Refactor avoiding checking the memory order

Author: Leporacanthicus

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

@@ -2780,8 +2780,6 @@ void OmpStructureChecker::Enter(const parser::OmpClause &x) {
 
 // Following clauses do not have a separate node in parse-tree.h.
 CHECK_SIMPLE_CLAUSE(Absent, OMPC_absent)
-CHECK_SIMPLE_CLAUSE(AcqRel, OMPC_acq_rel)
-CHECK_SIMPLE_CLAUSE(Acquire, OMPC_acquire)
 CHECK_SIMPLE_CLAUSE(Affinity, OMPC_affinity)
 CHECK_SIMPLE_CLAUSE(Capture, OMPC_capture)
 CHECK_SIMPLE_CLAUSE(Contains, OMPC_contains)
@@ -2817,9 +2815,6 @@ CHECK_SIMPLE_CLAUSE(Nogroup, OMPC_nogroup)
 CHECK_SIMPLE_CLAUSE(Notinbranch, OMPC_notinbranch)
 CHECK_SIMPLE_CLAUSE(Partial, OMPC_partial)
 CHECK_SIMPLE_CLAUSE(ProcBind, OMPC_proc_bind)
-CHECK_SIMPLE_CLAUSE(Release, OMPC_release)
-CHECK_SIMPLE_CLAUSE(Relaxed, OMPC_relaxed)
-CHECK_SIMPLE_CLAUSE(SeqCst, OMPC_seq_cst)
 CHECK_SIMPLE_CLAUSE(Simd, OMPC_simd)
 CHECK_SIMPLE_CLAUSE(Sizes, OMPC_sizes)
 CHECK_SIMPLE_CLAUSE(Permutation, OMPC_permutation)
@@ -2847,7 +2842,6 @@ CHECK_SIMPLE_CLAUSE(Compare, OMPC_compare)
 CHECK_SIMPLE_CLAUSE(CancellationConstructType, OMPC_cancellation_construct_type)
 CHECK_SIMPLE_CLAUSE(OmpxAttribute, OMPC_ompx_attribute)
 CHECK_SIMPLE_CLAUSE(OmpxBare, OMPC_ompx_bare)
-CHECK_SIMPLE_CLAUSE(Fail, OMPC_fail)
 CHECK_SIMPLE_CLAUSE(Weak, OMPC_weak)
 
 CHECK_REQ_SCALAR_INT_CLAUSE(NumTeams, OMPC_num_teams)
@@ -2860,6 +2854,53 @@ CHECK_REQ_CONSTANT_SCALAR_INT_CLAUSE(Collapse, OMPC_collapse)
 CHECK_REQ_CONSTANT_SCALAR_INT_CLAUSE(Safelen, OMPC_safelen)
 CHECK_REQ_CONSTANT_SCALAR_INT_CLAUSE(Simdlen, OMPC_simdlen)
 
+void OmpStructureChecker::Enter(const parser::OmpClause::AcqRel &) {
+  if (!isFailClause)
+    CheckAllowedClause(llvm::omp::Clause::OMPC_acq_rel);
+}
+
+void OmpStructureChecker::Enter(const parser::OmpClause::Acquire &) {
+  if (!isFailClause)
+    CheckAllowedClause(llvm::omp::Clause::OMPC_acquire);
+}
+
+void OmpStructureChecker::Enter(const parser::OmpClause::Release &) {
+  if (!isFailClause)
+    CheckAllowedClause(llvm::omp::Clause::OMPC_release);
+}
+
+void OmpStructureChecker::Enter(const parser::OmpClause::Relaxed &) {
+  if (!isFailClause)
+    CheckAllowedClause(llvm::omp::Clause::OMPC_relaxed);
+}
+
+void OmpStructureChecker::Enter(const parser::OmpClause::SeqCst &) {
+  if (!isFailClause)
+    CheckAllowedClause(llvm::omp::Clause::OMPC_seq_cst);
+}
+
+void OmpStructureChecker::Enter(const parser::OmpClause::Fail &) {
+  assert(!isFailClause && "Unexpected FAIL clause inside a FAIL clause?");
+  isFailClause = true;
+  CheckAllowedClause(llvm::omp::Clause::OMPC_fail);
+}
+
+void OmpStructureChecker::Leave(const parser::OmpClause::Fail &) {
+  assert(isFailClause && "Expected to be inside a FAIL clause here");
+  isFailClause = false;
+}
+
+void OmpStructureChecker::Enter(const parser::OmpFailClause &) {
+  assert(!isFailClause && "Unexpected FAIL clause inside a FAIL clause?");
+  isFailClause = true;
+  CheckAllowedClause(llvm::omp::Clause::OMPC_fail);
+}
+
+void OmpStructureChecker::Leave(const parser::OmpFailClause &) {
+  assert(isFailClause && "Expected to be inside a FAIL clause here");
+  isFailClause = false;
+}
+
 // Restrictions specific to each clause are implemented apart from the
 // generalized restrictions.
 

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

@@ -142,6 +142,10 @@ class OmpStructureChecker
 #define GEN_FLANG_CLAUSE_CHECK_ENTER
 #include "llvm/Frontend/OpenMP/OMP.inc"
 
+  void Leave(const parser::OmpClause::Fail &);
+  void Enter(const parser::OmpFailClause &);
+  void Leave(const parser::OmpFailClause &);
+
 private:
   bool CheckAllowedClause(llvmOmpClause clause);
   bool IsVariableListItem(const Symbol &sym);
@@ -272,6 +276,7 @@ class OmpStructureChecker
   using LoopConstruct = std::variant<const parser::DoConstruct *,
       const parser::OpenMPLoopConstruct *>;
   std::vector<LoopConstruct> loopStack_;
+  bool isFailClause{false};
 };
 
 /// Find a duplicate entry in the range, and return an iterator to it.

flang/lib/Semantics/semantics.cpp

@@ -114,11 +114,6 @@ class SemanticsVisitor : public virtual BaseChecker, public virtual C... {
     context_.set_location(std::nullopt);
   }
 
-  // This is necessary to avoid "walking" into the Fail clause,
-  // which confuses the CheckAllowed into thinking there's another
-  // memoryorder, when it's actually the argument to the fail clause.
-  bool Pre(const parser::OmpFailClause &) { return false; }
-
   bool Walk(const parser::Program &program) {
     parser::Walk(program, *this);
     return !context_.AnyFatalError();