[RFC] add --with-build-for-cc option

[Xerxes Rånby]

On 2010-06-21 14:54, Robert Schuster wrote:
> Hi all,
>
> Am 18.06.2010 13:42, schrieb Robert Schuster:
>   
>> Hi,
>> following examples for the autotools I added a --with-cc-for-build
>>   
>>     
> The documentation I am referencing here is actually this:
> http://makelinux.com/books/autobook-1.5/autobook_270.html
>
> Regards
> Robert
>
>   
>> option to IcedTea6's configure.ac, Makefile.am, acinclude.m4 that allows
>> specifying the compiler to use for helper programs that need to be
>> compiled with the build system's compiler (rather than the one for the
>> target). The patch also includes a change to the ARM assembler port's
>> makefile that makes it compile 'mkbc' with the build compiler. If used
>> the variable CROSS_COMPILATION to absolutely make sure that nothing
>> changes for non-cross builds. The change is only possible because the
>> mkbc tool does not depend on the sizes of data structures - genoffsets
>> is a different beast in that regard and I will come up with a different
>> solution for that later.
>>
>> Btw: AFAIK the patch does not interfere with the soon to be removed zero
>> sources.
>>   
>>     
> Hm, of course this stuff has been committed already ... but I had not
> read fully through the respective threads when I sent my mail. ;-)
>
>   
>> 2009-06-18  Robert Schuster  <robertschuster at fsfe.org>
>>
>>     * configure.ac: Added --with-cc-for-build option.
>>     * acinclude: New macro AC_CHECK_WITH_CC_FOR_BUILD.
>>     * Makefile.am: Provide CC_FOR_BUILD through icedtea-env.
>>     * ports/hotspot/make/linux/makefiles/zeroshark.make: Use
>>     CC_FOR_BUILD when cross-compiling.
>>
>> Ok, for commit?
>>
>> Regards
>> Robert
>>   
>>     


Hi Robert!

...
diff -r 1e95c787d40b ports/hotspot/make/linux/makefiles/zeroshark.make

--- a/ports/hotspot/make/linux/makefiles/zeroshark.make	Tue Jun 15 18:34:45 2010 +0100
+++ b/ports/hotspot/make/linux/makefiles/zeroshark.make	Fri Jun 18 13:30:12 2010 +0200
@@ -35,6 +35,12 @@
 #XXX and the updated calling convention for deopt (PR icedtea/484)
 #CFLAGS += -DHOTSPOT_ASM
 
+ifeq ($(CROSS_COMPILATION), true)
+  C_COMPILE_FOR_MKBC = $(CC_FOR_BUILD)
+else
+  C_COMPILE_FOR_MKBC = $(C_COMPILE)
+endif
+
 %.o: %.S
 	@echo Assembling $<
 	$(QUIETLY) $(REMOVE_TARGET)
@@ -53,7 +59,7 @@
 
 mkbc:	$(GAMMADIR)/tools/mkbc.c
 	@echo Compiling mkbc tool
-	$(CC_COMPILE) -o $@ $< $(COMPILE_DONE)
+	$(C_COMPILE_FOR_MKBC) -o $@ $< $(COMPILE_DONE)
 
 mkoffsets:	asm_helper.cpp
 	@echo Compiling offset generator

...

I do not see why we need to conditionalize the zeroshark.make code at all,
I think it would be better and cleaner to always use the passed
$(CC_FOR_BUILD) when compiling mkbc.c


Cheers
Xerxes