Added OpenMP 5.0 specification based semantic checks for CRITICAL construct name resolution

As reported in https://bugs.llvm.org/show_bug.cgi?id=48145, name resolution for omp critical construct was failing. This patch adds functionality to help that name resolution as well as implementation to catch name mismatches.

The following semantic restrictions are therefore handled here:

- If a name is specified on a critical directive, the same name must also be specified on the end critical directive

- If no name appears on the critical directive, no name can appear on the end critical directive

- If a name appears on either the start critical directive or the end critical directive

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D110502

flang/include/flang/Parser/parse-tree.h

@@ -3594,7 +3594,7 @@ struct OpenMPDeclarativeConstruct {
 struct OmpCriticalDirective {
   TUPLE_CLASS_BOILERPLATE(OmpCriticalDirective);
   CharBlock source;
-  std::tuple<Verbatim, std::optional<Name>, std::optional<OmpClause>> t;
+  std::tuple<Verbatim, std::optional<Name>, OmpClauseList> t;
 };
 struct OmpEndCriticalDirective {
   TUPLE_CLASS_BOILERPLATE(OmpEndCriticalDirective);

flang/lib/Parser/openmp-parsers.cpp

@@ -469,7 +469,7 @@ TYPE_PARSER(startOmpLine >>
         verbatim("END CRITICAL"_tok), maybe(parenthesized(name)))) /
         endOmpLine)
 TYPE_PARSER(sourced(construct<OmpCriticalDirective>(verbatim("CRITICAL"_tok),
-                maybe(parenthesized(name)), maybe(Parser<OmpClause>{}))) /
+                maybe(parenthesized(name)), Parser<OmpClauseList>{})) /
     endOmpLine)
 
 TYPE_PARSER(construct<OpenMPCriticalConstruct>(

flang/lib/Parser/unparse.cpp

@@ -2287,7 +2287,7 @@ public:
     BeginOpenMP();
     Word("!$OMP CRITICAL");
     Walk(" (", std::get<std::optional<Name>>(x.t), ")");
-    Walk(std::get<std::optional<OmpClause>>(x.t));
+    Walk(std::get<OmpClauseList>(x.t));
     Put("\n");
     EndOpenMP();
   }

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

@@ -1024,9 +1024,39 @@ void OmpStructureChecker::Leave(const parser::OpenMPCancelConstruct &) {
 
 void OmpStructureChecker::Enter(const parser::OpenMPCriticalConstruct &x) {
   const auto &dir{std::get<parser::OmpCriticalDirective>(x.t)};
+  const auto &endDir{std::get<parser::OmpEndCriticalDirective>(x.t)};
   PushContextAndClauseSets(dir.source, llvm::omp::Directive::OMPD_critical);
   const auto &block{std::get<parser::Block>(x.t)};
   CheckNoBranching(block, llvm::omp::Directive::OMPD_critical, dir.source);
+  const auto &dirName{std::get<std::optional<parser::Name>>(dir.t)};
+  const auto &endDirName{std::get<std::optional<parser::Name>>(endDir.t)};
+  const auto &ompClause{std::get<parser::OmpClauseList>(dir.t)};
+  if (dirName && endDirName &&
+      dirName->ToString().compare(endDirName->ToString())) {
+    context_
+        .Say(endDirName->source,
+            parser::MessageFormattedText{
+                "CRITICAL directive names do not match"_err_en_US})
+        .Attach(dirName->source, "should be "_en_US);
+  } else if (dirName && !endDirName) {
+    context_
+        .Say(dirName->source,
+            parser::MessageFormattedText{
+                "CRITICAL directive names do not match"_err_en_US})
+        .Attach(dirName->source, "should be NULL"_en_US);
+  } else if (!dirName && endDirName) {
+    context_
+        .Say(endDirName->source,
+            parser::MessageFormattedText{
+                "CRITICAL directive names do not match"_err_en_US})
+        .Attach(endDirName->source, "should be NULL"_en_US);
+  }
+  if (!dirName && !ompClause.source.empty() &&
+      ompClause.source.NULTerminatedToString() != "hint(omp_sync_hint_none)") {
+    context_.Say(dir.source,
+        parser::MessageFormattedText{
+            "Hint clause other than omp_sync_hint_none cannot be specified for an unnamed CRITICAL directive"_err_en_US});
+  }
 }
 
 void OmpStructureChecker::Leave(const parser::OpenMPCriticalConstruct &) {

flang/lib/Semantics/resolve-directives.cpp

@@ -293,6 +293,8 @@ public:
 
   bool Pre(const parser::OpenMPBlockConstruct &);
   void Post(const parser::OpenMPBlockConstruct &);
+  bool Pre(const parser::OmpCriticalDirective &x);
+  bool Pre(const parser::OmpEndCriticalDirective &x);
 
   void Post(const parser::OmpBeginBlockDirective &) {
     GetContext().withinConstruct = true;
@@ -476,7 +478,7 @@ private:
   static constexpr Symbol::Flags ompFlagsRequireNewSymbol{
       Symbol::Flag::OmpPrivate, Symbol::Flag::OmpLinear,
       Symbol::Flag::OmpFirstPrivate, Symbol::Flag::OmpLastPrivate,
-      Symbol::Flag::OmpReduction};
+      Symbol::Flag::OmpReduction, Symbol::Flag::OmpCriticalLock};
 
   static constexpr Symbol::Flags ompFlagsRequireMark{
       Symbol::Flag::OmpThreadprivate};
@@ -1374,6 +1376,22 @@ bool OmpAttributeVisitor::Pre(const parser::OpenMPSectionsConstruct &x) {
   return true;
 }
 
