Re: [PATCH v2] vsprintf: introduce %dE for error constants

[Rasmus Villemoes]

On 29/08/2019 10.12, Petr Mladek wrote:
> On Wed 2019-08-28 21:18:37, Uwe Kleine-König  wrote:

> BTW: I though more about generating or cut&pasting the arrary.
> I can't find any reasonable way how to generate it.

Something like this seems to work, though it probably needs some massage
to be accepted by kbuild folks:

define filechk_errcode.h
	echo '#include <linux/errno.h>' | \
	$(CPP) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) -dM - | \
	grep 'define E' | sort -k3,3n | \
	awk '{print "errcode("$$2")\t/* "$$3" */"}'
endef

include/generated/errcode.h: FORCE
	$(call filechk,errcode.h)

Then one can just #define errcode(foo) ... right before #include
<generated/errcode.h>. It cannot be used to generate cases in a switch()
because some expand to the same number, but that's ok, because I can't
imagine the switch actually generating good or small code. I haven't
checked how or whether it works in a cross-compile situation.

Rasmus