1 /* Read a symbol table in MIPS' format (Third-Eye).
3 Copyright (C) 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1998, 1999, 2000, 2001, 2003, 2004, 2007, 2008
5 Free Software Foundation, Inc.
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.
10 This file is part of GDB.
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
14 the Free Software Foundation; either version 3 of the License, or
15 (at your option) any later version.
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.
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>. */
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"
45 read_alphacoff_dynamic_symtab (struct section_offsets
*,
46 struct objfile
*objfile
);
48 /* Initialize anything that needs initializing when a completely new
49 symbol file is specified (not just adding some symbols from another
50 file, e.g. a shared library). */
53 mipscoff_new_init (struct objfile
*ignore
)
55 stabsread_new_init ();
59 /* Initialize to read a symbol file (nothing to do). */
62 mipscoff_symfile_init (struct objfile
*objfile
)
66 /* Read a symbol file from a file. */
69 mipscoff_symfile_read (struct objfile
*objfile
, int mainline
)
71 bfd
*abfd
= objfile
->obfd
;
72 struct cleanup
*back_to
;
74 init_minimal_symbol_collection ();
75 back_to
= make_cleanup_discard_minimal_symbols ();
77 /* Now that the executable file is positioned at symbol table,
78 process it and define symbols accordingly. */
80 if (!((*ecoff_backend (abfd
)->debug_swap
.read_debug_info
)
81 (abfd
, (asection
*) NULL
, &ecoff_data (abfd
)->debug_info
)))
82 error (_("Error reading symbol table: %s"), bfd_errmsg (bfd_get_error ()));
84 mdebug_build_psymtabs (objfile
, &ecoff_backend (abfd
)->debug_swap
,
85 &ecoff_data (abfd
)->debug_info
);
87 /* Add alpha coff dynamic symbols. */
89 read_alphacoff_dynamic_symtab (objfile
->section_offsets
, objfile
);
91 /* Install any minimal symbols that have been collected as the current
92 minimal symbols for this objfile. */
94 install_minimal_symbols (objfile
);
95 do_cleanups (back_to
);
98 /* Perform any local cleanups required when we are done with a
99 particular objfile. */
102 mipscoff_symfile_finish (struct objfile
*objfile
)
106 /* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a
107 standard COFF section. The ELF format for the symbols differs from
108 the format defined in elf/external.h. It seems that a normal ELF
109 32-bit format is used, and the representation only changes because
110 longs are 64-bit on the alpha. In addition, the handling of
111 text/data section indices for symbols is different from the ELF
112 ABI. As the BFD linker currently does not support dynamic linking
113 on the alpha, there seems to be no reason to pollute BFD with
114 another mixture of object file formats for now. */
116 /* Format of an alpha external ELF symbol. */
120 unsigned char st_name
[4]; /* Symbol name, index in string table. */
121 unsigned char st_pad
[4]; /* Pad to long word boundary. */
122 unsigned char st_value
[8]; /* Value of the symbol. */
123 unsigned char st_size
[4]; /* Associated symbol size. */
124 unsigned char st_info
[1]; /* Type and binding attributes. */
125 unsigned char st_other
[1]; /* No defined meaning, 0. */
126 unsigned char st_shndx
[2]; /* Associated section index. */
127 } Elfalpha_External_Sym
;
129 /* Format of an alpha external ELF dynamic info structure. */
133 unsigned char d_tag
[4]; /* Tag. */
134 unsigned char d_pad
[4]; /* Pad to long word boundary. */
137 unsigned char d_ptr
[8]; /* Pointer value. */
138 unsigned char d_val
[4]; /* Integer value. */
141 } Elfalpha_External_Dyn
;
143 /* Struct to obtain the section pointers for alpha dynamic symbol info. */
145 struct alphacoff_dynsecinfo
147 asection
*sym_sect
; /* Section pointer for .dynsym section. */
148 asection
*str_sect
; /* Section pointer for .dynstr section. */
149 asection
*dyninfo_sect
; /* Section pointer for .dynamic section. */
150 asection
*got_sect
; /* Section pointer for .got section. */
153 /* We are called once per section from read_alphacoff_dynamic_symtab.
