DWARF_GET_WEAKS(3)

DWARF_GET_WEAKS(3) | Library Functions Manual | DWARF_GET_WEAKS(3)

# NAME

`dwarf_get_weaks`, `dwarf_weak_cu_offset`, `dwarf_weak_die_offset`, `dwarf_weak_name_offsets`, `dwarf_weakname` — retrieve information about weak symbols

# LIBRARY

DWARF Access Library (libdwarf, -ldwarf)

# SYNOPSIS

`#include <libdwarf.h>`

int
`dwarf_get_weaks`(Dwarf_Debug dbg, Dwarf_Weak **weaks, Dwarf_Signed *nweaks, Dwarf_Error *err);

int
`dwarf_weak_cu_offset`(Dwarf_Weak weak, Dwarf_Off *cu_offset, Dwarf_Error *err);

int
`dwarf_weak_die_offset`(Dwarf_Weak weak, Dwarf_Off *die_offset, Dwarf_Error *err);

int
`dwarf_weak_name_offsets`(Dwarf_Weak weak, char **name, Dwarf_Off *die_offset, Dwarf_Off *cu_die_offset, Dwarf_Error *err);

int
`dwarf_weakname`(Dwarf_Weak weak, char **name, Dwarf_Error *err);

# DESCRIPTION

These functions retrieve information about weak symbols from the lookup tables in the (SGI-specific) “.debug_weaknames” section. Information about weak symbols is returned using opaque descriptors of type Dwarf_Weak. Applications need to use the functions described below to retrieve the name and offset information contained in these descriptors.

Function `dwarf_get_weaks`() retrieves descriptors for all the weak symbols associated with the DWARF debug context specified by argument dbg. The argument weaks should point to a location that will be set to a pointer to an array of Dwarf_Weak descriptors. The argument nweaks should point to a location that will be set to the number of descriptors returned.

Function `dwarf_weak_cu_offset`() returns the offset, relative to the “.debug_info” section, of the compilation unit that contains the debugging information entry associated with the argument weak. Argument cu_offset should point to a location that will hold the returned offset.

Function `dwarf_weak_die_offset`() retrieves the offset, relative to the “.debug_info” section, of the debugging information entry associated with the argument weak, and stores it into the location pointed to by the argument die_offset.

Function `dwarf_weak_name_offsets`() retrieves the name and offsets for the debugging information entry for argument weak. 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 the 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 the offset, relative to the “.debug_info” section, of the first debugging information entry in the compilation unit associated with argument weak.

Function `dwarf_weakname`() 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 weak.

## Memory Management

The memory area used for the array of Dwarf_Weak descriptors returned in argument weaks by function `dwarf_get_weaks`() 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_weaks_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_weak_name_offsets`() and `dwarf_weakname`() 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, weak, weaks, name, or nweaks was `NULL`.
[`DW_DLE_NO_ENTRY`]
  The DWARF debugging context referenced by argument dbg did not contain information about weak symbols.

# SEE ALSO

dwarf(3), dwarf_get_cu_die_offset_given_cu_header_offset(3), dwarf_weaks_dealloc(3)

April 10, 2011 | NetBSD 11.0