build: add a cmake based build system

This is far from complete, but is sufficient to build a Linux version of
libdispatch.  It shows what a potential cmake based build system could
look like, and if desired can be completed to build all the various
flavours with cmake.

Author: compnerd

CMakeLists.txt

@@ -0,0 +1,157 @@
+
+cmake_minimum_required(VERSION 3.4.3)
+
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
+
+project(dispatch C CXX)
+enable_testing()
+
+set(CMAKE_C_VISIBILITY_PRESET hidden)
+set(CMAKE_CXX_STANDARD 11)
+
+include(GNUInstallDirs)
+
+set(WITH_KQUEUE "" CACHE PATH "Path to kqueue headers")
+set(WITH_BLOCKS_RUNTIME "" CACHE PATH "Path to blocks runtime")
+set(WITH_PTHREAD_WORKQUEUES "" CACHE PATH "Path to pthread-workqueues")
+
+# TODO(compnerd) consider adding a flag for USE_GOLD_LINKER.  Currently, we
+# expect the user to specify `-fuse-ld=gold`
+
+include(DispatchAppleOptions)
+
+if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+  set(ENABLE_DISPATCH_INIT_CONSTRUCTOR_DEFAULT ON)
+else()
+  set(ENABLE_DISPATCH_INIT_CONSTRUCTOR_DEFAULT OFF)
+endif()
+option(ENABLE_DISPATCH_INIT_CONSTRUCTOR "enable libdispatch_init as a constructor"
+       ${ENABLE_DISPATCH_INIT_CONSTRUCTOR_DEFAULT})
+
+if(CMAKE_SYSTEM_NAME STREQUAL Linux)
+  set(ENABLE_THREAD_LOCAL_STORAGE_DEFAULT ON)
+else()
+  set(ENABLE_THREAD_LOCAL_STORAGE_DEFAULT OFF)
+endif()
+option(ENABLE_THREAD_LOCAL_STORAGE "enable usage of thread local storage via __thread"
+       ${ENABLE_THREAD_LOCAL_STORAGE_DEFAULT})
+
+if(ENABLE_DISPATCH_INIT_CONSTRUCTOR)
+  add_definitions(-DUSE_LIBDISPATCH_INIT_CONSTRUCTOR=1)
+endif()
+if(ENABLE_THREAD_LOCAL_STORAGE)
+  add_definitions(-DDISPATCH_USE_THREAD_LOCAL_STORAGE=1)
+endif()
+
+include(CheckCSourceCompiles)
+include(CheckFunctionExists)
+include(CheckIncludeFiles)
+include(CheckLibraryExists)
+include(CheckSymbolExists)
+
+check_c_source_compiles(
+"
+#include <features.h>
+#if defined(__GNU_LIBRARY__)
+int main() { return 0; }
+#endif
+"
+_GNU_SOURCE)
+if(_GNU_SOURCE)
+  set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -D_GNU_SOURCE)
+  add_definitions(-D_GNU_SOURCE)
+endif()
+
+find_library(HAVE_LIBRT NAMES rt)
+if(HAVE_LIBRT)
+  set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} rt)
+endif()
+
+check_function_exists(_pthread_workqueue_init HAVE__PTHREAD_WORKQUEUE_INIT)
+check_function_exists(getprogname HAVE_GETPROGNAME)
+check_function_exists(mach_absolute_time HAVE_MACH_ABSOLUTE_TIME)
+check_function_exists(mach_port_construct HAVE_MACH_PORT_CONSTRUCT)
+check_function_exists(malloc_create_zone HAVE_MALLOC_CREATE_ZONE)
+check_function_exists(pthread_key_init_np HAVE_PTHREAD_KEY_INIT_NP)
+check_function_exists(pthread_main_np HAVE_PTHREAD_MAIN_NP)
+check_function_exists(pthread_workqueue_setdispatch_np HAVE_PTHREAD_WORKQUEUE_SETDISPATCH_NP)
+check_function_exists(strlcpy HAVE_STRLCPY)
+check_function_exists(sysconf HAVE_SYSCONF)
+
+if(NOT HAVE_STRLCPY AND NOT HAVE_GETPROGNAME)
+  include(FindPkgConfig)
+  pkg_check_modules(BSD_OVERLAY libbsd-overlay)