154 We need to examine each section we are passed, check to see if it
155 is something we are interested in processing, and if so, stash away
156 some access information for the section. */
159 alphacoff_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, void *sip
)
161 struct alphacoff_dynsecinfo
*si
;
163 si
= (struct alphacoff_dynsecinfo
*) sip
;
165 if (strcmp (sectp
->name
, ".dynsym") == 0)
166 si
->sym_sect
= sectp
;
167 else if (strcmp (sectp
->name
, ".dynstr") == 0)
168 si
->str_sect
= sectp
;
169 else if (strcmp (sectp
->name
, ".dynamic") == 0)
170 si
->dyninfo_sect
= sectp
;
171 else if (strcmp (sectp
->name
, ".got") == 0)
172 si
->got_sect
= sectp
;
175 /* Scan an alpha dynamic symbol table for symbols of interest and add
176 them to the minimal symbol table. */
179 read_alphacoff_dynamic_symtab (struct section_offsets
*section_offsets
,
180 struct objfile
*objfile
)
182 bfd
*abfd
= objfile
->obfd
;
183 struct alphacoff_dynsecinfo si
;
186 char *dyninfo_secptr
;
188 bfd_size_type sym_secsize
;
189 bfd_size_type str_secsize
;
190 bfd_size_type dyninfo_secsize
;
191 bfd_size_type got_secsize
;
195 Elfalpha_External_Sym
*x_symp
;
198 int got_entry_size
= 8;
199 int dt_mips_local_gotno
= -1;
200 int dt_mips_gotsym
= -1;
201 struct cleanup
*cleanups
;
203 /* We currently only know how to handle alpha dynamic symbols. */
204 if (bfd_get_arch (abfd
) != bfd_arch_alpha
)
207 /* Locate the dynamic symbols sections and read them in. */
208 memset ((char *) &si
, 0, sizeof (si
));
209 bfd_map_over_sections (abfd
, alphacoff_locate_sections
, (void *) & si
);
210 if (si
.sym_sect
== NULL
|| si
.str_sect
== NULL
211 || si
.dyninfo_sect
== NULL
|| si
.got_sect
== NULL
)
214 sym_secsize
= bfd_get_section_size (si
.sym_sect
);
215 str_secsize
= bfd_get_section_size (si
.str_sect
);
216 dyninfo_secsize
= bfd_get_section_size (si
.dyninfo_sect
);
217 got_secsize
= bfd_get_section_size (si
.got_sect
);
218 sym_secptr
= xmalloc (sym_secsize
);
219 cleanups
= make_cleanup (free
, sym_secptr
);
220 str_secptr
= xmalloc (str_secsize
);
221 make_cleanup (free
, str_secptr
);
222 dyninfo_secptr
= xmalloc (dyninfo_secsize
);
223 make_cleanup (free
, dyninfo_secptr
);
224 got_secptr
= xmalloc (got_secsize
);
225 make_cleanup (free
, got_secptr
);
227 if (!bfd_get_section_contents (abfd
, si
.sym_sect
, sym_secptr
,
228 (file_ptr
) 0, sym_secsize
))
230 if (!bfd_get_section_contents (abfd
, si
.str_sect
, str_secptr
,
231 (file_ptr
) 0, str_secsize
))
233 if (!bfd_get_section_contents (abfd
, si
.dyninfo_sect
, dyninfo_secptr
,
234 (file_ptr
) 0, dyninfo_secsize
))
236 if (!bfd_get_section_contents (abfd
, si
.got_sect
, got_secptr
,
237 (file_ptr
) 0, got_secsize
))
240 /* Find the number of local GOT entries and the index for the the
241 first dynamic symbol in the GOT. */
242 for (dyninfo_p
= dyninfo_secptr
, dyninfo_end
= dyninfo_p
+ dyninfo_secsize
;
243 dyninfo_p
< dyninfo_end
;
244 dyninfo_p
+= sizeof (Elfalpha_External_Dyn
))
246 Elfalpha_External_Dyn
*x_dynp
= (Elfalpha_External_Dyn
*) dyninfo_p
;
249 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_tag
);
250 if (dyn_tag
== DT_NULL
)
252 else if (dyn_tag
== DT_MIPS_LOCAL_GOTNO
)
254 if (dt_mips_local_gotno
< 0)
256 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
258 else if (dyn_tag
== DT_MIPS_GOTSYM
)
260 if (dt_mips_gotsym
< 0)
262 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
265 if (dt_mips_local_gotno
< 0 || dt_mips_gotsym
< 0)
268 /* Scan all dynamic symbols and enter them into the minimal symbol
269 table if appropriate. */
270 sym_count
= sym_secsize
/ sizeof (Elfalpha_External_Sym
);
271 stripped
= (bfd_get_symcount (abfd
) == 0);
273 /* Skip first symbol, which is a null dummy. */
274 for (i
= 1, x_symp
= (Elfalpha_External_Sym
*) sym_secptr
+ 1;
281 unsigned char sym_info
;
282 unsigned int sym_shndx
;
284 enum minimal_symbol_type ms_type
;
286 strx
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_symp
->st_name
);
287 if (strx
>= str_secsize
)
289 name
= str_secptr
+ strx
;
290 if (*name
== '\0' || *name
== '.')
