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[v5,00/31] kconfig: move compiler capability tests to Kconfig

Message ID 1527499328-13213-1-git-send-email-yamada.masahiro@socionext.com
Headers show
Series kconfig: move compiler capability tests to Kconfig | expand

Message

Masahiro Yamada May 28, 2018, 9:21 a.m. UTC
[Introduction]

The motivation of this work is to move the compiler option tests to
Kconfig from Makefile.  A number of kernel features require the
compiler support.  Enabling such features blindly in Kconfig ends up
with a lot of nasty build-time testing in Makefiles.  If a chosen
feature turns out unsupported by the compiler, what the build system
can do is either to disable it (silently!) or to forcibly break the
build, despite Kconfig has let the user to enable it.  By moving the
compiler capability tests to Kconfig, Kconfig entries will be visible
only when they are available.

[Major Changes in V5]

V5 removed the complexity unnecessary for Kconfig.

 - In order to make the implementation simpler, I drop the lazy
   argument expansion.
   In V5, parameters are expanded before passed to a function.
   (the same behavior as v3)

 - Replace 'warning', 'error' functions with 'warning-if',
   'error-if' functions.  The new functions are effective
   only when the condition part is 'y'.

 - In V4, '$' must be followed by '$' or '('.
   '$$' meant an escaped '$'.

   V4 caused a build error for ARC architecture due to the
   following line:
   https://github.com/torvalds/linux/blob/v4.17-rc4/arch/arc/Kconfig#L252

   Of course, we could rephrase "D$" to "D cache", but
   I treaked the grammar a little bit.

   Kconfig decided to not support single-letter variable as in "$X".
   Nor curly braces as in "${CC}" are not supported.
   This means variable/function references in Kconfig always start
   with "$(".
   We can use '$' not followed by '(' as-is.
   We do not need the "$$" escape sequence.
   If necessary, we can use a trick to print '$(' verbatim.  See below.

 - Fix a wrong behavior of simply expanded variables.
   V4 expanded simply expanded variables when used, but it should not.

   For example,

   dollar := $
   X := 1
   Y := $(dollar)(X)
   $(info,$(Y))

   V5 prints '$(X)', not '1'.

 - Remove a space after a comma is $( ) context.
   Actually, spaces do not matter in most cases.

   You can write either

      $(cc-option,-fstack-protector)

   or

      $(cc-option, -fstack-protector)

   In fact, both style co-exist in our Makefiles too.
   However, there are some cases where they do matter.

   I remove spaces after commas for consistency.
   If you are unsure, no-space-after-comma is always safe.

[Major Changes in V4]

 - In V4, I slightly change the syntax of a function call.
   I chose grammatical consistency and simplicity.
   Anyway, Kconfig is deviating from Make behavior already.

   In v3, a function call looked like this:

      $(func-name arg1,arg2,arg3)

   In v4, a function is invoked like follows:

      $(func-name,arg1,arg2,arg3)

   The difference is that the function name and the first argument
   are separated by a comma.

 - V3 supported single-letter variable like $X.
   V4 dropped it because we do not need multiple ways to do the
   same thing.
   You must always enclose a variable name like $(X).

 - Support lazy argument expansion.  This is necessary for implementing
   'if', 'and', 'or' functions as in Make.

 - Add more built-in functions:
   'if', 'error', 'filename', 'lineno'

 - Error out if a recursive variable references itself eventually.
   For example,  X = $(X)
   ends up with a circular expansion.  It must be terminated
   since the expansion would continue eternally.

 - Update Documentation and unit-tests, accordingly.

[Major Changes in V3]

This version looks more like Make.

  - Use = operator instead of 'macro' keyword
    to define a user-defined function.

  - 'Recursively expanded variable' is implemented as a side-effect.
     A variable is a function with zero argument.

  - Support simply expanded variable which is defined by := operator

  - Support += operator.
    Probably, this feature will be useful to accumulate compiler flags.
    At least, Clang needs some prerequisite flags such as triplet
    to test other compiler flags.

  - Support $(info ...) and $(warning ...) built-in functions,
    which were useful while I was debugging this.

  - Add documentation

  - Add unit tests

  - Collect helpers to scripts/Kconfig.include

[Old Versions]

V4:  https://lkml.org/lkml/2018/5/17/97
V3:  https://lkml.org/lkml/2018/4/13/37
V2:  https://lkml.org/lkml/2018/2/16/610
V1:  https://lkml.org/lkml/2018/2/16/610
RFC: https://lkml.org/lkml/2018/2/8/429


