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DWARF_LOCLIST_FROM_EXPR(3) FreeBSD Library Functions Manual
NAME
dwarf_loclist_from_expr, dwarf_loclist_from_expr_a,
dwarf_loclist_from_expr_b - translate DWARF location expression bytes
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
int
dwarf_loclist_from_expr(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Locdesc **llbuf,
Dwarf_Signed *listlen, Dwarf_Error *err);
int
dwarf_loclist_from_expr_a(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Half addr_size,
Dwarf_Locdesc **llbuf, Dwarf_Signed *listlen, Dwarf_Error *err);
int
dwarf_loclist_from_expr_b(Dwarf_Debug dbg, Dwarf_Ptr bytes_in,
Dwarf_Unsigned bytes_len, Dwarf_Half addr_size,
Dwarf_Half offset_size, Dwarf_Small version, Dwarf_Locdesc **llbuf,
Dwarf_Signed *listlen, Dwarf_Error *error);
DESCRIPTION
Function dwarf_loclist_from_expr() translates DWARF location expression
bytes into a Dwarf_Locdesc descriptor. The size for address related data
is taken to be the default address size for the object being read.
Argument dbg should reference a DWARF debug context allocated using
dwarf_init(3).
Argument bytes_in should point to an array of DWARF location expression
bytes.
Argument bytes_len should specify the number of the location expression
bytes to be translated.
Argument llbuf should point to a location which will be set to a pointer
to a returned Dwarf_Locdesc descriptor.
Argument listlen should point to a location which will hold the number of
the Dwarf_Locdesc descriptors returned. In this case it is always set to
1.
If argument err is not NULL, it will be used to store error information
in case of an error.
Function dwarf_loclist_from_expr_a() is identical to function
dwarf_loclist_from_expr(), except that it requires one additional
argument addr_size, which specifies the address size to use when
translating the location expression bytes.
Function dwarf_loclist_from_expr_b() is identical to function
dwarf_loclist_from_expr_a() except that it requires two additional
allocated by DWARF Access Library (libdwarf, -ldwarf). When the
descriptor is no longer needed, application code should use function
dwarf_dealloc(3) to free the memory area in two steps:
1. First, the array of Dwarf_Loc descriptors pointed to by the ld_s
field of the Dwarf_Locdesc descriptor should be deallocated using
the allocation type DW_DLA_LOC_BLOCK.
2. Next, the application should free the llbuf pointer using the
allocation type DW_DLA_LOCDESC.
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 dbg, bytes_in, llbuf or
listlen was NULL.
[DW_DLE_ARGUMENT] Argument bytes_len was 0.
[DW_DLE_ARGUMENT] The value of argument addr_size was invalid.
[DW_DLE_LOC_EXPR_BAD] An unknown or invalid operation was found in the
location expression bytes provided in argument
bytes_in.
[DW_DLE_MEMORY] An out of memory condition was encountered during
the execution of this function.
SEE ALSO
dwarf(3), dwarf_dealloc(3), dwarf_get_fde_info_for_all_regs3(3),
dwarf_get_fde_info_for_cfa_reg3(3), dwarf_get_fde_info_for_reg3(3),
dwarf_get_loclist_entry(3), dwarf_loclist_n(3)
FreeBSD 14.0-RELEASE-p11 December 21, 2014 FreeBSD 14.0-RELEASE-p11