symfile_read (struct objfile
*objfile
, int mainline
)
84 bfd
*abfd
= objfile
->obfd
;
85 struct cleanup
*back_to
;
87 init_minimal_symbol_collection ();
88 back_to
= make_cleanup_discard_minimal_symbols ();
90 /* Now that the executable file is positioned at symbol table,
91 process it and define symbols accordingly. */
93 if (!((*ecoff_backend (abfd
)->debug_swap
.read_debug_info
)
94 (abfd
, (asection
*) NULL
, &ecoff_data (abfd
)->debug_info
)))
95 error ("Error reading symbol table: %s", bfd_errmsg (bfd_get_error ()));
97 mdebug_build_psymtabs (objfile
, &ecoff_backend (abfd
)->debug_swap
,
98 &ecoff_data (abfd
)->debug_info
);
100 /* Add alpha coff dynamic symbols. */
102 read_alphacoff_dynamic_symtab (objfile
->section_offsets
, objfile
);
104 /* Install any minimal symbols that have been collected as the current
105 minimal symbols for this objfile. */
107 install_minimal_symbols (objfile
);
109 /* If the entry_file bounds are still unknown after processing the
110 partial symbols, then try to set them from the minimal symbols
111 surrounding the entry_point. */
114 && objfile
->ei
.entry_point
!= INVALID_ENTRY_POINT
115 && objfile
->ei
.deprecated_entry_file_lowpc
== INVALID_ENTRY_LOWPC
)
117 struct minimal_symbol
*m
;
119 m
= lookup_minimal_symbol_by_pc (objfile
->ei
.entry_point
);
120 if (m
&& DEPRECATED_SYMBOL_NAME (m
+ 1))
122 objfile
->ei
.deprecated_entry_file_lowpc
= SYMBOL_VALUE_ADDRESS (m
);
123 objfile
->ei
.deprecated_entry_file_highpc
= SYMBOL_VALUE_ADDRESS (m
+ 1);
127 do_cleanups (back_to
);
130 /* Perform any local cleanups required when we are done with a
131 particular objfile. */
134 mipscoff_symfile_finish (struct objfile
*objfile
)
138 /* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a
139 standard coff section. The ELF format for the symbols differs from
140 the format defined in elf/external.h. It seems that a normal ELF 32 bit
141 format is used, and the representation only changes because longs are
142 64 bit on the alpha. In addition, the handling of text/data section
143 indices for symbols is different from the ELF ABI.
144 As the BFD linker currently does not support dynamic linking on the alpha,
145 there seems to be no reason to pollute BFD with another mixture of object
146 file formats for now. */
148 /* Format of an alpha external ELF symbol. */
152 unsigned char st_name
[4]; /* Symbol name, index in string tbl */
153 unsigned char st_pad
[4]; /* Pad to long word boundary */
154 unsigned char st_value
[8]; /* Value of the symbol */
155 unsigned char st_size
[4]; /* Associated symbol size */
156 unsigned char st_info
[1]; /* Type and binding attributes */
157 unsigned char st_other
[1]; /* No defined meaning, 0 */
158 unsigned char st_shndx
[2]; /* Associated section index */
160 Elfalpha_External_Sym
;
162 /* Format of an alpha external ELF dynamic info structure. */
166 unsigned char d_tag
[4]; /* Tag */
167 unsigned char d_pad
[4]; /* Pad to long word boundary */
170 unsigned char d_ptr
[8]; /* Pointer value */
171 unsigned char d_val
[4]; /* Integer value */
175 Elfalpha_External_Dyn
;
177 /* Struct to obtain the section pointers for alpha dynamic symbol info. */
179 struct alphacoff_dynsecinfo
181 asection
*sym_sect
; /* Section pointer for .dynsym section */
182 asection
*str_sect
; /* Section pointer for .dynstr section */
183 asection
*dyninfo_sect
; /* Section pointer for .dynamic section */
184 asection
*got_sect
; /* Section pointer for .got section */
187 /* We are called once per section from read_alphacoff_dynamic_symtab.
