http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57555
Bug ID: 57555
Summary: Warning on negation of constexpr uint8_t being
assigned to uint8_t
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: megari at mbnet dot fi
The following code produces a warning when it probably should not:
$ cat constexprbug.cpp
#include <cstdint>
uint8_t foo() {
static constexpr uint8_t foo = 0xff;
uint8_t ret = ~foo;
return ret;
}
uint8_t bar() {
static constexpr uint8_t foo = 0x00;
uint8_t ret = ~foo;
return ret;
}
int main() {
foo();
bar();
}
$ g++ -std=c++11 -o constexprbug constexprbug.cpp
constexprbug.cpp: In function ‘uint8_t foo()’:
constexprbug.cpp:6:20: warning: large integer implicitly truncated to unsigned
type [-Woverflow]
$ gcc --version
gcc (GCC) 4.7.2 20120921 (Red Hat 4.7.2-2)
Copyright (C) 2012 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.
The curious thing is that only the function foo() produces the warning. Also,
the variable needs to be constexpr for the warning to be emitted.
