bfd/libecoff.h

   1 /* BFD ECOFF object file private structure.
   2    Copyright (C) 1993, 94, 95, 96, 1997 Free Software Foundation, Inc.
   3    Written by Ian Lance Taylor, Cygnus Support.
   4
   5 This file is part of BFD, the Binary File Descriptor library.
   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, Boston, MA 02111-1307, USA.  */
  20
  21 #include "bfdlink.h"
  22
  23 #ifndef ECOFF_H
  24 #include "coff/ecoff.h"
  25 #endif
  26
  27 /* This is the backend information kept for ECOFF files.  This
  28    structure is constant for a particular backend.  The first element
  29    is the COFF backend data structure, so that ECOFF targets can use
  30    the generic COFF code.  */
  31
  32 #define ecoff_backend(abfd) \
  33   ((struct ecoff_backend_data *) (abfd)->xvec->backend_data)
  34
  35 struct ecoff_backend_data
  36 {
  37   /* COFF backend information.  This must be the first field.  */
  38   bfd_coff_backend_data coff;
  39   /* Supported architecture.  */
  40   enum bfd_architecture arch;
  41   /* Initial portion of armap string.  */
  42   const char *armap_start;
  43   /* The page boundary used to align sections in a demand-paged
  44      executable file.  E.g., 0x1000.  */
  45   bfd_vma round;
  46   /* True if the .rdata section is part of the text segment, as on the
  47      Alpha.  False if .rdata is part of the data segment, as on the
  48      MIPS.  */
  49   boolean rdata_in_text;
  50   /* Bitsize of constructor entries.  */
  51   unsigned int constructor_bitsize;
  52   /* Reloc to use for constructor entries.  */
  53   reloc_howto_type *constructor_reloc;
  54   /* How to swap debugging information.  */
  55   struct ecoff_debug_swap debug_swap;
  56   /* External reloc size.  */
  57   bfd_size_type external_reloc_size;
  58   /* Reloc swapping functions.  */
  59   void (*swap_reloc_in) PARAMS ((bfd *, PTR, struct internal_reloc *));
  60   void (*swap_reloc_out) PARAMS ((bfd *, const struct internal_reloc *, PTR));
  61   /* Backend reloc tweaking.  */
  62   void (*adjust_reloc_in) PARAMS ((bfd *, const struct internal_reloc *,
  63                                    arelent *));
  64   void (*adjust_reloc_out) PARAMS ((bfd *, const arelent *,
  65                                     struct internal_reloc *));
  66   /* Relocate section contents while linking.  */
  67   boolean (*relocate_section) PARAMS ((bfd *output_bfd, struct bfd_link_info *,
  68                                        bfd *input_bfd, asection *input_section,
  69                                        bfd_byte *contents,
  70                                        PTR external_relocs));
  71   /* Do final adjustments to filehdr and aouthdr.  */
  72   boolean (*adjust_headers) PARAMS ((bfd *, struct internal_filehdr *,
  73                                      struct internal_aouthdr *));
  74   /* Read an element from an archive at a given file position.  This
  75      is needed because OSF/1 3.2 uses a weird archive format.  */
  76   bfd *(*get_elt_at_filepos) PARAMS ((bfd *, file_ptr));
  77 };
  78
  79 /* This is the target specific information kept for ECOFF files.  */
  80
  81 #define ecoff_data(abfd) ((abfd)->tdata.ecoff_obj_data)
  82
  83 typedef struct ecoff_tdata
  84 {
  85   /* The reloc file position, set by
  86      ecoff_compute_section_file_positions.  */
  87   file_ptr reloc_filepos;
  88
  89   /* The symbol table file position, set by _bfd_ecoff_mkobject_hook.  */
  90   file_ptr sym_filepos;
  91
  92   /* The start and end of the text segment.  Only valid for an
  93      existing file, not for one we are creating.  */
  94   unsigned long text_start;
  95   unsigned long text_end;
  96
  97   /* The cached gp value.  This is used when relocating.  */
  98   bfd_vma gp;
  99
 100   /* The maximum size of objects to optimize using gp.  This is
 101      typically set by the -G option to the compiler, assembler or
 102      linker.  */
 103   unsigned int gp_size;
 104
 105   /* The register masks.  When linking, all the masks found in the
 106      input files are combined into the masks of the output file.
