Commit 14c04475 authored by mydeveloperday's avatar mydeveloperday Committed by paulhoad
Browse files

[clang-format] Add IndentCaseBlocks option 

Summary:
The documentation for IndentCaseLabels claimed that the "Switch
statement body is always indented one level more than case labels". This
is technically false for the code block immediately following the label.
Its closing bracket aligns with the start of the label.

If the case label are not indented, it leads to a style where the
closing bracket of the block aligns with the closing bracket of the
switch statement, which can be hard to parse.

This change introduces a new option, IndentCaseBlocks, which when true
treats the block as a scope block (which it technically is).

(Note: regenerated ClangFormatStyleOptions.rst using tools/dump_style.py)

Reviewed By: MyDeveloperDay

Patch By: capn

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D72276
parent d82adf32

clang/docs/ClangFormatStyleOptions.rst

+33 −2
Original line number Diff line number Diff line
@@ -1605,12 +1605,36 @@ the configuration (without a prefix: ``Auto``). 
  ``ClassImpl.hpp`` would not have the main include file put on top

  before any other include.



**IndentCaseBlocks** (``bool``)

  Indent case label blocks one level from the case label.



  When ``false``, the block following the case label uses the same

  indentation level as for the case label, treating the case label the same

  as an if-statement.

  When ``true``, the block gets indented as a scope block.



  .. code-block:: c++



     false:                                 true:

     switch (fool) {                vs.     switch (fool) {

     case 1: {                              case 1:

       bar();                                 {

     } break;                                   bar();

     default: {                               }

       plop();                                break;

     }                                      default:

     }                                        {

                                                plop();

                                              }

                                            }



**IndentCaseLabels** (``bool``)

  Indent case labels one level from the switch statement.



  When ``false``, use the same indentation level as for the switch

  statement. Switch statement body is always indented one level more than

  case labels.

  case labels (except the first block following the case label, which

  itself indents the code - unless IndentCaseBlocks is enabled).



  .. code-block:: c++
@@ -2329,7 +2353,14 @@ the configuration (without a prefix: ``Auto``). 
     x = ( int32 )y                 vs.     x = (int32)y



**SpacesInConditionalStatement** (``bool``)

  If ``true``, spaces will be inserted around if/for/while (and similar) conditions.

  If ``true``, spaces will be inserted around if/for/switch/while

  conditions.



  .. code-block:: c++



     true:                                  false:

     if ( a )  { ... }              vs.     if (a) { ... }

     while ( i < 5 )  { ... }               while (i < 5) { ... }



**SpacesInContainerLiterals** (``bool``)

  If ``true``, spaces are inserted inside container literals (e.g.

clang/docs/ReleaseNotes.rst

+19 −0
Original line number Diff line number Diff line
@@ -177,6 +177,25 @@ clang-format 
------------





- Option ``IndentCaseBlocks`` has been added to support treating the block

  following a switch case label as a scope block which gets indented itself.

  It helps avoid having the closing bracket align with the switch statement's

  closing bracket (when ``IndentCaseLabels`` is ``false``).



  .. code-block:: c++

  

    switch (fool) {                vs.     switch (fool) {

    case 1:                                case 1: {

      {                                      bar();

         bar();                            } break;

      }                                    default: {

      break;                                 plop();

    default:                               }

      {                                    }

        plop();

      }

    }



libclang

--------

clang/include/clang/Format/Format.h

+25 −1
Original line number Diff line number Diff line
@@ -1314,7 +1314,8 @@ struct FormatStyle { 
  ///

  /// When ``false``, use the same indentation level as for the switch

  /// statement. Switch statement body is always indented one level more than

  /// case labels.

  /// case labels (except the first block following the case label, which

  /// itself indents the code - unless IndentCaseBlocks is enabled).

  /// \code

  ///    false:                                 true:

  ///    switch (fool) {                vs.     switch (fool) {
@@ -1327,6 +1328,28 @@ struct FormatStyle { 
  /// \endcode

  bool IndentCaseLabels;



  /// Indent case label blocks one level from the case label.

  ///

  /// When ``false``, the block following the case label uses the same

  /// indentation level as for the case label, treating the case label the same

  /// as an if-statement.

  /// When ``true``, the block gets indented as a scope block.

  /// \code

  ///    false:                                 true:

  ///    switch (fool) {                vs.     switch (fool) {

  ///    case 1: {                              case 1:

  ///      bar();                                 {

  ///    } break;                                   bar();

  ///    default: {                               }

  ///      plop();                                break;

  ///    }                                      default:

  ///    }                                        {

  ///                                               plop();

  ///                                             }

  ///                                           }

  /// \endcode

  bool IndentCaseBlocks;



  /// Indent goto labels.

  ///

  /// When ``false``, goto labels are flushed left.
@@ -2119,6 +2142,7 @@ struct FormatStyle { 
           IncludeStyle.IncludeIsMainSourceRegex ==

               R.IncludeStyle.IncludeIsMainSourceRegex &&

           IndentCaseLabels == R.IndentCaseLabels &&

           IndentCaseBlocks == R.IndentCaseBlocks &&

           IndentGotoLabels == R.IndentGotoLabels &&

           IndentPPDirectives == R.IndentPPDirectives &&

           IndentWidth == R.IndentWidth && Language == R.Language &&

clang/lib/Format/Format.cpp

+2 −0
Original line number Diff line number Diff line
@@ -480,6 +480,7 @@ template <> struct MappingTraits<FormatStyle> { 
    IO.mapOptional("IncludeIsMainSourceRegex",

                   Style.IncludeStyle.IncludeIsMainSourceRegex);

    IO.mapOptional("IndentCaseLabels", Style.IndentCaseLabels);

    IO.mapOptional("IndentCaseBlocks", Style.IndentCaseBlocks);

    IO.mapOptional("IndentGotoLabels", Style.IndentGotoLabels);

    IO.mapOptional("IndentPPDirectives", Style.IndentPPDirectives);

    IO.mapOptional("IndentWidth", Style.IndentWidth);
@@ -782,6 +783,7 @@ FormatStyle getLLVMStyle(FormatStyle::LanguageKind Language) { 
  LLVMStyle.IncludeStyle.IncludeIsMainRegex = "(Test)?$";

  LLVMStyle.IncludeStyle.IncludeBlocks = tooling::IncludeStyle::IBS_Preserve;

  LLVMStyle.IndentCaseLabels = false;

  LLVMStyle.IndentCaseBlocks = false;

  LLVMStyle.IndentGotoLabels = true;

  LLVMStyle.IndentPPDirectives = FormatStyle::PPDIS_None;

  LLVMStyle.IndentWrappedFunctionNames = false;

clang/lib/Format/UnwrappedLineParser.cpp

+2 −1
Original line number Diff line number Diff line
@@ -2003,7 +2003,8 @@ void UnwrappedLineParser::parseLabel(bool LeftAlignLabel) { 
    --Line->Level;

  if (LeftAlignLabel)

    Line->Level = 0;

  if (CommentsBeforeNextToken.empty() && FormatTok->Tok.is(tok::l_brace)) {

  if (!Style.IndentCaseBlocks && CommentsBeforeNextToken.empty() &&

      FormatTok->Tok.is(tok::l_brace)) {

    CompoundStatementIndenter Indenter(this, Line->Level,

                                       Style.BraceWrapping.AfterCaseLabel,

                                       Style.BraceWrapping.IndentBraces);