[coroutines] Refactor SuspendExpr to create just one OpaqueValue (almost NFC)

GorNishanov · GorNishanov · commit ce43bd224293 · 2017-03-11T01:30:17.000Z
Summary: Create only one OpaqueValue for await_ready/await_suspend/await_resume. Store OpaqueValue used in the CoroutineSuspendExpr node, so that CodeGen does not have to hunt looking for it. Reviewers: rsmith, EricWF, aaron.ballman Reviewed By: EricWF Subscribers: mehdi_amini, cfe-commits Differential Revision: https://reviews.llvm.org/D30775 llvm-svn: 297541
diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
@@ -4123,16 +4123,18 @@ class CoroutineSuspendExpr : public Expr {
 
   enum SubExpr { Common, Ready, Suspend, Resume, Count };
   Stmt *SubExprs[SubExpr::Count];
+  OpaqueValueExpr *OpaqueValue = nullptr;
 
   friend class ASTStmtReader;
 public:
   CoroutineSuspendExpr(StmtClass SC, SourceLocation KeywordLoc, Expr *Common,
-                       Expr *Ready, Expr *Suspend, Expr *Resume)
+                       Expr *Ready, Expr *Suspend, Expr *Resume,
+                       OpaqueValueExpr *OpaqueValue)
       : Expr(SC, Resume->getType(), Resume->getValueKind(),
              Resume->getObjectKind(), Resume->isTypeDependent(),
              Resume->isValueDependent(), Common->isInstantiationDependent(),
              Common->containsUnexpandedParameterPack()),
-        KeywordLoc(KeywordLoc) {
+        KeywordLoc(KeywordLoc), OpaqueValue(OpaqueValue) {
     SubExprs[SubExpr::Common] = Common;
     SubExprs[SubExpr::Ready] = Ready;
     SubExprs[SubExpr::Suspend] = Suspend;
@@ -4161,6 +4163,8 @@ class CoroutineSuspendExpr : public Expr {
   Expr *getCommonExpr() const {
     return static_cast<Expr*>(SubExprs[SubExpr::Common]);
   }
+  /// \brief getOpaqueValue - Return the opaque value placeholder.
+  OpaqueValueExpr *getOpaqueValue() const { return OpaqueValue; }
 
   Expr *getReadyExpr() const {
     return static_cast<Expr*>(SubExprs[SubExpr::Ready]);
@@ -4194,10 +4198,11 @@ class CoawaitExpr : public CoroutineSuspendExpr {
   friend class ASTStmtReader;
 public:
   CoawaitExpr(SourceLocation CoawaitLoc, Expr *Operand, Expr *Ready,
-              Expr *Suspend, Expr *Resume, bool IsImplicit = false)
+              Expr *Suspend, Expr *Resume, OpaqueValueExpr *OpaqueValue,
+              bool IsImplicit = false)
       : CoroutineSuspendExpr(CoawaitExprClass, CoawaitLoc, Operand, Ready,
-                             Suspend, Resume) {
-      CoawaitBits.IsImplicit = IsImplicit;
+                             Suspend, Resume, OpaqueValue) {
+    CoawaitBits.IsImplicit = IsImplicit;
   }
   CoawaitExpr(SourceLocation CoawaitLoc, QualType Ty, Expr *Operand,
               bool IsImplicit = false)
@@ -4270,9 +4275,9 @@ class CoyieldExpr : public CoroutineSuspendExpr {
   friend class ASTStmtReader;
 public:
   CoyieldExpr(SourceLocation CoyieldLoc, Expr *Operand, Expr *Ready,
-              Expr *Suspend, Expr *Resume)
+              Expr *Suspend, Expr *Resume, OpaqueValueExpr *OpaqueValue)
       : CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Operand, Ready,
-                             Suspend, Resume) {}
+                             Suspend, Resume, OpaqueValue) {}
   CoyieldExpr(SourceLocation CoyieldLoc, QualType Ty, Expr *Operand)
       : CoroutineSuspendExpr(CoyieldExprClass, CoyieldLoc, Ty, Operand) {}
   CoyieldExpr(EmptyShell Empty)
diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
@@ -312,8 +312,9 @@ static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
 }
 
 struct ReadySuspendResumeResult {
-  bool IsInvalid;
   Expr *Results[3];
+  OpaqueValueExpr *OpaqueValue;
+  bool IsInvalid;
 };
 
 static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
@@ -336,8 +337,11 @@ static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
 /// expression.
 static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
                                                   SourceLocation Loc, Expr *E) {
+  OpaqueValueExpr *Operand = new (S.Context)
+      OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
+
   // Assume invalid until we see otherwise.
-  ReadySuspendResumeResult Calls = {true, {}};
+  ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
 
   ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
   if (CoroHandleRes.isInvalid())
@@ -347,9 +351,6 @@ static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
   const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
   MultiExprArg Args[] = {None, CoroHandle, None};
   for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
-    Expr *Operand = new (S.Context) OpaqueValueExpr(
-      Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
-
     ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
     if (Result.isInvalid())
       return Calls;
@@ -556,8 +557,9 @@ ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
   if (RSS.IsInvalid)
     return ExprError();
 
-  Expr *Res = new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
-                                        RSS.Results[2], IsImplicit);
+  Expr *Res =
+      new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
+                                RSS.Results[2], RSS.OpaqueValue, IsImplicit);
   if (!IsImplicit)
     Coroutine->CoroutineStmts.push_back(Res);
   return Res;
@@ -611,7 +613,7 @@ ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
     return ExprError();
 
   Expr *Res = new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
-                                        RSS.Results[2]);
+                                        RSS.Results[2], RSS.OpaqueValue);
   Coroutine->CoroutineStmts.push_back(Res);
   return Res;
 }
