From 25c85cacbdb06113e0b6411a285201bd65f7b6a2 Mon Sep 17 00:00:00 2001
From: Richard Trieu <rtrieu@google.com>
Date: Wed, 22 Oct 2014 02:52:00 +0000
Subject: [PATCH] Disable the uninitialized field warning in uninstantiated
 classes.

If a templated class is not instantiated, then the AST for it could be missing
some things that would throw the field checker off.  Wait until specialization
before emitting these warnings.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@220363 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaDeclCXX.cpp       |  3 +++
 test/SemaCXX/uninitialized.cpp | 43 ++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 1d87abb33f..283f032061 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -2525,6 +2525,9 @@ namespace {
 
     const CXXRecordDecl *RD = Constructor->getParent();
 
+    if (RD->getDescribedClassTemplate() != nullptr)
+      return;
+
     // Holds fields that are uninitialized.
     llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
 
diff --git a/test/SemaCXX/uninitialized.cpp b/test/SemaCXX/uninitialized.cpp
index 2596dd044d..61dabb2d00 100644
--- a/test/SemaCXX/uninitialized.cpp
+++ b/test/SemaCXX/uninitialized.cpp
@@ -1220,3 +1220,46 @@ namespace init_list {
     {}
   };
 }
+
+namespace template_class {
+class Foo {
+ public:
+    int *Create() { return nullptr; }
+};
+
+template <typename T>
+class A {
+public:
+  // Don't warn on foo here.
+  A() : ptr(foo->Create()) {}
+
+private:
+  Foo *foo = new Foo;
+  int *ptr;
+};
+
+template <typename T>
+class B {
+public:
+  // foo is uninitialized here, but class B is never instantiated.
+  B() : ptr(foo->Create()) {}
+
+private:
+  Foo *foo;
+  int *ptr;
+};
+
+template <typename T>
+class C {
+public:
+  C() : ptr(foo->Create()) {}
+  // expected-warning@-1 {{field 'foo' is uninitialized when used here}}
+private:
+  Foo *foo;
+  int *ptr;
+};
+
+C<int> c;
+// expected-note@-1 {{in instantiation of member function 'template_class::C<int>::C' requested here}}
+
+}
-- 
2.40.0