Makefile: remove BUILD_TAG from KBUILD_CFLAGS

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

Signed-off-by Stephen Warren <[email protected]>

---
  Makefile                | 4 ----
  lib/display_options.c   | 4 ----
  scripts/setlocalversion | 4 ++++
  3 files changed, 4 insertions(+), 8 deletions(-)

Makefile +0 -4

index 42fad45afee1..2265b8995a7b 100644
@@ -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)
 

lib/display_options.c +0 -4

index 29343fc00e3f..5dcdf4e429af 100644
@@ -15,11 +15,7 @@
 
  int display_options (void)
  {
-#if defined(BUILD_TAG)
-	printf ("\n\n%s, Build: %s\n\n", version_string, BUILD_TAG);
-#else
  	printf ("\n\n%s\n\n", version_string);
-#endif
  	return 0;
  }
 

scripts/setlocalversion +4 -0

index 63d91e22ed7c..4ef6603b5c27 100755
@@ -171,4 +171,8 @@ else
  	fi
  fi
 
+if test -n "${BUILD_TAG}"; then
+	res="$res-${BUILD_TAG}"
+fi
+
  echo "$res"

Quoted 15 lines · Stephen Warren

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 28 lines · James Chargin

Quoted 15 lines · Stephen Warren

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Quoted 36 lines · Tom Rini

Quoted 28 lines · James Chargin

Quoted 15 lines · Stephen Warren

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 5 lines

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Do you mean you think people currently rely upon the ", Build: xxx" format in the sign-on message, and the "version" command /not/ printing that information?

If so, I'll go back to trying to work out how to get Kbuild to transfer the environment variable into a CONFIG_XXX option so that modifying it only causes a rebuild of the one file that uses the value.

I could easily hack my Jenkins build scripts to unset that variable, but I do like the test logs showing the Jenkins build ID so I can validate the correct binary actually ran. So I'd rather not simply remove the tag from the message.

Quoted 43 lines · Stephen Warren

Quoted 36 lines · Tom Rini

Quoted 28 lines · James Chargin

Quoted 15 lines · Stephen Warren

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 5 lines

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Quoted 3 lines

Do you mean you think people currently rely upon the ", Build: xxx" format in the sign-on message, and the "version" command /not/ printing that information?

I mean that the places we construct strings like this are likely relied upon by people, yes.

Quoted 4 lines

If so, I'll go back to trying to work out how to get Kbuild to transfer the environment variable into a CONFIG_XXX option so that modifying it only causes a rebuild of the one file that uses the value.

A quick peak and I think that:
(a) LOCALVERSION needs a little love somewhere to ensure that it in fact does not exceed 64 characters (and pushing upstream to the kernel anything relevant here)
(b) Yes, adjusting BUILD_TAG into CONFIG_BUILD_TAG is probably the best answer and probably not even that bad. I don't think we need an automagic conversion, just noting it in the release emails and the sudden lack of Build: should get people that are using it to update their scripts.

Quoted 56 lines · Tom Rini

Quoted 43 lines · Stephen Warren

Quoted 36 lines · Tom Rini

Quoted 28 lines · James Chargin

Quoted 15 lines · Stephen Warren

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 5 lines

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Quoted 3 lines

Do you mean you think people currently rely upon the ", Build: xxx" format in the sign-on message, and the "version" command /not/ printing that information?

I mean that the places we construct strings like this are likely relied upon by people, yes.

Quoted 4 lines

If so, I'll go back to trying to work out how to get Kbuild to transfer the environment variable into a CONFIG_XXX option so that modifying it only causes a rebuild of the one file that uses the value.

Quoted 9 lines

A quick peak and I think that:
(a) LOCALVERSION needs a little love somewhere to ensure that it in fact does not exceed 64 characters (and pushing upstream to the kernel anything relevant here)
(b) Yes, adjusting BUILD_TAG into CONFIG_BUILD_TAG is probably the best answer and probably not even that bad. I don't think we need an automagic conversion, just noting it in the release emails and the sudden lack of Build: should get people that are using it to update their scripts.

Unfortunately, simply renaming the variable won't work; Kconfig/Kbuild need to know something about it in order to do their rebuild-only-on-change magic (and the value must be removed from CFLAGS too). I was having a hard time getting that to work, but I'll take another look.

Quoted 67 lines · Tom Rini

Quoted 56 lines · Stephen Warren

Quoted 43 lines · Tom Rini

Quoted 36 lines · James Chargin

Quoted 28 lines · Stephen Warren

Quoted 15 lines

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 5 lines

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Quoted 3 lines

Do you mean you think people currently rely upon the ", Build: xxx" format in the sign-on message, and the "version" command /not/ printing that information?

