libdw/libdwP.h

/* Internal definitions for libdwarf.
   Copyright (C) 2002-2011, 2013-2018 Red Hat, Inc.
   This file is part of elfutils.
   Written by Ulrich Drepper <drepper@redhat.com>, 2002.

   This file is free software; you can redistribute it and/or modify
   it under the terms of either

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at
       your option) any later version

   or

     * 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

   or both in parallel, as here.

   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 copies of the GNU General Public License and
   the GNU Lesser General Public License along with this program.  If
   not, see <http://www.gnu.org/licenses/>.  */

#ifndef _LIBDWP_H
#define _LIBDWP_H 1

#include <libintl.h>
#include <stdbool.h>

#include <libdw.h>
#include <dwarf.h>


/* gettext helper macros.  */
#define _(Str) dgettext ("elfutils", Str)


/* Known location expressions already decoded.  */
struct loc_s
{
  void *addr;
  Dwarf_Op *loc;
  size_t nloc;
};

/* Known DW_OP_implicit_value blocks already decoded.
   This overlaps struct loc_s exactly, but only the
   first member really has to match.  */
struct loc_block_s
{
  void *addr;
  unsigned char *data;
  size_t length;
};

/* Already decoded .debug_line units.  */
struct files_lines_s
{
  Dwarf_Off debug_line_offset;
  Dwarf_Files *files;
  Dwarf_Lines *lines;
};

/* Valid indeces for the section data.  */
enum
  {
    IDX_debug_info = 0,
    IDX_debug_types,
    IDX_debug_abbrev,
    IDX_debug_aranges,
    IDX_debug_line,
    IDX_debug_frame,
    IDX_debug_loc,
    IDX_debug_pubnames,
    IDX_debug_str,
    IDX_debug_macinfo,
    IDX_debug_macro,
    IDX_debug_ranges,
    IDX_gnu_debugaltlink,
    IDX_last
  };


/* Error values.  */
enum
{
  DWARF_E_NOERROR = 0,
  DWARF_E_UNKNOWN_ERROR,
  DWARF_E_INVALID_ACCESS,
  DWARF_E_NO_REGFILE,
  DWARF_E_IO_ERROR,
  DWARF_E_INVALID_ELF,
  DWARF_E_NO_DWARF,
  DWARF_E_COMPRESSED_ERROR,
  DWARF_E_NOELF,
  DWARF_E_GETEHDR_ERROR,
  DWARF_E_NOMEM,
  DWARF_E_UNIMPL,
  DWARF_E_INVALID_CMD,
  DWARF_E_INVALID_VERSION,
  DWARF_E_INVALID_FILE,
  DWARF_E_NO_ENTRY,
  DWARF_E_INVALID_DWARF,
  DWARF_E_NO_STRING,
  DWARF_E_NO_ADDR,
  DWARF_E_NO_CONSTANT,
  DWARF_E_NO_REFERENCE,
  DWARF_E_INVALID_REFERENCE,
  DWARF_E_NO_DEBUG_LINE,
  DWARF_E_INVALID_DEBUG_LINE,
  DWARF_E_TOO_BIG,
  DWARF_E_VERSION,
  DWARF_E_INVALID_DIR_IDX,
  DWARF_E_ADDR_OUTOFRANGE,
  DWARF_E_NO_LOCLIST,
  DWARF_E_NO_BLOCK,
  DWARF_E_INVALID_LINE_IDX,
  DWARF_E_INVALID_ARANGE_IDX,
  DWARF_E_NO_MATCH,
  DWARF_E_NO_FLAG,
  DWARF_E_INVALID_OFFSET,
  DWARF_E_NO_DEBUG_RANGES,
  DWARF_E_INVALID_CFI,
  DWARF_E_NO_ALT_DEBUGLINK,
  DWARF_E_INVALID_OPCODE,
  DWARF_E_NOT_CUDIE,
  DWARF_E_UNKNOWN_LANGUAGE,
};


#include "dwarf_sig8_hash.h"

