556 lines
22 KiB
C
556 lines
22 KiB
C
/* bfdlink.h -- header file for BFD link routines
|
||
Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
|
||
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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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_none, /* Don't discard any locals. */
|
||
discard_l, /* Discard local temporary symbols. */
|
||
discard_all /* Discard all locals. */
|
||
};
|
||
|
||
/* 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. */
|
||
};
|
||
|
||
/* 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 bfd_link_hash_type type;
|
||
|
||
/* Undefined and common symbols are kept in a linked list through
|
||
this field. This field is not in the union because that would
|
||
force us to remove entries from the list when we changed their
|
||
type, which would force the list to be doubly linked, which would
|
||
waste more memory. 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;
|
||
/* 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
|
||
{
|
||
bfd *abfd; /* BFD symbol was found in. */
|
||
} undef;
|
||
/* bfd_link_hash_defined, bfd_link_hash_defweak. */
|
||
struct
|
||
{
|
||
bfd_vma value; /* Symbol value. */
|
||
asection *section; /* Symbol section. */
|
||
} def;
|
||
/* bfd_link_hash_indirect, bfd_link_hash_warning. */
|
||
struct
|
||
{
|
||
struct bfd_link_hash_entry *link; /* Real symbol. */
|
||
const char *warning; /* Warning (bfd_link_hash_warning only). */
|
||
} i;
|
||
/* bfd_link_hash_common. */
|
||
struct
|
||
{
|
||
/* 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. */
|
||
bfd_size_type size; /* Common symbol size. */
|
||
struct bfd_link_hash_common_entry
|
||
{
|
||
unsigned int alignment_power; /* Alignment. */
|
||
asection *section; /* Symbol section. */
|
||
} *p;
|
||
} 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;
|
||
/* The back end which created this hash table. This indicates the
|
||
type of the entries in the hash table, which is sometimes
|
||
important information when linking object files of different
|
||
types together. */
|
||
const bfd_target *creator;
|
||
/* 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;
|
||
};
|
||
|
||
/* 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
|
||
PARAMS ((struct bfd_link_hash_table *, const char *, boolean create,
|
||
boolean copy, boolean 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
|
||
PARAMS ((bfd *, struct bfd_link_info *, const char *, boolean, boolean,
|
||
boolean));
|
||
|
||
/* Traverse a link hash table. */
|
||
extern void bfd_link_hash_traverse
|
||
PARAMS ((struct bfd_link_hash_table *,
|
||
boolean (*) (struct bfd_link_hash_entry *, PTR),
|
||
PTR));
|
||
|
||
/* Add an entry to the undefs list. */
|
||
extern void bfd_link_add_undef
|
||
PARAMS ((struct bfd_link_hash_table *, struct bfd_link_hash_entry *));
|
||
|
||
/* This structure holds all the information needed to communicate
|
||
between BFD and the linker when doing a link. */
|
||
|
||
struct bfd_link_info
|
||
{
|
||
/* Function callbacks. */
|
||
const struct bfd_link_callbacks *callbacks;
|
||
/* true if BFD should generate a relocateable object file. */
|
||
boolean relocateable;
|
||
/* true if BFD should generate relocation information in the final executable. */
|
||
boolean emitrelocations;
|
||
/* true if BFD should generate a "task linked" object file,
|
||
similar to relocatable but also with globals converted to statics. */
|
||
boolean task_link;
|
||
/* true if BFD should generate a shared object. */
|
||
boolean shared;
|
||
/* true if BFD should pre-bind symbols in a shared object. */
|
||
boolean symbolic;
|
||
/* true if shared objects should be linked directly, not shared. */
|
||
boolean static_link;
|
||
/* 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. */
|
||
boolean traditional_format;
|
||
/* true if we want to produced optimized output files. This might
|
||
need much more time and therefore must be explicitly selected. */
|
||
boolean optimize;
|
||
/* true if BFD should generate errors for undefined symbols
|
||
even if generating a shared object. */
|
||
boolean no_undefined;
|
||
/* true if BFD should allow undefined symbols in shared objects even
|
||
when no_undefined is set to disallow undefined symbols. The net
|
||
result will be that undefined symbols in regular objects will
|
||
still trigger an error, but undefined symbols in shared objects
|
||
will be ignored. The implementation of no_undefined makes the
|
||
assumption that the runtime linker will choke on undefined
|
||
symbols. However there is at least one system (BeOS) where
|
||
undefined symbols in shared libraries is normal since the kernel
|
||
patches them at load time to select which function is most
|
||
appropriate for the current architecture. I.E. dynamically
|
||
select an appropriate memset function. Apparently it is also
|
||
normal for HPPA shared libraries to have undefined symbols. */
|
||
boolean allow_shlib_undefined;
|
||
/* Which symbols to strip. */
|
||
enum bfd_link_strip strip;
|
||
/* Which local symbols to discard. */
|
||
enum bfd_link_discard discard;
|
||
/* true if symbols should be retained in memory, false if they
|
||
should be freed and reread. */
|
||
boolean keep_memory;
|
||
/* The list of input BFD's involved in the link. These are chained
|
||
together via the link_next field. */
|
||
bfd *input_bfds;
|
||
/* 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;
|
||
/* 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;
|
||
/* true if every symbol should be reported back via the notice
|
||
callback. */
|
||
boolean notice_all;
|
||
/* 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;
|
||
/* If a base output file is wanted, then this points to it */
|
||
PTR base_file;
|
||
|
||
/* If non-zero, specifies that branches which are problematic for the
|
||
MPC860 C0 (or earlier) should be checked for and modified. It gives the
|
||
number of bytes that should be checked at the end of each text page. */
|
||
int mpc860c0;
|
||
|
||
/* 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;
|
||
|
||
/* true if the new ELF dynamic tags are enabled. */
|
||
boolean new_dtags;
|
||
|
||
/* 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;
|
||
};
|
||
|
||
/* This structures holds a set of callback functions. These are
|
||
called by the BFD linker routines. The first argument to each
|
||
callback function is the bfd_link_info structure being used. Each
|
||
function returns a boolean value. If the function returns false,
|
||
then the BFD function which called it will 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. */
|
||
boolean (*add_archive_element) PARAMS ((struct bfd_link_info *,
|
||
bfd *abfd,
|
||
const char *name));
|
||
/* A function which is called when a symbol is found with multiple
|
||
definitions. NAME is the symbol which is defined multiple times.
