C++1y: provide full 'auto' return type deduction for lambda expressions. This
completes the implementation of N3638.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181669 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index b5ff7a3..6d568c4 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2362,22 +2362,37 @@
StmtResult
Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) {
// If this is the first return we've seen, infer the return type.
- // [expr.prim.lambda]p4 in C++11; block literals follow a superset of those
- // rules which allows multiple return statements.
+ // [expr.prim.lambda]p4 in C++11; block literals follow the same rules.
CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction());
QualType FnRetType = CurCap->ReturnType;
// 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 (CurCap->HasImplicitReturnType) {
+ 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 (RetValExp && !isa<InitListExpr>(RetValExp)) {
ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp);
if (Result.isInvalid())
return StmtError();
RetValExp = Result.take();
- if (!RetValExp->isTypeDependent())
+ if (!CurContext->isDependentContext())
FnRetType = RetValExp->getType();
else
FnRetType = CurCap->ReturnType = Context.DependentTy;
@@ -2553,7 +2568,6 @@
if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp))
return StmtError();
- // FIXME: Unify this and C++1y auto function handling.
if (isa<CapturingScopeInfo>(getCurFunction()))
return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp);