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
the latest GNU Make.

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
  ifneq ($(SUBMAKE),1)
  MAKEFLAGS += --no-print-directory
  all: ; $(MAKE) SUBMAKE=1
  else
  all: ; :
  endif

[before 8f9e7722ff0f]

  $ make -C /tmp
  make: Entering directory '/tmp'
  make SUBMAKE=1
  :
  make: Leaving directory '/tmp'

[after 8f9e7722ff0f]

  $ make -C /tmp
  make SUBMAKE=1
  :

Previously, the effect of --no-print-directory was delayed until Kbuild
started the directory descending, but it is no longer true with GNU Make
4.4.1.

This commit adds one more recursion to cater to GNU Make >= 4.4.1.

When Kbuild needs to change the working directory, __submake will be
executed twice.

  __submake without --no-print-directory  --> show "Entering directory ..."
  __submake with    --no-print-directory  --> parse the rest of Makefile

We end up with one more recursion than needed for GNU Make < 4.4.1, but
I do not want to complicate the version check.

Reported-by: David Howells <dhowells@redhat.com>
Closes: https://lore.kernel.org/all/2427604.1686237298@warthog.procyon.org.uk/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nicolas Schier <n.schier@avm.de>

0 files changed, 0 insertions, 0 deletions