[CODE HEALTH] Fix clang-tidy misc-use-internal-linkage warnings

.github/workflows/clang-tidy.yaml

@@ -17,9 +17,9 @@ jobs:
       matrix:
         include:
           - cmake_options: all-options-abiv1-preview
-            warning_limit: 490
+            warning_limit: 330
           - cmake_options: all-options-abiv2-preview
-            warning_limit: 492
+            warning_limit: 332
     env:
       CC: /usr/bin/clang-18
       CXX: /usr/bin/clang++-18

CHANGELOG.md

@@ -39,6 +39,9 @@ Increment the:
 * [EXAMPLES] Deprecated semantic conventions used
   [#3905](https://github.com/open-telemetry/opentelemetry-cpp/pull/3905)
 
+* [CODE HEALTH] Fix clang-tidy misc-use-internal-linkage warnings
+  [#3600](https://github.com/open-telemetry/opentelemetry-cpp/pull/3600)
+
 Important changes:
 
 * [BUILD] Revisit EventLogger deprecation

api/test/baggage/baggage_test.cc

@@ -15,7 +15,7 @@
 
 using namespace opentelemetry::baggage;
 
-std::string header_with_custom_entries(size_t num_entries)
+static std::string header_with_custom_entries(size_t num_entries)
 {
   std::string header;
   for (size_t i = 0; i < num_entries; i++)
@@ -31,7 +31,7 @@ std::string header_with_custom_entries(size_t num_entries)
   return header;
 }
 
-std::string header_with_custom_size(size_t key_value_size, size_t num_entries)
+static std::string header_with_custom_size(size_t key_value_size, size_t num_entries)
 {
   std::string header = "";
   for (size_t i = 0; i < num_entries; i++)

api/test/nostd/function_ref_test.cc

@@ -8,12 +8,12 @@
 
 using namespace opentelemetry::nostd;
 
-int Call(function_ref<int()> f)
+static int Call(function_ref<int()> f)
 {
   return f();
 }
 
-int Return3()
+static int Return3()
 {
   return 3;
 }

api/test/singleton/singleton_test.cc

@@ -32,7 +32,7 @@
 
 using namespace opentelemetry;
 
-void do_something()
+static void do_something()
 {
   do_something_in_a();
   do_something_in_b();
@@ -111,33 +111,33 @@ void do_something()
 #endif /* BAZEL_BUILD */
 }
 
-int span_a_lib_count   = 0;
-int span_a_f1_count    = 0;
-int span_a_f2_count    = 0;
-int span_b_lib_count   = 0;
-int span_b_f1_count    = 0;
-int span_b_f2_count    = 0;
-int span_c_lib_count   = 0;
-int span_c_f1_count    = 0;
-int span_c_f2_count    = 0;
-int span_d_lib_count   = 0;
-int span_d_f1_count    = 0;
-int span_d_f2_count    = 0;
-int span_e_lib_count   = 0;
-int span_e_f1_count    = 0;
-int span_e_f2_count    = 0;
-int span_f_lib_count   = 0;
-int span_f_f1_count    = 0;
-int span_f_f2_count    = 0;
-int span_g_lib_count   = 0;
-int span_g_f1_count    = 0;
-int span_g_f2_count    = 0;
-int span_h_lib_count   = 0;
-int span_h_f1_count    = 0;
-int span_h_f2_count    = 0;
-int unknown_span_count = 0;
-
-void reset_counts()
+static int span_a_lib_count   = 0;
+static int span_a_f1_count    = 0;
+static int span_a_f2_count    = 0;
+static int span_b_lib_count   = 0;
+static int span_b_f1_count    = 0;
+static int span_b_f2_count    = 0;
+static int span_c_lib_count   = 0;
+static int span_c_f1_count    = 0;
+static int span_c_f2_count    = 0;
+static int span_d_lib_count   = 0;
+static int span_d_f1_count    = 0;
+static int span_d_f2_count    = 0;
+static int span_e_lib_count   = 0;
+static int span_e_f1_count    = 0;
+static int span_e_f2_count    = 0;
+static int span_f_lib_count   = 0;
+static int span_f_f1_count    = 0;
+static int span_f_f2_count    = 0;
+static int span_g_lib_count   = 0;
+static int span_g_f1_count    = 0;
+static int span_g_f2_count    = 0;
+static int span_h_lib_count   = 0;
+static int span_h_f1_count    = 0;
+static int span_h_f2_count    = 0;
+static int unknown_span_count = 0;
+
+static void reset_counts()
 {
   span_a_lib_count   = 0;
   span_a_f1_count    = 0;
@@ -331,7 +331,7 @@ class MyTracerProvider : public trace::TracerProvider
 #endif
 };
 
