[clang][OpenMP] OMPFlushClause is synthetic, no such clause exists

[lebedev.ri]

Summary

As discussed in https://reviews.llvm.org/D57112#inline-506781,
'flush' clause does not exist in the OpenMP spec, it can not be
specified, and OMPFlushClause class is just a helper class.

Therefore OPENMP_CLAUSE() in clang/Basic/OpenMPKinds.def
should not contain 'flush' "clause".

I have simply removed the OPENMP_CLAUSE(flush, OMPFlushClause)
from clang/Basic/OpenMPKinds.def, grepped for OPENMP_CLAUSE
and added OPENMP_CLAUSE(flush, OMPFlushClause) back to the every
place where OPENMP_CLAUSE is defined and clang/Basic/OpenMPKinds.def
is then included.

So as-is, this patch is a NFC. Possibly, some of these
OPENMP_CLAUSE(flush, OMPFlushClause) should be dropped,
i don't really know.

Test plan: ninja check-clang

[ABataev]

LG with a nit

lib/Basic/OpenMPKinds.cpp

56

Just .Case("flush", OMPC_flush), similar to uniform

[lebedev.ri]

In D57280#1373547, @ABataev wrote:

LG with a nit

Thank you for the review!

[lebedev.ri]

lib/Basic/OpenMPKinds.cpp

56

Hm, we won't ever trigger that case, since we have if (Str == "flush") return OMPC_unknown; before this.

[ABataev]

lib/Basic/OpenMPKinds.cpp

56

Then just remove this new line completely.

[lebedev.ri]

lib/Basic/OpenMPKinds.cpp

56

Yep, great idea, did that.

include/clang/AST/OpenMPClause.h

 class OMPClauseVisitorBase {
 public:
 #define PTR(CLASS) typename Ptr<CLASS>::type
 #define DISPATCH(CLASS) \
   return static_cast<ImplClass*>(this)->Visit##CLASS(static_cast<PTR(CLASS)>(S))
 
 #define OPENMP_CLAUSE(Name, Class)                              \
   RetTy Visit ## Class (PTR(Class) S) { DISPATCH(Class); }
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
 
   RetTy Visit(PTR(OMPClause) S) {
     // Top switch clause: visit each OMPClause.
     switch (S->getClauseKind()) {
     default: llvm_unreachable("Unknown clause kind!");
 #define OPENMP_CLAUSE(Name, Class)                              \
     case OMPC_ ## Name : return Visit ## Class(static_cast<PTR(Class)>(S));
+    OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
     }
   }
   // Base case, ignore it. :)
   RetTy VisitOMPClause(PTR(OMPClause) Node) { return RetTy(); }
 #undef PTR
 #undef DISPATCH
 };
class OMPClausePrinter final : public OMPClauseVisitor<OMPClausePrinter> {
   /// Process clauses with list of variables.
   template <typename T> void VisitOMPClauseList(T *Node, char StartSym);
 
 public:
   OMPClausePrinter(raw_ostream &OS, const PrintingPolicy &Policy)
       : OS(OS), Policy(Policy) {}
 
 #define OPENMP_CLAUSE(Name, Class) void Visit##Class(Class *S);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
 };
 
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_OPENMPCLAUSE_H

include/clang/AST/RecursiveASTVisitor.h

#undef DEF_TRAVERSE_TMPL_INST
   bool TraverseDeclaratorHelper(DeclaratorDecl *D);
   bool TraverseDeclContextHelper(DeclContext *DC);
   bool TraverseFunctionHelper(FunctionDecl *D);
   bool TraverseVarHelper(VarDecl *D);
   bool TraverseOMPExecutableDirective(OMPExecutableDirective *S);
   bool TraverseOMPLoopDirective(OMPLoopDirective *S);
   bool TraverseOMPClause(OMPClause *C);
 #define OPENMP_CLAUSE(Name, Class) bool Visit##Class(Class *C);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   /// Process clauses with list of variables.
   template <typename T> bool VisitOMPClauseList(T *Node);
   /// Process clauses with pre-initis.
   bool VisitOMPClauseWithPreInit(OMPClauseWithPreInit *Node);
   bool VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *Node);
 
   bool dataTraverseNode(Stmt *S, DataRecursionQueue *Queue);

 bool RecursiveASTVisitor<Derived>::TraverseOMPClause(OMPClause *C) {
   if (!C)
     return true;
   switch (C->getClauseKind()) {
 #define OPENMP_CLAUSE(Name, Class)                                             \
   case OMPC_##Name:                                                            \
     TRY_TO(Visit##Class(static_cast<Class *>(C)));                             \
     break;
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   case OMPC_threadprivate:
   case OMPC_uniform:
   case OMPC_unknown:
     break;
   }
   return true;
 }

include/clang/Basic/OpenMPKinds.h

#include "clang/Basic/OpenMPKinds.def"
   OMPD_unknown
 };
 
