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DWARF_PRODUCER_INIT(3) Library Functions Manual DWARF_PRODUCER_INIT(3)
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 address 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:
DW_DLC_ISA_IA64 (Deprecated) The target instruction set architecture
is IA64. This flag is deprecated. Application code
should use the dwarf_producer_set_isa(3) function to
specify target instruction set architecture.
DW_DLC_ISA_MIPS (Deprecated) The target instruction set architecture
is MIPS. This flag is deprecated. Application code
should use the dwarf_producer_set_isa(3) function to
specify target instruction set architecture.
DW_DLC_SIZE_32 (Default) The target address size is 32-bit.
DW_DLC_SIZE_64 The target address size is 64-bit.
DW_DLC_STREAM_RELOCATIONS
(Default) Generate stream relocations.
DW_DLC_SYMBOLIC_RELOCATIONS
Generate symbolic relocations.
DW_DLC_TARGET_BIGENDIAN
The target is big endian.
DW_DLC_TARGET_LITTLEENDIAN
The target is little endian.
DW_DLC_WRITE (Required) Permit writing of DWARF information.
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:
name The name of the section being created.
size The sh_size value in the section header.
type The sh_type value in the section header.
flags The sh_flags value in the section header.
link The sh_link value in the section header.
info The sh_info value in the section header.
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.
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));
ERRORS
These functions can fail with:
[DW_DLE_ARGUMENT] Argument func was NULL.
[DW_DLE_ARGUMENT] The flag DW_DLC_WRITE was not set in argument
flags.
[DW_DLE_ARGUMENT] The flags DW_DLC_SIZE_32 and DW_DLC_SIZE_64 were
both set in argument flags.
[DW_DLE_ARGUMENT] The flags DW_DLC_ISA_IA64 and DW_DLC_ISA_MIPS
were both set in argument flags.
[DW_DLE_ARGUMENT] The flags DW_DLC_TARGET_BIGENDIAN and
DW_DLC_TARGET_LITTLEENDIAN were both set in
argument flags.
[DW_DLE_ARGUMENT] The flags DW_DLC_STREAM_RELOCATIONS and
DW_DLC_SYMBOLIC_RELOCATIONS were both set in
argument flags.
[DW_DLE_MEMORY] An out of memory condition was encountered.
SEE ALSO
dwarf(3), dwarf_errmsg(3), dwarf_producer_finish(3),
dwarf_producer_set_isa(3), dwarf_transform_to_disk_form(3)
NetBSD 10.99 August 20, 2011 NetBSD 10.99