For PR256:

* cache more values
* standardize cache value names
* organize configure script per autoconf recommendations (10 sections)
* Eliminate some redundancies and complexities in the script
* Provide better documentation in the script.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18232 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 399 insertions, 295 deletions

diff --git a/autoconf/configure.ac b/autoconf/configure.ac
index 3bfcd8c..6c1f876 100644
--- a/autoconf/configure.ac
+++ b/autoconf/configure.ac
@@ -1,23 +1,67 @@
-dnl Initialize autoconf
+dnl === configure.ac --------------------------------------------------------===
+dnl                     The LLVM Compiler Infrastructure
+dnl
+dnl This file was developed by the LLVM research group and is distributed under
+dnl the University of Illinois Open Source License. See LICENSE.TXT for details.
+dnl 
+dnl===-----------------------------------------------------------------------===
+dnl This is the LLVM configuration script. It is processed by the autoconf
+dnl program to produce a script named configure. This script contains the 
+dnl configuration checks that LLVM needs in order to support multiple platforms.
+dnl This file is composed of 10 sections per the recommended organization of
+dnl autoconf input defined in the autoconf documentation. As this file evolves,
+dnl please keep the various types of checks within their sections. The sections
+dnl are as follows:
+dnl
+dnl SECTION 1: Initialization & Setup
+dnl SECTION 2: Architecture, target, and host checks
+dnl SECTION 3: Command line arguments for the configure script.
+dnl SECTION 4: Check for programs we need and that they are the right version
+dnl SECTION 5: Check for libraries
+dnl SECTION 6: Check for header files
+dnl SECTION 7: Check for types and structures
+dnl SECTION 8: Check for specific functions needed
+dnl SECTION 9: Additional checks, variables, etc.
+dnl SECTION 10: Specify the output files and generate it
+dnl
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 1: Initialization & Setup
+dnl===
+dnl===-----------------------------------------------------------------------===
+dnl Initialize autoconf and define the package name, version number and
+dnl email address for reporting bugs.
 AC_INIT([[llvm]],[[1.4]],[llvmbugs@cs.uiuc.edu])
 
-dnl Place all of the extra autoconf files into the config subdirectory
-dnl Tell various tools where the m4 autoconf macros are
-dnl Have configure verify that the source directory is valid.
+dnl Provide a copyright substitution and ensure the copyright notice is included
+dnl in the output of --version option of the generated configure script.
+AC_SUBST(LLVM_COPYRIGHT,["Copyright (c) 2003-2005 U University of Illinois at Urbana-Champaign."])
+AC_COPYRIGHT($LLVM_COPYRIGHT)
+
+dnl Indicate that we require autoconf 2.59 or later. Ths is needed because we
+dnl use some autoconf macros only available in 2.59.
+AC_PREREQ(2.59)
+
+dnl Verify that the source directory is valid. This makes sure that we are
+dnl configuring LLVM and not some other package (it validates --srcdir argument)
+AC_CONFIG_SRCDIR([lib/VMCore/Module.cpp])
+
+dnl Place all of the extra autoconf files into the config subdirectory. Tell 
+dnl various tools where the m4 autoconf macros are. 
 AC_CONFIG_AUX_DIR([autoconf])
-dnl AC_CONFIG_MACRO_DIR(autoconf/m4)
-dnl Verify that the source directory is valid
-AC_CONFIG_SRCDIR(["Makefile.config.in"])
 
 dnl Quit if the source directory has already been configured.
 dnl NOTE: This relies upon undocumented autoconf behavior.
 if test ${srcdir} != "." ; then
-	if test -f ${srcdir}/include/llvm/Config/config.h ; then
-		AC_MSG_ERROR([Already configured in ${srcdir}])
-	fi
+  if test -f ${srcdir}/include/llvm/Config/config.h ; then
+    AC_MSG_ERROR([Already configured in ${srcdir}])
+  fi
 fi
 
-dnl Configure all of the projects present in our source tree.
+dnl Configure all of the projects present in our source tree. While we could
+dnl just AC_CONFIG_SUBDIRS on the set of directories in projects that have a
+dnl configure script, that usage of the AC_CONFIG_SUBDIRS macro is deprecated.
+dnl Instead we match on the known projects.
 for i in `ls ${srcdir}/projects`
 do
   if test -d ${srcdir}/projects/${i} ; then
@@ -39,178 +83,177 @@ do
   fi
 done
 
