1 dnl === configure.ac --------------------------------------------------------===
2 dnl The LLVM Compiler Infrastructure
4 dnl This file was developed by the LLVM research group and is distributed under
5 dnl the University of Illinois Open Source License. See LICENSE.TXT for details.
7 dnl===-----------------------------------------------------------------------===
8 dnl This is the LLVM configuration script. It is processed by the autoconf
9 dnl program to produce a script named configure. This script contains the
10 dnl configuration checks that LLVM needs in order to support multiple platforms.
11 dnl This file is composed of 10 sections per the recommended organization of
12 dnl autoconf input defined in the autoconf documentation. As this file evolves,
13 dnl please keep the various types of checks within their sections. The sections
16 dnl SECTION 1: Initialization & Setup
17 dnl SECTION 2: Architecture, target, and host checks
18 dnl SECTION 3: Command line arguments for the configure script.
19 dnl SECTION 4: Check for programs we need and that they are the right version
20 dnl SECTION 5: Check for libraries
21 dnl SECTION 6: Check for header files
22 dnl SECTION 7: Check for types and structures
23 dnl SECTION 8: Check for specific functions needed
24 dnl SECTION 9: Additional checks, variables, etc.
25 dnl SECTION 10: Specify the output files and generate it
27 dnl===-----------------------------------------------------------------------===
29 dnl=== SECTION 1: Initialization & Setup
31 dnl===-----------------------------------------------------------------------===
32 dnl Initialize autoconf and define the package name, version number and
33 dnl email address for reporting bugs.
34 AC_INIT([[llvm]],[[1.4]],[llvmbugs@cs.uiuc.edu])
36 dnl Provide a copyright substitution and ensure the copyright notice is included
37 dnl in the output of --version option of the generated configure script.
38 AC_SUBST(LLVM_COPYRIGHT,["Copyright (c) 2003-2005 U University of Illinois at Urbana-Champaign."])
39 AC_COPYRIGHT($LLVM_COPYRIGHT)
41 dnl Indicate that we require autoconf 2.59 or later. Ths is needed because we
42 dnl use some autoconf macros only available in 2.59.
45 dnl Verify that the source directory is valid. This makes sure that we are
46 dnl configuring LLVM and not some other package (it validates --srcdir argument)
47 AC_CONFIG_SRCDIR([lib/VMCore/Module.cpp])
49 dnl Place all of the extra autoconf files into the config subdirectory. Tell
50 dnl various tools where the m4 autoconf macros are.
51 AC_CONFIG_AUX_DIR([autoconf])
53 dnl Quit if the source directory has already been configured.
54 dnl NOTE: This relies upon undocumented autoconf behavior.
55 if test ${srcdir} != "." ; then
56 if test -f ${srcdir}/include/llvm/Config/config.h ; then
57 AC_MSG_ERROR([Already configured in ${srcdir}])
61 dnl Configure all of the projects present in our source tree. While we could
62 dnl just AC_CONFIG_SUBDIRS on the set of directories in projects that have a
63 dnl configure script, that usage of the AC_CONFIG_SUBDIRS macro is deprecated.
64 dnl Instead we match on the known projects.
65 for i in `ls ${srcdir}/projects`
67 if test -d ${srcdir}/projects/${i} ; then
70 "sample") AC_CONFIG_SUBDIRS([projects/sample]) ;;
71 "Stacker") AC_CONFIG_SUBDIRS([projects/Stacker]) ;;
72 "llvm-test") AC_CONFIG_SUBDIRS([projects/llvm-test]) ;;
73 "llvm-reopt") AC_CONFIG_SUBDIRS([projects/llvm-reopt]);;
74 "llvm-gcc") AC_CONFIG_SUBDIRS([projects/llvm-gcc]) ;;
75 "Java") AC_CONFIG_SUBDIRS([projects/Java]) ;;
76 "llvm-tv") AC_CONFIG_SUBDIRS([projects/llvm-tv]) ;;
77 "llvm-fefw") AC_CONFIG_SUBDIRS([projects/llvm-fefw]) ;;
78 "poolalloc") AC_CONFIG_SUBDIRS([projects/poolalloc]) ;;
80 AC_MSG_WARN([Unknown project (${i}) won't be configured automatically])
86 dnl===-----------------------------------------------------------------------===
88 dnl=== SECTION 2: Architecture, target, and host checks
90 dnl===-----------------------------------------------------------------------===
92 dnl Check the target for which we're compiling and the host that will do the
93 dnl compilations. This will tell us which LLVM compiler will be used for
94 dnl compiling SSA into object code. This needs to be done early because
95 dnl following tests depend on it.
