itial 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_GENERATE_WARNING, RM_GENERATE_ERROR }; typedef enum {with_flags, without_flags} flag_type; /* A section flag list. */ struct flag_info_list { flag_type with; const char *name; bfd_boolean 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; bfd_boolean 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 executable should not contain copy relocs. Setting this true may result in a non-sharable text segment. */ unsigned int nocopyreloc: 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 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 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; /* Which symbols to strip. */ ENUM_BITFIELD (bfd_link_strip) strip : 2; /* Which local symbols to discard. */ ENUM_BITFIELD (bfd_link_discard) discard : 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 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; /* 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; /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ unsigned int warn_shared_textrel: 1; /* TRUE if we should error when adding a DT_TEXTREL. */ unsigned int error_textrel: 1; /* 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 definition. */ unsigned int allow_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 BND prefix in PLT entries is always generated. */ unsigned int bndplt: 1; /* TRUE if generation of .interp/PT_INTERP should be suppressed. */ unsigned int nointerp: 1; /* TRUE if generate a 1-byte NOP as suffix for x86 call instruction. */ unsigned int call_nop_as_suffix : 1; /* The 1-byte NOP for x86 call instruction. */ char call_nop_byte; /* 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 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; /* 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; /* 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; /* 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; }; /* This structures holds a set of callback functions. These are called by the BFD linker routines. Except for the info functions, the first argument to each callback function is the bfd_link_info structure being used and each function returns a boolean value. If the function returns FALSE, then the BFD function which called it should return with a failure indication. */ 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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*constructor) (struct bfd_link_info *, bfd_boolean 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. */ bfd_boolean (*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. */ bfd_boolean (*undefined_symbol) (struct bfd_link_info *, const char *name, bfd *abfd, asection *section, bfd_vma address, bfd_boolean 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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*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. */ bfd_boolean (*override_segment_assignment) (struct bfd_link_info *, bfd * abfd, asection * current_section, asection * previous_section, bfd_boolean new_segment); };