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$Id: dwarf_get_weaks.3 3640 2018-10-14 14:09:13Z jkoshy $
.Dd April 10, 2011 .Dt DWARF_GET_WEAKS 3 .Os .Sh NAME .Nm dwarf_get_weaks , .Nm dwarf_weak_cu_offset , .Nm dwarf_weak_die_offset , .Nm dwarf_weak_name_offsets , .Nm dwarf_weakname .Nd retrieve information about weak symbols .Sh LIBRARY .Lb libdwarf .Sh SYNOPSIS n libdwarf.h .Ft int .Fo dwarf_get_weaks .Fa "Dwarf_Debug dbg" .Fa "Dwarf_Weak **weaks" .Fa "Dwarf_Signed *nweaks" .Fa "Dwarf_Error *err" .Fc .Ft int .Fo dwarf_weak_cu_offset .Fa "Dwarf_Weak weak" .Fa "Dwarf_Off *cu_offset" .Fa "Dwarf_Error *err" .Fc .Ft int .Fo dwarf_weak_die_offset .Fa "Dwarf_Weak weak" .Fa "Dwarf_Off *die_offset" .Fa "Dwarf_Error *err" .Fc .Ft int .Fo dwarf_weak_name_offsets .Fa "Dwarf_Weak weak" .Fa "char **name" .Fa "Dwarf_Off *die_offset" .Fa "Dwarf_Off *cu_die_offset" .Fa "Dwarf_Error *err" .Fc .Ft int .Fo dwarf_weakname .Fa "Dwarf_Weak weak" .Fa "char **name" .Fa "Dwarf_Error *err" .Fc .Sh DESCRIPTION These functions retrieve information about weak symbols from the lookup tables in the (SGI-specific) .Dq ".debug_weaknames" section. Information about weak symbols is returned using opaque descriptors of type .Vt Dwarf_Weak . Applications need to use the functions described below to retrieve the name and offset information contained in these descriptors.
p Function .Fn dwarf_get_weaks retrieves descriptors for all the weak symbols associated with the DWARF debug context specified by argument .Ar dbg . The argument .Ar weaks should point to a location that will be set to a pointer to an array of .Vt Dwarf_Weak descriptors. The argument .Ar nweaks should point to a location that will be set to the number of descriptors returned.
p Function .Fn dwarf_weak_cu_offset returns the offset, relative to the .Dq ".debug_info" section, of the compilation unit that contains the debugging information entry associated with the argument .Ar weak . Argument .Ar cu_offset should point to a location that will hold the returned offset.
p Function .Fn dwarf_weak_die_offset retrieves the offset, relative to the .Dq ".debug_info" section, of the debugging information entry associated with the argument .Ar weak , and stores it into the location pointed to by the argument .Ar die_offset .
p Function .Fn dwarf_weak_name_offsets retrieves the name and offsets for the debugging information entry for argument .Ar weak . Argument .Ar 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 .Ar die_offset should point to a location which will be set to the offset, relative to the .Dq ".debug_info" section, of the associated debugging information entry. Argument .Ar cu_die_offset should point to a location which will be set to the offset, relative to the .Dq ".debug_info" section, of the first debugging information entry in the compilation unit associated with argument .Ar weak .
p Function .Fn dwarf_weakname sets the location pointed to by argument .Ar name to a pointer to a NUL-terminated string holding the name of the debugging information entry associated with the argument .Ar weak . .Ss Memory Management The memory area used for the array of .Vt Dwarf_Weak descriptors returned in argument .Ar weaks by function .Fn dwarf_get_weaks is owned by the .Lb libdwarf . Application code should not attempt to directly free this pointer. Portable code should instead use the function .Xr dwarf_weaks_dealloc 3 to indicate that the memory area may be freed.
p The memory area used for the string returned in the .Ar name argument to functions .Fn dwarf_weak_name_offsets and .Fn dwarf_weakname is owned by the .Lb libdwarf . Portable code should indicate that the memory area can be freed using the .Xr dwarf_dealloc 3 function. .Ss Error Returns If argument .Ar err is not NULL, these functions will use it to store error information, in case of an error. .Sh RETURN VALUES On success, these functions returns .Dv DW_DLV_OK . In case of an error, they return .Dv DW_DLV_ERROR and set the argument .Ar err . .Sh ERRORS These functions may fail with the following errors: l -tag -width ".Bq Er DW_DLE_ARGUMENT" t Bq Er DW_DLE_ARGUMENT One of the arguments .Va cu_die_offset , .Va cu_offset , .Va dbg , .Va die_offset , .Va weak , .Va weaks , .Va name , or .Va nweaks was NULL. t Bq Er DW_DLE_NO_ENTRY The DWARF debugging context referenced by argument .Ar dbg did not contain information about weak symbols. .El .Sh SEE ALSO .Xr dwarf 3 , .Xr dwarf_get_cu_die_offset_given_cu_header_offset 3 , .Xr dwarf_weaks_dealloc 3