llvm-mirror/cmake/config-ix.cmake
Chandler Carruth 0d8e96fc35 Factor the option and checking of compiler version better. Put the
option with the others in the top level CMakeLists, and put the check in
HandleLLVMOptions. This will also let it be used from the standalone
Clang builds.

llvm-svn: 199149
2014-01-13 22:21:34 +00:00

501 lines
17 KiB
CMake
Executable File

if( WIN32 AND NOT CYGWIN )
# We consider Cygwin as another Unix
set(PURE_WINDOWS 1)
endif()
include(CheckIncludeFile)
include(CheckIncludeFileCXX)
include(CheckLibraryExists)
include(CheckSymbolExists)
include(CheckFunctionExists)
include(CheckCXXSourceCompiles)
include(TestBigEndian)
if( UNIX AND NOT BEOS )
# Used by check_symbol_exists:
set(CMAKE_REQUIRED_LIBRARIES m)
endif()
# Helper macros and functions
macro(add_cxx_include result files)
set(${result} "")
foreach (file_name ${files})
set(${result} "${${result}}#include<${file_name}>\n")
endforeach()
endmacro(add_cxx_include files result)
function(check_type_exists type files variable)
add_cxx_include(includes "${files}")
CHECK_CXX_SOURCE_COMPILES("
${includes} ${type} typeVar;
int main() {
return 0;
}
" ${variable})
endfunction()
# include checks
check_include_file_cxx(cxxabi.h HAVE_CXXABI_H)
check_include_file(dirent.h HAVE_DIRENT_H)
check_include_file(dlfcn.h HAVE_DLFCN_H)
check_include_file(errno.h HAVE_ERRNO_H)
check_include_file(execinfo.h HAVE_EXECINFO_H)
check_include_file(fcntl.h HAVE_FCNTL_H)
check_include_file(inttypes.h HAVE_INTTYPES_H)
check_include_file(limits.h HAVE_LIMITS_H)
check_include_file(malloc.h HAVE_MALLOC_H)
check_include_file(malloc/malloc.h HAVE_MALLOC_MALLOC_H)
check_include_file(ndir.h HAVE_NDIR_H)
if( NOT PURE_WINDOWS )
check_include_file(pthread.h HAVE_PTHREAD_H)
endif()
check_include_file(sanitizer/msan_interface.h HAVE_SANITIZER_MSAN_INTERFACE_H)
check_include_file(signal.h HAVE_SIGNAL_H)
check_include_file(stdint.h HAVE_STDINT_H)
check_include_file(sys/dir.h HAVE_SYS_DIR_H)
check_include_file(sys/ioctl.h HAVE_SYS_IOCTL_H)
check_include_file(sys/mman.h HAVE_SYS_MMAN_H)
check_include_file(sys/ndir.h HAVE_SYS_NDIR_H)
check_include_file(sys/param.h HAVE_SYS_PARAM_H)
check_include_file(sys/resource.h HAVE_SYS_RESOURCE_H)
check_include_file(sys/stat.h HAVE_SYS_STAT_H)
check_include_file(sys/time.h HAVE_SYS_TIME_H)
check_include_file(sys/uio.h HAVE_SYS_UIO_H)
check_include_file(sys/wait.h HAVE_SYS_WAIT_H)
check_include_file(termios.h HAVE_TERMIOS_H)
check_include_file(unistd.h HAVE_UNISTD_H)
check_include_file(utime.h HAVE_UTIME_H)
check_include_file(valgrind/valgrind.h HAVE_VALGRIND_VALGRIND_H)
check_include_file(zlib.h HAVE_ZLIB_H)
check_include_file(fenv.h HAVE_FENV_H)
check_symbol_exists(FE_ALL_EXCEPT "fenv.h" HAVE_DECL_FE_ALL_EXCEPT)
check_symbol_exists(FE_INEXACT "fenv.h" HAVE_DECL_FE_INEXACT)
check_include_file(mach/mach.h HAVE_MACH_MACH_H)
check_include_file(mach-o/dyld.h HAVE_MACH_O_DYLD_H)
# library checks
if( NOT PURE_WINDOWS )
check_library_exists(pthread pthread_create "" HAVE_LIBPTHREAD)
if (HAVE_LIBPTHREAD)
