https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71743
Bug ID: 71743
Summary: return with no value cannot be ignored [Possible
regression or undocumented change on
https://gcc.gnu.org/onlinedocs/gcc-5.4.0/gcc/Warning-O
ptions.html#Warning-Options]
Product: gcc
Version: 5.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: bastien.penavayre at epitech dot eu
Target Milestone: ---
Created attachment 38823
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38823&action=edit
gcc-4.9 -v -c test.c
Hi,
So since gcc-5, in manual at the warning section:
https://gcc.gnu.org/onlinedocs/gcc-5.4.0/gcc/Warning-Options.html#Warning-Options
and
https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/Warning-Options.html#Warning-Options
It's stated that:
"-Wreturn-type
... Also warn about any return statement with no return value in a function
whose return type is not void ... , and about a return statement with an
expression in a function whose return type is void."
The issue here is that this is not true as the following code still warns:
int func()
{
#pragma GCC diagnostic ignored "-Wreturn-type"
return ;
}
This one also :
void func()
{
#pragma GCC diagnostic ignored "-Wreturn-type"
return 42;
}
The only case where ignoring -Wreturn-type works is when :
"falling off the end of the function body is considered returning without a
value".
The first test worked as expected before gcc-5 and warns since then.
Before gcc-5 the second test warns as expected as the "a return statement with
an expression in a function whose return type is void" wasn't yet part of the
manual.