-dnl Configure header files
-AC_CONFIG_HEADERS(include/llvm/Config/config.h)
-
-dnl Configure other output file
-AC_CONFIG_FILES([Makefile.config tools/llvmc/st tools/llvmc/cpp tools/llvmc/ll 
-                 tools/llvmc/c])
-AC_CONFIG_HEADERS([include/llvm/Support/DataTypes.h])
-AC_CONFIG_HEADERS([include/llvm/ADT/hash_map])
-AC_CONFIG_HEADERS([include/llvm/ADT/hash_set])
-AC_CONFIG_HEADERS([include/llvm/Support/ThreadSupport.h])
-AC_CONFIG_HEADERS([include/llvm/ADT/iterator])
-
-dnl Do special configuration of Makefiles
-AC_CONFIG_MAKEFILE(Makefile)
-AC_CONFIG_MAKEFILE(Makefile.common)
-AC_CONFIG_MAKEFILE(examples/Makefile)
-AC_CONFIG_MAKEFILE(lib/Makefile)
-AC_CONFIG_MAKEFILE(runtime/Makefile)
-AC_CONFIG_MAKEFILE(test/Makefile)
-AC_CONFIG_MAKEFILE(test/Makefile.tests)
-AC_CONFIG_MAKEFILE(test/QMTest/llvm.py)
-AC_CONFIG_MAKEFILE(test/QMTest/llvmdb.py)
-AC_CONFIG_MAKEFILE(tools/Makefile)
-AC_CONFIG_MAKEFILE(tools/Makefile.JIT)
-AC_CONFIG_MAKEFILE(utils/Makefile)
-AC_CONFIG_MAKEFILE(projects/Makefile)
-
-dnl Find the install program (needs to be done before canonical stuff)
-AC_PROG_INSTALL
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 2: Architecture, target, and host checks
+dnl===
+dnl===-----------------------------------------------------------------------===
 
-dnl Check which host for which we're compiling.  This will tell us which LLVM
-dnl compiler will be used for compiling SSA into object code.
+dnl Check the target for which we're compiling and the host that will do the
+dnl compilations. This will tell us which LLVM compiler will be used for 
+dnl compiling SSA into object code. This needs to be done early because 
+dnl following tests depend on it.
 AC_CANONICAL_TARGET
 
-dnl Set the "OS" Makefile variable based on the system we are building on.
-dnl We will use the build machine information to set some variables.
-
-AC_MSG_CHECKING([support for generic build operating system])
-case $build in
-	*-*-aix*)
-             AC_SUBST(OS,[AIX])
-             platform_type="AIX"
-             ;;
-	*-*-cygwin*)
-             AC_SUBST(OS,[Cygwin])
-             platform_type="Cygwin"
-             ;;
-	*-*-darwin*)
-             AC_SUBST(OS,[Darwin])
-             platform_type="Darwin"
-             ;;
-        *-*-freebsd*)
-             AC_SUBST(OS,[Linux])
-             platform_type="FreeBSD"
-             ;;
-        *-*-interix*)
-             AC_SUBST(OS,[SunOS])
-             platform_type="Interix"
-             ;;
-	*-*-linux*)
-             AC_SUBST(OS,[Linux])
-             platform_type="Linux"
-             if test -d /home/vadve/lattner/local/x86/llvm-gcc
-	     then
-	       AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/x86/llvm-gcc/])
-             fi
-             ;;
-	*-*-solaris*)
-             AC_SUBST(OS,[SunOS])
-             platform_type="SunOS"
-             if test -d /home/vadve/lattner/local/sparc/llvm-gcc
-             then
-               AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/sparc/llvm-gcc/])
-             fi
-             ;;
-        *-*-win32*)
-             AC_SUBST(OS,[Win32])
-             platform_type="Win32"
-	     ;;
-        *-*-mingw*)
-             AC_SUBST(OS,[Win32])
-             platform_type="Win32"
-	     ;;
-	*)   
-             AC_SUBST(OS,[Unknown])
-             platform_type="Unknown"
-	     ;;
-esac
+dnl Determine the platform type and cache its value. This helps us configure
+dnl the System library to the correct build platform.
+AC_CACHE_CHECK([support for generic build operating system],
+               [llvm_cv_platform_type],
+[case $build in
+  *-*-aix*) llvm_cv_platform_type="AIX" ;;
+  *-*-cygwin*) llvm_cv_platform_type="Cygwin" ;;
+  *-*-darwin*) llvm_cv_platform_type="Darwin" ;;
+  *-*-freebsd*) llvm_cv_platform_type="FreeBSD" ;;
+  *-*-interix*) llvm_cv_platform_type="Interix" ;;
+  *-*-linux*) llvm_cv_platform_type="Linux" ;;
+  *-*-solaris*) llvm_cv_platform_type="SunOS" ;;
+  *-*-win32*) llvm_cv_platform_type="Win32" ;;
+  *-*-mingw*) llvm_cv_platform_type="Win32" ;;
+  *) llvm_cv_platform_type="Unknown" ;;
+esac])
 
 dnl Make sure we aren't attempting to configure for an unknown system
-if test "$platform_type" = "Unknown" ; then
-  AC_MSG_ERROR([Platform is unknown, configure can't continue])
+if test "$llvm_cv_platform_type" = "Unknown" ; then
+  AC_MSG_ERROR([Operating system platform is unknown, configure can't continue])
 fi
 
+dnl Set the "OS" Makefile variable based on the platform type so the
+dnl makefile can configure itself to specific build hosts
+AC_SUBST(OS,$llvm_cv_platform_type)
+
 dnl Make a link from lib/System/platform to lib/System/$platform_type
 dnl This helps the #inclusion of the system specific include files
-dnl for the operating system abstraction library
+dnl for the operating system abstraction library, lib/System.
 AC_CONFIG_LINKS(lib/System/platform:lib/System/$platform_type)
 