check_library_exists(pthread pthread_getspecific "" HAVE_PTHREAD_GETSPECIFIC)
check_library_exists(pthread pthread_rwlock_init "" HAVE_PTHREAD_RWLOCK_INIT)
check_library_exists(pthread pthread_mutex_lock "" HAVE_PTHREAD_MUTEX_LOCK)
else()
# this could be Android
check_library_exists(c pthread_create "" PTHREAD_IN_LIBC)
if (PTHREAD_IN_LIBC)
check_library_exists(c pthread_getspecific "" HAVE_PTHREAD_GETSPECIFIC)
check_library_exists(c pthread_rwlock_init "" HAVE_PTHREAD_RWLOCK_INIT)
check_library_exists(c pthread_mutex_lock "" HAVE_PTHREAD_MUTEX_LOCK)
endif()
endif()
check_library_exists(dl dlopen "" HAVE_LIBDL)
check_library_exists(rt clock_gettime "" HAVE_LIBRT)
if (LLVM_ENABLE_ZLIB)
check_library_exists(z compress2 "" HAVE_LIBZ)
else()
set(HAVE_LIBZ 0)
endif()
if(LLVM_ENABLE_TERMINFO)
set(HAVE_TERMINFO 0)
foreach(library tinfo terminfo curses ncurses ncursesw)
string(TOUPPER ${library} library_suffix)
check_library_exists(${library} setupterm "" HAVE_TERMINFO_${library_suffix})
if(HAVE_TERMINFO_${library_suffix})
set(HAVE_TERMINFO 1)
set(TERMINFO_LIBS "${library}")
break()
endif()
endforeach()
else()
set(HAVE_TERMINFO 0)
endif()
endif()
# function checks
check_symbol_exists(arc4random "stdlib.h" HAVE_ARC4RANDOM)
check_symbol_exists(backtrace "execinfo.h" HAVE_BACKTRACE)
check_symbol_exists(getpagesize unistd.h HAVE_GETPAGESIZE)
check_symbol_exists(getrusage sys/resource.h HAVE_GETRUSAGE)
check_symbol_exists(setrlimit sys/resource.h HAVE_SETRLIMIT)
check_symbol_exists(isatty unistd.h HAVE_ISATTY)
check_symbol_exists(isinf cmath HAVE_ISINF_IN_CMATH)
check_symbol_exists(isinf math.h HAVE_ISINF_IN_MATH_H)
check_symbol_exists(finite ieeefp.h HAVE_FINITE_IN_IEEEFP_H)
check_symbol_exists(isnan cmath HAVE_ISNAN_IN_CMATH)
check_symbol_exists(isnan math.h HAVE_ISNAN_IN_MATH_H)
check_symbol_exists(ceilf math.h HAVE_CEILF)
check_symbol_exists(floorf math.h HAVE_FLOORF)
check_symbol_exists(fmodf math.h HAVE_FMODF)
check_symbol_exists(log math.h HAVE_LOG)
check_symbol_exists(log2 math.h HAVE_LOG2)
check_symbol_exists(log10 math.h HAVE_LOG10)
check_symbol_exists(exp math.h HAVE_EXP)
check_symbol_exists(exp2 math.h HAVE_EXP2)
check_symbol_exists(exp10 math.h HAVE_EXP10)
check_symbol_exists(futimens sys/stat.h HAVE_FUTIMENS)
check_symbol_exists(futimes sys/time.h HAVE_FUTIMES)
if( HAVE_SETJMP_H )
check_symbol_exists(longjmp setjmp.h HAVE_LONGJMP)
check_symbol_exists(setjmp setjmp.h HAVE_SETJMP)
check_symbol_exists(siglongjmp setjmp.h HAVE_SIGLONGJMP)
check_symbol_exists(sigsetjmp setjmp.h HAVE_SIGSETJMP)
endif()
if( HAVE_SYS_UIO_H )
check_symbol_exists(writev sys/uio.h HAVE_WRITEV)
endif()
check_symbol_exists(nearbyintf math.h HAVE_NEARBYINTF)
check_symbol_exists(mallinfo malloc.h HAVE_MALLINFO)
check_symbol_exists(malloc_zone_statistics malloc/malloc.h
HAVE_MALLOC_ZONE_STATISTICS)
check_symbol_exists(mkdtemp "stdlib.h;unistd.h" HAVE_MKDTEMP)
check_symbol_exists(mkstemp "stdlib.h;unistd.h" HAVE_MKSTEMP)
check_symbol_exists(mktemp "stdlib.h;unistd.h" HAVE_MKTEMP)
check_symbol_exists(closedir "sys/types.h;dirent.h" HAVE_CLOSEDIR)
