| 1 | /* Read NLM (NetWare Loadable Module) format executable files for GDB. |
| 2 | Copyright 1993, 1994, 1998 Free Software Foundation, Inc. |
| 3 | Written by Fred Fish at Cygnus Support (fnf@cygnus.com). |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program; if not, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "gdb_string.h" |
| 24 | #include "bfd.h" |
| 25 | #include "symtab.h" |
| 26 | #include "symfile.h" |
| 27 | #include "objfiles.h" |
| 28 | #include "gdb-stabs.h" |
| 29 | #include "buildsym.h" |
| 30 | #include "stabsread.h" |
| 31 | |
| 32 | extern void _initialize_nlmread (void); |
| 33 | |
| 34 | static void nlm_new_init (struct objfile *); |
| 35 | |
| 36 | static void nlm_symfile_init (struct objfile *); |
| 37 | |
| 38 | static void nlm_symfile_read (struct objfile *, int); |
| 39 | |
| 40 | static void nlm_symfile_finish (struct objfile *); |
| 41 | |
| 42 | static void nlm_symtab_read (bfd *, CORE_ADDR, struct objfile *); |
| 43 | |
| 44 | /* Initialize anything that needs initializing when a completely new symbol |
| 45 | file is specified (not just adding some symbols from another file, e.g. a |
| 46 | shared library). |
| 47 | |
| 48 | We reinitialize buildsym, since gdb will be able to read stabs from an NLM |
| 49 | file at some point in the near future. */ |
| 50 | |
| 51 | static void |
| 52 | nlm_new_init (struct objfile *ignore) |
| 53 | { |
| 54 | stabsread_new_init (); |
| 55 | buildsym_new_init (); |
| 56 | } |
| 57 | |
| 58 | |
| 59 | /* NLM specific initialization routine for reading symbols. |
| 60 | |
| 61 | It is passed a pointer to a struct sym_fns which contains, among other |
| 62 | things, the BFD for the file whose symbols are being read, and a slot for |
| 63 | a pointer to "private data" which we can fill with goodies. |
| 64 | |
| 65 | For now at least, we have nothing in particular to do, so this function is |
| 66 | just a stub. */ |
| 67 | |
| 68 | static void |
| 69 | nlm_symfile_init (struct objfile *ignore) |
| 70 | { |
| 71 | } |
| 72 | |
| 73 | /* |
| 74 | |
| 75 | LOCAL FUNCTION |
| 76 | |
| 77 | nlm_symtab_read -- read the symbol table of an NLM file |
| 78 | |
| 79 | SYNOPSIS |
| 80 | |
| 81 | void nlm_symtab_read (bfd *abfd, CORE_ADDR addr, |
| 82 | struct objfile *objfile) |
| 83 | |
| 84 | DESCRIPTION |
| 85 | |
| 86 | Given an open bfd, a base address to relocate symbols to, and a |
| 87 | flag that specifies whether or not this bfd is for an executable |
| 88 | or not (may be shared library for example), add all the global |
| 89 | function and data symbols to the minimal symbol table. |
| 90 | */ |
| 91 | |
| 92 | static void |
| 93 | nlm_symtab_read (bfd *abfd, CORE_ADDR addr, struct objfile *objfile) |
| 94 | { |
| 95 | long storage_needed; |
| 96 | asymbol *sym; |
| 97 | asymbol **symbol_table; |
| 98 | long number_of_symbols; |
| 99 | long i; |
| 100 | struct cleanup *back_to; |
| 101 | CORE_ADDR symaddr; |
| 102 | enum minimal_symbol_type ms_type; |
| 103 | |
| 104 | storage_needed = bfd_get_symtab_upper_bound (abfd); |
| 105 | if (storage_needed < 0) |
| 106 | error ("Can't read symbols from %s: %s", bfd_get_filename (abfd), |
| 107 | bfd_errmsg (bfd_get_error ())); |
| 108 | if (storage_needed > 0) |
| 109 | { |
| 110 | symbol_table = (asymbol **) xmalloc (storage_needed); |
| 111 | back_to = make_cleanup (free, symbol_table); |
| 112 | number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table); |
| 113 | if (number_of_symbols < 0) |
| 114 | error ("Can't read symbols from %s: %s", bfd_get_filename (abfd), |
| 115 | bfd_errmsg (bfd_get_error ())); |
| 116 | |
| 117 | for (i = 0; i < number_of_symbols; i++) |
| 118 | { |
| 119 | sym = symbol_table[i]; |
| 120 | if ( /*sym -> flags & BSF_GLOBAL */ 1) |
| 121 | { |
| 122 | /* Bfd symbols are section relative. */ |
| 123 | symaddr = sym->value + sym->section->vma; |
| 124 | /* Relocate all non-absolute symbols by base address. */ |
| 125 | if (sym->section != &bfd_abs_section) |
| 126 | symaddr += addr; |
| 127 | |
| 128 | /* For non-absolute symbols, use the type of the section |
| 129 | they are relative to, to intuit text/data. BFD provides |
| 130 | no way of figuring this out for absolute symbols. */ |
| 131 | if (sym->section->flags & SEC_CODE) |
| 132 | ms_type = mst_text; |
| 133 | else if (sym->section->flags & SEC_DATA) |
| 134 | ms_type = mst_data; |
| 135 | else |
| 136 | ms_type = mst_unknown; |
| 137 | |
| 138 | prim_record_minimal_symbol (sym->name, symaddr, ms_type, |
| 139 | objfile); |
| 140 | } |
| 141 | } |