/* This is the structure representing the debugging state.  */
struct Dwarf
{
  /* The underlying ELF file.  */
  Elf *elf;

  /* dwz alternate DWARF file.  */
  Dwarf *alt_dwarf;

  /* The section data.  */
  Elf_Data *sectiondata[IDX_last];

  /* True if the file has a byte order different from the host.  */
  bool other_byte_order;

  /* If true, we allocated the ELF descriptor ourselves.  */
  bool free_elf;

  /* If >= 0, we allocated the alt_dwarf ourselves and must end it and
     close this file descriptor.  */
  int alt_fd;

  /* Information for traversing the .debug_pubnames section.  This is
     an array and separately allocated with malloc.  */
  struct pubnames_s
  {
    Dwarf_Off cu_offset;
    Dwarf_Off set_start;
    unsigned int cu_header_size;
    int address_len;
  } *pubnames_sets;
  size_t pubnames_nsets;

  /* Search tree for the CUs.  */
  void *cu_tree;
  Dwarf_Off next_cu_offset;

  /* Search tree and sig8 hash table for .debug_types type units.  */
  void *tu_tree;
  Dwarf_Off next_tu_offset;
  Dwarf_Sig8_Hash sig8_hash;

  /* Search tree for .debug_macro operator tables.  */
  void *macro_ops;

  /* Search tree for decoded .debug_line units.  */
  void *files_lines;

  /* Address ranges.  */
  Dwarf_Aranges *aranges;

  /* Cached info from the CFI section.  */
  struct Dwarf_CFI_s *cfi;

  /* Fake loc CU.  Used when synthesizing attributes for Dwarf_Ops that
     came from a location list entry in dwarf_getlocation_attr.  */
  struct Dwarf_CU *fake_loc_cu;

  /* Internal memory handling.  This is basically a simplified
     reimplementation of obstacks.  Unfortunately the standard obstack
     implementation is not usable in libraries.  */
  struct libdw_memblock
  {
    size_t size;
    size_t remaining;
    struct libdw_memblock *prev;
    char mem[0];
  } *mem_tail;

  /* Default size of allocated memory blocks.  */
  size_t mem_default_size;

  /* Registered OOM handler.  */
  Dwarf_OOM oom_handler;
};


/* Abbreviation representation.  */
struct Dwarf_Abbrev
{
  Dwarf_Off offset;	  /* Offset to start of abbrev into .debug_abbrev.  */
  unsigned char *attrp;   /* Pointer to start of attribute name/form pairs. */
  bool has_children : 1;  /* Whether or not the DIE has children. */
  unsigned int code : 31; /* The (unique) abbrev code.  */
  unsigned int tag;	  /* The tag of the DIE. */
} attribute_packed;

#include "dwarf_abbrev_hash.h"


/* Files in line information records.  */
struct Dwarf_Files_s
  {
    unsigned int ndirs;
    unsigned int nfiles;
    struct Dwarf_Fileinfo_s
    {
      char *name;
      Dwarf_Word mtime;
      Dwarf_Word length;
    } info[0];
    /* nfiles of those, followed by char *[ndirs].  */
  };
typedef struct Dwarf_Fileinfo_s Dwarf_Fileinfo;


/* Representation of a row in the line table.  */

struct Dwarf_Line_s
{
  Dwarf_Files *files;

  Dwarf_Addr addr;
  unsigned int file;
  int line;
  unsigned short int column;
  unsigned int is_stmt:1;
  unsigned int basic_block:1;
  unsigned int end_sequence:1;
  unsigned int prologue_end:1;
  unsigned int epilogue_begin:1;
  /* The remaining bit fields are not flags, but hold values presumed to be
     small.  All the flags and other bit fields should add up to 48 bits
     to give the whole struct a nice round size.  */
  unsigned int op_index:8;
  unsigned int isa:8;
  unsigned int discriminator:24;
};

struct Dwarf_Lines_s
{
  size_t nlines;
  struct Dwarf_Line_s info[0];
};

