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- /* bfdlink.h -- header file for BFD link routines
- Copyright (C) 1993-2022 Free Software Foundation, Inc.
- Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support.
- This file is part of BFD, the Binary File Descriptor library.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
- MA 02110-1301, USA. */
- #ifndef BFDLINK_H
- #define BFDLINK_H
- /* Which symbols to strip during a link. */
- enum bfd_link_strip
- {
- strip_none, /* Don't strip any symbols. */
- strip_debugger, /* Strip debugging symbols. */
- strip_some, /* keep_hash is the list of symbols to keep. */
- strip_all /* Strip all symbols. */
- };
- /* Which local symbols to discard during a link. This is irrelevant
- if strip_all is used. */
- enum bfd_link_discard
- {
- discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE
- sections. */
- discard_none, /* Don't discard any locals. */
- discard_l, /* Discard local temporary symbols. */
- discard_all /* Discard all locals. */
- };
- enum notice_asneeded_action {
- notice_as_needed,
- notice_not_needed,
- notice_needed
- };
- /* Whether to generate ELF common symbols with the STT_COMMON type
- during a relocatable link. */
- enum bfd_link_elf_stt_common
- {
- unchanged,
- elf_stt_common,
- no_elf_stt_common
- };
- /* Describes the type of hash table entry structure being used.
- Different hash table structure have different fields and so
- support different linking features. */
- enum bfd_link_hash_table_type
- {
- bfd_link_generic_hash_table,
- bfd_link_elf_hash_table
- };
- /* These are the possible types of an entry in the BFD link hash
- table. */
- enum bfd_link_hash_type
- {
- bfd_link_hash_new, /* Symbol is new. */
- bfd_link_hash_undefined, /* Symbol seen before, but undefined. */
- bfd_link_hash_undefweak, /* Symbol is weak and undefined. */
- bfd_link_hash_defined, /* Symbol is defined. */
- bfd_link_hash_defweak, /* Symbol is weak and defined. */
- bfd_link_hash_common, /* Symbol is common. */
- bfd_link_hash_indirect, /* Symbol is an indirect link. */
- bfd_link_hash_warning /* Like indirect, but warn if referenced. */
- };
- enum bfd_link_common_skip_ar_symbols
- {
- bfd_link_common_skip_none,
- bfd_link_common_skip_text,
- bfd_link_common_skip_data,
- bfd_link_common_skip_all
- };
- struct bfd_link_hash_common_entry
- {
- unsigned int alignment_power; /* Alignment. */
- asection *section; /* Symbol section. */
- };
- /* The linking routines use a hash table which uses this structure for
- its elements. */
- struct bfd_link_hash_entry
- {
- /* Base hash table entry structure. */
- struct bfd_hash_entry root;
- /* Type of this entry. */
- ENUM_BITFIELD (bfd_link_hash_type) type : 8;
- /* Symbol is referenced in a normal regular object file,
- as distinct from a LTO IR object file. */
- unsigned int non_ir_ref_regular : 1;
- /* Symbol is referenced in a normal dynamic object file,
- as distinct from a LTO IR object file. */
- unsigned int non_ir_ref_dynamic : 1;
- /* Symbol is a built-in define. These will be overridden by PROVIDE
- in a linker script. */
- unsigned int linker_def : 1;
- /* Symbol defined in a linker script. */
- unsigned int ldscript_def : 1;
- /* Symbol will be converted from absolute to section-relative. Set for
- symbols defined by a script from "dot" (also SEGMENT_START or ORIGIN)
- outside of an output section statement. */
- unsigned int rel_from_abs : 1;
- /* A union of information depending upon the type. */
- union
- {
- /* Nothing is kept for bfd_hash_new. */
- /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */
- struct
- {
- /* Undefined and common symbols are kept in a linked list through
- this field. This field is present in all of the union element
- so that we don't need to remove entries from the list when we
- change their type. Removing entries would either require the
- list to be doubly linked, which would waste more memory, or
- require a traversal. When an undefined or common symbol is
- created, it should be added to this list, the head of which is in
- the link hash table itself. As symbols are defined, they need
- not be removed from the list; anything which reads the list must
- doublecheck the symbol type.
- Weak symbols are not kept on this list.
- Defined and defweak symbols use this field as a reference marker.
