blob: cb07cb56a555da5a3d035bc8a805c82a3ed2c718 [file] [log] [blame]
//===--- Format.cpp - Format C++ code -------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file implements functions declared in Format.h. This will be
/// split into separate files as we go.
///
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "format-formatter"
#include "ContinuationIndenter.h"
#include "TokenAnnotator.h"
#include "UnwrappedLineParser.h"
#include "WhitespaceManager.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include "clang/Lex/Lexer.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/YAMLTraits.h"
#include <queue>
#include <string>
using clang::format::FormatStyle;
LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR(std::string)
namespace llvm {
namespace yaml {
template <> struct ScalarEnumerationTraits<FormatStyle::LanguageKind> {
static void enumeration(IO &IO, FormatStyle::LanguageKind &Value) {
IO.enumCase(Value, "Cpp", FormatStyle::LK_Cpp);
IO.enumCase(Value, "JavaScript", FormatStyle::LK_JavaScript);
IO.enumCase(Value, "Proto", FormatStyle::LK_Proto);
}
};
template <> struct ScalarEnumerationTraits<FormatStyle::LanguageStandard> {
static void enumeration(IO &IO, FormatStyle::LanguageStandard &Value) {
IO.enumCase(Value, "Cpp03", FormatStyle::LS_Cpp03);
IO.enumCase(Value, "C++03", FormatStyle::LS_Cpp03);
IO.enumCase(Value, "Cpp11", FormatStyle::LS_Cpp11);
IO.enumCase(Value, "C++11", FormatStyle::LS_Cpp11);
IO.enumCase(Value, "Auto", FormatStyle::LS_Auto);
}
};
template <> struct ScalarEnumerationTraits<FormatStyle::UseTabStyle> {
static void enumeration(IO &IO, FormatStyle::UseTabStyle &Value) {
IO.enumCase(Value, "Never", FormatStyle::UT_Never);
IO.enumCase(Value, "false", FormatStyle::UT_Never);
IO.enumCase(Value, "Always", FormatStyle::UT_Always);
IO.enumCase(Value, "true", FormatStyle::UT_Always);
IO.enumCase(Value, "ForIndentation", FormatStyle::UT_ForIndentation);
}
};
template <> struct ScalarEnumerationTraits<FormatStyle::BraceBreakingStyle> {
static void enumeration(IO &IO, FormatStyle::BraceBreakingStyle &Value) {
IO.enumCase(Value, "Attach", FormatStyle::BS_Attach);
IO.enumCase(Value, "Linux", FormatStyle::BS_Linux);
IO.enumCase(Value, "Stroustrup", FormatStyle::BS_Stroustrup);
IO.enumCase(Value, "Allman", FormatStyle::BS_Allman);
IO.enumCase(Value, "GNU", FormatStyle::BS_GNU);
}
};
template <>
struct ScalarEnumerationTraits<FormatStyle::NamespaceIndentationKind> {
static void enumeration(IO &IO,
FormatStyle::NamespaceIndentationKind &Value) {
IO.enumCase(Value, "None", FormatStyle::NI_None);
IO.enumCase(Value, "Inner", FormatStyle::NI_Inner);
IO.enumCase(Value, "All", FormatStyle::NI_All);
}
};
template <>
struct ScalarEnumerationTraits<FormatStyle::SpaceBeforeParensOptions> {
static void enumeration(IO &IO,
FormatStyle::SpaceBeforeParensOptions &Value) {
IO.enumCase(Value, "Never", FormatStyle::SBPO_Never);
IO.enumCase(Value, "ControlStatements",
FormatStyle::SBPO_ControlStatements);
IO.enumCase(Value, "Always", FormatStyle::SBPO_Always);
// For backward compatibility.
IO.enumCase(Value, "false", FormatStyle::SBPO_Never);
IO.enumCase(Value, "true", FormatStyle::SBPO_ControlStatements);
}
};
template <> struct MappingTraits<FormatStyle> {
static void mapping(IO &IO, FormatStyle &Style) {
// When reading, read the language first, we need it for getPredefinedStyle.
IO.mapOptional("Language", Style.Language);
if (IO.outputting()) {
StringRef StylesArray[] = { "LLVM", "Google", "Chromium",
"Mozilla", "WebKit", "GNU" };
ArrayRef<StringRef> Styles(StylesArray);
for (size_t i = 0, e = Styles.size(); i < e; ++i) {
StringRef StyleName(Styles[i]);
FormatStyle PredefinedStyle;
if (getPredefinedStyle(StyleName, Style.Language, &PredefinedStyle) &&
Style == PredefinedStyle) {
IO.mapOptional("# BasedOnStyle", StyleName);
break;
}
}
} else {
StringRef BasedOnStyle;
IO.mapOptional("BasedOnStyle", BasedOnStyle);
if (!BasedOnStyle.empty()) {
FormatStyle::LanguageKind OldLanguage = Style.Language;
FormatStyle::LanguageKind Language =
((FormatStyle *)IO.getContext())->Language;
if (!getPredefinedStyle(BasedOnStyle, Language, &Style)) {
IO.setError(Twine("Unknown value for BasedOnStyle: ", BasedOnStyle));
return;
}
Style.Language = OldLanguage;
}
}
IO.mapOptional("AccessModifierOffset", Style.AccessModifierOffset);
IO.mapOptional("ConstructorInitializerIndentWidth",
Style.ConstructorInitializerIndentWidth);
IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlinesLeft);
IO.mapOptional("AlignTrailingComments", Style.AlignTrailingComments);
IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
Style.AllowAllParametersOfDeclarationOnNextLine);
IO.mapOptional("AllowShortIfStatementsOnASingleLine",
Style.AllowShortIfStatementsOnASingleLine);
IO.mapOptional("AllowShortLoopsOnASingleLine",
Style.AllowShortLoopsOnASingleLine);
IO.mapOptional("AllowShortFunctionsOnASingleLine",
Style.AllowShortFunctionsOnASingleLine);
IO.mapOptional("AlwaysBreakTemplateDeclarations",
Style.AlwaysBreakTemplateDeclarations);
IO.mapOptional("AlwaysBreakBeforeMultilineStrings",
Style.AlwaysBreakBeforeMultilineStrings);
IO.mapOptional("BreakBeforeBinaryOperators",
Style.BreakBeforeBinaryOperators);
IO.mapOptional("BreakBeforeTernaryOperators",
Style.BreakBeforeTernaryOperators);
IO.mapOptional("BreakConstructorInitializersBeforeComma",
Style.BreakConstructorInitializersBeforeComma);
IO.mapOptional("BinPackParameters", Style.BinPackParameters);
IO.mapOptional("ColumnLimit", Style.ColumnLimit);
IO.mapOptional("ConstructorInitializerAllOnOneLineOrOnePerLine",
Style.ConstructorInitializerAllOnOneLineOrOnePerLine);
IO.mapOptional("DerivePointerBinding", Style.DerivePointerBinding);
IO.mapOptional("ExperimentalAutoDetectBinPacking",
Style.ExperimentalAutoDetectBinPacking);
IO.mapOptional("IndentCaseLabels", Style.IndentCaseLabels);
IO.mapOptional("MaxEmptyLinesToKeep", Style.MaxEmptyLinesToKeep);
IO.mapOptional("KeepEmptyLinesAtTheStartOfBlocks",
Style.KeepEmptyLinesAtTheStartOfBlocks);
IO.mapOptional("NamespaceIndentation", Style.NamespaceIndentation);
IO.mapOptional("ObjCSpaceAfterProperty", Style.ObjCSpaceAfterProperty);
IO.mapOptional("ObjCSpaceBeforeProtocolList",
Style.ObjCSpaceBeforeProtocolList);
IO.mapOptional("PenaltyBreakBeforeFirstCallParameter",
Style.PenaltyBreakBeforeFirstCallParameter);
IO.mapOptional("PenaltyBreakComment", Style.PenaltyBreakComment);
IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
IO.mapOptional("PenaltyBreakFirstLessLess",
Style.PenaltyBreakFirstLessLess);
IO.mapOptional("PenaltyExcessCharacter", Style.PenaltyExcessCharacter);
IO.mapOptional("PenaltyReturnTypeOnItsOwnLine",
Style.PenaltyReturnTypeOnItsOwnLine);
IO.mapOptional("PointerBindsToType", Style.PointerBindsToType);
IO.mapOptional("SpacesBeforeTrailingComments",
Style.SpacesBeforeTrailingComments);
IO.mapOptional("Cpp11BracedListStyle", Style.Cpp11BracedListStyle);
IO.mapOptional("Standard", Style.Standard);
IO.mapOptional("IndentWidth", Style.IndentWidth);
IO.mapOptional("TabWidth", Style.TabWidth);
IO.mapOptional("UseTab", Style.UseTab);
IO.mapOptional("BreakBeforeBraces", Style.BreakBeforeBraces);
IO.mapOptional("IndentFunctionDeclarationAfterType",
Style.IndentFunctionDeclarationAfterType);
IO.mapOptional("SpacesInParentheses", Style.SpacesInParentheses);
IO.mapOptional("SpacesInAngles", Style.SpacesInAngles);
IO.mapOptional("SpaceInEmptyParentheses", Style.SpaceInEmptyParentheses);
IO.mapOptional("SpacesInCStyleCastParentheses",
Style.SpacesInCStyleCastParentheses);
IO.mapOptional("SpacesInContainerLiterals",
Style.SpacesInContainerLiterals);
IO.mapOptional("SpaceBeforeAssignmentOperators",
Style.SpaceBeforeAssignmentOperators);
IO.mapOptional("ContinuationIndentWidth", Style.ContinuationIndentWidth);
IO.mapOptional("CommentPragmas", Style.CommentPragmas);
IO.mapOptional("ForEachMacros", Style.ForEachMacros);
// For backward compatibility.
if (!IO.outputting()) {
IO.mapOptional("SpaceAfterControlStatementKeyword",
Style.SpaceBeforeParens);
}
IO.mapOptional("SpaceBeforeParens", Style.SpaceBeforeParens);
}
};
// Allows to read vector<FormatStyle> while keeping default values.
