Merge upstream/main into probability-sampler

Resolve CHANGELOG.md conflicts by keeping upstream entries and the
ProbabilitySampler changelog line.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: ayush-that

.github/workflows/ci.yml

@@ -53,6 +53,28 @@ jobs:
       run: |
         ./ci/do_ci.sh cmake.test
 
+  cmake_api_only_test:
+    name: CMake API only test
+    runs-on: ubuntu-24.04
+    env:
+      CXX_STANDARD: '17'
+    steps:
+    - name: Harden the runner (Audit all outbound calls)
+      uses: step-security/harden-runner@9af89fc71515a100421586dfdb3dc9c984fbf411 # v2.19.4
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+      with:
+        submodules: 'recursive'
+    - name: setup
+      run: |
+        sudo -E ./ci/setup_ci_environment.sh
+        sudo -E apt-get install -y zlib1g-dev
+    - name: run cmake API only test
+      run: |
+        ./ci/do_ci.sh cmake.api_only.test
+
   cmake_fetch_content_test:
     name: CMake FetchContent usage with opentelemetry-cpp
     runs-on: ubuntu-24.04

.github/workflows/clang-tidy.yaml

@@ -17,9 +17,9 @@ jobs:
       matrix:
         include:
           - cmake_options: all-options-abiv1-preview
-            warning_limit: 328
+            warning_limit: 309
           - cmake_options: all-options-abiv2-preview
-            warning_limit: 338
+            warning_limit: 319
     env:
       CC: /usr/bin/clang-22
       CXX: /usr/bin/clang++-22

.github/workflows/dependencies_image.yml

@@ -22,14 +22,14 @@ jobs:
       uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
     -
       name: Set up QEMU
-      uses: docker/setup-qemu-action@06116385d9baf250c9f4dcb4858b16962ea869c3 # v4.1.0
+      uses: docker/setup-qemu-action@96fe6ef7f33517b61c61be40b68a1882f3264fb8 # v4.2.0
     -
       name: Set up Docker Buildx
       id: buildx
       uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
     -
       name: Build Image
-      uses: docker/build-push-action@f9f3042f7e2789586610d6e8b85c8f03e5195baf # v7.2.0
+      uses: docker/build-push-action@53b7df96c91f9c12dcc8a07bcb9ccacbed38856a # v7.3.0
       with:
         builder: ${{ steps.buildx.outputs.name }}
         context: ci/

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [CMAKE] Fix and test WITH_API_ONLY option
+  [#4201](https://github.com/open-telemetry/opentelemetry-cpp/pull/4201)
+
 * [API] Fix `TraceState::IsValidKey()` to comply with the W3C Trace Context
   Level 2, where keys containing `@` and keys with more than 241 characters
   before `@` or more than 14 characters after `@` are now accepted.
@@ -25,7 +28,7 @@ Increment the:
   [#4194](https://github.com/open-telemetry/opentelemetry-cpp/pull/4194)
 
 * [SDK] Add `TracerProvider::UpdateTracerConfigurator()` and example
-  [#4065](https://github.com/open-telemetry/opentelemetry-cpp/issues/4065)
+  [#4065](https://github.com/open-telemetry/opentelemetry-cpp/pull/4065)
 
 * [RELEASE] Bump main branch to 1.28.0-dev
   [#4081](https://github.com/open-telemetry/opentelemetry-cpp/pull/4081)
@@ -102,17 +105,24 @@ Increment the:
 * [CI] iwyu and clang-tidy: use install_thirdparty.sh for third-party
   [#4136](https://github.com/open-telemetry/opentelemetry-cpp/pull/4136)
 
+* [SDK] LogRecord attribute limits enforcement
+  [#4157](https://github.com/open-telemetry/opentelemetry-cpp/pull/4157)
+
 * [CONFIGURATION] File configuration: declarative resource detection types
   [#4148](https://github.com/open-telemetry/opentelemetry-cpp/pull/4148)
 
 * [SDK] Per-instrument creation time as delta first-interval start_ts
   [#4144](https://github.com/open-telemetry/opentelemetry-cpp/pull/4144)
 
 * [SDK] Add ComposableSampler and CompositeSampler with the consistent
-  probability sampling variants (AlwaysOn, AlwaysOff, TraceIdRatioBased,
+  probability sampling variants (AlwaysOn, AlwaysOff, ComposableProbability,
   ParentThreshold, RuleBased)
   [#4028](https://github.com/open-telemetry/opentelemetry-cpp/issues/4028)
 