-void setup_otel()
+static void setup_otel()
 {
   std::shared_ptr<opentelemetry::trace::TracerProvider> provider = MyTracerProvider::Create();
 
@@ -343,7 +343,7 @@ void setup_otel()
   trace_api::Provider::SetTracerProvider(provider);
 }
 
-void cleanup_otel()
+static void cleanup_otel()
 {
   std::shared_ptr<opentelemetry::trace::TracerProvider> provider(
       new opentelemetry::trace::NoopTracerProvider());

exporters/ostream/src/metric_exporter.cc

@@ -76,7 +76,7 @@ namespace metrics
 {
 
 template <typename Container>
-inline void printVec(std::ostream &os, Container &vec)
+static inline void printVec(std::ostream &os, Container &vec)
 {
   using T = typename std::decay<decltype(*vec.begin())>::type;
   os << '[';

exporters/ostream/src/span_exporter.cc

@@ -40,7 +40,7 @@ namespace exporter
 namespace trace
 {
 
-std::ostream &operator<<(std::ostream &os, trace_api::SpanKind span_kind)
+static std::ostream &operator<<(std::ostream &os, trace_api::SpanKind span_kind)
 {
   switch (span_kind)
   {

exporters/otlp/test/otlp_http_exporter_test.cc

@@ -56,8 +56,8 @@ static nostd::span<T, N> MakeSpan(T (&array)[N])
   return nostd::span<T, N>(array);
 }
 
-OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
-                                                bool async_mode)
+static OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
+                                                       bool async_mode)
 {
   std::shared_ptr<opentelemetry::sdk::common::ThreadInstrumentation> not_instrumented;
   OtlpHttpExporterOptions options;

exporters/otlp/test/otlp_http_log_record_exporter_test.cc

@@ -51,8 +51,8 @@ static nostd::span<T, N> MakeSpan(T (&array)[N])
   return nostd::span<T, N>(array);
 }
 
-OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
-                                                bool async_mode)
+static OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
+                                                       bool async_mode)
 {
   std::shared_ptr<opentelemetry::sdk::common::ThreadInstrumentation> not_instrumented;
   OtlpHttpLogRecordExporterOptions options;

exporters/otlp/test/otlp_http_metric_exporter_test.cc

@@ -72,8 +72,8 @@ static IntegerType JsonToInteger(nlohmann::json value)
   return value.get<IntegerType>();
 }
 
-OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
-                                                bool async_mode)
+static OtlpHttpClientOptions MakeOtlpHttpClientOptions(HttpRequestContentType content_type,
+                                                       bool async_mode)
 {
   std::shared_ptr<opentelemetry::sdk::common::ThreadInstrumentation> not_instrumented;
   OtlpHttpMetricExporterOptions options;

exporters/prometheus/src/exporter_options.cc

@@ -13,7 +13,7 @@ namespace exporter
 namespace metrics
 {
 
-inline const std::string GetPrometheusDefaultHttpEndpoint()
+static inline const std::string GetPrometheusDefaultHttpEndpoint()
 {
   constexpr char kPrometheusEndpointEnv[]     = "PROMETHEUS_EXPORTER_ENDPOINT";
   constexpr char kPrometheusEndpointDefault[] = "localhost:9464";
@@ -25,7 +25,7 @@ inline const std::string GetPrometheusDefaultHttpEndpoint()
   return exists ? endpoint : kPrometheusEndpointDefault;
 }
 
-inline bool GetPrometheusWithoutOtelScope()
+static inline bool GetPrometheusWithoutOtelScope()
 {
   constexpr char kPrometheusWithoutOtelScope[] = "OTEL_CPP_PROMETHEUS_EXPORTER_WITHOUT_OTEL_SCOPE";
 
@@ -36,7 +36,7 @@ inline bool GetPrometheusWithoutOtelScope()
   return exists ? setting : false;
 }
 
-inline bool GetPrometheusPopulateTargetInfo()
+static inline bool GetPrometheusPopulateTargetInfo()
 {
   constexpr char kPrometheusPopulateTargetInfo[] =
       "OTEL_CPP_PROMETHEUS_EXPORTER_POPULATE_TARGET_INFO";
@@ -48,7 +48,7 @@ inline bool GetPrometheusPopulateTargetInfo()
   return exists ? setting : true;
 }
 
