r308269 - [Index] Prevent canonical decl becoming nullptr

[Krasimir Georgiev via cfe-commits]

Author: krasimir
Date: Tue Jul 18 00:20:53 2017
New Revision: 308269

URL: http://llvm.org/viewvc/llvm-project?rev=308269&view=rev
Log:
[Index] Prevent canonical decl becoming nullptr

Summary:
This patch prevents getCanonicalDecl returning nullptr in case it finds
a canonical TemplateDeclaration with no attached TemplatedDecl.
Found by running the indexer over a version of the standard library deep inside
a template metaprogramming mess.

Reviewers: klimek, vsk

Reviewed By: vsk

Subscribers: vsk, arphaman, cfe-commits

Differential Revision: https://reviews.llvm.org/D35212

Added:
    cfe/trunk/test/Index/Core/no-templated-canonical-decl.cpp
Modified:
    cfe/trunk/lib/Index/IndexingContext.cpp

Modified: cfe/trunk/lib/Index/IndexingContext.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Index/IndexingContext.cpp?rev=308269&r1=308268&r2=308269&view=diff
==============================================================================
--- cfe/trunk/lib/Index/IndexingContext.cpp (original)
+++ cfe/trunk/lib/Index/IndexingContext.cpp Tue Jul 18 00:20:53 2017
@@ -260,8 +260,10 @@ static const Decl *adjustParent(const De
 static const Decl *getCanonicalDecl(const Decl *D) {
   D = D->getCanonicalDecl();
   if (auto TD = dyn_cast<TemplateDecl>(D)) {
-    D = TD->getTemplatedDecl();
-    assert(D->isCanonicalDecl());
+    if (auto TTD = TD->getTemplatedDecl()) {
+      D = TTD;
+      assert(D->isCanonicalDecl());
+    }
   }
 
   return D;

Added: cfe/trunk/test/Index/Core/no-templated-canonical-decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Index/Core/no-templated-canonical-decl.cpp?rev=308269&view=auto
==============================================================================
--- cfe/trunk/test/Index/Core/no-templated-canonical-decl.cpp (added)
+++ cfe/trunk/test/Index/Core/no-templated-canonical-decl.cpp Tue Jul 18 00:20:53 2017
@@ -0,0 +1,4 @@
+// RUN: c-index-test core -print-source-symbols -include-locals -- %s | FileCheck %s
+
+template <template <typename> class A> class B { typedef A<int> A_int; };
+// CHECK: [[@LINE-1]]:46 | class(Gen)/C++ | B | c:@ST>1#t>1#T at B | <no-cgname> | Def | rel: 0