-
-AC_MSG_CHECKING(target architecture)
 dnl If we are targetting a Sparc machine running Solaris, pretend that it is
 dnl V9, since that is all that we support at the moment, and autoconf will only
 dnl tell us we're a sparc.
 case $target in
-	sparc*-*-solaris*)  AC_SUBST(target,[[sparcv9-sun-solaris2.8]])
-	                    ;;
+  sparc*-*-solaris*)  AC_SUBST(target,[[sparcv9-sun-solaris2.8]])
+  ;;
 esac
 
 dnl Determine what our target architecture is and configure accordingly.
 dnl This will allow Makefiles to make a distinction between the hardware and
 dnl the OS.
-case $target in
-	i*86-*)       
-          ARCH="x86"
-          AC_SUBST(ARCH,[x86])
-	  ;;
-	sparc*-*)         
-          ARCH="Sparc"
-          AC_SUBST(ARCH,[Sparc])
-	  ;;
-	powerpc*-*)       
-          ARCH="PowerPC"
-          AC_SUBST(ARCH,[PowerPC])
-	  ;;
-	*)                
-          ARCH="Unknown"
-          AC_SUBST(ARCH,[Unknown])
-	  ;;
-esac
+AC_CACHE_CHECK([target architecture],[llvm_cv_target_arch],
+[case $target in
+  i*86-*)      llvm_cv_target_arch="x86" ;;
+  sparc*-*)    llvm_cv_target_arch="Sparc" ;;
+  powerpc*-*)  llvm_cv_target_arch="PowerPC" ;;
+  *)           llvm_cv_target_arch="Unknown" ;;
+esac])
+
+if test "$llvm_cv_target_arch" = "Unknown" ; then
+  AC_MSG_WARN([Configuring LLVM for an unknown target archicture])
+fi
 
-AC_MSG_RESULT($ARCH)
+dnl Define a substitution, ARCH, for the target architecture
+AC_SUBST(ARCH,$llvm_cv_target_arch)
 
-dnl Check for compilation tools
-AC_PROG_CXX
-AC_PROG_CC(gcc)
-dnl Ensure that compilation tools are GCC; we use GCC specific extensions
-if test "$GCC" != "yes"
-then
-	AC_MSG_ERROR([gcc required but not found])
-fi
-AC_PROG_CPP
-dnl Ensure that compilation tools are GCC; we use GCC specific extensions
-if test "$GXX" != "yes"
-then
-	AC_MSG_ERROR([g++ required but not found])
+dnl Check for the endianness of the target
+AC_C_BIGENDIAN(AC_SUBST([ENDIAN],[big]),AC_SUBST([ENDIAN],[little]))
+
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 3: Command line arguments for the configure script.
+dnl===
+dnl===-----------------------------------------------------------------------===
+
+dnl --enable-optimized : check whether they want to do an optimized build:
+AC_ARG_ENABLE(optimized,
+              AS_HELP_STRING([--enable-optimized,Compile with optimizations enabled (default is NO)]),,enableval=no)
+if test ${enableval} = "no" ; then
+  AC_SUBST(ENABLE_OPTIMIZED,[[]])
+else
+  AC_SUBST(ENABLE_OPTIMIZED,[[ENABLE_OPTIMIZED=1]])
 fi
 
-dnl Verify that GCC is version 3.0 or higher
-gccmajor=`$CC --version | head -n 1 | awk '{print $NF;}' | cut -d. -f1`
-if test "$gccmajor" -lt "3"
+dnl --enable-jit: check whether they want to enable the jit
+AC_ARG_ENABLE(jit,
+  AS_HELP_STRING(--enable-jit,
+                 [Enable Just In Time Compiling (default is YES)]),,
+  enableval=default)
+if test ${enableval} = "no"
 then
-	AC_MSG_ERROR([gcc 3.x required, but you have a lower version])
+  AC_SUBST(JIT,[[]])
+else
+  case "$llvm_cv_target_architecture" in
+    x86)     AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
+    Sparc)   AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
+    PowerPC) AC_SUBST(JIT,[[TARGET_HAS_JIT=1]]) ;;
+    *)       AC_SUBST(JIT,[[]]) ;;
+  esac
 fi
 
-dnl Check for GNU Make.  We use its extensions too, so don't build without it
-AC_CHECK_GNU_MAKE
-if test -z "$_cv_gnu_make_command"
-then
-	AC_MSG_ERROR([GNU Make required but not found])
+dnl Find the LLVM GCC-based C/C++ front end
+AC_ARG_WITH(llvmgccdir,
+  AS_HELP_STRING(--with-llvmgccdir,[Location of LLVM GCC front-end]),
+  AC_SUBST(LLVMGCCDIR,[$withval]))
+
+dnl Provide some defaults for LLVMGCC for UIUC environments.
+if test "x$LLVMGCCDIR" = x ; then
+  case "$llvm_cv_platform_type" in
+    Linux)
+      if test -d /home/vadve/lattner/local/x86/llvm-gcc ; then
+        AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/x86/llvm-gcc/])
+      fi
+      ;;
+    SunOS)
+      if test -d /home/vadve/lattner/local/sparc/llvm-gcc ; then
+        AC_SUBST(LLVMGCCDIR,[/home/vadve/lattner/local/sparc/llvm-gcc/])
+      fi
+      ;;
+  esac
 fi
 
