commit c75bd3a23915c3122070a95e1974e323543ffbe4
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Sun Sep 7 14:09:59 2014 +0200
Fix crash on Python frame filters with unreadable arg
https://bugzilla.redhat.com/show_bug.cgi?id=1126177
ERROR: AddressSanitizer: SEGV on unknown address 0x000000000050 (pc 0x000000992bef sp 0x7ffff9039530 bp 0x7ffff9039540
T0)
#0 0x992bee in value_type .../gdb/value.c:925
#1 0x87c951 in py_print_single_arg python/py-framefilter.c:445
#2 0x87cfae in enumerate_args python/py-framefilter.c:596
#3 0x87e0b0 in py_print_args python/py-framefilter.c:968
It crashes because frame_arg::val is documented it may contain NULL
(frame_arg::error is then non-NULL) but the code does not handle it.
Another bug is that py_print_single_arg() calls goto out of its TRY_CATCH
which messes up GDB cleanup chain crashing GDB later.
It is probably 7.7 regression (I have not verified it) due to the introduction
of Python frame filters.
gdb/ChangeLog
PR python/17355
* python/py-framefilter.c (py_print_single_arg): Handle NULL FA->VAL.
Fix goto out of TRY_CATCH.
gdb/testsuite/ChangeLog
PR python/17355
* gdb.python/amd64-py-framefilter-invalidarg.S: New file.
* gdb.python/py-framefilter-invalidarg-gdb.py.in: New file.
* gdb.python/py-framefilter-invalidarg.exp: New file.
* gdb.python/py-framefilter-invalidarg.py: New file.
### a/gdb/ChangeLog
### b/gdb/ChangeLog
## -1,3 +1,9 @@
+2014-09-07 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ PR python/17355
+ * python/py-framefilter.c (py_print_single_arg): Handle NULL FA->VAL.
+ Fix goto out of TRY_CATCH.
+
2014-09-06 Doug Evans <xdje42@gmail.com>
Tom Tromey <tromey@redhat.com>
### a/gdb/testsuite/ChangeLog
### b/gdb/testsuite/ChangeLog
## -1,3 +1,11 @@
+2014-09-07 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ PR python/17355
+ * gdb.python/amd64-py-framefilter-invalidarg.S: New file.
+ * gdb.python/py-framefilter-invalidarg-gdb.py.in: New file.
+ * gdb.python/py-framefilter-invalidarg.exp: New file.
+ * gdb.python/py-framefilter-invalidarg.py: New file.
+
2014-09-06 Doug Evans <xdje42@gmail.com>
PR 15276
Index: gdb-7.6.1/gdb/python/py-framefilter.c
===================================================================
--- gdb-7.6.1.orig/gdb/python/py-framefilter.c 2015-11-27 18:06:21.901228682 +0100
+++ gdb-7.6.1/gdb/python/py-framefilter.c 2015-11-27 18:06:22.445231731 +0100
@@ -365,9 +365,12 @@
{
struct value *val;
volatile struct gdb_exception except;
+ enum py_bt_status retval = PY_BT_OK;
if (fa != NULL)
{
+ if (fa->val == NULL && fa->error == NULL)
+ return PY_BT_OK;
language = language_def (SYMBOL_LANGUAGE (fa->sym));
val = fa->val;
}
@@ -433,16 +436,18 @@
/* For MI print the type, but only for simple values. This seems
weird, but this is how MI choose to format the various output
types. */
- if (args_type == MI_PRINT_SIMPLE_VALUES)
+ if (args_type == MI_PRINT_SIMPLE_VALUES && val != NULL)
{
if (py_print_type (out, val) == PY_BT_ERROR)
{
+ retval = PY_BT_ERROR;
do_cleanups (cleanups);
- goto error;
+ continue;
}
}
- annotate_arg_value (value_type (val));
+ if (val != NULL)
+ annotate_arg_value (value_type (val));
/* If the output is to the CLI, and the user option "set print
frame-arguments" is set to none, just output "...". */
@@ -454,27 +459,25 @@
for the case of MI_PRINT_NO_VALUES. */
if (args_type != NO_VALUES)
{
- if (py_print_value (out, val, opts, 0, args_type, language)
- == PY_BT_ERROR)
+ if (val == NULL)
{
- do_cleanups (cleanups);