// IO.getContext() should contain a pointer to the FormatStyle structure, that
// will be used to get default values for missing keys.
// If the first element has no Language specified, it will be treated as the
// default one for the following elements.
template <> struct DocumentListTraits<std::vector<FormatStyle> > {
static size_t size(IO &IO, std::vector<FormatStyle> &Seq) {
return Seq.size();
}
static FormatStyle &element(IO &IO, std::vector<FormatStyle> &Seq,
size_t Index) {
if (Index >= Seq.size()) {
assert(Index == Seq.size());
FormatStyle Template;
if (Seq.size() > 0 && Seq[0].Language == FormatStyle::LK_None) {
Template = Seq[0];
} else {
Template = *((const FormatStyle*)IO.getContext());
Template.Language = FormatStyle::LK_None;
}
Seq.resize(Index + 1, Template);
}
return Seq[Index];
}
};
}
}
namespace clang {
namespace format {
FormatStyle getLLVMStyle() {
FormatStyle LLVMStyle;
LLVMStyle.Language = FormatStyle::LK_Cpp;
LLVMStyle.AccessModifierOffset = -2;
LLVMStyle.AlignEscapedNewlinesLeft = false;
LLVMStyle.AlignTrailingComments = true;
LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
LLVMStyle.AllowShortFunctionsOnASingleLine = true;
LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
LLVMStyle.AllowShortLoopsOnASingleLine = false;
LLVMStyle.AlwaysBreakBeforeMultilineStrings = false;
LLVMStyle.AlwaysBreakTemplateDeclarations = false;
LLVMStyle.BinPackParameters = true;
LLVMStyle.BreakBeforeBinaryOperators = false;
LLVMStyle.BreakBeforeTernaryOperators = true;
LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
LLVMStyle.BreakConstructorInitializersBeforeComma = false;
LLVMStyle.ColumnLimit = 80;
LLVMStyle.CommentPragmas = "^ IWYU pragma:";
LLVMStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = false;
LLVMStyle.ConstructorInitializerIndentWidth = 4;
LLVMStyle.ContinuationIndentWidth = 4;
LLVMStyle.Cpp11BracedListStyle = true;
LLVMStyle.DerivePointerBinding = false;
LLVMStyle.ExperimentalAutoDetectBinPacking = false;
LLVMStyle.ForEachMacros.push_back("foreach");
LLVMStyle.ForEachMacros.push_back("Q_FOREACH");
LLVMStyle.ForEachMacros.push_back("BOOST_FOREACH");
LLVMStyle.IndentCaseLabels = false;
LLVMStyle.IndentFunctionDeclarationAfterType = false;
LLVMStyle.IndentWidth = 2;
LLVMStyle.TabWidth = 8;
LLVMStyle.MaxEmptyLinesToKeep = 1;
LLVMStyle.KeepEmptyLinesAtTheStartOfBlocks = true;
LLVMStyle.NamespaceIndentation = FormatStyle::NI_None;
LLVMStyle.ObjCSpaceAfterProperty = false;
LLVMStyle.ObjCSpaceBeforeProtocolList = true;
LLVMStyle.PointerBindsToType = false;
LLVMStyle.SpacesBeforeTrailingComments = 1;
LLVMStyle.Standard = FormatStyle::LS_Cpp11;
LLVMStyle.UseTab = FormatStyle::UT_Never;
LLVMStyle.SpacesInParentheses = false;
LLVMStyle.SpaceInEmptyParentheses = false;
LLVMStyle.SpacesInContainerLiterals = true;
LLVMStyle.SpacesInCStyleCastParentheses = false;
LLVMStyle.SpaceBeforeParens = FormatStyle::SBPO_ControlStatements;
LLVMStyle.SpaceBeforeAssignmentOperators = true;
LLVMStyle.SpacesInAngles = false;
LLVMStyle.PenaltyBreakComment = 300;
LLVMStyle.PenaltyBreakFirstLessLess = 120;
LLVMStyle.PenaltyBreakString = 1000;
LLVMStyle.PenaltyExcessCharacter = 1000000;
LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 60;
LLVMStyle.PenaltyBreakBeforeFirstCallParameter = 19;
return LLVMStyle;
}
FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
FormatStyle GoogleStyle = getLLVMStyle();
GoogleStyle.Language = Language;
GoogleStyle.AccessModifierOffset = -1;
GoogleStyle.AlignEscapedNewlinesLeft = true;
GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
GoogleStyle.AllowShortLoopsOnASingleLine = true;
GoogleStyle.AlwaysBreakBeforeMultilineStrings = true;
GoogleStyle.AlwaysBreakTemplateDeclarations = true;
GoogleStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
GoogleStyle.DerivePointerBinding = true;
GoogleStyle.IndentCaseLabels = true;
GoogleStyle.IndentFunctionDeclarationAfterType = true;
GoogleStyle.KeepEmptyLinesAtTheStartOfBlocks = false;
GoogleStyle.ObjCSpaceAfterProperty = false;
GoogleStyle.ObjCSpaceBeforeProtocolList = false;
GoogleStyle.PointerBindsToType = true;
GoogleStyle.SpacesBeforeTrailingComments = 2;
GoogleStyle.Standard = FormatStyle::LS_Auto;
GoogleStyle.PenaltyReturnTypeOnItsOwnLine = 200;
GoogleStyle.PenaltyBreakBeforeFirstCallParameter = 1;
if (Language == FormatStyle::LK_JavaScript) {
GoogleStyle.BreakBeforeTernaryOperators = false;
GoogleStyle.MaxEmptyLinesToKeep = 2;
GoogleStyle.SpacesInContainerLiterals = false;
} else if (Language == FormatStyle::LK_Proto) {
GoogleStyle.AllowShortFunctionsOnASingleLine = false;
}
return GoogleStyle;
}
FormatStyle getChromiumStyle(FormatStyle::LanguageKind Language) {
FormatStyle ChromiumStyle = getGoogleStyle(Language);
ChromiumStyle.AllowAllParametersOfDeclarationOnNextLine = false;
ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
ChromiumStyle.AllowShortLoopsOnASingleLine = false;
ChromiumStyle.BinPackParameters = false;
ChromiumStyle.DerivePointerBinding = false;
ChromiumStyle.Standard = FormatStyle::LS_Cpp03;
return ChromiumStyle;
}
FormatStyle getMozillaStyle() {
FormatStyle MozillaStyle = getLLVMStyle();
MozillaStyle.AllowAllParametersOfDeclarationOnNextLine = false;
MozillaStyle.Cpp11BracedListStyle = false;
MozillaStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
MozillaStyle.DerivePointerBinding = true;
MozillaStyle.IndentCaseLabels = true;
MozillaStyle.ObjCSpaceAfterProperty = true;
MozillaStyle.ObjCSpaceBeforeProtocolList = false;
MozillaStyle.PenaltyReturnTypeOnItsOwnLine = 200;
MozillaStyle.PointerBindsToType = true;
MozillaStyle.Standard = FormatStyle::LS_Cpp03;
return MozillaStyle;
}
FormatStyle getWebKitStyle() {
FormatStyle Style = getLLVMStyle();
Style.AccessModifierOffset = -4;
Style.AlignTrailingComments = false;
Style.BreakBeforeBinaryOperators = true;
Style.BreakBeforeBraces = FormatStyle::BS_Stroustrup;
Style.BreakConstructorInitializersBeforeComma = true;
Style.Cpp11BracedListStyle = false;
Style.ColumnLimit = 0;
Style.IndentWidth = 4;
Style.NamespaceIndentation = FormatStyle::NI_Inner;
Style.ObjCSpaceAfterProperty = true;
Style.PointerBindsToType = true;
Style.Standard = FormatStyle::LS_Cpp03;
return Style;
}
FormatStyle getGNUStyle() {
FormatStyle Style = getLLVMStyle();
Style.BreakBeforeBinaryOperators = true;
Style.BreakBeforeBraces = FormatStyle::BS_GNU;
Style.BreakBeforeTernaryOperators = true;
Style.Cpp11BracedListStyle = false;
Style.ColumnLimit = 79;
Style.SpaceBeforeParens = FormatStyle::SBPO_Always;
Style.Standard = FormatStyle::LS_Cpp03;
return Style;
}
bool getPredefinedStyle(StringRef Name, FormatStyle::LanguageKind Language,
FormatStyle *Style) {
if (Name.equals_lower("llvm")) {
*Style = getLLVMStyle();
} else if (Name.equals_lower("chromium")) {
*Style = getChromiumStyle(Language);
} else if (Name.equals_lower("mozilla")) {
*Style = getMozillaStyle();
} else if (Name.equals_lower("google")) {
*Style = getGoogleStyle(Language);
} else if (Name.equals_lower("webkit")) {
*Style = getWebKitStyle();
} else if (Name.equals_lower("gnu")) {
*Style = getGNUStyle();
} else {
return false;
}
Style->Language = Language;
return true;
}
llvm::error_code parseConfiguration(StringRef Text, FormatStyle *Style) {
assert(Style);
FormatStyle::LanguageKind Language = Style->Language;
assert(Language != FormatStyle::LK_None);
if (Text.trim().empty())
return llvm::make_error_code(llvm::errc::invalid_argument);
std::vector<FormatStyle> Styles;
llvm::yaml::Input Input(Text);
// DocumentListTraits<vector<FormatStyle>> uses the context to get default
// values for the fields, keys for which are missing from the configuration.