-dnl Checks for other tools
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 4: Check for programs we need and that they are the right version
+dnl===
+dnl===-----------------------------------------------------------------------===
+
+dnl Check for compilation tools
+AC_PROG_CPP
+AC_PROG_CC(gcc)
+AC_PROG_CXX(g++)
 AC_PROG_FLEX
 AC_PROG_BISON
+
+dnl Check for libtool and the library that has dlopen function (which must come
+dnl before the AC_PROG_LIBTOOL check in order to enable dlopening libraries with
+dnl libtool).
 AC_LIBTOOL_DLOPEN
 AC_PROG_LIBTOOL
-AC_PATH_PROG(TAR,[tar],[gtar])
+
+dnl Check for the tools that the makefiles require
+AC_CHECK_GNU_MAKE
+AC_PROG_LN_S
+AC_PATH_PROG(FIND, [find], [find])
+AC_PATH_PROG(GREP, [grep], [grep])
+AC_PATH_PROG(MKDIR,[mkdir],[mkdir])
+AC_PATH_PROG(MV,   [mv], [mv])
+AC_PROG_RANLIB
+AC_PATH_PROG(RM,   [rm], [rm])
+AC_PATH_PROG(SED,  [sed], [sed])
+AC_PATH_PROG(TAR,  [tar],[gtar])
+
+dnl Find the install program
+AC_PROG_INSTALL
 
 dnl Checks for tools we can get away with not having:
 AC_PATH_PROG(DOT,[dot],[true dot])
 AC_PATH_PROG(ETAGS,[etags],[true etags])
+
+dnl Check for optional testing tools
+AC_PATH_PROG(PYTHON,[python],[true python])
+AC_PATH_PROG(QMTEST,[qmtest],[true qmtest])
+AC_PATH_PROG(RUNTEST,[runtest],[true runtest])
+
+dnl Determine if the linker supports the -R option.
+AC_LINK_USE_R
+
 dnl Check if we know how to tell etags we are using C++:
 etags_version=`$ETAGS --version 2>&1`
 case "$etags_version" in
@@ -219,38 +262,67 @@ case "$etags_version" in
 	*) ETAGSFLAGS="" ;;
 esac
 AC_SUBST(ETAGSFLAGS,$ETAGSFLAGS)
-AC_PATH_PROG(PYTHON,[python],[true python])
+
+AC_MSG_CHECKING([tool compatibility])
+
+dnl Ensure that compilation tools are GCC; we use GCC specific extensions
+if test "$GCC" != "yes"
+then
+  AC_MSG_ERROR([gcc required but not found])
+fi
+dnl Ensure that compilation tools are GCC; we use GCC specific extensions
+if test "$GXX" != "yes"
+then
+  AC_MSG_ERROR([g++ required but not found])
+fi
+
+dnl Verify that GCC is version 3.0 or higher
+gccmajor=`$CC --version | head -n 1 | awk '{print $NF;}' | cut -d. -f1`
+if test "$gccmajor" -lt "3"
+then
+  AC_MSG_ERROR([gcc 3.x required, but you have a lower version])
+fi
+
+dnl Check for GNU Make.  We use its extensions, so don't build without it
+if test -z "$llvm_cv_gnu_make_command"
+then
+  AC_MSG_ERROR([GNU Make required but not found])
+fi
+
+dnl Tool compatibility is okay if we make it here.
+AC_MSG_RESULT([ok])
+
+dnl Generate warnings for things not found but not strictly needed
 if test "$PYTHON" = "false" ; then
-	AC_MSG_WARN([Python is required for the test suite, but it was not found])
+  AC_MSG_WARN([Python is required for the test suite, but it was not found])
 fi
-AC_PATH_PROG(QMTEST,[qmtest],[true qmtest])
 if test "$QMTEST" = "false" ; then
-	AC_MSG_WARN([QMTest is required for the test suite, but it was not found])
+  AC_MSG_WARN([QMTest is required for the test suite, but it was not found])
 fi
-AC_PATH_PROG(RUNTEST,[runtest],[true runtest])
 if test "$RUNTEST" = "false" ; then
   AC_MSG_WARN([runtest (Deja-Gnu) is required for the test sute, but it was not found])
 fi
-
-dnl Verify that the version of python available is high enough for qmtest
 pyversion=`$PYTHON -V 2>&1 | cut -d\  -f2`
 pymajor=`echo $pyversion | cut -d. -f1`
 pyminor=`echo $pyversion | cut -d. -f2`
-
-if test "$pymajor" -ge "2"
-then
-	if test "$pymajor" -eq "2"
-	then
-		if test "$pyminor" -lt "2"
-		then
-			AC_MSG_WARN([QMTest requires Python 2.2 or later])
-		fi
-	fi
+if test "$pymajor" -ge "2" ; then
+  if test "$pymajor" -eq "2" ; then
+    if test "$pyminor" -lt "2" ; then
+      AC_MSG_WARN([QMTest requires Python 2.2 or later])
+    fi
+  fi
 else
-	AC_MSG_WARN([QMTest requires Python 2.2 or later])
+  AC_MSG_WARN([QMTest requires Python 2.2 or later])
 fi
 