check_symbol_exists(opendir "sys/types.h;dirent.h" HAVE_OPENDIR)
check_symbol_exists(readdir "sys/types.h;dirent.h" HAVE_READDIR)
check_symbol_exists(getcwd unistd.h HAVE_GETCWD)
check_symbol_exists(gettimeofday sys/time.h HAVE_GETTIMEOFDAY)
check_symbol_exists(getrlimit "sys/types.h;sys/time.h;sys/resource.h" HAVE_GETRLIMIT)
check_symbol_exists(posix_spawn spawn.h HAVE_POSIX_SPAWN)
check_symbol_exists(pread unistd.h HAVE_PREAD)
check_symbol_exists(realpath stdlib.h HAVE_REALPATH)
check_symbol_exists(sbrk unistd.h HAVE_SBRK)
check_symbol_exists(srand48 stdlib.h HAVE_RAND48_SRAND48)
if( HAVE_RAND48_SRAND48 )
check_symbol_exists(lrand48 stdlib.h HAVE_RAND48_LRAND48)
if( HAVE_RAND48_LRAND48 )
check_symbol_exists(drand48 stdlib.h HAVE_RAND48_DRAND48)
if( HAVE_RAND48_DRAND48 )
set(HAVE_RAND48 1 CACHE INTERNAL "are srand48/lrand48/drand48 available?")
endif()
endif()
endif()
check_symbol_exists(strtoll stdlib.h HAVE_STRTOLL)
check_symbol_exists(strtoq stdlib.h HAVE_STRTOQ)
check_symbol_exists(strerror string.h HAVE_STRERROR)
check_symbol_exists(strerror_r string.h HAVE_STRERROR_R)
check_symbol_exists(strerror_s string.h HAVE_DECL_STRERROR_S)
check_symbol_exists(setenv stdlib.h HAVE_SETENV)
if( PURE_WINDOWS )
check_symbol_exists(_chsize_s io.h HAVE__CHSIZE_S)
check_function_exists(_alloca HAVE__ALLOCA)
check_function_exists(__alloca HAVE___ALLOCA)
check_function_exists(__chkstk HAVE___CHKSTK)
check_function_exists(___chkstk HAVE____CHKSTK)
check_function_exists(__ashldi3 HAVE___ASHLDI3)
check_function_exists(__ashrdi3 HAVE___ASHRDI3)
check_function_exists(__divdi3 HAVE___DIVDI3)
check_function_exists(__fixdfdi HAVE___FIXDFDI)
check_function_exists(__fixsfdi HAVE___FIXSFDI)
check_function_exists(__floatdidf HAVE___FLOATDIDF)
check_function_exists(__lshrdi3 HAVE___LSHRDI3)
check_function_exists(__moddi3 HAVE___MODDI3)
check_function_exists(__udivdi3 HAVE___UDIVDI3)
check_function_exists(__umoddi3 HAVE___UMODDI3)
check_function_exists(__main HAVE___MAIN)
check_function_exists(__cmpdi2 HAVE___CMPDI2)
endif()
if( HAVE_DLFCN_H )
if( HAVE_LIBDL )
list(APPEND CMAKE_REQUIRED_LIBRARIES dl)
endif()
check_symbol_exists(dlerror dlfcn.h HAVE_DLERROR)
check_symbol_exists(dlopen dlfcn.h HAVE_DLOPEN)
if( HAVE_LIBDL )
list(REMOVE_ITEM CMAKE_REQUIRED_LIBRARIES dl)
endif()
endif()
check_symbol_exists(__GLIBC__ stdio.h LLVM_USING_GLIBC)
if( LLVM_USING_GLIBC )
add_llvm_definitions( -D_GNU_SOURCE )
endif()
set(headers "sys/types.h")
if (HAVE_INTTYPES_H)
set(headers ${headers} "inttypes.h")
endif()
if (HAVE_STDINT_H)
set(headers ${headers} "stdint.h")
endif()
check_type_exists(int64_t "${headers}" HAVE_INT64_T)
check_type_exists(uint64_t "${headers}" HAVE_UINT64_T)
check_type_exists(u_int64_t "${headers}" HAVE_U_INT64_T)
# available programs checks
function(llvm_find_program name)
string(TOUPPER ${name} NAME)
string(REGEX REPLACE "\\." "_" NAME ${NAME})
find_program(LLVM_PATH_${NAME} NAMES ${ARGV})
mark_as_advanced(LLVM_PATH_${NAME})
if(LLVM_PATH_${NAME})
set(HAVE_${NAME} 1 CACHE INTERNAL "Is ${name} available ?")
