https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112867
Bug ID: 112867
Summary: extern function declaration in function scope behaves
differently in template
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: a.elovikov at gmail dot com
Target Milestone: ---
#ifdef GOOD
auto foo(int x)
#else
template <typename T0>
auto foo(T0 x)
#endif
{
return [](auto xs) {
extern int bar(decltype(xs));
return bar(xs);
}(x);
}
auto test(int x) { return foo(x); }
Fails like this (no options, https://godbolt.org/z/1EGsK75bW):
<source>: In instantiation of 'foo<int>(int)::<lambda(auto:1)> [with auto:1 =
int]':
<source>:11:6: required from 'auto foo(T0) [with T0 = int]'
8 | return [](auto xs) {
| ~~~~~~~~~~~~~
9 | extern int bar(decltype(xs));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 | return bar(xs);
| ~~~~~~~~~~~~~~~
11 | }(x);
| ~^~~
<source>:14:30: required from here
14 | auto test(int x) { return foo(x); }
| ~~~^~~
<source>:10:19: error: 'bar' was not declared in this scope
10 | return bar(xs);
| ~~~^~~~
Compiler returned: 1
Passes with -DGOOD (https://godbolt.org/z/dn8rzGMae).
