Refactor CMake to use more modern paradigms (#741)

Remove 2.6-isms
Remove 2.8-isms
Bump CMake minimum version to 3.4

Disable some options when used as a subdirectory

Use `CONFIGURE_DEPENDS` with `file(GLOB)` when possible

Backport CMake 3.15's MSVC_RUNTIME_LIBRARY setting.
Set all compile options as generator expressions.
Set all find-package files to be installed to the correct file.

Remove `export(PACKAGE)`, as this has been deprecated.
Remove fat binary support
Remove manual setting of iPhone settings. These should be set by parent
projects.
Remove use of ExternalProject for a local use
Conditionally remove format target unless clang-format is found

.travis.yml

@@ -18,10 +18,10 @@ before_script:
   - mkdir build
   - cd build
   - cmake ..
+  - cd ..
 script:
-  - make
-  - test/run-tests
-
+  - cmake --build build
+  - cmake --build build --target test
 matrix:
   exclude:
   - os: linux

test/CMakeLists.txt

-include(ExternalProject)
+find_package(Threads REQUIRED)
 
-if(MSVC)
-    # MS Visual Studio expects lib prefix on static libraries,
-    # but CMake compiles them without prefix
-    # See https://gitlab.kitware.com/cmake/cmake/issues/17338
-    set(CMAKE_STATIC_LIBRARY_PREFIX "")
-endif()
-
-ExternalProject_Add(
-	googletest_project
-	SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.8.0"
-	INSTALL_DIR "${CMAKE_CURRENT_BINARY_DIR}/prefix"
-	CMAKE_ARGS
-		-DCMAKE_INSTALL_PREFIX:PATH=<INSTALL_DIR>
-		-DBUILD_GMOCK=ON
-		-Dgtest_force_shared_crt=ON
-)
-
-add_library(gmock UNKNOWN IMPORTED)
-set_target_properties(gmock PROPERTIES
-    IMPORTED_LOCATION
-    ${PROJECT_BINARY_DIR}/test/prefix/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gmock${CMAKE_STATIC_LIBRARY_SUFFIX}
-)
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+set(BUILD_MOCK ON CACHE BOOL "" FORCE)
+set(CMAKE_POLICY_DEFAULT_CMP0048 NEW)
 
-find_package(Threads)
+add_subdirectory(
+  "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.8.0"
+  "${CMAKE_CURRENT_BINARY_DIR}/prefix")
 
-include_directories(SYSTEM "${PROJECT_BINARY_DIR}/test/prefix/include")
+include_directories(SYSTEM "${CMAKE_CURRENT_SOURCE_DIR}/gtest-1.8.0/googletest/include")
 
-if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR
-	CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-	set(yaml_test_flags "-Wno-variadic-macros -Wno-sign-compare")
-
-	if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-		set(yaml_test_flags "${yaml_test_flags} -Wno-c99-extensions")
-	endif()
+set(test-new-api-pattern "new-api/*.cpp")
+set(test-source-pattern "*.cpp" "integration/*.cpp" "node/*.cpp")
+if (CMAKE_VERSION VERSION_GREATER 3.11)
+  list(INSERT test-new-api-pattern 0 CONFIGURE_DEPENDS)
+  list(INSERT test-source-pattern 0 CONFIGURE_DEPENDS)
 endif()
 
-file(GLOB test_headers [a-z_]*.h)
-file(GLOB test_sources [a-z_]*.cpp integration/[a-z_]*.cpp node/[a-z_]*.cpp)
-file(GLOB test_new_api_sources new-api/[a-z]*.cpp)
-
-list(APPEND test_sources ${test_new_api_sources})
-add_sources(${test_sources} ${test_headers})
-
-include_directories(${YAML_CPP_SOURCE_DIR}/src)
-include_directories(${YAML_CPP_SOURCE_DIR}/test)
-
-add_executable(run-tests
-    ${test_sources}
-    ${test_headers}
-)
-
-set_target_properties(run-tests PROPERTIES
-    CXX_STANDARD 11
-    CXX_STANDARD_REQUIRED ON
-)
+file(GLOB test-new-api-sources ${test-new-api-pattern})
+file(GLOB test-sources ${test-source-pattern})
+
+add_executable(yaml-cpp-tests)
+target_sources(yaml-cpp-tests
+  PRIVATE
+    ${test-new-api-sources}
+    ${test-sources})
+target_include_directories(yaml-cpp-tests
+  PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}/integration
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${PROJECT_SOURCE_DIR}/src)
+target_compile_options(yaml-cpp-tests
+  PRIVATE
+    $<$<CXX_COMPILER_ID:Clang>:-Wno-c99-extensions -Wno-variadic-macros -Wno-sign-compare>
+    $<$<CXX_COMPILER_ID:GNU>:-Wno-variadic-macros -Wno-sign-compare>)
+target_link_libraries(yaml-cpp-tests
+  PRIVATE
+    Threads::Threads
+    yaml-cpp
+    gmock)
 
