build: revert back to C++11

gjasny · gjasny · commit 89e79f2003e5 · 2022-11-28T22:41:49.000+01:00
There seem to be many poor souls stuck to C++11. Because we don't really depend on C++14 features let's wait for a reason to bump up the standard to C++17 or later. Close: #619 Fix: #618 Fix: #615
diff --git a/.github/workflows/bazel-ci.yml b/.github/workflows/bazel-ci.yml
@@ -8,14 +8,6 @@ jobs:
     strategy:
       matrix:
         os: [macos-latest, ubuntu-latest, windows-latest]
-        include:
-          - os: macOS-latest
-            bazel_args: "--cxxopt=-std=c++14"
-          - os: ubuntu-latest
-            bazel_args: "--cxxopt=-std=c++14"
-          - os: windows-latest
-            bazel_args: "--cxxopt=/std:c++14"
-
     steps:
       - name: Checkout source
         uses: actions/checkout@v3
@@ -48,14 +40,14 @@ jobs:
         run: bazel test --config=ssl ${{ matrix.bazel_args }} --test_output=all //...
 
       - name: Build
-        run: bazel build ${{ matrix.bazel_args }} //...
+        run: bazel build //...
 
       - name: Test
         run: bazel test ${{ matrix.bazel_args }} --test_output=all //...
 
       - name: Scraping Test
         if: runner.os != 'Windows'
-        run: bazel test ${{ matrix.bazel_args }} --test_output=all //pull/tests/integration:scrape-test
+        run: bazel test --test_output=all //pull/tests/integration:scrape-test
 
       - name: Benchmark
-        run: bazel run ${{ matrix.bazel_args }} -c opt //core/benchmarks
+        run: bazel run -c opt //core/benchmarks
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -23,12 +23,12 @@ option(ENABLE_COMPRESSION "Enable gzip compression" ON)
 option(ENABLE_TESTING "Build tests" ON)
 option(USE_THIRDPARTY_LIBRARIES "Use 3rdParty submodules" ON)
 option(THIRDPARTY_CIVETWEB_WITH_SSL "Enable SSL support for embedded civetweb source code")
-option(OVERRIDE_CXX_STANDARD_FLAGS "Force building with -std=c++14 even if the CXXFLAGS are configured differently" ON)
+option(OVERRIDE_CXX_STANDARD_FLAGS "Force building with -std=c++11 even if the CXXFLAGS are configured differently" ON)
 option(GENERATE_PKGCONFIG "Generate and install pkg-config files" ${UNIX})
 option(RUN_IWYU "Run include-what-you-use" OFF)
 
 if(OVERRIDE_CXX_STANDARD_FLAGS)
-  set(CMAKE_CXX_STANDARD 14)
+  set(CMAKE_CXX_STANDARD 11)
   set(CMAKE_CXX_EXTENSIONS Off)
 endif()
 
diff --git a/README.md b/README.md
@@ -92,7 +92,7 @@ int main() {
 
 ## Requirements
 
-Using `prometheus-cpp` requires a C++14 compliant compiler. It has been successfully tested with GNU GCC 7.4 on Ubuntu Bionic (18.04) and Visual Studio 2017.
+Using `prometheus-cpp` requires a C++11 compliant compiler. It has been successfully tested with GNU GCC 7.4 on Ubuntu Bionic (18.04) and Visual Studio 2017.
 
 ## Building
 
@@ -247,19 +247,19 @@ guidelines](https://chris.beams.io/posts/git-commit/).
 
 You can check out this repo and build the library using
 ``` bash
-bazel build --cxxopt=-std=c++14 //...
+bazel build //...
 ```
 
 Run the unit tests using
 ```
-bazel test --cxxopt=-std=c++14 //...
+bazel test //...
 ```
 
 There is also an integration test that
 uses [telegraf](https://github.com/influxdata/telegraf) to scrape a
 sample server. With telegraf installed, it can be run using
 ```
-bazel test --cxxopt=-std=c++14 //pull/tests/integration:scrape-test
+bazel test //pull/tests/integration:scrape-test
 ```
 
 ## Benchmarks
diff --git a/cmake/project-import-pkgconfig/CMakeLists.txt b/cmake/project-import-pkgconfig/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
 
 project(prometheus-cpp-import)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 11)
 
 find_package(PkgConfig REQUIRED)
 
diff --git a/core/CMakeLists.txt b/core/CMakeLists.txt
@@ -20,7 +20,7 @@ add_library(${PROJECT_NAME}::core ALIAS core)
 
 target_compile_features(core
   PUBLIC
-    cxx_std_14
+    cxx_std_11
 )
 