/* Representation of address ranges.  */
struct Dwarf_Aranges_s
{
  Dwarf *dbg;
  size_t naranges;

  struct Dwarf_Arange_s
  {
    Dwarf_Addr addr;
    Dwarf_Word length;
    Dwarf_Off offset;
  } info[0];
};


/* CU representation.  */
struct Dwarf_CU
{
  Dwarf *dbg;
  Dwarf_Off start;
  Dwarf_Off end;
  uint8_t address_size;
  uint8_t offset_size;
  uint16_t version;

  size_t sec_idx; /* Normally .debug_info, could be .debug_type or "fake". */

  /* Zero if this is a normal CU.  Nonzero if it is a type unit.  */
  size_t type_offset;
  uint64_t type_sig8;

  /* Hash table for the abbreviations.  */
  Dwarf_Abbrev_Hash abbrev_hash;
  /* Offset of the first abbreviation.  */
  size_t orig_abbrev_offset;
  /* Offset past last read abbreviation.  */
  size_t last_abbrev_offset;

  /* The srcline information.  */
  Dwarf_Lines *lines;

  /* The source file information.  */
  Dwarf_Files *files;

  /* Known location lists.  */
  void *locs;

  /* Memory boundaries of this CU.  */
  void *startp;
  void *endp;
};

/* Compute the offset of a CU's first DIE from its offset.  This
   is either:
        LEN       VER     OFFSET    ADDR
      4-bytes + 2-bytes + 4-bytes + 1-byte  for 32-bit dwarf
     12-bytes + 2-bytes + 8-bytes + 1-byte  for 64-bit dwarf
   or in .debug_types, 			     SIGNATURE TYPE-OFFSET
      4-bytes + 2-bytes + 4-bytes + 1-byte + 8-bytes + 4-bytes  for 32-bit
     12-bytes + 2-bytes + 8-bytes + 1-byte + 8-bytes + 8-bytes  for 64-bit

   Note the trick in the computation.  If the offset_size is 4
   the '- 4' term changes the '3 *' into a '2 *'.  If the
   offset_size is 8 it accounts for the 4-byte escape value
   used at the start of the length.  */
#define DIE_OFFSET_FROM_CU_OFFSET(cu_offset, offset_size, type_unit)	\
  ((type_unit) ? ((cu_offset) + 4 * (offset_size) - 4 + 3 + 8)		\
   : ((cu_offset) + 3 * (offset_size) - 4 + 3))

#define CUDIE(fromcu)							      \
  ((Dwarf_Die)								      \
   {									      \
     .cu = (fromcu),							      \
     .addr = ((char *) fromcu->dbg->sectiondata[cu_sec_idx (fromcu)]->d_buf   \
	      + DIE_OFFSET_FROM_CU_OFFSET ((fromcu)->start,		      \
					   (fromcu)->offset_size,	      \
					   (fromcu)->type_offset != 0))	      \
   })									      \


/* Prototype of a single .debug_macro operator.  */
typedef struct
{
  Dwarf_Word nforms;
  unsigned char const *forms;
} Dwarf_Macro_Op_Proto;

/* Prototype table.  */
typedef struct
{
  /* Offset of .debug_macro section.  */
  Dwarf_Off offset;

  /* Offset of associated .debug_line section.  */
  Dwarf_Off line_offset;

  /* The source file information.  */
  Dwarf_Files *files;

  /* If this macro unit was opened through dwarf_getmacros or
     dwarf_getmacros_die, this caches value of DW_AT_comp_dir, if
     present.  */
  const char *comp_dir;

  /* Header length.  */
  Dwarf_Half header_len;

  uint16_t version;
  bool is_64bit;
  uint8_t sec_index;	/* IDX_debug_macro or IDX_debug_macinfo.  */

  /* Shows where in TABLE each opcode is defined.  Since opcode 0 is
     never used, it stores index of opcode X in X-1'th element.  The
     value of 0xff means not stored at all.  */
  unsigned char opcodes[255];

