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DWARF_GET_FDE_LIST(3) FreeBSD Library Functions Manual DWARF_GET_FDE_LIST(3)
NAME
dwarf_get_fde_list - retrieve frame information
LIBRARY
DWARF Access Library (libdwarf, -ldwarf)
SYNOPSIS
#include <libdwarf.h>
int
dwarf_get_fde_list(Dwarf_Debug dbg, Dwarf_Cie **cie_list,
Dwarf_Signed *cie_count, Dwarf_Fde **fde_list,
Dwarf_Signed *fde_count, Dwarf_Error *err);
int
dwarf_get_fde_list_eh(Dwarf_Debug dbg, Dwarf_Cie **cie_list,
Dwarf_Signed *cie_count, Dwarf_Fde **fde_list,
Dwarf_Signed *fde_count, Dwarf_Error *err);
DESCRIPTION
These functions retrieve frame related information for the specified
DWARF debug context.
Function dwarf_get_fde_list() retrieves frame information from the DWARF
section named ".debug_frame". For objects containing GNU style C++
exception handling information, the function dwarf_get_fde_list_eh()
retrieves frame information from the section named ".eh_frame".
Frame information is returned using opaque descriptors of type Dwarf_Cie
and Dwarf_Fde. Applications need to use the other frame related
functions in the DWARF(3) API set to retrieve the information contained
in these descriptors.
Argument dbg should reference a DWARF debug context allocated using
dwarf_init(3).
Argument cie_list should point to a location that will be set to a
pointer to an array of Dwarf_Cie descriptors.
Argument cie_count should point to a location that will be set to the
number of Dwarf_Cie descriptors returned.
Argument fde_list should point to a location that will be set to a
pointer to an array of Dwarf_Fde descriptors.
Argument fde_count should point to a location that will be set to the
number of Dwarf_Fde descriptors returned.
If argument err is not NULL, it will be used to store error information
in case of an error.
Memory Management
The memory areas used for the arrays returned in arguments cie_list and
fde_list are owned by the DWARF Access Library (libdwarf, -ldwarf).
Application code should not attempt to directly free these areas.
Portable applications should instead use the
dwarf_fde_cie_list_dealloc(3) function to indicate that these memory
EXAMPLES
To obtain frame information from the ".debug_frame" section, use:
Dwarf_Debug dbg;
Dwarf_Cie *cie_list, cie;
Dwarf_Fde *fde_list, fde;
Dwarf_Off fde_offset, cie_offset;
Dwarf_Unsigned func_len, fde_length, fde_instlen;
Dwarf_Signed cie_count, fde_count, cie_index;
Dwarf_Addr low_pc;
Dwarf_Ptr fde_addr, fde_inst, cie_inst;
Dwarf_Error de;
int i;
if (dwarf_get_fde_list(dbg, &cie_list, &cie_count,
&fde_list, &fde_count, &de) != DW_DLV_OK) {
errx(EXIT_FAILURE, "dwarf_get_fde_list failed: %s",
dwarf_errmsg(de));
}
for (i = 0; i < fde_count; i++) {
if (dwarf_get_fde_n(fde_list, i, &fde, &de) != DW_DLV_OK) {
warnx("dwarf_get_fde_n failed: %s",
dwarf_errmsg(de));
continue;
}
if (dwarf_get_cie_of_fde(fde, &cie, &de) != DW_DLV_OK) {
warnx("dwarf_get_fde_n failed: %s",
dwarf_errmsg(de));
continue;
}
if (dwarf_get_fde_range(fde, &low_pc, &func_len, &fde_addr,
&fde_length, &cie_offset, &cie_index, &fde_offset,
&de) != DW_DLV_OK) {
warnx("dwarf_get_fde_range failed: %s",
dwarf_errmsg(de));
continue;
}
if (dwarf_get_fde_instr_bytes(fde, &fde_inst, &fde_instlen,
&de) != DW_DLV_OK) {
warnx("dwarf_get_fde_instr_bytes failed: %s",
dwarf_errmsg(de));
continue;
}
/* ... Use the retrieved frame information ... */
}
/* Indicate that the returned arrays may be freed. */
dwarf_fde_cie_list_dealloc(dbg, cie_list, cie_count, fde_list,
fde_count);
ERRORS
These functions may fail with the following errors:
[DW_DLE_ARGUMENT] One of the arguments dbg, cie_list, cie_count,
fde_list or fde_count was NULL.
dwarf_set_frame_cfa_value(3), dwarf_set_frame_rule_initial_value(3),
dwarf_set_frame_rule_table_size(3), dwarf_set_frame_same_value(3),
dwarf_set_frame_undefined_value(3)
FreeBSD 14.0-RELEASE-p11 November 9, 2011 FreeBSD 14.0-RELEASE-p11