Fix old style cast warning

Fixes #2556

CMakeLists.txt

@@ -488,6 +488,8 @@ if(OTELCPP_MAINTAINER_MODE)
         $<$<STREQUAL:$<COMPILE_LANGUAGE>,CXX>:-Woverloaded-virtual>)
       add_compile_options(
         $<$<STREQUAL:$<COMPILE_LANGUAGE>,CXX>:-Wsuggest-override>)
+      add_compile_options(
+        $<$<STREQUAL:$<COMPILE_LANGUAGE>,CXX>:-Wold-style-cast>)
 
       # C and C++
       add_compile_options(-Wcast-qual)
@@ -527,6 +529,7 @@ if(OTELCPP_MAINTAINER_MODE)
       add_compile_options(-Wundef)
       add_compile_options(-Wundefined-reinterpret-cast)
       add_compile_options(-Wvla)
+      add_compile_options(-Wold-style-cast)
     endif()
   elseif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
     message("Building with msvc in maintainer mode.")

api/include/opentelemetry/trace/span_context.h

@@ -30,7 +30,7 @@ class SpanContext final
   SpanContext(bool sampled_flag, bool is_remote) noexcept
       : trace_id_(),
         span_id_(),
-        trace_flags_(trace::TraceFlags((uint8_t)sampled_flag)),
+        trace_flags_(trace::TraceFlags(static_cast<uint8_t>(sampled_flag))),
         is_remote_(is_remote),
         trace_state_(TraceState::GetDefault())
   {}

api/test/context/context_test.cc

@@ -12,15 +12,15 @@ using namespace opentelemetry;
 // Tests that the context constructor accepts an std::map.
 TEST(ContextTest, ContextIterableAcceptsMap)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context test_context                         = context::Context(map_test);
 }
 
 // Tests that the GetValue method returns the expected value.
 TEST(ContextTest, ContextGetValueReturnsExpectedValue)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123},
-                                                           {"foo_key", (int64_t)456}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)},
+                                                           {"foo_key", static_cast<int64_t>(456)}};
   const context::Context test_context                   = context::Context(map_test);
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("test_key")), 123);
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("foo_key")), 456);
@@ -29,8 +29,9 @@ TEST(ContextTest, ContextGetValueReturnsExpectedValue)
 // Tests that the SetValues method accepts an std::map.
 TEST(ContextTest, ContextSetValuesAcceptsMap)
 {
-  std::map<std::string, context::ContextValue> map_test       = {{"test_key", (int64_t)123}};
-  std::map<std::string, context::ContextValue> map_test_write = {{"foo_key", (int64_t)456}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
+  std::map<std::string, context::ContextValue> map_test_write = {
+      {"foo_key", static_cast<int64_t>(456)}};
 
   context::Context test_context = context::Context(map_test);
   context::Context foo_context  = test_context.SetValues(map_test_write);
@@ -44,7 +45,7 @@ TEST(ContextTest, ContextSetValuesAcceptsMap)
 TEST(ContextTest, ContextSetValuesAcceptsStringViewContextValue)
 {
   nostd::string_view string_view_test      = "string_view";
-  context::ContextValue context_value_test = (int64_t)123;
+  context::ContextValue context_value_test = static_cast<int64_t>(123);
 
   context::Context test_context = context::Context(string_view_test, context_value_test);
   context::Context foo_context  = test_context.SetValue(string_view_test, context_value_test);
@@ -56,21 +57,21 @@ TEST(ContextTest, ContextSetValuesAcceptsStringViewContextValue)
 // written to it.
 TEST(ContextTest, ContextImmutability)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
 
   context::Context context_test = context::Context(map_test);
-  context::Context context_foo  = context_test.SetValue("foo_key", (int64_t)456);
+  context::Context context_foo  = context_test.SetValue("foo_key", static_cast<int64_t>(456));
 
   EXPECT_FALSE(nostd::holds_alternative<int64_t>(context_test.GetValue("foo_key")));
 }
 
