[v3] Add .clang-format style file

  Went with version >= 11.0 since it covers most of the major features
and should be pretty universally accessibly.

There are some issues:

1.  indention of preprocessor directives:
    Unfortunately there doesn't appear to be a switch for a seperate
    'IndentWidth' for preprocessor directives vs. normal code so we
    are stuck either not indenting the directives or over-indenting
    them. i.e:
    Desired:
    ```
    #ifndef A
    # define B
    #endif
    ```
    Options:
    ```
    #ifndef A
    #  define B /* Two spaces instead of one.  */
    #endif

    #ifndef C
    #define D   /* No spaces.  */
    #endif
    ```
    Chose to over-indent as it generally seems easier to script
    halving all pre-processor indentations than counting the nested
    depth and indenting from scratch.

2.  concatenation of lines missing semi-colons:
    Throughout glibc there are macros used to setup aliasing that are
    outside of functions and don't end in semi-colons i.e:
    ```
    libc_hidden_def (__pthread_self)
    weak_alias (__pthread_self, pthread_self)
    ```

    clang-format reformats lines like these to:
    ```
    libc_hidden_def (__pthread_self) weak_alias (__pthread_self, pthread_self)
    ```

    which is generally undesirable.

Other than those two big concerns there are certainly some questions
diffs but for the most part it creates a easy to read and consistent
style.
---
 .clang-format | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 .clang-format
  

On 2022-03-30, Noah Goldstein via Libc-alpha wrote:
>Went with version >= 11.0 since it covers most of the major features
>and should be pretty universally accessibly.
>
>There are some issues:
>
>1.  indention of preprocessor directives:
>    Unfortunately there doesn't appear to be a switch for a seperate
>    'IndentWidth' for preprocessor directives vs. normal code so we
>    are stuck either not indenting the directives or over-indenting
>    them. i.e:
>    Desired:
>    ```
>    #ifndef A
>    # define B
>    #endif
>    ```
>    Options:
>    ```
>    #ifndef A
>    #  define B /* Two spaces instead of one.  */
>    #endif
>
>    #ifndef C
>    #define D   /* No spaces.  */
>    #endif
>    ```
>    Chose to over-indent as it generally seems easier to script
>    halving all pre-processor indentations than counting the nested
>    depth and indenting from scratch.
>
>2.  concatenation of lines missing semi-colons:
>    Throughout glibc there are macros used to setup aliasing that are
>    outside of functions and don't end in semi-colons i.e:
>    ```
>    libc_hidden_def (__pthread_self)
>    weak_alias (__pthread_self, pthread_self)
>    ```
>
>    clang-format reformats lines like these to:
>    ```
>    libc_hidden_def (__pthread_self) weak_alias (__pthread_self, pthread_self)
>    ```
>
>    which is generally undesirable.
>
>Other than those two big concerns there are certainly some questions
>diffs but for the most part it creates a easy to read and consistent
>style.

Thanks. I have spot checked a few files and having the file will be
helpful.

Side note: clang-format works even without .clang-format and falls back to LLVM
style. Having the file makes the format rules actually reflect the glibc coding
standard.

