ci: remove Clang-3.8 support (googleapis#7001)

coryan · web-flow · commit 2deedde0117b · 2021-07-16T15:50:36.000-04:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -75,6 +75,12 @@ value for the additional complexity. If you prefer to build all the dependencies
 from source using CMake, we recommend you use a package manager, such as
 [vcpkg][vcpkg-github].
 
+**We have dropped support for Clang < 6.0:** to support the latest Google Cloud
+services we need a version of Protobuf that can compile all the `.proto` files
+in https://github.com/googleapis/googleapis. At this time this requires
+Protobuf >= 3.15, and these versions of Protobuf do not support older versions
+of the Clang compiler.
+
 [vcpkg-github]: https://github.com/microsoft/vcpkg
 
 ## v1.29.0 - 2021-07
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -47,7 +47,7 @@ endif ()
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
 
-    # gcc-4.8 is the first release that claims C++11 support.
+    # GCC >= 5.4 is required by Abseil, so we must require it too.
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.4)
         message(
             FATAL_ERROR
@@ -57,11 +57,13 @@ if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
     endif ()
 elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 
-    # Before Clang-3.8 we ran into bugs with std::async() and exceptions.
-    if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.8)
+    # Clang > 3.8 is required by the versions of protobuf that can compile
+    # googleapis protos. We only test with >= 6.0 because that is easy to
+    # install in our CI systems.
+    if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.0)
         message(
             FATAL_ERROR
-                "Clang version must be at least 3.8. Older versions"
+                "Clang version must be at least 6.0. Older versions"
                 " either lack C++11 support or have bugs that prevent us from"
                 " using them.")
     endif ()
diff --git a/README.md b/README.md
@@ -156,7 +156,8 @@ int main(int argc, char* argv[]) {
 ## Support
 
 * This project supports Windows, macOS, Linux
-* This project supports C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* This project supports C++11 (and higher) compilers (we test with GCC >= 5.4,
+  Clang >= 6.0, and MSVC >= 2019)
 * This project supports Bazel and CMake builds. See the [Quickstart examples](https://github.com/googleapis/google-cloud-cpp#quickstart)
 * This project uses dependencies described in [doc/packaging.md](https://github.com/googleapis/google-cloud-cpp/blob/main/doc/packaging.md)
 * This project works with or without exceptions enabled
diff --git a/ci/cloudbuild/builds/clang-38.sh b/ci/cloudbuild/builds/clang-38.sh
diff --git a/ci/cloudbuild/triggers/clang-38-ci.yaml b/ci/cloudbuild/triggers/clang-38-ci.yaml
diff --git a/ci/cloudbuild/triggers/clang-38-pr.yaml b/ci/cloudbuild/triggers/clang-38-pr.yaml
diff --git a/ci/generate-markdown/generate-bigtable-readme.sh b/ci/generate-markdown/generate-bigtable-readme.sh
@@ -38,7 +38,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/ci/generate-markdown/generate-iam-readme.sh b/ci/generate-markdown/generate-iam-readme.sh
@@ -36,7 +36,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/ci/generate-markdown/generate-pubsub-readme.sh b/ci/generate-markdown/generate-pubsub-readme.sh
@@ -38,7 +38,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/ci/generate-markdown/generate-readme.sh b/ci/generate-markdown/generate-readme.sh
@@ -143,7 +143,8 @@ cat <<"EOF"
 ## Support
 
 * This project supports Windows, macOS, Linux
-* This project supports C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* This project supports C++11 (and higher) compilers (we test with GCC >= 5.4,
+  Clang >= 6.0, and MSVC >= 2019)
 * This project supports Bazel and CMake builds. See the [Quickstart examples](https://github.com/googleapis/google-cloud-cpp#quickstart)
 * This project uses dependencies described in [doc/packaging.md](https://github.com/googleapis/google-cloud-cpp/blob/main/doc/packaging.md)
 * This project works with or without exceptions enabled
diff --git a/ci/generate-markdown/generate-spanner-readme.sh b/ci/generate-markdown/generate-spanner-readme.sh
@@ -38,7 +38,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/ci/generate-markdown/generate-storage-readme.sh b/ci/generate-markdown/generate-storage-readme.sh
@@ -41,7 +41,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/README.md b/google/cloud/README.md
@@ -18,8 +18,8 @@ notice. These include `google/cloud/internal/`, and
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC >= 4.9, Clang >= 3.8,
-  and MSVC >= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/bigtable/README.md b/google/cloud/bigtable/README.md
@@ -13,7 +13,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/iam/README.md b/google/cloud/iam/README.md
@@ -11,7 +11,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/internal/port_platform.h b/google/cloud/internal/port_platform.h
@@ -57,9 +57,9 @@
 // further down in this file. Because Clang defines both __GNUC__ and __clang__
 // test for the Clang version first (sigh).
 #if defined(__clang__)
-#  if __clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 8)
-#    error "Only Clang >= 3.8 is supported."
-#  endif  // Clang < 3.8
+#  if __clang_major__ < 6
+#    error "Only Clang >= 6.0 is supported."
+#  endif  // Clang < 6.0
 #elif defined(__GNUC__)
 #  if __GNUC__ < 5 || (__GNUC__ == 5 && __GNUC_MINOR__ < 4)
 #    error "Only GCC >= 5.4 is supported."
diff --git a/google/cloud/internal/type_list_test.cc b/google/cloud/internal/type_list_test.cc
@@ -68,7 +68,7 @@ TEST(TypeList, Cat) {
 