Masahiro Yamada (31):
  kbuild: remove kbuild cache
  kbuild: remove CONFIG_CROSS_COMPILE support
  kconfig: reference environment variables directly and remove 'option
    env='
  kconfig: remove string expansion in file_lookup()
  kconfig: remove string expansion for mainmenu after yyparse()
  kconfig: remove sym_expand_string_value()
  kconfig: make default prompt of mainmenu less specific
  kconfig: add built-in function support
  kconfig: add 'shell' built-in function
  kconfig: replace $(UNAME_RELEASE) with function call
  kconfig: begin PARAM state only when seeing a command keyword
  kconfig: support user-defined function and recursively expanded
    variable
  kconfig: support simply expanded variable
  kconfig: support append assignment operator
  kconfig: expand lefthand side of assignment statement
  kconfig: add 'info', 'warning-if', and 'error-if' built-in functions
  kconfig: add 'filename' and 'lineno' built-in variables
  kconfig: error out if a recursive variable references itself
  Documentation: kconfig: document a new Kconfig macro language
  kconfig: test: add Kconfig macro language tests
  kconfig: show compiler version text in the top comment
  kconfig: add basic helper macros to scripts/Kconfig.include
  stack-protector: test compiler capability in Kconfig and drop AUTO
    mode
  kconfig: add CC_IS_GCC and GCC_VERSION
  kconfig: add CC_IS_CLANG and CLANG_VERSION
  gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT
  kcov: test compiler capability in Kconfig and correct dependency
  gcc-plugins: move GCC version check for PowerPC to Kconfig
  gcc-plugins: test plugin support in Kconfig and clean up Makefile
  gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST
  Documentation: kconfig: add recommended way to describe compiler
    support

 Documentation/kbuild/kconfig-language.txt          |  26 +-
 Documentation/kbuild/kconfig-macro-language.txt    | 242 +++++++++
 Kconfig                                            |  10 +-
 MAINTAINERS                                        |   3 +-
 Makefile                                           | 105 +---
 arch/Kconfig                                       |  49 +-
 arch/powerpc/Kconfig                               |   2 +-
 arch/sh/Kconfig                                    |   4 +-
 arch/sparc/Kconfig                                 |   4 +-
 arch/um/Kconfig.common                             |   4 -
 arch/x86/Kconfig                                   |  15 +-
 arch/x86/um/Kconfig                                |  10 +-
 init/Kconfig                                       |  40 +-
 kernel/gcov/Kconfig                                |  17 +-
 kernel/gcov/Makefile                               |   2 -
 lib/Kconfig.debug                                  |  11 +-
 scripts/Kbuild.include                             | 101 +---
 scripts/Kconfig.include                            |  30 ++
 scripts/Makefile.gcc-plugins                       |  91 +---
 scripts/Makefile.kcov                              |  10 +-
 scripts/clang-version.sh                           |  18 +-
 scripts/gcc-plugins/Makefile                       |   1 +
 scripts/gcc-x86_32-has-stack-protector.sh          |   7 +-
 scripts/gcc-x86_64-has-stack-protector.sh          |   5 -
 scripts/kconfig/confdata.c                         |  33 +-
 scripts/kconfig/kconf_id.c                         |   1 -
 scripts/kconfig/lkc.h                              |   5 +-
 scripts/kconfig/lkc_proto.h                        |  15 +-
 scripts/kconfig/menu.c                             |   3 -
 scripts/kconfig/preprocess.c                       | 572 +++++++++++++++++++++
 scripts/kconfig/symbol.c                           | 109 ----
 .../tests/no_write_if_dep_unmet/expected_config    |   2 +-
 .../kconfig/tests/preprocess/builtin_func/Kconfig  |  27 +
 .../tests/preprocess/builtin_func/__init__.py      |   9 +
 .../tests/preprocess/builtin_func/expected_stderr  |   5 +
 .../tests/preprocess/builtin_func/expected_stdout  |   1 +
 .../tests/preprocess/circular_expansion/Kconfig    |   5 +
 .../preprocess/circular_expansion/__init__.py      |  11 +
 .../preprocess/circular_expansion/expected_stderr  |   1 +
 scripts/kconfig/tests/preprocess/escape/Kconfig    |  44 ++
 .../kconfig/tests/preprocess/escape/__init__.py    |   8 +
 .../tests/preprocess/escape/expected_stderr        |  10 +
 scripts/kconfig/tests/preprocess/variable/Kconfig  |  53 ++
 .../kconfig/tests/preprocess/variable/__init__.py  |   8 +
 .../tests/preprocess/variable/expected_stderr      |   9 +
 scripts/kconfig/util.c                             |  33 +-
 scripts/kconfig/zconf.l                            |  95 +++-
 scripts/kconfig/zconf.y                            |  46 +-
 48 files changed, 1345 insertions(+), 567 deletions(-)
 create mode 100644 Documentation/kbuild/kconfig-macro-language.txt
 create mode 100644 scripts/Kconfig.include
 create mode 100644 scripts/kconfig/preprocess.c
 create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/Kconfig
 create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/__init__.py
 create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stderr
 create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stdout
 create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/Kconfig
 create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/__init__.py
 create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/expected_stderr
 create mode 100644 scripts/kconfig/tests/preprocess/escape/Kconfig
 create mode 100644 scripts/kconfig/tests/preprocess/escape/__init__.py
 create mode 100644 scripts/kconfig/tests/preprocess/escape/expected_stderr
 create mode 100644 scripts/kconfig/tests/preprocess/variable/Kconfig
 create mode 100644 scripts/kconfig/tests/preprocess/variable/__init__.py
 create mode 100644 scripts/kconfig/tests/preprocess/variable/expected_stderr

-- 
2.7.4

Comments

Masahiro Yamada May 28, 2018, 12:23 p.m. UTC | #1
2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>

> [Introduction]

>

> The motivation of this work is to move the compiler option tests to

> Kconfig from Makefile.  A number of kernel features require the

> compiler support.  Enabling such features blindly in Kconfig ends up

> with a lot of nasty build-time testing in Makefiles.  If a chosen

> feature turns out unsupported by the compiler, what the build system

> can do is either to disable it (silently!) or to forcibly break the

> build, despite Kconfig has let the user to enable it.  By moving the

> compiler capability tests to Kconfig, Kconfig entries will be visible

> only when they are available.

