Initial configure support for using Clang as the LLVM capable compiler.

Comes in two parts:
 1. Use --with-clang=path/to/clang/compiler to select an installed clang, or
    --with-built-clang to have the makefiles use the clang which will be built
    as the LLVM capable compiler. If neither is given, --with-built-clang will
    be used if the Clang sources are checked out into the standard location
    (tools/clang).

 2. Use --with-llvmcc={llvm-gcc,clang,none} to specify which LLVM capable
    compiler to use. If not given, then llvm-gcc will be used if available,
    otherwise Clang.

Makefile support still to come.

Eric, Doug, Chris, seem reasonable?

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96934 91177308-0d34-0410-b5e6-96231b3b80d8

Makefile.config.in

@@ -190,6 +190,14 @@ LLVMCC1  := @LLVMCC1@
 LLVMCC1PLUS := @LLVMCC1PLUS@
 LLVMGCC_LANGS := @LLVMGCC_LANGS@
 
+# Information on Clang, if configured.
+CLANGPATH := @CLANGPATH@
+CLANGXXPATH := @CLANGXXPATH@
+ENABLE_BUILT_CLANG := @ENABLE_BUILT_CLANG@
+
+# The LLVM capable compiler to use.
+LLVMCC_OPTION := @LLVMCC_OPTION@
+
 # Path to directory where object files should be stored during a build.
 # Set OBJ_ROOT to "." if you do not want to use a separate place for
 # object files.

autoconf/configure.ac

@@ -612,6 +612,56 @@ if test -n "$LLVMGXX" && test -z "$LLVMGCC"; then
    AC_MSG_ERROR([Invalid llvm-gcc. Use --with-llvmgcc when --with-llvmgxx is used]);
 fi
 
+dnl Allow a specific Clang compiler to be used with this LLVM config.
+AC_ARG_WITH(clang,
+  AS_HELP_STRING([--with-clang],
+    [Specify location of clang compiler (default is --with-built-clang)]),
+    [],[with_clang=default])
+
+dnl Enable use of the built Clang.
+AC_ARG_WITH(built-clang,
+  AS_HELP_STRING([--with-built-clang],
+    [Use the compiled Clang as the LLVM compiler (default=check)]),
+    [],[with_built_clang=check])
+
+dnl Select the Clang compiler option.
+dnl
+dnl If --with-clang is given, always honor that; otherwise honor
+dnl --with-built-clang, or check if we have the clang sources.
+AC_MSG_CHECKING([clang compiler])
+WITH_CLANGPATH=""
+WITH_BUILT_CLANG=0
+if test "$with_clang" != "default"; then
+   WITH_CLANGPATH="$with_clang"
+   if ! test -x "$WITH_CLANGPATH"; then
+     AC_MSG_ERROR([invalid --with-clang, path does not specify an executable])
+   fi
+elif test "$with_built_clang" = "yes"; then
+   WITH_BUILT_CLANG=1
+elif test "$with_built_clang" = "no"; then
+   WITH_BUILT_CLANG=0
+else
+   if test "$with_built_clang" != "check"; then
+      AC_MSG_ERROR([invalid value for --with-built-clang.])
+   fi
+
+   if test -f ${srcdir}/tools/clang/README.txt; then
+     WITH_BUILT_CLANG=1
+   fi
+fi
+
+if ! test -z "$WITH_CLANGPATH"; then
+   AC_MSG_RESULT([$WITH_CLANGPATH])
+   WITH_CLANGXXPATH=`"$WITH_CLANGPATH" --print-prog-name=clang++`
+elif test "$WITH_BUILT_CLANG" = "1"; then
+   AC_MSG_RESULT([built])
+else
+   AC_MSG_RESULT([none])
+fi
+AC_SUBST(CLANGPATH,$WITH_CLANGPATH)
+AC_SUBST(CLANGXXPATH,$WITH_CLANGXXPATH)
+AC_SUBST(ENABLE_BUILT_CLANG,$WITH_BUILT_CLANG)
+
 dnl Override the option to use for optimized builds.
 AC_ARG_WITH(optimize-option,
   AS_HELP_STRING([--with-optimize-option],
@@ -946,6 +996,29 @@ else
   AC_SUBST(LLVMGXXCOMMAND,$LLVMGXXCOMMAND)
 fi
 
+dnl Select the LLVM capable compiler to use, we default to using llvm-gcc if
+dnl found, otherwise clang if available.
+AC_ARG_WITH(llvmcc,
+  AS_HELP_STRING([--with-llvmcc=<name>],
+    [Choose the LLVM capable compiler to use (llvm-gcc, clang, or none; default=check)]),
+    [],[with_llvmcc=check])
+AC_MSG_CHECKING([LLVM capable compiler])
+if test "$with_llvmcc" != "check"; then
+   if (test "$with_llvmcc" != "llvm-gcc" &&
+       test "$with_llvmcc" != "clang" &&
+       test "$with_llvmcc" != "none"); then
+      AC_MSG_ERROR([invalid value for --with-llvmcc, expected 'llvm-gcc', 'clang', or 'none'.])
+   fi
+   WITH_LLVMCC="$with_llvmcc"
+elif test -n "$LLVMGCC"; then
+   WITH_LLVMCC=llvm-gcc
+elif test -n "$WITH_CLANGPATH" || test "$WITH_BUILT_CLANG" -ne "0"; then
+   WITH_LLVMCC=clang
+else
+   WITH_LLVMCC=none
+fi
+AC_MSG_RESULT([$WITH_LLVMCC])
+AC_SUBST(LLVMCC_OPTION,$WITH_LLVMCC)
 
