"error: identifier 'line' after '~' in destructor name does not name a type" in struct line that has line member

[nabijaczleweli]

#include <string_view>

struct line {
	std::string_view line;
	~line() {
		line = {};
	}
};

trunk returns

<source>:5:3: error: identifier 'line' after '~' in destructor name does not name a type

cmd/join.cpp:49:5: error: identifier 'line' after '~' in destructor name does not name a type
   49 |                         ~line() {
      |                          ^~~~
      |                          line
cmd/join.cpp:32:21: note: non-type declaration found by destructor name lookup
   32 |                         std::string_view line;
      |                                          ^

older versions return

<source>:5:3: error: expected the class name after '~' to name a destructor

All GCC versions accept this.

Don't particularly see why the member would factor into the lookup at all here, but it's not like I can call this ~(struct line)() { or ~struct line() {.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: наб (nabijaczleweli)

```cpp #include <string_view>

struct line {
std::string_view line;
~line() {
line = {};
}
};

trunk returns
> <source>:5:3: error: identifier 'line' after '~' in destructor name does not name a type

cmd/join.cpp:49:5: error: identifier 'line' after '~' in destructor name does not name a type
49 | ~line() {
| ^~~~
| line
cmd/join.cpp:32:21: note: non-type declaration found by destructor name lookup
32 | std::string_view line;
| ^

older versions return
> <source>:5:3: error: expected the class name after '~' to name a destructor

All GCC versions accept this.

Don't particularly see why the member would factor into the lookup at all here, but it's not like I can call this `~(struct line)() {` or `~struct line() {`.
</details>

[shafik]

Reduced: https://godbolt.org/z/EeGn5vTrY

struct line {
	int line;
	~line();
};

It looks like rule here is set by cwg80:

In addition, if class T has a user-declared constructor (11.4.5 [class.ctor] ), every nonstatic data member of class T shall have a name different from T.

see class.mem.general p24

So this applies to constructors but not destructors.

We handle this here:

llvm-project/clang/lib/Sema/SemaExprCXX.cpp

Lines 451 to 453 in aef2810

	Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype
	: diag::err_destructor_expr_mismatch)
	<< &II << SearchType << MakeFixItHint();

I think we need to handle the case where FoundDecls.size() == 2 and it is non-static data member.

[nabijaczleweli]

In this case it looks like this is FoundDecls.size() == 1 and SearchType.isNull().