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Diffstat (limited to 'contrib/binutils/bfd/doc/targets.texi')
| -rw-r--r-- | contrib/binutils/bfd/doc/targets.texi | 517 |
1 files changed, 0 insertions, 517 deletions
diff --git a/contrib/binutils/bfd/doc/targets.texi b/contrib/binutils/bfd/doc/targets.texi deleted file mode 100644 index 9b499cf419954..0000000000000 --- a/contrib/binutils/bfd/doc/targets.texi +++ /dev/null @@ -1,517 +0,0 @@ -@section Targets - - -@strong{Description}@* -Each port of BFD to a different machine requires the creation -of a target back end. All the back end provides to the root -part of BFD is a structure containing pointers to functions -which perform certain low level operations on files. BFD -translates the applications's requests through a pointer into -calls to the back end routines. - -When a file is opened with @code{bfd_openr}, its format and -target are unknown. BFD uses various mechanisms to determine -how to interpret the file. The operations performed are: - -@itemize @bullet - -@item -Create a BFD by calling the internal routine -@code{_bfd_new_bfd}, then call @code{bfd_find_target} with the -target string supplied to @code{bfd_openr} and the new BFD pointer. - -@item -If a null target string was provided to @code{bfd_find_target}, -look up the environment variable @code{GNUTARGET} and use -that as the target string. - -@item -If the target string is still @code{NULL}, or the target string is -@code{default}, then use the first item in the target vector -as the target type, and set @code{target_defaulted} in the BFD to -cause @code{bfd_check_format} to loop through all the targets. -@xref{bfd_target}. @xref{Formats}. - -@item -Otherwise, inspect the elements in the target vector -one by one, until a match on target name is found. When found, -use it. - -@item -Otherwise return the error @code{bfd_error_invalid_target} to -@code{bfd_openr}. - -@item -@code{bfd_openr} attempts to open the file using -@code{bfd_open_file}, and returns the BFD. -@end itemize -Once the BFD has been opened and the target selected, the file -format may be determined. This is done by calling -@code{bfd_check_format} on the BFD with a suggested format. -If @code{target_defaulted} has been set, each possible target -type is tried to see if it recognizes the specified format. -@code{bfd_check_format} returns @code{TRUE} when the caller guesses right. -@menu -* bfd_target:: -@end menu - -@node bfd_target, , Targets, Targets - -@subsection bfd_target - - -@strong{Description}@* -This structure contains everything that BFD knows about a -target. It includes things like its byte order, name, and which -routines to call to do various operations. - -Every BFD points to a target structure with its @code{xvec} -member. - -The macros below are used to dispatch to functions through the -@code{bfd_target} vector. They are used in a number of macros further -down in @file{bfd.h}, and are also used when calling various -routines by hand inside the BFD implementation. The @var{arglist} -argument must be parenthesized; it contains all the arguments -to the called function. - -They make the documentation (more) unpleasant to read, so if -someone wants to fix this and not break the above, please do. -@example -#define BFD_SEND(bfd, message, arglist) \ - ((*((bfd)->xvec->message)) arglist) - -#ifdef DEBUG_BFD_SEND -#undef BFD_SEND -#define BFD_SEND(bfd, message, arglist) \ - (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \ - ((*((bfd)->xvec->message)) arglist) : \ - (bfd_assert (__FILE__,__LINE__), NULL)) -#endif -@end example -For operations which index on the BFD format: -@example -#define BFD_SEND_FMT(bfd, message, arglist) \ - (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist) - -#ifdef DEBUG_BFD_SEND -#undef BFD_SEND_FMT -#define BFD_SEND_FMT(bfd, message, arglist) \ - (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \ - (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist) : \ - (bfd_assert (__FILE__,__LINE__), NULL)) -#endif - -@end example -This is the structure which defines the type of BFD this is. The -@code{xvec} member of the struct @code{bfd} itself points here. Each -module that implements access to a different target under BFD, -defines one of these. - -FIXME, these names should be rationalised with the names of -the entry points which call them. Too bad we can't have one -macro to define them both! -@example -enum bfd_flavour -@{ - bfd_target_unknown_flavour, - bfd_target_aout_flavour, - bfd_target_coff_flavour, - bfd_target_ecoff_flavour, - bfd_target_xcoff_flavour, - bfd_target_elf_flavour, - bfd_target_ieee_flavour, - bfd_target_nlm_flavour, - bfd_target_oasys_flavour, - bfd_target_tekhex_flavour, - bfd_target_srec_flavour, - bfd_target_ihex_flavour, - bfd_target_som_flavour, - bfd_target_os9k_flavour, - bfd_target_versados_flavour, - bfd_target_msdos_flavour, - bfd_target_ovax_flavour, - bfd_target_evax_flavour, - bfd_target_mmo_flavour, - bfd_target_mach_o_flavour, - bfd_target_pef_flavour, - bfd_target_pef_xlib_flavour, - bfd_target_sym_flavour -@}; - -enum bfd_endian @{ BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN @}; - -/* Forward declaration. */ -typedef struct bfd_link_info _bfd_link_info; - -typedef struct bfd_target -@{ - /* Identifies the kind of target, e.g., SunOS4, Ultrix, etc. */ - char *name; - - /* The "flavour" of a back end is a general indication about - the contents of a file. */ - enum bfd_flavour flavour; - - /* The order of bytes within the data area of a file. */ - enum bfd_endian byteorder; - - /* The order of bytes within the header parts of a file. */ - enum bfd_endian header_byteorder; - - /* A mask of all the flags which an executable may have set - - from the set @code{BFD_NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}. */ - flagword object_flags; - - /* A mask of all the flags which a section may have set - from - the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}. */ - flagword section_flags; - - /* The character normally found at the front of a symbol. - (if any), perhaps `_'. */ - char symbol_leading_char; - - /* The pad character for file names within an archive header. */ - char ar_pad_char; - - /* The maximum number of characters in an archive header. */ - unsigned short ar_max_namelen; - - /* Entries for byte swapping for data. These are different from the - other entry points, since they don't take a BFD asthe first argument. - Certain other handlers could do the same. */ - bfd_uint64_t (*bfd_getx64) (const void *); - bfd_int64_t (*bfd_getx_signed_64) (const void *); - void (*bfd_putx64) (bfd_uint64_t, void *); - bfd_vma (*bfd_getx32) (const void *); - bfd_signed_vma (*bfd_getx_signed_32) (const void *); - void (*bfd_putx32) (bfd_vma, void *); - bfd_vma (*bfd_getx16) (const void *); - bfd_signed_vma (*bfd_getx_signed_16) (const void *); - void (*bfd_putx16) (bfd_vma, void *); - - /* Byte swapping for the headers. */ - bfd_uint64_t (*bfd_h_getx64) (const void *); - bfd_int64_t (*bfd_h_getx_signed_64) (const void *); - void (*bfd_h_putx64) (bfd_uint64_t, void *); - bfd_vma (*bfd_h_getx32) (const void *); - bfd_signed_vma (*bfd_h_getx_signed_32) (const void *); - void (*bfd_h_putx32) (bfd_vma, void *); - bfd_vma (*bfd_h_getx16) (const void *); - bfd_signed_vma (*bfd_h_getx_signed_16) (const void *); - void (*bfd_h_putx16) (bfd_vma, void *); - - /* Format dependent routines: these are vectors of entry points - within the target vector structure, one for each format to check. */ - - /* Check the format of a file being read. Return a @code{bfd_target *} or zero. */ - const struct bfd_target *(*_bfd_check_format[bfd_type_end]) (bfd *); - - /* Set the format of a file being written. */ - bfd_boolean (*_bfd_set_format[bfd_type_end]) (bfd *); - - /* Write cached information into a file being written, at @code{bfd_close}. */ - bfd_boolean (*_bfd_write_contents[bfd_type_end]) (bfd *); - -@end example -The general target vector. These vectors are initialized using the -BFD_JUMP_TABLE macros. -@example - - /* Generic entry points. */ -#define BFD_JUMP_TABLE_GENERIC(NAME) \ - NAME##_close_and_cleanup, \ - NAME##_bfd_free_cached_info, \ - NAME##_new_section_hook, \ - NAME##_get_section_contents, \ - NAME##_get_section_contents_in_window - - /* Called when the BFD is being closed to do any necessary cleanup. */ - bfd_boolean (*_close_and_cleanup) (bfd *); - /* Ask the BFD to free all cached information. */ - bfd_boolean (*_bfd_free_cached_info) (bfd *); - /* Called when a new section is created. */ - bfd_boolean (*_new_section_hook) (bfd *, sec_ptr); - /* Read the contents of a section. */ - bfd_boolean (*_bfd_get_section_contents) - (bfd *, sec_ptr, void *, file_ptr, bfd_size_type); - bfd_boolean (*_bfd_get_section_contents_in_window) - (bfd *, sec_ptr, bfd_window *, file_ptr, bfd_size_type); - - /* Entry points to copy private data. */ -#define BFD_JUMP_TABLE_COPY(NAME) \ - NAME##_bfd_copy_private_bfd_data, \ - NAME##_bfd_merge_private_bfd_data, \ - NAME##_bfd_copy_private_section_data, \ - NAME##_bfd_copy_private_symbol_data, \ - NAME##_bfd_set_private_flags, \ - NAME##_bfd_print_private_bfd_data - - /* Called to copy BFD general private data from one object file - to another. */ - bfd_boolean (*_bfd_copy_private_bfd_data) (bfd *, bfd *); - /* Called to merge BFD general private data from one object file - to a common output file when linking. */ - bfd_boolean (*_bfd_merge_private_bfd_data) (bfd *, bfd *); - /* Called to copy BFD private section data from one object file - to another. */ - bfd_boolean (*_bfd_copy_private_section_data) - (bfd *, sec_ptr, bfd *, sec_ptr); - /* Called to copy BFD private symbol data from one symbol - to another. */ - bfd_boolean (*_bfd_copy_private_symbol_data) - (bfd *, asymbol *, bfd *, asymbol *); - /* Called to set private backend flags. */ - bfd_boolean (*_bfd_set_private_flags) (bfd *, flagword); - - /* Called to print private BFD data. */ - bfd_boolean (*_bfd_print_private_bfd_data) (bfd *, void *); - - /* Core file entry points. */ -#define BFD_JUMP_TABLE_CORE(NAME) \ - NAME##_core_file_failing_command, \ - NAME##_core_file_failing_signal, \ - NAME##_core_file_matches_executable_p - - char * (*_core_file_failing_command) (bfd *); - int (*_core_file_failing_signal) (bfd *); - bfd_boolean (*_core_file_matches_executable_p) (bfd *, bfd *); - - /* Archive entry points. */ -#define BFD_JUMP_TABLE_ARCHIVE(NAME) \ - NAME##_slurp_armap, \ - NAME##_slurp_extended_name_table, \ - NAME##_construct_extended_name_table, \ - NAME##_truncate_arname, \ - NAME##_write_armap, \ - NAME##_read_ar_hdr, \ - NAME##_openr_next_archived_file, \ - NAME##_get_elt_at_index, \ - NAME##_generic_stat_arch_elt, \ - NAME##_update_armap_timestamp - - bfd_boolean (*_bfd_slurp_armap) (bfd *); - bfd_boolean (*_bfd_slurp_extended_name_table) (bfd *); - bfd_boolean (*_bfd_construct_extended_name_table) - (bfd *, char **, bfd_size_type *, const char **); - void (*_bfd_truncate_arname) (bfd *, const char *, char *); - bfd_boolean (*write_armap) - (bfd *, unsigned int, struct orl *, unsigned int, int); - void * (*_bfd_read_ar_hdr_fn) (bfd *); - bfd * (*openr_next_archived_file) (bfd *, bfd *); -#define bfd_get_elt_at_index(b,i) BFD_SEND (b, _bfd_get_elt_at_index, (b,i)) - bfd * (*_bfd_get_elt_at_index) (bfd *, symindex); - int (*_bfd_stat_arch_elt) (bfd *, struct stat *); - bfd_boolean (*_bfd_update_armap_timestamp) (bfd *); - - /* Entry points used for symbols. */ -#define BFD_JUMP_TABLE_SYMBOLS(NAME) \ - NAME##_get_symtab_upper_bound, \ - NAME##_canonicalize_symtab, \ - NAME##_make_empty_symbol, \ - NAME##_print_symbol, \ - NAME##_get_symbol_info, \ - NAME##_bfd_is_local_label_name, \ - NAME##_get_lineno, \ - NAME##_find_nearest_line, \ - NAME##_bfd_make_debug_symbol, \ - NAME##_read_minisymbols, \ - NAME##_minisymbol_to_symbol - - long (*_bfd_get_symtab_upper_bound) (bfd *); - long (*_bfd_canonicalize_symtab) - (bfd *, struct bfd_symbol **); - struct bfd_symbol * - (*_bfd_make_empty_symbol) (bfd *); - void (*_bfd_print_symbol) - (bfd *, void *, struct bfd_symbol *, bfd_print_symbol_type); -#define bfd_print_symbol(b,p,s,e) BFD_SEND (b, _bfd_print_symbol, (b,p,s,e)) - void (*_bfd_get_symbol_info) - (bfd *, struct bfd_symbol *, symbol_info *); -#define bfd_get_symbol_info(b,p,e) BFD_SEND (b, _bfd_get_symbol_info, (b,p,e)) - bfd_boolean (*_bfd_is_local_label_name) (bfd *, const char *); - - alent * (*_get_lineno) (bfd *, struct bfd_symbol *); - bfd_boolean (*_bfd_find_nearest_line) - (bfd *, struct bfd_section *, struct bfd_symbol **, bfd_vma, - const char **, const char **, unsigned int *); - /* Back-door to allow format-aware applications to create debug symbols - while using BFD for everything else. Currently used by the assembler - when creating COFF files. */ - asymbol * (*_bfd_make_debug_symbol) - (bfd *, void *, unsigned long size); -#define bfd_read_minisymbols(b, d, m, s) \ - BFD_SEND (b, _read_minisymbols, (b, d, m, s)) - long (*_read_minisymbols) - (bfd *, bfd_boolean, void **, unsigned int *); -#define bfd_minisymbol_to_symbol(b, d, m, f) \ - BFD_SEND (b, _minisymbol_to_symbol, (b, d, m, f)) - asymbol * (*_minisymbol_to_symbol) - (bfd *, bfd_boolean, const void *, asymbol *); - - /* Routines for relocs. */ -#define BFD_JUMP_TABLE_RELOCS(NAME) \ - NAME##_get_reloc_upper_bound, \ - NAME##_canonicalize_reloc, \ - NAME##_bfd_reloc_type_lookup - - long (*_get_reloc_upper_bound) (bfd *, sec_ptr); - long (*_bfd_canonicalize_reloc) - (bfd *, sec_ptr, arelent **, struct bfd_symbol **); - /* See documentation on reloc types. */ - reloc_howto_type * - (*reloc_type_lookup) (bfd *, bfd_reloc_code_real_type); - - /* Routines used when writing an object file. */ -#define BFD_JUMP_TABLE_WRITE(NAME) \ - NAME##_set_arch_mach, \ - NAME##_set_section_contents - - bfd_boolean (*_bfd_set_arch_mach) - (bfd *, enum bfd_architecture, unsigned long); - bfd_boolean (*_bfd_set_section_contents) - (bfd *, sec_ptr, const void *, file_ptr, bfd_size_type); - - /* Routines used by the linker. */ -#define BFD_JUMP_TABLE_LINK(NAME) \ - NAME##_sizeof_headers, \ - NAME##_bfd_get_relocated_section_contents, \ - NAME##_bfd_relax_section, \ - NAME##_bfd_link_hash_table_create, \ - NAME##_bfd_link_hash_table_free, \ - NAME##_bfd_link_add_symbols, \ - NAME##_bfd_link_just_syms, \ - NAME##_bfd_final_link, \ - NAME##_bfd_link_split_section, \ - NAME##_bfd_gc_sections, \ - NAME##_bfd_merge_sections, \ - NAME##_bfd_discard_group - - int (*_bfd_sizeof_headers) (bfd *, bfd_boolean); - bfd_byte * (*_bfd_get_relocated_section_contents) - (bfd *, struct bfd_link_info *, struct bfd_link_order *, - bfd_byte *, bfd_boolean, struct bfd_symbol **); - - bfd_boolean (*_bfd_relax_section) - (bfd *, struct bfd_section *, struct bfd_link_info *, bfd_boolean *); - - /* Create a hash table for the linker. Different backends store - different information in this table. */ - struct bfd_link_hash_table * - (*_bfd_link_hash_table_create) (bfd *); - - /* Release the memory associated with the linker hash table. */ - void (*_bfd_link_hash_table_free) (struct bfd_link_hash_table *); - - /* Add symbols from this object file into the hash table. */ - bfd_boolean (*_bfd_link_add_symbols) (bfd *, struct bfd_link_info *); - - /* Indicate that we are only retrieving symbol values from this section. */ - void (*_bfd_link_just_syms) (asection *, struct bfd_link_info *); - - /* Do a link based on the link_order structures attached to each - section of the BFD. */ - bfd_boolean (*_bfd_final_link) (bfd *, struct bfd_link_info *); - - /* Should this section be split up into smaller pieces during linking. */ - bfd_boolean (*_bfd_link_split_section) (bfd *, struct bfd_section *); - - /* Remove sections that are not referenced from the output. */ - bfd_boolean (*_bfd_gc_sections) (bfd *, struct bfd_link_info *); - - /* Attempt to merge SEC_MERGE sections. */ - bfd_boolean (*_bfd_merge_sections) (bfd *, struct bfd_link_info *); - - /* Discard members of a group. */ - bfd_boolean (*_bfd_discard_group) (bfd *, struct bfd_section *); - - /* Routines to handle dynamic symbols and relocs. */ -#define BFD_JUMP_TABLE_DYNAMIC(NAME) \ - NAME##_get_dynamic_symtab_upper_bound, \ - NAME##_canonicalize_dynamic_symtab, \ - NAME##_get_dynamic_reloc_upper_bound, \ - NAME##_canonicalize_dynamic_reloc - - /* Get the amount of memory required to hold the dynamic symbols. */ - long (*_bfd_get_dynamic_symtab_upper_bound) (bfd *); - /* Read in the dynamic symbols. */ - long (*_bfd_canonicalize_dynamic_symtab) - (bfd *, struct bfd_symbol **); - /* Get the amount of memory required to hold the dynamic relocs. */ - long (*_bfd_get_dynamic_reloc_upper_bound) (bfd *); - /* Read in the dynamic relocs. */ - long (*_bfd_canonicalize_dynamic_reloc) - (bfd *, arelent **, struct bfd_symbol **); - -@end example -A pointer to an alternative bfd_target in case the current one is not -satisfactory. This can happen when the target cpu supports both big -and little endian code, and target chosen by the linker has the wrong -endianness. The function open_output() in ld/ldlang.c uses this field -to find an alternative output format that is suitable. -@example - /* Opposite endian version of this target. */ - const struct bfd_target * alternative_target; - - /* Data for use by back-end routines, which isn't - generic enough to belong in this structure. */ - const void *backend_data; - -@} bfd_target; - -@end example - -@findex bfd_set_default_target -@subsubsection @code{bfd_set_default_target} -@strong{Synopsis} -@example -bfd_boolean bfd_set_default_target (const char *name); -@end example -@strong{Description}@* -Set the default target vector to use when recognizing a BFD. -This takes the name of the target, which may be a BFD target -name or a configuration triplet. - -@findex bfd_find_target -@subsubsection @code{bfd_find_target} -@strong{Synopsis} -@example -const bfd_target *bfd_find_target (const char *target_name, bfd *abfd); -@end example -@strong{Description}@* -Return a pointer to the transfer vector for the object target -named @var{target_name}. If @var{target_name} is @code{NULL}, choose the -one in the environment variable @code{GNUTARGET}; if that is null or not -defined, then choose the first entry in the target list. -Passing in the string "default" or setting the environment -variable to "default" will cause the first entry in the target -list to be returned, and "target_defaulted" will be set in the -BFD. This causes @code{bfd_check_format} to loop over all the -targets to find the one that matches the file being read. - -@findex bfd_target_list -@subsubsection @code{bfd_target_list} -@strong{Synopsis} -@example -const char ** bfd_target_list (void); -@end example -@strong{Description}@* -Return a freshly malloced NULL-terminated -vector of the names of all the valid BFD targets. Do not -modify the names. - -@findex bfd_seach_for_target -@subsubsection @code{bfd_seach_for_target} -@strong{Synopsis} -@example -const bfd_target *bfd_search_for_target - (int (*search_func) (const bfd_target *, void *), - void *); -@end example -@strong{Description}@* -Return a pointer to the first transfer vector in the list of -transfer vectors maintained by BFD that produces a non-zero -result when passed to the function @var{search_func}. The -parameter @var{data} is passed, unexamined, to the search -function. - |