[U-Boot] [PATCH V3] Makefile: remove BUILD_TAG from KBUILD_CFLAGS
From: Stephen Warren swarren@nvidia.com
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, all files get rebuilt. In a continuous integration environment, the value will change every build. This wastes time, assuming that incremental builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS for just the one file that uses it. This does have the disadvantage that if any other files want to use the flag, we'll need to duplicate this custom CFLAGS setup logic. However, it seems unlikely we'll need this.
An alternative would be to add BUILD_TAG to the "local version" and remove the special case code from display_options.c. However, that would affect the format of the U-Boot signon message, which may negatively affect people looking for specific data there. The approach of using file-specific CFLAGS was suggested by Masahiro Yamada.
Signed-off-by: Stephen Warren swarren@nvidia.com --- v3: Undo accidental removal of bch.o. v2: Set CFLAGS on display_options.c rather than modifying scripts/setlocalversion to add BUILD_TAG to the local version. --- Makefile | 4 ---- lib/Makefile | 1 + 2 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/Makefile b/Makefile index 42fad45afee1..2265b8995a7b 100644 --- a/Makefile +++ b/Makefile @@ -562,10 +562,6 @@ else KBUILD_CFLAGS += -O2 endif
-ifdef BUILD_TAG -KBUILD_CFLAGS += -DBUILD_TAG='"$(BUILD_TAG)"' -endif - KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks)
diff --git a/lib/Makefile b/lib/Makefile index dd36f25b2a32..1e21bcc4c75a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -67,6 +67,7 @@ obj-$(CONFIG_ADDR_MAP) += addr_map.o obj-y += hashtable.o obj-y += errno.o obj-y += display_options.o +CFLAGS_display_options.o := $(if $(BUILD_TAG),-DBUILD_TAG='"$(BUILD_TAG)"') obj-$(CONFIG_BCH) += bch.o obj-y += crc32.o obj-y += ctype.o
On Wed, Feb 10, 2016 at 03:16:19PM -0700, Stephen Warren wrote:
From: Stephen Warren swarren@nvidia.com
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, all files get rebuilt. In a continuous integration environment, the value will change every build. This wastes time, assuming that incremental builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS for just the one file that uses it. This does have the disadvantage that if any other files want to use the flag, we'll need to duplicate this custom CFLAGS setup logic. However, it seems unlikely we'll need this.
An alternative would be to add BUILD_TAG to the "local version" and remove the special case code from display_options.c. However, that would affect the format of the U-Boot signon message, which may negatively affect people looking for specific data there. The approach of using file-specific CFLAGS was suggested by Masahiro Yamada.
Signed-off-by: Stephen Warren swarren@nvidia.com
Reviewed-by: Tom Rini trini@konsulko.com
2016-02-11 7:16 GMT+09:00 Stephen Warren swarren@wwwdotorg.org:
From: Stephen Warren swarren@nvidia.com
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, all files get rebuilt. In a continuous integration environment, the value will change every build. This wastes time, assuming that incremental builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS for just the one file that uses it. This does have the disadvantage that if any other files want to use the flag, we'll need to duplicate this custom CFLAGS setup logic. However, it seems unlikely we'll need this.
An alternative would be to add BUILD_TAG to the "local version" and remove the special case code from display_options.c. However, that would affect the format of the U-Boot signon message, which may negatively affect people looking for specific data there. The approach of using file-specific CFLAGS was suggested by Masahiro Yamada.
Signed-off-by: Stephen Warren swarren@nvidia.com
v3: Undo accidental removal of bch.o. v2: Set CFLAGS on display_options.c rather than modifying scripts/setlocalversion to add BUILD_TAG to the local version.
Reviewed-by: Masahiro Yamada yamada.masahiro@socionext.com
On 11 February 2016 at 00:59, Masahiro Yamada yamada.masahiro@socionext.com wrote:
2016-02-11 7:16 GMT+09:00 Stephen Warren swarren@wwwdotorg.org:
From: Stephen Warren swarren@nvidia.com
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, all files get rebuilt. In a continuous integration environment, the value will change every build. This wastes time, assuming that incremental builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS for just the one file that uses it. This does have the disadvantage that if any other files want to use the flag, we'll need to duplicate this custom CFLAGS setup logic. However, it seems unlikely we'll need this.
An alternative would be to add BUILD_TAG to the "local version" and remove the special case code from display_options.c. However, that would affect the format of the U-Boot signon message, which may negatively affect people looking for specific data there. The approach of using file-specific CFLAGS was suggested by Masahiro Yamada.
Signed-off-by: Stephen Warren swarren@nvidia.com
v3: Undo accidental removal of bch.o. v2: Set CFLAGS on display_options.c rather than modifying scripts/setlocalversion to add BUILD_TAG to the local version.
Reviewed-by: Masahiro Yamada yamada.masahiro@socionext.com
Acked-by: Simon Glass sjg@chromium.org
On Wed, Feb 10, 2016 at 03:16:19PM -0700, Stephen Warren wrote:
From: Stephen Warren swarren@nvidia.com
If BUILD_TAG is part of KBUILD_CFLAGS, then any time the value changes, all files get rebuilt. In a continuous integration environment, the value will change every build. This wastes time, assuming that incremental builds would otherwise occur.
To solve this, remove BUILD_TAG from KBUILD_CFLAGS and add it to CFLAGS for just the one file that uses it. This does have the disadvantage that if any other files want to use the flag, we'll need to duplicate this custom CFLAGS setup logic. However, it seems unlikely we'll need this.
An alternative would be to add BUILD_TAG to the "local version" and remove the special case code from display_options.c. However, that would affect the format of the U-Boot signon message, which may negatively affect people looking for specific data there. The approach of using file-specific CFLAGS was suggested by Masahiro Yamada.
Signed-off-by: Stephen Warren swarren@nvidia.com Reviewed-by: Tom Rini trini@konsulko.com Reviewed-by: Masahiro Yamada yamada.masahiro@socionext.com Acked-by: Simon Glass sjg@chromium.org
Applied to u-boot/master, thanks!
participants (4)
-
Masahiro Yamada -
Simon Glass -
Stephen Warren -
Tom Rini