// Mapping also uses the context to get the language to find the correct
// base style.
Input.setContext(Style);
Input >> Styles;
if (Input.error())
return Input.error();
for (unsigned i = 0; i < Styles.size(); ++i) {
// Ensures that only the first configuration can skip the Language option.
if (Styles[i].Language == FormatStyle::LK_None && i != 0)
return llvm::make_error_code(llvm::errc::invalid_argument);
// Ensure that each language is configured at most once.
for (unsigned j = 0; j < i; ++j) {
if (Styles[i].Language == Styles[j].Language) {
DEBUG(llvm::dbgs()
<< "Duplicate languages in the config file on positions " << j
<< " and " << i << "\n");
return llvm::make_error_code(llvm::errc::invalid_argument);
}
}
}
// Look for a suitable configuration starting from the end, so we can
// find the configuration for the specific language first, and the default
// configuration (which can only be at slot 0) after it.
for (int i = Styles.size() - 1; i >= 0; --i) {
if (Styles[i].Language == Language ||
Styles[i].Language == FormatStyle::LK_None) {
*Style = Styles[i];
Style->Language = Language;
return llvm::make_error_code(llvm::errc::success);
}
}
return llvm::make_error_code(llvm::errc::not_supported);
}
std::string configurationAsText(const FormatStyle &Style) {
std::string Text;
llvm::raw_string_ostream Stream(Text);
llvm::yaml::Output Output(Stream);
// We use the same mapping method for input and output, so we need a non-const
// reference here.
FormatStyle NonConstStyle = Style;
Output << NonConstStyle;
return Stream.str();
}
namespace {
class NoColumnLimitFormatter {
public:
NoColumnLimitFormatter(ContinuationIndenter *Indenter) : Indenter(Indenter) {}
/// \brief Formats the line starting at \p State, simply keeping all of the
/// input's line breaking decisions.
void format(unsigned FirstIndent, const AnnotatedLine *Line) {
LineState State =
Indenter->getInitialState(FirstIndent, Line, /*DryRun=*/false);
while (State.NextToken != NULL) {
bool Newline =
Indenter->mustBreak(State) ||
(Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
Indenter->addTokenToState(State, Newline, /*DryRun=*/false);
}
}
private:
ContinuationIndenter *Indenter;
};
class LineJoiner {
public:
LineJoiner(const FormatStyle &Style) : Style(Style) {}
/// \brief Calculates how many lines can be merged into 1 starting at \p I.
unsigned
tryFitMultipleLinesInOne(unsigned Indent,
SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E) {
// We can never merge stuff if there are trailing line comments.
const AnnotatedLine *TheLine = *I;
if (TheLine->Last->Type == TT_LineComment)
return 0;
if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit)
return 0;
unsigned Limit =
Style.ColumnLimit == 0 ? UINT_MAX : Style.ColumnLimit - Indent;
// If we already exceed the column limit, we set 'Limit' to 0. The different
// tryMerge..() functions can then decide whether to still do merging.
Limit = TheLine->Last->TotalLength > Limit
? 0
: Limit - TheLine->Last->TotalLength;
if (I + 1 == E || I[1]->Type == LT_Invalid)
return 0;
if (TheLine->Last->Type == TT_FunctionLBrace &&
TheLine->First != TheLine->Last) {
return Style.AllowShortFunctionsOnASingleLine
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
if (TheLine->Last->is(tok::l_brace)) {
return Style.BreakBeforeBraces == FormatStyle::BS_Attach
? tryMergeSimpleBlock(I, E, Limit)
: 0;
}
if (I[1]->First->Type == TT_FunctionLBrace &&
Style.BreakBeforeBraces != FormatStyle::BS_Attach) {
// Check for Limit <= 2 to account for the " {".
if (Limit <= 2 || (Style.ColumnLimit == 0 && containsMustBreak(TheLine)))
return 0;
Limit -= 2;
unsigned MergedLines = 0;
if (Style.AllowShortFunctionsOnASingleLine) {
MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
// If we managed to merge the block, count the function header, which is
// on a separate line.
if (MergedLines > 0)
++MergedLines;
}
return MergedLines;
}
if (TheLine->First->is(tok::kw_if)) {
return Style.AllowShortIfStatementsOnASingleLine
? tryMergeSimpleControlStatement(I, E, Limit)
: 0;
}
if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while)) {
return Style.AllowShortLoopsOnASingleLine
? tryMergeSimpleControlStatement(I, E, Limit)
: 0;
}
if (TheLine->InPPDirective &&
(TheLine->First->HasUnescapedNewline || TheLine->First->IsFirst)) {
return tryMergeSimplePPDirective(I, E, Limit);
}
return 0;
}
private:
unsigned
tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
if (Limit == 0)
return 0;
if (!I[1]->InPPDirective || I[1]->First->HasUnescapedNewline)
return 0;
if (I + 2 != E && I[2]->InPPDirective && !I[2]->First->HasUnescapedNewline)
return 0;
if (1 + I[1]->Last->TotalLength > Limit)
return 0;
return 1;
}
unsigned tryMergeSimpleControlStatement(
SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
if (Limit == 0)
return 0;
if ((Style.BreakBeforeBraces == FormatStyle::BS_Allman ||
Style.BreakBeforeBraces == FormatStyle::BS_GNU) &&
I[1]->First->is(tok::l_brace))
return 0;
if (I[1]->InPPDirective != (*I)->InPPDirective ||
(I[1]->InPPDirective && I[1]->First->HasUnescapedNewline))
return 0;
Limit = limitConsideringMacros(I + 1, E, Limit);
AnnotatedLine &Line = **I;
if (Line.Last->isNot(tok::r_paren))
return 0;
if (1 + I[1]->Last->TotalLength > Limit)
return 0;
if (I[1]->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for,
tok::kw_while) ||
I[1]->First->Type == TT_LineComment)
return 0;
// Only inline simple if's (no nested if or else).
if (I + 2 != E && Line.First->is(tok::kw_if) &&
I[2]->First->is(tok::kw_else))
return 0;
return 1;
}
unsigned
tryMergeSimpleBlock(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
// First, check that the current line allows merging. This is the case if
// we're not in a control flow statement and the last token is an opening
// brace.
AnnotatedLine &Line = **I;
if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::r_brace,
tok::kw_else, tok::kw_try, tok::kw_catch,
tok::kw_for,
// This gets rid of all ObjC @ keywords and methods.
tok::at, tok::minus, tok::plus))
return 0;
FormatToken *Tok = I[1]->First;
if (Tok->is(tok::r_brace) && !Tok->MustBreakBefore &&
(Tok->getNextNonComment() == NULL ||
Tok->getNextNonComment()->is(tok::semi))) {
// We merge empty blocks even if the line exceeds the column limit.
Tok->SpacesRequiredBefore = 0;
Tok->CanBreakBefore = true;
return 1;
} else if (Limit != 0 && Line.First->isNot(tok::kw_namespace)) {
// Check that we still have three lines and they fit into the limit.
if (I + 2 == E || I[2]->Type == LT_Invalid)
return 0;
Limit = limitConsideringMacros(I + 2, E, Limit);
if (!nextTwoLinesFitInto(I, Limit))
return 0;
// Second, check that the next line does not contain any braces - if it
// does, readability declines when putting it into a single line.
if (I[1]->Last->Type == TT_LineComment || Tok->MustBreakBefore)
return 0;
do {
if (Tok->isOneOf(tok::l_brace, tok::r_brace))
return 0;
Tok = Tok->Next;
} while (Tok != NULL);
// Last, check that the third line contains a single closing brace.
