Sema: Don't emit a warning when __func__ is used in a lambda outside of a function.

Fixes PR14518.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169510 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 67b1a7a..7656d9e 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -2571,8 +2571,14 @@
   // string.
 
   Decl *currentDecl = getCurFunctionOrMethodDecl();
-  if (!currentDecl && getCurBlock())
-    currentDecl = getCurBlock()->TheDecl;
+  // Blocks and lambdas can occur at global scope. Don't emit a warning.
+  if (!currentDecl) {
+    if (const BlockScopeInfo *BSI = getCurBlock())
+      currentDecl = BSI->TheDecl;
+    else if (const LambdaScopeInfo *LSI = getCurLambda())
+      currentDecl = LSI->CallOperator;
+  }
+
   if (!currentDecl) {
     Diag(Loc, diag::ext_predef_outside_function);
     currentDecl = Context.getTranslationUnitDecl();
diff --git a/test/SemaCXX/lambda-expressions.cpp b/test/SemaCXX/lambda-expressions.cpp
index 6f92373..a333f38 100644
--- a/test/SemaCXX/lambda-expressions.cpp
+++ b/test/SemaCXX/lambda-expressions.cpp
@@ -236,3 +236,7 @@
 namespace PR13854 {
   auto l = [](void){};
 }
+
+namespace PR14518 {
+  auto f = [](void) { return __func__; }; // no-warning
+}