  /* Individual opcode prototypes.  */
  Dwarf_Macro_Op_Proto table[];
} Dwarf_Macro_Op_Table;

struct Dwarf_Macro_s
{
  Dwarf_Macro_Op_Table *table;
  Dwarf_Attribute *attributes;
  uint8_t opcode;
};

static inline Dwarf_Word
libdw_macro_nforms (Dwarf_Macro *macro)
{
  return macro->table->table[macro->table->opcodes[macro->opcode - 1]].nforms;
}

/* We have to include the file at this point because the inline
   functions access internals of the Dwarf structure.  */
#include "memory-access.h"


/* Set error value.  */
extern void __libdw_seterrno (int value) internal_function;


/* Memory handling, the easy parts.  This macro does not do any locking.  */
#define libdw_alloc(dbg, type, tsize, cnt) \
  ({ struct libdw_memblock *_tail = (dbg)->mem_tail;			      \
     size_t _required = (tsize) * (cnt);				      \
     type *_result = (type *) (_tail->mem + (_tail->size - _tail->remaining));\
     size_t _padding = ((__alignof (type)				      \
			 - ((uintptr_t) _result & (__alignof (type) - 1)))    \
			& (__alignof (type) - 1));			      \
     if (unlikely (_tail->remaining < _required + _padding))		      \
       _result = (type *) __libdw_allocate (dbg, _required, __alignof (type));\
     else								      \
       {								      \
	 _required += _padding;						      \
	 _result = (type *) ((char *) _result + _padding);		      \
	 _tail->remaining -= _required;					      \
       }								      \
     _result; })

#define libdw_typed_alloc(dbg, type) \
  libdw_alloc (dbg, type, sizeof (type), 1)

/* Callback to allocate more.  */
extern void *__libdw_allocate (Dwarf *dbg, size_t minsize, size_t align)
     __attribute__ ((__malloc__)) __nonnull_attribute__ (1);

/* Default OOM handler.  */
extern void __libdw_oom (void) __attribute ((noreturn)) attribute_hidden;

/* Allocate the internal data for a unit not seen before.  */
extern struct Dwarf_CU *__libdw_intern_next_unit (Dwarf *dbg, bool debug_types)
     __nonnull_attribute__ (1) internal_function;

/* Find CU for given offset.  */
extern struct Dwarf_CU *__libdw_findcu (Dwarf *dbg, Dwarf_Off offset, bool tu)
     __nonnull_attribute__ (1) internal_function;

/* Get abbreviation with given code.  */
extern Dwarf_Abbrev *__libdw_findabbrev (struct Dwarf_CU *cu,
					 unsigned int code)
     __nonnull_attribute__ (1) internal_function;

/* Get abbreviation at given offset.  */
extern Dwarf_Abbrev *__libdw_getabbrev (Dwarf *dbg, struct Dwarf_CU *cu,
					Dwarf_Off offset, size_t *lengthp,
					Dwarf_Abbrev *result)
     __nonnull_attribute__ (1) internal_function;

/* Get abbreviation of given DIE, and optionally set *READP to the DIE memory
   just past the abbreviation code.  */
static inline Dwarf_Abbrev *
__nonnull_attribute__ (1)
__libdw_dieabbrev (Dwarf_Die *die, const unsigned char **readp)
{
  /* Do we need to get the abbreviation, or need to read after the code?  */
  if (die->abbrev == NULL || readp != NULL)
    {
      /* Get the abbreviation code.  */
      unsigned int code;
      const unsigned char *addr = die->addr;
      get_uleb128 (code, addr, die->cu->endp);
      if (readp != NULL)
	*readp = addr;

      /* Find the abbreviation.  */
      if (die->abbrev == NULL)
	die->abbrev = __libdw_findabbrev (die->cu, code);
    }
  return die->abbrev;
}

/* Helper functions for form handling.  */
extern size_t __libdw_form_val_compute_len (struct Dwarf_CU *cu,
					    unsigned int form,
					    const unsigned char *valp)
     __nonnull_attribute__ (1, 3) internal_function;

