Merge branch 'main' of https://github.com/open-telemetry/opentelemetr…

…y-cpp

.github/workflows/ci.yml

@@ -732,6 +732,8 @@ jobs:
         ./ci/install_windows_protobuf.ps1
     - name: run cmake test (DLL build)
       run: ./ci/do_ci.ps1 cmake.dll.test
+    - name: run cmake cxx20 test (DLL build)
+      run: ./ci/do_ci.ps1 cmake.dll.cxx20.test
     - name: run otprotocol test (DLL build)
       run: ./ci/do_ci.ps1 cmake.exporter.otprotocol.dll.test
 

CHANGELOG.md

@@ -21,6 +21,8 @@ Increment the:
   [#2449](https://github.com/open-telemetry/opentelemetry-cpp/pull/2449)
 * [BUILD] Introduce CXX 20 CI pipeline for MSVC/Windows
   [#2450](https://github.com/open-telemetry/opentelemetry-cpp/pull/2450)
+* [BUILD] Add DLL build CI pipeline with CXX20
+  [#2465](https://github.com/open-telemetry/opentelemetry-cpp/pull/2465)
 * [EXPORTER] Set `is_monotonic` flag for Observable Counters
   [#2478](https://github.com/open-telemetry/opentelemetry-cpp/pull/2478)
 * [PROTO] Upgrade to opentelemetry-proto v1.1.0

api/include/opentelemetry/nostd/internal/absl/base/policy_checks.h

@@ -71,13 +71,15 @@
 // C++ Version Check
 // -----------------------------------------------------------------------------
 
-// Enforce C++11 as the minimum.  Note that Visual Studio has not
-// advanced __cplusplus despite being good enough for our purposes, so
-// so we exempt it from the check.
-#if defined(__cplusplus) && !defined(_MSC_VER)
+// Enforce C++11 as the minimum.
+#if defined(_MSVC_LANG)
+#if _MSVC_LANG < 201103L
+#error "C++ versions less than C++11 are not supported."
+#endif  // _MSVC_LANG < 201103L
+#elif defined(__cplusplus)
 #if __cplusplus < 201103L
 #error "C++ versions less than C++11 are not supported."
-#endif
+#endif  // __cplusplus < 201103L
 #endif
 
 // -----------------------------------------------------------------------------

api/include/opentelemetry/nostd/internal/absl/meta/type_traits.h

@@ -618,7 +618,8 @@ using underlying_type_t = typename std::underlying_type<T>::type;
 
 namespace type_traits_internal {
 
-#if __cplusplus >= 201703L
+#if (!defined(_MSVC_LANG) && (__cplusplus >= 201703L)) || \
+    (defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L))
 // std::result_of is deprecated (C++17) or removed (C++20)
 template<typename> struct result_of;
 template<typename F, typename... Args>

ci/do_ci.ps1

@@ -90,6 +90,44 @@ switch ($action) {
       exit $exit
     }
   }
+  "cmake.dll.cxx20.test" {
+    cd "$BUILD_DIR"
+    cmake $SRC_DIR `
+      -DCMAKE_CXX_STANDARD=20 `
+      -DVCPKG_TARGET_TRIPLET=x64-windows `
+      -DOPENTELEMETRY_BUILD_DLL=1 `
+     "-DCMAKE_TOOLCHAIN_FILE=$VCPKG_DIR/scripts/buildsystems/vcpkg.cmake"
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    cmake --build . -j $nproc
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    ctest -C Debug
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    $env:PATH = "$BUILD_DIR\ext\src\dll\Debug;$env:PATH"
+    examples\simple\Debug\example_simple.exe
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    examples\metrics_simple\Debug\metrics_ostream_example.exe
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    examples\logs_simple\Debug\example_logs_simple.exe
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+  }
   "cmake.maintainer.test" {
     cd "$BUILD_DIR"
     cmake $SRC_DIR `

examples/common/logs_foo_library/foo_library.cc

@@ -32,7 +32,6 @@ void foo_library()
   auto scoped_span = trace::Scope(get_tracer()->StartSpan("foo_library"));
   auto ctx         = span->GetContext();
   auto logger      = get_logger();
-  logger->EmitLogRecord(opentelemetry::logs::Severity::kDebug, "body", ctx.trace_id(),
-                        ctx.span_id(), ctx.trace_flags(),
-                        opentelemetry::common::SystemTimestamp(std::chrono::system_clock::now()));
+
+  logger->Debug("body", ctx.trace_id(), ctx.span_id(), ctx.trace_flags());
 }

examples/logs_simple/README.md

@@ -1,16 +1,16 @@
-
 # Simple Logs Example
 
 In this example, the application in `main.cc` initializes an
 `OStreamLogRecordExporter` instance and registers a logger
 provider, as well as initializes a `StdoutSpanExporter` instance and registers a
-tracer provider from the [OpenTelemetry
+tracer provider from the [OpenTelemetry C++
 SDK](https://github.com/open-telemetry/opentelemetry-cpp).
 
-The application then calls a `logs_foo_library` which has been instrumented
-using the [OpenTelemetry
-API](https://github.com/open-telemetry/opentelemetry-cpp/tree/main/api).
-Resulting logs and traces are directed to stdout.
+The application then calls into
+[`logs_foo_library`](https://github.com/open-telemetry/opentelemetry-cpp/blob/main/examples/common/logs_foo_library/foo_library.cc)
+which has been instrumented using the [OpenTelemetry Logs
+API](../../api/include/opentelemetry/logs/logger.h). Resulting logs and traces
+are directed to stdout.
 
 See [CONTRIBUTING.md](../../CONTRIBUTING.md) for instructions on building and
 running the example.

exporters/ostream/include/opentelemetry/exporters/ostream/common_utils.h

@@ -58,7 +58,8 @@ void print_value(const nostd::span<T> &vec, std::ostream &sout)
 }
 
 // Prior to C++14, generic lambda is not available so fallback to functor.
-#if __cplusplus < 201402L
+#if (!defined(_MSVC_LANG) && (__cplusplus < 201402L)) || \
+    (defined(_MSVC_LANG) && (_MSVC_LANG < 201402L))
 
 class OwnedAttributeValueVisitor
 {
@@ -97,7 +98,8 @@ class AttributeValueVisitor
 inline void print_value(const opentelemetry::sdk::common::OwnedAttributeValue &value,
                         std::ostream &sout)
 {
-#if __cplusplus < 201402L
+#if (!defined(_MSVC_LANG) && (__cplusplus < 201402L)) || \
+    (defined(_MSVC_LANG) && (_MSVC_LANG < 201402L))
   opentelemetry::nostd::visit(OwnedAttributeValueVisitor(sout), value);
 #else
   opentelemetry::nostd::visit(
@@ -111,7 +113,8 @@ inline void print_value(const opentelemetry::sdk::common::OwnedAttributeValue &v
 
 inline void print_value(const opentelemetry::common::AttributeValue &value, std::ostream &sout)
 {
-#if __cplusplus < 201402L
+#if (!defined(_MSVC_LANG) && (__cplusplus < 201402L)) || \
+    (defined(_MSVC_LANG) && (_MSVC_LANG < 201402L))
   opentelemetry::nostd::visit(AttributeValueVisitor(sout), value);
 #else
   opentelemetry::nostd::visit(