+bool OmpAttributeVisitor::Pre(const parser::OmpCriticalDirective &x) {
+  const auto &name{std::get<std::optional<parser::Name>>(x.t)};
+  if (name) {
+    ResolveOmpName(*name, Symbol::Flag::OmpCriticalLock);
+  }
+  return true;
+}
+
+bool OmpAttributeVisitor::Pre(const parser::OmpEndCriticalDirective &x) {
+  const auto &name{std::get<std::optional<parser::Name>>(x.t)};
+  if (name) {
+    ResolveOmpName(*name, Symbol::Flag::OmpCriticalLock);
+  }
+  return true;
+}
+
 bool OmpAttributeVisitor::Pre(const parser::OpenMPCriticalConstruct &x) {
   const auto &criticalDir{std::get<parser::OmpCriticalDirective>(x.t)};
   PushContext(criticalDir.source, llvm::omp::Directive::OMPD_critical);
@@ -1497,6 +1515,13 @@ void OmpAttributeVisitor::ResolveOmpName(
         AddToContextObjectWithDSA(*resolvedSymbol, ompFlag);
       }
     }
+  } else if (ompFlagsRequireNewSymbol.test(ompFlag)) {
+    const auto pair{GetContext().scope.try_emplace(
+        name.source, Attrs{}, ObjectEntityDetails{})};
+    CHECK(pair.second);
+    name.symbol = &pair.first->second.get();
+  } else {
+    DIE("OpenMP Name resolution failed");
   }
 }
 

flang/test/Semantics/omp-sync-critical01.f90

@@ -0,0 +1,41 @@
+! RUN: %python %S/test_errors.py %s %flang -fopenmp
+
+! OpenMP Version 5.0
+! 2.17.1 critical construct
+! CRITICAL start and end CRITICAL directive names mismatch
+integer function timer_tick_sec()
+   implicit none
+   integer t
+
+   !$OMP CRITICAL
+   t = t + 1
+   !$OMP END CRITICAL
+
+   !$OMP CRITICAL (foo)
+   t = t + 1
+   !$OMP END CRITICAL (foo)
+
+   !$OMP CRITICAL (foo)
+   t = t + 1
+   !ERROR: CRITICAL directive names do not match
+   !$OMP END CRITICAL (bar)
+
+   !$OMP CRITICAL (bar)
+   t = t + 1
+   !ERROR: CRITICAL directive names do not match
+   !$OMP END CRITICAL (foo)
+
+   !ERROR: CRITICAL directive names do not match
+   !$OMP CRITICAL (bar)
+   t = t + 1
+   !$OMP END CRITICAL
+
+   !$OMP CRITICAL
+   t = t + 1
+   !ERROR: CRITICAL directive names do not match
+   !$OMP END CRITICAL (foo)
+
+   timer_tick_sec = t
+   return
+
+end function timer_tick_sec

flang/test/Semantics/omp-sync-critical02.f90

@@ -0,0 +1,53 @@
+! RUN: %python %S/test_errors.py %s %flang -fopenmp
+
+! OpenMP Version 5.0
+! 2.17.1 critical construct
+! If the hint clause is specified, the critical construct must have a name.
+program sample
+   use omp_lib
+   integer i, j
+   !ERROR: Hint clause other than omp_sync_hint_none cannot be specified for an unnamed CRITICAL directive
+   !$omp critical hint(omp_lock_hint_speculative)
+   j = j + 1
+   !$omp end critical
+
+   !$omp critical (foo) hint(omp_lock_hint_speculative)
+   i = i - 1
+   !$omp end critical (foo)
+
+   !ERROR: Hint clause other than omp_sync_hint_none cannot be specified for an unnamed CRITICAL directive
+   !$omp critical hint(omp_lock_hint_nonspeculative)
+   j = j + 1
+   !$omp end critical
+
+   !$omp critical (foo) hint(omp_lock_hint_nonspeculative)
+   i = i - 1
+   !$omp end critical (foo)
+
+   !ERROR: Hint clause other than omp_sync_hint_none cannot be specified for an unnamed CRITICAL directive
+   !$omp critical hint(omp_lock_hint_contended)
+   j = j + 1
+   !$omp end critical
+
+   !$omp critical (foo) hint(omp_lock_hint_contended)
+   i = i - 1
+   !$omp end critical (foo)
+
+   !ERROR: Hint clause other than omp_sync_hint_none cannot be specified for an unnamed CRITICAL directive
+   !$omp critical hint(omp_lock_hint_uncontended)
+   j = j + 1
+   !$omp end critical
+
+   !$omp critical (foo) hint(omp_lock_hint_uncontended)
+   i = i - 1
+   !$omp end critical (foo)
+ 
+   !$omp critical hint(omp_sync_hint_none)
+   j = j + 1
+   !$omp end critical
+
+   !$omp critical (foo) hint(omp_sync_hint_none)
+   i = i - 1
+   !$omp end critical (foo)
+
+end program sample