>

> [Major Changes in V5]

>

> V5 removed the complexity unnecessary for Kconfig.

>

>  - In order to make the implementation simpler, I drop the lazy

>    argument expansion.

>    In V5, parameters are expanded before passed to a function.

>    (the same behavior as v3)

>

>  - Replace 'warning', 'error' functions with 'warning-if',

>    'error-if' functions.  The new functions are effective

>    only when the condition part is 'y'.

>

>  - In V4, '$' must be followed by '$' or '('.

>    '$$' meant an escaped '$'.

>

>    V4 caused a build error for ARC architecture due to the

>    following line:

>    https://github.com/torvalds/linux/blob/v4.17-rc4/arch/arc/Kconfig#L252

>

>    Of course, we could rephrase "D$" to "D cache", but

>    I treaked the grammar a little bit.

>

>    Kconfig decided to not support single-letter variable as in "$X".

>    Nor curly braces as in "${CC}" are not supported.

>    This means variable/function references in Kconfig always start

>    with "$(".

>    We can use '$' not followed by '(' as-is.

>    We do not need the "$$" escape sequence.

>    If necessary, we can use a trick to print '$(' verbatim.  See below.

>

>  - Fix a wrong behavior of simply expanded variables.

>    V4 expanded simply expanded variables when used, but it should not.

>

>    For example,

>

>    dollar := $

>    X := 1

>    Y := $(dollar)(X)

>    $(info,$(Y))

>

>    V5 prints '$(X)', not '1'.

>

>  - Remove a space after a comma is $( ) context.

>    Actually, spaces do not matter in most cases.

>

>    You can write either

>

>       $(cc-option,-fstack-protector)

>

>    or

>

>       $(cc-option, -fstack-protector)

>

>    In fact, both style co-exist in our Makefiles too.

>    However, there are some cases where they do matter.

>

>    I remove spaces after commas for consistency.

>    If you are unsure, no-space-after-comma is always safe.

>

> [Major Changes in V4]

>

>  - In V4, I slightly change the syntax of a function call.

>    I chose grammatical consistency and simplicity.

>    Anyway, Kconfig is deviating from Make behavior already.

>

>    In v3, a function call looked like this:

>

>       $(func-name arg1,arg2,arg3)

>

>    In v4, a function is invoked like follows:

>

>       $(func-name,arg1,arg2,arg3)

>

>    The difference is that the function name and the first argument

>    are separated by a comma.

>

>  - V3 supported single-letter variable like $X.

>    V4 dropped it because we do not need multiple ways to do the

>    same thing.

>    You must always enclose a variable name like $(X).

>

>  - Support lazy argument expansion.  This is necessary for implementing

>    'if', 'and', 'or' functions as in Make.

>

>  - Add more built-in functions:

>    'if', 'error', 'filename', 'lineno'

>

>  - Error out if a recursive variable references itself eventually.

>    For example,  X = $(X)

>    ends up with a circular expansion.  It must be terminated

>    since the expansion would continue eternally.

>

>  - Update Documentation and unit-tests, accordingly.

>

> [Major Changes in V3]

>

> This version looks more like Make.

>

>   - Use = operator instead of 'macro' keyword

>     to define a user-defined function.

>

>   - 'Recursively expanded variable' is implemented as a side-effect.

>      A variable is a function with zero argument.

>

>   - Support simply expanded variable which is defined by := operator

>

>   - Support += operator.

>     Probably, this feature will be useful to accumulate compiler flags.

>     At least, Clang needs some prerequisite flags such as triplet

>     to test other compiler flags.

>

>   - Support $(info ...) and $(warning ...) built-in functions,

>     which were useful while I was debugging this.

>

>   - Add documentation

>

>   - Add unit tests

>

>   - Collect helpers to scripts/Kconfig.include

>

> [Old Versions]

>

> V4:  https://lkml.org/lkml/2018/5/17/97

> V3:  https://lkml.org/lkml/2018/4/13/37

> V2:  https://lkml.org/lkml/2018/2/16/610

> V1:  https://lkml.org/lkml/2018/2/16/610

> RFC: https://lkml.org/lkml/2018/2/8/429

>

>

> Masahiro Yamada (31):

>   kbuild: remove kbuild cache

>   kbuild: remove CONFIG_CROSS_COMPILE support

>   kconfig: reference environment variables directly and remove 'option

>     env='

>   kconfig: remove string expansion in file_lookup()

>   kconfig: remove string expansion for mainmenu after yyparse()

>   kconfig: remove sym_expand_string_value()

