libdw/libdw.h

/* Interfaces for libdw.
   Copyright (C) 2002, 2004, 2005, 2006, 2007 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.

   Red Hat elfutils 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 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
   under any Open Source Initiative certified open source license
   (http://www.opensource.org/licenses/index.php) which requires the
   distribution of source code with any binary distribution and to
   distribute linked combinations of the two.  Non-GPL Code permitted under
   this exception must only link to the code of Red Hat elfutils through
   those well defined interfaces identified in the file named EXCEPTION
   found in the source code files (the "Approved Interfaces").  The files
   of Non-GPL Code may instantiate templates or use macros or inline
   functions from the Approved Interfaces without causing the resulting
   work to be covered by the GNU General Public License.  Only Red Hat,
   Inc. may make changes or additions to the list of Approved Interfaces.
   Red Hat's grant of this exception is conditioned upon your not adding
   any new exceptions.  If you wish to add a new Approved Interface or
   exception, please contact Red Hat.  You must obey the GNU General Public
   License in all respects for all of the Red Hat elfutils code and other
   code used in conjunction with Red Hat elfutils except the Non-GPL Code
   covered by this exception.  If you modify this file, you may extend this
   exception to your version of the file, but you are not obligated to do
   so.  If you do not wish to provide this exception without modification,
   you must delete this exception statement from your version and license
   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
   included package.  Should you wish to participate in the Open Invention
   Network licensing program, please visit www.openinventionnetwork.com
   <http://www.openinventionnetwork.com>.  */

#ifndef _LIBDW_H
#define _LIBDW_H	1

#include <gelf.h>
#include <stdbool.h>
#include <stddef.h>


#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
# define __nonnull_attribute__(...) __attribute__ ((__nonnull__ (__VA_ARGS__)))
#else
# define __nonnull_attribute__(args...)
#endif


/* Mode for the session.  */
typedef enum
  {
    DWARF_C_READ,		/* Read .. */
    DWARF_C_RDWR,		/* Read and write .. */
    DWARF_C_WRITE,		/* Write .. */
  }
Dwarf_Cmd;


/* Callback results.  */
enum
{
  DWARF_CB_OK = 0,
  DWARF_CB_ABORT
};


/* Error values.  */
enum
  {
    DW_TAG_invalid = 0
#define DW_TAG_invalid	DW_TAG_invalid
  };


/* Type for offset in DWARF file.  */
typedef GElf_Off Dwarf_Off;

/* Type for address in DWARF file.  */
typedef GElf_Addr Dwarf_Addr;

/* Integer types.  Big enough to hold any numeric value.  */
typedef GElf_Xword Dwarf_Word;
typedef GElf_Sxword Dwarf_Sword;
/* For the times we know we do not need that much.  */
typedef GElf_Half Dwarf_Half;


/* DWARF abbreviation record.  */
typedef struct Dwarf_Abbrev Dwarf_Abbrev;

/* Returned to show the last DIE has be returned.  */
#define DWARF_END_ABBREV ((Dwarf_Abbrev *) -1l)

/* Source code line information for CU.  */
typedef struct Dwarf_Lines_s Dwarf_Lines;

/* One source code line information.  */
typedef struct Dwarf_Line_s Dwarf_Line;

/* Source file information.  */
typedef struct Dwarf_Files_s Dwarf_Files;

/* One address range record.  */
typedef struct Dwarf_Arange_s Dwarf_Arange;

/* Address ranges of a file.  */
typedef struct Dwarf_Aranges_s Dwarf_Aranges;

/* CU representation.  */
struct Dwarf_CU;

/* Macro information.  */
typedef struct Dwarf_Macro_s Dwarf_Macro;

/* Attribute representation.  */
typedef struct
{
  unsigned int code;
  unsigned int form;
  unsigned char *valp;
  struct Dwarf_CU *cu;
} Dwarf_Attribute;


/* Data block representation.  */
typedef struct
{
  Dwarf_Word length;
  unsigned char *data;
} Dwarf_Block;


