R9: Addressing review comments

Author: anchuraj

flang/include/flang/Semantics/symbol.h

@@ -755,7 +755,7 @@ class Symbol {
       OmpDeclarativeAllocateDirective, OmpExecutableAllocateDirective,
       OmpDeclareSimd, OmpDeclareTarget, OmpThreadprivate, OmpDeclareReduction,
       OmpFlushed, OmpCriticalLock, OmpIfSpecified, OmpNone, OmpPreDetermined,
-      OmpImplicit, OmpDependObject);
+      OmpImplicit, OmpDependObject, OmpInclusiveScan, OmpExclusiveScan);
   using Flags = common::EnumSet<Flag, Flag_enumSize>;
 
   const Scope &owner() const { return *owner_; }

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

@@ -981,14 +981,12 @@ void OmpStructureChecker::Leave(const parser::OpenMPLoopConstruct &x) {
   // 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.
-
   for (const auto &clause : clauseList.v) {
     if (const auto *reductionClause{
             std::get_if<parser::OmpClause::Reduction>(&clause.u)}) {
       const auto &maybeModifier{
           std::get<std::optional<ReductionModifier>>(reductionClause->v.t)};
       if (maybeModifier && *maybeModifier == ReductionModifier::Inscan) {
-
         const auto &objectList{
             std::get<parser::OmpObjectList>(reductionClause->v.t)};
         auto checkReductionSymbolInScan = [&](const parser::Name *name) {

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

@@ -75,11 +75,10 @@ class OmpStructureChecker
   using ReductionModifier = parser::OmpReductionClause::ReductionModifier;
   using Symbol = Fortran::semantics::Symbol;
   class ScanReductionInfo {
-
-  public:
-    std::set<Symbol *> usedInScanDirective;
+    std::set<Symbol *> usedInScan;
     std::map<Symbol *, ReductionModifier> reductionMod;
 
+  public:
     void mapSymbolsToReductionModifiers(
         const parser::OmpObjectList &x, const ReductionModifier &modifier) {
       for (const auto &ompObject : x.v) {
@@ -92,11 +91,11 @@ class OmpStructureChecker
     }
 
     void markSymbolAsUsedInScanConstruct(Symbol *sym) {
-      usedInScanDirective.insert(sym);
+      usedInScan.insert(sym);
     }
 
     bool findSymbolInScanConstruct(Symbol *sym) {
-      if (usedInScanDirective.find(sym) != usedInScanDirective.end()) {
+      if (usedInScan.find(sym) != usedInScan.end()) {
         return true;
       }
       return false;

flang/lib/Semantics/resolve-directives.cpp

@@ -21,7 +21,6 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
-#include <iostream>
 #include <list>
 #include <map>
 #include <sstream>
@@ -459,16 +458,12 @@ class OmpAttributeVisitor : DirectiveAttributeVisitor<llvm::omp::Directive> {
   }
 
   // 2.15.3 Data-Sharing Attribute Clauses
-  void ResolveNames(const parser::OmpObjectList &objList);
-
   bool Pre(const parser::OmpClause::Inclusive &x) {
-    const auto &objectList{x.v};
-    ResolveNames(objectList);
+    ResolveOmpObjectList(x.v, Symbol::Flag::OmpInclusiveScan);
     return false;
   }
   bool Pre(const parser::OmpClause::Exclusive &x) {
-    const auto &objectList{x.v};
-    ResolveNames(objectList);
+    ResolveOmpObjectList(x.v, Symbol::Flag::OmpExclusiveScan);
     return false;
   }
   void Post(const parser::OmpDefaultClause &);
@@ -705,8 +700,9 @@ class OmpAttributeVisitor : DirectiveAttributeVisitor<llvm::omp::Directive> {
       Symbol::Flag::OmpUseDevicePtr, Symbol::Flag::OmpUseDeviceAddr,
       Symbol::Flag::OmpIsDevicePtr, Symbol::Flag::OmpHasDeviceAddr};
 
-  Symbol::Flags ompFlagsRequireMark{
-      Symbol::Flag::OmpThreadprivate, Symbol::Flag::OmpDeclareTarget};
+  Symbol::Flags ompFlagsRequireMark{Symbol::Flag::OmpThreadprivate,
+      Symbol::Flag::OmpDeclareTarget, Symbol::Flag::OmpExclusiveScan,
+      Symbol::Flag::OmpInclusiveScan};
 
