2023-06-10 16:59:28

by Masahiro Yamada

[permalink] [raw]
Subject: [PATCH] kbuild: revive "Entering directory" for Make >= 4.4.1

With commit 9da0763bdd82 ("kbuild: Use relative path when building in
a subdir of the source tree"), compiler messages in out-of-tree builds
include relative paths, which are relative to the build directory, not
the directory where make was started.

To help IDEs/editors find the source files, Kbuild lets GNU Make print
"Entering directory ..." when it changes the working directory. It has
been working fine for a long time, but David reported it is broken with
GNU Make 4.4.1.

The behavior was changed by GNU Make commit 8f9e7722ff0f ("[SV 63537]
Fix setting -w in makefiles"). Previously, setting --no-print-directory
to MAKEFLAGS only affected child makes, but it is now interpreted in
the current make as soon as it is set.

[test code]

$ cat /tmp/Makefile
MAKEFLAGS += --no-print-directory
all: ; :

[before 8f9e7722ff0f]

$ make -C /tmp
make: Entering directory '/tmp'
:
make: Leaving directory '/tmp'

[after 8f9e7722ff0f]

$ make -C /tmp
:

This commit restores the previous behavior for GNU Make >= 4.4.1.

Reported-by: David Howells <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Signed-off-by: Masahiro Yamada <[email protected]>
---

Makefile | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index cc3fe09c4dec..9868186deb66 100644
--- a/Makefile
+++ b/Makefile
@@ -191,7 +191,7 @@ endif # ifneq ($(KBUILD_OUTPUT),)

ifeq ($(abs_objtree),$(CURDIR))
# Suppress "Entering directory ..." unless we are changing the work directory.
-MAKEFLAGS += --no-print-directory
+no-print-directory := --no-print-directory
else
need-sub-make := 1
endif
@@ -203,6 +203,15 @@ ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
$(error source directory cannot contain spaces or colons)
endif

+ifneq ($(filter jobserver-fifo,$(.FEATURES)),) # test $(MAKE_VERSION) >= 4.4
+ifeq ($(filter 4.4,$(MAKE_VERSION)),)
+# With GNU Make >= 4.4.1, a change in MAKEFLAGS takes effect as soon as it is
+# set. Run __sub-make all the time so that we can pass --no-print-directory
+# via the command line.
+need-sub-make := 1
+endif
+endif
+
ifneq ($(filter 3.%,$(MAKE_VERSION)),)
# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
# We need to invoke sub-make to avoid implicit rules in the top Makefile.
@@ -223,7 +232,8 @@ $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make

# Invoke a second make in the output directory, passing relevant variables
__sub-make:
- $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
+ $(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
+ -f $(abs_srctree)/Makefile $(MAKECMDGOALS)

endif # need-sub-make
endif # sub_make_done
@@ -234,6 +244,8 @@ ifeq ($(need-sub-make),)
# Do not print "Entering directory ...",
# but we want to display it when entering to the output directory
# so that IDEs/editors are able to understand relative filenames.
+# This line is needed to allow Make < 4.4.1 to skip __sub-make.
+# The newer Make versions runs __sub-make before seeing this line.
MAKEFLAGS += --no-print-directory

ifeq ($(abs_srctree),$(abs_objtree))
--
2.39.2



2023-06-14 21:17:39

by Nicolas Schier

[permalink] [raw]
Subject: Re: [PATCH] kbuild: revive "Entering directory" for Make >= 4.4.1

On Sun 11 Jun 2023 01:17:11 +0900, Masahiro Yamada wrote:
> With commit 9da0763bdd82 ("kbuild: Use relative path when building in
> a subdir of the source tree"), compiler messages in out-of-tree builds
> include relative paths, which are relative to the build directory, not
> the directory where make was started.
>
> To help IDEs/editors find the source files, Kbuild lets GNU Make print
> "Entering directory ..." when it changes the working directory. It has
> been working fine for a long time, but David reported it is broken with
> GNU Make 4.4.1.
>
> The behavior was changed by GNU Make commit 8f9e7722ff0f ("[SV 63537]
> Fix setting -w in makefiles"). Previously, setting --no-print-directory
> to MAKEFLAGS only affected child makes, but it is now interpreted in
> the current make as soon as it is set.
>
> [test code]
>
> $ cat /tmp/Makefile
> MAKEFLAGS += --no-print-directory
> all: ; :
>
> [before 8f9e7722ff0f]
>
> $ make -C /tmp
> make: Entering directory '/tmp'
> :
> make: Leaving directory '/tmp'
>
> [after 8f9e7722ff0f]
>
> $ make -C /tmp
> :
>
> This commit restores the previous behavior for GNU Make >= 4.4.1.
>
> Reported-by: David Howells <[email protected]>
> Closes: https://lore.kernel.org/all/[email protected]/
> Signed-off-by: Masahiro Yamada <[email protected]>
> ---
>
> Makefile | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index cc3fe09c4dec..9868186deb66 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -191,7 +191,7 @@ endif # ifneq ($(KBUILD_OUTPUT),)
>
> ifeq ($(abs_objtree),$(CURDIR))
> # Suppress "Entering directory ..." unless we are changing the work directory.
> -MAKEFLAGS += --no-print-directory
> +no-print-directory := --no-print-directory
> else
> need-sub-make := 1
> endif
> @@ -203,6 +203,15 @@ ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
> $(error source directory cannot contain spaces or colons)
> endif
>
> +ifneq ($(filter jobserver-fifo,$(.FEATURES)),) # test $(MAKE_VERSION) >= 4.4