/* DIE information.  */
typedef struct
{
  /* The offset can be computed from the address.  */
  void *addr;
  struct Dwarf_CU *cu;
  Dwarf_Abbrev *abbrev;
  // XXX We'll see what other information will be needed.
  long int padding__;
} Dwarf_Die;

/* Returned to show the last DIE has be returned.  */
#define DWARF_END_DIE ((Dwarf_Die *) -1l)


/* Global symbol information.  */
typedef struct
{
  Dwarf_Off cu_offset;
  Dwarf_Off die_offset;
  const char *name;
} Dwarf_Global;


/* One operation in a DWARF location expression.
   A location expression is an array of these.  */
typedef struct
{
  uint8_t atom;			/* Operation */
  Dwarf_Word number;		/* Operand */
  Dwarf_Word number2;		/* Possible second operand */
  Dwarf_Word offset;		/* Offset in location expression */
} Dwarf_Op;


/* Handle for debug sessions.  */
typedef struct Dwarf Dwarf;


/* Out-Of-Memory handler.  */
#if __GNUC__ < 4
typedef void (*Dwarf_OOM) (void);
#else
typedef void (*__attribute__ ((noreturn)) Dwarf_OOM) (void);
#endif


#ifdef __cplusplus
extern "C" {
#endif

/* Create a handle for a new debug session.  */
extern Dwarf *dwarf_begin (int fildes, Dwarf_Cmd cmd);

/* Create a handle for a new debug session for an ELF file.  */
extern Dwarf *dwarf_begin_elf (Elf *elf, Dwarf_Cmd cmd, Elf_Scn *scngrp);

/* Retrieve ELF descriptor used for DWARF access.  */
extern Elf *dwarf_getelf (Dwarf *dwarf);

/* Release debugging handling context.  */
extern int dwarf_end (Dwarf *dwarf);


/* Get the data block for the .debug_info section.  */
extern Elf_Data *dwarf_getscn_info (Dwarf *dwarf);

/* Read the header for the DWARF CU header.  */
extern int dwarf_nextcu (Dwarf *dwarf, Dwarf_Off off, Dwarf_Off *next_off,
			 size_t *header_sizep, Dwarf_Off *abbrev_offsetp,
			 uint8_t *address_sizep, uint8_t *offset_sizep)
     __nonnull_attribute__ (3);


/* Return DIE at given offset.  */
extern Dwarf_Die *dwarf_offdie (Dwarf *dbg, Dwarf_Off offset,
				Dwarf_Die *result) __nonnull_attribute__ (3);

/* Return offset of DIE.  */
extern Dwarf_Off dwarf_dieoffset (Dwarf_Die *die);

/* Return offset of DIE in CU.  */
extern Dwarf_Off dwarf_cuoffset (Dwarf_Die *die);

/* Return CU DIE containing given DIE.  */
extern Dwarf_Die *dwarf_diecu (Dwarf_Die *die, Dwarf_Die *result,
			       uint8_t *address_sizep, uint8_t *offset_sizep)
     __nonnull_attribute__ (2);

/* Return CU DIE containing given address.  */
extern Dwarf_Die *dwarf_addrdie (Dwarf *dbg, Dwarf_Addr addr,
				 Dwarf_Die *result) __nonnull_attribute__ (3);

/* Return child of current DIE.  */
extern int dwarf_child (Dwarf_Die *die, Dwarf_Die *result)
     __nonnull_attribute__ (2);

/* Return sibling of given DIE.  */
extern int dwarf_siblingof (Dwarf_Die *die, Dwarf_Die *result)
     __nonnull_attribute__ (2);

/* Check whether the DIE has children.  */
extern int dwarf_haschildren (Dwarf_Die *die) __nonnull_attribute__ (1);

/* Get attributes of the DIE.  */
extern ptrdiff_t dwarf_getattrs (Dwarf_Die *die,
				 int (*callback) (Dwarf_Attribute *, void *),
				 void *arg, ptrdiff_t offset)
     __nonnull_attribute__ (2);

/* Return tag of given DIE.  */
extern int dwarf_tag (Dwarf_Die *die) __nonnull_attribute__ (1);


