[PATCH 1/4] kbuild: merge scripts/mkmakefile to top Makefile

[PATCH 1/4] kbuild: merge scripts/mkmakefile to top Makefile

[Masahiro Yamada]

scripts/mkmakefile is simple enough to be merged in the Makefile.

Use $(call cmd,...) to show the log instead of doing it in the
shell script.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 Makefile           | 15 ++++++++++++---
 scripts/mkmakefile | 17 -----------------
 2 files changed, 12 insertions(+), 20 deletions(-)
 delete mode 100755 scripts/mkmakefile

diff --git a/Makefile b/Makefile
index 15b6476d0f89..50776cc3e894 100644
--- a/Makefile
+++ b/Makefile
@@ -544,14 +544,24 @@ scripts_basic:
 	$(Q)rm -f .tmp_quiet_recordmcount
 
 PHONY += outputmakefile
+ifdef building_out_of_srctree
 # Before starting out-of-tree build, make sure the source tree is clean.
 # outputmakefile generates a Makefile in the output directory, if using a
 # separate output directory. This allows convenient use of make in the
 # output directory.
 # At the same time when output Makefile generated, generate .gitignore to
 # ignore whole output directory
-outputmakefile:
-ifdef building_out_of_srctree
+
+quiet_cmd_makefile = GEN     $@
+      cmd_makefile = { \
+	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
+	echo "include $(srctree)/Makefile"; \
+	} > $@
+
+Makefile: FORCE
+	$(call cmd,makefile)
+
+outputmakefile: Makefile
 	$(Q)if [ -f $(srctree)/.config -o \
 		 -d $(srctree)/include/config -o \
 		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
@@ -562,7 +572,6 @@ ifdef building_out_of_srctree
 		false; \
 	fi
 	$(Q)ln -fsn $(srctree) source
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 	$(Q)test -e .gitignore || \
 	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 endif
diff --git a/scripts/mkmakefile b/scripts/mkmakefile
deleted file mode 100755
index 1cb174751429..000000000000
--- a/scripts/mkmakefile
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-# Generates a small Makefile used in the root of the output
-# directory, to allow make to be started from there.
-# The Makefile also allow for more convinient build of external modules
-
-# Usage
-# $1 - Kernel src directory
-
-if [ "${quiet}" != "silent_" ]; then
-	echo "  GEN     Makefile"
-fi
-
-cat << EOF > Makefile
-# Automatically generated by $0: don't edit
-include $1/Makefile
-EOF
-- 
2.27.0

[PATCH 2/4] init: use $(call cmd,) for generating include/generated/compile.h

[Masahiro Yamada]

The 'cmd' macro shows the short log only when $(quiet) is quiet_.
Do not do it manually.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 init/Makefile | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/init/Makefile b/init/Makefile
index 6bc37f64b361..2846113677ee 100644
--- a/init/Makefile
+++ b/init/Makefile
@@ -27,11 +27,11 @@ $(obj)/version.o: include/generated/compile.h
 # mkcompile_h will make sure to only update the
 # actual file if its content has changed.
 
-       chk_compile.h = :
- quiet_chk_compile.h = echo '  CHK     $@'
-silent_chk_compile.h = :
-include/generated/compile.h: FORCE
-	@$($(quiet)chk_compile.h)
-	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@	\
+quiet_cmd_compile.h = CHK     $@
+      cmd_compile.h = \
+	$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@	\
 	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)"	\
 	"$(CONFIG_PREEMPT_RT)" $(CONFIG_CC_VERSION_TEXT) "$(LD)"
+
+include/generated/compile.h: FORCE
+	$(call cmd,compile.h)
-- 
2.27.0

[PATCH 3/4] kbuild: sink stdout from cmd for silent build

[Masahiro Yamada]

When building with 'make -s', no output to stdout should be printed.

As Arnd Bergmann reported [1], mkimage shows the detailed information
of the generated images.