   Symbol::Flags dataCopyingAttributeFlags{
       Symbol::Flag::OmpCopyIn, Symbol::Flag::OmpCopyPrivate};
@@ -2970,19 +2966,4 @@ void OmpAttributeVisitor::IssueNonConformanceWarning(
   context_.Warn(common::UsageWarning::OpenMPUsage, source, "%s"_warn_en_US,
       warnStrOS.str());
 }
-void OmpAttributeVisitor::ResolveNames(const parser::OmpObjectList &objList) {
-  for (const auto &ompObj : objList.v) {
-    common::visit(
-        common::visitors{
-            [&](const parser::Designator &designator) {
-              if (const auto *name{
-                      semantics::getDesignatorNameIfDataRef(designator)}) {
-                ResolveName(name);
-              }
-            },
-            [&](const auto &name) { ResolveName(&name); },
-        },
-        ompObj.u);
-  }
-}
 } // namespace Fortran::semantics

flang/test/Semantics/OpenMP/scan1.f90

@@ -0,0 +1,33 @@
+! RUN: %python %S/../test_errors.py %s %flang_fc1 -fopenmp
+
+subroutine test_scan()
+ integer x, y, k, z
+ 
+ !ERROR: Orphaned SCAN directives are prohibited; perhaps you forgot to enclose the directive in to a WORKSHARING LOOP, a WORKSHARING LOOP SIMD or a SIMD directive.
+ !$omp scan inclusive(x)
+ !$omp parallel do simd
+ do k = 1, n
+ !ERROR: UNTIED clause is not allowed on the SCAN directive
+   !$omp scan untied
+ end do
+ 
+ !$omp parallel do simd
+ do k = 1, n
+ !ERROR: Exactly one of EXCLUSIVE or INCLUSIVE clause is expected
+   !$omp scan
+ end do
+
+!$omp parallel do simd reduction(inscan,+: x, y)
+ do k = 1, n
+ !ERROR: Exactly one of EXCLUSIVE or INCLUSIVE clause is expected
+   !$omp scan inclusive(x) exclusive(y)
+ end do
+
+!ERROR: List item y must appear in EXCLUSIVE or INCLUSIVE clause of an enclosed SCAN directive
+!$omp parallel do simd reduction(inscan,+: x, y)
+ do k = 1, n
+ !ERROR: Exactly one of EXCLUSIVE or INCLUSIVE clause is expected
+ !ERROR: List item z must appear in REDUCTION clause with the INSCAN modifier of the parent directive
+   !$omp scan inclusive(x) exclusive(z)
+ end do
+end subroutine

flang/test/Semantics/OpenMP/scan2.f90

@@ -0,0 +1,27 @@
+! RUN: %flang_fc1 -fopenmp -fdebug-dump-symbols -o - %s 2>&1 | FileCheck %s
+! Check scan reduction
+
+! CHECK: MainProgram scope: omp_reduction
+program omp_reduction
+  ! CHECK: i size=4 offset=0: ObjectEntity type: INTEGER(4)
+  integer i
+  ! CHECK: k size=4 offset=4: ObjectEntity type: INTEGER(4) init:10_4
+  integer :: k = 10
+  ! CHECK: m size=4 offset=8: ObjectEntity type: INTEGER(4) init:12_4
+  integer :: m = 12
+
+  ! CHECK: OtherConstruct scope
+  ! CHECK: i (OmpPrivate, OmpPreDetermined): HostAssoc
+  ! CHECK: k (OmpReduction, OmpInclusiveScan): HostAssoc
+  !$omp parallel do  reduction(inscan, +:k)
+  do i=1,10
+   !$omp scan inclusive(k)
+  end do
+  !$omp end parallel do
+  ! CHECK: m (OmpReduction, OmpExclusiveScan): HostAssoc
+  !$omp parallel do  reduction(inscan, +:m)
+  do i=1,10
+   !$omp scan exclusive(m)
+  end do
+  !$omp end parallel do
+end program omp_reduction