build: add --with-python option

This adds a new --with-python option to allow configuration of the python binary
for building.  If not specified, $PATH will be searched for common python binary
names (python, python2, python3).  If specified, and the path is not executable,
it will attempt to search $PATH.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
Reviewed-by: Eric Christopher <echristo@gmail.com>, Daniel Dunbar <daniel@zuster.org>
llvm-svn: 173890

Makefile.config.in

@@ -179,6 +179,7 @@ RANLIB     := @RANLIB@
 RM         := @RM@
 SED        := @SED@
 TAR        := @TAR@
+PYTHON     := @PYTHON@
 
 # Paths to miscellaneous programs we hope are present but might not be
 BZIP2      := @BZIP2@

Makefile.rules

@@ -97,7 +97,7 @@ endif
 $(LLVMBuildMakeFrag): $(PROJ_SRC_ROOT)/Makefile.rules \
 		      $(PROJ_OBJ_ROOT)/Makefile.config
 	$(Echo) Constructing LLVMBuild project information.
-	$(Verb) $(LLVMBuildTool) \
+	$(Verb)$(PYTHON) $(LLVMBuildTool) \
 	  --native-target "$(TARGET_NATIVE_ARCH)" \
 	  --enable-targets "$(TARGETS_TO_BUILD)" \
 	  --enable-optional-components "$(OPTIONAL_COMPONENTS)" \
@@ -826,7 +826,7 @@ ObjectsBC := $(BaseNameSources:%=$(ObjDir)/%.bc)
 #----------------------------------------------------------
 
 ifeq (-mingw32,$(findstring -mingw32,$(BUILD_TRIPLE)))
-  ECHOPATH := $(Verb)python -u -c "import sys;print ' '.join(sys.argv[1:])"
+  ECHOPATH := $(Verb)$(PYTHON) -u -c "import sys;print ' '.join(sys.argv[1:])"
 else
   ECHOPATH := $(Verb)$(ECHO)
 endif

autoconf/configure.ac

@@ -1298,6 +1298,35 @@ else
 fi
 AC_MSG_RESULT([$NO_VARIADIC_MACROS $NO_MISSING_FIELD_INITIALIZERS $COVERED_SWITCH_DEFAULT $NO_UNINITIALIZED $NO_MAYBE_UNINITIALIZED])
 
+AC_ARG_WITH([python],
+            [AS_HELP_STRING([--with-python], [path to python])],
+            [PYTHON="$withval"])
+
+if test -n "$PYTHON" && test -x "$PYTHON" ; then
+  AC_MSG_CHECKING([for python])
+  AC_MSG_RESULT([user defined: $with_python])
+else
+  if test -n "$PYTHON" ; then
+    AC_MSG_WARN([specified python ($PYTHON) is not usable, searching path])
+  fi
+
+  AC_PATH_PROG([PYTHON], [python python2 python26],
+               [AC_MSG_RESULT([not found])
+                AC_MSG_ERROR([could not find python 2.5 or higher])])
+fi
+
+AC_MSG_CHECKING([for python >= 2.5])
+ac_python_version=`$PYTHON -c 'import sys; print sys.version.split()[[0]]'`
+ac_python_version_major=`echo $ac_python_version | cut -d'.' -f1`
+ac_python_version_minor=`echo $ac_python_version | cut -d'.' -f2`
+ac_python_version_patch=`echo $ac_python_version | cut -d'.' -f3`
+if   test "$ac_python_version_major" -eq "2" \
+   && test "$ac_python_version_minor" -ge "5" ; then
+  AC_MSG_RESULT([$PYTHON ($ac_python_version)])
+else
+  AC_MSG_RESULT([not found])
+  AC_MSG_FAILURE([found python $ac_python_version ($PYTHON); required >= 2.5])
+fi
 
 dnl===-----------------------------------------------------------------------===
 dnl===

projects/sample/Makefile.llvm.rules

@@ -745,7 +745,7 @@ ObjectsBC := $(BaseNameSources:%=$(ObjDir)/%.bc)
 #----------------------------------------------------------
 
 ifeq (-mingw32,$(findstring -mingw32,$(BUILD_TRIPLE)))
-  ECHOPATH := $(Verb)python -u -c "import sys;print ' '.join(sys.argv[1:])"
+  ECHOPATH := $(Verb)$(PYTHON) -u -c "import sys;print ' '.join(sys.argv[1:])"
 else
   ECHOPATH := $(Verb)$(ECHO)
 endif

test/Makefile

@@ -87,14 +87,14 @@ endif # SunOS
 
 check-local:: lit.site.cfg Unit/lit.site.cfg
 	( $(ULIMIT) \
-	  $(LLVM_SRC_ROOT)/utils/lit/lit.py $(LIT_ARGS) $(LIT_TESTSUITE) )
+	  $(PYTHON) $(LLVM_SRC_ROOT)/utils/lit/lit.py $(LIT_ARGS) $(LIT_TESTSUITE) )
 
 # This is a legacy alias dating from when both DejaGNU and lit were in use.
 check-local-lit:: check-local
 
 check-local-all:: lit.site.cfg Unit/lit.site.cfg extra-site-cfgs
 	( $(ULIMIT) \
-	  $(LLVM_SRC_ROOT)/utils/lit/lit.py $(LIT_ARGS) $(LIT_ALL_TESTSUITES) )
+	  $(PYTHON) $(LLVM_SRC_ROOT)/utils/lit/lit.py $(LIT_ARGS) $(LIT_ALL_TESTSUITES) )
 
 clean::
 	$(RM) -rf `find $(LLVM_OBJ_ROOT)/test -name Output -type d -print`
@@ -138,7 +138,7 @@ lit.site.cfg: FORCE
 	@$(ECHOPATH) s=@LLVM_TOOLS_DIR@=$(ToolDir)=g >> lit.tmp
 	@$(ECHOPATH) s=@SHLIBDIR@=$(SharedLibDir)=g >> lit.tmp
 	@$(ECHOPATH) s=@SHLIBEXT@=$(SHLIBEXT)=g >> lit.tmp
-	@$(ECHOPATH) s=@PYTHON_EXECUTABLE@=python=g >> lit.tmp
+	@$(ECHOPATH) s=@PYTHON_EXECUTABLE@=$(PYTHON)=g >> lit.tmp
 	@$(ECHOPATH) s=@OCAMLOPT@=$(OCAMLOPT) -cc $(subst *,'\\\"',*$(subst =,"\\=",$(CXX_FOR_OCAMLOPT))*) -I $(LibDir)/ocaml=g >> lit.tmp
 	@$(ECHOPATH) s=@ENABLE_SHARED@=$(ENABLE_SHARED)=g >> lit.tmp
 	@$(ECHOPATH) s=@ENABLE_ASSERTIONS@=$(ENABLE_ASSERTIONS)=g >> lit.tmp