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From: "nnk at google dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/53562] New: Add -Werror= support for -D_FORTIFY_SOURCE / __builtin___memcpy_chk
Date: Sat, 02 Jun 2012 09:48:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53562

             Bug #: 53562
           Summary: Add -Werror= support for -D_FORTIFY_SOURCE /
                    __builtin___memcpy_chk
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: nnk@google.com


When compiling with -D_FORTIFY_SOURCE=1, its possible for gcc to detect, at
compile time, certain buffer overflows. This behavior is documented on the gcc
online documentation at
http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html

Currently, the only way to turn these compile warnings into errors is to enable
-Werror. Unfortunately, -Werror turns EVERY warning into an error, catching
unrelated warnings.

Can you please add a -Werror= option to error out on compile time buffer
overflow problems? Perhaps -Werror=array-bounds could be reused for this?

These error messages are generated in gcc/builtins.c (expand_builtin_memory_chk
is one such function).