| 142 | do_cleanups (back_to); |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | |
| 147 | /* Scan and build partial symbols for a symbol file. |
| 148 | We have been initialized by a call to nlm_symfile_init, which |
| 149 | currently does nothing. |
| 150 | |
| 151 | SECTION_OFFSETS is a set of offsets to apply to relocate the symbols |
| 152 | in each section. We simplify it down to a single offset for all |
| 153 | symbols. FIXME. |
| 154 | |
| 155 | MAINLINE is true if we are reading the main symbol |
| 156 | table (as opposed to a shared lib or dynamically loaded file). |
| 157 | |
| 158 | This function only does the minimum work necessary for letting the |
| 159 | user "name" things symbolically; it does not read the entire symtab. |
| 160 | Instead, it reads the external and static symbols and puts them in partial |
| 161 | symbol tables. When more extensive information is requested of a |
| 162 | file, the corresponding partial symbol table is mutated into a full |
| 163 | fledged symbol table by going back and reading the symbols |
| 164 | for real. |
| 165 | |
| 166 | Note that NLM files have two sets of information that is potentially |
| 167 | useful for building gdb's minimal symbol table. The first is a list |
| 168 | of the publically exported symbols, and is currently used to build |
| 169 | bfd's canonical symbol table. The second is an optional native debugging |
| 170 | format which contains additional symbols (and possibly duplicates of |
| 171 | the publically exported symbols). The optional native debugging format |
| 172 | is not currently used. */ |
| 173 | |
| 174 | static void |
| 175 | nlm_symfile_read (struct objfile *objfile, int mainline) |
| 176 | { |
| 177 | bfd *abfd = objfile->obfd; |
| 178 | struct cleanup *back_to; |
| 179 | CORE_ADDR offset; |
| 180 | struct symbol *mainsym; |
| 181 | |
| 182 | init_minimal_symbol_collection (); |
| 183 | back_to = make_cleanup_discard_minimal_symbols (); |
| 184 | |
| 185 | /* FIXME, should take a section_offsets param, not just an offset. */ |
| 186 | |
| 187 | offset = ANOFFSET (objfile->section_offsets, 0); |
| 188 | |
| 189 | /* Process the NLM export records, which become the bfd's canonical symbol |
| 190 | table. */ |
| 191 | |
| 192 | nlm_symtab_read (abfd, offset, objfile); |
| 193 | |
| 194 | stabsect_build_psymtabs (objfile, mainline, ".stab", |
| 195 | ".stabstr", ".text"); |
| 196 | |
| 197 | mainsym = lookup_symbol ("main", NULL, VAR_NAMESPACE, NULL, NULL); |
| 198 | |
| 199 | if (mainsym |
| 200 | && SYMBOL_CLASS (mainsym) == LOC_BLOCK) |
| 201 | { |
| 202 | objfile->ei.main_func_lowpc = BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym)); |
| 203 | objfile->ei.main_func_highpc = BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym)); |
| 204 | } |
| 205 | |
| 206 | /* FIXME: We could locate and read the optional native debugging format |
| 207 | here and add the symbols to the minimal symbol table. */ |
| 208 | |
| 209 | /* Install any minimal symbols that have been collected as the current |
| 210 | minimal symbols for this objfile. */ |
| 211 | |
| 212 | install_minimal_symbols (objfile); |
| 213 | |
| 214 | do_cleanups (back_to); |
| 215 | } |
| 216 | |
| 217 | |
| 218 | /* Perform any local cleanups required when we are done with a particular |
| 219 | objfile. I.E, we are in the process of discarding all symbol information |
| 220 | for an objfile, freeing up all memory held for it, and unlinking the |
| 221 | objfile struct from the global list of known objfiles. */ |
| 222 | |
| 223 | static void |
| 224 | nlm_symfile_finish (struct objfile *objfile) |
| 225 | { |
| 226 | if (objfile->sym_private != NULL) |
| 227 | { |
| 228 | mfree (objfile->md, objfile->sym_private); |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | /* Register that we are able to handle NLM file format. */ |
| 233 | |
| 234 | static struct sym_fns nlm_sym_fns = |
| 235 | { |
| 236 | bfd_target_nlm_flavour, |
| 237 | nlm_new_init, /* sym_new_init: init anything gbl to entire symtab */ |
| 238 | nlm_symfile_init, /* sym_init: read initial info, setup for sym_read() */ |
| 239 | nlm_symfile_read, /* sym_read: read a symbol file into symtab */ |
| 240 | nlm_symfile_finish, /* sym_finish: finished with file, cleanup */ |
| 241 | default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */ |
| 242 | NULL /* next: pointer to next struct sym_fns */ |
| 243 | }; |
| 244 | |
| 245 | void |
| 246 | _initialize_nlmread (void) |
| 247 | { |
| 248 | add_symtab_fns (&nlm_sym_fns); |
| 249 | } |