1 /* Read a symbol table in MIPS' format (Third-Eye).
2 Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
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"
35 #include "stabsread.h"
36 #include "gdb-stabs.h"
39 #include "coff/internal.h"
40 #include "coff/ecoff.h"
41 #include "libcoff.h" /* Private BFD COFF information. */
42 #include "libecoff.h" /* Private BFD ECOFF information. */
43 #include "elf/common.h"
46 extern void _initialize_mipsread (void);
48 static void mipscoff_new_init (struct objfile
*);
50 static void mipscoff_symfile_init (struct objfile
*);
52 static void mipscoff_symfile_read (struct objfile
*, int);
54 static void mipscoff_symfile_finish (struct objfile
*);
57 read_alphacoff_dynamic_symtab (struct section_offsets
*,
58 struct objfile
*objfile
);
60 /* Initialize anything that needs initializing when a completely new
61 symbol file is specified (not just adding some symbols from another
62 file, e.g. a shared library). */
64 extern CORE_ADDR sigtramp_address
;
67 mipscoff_new_init (struct objfile
*ignore
)
70 stabsread_new_init ();
74 /* Initialize to read a symbol file (nothing to do). */
77 mipscoff_symfile_init (struct objfile
*objfile
)
81 /* Read a symbol file from a file. */
84 mipscoff_symfile_read (struct objfile
*objfile
, int mainline
)
86 bfd
*abfd
= objfile
->obfd
;
87 struct cleanup
*back_to
;
89 init_minimal_symbol_collection ();
90 back_to
= make_cleanup_discard_minimal_symbols ();
92 /* Now that the executable file is positioned at symbol table,
93 process it and define symbols accordingly. */
95 if (!((*ecoff_backend (abfd
)->debug_swap
.read_debug_info
)
96 (abfd
, (asection
*) NULL
, &ecoff_data (abfd
)->debug_info
)))
97 error ("Error reading symbol table: %s", bfd_errmsg (bfd_get_error ()));
99 mdebug_build_psymtabs (objfile
, &ecoff_backend (abfd
)->debug_swap
,
100 &ecoff_data (abfd
)->debug_info
);
102 /* Add alpha coff dynamic symbols. */
104 read_alphacoff_dynamic_symtab (objfile
->section_offsets
, objfile
);
106 /* Install any minimal symbols that have been collected as the current
107 minimal symbols for this objfile. */
109 install_minimal_symbols (objfile
);
111 /* If the entry_file bounds are still unknown after processing the
112 partial symbols, then try to set them from the minimal symbols
113 surrounding the entry_point. */
116 && objfile
->ei
.entry_point
!= INVALID_ENTRY_POINT
117 && objfile
->ei
.entry_file_lowpc
== INVALID_ENTRY_LOWPC
)
119 struct minimal_symbol
*m
;
121 m
= lookup_minimal_symbol_by_pc (objfile
->ei
.entry_point
);
122 if (m
&& SYMBOL_NAME (m
+ 1))
124 objfile
->ei
.entry_file_lowpc
= SYMBOL_VALUE_ADDRESS (m
);
125 objfile
->ei
.entry_file_highpc
= SYMBOL_VALUE_ADDRESS (m
+ 1);
129 do_cleanups (back_to
);
132 /* Perform any local cleanups required when we are done with a
133 particular objfile. */
136 mipscoff_symfile_finish (struct objfile
*objfile
)
140 /* Alpha OSF/1 encapsulates the dynamic symbols in ELF format in a
141 standard coff section. The ELF format for the symbols differs from
142 the format defined in elf/external.h. It seems that a normal ELF 32 bit
143 format is used, and the representation only changes because longs are
144 64 bit on the alpha. In addition, the handling of text/data section
145 indices for symbols is different from the ELF ABI.
146 As the BFD linker currently does not support dynamic linking on the alpha,
147 there seems to be no reason to pollute BFD with another mixture of object
148 file formats for now. */
150 /* Format of an alpha external ELF symbol. */
154 unsigned char st_name
[4]; /* Symbol name, index in string tbl */
155 unsigned char st_pad
[4]; /* Pad to long word boundary */
156 unsigned char st_value
[8]; /* Value of the symbol */
157 unsigned char st_size
[4]; /* Associated symbol size */
158 unsigned char st_info
[1]; /* Type and binding attributes */
159 unsigned char st_other
[1]; /* No defined meaning, 0 */
160 unsigned char st_shndx
[2]; /* Associated section index */
162 Elfalpha_External_Sym
;
164 /* Format of an alpha external ELF dynamic info structure. */
168 unsigned char d_tag
[4]; /* Tag */
169 unsigned char d_pad
[4]; /* Pad to long word boundary */
172 unsigned char d_ptr
[8]; /* Pointer value */
173 unsigned char d_val
[4]; /* Integer value */
177 Elfalpha_External_Dyn
;
179 /* Struct to obtain the section pointers for alpha dynamic symbol info. */
181 struct alphacoff_dynsecinfo
183 asection
*sym_sect
; /* Section pointer for .dynsym section */
184 asection
*str_sect
; /* Section pointer for .dynstr section */
185 asection
*dyninfo_sect
; /* Section pointer for .dynamic section */
186 asection
*got_sect
; /* Section pointer for .got section */
189 static void alphacoff_locate_sections (bfd
*, asection
*, void *);
191 /* We are called once per section from read_alphacoff_dynamic_symtab.
