cmake: add mruby support, fix tests dir

mruby is always invoked now (mirrors the autotools behavior). It could
be optimized though to only trigger the mruby build when the static
library is missing.

Also fix typo in NGHTTP2_TESTS_DIR macro definition (detected when
invoking the Ninja generator).

CMakeLists.txt

@@ -295,7 +295,9 @@ if(ENABLE_EXAMPLES OR ENABLE_APP OR ENABLE_HPACK_TOOLS OR ENABLE_ASIO_LIB)
   # mruby (for src/nghttpx)
   if(WITH_MRUBY)
     set(HAVE_MRUBY 1)
-    # XXX add -lmruby and -lm libs
+    set(MRUBY_LIBRARY
+      "${CMAKE_BINARY_DIR}/third-party/mruby/build/lib/${CMAKE_STATIC_LIBRARY_PREFIX}mruby${CMAKE_STATIC_LIBRARY_SUFFIX}"
+    )
   else()
     set(HAVE_MRUBY 0)
   endif()

src/CMakeLists.txt

@@ -131,15 +131,7 @@ if(ENABLE_APP)
   )
 
   if(HAVE_MRUBY)
-    target_include_directories(nghttpx PRIVATE
-      "${CMAKE_SOURCE_DIR}/third-party/mruby/include"
-      # ${LIBMRUBY_CFLAGS}
-    )
-    target_link_libraries(nghttpx
-      # nghttpx_LDADD += -L${top_builddir}/third-party/mruby/build/lib
-      # XXX find_library or other absolute path?
-      # ${LIBMRUBY_LIBS}
-    )
+    target_link_libraries(nghttpx mruby-lib)
   endif()
 
   if(HAVE_NEVERBLEED)
@@ -170,16 +162,12 @@ if(ENABLE_APP)
     )
     target_include_directories(nghttpx-unittest PRIVATE ${CUNIT_INCLUDE_DIRS})
     target_compile_definitions(nghttpx-unittest
-      PRIVATE "-DNGHTTP2_TESTS_DIR=\"$(CMAKE_SOURCE_DIR)/tests\""
+      PRIVATE "-DNGHTTP2_TESTS_DIR=\"${CMAKE_SOURCE_DIR}/tests\""
     )
     target_link_libraries(nghttpx-unittest nghttpx ${CUNIT_LIBRARIES})
-  # if HAVE_MRUBY
-  # nghttpx_unittest_CPPFLAGS +=
-  #   -I${top_srcdir}/third-party/mruby/include @LIBMRUBY_CFLAGS@
-  # nghttpx_unittest_LDADD +=
-  #   -L${top_builddir}/third-party/mruby/build/lib @LIBMRUBY_LIBS@
-  # endif # HAVE_MRUBY
-  # 
+    if(HAVE_MRUBY)
+      target_link_libraries(nghttpx-unittest mruby-lib)
+    endif()
     if(HAVE_NEVERBLEED)
       target_link_libraries(nghttpx-unittest neverbleed)
     endif()

third-party/CMakeLists.txt

@@ -17,22 +17,47 @@ if(ENABLE_THIRD_PARTY)
   endif()
 
   if(HAVE_MRUBY)
-    ## EXTRA_DIST = build_config.rb mruby/*
+    # EXTRA_DIST = build_config.rb mruby/*
 
-    #.PHONY: all-local clean mruby
+    set(MRUBY_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/mruby/build")
+    set(MRUBY_LIBRARY
+      "${CMAKE_STATIC_LIBRARY_PREFIX}mruby${CMAKE_STATIC_LIBRARY_SUFFIX}"
+    )
 
-    #mruby:
-    #  MRUBY_CONFIG="${srcdir}/build_config.rb" \
-    #  BUILD_DIR="${abs_builddir}/mruby/build" \
-    #  INSTALL_DIR="${abs_builddir}/mruby/build/install/bin" \
-    #  CC="${CC}" CXX="${CXX}" LD="${LD}" \
-    #  CFLAGS="${CPPFLAGS} ${CFLAGS}" CXXFLAGS="${CPPFLAGS} ${CXXFLAGS}" \
-    #  LDFLAGS="${LDFLAGS}" \
-    #  "${srcdir}/mruby/minirake" -f "${srcdir}/mruby/Rakefile"
+    # The mruby build needs some env vars. Alternatively, look at cmake -P
+    if(CMAKE_VERSION VERSION_LESS "3.1")
+      # XXX works only for Unixes?
+      set(ENV_COMMAND env)
+    else()
+      set(ENV_COMMAND ${CMAKE_COMMAND} -E env)
+    endif()
+    # Required for the Ninja generator. For older CMake, you first have to
+    # invoke 'ninja mruby' before building dependents.
+    if(CMAKE_VERSION VERSION_LESS "3.2")
+      set(_byproducts)
+    else()
+      set(_byproducts BYPRODUCTS "mruby/build/lib/${MRUBY_LIBRARY}")
+    endif()
+    add_custom_target(mruby
+      COMMAND ${ENV_COMMAND}
+        "MRUBY_CONFIG=${CMAKE_CURRENT_SOURCE_DIR}/build_config.rb"
+        "BUILD_DIR=${MRUBY_BUILD_DIR}"
+        "INSTALL_DIR=${MRUBY_BUILD_DIR}/install/bin"
+        "CC=${CMAKE_C_COMPILER}" "CXX=${CMAKE_CXX_COMPILER}"
+        "${CMAKE_CURRENT_SOURCE_DIR}/mruby/minirake"
+        -f "${CMAKE_CURRENT_SOURCE_DIR}/mruby/Rakefile"
+      ${_byproducts}
+      VERBATIM
+    )
 
-    #all-local: mruby
+    # Make the mruby library available to others in this project without them
+    # having to worry about include dirs and the mruby location.
+    add_library(mruby-lib STATIC IMPORTED GLOBAL)
+    set_target_properties(mruby-lib PROPERTIES
+      IMPORTED_LOCATION "${MRUBY_BUILD_DIR}/lib/${MRUBY_LIBRARY}"
+      INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_SOURCE_DIR}/mruby/include"
+    )
 
-    #clean-local:
-    #  -rm -rf "${abs_builddir}/mruby/build"
+    # XXX clean ${CMAKE_CURRENT_BINARY_DIR}/mruby/build
   endif()
 endif()