- If the field is not NULL, or this structure is the tail of the
- undefined symbol list, the symbol has been referenced. If the
- symbol is undefined and becomes defined, this field will
- automatically be non-NULL since the symbol will have been on the
- undefined symbol list. */
- struct bfd_link_hash_entry *next;
- /* BFD symbol was found in. */
- bfd *abfd;
- } undef;
- /* bfd_link_hash_defined, bfd_link_hash_defweak. */
- struct
- {
- struct bfd_link_hash_entry *next;
- /* Symbol section. */
- asection *section;
- /* Symbol value. */
- bfd_vma value;
- } def;
- /* bfd_link_hash_indirect, bfd_link_hash_warning. */
- struct
- {
- struct bfd_link_hash_entry *next;
- /* Real symbol. */
- struct bfd_link_hash_entry *link;
- /* Warning message (bfd_link_hash_warning only). */
- const char *warning;
- } i;
- /* bfd_link_hash_common. */
- struct
- {
- struct bfd_link_hash_entry *next;
- /* The linker needs to know three things about common
- symbols: the size, the alignment, and the section in
- which the symbol should be placed. We store the size
- here, and we allocate a small structure to hold the
- section and the alignment. The alignment is stored as a
- power of two. We don't store all the information
- directly because we don't want to increase the size of
- the union; this structure is a major space user in the
- linker. */
- struct bfd_link_hash_common_entry *p;
- /* Common symbol size. */
- bfd_size_type size;
- } c;
- } u;
- };
- /* This is the link hash table. It is a derived class of
- bfd_hash_table. */
- struct bfd_link_hash_table
- {
- /* The hash table itself. */
- struct bfd_hash_table table;
- /* A linked list of undefined and common symbols, linked through the
- next field in the bfd_link_hash_entry structure. */
- struct bfd_link_hash_entry *undefs;
- /* Entries are added to the tail of the undefs list. */
- struct bfd_link_hash_entry *undefs_tail;
- /* Function to free the hash table on closing BFD. */
- void (*hash_table_free) (bfd *);
- /* The type of the link hash table. */
- enum bfd_link_hash_table_type type;
- };
- /* Look up an entry in a link hash table. If FOLLOW is TRUE, this
- follows bfd_link_hash_indirect and bfd_link_hash_warning links to
- the real symbol. */
- extern struct bfd_link_hash_entry *bfd_link_hash_lookup
- (struct bfd_link_hash_table *, const char *, bool create,
- bool copy, bool follow);
- /* Look up an entry in the main linker hash table if the symbol might
- be wrapped. This should only be used for references to an
- undefined symbol, not for definitions of a symbol. */
- extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup
- (bfd *, struct bfd_link_info *, const char *, bool, bool, bool);
- /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_"
- and the remainder is found in wrap_hash, return the real symbol. */
- extern struct bfd_link_hash_entry *unwrap_hash_lookup
- (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *);
- /* Traverse a link hash table. */
- extern void bfd_link_hash_traverse
- (struct bfd_link_hash_table *,
- bool (*) (struct bfd_link_hash_entry *, void *),
- void *);
- /* Add an entry to the undefs list. */
- extern void bfd_link_add_undef
- (struct bfd_link_hash_table *, struct bfd_link_hash_entry *);
- /* Remove symbols from the undefs list that don't belong there. */
- extern void bfd_link_repair_undef_list
- (struct bfd_link_hash_table *table);
- /* Read symbols and cache symbol pointer array in outsymbols. */
- extern bool bfd_generic_link_read_symbols (bfd *);
- /* Check the relocs in the BFD. Called after all the input
- files have been loaded, and garbage collection has tagged
- any unneeded sections. */
- extern bool bfd_link_check_relocs (bfd *,struct bfd_link_info *);
- struct bfd_sym_chain
- {
- struct bfd_sym_chain *next;
- const char *name;
- };
- /* How to handle unresolved symbols.
- There are four possibilities which are enumerated below: */
- enum report_method
- {
- /* This is the initial value when then link_info structure is created.
