NAME

dwarf_producer_init dwarf_producer_init_b — allocate a DWARF producer descriptor

LIBRARY

DWARF Access Library (libdwarf, -ldwarf)

SYNOPSIS

#include <libdwarf.h>

Dwarf_P_Debug
dwarf_producer_init(Dwarf_Unsigned flags, Dwarf_Callback_Func func, Dwarf_Handler errhand, Dwarf_Ptr errarg, Dwarf_Error *err);

Dwarf_P_Debug
dwarf_producer_init_b(Dwarf_Unsigned flags, Dwarf_Callback_Func_b func, Dwarf_Handler errhand, Dwarf_Ptr errarg, Dwarf_Error *error);

DESCRIPTION

These functions allocate and return a Dwarf_P_Debug descriptor representing a DWARF producer instance.

The argument errhand should contain the adddress of a function to be called in case of an error. If this argument is NULL, the default error handling scheme is used, see dwarf(3).

The argument errarg will be passed to the error handler function when it is invoked.

The argument err references a memory location that would hold a Dwarf_Error descriptor in case of an error.

The argument flags specifies additional characteristics of the DWARF producer instance. The following flags are recognized:

The following flags are mutually exclusive.

Flags DW_DLC_ISA_IA64 and DW_DLC_ISA_MIPS.
Flags DW_DLC_SIZE_32 and DW_DLC_SIZE_64.
Flags DW_DLC_STREAM_RELOCATIONS and DW_DLC_SYMBOLIC_RELOCATIONS.
Flags DW_DLC_TARGET_BIGENDIAN and DW_DLC_TARGET_LITTLEENDIAN.

If neither of the flags DW_DLC_TARGET_BIGENDIAN and DW_DLC_TARGET_LITTLEENDIAN is set, the target's endianness is assumed to be the same as the host's endianness.

Argument func should point to an application-provided callback function of type Dwarf_Callback_Func_b. The type Dwarf_Callback_Func_b is defined in the header file <libdwarf.h> as:

typedef int (*Dwarf_Callback_Func_b)(char *name, int size, 
    Dwarf_Unsigned type, Dwarf_Unsigned flags, Dwarf_Unsigned link, 
    Dwarf_Unsigned info, Dwarf_Unsigned *index, int *error);

This function is called by the DWARF Access Library (libdwarf, -ldwarf) once for each section in the object file that the library needs to create. The arguments to this callback function specify the values in the ELF section header for the section being created:

On success, the callback function should return the section index value of the created section, and set the location pointed to by argument index to the symbol table index of the symbol that associated with the newly created section. This symbol table index will be used in relocation entries referring to the created section.

In case of failure, the callback function should return -1 and set the location pointed to by argument error to an application-defined error code. This application returned error code is currently ignored by the library.

Function dwarf_producer_init() is deprecated. Function dwarf_producer_init() is identical to function dwarf_producer_init_b() except that the callback function it expects can not properly handle arbitrary section symbol index values.

Memory Management

The Dwarf_P_Debug instance returned by these functions should be freed using the function dwarf_producer_finish().

RETURN VALUES

On success, these functions return the created DWARF producer descriptor. In case of an error, they return DW_DLV_BADADDR and set the argument err.

ERRORS

These functions can fail with:

EXAMPLES

To initialize a Dwarf_P_Debug instance for a MIPS32 big endian object, use:

Dwarf_P_Debug dbg; 
Dwarf_Unsigned flags; 
Dwarf_Error de; 
 
/* ... assume cb_func points to the callback function ... */ 
 
flags = DW_DLC_WRITE | DW_DLC_SIZE_32 | DW_DLC_ISA_MIPS | 
    DW_DLC_STREAM_RELOCATIONS | DW_DLC_TARGET_BIGENDIAN; 
if ((dbg = dwarf_producer_init(flags, cb_func, NULL, NULL, &de)) == 
    DW_DLV_BADADDR) 
	warnx("dwarf_producer_init failed: %s", dwarf_errmsg(-1));

Manual browser: dwarf_producer_init_b(3)