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//===--- Format.h - Format C++ code -----------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
/// \file
/// Various functions to configurably format source code.
#include "clang/Frontend/FrontendAction.h"
#include "clang/Tooling/Refactoring.h"
#include "llvm/Support/system_error.h"
namespace clang {
class Lexer;
class SourceManager;
class DiagnosticConsumer;
namespace format {
/// \brief The \c FormatStyle is used to configure the formatting to follow
/// specific guidelines.
struct FormatStyle {
/// \brief Supported languages. When stored in a configuration file, specifies
/// the language, that the configuration targets. When passed to the
/// reformat() function, enables syntax features specific to the language.
enum LanguageKind {
/// Do not use.
/// Should be used for C, C++, ObjectiveC, ObjectiveC++.
/// Should be used for JavaScript.
/// Should be used for Protocol Buffers
/// (
/// \brief Language, this format style is targeted at.
LanguageKind Language;
/// \brief The column limit.
/// A column limit of \c 0 means that there is no column limit. In this case,
/// clang-format will respect the input's line breaking decisions within
/// statements unless they contradict other rules.
unsigned ColumnLimit;
/// \brief The maximum number of consecutive empty lines to keep.
unsigned MaxEmptyLinesToKeep;
/// \brief If true, empty lines at the start of blocks are kept.
bool KeepEmptyLinesAtTheStartOfBlocks;
/// \brief The penalty for each line break introduced inside a comment.
unsigned PenaltyBreakComment;
/// \brief The penalty for each line break introduced inside a string literal.
unsigned PenaltyBreakString;
/// \brief The penalty for each character outside of the column limit.
unsigned PenaltyExcessCharacter;
/// \brief The penalty for breaking before the first \c <<.
unsigned PenaltyBreakFirstLessLess;
/// \brief The penalty for breaking a function call after "call(".
unsigned PenaltyBreakBeforeFirstCallParameter;
/// \brief Set whether & and * bind to the type as opposed to the variable.
bool PointerBindsToType;
/// \brief If \c true, analyze the formatted file for the most common binding
/// and use \c PointerBindsToType only as fallback.
bool DerivePointerBinding;
/// \brief The extra indent or outdent of access modifiers, e.g. \c public:.
int AccessModifierOffset;
/// \brief Supported language standards.
enum LanguageStandard {
/// Use C++03-compatible syntax.
/// Use features of C++11 (e.g. \c A<A<int>> instead of
/// <tt>A<A<int> ></tt>).
/// Automatic detection based on the input.
/// \brief Format compatible with this standard, e.g. use
/// <tt>A<A<int> ></tt> instead of \c A<A<int>> for LS_Cpp03.
LanguageStandard Standard;
/// \brief Indent case labels one level from the switch statement.
/// When \c false, use the same indentation level as for the switch statement.
/// Switch statement body is always indented one level more than case labels.
bool IndentCaseLabels;
/// \brief Different ways to indent namespace contents.
enum NamespaceIndentationKind {
/// Don't indent in namespaces.
/// Indent only in inner namespaces (nested in other namespaces).
/// Indent in all namespaces.
/// \brief The indentation used for namespaces.
NamespaceIndentationKind NamespaceIndentation;
/// \brief The number of spaces to before trailing line comments.
unsigned SpacesBeforeTrailingComments;
/// \brief If \c false, a function call's or function definition's parameters
/// will either all be on the same line or will have one line each.
bool BinPackParameters;
/// \brief If \c true, clang-format detects whether function calls and
/// definitions are formatted with one parameter per line.
/// Each call can be bin-packed, one-per-line or inconclusive. If it is
/// inconclusive, e.g. completely on one line, but a decision needs to be
/// made, clang-format analyzes whether there are other bin-packed cases in
/// the input file and act accordingly.
/// NOTE: This is an experimental flag, that might go away or be renamed. Do
/// not use this in config files, etc. Use at your own risk.
bool ExperimentalAutoDetectBinPacking;
/// \brief Allow putting all parameters of a function declaration onto
/// the next line even if \c BinPackParameters is \c false.
bool AllowAllParametersOfDeclarationOnNextLine;
/// \brief Penalty for putting the return type of a function onto its own
/// line.
unsigned PenaltyReturnTypeOnItsOwnLine;
/// \brief If the constructor initializers don't fit on a line, put each
/// initializer on its own line.
bool ConstructorInitializerAllOnOneLineOrOnePerLine;
/// \brief Always break constructor initializers before commas and align
/// the commas with the colon.
bool BreakConstructorInitializersBeforeComma;
/// \brief If \c true, <tt>if (a) return;</tt> can be put on a single
/// line.
bool AllowShortIfStatementsOnASingleLine;
/// \brief If \c true, <tt>while (true) continue;</tt> can be put on a
/// single line.
bool AllowShortLoopsOnASingleLine;
/// \brief If \c true, <tt>int f() { return 0; }</tt> can be put on a single
/// line.
bool AllowShortFunctionsOnASingleLine;
/// \brief Add a space after \c @property in Objective-C, i.e. use
/// <tt>@property (readonly)</tt> instead of <tt>@property(readonly)</tt>.
bool ObjCSpaceAfterProperty;
/// \brief Add a space in front of an Objective-C protocol list, i.e. use
/// <tt>Foo <Protocol></tt> instead of \c Foo<Protocol>.
bool ObjCSpaceBeforeProtocolList;
/// \brief If \c true, aligns trailing comments.
bool AlignTrailingComments;
/// \brief If \c true, aligns escaped newlines as far left as possible.
/// Otherwise puts them into the right-most column.
bool AlignEscapedNewlinesLeft;
/// \brief The number of columns to use for indentation.
unsigned IndentWidth;
/// \brief The number of columns used for tab stops.
unsigned TabWidth;
/// \brief The number of characters to use for indentation of constructor
/// initializer lists.
unsigned ConstructorInitializerIndentWidth;
/// \brief If \c true, always break after the <tt>template<...></tt> of a
/// template declaration.
bool AlwaysBreakTemplateDeclarations;
/// \brief If \c true, always break before multiline string literals.
bool AlwaysBreakBeforeMultilineStrings;
/// \brief Different ways to use tab in formatting.
enum UseTabStyle {
/// Never use tab.
/// Use tabs only for indentation.
/// Use tabs whenever we need to fill whitespace that spans at least from
/// one tab stop to the next one.
/// \brief The way to use tab characters in the resulting file.
UseTabStyle UseTab;
/// \brief If \c true, binary operators will be placed after line breaks.
bool BreakBeforeBinaryOperators;
/// \brief If \c true, ternary operators will be placed after line breaks.
bool BreakBeforeTernaryOperators;
/// \brief Different ways to attach braces to their surrounding context.
enum BraceBreakingStyle {
/// Always attach braces to surrounding context.
/// Like \c Attach, but break before braces on function, namespace and
/// class definitions.
/// Like \c Attach, but break before function definitions.
/// Always break before braces.
/// Always break before braces and add an extra level of indentation to
/// braces of control statements, not to those of class, function
/// or other definitions.
/// \brief The brace breaking style to use.
BraceBreakingStyle BreakBeforeBraces;
/// \brief If \c true, format braced lists as best suited for C++11 braced
/// lists.
/// Important differences:
/// - No spaces inside the braced list.
/// - No line break before the closing brace.
/// - Indentation with the continuation indent, not with the block indent.
/// Fundamentally, C++11 braced lists are formatted exactly like function
/// calls would be formatted in their place. If the braced list follows a name
/// (e.g. a type or variable name), clang-format formats as if the \c {} were
/// the parentheses of a function call with that name. If there is no name,
/// a zero-length name is assumed.
bool Cpp11BracedListStyle;
/// \brief If \c true, indent when breaking function declarations which
/// are not also definitions after the type.
bool IndentFunctionDeclarationAfterType;
/// \brief If \c true, spaces will be inserted after '(' and before ')'.
bool SpacesInParentheses;
/// \brief If \c true, spaces will be inserted after '<' and before '>' in
/// template argument lists
bool SpacesInAngles;
/// \brief If \c true, spaces may be inserted into '()'.
bool SpaceInEmptyParentheses;
/// \brief If \c true, spaces are inserted inside container literals (e.g.
/// ObjC and Javascript array and dict literals).
bool SpacesInContainerLiterals;
/// \brief If \c true, spaces may be inserted into C style casts.
bool SpacesInCStyleCastParentheses;
/// \brief Different ways to put a space before opening parentheses.
enum SpaceBeforeParensOptions {
/// Never put a space before opening parentheses.
/// Put a space before opening parentheses only after control statement
/// keywords (<tt>for/if/while...</tt>).
/// Always put a space before opening parentheses, except when it's
/// prohibited by the syntax rules (in function-like macro definitions) or
/// when determined by other style rules (after unary operators, opening
/// parentheses, etc.)
/// \brief Defines in which cases to put a space before opening parentheses.
SpaceBeforeParensOptions SpaceBeforeParens;
/// \brief If \c false, spaces will be removed before assignment operators.
bool SpaceBeforeAssignmentOperators;
/// \brief Indent width for line continuations.
unsigned ContinuationIndentWidth;
/// \brief A regular expression that describes comments with special meaning,
/// which should not be split into lines or otherwise changed.
std::string CommentPragmas;
/// \brief A vector of macros that should be interpreted as foreach loops
/// instead of as function calls.
/// These are expected to be macros of the form:
/// \code
/// FOREACH(<variable-declaration>, ...)
/// <loop-body>
/// \endcode
/// For example: BOOST_FOREACH.
std::vector<std::string> ForEachMacros;
bool operator==(const FormatStyle &R) const {
return AccessModifierOffset == R.AccessModifierOffset &&
ConstructorInitializerIndentWidth ==
R.ConstructorInitializerIndentWidth &&
AlignEscapedNewlinesLeft == R.AlignEscapedNewlinesLeft &&
AlignTrailingComments == R.AlignTrailingComments &&
AllowAllParametersOfDeclarationOnNextLine ==
R.AllowAllParametersOfDeclarationOnNextLine &&
AllowShortFunctionsOnASingleLine ==
R.AllowShortFunctionsOnASingleLine &&
AllowShortIfStatementsOnASingleLine ==
R.AllowShortIfStatementsOnASingleLine &&
AllowShortLoopsOnASingleLine == R.AllowShortLoopsOnASingleLine &&
AlwaysBreakTemplateDeclarations ==
R.AlwaysBreakTemplateDeclarations &&
AlwaysBreakBeforeMultilineStrings ==
R.AlwaysBreakBeforeMultilineStrings &&
BinPackParameters == R.BinPackParameters &&
BreakBeforeBinaryOperators == R.BreakBeforeBinaryOperators &&
BreakBeforeTernaryOperators == R.BreakBeforeTernaryOperators &&
BreakBeforeBraces == R.BreakBeforeBraces &&
BreakConstructorInitializersBeforeComma ==
R.BreakConstructorInitializersBeforeComma &&
ColumnLimit == R.ColumnLimit &&
ConstructorInitializerAllOnOneLineOrOnePerLine ==
R.ConstructorInitializerAllOnOneLineOrOnePerLine &&
DerivePointerBinding == R.DerivePointerBinding &&
ExperimentalAutoDetectBinPacking ==
R.ExperimentalAutoDetectBinPacking &&
IndentCaseLabels == R.IndentCaseLabels &&
IndentFunctionDeclarationAfterType ==
R.IndentFunctionDeclarationAfterType &&
IndentWidth == R.IndentWidth && Language == R.Language &&
MaxEmptyLinesToKeep == R.MaxEmptyLinesToKeep &&
KeepEmptyLinesAtTheStartOfBlocks ==
R.KeepEmptyLinesAtTheStartOfBlocks &&
NamespaceIndentation == R.NamespaceIndentation &&
ObjCSpaceAfterProperty == R.ObjCSpaceAfterProperty &&
ObjCSpaceBeforeProtocolList == R.ObjCSpaceBeforeProtocolList &&
PenaltyBreakComment == R.PenaltyBreakComment &&
PenaltyBreakFirstLessLess == R.PenaltyBreakFirstLessLess &&
PenaltyBreakString == R.PenaltyBreakString &&
PenaltyExcessCharacter == R.PenaltyExcessCharacter &&
PenaltyReturnTypeOnItsOwnLine == R.PenaltyReturnTypeOnItsOwnLine &&
PointerBindsToType == R.PointerBindsToType &&
SpacesBeforeTrailingComments == R.SpacesBeforeTrailingComments &&
Cpp11BracedListStyle == R.Cpp11BracedListStyle &&
Standard == R.Standard && TabWidth == R.TabWidth &&
UseTab == R.UseTab && SpacesInParentheses == R.SpacesInParentheses &&
SpacesInAngles == R.SpacesInAngles &&
SpaceInEmptyParentheses == R.SpaceInEmptyParentheses &&
SpacesInContainerLiterals == R.SpacesInContainerLiterals &&
SpacesInCStyleCastParentheses == R.SpacesInCStyleCastParentheses &&
SpaceBeforeParens == R.SpaceBeforeParens &&
SpaceBeforeAssignmentOperators == R.SpaceBeforeAssignmentOperators &&
ContinuationIndentWidth == R.ContinuationIndentWidth &&
CommentPragmas == R.CommentPragmas &&
ForEachMacros == R.ForEachMacros;
/// \brief Returns a format style complying with the LLVM coding standards:
FormatStyle getLLVMStyle();
/// \brief Returns a format style complying with one of Google's style guides:
FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language);
/// \brief Returns a format style complying with Chromium's style guide:
FormatStyle getChromiumStyle(FormatStyle::LanguageKind Language);
/// \brief Returns a format style complying with Mozilla's style guide:
FormatStyle getMozillaStyle();
/// \brief Returns a format style complying with Webkit's style guide:
FormatStyle getWebKitStyle();
/// \brief Returns a format style complying with GNU Coding Standards:
FormatStyle getGNUStyle();
/// \brief Gets a predefined style for the specified language by name.
/// Currently supported names: LLVM, Google, Chromium, Mozilla. Names are
/// compared case-insensitively.
/// Returns \c true if the Style has been set.
bool getPredefinedStyle(StringRef Name, FormatStyle::LanguageKind Language,
FormatStyle *Style);
/// \brief Parse configuration from YAML-formatted text.
/// Style->Language is used to get the base style, if the \c BasedOnStyle
/// option is present.
/// When \c BasedOnStyle is not present, options not present in the YAML
/// document, are retained in \p Style.
llvm::error_code parseConfiguration(StringRef Text, FormatStyle *Style);
/// \brief Gets configuration in a YAML string.
std::string configurationAsText(const FormatStyle &Style);
/// \brief Reformats the given \p Ranges in the token stream coming out of
/// \c Lex.
/// Each range is extended on either end to its next bigger logic unit, i.e.
/// everything that might influence its formatting or might be influenced by its
/// formatting.
/// Returns the \c Replacements necessary to make all \p Ranges comply with
/// \p Style.
tooling::Replacements reformat(const FormatStyle &Style, Lexer &Lex,
SourceManager &SourceMgr,
std::vector<CharSourceRange> Ranges);
/// \brief Reformats the given \p Ranges in \p Code.
/// Otherwise identical to the reformat() function consuming a \c Lexer.
tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
std::vector<tooling::Range> Ranges,
StringRef FileName = "<stdin>");
/// \brief Returns the \c LangOpts that the formatter expects you to set.
/// \param Standard determines lexing mode: LC_Cpp11 and LS_Auto turn on C++11
/// lexing mode, LS_Cpp03 - C++03 mode.
LangOptions getFormattingLangOpts(FormatStyle::LanguageStandard Standard =
/// \brief Description to be used for help text for a llvm::cl option for
/// specifying format style. The description is closely related to the operation
/// of getStyle().
extern const char *StyleOptionHelpDescription;
/// \brief Construct a FormatStyle based on \c StyleName.
/// \c StyleName can take several forms:
/// \li "{<key>: <value>, ...}" - Set specic style parameters.
/// \li "<style name>" - One of the style names supported by
/// getPredefinedStyle().
/// \li "file" - Load style configuration from a file called '.clang-format'
/// located in one of the parent directories of \c FileName or the current
/// directory if \c FileName is empty.
/// \param[in] StyleName Style name to interpret according to the description
/// above.
/// \param[in] FileName Path to start search for .clang-format if \c StyleName
/// == "file".
/// \param[in] FallbackStyle The name of a predefined style used to fallback to
/// in case the style can't be determined from \p StyleName.
/// \returns FormatStyle as specified by \c StyleName. If no style could be
/// determined, the default is LLVM Style (see getLLVMStyle()).
FormatStyle getStyle(StringRef StyleName, StringRef FileName,
StringRef FallbackStyle);
} // end namespace format
} // end namespace clang