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[Bug gcov-profile/83505] New: [GCOV] a pointer assignment before label lead to incorrect coverage in gcov
- From: "yangyibiao at nju dot edu.cn" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 20 Dec 2017 06:31:50 +0000
- Subject: [Bug gcov-profile/83505] New: [GCOV] a pointer assignment before label lead to incorrect coverage in gcov
- Auto-submitted: auto-generated
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83505
Bug ID: 83505
Summary: [GCOV] a pointer assignment before label lead to
incorrect coverage in gcov
Product: gcc
Version: 7.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: gcov-profile
Assignee: unassigned at gcc dot gnu.org
Reporter: yangyibiao at nju dot edu.cn
CC: marxin at gcc dot gnu.org
Target Milestone: ---
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.2.0-8ubuntu3'
--with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-7
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie
--with-system-zlib --with-target-system-zlib --enable-objc-gc=auto
--enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64
--with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none --without-cuda-driver
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 7.2.0 (Ubuntu 7.2.0-8ubuntu3)
$ cat small.c
int main()
{
int t = 1;
int *p = &t;
lbl:
if (t > 0) {
if (0)
return 0;
if (0)
goto lbl;
return 1;
}
}
$ gcc small.c -fprofile-arcs -ftest-coverage; ./a.out; gcov small.c; cat
small.c.gcov
File 'small.c'
Lines executed:100.00% of 7
Creating 'small.c.gcov'
-: 0:Source:small.c
-: 0:Graph:small.gcno
-: 0:Data:small.gcda
-: 0:Runs:1
-: 0:Programs:1
1: 1:int main()
-: 2:{
1: 3: int t = 1;
1: 4: int *p = &t;
1: 5:lbl:
1: 6: if (t > 0) {
-: 7: if (0)
1: 8: return 0;
-: 9: if (0)
-: 10: goto lbl;
1: 11: return 1;
-: 12: }
-: 13:}
Line #8 is wrongly marked as executed. It is obvious that it is not executed
since it is in the if false statement.
While removing Line #4, the result is correct.