In scripts/Kbuild.include, we use $(intcmp) to check against Make
version >= 4.4, cp. commit fccb3d3eda8d ("kbuild: add
test-{ge,gt,le,lt} macros", 2022-12-11). Might it make sense to use
the same test here too?

> +ifeq ($(filter 4.4,$(MAKE_VERSION)),)
> +# With GNU Make >= 4.4.1, a change in MAKEFLAGS takes effect as soon as it is
> +# set. Run __sub-make all the time so that we can pass --no-print-directory
> +# via the command line.
> +need-sub-make := 1
> +endif
> +endif
> +
> ifneq ($(filter 3.%,$(MAKE_VERSION)),)
> # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
> # We need to invoke sub-make to avoid implicit rules in the top Makefile.
> @@ -223,7 +232,8 @@ $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
>
> # Invoke a second make in the output directory, passing relevant variables
> __sub-make:
> - $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
> + $(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
> + -f $(abs_srctree)/Makefile $(MAKECMDGOALS)

I like that solution, thanks!

Reviewed-by: Nicolas Schier <[email protected]>

>
> endif # need-sub-make
> endif # sub_make_done
> @@ -234,6 +244,8 @@ ifeq ($(need-sub-make),)
> # Do not print "Entering directory ...",
> # but we want to display it when entering to the output directory
> # so that IDEs/editors are able to understand relative filenames.
> +# This line is needed to allow Make < 4.4.1 to skip __sub-make.
> +# The newer Make versions runs __sub-make before seeing this line.
> MAKEFLAGS += --no-print-directory
>
> ifeq ($(abs_srctree),$(abs_objtree))
> --
> 2.39.2

-- Nicolas Schier


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2023-06-15 14:59:39

by Masahiro Yamada

[permalink] [raw]
Subject: Re: [PATCH] kbuild: revive "Entering directory" for Make >= 4.4.1

On Thu, Jun 15, 2023 at 5:34 AM Nicolas Schier <[email protected]> wrote:
>
> On Sun 11 Jun 2023 01:17:11 +0900, Masahiro Yamada wrote:
> > With commit 9da0763bdd82 ("kbuild: Use relative path when building in
> > a subdir of the source tree"), compiler messages in out-of-tree builds
> > include relative paths, which are relative to the build directory, not
> > the directory where make was started.
> >
> > To help IDEs/editors find the source files, Kbuild lets GNU Make print
> > "Entering directory ..." when it changes the working directory. It has
> > been working fine for a long time, but David reported it is broken with
> > GNU Make 4.4.1.
> >
> > The behavior was changed by GNU Make commit 8f9e7722ff0f ("[SV 63537]
> > Fix setting -w in makefiles"). Previously, setting --no-print-directory
> > to MAKEFLAGS only affected child makes, but it is now interpreted in
> > the current make as soon as it is set.
> >
> > [test code]
> >
> > $ cat /tmp/Makefile
> > MAKEFLAGS += --no-print-directory
> > all: ; :
> >
> > [before 8f9e7722ff0f]
> >
> > $ make -C /tmp
> > make: Entering directory '/tmp'
> > :
> > make: Leaving directory '/tmp'
> >
> > [after 8f9e7722ff0f]
> >
> > $ make -C /tmp
> > :
> >
> > This commit restores the previous behavior for GNU Make >= 4.4.1.
> >
> > Reported-by: David Howells <[email protected]>
> > Closes: https://lore.kernel.org/all/[email protected]/
> > Signed-off-by: Masahiro Yamada <[email protected]>
> > ---


Sorry, I retract this patch.
It does not work.

--
Best Regards
Masahiro Yamada