[Lldb-commits] [clang] [lldb] [clang][AST] fix ast-print of extern <lang> with >=2 declarators, fixed (PR #93913)

[Artem Yurchenko via lldb-commits]

================
@@ -2380,7 +2380,7 @@ FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
   }
 
   FunctionDecl *New = FunctionDecl::Create(Context, Parent, Loc, Loc, II, Type,
-                                           /*TInfo=*/nullptr, SC_Extern,
+                                           /*TInfo=*/nullptr, SC_None,
----------------
temyurchenko wrote:

> That's not actually correct -- the declaration of a function at block scope should definitely _not_ be extern, it should have no linkage: https://godbolt.org/z/81fMaPaTq

I may be wrong to rely on cppreference, but the following page tells that indeed a function at a block scope has implicit `extern`, which could also be made explicit: https://en.cppreference.com/w/c/language/storage_duration.

I also checked your example locally by compiling (via clang) `main.c` with an additional `defs.c`: 
main.c:
```c
int main(void) {
  void f();
  extern void g();

  f();
  g();

  return 0;
}
```

defs.c: 
```c
#include <stdio.h>

void f() {
  printf("f\n");
}

void g() {
  printf("g\n");
}

```

The executable works as expected. 

I will also take a look at the C99 standard draft. 

https://github.com/llvm/llvm-project/pull/93913