fixes #577 target library dependencies should be public

This is a significant refactor of the library configuration.
We use the modern package configuration helper, with a template
script that also does the find_package dance for any of our
dependencies.

We also have restructured the code so that most protocols and
transports have their configuration isolated to their own CMakeLists
file, reducing the size of the global CMakeLists file.

1 files changed, 66 insertions, 30 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index d58f0b2e..428fb56d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -24,7 +24,8 @@
 #   IN THE SOFTWARE.
 #
 
-set (NNG_SOURCES
+set (NNG_HDRS nng.h)
+set (NNG_SRCS
     nng.c
     nng.h
 
@@ -87,7 +88,10 @@ set (NNG_SOURCES
 )
 
 if (NNG_PLATFORM_POSIX)
-    set (NNG_SOURCES ${NNG_SOURCES}
+    find_package (Threads REQUIRED)
+    set(NNG_LIBS Threads::Threads)
+
+    set (NNG_SRCS ${NNG_SRCS}
         platform/posix/posix_impl.h
         platform/posix/posix_ipc.h
         platform/posix/posix_config.h
@@ -114,26 +118,26 @@ if (NNG_PLATFORM_POSIX)
     )
 
     if (NNG_HAVE_PORT_CREATE)
-        set (NNG_SOURCES ${NNG_SOURCES}
+        set (NNG_SRCS ${NNG_SRCS}
             platform/posix/posix_pollq_port.c
         )
     elseif (NNG_HAVE_KQUEUE)
-        set (NNG_SOURCES ${NNG_SOURCES}
+        set (NNG_SRCS ${NNG_SRCS}
             platform/posix/posix_pollq_kqueue.c
         )
     elseif (NNG_HAVE_EPOLL AND NNG_HAVE_EVENTFD)
-        set (NNG_SOURCES ${NNG_SOURCES}
+        set (NNG_SRCS ${NNG_SRCS}
             platform/posix/posix_pollq_epoll.c
         )
     else()
-        set (NNG_SOURCES ${NNG_SOURCES}
+        set (NNG_SRCS ${NNG_SRCS}
             platform/posix/posix_pollq_poll.c
         )
     endif()
 endif()
 
 if (NNG_PLATFORM_WINDOWS)
-    set (NNG_SOURCES ${NNG_SOURCES}
+    set (NNG_SRCS ${NNG_SRCS}
         platform/windows/win_impl.h
         platform/windows/win_ipc.h
         platform/windows/win_tcp.h
@@ -158,17 +162,9 @@ if (NNG_PLATFORM_WINDOWS)
         )
 endif()
 
-set (NNG_HEADERS nng.h)
 
 add_subdirectory(compat/nanomsg)
 
-add_subdirectory(supplemental/base64)
-add_subdirectory(supplemental/http)
-add_subdirectory(supplemental/sha1)
-add_subdirectory(supplemental/tls)
-add_subdirectory(supplemental/util)
-add_subdirectory(supplemental/websocket)
-
 add_subdirectory(protocol/bus0)
 add_subdirectory(protocol/pair0)
 add_subdirectory(protocol/pair1)
@@ -184,14 +180,24 @@ add_subdirectory(transport/tls)
 add_subdirectory(transport/ws)
 add_subdirectory(transport/zerotier)
 
-include_directories(AFTER SYSTEM ${PROJECT_SOURCE_DIR}/src
-    ${NNG_REQUIRED_INCLUDES})
+add_subdirectory(supplemental/base64)
+add_subdirectory(supplemental/http)
+add_subdirectory(supplemental/sha1)
+add_subdirectory(supplemental/tls)
+add_subdirectory(supplemental/util)
+add_subdirectory(supplemental/websocket)
+
+include_directories(AFTER SYSTEM ${PROJECT_SOURCE_DIR}/src ${NNG_INCS})
+
+add_definitions(${NNG_DEFS})
 
-add_definitions(${NNG_DEFINES})
+foreach(_PKG IN ITEMS ${NNG_PKGS})
+	find_package(${_PKG} REQUIRED)
+endforeach ()
 
