/usr/src/gcc-4.6/debian/patches/gcc-default-format-security.diff is in gcc-4.6-source 4.6.4-6ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 | # DP: Turn on -Wformat -Wformat-security by default for C, C++, ObjC, ObjC++.
---
gcc/c-common.c | 2 +-
gcc/c.opt | 2 +-
gcc/doc/invoke.texi | 8 ++++++++
3 files changed, 10 insertions(+), 2 deletions(-)
--- a/src/gcc/c-family/c-common.c
+++ b/src/gcc/c-family/c-common.c
@@ -201,7 +201,7 @@
/* Warn about format/argument anomalies in calls to formatted I/O functions
(*printf, *scanf, strftime, strfmon, etc.). */
-int warn_format;
+int warn_format = 1;
/* C/ObjC language option variables. */
--- a/src/gcc/c-family/c.opt
+++ b/src/gcc/c-family/c.opt
@@ -384,7 +384,7 @@
Warn about format strings that contain NUL bytes
Wformat-security
-C ObjC C++ ObjC++ Var(warn_format_security) Warning
+C ObjC C++ ObjC++ Var(warn_format_security) Init(1) Warning
Warn about possible security problems with format functions
Wformat-y2k
--- a/src/gcc/doc/invoke.texi
+++ b/src/gcc/doc/invoke.texi
@@ -3102,6 +3102,9 @@
@option{-Wformat-nonliteral}, @option{-Wformat-security}, and
@option{-Wformat=2} are available, but are not included in @option{-Wall}.
+NOTE: In Ubuntu 8.10 and later versions this option is enabled by default
+for C, C++, ObjC, ObjC++. To disable, use @option{-Wformat=0}.
+
@item -Wformat-y2k
@opindex Wformat-y2k
@opindex Wno-format-y2k
@@ -3155,6 +3158,11 @@
in future warnings may be added to @option{-Wformat-security} that are not
included in @option{-Wformat-nonliteral}.)
+NOTE: In Ubuntu 8.10 and later versions this option is enabled by default
+for C, C++, ObjC, ObjC++. To disable, use @option{-Wno-format-security},
+or disable all format warnings with @option{-Wformat=0}. To make format
+security warnings fatal, specify @option{-Werror=format-security}.
+
@item -Wformat=2
@opindex Wformat=2
@opindex Wno-format=2
|