192 We need to examine each section we are passed, check to see
193 if it is something we are interested in processing, and
194 if so, stash away some access information for the section. */
197 alphacoff_locate_sections (bfd
*ignore_abfd
, asection
*sectp
, PTR sip
)
199 register struct alphacoff_dynsecinfo
*si
;
201 si
= (struct alphacoff_dynsecinfo
*) sip
;
203 if (STREQ (sectp
->name
, ".dynsym"))
205 si
->sym_sect
= sectp
;
207 else if (STREQ (sectp
->name
, ".dynstr"))
209 si
->str_sect
= sectp
;
211 else if (STREQ (sectp
->name
, ".dynamic"))
213 si
->dyninfo_sect
= sectp
;
215 else if (STREQ (sectp
->name
, ".got"))
217 si
->got_sect
= sectp
;
221 /* Scan an alpha dynamic symbol table for symbols of interest and
222 add them to the minimal symbol table. */
225 read_alphacoff_dynamic_symtab (struct section_offsets
*section_offsets
,
226 struct objfile
*objfile
)
228 bfd
*abfd
= objfile
->obfd
;
229 struct alphacoff_dynsecinfo si
;
232 char *dyninfo_secptr
;
234 bfd_size_type sym_secsize
;
235 bfd_size_type str_secsize
;
236 bfd_size_type dyninfo_secsize
;
237 bfd_size_type got_secsize
;
241 Elfalpha_External_Sym
*x_symp
;
244 int got_entry_size
= 8;
245 int dt_mips_local_gotno
= -1;
246 int dt_mips_gotsym
= -1;
247 struct cleanup
*cleanups
;
250 /* We currently only know how to handle alpha dynamic symbols. */
251 if (bfd_get_arch (abfd
) != bfd_arch_alpha
)
254 /* Locate the dynamic symbols sections and read them in. */
255 memset ((char *) &si
, 0, sizeof (si
));
256 bfd_map_over_sections (abfd
, alphacoff_locate_sections
, (PTR
) & si
);
257 if (si
.sym_sect
== NULL
258 || si
.str_sect
== NULL
259 || si
.dyninfo_sect
== NULL
260 || si
.got_sect
== NULL
)
263 sym_secsize
= bfd_get_section_size_before_reloc (si
.sym_sect
);
264 str_secsize
= bfd_get_section_size_before_reloc (si
.str_sect
);
265 dyninfo_secsize
= bfd_get_section_size_before_reloc (si
.dyninfo_sect
);
266 got_secsize
= bfd_get_section_size_before_reloc (si
.got_sect
);
267 sym_secptr
= xmalloc (sym_secsize
);
268 cleanups
= make_cleanup (free
, sym_secptr
);
269 str_secptr
= xmalloc (str_secsize
);
270 make_cleanup (free
, str_secptr
);
271 dyninfo_secptr
= xmalloc (dyninfo_secsize
);
272 make_cleanup (free
, dyninfo_secptr
);
273 got_secptr
= xmalloc (got_secsize
);
274 make_cleanup (free
, got_secptr
);
276 if (!bfd_get_section_contents (abfd
, si
.sym_sect
, sym_secptr
,
277 (file_ptr
) 0, sym_secsize
))
279 if (!bfd_get_section_contents (abfd
, si
.str_sect
, str_secptr
,
280 (file_ptr
) 0, str_secsize
))
282 if (!bfd_get_section_contents (abfd
, si
.dyninfo_sect
, dyninfo_secptr
,
283 (file_ptr
) 0, dyninfo_secsize
))
285 if (!bfd_get_section_contents (abfd
, si
.got_sect
, got_secptr
,
286 (file_ptr
) 0, got_secsize
))
289 /* Find the number of local GOT entries and the index for the
290 the first dynamic symbol in the GOT. */
291 for (dyninfo_p
= dyninfo_secptr
, dyninfo_end
= dyninfo_p
+ dyninfo_secsize
;
292 dyninfo_p
< dyninfo_end
;
293 dyninfo_p
+= sizeof (Elfalpha_External_Dyn
))
295 Elfalpha_External_Dyn
*x_dynp
= (Elfalpha_External_Dyn
*) dyninfo_p
;
298 dyn_tag
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_tag
);
299 if (dyn_tag
== DT_NULL
)
301 else if (dyn_tag
== DT_MIPS_LOCAL_GOTNO
)
303 if (dt_mips_local_gotno
< 0)
305 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
307 else if (dyn_tag