>   kconfig: make default prompt of mainmenu less specific

>   kconfig: add built-in function support

>   kconfig: add 'shell' built-in function

>   kconfig: replace $(UNAME_RELEASE) with function call

>   kconfig: begin PARAM state only when seeing a command keyword

>   kconfig: support user-defined function and recursively expanded

>     variable

>   kconfig: support simply expanded variable

>   kconfig: support append assignment operator

>   kconfig: expand lefthand side of assignment statement

>   kconfig: add 'info', 'warning-if', and 'error-if' built-in functions

>   kconfig: add 'filename' and 'lineno' built-in variables

>   kconfig: error out if a recursive variable references itself

>   Documentation: kconfig: document a new Kconfig macro language

>   kconfig: test: add Kconfig macro language tests

>   kconfig: show compiler version text in the top comment

>   kconfig: add basic helper macros to scripts/Kconfig.include

>   stack-protector: test compiler capability in Kconfig and drop AUTO

>     mode

>   kconfig: add CC_IS_GCC and GCC_VERSION

>   kconfig: add CC_IS_CLANG and CLANG_VERSION

>   gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT

>   kcov: test compiler capability in Kconfig and correct dependency

>   gcc-plugins: move GCC version check for PowerPC to Kconfig

>   gcc-plugins: test plugin support in Kconfig and clean up Makefile

>   gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST

>   Documentation: kconfig: add recommended way to describe compiler

>     support

>

>  Documentation/kbuild/kconfig-language.txt          |  26 +-

>  Documentation/kbuild/kconfig-macro-language.txt    | 242 +++++++++

>  Kconfig                                            |  10 +-

>  MAINTAINERS                                        |   3 +-

>  Makefile                                           | 105 +---

>  arch/Kconfig                                       |  49 +-

>  arch/powerpc/Kconfig                               |   2 +-

>  arch/sh/Kconfig                                    |   4 +-

>  arch/sparc/Kconfig                                 |   4 +-

>  arch/um/Kconfig.common                             |   4 -

>  arch/x86/Kconfig                                   |  15 +-

>  arch/x86/um/Kconfig                                |  10 +-

>  init/Kconfig                                       |  40 +-

>  kernel/gcov/Kconfig                                |  17 +-

>  kernel/gcov/Makefile                               |   2 -

>  lib/Kconfig.debug                                  |  11 +-

>  scripts/Kbuild.include                             | 101 +---

>  scripts/Kconfig.include                            |  30 ++

>  scripts/Makefile.gcc-plugins                       |  91 +---

>  scripts/Makefile.kcov                              |  10 +-

>  scripts/clang-version.sh                           |  18 +-

>  scripts/gcc-plugins/Makefile                       |   1 +

>  scripts/gcc-x86_32-has-stack-protector.sh          |   7 +-

>  scripts/gcc-x86_64-has-stack-protector.sh          |   5 -

>  scripts/kconfig/confdata.c                         |  33 +-

>  scripts/kconfig/kconf_id.c                         |   1 -

>  scripts/kconfig/lkc.h                              |   5 +-

>  scripts/kconfig/lkc_proto.h                        |  15 +-

>  scripts/kconfig/menu.c                             |   3 -

>  scripts/kconfig/preprocess.c                       | 572 +++++++++++++++++++++

>  scripts/kconfig/symbol.c                           | 109 ----

>  .../tests/no_write_if_dep_unmet/expected_config    |   2 +-

>  .../kconfig/tests/preprocess/builtin_func/Kconfig  |  27 +

>  .../tests/preprocess/builtin_func/__init__.py      |   9 +

>  .../tests/preprocess/builtin_func/expected_stderr  |   5 +

>  .../tests/preprocess/builtin_func/expected_stdout  |   1 +

>  .../tests/preprocess/circular_expansion/Kconfig    |   5 +

>  .../preprocess/circular_expansion/__init__.py      |  11 +

>  .../preprocess/circular_expansion/expected_stderr  |   1 +

>  scripts/kconfig/tests/preprocess/escape/Kconfig    |  44 ++

>  .../kconfig/tests/preprocess/escape/__init__.py    |   8 +

>  .../tests/preprocess/escape/expected_stderr        |  10 +

>  scripts/kconfig/tests/preprocess/variable/Kconfig  |  53 ++

>  .../kconfig/tests/preprocess/variable/__init__.py  |   8 +

>  .../tests/preprocess/variable/expected_stderr      |   9 +

>  scripts/kconfig/util.c                             |  33 +-

>  scripts/kconfig/zconf.l                            |  95 +++-

>  scripts/kconfig/zconf.y                            |  46 +-

>  48 files changed, 1345 insertions(+), 567 deletions(-)

>  create mode 100644 Documentation/kbuild/kconfig-macro-language.txt

>  create mode 100644 scripts/Kconfig.include

>  create mode 100644 scripts/kconfig/preprocess.c

>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/Kconfig

>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/__init__.py

>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stderr

>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stdout

>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/Kconfig

>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/__init__.py

>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/expected_stderr

>  create mode 100644 scripts/kconfig/tests/preprocess/escape/Kconfig

>  create mode 100644 scripts/kconfig/tests/preprocess/escape/__init__.py

>  create mode 100644 scripts/kconfig/tests/preprocess/escape/expected_stderr

>  create mode 100644 scripts/kconfig/tests/preprocess/variable/Kconfig

>  create mode 100644 scripts/kconfig/tests/preprocess/variable/__init__.py

>  create mode 100644 scripts/kconfig/tests/preprocess/variable/expected_stderr

>

> --

> 2.7.4

>




I pushed this series to

git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git
kconfig-shell-v5


-- 
Best Regards
Masahiro Yamada
Masahiro Yamada May 30, 2018, 12:38 a.m. UTC | #2
2018-05-28 21:23 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
> 2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>>

>> [Introduction]

>>

>> The motivation of this work is to move the compiler option tests to

>> Kconfig from Makefile.  A number of kernel features require the

>> compiler support.  Enabling such features blindly in Kconfig ends up

>> with a lot of nasty build-time testing in Makefiles.  If a chosen

>> feature turns out unsupported by the compiler, what the build system

>> can do is either to disable it (silently!) or to forcibly break the

>> build, despite Kconfig has let the user to enable it.  By moving the

>> compiler capability tests to Kconfig, Kconfig entries will be visible

>> only when they are available.

