It looks like I've managed to do it using MULTILIB: MULTILIB_OPTIONS = mopt1 mopt2 MULTILIB_DIRNAMES = opt1 opt2 but of course this spends ages building all 4 options ((!mopt1,!mopt2), (mopt1,!mopt2),(!mopt1,mopt2),(mopt1,mopt2)) whereas I only really want (mopt1,mopt2). However, I guess this may be useful as the two options I need will be the most likely to be switched about in application building so the multilibs may actually be useful. I did try: CFLAGS_FOR_TARGET += -mopt1 -mopt2 in the t-default Makefile segment but that only compiled 4 files (crtstuff.c -DCRT_BEGIN, crtstuff.c -DCRT_END, crti.S and crtn.S) with these flags. I didn't want to start messing about with actual Makefiles as configure will change these anyway. So I would still appreciate it if anyone can tell me the proper way of doing it - there must be one, surely? Robert Cragie, Design Engineer _______________________________________________________________ Jennic Ltd, Furnival Street, Sheffield, S1 4QT, UK http://www.jennic.com Tel: +44 (0) 114 281 2655 _______________________________________________________________ > -----Original Message----- > From: Kai Ruottu [mailto:karuottu@xxxxxxxx] > Sent: 18 September 2007 12:30 > To: rcc@xxxxxxxxxx > Cc: gcc-help@xxxxxxxxxxx > Subject: Re: Specifying cross-compile flags for newlib > > > Robert Cragie wrote: > > I am building a cross compiler and automatically building in newlib > > with --with-newlib in the configure options. I need to pass additional > > compiler flags to the just-build cross-compiler when compiling > libgcc2 and > > newlib. I can figure out what to do for libgcc2 - specify > > TARGET_LIBGCC2_CFLAGS in the t-default Makefile segment in the > > gcc/contrib/<arch> subdir. However, these flags don't get > passed to newlib - > > how do I do the same for newlib? > > > What about browsing the main 'Makefile' and searching for 'CFLAGS' ? > > After the $build ('*_FOR_BUILD' and $host settings, there will be > settings '_FOR_TARGET' like : > > CC_FOR_TARGET = $(STAGE_CC_WRAPPER) $$r/gcc/xgcc -B$$r/gcc/ > $(FLAGS_FOR_TARGET) > # During gcc bootstrap, if we use some random cc for stage1 then > # CFLAGS will be just -g. We want to ensure that TARGET libraries > # (which we know are built with gcc) are built with optimizations so > # prepend -O2 when setting CFLAGS_FOR_TARGET. > CFLAGS_FOR_TARGET = -O2 $(CFLAGS) > # If GCC_FOR_TARGET is not overriden on the command line, then this > # variable is passed down to the gcc Makefile, where it is used to > # build libgcc2.a. We define it here so that it can itself be > # overridden on the command line. > GCC_FOR_TARGET=$(USUAL_GCC_FOR_TARGET) > > The 'CFLAGS_FOR_TARGET' most probably would be the setting you should > customize! This should > be possible already when configuring, for instance : > > CFLAGS_FOR_TARGET="-Os -omit-frame-pointer" \ > $GCC_SRC/configure ...... > > but the previous comments don't tell about "overriding" this, so maybe > it will not be looked > in the 'environment settings'.... > > > Thanks in advance > > > > Robert Cragie, Design Engineer > > _______________________________________________________________ > > Jennic Ltd, Furnival Street, Sheffield, S1 4QT, UK > > http://www.jennic.com Tel: +44 (0) 114 281 2655 > > _______________________________________________________________ > > > > > > > > > > >
