[dpdk-dev] [PATCH 01/15 v2] makefiles: Fixed -share command line option error

[Neil Horman]

On Fri, Apr 18, 2014 at 01:23:19PM +0200, Thomas Monjalon wrote:
> Hi Neil,
> 
> 2014-04-16 09:51, Neil Horman:
> > The shared libraries built with the current makefile set produce static
> > libraries rather than actual shared objects.  This is due to several missing
> > options that are required to correctly build shared objects using ld, as
> > well as a mis-specified -share option (which should be -shared). Switching
> > to the use of CC rather than LD and fixing the -shared option corrects
> > these problems and builds the DSOs correctly.
> > 
> > Signed-off-by: Neil Horman <nhorman at tuxdriver.com>
> [...]
> > --- a/mk/rte.lib.mk
> > +++ b/mk/rte.lib.mk
> [...]
> > +ifeq ($(LINK_USING_CC),1)
> > +# Override the definition of LD here, since we're linking with CC
> > +LD := $(CC)
> > +endif
> [...]
> > -O_TO_S = $(LD) $(CPU_LDFLAGS) -z muldefs -share $(OBJS-y) -o $(LIB)
> > +O_TO_S = $(LD) $(CPU_LDFLAGS) -z muldefs -shared $(OBJS-y) -o $(LIB)
> 
> I think that CPU_LDFLAGS should be prefixed with -Wl, in case of CC linking.
> So blindly assigning CC to LD variable seems a bad idea.
> Other makefiles have different O_TO_S commands depending of LINK_USING_CC.
> 
I'm not so sure about that.  Or more specifically, I wonder if some more rework
isn't needed here.  I say that because, while what you say makes sense in terms
of formatting the CPU_FLAGS variable for use with CC, the only current use of
CPU_LDFLAGS set -melf_i386, which IIRC is a gcc flag, not meant to be passed to
LD.  I can change the makefile to completely rewrite the comand based on
LINK_USING_CC, but it seems to me that CPU_LDFLAGS should not be passed in the
use of the LD case.  

thoughts?
Neil

> > --- a/mk/rte.sharelib.mk
> > +++ b/mk/rte.sharelib.mk
> [...]
> > -O_TO_S = $(LD) $(CPU_LDFLAGS) -share $(OBJS) -o $(RTE_OUTPUT)/lib/$(LIB_ONE)
> > +O_TO_S = $(LD) $(CPU_LDFLAGS) -shared $(OBJS) -o $(RTE_OUTPUT)/lib/$(LIB_ONE)
> 
> Why not using CC here whether LINK_USING_CC is enabled?
> 
> Feel free to send a v3 ;)
> -- 
> Thomas
>