>>

>> [Major Changes in V5]

>>

>> V5 removed the complexity unnecessary for Kconfig.

>>

>>  - In order to make the implementation simpler, I drop the lazy

>>    argument expansion.

>>    In V5, parameters are expanded before passed to a function.

>>    (the same behavior as v3)

>>

>>  - Replace 'warning', 'error' functions with 'warning-if',

>>    'error-if' functions.  The new functions are effective

>>    only when the condition part is 'y'.

>>

>>  - In V4, '$' must be followed by '$' or '('.

>>    '$$' meant an escaped '$'.

>>

>>    V4 caused a build error for ARC architecture due to the

>>    following line:

>>    https://github.com/torvalds/linux/blob/v4.17-rc4/arch/arc/Kconfig#L252

>>

>>    Of course, we could rephrase "D$" to "D cache", but

>>    I treaked the grammar a little bit.

>>

>>    Kconfig decided to not support single-letter variable as in "$X".

>>    Nor curly braces as in "${CC}" are not supported.

>>    This means variable/function references in Kconfig always start

>>    with "$(".

>>    We can use '$' not followed by '(' as-is.

>>    We do not need the "$$" escape sequence.

>>    If necessary, we can use a trick to print '$(' verbatim.  See below.

>>

>>  - Fix a wrong behavior of simply expanded variables.

>>    V4 expanded simply expanded variables when used, but it should not.

>>

>>    For example,

>>

>>    dollar := $

>>    X := 1

>>    Y := $(dollar)(X)

>>    $(info,$(Y))

>>

>>    V5 prints '$(X)', not '1'.

>>

>>  - Remove a space after a comma is $( ) context.

>>    Actually, spaces do not matter in most cases.

>>

>>    You can write either

>>

>>       $(cc-option,-fstack-protector)

>>

>>    or

>>

>>       $(cc-option, -fstack-protector)

>>

>>    In fact, both style co-exist in our Makefiles too.

>>    However, there are some cases where they do matter.

>>

>>    I remove spaces after commas for consistency.

>>    If you are unsure, no-space-after-comma is always safe.

>>

>> [Major Changes in V4]

>>

>>  - In V4, I slightly change the syntax of a function call.

>>    I chose grammatical consistency and simplicity.

>>    Anyway, Kconfig is deviating from Make behavior already.

>>

>>    In v3, a function call looked like this:

>>

>>       $(func-name arg1,arg2,arg3)

>>

>>    In v4, a function is invoked like follows:

>>

>>       $(func-name,arg1,arg2,arg3)

>>

>>    The difference is that the function name and the first argument

>>    are separated by a comma.

>>

>>  - V3 supported single-letter variable like $X.

>>    V4 dropped it because we do not need multiple ways to do the

>>    same thing.

>>    You must always enclose a variable name like $(X).

>>

>>  - Support lazy argument expansion.  This is necessary for implementing

>>    'if', 'and', 'or' functions as in Make.

>>

>>  - Add more built-in functions:

>>    'if', 'error', 'filename', 'lineno'

>>

>>  - Error out if a recursive variable references itself eventually.

>>    For example,  X = $(X)

>>    ends up with a circular expansion.  It must be terminated

>>    since the expansion would continue eternally.

>>

>>  - Update Documentation and unit-tests, accordingly.

>>

>> [Major Changes in V3]

>>

>> This version looks more like Make.

>>

>>   - Use = operator instead of 'macro' keyword

>>     to define a user-defined function.

>>

>>   - 'Recursively expanded variable' is implemented as a side-effect.

>>      A variable is a function with zero argument.

>>

>>   - Support simply expanded variable which is defined by := operator

>>

>>   - Support += operator.

>>     Probably, this feature will be useful to accumulate compiler flags.

>>     At least, Clang needs some prerequisite flags such as triplet

>>     to test other compiler flags.

>>

>>   - Support $(info ...) and $(warning ...) built-in functions,

>>     which were useful while I was debugging this.