-inline bool GetPrometheusWithoutUnits()
+static inline bool GetPrometheusWithoutUnits()
 {
   constexpr char kPrometheusWithoutUnits[] = "OTEL_CPP_PROMETHEUS_EXPORTER_WITHOUT_UNITS";
   bool setting{};
@@ -58,7 +58,7 @@ inline bool GetPrometheusWithoutUnits()
   return exists ? setting : false;
 }
 
-inline bool GetPrometheusWithoutTypeSuffix()
+static inline bool GetPrometheusWithoutTypeSuffix()
 {
   constexpr char kPrometheusWithoutTypeSuffix[] =
       "OTEL_CPP_PROMETHEUS_EXPORTER_WITHOUT_TYPE_SUFFIX";

exporters/prometheus/test/exporter_utils_test.cc

@@ -79,12 +79,12 @@ class SanitizeNameTester
 }  // namespace exporter
 
 template <typename T>
-void assert_basic(prometheus_client::MetricFamily &metric,
-                  const std::string &expected_name,
-                  const std::string &description,
-                  prometheus_client::MetricType type,
-                  size_t label_num,
-                  std::vector<T> vals)
+static void assert_basic(prometheus_client::MetricFamily &metric,
+                         const std::string &expected_name,
+                         const std::string &description,
+                         prometheus_client::MetricType type,
+                         size_t label_num,
+                         std::vector<T> vals)
 {
   ASSERT_EQ(metric.name, expected_name);  // name sanitized
   ASSERT_EQ(metric.help, description);    // description not changed
@@ -130,9 +130,9 @@ void assert_basic(prometheus_client::MetricFamily &metric,
   }
 }
 
-void assert_histogram(prometheus_client::MetricFamily &metric,
-                      const std::list<double> &boundaries,
-                      std::vector<int> correct)
+static void assert_histogram(prometheus_client::MetricFamily &metric,
+                             const std::list<double> &boundaries,
+                             std::vector<int> correct)
 {
   int cumulative_count = 0;
   auto buckets         = metric.metric[0].histogram.bucket;

exporters/zipkin/src/recordable.cc

@@ -70,9 +70,9 @@ void Recordable::SetIdentity(const trace_api::SpanContext &span_context,
   span_["traceId"] = std::string(trace_id_lower_base16, 32);
 }
 
-void PopulateAttribute(nlohmann::json &attribute,
-                       nostd::string_view key,
-                       const common::AttributeValue &value)
+static void PopulateAttribute(nlohmann::json &attribute,
+                              nostd::string_view key,
+                              const common::AttributeValue &value)
 {
   // Assert size of variant to ensure that this method gets updated if the variant
   // definition changes

exporters/zipkin/test/zipkin_exporter_test.cc

@@ -101,7 +101,7 @@ class IsValidMessageMatcher
   std::string trace_id_;
 };
 
-PolymorphicMatcher<IsValidMessageMatcher> IsValidMessage(const std::string &trace_id)
+static PolymorphicMatcher<IsValidMessageMatcher> IsValidMessage(const std::string &trace_id)
 {
   return MakePolymorphicMatcher(IsValidMessageMatcher(trace_id));
 }

ext/src/http/client/curl/http_client_curl.cc

@@ -67,7 +67,7 @@ nostd::shared_ptr<HttpCurlGlobalInitializer> HttpCurlGlobalInitializer::GetInsta
 #ifdef ENABLE_OTLP_COMPRESSION_PREVIEW
 // Original source:
 // https://stackoverflow.com/questions/12398377/is-it-possible-to-have-zlib-read-from-and-write-to-the-same-memory-buffer/12412863#12412863
-int deflateInPlace(z_stream *strm, unsigned char *buf, uint32_t len, uint32_t *max_len)
+static int deflateInPlace(z_stream *strm, unsigned char *buf, uint32_t len, uint32_t *max_len)
 {
   // must be large enough to hold zlib or gzip header (if any) and one more byte -- 11 works for the
   // worst case here, but if gzip encoding is used and a deflateSetHeader() call is inserted in this

ext/test/w3c_tracecontext_http_test_server/main.cc

@@ -138,7 +138,7 @@ class NoopEventHandler : public http_client::EventHandler
 }  // namespace
 
 // Sends an HTTP POST request to the given url, with the given body.
-void send_request(curl::HttpClient &client, const std::string &url, const std::string &body)
+static void send_request(curl::HttpClient &client, const std::string &url, const std::string &body)
 {
   static std::shared_ptr<http_client::EventHandler> handler(new NoopEventHandler());