/* Return specific attribute of DIE.  */
extern Dwarf_Attribute *dwarf_attr (Dwarf_Die *die, unsigned int search_name,
				    Dwarf_Attribute *result)
     __nonnull_attribute__ (3);

/* Check whether given DIE has specific attribute.  */
extern int dwarf_hasattr (Dwarf_Die *die, unsigned int search_name);

/* These are the same as dwarf_attr and dwarf_hasattr, respectively,
   but they resolve an indirect attribute through DW_AT_abstract_origin.  */
extern Dwarf_Attribute *dwarf_attr_integrate (Dwarf_Die *die,
					      unsigned int search_name,
					      Dwarf_Attribute *result)
     __nonnull_attribute__ (3);
extern int dwarf_hasattr_integrate (Dwarf_Die *die, unsigned int search_name);




/* Check whether given attribute has specific form.  */
extern int dwarf_hasform (Dwarf_Attribute *attr, unsigned int search_form);

/* Return attribute code of given attribute.  */
extern unsigned int dwarf_whatattr (Dwarf_Attribute *attr);

/* Return form code of given attribute.  */
extern unsigned int dwarf_whatform (Dwarf_Attribute *attr);


/* Return string associated with given attribute.  */
extern const char *dwarf_formstring (Dwarf_Attribute *attrp);

/* Return unsigned constant represented by attribute.  */
extern int dwarf_formudata (Dwarf_Attribute *attr, Dwarf_Word *return_uval)
     __nonnull_attribute__ (2);

/* Return signed constant represented by attribute.  */
extern int dwarf_formsdata (Dwarf_Attribute *attr, Dwarf_Sword *return_uval)
     __nonnull_attribute__ (2);

/* Return address represented by attribute.  */
extern int dwarf_formaddr (Dwarf_Attribute *attr, Dwarf_Addr *return_addr)
     __nonnull_attribute__ (2);

/* Return reference offset represented by attribute.  */
extern int dwarf_formref (Dwarf_Attribute *attr, Dwarf_Off *return_offset)
     __nonnull_attribute__ (2);

/* Look up the DIE in a reference-form attribute.  */
extern Dwarf_Die *dwarf_formref_die (Dwarf_Attribute *attr, Dwarf_Die *die_mem)
     __nonnull_attribute__ (2);

/* Return block represented by attribute.  */
extern int dwarf_formblock (Dwarf_Attribute *attr, Dwarf_Block *return_block)
     __nonnull_attribute__ (2);

/* Return flag represented by attribute.  */
extern int dwarf_formflag (Dwarf_Attribute *attr, bool *return_bool)
     __nonnull_attribute__ (2);


/* Simplified attribute value access functions.  */

/* Return string in name attribute of DIE.  */
extern const char *dwarf_diename (Dwarf_Die *die);

/* Return high PC attribute of DIE.  */
extern int dwarf_highpc (Dwarf_Die *die, Dwarf_Addr *return_addr)
     __nonnull_attribute__ (2);

/* Return low PC attribute of DIE.  */
extern int dwarf_lowpc (Dwarf_Die *die, Dwarf_Addr *return_addr)
     __nonnull_attribute__ (2);

/* Return entry_pc or low_pc attribute of DIE.  */
extern int dwarf_entrypc (Dwarf_Die *die, Dwarf_Addr *return_addr)
     __nonnull_attribute__ (2);

/* Return 1 if DIE's lowpc/highpc or ranges attributes match the PC address,
   0 if not, or -1 for errors.  */
extern int dwarf_haspc (Dwarf_Die *die, Dwarf_Addr pc);

/* Enumerate the PC address ranges covered by this DIE, covering all
   addresses where dwarf_haspc returns true.  In the first call OFFSET
   should be zero and *BASEP need not be initialized.  Returns -1 for
   errors, zero when there are no more address ranges to report, or a
   nonzero OFFSET value to pass to the next call.  Each subsequent call
   must preserve *BASEP from the prior call.  Successful calls fill in
   *STARTP and *ENDP with a contiguous address range.  */
extern ptrdiff_t dwarf_ranges (Dwarf_Die *die,
			       ptrdiff_t offset, Dwarf_Addr *basep,
			       Dwarf_Addr *startp, Dwarf_Addr *endp);


