libebl/libebl.h

/* Interface for libebl.
   Copyright (C) 2000, 2001, 2002, 2004, 2005 Red Hat, Inc.
   This file is part of Red Hat elfutils.

   Red Hat elfutils 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; version 2 of the License.

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   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 Red Hat elfutils; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.

   In addition, as a special exception, Red Hat, Inc. gives You the
   additional right to link the code of Red Hat elfutils with code licensed
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   this file solely under the GPL without exception.

   Red Hat elfutils is an included package of the Open Invention Network.
   An included package of the Open Invention Network is a package for which
   Open Invention Network licensees cross-license their patents.  No patent
   license is granted, either expressly or impliedly, by designation as an
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#ifndef _LIBEBL_H
#define _LIBEBL_H 1

#include <gelf.h>
#include "libdw.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#include "elf-knowledge.h"


/* Opaque type for the handle.  */
typedef struct ebl Ebl;


/* Get backend handle for object associated with ELF handle.  */
extern Ebl *ebl_openbackend (Elf *elf);
/* Similar but without underlying ELF file.  */
extern Ebl *ebl_openbackend_machine (GElf_Half machine);
/* Similar but with emulation name given.  */
extern Ebl *ebl_openbackend_emulation (const char *emulation);

/* Free resources allocated for backend handle.  */
extern void ebl_closebackend (Ebl *bh);


/* Information about the descriptor.  */

/* Get ELF machine.  */
extern int ebl_get_elfmachine (Ebl *ebl) __attribute__ ((__pure__));

/* Get ELF class.  */
extern int ebl_get_elfclass (Ebl *ebl) __attribute__ ((__pure__));

/* Get ELF data encoding.  */
extern int ebl_get_elfdata (Ebl *ebl) __attribute__ ((__pure__));


/* Function to call the callback functions including default ELF
   handling.  */

/* Return backend name.  */
extern const char *ebl_backend_name (Ebl *ebl);

/* Return relocation type name.  */
extern const char *ebl_object_type_name (Ebl *ebl, int object,
					 char *buf, size_t len);

/* Return relocation type name.  */
extern const char *ebl_reloc_type_name (Ebl *ebl, int reloc,
					char *buf, size_t len);

/* Check relocation type.  */
extern bool ebl_reloc_type_check (Ebl *ebl, int reloc);

/* Check relocation type use.  */
extern bool ebl_reloc_valid_use (Ebl *ebl, int reloc);

/* Check if relocation type is for simple absolute relocations.
   Return ELF_T_{BYTE,HALF,SWORD,SXWORD} for a simple type, else ELF_T_NUM.  */
extern Elf_Type ebl_reloc_simple_type (Ebl *ebl, int reloc);

/* Return true if the symbol type is that referencing the GOT.  E.g.,
   R_386_GOTPC.  */
extern bool ebl_gotpc_reloc_check (Ebl *ebl, int reloc);

/* Return segment type name.  */
extern const char *ebl_segment_type_name (Ebl *ebl, int segment,
					  char *buf, size_t len);

/* Return section type name.  */
extern const char *ebl_section_type_name (Ebl *ebl, int section,
					  char *buf, size_t len);

/* Return section name.  */
extern const char *ebl_section_name (Ebl *ebl, int section, int xsection,
				     char *buf, size_t len,
				     const char *scnnames[], size_t shnum);

/* Return machine flag names.  */
extern const char *ebl_machine_flag_name (Ebl *ebl, GElf_Word flags,
					  char *buf, size_t len);

/* Check whether machine flag is valid.  */
extern bool ebl_machine_flag_check (Ebl *ebl, GElf_Word flags);

/* Return symbol type name.  */
extern const char *ebl_symbol_type_name (Ebl *ebl, int symbol,
					 char *buf, size_t len);

/* Return symbol binding name.  */
extern const char *ebl_symbol_binding_name (Ebl *ebl, int binding,
					    char *buf, size_t len);

/* Return dynamic tag name.  */
extern const char *ebl_dynamic_tag_name (Ebl *ebl, int64_t tag,
					 char *buf, size_t len);

/* Check dynamic tag.  */
extern bool ebl_dynamic_tag_check (Ebl *ebl, int64_t tag);

/* Check whether given symbol's st_value and st_size are OK despite failing
   normal checks.  */
extern bool ebl_check_special_symbol (Ebl *ebl, GElf_Ehdr *ehdr,
				      const GElf_Sym *sym, const char *name,
				      const GElf_Shdr *destshdr);

/* Return combined section header flags value.  */
extern GElf_Word ebl_sh_flags_combine (Ebl *ebl, GElf_Word flags1,
				       GElf_Word flags2);

/* Return symbolic representation of OS ABI.  */
extern const char *ebl_osabi_name (Ebl *ebl, int osabi, char *buf, size_t len);


/* Return name of the note section type for a core file.  */
extern const char *ebl_core_note_type_name (Ebl *ebl, uint32_t type, char *buf,
					    size_t len);

/* Return name of the note section type for an object file.  */
extern const char *ebl_object_note_type_name (Ebl *ebl, uint32_t type,
					      char *buf, size_t len);

