Ping: https://gcc.gnu.org/pipermail/gcc-patches/2020-October/555225.html
On 10/8/20 8:43 AM, Martin Sebor wrote:
Ping: https://gcc.gnu.org/pipermail/gcc-patches/2020-October/555225.html
On 9/30/20 6:14 PM, Martin Sebor wrote:
-Wstring-compare triggers under the same strict conditions as
the strcmp/strncmp call is folded into a constant: only when
all the uses of the result are [in]equality expressions with
zero. However, even when the call cannot be folded into
a constant because the result is in addition used in other
expressions besides equality to zero, GCC still sets the range
of the result to nonzero. So in more complex functions where
some of the uses of the same result are in tests for equality
to zero and others in other expressions, the warning fails to
point out the very mistake it's designed to detect.
The attached change enhances the function that determines how
the strcmp/strncmp is used to also make it possible to detect
the mistakes in the multi-use situations.
Tested on x86_64-linux & by building Glibc and Binutils/GDB
and confirming it triggers no new warnings.
Martin