/* Find the length of a form attribute.  */
static inline size_t
__nonnull_attribute__ (1, 3)
__libdw_form_val_len (struct Dwarf_CU *cu, unsigned int form,
		      const unsigned char *valp)
{
  /* Small lookup table of forms with fixed lengths.  Absent indexes are
     initialized 0, so any truly desired 0 is set to 0x80 and masked.  */
  static const uint8_t form_lengths[] =
    {
      [DW_FORM_flag_present] = 0x80,
      [DW_FORM_data1] = 1, [DW_FORM_ref1] = 1, [DW_FORM_flag] = 1,
      [DW_FORM_data2] = 2, [DW_FORM_ref2] = 2,
      [DW_FORM_data4] = 4, [DW_FORM_ref4] = 4,
      [DW_FORM_data8] = 8, [DW_FORM_ref8] = 8, [DW_FORM_ref_sig8] = 8,
    };

  /* Return immediately for forms with fixed lengths.  */
  if (form < sizeof form_lengths / sizeof form_lengths[0])
    {
      uint8_t len = form_lengths[form];
      if (len != 0)
	{
	  const unsigned char *endp = cu->endp;
	  len &= 0x7f; /* Mask to allow 0x80 -> 0.  */
	  if (unlikely (len > (size_t) (endp - valp)))
	    {
	      __libdw_seterrno (DWARF_E_INVALID_DWARF);
	      return -1;
	    }
	  return len;
	}
    }

  /* Other forms require some computation.  */
  return __libdw_form_val_compute_len (cu, form, valp);
}

/* Helper function for DW_FORM_ref* handling.  */
extern int __libdw_formref (Dwarf_Attribute *attr, Dwarf_Off *return_offset)
     __nonnull_attribute__ (1, 2) internal_function;


/* Helper function to locate attribute.  */
extern unsigned char *__libdw_find_attr (Dwarf_Die *die,
					 unsigned int search_name,
					 unsigned int *codep,
					 unsigned int *formp)
     __nonnull_attribute__ (1) internal_function;

/* Helper function to access integer attribute.  */
extern int __libdw_attr_intval (Dwarf_Die *die, int *valp, int attval)
     __nonnull_attribute__ (1, 2) internal_function;

/* Helper function to walk scopes.  */
struct Dwarf_Die_Chain
{
  Dwarf_Die die;
  struct Dwarf_Die_Chain *parent;
  bool prune;			/* The PREVISIT function can set this.  */
};
extern int __libdw_visit_scopes (unsigned int depth,
				 struct Dwarf_Die_Chain *root,
				 struct Dwarf_Die_Chain *imports,
				 int (*previsit) (unsigned int depth,
						  struct Dwarf_Die_Chain *,
						  void *arg),
				 int (*postvisit) (unsigned int depth,
						   struct Dwarf_Die_Chain *,
						   void *arg),
				 void *arg)
  __nonnull_attribute__ (2, 4) internal_function;

/* Parse a DWARF Dwarf_Block into an array of Dwarf_Op's,
   and cache the result (via tsearch).  */
extern int __libdw_intern_expression (Dwarf *dbg,
				      bool other_byte_order,
				      unsigned int address_size,
				      unsigned int ref_size,
				      void **cache, const Dwarf_Block *block,
				      bool cfap, bool valuep,
				      Dwarf_Op **llbuf, size_t *listlen,
				      int sec_index)
  __nonnull_attribute__ (5, 6, 9, 10) internal_function;

extern Dwarf_Die *__libdw_offdie (Dwarf *dbg, Dwarf_Off offset,
				  Dwarf_Die *result, bool debug_types)
  internal_function;