 AC_MSG_CHECKING([tool compatibility])
 

configure

@@ -695,6 +695,9 @@ LLVM_ENUM_ASM_PRINTERS
 LLVM_ENUM_ASM_PARSERS
 LLVM_ENUM_DISASSEMBLERS
 ENABLE_CBE_PRINTF_A
+CLANGPATH
+CLANGXXPATH
+ENABLE_BUILT_CLANG
 OPTIMIZE_OPTION
 EXTRA_OPTIONS
 BINUTILS_INCDIR
@@ -754,6 +757,7 @@ LLVMGCCCOMMAND
 LLVMGXXCOMMAND
 LLVMGCC
 LLVMGXX
+LLVMCC_OPTION
 NO_VARIADIC_MACROS
 NO_MISSING_FIELD_INITIALIZERS
 USE_UDIS86
@@ -1423,6 +1427,10 @@ Optional Packages:
                           searches PATH)
   --with-llvmgxx          Specify location of llvm-g++ driver (default
                           searches PATH)
+  --with-clang            Specify location of clang compiler (default is
+                          --with-built-clang)
+  --with-built-clang      Use the compiled Clang as the LLVM compiler
+                          (default=check)
   --with-optimize-option  Select the compiler options to use for optimized
                           builds
   --with-extra-options    Specify additional options to compile LLVM with
@@ -1439,6 +1447,8 @@ Optional Packages:
   --with-binutils-include Specify path to binutils/include/ containing
                           plugin-api.h file for gold plugin.
   --with-tclinclude       directory where tcl headers are
+  --with-llvmcc=<name>    Choose the LLVM capable compiler to use (llvm-gcc,
+                          clang, or none; default=check)
   --with-udis86=<path>    Use udis86 external x86 disassembler library
   --with-oprofile=<prefix>
                           Tell OProfile >= 0.9.4 how to symbolize JIT output
@@ -5026,6 +5036,69 @@ echo "$as_me: error: Invalid llvm-gcc. Use --with-llvmgcc when --with-llvmgxx is
 fi
 
 
+# Check whether --with-clang was given.
+if test "${with_clang+set}" = set; then
+  withval=$with_clang;
+else
+  with_clang=default
+fi
+
+
+
+# Check whether --with-built-clang was given.
+if test "${with_built_clang+set}" = set; then
+  withval=$with_built_clang;
+else
+  with_built_clang=check
+fi
+
+
+{ echo "$as_me:$LINENO: checking clang compiler" >&5
+echo $ECHO_N "checking clang compiler... $ECHO_C" >&6; }
+WITH_CLANGPATH=""
+WITH_BUILT_CLANG=0
+if test "$with_clang" != "default"; then
+   WITH_CLANGPATH="$with_clang"
+   if ! test -x "$WITH_CLANGPATH"; then
+     { { echo "$as_me:$LINENO: error: invalid --with-clang, path does not specify an executable" >&5
+echo "$as_me: error: invalid --with-clang, path does not specify an executable" >&2;}
+   { (exit 1); exit 1; }; }
+   fi
+elif test "$with_built_clang" = "yes"; then
+   WITH_BUILT_CLANG=1
+elif test "$with_built_clang" = "no"; then
+   WITH_BUILT_CLANG=0
+else
+   if test "$with_built_clang" != "check"; then
+      { { echo "$as_me:$LINENO: error: invalid value for --with-built-clang." >&5
+echo "$as_me: error: invalid value for --with-built-clang." >&2;}
+   { (exit 1); exit 1; }; }
+   fi
+
+   if test -f ${srcdir}/tools/clang/README.txt; then
+     WITH_BUILT_CLANG=1
+   fi
+fi
+
+if ! test -z "$WITH_CLANGPATH"; then
+   { echo "$as_me:$LINENO: result: $WITH_CLANGPATH" >&5
+echo "${ECHO_T}$WITH_CLANGPATH" >&6; }
+   WITH_CLANGXXPATH=`"$WITH_CLANGPATH" --print-prog-name=clang++`
+elif test "$WITH_BUILT_CLANG" = "1"; then
+   { echo "$as_me:$LINENO: result: built" >&5
+echo "${ECHO_T}built" >&6; }
+else
+   { echo "$as_me:$LINENO: result: none" >&5
+echo "${ECHO_T}none" >&6; }
+fi
+CLANGPATH=$WITH_CLANGPATH
+
+CLANGXXPATH=$WITH_CLANGXXPATH
+
+ENABLE_BUILT_CLANG=$WITH_BUILT_CLANG
+
+
+
 # Check whether --with-optimize-option was given.
 if test "${with_optimize_option+set}" = set; then
   withval=$with_optimize_option;
@@ -11032,7 +11105,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<EOF
-#line 11035 "configure"
+#line 11108 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12802,6 +12875,36 @@ else
 fi
 