-dnl Checks for libraries:
+AC_MSG_RESULT([])
+
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 5: Check for libraries
+dnl===
+dnl===-----------------------------------------------------------------------===
+
 dnl libelf is for sparc only; we can ignore it if we don't have it
 AC_CHECK_LIB(elf, elf_begin)
 
@@ -264,7 +336,6 @@ if test $zlib_found -eq 1; then
 else
   AC_SUBST([HAVE_ZLIB],[0])
 fi
-
 AC_CHECK_LIB(bz2,BZ2_bzCompressInit,[bzip2_found=1],[bzip2_found=0])
 if test $bzip2_found -eq 1 ; then
   AC_DEFINE([HAVE_BZIP2],[1],
@@ -281,145 +352,131 @@ AC_SEARCH_LIBS(lt_dlopen,ltdl,AC_DEFINE([HAVE_LT_DLOPEN],[1],
                            not be available]))
 
 dnl dlopen() is required for plugin support.
-AC_SEARCH_LIBS(dlopen,dl,AC_DEFINE([HAVE_DLOPEN],[1],[Define if dlopen() is available on this platform.]),AC_MSG_WARN([dlopen() not found - disabling plugin support]))
+AC_SEARCH_LIBS(dlopen,dl,AC_DEFINE([HAVE_DLOPEN],[1],
+               [Define if dlopen() is available on this platform.]),
+               AC_MSG_WARN([dlopen() not found - disabling plugin support]))
 
 dnl mallinfo is optional; the code can compile (minus features) without it
-AC_SEARCH_LIBS(mallinfo,malloc,AC_DEFINE([HAVE_MALLINFO],[1],[Define if mallinfo() is available on this platform.]))
+AC_SEARCH_LIBS(mallinfo,malloc,AC_DEFINE([HAVE_MALLINFO],[1],
+               [Define if mallinfo() is available on this platform.]))
 
 dnl pthread locking functions are optional - but llvm will not be thread-safe
 dnl without locks.
-AC_SEARCH_LIBS(pthread_mutex_lock,pthread,AC_DEFINE([HAVE_PTHREAD_MUTEX_LOCK],[1],[Have pthread_mutex_lock]))
-dnl AC_SUBST(HAVE_PTHREAD_MUTEX_LOCK)
+AC_SEARCH_LIBS(pthread_mutex_lock,pthread,
+               AC_DEFINE([HAVE_PTHREAD_MUTEX_LOCK],[1],
+                         [Have pthread_mutex_lock]))
+
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 6: Check for header files
+dnl===
+dnl===-----------------------------------------------------------------------===
 
-dnl Checks for header files.
 dnl We don't check for ancient stuff or things that are guaranteed to be there
 dnl by the C++ standard. We always use the <cfoo> versions of <foo.h> C headers.
 AC_HEADER_STDC
-AC_HEADER_SYS_WAIT
 
-dnl Checks for POSIX and other various system-specific header files
-AC_CHECK_HEADERS([fcntl.h limits.h sys/time.h unistd.h malloc.h sys/mman.h sys/resource.h dlfcn.h ltdl.h link.h execinfo.h windows.h bzlib.h zlib.h])
+dnl However, we do need some system specific header files. Generally we're
+dnl looking for POSIX headers.
+AC_HEADER_SYS_WAIT
+AC_CHECK_HEADERS([sys/time.h sys/mman.h sys/resource.h sys/time.h sys/types.h])
+AC_CHECK_HEADERS([bzlib.h dlfcn.h execinfo.h fcntl.h limits.h link.h ltdl.h])
+AC_CHECK_HEADERS([malloc.h unistd.h windows.h zlib.h])
+AC_HEADER_TIME
+AC_HEADER_MMAP_ANONYMOUS
 
 dnl Check for things that need to be included in public headers, and so
 dnl for which we may not have access to a HAVE_* preprocessor #define.
 dnl (primarily used in DataTypes.h)
-AC_CHECK_HEADER([sys/types.h])
-AC_CHECK_HEADER([inttypes.h])
-AC_CHECK_HEADER([stdint.h])
+AC_CHECK_HEADERS([inttypes.h stdint.h])
+
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 7: Check for types and structures
+dnl===
+dnl===-----------------------------------------------------------------------===
 
-dnl Check for types
 AC_TYPE_PID_T
 AC_TYPE_SIZE_T
+AC_TYPE_SIGNAL
+AC_STRUCT_TM
 AC_CHECK_TYPES([int64_t],,AC_MSG_ERROR([Type int64_t required but not found]))
 AC_CHECK_TYPES([uint64_t],,
-               AC_CHECK_TYPES([u_int64_t],,
-                              AC_MSG_ERROR([Type uint64_t or u_int64_t required but not found])))
-AC_HEADER_TIME
-AC_STRUCT_TM
+         AC_CHECK_TYPES([u_int64_t],,
+         AC_MSG_ERROR([Type uint64_t or u_int64_t required but not found])))
 