- It allows the various stages of the linker to determine whether they
- allowed to set the value. */
- RM_NOT_YET_SET = 0,
- RM_IGNORE,
- RM_DIAGNOSE,
- };
- /* How to handle DT_TEXTREL. */
- enum textrel_check_method
- {
- textrel_check_none,
- textrel_check_warning,
- textrel_check_error
- };
- #define bfd_link_textrel_check(info) \
- (info->textrel_check != textrel_check_none)
- typedef enum {with_flags, without_flags} flag_type;
- /* A section flag list. */
- struct flag_info_list
- {
- flag_type with;
- const char *name;
- bool valid;
- struct flag_info_list *next;
- };
- /* Section flag info. */
- struct flag_info
- {
- flagword only_with_flags;
- flagword not_with_flags;
- struct flag_info_list *flag_list;
- bool flags_initialized;
- };
- struct bfd_elf_dynamic_list;
- struct bfd_elf_version_tree;
- /* Types of output. */
- enum output_type
- {
- type_pde,
- type_pie,
- type_relocatable,
- type_dll,
- };
- #define bfd_link_pde(info) ((info)->type == type_pde)
- #define bfd_link_dll(info) ((info)->type == type_dll)
- #define bfd_link_relocatable(info) ((info)->type == type_relocatable)
- #define bfd_link_pie(info) ((info)->type == type_pie)
- #define bfd_link_executable(info) (bfd_link_pde (info) || bfd_link_pie (info))
- #define bfd_link_pic(info) (bfd_link_dll (info) || bfd_link_pie (info))
- /* This structure holds all the information needed to communicate
- between BFD and the linker when doing a link. */
- struct bfd_link_info
- {
- /* Output type. */
- ENUM_BITFIELD (output_type) type : 2;
- /* TRUE if BFD should pre-bind symbols in a shared object. */
- unsigned int symbolic: 1;
- /* TRUE if BFD should export all symbols in the dynamic symbol table
- of an executable, rather than only those used. */
- unsigned int export_dynamic: 1;
- /* TRUE if a default symbol version should be created and used for
- exported symbols. */
- unsigned int create_default_symver: 1;
- /* TRUE if unreferenced sections should be removed. */
- unsigned int gc_sections: 1;
- /* TRUE if exported symbols should be kept during section gc. */
- unsigned int gc_keep_exported: 1;
- /* TRUE if every symbol should be reported back via the notice
- callback. */
- unsigned int notice_all: 1;
- /* TRUE if the LTO plugin is active. */
- unsigned int lto_plugin_active: 1;
- /* TRUE if all LTO IR symbols have been read. */
- unsigned int lto_all_symbols_read : 1;
- /* TRUE if global symbols in discarded sections should be stripped. */
- unsigned int strip_discarded: 1;
- /* TRUE if all data symbols should be dynamic. */
- unsigned int dynamic_data: 1;
- /* TRUE if section groups should be resolved. */
- unsigned int resolve_section_groups: 1;
- /* Set if output file is big-endian, or if that is unknown, from
- the command line or first input file endianness. */
- unsigned int big_endian : 1;
- /* Which symbols to strip. */
- ENUM_BITFIELD (bfd_link_strip) strip : 2;
- /* Which local symbols to discard. */
- ENUM_BITFIELD (bfd_link_discard) discard : 2;
- /* Whether to generate ELF common symbols with the STT_COMMON type. */
- ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2;
- /* Criteria for skipping symbols when determining
- whether to include an object from an archive. */
- ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2;
- /* What to do with unresolved symbols in an object file.
- When producing executables the default is GENERATE_ERROR.
- When producing shared libraries the default is IGNORE. The
- assumption with shared libraries is that the reference will be
- resolved at load/execution time. */
- ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2;
- /* What to do with unresolved symbols in a shared library.