- goto error;
+ gdb_assert (fa != NULL && fa->error != NULL);
+ ui_out_field_fmt (out, "value",
+ _("<error reading variable: %s>"),
+ fa->error);
}
+ else if (py_print_value (out, val, opts, 0, args_type, language)
+ == PY_BT_ERROR)
+ retval = PY_BT_ERROR;
}
}
do_cleanups (cleanups);
}
if (except.reason < 0)
- {
- gdbpy_convert_exception (except);
- goto error;
- }
-
- return PY_BT_OK;
+ gdbpy_convert_exception (except);
- error:
- return PY_BT_ERROR;
+ return retval;
}
/* Helper function to loop over frame arguments provided by the
Index: gdb-7.6.1/gdb/testsuite/gdb.python/amd64-py-framefilter-invalidarg.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.6.1/gdb/testsuite/gdb.python/amd64-py-framefilter-invalidarg.S 2015-11-27 18:06:22.446231736 +0100
@@ -0,0 +1,261 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2014 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* This file is compiled from a single line
+ int main (int argc, char **argv) { return 0; }
+ using -g -dA -S -O2 and patched as #if-ed below. */
+
+ .file "py-framefilter-invalidarg.c"
+ .text
+.Ltext0:
+ .globl main
+ .type main, @function
+main:
+.LFB0:
+ .file 1 "py-framefilter-invalidarg.c"
+ # py-framefilter-invalidarg.c:1
+ .loc 1 1 0
+ .cfi_startproc
+# BLOCK 2 seq:0
+# PRED: ENTRY (FALLTHRU)
+ pushq %rbp
+ .cfi_def_cfa_offset 16
+ .cfi_offset 6, -16
+ movq %rsp, %rbp
+ .cfi_def_cfa_register 6
+ movl %edi, -4(%rbp)
+ movq %rsi, -16(%rbp)
+ # py-framefilter-invalidarg.c:2
+ .loc 1 2 0
+ movl $0, %eax
+ # py-framefilter-invalidarg.c:3
+ .loc 1 3 0
+ popq %rbp
+ .cfi_def_cfa 7, 8
+# SUCC: EXIT [100.0%]
+ ret
+ .cfi_endproc
+.LFE0:
+ .size main, .-main
+.Letext0:
+ .section .debug_info,"",@progbits
+.Ldebug_info0:
+ .long .Le - .Ls # Length of Compilation Unit Info
+.Ls:
+ .value 0x4 # DWARF version number
+ .long .Ldebug_abbrev0 # Offset Into Abbrev. Section
+ .byte 0x8 # Pointer Size (in bytes)
+ .uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit)
+ .long .LASF3 # DW_AT_producer: "GNU C 4.9.1 20140813 (Red Hat 4.9.1-7) -mtune=generic -march=x86-64 -g"
+ .byte 0x1 # DW_AT_language
+ .long .LASF4 # DW_AT_name: "py-framefilter-invalidarg.c"
+ .long .LASF5 # DW_AT_comp_dir: ""
+ .quad .Ltext0 # DW_AT_low_pc
+ .quad .Letext0-.Ltext0 # DW_AT_high_pc
+ .long .Ldebug_line0 # DW_AT_stmt_list
+die2d:
+ .uleb128 0x2 # (DIE (0x2d) DW_TAG_subprogram)
+ # DW_AT_external
+ .long .LASF6 # DW_AT_name: "main"
+ .byte 0x1 # DW_AT_decl_file (py-framefilter-invalidarg.c)
+ .byte 0x1 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long die6b-.Ldebug_info0 # DW_AT_type
+ .quad .LFB0 # DW_AT_low_pc
+ .quad .LFE0-.LFB0 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+die4e:
+ .uleb128 0x3 # (DIE (0x4e) DW_TAG_formal_parameter)
+ .long .LASF0 # DW_AT_name: "argc"
+ .byte 0x1 # DW_AT_decl_file (py-framefilter-invalidarg.c)
+ .byte 0x1 # DW_AT_decl_line
+ .long die6b-.Ldebug_info0 # DW_AT_type
+#if 0
+ .uleb128 0x2 # DW_AT_location
+ .byte 0x91 # DW_OP_fbreg
+ .sleb128 -20
+#endif
+#if 0
+ .uleb128 1f - 2f # DW_AT_location
+2:
+ .byte 0x03 # DW_OP_addr
+ .quad 0
+1:
+#endif
+#if 1
+ .uleb128 1f - 2f # DW_AT_location
+2:
+ .byte 0x13 # DW_OP_drop
+ .quad 0
+1:
+#endif
+die5c:
+ .uleb128 0x3 # (DIE (0x5c) DW_TAG_formal_parameter)
+ .long .LASF1 # DW_AT_name: "argv"
+ .byte 0x1 # DW_AT_decl_file (py-framefilter-invalidarg.c)
+ .byte 0x1 # DW_AT_decl_line
+ .long die72-.Ldebug_info0 # DW_AT_type
+ .uleb128 0x2 # DW_AT_location
+ .byte 0x91 # DW_OP_fbreg