Tok = I[2]->First;
if (Tok->getNextNonComment() != NULL || Tok->isNot(tok::r_brace) ||
Tok->MustBreakBefore)
return 0;
return 2;
}
return 0;
}
/// Returns the modified column limit for \p I if it is inside a macro and
/// needs a trailing '\'.
unsigned
limitConsideringMacros(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
SmallVectorImpl<AnnotatedLine *>::const_iterator E,
unsigned Limit) {
if (I[0]->InPPDirective && I + 1 != E &&
!I[1]->First->HasUnescapedNewline && !I[1]->First->is(tok::eof)) {
return Limit < 2 ? 0 : Limit - 2;
}
return Limit;
}
bool nextTwoLinesFitInto(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
unsigned Limit) {
return 1 + I[1]->Last->TotalLength + 1 + I[2]->Last->TotalLength <= Limit;
}
bool containsMustBreak(const AnnotatedLine *Line) {
for (const FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
if (Tok->MustBreakBefore)
return true;
}
return false;
}
const FormatStyle &Style;
};
class UnwrappedLineFormatter {
public:
UnwrappedLineFormatter(ContinuationIndenter *Indenter,
WhitespaceManager *Whitespaces,
const FormatStyle &Style)
: Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
Joiner(Style) {}
unsigned format(const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
int AdditionalIndent = 0, bool FixBadIndentation = false) {
assert(!Lines.empty());
unsigned Penalty = 0;
std::vector<int> IndentForLevel;
for (unsigned i = 0, e = Lines[0]->Level; i != e; ++i)
IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
const AnnotatedLine *PreviousLine = NULL;
for (SmallVectorImpl<AnnotatedLine *>::const_iterator I = Lines.begin(),
E = Lines.end();
I != E; ++I) {
const AnnotatedLine &TheLine = **I;
const FormatToken *FirstTok = TheLine.First;
int Offset = getIndentOffset(*FirstTok);
// Determine indent and try to merge multiple unwrapped lines.
unsigned Indent;
if (TheLine.InPPDirective) {
Indent = TheLine.Level * Style.IndentWidth;
} else {
while (IndentForLevel.size() <= TheLine.Level)
IndentForLevel.push_back(-1);
IndentForLevel.resize(TheLine.Level + 1);
Indent = getIndent(IndentForLevel, TheLine.Level);
}
unsigned LevelIndent = Indent;
if (static_cast<int>(Indent) + Offset >= 0)
Indent += Offset;
// Merge multiple lines if possible.
unsigned MergedLines = Joiner.tryFitMultipleLinesInOne(Indent, I, E);
if (MergedLines > 0 && Style.ColumnLimit == 0) {
// Disallow line merging if there is a break at the start of one of the
// input lines.
for (unsigned i = 0; i < MergedLines; ++i) {
if (I[i + 1]->First->NewlinesBefore > 0)
MergedLines = 0;
}
}
if (!DryRun) {
for (unsigned i = 0; i < MergedLines; ++i) {
join(*I[i], *I[i + 1]);
}
}
I += MergedLines;
bool FixIndentation =
FixBadIndentation && (LevelIndent != FirstTok->OriginalColumn);
if (TheLine.First->is(tok::eof)) {
if (PreviousLine && PreviousLine->Affected && !DryRun) {
// Remove the file's trailing whitespace.
unsigned Newlines = std::min(FirstTok->NewlinesBefore, 1u);
Whitespaces->replaceWhitespace(*TheLine.First, Newlines,
/*IndentLevel=*/0, /*Spaces=*/0,
/*TargetColumn=*/0);
}
} else if (TheLine.Type != LT_Invalid &&
(TheLine.Affected || FixIndentation)) {
if (FirstTok->WhitespaceRange.isValid()) {
if (!DryRun)
formatFirstToken(*TheLine.First, PreviousLine, TheLine.Level,
Indent, TheLine.InPPDirective);
} else {
Indent = LevelIndent = FirstTok->OriginalColumn;
}
// If everything fits on a single line, just put it there.
unsigned ColumnLimit = Style.ColumnLimit;
if (I + 1 != E) {
AnnotatedLine *NextLine = I[1];
if (NextLine->InPPDirective && !NextLine->First->HasUnescapedNewline)
ColumnLimit = getColumnLimit(TheLine.InPPDirective);
}
if (TheLine.Last->TotalLength + Indent <= ColumnLimit) {
LineState State = Indenter->getInitialState(Indent, &TheLine, DryRun);
while (State.NextToken != NULL)
Indenter->addTokenToState(State, /*Newline=*/false, DryRun);
} else if (Style.ColumnLimit == 0) {
// FIXME: Implement nested blocks for ColumnLimit = 0.
NoColumnLimitFormatter Formatter(Indenter);
if (!DryRun)
Formatter.format(Indent, &TheLine);
} else {
Penalty += format(TheLine, Indent, DryRun);
}
if (!TheLine.InPPDirective)
IndentForLevel[TheLine.Level] = LevelIndent;
} else if (TheLine.ChildrenAffected) {
format(TheLine.Children, DryRun);
} else {
// Format the first token if necessary, and notify the WhitespaceManager
// about the unchanged whitespace.
for (FormatToken *Tok = TheLine.First; Tok != NULL; Tok = Tok->Next) {
if (Tok == TheLine.First &&
(Tok->NewlinesBefore > 0 || Tok->IsFirst)) {
unsigned LevelIndent = Tok->OriginalColumn;
if (!DryRun) {
// Remove trailing whitespace of the previous line.
if ((PreviousLine && PreviousLine->Affected) ||
TheLine.LeadingEmptyLinesAffected) {
formatFirstToken(*Tok, PreviousLine, TheLine.Level, LevelIndent,
TheLine.InPPDirective);
} else {
Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
}
}
if (static_cast<int>(LevelIndent) - Offset >= 0)
LevelIndent -= Offset;
if (Tok->isNot(tok::comment) && !TheLine.InPPDirective)
IndentForLevel[TheLine.Level] = LevelIndent;
} else if (!DryRun) {
Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
}
}
}
if (!DryRun) {
for (FormatToken *Tok = TheLine.First; Tok != NULL; Tok = Tok->Next) {
Tok->Finalized = true;
}
}
PreviousLine = *I;
}
return Penalty;
}
private:
/// \brief Formats an \c AnnotatedLine and returns the penalty.
///
/// If \p DryRun is \c false, directly applies the changes.
unsigned format(const AnnotatedLine &Line, unsigned FirstIndent,
bool DryRun) {
LineState State = Indenter->getInitialState(FirstIndent, &Line, DryRun);
// If the ObjC method declaration does not fit on a line, we should format
// it with one arg per line.
if (State.Line->Type == LT_ObjCMethodDecl)
State.Stack.back().BreakBeforeParameter = true;
// Find best solution in solution space.
return analyzeSolutionSpace(State, DryRun);
}
/// \brief An edge in the solution space from \c Previous->State to \c State,
/// inserting a newline dependent on the \c NewLine.
struct StateNode {
StateNode(const LineState &State, bool NewLine, StateNode *Previous)
: State(State), NewLine(NewLine), Previous(Previous) {}
LineState State;
bool NewLine;
StateNode *Previous;
};
/// \brief A pair of <penalty, count> that is used to prioritize the BFS on.
///
/// In case of equal penalties, we want to prefer states that were inserted
/// first. During state generation we make sure that we insert states first
/// that break the line as late as possible.
typedef std::pair<unsigned, unsigned> OrderedPenalty;
/// \brief An item in the prioritized BFS search queue. The \c StateNode's
/// \c State has the given \c OrderedPenalty.
typedef std::pair<OrderedPenalty, StateNode *> QueueItem;
/// \brief The BFS queue type.
typedef std::priority_queue<QueueItem, std::vector<QueueItem>,
std::greater<QueueItem> > QueueType;
/// \brief Get the offset of the line relatively to the level.