mark_as_advanced(HAVE_${NAME})
else(LLVM_PATH_${NAME})
set(HAVE_${NAME} "" CACHE INTERNAL "Is ${name} available ?")
endif(LLVM_PATH_${NAME})
endfunction()
llvm_find_program(gv)
llvm_find_program(circo)
llvm_find_program(twopi)
llvm_find_program(neato)
llvm_find_program(fdp)
llvm_find_program(dot)
llvm_find_program(dotty)
llvm_find_program(xdot xdot.py)
llvm_find_program(Graphviz)
if( LLVM_ENABLE_FFI )
find_path(FFI_INCLUDE_PATH ffi.h PATHS ${FFI_INCLUDE_DIR})
if( FFI_INCLUDE_PATH )
set(FFI_HEADER ffi.h CACHE INTERNAL "")
set(HAVE_FFI_H 1 CACHE INTERNAL "")
else()
find_path(FFI_INCLUDE_PATH ffi/ffi.h PATHS ${FFI_INCLUDE_DIR})
if( FFI_INCLUDE_PATH )
set(FFI_HEADER ffi/ffi.h CACHE INTERNAL "")
set(HAVE_FFI_FFI_H 1 CACHE INTERNAL "")
endif()
endif()
if( NOT FFI_HEADER )
message(FATAL_ERROR "libffi includes are not found.")
endif()
find_library(FFI_LIBRARY_PATH ffi PATHS ${FFI_LIBRARY_DIR})
if( NOT FFI_LIBRARY_PATH )
message(FATAL_ERROR "libffi is not found.")
endif()
list(APPEND CMAKE_REQUIRED_LIBRARIES ${FFI_LIBRARY_PATH})
list(APPEND CMAKE_REQUIRED_INCLUDES ${FFI_INCLUDE_PATH})
check_symbol_exists(ffi_call ${FFI_HEADER} HAVE_FFI_CALL)
list(REMOVE_ITEM CMAKE_REQUIRED_INCLUDES ${FFI_INCLUDE_PATH})
list(REMOVE_ITEM CMAKE_REQUIRED_LIBRARIES ${FFI_LIBRARY_PATH})
else()
unset(HAVE_FFI_FFI_H CACHE)
unset(HAVE_FFI_H CACHE)
unset(HAVE_FFI_CALL CACHE)
endif( LLVM_ENABLE_FFI )
# Define LLVM_HAS_ATOMICS if gcc or MSVC atomic builtins are supported.
include(CheckAtomic)
if( LLVM_ENABLE_PIC )
set(ENABLE_PIC 1)
else()
set(ENABLE_PIC 0)
endif()
find_package(LibXml2)
if (LIBXML2_FOUND)
set(CLANG_HAVE_LIBXML 1)
# When cross-compiling, liblzma is not detected as a dependency for libxml2,
# which makes linking c-index-test fail. But for native builds, all libraries
# are installed and checked by CMake before Makefiles are generated and everything
# works according to the plan. However, if a -llzma is added to native builds,
# an additional requirement on the static liblzma.a is required, but will not
# be checked by CMake, breaking native compilation.
# Since this is only pertinent to cross-compilations, and there's no way CMake
# can check for every foreign library on every OS, we add the dep and warn the dev.
if ( CMAKE_CROSSCOMPILING )
if (NOT PC_LIBXML_VERSION VERSION_LESS "2.8.0")
message(STATUS "Adding LZMA as a dep to XML2 for cross-compilation, make sure liblzma.a is available.")
