[flang-commits] [flang] [flang] A module that USEs itself directly in its specification part … (PR #228489)

[Eugene Epshteyn via flang-commits]

================
@@ -4916,7 +4916,8 @@ Scope *ModuleVisitor::FindModule(const parser::Name &name,
   Scope *scope{
       reader.Read(name.source, isIntrinsic, ancestor, /*silent=*/false)};
   if (scope) {
-    if (DoesScopeContain(scope, currScope())) { // 14.2.2(1)
+    if (DoesScopeContain(scope, currScope()) ||
+        scope->Contains(currScope())) { // 14.2.2(1)
----------------
eugeneepshteyn wrote:

(This comment was generated with the help of AI)

The second reproducer in issue 227340 still gets the misleading message the issue describes, now in addition to the new error:

```fortran
module m1
  use m1, only: y
  integer :: y = 1
end module m1
```

```console
$ flang -fsyntax-only repro2.f90
error: Semantic errors in repro2.f90
repro2.f90:2:7: error: Module 'm1' cannot USE itself
    use m1, only: y
        ^^
repro2.f90:2:17: error: 'y' not found in module 'm1'
    use m1, only: y
                  ^
```

I'd suggest suppressing only the "'%s' not found in module '%s'" error in `ModuleVisitor::AddUse` when `useModuleScope_` contains the current scope, because that USE has already been reported here. 

https://github.com/llvm/llvm-project/pull/228489