98 dnl Determine the platform type and cache its value. This helps us configure
99 dnl the System library to the correct build platform.
100 AC_CACHE_CHECK([support for generic build operating system],
101 [llvm_cv_platform_type],
103 *-*-aix*) llvm_cv_platform_type="AIX" ;;
104 *-*-cygwin*) llvm_cv_platform_type="Cygwin" ;;
105 *-*-darwin*) llvm_cv_platform_type="Darwin" ;;
106 *-*-freebsd*) llvm_cv_platform_type="FreeBSD" ;;
107 *-*-interix*) llvm_cv_platform_type="Interix" ;;
108 *-*-linux*) llvm_cv_platform_type="Linux" ;;
109 *-*-solaris*) llvm_cv_platform_type="SunOS" ;;
110 *-*-win32*) llvm_cv_platform_type="Win32" ;;
111 *-*-mingw*) llvm_cv_platform_type="Win32" ;;
112 *) llvm_cv_platform_type="Unknown" ;;
115 dnl Make sure we aren't attempting to configure for an unknown system
116 if test "$llvm_cv_platform_type" = "Unknown" ; then
117 AC_MSG_ERROR([Operating system platform is unknown, configure can't continue])
120 dnl Set the "OS" Makefile variable based on the platform type so the
121 dnl makefile can configure itself to specific build hosts
122 AC_SUBST(OS,$llvm_cv_platform_type)
124 dnl Make a link from lib/System/platform to lib/System/$llvm_cv_platform_type
125 dnl This helps the #inclusion of the system specific include files
126 dnl for the operating system abstraction library, lib/System.
127 AC_CONFIG_LINKS(lib/System/platform:lib/System/$llvm_cv_platform_type)
129 dnl If we are targetting a Sparc machine running Solaris, pretend that it is
130 dnl V9, since that is all that we support at the moment, and autoconf will only
131 dnl tell us we're a sparc.
133 sparc*-*-solaris*) AC_SUBST(target,[[sparcv9-sun-solaris2.8]])
137 dnl Determine what our target architecture is and configure accordingly.
138 dnl This will allow Makefiles to make a distinction between the hardware and
140 AC_CACHE_CHECK([target architecture],[llvm_cv_target_arch],
142 i*86-*) llvm_cv_target_arch="x86" ;;
143 sparc*-*) llvm_cv_target_arch="Sparc" ;;
144 powerpc*-*) llvm_cv_target_arch="PowerPC" ;;
145 *) llvm_cv_target_arch="Unknown" ;;
148 if test "$llvm_cv_target_arch" = "Unknown" ; then
149 AC_MSG_WARN([Configuring LLVM for an unknown target archicture])
152 dnl Define a substitution, ARCH, for the target architecture
153 AC_SUBST(ARCH,$llvm_cv_target_arch)
155 dnl Check for the endianness of the target
156 AC_C_BIGENDIAN(AC_SUBST([ENDIAN],[big]),AC_SUBST([ENDIAN],[little]))
158 dnl===-----------------------------------------------------------------------===
160 dnl=== SECTION 3: Command line arguments for the configure script.