/* Return byte size attribute of DIE.  */
extern int dwarf_bytesize (Dwarf_Die *die);

/* Return bit size attribute of DIE.  */
extern int dwarf_bitsize (Dwarf_Die *die);

/* Return bit offset attribute of DIE.  */
extern int dwarf_bitoffset (Dwarf_Die *die);

/* Return array order attribute of DIE.  */
extern int dwarf_arrayorder (Dwarf_Die *die);

/* Return source language attribute of DIE.  */
extern int dwarf_srclang (Dwarf_Die *die);


/* Get abbreviation at given offset for given DIE.  */
extern Dwarf_Abbrev *dwarf_getabbrev (Dwarf_Die *die, Dwarf_Off offset,
				      size_t *lengthp);

/* Get abbreviation at given offset in .debug_abbrev section.  */
extern int dwarf_offabbrev (Dwarf *dbg, Dwarf_Off offset, size_t *lengthp,
			    Dwarf_Abbrev *abbrevp)
     __nonnull_attribute__ (4);

/* Get abbreviation code.  */
extern unsigned int dwarf_getabbrevcode (Dwarf_Abbrev *abbrev);

/* Get abbreviation tag.  */
extern unsigned int dwarf_getabbrevtag (Dwarf_Abbrev *abbrev);

/* Return true if abbreviation is children flag set.  */
extern int dwarf_abbrevhaschildren (Dwarf_Abbrev *abbrev);

/* Get number of attributes of abbreviation.  */
extern int dwarf_getattrcnt (Dwarf_Abbrev *abbrev, size_t *attrcntp)
     __nonnull_attribute__ (2);

/* Get specific attribute of abbreviation.  */
extern int dwarf_getabbrevattr (Dwarf_Abbrev *abbrev, size_t idx,
				unsigned int *namep, unsigned int *formp,
				Dwarf_Off *offset);


/* Get string from-debug_str section.  */
extern const char *dwarf_getstring (Dwarf *dbg, Dwarf_Off offset,
				    size_t *lenp);


/* Get public symbol information.  */
extern ptrdiff_t dwarf_getpubnames (Dwarf *dbg,
				    int (*callback) (Dwarf *, Dwarf_Global *,
						     void *),
				    void *arg, ptrdiff_t offset)
     __nonnull_attribute__ (2);


/* Get source file information for CU.  */
extern int dwarf_getsrclines (Dwarf_Die *cudie, Dwarf_Lines **lines,
			      size_t *nlines) __nonnull_attribute__ (2, 3);

/* Return one of the source lines of the CU.  */
extern Dwarf_Line *dwarf_onesrcline (Dwarf_Lines *lines, size_t idx);

/* Get the file source files used in the CU.  */
extern int dwarf_getsrcfiles (Dwarf_Die *cudie, Dwarf_Files **files,
			      size_t *nfiles)
     __nonnull_attribute__ (2);


/* Get source for address in CU.  */
extern Dwarf_Line *dwarf_getsrc_die (Dwarf_Die *cudie, Dwarf_Addr addr);

/* Get source for file and line number.  */
extern int dwarf_getsrc_file (Dwarf *dbg, const char *fname, int line, int col,
			      Dwarf_Line ***srcsp, size_t *nsrcs)
     __nonnull_attribute__ (2, 5, 6);


/* Return line address.  */
extern int dwarf_lineaddr (Dwarf_Line *line, Dwarf_Addr *addrp);

/* Return line number.  */
extern int dwarf_lineno (Dwarf_Line *line, int *linep)
     __nonnull_attribute__ (2);

/* Return column in line.  */
extern int dwarf_linecol (Dwarf_Line *line, int *colp)
     __nonnull_attribute__ (2);

/* Return true if record is for beginning of a statement.  */
extern int dwarf_linebeginstatement (Dwarf_Line *line, bool *flagp)
     __nonnull_attribute__ (2);