 /// OpenMP clauses.
 enum OpenMPClauseKind {
 #define OPENMP_CLAUSE(Name, Class) \
   OMPC_##Name,
 #include "clang/Basic/OpenMPKinds.def"
+  OMPC_flush,
   OMPC_threadprivate,
   OMPC_uniform,
   OMPC_unknown
 };
 
 /// OpenMP attributes for 'default' clause.
 enum OpenMPDefaultClauseKind {
 #define OPENMP_DEFAULT_KIND(Name) \

include/clang/Basic/OpenMPKinds.def

 OPENMP_CLAUSE(copyin,  OMPCopyinClause)
 OPENMP_CLAUSE(copyprivate,  OMPCopyprivateClause)
 OPENMP_CLAUSE(proc_bind, OMPProcBindClause)
 OPENMP_CLAUSE(schedule, OMPScheduleClause)
 OPENMP_CLAUSE(ordered, OMPOrderedClause)
 OPENMP_CLAUSE(nowait, OMPNowaitClause)
 OPENMP_CLAUSE(untied, OMPUntiedClause)
 OPENMP_CLAUSE(mergeable, OMPMergeableClause)
-OPENMP_CLAUSE(flush, OMPFlushClause)
 OPENMP_CLAUSE(read, OMPReadClause)
 OPENMP_CLAUSE(write, OMPWriteClause)
 OPENMP_CLAUSE(update, OMPUpdateClause)
 OPENMP_CLAUSE(capture, OMPCaptureClause)
 OPENMP_CLAUSE(seq_cst, OMPSeqCstClause)
 OPENMP_CLAUSE(depend, OMPDependClause)
 OPENMP_CLAUSE(device, OMPDeviceClause)
 OPENMP_CLAUSE(threads, OMPThreadsClause)

include/clang/Serialization/ASTReader.h

class OMPClauseReader : public OMPClauseVisitor<OMPClauseReader> {
   ASTRecordReader &Record;
   ASTContext &Context;
 
 public:
   OMPClauseReader(ASTRecordReader &Record)
       : Record(Record), Context(Record.getContext()) {}
 
 #define OPENMP_CLAUSE(Name, Class) void Visit##Class(Class *C);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   OMPClause *readClause();
   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
 };
 
 } // namespace clang
 
 #endif // LLVM_CLANG_SERIALIZATION_ASTREADER_H

include/clang/Serialization/ASTWriter.h

 };
 
 class OMPClauseWriter : public OMPClauseVisitor<OMPClauseWriter> {
   ASTRecordWriter &Record;
 
 public:
   OMPClauseWriter(ASTRecordWriter &Record) : Record(Record) {}
 #define OPENMP_CLAUSE(Name, Class) void Visit##Class(Class *S);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   void writeClause(OMPClause *C);
   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
 };
 
 } // namespace clang
 
 #endif // LLVM_CLANG_SERIALIZATION_ASTWRITER_H

lib/AST/OpenMPClause.cpp

 
 OMPClause::child_range OMPClause::children() {
   switch (getClauseKind()) {
   default:
     break;
 #define OPENMP_CLAUSE(Name, Class)                                             \
   case OMPC_##Name:                                                            \
     return static_cast<Class *>(this)->children();
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   }
   llvm_unreachable("unknown OMPClause");
 }
 
