[flang][OpenMP] Extract check into separate function, NFC (llvm#170728)

Author: kparzysz

flang/lib/Semantics/check-omp-loop.cpp

@@ -588,50 +588,52 @@ void OmpStructureChecker::CheckNestedFuse(
   }
 }
 
+void OmpStructureChecker::CheckScanModifier(
+    const parser::OmpClause::Reduction &x) {
+  using ReductionModifier = parser::OmpReductionModifier;
+
+  auto checkReductionSymbolInScan{[&](const parser::Name &name) {
+    if (auto *symbol{name.symbol}) {
+      if (!symbol->test(Symbol::Flag::OmpInclusiveScan) &&
+          !symbol->test(Symbol::Flag::OmpExclusiveScan)) {
+        context_.Say(name.source,
+            "List item %s must appear in EXCLUSIVE or INCLUSIVE clause of an enclosed SCAN directive"_err_en_US,
+            name.ToString());
+      }
+    }
+  }};
+
+  auto &modifiers{OmpGetModifiers(x.v)};
+  auto *maybeModifier{OmpGetUniqueModifier<ReductionModifier>(modifiers)};
+  if (maybeModifier && maybeModifier->v == ReductionModifier::Value::Inscan) {
+    for (const auto &ompObj : parser::omp::GetOmpObjectList(x)->v) {
+      common::visit(
+          common::visitors{
+              [&](const parser::Designator &desg) {
+                if (auto *name{parser::GetDesignatorNameIfDataRef(desg)}) {
+                  checkReductionSymbolInScan(*name);
+                }
+              },
+              [&](const parser::Name &name) {
+                checkReductionSymbolInScan(name);
+              },
+              [&](const parser::OmpObject::Invalid &invalid) {},
+          },
+          ompObj.u);
+    }
+  }
+}
+
 void OmpStructureChecker::Leave(const parser::OpenMPLoopConstruct &x) {
   const parser::OmpClauseList &clauseList{x.BeginDir().Clauses()};
 
   // A few semantic checks for InScan reduction are performed below as SCAN
   // constructs inside LOOP may add the relevant information. Scan reduction is
   // supported only in loop constructs, so same checks are not applicable to
   // other directives.
-  using ReductionModifier = parser::OmpReductionModifier;
   for (const auto &clause : clauseList.v) {
-    if (const auto *reductionClause{
-            std::get_if<parser::OmpClause::Reduction>(&clause.u)}) {
-      auto &modifiers{OmpGetModifiers(reductionClause->v)};
-      auto *maybeModifier{OmpGetUniqueModifier<ReductionModifier>(modifiers)};
-      if (maybeModifier &&
-          maybeModifier->v == ReductionModifier::Value::Inscan) {
-        auto checkReductionSymbolInScan = [&](const parser::Name *name) {
-          if (auto &symbol = name->symbol) {
-            if (!symbol->test(Symbol::Flag::OmpInclusiveScan) &&
-                !symbol->test(Symbol::Flag::OmpExclusiveScan)) {
-              context_.Say(name->source,
-                  "List item %s must appear in EXCLUSIVE or "
-                  "INCLUSIVE clause of an "
-                  "enclosed SCAN directive"_err_en_US,
-                  name->ToString());
-            }
-          }
-        };
-        for (const auto &ompObj : parser::omp::GetOmpObjectList(clause)->v) {
-          common::visit(
-              common::visitors{
-                  [&](const parser::Designator &designator) {
-                    if (const auto *name{
-                            parser::GetDesignatorNameIfDataRef(designator)}) {
-                      checkReductionSymbolInScan(name);
-                    }
-                  },
-                  [&](const parser::Name &name) {
-                    checkReductionSymbolInScan(&name);
-                  },
-                  [&](const parser::OmpObject::Invalid &invalid) {},
-              },
-              ompObj.u);
-        }
-      }
+    if (auto *reduction{std::get_if<parser::OmpClause::Reduction>(&clause.u)}) {
+      CheckScanModifier(*reduction);
     }
   }
   if (llvm::omp::allSimdSet.test(GetContext().directive)) {

flang/lib/Semantics/check-omp-structure.h

@@ -321,6 +321,7 @@ class OmpStructureChecker : public OmpStructureCheckerBase {
   void CheckAtomicWrite(const parser::OpenMPAtomicConstruct &x);
   void CheckAtomicUpdate(const parser::OpenMPAtomicConstruct &x);
 
+  void CheckScanModifier(const parser::OmpClause::Reduction &x);
   void CheckLooprangeBounds(const parser::OpenMPLoopConstruct &x);
   void CheckNestedFuse(const parser::OpenMPLoopConstruct &x);
   void CheckDistLinear(const parser::OpenMPLoopConstruct &x);