https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79021
Bug ID: 79021
Summary: attribute noreturn on function template ignored in
generic lambda
Product: gcc
Version: 6.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: akim.demaille at gmail dot com
Target Milestone: ---
When a generic lambda calls a function templates declared noreturn, we still
get warnings about missing return values.
$ cat foo.cc
template <typename T>
[[noreturn]]
int f(T)
{
throw "error";
}
int g()
{
f(12);
}
template <typename T>
int h(T)
{
f(12);
}
int main()
{
auto g = [](auto a) -> int { f(a); };
}
$ g++-mp-6 --version
g++-mp-6 (MacPorts gcc6 6.2.0_2) 6.2.0
Copyright (C) 2016 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 -std=c++14 foo.cc -Wreturn-type
foo.cc: In lambda function:
foo.cc:21:38: warning: no return statement in function returning non-void
[-Wreturn-type]
auto g = [](auto a) -> int { f(a); };
^
$ clang++-mp-3.9 -std=c++14 foo.cc -Wreturn-type
$
Please note that:
- if f is not templated, there is no warning
- if the lambda is not generic, there is no warning
- if calling from a function template rather than from a generic template
(i.e., the function h), it does not trigger any warning (even if I do use h).