+ .sleb128 -32
+ .byte 0 # end of children of DIE 0x2d
+die6b:
+ .uleb128 0x4 # (DIE (0x6b) DW_TAG_base_type)
+ .byte 0x4 # DW_AT_byte_size
+ .byte 0x5 # DW_AT_encoding
+ .ascii "int\0" # DW_AT_name
+die72:
+ .uleb128 0x5 # (DIE (0x72) DW_TAG_pointer_type)
+ .byte 0x8 # DW_AT_byte_size
+ .long die78-.Ldebug_info0 # DW_AT_type
+die78:
+ .uleb128 0x5 # (DIE (0x78) DW_TAG_pointer_type)
+ .byte 0x8 # DW_AT_byte_size
+ .long die7e-.Ldebug_info0 # DW_AT_type
+die7e:
+ .uleb128 0x6 # (DIE (0x7e) DW_TAG_base_type)
+ .byte 0x1 # DW_AT_byte_size
+ .byte 0x6 # DW_AT_encoding
+ .long .LASF2 # DW_AT_name: "char"
+ .byte 0 # end of children of DIE 0xb
+.Le:
+ .section .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+ .uleb128 0x1 # (abbrev code)
+ .uleb128 0x11 # (TAG: DW_TAG_compile_unit)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x25 # (DW_AT_producer)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x13 # (DW_AT_language)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x1b # (DW_AT_comp_dir)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x10 # (DW_AT_stmt_list)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .byte 0
+ .byte 0
+ .uleb128 0x2 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3f # (DW_AT_external)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .byte 0
+ .byte 0
+ .uleb128 0x3 # (abbrev code)
+ .uleb128 0x5 # (TAG: DW_TAG_formal_parameter)
+ .byte 0 # DW_children_no
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x2 # (DW_AT_location)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .byte 0
+ .byte 0
+ .uleb128 0x4 # (abbrev code)
+ .uleb128 0x24 # (TAG: DW_TAG_base_type)
+ .byte 0 # DW_children_no
+ .uleb128 0xb # (DW_AT_byte_size)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3e # (DW_AT_encoding)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0x8 # (DW_FORM_string)
+ .byte 0
+ .byte 0
+ .uleb128 0x5 # (abbrev code)
+ .uleb128 0xf # (TAG: DW_TAG_pointer_type)
+ .byte 0 # DW_children_no
+ .uleb128 0xb # (DW_AT_byte_size)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x6 # (abbrev code)
+ .uleb128 0x24 # (TAG: DW_TAG_base_type)
+ .byte 0 # DW_children_no
+ .uleb128 0xb # (DW_AT_byte_size)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3e # (DW_AT_encoding)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .byte 0
+ .byte 0
+ .byte 0
+ .section .debug_aranges,"",@progbits
+ .long 0x2c # Length of Address Ranges Info
+ .value 0x2 # DWARF Version
+ .long .Ldebug_info0 # Offset of Compilation Unit Info
+ .byte 0x8 # Size of Address
+ .byte 0 # Size of Segment Descriptor
+ .value 0 # Pad to 16 byte boundary
+ .value 0
+ .quad .Ltext0 # Address
+ .quad .Letext0-.Ltext0 # Length
+ .quad 0
+ .quad 0
+ .section .debug_line,"",@progbits
+.Ldebug_line0:
+ .section .debug_str,"MS",@progbits,1
+.LASF1:
+ .string "argv"
+.LASF4:
+ .string "py-framefilter-invalidarg.c"
+.LASF5:
+ .string ""
+.LASF0:
+ .string "argc"
+.LASF3:
+ .string "GNU C 4.9.1 20140813 (Red Hat 4.9.1-7) -mtune=generic -march=x86-64 -g"
+.LASF6:
+ .string "main"
+.LASF2:
+ .string "char"
+ .ident "GCC: (GNU) 4.9.1 20140813 (Red Hat 4.9.1-7)"
+ .section .note.GNU-stack,"",@progbits
Index: gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg-gdb.py.in
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg-gdb.py.in 2015-11-27 18:06:22.446231736 +0100
@@ -0,0 +1,48 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the GDB testsuite. It tests Python-based
+# frame-filters.
