/* 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) 1993-2020 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. */
};
+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. */
/* Type of this entry. */
ENUM_BITFIELD (bfd_link_hash_type) type : 8;
- unsigned int non_ir_ref : 1;
+ /* 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
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;
} 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 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;
/* 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 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;
/* 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;
/* 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;
+ /* 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;
/* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
unsigned int warn_shared_textrel: 1;
/* TRUE if ok to have multiple definition. */
unsigned int allow_multiple_definition: 1;
+ /* TRUE if ok to have prohibit multiple definition of absolute symbols. */
+ unsigned int prohibit_multiple_definition_absolute: 1;
+
/* TRUE if ok to have version with no definition. */
unsigned int allow_undefined_version: 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;
+
/* 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;
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. */
+ 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;
+
+ /* 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. */
struct bfd_elf_version_tree *version_info;
};
+/* Some forward-definitions used by some callbacks. */
+
+struct elf_strtab_hash;
+struct elf_sym_strtab;
+
/* 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. */
+ by the BFD linker routines. */
struct bfd_link_callbacks
{
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. */
+ original BFD's symbols. Returns TRUE if the object should be
+ added, FALSE if it should be skipped. */
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)
+ 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
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)
+ 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 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)
+ 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. 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)
+ void (*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
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)
+ 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
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)
+ void (*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
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)
+ 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);
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)
+ 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
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)
+ 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. 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, ...);
(struct bfd_link_info *, bfd * abfd,
asection * current_section, asection * previous_section,
bfd_boolean new_segment);
+ /* This callback provides a chance for callers of the BFD to examine the
+ ELF string table and symbol table once they are complete and indexes and
+ offsets assigned. */
+ void (*examine_strtab)
+ (struct elf_sym_strtab *syms, bfd_size_type symcount,
+ struct elf_strtab_hash *symstrtab);
+ /* 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);
};
\f
/* The linker builds link_order structures which tell the code how to
} indirect;
struct
{
- /* Size of contents, or zero when contents should be filled by
+ /* 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. */
/* 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 bfd_boolean bfd_section_already_linked_table_init (void);
+extern void bfd_section_already_linked_table_free (void);
+extern bfd_boolean _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
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