include/pub_tool_debuginfo.h

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/*--- DebugInfo.                              pub_tool_debuginfo.h ---*/
/*--------------------------------------------------------------------*/

/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2000-2012 Julian Seward
      jseward@acm.org

   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.

   The GNU General Public License is contained in the file COPYING.
*/

#ifndef __PUB_TOOL_DEBUGINFO_H
#define __PUB_TOOL_DEBUGINFO_H

/*====================================================================*/
/*=== Obtaining debug information                                  ===*/
/*====================================================================*/

/* Get the file/function/line number of the instruction at address
   'a'.  For these four, if debug info for the address is found, it
   copies the info into the buffer/UInt and returns True.  If not, it
   returns False and nothing is copied.  VG_(get_fnname) always
   demangles C++ function names.  VG_(get_fnname_w_offset) is the
   same, except it appends "+N" to symbol names to indicate offsets.  */
extern Bool VG_(get_filename) ( Addr a, Char* filename, Int n_filename );
extern Bool VG_(get_fnname)   ( Addr a, Char* fnname,   Int n_fnname   );
extern Bool VG_(get_linenum)  ( Addr a, UInt* linenum );
extern Bool VG_(get_fnname_w_offset)
                              ( Addr a, Char* fnname,   Int n_fnname   );

/* This one is the most general.  It gives filename, line number and
   optionally directory name.  filename and linenum may not be NULL.
   dirname may be NULL, meaning that the caller does not want
   directory name info, in which case dirname_available must also be
   NULL.  If dirname is non-null, directory info is written to it, if
   it is available; if not available, '\0' is written to the first
   byte.  In either case *dirname_available is set to indicate whether
   or not directory information was available.

   Returned value indicates whether any filename/line info could be
   found. */
extern Bool VG_(get_filename_linenum)
                              ( Addr a, 
                                /*OUT*/Char* filename, Int n_filename,
                                /*OUT*/Char* dirname,  Int n_dirname,
                                /*OUT*/Bool* dirname_available,
                                /*OUT*/UInt* linenum );

/* Succeeds only if we find from debug info that 'a' is the address of the
   first instruction in a function -- as opposed to VG_(get_fnname) which
   succeeds if we find from debug info that 'a' is the address of any
   instruction in a function.  Use this to instrument the start of
   a particular function.  Nb: if an executable/shared object is stripped
   of its symbols, this function will not be able to recognise function
   entry points within it. */
extern Bool VG_(get_fnname_if_entry) ( Addr a, Char* fnname, Int n_fnname );

typedef
   enum {
      Vg_FnNameNormal,        // A normal function.
      Vg_FnNameMain,          // "main"
      Vg_FnNameBelowMain      // Something below "main", eg. __libc_start_main.
   } Vg_FnNameKind;           //   Such names are often filtered.

/* Indicates what kind of fnname it is. */
extern Vg_FnNameKind VG_(get_fnname_kind) ( Char* name );

/* Like VG_(get_fnname_kind), but takes a code address. */
extern Vg_FnNameKind VG_(get_fnname_kind_from_IP) ( Addr ip );

/* Looks up data_addr in the collection of data symbols, and if found
   puts its name (or as much as will fit) into dname[0 .. n_dname-1],
   which is guaranteed to be zero terminated.  Also data_addr's offset
   from the symbol start is put into *offset. */
extern Bool VG_(get_datasym_and_offset)( Addr data_addr,
                                         /*OUT*/Char* dname, Int n_dname,
                                         /*OUT*/PtrdiffT* offset );

/* Try to form some description of DATA_ADDR by looking at the DWARF3
   debug info we have.  This considers all global variables, and all
   frames in the stacks of all threads.  Result is written at the ends
   of DNAME{1,2}V, which are XArray*s of HChar, that have been
   initialised by the caller, and True is returned.  If no description
   is created, False is returned.  Regardless of the return value,
   DNAME{1,2}V are guaranteed to be zero terminated after the call.

   Note that after the call, DNAME{1,2} may have more than one
   trailing zero, so callers should establish the useful text length
   using VG_(strlen) on the contents, rather than VG_(sizeXA) on the
   XArray itself.
*/
Bool VG_(get_data_description)( 
        /*MOD*/ void* /* really, XArray* of HChar */ dname1v,
        /*MOD*/ void* /* really, XArray* of HChar */ dname2v,
        Addr data_addr
     );

/* Succeeds if the address is within a shared object or the main executable.
   It doesn't matter if debug info is present or not. */
extern Bool VG_(get_objname)  ( Addr a, Char* objname, Int n_objname );

/* Puts into 'buf' info about the code address %eip:  the address, function
   name (if known) and filename/line number (if known), like this:

      0x4001BF05: realloc (vg_replace_malloc.c:339)

   'n_buf' gives length of 'buf'.  Returns 'buf'.
*/
extern Char* VG_(describe_IP)(Addr eip, Char* buf, Int n_buf);