- The same defaults apply. */
- ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2;
- /* TRUE if unresolved symbols are to be warned, rather than errored. */
- unsigned int warn_unresolved_syms: 1;
- /* TRUE if shared objects should be linked directly, not shared. */
- unsigned int static_link: 1;
- /* TRUE if symbols should be retained in memory, FALSE if they
- should be freed and reread. */
- unsigned int keep_memory: 1;
- /* TRUE if BFD should generate relocation information in the final
- executable. */
- unsigned int emitrelocations: 1;
- /* TRUE if PT_GNU_RELRO segment should be created. */
- unsigned int relro: 1;
- /* TRUE if DT_RELR should be enabled for compact relative
- relocations. */
- unsigned int enable_dt_relr: 1;
- /* TRUE if separate code segment should be created. */
- unsigned int separate_code: 1;
- /* Nonzero if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
- should be created. 1 for DWARF2 tables, 2 for compact tables. */
- unsigned int eh_frame_hdr_type: 2;
- /* What to do with DT_TEXTREL in output. */
- ENUM_BITFIELD (textrel_check_method) textrel_check: 2;
- /* TRUE if .hash section should be created. */
- unsigned int emit_hash: 1;
- /* TRUE if .gnu.hash section should be created. */
- unsigned int emit_gnu_hash: 1;
- /* If TRUE reduce memory overheads, at the expense of speed. This will
- cause map file generation to use an O(N^2) algorithm and disable
- caching ELF symbol buffer. */
- unsigned int reduce_memory_overheads: 1;
- /* TRUE if the output file should be in a traditional format. This
- is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag
- on the output file, but may be checked when reading the input
- files. */
- unsigned int traditional_format: 1;
- /* TRUE if non-PLT relocs should be merged into one reloc section
- and sorted so that relocs against the same symbol come together. */
- unsigned int combreloc: 1;
- /* TRUE if a default symbol version should be created and used for
- imported symbols. */
- unsigned int default_imported_symver: 1;
- /* TRUE if the new ELF dynamic tags are enabled. */
- unsigned int new_dtags: 1;
- /* FALSE if .eh_frame unwind info should be generated for PLT and other
- linker created sections, TRUE if it should be omitted. */
- unsigned int no_ld_generated_unwind_info: 1;
- /* TRUE if BFD should generate a "task linked" object file,
- similar to relocatable but also with globals converted to
- statics. */
- unsigned int task_link: 1;
- /* TRUE if ok to have multiple definitions, without warning. */
- unsigned int allow_multiple_definition: 1;
- /* TRUE if multiple definition of absolute symbols (eg. from -R) should
- be reported. */
- unsigned int prohibit_multiple_definition_absolute: 1;
- /* TRUE if multiple definitions should only warn. */
- unsigned int warn_multiple_definition: 1;
- /* TRUE if ok to have version with no definition. */
- unsigned int allow_undefined_version: 1;
- /* TRUE if some symbols have to be dynamic, controlled by
- --dynamic-list command line options. */
- unsigned int dynamic: 1;
- /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
- flags. */
- unsigned int execstack: 1;
- /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
- flags. */
- unsigned int noexecstack: 1;
- /* TRUE if we want to produced optimized output files. This might
- need much more time and therefore must be explicitly selected. */
- unsigned int optimize: 1;
- /* TRUE if user should be informed of removed unreferenced sections. */
- unsigned int print_gc_sections: 1;
- /* TRUE if we should warn alternate ELF machine code. */
- unsigned int warn_alternate_em: 1;
- /* TRUE if the linker script contained an explicit PHDRS command. */
- unsigned int user_phdrs: 1;
- /* TRUE if program headers ought to be loaded. */
- unsigned int load_phdrs: 1;
- /* TRUE if we should check relocations after all input files have
- been opened. */
- unsigned int check_relocs_after_open_input: 1;
- /* TRUE if generation of .interp/PT_INTERP should be suppressed. */
- unsigned int nointerp: 1;
- /* TRUE if common symbols should be treated as undefined. */
- unsigned int inhibit_common_definition : 1;
- /* TRUE if "-Map map" is passed to linker. */
- unsigned int has_map_file : 1;
- /* TRUE if "--enable-non-contiguous-regions" is passed to the
- linker. */
- unsigned int non_contiguous_regions : 1;
- /* TRUE if "--enable-non-contiguous-regions-warnings" is passed to
- the linker. */
- unsigned int non_contiguous_regions_warnings : 1;
- /* TRUE if all symbol names should be unique. */
- unsigned int unique_symbol : 1;
- /* TRUE if maxpagesize is set on command-line. */
- unsigned int maxpagesize_is_set : 1;
- /* TRUE if commonpagesize is set on command-line. */
- unsigned int commonpagesize_is_set : 1;
- /* Char that may appear as the first char of a symbol, but should be
- skipped (like symbol_leading_char) when looking up symbols in
- wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
- char wrap_char;
- /* Separator between archive and filename in linker script filespecs. */
- char path_separator;
- /* Compress DWARF debug sections. */
- enum compressed_debug_section_type compress_debug;
- /* Default stack size. Zero means default (often zero itself), -1
- means explicitly zero-sized. */
- bfd_signed_vma stacksize;
- /* Enable or disable target specific optimizations.
- Not all targets have optimizations to enable.
- Normally these optimizations are disabled by default but some targets
- prefer to enable them by default. So this field is a tri-state variable.
- The values are:
- zero: Enable the optimizations (either from --relax being specified on
- the command line or the backend's before_allocation emulation function.
- positive: The user has requested that these optimizations be disabled.
- (Via the --no-relax command line option).