-dnl Check for various C features
-AC_C_PRINTF_A
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 8: Check for specific functions needed
+dnl===
+dnl===-----------------------------------------------------------------------===
 
-dnl Check for the endianness of the target
-AC_C_BIGENDIAN(AC_SUBST([ENDIAN],[big]),AC_SUBST([ENDIAN],[little]))
+AC_CHECK_FUNCS([backtrace getcwd gettimeofday isatty getrusage mkstemp]) 
+AC_CHECK_FUNCS([strdup strtoq strtoll])
+AC_C_PRINTF_A
+AC_FUNC_ALLOCA
+AC_FUNC_RAND48
 
-dnl Check for C++ extensions
+dnl Check for variations in the Standard C++ library and STL. These macros are
+dnl provided by LLVM in the autoconf/m4 directory.
 AC_CXX_HAVE_HASH_MAP
 AC_CXX_HAVE_HASH_SET
 AC_CXX_HAVE_STD_ITERATOR
 AC_CXX_HAVE_BI_ITERATOR
 AC_CXX_HAVE_FWD_ITERATOR
-
 AC_FUNC_ISNAN
 AC_FUNC_ISINF
-AC_FUNC_RAND48
 
-dnl Checks for library functions.
-AC_FUNC_ALLOCA
+dnl Check for mmap and mprotect support. We need both to do the JIT and for
+dnl bytecode loading, etc.
 AC_FUNC_MMAP
-if test "$ac_cv_func_mmap_fixed_mapped" = "no"
-then
-	AC_MSG_WARN([mmap() required but not found])
-fi
 AC_FUNC_MMAP_FILE
-if test "$ac_cv_func_mmap_file" = "no"
-then
-	AC_MSG_WARN([mmap() of files required but not found])
-fi
-AC_HEADER_MMAP_ANONYMOUS
-AC_TYPE_SIGNAL
-AC_CHECK_FUNCS(getcwd gettimeofday strdup strtoq strtoll backtrace isatty mkstemp getrusage)
-AC_CHECK_FUNC(mprotect,,AC_MSG_ERROR([Function mprotect() required but not found]))
+AC_CHECK_FUNC(mprotect,,
+              AC_MSG_ERROR([Function mprotect() required but not found]))
 
-dnl Determine if the linker supports the -R option.
-AC_LINK_USE_R
-
-dnl --enable/--with command-line options:
-dnl Check whether they want to do an optimized build:
-AC_ARG_ENABLE(optimized,AS_HELP_STRING(--enable-optimized,Compile with optimizations enabled (default is NO)),,enableval=no)
-if test ${enableval} = "no"
+if test "$ac_cv_func_mmap_fixed_mapped" = "no"
 then
-	AC_SUBST(ENABLE_OPTIMIZED,[[]])
-else
-	AC_SUBST(ENABLE_OPTIMIZED,[[ENABLE_OPTIMIZED=1]])
+  AC_MSG_WARN([mmap() required but not found])
 fi
-
-dnl JIT Option
-AC_ARG_ENABLE(jit,AS_HELP_STRING(--enable-jit,Enable Just In Time Compiling (default is YES)),,enableval=default)
-if test ${enableval} = "no"
+if test "$ac_cv_func_mmap_file" = "no"
 then
-	AC_SUBST(JIT,[[]])
-else
-	case $target in
-		*i*86*)
-			AC_SUBST(JIT,[[TARGET_HAS_JIT=1]])
-			;;
-		*sparc*)
-			AC_SUBST(JIT,[[TARGET_HAS_JIT=1]])
-			;;
-		*)
-			AC_SUBST(JIT,[[]])
-			;;
-	esac
+  AC_MSG_WARN([mmap() of files required but not found])
 fi
 