+  if(BSD_OVERLAY_FOUND)
+    set(HAVE_STRLCPY 1 CACHE INTERNAL "Have function strlcpy" FORCE)
+    set(HAVE_GETPROGNAME 1 CACHE INTERNAL "Have function getprogname" FORCE)
+  endif()
+endif()
+
+find_package(Threads REQUIRED)
+
+check_include_files("TargetConditionals.h" HAVE_TARGETCONDITIONALS_H)
+check_include_files("dlfcn.h" HAVE_DLFCN_H)
+check_include_files("fcntl.h" HAVE_FCNTL_H)
+check_include_files("inttypes.h" HAVE_INTTYPES_H)
+check_include_files("libkern/OSAtomic.h" HAVE_LIBKERN_OSATOMIC_H)
+check_include_files("libkern/OSCrossEndian.h" HAVE_LIBKERN_OSCROSSENDIAN_H)
+check_include_files("libproc_internal.h" HAVE_LIBPROC_INTERNAL_H)
+check_include_files("mach/mach.h" HAVE_MACH)
+if(HAVE_MACH)
+  set(__DARWIN_NON_CANCELABLE 1)
+  set(USE_MACH_SEM 1)
+else()
+  set(__DARWIN_NON_CANCELABLE 0)
+  set(USE_MACH_SEM 0)
+endif()
+check_include_files("malloc/malloc.h" HAVE_MALLOC_MALLOC_H)
+check_include_files("memory.h" HAVE_MEMORY_H)
+check_include_files("pthread/qos.h" HAVE_PTHREAD_QOS_H)
+check_include_files("pthread/workqueue_private.h" HAVE_PTHREAD_WORKQUEUE_PRIVATE_H)
+check_include_files("pthread_machdep.h" HAVE_PTHREAD_MACHDEP_H)
+check_include_files("pthread_np.h" HAVE_PTHREAD_NP_H)
+check_include_files("pthread_workqueue.h" HAVE_PTHREAD_WORKQUEUE_H)
+check_include_files("stdint.h" HAVE_STDINT_H)
+check_include_files("stdlib.h" HAVE_STDLIB_H)
+check_include_files("string.h" HAVE_STRING_H)
+check_include_files("strings.h" HAVE_STRINGS_H)
+check_include_files("sys/cdefs.h" HAVE_SYS_CDEFS_H)
+check_include_files("sys/guarded.h" HAVE_SYS_GUARDED_H)
+check_include_files("sys/stat.h" HAVE_SYS_STAT_H)
+check_include_files("sys/types.h" HAVE_SYS_TYPES_H)
+check_include_files("unistd.h" HAVE_UNISTD_H)
+
+check_library_exists(pthread sem_init "" USE_POSIX_SEM)
+
+check_symbol_exists(CLOCK_UPTIME "time.h" HAVE_DECL_CLOCK_UPTIME)
+check_symbol_exists(CLOCK_MONOTONIC "time.h" HAVE_DECL_CLOCK_MONOTONIC)
+check_symbol_exists(FD_COPY "sys/select.h" HAVE_DECL_FD_COPY)
+check_symbol_exists(NOTE_NONE "sys/event.h" HAVE_DECL_NOTE_NONE)
+check_symbol_exists(NOTE_REAP "sys/event.h" HAVE_DECL_NOTE_REAP)
+check_symbol_exists(NOTE_REVOKE "sys/event.h" HAVE_DECL_NOTE_REVOKE)
+check_symbol_exists(NOTE_SIGNAL "sys/event.h" HAVE_DECL_NOTE_SIGNAL)
+check_symbol_exists(SIGEMT "signal.h" HAVE_DECL_SIGEMT)
+check_symbol_exists(VQ_QUOTA "sys/mount.h" HAVE_DECL_VQ_QUOTA)
+check_symbol_exists(VQ_UPDATE "sys/mount.h" HAVE_DECL_VQ_UPDATE)
+check_symbol_exists(VQ_VERYLOWDISK "sys/mount.h" HAVE_DECL_VQ_VERYLOWDISK)
+
+check_symbol_exists(program_invocation_name "errno.h" HAVE_DECL_PROGRAM_INVOCATION_SHORT_NAME)
+
+if(CMAKE_SYSTEM_NAME STREQUAL Darwin)
+  add_definitions(-DDISPATCH_USE_DTRACE=1)
+else()
+  add_definitions(-DDISPATCH_USE_DTRACE=0)
+endif()
+
+configure_file("${CMAKE_SOURCE_DIR}/cmake/config.h.in"
+               "${CMAKE_BINARY_DIR}/config/config.h")
+
+add_subdirectory(dispatch)
+add_subdirectory(man)
+add_subdirectory(os)
+add_subdirectory(private)
+add_subdirectory(src)
+if(ENABLE_TESTING)
+  add_subdirectory(tests)
+endif()
+