Re: [Qemu-devel] [PATCH] rules: don't try to create missing include dirs

[Peter Maydell]

On 6 February 2017 at 11:29, Daniel P. Berrange <address@hidden> wrote:
> In
>
>   commit ba78db44f6532d66a1e704bd44613e841baa2fc5
>   Author: Daniel P. Berrange <address@hidden>
>   Date:   Wed Jan 25 16:14:10 2017 +0000
>
>   make: move top level dir to end of include search path
>
> The dir $(BUILD_DIR)/$(@D) was added to the include
> path. This would sometimes point to a non-existant
> directory, if the sub-dir in question did not contain
> any target-independant files (eg tcg/). To deal with
> this the rules.mak attempted to create the directory.
>
> While this was succesful, it also caused accidental
> creation of files in the parent of the build dir.
> e.g. when building common source files into target
> specific output files.

Aha, that's where those directories came from!

> Rather than trying to workaround this, just revert
> the code that attempted to mkdir the missing include
> directories. Instead just turn off the compiler warning
> in question as the missing dir is expected & harmless
> in general.
>
> Signed-off-by: Daniel P. Berrange <address@hidden>
> ---
>  configure | 2 +-
>  rules.mak | 1 -
>  2 files changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/configure b/configure
> index 86fd833..6325339 100755
> --- a/configure
> +++ b/configure
> @@ -1474,7 +1474,7 @@ fi
>
>  gcc_flags="-Wold-style-declaration -Wold-style-definition -Wtype-limits"
>  gcc_flags="-Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers 
> $gcc_flags"
> -gcc_flags="-Wmissing-include-dirs -Wempty-body -Wnested-externs $gcc_flags"
> +gcc_flags="-Wno-missing-include-dirs -Wempty-body -Wnested-externs 
> $gcc_flags"
>  gcc_flags="-Wendif-labels -Wno-shift-negative-value $gcc_flags"
>  gcc_flags="-Wno-initializer-overrides $gcc_flags"
>  gcc_flags="-Wno-string-plus-int $gcc_flags"
> diff --git a/rules.mak b/rules.mak
> index 575a3af..83d6dd1 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -374,7 +374,6 @@ define unnest-vars
>                  $(eval $(o:%.mo=%$(DSOSUF)): module-common.o $($o-objs)),
>                  $(error $o added in $v but $o-objs is not set)))
>          $(shell mkdir -p ./ $(sort $(dir $($v))))
> -        $(shell cd $(BUILD_DIR) && mkdir -p ./ $(sort $(dir $($v))))

I know this is the same syntax as the existing line above
and we're deleting it anyway, but what does it actually do?
When does telling mkdir to create "./" make sense?

thanks
-- PMM