Reviewed-by: Fangrui Song <maskray@google.com>

>---
> .clang-format | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 175 insertions(+)
> create mode 100644 .clang-format
>
>diff --git a/.clang-format b/.clang-format
>new file mode 100644
>index 0000000000..fcb344ef70
>--- /dev/null
>+++ b/.clang-format
>@@ -0,0 +1,175 @@
>+#  clang-format file for GLIBC
>+#  Copyright (C) 2022 Free Software Foundation, Inc.
>+#  This file is part of the GNU C Library.
>+#
>+#  The GNU C Library is free software; you can redistribute it and/or
>+#  modify it under the terms of the GNU Lesser General Public
>+#  License as published by the Free Software Foundation; either
>+#  version 2.1 of the License, or (at your option) any later version.
>+#
>+#  The GNU C Library is distributed in the hope that it will be useful,
>+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
>+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>+#  Lesser General Public License for more details.
>+#
>+#  You should have received a copy of the GNU Lesser General Public
>+#  License along with the GNU C Library; if not, see
>+#  <https://www.gnu.org/licenses/>.
>+#
>+#  Requires clang-format version >= 11.0
>+#
>+#  For more information, see:
>+#
>+#   Documentation/process/clang-format.rst
>+#   https://clang.llvm.org/docs/ClangFormat.html
>+#   https://clang.llvm.org/docs/ClangFormatStyleOptions.html
>+#
>+#  There are some known cases that this doesn't produce the desired
>+#  style (i.e Preprocessor Directives are over-indented and not
>+#  auto-commented). As a result, this is meant to be a utility to make
>+#  formatting easier, not a definitive standard.
>+#
>+#  To format the current git diff inplace (-i) the follow command can
>+#  be used:
>+#  $> git diff -U0 --no-color HEAD^ | clang-format-diff -i -p1
>+#
>+#  To just view the diff clang-format would generate:
>+#  $> git diff -U0 --no-color HEAD^ | clang-format-diff -p1
>+#
>+#  NB: clang-format-diff, along with other clang-format related tools,
>+#      can be found at: /path/to/llvm-project/clang/tools/clang-format/
>+#

The ability to re-format blocks of code is especially useful for
contributors sending patches. Thanks for highlighting it.

>+#
>+---
>+# BasedOnStyle:  GNU
>+AccessModifierOffset: -2
>+AlignAfterOpenBracket: Align
>+AlignConsecutiveMacros: false
>+AlignConsecutiveAssignments: false
>+AlignConsecutiveBitFields: false
>+AlignConsecutiveDeclarations: false
>+AlignEscapedNewlines: Right
>+AlignOperands:   true
>+AlignTrailingComments: true
>+AllowAllArgumentsOnNextLine: true
>+AllowAllConstructorInitializersOnNextLine: true
>+AllowAllParametersOfDeclarationOnNextLine: true
>+AllowShortEnumsOnASingleLine: true
>+AllowShortBlocksOnASingleLine: false
>+AllowShortCaseLabelsOnASingleLine: false
>+AllowShortFunctionsOnASingleLine: All
>+AllowShortLambdasOnASingleLine: All
>+AllowShortIfStatementsOnASingleLine: Never
>+AllowShortLoopsOnASingleLine: false
>+AlwaysBreakAfterDefinitionReturnType: All
>+AlwaysBreakAfterReturnType: AllDefinitions
>+AlwaysBreakBeforeMultilineStrings: false
>+AlwaysBreakTemplateDeclarations: MultiLine
>+BinPackArguments: true
>+BinPackParameters: true
>+BraceWrapping:
>+  AfterCaseLabel:  true
>+  AfterClass:      true
>+  AfterControlStatement: true
>+  AfterEnum:       true
>+  AfterFunction:   true
>+  AfterNamespace:  true
>+  AfterStruct:     true
>+  AfterUnion:      true
>+  AfterExternBlock: true
>+  BeforeCatch:     true
>+  BeforeElse:      true
>+  BeforeWhile:     true
>+  IndentBraces:    true
>+  SplitEmptyFunction: true
>+  SplitEmptyRecord: true
>+  SplitEmptyNamespace: true
>+BreakBeforeBinaryOperators: All
>+BreakBeforeBraces: GNU
>+BreakBeforeInheritanceComma: false
>+BreakInheritanceList: BeforeColon
>+BreakBeforeTernaryOperators: true
>+BreakConstructorInitializersBeforeComma: false
>+BreakConstructorInitializers: BeforeColon
>+BreakStringLiterals: true
>+ColumnLimit:     79
>+CommentPragmas:  '^ IWYU pragma:'
>+CompactNamespaces: false
>+ConstructorInitializerAllOnOneLineOrOnePerLine: false
>+ConstructorInitializerIndentWidth: 4
>+ContinuationIndentWidth: 4
>+Cpp11BracedListStyle: false
>+DeriveLineEnding: true
>+DerivePointerAlignment: false
>+DisableFormat:   false
>+ExperimentalAutoDetectBinPacking: false
>+FixNamespaceComments: false
>+ForEachMacros:
>+  - foreach
>+  - Q_FOREACH
>+  - BOOST_FOREACH
>+IncludeBlocks:   Preserve
>+IncludeCategories:
>+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
>+    Priority:        2
>+  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
>+    Priority:        3
>+  - Regex:           '.*'
>+    Priority:        1
>+IncludeIsMainRegex: '(Test)?$'
>+IndentCaseLabels: false
>+IndentCaseBlocks: false
>+IndentGotoLabels: true
>+IndentWidth:     2
>+IndentPPDirectives: AfterHash
>+IndentExternBlock: AfterExternBlock
>+IndentWrappedFunctionNames: false
>+InsertTrailingCommas: None
>+KeepEmptyLinesAtTheStartOfBlocks: true
>+MacroBlockBegin: ''
>+MacroBlockEnd:   ''
>+MaxEmptyLinesToKeep: 1
>+NamespaceIndentation: None
>+PenaltyBreakAssignment: 2
>+PenaltyBreakBeforeFirstCallParameter: 19
>+PenaltyBreakComment: 300
>+PenaltyBreakFirstLessLess: 120
>+PenaltyBreakString: 1000
>+PenaltyBreakTemplateDeclaration: 10
>+PenaltyExcessCharacter: 1000000
>+PenaltyReturnTypeOnItsOwnLine: 60
>+PointerAlignment: Right
>+ReflowComments:  true
>+SortIncludes:    false
>+SortUsingDeclarations: true
>+SpaceAfterCStyleCast: true
>+SpaceAfterLogicalNot: false
>+SpaceAfterTemplateKeyword: true
>+SpaceBeforeAssignmentOperators: true
>+SpaceBeforeCpp11BracedList: false
>+SpaceBeforeCtorInitializerColon: true
>+SpaceBeforeInheritanceColon: true
>+SpaceBeforeParens: Always
>+SpaceBeforeRangeBasedForLoopColon: true
>+SpaceInEmptyBlock: false
>+SpaceInEmptyParentheses: false
>+SpacesBeforeTrailingComments: 1
>+SpacesInAngles:  false
>+SpacesInConditionalStatement: false
>+SpacesInContainerLiterals: true
>+SpacesInCStyleCastParentheses: false
>+SpacesInParentheses: false
>+SpacesInSquareBrackets: false
>+SpaceBeforeSquareBrackets: false
>+Standard:        Cpp03
>+StatementMacros:
>+  - Q_UNUSED
>+  - QT_REQUIRE_VERSION
>+TabWidth:        8
>+UseTab:          Never
>+ForEachMacros:
>+  - 'FOR_EACH_IMPL'
>+  - 'list_for_each'
>+  - 'list_for_each_prev'
>+  - 'list_for_each_prev_safe'
>+...
>-- 
>2.25.1
>
  

* Noah Goldstein via Libc-alpha:

> Went with version >= 11.0 since it covers most of the major features
> and should be pretty universally accessibly.
>
> There are some issues:
>
> 1.  indention of preprocessor directives:
>     Unfortunately there doesn't appear to be a switch for a seperate
>     'IndentWidth' for preprocessor directives vs. normal code so we
>     are stuck either not indenting the directives or over-indenting
>     them. i.e:
>     Desired:
>     ```
>     #ifndef A
>     # define B
>     #endif
>     ```
>     Options:
>     ```
>     #ifndef A
>     #  define B /* Two spaces instead of one.  */
>     #endif
>
>     #ifndef C
>     #define D   /* No spaces.  */
>     #endif
>     ```
>     Chose to over-indent as it generally seems easier to script
>     halving all pre-processor indentations than counting the nested
>     depth and indenting from scratch.
>
> 2.  concatenation of lines missing semi-colons:
>     Throughout glibc there are macros used to setup aliasing that are
>     outside of functions and don't end in semi-colons i.e:
>     ```
>     libc_hidden_def (__pthread_self)
>     weak_alias (__pthread_self, pthread_self)
>     ```
>
>     clang-format reformats lines like these to:
>     ```
>     libc_hidden_def (__pthread_self) weak_alias (__pthread_self, pthread_self)
>     ```
>
>     which is generally undesirable.
>
> Other than those two big concerns there are certainly some questions
> diffs but for the most part it creates a easy to read and consistent
> style.
> ---
>  .clang-format | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 175 insertions(+)
>  create mode 100644 .clang-format
>
> diff --git a/.clang-format b/.clang-format
> new file mode 100644
> index 0000000000..fcb344ef70
> --- /dev/null
> +++ b/.clang-format
> @@ -0,0 +1,175 @@
> +#  clang-format file for GLIBC
> +#  Copyright (C) 2022 Free Software Foundation, Inc.
> +#  This file is part of the GNU C Library.
> +#
> +#  The GNU C Library is free software; you can redistribute it and/or
> +#  modify it under the terms of the GNU Lesser General Public
> +#  License as published by the Free Software Foundation; either
> +#  version 2.1 of the License, or (at your option) any later version.
> +#
> +#  The GNU C Library is distributed in the hope that it will be useful,
> +#  but WITHOUT ANY WARRANTY; without even the implied warranty of
> +#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +#  Lesser General Public License for more details.
> +#
> +#  You should have received a copy of the GNU Lesser General Public
> +#  License along with the GNU C Library; if not, see
> +#  <https://www.gnu.org/licenses/>.
> +#
> +#  Requires clang-format version >= 11.0
> +#
> +#  For more information, see:
> +#
> +#   Documentation/process/clang-format.rst

That's not a valid path in the glibc source tree.

> +# BasedOnStyle:  GNU

Why is this commented out?

> +AccessModifierOffset: -2
> +AlignAfterOpenBracket: Align
> +AlignConsecutiveMacros: false
> +AlignConsecutiveAssignments: false
> +AlignConsecutiveBitFields: false
> +AlignConsecutiveDeclarations: false
> +AlignEscapedNewlines: Right
> +AlignOperands:   true
> +AlignTrailingComments: true
> +AllowAllArgumentsOnNextLine: true
> +AllowAllConstructorInitializersOnNextLine: true
> +AllowAllParametersOfDeclarationOnNextLine: true
> +AllowShortEnumsOnASingleLine: true
> +AllowShortBlocksOnASingleLine: false
> +AllowShortCaseLabelsOnASingleLine: false
> +AllowShortFunctionsOnASingleLine: All
> +AllowShortLambdasOnASingleLine: All
> +AllowShortIfStatementsOnASingleLine: Never
> +AllowShortLoopsOnASingleLine: false
> +AlwaysBreakAfterDefinitionReturnType: All
> +AlwaysBreakAfterReturnType: AllDefinitions
> +AlwaysBreakBeforeMultilineStrings: false
> +AlwaysBreakTemplateDeclarations: MultiLine
> +BinPackArguments: true
> +BinPackParameters: true
> +BraceWrapping:
> +  AfterCaseLabel:  true
> +  AfterClass:      true
> +  AfterControlStatement: true
> +  AfterEnum:       true
> +  AfterFunction:   true
> +  AfterNamespace:  true
> +  AfterStruct:     true
> +  AfterUnion:      true
> +  AfterExternBlock: true
> +  BeforeCatch:     true
> +  BeforeElse:      true
> +  BeforeWhile:     true
> +  IndentBraces:    true
> +  SplitEmptyFunction: true
> +  SplitEmptyRecord: true
> +  SplitEmptyNamespace: true
> +BreakBeforeBinaryOperators: All
> +BreakBeforeBraces: GNU
> +BreakBeforeInheritanceComma: false
> +BreakInheritanceList: BeforeColon
> +BreakBeforeTernaryOperators: true
> +BreakConstructorInitializersBeforeComma: false
> +BreakConstructorInitializers: BeforeColon
> +BreakStringLiterals: true
> +ColumnLimit:     79
> +CommentPragmas:  '^ IWYU pragma:'
> +CompactNamespaces: false
> +ConstructorInitializerAllOnOneLineOrOnePerLine: false
> +ConstructorInitializerIndentWidth: 4
> +ContinuationIndentWidth: 4
> +Cpp11BracedListStyle: false
> +DeriveLineEnding: true
> +DerivePointerAlignment: false
> +DisableFormat:   false
> +ExperimentalAutoDetectBinPacking: false
> +FixNamespaceComments: false
> +ForEachMacros:
> +  - foreach
> +  - Q_FOREACH
> +  - BOOST_FOREACH