162 dnl===-----------------------------------------------------------------------===
164 dnl --enable-optimized : check whether they want to do an optimized build:
165 AC_ARG_ENABLE(optimized,
166 AS_HELP_STRING([--enable-optimized,Compile with optimizations enabled (default is NO)]),,enableval=no)
167 if test ${enableval} = "no" ; then
168 AC_SUBST(ENABLE_OPTIMIZED,[[]])
170 AC_SUBST(ENABLE_OPTIMIZED,[[ENABLE_OPTIMIZED=1]])
173 dnl --enable-jit: check whether they want to enable the jit
175 AS_HELP_STRING(--enable-jit,
176 [Enable Just In Time Compiling (default is YES)]),,
178 if test ${enableval} = "no"
182 case "$llvm_cv_target_arch" in
183 x86) AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
184 Sparc) AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
185 PowerPC) AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
186 *) AC_SUBST(JIT,[[]]) ;;
190 dnl Allow enablement of doxygen generated documentation
191 AC_ARG_ENABLE(doxygen,
192 AS_HELP_STRING([--enable-doxygen],
193 [Build doxygen documentation (default is NO)]),,
196 yes) AC_SUBST(ENABLE_DOXYGEN,[1]) ;;
197 no) AC_SUBST(ENABLE_DOXYGEN,[0]) ;;
198 default) AC_SUBST(ENABLE_DOXYGEN,[0]) ;;
199 *) AC_MSG_ERROR([Invalid setting for --enable-doxygen. Use "yes" or "no"]) ;;
202 dnl Find the LLVM GCC-based C/C++ front end
203 AC_ARG_WITH(llvmgccdir,
204 AS_HELP_STRING(--with-llvmgccdir,[Location of LLVM GCC front-end]),
205 AC_SUBST(LLVMGCCDIR,[$withval]))
207 dnl Provide some defaults for LLVMGCC for UIUC environments.
208 if test "x$LLVMGCCDIR" = x ; then
209 case "$llvm_cv_platform_type" in
211 if test -d /home/vadve/lattner/local/x86/llvm-gcc ; then
212 AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/x86/llvm-gcc/])
216 if test -d /home/vadve/lattner/local/sparc/llvm-gcc ; then
217 AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/sparc/llvm-gcc/])
224 dnl===-----------------------------------------------------------------------===
226 dnl=== SECTION 4: Check for programs we need and that they are the right version
228 dnl===-----------------------------------------------------------------------===
230 dnl Check for compilation tools
237 dnl Check for the tools that the makefiles require
240 AC_PATH_PROG(DATE, [date], [date])
241 AC_PATH_PROG(FIND, [find], [find])
242 AC_PATH_PROG(GREP, [grep], [grep])
243 AC_PATH_PROG(MKDIR,[mkdir],[mkdir])
244 AC_PATH_PROG(MV, [mv], [mv])
245 AC_PATH_PROG(PAX, [pax], [pax])
247 AC_PATH_PROG(RM, [rm], [rm])
248 AC_PATH_PROG(SED, [sed], [sed])
249 AC_PATH_PROG(TAR, [tar], [gtar])
251 dnl Find the install program
254 dnl Checks for documentation and testing tools that we can do without. If these
255 dnl are not found then they are set to "true" which always succeeds but does
256 dnl nothing. This just lets the build output show that we could have done
257 dnl something if the tool was available.
258 AC_PATH_PROG(BZIP2,[bzip2],[true bzip2])
259 AC_PATH_PROG(DOT,[dot],[true dot])
260 AC_PATH_PROG(DOXYGEN,[doxygen],[true doxygen])
261 AC_PATH_PROG(ETAGS,[etags],[true etags])
262 AC_PATH_PROG(GROFF,[groff],[true groff])
263 AC_PATH_PROG(GZIP,[gzip],[true gzip])
264 AC_PATH_PROG(POD2HTML,[pod2html],[true pod2html])
265 AC_PATH_PROG(POD2MAN,[pod2man],[true pod2man])
266 AC_PATH_PROG(RUNTEST,[runtest],[true runtest])
268 AC_PATH_PROG(ZIP,[zip],[true zip])
270 dnl Determine if the linker supports the -R option.
273 dnl Check for libtool and the library that has dlopen function (which must come
274 dnl before the AC_PROG_LIBTOOL check in order to enable dlopening libraries with
280 dnl Check if we know how to tell etags we are using C++:
281 etags_version=`$ETAGS --version 2>&1`
282 case "$etags_version" in
283 *[Ee]xuberant*) ETAGSFLAGS="--language-force=c++" ;;
284 *GNU\ Emacs*) ETAGSFLAGS="-l c++" ;;
287 AC_SUBST(ETAGSFLAGS,$ETAGSFLAGS)
289 AC_MSG_CHECKING([tool compatibility])
291 dnl Ensure that compilation tools are GCC or a GNU compatible compiler such as
292 dnl ICC; we use GCC specific options in the makefiles so the compiler needs
293 dnl to support those options.