>>

>>   - Add documentation

>>

>>   - Add unit tests

>>

>>   - Collect helpers to scripts/Kconfig.include

>>

>> [Old Versions]

>>

>> V4:  https://lkml.org/lkml/2018/5/17/97

>> V3:  https://lkml.org/lkml/2018/4/13/37

>> V2:  https://lkml.org/lkml/2018/2/16/610

>> V1:  https://lkml.org/lkml/2018/2/16/610

>> RFC: https://lkml.org/lkml/2018/2/8/429

>>

>>

>> Masahiro Yamada (31):

>>   kbuild: remove kbuild cache

>>   kbuild: remove CONFIG_CROSS_COMPILE support

>>   kconfig: reference environment variables directly and remove 'option

>>     env='

>>   kconfig: remove string expansion in file_lookup()

>>   kconfig: remove string expansion for mainmenu after yyparse()

>>   kconfig: remove sym_expand_string_value()

>>   kconfig: make default prompt of mainmenu less specific

>>   kconfig: add built-in function support

>>   kconfig: add 'shell' built-in function

>>   kconfig: replace $(UNAME_RELEASE) with function call

>>   kconfig: begin PARAM state only when seeing a command keyword

>>   kconfig: support user-defined function and recursively expanded

>>     variable

>>   kconfig: support simply expanded variable

>>   kconfig: support append assignment operator

>>   kconfig: expand lefthand side of assignment statement

>>   kconfig: add 'info', 'warning-if', and 'error-if' built-in functions

>>   kconfig: add 'filename' and 'lineno' built-in variables

>>   kconfig: error out if a recursive variable references itself

>>   Documentation: kconfig: document a new Kconfig macro language

>>   kconfig: test: add Kconfig macro language tests

>>   kconfig: show compiler version text in the top comment

>>   kconfig: add basic helper macros to scripts/Kconfig.include

>>   stack-protector: test compiler capability in Kconfig and drop AUTO

>>     mode

>>   kconfig: add CC_IS_GCC and GCC_VERSION

>>   kconfig: add CC_IS_CLANG and CLANG_VERSION

>>   gcov: remove CONFIG_GCOV_FORMAT_AUTODETECT

>>   kcov: test compiler capability in Kconfig and correct dependency

>>   gcc-plugins: move GCC version check for PowerPC to Kconfig

>>   gcc-plugins: test plugin support in Kconfig and clean up Makefile

>>   gcc-plugins: allow to enable GCC_PLUGINS for COMPILE_TEST

>>   Documentation: kconfig: add recommended way to describe compiler

>>     support

>>

>>  Documentation/kbuild/kconfig-language.txt          |  26 +-

>>  Documentation/kbuild/kconfig-macro-language.txt    | 242 +++++++++

>>  Kconfig                                            |  10 +-

>>  MAINTAINERS                                        |   3 +-

>>  Makefile                                           | 105 +---

>>  arch/Kconfig                                       |  49 +-

>>  arch/powerpc/Kconfig                               |   2 +-

>>  arch/sh/Kconfig                                    |   4 +-

>>  arch/sparc/Kconfig                                 |   4 +-

>>  arch/um/Kconfig.common                             |   4 -

>>  arch/x86/Kconfig                                   |  15 +-

>>  arch/x86/um/Kconfig                                |  10 +-

>>  init/Kconfig                                       |  40 +-

>>  kernel/gcov/Kconfig                                |  17 +-

>>  kernel/gcov/Makefile                               |   2 -

>>  lib/Kconfig.debug                                  |  11 +-

>>  scripts/Kbuild.include                             | 101 +---

>>  scripts/Kconfig.include                            |  30 ++

>>  scripts/Makefile.gcc-plugins                       |  91 +---

>>  scripts/Makefile.kcov                              |  10 +-

>>  scripts/clang-version.sh                           |  18 +-

>>  scripts/gcc-plugins/Makefile                       |   1 +

>>  scripts/gcc-x86_32-has-stack-protector.sh          |   7 +-

>>  scripts/gcc-x86_64-has-stack-protector.sh          |   5 -

>>  scripts/kconfig/confdata.c                         |  33 +-

>>  scripts/kconfig/kconf_id.c                         |   1 -

>>  scripts/kconfig/lkc.h                              |   5 +-

>>  scripts/kconfig/lkc_proto.h                        |  15 +-

>>  scripts/kconfig/menu.c                             |   3 -

>>  scripts/kconfig/preprocess.c                       | 572 +++++++++++++++++++++

>>  scripts/kconfig/symbol.c                           | 109 ----

>>  .../tests/no_write_if_dep_unmet/expected_config    |   2 +-

>>  .../kconfig/tests/preprocess/builtin_func/Kconfig  |  27 +

>>  .../tests/preprocess/builtin_func/__init__.py      |   9 +

>>  .../tests/preprocess/builtin_func/expected_stderr  |   5 +

>>  .../tests/preprocess/builtin_func/expected_stdout  |   1 +

>>  .../tests/preprocess/circular_expansion/Kconfig    |   5 +

>>  .../preprocess/circular_expansion/__init__.py      |  11 +

>>  .../preprocess/circular_expansion/expected_stderr  |   1 +

>>  scripts/kconfig/tests/preprocess/escape/Kconfig    |  44 ++

>>  .../kconfig/tests/preprocess/escape/__init__.py    |   8 +

>>  .../tests/preprocess/escape/expected_stderr        |  10 +

>>  scripts/kconfig/tests/preprocess/variable/Kconfig  |  53 ++

>>  .../kconfig/tests/preprocess/variable/__init__.py  |   8 +

>>  .../tests/preprocess/variable/expected_stderr      |   9 +

>>  scripts/kconfig/util.c                             |  33 +-

>>  scripts/kconfig/zconf.l                            |  95 +++-

>>  scripts/kconfig/zconf.y                            |  46 +-

>>  48 files changed, 1345 insertions(+), 567 deletions(-)