I think this should be done by the 'cmd' macro instead of by individual
scripts.

Insert 'exec >/dev/null;' in order to redirect stdout to /dev/null for
silent builds.

[Note about this implementation]

'exec >/dev/null;' may look somewhat tricky, but this has a reason.

At first, I tried this:

  cmd = @set -e; $(echo-cmd) $(cmd_$(1)) >/dev/null

Appending '>/dev/null' is a commonly used way for redirection, but it
would not work if $(cmd_$(1)) itself contains a redirection.

For example, cmd_wrap in scripts/Makefile.asm-generic redirects the
output from the 'echo' command into the target file.

'$(cmd_$(1)) >/dev/null' would be expanded into:

  echo "#include <asm-generic/$*.h>" > $@ >/dev/null

Then, the target file gets empty because the string will go to /dev/null
instead of $@.

Next, I tried this:

  cmd = @set -e; $(echo-cmd) { $(cmd_$(1)); } >/dev/null

The form above would be expanded into:

  { echo "#include <asm-generic/$*.h>" > $@; } >/dev/null

This works as expected. However, it would be a syntax error if
$(cmd_$(1)) is empty.

When CONFIG_TRIM_UNUSED_KSYMS is disabled, $(call cmd,gen_ksymdeps) in
scripts/Makefile.build would be expanded into:

  set -e;  { ; } >/dev/null

..., which causes an syntax error.

The following does not work for the same reason.

  cmd = @set -e; $(echo-cmd) ( $(cmd_$(1)) ) >/dev/null

So, finally I adopted:

  cmd = @set -e; $(echo-cmd) exec >/dev/null; $(cmd_$(1))

[1]: https://lore.kernel.org/lkml/20210514135752.2910387-1-arnd@kernel.org/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 scripts/Kbuild.include | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 82dd1b65b7a8..f247e691562d 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -90,8 +90,13 @@ clean := -f $(srctree)/scripts/Makefile.clean obj
 echo-cmd = $(if $($(quiet)cmd_$(1)),\
 	echo '  $(call escsq,$($(quiet)cmd_$(1)))$(echo-why)';)
 
+# sink stdout for 'make -s'
+       redirect :=
+ quiet_redirect :=
+silent_redirect := exec >/dev/null;
+
 # printing commands
-cmd = @set -e; $(echo-cmd) $(cmd_$(1))
+cmd = @set -e; $(echo-cmd) $($(quiet)redirect) $(cmd_$(1))
 
 ###
 # if_changed      - execute command if any prerequisite is newer than
-- 
2.27.0

[PATCH 4/4] kbuild: clean up ${quiet} checks in shell scripts

[Masahiro Yamada]

There were efforts to make 'make -s' really silent when it is a
warning-free build.

The conventional way was to let scripts check ${quiet}, and if it
is 'silent_', suppress the output by their own.

With the previous commit, the 'cmd' takes care of it now. The 'cmd' is
also invoked from if_changed, if_changed_dep, and if_changed_rule.

You can omit ${quiet} checks in shell scripts when they are invoked
from the 'cmd' macro.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 kernel/gen_kheaders.sh  | 4 +---
 scripts/link-vmlinux.sh | 4 +---
 scripts/mkcompile_h     | 4 +---
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
index 34a1dc2abc7d..1966a749e0d9 100755
--- a/kernel/gen_kheaders.sh
+++ b/kernel/gen_kheaders.sh
@@ -56,9 +56,7 @@ if [ -f kernel/kheaders.md5 ] &&
 		exit
 fi
 
-if [ "${quiet}" != "silent_" ]; then
-       echo "  GEN     $tarfile"
-fi
+echo "  GEN     $tarfile"
 
 rm -rf $cpio_dir
 mkdir $cpio_dir
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index f4de4c97015b..3b342b0b0b38 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -38,9 +38,7 @@ LDFLAGS_vmlinux="$3"
 # Will be supressed by "make -s"
 info()
 {
-	if [ "${quiet}" != "silent_" ]; then
-		printf "  %-7s %s\n" "${1}" "${2}"
-	fi
+	printf "  %-7s %s\n" "${1}" "${2}"
 }
 
