Make ShBuiltInResources comparable with memcmp

include/GLSLANG/ShaderLang.h

@@ -280,6 +280,8 @@ typedef struct
 
 //
 // Initialize built-in resources with minimum expected values.
+// Parameters:
+// resources: The object to initialize. Will be comparable with memcmp.
 //
 COMPILER_EXPORT void ShInitBuiltInResources(ShBuiltInResources* resources);
 

src/compiler/translator/ShaderLang.cpp

@@ -183,6 +183,9 @@ int ShFinalize()
 //
 void ShInitBuiltInResources(ShBuiltInResources* resources)
 {
+    // Make comparable.
+    memset(resources, 0, sizeof(*resources));
+
     // Constants.
     resources->MaxVertexAttribs = 8;
     resources->MaxVertexUniformVectors = 128;

tests/compiler_tests/API_test.cpp

+//
+// Copyright (c) 2014 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// API_test.cpp:
+//   Some tests for the compiler API.
+//
+
+#include "angle_gl.h"
+#include "gtest/gtest.h"
+#include "GLSLANG/ShaderLang.h"
+
+TEST(APITest, CompareShBuiltInResources)
+{
+    ShBuiltInResources a_resources;
+    memset(&a_resources, 88, sizeof(a_resources));
+    ShInitBuiltInResources(&a_resources);
+
+    ShBuiltInResources b_resources;
+    memset(&b_resources, 77, sizeof(b_resources));
+    ShInitBuiltInResources(&b_resources);
+
+    EXPECT_TRUE(memcmp(&a_resources, &b_resources, sizeof(a_resources)) == 0);
+}
+