From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Fri, 26 Jul 2013 22:53:54 +0000 (+0000)
Subject: PR16708: If a lambda has an implicit return type, don't get confused if its return... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ec0808decc682f76e411eed7206a82a34b87dd7d;p=clang

PR16708: If a lambda has an implicit return type, don't get confused if its return type has already been determined to be a type containing an 'auto'.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@187266 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 5502a041d2..7feb96f6a6 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2368,23 +2368,8 @@ Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
   // For blocks/lambdas with implicit return types, we check each return
   // statement individually, and deduce the common return type when the block
   // or lambda is completed.
-  if (AutoType *AT =
-          FnRetType.isNull() ? 0 : FnRetType->getContainedAutoType()) {
-    // In C++1y, the return type may involve 'auto'.
-    FunctionDecl *FD = cast<LambdaScopeInfo>(CurCap)->CallOperator;
-    if (CurContext->isDependentContext()) {
-      // C++1y [dcl.spec.auto]p12:
-      //   Return type deduction [...] occurs when the definition is
-      //   instantiated even if the function body contains a return
-      //   statement with a non-type-dependent operand.
-      CurCap->ReturnType = FnRetType = Context.DependentTy;
-    } else if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
-      FD->setInvalidDecl();
-      return StmtError();
-    } else
-      CurCap->ReturnType = FnRetType = FD->getResultType();
-  } else if (CurCap->HasImplicitReturnType) {
-    // FIXME: Fold this into the 'auto' codepath above.
+  if (CurCap->HasImplicitReturnType) {
+    // FIXME: Fold this into the 'auto' codepath below.
     if (RetValExp && !isa<InitListExpr>(RetValExp)) {
       ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
       if (Result.isInvalid())
@@ -2411,6 +2396,21 @@ Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
     // make sure we provide a return type now for better error recovery.
     if (CurCap->ReturnType.isNull())
       CurCap->ReturnType = FnRetType;
+  } else if (AutoType *AT =
+                 FnRetType.isNull() ? 0 : FnRetType->getContainedAutoType()) {
+    // In C++1y, the return type may involve 'auto'.
+    FunctionDecl *FD = cast<LambdaScopeInfo>(CurCap)->CallOperator;
+    if (CurContext->isDependentContext()) {
+      // C++1y [dcl.spec.auto]p12:
+      //   Return type deduction [...] occurs when the definition is
+      //   instantiated even if the function body contains a return
+      //   statement with a non-type-dependent operand.
+      CurCap->ReturnType = FnRetType = Context.DependentTy;
+    } else if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
+      FD->setInvalidDecl();
+      return StmtError();
+    } else
+      CurCap->ReturnType = FnRetType = FD->getResultType();
   }
   assert(!FnRetType.isNull());
 
diff --git a/test/SemaCXX/lambda-expressions.cpp b/test/SemaCXX/lambda-expressions.cpp
index 83c5215d74..8736afe4b0 100644
--- a/test/SemaCXX/lambda-expressions.cpp
+++ b/test/SemaCXX/lambda-expressions.cpp
@@ -243,3 +243,11 @@ namespace PR13854 {
 namespace PR14518 {
   auto f = [](void) { return __func__; }; // no-warning
 }
+
+namespace PR16708 {
+  auto L = []() {
+    auto ret = 0;
+    return ret;
+    return 0;
+  };
+}