/* 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;
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 shared object (or a pie). */
- unsigned int shared: 1;
+ type_pde,
+ type_pie,
+ type_relocatable,
+ type_dll,
+};
- /* TRUE if generating an executable, position independent or not. */
- unsigned int executable : 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 generating a position independent executable. */
- unsigned int pie: 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 relocatable object file. */
- unsigned int relocatable: 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;
callback. */
unsigned int notice_all: 1;
- /* TRUE if we are loading LTO outputs. */
- unsigned int loading_lto_outputs: 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;
/* 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;
/* TRUE if PT_GNU_RELRO segment should be created. */
unsigned int relro: 1;
- /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment
- should be created. */
- unsigned int eh_frame_hdr: 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 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
wrap_hash. Used by PowerPC Linux for 'dot' symbols. */
/* 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;
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;
- /* Non-NULL if .note.gnu.build-id section should be created. */
- char *emit_note_gnu_build_id;
-
/* 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
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. */
(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, ...);