/* Return true if record is for end of sequence.  */
extern int dwarf_lineendsequence (Dwarf_Line *line, bool *flagp)
     __nonnull_attribute__ (2);

/* Return true if record is for beginning of a basic block.  */
extern int dwarf_lineblock (Dwarf_Line *line, bool *flagp)
     __nonnull_attribute__ (2);

/* Return true if record is for end of prologue.  */
extern int dwarf_lineprologueend (Dwarf_Line *line, bool *flagp)
     __nonnull_attribute__ (2);

/* Return true if record is for beginning of epilogue.  */
extern int dwarf_lineepiloguebegin (Dwarf_Line *line, bool *flagp)
     __nonnull_attribute__ (2);


/* Find line information for address.  */
extern const char *dwarf_linesrc (Dwarf_Line *line,
				  Dwarf_Word *mtime, Dwarf_Word *length);

/* Return file information.  */
extern const char *dwarf_filesrc (Dwarf_Files *file, size_t idx,
				  Dwarf_Word *mtime, Dwarf_Word *length);

/* Return the directory list used in the file information extracted.
   (*RESULT)[0] is the CU's DW_AT_comp_dir value, and may be null.
   (*RESULT)[0..*NDIRS-1] are the compile-time include directory path
   encoded by the compiler.  */
extern int dwarf_getsrcdirs (Dwarf_Files *files,
			     const char *const **result, size_t *ndirs)
  __nonnull_attribute__ (2, 3);


/* Return location expression, decoded as a list of operations.  */
extern int dwarf_getlocation (Dwarf_Attribute *attr, Dwarf_Op **expr,
			      size_t *exprlen) __nonnull_attribute__ (2, 3);

/* Return location expressions.  If the attribute uses a location list,
   ADDRESS selects the relevant location expressions from the list.
   There can be multiple matches, resulting in multiple expressions to
   return.  EXPRS and EXPRLENS are parallel arrays of NLOCS slots to
   fill in.  Returns the number of locations filled in, or -1 for
   errors.  If EXPRS is a null pointer, stores nothing and returns the
   total number of locations.  A return value of zero means that the
   location list indicated no value is accessible.  */
extern int dwarf_getlocation_addr (Dwarf_Attribute *attr, Dwarf_Addr address,
				   Dwarf_Op **exprs, size_t *exprlens,
				   size_t nlocs);


/* Return scope DIEs containing PC address.
   Sets *SCOPES to a malloc'd array of Dwarf_Die structures,
   and returns the number of elements in the array.
   (*SCOPES)[0] is the DIE for the innermost scope containing PC,
   (*SCOPES)[1] is the DIE for the scope containing that scope, and so on.
   Returns -1 for errors or 0 if no scopes match PC.  */
extern int dwarf_getscopes (Dwarf_Die *cudie, Dwarf_Addr pc,
			    Dwarf_Die **scopes);

/* Return scope DIEs containing the given DIE.
   Sets *SCOPES to a malloc'd array of Dwarf_Die structures,
   and returns the number of elements in the array.
   (*SCOPES)[0] is a copy of DIE.
   (*SCOPES)[1] is the DIE for the scope containing that scope, and so on.
   Returns -1 for errors or 0 if DIE is not found in any scope entry.  */
extern int dwarf_getscopes_die (Dwarf_Die *die, Dwarf_Die **scopes);


/* Search SCOPES[0..NSCOPES-1] for a variable called NAME.
   Ignore the first SKIP_SHADOWS scopes that match the name.
   If MATCH_FILE is not null, accept only declaration in that source file;
   if MATCH_LINENO or MATCH_LINECOL are also nonzero, accept only declaration
   at that line and column.

