r259287 - [SemaCXX] Fix crash-on-invalid while trying to deduce return type of a lambda.

[Argyrios Kyrtzidis via cfe-commits]

Author: akirtzidis
Date: Fri Jan 29 19:51:20 2016
New Revision: 259287

URL: http://llvm.org/viewvc/llvm-project?rev=259287&view=rev
Log:
[SemaCXX] Fix crash-on-invalid while trying to deduce return type of a lambda.

rdar://22032373

Modified:
    cfe/trunk/lib/Sema/SemaStmt.cpp
    cfe/trunk/test/SemaCXX/lambda-expressions.cpp

Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=259287&r1=259286&r2=259287&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Fri Jan 29 19:51:20 2016
@@ -3066,22 +3066,23 @@ bool Sema::DeduceFunctionTypeFromReturnE
   //  has multiple return statements, the return type is deduced for each return
   //  statement. [...] if the type deduced is not the same in each deduction,
   //  the program is ill-formed.
-  if (AT->isDeduced() && !FD->isInvalidDecl()) {
+  QualType DeducedT = AT->getDeducedType();
+  if (!DeducedT.isNull() && !FD->isInvalidDecl()) {
     AutoType *NewAT = Deduced->getContainedAutoType();
     CanQualType OldDeducedType = Context.getCanonicalFunctionResultType(
-                                   AT->getDeducedType());
+                                   DeducedT);
     CanQualType NewDeducedType = Context.getCanonicalFunctionResultType(
                                    NewAT->getDeducedType());
     if (!FD->isDependentContext() && OldDeducedType != NewDeducedType) {
       const LambdaScopeInfo *LambdaSI = getCurLambda();
       if (LambdaSI && LambdaSI->HasImplicitReturnType) {
         Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible)
-          << NewAT->getDeducedType() << AT->getDeducedType()
+          << NewAT->getDeducedType() << DeducedT
           << true /*IsLambda*/;
       } else {
         Diag(ReturnLoc, diag::err_auto_fn_different_deductions)
           << (AT->isDecltypeAuto() ? 1 : 0)
-          << NewAT->getDeducedType() << AT->getDeducedType();
+          << NewAT->getDeducedType() << DeducedT;
       }
       return true;
     }

Modified: cfe/trunk/test/SemaCXX/lambda-expressions.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/lambda-expressions.cpp?rev=259287&r1=259286&r2=259287&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/lambda-expressions.cpp (original)
+++ cfe/trunk/test/SemaCXX/lambda-expressions.cpp Fri Jan 29 19:51:20 2016
@@ -476,3 +476,14 @@ int main() {
 
 A<int> a;
 }
+
+// rdar://22032373
+namespace rdar22032373 {
+void foo() {
+  auto blk = [](bool b) {
+    if (b)
+      return undeclared_error; // expected-error {{use of undeclared identifier}}
+    return 0;
+  };
+}
+}