[BUILD] Support to use different cmake package CONFIG of dependencies.

CMakeLists.txt

@@ -688,6 +688,7 @@ if(NOT WITH_API_ONLY)
 endif()
 
 include(cmake/opentelemetry-build-external-component.cmake)
+include(cmake/patch-imported-config.cmake)
 
 if(OPENTELEMETRY_INSTALL)
   # Export cmake config and support find_packages(opentelemetry-cpp CONFIG)

cmake/patch-imported-config.cmake

@@ -0,0 +1,141 @@
+# Copyright The OpenTelemetry Authors
+# SPDX-License-Identifier: Apache-2.0
+
+# Some prebuilt or installed targets may have different CONFIG settings than
+# what we use to configure otel-cpp. This file applies patches to the imported
+# targets in order to use compatible CONFIG settings for fallback.
+
+# Common dependencies
+project_build_tools_patch_default_imported_config(ZLIB::ZLIB)
+
+# protobuf targets
+if(Protobuf_FOUND OR PROTOBUF_FOUND)
+  project_build_tools_patch_default_imported_config(
+    utf8_range::utf8_range utf8_range::utf8_validity protobuf::libprotobuf-lite
+    protobuf::libprotobuf protobuf::libprotoc)
+endif()
+
+# cares targets
+if(TARGET c-ares::cares)
+  project_build_tools_patch_default_imported_config(c-ares::cares)
+endif()
+
+# curl targets
+if(TARGET CURL::libcurl)
+  project_build_tools_patch_default_imported_config(CURL::libcurl)
+endif()
+
+# abseil targets
+if(WITH_ABSEIL)
+  project_build_tools_patch_default_imported_config(
+    absl::bad_variant_access
+    absl::raw_logging_internal
+    absl::log_severity
+    absl::log_internal_check_op
+    absl::log_internal_nullguard
+    absl::strings
+    absl::strings_internal
+    absl::base
+    absl::spinlock_wait
+    absl::int128
+    absl::throw_delegate
+    absl::log_internal_message
+    absl::examine_stack
+    absl::stacktrace
+    absl::debugging_internal
+    absl::symbolize
+    absl::demangle_internal
+    absl::malloc_internal
+    absl::log_internal_format
+    absl::log_internal_globals
+    absl::time
+    absl::civil_time
+    absl::time_zone
+    absl::str_format_internal
+    absl::log_internal_proto
+    absl::log_internal_log_sink_set
+    absl::log_globals
+    absl::hash
+    absl::city
+    absl::bad_optional_access
+    absl::low_level_hash
+    absl::log_entry
+    absl::log_sink
+    absl::synchronization
+    absl::graphcycles_internal
+    absl::strerror
+    absl::log_internal_conditions
+    absl::cord
+    absl::cord_internal
+    absl::crc_cord_state
+    absl::crc32c
+    absl::crc_cpu_detect
+    absl::crc_internal
+    absl::cordz_functions
+    absl::exponential_biased
+    absl::cordz_info
+    absl::cordz_handle
+    absl::leak_check
+    absl::die_if_null
+    absl::flags
+    absl::flags_commandlineflag
+    absl::flags_commandlineflag_internal
+    absl::flags_config
+    absl::flags_program_name
+    absl::flags_internal
+    absl::flags_marshalling
+    absl::flags_reflection
+    absl::flags_private_handle_accessor
+    absl::raw_hash_set
+    absl::hashtablez_sampler
+    absl::log_initialize
+    absl::status
+    absl::statusor)
+endif()
+
+# gRPC targets
+if(TARGET gRPC::grpc++)
+  project_build_tools_patch_default_imported_config(
+    gRPC::cares
+    gRPC::re2
+    gRPC::ssl
+    gRPC::crypto
+    gRPC::zlibstatic
+    gRPC::address_sorting
+    gRPC::gpr
+    gRPC::grpc
+    gRPC::grpc_unsecure
+    gRPC::grpc++
+    gRPC::grpc++_alts
+    gRPC::grpc++_error_details
+    gRPC::grpc++_reflection
+    gRPC::grpc++_unsecure
+    gRPC::grpc_authorization_provider
+    gRPC::grpc_plugin_support
+    gRPC::grpcpp_channelz
+    gRPC::upb)
+endif()
+
+# prometheus targets
+if(TARGET prometheus-cpp::core)
+  project_build_tools_patch_default_imported_config(
+    prometheus-cpp::core prometheus-cpp::pull prometheus-cpp::push)
+endif()
+
+# civetweb targets
+if(TARGET civetweb::civetweb)
+  project_build_tools_patch_default_imported_config(
+    civetweb::civetweb civetweb::server civetweb::civetweb-cpp)
+endif()
+
+if(BUILD_TESTING)
+  project_build_tools_patch_default_imported_config(
+    GTest::gtest
+    GTest::gtest_main
+    GTest::gmock
+    GTest::gmock_main
+    GTest::GTest
+    GTest::Main
+    benchmark::benchmark
+    benchmark::benchmark_main)
+endif()