 // Tests that writing the same to a context overwrites the original value.
 TEST(ContextTest, ContextKeyOverwrite)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
 
   context::Context context_test = context::Context(map_test);
-  context::Context context_foo  = context_test.SetValue("test_key", (int64_t)456);
+  context::Context context_foo  = context_test.SetValue("test_key", static_cast<int64_t>(456));
 
   EXPECT_EQ(nostd::get<int64_t>(context_foo.GetValue("test_key")), 456);
 }
@@ -81,8 +82,8 @@ TEST(ContextTest, ContextInheritance)
 {
   using M = std::map<std::string, context::ContextValue>;
 
-  M m1 = {{"test_key", (int64_t)123}, {"foo_key", (int64_t)321}};
-  M m2 = {{"other_key", (int64_t)789}, {"another_key", (int64_t)987}};
+  M m1 = {{"test_key", static_cast<int64_t>(123)}, {"foo_key", static_cast<int64_t>(321)}};
+  M m2 = {{"other_key", static_cast<int64_t>(789)}, {"another_key", static_cast<int64_t>(987)}};
 
   context::Context test_context = context::Context(m1);
   context::Context foo_context  = test_context.SetValues(m2);
@@ -100,7 +101,9 @@ TEST(ContextTest, ContextInheritance)
 TEST(ContextTest, ContextCopyOperator)
 {
   std::map<std::string, context::ContextValue> test_map = {
-      {"test_key", (int64_t)123}, {"foo_key", (int64_t)456}, {"other_key", (int64_t)789}};
+      {"test_key", static_cast<int64_t>(123)},
+      {"foo_key", static_cast<int64_t>(456)},
+      {"other_key", static_cast<int64_t>(789)}};
 
   context::Context test_context   = context::Context(test_map);
   context::Context copied_context = test_context;
@@ -121,7 +124,7 @@ TEST(ContextTest, ContextEmptyMap)
 // false if not.
 TEST(ContextTest, ContextHasKey)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   const context::Context context_test                   = context::Context(map_test);
   EXPECT_TRUE(context_test.HasKey("test_key"));
   EXPECT_FALSE(context_test.HasKey("foo_key"));
@@ -130,7 +133,7 @@ TEST(ContextTest, ContextHasKey)
 // Tests that a copied context returns true when compared
 TEST(ContextTest, ContextCopyCompare)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context context_test                         = context::Context(map_test);
   context::Context copied_test                          = context_test;
   EXPECT_TRUE(context_test == copied_test);
@@ -139,8 +142,8 @@ TEST(ContextTest, ContextCopyCompare)
 // Tests that two differently constructed contexts return false when compared
 TEST(ContextTest, ContextDiffCompare)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
-  std::map<std::string, context::ContextValue> map_foo  = {{"foo_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
+  std::map<std::string, context::ContextValue> map_foo  = {{"foo_key", static_cast<int64_t>(123)}};
   context::Context context_test                         = context::Context(map_test);
   context::Context foo_test                             = context::Context(map_foo);
   EXPECT_FALSE(context_test == foo_test);

api/test/context/runtime_context_test.cc

@@ -14,7 +14,7 @@ using namespace opentelemetry;
 // Tests that GetCurrent returns the current context
 TEST(RuntimeContextTest, GetCurrent)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context test_context                         = context::Context(map_test);
   auto old_context = context::RuntimeContext::Attach(test_context);
   EXPECT_EQ(context::RuntimeContext::GetCurrent(), test_context);
@@ -23,7 +23,7 @@ TEST(RuntimeContextTest, GetCurrent)
 // Tests that detach resets the context to the previous context
 TEST(RuntimeContextTest, Detach)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context test_context                         = context::Context(map_test);
   context::Context foo_context                          = context::Context(map_test);
 