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


/* Reader hooks.  */

/* Relocation hooks return -1 on error (in that case the error code
   must already have been set), 0 if there is no relocation and 1 if a
   relocation was present.*/

static inline int
__libdw_relocate_address (Dwarf *dbg __attribute__ ((unused)),
			  int sec_index __attribute__ ((unused)),
			  const void *addr __attribute__ ((unused)),
			  int width __attribute__ ((unused)),
			  Dwarf_Addr *val __attribute__ ((unused)))
{
  return 0;
}

static inline int
__libdw_relocate_offset (Dwarf *dbg __attribute__ ((unused)),
			 int sec_index __attribute__ ((unused)),
			 const void *addr __attribute__ ((unused)),
			 int width __attribute__ ((unused)),
			 Dwarf_Off *val __attribute__ ((unused)))
{
  return 0;
}

static inline Elf_Data *
__libdw_checked_get_data (Dwarf *dbg, int sec_index)
{
  Elf_Data *data = dbg->sectiondata[sec_index];
  if (unlikely (data == NULL)
      || unlikely (data->d_buf == NULL))
    {
      __libdw_seterrno (DWARF_E_INVALID_DWARF);
      return NULL;
    }
  return data;
}

static inline int
__libdw_offset_in_section (Dwarf *dbg, int sec_index,
			   Dwarf_Off offset, size_t size)
{
  Elf_Data *data = __libdw_checked_get_data (dbg, sec_index);
  if (data == NULL)
    return -1;
  if (unlikely (offset > data->d_size)
      || unlikely (data->d_size < size)
      || unlikely (offset > data->d_size - size))
    {
      __libdw_seterrno (DWARF_E_INVALID_OFFSET);
      return -1;
    }

  return 0;
}

static inline bool
__libdw_in_section (Dwarf *dbg, int sec_index,
		    const void *addr, size_t size)
{
  Elf_Data *data = __libdw_checked_get_data (dbg, sec_index);
  if (data == NULL)
    return false;
  if (unlikely (addr < data->d_buf)
      || unlikely (data->d_size < size)
      || unlikely ((size_t)(addr - data->d_buf) > data->d_size - size))
    {
      __libdw_seterrno (DWARF_E_INVALID_OFFSET);
      return false;
    }

  return true;
}

#define READ_AND_RELOCATE(RELOC_HOOK, VAL)				\
  ({									\
    if (!__libdw_in_section (dbg, sec_index, addr, width))		\
      return -1;							\
									\
    const unsigned char *orig_addr = addr;				\
    if (width == 4)							\
      VAL = read_4ubyte_unaligned_inc (dbg, addr);			\
    else								\
      VAL = read_8ubyte_unaligned_inc (dbg, addr);			\
									\
    int status = RELOC_HOOK (dbg, sec_index, orig_addr, width, &VAL);	\
    if (status < 0)							\
      return status;							\
    status > 0;								\
   })

static inline int
__libdw_read_address_inc (Dwarf *dbg,
			  int sec_index, const unsigned char **addrp,
			  int width, Dwarf_Addr *ret)
{
  const unsigned char *addr = *addrp;
  READ_AND_RELOCATE (__libdw_relocate_address, (*ret));
  *addrp = addr;
  return 0;
}

static inline int
__libdw_read_address (Dwarf *dbg,
		      int sec_index, const unsigned char *addr,
		      int width, Dwarf_Addr *ret)
{
  READ_AND_RELOCATE (__libdw_relocate_address, (*ret));
  return 0;
}

static inline int
__libdw_read_offset_inc (Dwarf *dbg,
			 int sec_index, const unsigned char **addrp,
			 int width, Dwarf_Off *ret, int sec_ret,
			 size_t size)
{
  const unsigned char *addr = *addrp;
  READ_AND_RELOCATE (__libdw_relocate_offset, (*ret));
  *addrp = addr;
  return __libdw_offset_in_section (dbg, sec_ret, *ret, size);
}

static inline int
__libdw_read_offset (Dwarf *dbg, Dwarf *dbg_ret,
		     int sec_index, const unsigned char *addr,
		     int width, Dwarf_Off *ret, int sec_ret,
		     size_t size)
{
  READ_AND_RELOCATE (__libdw_relocate_offset, (*ret));
  return __libdw_offset_in_section (dbg_ret, sec_ret, *ret, size);
}

static inline size_t
cu_sec_idx (struct Dwarf_CU *cu)
{
  return cu->sec_idx;
}

static inline bool
is_cudie (Dwarf_Die *cudie)
{
  return CUDIE (cudie->cu).addr == cudie->addr;
}

