clang allows looser exception specification in explicit template instantiation

[alexey-bataev]

Bugzilla Link	14297
Version	trunk
OS	MacOS X
CC	@DougGregor

Extended Description

According to 15.4p3 "If any declaration of a function has an exception-specification, all declarations, including the definition and an explicit
specialization, of that function shall have an exception-specification with the same set of type-ids".

Clang does not generate error message for the following example

struct SomeStruct{};
template void Foo(T i) throw(T) { throw i; }
template void Foo(int a) throw (char); // explicit instantiation, argument is deduced. Wrong exception specification is provided

int main() {
try {
SomeStruct slawa;
Foo(slawa);
}
catch(...) { ;}
return(0);
}

clang++ -c test.cpp

Alexey Bataev
Software Engineer
Intel Compiler Team
Intel Corp.

[xgupta]

This issue seems to be fixed on trunk - https://godbolt.org/z/hse5v8Y8K

<source>:3:10: error: exception specification in explicit instantiation does not match instantiated one
    3 | template void Foo(int a) throw (char);  // explicit instantiation, argument is deduced. Wrong exception specification is provided
      |          ^
<source>:2:25: note: explicit instantiation refers here
    2 | template <class T> void Foo(T i) throw(T) { throw i; }
      |