///
/// For example, 'public:' labels in classes are offset by 1 or 2
/// characters to the left from their level.
int getIndentOffset(const FormatToken &RootToken) {
if (RootToken.isAccessSpecifier(false) || RootToken.isObjCAccessSpecifier())
return Style.AccessModifierOffset;
return 0;
}
/// \brief Add a new line and the required indent before the first Token
/// of the \c UnwrappedLine if there was no structural parsing error.
void formatFirstToken(FormatToken &RootToken,
const AnnotatedLine *PreviousLine, unsigned IndentLevel,
unsigned Indent, bool InPPDirective) {
unsigned Newlines =
std::min(RootToken.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1);
// Remove empty lines before "}" where applicable.
if (RootToken.is(tok::r_brace) &&
(!RootToken.Next ||
(RootToken.Next->is(tok::semi) && !RootToken.Next->Next)))
Newlines = std::min(Newlines, 1u);
if (Newlines == 0 && !RootToken.IsFirst)
Newlines = 1;
// Remove empty lines after "{".
if (!Style.KeepEmptyLinesAtTheStartOfBlocks && PreviousLine &&
PreviousLine->Last->is(tok::l_brace) &&
PreviousLine->First->isNot(tok::kw_namespace))
Newlines = 1;
// Insert extra new line before access specifiers.
if (PreviousLine && PreviousLine->Last->isOneOf(tok::semi, tok::r_brace) &&
RootToken.isAccessSpecifier() && RootToken.NewlinesBefore == 1)
++Newlines;
// Remove empty lines after access specifiers.
if (PreviousLine && PreviousLine->First->isAccessSpecifier())
Newlines = std::min(1u, Newlines);
Whitespaces->replaceWhitespace(RootToken, Newlines, IndentLevel, Indent,
Indent, InPPDirective &&
!RootToken.HasUnescapedNewline);
}
/// \brief Get the indent of \p Level from \p IndentForLevel.
///
/// \p IndentForLevel must contain the indent for the level \c l
/// at \p IndentForLevel[l], or a value < 0 if the indent for
/// that level is unknown.
unsigned getIndent(const std::vector<int> IndentForLevel, unsigned Level) {
if (IndentForLevel[Level] != -1)
return IndentForLevel[Level];
if (Level == 0)
return 0;
return getIndent(IndentForLevel, Level - 1) + Style.IndentWidth;
}
void join(AnnotatedLine &A, const AnnotatedLine &B) {
assert(!A.Last->Next);
assert(!B.First->Previous);
if (B.Affected)
A.Affected = true;
A.Last->Next = B.First;
B.First->Previous = A.Last;
B.First->CanBreakBefore = true;
unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore;
for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) {
Tok->TotalLength += LengthA;
A.Last = Tok;
}
}
unsigned getColumnLimit(bool InPPDirective) const {
// In preprocessor directives reserve two chars for trailing " \"
return Style.ColumnLimit - (InPPDirective ? 2 : 0);
}
/// \brief Analyze the entire solution space starting from \p InitialState.
///
/// This implements a variant of Dijkstra's algorithm on the graph that spans
/// the solution space (\c LineStates are the nodes). The algorithm tries to
/// find the shortest path (the one with lowest penalty) from \p InitialState
/// to a state where all tokens are placed. Returns the penalty.
///
/// If \p DryRun is \c false, directly applies the changes.
unsigned analyzeSolutionSpace(LineState &InitialState, bool DryRun = false) {
std::set<LineState> Seen;
// Increasing count of \c StateNode items we have created. This is used to
// create a deterministic order independent of the container.
unsigned Count = 0;
QueueType Queue;
// Insert start element into queue.
StateNode *Node =
new (Allocator.Allocate()) StateNode(InitialState, false, NULL);
Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
++Count;
unsigned Penalty = 0;
// While not empty, take first element and follow edges.
while (!Queue.empty()) {
Penalty = Queue.top().first.first;
StateNode *Node = Queue.top().second;
if (Node->State.NextToken == NULL) {
DEBUG(llvm::dbgs() << "\n---\nPenalty for line: " << Penalty << "\n");
break;
}
Queue.pop();
// Cut off the analysis of certain solutions if the analysis gets too
// complex. See description of IgnoreStackForComparison.
if (Count > 10000)
Node->State.IgnoreStackForComparison = true;
if (!Seen.insert(Node->State).second)
// State already examined with lower penalty.
continue;
FormatDecision LastFormat = Node->State.NextToken->Decision;
if (LastFormat == FD_Unformatted || LastFormat == FD_Continue)
addNextStateToQueue(Penalty, Node, /*NewLine=*/false, &Count, &Queue);
if (LastFormat == FD_Unformatted || LastFormat == FD_Break)
addNextStateToQueue(Penalty, Node, /*NewLine=*/true, &Count, &Queue);
}
if (Queue.empty()) {
// We were unable to find a solution, do nothing.
// FIXME: Add diagnostic?
DEBUG(llvm::dbgs() << "Could not find a solution.\n");
return 0;
}
// Reconstruct the solution.
if (!DryRun)
reconstructPath(InitialState, Queue.top().second);
DEBUG(llvm::dbgs() << "Total number of analyzed states: " << Count << "\n");
DEBUG(llvm::dbgs() << "---\n");
return Penalty;
}
void reconstructPath(LineState &State, StateNode *Current) {
std::deque<StateNode *> Path;
// We do not need a break before the initial token.
while (Current->Previous) {
Path.push_front(Current);
Current = Current->Previous;
}
for (std::deque<StateNode *>::iterator I = Path.begin(), E = Path.end();
I != E; ++I) {
unsigned Penalty = 0;
formatChildren(State, (*I)->NewLine, /*DryRun=*/false, Penalty);
Penalty += Indenter->addTokenToState(State, (*I)->NewLine, false);
DEBUG({
if ((*I)->NewLine) {
llvm::dbgs() << "Penalty for placing "
<< (*I)->Previous->State.NextToken->Tok.getName() << ": "
<< Penalty << "\n";
}
});
}
}
/// \brief Add the following state to the analysis queue \c Queue.
///
/// Assume the current state is \p PreviousNode and has been reached with a
/// penalty of \p Penalty. Insert a line break if \p NewLine is \c true.
void addNextStateToQueue(unsigned Penalty, StateNode *PreviousNode,
bool NewLine, unsigned *Count, QueueType *Queue) {
if (NewLine && !Indenter->canBreak(PreviousNode->State))
return;
if (!NewLine && Indenter->mustBreak(PreviousNode->State))
return;
StateNode *Node = new (Allocator.Allocate())
StateNode(PreviousNode->State, NewLine, PreviousNode);
if (!formatChildren(Node->State, NewLine, /*DryRun=*/true, Penalty))
return;
Penalty += Indenter->addTokenToState(Node->State, NewLine, true);
Queue->push(QueueItem(OrderedPenalty(Penalty, *Count), Node));
++(*Count);
}
/// \brief If the \p State's next token is an r_brace closing a nested block,
/// format the nested block before it.
///
/// Returns \c true if all children could be placed successfully and adapts
/// \p Penalty as well as \p State. If \p DryRun is false, also directly
/// creates changes using \c Whitespaces.
///
/// The crucial idea here is that children always get formatted upon
/// encountering the closing brace right after the nested block. Now, if we
/// are currently trying to keep the "}" on the same line (i.e. \p NewLine is
/// \c false), the entire block has to be kept on the same line (which is only
/// possible if it fits on the line, only contains a single statement, etc.
///
/// If \p NewLine is true, we format the nested block on separate lines, i.e.
/// break after the "{", format all lines with correct indentation and the put
/// the closing "}" on yet another new line.
///
/// This enables us to keep the simple structure of the
/// \c UnwrappedLineFormatter, where we only have two options for each token:
/// break or don't break.
bool formatChildren(LineState &State, bool NewLine, bool DryRun,
unsigned &Penalty) {
FormatToken &Previous = *State.NextToken->Previous;
const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
if (!LBrace || LBrace->isNot(tok::l_brace) ||
LBrace->BlockKind != BK_Block || Previous.Children.size() == 0)
// The previous token does not open a block. Nothing to do. We don't
// assert so that we can simply call this function for all tokens.
return true;
if (NewLine) {
int AdditionalIndent = State.Stack.back().Indent -
Previous.Children[0]->Level * Style.IndentWidth;
Penalty += format(Previous.Children, DryRun, AdditionalIndent,
/*FixBadIndentation=*/true);
return true;
}
// Cannot merge multiple statements into a single line.
if (Previous.Children.size() > 1)
return false;
// We can't put the closing "}" on a line with a trailing comment.
