[U-Boot] [PATCH] Fix build failure in examples/standalone

[Mike Frysinger]

On Friday 06 November 2009 10:00:13 Premi, Sanjeev wrote:
> From: Premi, Sanjeev
> > From: Wolfgang Denk
> > > Sanjeev Premi wrote:
> > > > The variable ELF contains many leading spaces. This adds
> > > > a 'fake' source file variable COBJS. It leads to build
> > > > failure as below:
> > >
> > > I read about the bug reports, but I cannot reproduce this on any
> > > system I'm running.
> > >
> > > Also, why would any white space matter here?
> >
> > I was surprised too. It is the first time ever I have seen
> > this problem
> > with any Makefile over years.
> >
> > To debug I tried this:
> >
> > --- a/examples/standalone/Makefile
> > +++ b/examples/standalone/Makefile
> > @@ -42,7 +42,9 @@ ELF := $(ELF-y) $(ELF-$(ARCH))
> > $(ELF-$(BOARD)) $(ELF-$(CPU))
> >  SREC = $(addsuffix .srec,$(ELF))
> >  BIN  = $(addsuffix .bin,$(ELF))
> >
> > +
> >  COBJS  := $(ELF:=.o)
> > +$(error *** COBJS evaluates to [$(COBJS)])
> >
> >  LIB    = $(obj)libstubs.a
> >
> > And the result is:
> >
> > premi # make
> > Makefile:47: *** *** COBJS evaluates to [hello_world.o
> > smc911x_eeprom.o   .o].  Stop.
> >
> > Notice the "empty" .o in the output. This prompted me to use
> > $(strip ...)
> 
> Just after pressing this "ENTER", I tried the following:
> [Moved $(ELF-y) to end of the assignment and kill trailing spaces]
> 
> -ELF := $(ELF-y) $(ELF-$(ARCH)) $(ELF-$(BOARD)) $(ELF-$(CPU))
> +ELF := $(ELF-$(ARCH)) $(ELF-$(BOARD)) $(ELF-$(CPU)) $(ELF-y)
> 
> And it worked! The message for COBJS shows:
> 
> Makefile:47: *** *** COBJS evaluates to [   hello_world.o
>  smc911x_eeprom.o].  Stop.
> 
> So, maybe "make v3.80" has problems with trailing spaces.
> 
> For the fix, I can resubmit with the change shown above OR we could
> keep the original. Let me know your thoughts.

i kind of prefer this method.  if we go with the first method, it needs to 
have a comment there explaining why the strip exists:
# we need the strip to workaround a bug in make-3.80 and whitespace/:=
-mike
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