Add a generic component export macro
Adds base/component_export.h with a parameterized COMPONENT_EXPORT macro
to be used in place of traditional custom export headers and
definitions.
Originally discussed on https://goo.gl/bHPA4U
Usage is straightforward:
C++ header:
#include "base/component_export.h"
class COMPONENT_EXPORT(MY_COMPONENT) MyClass {};
GN component target:
component("my_component") {
sources = [ ... ]
defines = [ "IS_MY_COMPONENT_IMPL" ]
}
This CL also uses the new header to replace the custom //ipc
export header as a minimal proof-of-concept.
Bug: None
Test: ipc-dependent targets compile & link in component and non-component builds
Change-Id: I4189c6456d2c61944e6c704660ab52b5f4def984
Reviewed-on: https://chromium-review.googlesource.com/876884
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Tom Sepez <[email protected]>
Commit-Queue: Ken Rockot <[email protected]>
Cr-Commit-Position: refs/heads/master@{#531136}diff --git a/base/component_export_unittest.cc b/base/component_export_unittest.cc
new file mode 100644
index 0000000..e9943537
--- /dev/null
+++ b/base/component_export_unittest.cc
@@ -0,0 +1,82 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/component_export.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace {
+
+using ComponentExportTest = testing::Test;
+
+#define IS_TEST_COMPONENT_A_IMPL 1
+#define IS_TEST_COMPONENT_B_IMPL
+#define IS_TEST_COMPONENT_C_IMPL 0
+#define IS_TEST_COMPONENT_D_IMPL 2
+#define IS_TEST_COMPONENT_E_IMPL xyz
+
+TEST(ComponentExportTest, ImportExport) {
+ // Defined as 1. Treat as export.
+ EXPECT_EQ(1, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_A));
+
+ // Defined, but empty. Treat as import.
+ EXPECT_EQ(0, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_B));
+
+ // Defined, but 0. Treat as import.
+ EXPECT_EQ(0, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_C));
+
+ // Defined, but some other arbitrary thing that isn't 1. Treat as import.
+ EXPECT_EQ(0, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_D));
+ EXPECT_EQ(0, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_E));
+
+ // Undefined. Treat as import.
+ EXPECT_EQ(0, INSIDE_COMPONENT_IMPL(TEST_COMPONENT_F));
+
+ // And just for good measure, ensure that the macros evaluate properly in the
+ // context of preprocessor #if blocks.
+#if INSIDE_COMPONENT_IMPL(TEST_COMPONENT_A)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+
+#if !INSIDE_COMPONENT_IMPL(TEST_COMPONENT_B)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+
+#if !INSIDE_COMPONENT_IMPL(TEST_COMPONENT_C)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+
+#if !INSIDE_COMPONENT_IMPL(TEST_COMPONENT_D)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+
+#if !INSIDE_COMPONENT_IMPL(TEST_COMPONENT_E)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+
+#if !INSIDE_COMPONENT_IMPL(TEST_COMPONENT_F)
+ EXPECT_TRUE(true);
+#else
+ EXPECT_TRUE(false);
+#endif
+}
+
+#undef IS_TEST_COMPONENT_A_IMPL
+#undef IS_TEST_COMPONENT_B_IMPL
+#undef IS_TEST_COMPONENT_C_IMPL
+#undef IS_TEST_COMPONENT_D_IMPL
+#undef IS_TEST_COMPONENT_E_IMPL
+
+} // namespace
+} // namespace base
