Add tests for <endian.h>.

Also, for the stuff that's also in <netinet/in.h> as real functions,
check that they're there too (and as functions rather than macros,
since that was historically not true).

Bug: http://b/28432448
Test: ran tests
Change-Id: I7e4ae926f7e02de3b6dd38d1953e5b3b43d44f74
diff --git a/tests/Android.bp b/tests/Android.bp
index 2ccdbf8..1cca332 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -58,6 +58,7 @@
         "complex_test.cpp",
         "ctype_test.cpp",
         "dirent_test.cpp",
+        "endian_test.cpp",
         "error_test.cpp",
         "eventfd_test.cpp",
         "fcntl_test.cpp",
diff --git a/tests/endian_test.cpp b/tests/endian_test.cpp
new file mode 100644
index 0000000..85d56f0
--- /dev/null
+++ b/tests/endian_test.cpp
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <endian.h>
+
+#include <gtest/gtest.h>
+
+static constexpr uint16_t le16 = 0x1234;
+static constexpr uint32_t le32 = 0x12345678;
+static constexpr uint64_t le64 = 0x123456789abcdef0;
+
+static constexpr uint16_t be16 = 0x3412;
+static constexpr uint32_t be32 = 0x78563412;
+static constexpr uint64_t be64 = 0xf0debc9a78563412;
+
+TEST(endian, constants) {
+  ASSERT_TRUE(__LITTLE_ENDIAN == LITTLE_ENDIAN);
+  ASSERT_TRUE(__BIG_ENDIAN == BIG_ENDIAN);
+  ASSERT_TRUE(__BYTE_ORDER == BYTE_ORDER);
+
+#if defined(__BIONIC__)
+  ASSERT_TRUE(_LITTLE_ENDIAN == LITTLE_ENDIAN);
+  ASSERT_TRUE(_BIG_ENDIAN == BIG_ENDIAN);
+  ASSERT_TRUE(_BYTE_ORDER == BYTE_ORDER);
+#endif
+
+  ASSERT_EQ(__LITTLE_ENDIAN, __BYTE_ORDER);
+}
+
+TEST(endian, htons_htonl_htonq_macros) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(be16, htons(le16));
+  ASSERT_EQ(be32, htonl(le32));
+  ASSERT_EQ(be64, htonq(le64));
+#else
+  GTEST_LOG_(INFO) << "glibc doesn't have these macros";
+#endif
+}
+
+TEST(endian, ntohs_ntohl_ntohq_macros) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(le16, ntohs(be16));
+  ASSERT_EQ(le32, ntohl(be32));
+  ASSERT_EQ(le64, ntohq(be64));
+#else
+  GTEST_LOG_(INFO) << "glibc doesn't have these macros";
+#endif
+}
+
+TEST(endian, htobe16_htobe32_htobe64) {
+  ASSERT_EQ(be16, htobe16(le16));
+  ASSERT_EQ(be32, htobe32(le32));
+  ASSERT_EQ(be64, htobe64(le64));
+}
+
+TEST(endian, htole16_htole32_htole64) {
+  ASSERT_EQ(le16, htole16(le16));
+  ASSERT_EQ(le32, htole32(le32));
+  ASSERT_EQ(le64, htole64(le64));
+}
+
+TEST(endian, be16toh_be32toh_be64toh) {
+  ASSERT_EQ(le16, be16toh(be16));
+  ASSERT_EQ(le32, be32toh(be32));
+  ASSERT_EQ(le64, be64toh(be64));
+}
+
+TEST(endian, le16toh_le32toh_le64toh) {
+  ASSERT_EQ(le16, le16toh(le16));
+  ASSERT_EQ(le32, le32toh(le32));
+  ASSERT_EQ(le64, le64toh(le64));
+}
+
+TEST(endian, betoh16_betoh32_betoh64) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(le16, betoh16(be16));
+  ASSERT_EQ(le32, betoh32(be32));
+  ASSERT_EQ(le64, betoh64(be64));
+#else
+  GTEST_LOG_(INFO) << "glibc doesn't have these macros";
+#endif
+}
+
+TEST(endian, letoh16_letoh32_letoh64) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(le16, letoh16(le16));
+  ASSERT_EQ(le32, letoh32(le32));
+  ASSERT_EQ(le64, letoh64(le64));
+#else
+  GTEST_LOG_(INFO) << "glibc doesn't have these macros";
+#endif
+}
diff --git a/tests/netinet_in_test.cpp b/tests/netinet_in_test.cpp
index a337770..c0d3bc8 100644
--- a/tests/netinet_in_test.cpp
+++ b/tests/netinet_in_test.cpp
@@ -20,6 +20,16 @@
 
 #include <gtest/gtest.h>
 
+#include <android-base/macros.h>
+
+static constexpr uint16_t le16 = 0x1234;
+static constexpr uint32_t le32 = 0x12345678;
+static constexpr uint64_t le64 = 0x123456789abcdef0;
+
+static constexpr uint16_t be16 = 0x3412;
+static constexpr uint32_t be32 = 0x78563412;
+static constexpr uint64_t be64 = 0xf0debc9a78563412;
+
 TEST(netinet_in, bindresvport) {
   // This isn't something we can usually test, so just check the symbol's there.
   ASSERT_EQ(-1, bindresvport(-1, nullptr));
@@ -34,3 +44,35 @@
   in6_addr loopback = IN6ADDR_LOOPBACK_INIT;
   ASSERT_EQ(0, memcmp(&loopback, &in6addr_loopback, sizeof(in6addr_loopback)));
 }
+
+TEST(netinet_in, htons_function) {
+  ASSERT_EQ(be16, (htons)(le16));
+}
+
+TEST(netinet_in, htonl_function) {
+  ASSERT_EQ(be32, (htonl)(le32));
+}
+
+TEST(netinet_in, htonq_macro) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(be64, htonq(le64));
+#else
+  UNUSED(be64);
+#endif
+}
+
+TEST(netinet_in, ntohs_function) {
+  ASSERT_EQ(le16, (ntohs)(be16));
+}
+
+TEST(netinet_in, ntohl_function) {
+  ASSERT_EQ(le32, (ntohl)(be32));
+}
+
+TEST(netinet_in, ntohq_macro) {
+#if defined(__BIONIC__)
+  ASSERT_EQ(le64, ntohq(be64));
+#else
+  UNUSED(le64);
+#endif
+}