Hello,
I mess around with a lot of generated code. That means I do automated
construction of libraries that use literal strings. In order to
reduce address fixups, I often put all the literal strings into one long
string with each piece separated from the others with a NUL byte.
Unfortunately, I am then constrained from using ``-Wformat'' because
it fears I might accidentally be doing something wrong.
I believe the attached patch is sufficient to implement
-Wno-format-contains-nul
(I am bootstrapping GCC and will be testing for a few hours.)
I'd like to hear any complaints about the change before I
spend too much time polishing it. Thank you!
Regards, Bruce
patterned after usage of "format-nonliteral"
Index: c-format.c
===================================================================
--- c-format.c (revision 123186)
+++ c-format.c (working copy)
@@ -43,6 +43,7 @@
if (setting != 1)
{
warn_format_nonliteral = setting;
+ warn_format_contains_nul = setting;
warn_format_security = setting;
warn_format_y2k = setting;
}
@@ -1482,7 +1483,7 @@
if (*format_chars == 0)
{
if (format_chars - orig_format_chars != format_length)
- warning (OPT_Wformat, "embedded %<\\0%> in format");
+ warning (OPT_Wformat_contains_nul, "embedded %<\\0%> in format");
if (info->first_arg_num != 0 && params != 0
&& has_operand_number <= 0)
{
Index: c.opt
===================================================================
--- c.opt (revision 123186)
+++ c.opt (working copy)
@@ -216,6 +216,10 @@
C ObjC C++ ObjC++ Var(warn_format_nonliteral) Warning
Warn about format strings that are not literals
+Wformat-contains-nul
+C ObjC C++ ObjC++ Var(warn_format_contains_nul)
+Warn about format strings that contain NUL bytes
+
Wformat-security
C ObjC C++ ObjC++ Var(warn_format_security) Warning
Warn about possible security problems with format functions
Index: c-opts.c
===================================================================
--- c-opts.c (revision 123186)
+++ c-opts.c (working copy)
@@ -1106,6 +1106,8 @@
"-Wformat-zero-length ignored without -Wformat");
warning (OPT_Wformat_nonliteral,
"-Wformat-nonliteral ignored without -Wformat");
+ warning (OPT_Wformat_contains_nul,
+ "-Wformat-contains-nul ignored without -Wformat");
warning (OPT_Wformat_security,
"-Wformat-security ignored without -Wformat");
}
