1 //===--- Format.cpp - Format C++ code -------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// \file
11 /// \brief This file implements functions declared in Format.h. This will be
12 /// split into separate files as we go.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #include "clang/Format/Format.h"
17 #include "AffectedRangeManager.h"
18 #include "ContinuationIndenter.h"
19 #include "FormatTokenLexer.h"
20 #include "NamespaceEndCommentsFixer.h"
21 #include "SortJavaScriptImports.h"
22 #include "TokenAnalyzer.h"
23 #include "TokenAnnotator.h"
24 #include "UnwrappedLineFormatter.h"
25 #include "UnwrappedLineParser.h"
26 #include "WhitespaceManager.h"
27 #include "clang/Basic/Diagnostic.h"
28 #include "clang/Basic/DiagnosticOptions.h"
29 #include "clang/Basic/SourceManager.h"
30 #include "clang/Basic/VirtualFileSystem.h"
31 #include "clang/Lex/Lexer.h"
32 #include "llvm/ADT/STLExtras.h"
33 #include "llvm/Support/Allocator.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/Path.h"
36 #include "llvm/Support/Regex.h"
37 #include "llvm/Support/YAMLTraits.h"
38 #include <algorithm>
39 #include <memory>
40 #include <string>
41 
42 #define DEBUG_TYPE "format-formatter"
43 
44 using clang::format::FormatStyle;
45 
46 LLVM_YAML_IS_FLOW_SEQUENCE_VECTOR(std::string)
47 LLVM_YAML_IS_SEQUENCE_VECTOR(clang::format::FormatStyle::IncludeCategory)
48 
49 namespace llvm {
50 namespace yaml {
51 template <> struct ScalarEnumerationTraits<FormatStyle::LanguageKind> {
52   static void enumeration(IO &IO, FormatStyle::LanguageKind &Value) {
53     IO.enumCase(Value, "Cpp", FormatStyle::LK_Cpp);
54     IO.enumCase(Value, "Java", FormatStyle::LK_Java);
55     IO.enumCase(Value, "JavaScript", FormatStyle::LK_JavaScript);
56     IO.enumCase(Value, "ObjC", FormatStyle::LK_ObjC);
57     IO.enumCase(Value, "Proto", FormatStyle::LK_Proto);
58     IO.enumCase(Value, "TableGen", FormatStyle::LK_TableGen);
59   }
60 };
61 
62 template <> struct ScalarEnumerationTraits<FormatStyle::LanguageStandard> {
63   static void enumeration(IO &IO, FormatStyle::LanguageStandard &Value) {
64     IO.enumCase(Value, "Cpp03", FormatStyle::LS_Cpp03);
65     IO.enumCase(Value, "C++03", FormatStyle::LS_Cpp03);
66     IO.enumCase(Value, "Cpp11", FormatStyle::LS_Cpp11);
67     IO.enumCase(Value, "C++11", FormatStyle::LS_Cpp11);
68     IO.enumCase(Value, "Auto", FormatStyle::LS_Auto);
69   }
70 };
71 
72 template <> struct ScalarEnumerationTraits<FormatStyle::UseTabStyle> {
73   static void enumeration(IO &IO, FormatStyle::UseTabStyle &Value) {
74     IO.enumCase(Value, "Never", FormatStyle::UT_Never);
75     IO.enumCase(Value, "false", FormatStyle::UT_Never);
76     IO.enumCase(Value, "Always", FormatStyle::UT_Always);
77     IO.enumCase(Value, "true", FormatStyle::UT_Always);
78     IO.enumCase(Value, "ForIndentation", FormatStyle::UT_ForIndentation);
79     IO.enumCase(Value, "ForContinuationAndIndentation",
80                 FormatStyle::UT_ForContinuationAndIndentation);
81   }
82 };
83 
84 template <> struct ScalarEnumerationTraits<FormatStyle::JavaScriptQuoteStyle> {
85   static void enumeration(IO &IO, FormatStyle::JavaScriptQuoteStyle &Value) {
86     IO.enumCase(Value, "Leave", FormatStyle::JSQS_Leave);
87     IO.enumCase(Value, "Single", FormatStyle::JSQS_Single);
88     IO.enumCase(Value, "Double", FormatStyle::JSQS_Double);
89   }
90 };
91 
92 template <> struct ScalarEnumerationTraits<FormatStyle::ShortFunctionStyle> {
93   static void enumeration(IO &IO, FormatStyle::ShortFunctionStyle &Value) {
94     IO.enumCase(Value, "None", FormatStyle::SFS_None);
95     IO.enumCase(Value, "false", FormatStyle::SFS_None);
96     IO.enumCase(Value, "All", FormatStyle::SFS_All);
97     IO.enumCase(Value, "true", FormatStyle::SFS_All);
98     IO.enumCase(Value, "Inline", FormatStyle::SFS_Inline);
99     IO.enumCase(Value, "Empty", FormatStyle::SFS_Empty);
100   }
101 };
102 
103 template <> struct ScalarEnumerationTraits<FormatStyle::BinaryOperatorStyle> {
104   static void enumeration(IO &IO, FormatStyle::BinaryOperatorStyle &Value) {
105     IO.enumCase(Value, "All", FormatStyle::BOS_All);
106     IO.enumCase(Value, "true", FormatStyle::BOS_All);
107     IO.enumCase(Value, "None", FormatStyle::BOS_None);
108     IO.enumCase(Value, "false", FormatStyle::BOS_None);
109     IO.enumCase(Value, "NonAssignment", FormatStyle::BOS_NonAssignment);