188 We need to examine each section we are passed, check to see
189 if it is something we are interested in processing, and
190 if so, stash away some access information for the section. */
193 alphacoff_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *sip
)
195 struct alphacoff_dynsecinfo
*si
;
197 si
= (struct alphacoff_dynsecinfo
*) sip
;
199 if (DEPRECATED_STREQ (sectp
->name
, ".dynsym"))
201 si
->sym_sect
= sectp
;
203 else if (DEPRECATED_STREQ (sectp
->name
, ".dynstr"))
205 si
->str_sect
= sectp
;
207 else if (DEPRECATED_STREQ (sectp
->name
, ".dynamic"))
209 si
->dyninfo_sect
= sectp
;
211 else if (DEPRECATED_STREQ (sectp
->name
, ".got"))
213 si
->got_sect
= sectp
;
217 /* Scan an alpha dynamic symbol table for symbols of interest and
218 add them to the minimal symbol table. */
221 read_alphacoff_dynamic_symtab (struct section_offsets
*section_offsets
,
222 struct objfile
*objfile
)
224 bfd
*abfd
= objfile
->obfd
;
225 struct alphacoff_dynsecinfo si
;
228 char *dyninfo_secptr
;
230 bfd_size_type sym_secsize
;
231 bfd_size_type str_secsize
;
232 bfd_size_type dyninfo_secsize
;
233 bfd_size_type got_secsize
;
237 Elfalpha_External_Sym
*x_symp
;
240 int got_entry_size
= 8;
241 int dt_mips_local_gotno
= -1;
242 int dt_mips_gotsym
= -1;
243 struct cleanup
*cleanups
;
246 /* We currently only know how to handle alpha dynamic symbols. */
247 if (bfd_get_arch (abfd
) != bfd_arch_alpha
)
250 /* Locate the dynamic symbols sections and read them in. */
251 memset ((char *) &si
, 0, sizeof (si
));
252 bfd_map_over_sections (abfd
, alphacoff_locate_sections
, (void *) & si
);
253 if (si
.sym_sect
== NULL
254 || si
.str_sect
== NULL
255 || si
.dyninfo_sect
== NULL
256 || si
.got_sect
== NULL
)
259 sym_secsize
= bfd_get_section_size_before_reloc (si
.sym_sect
);
260 str_secsize
= bfd_get_section_size_before_reloc (si
.str_sect
);
261 dyninfo_secsize
= bfd_get_section_size_before_reloc (si
.dyninfo_sect
);
262 got_secsize
= bfd_get_section_size_before_reloc (si
.got_sect
);
263 sym_secptr
= xmalloc (sym_secsize
);
264 cleanups
= make_cleanup (free
, sym_secptr
);
265 str_secptr
= xmalloc (str_secsize
);
266 make_cleanup (free
, str_secptr
);
267 dyninfo_secptr
= xmalloc (dyninfo_secsize
);
268 make_cleanup (free
, dyninfo_secptr
);
269 got_secptr
= xmalloc (got_secsize
);
270 make_cleanup (free
, got_secptr
);
272 if (!bfd_get_section_contents (abfd
, si
.sym_sect
, sym_secptr
,
273 (file_ptr
) 0, sym_secsize
))
275 if (!bfd_get_section_contents (abfd
, si
.str_sect
, str_secptr
,
276 (file_ptr
) 0, str_secsize
))
278 if (!bfd_get_section_contents (abfd
, si
.dyninfo_sect
, dyninfo_secptr
,
279 (file_ptr
) 0, dyninfo_secsize
))
281 if (!bfd_get_section_contents (abfd
, si
.got_sect
, got_secptr
,
282 (file_ptr
) 0, got_secsize
))
285 /* Find the number of local GOT entries and the index for the
286 the first dynamic symbol in the GOT. */
287 for (dyninfo_p
= dyninfo_secptr
, dyninfo_end
= dyninfo_p
+ dyninfo_secsize
;
288 dyninfo_p
< dyninfo_end
;
289 dyninfo_p
+= sizeof (Elfalpha_External_Dyn
))
291 Elfalpha_External_Dyn
*x_dynp
= (Elfalpha_External_Dyn
*) dyninfo_p
;
294 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_tag
);
295 if (dyn_tag
== DT_NULL
)
297 else if (dyn_tag
== DT_MIPS_LOCAL_GOTNO
)
299 if (dt_mips_local_gotno
< 0)
301 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
303 else if (dyn_tag
== DT_MIPS_GOTSYM
)
305 if (dt_mips_gotsym
< 0)
307 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
310 if (dt_mips_local_gotno
< 0 || dt_mips_gotsym
< 0)
313 /* Scan all dynamic symbols and enter them into the minimal symbol table
315 sym_count
= sym_secsize
/ sizeof (Elfalpha_External_Sym
);
316 stripped
= (bfd_get_symcount (abfd
) == 0);
318 /* Skip first symbol, which is a null dummy. */
319 for (i
= 1, x_symp
= (Elfalpha_External_Sym
*) sym_secptr
+ 1;
326 unsigned char sym_info
;
327 unsigned int sym_shndx
;
329 enum minimal_symbol_type ms_type
;
331 strx
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_symp
->st_name
);
332 if (strx
>= str_secsize
)
334 name
= str_secptr
+ strx
;
335 if (*name
== '\0' || *name
== '.')