if (Previous.Children[0]->Last->isTrailingComment())
return false;
if (!DryRun) {
Whitespaces->replaceWhitespace(
*Previous.Children[0]->First,
/*Newlines=*/0, /*IndentLevel=*/0, /*Spaces=*/1,
/*StartOfTokenColumn=*/State.Column, State.Line->InPPDirective);
}
Penalty += format(*Previous.Children[0], State.Column + 1, DryRun);
State.Column += 1 + Previous.Children[0]->Last->TotalLength;
return true;
}
ContinuationIndenter *Indenter;
WhitespaceManager *Whitespaces;
FormatStyle Style;
LineJoiner Joiner;
llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
};
class FormatTokenLexer {
public:
FormatTokenLexer(Lexer &Lex, SourceManager &SourceMgr, FormatStyle &Style,
encoding::Encoding Encoding)
: FormatTok(NULL), IsFirstToken(true), GreaterStashed(false), Column(0),
TrailingWhitespace(0), Lex(Lex), SourceMgr(SourceMgr), Style(Style),
IdentTable(getFormattingLangOpts()), Encoding(Encoding) {
Lex.SetKeepWhitespaceMode(true);
for (const std::string& ForEachMacro : Style.ForEachMacros)
ForEachMacros.push_back(&IdentTable.get(ForEachMacro));
std::sort(ForEachMacros.begin(), ForEachMacros.end());
}
ArrayRef<FormatToken *> lex() {
assert(Tokens.empty());
do {
Tokens.push_back(getNextToken());
tryMergePreviousTokens();
} while (Tokens.back()->Tok.isNot(tok::eof));
return Tokens;
}
IdentifierTable &getIdentTable() { return IdentTable; }
private:
void tryMergePreviousTokens() {
if (tryMerge_TMacro())
return;
if (Style.Language == FormatStyle::LK_JavaScript) {
static tok::TokenKind JSIdentity[] = { tok::equalequal, tok::equal };
static tok::TokenKind JSNotIdentity[] = { tok::exclaimequal, tok::equal };
static tok::TokenKind JSShiftEqual[] = { tok::greater, tok::greater,
tok::greaterequal };
// FIXME: We probably need to change token type to mimic operator with the
// correct priority.
if (tryMergeTokens(JSIdentity))
return;
if (tryMergeTokens(JSNotIdentity))
return;
if (tryMergeTokens(JSShiftEqual))
return;
}
}
bool tryMergeTokens(ArrayRef<tok::TokenKind> Kinds) {
if (Tokens.size() < Kinds.size())
return false;
SmallVectorImpl<FormatToken *>::const_iterator First =
Tokens.end() - Kinds.size();
if (!First[0]->is(Kinds[0]))
return false;
unsigned AddLength = 0;
for (unsigned i = 1; i < Kinds.size(); ++i) {
if (!First[i]->is(Kinds[i]) || First[i]->WhitespaceRange.getBegin() !=
First[i]->WhitespaceRange.getEnd())
return false;
AddLength += First[i]->TokenText.size();
}
Tokens.resize(Tokens.size() - Kinds.size() + 1);
First[0]->TokenText = StringRef(First[0]->TokenText.data(),
First[0]->TokenText.size() + AddLength);
First[0]->ColumnWidth += AddLength;
return true;
}
bool tryMerge_TMacro() {
if (Tokens.size() < 4)
return false;
FormatToken *Last = Tokens.back();
if (!Last->is(tok::r_paren))
return false;
FormatToken *String = Tokens[Tokens.size() - 2];
if (!String->is(tok::string_literal) || String->IsMultiline)
return false;
if (!Tokens[Tokens.size() - 3]->is(tok::l_paren))
return false;
FormatToken *Macro = Tokens[Tokens.size() - 4];
if (Macro->TokenText != "_T")
return false;
const char *Start = Macro->TokenText.data();
const char *End = Last->TokenText.data() + Last->TokenText.size();
String->TokenText = StringRef(Start, End - Start);
String->IsFirst = Macro->IsFirst;
String->LastNewlineOffset = Macro->LastNewlineOffset;
String->WhitespaceRange = Macro->WhitespaceRange;
String->OriginalColumn = Macro->OriginalColumn;
String->ColumnWidth = encoding::columnWidthWithTabs(
String->TokenText, String->OriginalColumn, Style.TabWidth, Encoding);
Tokens.pop_back();
Tokens.pop_back();
Tokens.pop_back();
Tokens.back() = String;
return true;
}
FormatToken *getNextToken() {
if (GreaterStashed) {
// Create a synthesized second '>' token.
// FIXME: Increment Column and set OriginalColumn.
Token Greater = FormatTok->Tok;
FormatTok = new (Allocator.Allocate()) FormatToken;
FormatTok->Tok = Greater;
SourceLocation GreaterLocation =
FormatTok->Tok.getLocation().getLocWithOffset(1);
FormatTok->WhitespaceRange =
SourceRange(GreaterLocation, GreaterLocation);
FormatTok->TokenText = ">";
FormatTok->ColumnWidth = 1;
GreaterStashed = false;
return FormatTok;
}
FormatTok = new (Allocator.Allocate()) FormatToken;
readRawToken(*FormatTok);
SourceLocation WhitespaceStart =
FormatTok->Tok.getLocation().getLocWithOffset(-TrailingWhitespace);
FormatTok->IsFirst = IsFirstToken;
IsFirstToken = false;
// Consume and record whitespace until we find a significant token.
unsigned WhitespaceLength = TrailingWhitespace;
while (FormatTok->Tok.is(tok::unknown)) {
for (int i = 0, e = FormatTok->TokenText.size(); i != e; ++i) {
switch (FormatTok->TokenText[i]) {
case '\n':
++FormatTok->NewlinesBefore;
// FIXME: This is technically incorrect, as it could also
// be a literal backslash at the end of the line.
if (i == 0 || (FormatTok->TokenText[i - 1] != '\\' &&
(FormatTok->TokenText[i - 1] != '\r' || i == 1 ||
FormatTok->TokenText[i - 2] != '\\')))
FormatTok->HasUnescapedNewline = true;
FormatTok->LastNewlineOffset = WhitespaceLength + i + 1;
Column = 0;
break;
case '\r':
case '\f':
case '\v':
Column = 0;
break;
case ' ':
++Column;
break;
case '\t':
Column += Style.TabWidth - Column % Style.TabWidth;
break;
case '\\':
++Column;
if (i + 1 == e || (FormatTok->TokenText[i + 1] != '\r' &&
FormatTok->TokenText[i + 1] != '\n'))
FormatTok->Type = TT_ImplicitStringLiteral;
break;
default:
FormatTok->Type = TT_ImplicitStringLiteral;
++Column;
break;
}
}
if (FormatTok->Type == TT_ImplicitStringLiteral)
break;
WhitespaceLength += FormatTok->Tok.getLength();
readRawToken(*FormatTok);
}
// In case the token starts with escaped newlines, we want to
// take them into account as whitespace - this pattern is quite frequent
// in macro definitions.
// FIXME: Add a more explicit test.
while (FormatTok->TokenText.size() > 1 && FormatTok->TokenText[0] == '\\' &&
FormatTok->TokenText[1] == '\n') {
// FIXME: ++FormatTok->NewlinesBefore is missing...
WhitespaceLength += 2;
Column = 0;
FormatTok->TokenText = FormatTok->TokenText.substr(2);
}
FormatTok->WhitespaceRange = SourceRange(
WhitespaceStart, WhitespaceStart.getLocWithOffset(WhitespaceLength));
FormatTok->OriginalColumn = Column;
TrailingWhitespace = 0;
if (FormatTok->Tok.is(tok::comment)) {
// FIXME: Add the trimmed whitespace to Column.
StringRef UntrimmedText = FormatTok->TokenText;
FormatTok->TokenText = FormatTok->TokenText.rtrim(" \t\v\f");
TrailingWhitespace = UntrimmedText.size() - FormatTok->TokenText.size();
} else if (FormatTok->Tok.is(tok::raw_identifier)) {
IdentifierInfo &Info = IdentTable.get(FormatTok->TokenText);
FormatTok->Tok.setIdentifierInfo(&Info);
FormatTok->Tok.setKind(Info.getTokenID());
} else if (FormatTok->Tok.is(tok::greatergreater)) {
FormatTok->Tok.setKind(tok::greater);
FormatTok->TokenText = FormatTok->TokenText.substr(0, 1);
GreaterStashed = true;
}
// Now FormatTok is the next non-whitespace token.
StringRef Text = FormatTok->TokenText;
size_t FirstNewlinePos = Text.find('\n');
if (FirstNewlinePos == StringRef::npos) {
// FIXME: ColumnWidth actually depends on the start column, we need to
// take this into account when the token is moved.
FormatTok->ColumnWidth =
encoding::columnWidthWithTabs(Text, Column, Style.TabWidth, Encoding);
Column += FormatTok->ColumnWidth;
} else {
FormatTok->IsMultiline = true;
// FIXME: ColumnWidth actually depends on the start column, we need to
// take this into account when the token is moved.
FormatTok->ColumnWidth = encoding::columnWidthWithTabs(
Text.substr(0, FirstNewlinePos), Column, Style.TabWidth, Encoding);
// The last line of the token always starts in column 0.
// Thus, the length can be precomputed even in the presence of tabs.
