When TARGET_CFLAGS (or _LDFLAGS or _CXXFLAGS) are empty, but were
constructed by appending other variables, like:
TARGET_CFLAGS = $(SOMETHING) $(SOMETHING_ELSE)
and both variables are empty, then $(TARGET_CFLAGS) is _not_ the
null-string; it's value is a string made of a single space.
This means that the construct:
$(if $(TARGET_CFLAGS),true,false)
will in fact return 'true'.
In our case, it means that we will call:
`printf '"%s", ' `
which expands to just:
"",
which we are then happy to insert as-is in the generated
cross-compilation.conf.
Then meson, will happily call the compiler with an empty argument.
The compiler is less happy, though:
arm-none-linux-gnueabi-gcc: error: : No such file or directory
And this is not even trivial to debug either... The only clue being that
there seems to be something missing between ': :'
We fix that testing the $(strip)ed value. We can still pass the
non-$(strip) expansion, because the shell will just do it for us, and we
are then sure there is at least one non-blank word in there.
Thanks a lot to Adam for his invaluable help debugging this!
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Adam Duskett <aduskett@gmail.com>
Cc: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit e9de6d9e0a)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
721208a871