 
+# Check whether --with-llvmcc was given.
+if test "${with_llvmcc+set}" = set; then
+  withval=$with_llvmcc;
+else
+  with_llvmcc=check
+fi
+
+{ echo "$as_me:$LINENO: checking LLVM capable compiler" >&5
+echo $ECHO_N "checking LLVM capable compiler... $ECHO_C" >&6; }
+if test "$with_llvmcc" != "check"; then
+   if (test "$with_llvmcc" != "llvm-gcc" &&
+       test "$with_llvmcc" != "clang" &&
+       test "$with_llvmcc" != "none"); then
+      { { echo "$as_me:$LINENO: error: invalid value for --with-llvmcc, expected 'llvm-gcc', 'clang', or 'none'." >&5
+echo "$as_me: error: invalid value for --with-llvmcc, expected 'llvm-gcc', 'clang', or 'none'." >&2;}
+   { (exit 1); exit 1; }; }
+   fi
+   WITH_LLVMCC="$with_llvmcc"
+elif test -n "$LLVMGCC"; then
+   WITH_LLVMCC=llvm-gcc
+elif test -n "$WITH_CLANGPATH" || test "$WITH_BUILT_CLANG" -ne "0"; then
+   WITH_LLVMCC=clang
+else
+   WITH_LLVMCC=none
+fi
+{ echo "$as_me:$LINENO: result: $WITH_LLVMCC" >&5
+echo "${ECHO_T}$WITH_LLVMCC" >&6; }
+LLVMCC_OPTION=$WITH_LLVMCC
+
+
 { echo "$as_me:$LINENO: checking tool compatibility" >&5
 echo $ECHO_N "checking tool compatibility... $ECHO_C" >&6; }
 
@@ -20646,10 +20749,10 @@ LLVM_ENUM_ASM_PRINTERS!$LLVM_ENUM_ASM_PRINTERS$ac_delim
 LLVM_ENUM_ASM_PARSERS!$LLVM_ENUM_ASM_PARSERS$ac_delim
 LLVM_ENUM_DISASSEMBLERS!$LLVM_ENUM_DISASSEMBLERS$ac_delim
 ENABLE_CBE_PRINTF_A!$ENABLE_CBE_PRINTF_A$ac_delim
+CLANGPATH!$CLANGPATH$ac_delim
+CLANGXXPATH!$CLANGXXPATH$ac_delim
+ENABLE_BUILT_CLANG!$ENABLE_BUILT_CLANG$ac_delim
 OPTIMIZE_OPTION!$OPTIMIZE_OPTION$ac_delim
-EXTRA_OPTIONS!$EXTRA_OPTIONS$ac_delim
-BINUTILS_INCDIR!$BINUTILS_INCDIR$ac_delim
-ENABLE_LLVMC_DYNAMIC!$ENABLE_LLVMC_DYNAMIC$ac_delim
 _ACEOF
 
   if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 97; then
@@ -20691,6 +20794,9 @@ _ACEOF
 ac_delim='%!_!# '
 for ac_last_try in false false false false false :; do
   cat >conf$$subs.sed <<_ACEOF
+EXTRA_OPTIONS!$EXTRA_OPTIONS$ac_delim
+BINUTILS_INCDIR!$BINUTILS_INCDIR$ac_delim
+ENABLE_LLVMC_DYNAMIC!$ENABLE_LLVMC_DYNAMIC$ac_delim
 ENABLE_LLVMC_DYNAMIC_PLUGINS!$ENABLE_LLVMC_DYNAMIC_PLUGINS$ac_delim
 CXX!$CXX$ac_delim
 CXXFLAGS!$CXXFLAGS$ac_delim
@@ -20746,6 +20852,7 @@ LLVMGCCCOMMAND!$LLVMGCCCOMMAND$ac_delim
 LLVMGXXCOMMAND!$LLVMGXXCOMMAND$ac_delim
 LLVMGCC!$LLVMGCC$ac_delim
 LLVMGXX!$LLVMGXX$ac_delim
+LLVMCC_OPTION!$LLVMCC_OPTION$ac_delim
 NO_VARIADIC_MACROS!$NO_VARIADIC_MACROS$ac_delim
 NO_MISSING_FIELD_INITIALIZERS!$NO_MISSING_FIELD_INITIALIZERS$ac_delim
 USE_UDIS86!$USE_UDIS86$ac_delim
@@ -20778,7 +20885,7 @@ LIBOBJS!$LIBOBJS$ac_delim
 LTLIBOBJS!$LTLIBOBJS$ac_delim
 _ACEOF
 
-  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 85; then
+  if test `sed -n "s/.*$ac_delim\$/X/p" conf$$subs.sed | grep -c X` = 89; then
     break
   elif $ac_last_try; then
     { { echo "$as_me:$LINENO: error: could not make $CONFIG_STATUS" >&5