@@ -38,7 +38,7 @@ TEST(RuntimeContextTest, Detach)
 // Tests that detach returns false when the wrong context is provided
 TEST(RuntimeContextTest, DetachWrongContext)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context test_context                         = context::Context(map_test);
   auto test_context_token = context::RuntimeContext::Attach(test_context);
   EXPECT_TRUE(context::RuntimeContext::Detach(*test_context_token));
@@ -48,7 +48,7 @@ TEST(RuntimeContextTest, DetachWrongContext)
 // Tests that the ThreadLocalContext can handle three attached contexts
 TEST(RuntimeContextTest, ThreeAttachDetach)
 {
-  std::map<std::string, context::ContextValue> map_test = {{"test_key", (int64_t)123}};
+  std::map<std::string, context::ContextValue> map_test = {{"test_key", static_cast<int64_t>(123)}};
   context::Context test_context                         = context::Context(map_test);
   context::Context foo_context                          = context::Context(map_test);
   context::Context other_context                        = context::Context(map_test);
@@ -66,9 +66,10 @@ TEST(RuntimeContextTest, ThreeAttachDetach)
 // RuntimeContext::SetValue method.
 TEST(RuntimeContextTest, SetValueRuntimeContext)
 {
-  context::Context foo_context  = context::Context("foo_key", (int64_t)596);
-  auto old_context_token        = context::RuntimeContext::Attach(foo_context);
-  context::Context test_context = context::RuntimeContext::SetValue("test_key", (int64_t)123);
+  context::Context foo_context = context::Context("foo_key", static_cast<int64_t>(596));
+  auto old_context_token       = context::RuntimeContext::Attach(foo_context);
+  context::Context test_context =
+      context::RuntimeContext::SetValue("test_key", static_cast<int64_t>(123));
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("test_key")), 123);
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("foo_key")), 596);
 }
@@ -78,9 +79,9 @@ TEST(RuntimeContextTest, SetValueRuntimeContext)
 // RuntimeContext::SetValue method.
 TEST(RuntimeContextTest, SetValueOtherContext)
 {
-  context::Context foo_context = context::Context("foo_key", (int64_t)596);
+  context::Context foo_context = context::Context("foo_key", static_cast<int64_t>(596));
   context::Context test_context =
-      context::RuntimeContext::SetValue("test_key", (int64_t)123, &foo_context);
+      context::RuntimeContext::SetValue("test_key", static_cast<int64_t>(123), &foo_context);
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("test_key")), 123);
   EXPECT_EQ(nostd::get<int64_t>(test_context.GetValue("foo_key")), 596);
 }
@@ -89,7 +90,7 @@ TEST(RuntimeContextTest, SetValueOtherContext)
 // passed in string and the current Runtime Context
 TEST(RuntimeContextTest, GetValueRuntimeContext)
 {
-  context::Context foo_context = context::Context("foo_key", (int64_t)596);
+  context::Context foo_context = context::Context("foo_key", static_cast<int64_t>(596));
   auto old_context_token       = context::RuntimeContext::Attach(foo_context);
   EXPECT_EQ(nostd::get<int64_t>(context::RuntimeContext::GetValue("foo_key")), 596);
 }
@@ -98,7 +99,7 @@ TEST(RuntimeContextTest, GetValueRuntimeContext)
 // passed in string and the passed in context
 TEST(RuntimeContextTest, GetValueOtherContext)
 {
-  context::Context foo_context = context::Context("foo_key", (int64_t)596);
+  context::Context foo_context = context::Context("foo_key", static_cast<int64_t>(596));
   EXPECT_EQ(nostd::get<int64_t>(context::RuntimeContext::GetValue("foo_key", &foo_context)), 596);
 }
 
@@ -114,7 +115,7 @@ TEST(RuntimeContextTest, DetachOutOfOrder)
   std::vector<context::Context> contexts;
   for (auto i : indices)
   {
-    contexts.push_back(context::Context("index", (int64_t)i));
+    contexts.push_back(context::Context("index", static_cast<int64_t>(i)));
   }
 
   do

api/test/nostd/span_test.cc

@@ -167,10 +167,10 @@ TEST(SpanTest, Iteration)
   std::array<int, 3> array = {1, 2, 3};
 
   span<int> s1{array.data(), array.size()};
-  EXPECT_EQ(std::distance(s1.begin(), s1.end()), (ptrdiff_t)array.size());
+  EXPECT_EQ(std::distance(s1.begin(), s1.end()), static_cast<ptrdiff_t>(array.size()));
   EXPECT_TRUE(std::equal(s1.begin(), s1.end(), array.begin()));
 
   span<int, 3> s2{array.data(), array.size()};
-  EXPECT_EQ(std::distance(s2.begin(), s2.end()), (ptrdiff_t)array.size());
+  EXPECT_EQ(std::distance(s2.begin(), s2.end()), static_cast<ptrdiff_t>(array.size()));
   EXPECT_TRUE(std::equal(s2.begin(), s2.end(), array.begin()));
 }

api/test/singleton/singleton_test.cc

@@ -55,7 +55,7 @@ void do_something()
   void *component_g = dlopen("libcomponent_g.so", RTLD_NOW);
   EXPECT_NE(component_g, nullptr);
 
