DWARF_GET_VARS(3) Library Functions Manual DWARF_GET_VARS(3)

dwarf_get_vars, dwarf_var_cu_offset, dwarf_var_die_offset, dwarf_var_name_offsets, dwarf_varname — retrieve information about static variables

DWARF Access Library (libdwarf, -ldwarf)

#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);

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 () 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 () 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 () 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 () 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 () 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.

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 () 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.

If argument err is not NULL, these functions will use it to store error information, in case of an error.

On success, these functions returns DW_DLV_OK. In case of an error, they return DW_DLV_ERROR and set the argument err.

These functions may fail with the following errors:

[]
One of the arguments cu_die_offset, cu_offset, dbg, die_offset, var, vars, name, or nvars was NULL.

dwarf(3), dwarf_dealloc(3), dwarf_get_cu_die_offset_given_cu_header_offset(3), dwarf_vars_dealloc(3)

April 2, 2011 NetBSD 11.0