- negative: The optimizations are disabled. (Set when initializing the
- args_type structure in ldmain.c:main. */
- signed int disable_target_specific_optimizations;
- /* Function callbacks. */
- const struct bfd_link_callbacks *callbacks;
- /* Hash table handled by BFD. */
- struct bfd_link_hash_table *hash;
- /* Hash table of symbols to keep. This is NULL unless strip is
- strip_some. */
- struct bfd_hash_table *keep_hash;
- /* Hash table of symbols to report back via the notice callback. If
- this is NULL, and notice_all is FALSE, then no symbols are
- reported back. */
- struct bfd_hash_table *notice_hash;
- /* Hash table of symbols which are being wrapped (the --wrap linker
- option). If this is NULL, no symbols are being wrapped. */
- struct bfd_hash_table *wrap_hash;
- /* Hash table of symbols which may be left unresolved during
- a link. If this is NULL, no symbols can be left unresolved. */
- struct bfd_hash_table *ignore_hash;
- /* The output BFD. */
- bfd *output_bfd;
- /* The import library generated. */
- bfd *out_implib_bfd;
- /* The list of input BFD's involved in the link. These are chained
- together via the link.next field. */
- bfd *input_bfds;
- bfd **input_bfds_tail;
- /* If a symbol should be created for each input BFD, this is section
- where those symbols should be placed. It must be a section in
- the output BFD. It may be NULL, in which case no such symbols
- will be created. This is to support CREATE_OBJECT_SYMBOLS in the
- linker command language. */
- asection *create_object_symbols_section;
- /* List of global symbol names that are starting points for marking
- sections against garbage collection. */
- struct bfd_sym_chain *gc_sym_list;
- /* If a base output file is wanted, then this points to it */
- void *base_file;
- /* The function to call when the executable or shared object is
- loaded. */
- const char *init_function;
- /* The function to call when the executable or shared object is
- unloaded. */
- const char *fini_function;
- /* Number of relaxation passes. Usually only one relaxation pass
- is needed. But a backend can have as many relaxation passes as
- necessary. During bfd_relax_section call, it is set to the
- current pass, starting from 0. */
- int relax_pass;
- /* Number of relaxation trips. This number is incremented every
- time the relaxation pass is restarted due to a previous
- relaxation returning true in *AGAIN. */
- int relax_trip;
- /* > 0 to treat protected data defined in the shared library as
- reference external. 0 to treat it as internal. -1 to let
- backend to decide. */
- int extern_protected_data;
- /* 1 to make undefined weak symbols dynamic when building a dynamic
- object. 0 to resolve undefined weak symbols to zero. -1 to let
- the backend decide. */
- int dynamic_undefined_weak;
- /* Non-zero if auto-import thunks for DATA items in pei386 DLLs
- should be generated/linked against. Set to 1 if this feature
- is explicitly requested by the user, -1 if enabled by default. */
- int pei386_auto_import;
- /* Non-zero if runtime relocs for DATA items with non-zero addends
- in pei386 DLLs should be generated. Set to 1 if this feature
- is explicitly requested by the user, -1 if enabled by default. */
- int pei386_runtime_pseudo_reloc;
- /* How many spare .dynamic DT_NULL entries should be added? */
- unsigned int spare_dynamic_tags;
- /* GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS control:
- > 1: Turn on by -z indirect-extern-access or by backend.
- == 1: Turn on by an input.
- 0: Turn off.
- < 0: Turn on if it is set on any inputs or let backend to
- decide. */
- int indirect_extern_access;
- /* Non-zero if executable should not contain copy relocs.
- > 1: Implied by indirect_extern_access.
- == 1: Turn on by -z nocopyreloc.
- 0: Turn off.