 107      These are not all used for all targets, but that's OK, because
 108      the relevant ones are the only ones swapped in and out.  */
 109   unsigned long gprmask;
 110   unsigned long fprmask;
 111   unsigned long cprmask[4];
 112
 113   /* The ECOFF symbolic debugging information.  */
 114   struct ecoff_debug_info debug_info;
 115
 116   /* The unswapped ECOFF symbolic information.  */
 117   PTR raw_syments;
 118
 119   /* The canonical BFD symbols.  */
 120   struct ecoff_symbol_struct *canonical_symbols;
 121
 122   /* A mapping from external symbol numbers to entries in the linker
 123      hash table, used when linking.  */
 124   struct ecoff_link_hash_entry **sym_hashes;
 125
 126   /* A mapping from reloc symbol indices to sections, used when
 127      linking.  */
 128   asection **symndx_to_section;
 129
 130   /* True if this BFD was written by the backend linker.  */
 131   boolean linker;
 132
 133   /* True if a warning that multiple global pointer values are
 134      needed in the output binary was issued already.  */
 135   boolean issued_multiple_gp_warning;
 136
 137   /* Used by find_nearest_line entry point.  The structure could be
 138      included directly in this one, but there's no point to wasting
 139      the memory just for the infrequently called find_nearest_line.  */
 140   struct ecoff_find_line *find_line_info;
 141
 142   /* Whether the .rdata section is in the text segment for this
 143      particular ECOFF file.  This is not valid until
 144      ecoff_compute_section_file_positions is called.  */
 145   boolean rdata_in_text;
 146
 147 } ecoff_data_type;
 148
 149 /* Each canonical asymbol really looks like this.  */
 150
 151 typedef struct ecoff_symbol_struct
 152 {
 153   /* The actual symbol which the rest of BFD works with */
 154   asymbol symbol;
 155
 156   /* The fdr for this symbol.  */
 157   FDR *fdr;
 158
 159   /* true if this is a local symbol rather than an external one.  */
 160   boolean local;
 161
 162   /* A pointer to the unswapped hidden information for this symbol.
 163      This is either a struct sym_ext or a struct ext_ext, depending on
 164      the value of the local field above.  */
 165   PTR native;
 166 } ecoff_symbol_type;
 167
 168 /* We take the address of the first element of a asymbol to ensure that the
 169    macro is only ever applied to an asymbol.  */
 170 #define ecoffsymbol(asymbol) ((ecoff_symbol_type *) (&((asymbol)->the_bfd)))
 171
 172 /* We need to save the index of an external symbol when we write it
 173    out so that can set the symbol index correctly when we write out
 174    the relocs.  */
 175 #define ecoff_get_sym_index(symbol) ((symbol)->udata.i)
 176 #define ecoff_set_sym_index(symbol, idx) ((symbol)->udata.i = (idx))
 177
 178 /* When generating MIPS embedded PIC code, the linker relaxes the code
 179    to turn PC relative branches into longer code sequences when the PC
 180    relative branch is out of range.  This involves reading the relocs
 181    in bfd_relax_section as well as in bfd_final_link, and requires the
 182    code to keep track of which relocs have been expanded.  A pointer
 183    to this structure is put in the used_by_bfd pointer of a section to
 184    keep track of this information.  The user_by_bfd pointer will be
 185    NULL if the information was not needed.  */
 186
 187 struct ecoff_section_tdata
 188 {
 189   /* The unswapped relocs for this section.  These are stored in
 190      memory so the input file does not have to be read twice.  */
 191   PTR external_relocs;
 192
 193   /* The contents of the section.  These bytes may or may not be saved
 194      in memory, but if it is this is a pointer to them.  */
 195   bfd_byte *contents;
 196
 197   /* Offset adjustments for PC relative branches.  A number other than
 198      1 is an addend for a PC relative branch, or a switch table entry
 199      which is the difference of two .text locations; this addend
 200      arises because the branch or difference crosses one or more
 201      branches which were expanded into a larger code sequence.  A 1
 202      means that this branch was itself expanded into a larger code
 203      sequence.  1 is not a possible offset, since all offsets must be
 204      multiples of the instruction size, which is 4; also, the only
 205      relocs with non-zero offsets will be PC relative branches or
 206      switch table entries within the same object file.  If this field
 207      is NULL, no branches were expanded and no offsets are required.