-dnl Find the LLVM GCC-based C/C++ front end
-AC_ARG_WITH(llvmgccdir,AS_HELP_STRING(--with-llvmgccdir,Location of LLVM GCC front-end),AC_SUBST(LLVMGCCDIR,[$withval]))
-AC_MSG_CHECKING([for llvm-gcc])
-LLVM_GCC_CHECK=no
-if test -d "$LLVMGCCDIR"
-then
-	if test -x "$LLVMGCCDIR/bin/gcc"
-	then
-		LLVM_GCC_CHECK="$LLVMGCCDIR/bin/gcc"
-	fi
-fi
-llvmgccwarn=no
-AC_MSG_RESULT($LLVM_GCC_CHECK)
-if test "$LLVM_GCC_CHECK" = "no"
-then
-    llvmgccwarn=yes
-fi
-AC_MSG_CHECKING([whether llvm-gcc is sane])
-LLVM_GCC_SANE=no
-if test -x "$LLVM_GCC_CHECK"
-then
-	cp /dev/null conftest.c
-    "$LLVM_GCC_CHECK" -S -o - conftest.c | grep implementation > /dev/null 2>&1
-	if test $? -eq 0
-	then
-		LLVM_GCC_SANE=yes
-	fi
-	rm conftest.c
-	llvmcc1path=`"$LLVM_GCC_CHECK" --print-prog-name=cc1`
-	AC_SUBST(LLVMCC1,$llvmcc1path)
-	llvmcc1pluspath=`"$LLVM_GCC_CHECK" --print-prog-name=cc1plus`
-	AC_SUBST(LLVMCC1PLUS,$llvmcc1pluspath)
-fi
-AC_MSG_RESULT($LLVM_GCC_SANE)
-if test "$LLVM_GCC_SANE" = "no"
-then
-	llvmgccwarn=yes
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 9: Additional checks, variables, etc.
+dnl===
+dnl===-----------------------------------------------------------------------===
+
+dnl Figure out if there's an executable llvm-gcc in the llvmgccdir.
+AC_CACHE_CHECK([for llvm-gcc],[llvm_cv_llvmgcc],
+[llvm_cv_llvmgcc='llvmgcc_not_found'
+if test -d "$LLVMGCCDIR" ; then
+  if test -x "$LLVMGCCDIR/bin/gcc" ; then
+    llvm_cv_llvmgcc="$LLVMGCCDIR/bin/gcc"
+  fi
+fi])
+
+dnl See if the llvmgcc executable can compile to LLVM assembly
+AC_CACHE_CHECK([whether llvm-gcc is sane],[llvm_cv_llvmgcc_sanity],
+[llvm_cv_llvmgcc_sanity="no"
+if test -x "$llvm_cv_llvmgcc" ; then
+  cp /dev/null conftest.c
+  "$llvm_cv_llvmgcc" -S -o - conftest.c | grep implementation > /dev/null 2>&1
+  if test $? -eq 0 ; then
+    llvm_cv_llvmgcc_sanity="yes"
+  fi
+  rm conftest.c
+fi])
+
+dnl Since we have a sane llvmgcc, identify it and its sub-tools 
+if test "$llvm_cv_llvmgcc_sanity" = "yes" ; then
+  AC_SUBST(LLVMGCC,"$llvm_cv_llvmgcc")
+  llvmcc1path=`"$llvm_cv_llvmgcc" --print-prog-name=cc1`
+  AC_SUBST(LLVMCC1,$llvmcc1path)
+  llvmcc1pluspath=`"$llvm_cv_llvmgcc" --print-prog-name=cc1plus`
+  AC_SUBST(LLVMCC1PLUS,$llvmcc1pluspath)
 fi
 
 dnl Get libtool's idea of what the shared library suffix is.
@@ -433,8 +490,8 @@ AC_DEFINE_UNQUOTED(SHLIBEXT,"$SHLIBEXT",
                    [Extension that shared libraries have, e.g., ".so".])
 
