[BUILD] Remove WITH_ABSEIL (open-telemetry#3318)

Author: owent

.devcontainer/README.md

@@ -12,7 +12,7 @@ environment variables (for evaluation in `devcontainer.json`).
 
 * **abseil-cpp version:**
   This is the version of abseil-cpp that will be used to build protobuf, gRPC,
-  and opentelemetry-cpp (when WITH_ABSEIL is set).
+  and opentelemetry-cpp.
   * Docker ARG:
    `ABSEIL_CPP_VERSION`
   * Host Environment Variable:

.github/workflows/ci.yml

@@ -30,15 +30,6 @@ jobs:
 #        sudo -E ./ci/setup_googletest.sh
 #        sudo -E ./ci/install_abseil.sh
 #        sudo -E ./ci/install_protobuf.sh
-#    - name: run otlp exporter tests
-#      env:
-#        CC: /usr/bin/gcc-10
-#        CXX: /usr/bin/g++-10
-#        WITH_ABSEIL: 'ON'
-#        CXX_STANDARD: '14'
-#      run: |
-#        sudo -E ./ci/setup_grpc.sh -m -p protobuf -p abseil-cpp
-#        ./ci/do_ci.sh cmake.exporter.otprotocol.test
 
   cmake_test:
     name: CMake test (prometheus, elasticsearch, zipkin)
@@ -528,7 +519,6 @@ jobs:
         sudo -E ./ci/install_protobuf.sh
     - name: run otlp exporter tests
       env:
-        WITH_ABSEIL: 'ON'
         CXX_STANDARD: '14'
       run: |
         sudo -E ./ci/setup_grpc.sh -m -p protobuf -p abseil-cpp

.github/workflows/clang-tidy.yaml

@@ -78,4 +78,4 @@ jobs:
           COUNT=$(grep -c "warning:" clang-tidy.log)
           echo "clang-tidy reported ${COUNT} warning(s)"
 
-# TODO: include WITH_OTLP_GRPC and WITH_ABSEIL flags.
+# TODO: include WITH_OTLP_GRPC flags.

CHANGELOG.md

@@ -15,6 +15,9 @@ Increment the:
 
 ## [Unreleased]
 
+* [API] Remove `WITH_ABSEIL` and `HAVE_ABSEIL`
+  [#3318](https://github.com/open-telemetry/opentelemetry-cpp/pull/3318)
+
 ## [1.20 2025-04-01]
 
 * [BUILD] Update opentelemetry-proto version

CMakeLists.txt

@@ -188,8 +188,6 @@ set(WITH_STL
 option(WITH_GSL
        "Whether to use Guidelines Support Library for C++ latest features" OFF)
 
-option(WITH_ABSEIL "Whether to use Abseil for C++latest features" OFF)
-
 set(OPENTELEMETRY_INSTALL_default ON)
 if(NOT CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   set(OPENTELEMETRY_INSTALL_default OFF)
@@ -400,10 +398,8 @@ if(WITH_PROMETHEUS)
   endif()
 endif()
 
-if(WITH_ABSEIL)
-  if(NOT TARGET absl::strings)
-    find_package(absl CONFIG REQUIRED)
-  endif()
+if(WITH_OTLP_GRPC)
+  find_package(absl CONFIG REQUIRED)
 endif()
 
 if(WITH_OTLP_GRPC

api/BUILD

@@ -23,7 +23,7 @@ string_flag(
 cc_library(
     name = "api",
     hdrs = glob(["include/**/*.h"]),
-    defines = ["HAVE_ABSEIL"] + select({
+    defines = select({
         ":set_cxx_stdlib_none": [],
         ### automatic selection
         ":set_cxx_stdlib_best": ["OPENTELEMETRY_STL_VERSION=(__cplusplus/100)"],

api/CMakeLists.txt

@@ -35,21 +35,6 @@ if(WITH_NO_DEPRECATED_CODE)
                              INTERFACE OPENTELEMETRY_NO_DEPRECATED_CODE)
 endif()
 
-if(WITH_ABSEIL)
-  target_compile_definitions(opentelemetry_api INTERFACE HAVE_ABSEIL)
-  target_link_libraries(
-    opentelemetry_api INTERFACE absl::bad_variant_access absl::any absl::base
-                                absl::bits absl::city)
-  list(
-    APPEND
-    TARGET_DEPS
-    "absl_bad_variant_access"
-    "absl_any"
-    "absl_base"
-    "absl_bits"
-    "absl_city")
-endif()
-
 if(WITH_STL STREQUAL "OFF")
   message(STATUS "Building WITH_STL=OFF")
 elseif(WITH_STL STREQUAL "CXX11")

api/include/opentelemetry/nostd/variant.h

@@ -14,13 +14,12 @@
 
 #if !defined(OPENTELEMETRY_HAVE_STD_VARIANT)
 
-#  ifndef HAVE_ABSEIL
 // We use a LOCAL snapshot of Abseil that is known to compile with Visual Studio 2015.
 // Header-only. Without compiling the actual Abseil binary. As Abseil moves on to new
 // toolchains, it may drop support for Visual Studio 2015 in future versions.
 
-#    if defined(__EXCEPTIONS)
-#      include <exception>
+#  if defined(__EXCEPTIONS)
+#    include <exception>
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace nostd
 {
@@ -37,10 +36,9 @@ class bad_variant_access : public std::exception
 }
 }  // namespace nostd
 OPENTELEMETRY_END_NAMESPACE
-#      define THROW_BAD_VARIANT_ACCESS opentelemetry::nostd::throw_bad_variant_access()
-#    else
-#      define THROW_BAD_VARIANT_ACCESS std::terminate()
-#    endif
+#    define THROW_BAD_VARIANT_ACCESS opentelemetry::nostd::throw_bad_variant_access()
+#  else
+#    define THROW_BAD_VARIANT_ACCESS std::terminate()
 #  endif
 
 #  ifdef _MSC_VER
@@ -51,10 +49,7 @@ OPENTELEMETRY_END_NAMESPACE
 #    pragma warning(disable : 4127)  // conditional expression is constant
 #  endif
 
-#  ifdef HAVE_ABSEIL
-#    include "absl/types/variant.h"
-#  else
-#    include "opentelemetry/nostd/internal/absl/base/options.h"
+#  include "opentelemetry/nostd/internal/absl/base/options.h"
 
 namespace absl
 {
@@ -67,8 +62,7 @@ class variant;
 }  // namespace OTABSL_OPTION_NAMESPACE_NAME
 }  // namespace absl
 
-#    include "opentelemetry/nostd/internal/absl/types/variant.h"
-#  endif
+#  include "opentelemetry/nostd/internal/absl/types/variant.h"
 
 #  ifdef _MSC_VER
 #    pragma warning(pop)
@@ -77,17 +71,6 @@ class variant;
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace nostd
 {
-#  ifdef HAVE_ABSEIL
-using absl::bad_variant_access;
-using absl::get;
-using absl::get_if;
-using absl::holds_alternative;
-using absl::monostate;
-using absl::variant;
-using absl::variant_alternative_t;
-using absl::variant_size;
-using absl::visit;
-#  else
 using absl::OTABSL_OPTION_NAMESPACE_NAME::get;
 using absl::OTABSL_OPTION_NAMESPACE_NAME::get_if;
 using absl::OTABSL_OPTION_NAMESPACE_NAME::holds_alternative;
@@ -96,7 +79,6 @@ using absl::OTABSL_OPTION_NAMESPACE_NAME::variant;
 using absl::OTABSL_OPTION_NAMESPACE_NAME::variant_alternative_t;
 using absl::OTABSL_OPTION_NAMESPACE_NAME::variant_size;
 using absl::OTABSL_OPTION_NAMESPACE_NAME::visit;
-#  endif
 }  // namespace nostd
 OPENTELEMETRY_END_NAMESPACE
 

cmake/opentelemetry-cpp-config.cmake.in

@@ -1,17 +1,13 @@
 # Copyright The OpenTelemetry Authors
 # SPDX-License-Identifier: Apache-2.0
 
