add support for building clang/LLVM with an alternative gcc compiler.

This requires the setting of the --with-gcc-toolchain option in ./configure,
in addition to the --with-cc and --with-c++ options, which are then passed
to the clang/LLVM build procedure.


git-svn-id: http://root.cern.ch/svn/root/trunk@48841 27541ba8-7e3a-0410-8455-c3a389f83636

config/Makefile-comp.in

@@ -8,3 +8,4 @@ CC    = @altcc@
 CXX   = @altcxx@
 F77   = @altf77@
 LD    = @altld@
+GCCTOOLCHAIN = @gcctoolchain@

configure

@@ -27,6 +27,7 @@ altcc=
 altcxx=
 altf77=
 altld=
+gcctoolchain=
 host=
 
 deprecated_options="         \
@@ -1668,6 +1669,8 @@ with compiler options, prefix with --with-, overrides default value
   cxx                alternative C++ compiler and options to be used
   f77                alternative Fortran compiler and options to be used
   ld                 alternative Linker and options to be used
+  gcc-toolchain      directory where gcc is installed (needed for compilation
+                     of clang/LLVM in case not the default gcc is used)
   clang              use clang compiler instead of gcc (mutual exclusive with
                      the cc, cxx and ld options)
 
@@ -2004,6 +2007,7 @@ if test $# -gt 0 ; then
       --with-cxx=*)            altcxx=$optarg        ;;
       --with-f77=*)            altf77=$optarg        ;;
       --with-ld=*)             altld=$optarg         ;;
+      --with-gcc-toolchain=*)  gcctoolchain=$optarg  ;;
       --with-clang) altcc=clang; altcxx=clang++; altld=clang++ ;;
       --with-hostcc=*)         hostcc=$optarg        ;;
       --with-hostcxx=*)        hostcxx=$optarg       ;;
@@ -6848,6 +6852,7 @@ sed -e "s|@altcc@|$altcc|"     \
     -e "s|@altcxx@|$altcxx|"   \
     -e "s|@altf77@|$altf77|"   \
     -e "s|@altld@|$altld|"     \
+    -e "s|@gcctoolchain@|$gcctoolchain|" \
     < Makefile-comp.tmp > $MAKECOMPOUT
 rm -f Makefile-comp.tmp
 

interpreter/llvm/Module.mk

@@ -147,6 +147,9 @@ $(LLVMDEPO): $(LLVMDEPS)
 		if [ "x$$LLVM_EXTRA_OPTIONS" = "x" ]; then \
 			LLVM_EXTRA_OPTIONS="--with-extra-options="; \
 		fi; \
+		if [ x$(GCCTOOLCHAIN) != "x" ]; then \
+			LLVM_GCC_TOOLCHAIN="--with-gcc-toolchain=$(GCCTOOLCHAIN)"; \
+		fi; \
 		echo "*** Configuring LLVM in $(dir $@) ..."; \
 		mkdir -p $(dir $@) && \
 		cd $(dir $@)  && \
@@ -162,6 +165,7 @@ $(LLVMDEPO): $(LLVMDEPS)
 		$(LLVMOPTFLAGS) \
 		--enable-targets=host \
 		"$$LLVM_EXTRA_OPTIONS" \
+		$$LLVM_GCC_TOOLCHAIN \
 		CC=$$LLVMCC CXX=$$LLVMCXX \
 		$$LLVM_BUILD_CC $$LLVM_BUILD_CXX \
 		CFLAGS="$$LLVM_CFLAGS" CXXFLAGS="$$LLVM_CFLAGS" )