Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler

1 files changed, 44 insertions, 1 deletions

diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 6515ebc12b6f..b81b8913a5a3 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -368,6 +368,14 @@ more details, with real examples.
 
 		subdir-ccflags-y := -Werror
 
+    ccflags-remove-y, asflags-remove-y
+	These flags are used to remove particular flags for the compiler,
+	assembler invocations.
+
+	Example::
+
+		ccflags-remove-$(CONFIG_MCOUNT) += -pg
+
     CFLAGS_$@, AFLAGS_$@
 	CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
 	kbuild makefile.
@@ -375,6 +383,9 @@ more details, with real examples.
 	$(CFLAGS_$@) specifies per-file options for $(CC).  The $@
 	part has a literal value which specifies the file that it is for.
 
+	CFLAGS_$@ has the higher priority than ccflags-remove-y; CFLAGS_$@
+	can re-add compiler flags that were removed by ccflags-remove-y.
+
 	Example::
 
 		# drivers/scsi/Makefile
@@ -387,6 +398,9 @@ more details, with real examples.
 	$(AFLAGS_$@) is a similar feature for source files in assembly
 	languages.
 
+	AFLAGS_$@ has the higher priority than asflags-remove-y; AFLAGS_$@
+	can re-add assembler flags that were removed by asflags-remove-y.
+
 	Example::
 
 		# arch/arm/kernel/Makefile
@@ -735,6 +749,10 @@ Both possibilities are described in the following.
 		hostprogs     := lxdialog
 		always-y      := $(hostprogs)
 
+	Kbuild provides the following shorthand for this:
+
+		hostprogs-always-y := lxdialog
+
 	This will tell kbuild to build lxdialog even if not referenced in
 	any rule.
 
@@ -817,7 +835,32 @@ The syntax is quite similar. The difference is to use "userprogs" instead of
 5.4 When userspace programs are actually built
 ----------------------------------------------
 
-	Same as "When host programs are actually built".
+	Kbuild builds userspace programs only when told to do so.
+	There are two ways to do this.
+
+	(1) Add it as the prerequisite of another file
+
+	Example::
+
+		#net/bpfilter/Makefile
+		userprogs := bpfilter_umh
+		$(obj)/bpfilter_umh_blob.o: $(obj)/bpfilter_umh
+
+	$(obj)/bpfilter_umh is built before $(obj)/bpfilter_umh_blob.o
+
+	(2) Use always-y
+
+	Example::
+
+		userprogs := binderfs_example
+		always-y := $(userprogs)
+
+	Kbuild provides the following shorthand for this:
+
+		userprogs-always-y := binderfs_example
+
+	This will tell Kbuild to build binderfs_example when it visits this
+	Makefile.
 
 6 Kbuild clean infrastructure
 =============================