[coroutines] Factor out co_await representation into common base class for co_await and co_yield, and use it to hold await_* calls.

llvm-svn: 253811
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 9e53c47..e2d044c 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -7493,18 +7493,16 @@
     CheckImplicitConversion(S, E, T, CC);
 
   // Now continue drilling into this expression.
-  
-  if (PseudoObjectExpr * POE = dyn_cast<PseudoObjectExpr>(E)) {
-    if (POE->getResultExpr())
-      E = POE->getResultExpr();
+
+  if (PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
+    // The bound subexpressions in a PseudoObjectExpr are not reachable
+    // as transitive children.
+    // FIXME: Use a more uniform representation for this.
+    for (auto *SE : POE->semantics())
+      if (auto *OVE = dyn_cast<OpaqueValueExpr>(SE))
+        AnalyzeImplicitConversions(S, OVE->getSourceExpr(), CC);
   }
-  
-  if (const OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
-    if (OVE->getSourceExpr())
-      AnalyzeImplicitConversions(S, OVE->getSourceExpr(), CC);
-    return;
-  }
-  
+
   // Skip past explicit casts.
   if (isa<ExplicitCastExpr>(E)) {
     E = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreParenImpCasts();
diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index 8d91e43..a0d24b8 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -300,8 +300,22 @@
     E = R.get();
   }
 
-  // FIXME: Build await_* calls.
-  Expr *Res = new (Context) CoyieldExpr(Loc, Context.VoidTy, E);
+  if (E->getType()->isDependentType()) {
+    Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
+    Coroutine->CoroutineStmts.push_back(Res);
+    return Res;
+  }
+
+  // FIXME: If E is a prvalue, create a temporary.
+  // FIXME: If E is an xvalue, convert to lvalue.
+
+  // Build the await_ready, await_suspend, await_resume calls.
+  ReadySuspendResumeResult RSS = buildCoawaitCalls(*this, Loc, E);
+  if (RSS.IsInvalid)
+    return ExprError();
+
+  Expr *Res = new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
+                                        RSS.Results[2]);
   Coroutine->CoroutineStmts.push_back(Res);
   return Res;
 }