GELF_GETSYMSHNDX(3)

NAME
gelf_getsymshndx, gelf_update_symshndx - read and update symbol information using extended section indices

LIBRARY
libelf

SYNOPSIS
#include <gelf.h>
GElf_Sym *
gelf_getsymshndx(Elf_Data *symdata, Elf_Data *xndxdata, int ndx, GElf_Sym *sym, Elf32_Word *xndxptr);
int
gelf_update_symshndx(Elf_Data *symdata, Elf_Data *xndxdata, int ndx, GElf_Sym *sym, Elf32_Word xndx);

DESCRIPTION
These functions are analogous to gelf_getsym() and gelf_update_sym() respectively, but are capable of handling symbol tables using extended section numbering.

Argument symdata is an Elf_Data descriptor associated with a section of type SHT_SYMTAB. Argument xndxdata is an Elf_Data descriptor associated with a section of type SHT_SYMTAB_SHNDX. Argument ndx is the index of the symbol table entry being retrieved or updated. Argument sym is a pointer to a class-independent GElf_Sym structure. GElf_Sym structures are described in detail in gelf(3).

Function gelf_getsymshndx() retrieves symbol information at index ndx from the data descriptor specified by argument symdata and stores it in class-independent form in argument sym. Additionally:

•   If the arguments xndxdata and xndxptr are both not NULL, it retrieves the extended section index for the symbol from the data buffer pointed to by the argument xndxdata and stores it into the location pointed to by argument xndxptr.

•   Otherwise, if the argument xndxptr is not NULL, a value of zero is stored into the location pointed to by argument xndxptr.

Function gelf_update_symshndx() updates the underlying symbol table entry in the data descriptor symdata with the information in argument sym. In addition it sets the extended section index in data buffer xndxdata to the value of argument xndx.

RETURN VALUES
Function gelf_getsymshndx() returns the value of argument sym if successful, or NULL in case of an error.

Function gelf_update_symshndx() returns a non-zero value if successful, or zero in case of an error.

ERRORS
These functions may fail with the following errors:

[ELF_E_ARGUMENT]
    Arguments symdata, xndxdata, xndxptr or sym were NULL.

[ELF_E_ARGUMENT]
    Argument ndx was less than zero, or too large for either of descriptors symdata or xndxdata.

[ELF_E_ARGUMENT]
    Data descriptor symdata was not associated with a section of type SHT_SYMTAB.

[ELF_E_ARGUMENT]
    Data descriptor xndxdata was not associated with a section of type SHT_SYMTAB_SHNDX.

[ELF_E_ARGUMENT]
    Data descriptor symdata and xndxdata were associated with different ELF objects.

[ELF_E_VERSION]
    The Elf_Data descriptors denoted by arguments symdata and xndxdata are associated with an ELF object with an unsupported version.

SEE ALSO
elf(3), elf_getdata(3), elf_getscn(3), gelf(3), gelf_getsym(3), gelf_update_sym(3)