cmake/tools.cmake

@@ -117,3 +117,83 @@ function(project_build_tools_get_imported_location OUTPUT_VAR_NAME TARGET_NAME)
         PARENT_SCOPE)
   endif()
 endfunction()
+
+#[[
+If we build third party packages with a different CONFIG setting from building
+otel-cpp, cmake may not find a suitable file in imported targets (#705, #1359)
+when linking. But on some platforms, different CONFIG settings can be used when
+these CONFIG settings have the same ABI. For example, on Linux, we can build
+gRPC and protobuf with -DCMAKE_BUILD_TYPE=Release, but build otel-cpp with
+-DCMAKE_BUILD_TYPE=Debug and link these libraries together.
+The properties of imported targets can be found here:
+https://cmake.org/cmake/help/latest/manual/cmake-properties.7.html#properties-on-targets
+]]
+function(project_build_tools_patch_default_imported_config)
+  set(PATCH_VARS
+      IMPORTED_IMPLIB
+      IMPORTED_LIBNAME
+      IMPORTED_LINK_DEPENDENT_LIBRARIES
+      IMPORTED_LINK_INTERFACE_LANGUAGES
+      IMPORTED_LINK_INTERFACE_LIBRARIES
+      IMPORTED_LINK_INTERFACE_MULTIPLICITY
+      IMPORTED_LOCATION
+      IMPORTED_NO_SONAME
+      IMPORTED_OBJECTS
+      IMPORTED_SONAME)
+  foreach(TARGET_NAME ${ARGN})
+    if(TARGET ${TARGET_NAME})
+      get_target_property(IS_IMPORTED_TARGET ${TARGET_NAME} IMPORTED)
+      if(NOT IS_IMPORTED_TARGET)
+        continue()
+      endif()
+
+      if(CMAKE_VERSION VERSION_LESS "3.19.0")
+        get_target_property(TARGET_TYPE_NAME ${TARGET_NAME} TYPE)
+        if(TARGET_TYPE_NAME STREQUAL "INTERFACE_LIBRARY")
+          continue()
+        endif()
+      endif()
+
+      get_target_property(DO_NOT_OVERWRITE ${TARGET_NAME} IMPORTED_LOCATION)
+      if(DO_NOT_OVERWRITE)
+        continue()
+      endif()
+
+      # MSVC's STL and debug level must match the target, so we can only move
+      # out IMPORTED_LOCATION_NOCONFIG
+      if(MSVC)
+        set(PATCH_IMPORTED_CONFIGURATION "NOCONFIG")
+      else()
+        get_target_property(PATCH_IMPORTED_CONFIGURATION ${TARGET_NAME}
+                            IMPORTED_CONFIGURATIONS)
+      endif()
+
+      if(NOT PATCH_IMPORTED_CONFIGURATION)
+        continue()
+      endif()
+
+      get_target_property(PATCH_TARGET_LOCATION ${TARGET_NAME}
+                          "IMPORTED_LOCATION_${PATCH_IMPORTED_CONFIGURATION}")
+      if(NOT PATCH_TARGET_LOCATION)
+        continue()
+      endif()
+
+      foreach(PATCH_IMPORTED_KEY IN LISTS PATCH_VARS)
+        get_target_property(
+          PATCH_IMPORTED_VALUE ${TARGET_NAME}
+          "${PATCH_IMPORTED_KEY}_${PATCH_IMPORTED_CONFIGURATION}")
+        if(PATCH_IMPORTED_VALUE)
+          set_target_properties(
+            ${TARGET_NAME} PROPERTIES "${PATCH_IMPORTED_KEY}"
+                                      "${PATCH_IMPORTED_VALUE}")
+          if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+            message(
+              STATUS
+                "Patch: ${TARGET_NAME} ${PATCH_IMPORTED_KEY} will use ${PATCH_IMPORTED_KEY}_${PATCH_IMPORTED_CONFIGURATION}(\"${PATCH_IMPORTED_VALUE}\") by default."
+            )
+          endif()
+        endif()
+      endforeach()
+    endif()
+  endforeach()
+endfunction()