| Message ID | 096cf240-55e1-37e1-2810-0594a76492c0@mentor.com |
|---|---|
| State | New |
| Headers | show |
| Series | [testsuite,committed] Compile strncpy-fix-1.c with -Wno-stringop-truncation | expand |
On 11/15/2017 08:12 AM, Tom de Vries wrote: > [ Re: [PATCH 3/4] enhance overflow and truncation detection in strncpy > and strncat (PR 81117) ] > > On 08/06/2017 10:07 PM, Martin Sebor wrote: >> Part 3 of the series contains the meat of the patch: the new >> -Wstringop-truncation option, and enhancements to -Wstringop- >> overflow, and -Wpointer-sizeof-memaccess to detect misuses of >> strncpy and strncat. >> >> Martin >> >> gcc-81117-3.diff >> >> >> PR c/81117 - Improve buffer overflow checking in strncpy >> > >> gcc/testsuite/ChangeLog: >> >> PR c/81117 >> * c-c++-common/Wsizeof-pointer-memaccess3.c: New test. >> * c-c++-common/Wstringop-overflow.c: Same. >> * c-c++-common/Wstringop-truncation.c: Same. >> * c-c++-common/Wsizeof-pointer-memaccess2.c: Adjust. >> * c-c++-common/attr-nonstring-2.c: New test. >> * g++.dg/torture/Wsizeof-pointer-memaccess1.C: Adjust. >> * g++.dg/torture/Wsizeof-pointer-memaccess2.C: Same. >> * gcc.dg/torture/pr63554.c: Same. >> * gcc.dg/Walloca-1.c: Disable macro tracking. >> > > Hi, > > this also caused a regression in strncpy-fix-1.c. I noticed it for nvptx > (but I also saw it in other test results, f.i. for > x86_64-unknown-freebsd12.0 at > https://gcc.gnu.org/ml/gcc-testresults/2017-11/msg01276.html ). > > On linux you don't see this unless you add -Wsystem-headers: Yes, some Glibc versions (I think 2.24 and prior) define strncpy as a macro. The macro has been removed from newer versions, which makes the warning show up inconsistently. I test on Fedora 25 with the older Glibc so I don't see all these warnings. I'm tracking the problem bug 82944. > ... > $ gcc src/gcc/testsuite/gcc.dg/strncpy-fix-1.c > -fno-diagnostics-show-caret -fdiagnostics-color=never -O2 -Wall > -Wsystem-headers -S -o strncpy-fix-1.s > In file included from /usr/include/string.h:630, > from src/gcc/testsuite/gcc.dg/strncpy-fix-1.c:6: > src/gcc/testsuite/gcc.dg/strncpy-fix-1.c: In function ‘f’: > src/gcc/testsuite/gcc.dg/strncpy-fix-1.c:10:3: warning: > ‘__builtin_strncpy’ output truncated before terminating nul copying 2 > bytes from a string of the same length [-Wstringop-truncation] > ... > > Fixed by adding -Wno-stringop-truncation. > > Committed as obvious. Thanks Martin
Compile strncpy-fix-1.c with -Wno-stringop-truncation 2017-11-15 Tom de Vries <tom@codesourcery.com> * gcc.dg/strncpy-fix-1.c: Add -Wno-stringop-truncation to dg-options. --- gcc/testsuite/gcc.dg/strncpy-fix-1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gcc/testsuite/gcc.dg/strncpy-fix-1.c b/gcc/testsuite/gcc.dg/strncpy-fix-1.c index b8bc916..b4fd4aa 100644 --- a/gcc/testsuite/gcc.dg/strncpy-fix-1.c +++ b/gcc/testsuite/gcc.dg/strncpy-fix-1.c @@ -1,7 +1,7 @@ /* Test that use of strncpy does not result in a "value computed is not used" warning. */ /* { dg-do compile } */ -/* { dg-options "-O2 -Wall" } */ +/* { dg-options "-O2 -Wall -Wno-stringop-truncation" } */ #include <string.h> void