Add make make OS_ID=0.n.m for building other platforms. See my blog.

make/makefile

@@ -1,8 +1,15 @@
-# REBOL Makefile -- Generated by make-make.r (do not edit) on 24-Dec-2012/15:28:24-8:00
+# REBOL Makefile -- Generated by make-make.r (do not edit) on 26-Dec-2012/12:30:23-8:00
 # This makefile is intentional kept simple to make builds possible on
 # a wider range of target platforms.
 
-# To cross compile or build for other target:
+# To regenerate this file:
+#    make make
+
+# To generate this file for a different platform, check systems.r file
+# and provide an OS_ID (from the systems table). Linux 2.5 for example:
+#    make make OS_ID=0.4.3
+
+# To cross compile using a different toolchain and include files:
 #    $TOOLS - should point to bin where gcc is found
 #    $INCL  - should point to the dir for includes
 # Example make:
@@ -30,12 +37,12 @@ R=	$S/core
 INCL ?= .
 I= -I$(INCL) -I$S/include/
 
-TO_OS=	 TO_LINUX
-OS_ID=	 0.4.4
-BIN_SUFFIX=	
-RAPI_FLAGS=	  -O2 -fvisibility=hidden -m32
+TO_OS?= TO_LINUX
+OS_ID?= 0.4.4
+BIN_SUFFIX=
+RAPI_FLAGS=  -O2 -fvisibility=hidden -m32
 HOST_FLAGS=	-DREB_EXE  -O2 -fvisibility=hidden -m32 -D_FILE_OFFSET_BITS=64
-RLIB_FLAGS=	
+RLIB_FLAGS=
 
 # Flags for core and for host:
 RFLAGS= -c -D$(TO_OS) -DREB_API  $(RAPI_FLAGS) $I

src/tools/make-make.r

@@ -28,13 +28,22 @@ path-incl:   %../../src/include/
 
 ;******************************************************************************
 
+; (Warning: format is a bit sensitive to extra spacing. E.g. see macro+ func)
+
 makefile-head:
 
 {# REBOL Makefile -- Generated by make-make.r (do not edit) on !date
 # This makefile is intentional kept simple to make builds possible on
 # a wider range of target platforms.
 
-# To cross compile or build for other target:
+# To regenerate this file:
+#    make make
+
+# To generate this file for a different platform, check systems.r file
+# and provide an OS_ID (from the systems table). Linux 2.5 for example:
+#    make make OS_ID=0.4.3
+
+# To cross compile using a different toolchain and include files:
 #    $TOOLS - should point to bin where gcc is found
 #    $INCL  - should point to the dir for includes
 # Example make:
@@ -62,12 +71,12 @@ R=	$S/core
 INCL ?= .
 I= -I$(INCL) -I$S/include/
 
-TO_OS=	
-OS_ID=	
-BIN_SUFFIX=	
-RAPI_FLAGS=	
+TO_OS?=
+OS_ID?=
+BIN_SUFFIX=
+RAPI_FLAGS=
 HOST_FLAGS=	-DREB_EXE
-RLIB_FLAGS=	
+RLIB_FLAGS=
 
 # Flags for core and for host:
 RFLAGS= -c -D$(TO_OS) -DREB_API  $(RAPI_FLAGS) $I
@@ -267,10 +276,15 @@ macro+: func [
 	"Appends value to end of macro= line"
 	'name
 	value
+	/local str
 ][
-	name: find find/tail makefile-head join newline join name "=" newline
-	if name/-1 != space [name: insert name space]
-	insert name value
+	; (this should use parse!)
+	str: any [
+		find find/tail makefile-head join newline join name "=" newline
+		find find/tail makefile-head join newline join name "?=" newline
+	]
+	unless str [print ajoin ["Cannot find " name "= definition"] exit]
+	insert insert str space value
 ]
 
 macro++: funct ['name obj [object!]] [