/* Print information about core note if available.  */
extern void ebl_core_note (Ebl *ebl, const char *name, uint32_t type,
			   uint32_t descsz, const char *desc);

/* Print information about object note if available.  */
extern void ebl_object_note (Ebl *ebl, const char *name, uint32_t type,
			     uint32_t descsz, const char *desc);

/* Check section name for being that of a debug informatino section.  */
extern bool ebl_debugscn_p (Ebl *ebl, const char *name);

/* Check whether given relocation is a copy relocation.  */
extern bool ebl_copy_reloc_p (Ebl *ebl, int reloc);

/* Check whether section should be stripped.  */
extern bool ebl_section_strip_p (Ebl *ebl, const GElf_Ehdr *ehdr,
				 const GElf_Shdr *shdr, const char *name,
				 bool remove_comment, bool only_remove_debug);

/* Check if backend uses a bss PLT in this file.  */
extern bool ebl_bss_plt_p (Ebl *ebl, GElf_Ehdr *ehdr);

/* Return location expression to find return value given a
   DW_TAG_subprogram, DW_TAG_subroutine_type, or similar DIE describing
   function itself (whose DW_AT_type attribute describes its return type).
   Returns -1 for a libdw error (see dwarf_errno).
   Returns -2 for an unrecognized type formation.
   Returns zero if the function has no return value (e.g. "void" in C).
   Otherwise, *LOCOPS gets a location expression to find the return value,
   and returns the number of operations in the expression.  The pointer is
   permanently allocated at least as long as the Ebl handle is open.  */
extern int ebl_return_value_location (Ebl *ebl,
				      Dwarf_Die *functypedie,
				      const Dwarf_Op **locops);

/* Fill in register name information given DWARF register numbers.
   If NAME is null, return the maximum REGNO + 1 that has a name.
   Otherwise, store in NAME the name for DWARF register number REGNO
   and return the number of bytes written (including '\0' terminator).
   Return -1 if NAMELEN is too short or REGNO is negative or too large.
   Return 0 if REGNO is unused (a gap in the DWARF number assignment).
   On success, set *SETNAME to a description like "integer" or "FPU"
   fit for "%s registers" title display, and *PREFIX to the string
   that precedes NAME in canonical assembler syntax (e.g. "%" or "$").
   The NAME string contains identifier characters only (maybe just digits).  */
extern ssize_t ebl_register_name (Ebl *ebl,
				  int regno, char *name, size_t namelen,
				  const char **prefix, const char **setname);


/* ELF string table handling.  */
struct Ebl_Strtab;
struct Ebl_Strent;

/* Create new ELF string table object in memory.  */
extern struct Ebl_Strtab *ebl_strtabinit (bool nullstr);

/* Free resources allocated for ELF string table ST.  */
extern void ebl_strtabfree (struct Ebl_Strtab *st);

/* Add string STR (length LEN is != 0) to ELF string table ST.  */
extern struct Ebl_Strent *ebl_strtabadd (struct Ebl_Strtab *st,
					 const char *str, size_t len);

/* Finalize string table ST and store size and memory location information
   in DATA.  */
extern void ebl_strtabfinalize (struct Ebl_Strtab *st, Elf_Data *data);

/* Get offset in string table for string associated with SE.  */
extern size_t ebl_strtaboffset (struct Ebl_Strent *se);

/* Return the string associated with SE.  */
extern const char *ebl_string (struct Ebl_Strent *se);


/* ELF wide char string table handling.  */
struct Ebl_WStrtab;
struct Ebl_WStrent;

/* Create new ELF wide char string table object in memory.  */
extern struct Ebl_WStrtab *ebl_wstrtabinit (bool nullstr);

/* Free resources allocated for ELF wide char string table ST.  */
extern void ebl_wstrtabfree (struct Ebl_WStrtab *st);

/* Add string STR (length LEN is != 0) to ELF string table ST.  */
extern struct Ebl_WStrent *ebl_wstrtabadd (struct Ebl_WStrtab *st,
					   const wchar_t *str, size_t len);

/* Finalize string table ST and store size and memory location information
   in DATA.  */
extern void ebl_wstrtabfinalize (struct Ebl_WStrtab *st, Elf_Data *data);

/* Get offset in wide char string table for string associated with SE.  */
extern size_t ebl_wstrtaboffset (struct Ebl_WStrent *se);


/* Generic string table handling.  */
struct Ebl_GStrtab;
struct Ebl_GStrent;

/* Create new string table object in memory.  */
extern struct Ebl_GStrtab *ebl_gstrtabinit (unsigned int width, bool nullstr);

/* Free resources allocated for string table ST.  */
extern void ebl_gstrtabfree (struct Ebl_GStrtab *st);

/* Add string STR (length LEN is != 0) to string table ST.  */
extern struct Ebl_GStrent *ebl_gstrtabadd (struct Ebl_GStrtab *st,
					   const char *str, size_t len);

/* Finalize string table ST and store size and memory location information
   in DATA.  */
extern void ebl_gstrtabfinalize (struct Ebl_GStrtab *st, Elf_Data *data);

/* Get offset in wide char string table for string associated with SE.  */
extern size_t ebl_gstrtaboffset (struct Ebl_GStrent *se);

#endif	/* libebl.h */