FormatTok->LastLineColumnWidth = encoding::columnWidthWithTabs(
Text.substr(Text.find_last_of('\n') + 1), 0, Style.TabWidth,
Encoding);
Column = FormatTok->LastLineColumnWidth;
}
FormatTok->IsForEachMacro =
std::binary_search(ForEachMacros.begin(), ForEachMacros.end(),
FormatTok->Tok.getIdentifierInfo());
return FormatTok;
}
FormatToken *FormatTok;
bool IsFirstToken;
bool GreaterStashed;
unsigned Column;
unsigned TrailingWhitespace;
Lexer &Lex;
SourceManager &SourceMgr;
FormatStyle &Style;
IdentifierTable IdentTable;
encoding::Encoding Encoding;
llvm::SpecificBumpPtrAllocator<FormatToken> Allocator;
SmallVector<FormatToken *, 16> Tokens;
SmallVector<IdentifierInfo*, 8> ForEachMacros;
void readRawToken(FormatToken &Tok) {
Lex.LexFromRawLexer(Tok.Tok);
Tok.TokenText = StringRef(SourceMgr.getCharacterData(Tok.Tok.getLocation()),
Tok.Tok.getLength());
// For formatting, treat unterminated string literals like normal string
// literals.
if (Tok.is(tok::unknown)) {
if (!Tok.TokenText.empty() && Tok.TokenText[0] == '"') {
Tok.Tok.setKind(tok::string_literal);
Tok.IsUnterminatedLiteral = true;
} else if (Style.Language == FormatStyle::LK_JavaScript &&
Tok.TokenText == "''") {
Tok.Tok.setKind(tok::char_constant);
}
}
}
};
static StringRef getLanguageName(FormatStyle::LanguageKind Language) {
switch (Language) {
case FormatStyle::LK_Cpp:
return "C++";
case FormatStyle::LK_JavaScript:
return "JavaScript";
case FormatStyle::LK_Proto:
return "Proto";
default:
return "Unknown";
}
}
class Formatter : public UnwrappedLineConsumer {
public:
Formatter(const FormatStyle &Style, Lexer &Lex, SourceManager &SourceMgr,
const std::vector<CharSourceRange> &Ranges)
: Style(Style), Lex(Lex), SourceMgr(SourceMgr),
Whitespaces(SourceMgr, Style, inputUsesCRLF(Lex.getBuffer())),
Ranges(Ranges.begin(), Ranges.end()), UnwrappedLines(1),
Encoding(encoding::detectEncoding(Lex.getBuffer())) {
DEBUG(llvm::dbgs() << "File encoding: "
<< (Encoding == encoding::Encoding_UTF8 ? "UTF8"
: "unknown")
<< "\n");
DEBUG(llvm::dbgs() << "Language: " << getLanguageName(Style.Language)
<< "\n");
}
tooling::Replacements format() {
tooling::Replacements Result;
FormatTokenLexer Tokens(Lex, SourceMgr, Style, Encoding);
UnwrappedLineParser Parser(Style, Tokens.lex(), *this);
bool StructuralError = Parser.parse();
assert(UnwrappedLines.rbegin()->empty());
for (unsigned Run = 0, RunE = UnwrappedLines.size(); Run + 1 != RunE;
++Run) {
DEBUG(llvm::dbgs() << "Run " << Run << "...\n");
SmallVector<AnnotatedLine *, 16> AnnotatedLines;
for (unsigned i = 0, e = UnwrappedLines[Run].size(); i != e; ++i) {
AnnotatedLines.push_back(new AnnotatedLine(UnwrappedLines[Run][i]));
}
tooling::Replacements RunResult =
format(AnnotatedLines, StructuralError, Tokens);
DEBUG({
llvm::dbgs() << "Replacements for run " << Run << ":\n";
for (tooling::Replacements::iterator I = RunResult.begin(),
E = RunResult.end();
I != E; ++I) {
llvm::dbgs() << I->toString() << "\n";
}
});
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
delete AnnotatedLines[i];
}
Result.insert(RunResult.begin(), RunResult.end());
Whitespaces.reset();
}
return Result;
}
tooling::Replacements format(SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
bool StructuralError, FormatTokenLexer &Tokens) {
TokenAnnotator Annotator(Style, Tokens.getIdentTable().get("in"));
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
Annotator.annotate(*AnnotatedLines[i]);
}
deriveLocalStyle(AnnotatedLines);
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
Annotator.calculateFormattingInformation(*AnnotatedLines[i]);
}
computeAffectedLines(AnnotatedLines.begin(), AnnotatedLines.end());
Annotator.setCommentLineLevels(AnnotatedLines);
ContinuationIndenter Indenter(Style, SourceMgr, Whitespaces, Encoding,
BinPackInconclusiveFunctions);
UnwrappedLineFormatter Formatter(&Indenter, &Whitespaces, Style);
Formatter.format(AnnotatedLines, /*DryRun=*/false);
return Whitespaces.generateReplacements();
}
private:
// Determines which lines are affected by the SourceRanges given as input.
// Returns \c true if at least one line between I and E or one of their
// children is affected.
bool computeAffectedLines(SmallVectorImpl<AnnotatedLine *>::iterator I,
SmallVectorImpl<AnnotatedLine *>::iterator E) {
bool SomeLineAffected = false;
const AnnotatedLine *PreviousLine = NULL;
while (I != E) {
AnnotatedLine *Line = *I;
Line->LeadingEmptyLinesAffected = affectsLeadingEmptyLines(*Line->First);
// If a line is part of a preprocessor directive, it needs to be formatted
// if any token within the directive is affected.
if (Line->InPPDirective) {
FormatToken *Last = Line->Last;
SmallVectorImpl<AnnotatedLine *>::iterator PPEnd = I + 1;
while (PPEnd != E && !(*PPEnd)->First->HasUnescapedNewline) {
Last = (*PPEnd)->Last;
++PPEnd;
}
if (affectsTokenRange(*Line->First, *Last,
/*IncludeLeadingNewlines=*/false)) {
SomeLineAffected = true;
markAllAsAffected(I, PPEnd);
}
I = PPEnd;
continue;
}
if (nonPPLineAffected(Line, PreviousLine))
SomeLineAffected = true;
PreviousLine = Line;
++I;
}
return SomeLineAffected;
}
// Determines whether 'Line' is affected by the SourceRanges given as input.
// Returns \c true if line or one if its children is affected.
bool nonPPLineAffected(AnnotatedLine *Line,
const AnnotatedLine *PreviousLine) {
bool SomeLineAffected = false;
Line->ChildrenAffected =
computeAffectedLines(Line->Children.begin(), Line->Children.end());
if (Line->ChildrenAffected)
SomeLineAffected = true;
// Stores whether one of the line's tokens is directly affected.
bool SomeTokenAffected = false;
// Stores whether we need to look at the leading newlines of the next token
// in order to determine whether it was affected.
bool IncludeLeadingNewlines = false;
// Stores whether the first child line of any of this line's tokens is
// affected.
bool SomeFirstChildAffected = false;
for (FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
// Determine whether 'Tok' was affected.
if (affectsTokenRange(*Tok, *Tok, IncludeLeadingNewlines))
SomeTokenAffected = true;
// Determine whether the first child of 'Tok' was affected.
if (!Tok->Children.empty() && Tok->Children.front()->Affected)
SomeFirstChildAffected = true;
IncludeLeadingNewlines = Tok->Children.empty();
}
// Was this line moved, i.e. has it previously been on the same line as an
// affected line?
bool LineMoved = PreviousLine && PreviousLine->Affected &&
Line->First->NewlinesBefore == 0;
bool IsContinuedComment = Line->First->is(tok::comment) &&
Line->First->Next == NULL &&
Line->First->NewlinesBefore < 2 && PreviousLine &&
PreviousLine->Affected &&
PreviousLine->Last->is(tok::comment);
if (SomeTokenAffected || SomeFirstChildAffected || LineMoved ||
IsContinuedComment) {
Line->Affected = true;
SomeLineAffected = true;
}
return SomeLineAffected;
}
// Marks all lines between I and E as well as all their children as affected.
void markAllAsAffected(SmallVectorImpl<AnnotatedLine *>::iterator I,
SmallVectorImpl<AnnotatedLine *>::iterator E) {
while (I != E) {
(*I)->Affected = true;
markAllAsAffected((*I)->Children.begin(), (*I)->Children.end());
++I;
}
}
// Returns true if the range from 'First' to 'Last' intersects with one of the
// input ranges.
bool affectsTokenRange(const FormatToken &First, const FormatToken &Last,
bool IncludeLeadingNewlines) {
SourceLocation Start = First.WhitespaceRange.getBegin();
if (!IncludeLeadingNewlines)
Start = Start.getLocWithOffset(First.LastNewlineOffset);
SourceLocation End = Last.getStartOfNonWhitespace();
if (Last.TokenText.size() > 0)
End = End.getLocWithOffset(Last.TokenText.size() - 1);
CharSourceRange Range = CharSourceRange::getCharRange(Start, End);
return affectsCharSourceRange(Range);
}
// Returns true if one of the input ranges intersect the leading empty lines
// before 'Tok'.
bool affectsLeadingEmptyLines(const FormatToken &Tok) {
CharSourceRange EmptyLineRange = CharSourceRange::getCharRange(
Tok.WhitespaceRange.getBegin(),
Tok.WhitespaceRange.getBegin().getLocWithOffset(Tok.LastNewlineOffset));
return affectsCharSourceRange(EmptyLineRange);
}
// Returns true if 'Range' intersects with one of the input ranges.
