[OpenACC] Initial sema implementation of 'update' construct

This executable construct has a larger list of clauses than some of the
others, plus has some additional restrictions.  This patch implements
the AST node, plus the 'cannot be the body of a if, while, do, switch,
    or label' statement restriction.  Future patches will handle the
    rest of the restrictions, which are based on clauses.

Author: erichkeane

clang/include/clang-c/Index.h

@@ -2202,7 +2202,11 @@ enum CXCursorKind {
    */
   CXCursor_OpenACCSetConstruct = 330,
 
-  CXCursor_LastStmt = CXCursor_OpenACCSetConstruct,
+  /** OpenACC update Construct.
+   */
+  CXCursor_OpenACCUpdateConstruct = 331,
+
+  CXCursor_LastStmt = CXCursor_OpenACCUpdateConstruct,
 
   /**
    * Cursor that represents the translation unit itself.

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -4082,6 +4082,8 @@ DEF_TRAVERSE_STMT(OpenACCShutdownConstruct,
                   { TRY_TO(VisitOpenACCClauseList(S->clauses())); })
 DEF_TRAVERSE_STMT(OpenACCSetConstruct,
                   { TRY_TO(VisitOpenACCClauseList(S->clauses())); })
+DEF_TRAVERSE_STMT(OpenACCUpdateConstruct,
+                  { TRY_TO(VisitOpenACCClauseList(S->clauses())); })
 
 // Traverse HLSL: Out argument expression
 DEF_TRAVERSE_STMT(HLSLOutArgExpr, {})

clang/include/clang/AST/StmtOpenACC.h

@@ -712,5 +712,44 @@ class OpenACCSetConstruct final
                                      SourceLocation End,
                                      ArrayRef<const OpenACCClause *> Clauses);
 };
+// This class represents an 'update' construct, which has just a clause list.
+class OpenACCUpdateConstruct final
+    : public OpenACCConstructStmt,
+      private llvm::TrailingObjects<OpenACCUpdateConstruct,
+                                    const OpenACCClause *> {
+  friend TrailingObjects;
+  OpenACCUpdateConstruct(unsigned NumClauses)
+      : OpenACCConstructStmt(OpenACCUpdateConstructClass,
+                             OpenACCDirectiveKind::Update, SourceLocation{},
+                             SourceLocation{}, SourceLocation{}) {
+    std::uninitialized_value_construct(
+        getTrailingObjects<const OpenACCClause *>(),
+        getTrailingObjects<const OpenACCClause *>() + NumClauses);
+    setClauseList(MutableArrayRef(getTrailingObjects<const OpenACCClause *>(),
+                                  NumClauses));
+  }
+
+  OpenACCUpdateConstruct(SourceLocation Start, SourceLocation DirectiveLoc,
+                         SourceLocation End,
+                         ArrayRef<const OpenACCClause *> Clauses)
+      : OpenACCConstructStmt(OpenACCUpdateConstructClass,
+                             OpenACCDirectiveKind::Update, Start, DirectiveLoc,
+                             End) {
+    std::uninitialized_copy(Clauses.begin(), Clauses.end(),
+                            getTrailingObjects<const OpenACCClause *>());
+    setClauseList(MutableArrayRef(getTrailingObjects<const OpenACCClause *>(),
+                                  Clauses.size()));
+  }
+
+public:
+  static bool classof(const Stmt *T) {
+    return T->getStmtClass() == OpenACCUpdateConstructClass;
+  }
+  static OpenACCUpdateConstruct *CreateEmpty(const ASTContext &C,
+                                             unsigned NumClauses);
+  static OpenACCUpdateConstruct *
+  Create(const ASTContext &C, SourceLocation Start, SourceLocation DirectiveLoc,
+         SourceLocation End, ArrayRef<const OpenACCClause *> Clauses);
+};
 } // namespace clang
 #endif // LLVM_CLANG_AST_STMTOPENACC_H

clang/include/clang/AST/TextNodeDumper.h

@@ -419,6 +419,7 @@ class TextNodeDumper
   void VisitOpenACCInitConstruct(const OpenACCInitConstruct *S);
   void VisitOpenACCSetConstruct(const OpenACCSetConstruct *S);
   void VisitOpenACCShutdownConstruct(const OpenACCShutdownConstruct *S);
+  void VisitOpenACCUpdateConstruct(const OpenACCUpdateConstruct *S);
   void VisitOpenACCAsteriskSizeExpr(const OpenACCAsteriskSizeExpr *S);
   void VisitEmbedExpr(const EmbedExpr *S);
   void VisitAtomicExpr(const AtomicExpr *AE);