> +IncludeBlocks:   Preserve
> +IncludeCategories:
> +  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
> +    Priority:        2
> +  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
> +    Priority:        3
> +  - Regex:           '.*'
> +    Priority:        1

These regular expression do not seem to be relevant to glibc.

> +UseTab:          Never

I prefer not using tabs, but others disagree, and most of the source
files use tabs instead of 8 spaces (and not just for indentation).

> +ForEachMacros:
> +  - 'FOR_EACH_IMPL'
> +  - 'list_for_each'
> +  - 'list_for_each_prev'
> +  - 'list_for_each_prev_safe'

If this is a YAML file, do these duplicate FoEachMacros keys have any
effect?  Only the second one is relevant to glibc.
  

On Wed, Mar 30, 2022 at 3:01 PM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * Noah Goldstein via Libc-alpha:
>
> > Went with version >= 11.0 since it covers most of the major features
> > and should be pretty universally accessibly.
> >
> > There are some issues:
> >
> > 1.  indention of preprocessor directives:
> >     Unfortunately there doesn't appear to be a switch for a seperate
> >     'IndentWidth' for preprocessor directives vs. normal code so we
> >     are stuck either not indenting the directives or over-indenting
> >     them. i.e:
> >     Desired:
> >     ```
> >     #ifndef A
> >     # define B
> >     #endif
> >     ```
> >     Options:
> >     ```
> >     #ifndef A
> >     #  define B /* Two spaces instead of one.  */
> >     #endif
> >
> >     #ifndef C
> >     #define D   /* No spaces.  */
> >     #endif
> >     ```
> >     Chose to over-indent as it generally seems easier to script
> >     halving all pre-processor indentations than counting the nested
> >     depth and indenting from scratch.
> >
> > 2.  concatenation of lines missing semi-colons:
> >     Throughout glibc there are macros used to setup aliasing that are
> >     outside of functions and don't end in semi-colons i.e:
> >     ```
> >     libc_hidden_def (__pthread_self)
> >     weak_alias (__pthread_self, pthread_self)
> >     ```
> >
> >     clang-format reformats lines like these to:
> >     ```
> >     libc_hidden_def (__pthread_self) weak_alias (__pthread_self, pthread_self)
> >     ```
> >
> >     which is generally undesirable.
> >
> > Other than those two big concerns there are certainly some questions
> > diffs but for the most part it creates a easy to read and consistent
> > style.
> > ---
> >  .clang-format | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 175 insertions(+)
> >  create mode 100644 .clang-format
> >
> > diff --git a/.clang-format b/.clang-format
> > new file mode 100644
> > index 0000000000..fcb344ef70
> > --- /dev/null
> > +++ b/.clang-format
> > @@ -0,0 +1,175 @@
> > +#  clang-format file for GLIBC
> > +#  Copyright (C) 2022 Free Software Foundation, Inc.
> > +#  This file is part of the GNU C Library.
> > +#
> > +#  The GNU C Library is free software; you can redistribute it and/or
> > +#  modify it under the terms of the GNU Lesser General Public
> > +#  License as published by the Free Software Foundation; either
> > +#  version 2.1 of the License, or (at your option) any later version.
> > +#
> > +#  The GNU C Library is distributed in the hope that it will be useful,