/* Get an XArray of StackBlock which describe the stack (auto) blocks
   for this ip.  The caller is expected to free the XArray at some
   point.  If 'arrays_only' is True, only array-typed blocks are
   returned; otherwise blocks of all types are returned. */

typedef
   struct {
      PtrdiffT base;       /* offset from sp or fp */
      SizeT    szB;        /* size in bytes */
      Bool     spRel;      /* True => sp-rel, False => fp-rel */
      Bool     isVec;      /* does block have an array type, or not? */
      HChar    name[16];   /* first 15 chars of name (asciiz) */
   }
   StackBlock;

extern void* /* really, XArray* of StackBlock */
             VG_(di_get_stack_blocks_at_ip)( Addr ip, Bool arrays_only );


/* Get an array of GlobalBlock which describe the global blocks owned
   by the shared object characterised by the given di_handle.  Asserts
   if the handle is invalid.  The caller is responsible for freeing
   the array at some point.  If 'arrays_only' is True, only
   array-typed blocks are returned; otherwise blocks of all types are
   returned. */

typedef
   struct {
      Addr  addr;
      SizeT szB;
      Bool  isVec;      /* does block have an array type, or not? */
      HChar name[16];   /* first 15 chars of name (asciiz) */
      HChar soname[16]; /* first 15 chars of name (asciiz) */
   }
   GlobalBlock;

extern void* /* really, XArray* of GlobalBlock */
VG_(di_get_global_blocks_from_dihandle) ( ULong di_handle,
                                          Bool  arrays_only );


/*====================================================================*/
/*=== Obtaining debug information                                  ===*/
/*====================================================================*/

/* A way to make limited debuginfo queries on a per-mapped-object
   basis. */
typedef  struct _DebugInfo  DebugInfo;

/* Returns NULL if the DebugInfo isn't found.  It doesn't matter if
   debug info is present or not. */
DebugInfo* VG_(find_DebugInfo) ( Addr a );

/* Fish bits out of DebugInfos. */
Addr          VG_(DebugInfo_get_text_avma)   ( const DebugInfo *di );
SizeT         VG_(DebugInfo_get_text_size)   ( const DebugInfo *di );
Addr          VG_(DebugInfo_get_plt_avma)    ( const DebugInfo *di );
SizeT         VG_(DebugInfo_get_plt_size)    ( const DebugInfo *di );
Addr          VG_(DebugInfo_get_gotplt_avma) ( const DebugInfo *di );
SizeT         VG_(DebugInfo_get_gotplt_size) ( const DebugInfo *di );
Addr          VG_(DebugInfo_get_got_avma)    ( const DebugInfo *di );
SizeT         VG_(DebugInfo_get_got_size)    ( const DebugInfo *di );
const UChar*  VG_(DebugInfo_get_soname)      ( const DebugInfo *di );
const UChar*  VG_(DebugInfo_get_filename)    ( const DebugInfo *di );
PtrdiffT      VG_(DebugInfo_get_text_bias)   ( const DebugInfo *di );

/* Function for traversing the DebugInfo list.  When called with NULL
   it returns the first element; otherwise it returns the given
   element's successor.  Note that the order of elements in the list
   changes in response to most of the queries listed in this header,
   that explicitly or implicitly have to search the list for a
   particular code address.  So it isn't safe to assume that the order
   of the list stays constant. */
const DebugInfo* VG_(next_DebugInfo)    ( const DebugInfo *di );

/* Functions for traversing all the symbols in a DebugInfo.  _howmany
   tells how many symbol table entries there are.  _getidx retrieves
   the n'th entry, for n in 0 .. _howmany-1.  You may not modify the
   function names thereby acquired; if you want to do so, first strdup
   them.  The primary name is returned in *pri_name, and *sec_names is
   set either to NULL or to a NULL terminated vector containing
   pointers to the secondary names. */
Int  VG_(DebugInfo_syms_howmany) ( const DebugInfo *di );
void VG_(DebugInfo_syms_getidx)  ( const DebugInfo *di, 
                                   Int idx,
                                   /*OUT*/Addr*    avma,
                                   /*OUT*/Addr*    tocptr,
                                   /*OUT*/UInt*    size,
                                   /*OUT*/HChar**  pri_name,
                                   /*OUT*/HChar*** sec_names,
                                   /*OUT*/Bool*    isText,
                                   /*OUT*/Bool*    isIFunc );

/* A simple enumeration to describe the 'kind' of various kinds of
   segments that arise from the mapping of object files. */
typedef
   enum {
      Vg_SectUnknown,
      Vg_SectText,
      Vg_SectData,
      Vg_SectBSS,
      Vg_SectGOT,
      Vg_SectPLT,
      Vg_SectGOTPLT,
      Vg_SectOPD
   }
   VgSectKind;

/* Convert a VgSectKind to a string, which must be copied if you want
   to change it. */
const HChar* VG_(pp_SectKind)( VgSectKind kind );

/* Given an address 'a', make a guess of which section of which object
   it comes from.  If name is non-NULL, then the last n_name-1
   characters of the object's name is put in name[0 .. n_name-2], and
   name[n_name-1] is set to zero (guaranteed zero terminated). */
VgSectKind VG_(DebugInfo_sect_kind)( /*OUT*/UChar* name, SizeT n_name, 
                                     Addr a);


#endif   // __PUB_TOOL_DEBUGINFO_H

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/*--- end                                                          ---*/
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