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

Mark list_test_cases in func_grpc_main as static, and make the
thread_local RNG in circular_buffer_benchmark explicitly static.
The foo_library functions in the common example libraries are
exported via headers and linked into multiple example binaries,
so internal linkage is not possible; suppress those two with
NOLINTNEXTLINE instead. Decrement clang-tidy warning limits by 4
to match the fewer unique warnings.

Fixes #3977

Signed-off-by: Mateen Anjum <mateenali66@gmail.com>

Author: mateenali66

.github/workflows/clang-tidy.yaml

@@ -17,9 +17,9 @@ jobs:
       matrix:
         include:
           - cmake_options: all-options-abiv1-preview
-            warning_limit: 57
+            warning_limit: 53
           - cmake_options: all-options-abiv2-preview
-            warning_limit: 59
+            warning_limit: 55
     env:
       CC: /usr/bin/clang-18
       CXX: /usr/bin/clang++-18

CHANGELOG.md

@@ -37,6 +37,9 @@ Increment the:
 * [CODE HEALTH] Cleanup nostd variant access in API and SDK
   [#3965](https://github.com/open-telemetry/opentelemetry-cpp/pull/3965)
 
+* [CODE HEALTH] Fix clang-tidy misc-use-internal-linkage warnings
+  [#3977](https://github.com/open-telemetry/opentelemetry-cpp/issues/3977)
+
 * Enable WITH_OTLP_RETRY_PREVIEW by default
   [#3953](https://github.com/open-telemetry/opentelemetry-cpp/pull/3953)
 

examples/common/foo_library/foo_library.cc

@@ -33,6 +33,7 @@ void f2()
 }
 }  // namespace
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 void foo_library()
 {
   auto scoped_span = trace::Scope(get_tracer()->StartSpan("library"));

examples/common/logs_foo_library/foo_library.cc

@@ -31,6 +31,7 @@ opentelemetry::nostd::shared_ptr<logs::Logger> get_logger()
 }
 }  // namespace
 
+// NOLINTNEXTLINE(misc-use-internal-linkage)
 void foo_library()
 {
   auto span        = get_tracer()->StartSpan("span 1");

functional/otlp/func_grpc_main.cc

@@ -353,7 +353,7 @@ static const test_case all_tests[] = {{"basic", test_basic},
 #endif  // ENABLE_OTLP_GRPC_SSL_MTLS_PREVIEW
                                       {"", nullptr}};
 
-void list_test_cases()
+static void list_test_cases()
 {
   const test_case *current = all_tests;
 

sdk/test/common/circular_buffer_benchmark.cc

@@ -55,7 +55,7 @@ static uint64_t ConsumeBufferNumbers(CircularBuffer<uint64_t> &buffer) noexcept
 template <class Buffer>
 static void GenerateNumbersForThread(Buffer &buffer, int n, std::atomic<uint64_t> &sum) noexcept
 {
-  thread_local std::mt19937_64 random_number_generator{std::random_device{}()};
+  static thread_local std::mt19937_64 random_number_generator{std::random_device{}()};
   for (int i = 0; i < n; ++i)
   {
     auto x = random_number_generator();