>>  create mode 100644 Documentation/kbuild/kconfig-macro-language.txt

>>  create mode 100644 scripts/Kconfig.include

>>  create mode 100644 scripts/kconfig/preprocess.c

>>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/Kconfig

>>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/__init__.py

>>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stderr

>>  create mode 100644 scripts/kconfig/tests/preprocess/builtin_func/expected_stdout

>>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/Kconfig

>>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/__init__.py

>>  create mode 100644 scripts/kconfig/tests/preprocess/circular_expansion/expected_stderr

>>  create mode 100644 scripts/kconfig/tests/preprocess/escape/Kconfig

>>  create mode 100644 scripts/kconfig/tests/preprocess/escape/__init__.py

>>  create mode 100644 scripts/kconfig/tests/preprocess/escape/expected_stderr

>>  create mode 100644 scripts/kconfig/tests/preprocess/variable/Kconfig

>>  create mode 100644 scripts/kconfig/tests/preprocess/variable/__init__.py

>>  create mode 100644 scripts/kconfig/tests/preprocess/variable/expected_stderr

>>

>> --

>> 2.7.4

>>

>

>

>

> I pushed this series to

>

> git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git

> kconfig-shell-v5

>



I pushed this series to the for-next branch.
Unless a significant problem is reported,
I'd like to merge this series in the upcoming MW.
At least, I need to keep it in linux-next for a while.

Your comments and tags are still appreciated.
I will add tags (or replace patches if necessary) later,
but I want this series tested in linux-next
to expose to more developers' eyes.

It passed my local test.  O-day bot did not report anything so far.


-- 
Best Regards
Masahiro Yamada
Arnd Bergmann June 1, 2018, 8:31 a.m. UTC | #3
On Wed, May 30, 2018 at 2:38 AM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> 2018-05-28 21:23 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>> 2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:


>

> I pushed this series to the for-next branch.

> Unless a significant problem is reported,

> I'd like to merge this series in the upcoming MW.

> At least, I need to keep it in linux-next for a while.

>

> Your comments and tags are still appreciated.

> I will add tags (or replace patches if necessary) later,

> but I want this series tested in linux-next

> to expose to more developers' eyes.

>

> It passed my local test.  O-day bot did not report anything so far.


I found a problem when using ccache, resulting in this output while building
scripts/kconfig:

$  make V=1 O=obj-tmp/ CC="ccache gcc" defconfig
make[1]: Entering directory '/git/arm-soc'
make -C /home/arnd/arm-soc/obj-tmp KBUILD_SRC=/git/arm-soc \
-f /git/arm-soc/Makefile defconfig
make[2]: Entering directory '/git/arm-soc/obj-tmp'
make -f ../scripts/Makefile.build obj=scripts/basic
  gcc -Wp,-MD,scripts/basic/.fixdep.d -Iscripts/basic -Wall
-Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
-std=gnu89  -o scripts/basic/fixdep ../scripts/basic/fixdep.c
rm -f .tmp_quiet_recordmcount
ln -fsn .. source
/bin/bash ../scripts/mkmakefile \
    .. . 4 17
make -f ../scripts/Makefile.build obj=scripts/kconfig defconfig
  gcc -Wp,-MD,scripts/kconfig/.conf.o.d -Iscripts/kconfig -Wall
-Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
-std=gnu89 -c -o scripts/kconfig/conf.o ../scripts/kconfig/conf.c
  bison -oscripts/kconfig/zconf.tab.c -t -l ../scripts/kconfig/zconf.y
  flex -oscripts/kconfig/zconf.lex.c -L ../scripts/kconfig/zconf.l
  gcc -Wp,-MD,scripts/kconfig/.zconf.tab.o.d -Iscripts/kconfig -Wall
-Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
-std=gnu89  -I../scripts/kconfig -c -o scripts/kconfig/zconf.tab.o
scripts/kconfig/zconf.tab.c
  gcc  -o scripts/kconfig/conf scripts/kconfig/conf.o
scripts/kconfig/zconf.tab.o
scripts/kconfig/conf  --defconfig=arch/arm/configs/multi_v7_defconfig Kconfig
ccache: invalid option -- 'r'
Usage:
    ccache [options]
    ccache compiler [compiler options]
    compiler [compiler options]          (via symbolic link)

Options:
    -c, --cleanup         delete old files and recalculate size counters
                          (normally not needed as this is done automatically)
    -C, --clear           clear the cache completely (except configuration)
    -F, --max-files=N     set maximum number of files in cache to N (use 0 for
                          no limit)
    -M, --max-size=SIZE   set maximum size of cache to SIZE (use 0 for no
                          limit); available suffixes: k, M, G, T (decimal) and
                          Ki, Mi, Gi, Ti (binary); default suffix: G
    -o, --set-config=K=V  set configuration key K to value V
    -p, --print-config    print current configuration options
    -s, --show-stats      show statistics summary
    -z, --zero-stats      zero statistics counters

    -h, --help            print this help text
    -V, --version         print version and copyright information

See also <https://ccache.samba.org>.
#
# configuration written to .config
#
make[2]: Leaving directory '/git/arm-soc/obj-tmp'
make[1]: Leaving directory '/git/arm-soc'

It appears to just keep going after this output, but clearly something is wrong.
I bisected it to bde197706614 ("gcc-plugins: test plugin support in Kconfig
and clean up Makefile").

