[flang][Semantics] set scope even for module subroutines outside modules

[tblah]

The missing scope information led to a crash in OpenMP semantic checks run before printing the error that was already discovered in the code.

The following block has to be skipped for this invalid code so that we don't emit a second spurious error.

Fixes #82913

[llvmbot]

@llvm/pr-subscribers-flang-semantics

@llvm/pr-subscribers-flang-openmp

Author: Tom Eccles (tblah)

Changes

The missing scope information led to a crash in OpenMP semantic checks run before printing the error that was already discovered in the code.

The following block has to be skipped for this invalid code so that we don't emit a second spurious error.

Fixes #82913

---

Full diff: https://github.com/llvm/llvm-project/pull/109009.diff

2 Files Affected:

• (modified) flang/lib/Semantics/resolve-names.cpp (+5-2)
• (added) flang/test/Semantics/OpenMP/bad_module_subroutine.f90 (+6)

diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
index d8f601212d8d01..eb57ae7a64ec16 100644
--- a/flang/lib/Semantics/resolve-names.cpp
+++ b/flang/lib/Semantics/resolve-names.cpp
@@ -4344,15 +4344,18 @@ bool SubprogramVisitor::BeginSubprogram(const parser::Name &name,
     Symbol::Flag subpFlag, bool hasModulePrefix,
     const parser::LanguageBindingSpec *bindingSpec,
     const ProgramTree::EntryStmtList *entryStmts) {
+  bool isValid{true};
   if (hasModulePrefix && !currScope().IsModule() &&
       !currScope().IsSubmodule()) { // C1547
     Say(name,
         "'%s' is a MODULE procedure which must be declared within a "
         "MODULE or SUBMODULE"_err_en_US);
-    return false;
+    // Don't return here because it can be useful to have the scope set for
+    // other semantic checks run before we print the errors
+    isValid = false;
   }
   Symbol *moduleInterface{nullptr};
-  if (hasModulePrefix && !inInterfaceBlock()) {
+  if (isValid && hasModulePrefix && !inInterfaceBlock()) {
     moduleInterface = FindSeparateModuleProcedureInterface(name);
     if (moduleInterface && &moduleInterface->owner() == &currScope()) {
       // Subprogram is MODULE FUNCTION or MODULE SUBROUTINE with an interface
diff --git a/flang/test/Semantics/OpenMP/bad_module_subroutine.f90 b/flang/test/Semantics/OpenMP/bad_module_subroutine.f90
new file mode 100644
index 00000000000000..339d6bf27e7dfd
--- /dev/null
+++ b/flang/test/Semantics/OpenMP/bad_module_subroutine.f90
@@ -0,0 +1,6 @@
+! RUN: %python %S/../test_errors.py %s %flang_fc1 -fopenmp
+! Test that we don't crash on this code inside of openmp semantics checks
+
+!ERROR: 'e' is a MODULE procedure which must be declared within a MODULE or SUBMODULE
+impure elemental module subroutine e()
+end subroutine

[Thirumalai-Shaktivel]

LGTM!