 208      Otherwise there are as many entries as there are relocs in the
 209      section, and the entry for any reloc that is not PC relative is
 210      zero.  */
 211   long *offsets;
 212
 213   /* When producing an executable (i.e., final, non-relocatable link)
 214      on the Alpha, we may need to use multiple global pointer values
 215      to span the entire .lita section.  In essence, we allow each
 216      input .lita section to have its own gp value.  To support this,
 217      we need to keep track of the gp values that we picked for each
 218      input .lita section . */
 219   bfd_vma gp;
 220 };
 221
 222 /* An accessor macro for the ecoff_section_tdata structure.  */
 223 #define ecoff_section_data(abfd, sec) \
 224   ((struct ecoff_section_tdata *) (sec)->used_by_bfd)
 225
 226 /* ECOFF linker hash table entries.  */
 227
 228 struct ecoff_link_hash_entry
 229 {
 230   struct bfd_link_hash_entry root;
 231   /* Symbol index in output file.  */
 232   long indx;
 233   /* BFD that ext field value came from.  */
 234   bfd *abfd;
 235   /* ECOFF external symbol information.  */
 236   EXTR esym;
 237   /* Nonzero if this symbol has been written out.  */
 238   char written;
 239   /* Nonzero if this symbol was referred to as small undefined.  */
 240   char small;
 241 };
 242
 243 /* ECOFF linker hash table.  */
 244
 245 struct ecoff_link_hash_table
 246 {
 247   struct bfd_link_hash_table root;
 248 };
 249
 250 /* Make an ECOFF object.  */
 251 extern boolean _bfd_ecoff_mkobject PARAMS ((bfd *));
 252
 253 /* Read in the ECOFF symbolic debugging information.  */
 254 extern boolean _bfd_ecoff_slurp_symbolic_info
 255   PARAMS ((bfd *, asection *, struct ecoff_debug_info *));
 256
 257 /* Generic ECOFF BFD backend vectors.  */
 258
 259 extern boolean _bfd_ecoff_write_object_contents PARAMS ((bfd *abfd));
 260 extern const bfd_target *_bfd_ecoff_archive_p PARAMS ((bfd *abfd));
 261
 262 #define _bfd_ecoff_close_and_cleanup _bfd_generic_close_and_cleanup
 263 #define _bfd_ecoff_bfd_free_cached_info _bfd_generic_bfd_free_cached_info
 264 extern boolean _bfd_ecoff_new_section_hook
 265   PARAMS ((bfd *, asection *));
 266 extern boolean _bfd_ecoff_get_section_contents
 267   PARAMS ((bfd *, asection *, PTR location, file_ptr, bfd_size_type));
 268
 269 #define _bfd_ecoff_bfd_link_split_section _bfd_generic_link_split_section
 270
 271 extern boolean _bfd_ecoff_bfd_copy_private_bfd_data PARAMS ((bfd *, bfd *));
 272 #define _bfd_ecoff_bfd_copy_private_section_data \
 273   _bfd_generic_bfd_copy_private_section_data
 274
 275 #define _bfd_ecoff_bfd_copy_private_symbol_data \
 276   _bfd_generic_bfd_copy_private_symbol_data
 277
 278 #define _bfd_ecoff_bfd_print_private_bfd_data \
 279   _bfd_generic_bfd_print_private_bfd_data
 280
 281 #define _bfd_ecoff_bfd_merge_private_bfd_data \
 282   _bfd_generic_bfd_merge_private_bfd_data
 283
 284 #define _bfd_ecoff_bfd_set_private_flags _bfd_generic_bfd_set_private_flags
 285 extern boolean _bfd_ecoff_slurp_armap PARAMS ((bfd *abfd));
 286 #define _bfd_ecoff_slurp_extended_name_table _bfd_slurp_extended_name_table
 287 #define _bfd_ecoff_construct_extended_name_table \
 288   _bfd_archive_bsd_construct_extended_name_table
 289 #define _bfd_ecoff_truncate_arname bfd_dont_truncate_arname
 290 extern boolean _bfd_ecoff_write_armap
 291   PARAMS ((bfd *, unsigned int, struct orl *, unsigned int, int));
 292 #define _bfd_ecoff_read_ar_hdr _bfd_generic_read_ar_hdr
