[libclang] Fix a crash with invalid code, while skip function bodies is enabled.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175860 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseStmt.cpp b/lib/Parse/ParseStmt.cpp
index a77c034..71a7b2c 100644
--- a/lib/Parse/ParseStmt.cpp
+++ b/lib/Parse/ParseStmt.cpp
@@ -1974,7 +1974,7 @@
   assert(Tok.is(tok::l_brace));
   SourceLocation LBraceLoc = Tok.getLocation();
 
-  if (SkipFunctionBodies && Actions.canSkipFunctionBody(Decl) &&
+  if (SkipFunctionBodies && (!Decl || Actions.canSkipFunctionBody(Decl)) &&
       trySkippingFunctionBody()) {
     BodyScope.Exit();
     return Actions.ActOnSkippedFunctionBody(Decl);
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 189b3d9..03d18d4 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -8449,9 +8449,9 @@
 }
 
 Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) {
-  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Decl))
+  if (FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Decl))
     FD->setHasSkippedBody();
-  else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Decl))
+  else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(Decl))
     MD->setHasSkippedBody();
   return ActOnFinishFunctionBody(Decl, 0);
 }
diff --git a/test/Index/index-file.cpp b/test/Index/index-file.cpp
index bf2d62c..7634c0d 100644
--- a/test/Index/index-file.cpp
+++ b/test/Index/index-file.cpp
@@ -1,5 +1,9 @@
 using MyTypeAlias = int;
 
+extern "C" {
+  template < typename T > *Allocate() { }
+}
+
 // RUN: c-index-test -index-file %s > %t
 // RUN: FileCheck %s -input-file=%t