     Arnd
Masahiro Yamada June 1, 2018, 10:29 a.m. UTC | #4
2018-06-01 17:31 GMT+09:00 Arnd Bergmann <arnd@arndb.de>:
> On Wed, May 30, 2018 at 2:38 AM, Masahiro Yamada

> <yamada.masahiro@socionext.com> wrote:

>> 2018-05-28 21:23 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>>> 2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>

>>

>> I pushed this series to the for-next branch.

>> Unless a significant problem is reported,

>> I'd like to merge this series in the upcoming MW.

>> At least, I need to keep it in linux-next for a while.

>>

>> Your comments and tags are still appreciated.

>> I will add tags (or replace patches if necessary) later,

>> but I want this series tested in linux-next

>> to expose to more developers' eyes.

>>

>> It passed my local test.  O-day bot did not report anything so far.

>

> I found a problem when using ccache, resulting in this output while building

> scripts/kconfig:

>

> $  make V=1 O=obj-tmp/ CC="ccache gcc" defconfig

> make[1]: Entering directory '/git/arm-soc'

> make -C /home/arnd/arm-soc/obj-tmp KBUILD_SRC=/git/arm-soc \

> -f /git/arm-soc/Makefile defconfig

> make[2]: Entering directory '/git/arm-soc/obj-tmp'

> make -f ../scripts/Makefile.build obj=scripts/basic

>   gcc -Wp,-MD,scripts/basic/.fixdep.d -Iscripts/basic -Wall

> -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer

> -std=gnu89  -o scripts/basic/fixdep ../scripts/basic/fixdep.c

> rm -f .tmp_quiet_recordmcount

> ln -fsn .. source

> /bin/bash ../scripts/mkmakefile \

>     .. . 4 17

> make -f ../scripts/Makefile.build obj=scripts/kconfig defconfig

>   gcc -Wp,-MD,scripts/kconfig/.conf.o.d -Iscripts/kconfig -Wall

> -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer

> -std=gnu89 -c -o scripts/kconfig/conf.o ../scripts/kconfig/conf.c

>   bison -oscripts/kconfig/zconf.tab.c -t -l ../scripts/kconfig/zconf.y

>   flex -oscripts/kconfig/zconf.lex.c -L ../scripts/kconfig/zconf.l

>   gcc -Wp,-MD,scripts/kconfig/.zconf.tab.o.d -Iscripts/kconfig -Wall

> -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer

> -std=gnu89  -I../scripts/kconfig -c -o scripts/kconfig/zconf.tab.o

> scripts/kconfig/zconf.tab.c

>   gcc  -o scripts/kconfig/conf scripts/kconfig/conf.o

> scripts/kconfig/zconf.tab.o

> scripts/kconfig/conf  --defconfig=arch/arm/configs/multi_v7_defconfig Kconfig

> ccache: invalid option -- 'r'

> Usage:

>     ccache [options]

>     ccache compiler [compiler options]

>     compiler [compiler options]          (via symbolic link)

>

> Options:

>     -c, --cleanup         delete old files and recalculate size counters

>                           (normally not needed as this is done automatically)

>     -C, --clear           clear the cache completely (except configuration)

>     -F, --max-files=N     set maximum number of files in cache to N (use 0 for

>                           no limit)

>     -M, --max-size=SIZE   set maximum size of cache to SIZE (use 0 for no

>                           limit); available suffixes: k, M, G, T (decimal) and

>                           Ki, Mi, Gi, Ti (binary); default suffix: G

>     -o, --set-config=K=V  set configuration key K to value V

>     -p, --print-config    print current configuration options

>     -s, --show-stats      show statistics summary

>     -z, --zero-stats      zero statistics counters

>

>     -h, --help            print this help text

>     -V, --version         print version and copyright information

>

> See also <https://ccache.samba.org>.

> #

> # configuration written to .config

> #

> make[2]: Leaving directory '/git/arm-soc/obj-tmp'

> make[1]: Leaving directory '/git/arm-soc'

>

> It appears to just keep going after this output, but clearly something is wrong.

> I bisected it to bde197706614 ("gcc-plugins: test plugin support in Kconfig

> and clean up Makefile").



Thanks for the report!


In the original scripts/Makefile.gcc-plugins,
the parameters to scripts/gcc-plugin.sh were quoted by "..."

I need to keep quoting.
https://patchwork.kernel.org/patch/10442941/

Hmm, too much quoting is messy.
It works though...





-- 
Best Regards
Masahiro Yamada
Arnd Bergmann June 1, 2018, 11:09 a.m. UTC | #5
On Fri, Jun 1, 2018 at 12:29 PM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> 2018-06-01 17:31 GMT+09:00 Arnd Bergmann <arnd@arndb.de>:

>> On Wed, May 30, 2018 at 2:38 AM, Masahiro Yamada

>> <yamada.masahiro@socionext.com> wrote:

>>> 2018-05-28 21:23 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>>>> 2018-05-28 18:21 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

>

> In the original scripts/Makefile.gcc-plugins,

> the parameters to scripts/gcc-plugin.sh were quoted by "..."

>

> I need to keep quoting.

> https://patchwork.kernel.org/patch/10442941/

>

> Hmm, too much quoting is messy.

> It works though...


Ok, confirmed it fixes the problem for me.

      Arnd