-  auto *func_g = (void (*)())dlsym(component_g, "do_something_in_g");
+  auto *func_g = reinterpret_cast<void (*)()>(dlsym(component_g, "do_something_in_g"));
   EXPECT_NE(func_g, nullptr);
 
   (*func_g)();
@@ -67,7 +67,7 @@ void do_something()
   void *component_h = dlopen("libcomponent_h.so", RTLD_NOW);
   EXPECT_NE(component_h, nullptr);
 
-  auto *func_h = (void (*)())dlsym(component_h, "do_something_in_h");
+  auto *func_h = reinterpret_cast<void (*)()>(dlsym(component_h, "do_something_in_h"));
   EXPECT_NE(func_h, nullptr);
 
   (*func_h)();

examples/batch/main.cc

@@ -38,7 +38,8 @@ void InitTracer()
   // We export `kNumSpans` after every `schedule_delay_millis` milliseconds.
   options.max_export_batch_size = kNumSpans;
 
-  resource::ResourceAttributes attributes = {{"service", "test_service"}, {"version", (uint32_t)1}};
+  resource::ResourceAttributes attributes = {{"service", "test_service"},
+                                             {"version", static_cast<uint32_t>(1)}};
   auto resource                           = resource::Resource::Create(attributes);
 
   auto processor = trace_sdk::BatchSpanProcessorFactory::Create(std::move(exporter), options);

examples/http/client.cc

@@ -82,7 +82,7 @@ int main(int argc, char *argv[])
   // The port the validation service listens to can be specified via the command line.
   if (argc > 1)
   {
-    port = (uint16_t)(atoi(argv[1]));
+    port = static_cast<uint16_t>(atoi(argv[1]));
   }
   else
   {

examples/http/server.cc

@@ -75,7 +75,7 @@ int main(int argc, char *argv[])
   // The port the validation service listens to can be specified via the command line.
   if (argc > 1)
   {
-    server_port = (uint16_t)atoi(argv[1]);
+    server_port = static_cast<uint16_t>(atoi(argv[1]));
   }
 
   HttpServer http_server(server_name, server_port);

exporters/ostream/test/ostream_metric_test.cc

@@ -109,7 +109,7 @@ TEST(OStreamMetricsExporter, ExportHistogramPointData)
   histogram_point_data2.boundaries_ = std::vector<double>{10.0, 20.0, 30.0};
   histogram_point_data2.count_      = 3;
   histogram_point_data2.counts_     = {200, 300, 400, 500};
-  histogram_point_data2.sum_        = (int64_t)900;
+  histogram_point_data2.sum_        = static_cast<int64_t>(900);
   metric_sdk::ResourceMetrics data;
   auto resource = opentelemetry::sdk::resource::Resource::Create(
       opentelemetry::sdk::resource::ResourceAttributes{});
@@ -191,7 +191,7 @@ TEST(OStreamMetricsExporter, ExportLastValuePointData)
   last_value_point_data.is_lastvalue_valid_ = true;
   last_value_point_data.sample_ts_          = opentelemetry::common::SystemTimestamp{};
   metric_sdk::LastValuePointData last_value_point_data2{};
-  last_value_point_data2.value_              = (int64_t)20;
+  last_value_point_data2.value_              = static_cast<int64_t>(20);
   last_value_point_data2.is_lastvalue_valid_ = true;
   last_value_point_data2.sample_ts_          = opentelemetry::common::SystemTimestamp{};
   metric_sdk::MetricData metric_data{