 OMPClauseWithPreInit *OMPClauseWithPreInit::get(OMPClause *C) {
   auto *Res = OMPClauseWithPreInit::get(const_cast<const OMPClause *>(C));
   return Res ? const_cast<OMPClauseWithPreInit *>(Res) : nullptr;

lib/AST/StmtProfile.cpp

class OMPClauseProfiler : public ConstOMPClauseVisitor<OMPClauseProfiler> {
   /// Process clauses with list of variables.
   template <typename T>
   void VisitOMPClauseList(T *Node);
 
 public:
   OMPClauseProfiler(StmtProfiler *P) : Profiler(P) { }
 #define OPENMP_CLAUSE(Name, Class)                                             \
   void Visit##Class(const Class *C);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   void VistOMPClauseWithPreInit(const OMPClauseWithPreInit *C);
   void VistOMPClauseWithPostUpdate(const OMPClauseWithPostUpdate *C);
 };
 
 void OMPClauseProfiler::VistOMPClauseWithPreInit(
     const OMPClauseWithPreInit *C) {
   if (auto *S = C->getPreInitStmt())

lib/Basic/OpenMPKinds.cpp

OpenMPClauseKind clang::getOpenMPClauseKind(StringRef Str) {
   // 'flush' clause cannot be specified explicitly, because this is an implicit
   // clause for 'flush' directive. If the 'flush' clause is explicitly specified
   // the Parser should generate a warning about extra tokens at the end of the
   // directive.
   if (Str == "flush")
     return OMPC_unknown;
   return llvm::StringSwitch<OpenMPClauseKind>(Str)
 #define OPENMP_CLAUSE(Name, Class) .Case(#Name, OMPC_##Name)
+      OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
       .Case("uniform", OMPC_uniform)
       .Default(OMPC_unknown);
 }
 
 const char *clang::getOpenMPClauseName(OpenMPClauseKind Kind) {
   assert(Kind <= OMPC_unknown);
   switch (Kind) {
   case OMPC_unknown:
     return "unknown";
 #define OPENMP_CLAUSE(Name, Class)                                             \
   case OMPC_##Name:                                                            \
     return #Name;
 #include "clang/Basic/OpenMPKinds.def"
+  case OMPC_flush:
+    return "flush";
   case OMPC_uniform:
     return "uniform";
   case OMPC_threadprivate:
     return "threadprivate or thread local";
   }
   llvm_unreachable("Invalid OpenMP clause kind");
 }
 

lib/Sema/TreeTransform.h

#define EXPR(Node, Parent)                        \
   LLVM_ATTRIBUTE_NOINLINE \
   ExprResult Transform##Node(Node *E);
 #define ABSTRACT_STMT(Stmt)
 #include "clang/AST/StmtNodes.inc"
 
 #define OPENMP_CLAUSE(Name, Class)                        \
   LLVM_ATTRIBUTE_NOINLINE \
   OMPClause *Transform ## Class(Class *S);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
 
   /// Build a new qualified type given its unqualified type and type location.
   ///
   /// By default, this routine adds type qualifiers only to types that can
   /// have qualifiers, and silently suppresses those qualifiers that are not
   /// permitted. Subclasses may override this routine to provide different
   /// behavior.
if (!S)
     return S;
 
   switch (S->getClauseKind()) {
   default: break;
   // Transform individual clause nodes
 #define OPENMP_CLAUSE(Name, Class)                                             \
   case OMPC_ ## Name :                                                         \
     return getDerived().Transform ## Class(cast<Class>(S));
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   }
 
   return S;
 }
 
 
 template<typename Derived>

tools/libclang/CIndex.cpp

class OMPClauseEnqueue : public ConstOMPClauseVisitor<OMPClauseEnqueue> {
   EnqueueVisitor *Visitor;
   /// Process clauses with list of variables.
   template <typename T>
   void VisitOMPClauseList(T *Node);
 public:
   OMPClauseEnqueue(EnqueueVisitor *Visitor) : Visitor(Visitor) { }
 #define OPENMP_CLAUSE(Name, Class)                                             \
   void Visit##Class(const Class *C);
+  OPENMP_CLAUSE(flush, OMPFlushClause)
 #include "clang/Basic/OpenMPKinds.def"
   void VisitOMPClauseWithPreInit(const OMPClauseWithPreInit *C);
   void VisitOMPClauseWithPostUpdate(const OMPClauseWithPostUpdate *C);
 };
 
 void OMPClauseEnqueue::VisitOMPClauseWithPreInit(
     const OMPClauseWithPreInit *C) {
   Visitor->AddStmt(C->getPreInitStmt());