set(LIBXML2_LIBRARIES ${LIBXML2_LIBRARIES} "-llzma")
endif ()
endif ()
endif ()
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-Wno-variadic-macros" SUPPORTS_NO_VARIADIC_MACROS_FLAG)
set(USE_NO_MAYBE_UNINITIALIZED 0)
set(USE_NO_UNINITIALIZED 0)
# Disable gcc's potentially uninitialized use analysis as it presents lots of
# false positives.
if (CMAKE_COMPILER_IS_GNUCXX)
check_cxx_compiler_flag("-Wmaybe-uninitialized" HAS_MAYBE_UNINITIALIZED)
if (HAS_MAYBE_UNINITIALIZED)
set(USE_NO_MAYBE_UNINITIALIZED 1)
else()
# Only recent versions of gcc make the distinction between -Wuninitialized
# and -Wmaybe-uninitialized. If -Wmaybe-uninitialized isn't supported, just
# turn off all uninitialized use warnings.
check_cxx_compiler_flag("-Wuninitialized" HAS_UNINITIALIZED)
set(USE_NO_UNINITIALIZED ${HAS_UNINITIALIZED})
endif()
endif()
# By default, we target the host, but this can be overridden at CMake
# invocation time.
include(GetHostTriple)
get_host_triple(LLVM_INFERRED_HOST_TRIPLE)
set(LLVM_HOST_TRIPLE "${LLVM_INFERRED_HOST_TRIPLE}" CACHE STRING
"Host on which LLVM binaries will run")
# Determine the native architecture.
string(TOLOWER "${LLVM_TARGET_ARCH}" LLVM_NATIVE_ARCH)
if( LLVM_NATIVE_ARCH STREQUAL "host" )
string(REGEX MATCH "^[^-]*" LLVM_NATIVE_ARCH ${LLVM_HOST_TRIPLE})
endif ()
if (LLVM_NATIVE_ARCH MATCHES "i[2-6]86")
set(LLVM_NATIVE_ARCH X86)
elseif (LLVM_NATIVE_ARCH STREQUAL "x86")
set(LLVM_NATIVE_ARCH X86)
elseif (LLVM_NATIVE_ARCH STREQUAL "amd64")
set(LLVM_NATIVE_ARCH X86)
elseif (LLVM_NATIVE_ARCH STREQUAL "x86_64")
set(LLVM_NATIVE_ARCH X86)
elseif (LLVM_NATIVE_ARCH MATCHES "sparc")
set(LLVM_NATIVE_ARCH Sparc)
elseif (LLVM_NATIVE_ARCH MATCHES "powerpc")
set(LLVM_NATIVE_ARCH PowerPC)
elseif (LLVM_NATIVE_ARCH MATCHES "aarch64")
set(LLVM_NATIVE_ARCH AArch64)
elseif (LLVM_NATIVE_ARCH MATCHES "arm")
set(LLVM_NATIVE_ARCH ARM)
elseif (LLVM_NATIVE_ARCH MATCHES "mips")
set(LLVM_NATIVE_ARCH Mips)
elseif (LLVM_NATIVE_ARCH MATCHES "xcore")
set(LLVM_NATIVE_ARCH XCore)
elseif (LLVM_NATIVE_ARCH MATCHES "msp430")
set(LLVM_NATIVE_ARCH MSP430)
elseif (LLVM_NATIVE_ARCH MATCHES "hexagon")
set(LLVM_NATIVE_ARCH Hexagon)
elseif (LLVM_NATIVE_ARCH MATCHES "s390x")
set(LLVM_NATIVE_ARCH SystemZ)
else ()
message(FATAL_ERROR "Unknown architecture ${LLVM_NATIVE_ARCH}")
endif ()
# If build targets includes "host", then replace with native architecture.
list(FIND LLVM_TARGETS_TO_BUILD "host" idx)
if( NOT idx LESS 0 )
list(REMOVE_AT LLVM_TARGETS_TO_BUILD ${idx})
list(APPEND LLVM_TARGETS_TO_BUILD ${LLVM_NATIVE_ARCH})
list(REMOVE_DUPLICATES LLVM_TARGETS_TO_BUILD)
endif()
list(FIND LLVM_TARGETS_TO_BUILD ${LLVM_NATIVE_ARCH} NATIVE_ARCH_IDX)
if (NATIVE_ARCH_IDX EQUAL -1)
message(STATUS
"Native target ${LLVM_NATIVE_ARCH} is not selected; lli will not JIT code")
else ()
message(STATUS "Native target architecture is ${LLVM_NATIVE_ARCH}")
set(LLVM_NATIVE_TARGET LLVMInitialize${LLVM_NATIVE_ARCH}Target)
set(LLVM_NATIVE_TARGETINFO LLVMInitialize${LLVM_NATIVE_ARCH}TargetInfo)
set(LLVM_NATIVE_TARGETMC LLVMInitialize${LLVM_NATIVE_ARCH}TargetMC)
set(LLVM_NATIVE_ASMPRINTER LLVMInitialize${LLVM_NATIVE_ARCH}AsmPrinter)