 # Translate the various configuration directories and other basic
-# information into substitutions that will end up in config.h.in so
-# that these configured values can be hard-wired into a program.
+# information into substitutions that will end up in Makefile.config.in 
+# that these configured values can be used by the makefiles
 eval LLVM_PREFIX="${prefix}";
 eval LLVM_BINDIR="${prefix}/bin";
 eval LLVM_LIBDIR="${prefix}/lib";
@@ -455,37 +512,84 @@ AC_SUBST(LLVM_INCLUDEDIR)
 AC_SUBST(LLVM_INFODIR)
 AC_SUBST(LLVM_MANDIR)
 AC_SUBST(LLVM_CONFIGTIME)
-AC_DEFINE_UNQUOTED(LLVM_PREFIX,"$LLVM_PREFIX", [Installation prefix directory])
-AC_DEFINE_UNQUOTED(LLVM_BINDIR, "$LLVM_BINDIR", [Installation directory for binary executables])
-AC_DEFINE_UNQUOTED(LLVM_LIBDIR, "$LLVM_LIBDIR", [Installation directory for libraries])
-AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DATADIR", [Installation directory for data files])
-AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DOCSDIR", [Installation directory for documentation])
-AC_DEFINE_UNQUOTED(LLVM_ETCDIR, "$LLVM_ETCDIR", [Installation directory for config files])
-AC_DEFINE_UNQUOTED(LLVM_INCLUDEDIR, "$LLVM_INCLUDEDIR", [Installation directory for include files])
-AC_DEFINE_UNQUOTED(LLVM_INFODIR, "$LLVM_INFODIR", [Installation directory for .info files])
-AC_DEFINE_UNQUOTED(LLVM_MANDIR, "$LLVM_MANDIR", [Installation directory for man pages])
-AC_DEFINE_UNQUOTED(LLVM_CONFIGTIME, "$LLVM_CONFIGTIME", [Time at which LLVM was configured])
-
-dnl Create the output files
+
+# Place the various directores into the config.h file as #defines so that we
+# can know about the installation paths within LLVM.
+AC_DEFINE_UNQUOTED(LLVM_PREFIX,"$LLVM_PREFIX", 
+                   [Installation prefix directory])
+AC_DEFINE_UNQUOTED(LLVM_BINDIR, "$LLVM_BINDIR", 
+                   [Installation directory for binary executables])
+AC_DEFINE_UNQUOTED(LLVM_LIBDIR, "$LLVM_LIBDIR", 
+                   [Installation directory for libraries])
+AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DATADIR", 
+                   [Installation directory for data files])
+AC_DEFINE_UNQUOTED(LLVM_DATADIR, "$LLVM_DOCSDIR", 
+                   [Installation directory for documentation])
+AC_DEFINE_UNQUOTED(LLVM_ETCDIR, "$LLVM_ETCDIR", 
+                   [Installation directory for config files])
+AC_DEFINE_UNQUOTED(LLVM_INCLUDEDIR, "$LLVM_INCLUDEDIR", 
+                   [Installation directory for include files])
+AC_DEFINE_UNQUOTED(LLVM_INFODIR, "$LLVM_INFODIR", 
+                   [Installation directory for .info files])
+AC_DEFINE_UNQUOTED(LLVM_MANDIR, "$LLVM_MANDIR", 
+                   [Installation directory for man pages])
+AC_DEFINE_UNQUOTED(LLVM_CONFIGTIME, "$LLVM_CONFIGTIME", 
+                   [Time at which LLVM was configured])
+
+dnl===-----------------------------------------------------------------------===
+dnl===
+dnl=== SECTION 10: Specify the output files and generate it
+dnl===
+dnl===-----------------------------------------------------------------------===
+
+dnl Configure header files
+AC_CONFIG_HEADERS(include/llvm/Config/config.h)
+
+AC_CONFIG_HEADERS([include/llvm/Support/DataTypes.h])
+AC_CONFIG_HEADERS([include/llvm/ADT/hash_map])
+AC_CONFIG_HEADERS([include/llvm/ADT/hash_set])
+AC_CONFIG_HEADERS([include/llvm/Support/ThreadSupport.h])
+AC_CONFIG_HEADERS([include/llvm/ADT/iterator])
+
+dnl Configure the makefile's configuration data
+AC_CONFIG_FILES([Makefile.config])
+
+dnl Configure llvmc's configuration files
+AC_CONFIG_FILES([tools/llvmc/st tools/llvmc/cpp tools/llvmc/ll tools/llvmc/c])
+
+dnl Do special configuration of Makefiles
+AC_CONFIG_MAKEFILE(Makefile)
+AC_CONFIG_MAKEFILE(Makefile.common)
+AC_CONFIG_MAKEFILE(examples/Makefile)
+AC_CONFIG_MAKEFILE(lib/Makefile)
+AC_CONFIG_MAKEFILE(runtime/Makefile)
+AC_CONFIG_MAKEFILE(test/Makefile)
+AC_CONFIG_MAKEFILE(test/Makefile.tests)
+AC_CONFIG_MAKEFILE(test/QMTest/llvm.py)
+AC_CONFIG_MAKEFILE(test/QMTest/llvmdb.py)
+AC_CONFIG_MAKEFILE(tools/Makefile)
+AC_CONFIG_MAKEFILE(tools/Makefile.JIT)
+AC_CONFIG_MAKEFILE(utils/Makefile)
+AC_CONFIG_MAKEFILE(projects/Makefile)
+
+dnl Finally, crank out the output
 AC_OUTPUT
 
 dnl Warn if we don't have a compression library
 if test $bzip2_found -ne 1 ; then
-  if test $zlib_found -ne 1 ; then
-    AC_MSG_WARN([*** Neither zlib nor bzip2 compression libraries were found.])
-    AC_MSG_WARN([*** Bytecode archives will not support compression!])
-    AC_MSG_WARN([*** To correct, install the libraries and and re-run configure.])
-  fi
+ if test $zlib_found -ne 1 ; then
+  AC_MSG_WARN([*** Neither zlib nor bzip2 compression libraries were found.])
+  AC_MSG_WARN([*** Bytecode archives will not support compression!])
+  AC_MSG_WARN([*** To correct, install the libraries and and re-run configure.])
+ fi
 fi
 
 dnl Warn loudly if llvm-gcc was not obviously working
-if test $llvmgccwarn = yes
-then
-	AC_MSG_WARN([***** llvm C/C++ front end was not found, or does not])
-	AC_MSG_WARN([***** appear to be working.])
-	AC_MSG_WARN([***** ])
-	AC_MSG_WARN([***** Please check configure's --with-llvmgccdir option.])
-	AC_MSG_WARN([***** Runtime libraries (in llvm/runtime) will not be built,])
-	AC_MSG_WARN([***** but you should be able to build the llvm tools.])
+if test "$llvm_cv_llvmgcc_sanity" = "no" ; then
+ AC_MSG_WARN([***** llvm C/C++ front end was not found, or does not])
+ AC_MSG_WARN([***** appear to be working.])
+ AC_MSG_WARN([***** ])
+ AC_MSG_WARN([***** Please check configure's --with-llvmgccdir option.])
+ AC_MSG_WARN([***** Runtime libraries (in llvm/runtime) will not be built,])
+ AC_MSG_WARN([***** but you should be able to build the llvm tools.])
 fi
-