-add_dependencies(run-tests googletest_project)
+set_property(TARGET yaml-cpp-tests PROPERTY CXX_STANDARD_REQUIRED ON)
+if (NOT DEFINED CMAKE_CXX_STANDARD)
+  set_target_properties(yaml-cpp-tests PROPERTIES CXX_STANDARD 11)
+endif()
 
-set_target_properties(run-tests PROPERTIES
-    COMPILE_FLAGS "${yaml_c_flags} ${yaml_cxx_flags} ${yaml_test_flags}"
-)
-target_link_libraries(run-tests
-    yaml-cpp
-    gmock
-    ${CMAKE_THREAD_LIBS_INIT})
 
-add_test(yaml-test ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/run-tests)
+add_test(yaml-cpp::test yaml-cpp-tests)

test/ostream_wrapper_test.cpp

-#include <stddef.h>
 #include <sstream>
+#include <cstddef>
 
 #include "gtest/gtest.h"
 #include "yaml-cpp/ostream_wrapper.h"

util/CMakeLists.txt

-cmake_minimum_required(VERSION 3.5)
+add_executable(yaml-cpp-sandbox sandbox.cpp)
+add_executable(yaml-cpp-parse parse.cpp)
+add_executable(yaml-cpp-read read.cpp)
 
-add_sources(parse.cpp)
-add_executable(parse parse.cpp)
-set_target_properties(parse PROPERTIES
-    CXX_STANDARD 11
+target_link_libraries(yaml-cpp-sandbox PRIVATE yaml-cpp)
+target_link_libraries(yaml-cpp-parse PRIVATE yaml-cpp)
+target_link_libraries(yaml-cpp-read PRIVATE yaml-cpp)
+
+set_property(TARGET yaml-cpp-sandbox PROPERTY OUTPUT_NAME sandbox)
+set_property(TARGET yaml-cpp-parse PROPERTY OUTPUT_NAME parse)
+set_property(TARGET yaml-cpp-read PROPERTY OUTPUT_NAME read)
+
+set_target_properties(yaml-cpp-sandbox
+  PROPERTIES
     CXX_STANDARD_REQUIRED ON
-)
-target_link_libraries(parse yaml-cpp)
+    OUTPUT_NAME sandbox)
 
-add_sources(sandbox.cpp)
-add_executable(sandbox sandbox.cpp)
-set_target_properties(sandbox PROPERTIES
-    CXX_STANDARD 11
+set_target_properties(yaml-cpp-parse
+  PROPERTIES
     CXX_STANDARD_REQUIRED ON
-)
-target_link_libraries(sandbox yaml-cpp)
+    OUTPUT_NAME parse)
 
-add_sources(read.cpp)
-add_executable(read read.cpp)
-set_target_properties(read PROPERTIES
-    CXX_STANDARD 11
+set_target_properties(yaml-cpp-read
+  PROPERTIES
     CXX_STANDARD_REQUIRED ON
-)
-target_link_libraries(read yaml-cpp)
+    OUTPUT_NAME read)
 
+if (NOT DEFINED CMAKE_CXX_STANDARD)
+  set_target_properties(yaml-cpp-sandbox yaml-cpp-parse yaml-cpp-read
+    PROPERTIES
+      CXX_STANDARD 11)
+endif()

yaml-cpp-config-version.cmake.in

-set(PACKAGE_VERSION "@YAML_CPP_VERSION@")
-
-# Check whether the requested PACKAGE_FIND_VERSION is compatible
-if("${PACKAGE_VERSION}" VERSION_LESS "${PACKAGE_FIND_VERSION}")
-	set(PACKAGE_VERSION_COMPATIBLE FALSE)
-else()
-	set(PACKAGE_VERSION_COMPATIBLE TRUE)
-	if ("${PACKAGE_VERSION}" VERSION_EQUAL "${PACKAGE_FIND_VERSION}")
-		set(PACKAGE_VERSION_EXACT TRUE)
-	endif()
-endif()

yaml-cpp.pc.cmake → yaml-cpp.pc.in

 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=${prefix}
-includedir=${prefix}/@INCLUDE_INSTALL_ROOT_DIR@
-libdir=${exec_prefix}/@LIB_INSTALL_DIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+libdir=${exec_prefix}/@CMAKE_INSTALL_LIBDIR@
 
 Name: Yaml-cpp
 Description: A YAML parser and emitter for C++