293 sym_value
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_symp
->st_value
);
294 sym_info
= bfd_h_get_8 (abfd
, (bfd_byte
*) x_symp
->st_info
);
295 sym_shndx
= bfd_h_get_16 (abfd
, (bfd_byte
*) x_symp
->st_shndx
);
296 isglobal
= (ELF_ST_BIND (sym_info
) == STB_GLOBAL
);
298 if (sym_shndx
== SHN_UNDEF
)
300 /* Handle undefined functions which are defined in a shared
302 if (ELF_ST_TYPE (sym_info
) != STT_FUNC
303 || ELF_ST_BIND (sym_info
) != STB_GLOBAL
)
306 ms_type
= mst_solib_trampoline
;
308 /* If sym_value is nonzero, it points to the shared library
309 trampoline entry, which is what we are looking for.
311 If sym_value is zero, then we have to get the GOT entry
314 If the GOT entry is nonzero, it represents the quickstart
315 address of the function and we use that as the symbol
318 If the GOT entry is zero, the function address has to be
319 resolved by the runtime loader before the executable is
320 started. We are unable to find any meaningful address
321 for these functions in the executable file, so we skip
325 int got_entry_offset
=
326 (i
- dt_mips_gotsym
+ dt_mips_local_gotno
) * got_entry_size
;
328 if (got_entry_offset
< 0 || got_entry_offset
>= got_secsize
)
332 (bfd_byte
*) (got_secptr
+ got_entry_offset
));
339 /* Symbols defined in the executable itself. We only care
340 about them if this is a stripped executable, otherwise
341 they have been retrieved from the normal symbol table
346 if (sym_shndx
== SHN_MIPS_TEXT
)
351 ms_type
= mst_file_text
;
352 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_TEXT (objfile
));
354 else if (sym_shndx
== SHN_MIPS_DATA
)
359 ms_type
= mst_file_data
;
360 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_DATA (objfile
));
362 else if (sym_shndx
== SHN_MIPS_ACOMMON
)
367 ms_type
= mst_file_bss
;
368 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_BSS (objfile
));
370 else if (sym_shndx
== SHN_ABS
)
380 prim_record_minimal_symbol (name
, sym_value
, ms_type
, objfile
);
383 do_cleanups (cleanups
);
386 /* Initialization. */
388 static struct sym_fns ecoff_sym_fns
=
390 bfd_target_ecoff_flavour
,
391 mipscoff_new_init
, /* sym_new_init: init anything gbl to entire symtab */
392 mipscoff_symfile_init
, /* sym_init: read initial info, setup for sym_read() */
393 mipscoff_symfile_read
, /* sym_read: read a symbol file into symtab */
394 mipscoff_symfile_finish
, /* sym_finish: finished with file, cleanup */
395 default_symfile_offsets
, /* sym_offsets: dummy FIXME til implem sym reloc */
396 default_symfile_segments
, /* sym_segments: Get segment information from
398 NULL
, /* sym_read_linetable */
399 NULL
/* next: pointer to next struct sym_fns */
402 /* Provide a prototype to silence -Wmissing-prototypes. */
403 void _initialize_mipsread (void);
406 _initialize_mipsread (void)
408 add_symtab_fns (&ecoff_sym_fns
);