https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101090
Bug ID: 101090
Summary: incorrect -Wunused-value warning on remquo with
constant values
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: vincent-gcc at vinc17 dot net
Target Milestone: ---
When remquo is used with constant values, GCC emits the following warning:
warning: right-hand operand of comma expression has no effect [-Wunused-value]
According to the following testcase compiled with the "-Wunused-value -c"
options, the warning is obtained only for f2, i.e. is does not occur when the
function is not called remquo or when non-constant values are used.
double r (double, double, int *);
double remquo (double, double, int *);
int f1 (void)
{
int quo;
r (1.0, 3.0, &quo);
return quo;
}
int f2 (void)
{
int quo;
remquo (1.0, 3.0, &quo);
return quo;
}
int f3 (double x, double y)
{
int quo;
remquo (x, y, &quo);
return quo;
}
Testcase also available on https://godbolt.org/z/Px44sxn4h for testing, where I
can see that this bug was introduced in GCC 9.1.0 and is still present in the
trunk.
