Fix memory leak for APValues that do memory allocation.

This patch ensures that APValues are deallocated with the ASTContext by
registering a deallocation function for APValues to the ASTContext.

Original version of the patch by James Dennett.

llvm-svn: 183101
diff --git a/clang/unittests/AST/DeclTest.cpp b/clang/unittests/AST/DeclTest.cpp
new file mode 100644
index 0000000..ff7c30c
--- /dev/null
+++ b/clang/unittests/AST/DeclTest.cpp
@@ -0,0 +1,56 @@
+//===- unittests/AST/DeclTest.cpp --- Declaration tests -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Unit tests for Decl nodes in the AST.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Tooling/Tooling.h"
+#include "gtest/gtest.h"
+
+using namespace clang::ast_matchers;
+using namespace clang::tooling;
+
+TEST(Decl, CleansUpAPValues) {
+  MatchFinder Finder;
+  llvm::OwningPtr<FrontendActionFactory> Factory(
+      newFrontendActionFactory(&Finder));
+
+  // This is a regression test for a memory leak in APValues for structs that
+  // allocate memory. This test only fails if run under valgrind with full leak
+  // checking enabled.
+  std::vector<std::string> Args(1, "-std=c++11");
+  ASSERT_TRUE(runToolOnCodeWithArgs(
+      Factory->create(),
+      "struct X { int a; }; constexpr X x = { 42 };"
+      "union Y { constexpr Y(int a) : a(a) {} int a; }; constexpr Y y = { 42 };"
+      "constexpr int z[2] = { 42, 43 };"
+      "constexpr int __attribute__((vector_size(16))) v1 = {};"
+      "constexpr __uint128_t large_int = 0xffffffffffffffff;"
+      "constexpr __uint128_t small_int = 1;"
+      "constexpr double d1 = 42.42;"
+      "constexpr long double d2 = 42.42;"
+      "constexpr _Complex long double c1 = 42.0i;"
+      "constexpr _Complex long double c2 = 42.0;"
+      "template<int N> struct A : A<N-1> {};"
+      "template<> struct A<0> { int n; }; A<50> a;"
+      "constexpr int &r = a.n;"
+      "constexpr int A<50>::*p = &A<50>::n;"
+      "void f() { foo: bar: constexpr int k = __builtin_constant_p(0) ?"
+      "                         (char*)&&foo - (char*)&&bar : 0; }",
+      Args));
+
+  // FIXME: Once this test starts breaking we can test APValue::needsCleanup
+  // for ComplexInt.
+  ASSERT_FALSE(runToolOnCodeWithArgs(
+      Factory->create(),
+      "constexpr _Complex __uint128_t c = 0xffffffffffffffff;",
+      Args));
+}