# We don't have an ASM parser for all architectures yet.
if (EXISTS ${CMAKE_SOURCE_DIR}/lib/Target/${LLVM_NATIVE_ARCH}/AsmParser/CMakeLists.txt)
set(LLVM_NATIVE_ASMPARSER LLVMInitialize${LLVM_NATIVE_ARCH}AsmParser)
endif ()
# We don't have an disassembler for all architectures yet.
if (EXISTS ${CMAKE_SOURCE_DIR}/lib/Target/${LLVM_NATIVE_ARCH}/Disassembler/CMakeLists.txt)
set(LLVM_NATIVE_DISASSEMBLER LLVMInitialize${LLVM_NATIVE_ARCH}Disassembler)
endif ()
endif ()
if( MINGW )
set(HAVE_LIBIMAGEHLP 1)
set(HAVE_LIBPSAPI 1)
set(HAVE_LIBSHELL32 1)
# TODO: Check existence of libraries.
# include(CheckLibraryExists)
# CHECK_LIBRARY_EXISTS(imagehlp ??? . HAVE_LIBIMAGEHLP)
endif( MINGW )
if (NOT HAVE_STRTOLL)
# Use _strtoi64 if strtoll is not available.
check_symbol_exists(_strtoi64 stdlib.h have_strtoi64)
if (have_strtoi64)
set(HAVE_STRTOLL 1)
set(strtoll "_strtoi64")
set(strtoull "_strtoui64")
endif ()
endif ()
if( MSVC )
set(SHLIBEXT ".lib")
set(stricmp "_stricmp")
set(strdup "_strdup")
endif( MSVC )
if( PURE_WINDOWS )
CHECK_CXX_SOURCE_COMPILES("
#include <windows.h>
#include <imagehlp.h>
extern \"C\" void foo(PENUMLOADED_MODULES_CALLBACK);
extern \"C\" void foo(BOOL(CALLBACK*)(PCSTR,ULONG_PTR,ULONG,PVOID));
int main(){return 0;}"
HAVE_ELMCB_PCSTR)
if( HAVE_ELMCB_PCSTR )
set(WIN32_ELMCB_PCSTR "PCSTR")
else()
set(WIN32_ELMCB_PCSTR "PSTR")
endif()
endif( PURE_WINDOWS )
# FIXME: Signal handler return type, currently hardcoded to 'void'
set(RETSIGTYPE void)
if( LLVM_ENABLE_THREADS )
# Check if threading primitives aren't supported on this platform
if( NOT HAVE_PTHREAD_H AND NOT WIN32 )
set(LLVM_ENABLE_THREADS 0)
endif()
endif()
if( LLVM_ENABLE_THREADS )
message(STATUS "Threads enabled.")
else( LLVM_ENABLE_THREADS )
message(STATUS "Threads disabled.")
endif()
if (LLVM_ENABLE_ZLIB )
# Check if zlib is available in the system.
if ( NOT HAVE_ZLIB_H OR NOT HAVE_LIBZ )
set(LLVM_ENABLE_ZLIB 0)
endif()
endif()
set(LLVM_PREFIX ${CMAKE_INSTALL_PREFIX})
if (LLVM_ENABLE_DOXYGEN)
message(STATUS "Doxygen enabled.")
find_package(Doxygen)
if (DOXYGEN_FOUND)
# If we find doxygen and we want to enable doxygen by default create a
# global aggregate doxygen target for generating llvm and any/all
# subprojects doxygen documentation.
if (LLVM_BUILD_DOCS)
add_custom_target(doxygen ALL)
endif()
option(LLVM_DOXYGEN_EXTERNAL_SEARCH "Enable doxygen external search." OFF)
if (LLVM_DOXYGEN_EXTERNAL_SEARCH)
set(LLVM_DOXYGEN_SEARCHENGINE_URL "" CACHE STRING "URL to use for external searhc.")
set(LLVM_DOXYGEN_SEARCH_MAPPINGS "" CACHE STRING "Doxygen Search Mappings")
endif()
endif()
else()
message(STATUS "Doxygen disabled.")
endif()