+* [SDK] Rename ComposableTraceIdRatioBasedSampler to ComposableProbabilitySampler
+  to align with the OpenTelemetry specification
+  [#4161](https://github.com/open-telemetry/opentelemetry-cpp/issues/4161)
+
 * [SDK] Implement the ProbabilitySampler
   [#4135](https://github.com/open-telemetry/opentelemetry-cpp/pull/4135)
 
@@ -128,6 +138,15 @@ Increment the:
 * [CONFIGURATION] Apply default sampler when none is specified
   [#4170](https://github.com/open-telemetry/opentelemetry-cpp/pull/4170)
 
+* [CODE HEALTH] Move trace and baggage propagation test classes into anonymous namespace
+  [#4199](https://github.com/open-telemetry/opentelemetry-cpp/pull/4199)
+
+* [CODE HEALTH] Move context propagation test classes into anonymous namespace
+  [#4200](https://github.com/open-telemetry/opentelemetry-cpp/pull/4200)
+
+* [CODE HEALTH] Fix clang-tidy bugprone-unused-local-non-trivial-variable warnings
+  [#4202](https://github.com/open-telemetry/opentelemetry-cpp/pull/4202)
+
 ## [1.27.0] 2026-05-13
 
 * [RELEASE] Bump main branch to 1.27.0-dev

CMakeLists.txt

@@ -269,7 +269,9 @@ if(WITH_GSL)
   include("${opentelemetry-cpp_SOURCE_DIR}/cmake/ms-gsl.cmake")
 endif()
 
-find_package(Threads)
+if(NOT WITH_API_ONLY)
+  find_package(Threads)
+endif()
 
 function(set_target_version target_name)
   if(OTELCPP_VERSIONED_LIBS)
@@ -306,21 +308,44 @@ cmake_dependent_option(
   "WITH_OTLP_HTTP OR WITH_ELASTICSEARCH OR WITH_ZIPKIN OR BUILD_W3CTRACECONTEXT_TEST OR WITH_EXAMPLES_HTTP"
   OFF)
 
+#
+# Locally override options if WITH_API_ONLY is set to prevent third party
+# dependencies from being imported
+#
+
+if(WITH_API_ONLY)
+  set(WITH_EXAMPLES OFF)
+  set(WITH_EXAMPLES_HTTP OFF)
+  set(WITH_OTLP_GRPC OFF)
+  set(WITH_OTLP_HTTP OFF)
+  set(WITH_OTLP_FILE OFF)
+  set(WITH_ZIPKIN OFF)
+  set(WITH_PROMETHEUS OFF)
+  set(WITH_ELASTICSEARCH OFF)
+  set(WITH_OPENTRACING OFF)
+  set(WITH_ETW OFF)
+  set(WITH_CONFIGURATION OFF)
+  set(WITH_HTTP_CLIENT_CURL OFF)
+  set(WITH_OTLP_HTTP_COMPRESSION OFF)
+  set(WITH_BENCHMARK OFF)
+  set(WITH_FUNC_TESTS OFF)
+  set(BUILD_TESTING OFF)
+  set(BUILD_W3CTRACECONTEXT_TEST OFF)
+endif()
+
 #
 # Do we need ZLIB ?
 #
 
-if((NOT WITH_API_ONLY)
-   AND WITH_HTTP_CLIENT_CURL
-   AND WITH_OTLP_HTTP_COMPRESSION)
+if(WITH_HTTP_CLIENT_CURL AND WITH_OTLP_HTTP_COMPRESSION)
   include("${opentelemetry-cpp_SOURCE_DIR}/cmake/zlib.cmake")
 endif()
 
 #
 # Do we need CURL ?
 #
 
-if((NOT WITH_API_ONLY) AND WITH_HTTP_CLIENT_CURL)
+if(WITH_HTTP_CLIENT_CURL)
   include("${opentelemetry-cpp_SOURCE_DIR}/cmake/curl.cmake")
 endif()
 
@@ -366,15 +391,15 @@ else()
   set(USE_NLOHMANN_JSON OFF)
 endif()
 
-if((NOT WITH_API_ONLY) AND USE_NLOHMANN_JSON)
+if(USE_NLOHMANN_JSON)
   include("${opentelemetry-cpp_SOURCE_DIR}/cmake/nlohmann-json.cmake")
 endif()
 
 #
 # Do we need RapidYaml ?
 #
 
-if((NOT WITH_API_ONLY) AND WITH_CONFIGURATION)
+if(WITH_CONFIGURATION)
   include("${opentelemetry-cpp_SOURCE_DIR}/cmake/ryml.cmake")
 endif()
 