   If successful, fill in *RESULT with the DIE of the variable found,
   and return N where SCOPES[N] is the scope defining the variable.
   Return -1 for errors or -2 for no matching variable found.  */
extern int dwarf_getscopevar (Dwarf_Die *scopes, int nscopes,
			      const char *name, int skip_shadows,
			      const char *match_file,
			      int match_lineno, int match_linecol,
			      Dwarf_Die *result);



/* Return list address ranges.  */
extern int dwarf_getaranges (Dwarf *dbg, Dwarf_Aranges **aranges,
			     size_t *naranges)
     __nonnull_attribute__ (2);

/* Return one of the address range entries.  */
extern Dwarf_Arange *dwarf_onearange (Dwarf_Aranges *aranges, size_t idx);

/* Return information in address range record.  */
extern int dwarf_getarangeinfo (Dwarf_Arange *arange, Dwarf_Addr *addrp,
				Dwarf_Word *lengthp, Dwarf_Off *offsetp);

/* Get address range which includes given address.  */
extern Dwarf_Arange *dwarf_getarange_addr (Dwarf_Aranges *aranges,
					   Dwarf_Addr addr);



/* Get functions in CUDIE.  */
extern ptrdiff_t dwarf_getfuncs (Dwarf_Die *cudie,
				 int (*callback) (Dwarf_Die *, void *),
				 void *arg, ptrdiff_t offset);


/* Return file name containing definition of the given declaration.  */
extern const char *dwarf_decl_file (Dwarf_Die *decl);

/* Get line number of beginning of given declaration.  */
extern int dwarf_decl_line (Dwarf_Die *decl, int *linep)
     __nonnull_attribute__ (2);

/* Get column number of beginning of given declaration.  */
extern int dwarf_decl_column (Dwarf_Die *decl, int *colp)
     __nonnull_attribute__ (2);


/* Return nonzero if given function is an abstract inline definition.  */
extern int dwarf_func_inline (Dwarf_Die *func);

/* Find each concrete inlined instance of the abstract inline definition.  */
extern int dwarf_func_inline_instances (Dwarf_Die *func,
					int (*callback) (Dwarf_Die *, void *),
					void *arg);


/* Find the appropriate PC location or locations for function entry
   breakpoints for the given DW_TAG_subprogram DIE.  Returns -1 for errors.
   On success, returns the number of breakpoint locations (never zero)
   and sets *BKPTS to a malloc'd vector of addresses.  */
extern int dwarf_entry_breakpoints (Dwarf_Die *die, Dwarf_Addr **bkpts);


/* Call callback function for each of the macro information entry for
   the CU.  */
extern ptrdiff_t dwarf_getmacros (Dwarf_Die *cudie,
				  int (*callback) (Dwarf_Macro *, void *),
				  void *arg, ptrdiff_t offset)
     __nonnull_attribute__ (2);

/* Return macro opcode.  */
extern int dwarf_macro_opcode (Dwarf_Macro *macro, unsigned int *opcodep)
     __nonnull_attribute__ (2);

/* Return first macro parameter.  */
extern int dwarf_macro_param1 (Dwarf_Macro *macro, Dwarf_Word *paramp)
     __nonnull_attribute__ (2);

/* Return second macro parameter.  */
extern int dwarf_macro_param2 (Dwarf_Macro *macro, Dwarf_Word *paramp,
			       const char **strp);


/* Return error code of last failing function call.  This value is kept
   separately for each thread.  */
extern int dwarf_errno (void);

/* Return error string for ERROR.  If ERROR is zero, return error string
   for most recent error or NULL is none occurred.  If ERROR is -1 the
   behaviour is similar to the last case except that not NULL but a legal
   string is returned.  */
extern const char *dwarf_errmsg (int err);


/* Register new Out-Of-Memory handler.  The old handler is returned.  */
extern Dwarf_OOM dwarf_new_oom_handler (Dwarf *dbg, Dwarf_OOM handler);


/* Inline optimizations.  */
#ifdef __OPTIMIZE__
/* Return attribute code of given attribute.  */
extern inline unsigned int
dwarf_whatattr (Dwarf_Attribute *attr)
{
  return attr == NULL ? 0 : attr->code;
}

/* Return attribute code of given attribute.  */
extern inline unsigned int
dwarf_whatform (Dwarf_Attribute *attr)
{
  return attr == NULL ? 0 : attr->form;
}
#endif	/* Optimize.  */

#ifdef __cplusplus
}
#endif

#endif	/* libdw.h */