https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120918
Bug ID: 120918
Summary: -Wreturn-type warning is confused by macro
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
Target Milestone: ---
#define assert(...) ((__VA_ARGS__) ? (void)(1?1:bool(__VA_ARGS__)) :
(void)__builtin_abort())
int f()
{
assert( []{return 1;}() );
}
GCC says:
a.cc: In function 'int f()':
a.cc:5:11: warning: control reaches end of non-void function [-Wreturn-type]
5 | assert( []{return 1;}() );
| ^~~~~~~~~~~~~
a.cc:1:23: note: in definition of macro 'assert'
1 | #define assert(...) ((__VA_ARGS__) ? (void)(1?1:bool(__VA_ARGS__)) :
(void)__builtin_abort())
| ^~~~~~~~~~~
The problem is that f() doesn't return, but the location points to the lambda
expression, which certainly does return.
Clang gets it right:
a.cc:6:1: warning: non-void function does not return a value [-Wreturn-type]
6 | }
| ^
1 warning generated.
And EDG too:
"a.cc", line 6: warning: missing return statement at end of non-void function
"f"
}
^
