
/*--------------------------------------------------------------------*/
/*--- Header for symbol table stuff.                 priv_symtab.h ---*/
/*--------------------------------------------------------------------*/

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

   Copyright (C) 2000-2005 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 __PRIV_SYMTAB_H
#define __PRIV_SYMTAB_H

/* A structure to hold an ELF symbol (very crudely). */
typedef 
   struct { 
      Addr addr;   /* lowest address of entity */
      UInt size;   /* size in bytes */
      Char *name;  /* name */
   }
   RiSym;

/* Line count at which overflow happens, due to line numbers being stored as
 * shorts in `struct nlist' in a.out.h. */
#define LINENO_OVERFLOW (1 << (sizeof(short) * 8))

#define LINENO_BITS     20
#define LOC_SIZE_BITS  (32 - LINENO_BITS)
#define MAX_LINENO     ((1 << LINENO_BITS) - 1)

/* Unlikely to have any lines with instruction ranges > 4096 bytes */
#define MAX_LOC_SIZE   ((1 << LOC_SIZE_BITS) - 1)

/* Number used to detect line number overflows;  if one line is 60000-odd
 * smaller than the previous, is was probably an overflow.  
 */
#define OVERFLOW_DIFFERENCE     (LINENO_OVERFLOW - 5000)

/* A structure to hold addr-to-source info for a single line.  There can be a
 * lot of these, hence the dense packing. */
typedef
   struct {
      /* Word 1 */
      Addr   addr;                  /* lowest address for this line */
      /* Word 2 */
      UShort size:LOC_SIZE_BITS;    /* byte size; we catch overflows of this */
      UInt   lineno:LINENO_BITS;    /* source line number, or zero */
      /* Word 3 */
      Char*  filename;              /* source filename */
      /* Word 4 */
      Char*  dirname;               /* source directory name */
   }
   RiLoc;


/* A structure to hold a set of variables in a particular scope */
typedef struct _Scope Scope;	/* a set of symbols in one scope */
typedef struct _Sym Sym;	/* a single symbol */
typedef struct _ScopeRange ScopeRange; /* a range of code addreses a scope covers */

typedef enum {
      SyESPrel,			/* on the stack (relative to ESP) */
      SyEBPrel,			/* on the stack (relative to EBP) */
      SyReg,			/* in a register */
      SyType,			/* a type definition */
      SyStatic,			/* a static variable */
      SyGlobal,			/* a global variable (XXX any different to static
				   in an outer scope?) */
} SyKind;

struct _Sym {
   SymType	*type;		/* type */
   Char		*name;		/* name */
   SyKind	kind;		/* kind of symbol */

   /* a value, depending on kind */
   union {
      OffT	offset;		/* offset on stack (-ve -> ebp; +ve -> esp) */
      Int	regno;		/* register number */
      Addr	addr;		/* static or global address */
   } u;
};

struct _Scope {
   Scope	*outer;		/* outer (containing) scope */
   UInt		nsyms;		/* number of symbols in this scope */
   UInt		depth;		/* depth of scope */
   Sym	        *syms;		/* the symbols */
};

/* A structure to map a scope to a range of code addresses; scopes may
   be broken into multiple ranges (before and after a nested scope) */
struct _ScopeRange {
   Addr		addr;			/* start address of this scope */
   Int		size;			/* length of scope */
   Scope       *scope;			/* symbols in scope */
};

#define STRCHUNKSIZE	(64*1024)


/* A structure to summarise CFI summary info for the code address
   range [base .. base+len-1].  In short, if you know (sp,fp,ip) at
   some point and ip is in the range [base .. base+len-1], it tells
   you how to calculate (sp,fp) for the caller of the current
   frame and also ra, the return address of the current frame.

   First off, calculate CFA, the Canonical Frame Address, thusly:

     cfa = if cfa_sprel then sp+cfa_off else fp+cfa_off

   Once that is done, the previous frame's sp/fp values and this
   frame's ra value can be calculated like this:

      old_sp/fp/ra
         = case sp/fp/ra_how of
              CFIR_UNKNOWN   -> we don't know, sorry
              CFIR_SAME      -> same as it was before (sp/fp only)
              CFIR_CFAREL    -> cfa + sp/fp/ra_off
              CFIR_MEMCFAREL -> *( cfa + sp/fp/ra_off )
*/