338 sym_value
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_symp
->st_value
);
339 sym_info
= bfd_h_get_8 (abfd
, (bfd_byte
*) x_symp
->st_info
);
340 sym_shndx
= bfd_h_get_16 (abfd
, (bfd_byte
*) x_symp
->st_shndx
);
341 isglobal
= (ELF_ST_BIND (sym_info
) == STB_GLOBAL
);
343 if (sym_shndx
== SHN_UNDEF
)
345 /* Handle undefined functions which are defined in a shared
347 if (ELF_ST_TYPE (sym_info
) != STT_FUNC
348 || ELF_ST_BIND (sym_info
) != STB_GLOBAL
)
351 ms_type
= mst_solib_trampoline
;
353 /* If sym_value is nonzero, it points to the shared library
354 trampoline entry, which is what we are looking for.
356 If sym_value is zero, then we have to get the GOT entry
358 If the GOT entry is nonzero, it represents the quickstart
359 address of the function and we use that as the symbol value.
361 If the GOT entry is zero, the function address has to be resolved
362 by the runtime loader before the executable is started.
363 We are unable to find any meaningful address for these
364 functions in the executable file, so we skip them. */
367 int got_entry_offset
=
368 (i
- dt_mips_gotsym
+ dt_mips_local_gotno
) * got_entry_size
;
370 if (got_entry_offset
< 0 || got_entry_offset
>= got_secsize
)
374 (bfd_byte
*) (got_secptr
+ got_entry_offset
));
381 /* Symbols defined in the executable itself. We only care about
382 them if this is a stripped executable, otherwise they have
383 been retrieved from the normal symbol table already. */
387 if (sym_shndx
== SHN_MIPS_TEXT
)
392 ms_type
= mst_file_text
;
393 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_TEXT (objfile
));
395 else if (sym_shndx
== SHN_MIPS_DATA
)
400 ms_type
= mst_file_data
;
401 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_DATA (objfile
));
403 else if (sym_shndx
== SHN_MIPS_ACOMMON
)
408 ms_type
= mst_file_bss
;
409 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_BSS (objfile
));
411 else if (sym_shndx
== SHN_ABS
)
421 prim_record_minimal_symbol (name
, sym_value
, ms_type
, objfile
);
424 do_cleanups (cleanups
);
429 static struct sym_fns ecoff_sym_fns
=
431 bfd_target_ecoff_flavour
,
432 mipscoff_new_init
, /* sym_new_init: init anything gbl to entire symtab */
433 mipscoff_symfile_init
, /* sym_init: read initial info, setup for sym_read() */
434 mipscoff_symfile_read
, /* sym_read: read a symbol file into symtab */
435 mipscoff_symfile_finish
, /* sym_finish: finished with file, cleanup */
436 default_symfile_offsets
, /* sym_offsets: dummy FIXME til implem sym reloc */
437 NULL
/* next: pointer to next struct sym_fns */
441 _initialize_mipsread (void)
443 add_symtab_fns (&ecoff_sym_fns
);