/* bfdlink.h -- header file for BFD link routines
- Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
- 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 1993-2016 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.
discard_all /* Discard all locals. */
};
+/* 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. */
/* Type of this entry. */
ENUM_BITFIELD (bfd_link_hash_type) type : 8;
+ /* Symbol is referenced in a normal object file, as distict from a LTO
+ IR object file. */
unsigned int non_ir_ref : 1;
+ /* Symbol is a built-in define. These will be overridden by PROVIDE
+ in a linker script. */
+ unsigned int linker_def : 1;
+
/* A union of information depending upon the type. */
union
{
automatically be non-NULL since the symbol will have been on the
undefined symbol list. */
struct bfd_link_hash_entry *next;
- bfd *abfd; /* BFD symbol was found in. */
+ /* BFD symbol was found in. */
+ bfd *abfd;
+ /* For __start_<name> and __stop_<name> symbols, the first
+ input section matching the name. */
+ asection *section;
} undef;
/* bfd_link_hash_defined, bfd_link_hash_defweak. */
struct
{
struct bfd_link_hash_entry *next;
- asection *section; /* Symbol section. */
- bfd_vma value; /* Symbol value. */
+ /* 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;
- struct bfd_link_hash_entry *link; /* Real symbol. */
- const char *warning; /* Warning (bfd_link_hash_warning only). */
+ /* Real symbol. */
+ struct bfd_link_hash_entry *link;
+ /* Warning message (bfd_link_hash_warning only). */
+ const char *warning;
} i;
/* bfd_link_hash_common. */
struct
the union; this structure is a major space user in the
linker. */
struct bfd_link_hash_common_entry *p;
- bfd_size_type size; /* Common symbol size. */
+ /* Common symbol size. */
+ bfd_size_type size;
} c;
} u;
};
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;
};
(bfd *, struct bfd_link_info *, const char *, bfd_boolean,
bfd_boolean, bfd_boolean);
+/* 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 *,
/* Read symbols and cache symbol pointer array in outsymbols. */
extern bfd_boolean 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 bfd_boolean bfd_link_check_relocs (bfd *,struct bfd_link_info *);
+
struct bfd_sym_chain
{
struct bfd_sym_chain *next;
/* A section flag list. */
struct flag_info_list
{
- flag_type with;
+ flag_type with;
const char *name;
bfd_boolean valid;
struct flag_info_list *next;
};
struct bfd_elf_dynamic_list;
+struct bfd_elf_version_tree;
-/* This structure holds all the information needed to communicate
- between BFD and the linker when doing a link. */
+/* Types of output. */
-struct bfd_link_info
+enum output_type
{
- /* TRUE if BFD should generate a relocatable object file. */
- unsigned int relocatable: 1;
+ type_pde,
+ type_pie,
+ type_relocatable,
+ type_dll,
+};
- /* TRUE if BFD should generate relocation information in the final
- executable. */
- unsigned int emitrelocations: 1;
+#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))
- /* 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;
+/* This structure holds all the information needed to communicate
+ between BFD and the linker when doing a link. */
- /* TRUE if BFD should generate a shared object. */
- unsigned int shared: 1;
+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 shared objects should be linked directly, not shared. */
- unsigned int static_link: 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 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 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 a default symbol version should be created and used for
exported symbols. */
unsigned int create_default_symver: 1;
- /* TRUE if a default symbol version should be created and used for
- imported symbols. */
- unsigned int default_imported_symver: 1;
-
- /* TRUE if symbols should be retained in memory, FALSE if they
- should be freed and reread. */
- unsigned int keep_memory: 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 executable should not contain copy relocs.
- Setting this true may result in a non-sharable text segment. */
- unsigned int nocopyreloc: 1;
+ /* TRUE if the LTO plugin is active. */
+ unsigned int lto_plugin_active: 1;
- /* TRUE if the new ELF dynamic tags are enabled. */
- unsigned int new_dtags: 1;
+ /* TRUE if global symbols in discarded sections should be stripped. */
+ unsigned int strip_discarded: 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 all data symbols should be dynamic. */
+ unsigned int dynamic_data: 1;
- /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
- should be created. */
- unsigned int eh_frame_hdr: 1;
+ /* Which symbols to strip. */
+ ENUM_BITFIELD (bfd_link_strip) strip : 2;
- /* TRUE if global symbols in discarded sections should be stripped. */
- unsigned int strip_discarded: 1;
+ /* Which local symbols to discard. */
+ ENUM_BITFIELD (bfd_link_discard) discard : 2;
- /* TRUE if generating a position independent executable. */
- unsigned int pie: 1;
+ /* Whether to generate ELF common symbols with the STT_COMMON type. */
+ ENUM_BITFIELD (bfd_link_elf_stt_common) elf_stt_common : 2;
- /* TRUE if generating an executable, position independent or not. */
- unsigned int executable : 1;
+ /* 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;
- /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
- flags. */
- unsigned int execstack: 1;
+ /* 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;
- /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
- flags. */
- unsigned int noexecstack: 1;
+ /* 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 warn alternate ELF machine code. */
- unsigned int warn_alternate_em: 1;
-
- /* TRUE if unreferenced sections should be removed. */
- unsigned int gc_sections: 1;
-
- /* TRUE if user shoudl be informed of removed unreferenced sections. */
- unsigned int print_gc_sections: 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;
caching ELF symbol buffer. */
unsigned int reduce_memory_overheads: 1;
- /* TRUE if all data symbols should be dynamic. */
- unsigned int dynamic_data: 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 some symbols have to be dynamic, controlled by
- --dynamic-list command line options. */
- unsigned int dynamic: 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 we are loading LTO outputs. */
- unsigned int loading_lto_outputs: 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;
- /* Non-NULL if .note.gnu.build-id section should be created. */
- char *emit_note_gnu_build_id;
+ /* TRUE if ok to have multiple definition. */
+ unsigned int allow_multiple_definition: 1;
- /* 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 report_method unresolved_syms_in_objects;
+ /* TRUE if ok to have version with no definition. */
+ unsigned int allow_undefined_version: 1;
- /* What to do with unresolved symbols in a shared library.
- The same defaults apply. */
- enum report_method unresolved_syms_in_shared_libs;
+ /* TRUE if some symbols have to be dynamic, controlled by
+ --dynamic-list command line options. */
+ unsigned int dynamic: 1;
- /* Which symbols to strip. */
- enum bfd_link_strip strip;
+ /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X
+ flags. */
+ unsigned int execstack: 1;
- /* Which local symbols to discard. */
- enum bfd_link_discard discard;
+ /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W
+ flags. */
+ unsigned int noexecstack: 1;
- /* Criteria for skipping symbols when determining
- whether to include an object from an archive. */
- enum bfd_link_common_skip_ar_symbols common_skip_ar_symbols;
+ /* 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 we should check relocations after all input files have
+ been opened. */
+ unsigned int check_relocs_after_open_input: 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 we shouldn't check relocation overflow. */
+ unsigned int no_reloc_overflow_check: 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
/* 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;
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. */
+ together via the link.next field. */
bfd *input_bfds;
bfd **input_bfds_tail;
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;
+
+ /* > 0 to treat undefined weak symbol in the executable as dynamic,
+ requiring dynamic relocation. */
+ 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. */
/* 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
(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. 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. STRING is the name of the symbol to indirect to if
- the sym is indirect, or the warning string if a warning sym. */
+ 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,
- bfd *abfd, asection *section, bfd_vma address, flagword flags,
- const char *string);
+ 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, ...);
} indirect;
struct
{
- /* Size of contents, or zero when contents size == size
- within output section.
+ /* 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;
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