 # Generate a linker script to ensure correct ordering of initcalls.
diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
index 4ae735039daf..06bbf4c2c66c 100755
--- a/scripts/mkcompile_h
+++ b/scripts/mkcompile_h
@@ -9,8 +9,6 @@ PREEMPT_RT=$5
 CC_VERSION="$6"
 LD=$7
 
-vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
-
 # Do not expand names
 set -f
 
@@ -82,7 +80,7 @@ if [ -r $TARGET ] && \
       cmp -s .tmpver.1 .tmpver.2; then
    rm -f .tmpcompile
 else
-   vecho "  UPD     $TARGET"
+   echo "  UPD     $TARGET"
    mv -f .tmpcompile $TARGET
 fi
 rm -f .tmpver.1 .tmpver.2
-- 
2.27.0

Re: [PATCH 1/4] kbuild: merge scripts/mkmakefile to top Makefile

[Masahiro Yamada]

On Mon, May 17, 2021 at 4:03 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> scripts/mkmakefile is simple enough to be merged in the Makefile.
>
> Use $(call cmd,...) to show the log instead of doing it in the
> shell script.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---

Applied to linux-kbuild.


>  Makefile           | 15 ++++++++++++---
>  scripts/mkmakefile | 17 -----------------
>  2 files changed, 12 insertions(+), 20 deletions(-)
>  delete mode 100755 scripts/mkmakefile
>
> diff --git a/Makefile b/Makefile
> index 15b6476d0f89..50776cc3e894 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -544,14 +544,24 @@ scripts_basic:
>         $(Q)rm -f .tmp_quiet_recordmcount
>
>  PHONY += outputmakefile
> +ifdef building_out_of_srctree
>  # Before starting out-of-tree build, make sure the source tree is clean.
>  # outputmakefile generates a Makefile in the output directory, if using a
>  # separate output directory. This allows convenient use of make in the
>  # output directory.
>  # At the same time when output Makefile generated, generate .gitignore to
>  # ignore whole output directory
> -outputmakefile:
> -ifdef building_out_of_srctree
> +
> +quiet_cmd_makefile = GEN     $@
> +      cmd_makefile = { \
> +       echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
> +       echo "include $(srctree)/Makefile"; \
> +       } > $@
> +
> +Makefile: FORCE
> +       $(call cmd,makefile)
> +
> +outputmakefile: Makefile
>         $(Q)if [ -f $(srctree)/.config -o \
>                  -d $(srctree)/include/config -o \
>                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
> @@ -562,7 +572,6 @@ ifdef building_out_of_srctree
>                 false; \
>         fi
>         $(Q)ln -fsn $(srctree) source
> -       $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
>         $(Q)test -e .gitignore || \
>         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
>  endif
> diff --git a/scripts/mkmakefile b/scripts/mkmakefile
> deleted file mode 100755
> index 1cb174751429..000000000000
> --- a/scripts/mkmakefile
> +++ /dev/null
> @@ -1,17 +0,0 @@
> -#!/bin/sh
> -# SPDX-License-Identifier: GPL-2.0
> -# Generates a small Makefile used in the root of the output
> -# directory, to allow make to be started from there.
> -# The Makefile also allow for more convinient build of external modules
> -
> -# Usage
> -# $1 - Kernel src directory
> -
> -if [ "${quiet}" != "silent_" ]; then
> -       echo "  GEN     Makefile"
> -fi
> -
> -cat << EOF > Makefile
> -# Automatically generated by $0: don't edit
> -include $1/Makefile
> -EOF
> --
> 2.27.0
>


-- 
Best Regards
Masahiro Yamada