|
||
OBFD is the old BFD, OSEC is the old section, OVAL is the old
|
||
value, NBFD is the new BFD, NSEC is the new section, and NVAL is
|
||
the new value. OBFD may be NULL. OSEC and NSEC may be
|
||
bfd_com_section or bfd_ind_section. */
|
||
boolean (*multiple_definition) PARAMS ((struct bfd_link_info *,
|
||
const char *name,
|
||
bfd *obfd,
|
||
asection *osec,
|
||
bfd_vma oval,
|
||
bfd *nbfd,
|
||
asection *nsec,
|
||
bfd_vma nval));
|
||
/* A function which is called when a common symbol is defined
|
||
multiple times. NAME is the symbol appearing multiple times.
|
||
OBFD is the BFD of the existing symbol; it may be NULL if this is
|
||
not known. OTYPE is the type of the existing symbol, which may
|
||
be bfd_link_hash_defined, bfd_link_hash_defweak,
|
||
bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is
|
||
bfd_link_hash_common, OSIZE is the size of the existing symbol.
|
||
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. */
|
||
boolean (*multiple_common) PARAMS ((struct bfd_link_info *,
|
||
const char *name,
|
||
bfd *obfd,
|
||
enum bfd_link_hash_type otype,
|
||
bfd_vma osize,
|
||
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 relocateable 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. */
|
||
boolean (*add_to_set) PARAMS ((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
|
||
relocateable file. NAME is the name of the symbol found. ABFD,
|
||
SECTION and VALUE are the value of the symbol. */
|
||
boolean (*constructor) PARAMS ((struct bfd_link_info *,
|
||
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. */
|
||
boolean (*warning) PARAMS ((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. FATAL indicates whether an undefined symbol is
|
||
a fatal error or not. In some cases SECTION may be NULL. */
|
||
boolean (*undefined_symbol) PARAMS ((struct bfd_link_info *,
|
||
const char *name, bfd *abfd,
|
||
asection *section,
|
||
bfd_vma address,
|
||
boolean fatal));
|
||
/* A function which is called when a reloc overflow occurs. NAME is
|
||
the name of the 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. */
|
||
boolean (*reloc_overflow) PARAMS ((struct bfd_link_info *,
|
||
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.
|
||
The canonical example is an a29k IHCONST reloc which does not
|
||
follow an IHIHALF reloc. 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. */
|
||
boolean (*reloc_dangerous) PARAMS ((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. */
|
||
boolean (*unattached_reloc) PARAMS ((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. NAME is the symbol. ABFD, SECTION and
|
||
ADDRESS are the value of the symbol. If SECTION is
|
||
bfd_und_section, this is a reference. */
|
||
boolean (*notice) PARAMS ((struct bfd_link_info *, const char *name,
|
||
bfd *abfd, asection *section, bfd_vma address));
|
||
};
|
||
|
||
/* 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_fill_link_order, /* Fill with a 16 bit constant. */
|
||
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 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. */
|
||
bfd_vma offset;
|
||
/* Size within output section. */
|
||
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->_raw_size
|
||
must equal the link_order size field. Maybe these
|
||
restrictions should be relaxed someday. */
|
||
asection *section;
|
||
} indirect;
|
||
struct
|
||
{
|
||
/* Value to fill with. */
|
||
unsigned int value;
|
||
} fill;
|
||
struct
|
||
{
|
||
/* Data to put into file. The size field gives the number
|
||
of bytes which this field points to. */
|
||
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 PARAMS ((bfd *, asection *));
|
||
|
||
/* 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. */
|
||
|
||
/* Regular expressions for a version. */
|
||
|
||
struct bfd_elf_version_expr
|
||
{
|
||
/* Next regular expression for this version. */
|
||
struct bfd_elf_version_expr *next;
|
||
/* Regular expression. */
|
||
const char *pattern;
|
||
/* Matching function. */
|
||
int (*match) PARAMS((struct bfd_elf_version_expr *, const char *));
|
||
};
|
||
|
||
/* 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 *globals;
|
||
/* Regular expressions for local symbols in this version. */
|
||
struct bfd_elf_version_expr *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;
|
||
};
|
||
|
||
#endif
|