294 dnl "icc" emits gcc signatures
295 dnl "icc -no-gcc" emits no gcc signature BUT is still compatible
307 if test "$GCC" != "yes" && test "$ICC" != "yes"
309 AC_MSG_ERROR([gcc|icc required but not found])
312 dnl Ensure that compilation tools are GCC; we use GCC specific extensions
313 if test "$GXX" != "yes" && test "$IXX" != "yes"
315 AC_MSG_ERROR([g++|icc required but not found])
318 dnl Verify that GCC is version 3.0 or higher
319 if test "$GCC" = "yes"
321 gccmajor=`$CC --version | head -n 1 | awk '{print $NF;}' | cut -d. -f1`
322 if test "$gccmajor" -lt "3"
324 AC_MSG_ERROR([gcc 3.x required, but you have a lower version])
328 dnl Check for GNU Make. We use its extensions, so don't build without it
329 if test -z "$llvm_cv_gnu_make_command"
331 AC_MSG_ERROR([GNU Make required but not found])
334 dnl Tool compatibility is okay if we make it here.
337 dnl===-----------------------------------------------------------------------===
339 dnl=== SECTION 5: Check for libraries
341 dnl===-----------------------------------------------------------------------===
343 dnl libelf is for sparc only; we can ignore it if we don't have it
344 AC_CHECK_LIB(elf, elf_begin)
346 dnl lt_dlopen may be required for plugin support.
347 AC_SEARCH_LIBS(lt_dlopen,ltdl,AC_DEFINE([HAVE_LT_DLOPEN],[1],
348 [Define if lt_dlopen() is available on this platform]),
349 AC_MSG_WARN([lt_dlopen() not found - plugin support might
352 dnl dlopen() is required for plugin support.
353 AC_SEARCH_LIBS(dlopen,dl,AC_DEFINE([HAVE_DLOPEN],[1],
354 [Define if dlopen() is available on this platform.]),
355 AC_MSG_WARN([dlopen() not found - disabling plugin support]))
357 dnl mallinfo is optional; the code can compile (minus features) without it
358 AC_SEARCH_LIBS(mallinfo,malloc,AC_DEFINE([HAVE_MALLINFO],[1],
359 [Define if mallinfo() is available on this platform.]))
361 dnl pthread locking functions are optional - but llvm will not be thread-safe
363 AC_SEARCH_LIBS(pthread_mutex_lock,pthread,
364 AC_DEFINE([HAVE_PTHREAD_MUTEX_LOCK],[1],
365 [Have pthread_mutex_lock]))
367 dnl===-----------------------------------------------------------------------===
369 dnl=== SECTION 6: Check for header files
371 dnl===-----------------------------------------------------------------------===
373 dnl We don't check for ancient stuff or things that are guaranteed to be there
374 dnl by the C++ standard. We always use the <cfoo> versions of <foo.h> C headers.
377 dnl However, we do need some system specific header files. Generally we're
378 dnl looking for POSIX headers.
380 AC_CHECK_HEADERS([sys/time.h sys/mman.h sys/resource.h sys/time.h sys/types.h])
381 AC_CHECK_HEADERS([dlfcn.h execinfo.h fcntl.h limits.h link.h])
382 AC_CHECK_HEADERS([malloc.h unistd.h windows.h])
384 AC_HEADER_MMAP_ANONYMOUS
386 dnl Check for things that need to be included in public headers, and so
387 dnl for which we may not have access to a HAVE_* preprocessor #define.
388 dnl (primarily used in DataTypes.h)
389 AC_CHECK_HEADERS([inttypes.h stdint.h])
391 dnl===-----------------------------------------------------------------------===
393 dnl=== SECTION 7: Check for types and structures
395 dnl===-----------------------------------------------------------------------===
401 AC_CHECK_TYPES([int64_t],,AC_MSG_ERROR([Type int64_t required but not found]))
402 AC_CHECK_TYPES([uint64_t],,
403 AC_CHECK_TYPES([u_int64_t],,
404 AC_MSG_ERROR([Type uint64_t or u_int64_t required but not found])))
406 dnl===-----------------------------------------------------------------------===
408 dnl=== SECTION 8: Check for specific functions needed
410 dnl===-----------------------------------------------------------------------===
412 AC_CHECK_FUNCS([backtrace getcwd gettimeofday isatty getrusage mkstemp mktemp
414 AC_CHECK_FUNCS([strdup strtoq strtoll])
419 dnl Check for variations in the Standard C++ library and STL. These macros are
420 dnl provided by LLVM in the autoconf/m4 directory.