 TEST(TypeList, Big) {
   // Verifies that we can concatenate lots of types, which breaks with
-  // `std::tuple` on clang 3.8
+  // `std::tuple` on older versions of Clang
   using BigList = TypeList<int, int, int, int, int, int, int, int, int, int>;
   using BiggerList = TypeListCatT<BigList, BigList, BigList, BigList, BigList>;
   static_assert(!std::is_same<BigList, BiggerList>::value, "");
diff --git a/google/cloud/log.cc b/google/cloud/log.cc
@@ -46,18 +46,10 @@ std::ostream& operator<<(std::ostream& os, Timestamp const& ts) {
 
 auto constexpr kSeverityCount = static_cast<int>(Severity::GCP_LS_HIGHEST) + 1;
 
-// Double braces needed to workaround a clang-3.8 bug.
-std::array<char const*, kSeverityCount> constexpr kSeverityNames{{
-    "TRACE",
-    "DEBUG",
-    "INFO",
-    "NOTICE",
-    "WARNING",
-    "ERROR",
-    "CRITICAL",
-    "ALERT",
-    "FATAL",
-}};
+std::array<char const*, kSeverityCount> constexpr kSeverityNames{
+    "TRACE", "DEBUG",    "INFO",  "NOTICE", "WARNING",
+    "ERROR", "CRITICAL", "ALERT", "FATAL",
+};
 
 absl::optional<Severity> ParseSeverity(std::string const& name) {
   int i = 0;
diff --git a/google/cloud/pubsub/README.md b/google/cloud/pubsub/README.md
@@ -13,7 +13,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 5.4, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/spanner/README.md b/google/cloud/spanner/README.md
@@ -13,7 +13,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/spanner/bytes_test.cc b/google/cloud/spanner/bytes_test.cc
@@ -158,8 +158,7 @@ TEST(Bytes, OutputStreamEscapingCannotFail) {
   for (int i = 0; i < std::numeric_limits<ByteType>::max() + 1; ++i) {
     auto const b = static_cast<ByteType>(i);
     std::ostringstream ss;
-    // Workaround clang-3.8 bug by using double braces
-    ss << Bytes(std::array<ByteType, 1>{{b}});
+    ss << Bytes(std::array<ByteType, 1>{b});
     EXPECT_NE(ss.str(), R"(B"\?")") << "i=" << i;
   }
 }
diff --git a/google/cloud/storage/README.md b/google/cloud/storage/README.md
@@ -16,7 +16,8 @@ Please note that the Google Cloud C++ client libraries do **not** follow
 ## Supported Platforms
 
 * Windows, macOS, Linux
-* C++11 (and higher) compilers (we test with GCC \>= 4.9, Clang >= 3.8, and MSVC \>= 2019)
+* C++11 (and higher) compilers (we test with GCC >= 5.4, Clang >= 6.0, and
+  MSVC >= 2019)
 * Environments with or without exceptions
 * Bazel and CMake builds
 
diff --git a/google/cloud/storage/parallel_upload.h b/google/cloud/storage/parallel_upload.h
@@ -1109,14 +1109,7 @@ struct CreateParallelUploadShards {
           offset, shard_end - offset, upload_buffer_size));
       offset = shard_end;
     }
-#if defined(__clang__) && \
-    (__clang_major__ < 4 || (__clang_major__ == 3 && __clang_minor__ <= 8))
-    // The extra std::move() is required to workaround a Clang <= 3.8 bug, which
-    // tries to copy the result otherwise.
-    return std::move(res);
-#else
     return res;
-#endif
   }
 };
 