> > +#  but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +#  Lesser General Public License for more details.
> > +#
> > +#  You should have received a copy of the GNU Lesser General Public
> > +#  License along with the GNU C Library; if not, see
> > +#  <https://www.gnu.org/licenses/>.
> > +#
> > +#  Requires clang-format version >= 11.0
> > +#
> > +#  For more information, see:
> > +#
> > +#   Documentation/process/clang-format.rst
>
> That's not a valid path in the glibc source tree.
>
> > +# BasedOnStyle:  GNU
>
> Why is this commented out?
>
> > +AccessModifierOffset: -2
> > +AlignAfterOpenBracket: Align
> > +AlignConsecutiveMacros: false
> > +AlignConsecutiveAssignments: false
> > +AlignConsecutiveBitFields: false
> > +AlignConsecutiveDeclarations: false
> > +AlignEscapedNewlines: Right
> > +AlignOperands:   true
> > +AlignTrailingComments: true
> > +AllowAllArgumentsOnNextLine: true
> > +AllowAllConstructorInitializersOnNextLine: true
> > +AllowAllParametersOfDeclarationOnNextLine: true
> > +AllowShortEnumsOnASingleLine: true
> > +AllowShortBlocksOnASingleLine: false
> > +AllowShortCaseLabelsOnASingleLine: false
> > +AllowShortFunctionsOnASingleLine: All
> > +AllowShortLambdasOnASingleLine: All
> > +AllowShortIfStatementsOnASingleLine: Never
> > +AllowShortLoopsOnASingleLine: false
> > +AlwaysBreakAfterDefinitionReturnType: All
> > +AlwaysBreakAfterReturnType: AllDefinitions
> > +AlwaysBreakBeforeMultilineStrings: false
> > +AlwaysBreakTemplateDeclarations: MultiLine
> > +BinPackArguments: true
> > +BinPackParameters: true
> > +BraceWrapping:
> > +  AfterCaseLabel:  true
> > +  AfterClass:      true
> > +  AfterControlStatement: true
> > +  AfterEnum:       true
> > +  AfterFunction:   true
> > +  AfterNamespace:  true
> > +  AfterStruct:     true
> > +  AfterUnion:      true
> > +  AfterExternBlock: true
> > +  BeforeCatch:     true
> > +  BeforeElse:      true
> > +  BeforeWhile:     true
> > +  IndentBraces:    true
> > +  SplitEmptyFunction: true
> > +  SplitEmptyRecord: true
> > +  SplitEmptyNamespace: true
> > +BreakBeforeBinaryOperators: All
> > +BreakBeforeBraces: GNU
> > +BreakBeforeInheritanceComma: false
> > +BreakInheritanceList: BeforeColon
> > +BreakBeforeTernaryOperators: true
> > +BreakConstructorInitializersBeforeComma: false
> > +BreakConstructorInitializers: BeforeColon
> > +BreakStringLiterals: true
> > +ColumnLimit:     79
> > +CommentPragmas:  '^ IWYU pragma:'
> > +CompactNamespaces: false
> > +ConstructorInitializerAllOnOneLineOrOnePerLine: false
> > +ConstructorInitializerIndentWidth: 4
> > +ContinuationIndentWidth: 4
> > +Cpp11BracedListStyle: false
> > +DeriveLineEnding: true
> > +DerivePointerAlignment: false
> > +DisableFormat:   false
> > +ExperimentalAutoDetectBinPacking: false
> > +FixNamespaceComments: false
> > +ForEachMacros:
> > +  - foreach
> > +  - Q_FOREACH
> > +  - BOOST_FOREACH
>
> > +IncludeBlocks:   Preserve
> > +IncludeCategories:
> > +  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
> > +    Priority:        2
> > +  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
> > +    Priority:        3
> > +  - Regex:           '.*'
> > +    Priority:        1
>
> These regular expression do not seem to be relevant to glibc.