423 AC_CXX_HAVE_STD_ITERATOR
424 AC_CXX_HAVE_BI_ITERATOR
425 AC_CXX_HAVE_FWD_ITERATOR
429 dnl Check for mmap and mprotect support. We need both to do the JIT and for
430 dnl bytecode loading, etc.
433 AC_CHECK_FUNC(mprotect,,
434 AC_MSG_ERROR([Function mprotect() required but not found]))
436 if test "$ac_cv_func_mmap_fixed_mapped" = "no"
438 AC_MSG_WARN([mmap() required but not found])
440 if test "$ac_cv_func_mmap_file" = "no"
442 AC_MSG_WARN([mmap() of files required but not found])
445 dnl===-----------------------------------------------------------------------===
447 dnl=== SECTION 9: Additional checks, variables, etc.
449 dnl===-----------------------------------------------------------------------===
451 dnl Figure out if there's an executable llvm-gcc in the llvmgccdir.
452 AC_CACHE_CHECK([for llvm-gcc],[llvm_cv_llvmgcc],
453 [llvm_cv_llvmgcc='llvmgcc_not_found'
454 if test -d "$LLVMGCCDIR" ; then
455 if test -x "$LLVMGCCDIR/bin/gcc" ; then
456 llvm_cv_llvmgcc="$LLVMGCCDIR/bin/gcc"
460 dnl See if the llvmgcc executable can compile to LLVM assembly
461 AC_CACHE_CHECK([whether llvm-gcc is sane],[llvm_cv_llvmgcc_sanity],
462 [llvm_cv_llvmgcc_sanity="no"
463 if test -x "$llvm_cv_llvmgcc" ; then
464 cp /dev/null conftest.c
465 "$llvm_cv_llvmgcc" -S -o - conftest.c | grep implementation > /dev/null 2>&1
466 if test $? -eq 0 ; then
467 llvm_cv_llvmgcc_sanity="yes"
472 dnl Since we have a sane llvmgcc, identify it and its sub-tools
473 if test "$llvm_cv_llvmgcc_sanity" = "yes" ; then
474 AC_SUBST(LLVMGCC,"$llvm_cv_llvmgcc")
475 llvmcc1path=`"$llvm_cv_llvmgcc" --print-prog-name=cc1`
476 AC_SUBST(LLVMCC1,$llvmcc1path)
477 llvmcc1pluspath=`"$llvm_cv_llvmgcc" --print-prog-name=cc1plus`
478 AC_SUBST(LLVMCC1PLUS,$llvmcc1pluspath)
481 dnl Propagate the shared library extension that the libltdl checks did to
482 dnl the Makefiles so we can use it there too
483 AC_SUBST(SHLIBEXT,$libltdl_cv_shlibext)
485 # Translate the various configuration directories and other basic
486 # information into substitutions that will end up in Makefile.config.in
487 # that these configured values can be used by the makefiles
488 eval LLVM_PREFIX="${prefix}";
489 eval LLVM_BINDIR="${prefix}/bin";
490 eval LLVM_LIBDIR="${prefix}/lib";
491 eval LLVM_DATADIR="${prefix}/share/llvm";
492 eval LLVM_DOCSDIR="${prefix}/docs/llvm";
493 eval LLVM_ETCDIR="${prefix}/etc/llvm";
494 eval LLVM_INCLUDEDIR="${prefix}/include";
495 eval LLVM_INFODIR="${prefix}/info";
496 eval LLVM_MANDIR="${prefix}/man";
497 LLVM_CONFIGTIME=`date`
498 AC_SUBST(LLVM_PREFIX)
499 AC_SUBST(LLVM_BINDIR)
500 AC_SUBST(LLVM_LIBDIR)
501 AC_SUBST(LLVM_DATADIR)
502 AC_SUBST(LLVM_DOCSDIR)
503 AC_SUBST(LLVM_ETCDIR)
504 AC_SUBST(LLVM_INCLUDEDIR)
505 AC_SUBST(LLVM_INFODIR)
506 AC_SUBST(LLVM_MANDIR)
507 AC_SUBST(LLVM_CONFIGTIME)
509 # Place the various directores into the config.h file as #defines so that we
510 # can know about the installation paths within LLVM.