+#[[
 #.rst:
 # opentelemetry-cpp-config.cmake
 # --------
 #
 # Find the native opentelemetry-cpp includes and library.
 #
-# Result Variables
-# ^^^^^^^^^^^^^^^^
-#
-# This module defines the following variables:
-#
 # ::
 #
 #   OPENTELEMETRY_CPP_INCLUDE_DIRS  - Include directories of opentelemetry-cpp.
@@ -52,10 +48,9 @@
 #   opentelemetry-cpp::http_client_curl                  - Imported target of opentelemetry-cpp::http_client_curl
 #   opentelemetry-cpp::opentracing_shim                  - Imported target of opentelemetry-cpp::opentracing_shim
 #
-
+]]
 # =============================================================================
-# Copyright The OpenTelemetry Authors
-# SPDX-License-Identifier: Apache-2.0
+# Copyright The OpenTelemetry Authors SPDX-License-Identifier: Apache-2.0
 # =============================================================================
 
 set(OPENTELEMETRY_ABI_VERSION_NO
@@ -73,10 +68,6 @@ include(CMakeFindDependencyMacro)
 
 find_dependency(Threads)
 
-if(@WITH_ABSEIL@)
-  find_dependency(absl)
-endif()
-
 if(@WITH_OTLP_GRPC@)
   find_dependency(gRPC)
 endif()
@@ -93,7 +84,7 @@ if("@Protobuf_FOUND@" OR "@PROTOBUF_FOUND@")
   find_dependency(Protobuf)
 endif()
 
-if (@WITH_HTTP_CLIENT_CURL@ AND NOT @BUILD_SHARED_LIBS@)
+if(@WITH_HTTP_CLIENT_CURL@ AND NOT @BUILD_SHARED_LIBS@)
   if("@CURL_FOUND@")
     find_dependency(CURL)
   endif()
@@ -103,7 +94,7 @@ if (@WITH_HTTP_CLIENT_CURL@ AND NOT @BUILD_SHARED_LIBS@)
   endif()
 endif()
 
-if(@WITH_ABSEIL@ OR @WITH_OTLP_GRPC@)
+if(@WITH_OTLP_GRPC@)
   find_package(absl CONFIG)
 elseif(@WITH_OTLP_HTTP@ OR @WITH_OTLP_FILE@)
   if("@Protobuf_VERSION@" VERSION_GREATER_EQUAL "3.22.0")

cmake/opentelemetry-proto.cmake

@@ -286,11 +286,9 @@ add_custom_command(
     ${PROTOBUF_PROTOC_EXECUTABLE} ${PROTOBUF_COMMON_FLAGS}
     ${PROTOBUF_INCLUDE_FLAGS} ${COMMON_PROTO} ${RESOURCE_PROTO} ${TRACE_PROTO}
     ${LOGS_PROTO} ${METRICS_PROTO} ${TRACE_SERVICE_PROTO} ${LOGS_SERVICE_PROTO}
-    ${METRICS_SERVICE_PROTO} ${PROFILES_PROTO}
-    ${PROFILES_SERVICE_PROTO}
+    ${METRICS_SERVICE_PROTO} ${PROFILES_PROTO} ${PROFILES_SERVICE_PROTO}
   COMMENT "[Run]: ${PROTOBUF_RUN_PROTOC_COMMAND}"
-  DEPENDS ${PROTOBUF_PROTOC_EXECUTABLE}
-  )
+  DEPENDS ${PROTOBUF_PROTOC_EXECUTABLE})
 
 include_directories("${GENERATED_PROTOBUF_PATH}")
 
@@ -343,7 +341,8 @@ if(WITH_OTLP_GRPC)
   set_target_version(opentelemetry_proto_grpc)
 
   # Disable include-what-you-use on generated code.
-  set_target_properties(opentelemetry_proto_grpc PROPERTIES CXX_INCLUDE_WHAT_YOU_USE "")
+  set_target_properties(opentelemetry_proto_grpc
+                        PROPERTIES CXX_INCLUDE_WHAT_YOU_USE "")
 
   list(APPEND OPENTELEMETRY_PROTO_TARGETS opentelemetry_proto_grpc)
   target_link_libraries(opentelemetry_proto_grpc PUBLIC opentelemetry_proto)
@@ -392,7 +391,6 @@ else() # cmake 3.8 or lower
 endif()
 
 if(WITH_OTLP_GRPC)
-  find_package(absl CONFIG)
   if(TARGET absl::synchronization)
     target_link_libraries(opentelemetry_proto_grpc
                           PRIVATE absl::synchronization)

cmake/patch-imported-config.cmake

@@ -29,7 +29,7 @@ if(TARGET CURL::libcurl
 endif()
 