exporters/otlp/test/otlp_http_metric_exporter_test.cc

@@ -308,7 +308,7 @@ class OtlpHttpMetricExporterTestPeer : public ::testing::Test
     last_value_point_data.is_lastvalue_valid_ = true;
     last_value_point_data.sample_ts_          = opentelemetry::common::SystemTimestamp{};
     opentelemetry::sdk::metrics::LastValuePointData last_value_point_data2{};
-    last_value_point_data2.value_              = (int64_t)20;
+    last_value_point_data2.value_              = static_cast<int64_t>(20);
     last_value_point_data2.is_lastvalue_valid_ = true;
     last_value_point_data2.sample_ts_          = opentelemetry::common::SystemTimestamp{};
     opentelemetry::sdk::metrics::MetricData metric_data{
@@ -404,7 +404,7 @@ class OtlpHttpMetricExporterTestPeer : public ::testing::Test
     last_value_point_data.is_lastvalue_valid_ = true;
     last_value_point_data.sample_ts_          = opentelemetry::common::SystemTimestamp{};
     opentelemetry::sdk::metrics::LastValuePointData last_value_point_data2{};
-    last_value_point_data2.value_              = (int64_t)20;
+    last_value_point_data2.value_              = static_cast<int64_t>(20);
     last_value_point_data2.is_lastvalue_valid_ = true;
     last_value_point_data2.sample_ts_          = opentelemetry::common::SystemTimestamp{};
     opentelemetry::sdk::metrics::MetricData metric_data{
@@ -504,7 +504,7 @@ class OtlpHttpMetricExporterTestPeer : public ::testing::Test
     histogram_point_data2.boundaries_ = {10.0, 20.0, 30.0};
     histogram_point_data2.count_      = 3;
     histogram_point_data2.counts_     = {200, 300, 400, 500};
-    histogram_point_data2.sum_        = (int64_t)900;
+    histogram_point_data2.sum_        = static_cast<int64_t>(900);
 
     opentelemetry::sdk::metrics::MetricData metric_data{
         opentelemetry::sdk::metrics::InstrumentDescriptor{
@@ -639,7 +639,7 @@ class OtlpHttpMetricExporterTestPeer : public ::testing::Test
     histogram_point_data2.boundaries_ = {10.0, 20.0, 30.0};
     histogram_point_data2.count_      = 3;
     histogram_point_data2.counts_     = {200, 300, 400, 500};
-    histogram_point_data2.sum_        = (int64_t)900;
+    histogram_point_data2.sum_        = static_cast<int64_t>(900);
 
     opentelemetry::sdk::metrics::MetricData metric_data{
         opentelemetry::sdk::metrics::InstrumentDescriptor{

exporters/prometheus/src/exporter_utils.cc

@@ -56,7 +56,7 @@ inline std::string Sanitize(std::string name, const T &valid)
   constexpr const auto replacement_dup = '=';
 
   bool has_dup = false;
-  for (int i = 0; i < (int)name.size(); ++i)
+  for (int i = 0; i < static_cast<int>(name.size()); ++i)
   {
     if (valid(i, name[i]) && name[i] != replacement)
     {
@@ -172,8 +172,9 @@ std::vector<prometheus_client::MetricFamily> PrometheusExporterUtils::TranslateT
           {
             sum = static_cast<double>(nostd::get<int64_t>(histogram_point_data.sum_));
           }
-          SetData(std::vector<double>{sum, (double)histogram_point_data.count_}, boundaries, counts,
-                  point_data_attr.attributes, scope, time, &metric_family, data.resource_);
+          SetData(std::vector<double>{sum, static_cast<double>(histogram_point_data.count_)},
+                  boundaries, counts, point_data_attr.attributes, scope, time, &metric_family,
+                  data.resource_);
         }
         else if (type == prometheus_client::MetricType::Gauge)
         {
@@ -258,7 +259,7 @@ std::string PrometheusExporterUtils::SanitizeNames(std::string name)
   };
 
   bool has_dup = false;
-  for (int i = 0; i < (int)name.size(); ++i)
+  for (int i = 0; i < static_cast<int>(name.size()); ++i)
   {
     if (valid(i, name[i]))
     {