@@ -640,11 +665,11 @@ endif()
 
 add_subdirectory(api)
 
-if(WITH_OPENTRACING)
-  add_subdirectory(opentracing-shim)
-endif()
-
 if(NOT WITH_API_ONLY)
+  if(WITH_OPENTRACING)
+    add_subdirectory(opentracing-shim)
+  endif()
+
   set(BUILD_TESTING ${BUILD_TESTING})
 
   add_subdirectory(sdk)
@@ -663,11 +688,12 @@ if(NOT WITH_API_ONLY)
   if(WITH_FUNC_TESTS)
     add_subdirectory(functional)
   endif()
+
+  include(
+    "${opentelemetry-cpp_SOURCE_DIR}/cmake/opentelemetry-build-external-component.cmake"
+  )
 endif()
 
-include(
-  "${opentelemetry-cpp_SOURCE_DIR}/cmake/opentelemetry-build-external-component.cmake"
-)
 include("${opentelemetry-cpp_SOURCE_DIR}/cmake/patch-imported-config.cmake")
 
 if(OPENTELEMETRY_INSTALL)

api/test/baggage/baggage_benchmark.cc

@@ -102,7 +102,7 @@ void BM_BaggageToHeaderTenEntries(benchmark::State &state)
   auto baggage = Baggage::FromHeader(header_with_custom_entries(kNumEntries));
   while (state.KeepRunning())
   {
-    auto new_baggage = baggage->ToHeader();
+    benchmark::DoNotOptimize(baggage->ToHeader());
   }
 }
 BENCHMARK(BM_BaggageToHeaderTenEntries);
@@ -112,7 +112,7 @@ void BM_BaggageToHeader180Entries(benchmark::State &state)
   auto baggage = Baggage::FromHeader(header_with_custom_entries(Baggage::kMaxKeyValuePairs));
   while (state.KeepRunning())
   {
-    auto new_baggage = baggage->ToHeader();
+    benchmark::DoNotOptimize(baggage->ToHeader());
   }
 }
 BENCHMARK(BM_BaggageToHeader180Entries);

api/test/baggage/propagation/baggage_propagator_test.cc

@@ -20,6 +20,9 @@
 using namespace opentelemetry;
 using namespace opentelemetry::baggage::propagation;
 
+namespace
+{
+
 class BaggageCarrierTest : public context::propagation::TextMapCarrier
 {
 public:
@@ -120,3 +123,5 @@ TEST(BaggagePropagatorTest, InjectEmptyHeader)
     EXPECT_EQ(carrier.headers_.find(baggage::kBaggageHeader), carrier.headers_.end());
   }
 }
+
+}  // namespace

api/test/context/propagation/composite_propagator_test.cc

@@ -38,6 +38,9 @@ static std::string Hex(const T &id_item)
   return std::string(buf, sizeof(buf));
 }
 
+namespace
+{
+
 class TextMapCarrierTest : public context::propagation::TextMapCarrier
 {
 public:
@@ -147,3 +150,5 @@ TEST_F(CompositePropagatorTest, Inject)
   EXPECT_EQ(fields[1], trace::propagation::kTraceState);
   EXPECT_EQ(fields[2], trace::propagation::kB3CombinedHeader);
 }
+
+}  // namespace

api/test/context/propagation/environment_carrier_test.cc

@@ -56,6 +56,9 @@ static std::string Hex(const T &id_item)
   return std::string(buf, sizeof(buf));
 }
 
+namespace
+{
+
 class EnvironmentCarrierTest : public ::testing::Test
 {
 protected:
@@ -306,3 +309,5 @@ TEST_F(EnvironmentCarrierTest, RoundTrip)
   EXPECT_EQ(extracted_span->GetContext().IsSampled(), span_context.IsSampled());
   EXPECT_TRUE(extracted_span->GetContext().IsRemote());
 }
+
+}  // namespace

api/test/trace/propagation/b3_propagation_test.cc

@@ -27,6 +27,9 @@
 
 using namespace opentelemetry;
 
+namespace
+{
+
 class TextMapCarrierTest : public context::propagation::TextMapCarrier
 {
 public:
@@ -219,3 +222,5 @@ TEST(B3PropagationTest, GetCurrentSpanMultiHeader)
   EXPECT_EQ(carrier.headers_["X-B3-SpanId"], "0102030405060708");
   EXPECT_EQ(carrier.headers_["X-B3-Sampled"], "1");
 }
+
+}  // namespace