+To Arnd
+To Michal
2017-03-19 6:58 GMT+09:00 Ben Hutchings <ben@xxxxxxxxxxxxxxx>:
> systemtap currently fails to build modules when the kernel source and
> object trees are separate.
>
> systemtap adds something like -I"/usr/share/systemtap/runtime" to
> EXTRA_CFLAGS, and addtree should not adjust this as it's specifying an
> absolute directory. But since make has no understanding of shell
> quoting, it does anyway.
>
> For a long time this didn't matter, because addtree would still emit
> the original -I option after the adjusted one. However, commit
> db547ef19064 ("Kbuild: don't add obj tree in additional includes")
> changed it to remove the original -I option.
>
> Remove quotes (both double and single) before matching against the
> excluded patterns.
>
> References: https://bugs.debian.org/856474
> Reported-and-tested-by: Jack Henschel <jackdev@xxxxxxxxxxx>
> Reported-and-tested-by: Ritesh Raj Sarraf <rrs@xxxxxxxxxx>
> Fixes: db547ef19064 ("Kbuild: don't add obj tree in additional includes")
> Cc: stable@xxxxxxxxxxxxxxx # 4.8+
> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> ---
> --- a/scripts/Kbuild.include
> +++ b/scripts/Kbuild.include
> @@ -207,7 +207,7 @@ hdr-inst := -f $(srctree)/scripts/Makefi
> # Prefix -I with $(srctree) if it is not an absolute path.
> # skip if -I has no parameter
> addtree = $(if $(patsubst -I%,%,$(1)), \
> -$(if $(filter-out -I/% -I./% -I../%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
> +$(if $(filter-out -I/% -I./% -I../%,$(subst $(quote),,$(subst $(squote),,$(1)))),$(patsubst -I%,-I$(srctree)/%,$(1)),$(1)))
>
> # Find all -I options and call addtree
> flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
I have been thinking about this patch.
We touched addtree every time a new problem popped up.
It would be easy to pick up this patch,
but it looks like a crazy idea
to play pattern-matching in the addtree even more.
[1] -Ifoo/bar/baz
[2] -I"foo/bar/baz"
[3] -I foo/bar/baz (whitespace(s) after -I)
All of these are valid notation,
and should be handled in the same way.
However, addtree expects only [1],
(then this patch is going to add [2] in the soup).
Each Makefile knows it wants to see
additional headers in the source tree, or objtree.
I am guessing the right approach in a long run is,
we require -I to specify $(srctree) or $(objtree) explicitly.
ccflags-y := -I$(srctree)/foo/bar/baz
or
ccflags-y := -I$(objtree)/foo/bar/baz
(For the latter, we can omit $(objtree)/ as it is ./)
Then, delete $(call flags,_c_flags) after the conversion.
Any comments?
--
Best Regards
Masahiro Yamada