R4: Addressing review comments

Author: anchuraj

flang/include/flang/Semantics/openmp-directive-sets.h

@@ -187,15 +187,17 @@ static const OmpDirectiveSet allTeamsSet{
 // Directive sets for groups of multiple directives
 //===----------------------------------------------------------------------===//
 
-// Composite constructs
+// Directive sets for parent directives that do allow/not allow a construct
+static const OmpDirectiveSet scanAllowedSet{allDoSet | allSimdSet};
+
+// Directive sets that form Composite constructs
 static const OmpDirectiveSet allDistributeParallelDoSet{
     allDistributeSet & allParallelSet & allDoSet};
 static const OmpDirectiveSet allDistributeParallelDoSimdSet{
     allDistributeSet & allParallelSet & allDoSet & allSimdSet};
 static const OmpDirectiveSet allDistributeSimdSet{
     allDistributeSet & allSimdSet};
 static const OmpDirectiveSet allDoSimdSet{allDoSet & allSimdSet};
-static const OmpDirectiveSet scanAllowedSet{allDoSet | allSimdSet};
 static const OmpDirectiveSet allTaskloopSimdSet{allTaskloopSet & allSimdSet};
 
 static const OmpDirectiveSet compositeConstructSet{

flang/lib/Semantics/resolve-directives.cpp

@@ -1639,12 +1639,12 @@ bool OmpAttributeVisitor::Pre(
     break;
   }
   if (standaloneDir.v == llvm::omp::Directive::OMPD_scan) {
-    if ((std::get<parser::OmpClauseList>(x.t).v.size() != 1)) {
+    if (std::get<parser::OmpClauseList>(x.t).v.size() != 1) {
       context_.Say(standaloneDir.source,
           "Exactly one of `exclusive` or `inclusive` clause is expected"_err_en_US);
     }
     if (!parentContext ||
-        (!llvm::omp::scanAllowedSet.test(parentContext->directive))) {
+        !llvm::omp::scanAllowedSet.test(parentContext->directive)) {
       context_.Say(standaloneDir.source,
           "Orphaned `omp scan` directives are prohibited; perhaps you forgot "
           "to enclose the directive in to a worksharing loop, a worksharing "

flang/test/Parser/OpenMP/scan.f90

@@ -32,7 +32,7 @@ subroutine test_scan(n, a, b)
     x = x + a(k)
   end do
 
-  !$omp parallel do simd reduction(inscan,+: x)
+  !$omp parallel do simd reduction(inscan,+: x, y)
   do k = 1, n
     x = x + a(k)
     !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPStandaloneConstruct -> OpenMPSimpleStandaloneConstruct
@@ -44,7 +44,7 @@ subroutine test_scan(n, a, b)
       b(k) = x
   end do
 
-  !$omp parallel do simd reduction(inscan,+: x)
+  !$omp parallel do simd reduction(inscan,+: x, y)
   do k = 1, n
     x = x + a(k)
     !PARSE-TREE: ExecutionPartConstruct -> ExecutableConstruct -> OpenMPConstruct -> OpenMPStandaloneConstruct -> OpenMPSimpleStandaloneConstruct

flang/test/Semantics/OpenMP/out

@@ -17,7 +17,7 @@ subroutine test_scan()
    !$omp scan
  end do
 
-!$omp parallel do simd reduction(inscan,+: x)
+!$omp parallel do simd reduction(inscan,+: x, y)
  do k = 1, n
  !ERROR: Exactly one of `exclusive` or `inclusive` clause is expected
    !$omp scan inclusive(x) exclusive(y)