- Setting this to non-zero may result in a non-sharable text
- segment. */
- int nocopyreloc;
- /* Pointer to the GNU_PROPERTY_1_NEEDED property in memory. */
- bfd_byte *needed_1_p;
- /* May be used to set DT_FLAGS for ELF. */
- bfd_vma flags;
- /* May be used to set DT_FLAGS_1 for ELF. */
- bfd_vma flags_1;
- /* May be used to set DT_GNU_FLAGS_1 for ELF. */
- bfd_vma gnu_flags_1;
- /* TRUE if references to __start_/__stop_ synthesized symbols do not
- specially retain C identifier named sections. */
- int start_stop_gc;
- /* May be used to set ELF visibility for __start_* / __stop_. */
- unsigned int start_stop_visibility;
- /* The maximum page size for ELF. */
- bfd_vma maxpagesize;
- /* The common page size for ELF. */
- bfd_vma commonpagesize;
- /* Start and end of RELRO region. */
- bfd_vma relro_start, relro_end;
- /* List of symbols should be dynamic. */
- struct bfd_elf_dynamic_list *dynamic_list;
- /* The version information. */
- struct bfd_elf_version_tree *version_info;
- /* Size of cache. Backend can use it to keep strace cache size. */
- bfd_size_type cache_size;
- /* The maximum cache size. Backend can use cache_size and and
- max_cache_size to decide if keep_memory should be honored. */
- bfd_size_type max_cache_size;
- };
- /* Some forward-definitions used by some callbacks. */
- struct elf_strtab_hash;
- struct elf_internal_sym;
- /* This structures holds a set of callback functions. These are called
- by the BFD linker routines. */
- struct bfd_link_callbacks
- {
- /* A function which is called when an object is added from an
- archive. ABFD is the archive element being added. NAME is the
- name of the symbol which caused the archive element to be pulled
- in. This function may set *SUBSBFD to point to an alternative
- BFD from which symbols should in fact be added in place of the
- original BFD's symbols. Returns TRUE if the object should be
- added, FALSE if it should be skipped. */
- bool (*add_archive_element)
- (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd);
- /* A function which is called when a symbol is found with multiple
- definitions. H is the symbol which is defined multiple times.
- NBFD is the new BFD, NSEC is the new section, and NVAL is the new
- value. NSEC may be bfd_com_section or bfd_ind_section. */
- void (*multiple_definition)
- (struct bfd_link_info *, struct bfd_link_hash_entry *h,
- bfd *nbfd, asection *nsec, bfd_vma nval);
- /* A function which is called when a common symbol is defined
- multiple times. H is the symbol appearing multiple times.
- NBFD is the BFD of the new symbol. NTYPE is the type of the new
- symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or
- bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE
- is the size of the new symbol. */
- void (*multiple_common)
- (struct bfd_link_info *, struct bfd_link_hash_entry *h,
- bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize);
- /* A function which is called to add a symbol to a set. ENTRY is
- the link hash table entry for the set itself (e.g.,
- __CTOR_LIST__). RELOC is the relocation to use for an entry in
- the set when generating a relocatable file, and is also used to
- get the size of the entry when generating an executable file.
- ABFD, SEC and VALUE identify the value to add to the set. */
- void (*add_to_set)
- (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
- bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value);
- /* A function which is called when the name of a g++ constructor or
- destructor is found. This is only called by some object file
- formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a
- destructor. This will use BFD_RELOC_CTOR when generating a
- relocatable file. NAME is the name of the symbol found. ABFD,
- SECTION and VALUE are the value of the symbol. */
- void (*constructor)
- (struct bfd_link_info *, bool constructor, const char *name,
- bfd *abfd, asection *sec, bfd_vma value);
- /* A function which is called to issue a linker warning. For
- example, this is called when there is a reference to a warning
- symbol. WARNING is the warning to be issued. SYMBOL is the name
- of the symbol which triggered the warning; it may be NULL if
- there is none. ABFD, SECTION and ADDRESS identify the location
- which trigerred the warning; either ABFD or SECTION or both may
- be NULL if the location is not known. */
- void (*warning)
- (struct bfd_link_info *, const char *warning, const char *symbol,
- bfd *abfd, asection *section, bfd_vma address);
- /* A function which is called when a relocation is attempted against
- an undefined symbol. NAME is the symbol which is undefined.
- ABFD, SECTION and ADDRESS identify the location from which the
- reference is made. IS_FATAL indicates whether an undefined symbol is
- a fatal error or not. In some cases SECTION may be NULL. */
- void (*undefined_symbol)
- (struct bfd_link_info *, const char *name, bfd *abfd,
- asection *section, bfd_vma address, bool is_fatal);
- /* A function which is called when a reloc overflow occurs. ENTRY is
- the link hash table entry for the symbol the reloc is against.
- NAME is the name of the local symbol or section the reloc is
- against, RELOC_NAME is the name of the relocation, and ADDEND is
- any addend that is used. ABFD, SECTION and ADDRESS identify the
- location at which the overflow occurs; if this is the result of a
- bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
- ABFD will be NULL. */
- void (*reloc_overflow)
- (struct bfd_link_info *, struct bfd_link_hash_entry *entry,
- const char *name, const char *reloc_name, bfd_vma addend,
- bfd *abfd, asection *section, bfd_vma address);
- /* A function which is called when a dangerous reloc is performed.
