gRPC depends abseil-cp, so we always enable abseil-cpp when have WITH_OTLP_GRPC

Author: owent

CMakeLists.txt

@@ -363,7 +363,7 @@ if(WITH_PROMETHEUS)
   endif()
 endif()
 
-if(WITH_ABSEIL)
+if(WITH_ABSEIL OR WITH_OTLP_GRPC)
   if(NOT TARGET absl::strings)
     find_package(absl CONFIG REQUIRED)
   endif()
@@ -374,7 +374,7 @@ if(WITH_OTLP_GRPC
    OR WITH_OTLP_FILE)
   find_package(Protobuf)
   if(Protobuf_VERSION AND Protobuf_VERSION VERSION_GREATER_EQUAL "3.22.0")
-    if(NOT WITH_ABSEIL)
+    if(NOT WITH_ABSEIL AND NOT WITH_OTLP_GRPC)
       message(
         FATAL_ERROR
           "Protobuf 3.22 or upper require abseil-cpp(Recommended version: 20230125 or upper)"

api/CMakeLists.txt

@@ -35,7 +35,7 @@ if(WITH_NO_DEPRECATED_CODE)
                              INTERFACE OPENTELEMETRY_NO_DEPRECATED_CODE)
 endif()
 
-if(WITH_ABSEIL)
+if(WITH_ABSEIL OR WITH_OTLP_GRPC)
   target_compile_definitions(opentelemetry_api INTERFACE HAVE_ABSEIL)
   target_link_libraries(
     opentelemetry_api INTERFACE absl::bad_variant_access absl::any absl::base

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_client.h

@@ -13,14 +13,18 @@
 
 #include "opentelemetry/exporters/otlp/otlp_grpc_client_options.h"
 
+// clang-format off
 #include "opentelemetry/exporters/otlp/protobuf_include_prefix.h"
+// clang-format on
 
 #include "google/protobuf/arena.h"
 #include "opentelemetry/proto/collector/logs/v1/logs_service.grpc.pb.h"
 #include "opentelemetry/proto/collector/metrics/v1/metrics_service.grpc.pb.h"
 #include "opentelemetry/proto/collector/trace/v1/trace_service.grpc.pb.h"
 
+// clang-format off
 #include "opentelemetry/exporters/otlp/protobuf_include_suffix.h"
+// clang-format on
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace exporter