NAME
dwarf_get_vars,
dwarf_var_cu_offset,
dwarf_var_die_offset,
dwarf_var_name_offsets,
dwarf_varname
—
retrieve information about static variables
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
int
dwarf_get_vars(
Dwarf_Debug dbg,
Dwarf_Var **vars,
Dwarf_Signed
*nvars,
Dwarf_Error *err);
int
dwarf_var_cu_offset(
Dwarf_Var var,
Dwarf_Off *cu_offset,
Dwarf_Error
*err);
int
dwarf_var_die_offset(
Dwarf_Var var,
Dwarf_Off *die_offset,
Dwarf_Error
*err);
int
dwarf_var_name_offsets(
Dwarf_Var var,
char **name,
Dwarf_Off
*die_offset,
Dwarf_Off *cu_die_offset,
Dwarf_Error *err);
int
dwarf_varname(
Dwarf_Var var,
char **name,
Dwarf_Error *err);
DESCRIPTION
These functions retrieve information about the file scope static variables
associated with a DWARF debug context. Information about these static
variables is returned using opaque descriptors of type
Dwarf_Var. Applications need to use the functions
described below to retrieve the name and offset information contained in these
descriptors.
Function
dwarf_get_vars() retrieves descriptors for all the
static variables associated with the DWARF debug context specified by argument
dbg. The argument
vars should
point to a location that will be set to a pointer to an array of
Dwarf_Var descriptors. The argument
nvars should point to a location that will be set to the
number of descriptors returned.
Function
dwarf_var_cu_offset() returns the section-relative
offset, relative to the “.debug_info” section, of the compilation
unit that contains the debugging information entry associated with the
argument
var. Argument
cu_offset
should point to a location that will hold the returned offset.
Function
dwarf_var_die_offset() retrieves the section-relative
offset, relative to the “.debug_info” section, of the debugging
information entry associated with the argument
var, and
stores it into the location pointed to by the argument
die_offset.
Function
dwarf_var_name_offsets() retrieves both the name and
the associated offsets for the debugging information entry for argument
var. Argument
name should point to
a location which will be set to a pointer to a NUL-terminated string
containing the name of the associated debugging information entry. Argument
die_offset should point to a location which will be set
to a section-relative offset, relative to the “.debug_info”
section, of the associated debugging information entry. Argument
cu_die_offset should point to a location which will be
set to a section-relative offset, relative to the “.debug_info”
section, of the first debugging information entry in the compilation unit
associated with argument
var.
Function
dwarf_varname() sets the location pointed to by
argument
name to a pointer to a NUL-terminated string
holding the name of the debugging information entry associated with the
argument
var.
Memory Management
The memory area used for the array of
Dwarf_Var
descriptors returned in argument
vars by function
dwarf_get_vars() is owned by the
DWARF
Access Library (libdwarf, -ldwarf). Application code should not attempt
to directly free this pointer. Portable code should instead use the function
dwarf_vars_dealloc(3)
to indicate that the memory area may be freed.
The memory area used for the string returned in the
name
argument to functions
dwarf_var_name_offsets() and
dwarf_varname() is owned by the
DWARF
Access Library (libdwarf, -ldwarf). Portable code should indicate that
the memory area can be freed using the
dwarf_dealloc(3)
function.
Error Returns
If argument
err is not NULL, these functions will use it
to store error information, in case of an error.
RETURN VALUES
On success, these functions returns
DW_DLV_OK
. In case
of an error, they return
DW_DLV_ERROR
and set the
argument
err.
ERRORS
These functions may fail with the following errors:
-
-
- [
DW_DLE_ARGUMENT
]
- One of the arguments cu_die_offset,
cu_offset, dbg,
die_offset, var,
vars, name, or
nvars was NULL.
SEE ALSO
dwarf(3),
dwarf_dealloc(3),
dwarf_get_cu_die_offset_given_cu_header_offset(3),
dwarf_vars_dealloc(3)