/* Read up begin/end pair and increment read pointer.
    - If it's normal range record, set up *BEGINP and *ENDP and return 0.
    - If it's base address selection record, set up *BASEP and return 1.
    - If it's end of rangelist, don't set anything and return 2
    - If an error occurs, don't set anything and return <0.  */
int __libdw_read_begin_end_pair_inc (Dwarf *dbg, int sec_index,
				     unsigned char **addr, int width,
				     Dwarf_Addr *beginp, Dwarf_Addr *endp,
				     Dwarf_Addr *basep)
  internal_function;

unsigned char * __libdw_formptr (Dwarf_Attribute *attr, int sec_index,
				 int err_nodata, unsigned char **endpp,
				 Dwarf_Off *offsetp)
  internal_function;

/* Fills in the given attribute to point at an empty location expression.  */
void __libdw_empty_loc_attr (Dwarf_Attribute *attr)
  internal_function;

/* Load .debug_line unit at DEBUG_LINE_OFFSET.  COMP_DIR is a value of
   DW_AT_comp_dir or NULL if that attribute is not available.  Caches
   the loaded unit and optionally set *LINESP and/or *FILESP (if not
   NULL) with loaded information.  Returns 0 for success or a negative
   value for failure.  */
int __libdw_getsrclines (Dwarf *dbg, Dwarf_Off debug_line_offset,
			 const char *comp_dir, unsigned address_size,
			 Dwarf_Lines **linesp, Dwarf_Files **filesp)
  internal_function
  __nonnull_attribute__ (1);

/* Load and return value of DW_AT_comp_dir from CUDIE.  */
const char *__libdw_getcompdir (Dwarf_Die *cudie);

/* Given a file descriptor, dir and file returns a full path.  If the
   file is absolute (starts with a /) a copy of file is returned.  If
   the file isn't absolute, but dir is absolute, then a path that is
   the concatenation of dir and file is returned.  If neither file,
   nor dir is absolute, the path will be constructed using dir (if not
   NULL) and file relative to the path of the given file descriptor
   (if valid).

   The file descriptor may be -1 and the dir may be NULL (in which
   case they aren't used). If file is NULL, or no full path can be
   constructed NULL is returned.

   The caller is responsible for freeing the result if not NULL.  */
char * filepath (int fd, const char *dir, const char *file)
  internal_function;


/* Aliases to avoid PLTs.  */
INTDECL (dwarf_aggregate_size)
INTDECL (dwarf_attr)
INTDECL (dwarf_attr_integrate)
INTDECL (dwarf_begin)
INTDECL (dwarf_begin_elf)
INTDECL (dwarf_child)
INTDECL (dwarf_default_lower_bound)
INTDECL (dwarf_dieoffset)
INTDECL (dwarf_diename)
INTDECL (dwarf_end)
INTDECL (dwarf_entrypc)
INTDECL (dwarf_errmsg)
INTDECL (dwarf_formaddr)
INTDECL (dwarf_formblock)
INTDECL (dwarf_formref_die)
INTDECL (dwarf_formsdata)
INTDECL (dwarf_formstring)
INTDECL (dwarf_formudata)
INTDECL (dwarf_getalt)
INTDECL (dwarf_getarange_addr)
INTDECL (dwarf_getarangeinfo)
INTDECL (dwarf_getaranges)
INTDECL (dwarf_getlocation_die)
INTDECL (dwarf_getsrcfiles)
INTDECL (dwarf_getsrclines)
INTDECL (dwarf_hasattr)
INTDECL (dwarf_haschildren)
INTDECL (dwarf_haspc)
INTDECL (dwarf_highpc)
INTDECL (dwarf_lowpc)
INTDECL (dwarf_nextcu)
INTDECL (dwarf_next_unit)
INTDECL (dwarf_offdie)
INTDECL (dwarf_peel_type)
INTDECL (dwarf_ranges)
INTDECL (dwarf_setalt)
INTDECL (dwarf_siblingof)
INTDECL (dwarf_srclang)
INTDECL (dwarf_tag)

#endif	/* libdwP.h */