- MESSAGE is an appropriate message.
- ABFD, SECTION and ADDRESS identify the location at which the
- problem occurred; if this is the result of a
- bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
- ABFD will be NULL. */
- void (*reloc_dangerous)
- (struct bfd_link_info *, const char *message,
- bfd *abfd, asection *section, bfd_vma address);
- /* A function which is called when a reloc is found to be attached
- to a symbol which is not being written out. NAME is the name of
- the symbol. ABFD, SECTION and ADDRESS identify the location of
- the reloc; if this is the result of a
- bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then
- ABFD will be NULL. */
- void (*unattached_reloc)
- (struct bfd_link_info *, const char *name,
- bfd *abfd, asection *section, bfd_vma address);
- /* A function which is called when a symbol in notice_hash is
- defined or referenced. H is the symbol, INH the indirect symbol
- if applicable. ABFD, SECTION and ADDRESS are the (new) value of
- the symbol. If SECTION is bfd_und_section, this is a reference.
- FLAGS are the symbol BSF_* flags. */
- bool (*notice)
- (struct bfd_link_info *, struct bfd_link_hash_entry *h,
- struct bfd_link_hash_entry *inh,
- bfd *abfd, asection *section, bfd_vma address, flagword flags);
- /* Error or warning link info message. */
- void (*einfo)
- (const char *fmt, ...);
- /* General link info message. */
- void (*info)
- (const char *fmt, ...);
- /* Message to be printed in linker map file. */
- void (*minfo)
- (const char *fmt, ...);
- /* This callback provides a chance for users of the BFD library to
- override its decision about whether to place two adjacent sections
- into the same segment. */
- bool (*override_segment_assignment)
- (struct bfd_link_info *, bfd * abfd,
- asection * current_section, asection * previous_section,
- bool new_segment);
- /* This callback provides a chance for callers of the BFD to examine the
- ELF (dynamic) string table once it is complete. */
- void (*examine_strtab)
- (struct elf_strtab_hash *symstrtab);
- /* This callback is called just before a symbol is swapped out, so that the
- CTF machinery can look up symbols during construction. The name is
- already an external strtab offset at this point. */
- void (*ctf_new_symbol)
- (int symidx, struct elf_internal_sym *sym);
- /* Likewise, for dynamic symbols. */
- void (*ctf_new_dynsym)
- (int symidx, struct elf_internal_sym *sym);
- /* This callback should emit the CTF section into a non-loadable section in
- the output BFD named .ctf or a name beginning with ".ctf.". */
- void (*emit_ctf)
- (void);
- };
- /* The linker builds link_order structures which tell the code how to
- include input data in the output file. */
- /* These are the types of link_order structures. */
- enum bfd_link_order_type
- {
- bfd_undefined_link_order, /* Undefined. */
- bfd_indirect_link_order, /* Built from a section. */
- bfd_data_link_order, /* Set to explicit data. */
- bfd_section_reloc_link_order, /* Relocate against a section. */
- bfd_symbol_reloc_link_order /* Relocate against a symbol. */
- };
- /* This is the link_order structure itself. These form a chain
- attached to the output section whose contents they are describing. */
- struct bfd_link_order
- {
- /* Next link_order in chain. */
- struct bfd_link_order *next;
- /* Type of link_order. */
- enum bfd_link_order_type type;
- /* Offset within output section in bytes. */
- bfd_vma offset;
- /* Size within output section in octets. */
- bfd_size_type size;
- /* Type specific information. */
- union
- {
- struct
- {
- /* Section to include. If this is used, then
- section->output_section must be the section the
- link_order is attached to, section->output_offset must
- equal the link_order offset field, and section->size
- must equal the link_order size field. Maybe these
- restrictions should be relaxed someday. */
- asection *section;
- } indirect;
- struct
- {
- /* Size of contents, or zero when contents should be filled by
- the architecture-dependent fill function.
- A non-zero value allows filling of the output section
- with an arbitrary repeated pattern. */
- unsigned int size;
- /* Data to put into file. */
- bfd_byte *contents;
- } data;
- struct
- {
- /* Description of reloc to generate. Used for
- bfd_section_reloc_link_order and
- bfd_symbol_reloc_link_order. */
- struct bfd_link_order_reloc *p;
- } reloc;
- } u;
- };
- /* A linker order of type bfd_section_reloc_link_order or
- bfd_symbol_reloc_link_order means to create a reloc against a
- section or symbol, respectively. This is used to implement -Ur to
- generate relocs for the constructor tables. The
- bfd_link_order_reloc structure describes the reloc that BFD should
- create. It is similar to a arelent, but I didn't use arelent
- because the linker does not know anything about most symbols, and
- any asymbol structure it creates will be partially meaningless.