I mean that the places we construct strings like this are likely relied upon by people, yes.

Quoted 4 lines

If so, I'll go back to trying to work out how to get Kbuild to transfer the environment variable into a CONFIG_XXX option so that modifying it only causes a rebuild of the one file that uses the value.

Quoted 9 lines

A quick peak and I think that:
(a) LOCALVERSION needs a little love somewhere to ensure that it in fact does not exceed 64 characters (and pushing upstream to the kernel anything relevant here)
(b) Yes, adjusting BUILD_TAG into CONFIG_BUILD_TAG is probably the best answer and probably not even that bad. I don't think we need an automagic conversion, just noting it in the release emails and the sudden lack of Build: should get people that are using it to update their scripts.

Quoted 5 lines

Unfortunately, simply renaming the variable won't work; Kconfig/Kbuild need to know something about it in order to do their rebuild-only-on-change magic (and the value must be removed from CFLAGS too). I was having a hard time getting that to work, but I'll take another look.

Right. Can't we just make it another string Kconfig like LOCALVERSION, not need to pass -D.... and then it's set via poking the config file by CI, etc?

2016-02-10 3:18 GMT+09:00 Tom Rini <[email protected]>:

Quoted 74 lines · Stephen Warren

Quoted 67 lines · Tom Rini

Quoted 56 lines · Stephen Warren

Quoted 43 lines · Tom Rini

Quoted 36 lines · James Chargin

Quoted 28 lines · Stephen Warren

Quoted 15 lines

From: Stephen Warren <[email protected]>

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_FLAGS and add it to the end of "local version".

This has other advantages too:
- The special case for BUILD_TAG in display_options.c can be removed.
- The version printed by the "version" command exactly matches what is printed at boot.

Quoted 5 lines

Old sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b (Feb ...), Build: bar-bas

New sign-on message:
U-Boot 2016.03-rc1-00044-g4085db5e767b-bar-baz (Feb ...)

I would urge this not be done. The display of the BUILD_TAG on startup is pretty useful in my environment. It's been there for a long time and some of my users have grown used to it.

Quoted 6 lines

Of all the parts of the sign-on message, I'd rather the git hash go away than the BUILD_TAG. None of my users really care about the level of detail of the git hash and won't spend the time required to use this hash to determine if they have the version they want. (Some don't have a repo clone, and don't care to, and so can't easily make the correspondence even if they wanted to).

Quoted 5 lines

Yeah, I think this is too widely used of a thing to change. FWIW, I really like githashes since it means you can see if $random-binary is something you have in $vendor-tree or not. So I think in this case, NAK on the patch and maybe need to poke Travis-CI on how to or not to tag things?

Quoted 3 lines

Do you mean you think people currently rely upon the ", Build: xxx" format in the sign-on message, and the "version" command /not/ printing that information?

I mean that the places we construct strings like this are likely relied upon by people, yes.

Quoted 4 lines

If so, I'll go back to trying to work out how to get Kbuild to transfer the environment variable into a CONFIG_XXX option so that modifying it only causes a rebuild of the one file that uses the value.

Quoted 9 lines

A quick peak and I think that:
(a) LOCALVERSION needs a little love somewhere to ensure that it in fact does not exceed 64 characters (and pushing upstream to the kernel anything relevant here)
(b) Yes, adjusting BUILD_TAG into CONFIG_BUILD_TAG is probably the best answer and probably not even that bad. I don't think we need an automagic conversion, just noting it in the release emails and the sudden lack of Build: should get people that are using it to update their scripts.

Quoted 5 lines

Unfortunately, simply renaming the variable won't work; Kconfig/Kbuild need to know something about it in order to do their rebuild-only-on-change magic (and the value must be removed from CFLAGS too). I was having a hard time getting that to work, but I'll take another look.

Quoted 3 lines

Right. Can't we just make it another string Kconfig like LOCALVERSION, not need to pass -D.... and then it's set via poking the config file by CI, etc?

We are discussing two things together.

[1] avoid full build
[2] change of the version string format and build-flow

Nobody would complain about fixing [1] only. (Feel free to continue discussion if you want [2].)

As Stephen pointed out, KBUILD_CFLAGS is passed to all the C files.

The environment "BUILD_TAG" is only referenced from lib/display_option.c, so how about passing the flag to the file only?

Try the following patch: