This is the additional indent beyond the standard code indentation level.
The Arduino IDE 1.x formatting style indented access modifiers (equivalent to AccessModifierOffset: 0), but also added an extra indent for the members. So non-indented access modifiers (AccessModifierOffset: -2) is actually closest to the previous formatting style.
It is not clear from the documentation, but this truly is an "allow" setting, rather than ClangFormat's usual approach of forcing a specific formatting style. So the value AllIfsAndElse allows the user to break if statements according to their whims, in alignment with the Arduino IDE 1.x formatter behavior, while the Never is completely restrictive, not allowing short if, else if, or else statements under any conditions.
This key is irrelevant because we define all configuration keys.
Even though it is not one of the documented possible values, clang-format --dump-config outputs BasedOnStyle: ''.
This key is ignored when BreakBeforeBraces is set to anything other than Custom.
true forces the break.
false allows the user to break or not break at their whim, in alignment with the Arduino IDE 1.x formatter behavior and Arduino's AlwaysBreakTemplateDeclarations: No configuration.
Seems to be a backwards compatibility name for BreakInheritanceList: BeforeComma:
Seems to be a backwards compatibility name for BreakConstructorInitializers: BeforeComma:
Setting this to an empty string (e.g., "") prevents any comments from being matched.
ConstructorInitializerAllOnOneLineOrOnePerLine: true forces PackConstructorInitializers: NextLine in the effective configuration even if PackConstructorInitializers is set to the desired BinPack in the configuration file.
Since ConstructorInitializerAllOnOneLineOrOnePerLine is deprecated, superseded by PackConstructorInitializers, ConstructorInitializerAllOnOneLineOrOnePerLine is set to the default false value that allows the desired setting for PackConstructorInitializers to be attained.
Setting this to an empty string (e.g., "") prevents any #include directives from being matched.
The Arduino IDE 1.x formatting style for classes is equivalent to IndentAccessModifiers: true. Unfortunately, this key also controls the indentation of struct members, the Arduino IDE 1.x formatting style of which is equivalent to IndentAccessModifiers: false. For this reason, the key must be set to false and the previous approach of aligning the class formatting style as closely as possible via the AccessModifierOffset configuration continued.
Note that empty lines at the ends of blocks are always removed.
Since the established behavior of the "Auto Format" feature from Arduino IDE 1.x is to allow any number of empty lines, this is set to a very large number to effectively reproduce the same.
Note that empty lines at the ends of blocks are always removed.
This key is omitted from the clang-format --dump-config output when it is set to an empty array. Since Arduino's configuration does not have any need to define such macros, it is expected that this key will be absent from the configuration file even though present in the ClangFormat documentation.
With Arduino's ColumnLimit setting of 0 (no limit), PackConstructorInitializers: BinPack is the most permissive setting,
The DerivePointerAlignment: true configuration causes whatever pointer alignment style is predominant in the code to be used by ClangFormat. In the event no prevailing style can be can't be detected from code, this value is used as a fallback.
This key is omitted from the clang-format --dump-config output when it is set to an empty array. Since Arduino's configuration does not have any need to define such formats, it is expected that this key will be absent from the configuration file even though present in the ClangFormat documentation.
During the formatting process, ClangFormat always uses spaces initially for indentation and alignment, according to the IndentWidth configuration setting value.
If use of tabs for the final indents or alignment is indicated by the UseTab configuration setting, those spaces are then converted to tabs according to the value of TabWidth. For example, if TabWidth is set to 4, then every occurrence of four spaces within the scope of the UseTab setting is converted to a tab.
This means there is a complex interaction between the IndentWidth and TabWidth values, which can produce unexpected results. For example, if IndentWidth is set to 2 and TabWidth to 4, every two indent levels is converted to a single tab, leaving two spaces for the final indentation of each odd level.
For this reason, TabWidth must always be set to the same value as IndentWidth.
This key is omitted from the clang-format --dump-config output when it is set to an empty array. Since Arduino's configuration does not have any need to define such macros, it is expected that this key will be absent from the configuration file even though present in the ClangFormat documentation.
The DeriveLineEnding: true configuration causes whatever line endings are predominant in the code to be used by ClangFormat. In the event no prevailing style can be can't be detected from code, this value is used as a fallback.
These keys (e.g., PenaltyBreakAssignment) are not applicable when wrapping is disabled by setting ColumnLimit to 0, as is done in Arduino's configuration. They are all arbitrarily set to 1.
The following keys are specific to languages other than the Arduino/C++/C targeted by this configuration. For this reason, their values are inconsequential.
They should be set to ClangFormat's default values.
BreakAfterJavaFieldAnnotationsJavaImportGroupsSortJavaStaticImport
InsertTrailingCommasJavaScriptQuotesJavaScriptWrapImports
AfterObjCDeclarationObjCBinPackProtocolListObjCBlockIndentWidthObjCBreakBeforeNestedBlockParamObjCSpaceAfterPropertyObjCSpaceBeforeProtocolList
Some sequence type keys have a base set of values which are hard coded into ClangFormat. These are appended to any custom values set in the configuration file and thus can not be overridden, even by setting the key to an empty array (e.g., AttributeMacros: []).
Arduino's configuration file sets these base set values explicitly even when they are not relevant to the Arduino code style. This provides transparency of the effective configuration and facilitates the maintenance of the configuration file
AttributeMacrosForEachMacrosIfMacrosIncludeCategoriesStatementAttributeLikeMacrosStatementMacrosWhitespaceSensitiveMacros