5fc10e76fa
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.