 # abseil targets
-if(WITH_ABSEIL OR WITH_OTLP_GRPC)
+if(TARGET absl::bad_variant_access)
   project_build_tools_patch_default_imported_config(
     absl::bad_variant_access
     absl::raw_logging_internal

docs/dependencies.md

@@ -34,9 +34,6 @@ Both these dependencies are listed here:
       .We don't use the std::span in this situation.Users can also define
       `OPENTELEMETRY_OPTION_USE_STD_SPAN=0` to indicate nostd:span will always
       not be a alias for std::span.
-  - Uses Abseil C++ Library for `absl::variant` as default `nostd::variant` if
-    `WITH_ABSEIL` cmake option (always enabled with bazel)
-    License: `Apache License 2.0`
 
 - [OTLP/HTTP+JSON](/exporters/otlp)
   exporter:

examples/grpc/CMakeLists.txt

@@ -42,7 +42,7 @@ else()
   target_link_libraries(example_grpc_proto PUBLIC gRPC::grpc++
                                                   ${Protobuf_LIBRARIES})
 endif()
-if(WITH_ABSEIL OR WITH_OTLP_GRPC)
+if(WITH_OTLP_GRPC)
   target_link_libraries(example_grpc_proto PUBLIC absl::bad_variant_access)
 endif()
 

exporters/otlp/CMakeLists.txt

@@ -41,7 +41,8 @@ if(WITH_OTLP_GRPC)
     PUBLIC opentelemetry_sdk opentelemetry_common opentelemetry_ext
            # gRPC::grpc++ must be linked before opentelemetry_proto_grpc.
            opentelemetry_proto_grpc
-    PRIVATE gRPC::grpc++)
+    PRIVATE gRPC::grpc++ absl::bad_variant_access absl::any absl::base
+            absl::bits absl::city)
 
   get_target_property(GRPC_INCLUDE_DIRECTORY gRPC::grpc++
                       INTERFACE_INCLUDE_DIRECTORIES)

exporters/otlp/test/otlp_file_exporter_test.cc

@@ -108,9 +108,9 @@ class OtlpFileExporterTestPeer : public ::testing::Test
     std::string report_trace_id;
 
 #if OPENTELEMETRY_ABI_VERSION_NO >= 2
-    auto tracer = provider->GetTracer("scope_name", "scope_version", "scope_url",
-                                      {{ "scope_key",
-                                         "scope_value" }});
+    std::unordered_map<std::string, common::AttributeValue> scope_attributes;
+    scope_attributes["scope_key"] = common::AttributeValue("scope_value");
+    auto tracer = provider->GetTracer("scope_name", "scope_version", "scope_url", scope_attributes);
 #else
     auto tracer = provider->GetTracer("scope_name", "scope_version", "scope_url");
 #endif
@@ -139,6 +139,12 @@ class OtlpFileExporterTestPeer : public ::testing::Test
     auto check_json_text = output.str();
     if (!check_json_text.empty())
     {
+      // If the exporting is splited to two standalone resource_span, just checking the first one.
+      std::string::size_type eol = check_json_text.find('\n');
+      if (eol != std::string::npos)
+      {
+        check_json_text = check_json_text.substr(0, eol);
+      }
       auto check_json = nlohmann::json::parse(check_json_text, nullptr, false);
       if (!check_json.is_discarded())
       {

sdk/src/common/CMakeLists.txt

@@ -18,7 +18,7 @@ target_link_libraries(
   opentelemetry_common PUBLIC opentelemetry_api opentelemetry_sdk
                               Threads::Threads)
 
-if(WITH_ABSEIL OR WITH_OTLP_GRPC)
+if(WITH_OTLP_GRPC)
   target_link_libraries(opentelemetry_common PUBLIC absl::strings)
 endif()