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -12827,6 +12827,10 @@ def err_acc_loop_not_monotonic
             "('++', '--', or compound assignment)">;
 def err_acc_construct_one_clause_of
     : Error<"OpenACC '%0' construct must have at least one %1 clause">;
+def err_acc_update_as_body
+    : Error<"OpenACC 'update' construct may not appear in place of the "
+            "statement following a%select{n if statement| while statement| do "
+            "statement| switch statement| label statement}0">;
 
 // AMDGCN builtins diagnostics
 def err_amdgcn_global_load_lds_size_invalid_value : Error<"invalid size value">;

clang/include/clang/Basic/StmtNodes.td

@@ -316,6 +316,7 @@ def OpenACCWaitConstruct : StmtNode<OpenACCConstructStmt>;
 def OpenACCInitConstruct : StmtNode<OpenACCConstructStmt>;
 def OpenACCShutdownConstruct : StmtNode<OpenACCConstructStmt>;
 def OpenACCSetConstruct : StmtNode<OpenACCConstructStmt>;
+def OpenACCUpdateConstruct : StmtNode<OpenACCConstructStmt>;
 
 // OpenACC Additional Expressions.
 def OpenACCAsteriskSizeExpr : StmtNode<Expr>;

clang/include/clang/Serialization/ASTBitCodes.h

@@ -2025,6 +2025,7 @@ enum StmtCode {
   STMT_OPENACC_INIT_CONSTRUCT,
   STMT_OPENACC_SHUTDOWN_CONSTRUCT,
   STMT_OPENACC_SET_CONSTRUCT,
+  STMT_OPENACC_UPDATE_CONSTRUCT,
 
   // HLSL Constructs
   EXPR_HLSL_OUT_ARG,

clang/lib/AST/StmtOpenACC.cpp

@@ -284,3 +284,24 @@ OpenACCSetConstruct::Create(const ASTContext &C, SourceLocation Start,
   auto *Inst = new (Mem) OpenACCSetConstruct(Start, DirectiveLoc, End, Clauses);
   return Inst;
 }
+
+OpenACCUpdateConstruct *
+OpenACCUpdateConstruct::CreateEmpty(const ASTContext &C, unsigned NumClauses) {
+  void *Mem = C.Allocate(
+      OpenACCUpdateConstruct::totalSizeToAlloc<const OpenACCClause *>(
+          NumClauses));
+  auto *Inst = new (Mem) OpenACCUpdateConstruct(NumClauses);
+  return Inst;
+}
+
+OpenACCUpdateConstruct *
+OpenACCUpdateConstruct::Create(const ASTContext &C, SourceLocation Start,
+                               SourceLocation DirectiveLoc, SourceLocation End,
+                               ArrayRef<const OpenACCClause *> Clauses) {
+  void *Mem = C.Allocate(
+      OpenACCUpdateConstruct::totalSizeToAlloc<const OpenACCClause *>(
+          Clauses.size()));
+  auto *Inst =
+      new (Mem) OpenACCUpdateConstruct(Start, DirectiveLoc, End, Clauses);
+  return Inst;
+}

clang/lib/AST/StmtPrinter.cpp

@@ -1204,10 +1204,12 @@ void StmtPrinter::VisitOpenACCInitConstruct(OpenACCInitConstruct *S) {
 void StmtPrinter::VisitOpenACCShutdownConstruct(OpenACCShutdownConstruct *S) {
   PrintOpenACCConstruct(S);
 }
-
 void StmtPrinter::VisitOpenACCSetConstruct(OpenACCSetConstruct *S) {
   PrintOpenACCConstruct(S);
 }
+void StmtPrinter::VisitOpenACCUpdateConstruct(OpenACCUpdateConstruct *S) {
+  PrintOpenACCConstruct(S);
+}
 
 void StmtPrinter::VisitOpenACCWaitConstruct(OpenACCWaitConstruct *S) {
   Indent() << "#pragma acc wait";

clang/lib/AST/StmtProfile.cpp

@@ -2780,6 +2780,13 @@ void StmtProfiler::VisitOpenACCSetConstruct(const OpenACCSetConstruct *S) {
   P.VisitOpenACCClauseList(S->clauses());
 }
 
+void StmtProfiler::VisitOpenACCUpdateConstruct(
+    const OpenACCUpdateConstruct *S) {
+  VisitStmt(S);
+  OpenACCClauseProfiler P{*this};
+  P.VisitOpenACCClauseList(S->clauses());
+}
+
 void StmtProfiler::VisitHLSLOutArgExpr(const HLSLOutArgExpr *S) {
   VisitStmt(S);
 }