https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81714
Bug ID: 81714
Summary: incorrect location for uninitialised variable
Product: gcc
Version: 7.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: akim.demaille at gmail dot com
Target Milestone: ---
Hi,
This seems to be different from #55874 and #60350, but I might be wrong. The
caret-display makes it particularly visible. This affects GCC 4.9, 5.4.0,
6.3.0, and 7.1.1.
$ cat /tmp/foo.cc
int main()
{
int i;
return i + 42;
}
$ g++-mp-7 -Wall /tmp/foo.cc
/tmp/foo.cc: In function 'int main()':
/tmp/foo.cc:4:14: warning: 'i' is used uninitialized in this function
[-Wuninitialized]
return i + 42;
^~
$ gcc-mp-7 --version
gcc-mp-7 (MacPorts gcc7 7-20170622_0) 7.1.
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$ g++-mp-6 -Wall /tmp/foo.cc
/tmp/foo.cc: In function 'int main()':
/tmp/foo.cc:4:14: warning: 'i' is used uninitialized in this function
[-Wuninitialized]
return i + 42;
^~
$ g++-mp-5 -Wall /tmp/foo.cc
/tmp/foo.cc: In function 'int main()':
/tmp/foo.cc:4:14: warning: 'i' is used uninitialized in this function
[-Wuninitialized]
return i + 42;
^
$ g++-mp-4.9 -Wall /tmp/foo.cc
/tmp/foo.cc: In function 'int main()':
/tmp/foo.cc:4:14: warning: 'i' is used uninitialized in this function
[-Wuninitialized]
return i + 42;
^
In C mode, GCC is not affected, but the location is not very accurate either.
$ cat /tmp/foo.c
int main()
{
int i;
return i + 42;
}
$ gcc-mp-7 -Wall /tmp/foo.c
/tmp/foo.c: In function 'main':
/tmp/foo.c:4:12: warning: 'i' is used uninitialized in this function
[-Wuninitialized]
return i + 42;
~~^~~~
It seems somewhat specific to this particular warning.
$ cat /tmp/foo.cc
int main()
{
[[deprecated]]
int a;
return 1 + a;
}
$ g++-mp-7 -Wall /tmp/foo.cc -std=c++14
/tmp/foo.cc: In function 'int main()':
/tmp/foo.cc:5:14: warning: 'a' is deprecated [-Wdeprecated-declarations]
return 1 + a;
^
/tmp/foo.cc:4:9: note: declared here
int a;
^
/tmp/foo.cc:5:14: warning: 'a' is used uninitialized in this function
[-Wuninitialized]
return 1 + a;
^
Cheers!