511 AC_DEFINE_UNQUOTED(LLVM_PREFIX,"$LLVM_PREFIX",
512 [Installation prefix directory])
513 AC_DEFINE_UNQUOTED(LLVM_BINDIR, "$LLVM_BINDIR",
514 [Installation directory for binary executables])
515 AC_DEFINE_UNQUOTED(LLVM_LIBDIR, "$LLVM_LIBDIR",
516 [Installation directory for libraries])
517 AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DATADIR",
518 [Installation directory for data files])
519 AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DOCSDIR",
520 [Installation directory for documentation])
521 AC_DEFINE_UNQUOTED(LLVM_ETCDIR, "$LLVM_ETCDIR",
522 [Installation directory for config files])
523 AC_DEFINE_UNQUOTED(LLVM_INCLUDEDIR, "$LLVM_INCLUDEDIR",
524 [Installation directory for include files])
525 AC_DEFINE_UNQUOTED(LLVM_INFODIR, "$LLVM_INFODIR",
526 [Installation directory for .info files])
527 AC_DEFINE_UNQUOTED(LLVM_MANDIR, "$LLVM_MANDIR",
528 [Installation directory for man pages])
529 AC_DEFINE_UNQUOTED(LLVM_CONFIGTIME, "$LLVM_CONFIGTIME",
530 [Time at which LLVM was configured])
531 AC_DEFINE_UNQUOTED([LLVMGCCDIR],"$LLVMGCCDIR",
532 [Installation directory of llvm-gcc])
534 dnl===-----------------------------------------------------------------------===
536 dnl=== SECTION 10: Specify the output files and generate it
538 dnl===-----------------------------------------------------------------------===
540 dnl Configure header files
541 AC_CONFIG_HEADERS(include/llvm/Config/config.h)
543 AC_CONFIG_HEADERS([include/llvm/Support/DataTypes.h])
544 AC_CONFIG_HEADERS([include/llvm/ADT/hash_map])
545 AC_CONFIG_HEADERS([include/llvm/ADT/hash_set])
546 AC_CONFIG_HEADERS([include/llvm/Support/ThreadSupport.h])
547 AC_CONFIG_HEADERS([include/llvm/ADT/iterator])
549 dnl Configure the makefile's configuration data
550 AC_CONFIG_FILES([Makefile.config])
552 dnl Configure llvmc's configuration files
553 AC_CONFIG_FILES([tools/llvmc/st tools/llvmc/cpp tools/llvmc/ll tools/llvmc/c])
555 dnl Configure doxygen's configuration file
556 AC_CONFIG_FILES([docs/doxygen.cfg])
558 dnl Do special configuration of Makefiles
559 AC_CONFIG_MAKEFILE(Makefile)
560 AC_CONFIG_MAKEFILE(Makefile.common)
561 AC_CONFIG_MAKEFILE(examples/Makefile)
562 AC_CONFIG_MAKEFILE(lib/Makefile)
563 AC_CONFIG_MAKEFILE(runtime/Makefile)
564 AC_CONFIG_MAKEFILE(test/Makefile)
565 AC_CONFIG_MAKEFILE(test/Makefile.tests)
566 AC_CONFIG_MAKEFILE(tools/Makefile)
567 AC_CONFIG_MAKEFILE(utils/Makefile)
568 AC_CONFIG_MAKEFILE(projects/Makefile)
570 dnl Finally, crank out the output
573 dnl Warn loudly if llvm-gcc was not obviously working
574 if test "$llvm_cv_llvmgcc_sanity" = "no" ; then
575 AC_MSG_WARN([***** llvm C/C++ front end was not found, or does not])
576 AC_MSG_WARN([***** appear to be working.])
577 AC_MSG_WARN([***** ])
578 AC_MSG_WARN([***** Please check configure's --with-llvmgccdir option.])
579 AC_MSG_WARN([***** Runtime libraries (in llvm/runtime) will not be built,])
580 AC_MSG_WARN([***** but you should be able to build the llvm tools.])