 293 #define _bfd_ecoff_openr_next_archived_file \
 294   bfd_generic_openr_next_archived_file
 295 #define _bfd_ecoff_get_elt_at_index _bfd_generic_get_elt_at_index
 296 #define _bfd_ecoff_generic_stat_arch_elt bfd_generic_stat_arch_elt
 297 #define _bfd_ecoff_update_armap_timestamp bfd_true
 298
 299 extern long _bfd_ecoff_get_symtab_upper_bound PARAMS ((bfd *abfd));
 300 extern long _bfd_ecoff_get_symtab PARAMS ((bfd *abfd, asymbol **alocation));
 301 extern asymbol *_bfd_ecoff_make_empty_symbol PARAMS ((bfd *abfd));
 302 extern void _bfd_ecoff_print_symbol
 303   PARAMS ((bfd *, PTR filep, asymbol *, bfd_print_symbol_type));
 304 extern void _bfd_ecoff_get_symbol_info
 305   PARAMS ((bfd *, asymbol *, symbol_info *));
 306 extern boolean _bfd_ecoff_bfd_is_local_label_name
 307   PARAMS ((bfd *, const char *));
 308 #define _bfd_ecoff_get_lineno _bfd_nosymbols_get_lineno
 309 extern boolean _bfd_ecoff_find_nearest_line
 310   PARAMS ((bfd *, asection *, asymbol **, bfd_vma offset,
 311            const char **filename_ptr, const char **fnname_ptr,
 312            unsigned int *retline_ptr));
 313 #define _bfd_ecoff_bfd_make_debug_symbol _bfd_nosymbols_bfd_make_debug_symbol
 314 #define _bfd_ecoff_read_minisymbols _bfd_generic_read_minisymbols
 315 #define _bfd_ecoff_minisymbol_to_symbol _bfd_generic_minisymbol_to_symbol
 316
 317 #define _bfd_ecoff_get_reloc_upper_bound coff_get_reloc_upper_bound
 318 extern long _bfd_ecoff_canonicalize_reloc
 319   PARAMS ((bfd *, asection *, arelent **, asymbol **symbols));
 320 /* ecoff_bfd_reloc_type_lookup defined by backend. */
 321
 322 extern boolean _bfd_ecoff_set_arch_mach
 323   PARAMS ((bfd *, enum bfd_architecture, unsigned long machine));
 324 extern boolean _bfd_ecoff_set_section_contents
 325   PARAMS ((bfd *, asection *, PTR location, file_ptr, bfd_size_type));
 326
 327 extern int _bfd_ecoff_sizeof_headers PARAMS ((bfd *abfd, boolean reloc));
 328 /* ecoff_bfd_get_relocated_section_contents defined by backend.  */
 329 /* ecoff_bfd_relax_section defined by backend.  */
 330 extern struct bfd_link_hash_table *_bfd_ecoff_bfd_link_hash_table_create
 331   PARAMS ((bfd *));
 332 extern boolean _bfd_ecoff_bfd_link_add_symbols
 333   PARAMS ((bfd *, struct bfd_link_info *));
 334 extern boolean _bfd_ecoff_bfd_final_link
 335   PARAMS ((bfd *, struct bfd_link_info *));
 336
 337 /* Hook functions for the generic COFF section reading code.  */
 338
 339 extern PTR _bfd_ecoff_mkobject_hook PARAMS ((bfd *, PTR filehdr, PTR aouthdr));
 340 #define _bfd_ecoff_set_alignment_hook \
 341   ((void (*) PARAMS ((bfd *, asection *, PTR))) bfd_void)
 342 extern boolean _bfd_ecoff_set_arch_mach_hook PARAMS ((bfd *abfd, PTR filehdr));
 343 extern flagword _bfd_ecoff_styp_to_sec_flags
 344   PARAMS ((bfd *abfd, PTR hdr, const char *name));
 345 extern boolean _bfd_ecoff_slurp_symbol_table PARAMS ((bfd *abfd));
 346
 347 /* ECOFF auxiliary information swapping routines.  These are the same
 348    for all ECOFF targets, so they are defined in ecofflink.c.  */
 349
 350 extern void _bfd_ecoff_swap_tir_in
 351   PARAMS ((int, const struct tir_ext *, TIR *));
 352 extern void _bfd_ecoff_swap_tir_out
 353   PARAMS ((int, const TIR *, struct tir_ext *));
 354 extern void _bfd_ecoff_swap_rndx_in
 355   PARAMS ((int, const struct rndx_ext *, RNDXR *));
 356 extern void _bfd_ecoff_swap_rndx_out
 357   PARAMS ((int, const RNDXR *, struct rndx_ext *));