From: Alex Lorenz <arphaman@gmail.com>
Date: Mon, 15 May 2017 10:20:39 +0000 (+0000)
Subject: [index] Avoid a crash that happens when looking up a dependent name
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=7c14490d8a1bffaff51996c6c0619242f35725fa;p=clang

[index] Avoid a crash that happens when looking up a dependent name
in a record that has no definition

rdar://32194921


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303045 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Index/IndexBody.cpp b/lib/Index/IndexBody.cpp
index 9439c11dac..08d233fb83 100644
--- a/lib/Index/IndexBody.cpp
+++ b/lib/Index/IndexBody.cpp
@@ -165,6 +165,9 @@ public:
     if (!TD)
       return true;
     CXXRecordDecl *RD = TD->getTemplatedDecl();
+    if (!RD->hasDefinition())
+      return true;
+    RD = RD->getDefinition();
     std::vector<const NamedDecl *> Symbols =
         RD->lookupDependentName(NameInfo.getName(), Filter);
     // FIXME: Improve overload handling.
diff --git a/lib/Index/IndexTypeSourceInfo.cpp b/lib/Index/IndexTypeSourceInfo.cpp
index 7e2041c6cb..e9ca651e00 100644
--- a/lib/Index/IndexTypeSourceInfo.cpp
+++ b/lib/Index/IndexTypeSourceInfo.cpp
@@ -157,6 +157,9 @@ public:
     if (!TD)
       return true;
     CXXRecordDecl *RD = TD->getTemplatedDecl();
+    if (!RD->hasDefinition())
+      return true;
+    RD = RD->getDefinition();
     DeclarationName Name(DNT->getIdentifier());
     std::vector<const NamedDecl *> Symbols = RD->lookupDependentName(
         Name, [](const NamedDecl *ND) { return isa<TypeDecl>(ND); });
diff --git a/test/Index/Core/index-dependent-source.cpp b/test/Index/Core/index-dependent-source.cpp
index 35f5cf45c3..25410799a8 100644
--- a/test/Index/Core/index-dependent-source.cpp
+++ b/test/Index/Core/index-dependent-source.cpp
@@ -122,3 +122,12 @@ void indexDependentOverloads(const TemplateClass<T, S> &object) {
   object.overload1(Y());
 // CHECK-NOT: [[@LINE-1]]
 }
+
+template<typename T> struct UndefinedTemplateClass;
+
+template<typename T>
+void undefinedTemplateLookup(UndefinedTemplateClass<T> &x) {
+// Shouldn't crash!
+  x.lookup;
+  typename UndefinedTemplateClass<T>::Type y;
+}