- This information could logically be in the bfd_link_order struct,
- but I didn't want to waste the space since these types of relocs
- are relatively rare. */
- struct bfd_link_order_reloc
- {
- /* Reloc type. */
- bfd_reloc_code_real_type reloc;
- union
- {
- /* For type bfd_section_reloc_link_order, this is the section
- the reloc should be against. This must be a section in the
- output BFD, not any of the input BFDs. */
- asection *section;
- /* For type bfd_symbol_reloc_link_order, this is the name of the
- symbol the reloc should be against. */
- const char *name;
- } u;
- /* Addend to use. The object file should contain zero. The BFD
- backend is responsible for filling in the contents of the object
- file correctly. For some object file formats (e.g., COFF) the
- addend must be stored into in the object file, and for some
- (e.g., SPARC a.out) it is kept in the reloc. */
- bfd_vma addend;
- };
- /* Allocate a new link_order for a section. */
- extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *);
- struct bfd_section_already_linked;
- extern bool bfd_section_already_linked_table_init (void);
- extern void bfd_section_already_linked_table_free (void);
- extern bool _bfd_handle_already_linked
- (struct bfd_section *, struct bfd_section_already_linked *,
- struct bfd_link_info *);
- extern struct bfd_section *_bfd_nearby_section
- (bfd *, struct bfd_section *, bfd_vma);
- extern void _bfd_fix_excluded_sec_syms
- (bfd *, struct bfd_link_info *);
- /* These structures are used to describe version information for the
- ELF linker. These structures could be manipulated entirely inside
- BFD, but it would be a pain. Instead, the regular linker sets up
- these structures, and then passes them into BFD. */
- /* Glob pattern for a version. */
- struct bfd_elf_version_expr
- {
- /* Next glob pattern for this version. */
- struct bfd_elf_version_expr *next;
- /* Glob pattern. */
- const char *pattern;
- /* Set if pattern is not a glob. */
- unsigned int literal : 1;
- /* Defined by ".symver". */
- unsigned int symver : 1;
- /* Defined by version script. */
- unsigned int script : 1;
- /* Pattern type. */
- #define BFD_ELF_VERSION_C_TYPE 1
- #define BFD_ELF_VERSION_CXX_TYPE 2
- #define BFD_ELF_VERSION_JAVA_TYPE 4
- unsigned int mask : 3;
- };
- struct bfd_elf_version_expr_head
- {
- /* List of all patterns, both wildcards and non-wildcards. */
- struct bfd_elf_version_expr *list;
- /* Hash table for non-wildcards. */
- void *htab;
- /* Remaining patterns. */
- struct bfd_elf_version_expr *remaining;
- /* What kind of pattern types are present in list (bitmask). */
- unsigned int mask;
- };
- /* Version dependencies. */
- struct bfd_elf_version_deps
- {
- /* Next dependency for this version. */
- struct bfd_elf_version_deps *next;
- /* The version which this version depends upon. */
- struct bfd_elf_version_tree *version_needed;
- };
- /* A node in the version tree. */
- struct bfd_elf_version_tree
- {
- /* Next version. */
- struct bfd_elf_version_tree *next;
- /* Name of this version. */
- const char *name;
- /* Version number. */
- unsigned int vernum;
- /* Regular expressions for global symbols in this version. */
- struct bfd_elf_version_expr_head globals;
- /* Regular expressions for local symbols in this version. */
- struct bfd_elf_version_expr_head locals;
- /* List of versions which this version depends upon. */
- struct bfd_elf_version_deps *deps;
- /* Index of the version name. This is used within BFD. */
- unsigned int name_indx;
- /* Whether this version tree was used. This is used within BFD. */
- int used;
- /* Matching hook. */
- struct bfd_elf_version_expr *(*match)
- (struct bfd_elf_version_expr_head *head,
- struct bfd_elf_version_expr *prev, const char *sym);
- };
- struct bfd_elf_dynamic_list
- {
- struct bfd_elf_version_expr_head head;
- struct bfd_elf_version_expr *(*match)
- (struct bfd_elf_version_expr_head *head,
- struct bfd_elf_version_expr *prev, const char *sym);
- };
- #endif
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