 target_link_libraries(core
diff --git a/core/include/prometheus/detail/future_std.h b/core/include/prometheus/detail/future_std.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <memory>
+#include <utility>
+
+namespace prometheus {
+namespace detail {
+
+// Remove as soon C++14 can be used.
+template <typename T, typename... Args>
+std::unique_ptr<T> make_unique(Args&&... args) {
+  return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
+}
+
+}  // namespace detail
+}  // namespace prometheus
diff --git a/core/include/prometheus/family.h b/core/include/prometheus/family.h
@@ -9,6 +9,7 @@
 #include "prometheus/client_metric.h"
 #include "prometheus/collectable.h"
 #include "prometheus/detail/core_export.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/detail/utils.h"
 #include "prometheus/labels.h"
 #include "prometheus/metric_family.h"
@@ -110,7 +111,7 @@ class PROMETHEUS_CPP_CORE_EXPORT Family : public Collectable {
   /// \throw std::runtime_exception on invalid label names.
   template <typename... Args>
   T& Add(const Labels& labels, Args&&... args) {
-    return Add(labels, std::make_unique<T>(args...));
+    return Add(labels, detail::make_unique<T>(args...));
   }
 
   /// \brief Remove the given dimensional data.
diff --git a/core/src/family.cc b/core/src/family.cc
@@ -4,7 +4,6 @@
 #include <cassert>
 #include <map>
 #include <stdexcept>
-#include <type_traits>
 #include <utility>
 
 #include "prometheus/check_names.h"
diff --git a/core/src/registry.cc b/core/src/registry.cc
@@ -2,11 +2,11 @@
 
 #include <algorithm>
 #include <iterator>
-#include <memory>
 #include <stdexcept>
 #include <tuple>
 
 #include "prometheus/counter.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/gauge.h"
 #include "prometheus/histogram.h"
 #include "prometheus/info.h"
@@ -141,7 +141,7 @@ Family<T>& Registry::Add(const std::string& name, const std::string& help,
     throw std::invalid_argument("Family name already exists");
   }
 
-  auto family = std::make_unique<Family<T>>(name, help, labels);
+  auto family = detail::make_unique<Family<T>>(name, help, labels);
   auto& ref = *family;
   families.push_back(std::move(family));
   return ref;
diff --git a/core/tests/family_test.cc b/core/tests/family_test.cc
@@ -7,6 +7,7 @@
 
 #include "prometheus/client_metric.h"
 #include "prometheus/counter.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/histogram.h"
 #include "prometheus/labels.h"
 #include "prometheus/summary.h"
@@ -81,16 +82,16 @@ TEST(FamilyTest, add_twice) {
 
 TEST(FamilyTest, throw_on_invalid_metric_name) {
   auto create_family_with_invalid_name = []() {
-    return std::make_unique<Family<Counter>>("", "empty name", Labels{});
+    return detail::make_unique<Family<Counter>>("", "empty name", Labels{});
   };
   EXPECT_ANY_THROW(create_family_with_invalid_name());
 }
 
 TEST(FamilyTest, throw_on_invalid_constant_label_name) {
   auto create_family_with_invalid_labels = []() {
-    return std::make_unique<Family<Counter>>("total_requests",
-                                             "Counts all requests",
-                                             Labels{{"__invalid", "counter1"}});
+    return detail::make_unique<Family<Counter>>(
+        "total_requests", "Counts all requests",
+        Labels{{"__inavlid", "counter1"}});
   };
   EXPECT_ANY_THROW(create_family_with_invalid_labels());
 }
@@ -118,7 +119,8 @@ TEST(FamilyTest, query_family_if_metric_already_exists) {
 
 TEST(FamilyTest, reject_histogram_with_constant_le_label) {
   auto labels = Labels{{"le", "test"}};
-  EXPECT_ANY_THROW(std::make_unique<Family<Histogram>>("name", "help", labels));
+  EXPECT_ANY_THROW(
+      detail::make_unique<Family<Histogram>>("name", "help", labels));
 }
 
 TEST(FamilyTest, reject_histogram_with_le_label) {
@@ -129,7 +131,8 @@ TEST(FamilyTest, reject_histogram_with_le_label) {
 
 TEST(FamilyTest, reject_summary_with_constant_quantile_label) {
   auto labels = Labels{{"quantile", "test"}};
-  EXPECT_ANY_THROW(std::make_unique<Family<Summary>>("name", "help", labels));
+  EXPECT_ANY_THROW(
+      detail::make_unique<Family<Summary>>("name", "help", labels));
 }
 
 TEST(FamilyTest, reject_summary_with_quantile_label) {
diff --git a/core/tests/serializer_test.cc b/core/tests/serializer_test.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "prometheus/counter.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/family.h"
 #include "prometheus/metric_family.h"
 #include "prometheus/text_serializer.h"
@@ -40,7 +41,7 @@ TEST_F(SerializerTest, shouldSerializeLocaleIndependent) {
   // ignore missing locale and skip test if setup fails
   try {
     localeWithCommaDecimalSeparator =
-        std::make_unique<RAIILocale>("de_DE.UTF-8");
+        detail::make_unique<RAIILocale>("de_DE.UTF-8");
   } catch (std::runtime_error&) {
     GTEST_SKIP();
   }
diff --git a/pull/CMakeLists.txt b/pull/CMakeLists.txt
@@ -39,7 +39,7 @@ add_library(${PROJECT_NAME}::pull ALIAS pull)
 
 target_compile_features(pull
   PUBLIC
-    cxx_std_14
+    cxx_std_11
 )
 
 target_link_libraries(pull
diff --git a/pull/src/endpoint.cc b/pull/src/endpoint.cc
@@ -1,10 +1,10 @@
 #include "endpoint.h"
 