== DT_MIPS_GOTSYM
)
309 if (dt_mips_gotsym
< 0)
311 = bfd_h_get_32 (abfd
, (bfd_byte
*) x_dynp
->d_un
.d_val
);
314 if (dt_mips_local_gotno
< 0 || dt_mips_gotsym
< 0)
317 /* Scan all dynamic symbols and enter them into the minimal symbol table
319 sym_count
= sym_secsize
/ sizeof (Elfalpha_External_Sym
);
320 stripped
= (bfd_get_symcount (abfd
) == 0);
322 /* Skip first symbol, which is a null dummy. */
323 for (i
= 1, x_symp
= (Elfalpha_External_Sym
*) sym_secptr
+ 1;
330 unsigned char sym_info
;
331 unsigned int sym_shndx
;
333 enum minimal_symbol_type ms_type
;
335 strx
= bfd_h_get_32 (abfd
, (bfd_byte
*) x_symp
->st_name
);
336 if (strx
>= str_secsize
)
338 name
= str_secptr
+ strx
;
339 if (*name
== '\0' || *name
== '.')
342 sym_value
= bfd_h_get_64 (abfd
, (bfd_byte
*) x_symp
->st_value
);
343 sym_info
= bfd_h_get_8 (abfd
, (bfd_byte
*) x_symp
->st_info
);
344 sym_shndx
= bfd_h_get_16 (abfd
, (bfd_byte
*) x_symp
->st_shndx
);
345 isglobal
= (ELF_ST_BIND (sym_info
) == STB_GLOBAL
);
347 if (sym_shndx
== SHN_UNDEF
)
349 /* Handle undefined functions which are defined in a shared
351 if (ELF_ST_TYPE (sym_info
) != STT_FUNC
352 || ELF_ST_BIND (sym_info
) != STB_GLOBAL
)
355 ms_type
= mst_solib_trampoline
;
357 /* If sym_value is nonzero, it points to the shared library
358 trampoline entry, which is what we are looking for.
360 If sym_value is zero, then we have to get the GOT entry
362 If the GOT entry is nonzero, it represents the quickstart
363 address of the function and we use that as the symbol value.
365 If the GOT entry is zero, the function address has to be resolved
366 by the runtime loader before the executable is started.
367 We are unable to find any meaningful address for these
368 functions in the executable file, so we skip them. */
371 int got_entry_offset
=
372 (i
- dt_mips_gotsym
+ dt_mips_local_gotno
) * got_entry_size
;
374 if (got_entry_offset
< 0 || got_entry_offset
>= got_secsize
)
378 (bfd_byte
*) (got_secptr
+ got_entry_offset
));
385 /* Symbols defined in the executable itself. We only care about
386 them if this is a stripped executable, otherwise they have
387 been retrieved from the normal symbol table already. */
391 if (sym_shndx
== SHN_MIPS_TEXT
)
396 ms_type
= mst_file_text
;
397 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_TEXT (objfile
));
399 else if (sym_shndx
== SHN_MIPS_DATA
)
404 ms_type
= mst_file_data
;
405 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_DATA (objfile
));
407 else if (sym_shndx
== SHN_MIPS_ACOMMON
)
412 ms_type
= mst_file_bss
;
413 sym_value
+= ANOFFSET (section_offsets
, SECT_OFF_BSS (objfile
));
415 else if (sym_shndx
== SHN_ABS
)
425 prim_record_minimal_symbol (name
, sym_value
, ms_type
, objfile
);
428 do_cleanups (cleanups
);
433 static struct sym_fns ecoff_sym_fns
=
435 bfd_target_ecoff_flavour
,
436 mipscoff_new_init
, /* sym_new_init: init anything gbl to entire symtab */
437 mipscoff_symfile_init
, /* sym_init: read initial info, setup for sym_read() */
438 mipscoff_symfile_read
, /* sym_read: read a symbol file into symtab */
439 mipscoff_symfile_finish
, /* sym_finish: finished with file, cleanup */
440 default_symfile_offsets
, /* sym_offsets: dummy FIXME til implem sym reloc */
441 NULL
/* next: pointer to next struct sym_fns */
445 _initialize_mipsread (void)
447 add_symtab_fns (&ecoff_sym_fns
);