+import gdb
+import itertools
+from gdb.FrameDecorator import FrameDecorator
+
+
+class FrameObjFile ():
+
+ def __init__ (self):
+ self.name = "Filter1"
+ self.priority = 1
+ self.enabled = False
+ gdb.current_progspace().frame_filters ["Progspace" + self.name] = self
+ gdb.current_objfile().frame_filters ["ObjectFile" + self.name] = self
+
+ def filter (self, frame_iter):
+ return frame_iter
+
+class FrameObjFile2 ():
+
+ def __init__ (self):
+ self.name = "Filter2"
+ self.priority = 100
+ self.enabled = True
+ gdb.current_progspace().frame_filters ["Progspace" + self.name] = self
+ gdb.current_objfile().frame_filters ["ObjectFile" + self.name] = self
+
+ def filter (self, frame_iter):
+ return frame_iter
+
+FrameObjFile()
+FrameObjFile2()
Index: gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg.exp
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg.exp 2015-11-27 18:19:26.346625521 +0100
@@ -0,0 +1,86 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+load_lib gdb-python.exp
+
+standard_testfile amd64-py-framefilter-invalidarg.S
+
+if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
+ verbose "Skipping py-framefilter-invalidarg."
+ return
+}
+
+# We cannot use prepare_for_testing as we have to set the safe-patch
+# to check objfile and progspace printers.
+if {[build_executable $testfile.exp $testfile $srcfile {}] == -1} {
+ return -1
+}
+
+# Start with a fresh gdb.
+gdb_exit
+gdb_start
+
+# Skip all tests if Python scripting is not enabled.
+if { [skip_python_tests] } { continue }
+
+### IMPORT:
+# Like remote_download but provides a gdb-specific behavior. If DEST
+# is "host", and the host is not remote, and TOFILE is not specified,
+# then the [file tail] of FROMFILE is passed through
+# standard_output_file to compute the destination.
+
+proc gdb_remote_download {dest fromfile {tofile {}}} {
+ if {$dest == "host" && ![is_remote host] && $tofile == ""} {
+ set tofile [standard_output_file [file tail $fromfile]]
+ }
+
+ if { $tofile == "" } {
+ return [remote_download $dest $fromfile]
+ } else {
+ return [remote_download $dest $fromfile $tofile]
+ }
+}
+### IMPORT^
+
+# Make the -gdb.py script available to gdb, it is automagically loaded by gdb.
+# Care is taken to put it in the same directory as the binary so that
+# gdb will find it.
+set remote_obj_python_file \
+ [remote_download \
+ host ${srcdir}/${subdir}/${testfile}-gdb.py.in \
+ [standard_output_file ${testfile}-gdb.py]]
+
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_test_no_output "set auto-load safe-path ${remote_obj_python_file}" \
+ "set auto-load safe-path"
+gdb_load ${binfile}
+# Verify gdb loaded the script.
+gdb_test "info auto-load python-scripts" "Yes.*/${testfile}-gdb.py.*" \
+ "Test auto-load had loaded python scripts"
+
+if ![runto_main] then {
+ perror "couldn't run to breakpoint"
+ return
+}
+gdb_test_no_output "set python print-stack full" \
+ "Set python print-stack to full"
+
+# Load global frame-filters
+set remote_python_file [gdb_remote_download host \
+ ${srcdir}/${subdir}/${testfile}.py]
+gdb_test_no_output "python exec (open ('${remote_python_file}').read ())" \
+ "Load python file"
+
+gdb_test "bt" " in niam \\(argc=<error reading variable: dwarf expression stack underflow>, argv=0x\[0-9a-f\]+\\) at py-framefilter-invalidarg.c:\[0-9\]+" "bt full with filters"
Index: gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gdb-7.6.1/gdb/testsuite/gdb.python/py-framefilter-invalidarg.py 2015-11-27 18:06:22.447231742 +0100
@@ -0,0 +1,59 @@
+# Copyright (C) 2014 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# This file is part of the GDB testsuite. It tests Python-based
+# frame-filters.
+import gdb
+import itertools
+from gdb.FrameDecorator import FrameDecorator
+import copy
+
+class Reverse_Function (FrameDecorator):
+
+ def __init__(self, fobj):
+ super(Reverse_Function, self).__init__(fobj)
+ self.fobj = fobj
+
+ def function (self):
+ fname = str (self.fobj.function())
+ if (fname == None or fname == ""):
+ return None
+ if fname == 'end_func':
+ extra = self.fobj.inferior_frame().read_var('str').string()
+ else:
+ extra = ''
+ fname = fname[::-1] + extra
+ return fname
+
+class FrameFilter ():
+
+ def __init__ (self):
+ self.name = "Reverse"
+ self.priority = 100
+ self.enabled = True
+ gdb.frame_filters [self.name] = self
+
+ def filter (self, frame_iter):
+ # Python 3.x moved the itertools.imap functionality to map(),
+ # so check if it is available.
+ if hasattr(itertools, "imap"):
+ frame_iter = itertools.imap (Reverse_Function,
+ frame_iter)
+ else:
+ frame_iter = map(Reverse_Function, frame_iter)
+
+ return frame_iter
+
+FrameFilter()