bool affectsCharSourceRange(const CharSourceRange &Range) {
for (SmallVectorImpl<CharSourceRange>::const_iterator I = Ranges.begin(),
E = Ranges.end();
I != E; ++I) {
if (!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(), I->getBegin()) &&
!SourceMgr.isBeforeInTranslationUnit(I->getEnd(), Range.getBegin()))
return true;
}
return false;
}
static bool inputUsesCRLF(StringRef Text) {
return Text.count('\r') * 2 > Text.count('\n');
}
void
deriveLocalStyle(const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
unsigned CountBoundToVariable = 0;
unsigned CountBoundToType = 0;
bool HasCpp03IncompatibleFormat = false;
bool HasBinPackedFunction = false;
bool HasOnePerLineFunction = false;
for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
if (!AnnotatedLines[i]->First->Next)
continue;
FormatToken *Tok = AnnotatedLines[i]->First->Next;
while (Tok->Next) {
if (Tok->Type == TT_PointerOrReference) {
bool SpacesBefore =
Tok->WhitespaceRange.getBegin() != Tok->WhitespaceRange.getEnd();
bool SpacesAfter = Tok->Next->WhitespaceRange.getBegin() !=
Tok->Next->WhitespaceRange.getEnd();
if (SpacesBefore && !SpacesAfter)
++CountBoundToVariable;
else if (!SpacesBefore && SpacesAfter)
++CountBoundToType;
}
if (Tok->WhitespaceRange.getBegin() == Tok->WhitespaceRange.getEnd()) {
if (Tok->is(tok::coloncolon) &&
Tok->Previous->Type == TT_TemplateOpener)
HasCpp03IncompatibleFormat = true;
if (Tok->Type == TT_TemplateCloser &&
Tok->Previous->Type == TT_TemplateCloser)
HasCpp03IncompatibleFormat = true;
}
if (Tok->PackingKind == PPK_BinPacked)
HasBinPackedFunction = true;
if (Tok->PackingKind == PPK_OnePerLine)
HasOnePerLineFunction = true;
Tok = Tok->Next;
}
}
if (Style.DerivePointerBinding) {
if (CountBoundToType > CountBoundToVariable)
Style.PointerBindsToType = true;
else if (CountBoundToType < CountBoundToVariable)
Style.PointerBindsToType = false;
}
if (Style.Standard == FormatStyle::LS_Auto) {
Style.Standard = HasCpp03IncompatibleFormat ? FormatStyle::LS_Cpp11
: FormatStyle::LS_Cpp03;
}
BinPackInconclusiveFunctions =
HasBinPackedFunction || !HasOnePerLineFunction;
}
void consumeUnwrappedLine(const UnwrappedLine &TheLine) override {
assert(!UnwrappedLines.empty());
UnwrappedLines.back().push_back(TheLine);
}
void finishRun() override {
UnwrappedLines.push_back(SmallVector<UnwrappedLine, 16>());
}
FormatStyle Style;
Lexer &Lex;
SourceManager &SourceMgr;
WhitespaceManager Whitespaces;
SmallVector<CharSourceRange, 8> Ranges;
SmallVector<SmallVector<UnwrappedLine, 16>, 2> UnwrappedLines;
encoding::Encoding Encoding;
bool BinPackInconclusiveFunctions;
};
} // end anonymous namespace
tooling::Replacements reformat(const FormatStyle &Style, Lexer &Lex,
SourceManager &SourceMgr,
std::vector<CharSourceRange> Ranges) {
Formatter formatter(Style, Lex, SourceMgr, Ranges);
return formatter.format();
}
tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
std::vector<tooling::Range> Ranges,
StringRef FileName) {
FileManager Files((FileSystemOptions()));
DiagnosticsEngine Diagnostics(
IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs),
new DiagnosticOptions);
SourceManager SourceMgr(Diagnostics, Files);
llvm::MemoryBuffer *Buf = llvm::MemoryBuffer::getMemBuffer(Code, FileName);
const clang::FileEntry *Entry =
Files.getVirtualFile(FileName, Buf->getBufferSize(), 0);
SourceMgr.overrideFileContents(Entry, Buf);
FileID ID =
SourceMgr.createFileID(Entry, SourceLocation(), clang::SrcMgr::C_User);
Lexer Lex(ID, SourceMgr.getBuffer(ID), SourceMgr,
getFormattingLangOpts(Style.Standard));
SourceLocation StartOfFile = SourceMgr.getLocForStartOfFile(ID);
std::vector<CharSourceRange> CharRanges;
for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
SourceLocation Start = StartOfFile.getLocWithOffset(Ranges[i].getOffset());
SourceLocation End = Start.getLocWithOffset(Ranges[i].getLength());
CharRanges.push_back(CharSourceRange::getCharRange(Start, End));
}
return reformat(Style, Lex, SourceMgr, CharRanges);
}
LangOptions getFormattingLangOpts(FormatStyle::LanguageStandard Standard) {
LangOptions LangOpts;
LangOpts.CPlusPlus = 1;
LangOpts.CPlusPlus11 = Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
LangOpts.LineComment = 1;
LangOpts.Bool = 1;
LangOpts.ObjC1 = 1;
LangOpts.ObjC2 = 1;
return LangOpts;
}
const char *StyleOptionHelpDescription =
"Coding style, currently supports:\n"
" LLVM, Google, Chromium, Mozilla, WebKit.\n"
"Use -style=file to load style configuration from\n"
".clang-format file located in one of the parent\n"
"directories of the source file (or current\n"
"directory for stdin).\n"
"Use -style=\"{key: value, ...}\" to set specific\n"
"parameters, e.g.:\n"
" -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\"";
static FormatStyle::LanguageKind getLanguageByFileName(StringRef FileName) {
if (FileName.endswith_lower(".js")) {
return FormatStyle::LK_JavaScript;
} else if (FileName.endswith_lower(".proto") ||
FileName.endswith_lower(".protodevel")) {
return FormatStyle::LK_Proto;
}
return FormatStyle::LK_Cpp;
}
FormatStyle getStyle(StringRef StyleName, StringRef FileName,
StringRef FallbackStyle) {
FormatStyle Style = getLLVMStyle();
Style.Language = getLanguageByFileName(FileName);
if (!getPredefinedStyle(FallbackStyle, Style.Language, &Style)) {
llvm::errs() << "Invalid fallback style \"" << FallbackStyle
<< "\" using LLVM style\n";
return Style;
}
if (StyleName.startswith("{")) {
// Parse YAML/JSON style from the command line.
if (llvm::error_code ec = parseConfiguration(StyleName, &Style)) {
llvm::errs() << "Error parsing -style: " << ec.message() << ", using "
<< FallbackStyle << " style\n";
}
return Style;
}
if (!StyleName.equals_lower("file")) {
if (!getPredefinedStyle(StyleName, Style.Language, &Style))
llvm::errs() << "Invalid value for -style, using " << FallbackStyle
<< " style\n";
return Style;
}
// Look for .clang-format/_clang-format file in the file's parent directories.
SmallString<128> UnsuitableConfigFiles;
SmallString<128> Path(FileName);
llvm::sys::fs::make_absolute(Path);
for (StringRef Directory = Path; !Directory.empty();
Directory = llvm::sys::path::parent_path(Directory)) {
if (!llvm::sys::fs::is_directory(Directory))
continue;
SmallString<128> ConfigFile(Directory);
llvm::sys::path::append(ConfigFile, ".clang-format");
DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
bool IsFile = false;
// Ignore errors from is_regular_file: we only need to know if we can read
// the file or not.
llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
if (!IsFile) {
// Try _clang-format too, since dotfiles are not commonly used on Windows.
ConfigFile = Directory;
llvm::sys::path::append(ConfigFile, "_clang-format");
DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
llvm::sys::fs::is_regular_file(Twine(ConfigFile), IsFile);
}
if (IsFile) {
std::unique_ptr<llvm::MemoryBuffer> Text;
if (llvm::error_code ec =
llvm::MemoryBuffer::getFile(ConfigFile.c_str(), Text)) {
llvm::errs() << ec.message() << "\n";
break;
}
if (llvm::error_code ec = parseConfiguration(Text->getBuffer(), &Style)) {
if (ec == llvm::errc::not_supported) {
if (!UnsuitableConfigFiles.empty())
UnsuitableConfigFiles.append(", ");
UnsuitableConfigFiles.append(ConfigFile);
continue;
}
llvm::errs() << "Error reading " << ConfigFile << ": " << ec.message()
<< "\n";
break;
}
DEBUG(llvm::dbgs() << "Using configuration file " << ConfigFile << "\n");
return Style;
}
}
llvm::errs() << "Can't find usable .clang-format, using " << FallbackStyle
<< " style\n";
if (!UnsuitableConfigFiles.empty()) {
llvm::errs() << "Configuration file(s) do(es) not support "
<< getLanguageName(Style.Language) << ": "
<< UnsuitableConfigFiles << "\n";
}
return Style;
}
} // namespace format
} // namespace clang