 # Provide same folder structure in IDE as on disk
 # XXX: Consider replacing this with source_group(TREE...)
-foreach (f ${NNG_SOURCES})
+foreach (f ${NNG_SRCS})
     # Get the path of the file relative to source directory
     if (IS_ABSOLUTE "${f}")
         file (RELATIVE_PATH f ${CMAKE_CURRENT_SOURCE_DIR} ${f})
@@ -207,8 +213,9 @@ foreach (f ${NNG_SOURCES})
     source_group ("${SRC_GROUP}" FILES ${f})
 endforeach ()
 
+
 # Library
-add_library (${PROJECT_NAME} ${NNG_SOURCES})
+add_library (${PROJECT_NAME} ${NNG_SRCS})
 
 # When building shared libraries we prefer to suppress default symbol
 # visibility, so that only the symbols that should be exposed in the
@@ -237,33 +244,62 @@ set_target_properties (${PROJECT_NAME}
 set_target_properties (${PROJECT_NAME} ${PROJECT_NAME}
 	PROPERTIES FRAMEWORK OFF)
 
-target_link_libraries (${PROJECT_NAME} PRIVATE ${NNG_REQUIRED_LIBRARIES})
-target_link_libraries (${PROJECT_NAME} PRIVATE Threads::Threads)
+target_link_libraries (${PROJECT_NAME} PRIVATE ${NNG_LIBS})
 
 target_include_directories (${PROJECT_NAME} INTERFACE $<INSTALL_INTERFACE:include>)
 
 install (TARGETS ${PROJECT_NAME}
     EXPORT ${PROJECT_NAME}-target
-    FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT library
-    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT library
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT library
-    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT tools
+    FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT Library
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT Library
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR} COMPONENT Library
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR} COMPONENT Tools
 )
 
 install (EXPORT ${PROJECT_NAME}-target
-    FILE ${PROJECT_NAME}-config.cmake
+    FILE ${PROJECT_NAME}-targets.cmake
     NAMESPACE nng::
     DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
+    COMPONENT Library
 )
 
 # Install the header files.  It would be much better if we could use
 # the PUBLIC_HEADER facility, but it stupidly flattens the directories.
-foreach (f ${NNG_HEADERS})
+foreach (f ${NNG_HDRS})
 	get_filename_component(d ${f} DIRECTORY)
 	install(FILES ${f}
 		DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/nng/${d}
-		COMPONENT headers)
+		COMPONENT Headers)
 endforeach()
 
 # Promote settings to parent
-set(NNG_REQUIRED_LIBRARIES ${NNG_REQUIRED_LIBRARIES} PARENT_SCOPE)
+set(NNG_LIBS ${NNG_LIBS} PARENT_SCOPE)
+set(NNG_PKGS ${NNG_PKGS} PARENT_SCOPE)
+set(NNG_DEFS ${NNG_DEFS} PARENT_SCOPE)
+
+# These are promoted for testing
+set(NNG_SUPP_BASE64 ${NNG_SUPP_BASE64} PARENT_SCOPE)
+set(NNG_SUPP_HTTP ${NNG_SUPP_HTTP} PARENT_SCOPE)
+set(NNG_SUPP_SHA1 ${NNG_SUPP_SHA1} PARENT_SCOPE)
+set(NNG_SUPP_TLS ${NNG_SUPP_TLS} PARENT_SCOPE)
+set(NNG_SUPP_WEBSOCKET ${NNG_SUPP_WEBSOCKET} PARENT_SCOPE)
+
+# Configure files
+
+set(INCLUDE_INSTALL_DIRS "${CMAKE_INSTALL_INCLUDEDIR}/nng")
+
+include(CMakePackageConfigHelpers)
+set(version_config "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config-version.cmake")
+set(project_config "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}-config.cmake")
+
+write_basic_package_version_file("${version_config}"
+    VERSION ${NNG_PACKAGE_VERSION}
+    COMPATIBILITY SameMajorVersion
+)
+configure_package_config_file(${CMAKE_SOURCE_DIR}/cmake/${PROJECT_NAME}-config.cmake.in "${project_config}"
+    INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
+    PATH_VARS INCLUDE_INSTALL_DIRS)
+
+install(FILES "${project_config}" "${version_config}"
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
+    COMPONENT Library)