-#include <memory>
 #include <utility>
 
 #include "basic_auth.h"
 #include "handler.h"
+#include "prometheus/detail/future_std.h"
 
 namespace prometheus {
 namespace detail {
@@ -21,7 +21,8 @@ Endpoint::Endpoint(CivetServer& server, std::string uri)
     : server_(server),
       uri_(std::move(uri)),
       endpoint_registry_(std::make_shared<Registry>()),
-      metrics_handler_(std::make_unique<MetricsHandler>(*endpoint_registry_)) {
+      metrics_handler_(
+          detail::make_unique<MetricsHandler>(*endpoint_registry_)) {
   RegisterCollectable(endpoint_registry_);
   server_.addHandler(uri_, metrics_handler_.get());
 }
@@ -46,7 +47,7 @@ void Endpoint::RegisterAuth(
   // split creating, assigning, and storing to avoid a race-condition when
   // being called the second time and the handler is replaced
   auto new_handler =
-      std::make_unique<BasicAuthHandler>(std::move(authCB), realm);
+      detail::make_unique<BasicAuthHandler>(std::move(authCB), realm);
   server_.addAuthHandler(uri_, new_handler.get());
   auth_handler_ = std::move(new_handler);
 }
diff --git a/pull/src/exposer.cc b/pull/src/exposer.cc
@@ -2,12 +2,12 @@
 
 #include <algorithm>
 #include <iterator>
-#include <memory>
 #include <string>
 #include <utility>
 
 #include "CivetServer.h"
 #include "endpoint.h"
+#include "prometheus/detail/future_std.h"
 
 namespace prometheus {
 
@@ -20,7 +20,8 @@ Exposer::Exposer(const std::string& bind_address, const std::size_t num_threads,
 
 Exposer::Exposer(std::vector<std::string> options,
                  const CivetCallbacks* callbacks)
-    : server_(std::make_unique<CivetServer>(std::move(options), callbacks)) {}
+    : server_(detail::make_unique<CivetServer>(std::move(options), callbacks)) {
+}
 
 Exposer::~Exposer() = default;
 
@@ -59,7 +60,7 @@ detail::Endpoint& Exposer::GetEndpointForUri(const std::string& uri) {
     return *it->get();
   }
 
-  endpoints_.emplace_back(std::make_unique<detail::Endpoint>(*server_, uri));
+  endpoints_.emplace_back(detail::make_unique<detail::Endpoint>(*server_, uri));
   return *endpoints_.back().get();
 }
 
diff --git a/pull/tests/integration/integration_test.cc b/pull/tests/integration/integration_test.cc
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "prometheus/counter.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/exposer.h"
 #include "prometheus/family.h"
 #include "prometheus/registry.h"
@@ -22,7 +23,7 @@ using namespace testing;
 class IntegrationTest : public testing::Test {
  public:
   void SetUp() override {
-    exposer_ = std::make_unique<Exposer>("127.0.0.1:0");
+    exposer_ = detail::make_unique<Exposer>("127.0.0.1:0");
     auto ports = exposer_->GetListeningPorts();
     base_url_ = std::string("http://127.0.0.1:") + std::to_string(ports.at(0));
   }
diff --git a/push/CMakeLists.txt b/push/CMakeLists.txt
@@ -11,7 +11,7 @@ add_library(${PROJECT_NAME}::push ALIAS push)
 
 target_compile_features(push
   PUBLIC
-    cxx_std_14
+    cxx_std_11
 )
 
 target_link_libraries(push
diff --git a/push/src/gateway.cc b/push/src/gateway.cc
@@ -9,6 +9,7 @@
 #include <sstream>
 
 #include "curl_wrapper.h"
+#include "prometheus/detail/future_std.h"
 #include "prometheus/metric_family.h"  // IWYU pragma: keep
 #include "prometheus/text_serializer.h"
 
@@ -20,7 +21,7 @@ namespace prometheus {
 Gateway::Gateway(const std::string& host, const std::string& port,
                  const std::string& jobname, const Labels& labels,
                  const std::string& username, const std::string& password) {
-  curlWrapper_ = std::make_unique<detail::CurlWrapper>(username, password);
+  curlWrapper_ = detail::make_unique<detail::CurlWrapper>(username, password);
 
   std::stringstream jobUriStream;
   jobUriStream << host << ':' << port << "/metrics/job/" << jobname;

Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,7 @@ add_library(${PROJECT_NAME}::core ALIAS core)`
`20`	`20`
`21`	`21`	`target_compile_features(core`
`22`	`22`	`PUBLIC`
`23`		`- cxx_std_14`
	`23`	`+ cxx_std_11`
`24`	`24`	`)`
`25`	`25`
`26`	`26`	`target_link_libraries(core`