| /* bfdlink.h -- header file for BFD link routines |
| Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002 |
| 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_sec_merge, /* Discard local temporary symbols in SEC_MERGE |
| sections. */ |
| discard_none, /* Don't discard any locals. */ |
| discard_l, /* Discard local temporary symbols. */ |
| discard_all /* Discard all locals. */ |
| }; |
| |
| /* Describes the type of hash table entry structure being used. |
| Different hash table structure have different fields and so |
| support different linking features. */ |
| enum bfd_link_hash_table_type |
| { |
| bfd_link_generic_hash_table, |
| bfd_link_elf_hash_table |
| }; |
| |
| /* 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; |
| /* The type of the ink hash table. */ |
| enum bfd_link_hash_table_type type; |
| }; |
| |
| /* 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 *)); |
| |
| struct bfd_sym_chain |
| { |
| struct bfd_sym_chain *next; |
| const char *name; |
| }; |
| |
| /* 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 BFD should export all symbols in the dynamic symbol table |
| of an executable, rather than only those used. */ |
| boolean export_dynamic; |
| |
| /* 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; |
| |
| /* true if ok to have multiple definition. */ |
| boolean allow_multiple_definition; |
| |
| /* 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; |
| |
| /* List of global symbol names that are starting points for marking |
| sections against garbage collection. */ |
| struct bfd_sym_chain *gc_sym_list; |
| |
| /* 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; |
| |
| /* 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; |
| |
| /* True if non-PLT relocs should be merged into one reloc section |
| and sorted so that relocs against the same symbol come together. */ |
| boolean combreloc; |
| |
| /* True if executable should not contain copy relocs. |
| Setting this true may result in a non-sharable text segment. */ |
| boolean nocopyreloc; |
| |
| /* True if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment |
| should be created. */ |
| boolean eh_frame_hdr; |
| |
| /* How many spare .dynamic DT_NULL entries should be added? */ |
| unsigned int spare_dynamic_tags; |
| }; |
| |
| /* 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_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 |
| { |
| /* Size of contents, or zero when contents size == size |
| within output section. |
| A non-zero value allows filling of the output section |
| with an arbitrary repeated pattern. */ |
| unsigned int size; |
| /* Data to put into file. */ |
| 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 |