#define CFIR_UNKNOWN   ((UChar)0)
#define CFIR_SAME      ((UChar)1)
#define CFIR_CFAREL    ((UChar)2)
#define CFIR_MEMCFAREL ((UChar)3)

typedef
   struct {
      Addr  base;
      UInt  len;
      Bool  cfa_sprel;
      UChar ra_how; /* a CFIR_ value */
      UChar sp_how; /* a CFIR_ value */
      UChar fp_how; /* a CFIR_ value */
      Int   cfa_off;
      Int   ra_off;
      Int   sp_off;
      Int   fp_off;
   }
   CfiSI;

extern void ML_(ppCfiSI)   ( CfiSI* );


/* A structure which contains information pertaining to one mapped
   text segment. (typedef in tool.h) */
struct _SegInfo {
   struct _SegInfo* next;	/* list of SegInfos */

   Int	  ref;

   /* Description of the mapped segment. */
   Addr   start;
   UInt   size;
   Char*  filename; /* in mallocville */
   OffT   foffset;
   Char*  soname;

   /* An expandable array of symbols. */
   RiSym* symtab;
   UInt   symtab_used;
   UInt   symtab_size;
   /* An expandable array of locations. */
   RiLoc* loctab;
   UInt   loctab_used;
   UInt   loctab_size;
   /* An expandable array of scope ranges. */
   ScopeRange *scopetab;
   UInt        scopetab_used;
   UInt        scopetab_size;
   /* An expandable array of CFI summary info records.  Also includes
      summary address bounds, showing the min and max address covered
      by any of the records, as an aid to fast searching. */
   CfiSI* cfisi;
   UInt   cfisi_used;
   UInt   cfisi_size;
   Addr   cfisi_minaddr;
   Addr   cfisi_maxaddr;

   /* Expandable arrays of characters -- the string table.
      Pointers into this are stable (the arrays are not reallocated)
    */
   struct strchunk {
      UInt   strtab_used;
      struct strchunk *next;
      Char   strtab[STRCHUNKSIZE];
   }      *strchunks;

   /* offset    is what we need to add to symbol table entries
      to get the real location of that symbol in memory.
   */
   OffT   offset;

   /* Bounds of data, BSS, PLT and GOT, so that tools can see what
      section an address is in */
   Addr	  plt_start;
   UInt   plt_size;
   Addr   got_start;
   UInt   got_size;
   Addr   data_start;
   UInt   data_size;
   Addr   bss_start;
   UInt   bss_size;

   /* data used by stabs parser */
   struct _StabTypeTab	*stab_typetab;
};

extern
Char *ML_(addStr) ( SegInfo* si, Char* str, Int len );

extern
void ML_(addScopeInfo) ( SegInfo* si, Addr this, Addr next, Scope *scope);

extern
void ML_(addLineInfo) ( SegInfo* si, 
                        Char* filename, 
                        Char* dirname,  /* NULL is allowable */
                        Addr this, Addr next, Int lineno, Int entry);

extern
void ML_(addCfiSI) ( SegInfo* si, CfiSI* cfisi );

/* Non-fatal -- use vg_panic if terminal. */
extern
void ML_(symerr) ( Char* msg );

/* --------------------
   Stabs reader
   -------------------- */
extern
void ML_(read_debuginfo_stabs) ( SegInfo* si,
				 UChar* stabC,   Int stab_sz, 
				 UChar* stabstr, Int stabstr_sz );

/* --------------------
   DWARF2 reader
   -------------------- */
extern
void ML_(read_debuginfo_dwarf2) 
        ( SegInfo* si,
          UChar* debuginfo,   Int debug_info_sz,  /* .debug_info */
          UChar* debugabbrev,                     /* .debug_abbrev */
          UChar* debugline,   Int debug_line_sz,  /* .debug_line */
          UChar* debugstr );

/* --------------------
   DWARF1 reader
   -------------------- */
extern
void ML_(read_debuginfo_dwarf1) ( SegInfo* si, 
                                  UChar* dwarf1d, Int dwarf1d_sz, 
                                  UChar* dwarf1l, Int dwarf1l_sz );

/* --------------------
   CFI reader
   -------------------- */
extern
void ML_(read_callframe_info_dwarf2) 
    ( /*OUT*/SegInfo* si, UChar* ehframe, Int ehframe_sz, Addr ehframe_addr );


#endif   // __PRIV_SYMTAB_H

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/*--- end                                                          ---*/
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