Yeah. Will fix in v4.
>
> > +UseTab:          Never
>
> I prefer not using tabs, but others disagree, and most of the source
> files use tabs instead of 8 spaces (and not just for indentation).

+1 but yeah the consistent style seems to be tabs so will update in v4.
>
> > +ForEachMacros:
> > +  - 'FOR_EACH_IMPL'
> > +  - 'list_for_each'
> > +  - 'list_for_each_prev'
> > +  - 'list_for_each_prev_safe'
>
> If this is a YAML file, do these duplicate FoEachMacros keys have any
> effect?  Only the second one is relevant to glibc.

They all seem to have an effect.

What do you mean only the second is relevant? I see all but `list_for_each_prev`
used and `list_for_each_prev` appears to be defined so it could be used
to make a loop.
  

* Noah Goldstein:

>> > +UseTab:          Never
>>
>> I prefer not using tabs, but others disagree, and most of the source
>> files use tabs instead of 8 spaces (and not just for indentation).
>
> +1 but yeah the consistent style seems to be tabs so will update in v4.

Is there an option to use tabs only if the file contains tab?

>> > +ForEachMacros:
>> > +  - 'FOR_EACH_IMPL'
>> > +  - 'list_for_each'
>> > +  - 'list_for_each_prev'
>> > +  - 'list_for_each_prev_safe'
>>
>> If this is a YAML file, do these duplicate FoEachMacros keys have any
>> effect?  Only the second one is relevant to glibc.
>
> They all seem to have an effect.

<https://yaml.org/spec/1.2.2/#mapping> says that keys have to be
unique, so I don't think to ForEachMacros is valid YAML syntax.

> What do you mean only the second is relevant?

glibc does not use the Boost and Qt macros.
  

On Wed, Mar 30, 2022 at 3:14 PM Florian Weimer <fw@deneb.enyo.de> wrote:
>
> * Noah Goldstein:
>
> >> > +UseTab:          Never
> >>
> >> I prefer not using tabs, but others disagree, and most of the source
> >> files use tabs instead of 8 spaces (and not just for indentation).
> >
> > +1 but yeah the consistent style seems to be tabs so will update in v4.
>
> Is there an option to use tabs only if the file contains tab?

There doesn't appear to be one. Only



https://clang.llvm.org/docs/ClangFormatStyleOptions.html

UT_Never (in configuration: Never) Never use tab.
UT_ForIndentation (in configuration: ForIndentation) Use tabs only for
indentation.
UT_ForContinuationAndIndentation (in configuration:
ForContinuationAndIndentation) Fill all leading whitespace with tabs,
and use spaces for alignment that appears within a line (e.g.
consecutive assignments and declarations).
UT_AlignWithSpaces (in configuration: AlignWithSpaces) Use tabs for
line continuation and indentation, and spaces for alignment.
UT_Always (in configuration: Always) Use tabs whenever we need to fill
whitespace that spans at least from one tab stop to the next one.

>
> >> > +ForEachMacros:
> >> > +  - 'FOR_EACH_IMPL'
> >> > +  - 'list_for_each'
> >> > +  - 'list_for_each_prev'
> >> > +  - 'list_for_each_prev_safe'
> >>
> >> If this is a YAML file, do these duplicate FoEachMacros keys have any
> >> effect?  Only the second one is relevant to glibc.
> >
> > They all seem to have an effect.
>
> <https://yaml.org/spec/1.2.2/#mapping> says that keys have to be
> unique, so I don't think to ForEachMacros is valid YAML syntax.
>
> > What do you mean only the second is relevant?
>
> glibc does not use the Boost and Qt macros.

Oh I see, sorry started from the clang default GNU style.
clang-format will pick up latest configuration. Thought you
had meant the second one meaning 'list_for_each'.