110   }
111 };
112 
113 template <> struct ScalarEnumerationTraits<FormatStyle::BraceBreakingStyle> {
114   static void enumeration(IO &IO, FormatStyle::BraceBreakingStyle &Value) {
115     IO.enumCase(Value, "Attach", FormatStyle::BS_Attach);
116     IO.enumCase(Value, "Linux", FormatStyle::BS_Linux);
117     IO.enumCase(Value, "Mozilla", FormatStyle::BS_Mozilla);
118     IO.enumCase(Value, "Stroustrup", FormatStyle::BS_Stroustrup);
119     IO.enumCase(Value, "Allman", FormatStyle::BS_Allman);
120     IO.enumCase(Value, "GNU", FormatStyle::BS_GNU);
121     IO.enumCase(Value, "WebKit", FormatStyle::BS_WebKit);
122     IO.enumCase(Value, "Custom", FormatStyle::BS_Custom);
123   }
124 };
125 
126 template <> struct ScalarEnumerationTraits<FormatStyle::BreakConstructorInitializersStyle> {
127   static void enumeration(IO &IO, FormatStyle::BreakConstructorInitializersStyle &Value) {
128     IO.enumCase(Value, "BeforeColon", FormatStyle::BCIS_BeforeColon);
129     IO.enumCase(Value, "BeforeComma", FormatStyle::BCIS_BeforeComma);
130     IO.enumCase(Value, "AfterColon", FormatStyle::BCIS_AfterColon);
131   }
132 };
133 
134 template <>
135 struct ScalarEnumerationTraits<FormatStyle::ReturnTypeBreakingStyle> {
136   static void enumeration(IO &IO, FormatStyle::ReturnTypeBreakingStyle &Value) {
137     IO.enumCase(Value, "None", FormatStyle::RTBS_None);
138     IO.enumCase(Value, "All", FormatStyle::RTBS_All);
139     IO.enumCase(Value, "TopLevel", FormatStyle::RTBS_TopLevel);
140     IO.enumCase(Value, "TopLevelDefinitions",
141                 FormatStyle::RTBS_TopLevelDefinitions);
142     IO.enumCase(Value, "AllDefinitions", FormatStyle::RTBS_AllDefinitions);
143   }
144 };
145 
146 template <>
147 struct ScalarEnumerationTraits<FormatStyle::DefinitionReturnTypeBreakingStyle> {
148   static void
149   enumeration(IO &IO, FormatStyle::DefinitionReturnTypeBreakingStyle &Value) {
150     IO.enumCase(Value, "None", FormatStyle::DRTBS_None);
151     IO.enumCase(Value, "All", FormatStyle::DRTBS_All);
152     IO.enumCase(Value, "TopLevel", FormatStyle::DRTBS_TopLevel);
153 
154     // For backward compatibility.
155     IO.enumCase(Value, "false", FormatStyle::DRTBS_None);
156     IO.enumCase(Value, "true", FormatStyle::DRTBS_All);
157   }
158 };
159 
160 template <>
161 struct ScalarEnumerationTraits<FormatStyle::NamespaceIndentationKind> {
162   static void enumeration(IO &IO,
163                           FormatStyle::NamespaceIndentationKind &Value) {
164     IO.enumCase(Value, "None", FormatStyle::NI_None);
165     IO.enumCase(Value, "Inner", FormatStyle::NI_Inner);
166     IO.enumCase(Value, "All", FormatStyle::NI_All);
167   }
168 };
169 
170 template <> struct ScalarEnumerationTraits<FormatStyle::BracketAlignmentStyle> {
171   static void enumeration(IO &IO, FormatStyle::BracketAlignmentStyle &Value) {
172     IO.enumCase(Value, "Align", FormatStyle::BAS_Align);
173     IO.enumCase(Value, "DontAlign", FormatStyle::BAS_DontAlign);
174     IO.enumCase(Value, "AlwaysBreak", FormatStyle::BAS_AlwaysBreak);
175 
176     // For backward compatibility.
177     IO.enumCase(Value, "true", FormatStyle::BAS_Align);
178     IO.enumCase(Value, "false", FormatStyle::BAS_DontAlign);
179   }
180 };
181 
182 template <> struct ScalarEnumerationTraits<FormatStyle::EscapedNewlineAlignmentStyle> {
183   static void enumeration(IO &IO, FormatStyle::EscapedNewlineAlignmentStyle &Value) {
184     IO.enumCase(Value, "DontAlign", FormatStyle::ENAS_DontAlign);
185     IO.enumCase(Value, "Left", FormatStyle::ENAS_Left);
186     IO.enumCase(Value, "Right", FormatStyle::ENAS_Right);
187 
188     // For backward compatibility.
189     IO.enumCase(Value, "true", FormatStyle::ENAS_Left);
190     IO.enumCase(Value, "false", FormatStyle::ENAS_Right);
191   }
192 };
193 
194 template <> struct ScalarEnumerationTraits<FormatStyle::PointerAlignmentStyle> {
195   static void enumeration(IO &IO, FormatStyle::PointerAlignmentStyle &Value) {
196     IO.enumCase(Value, "Middle", FormatStyle::PAS_Middle);
197     IO.enumCase(Value, "Left", FormatStyle::PAS_Left);
198     IO.enumCase(Value, "Right", FormatStyle::PAS_Right);
199 
200     // For backward compatibility.
201     IO.enumCase(Value, "true", FormatStyle::PAS_Left);
202     IO.enumCase(Value, "false", FormatStyle::PAS_Right);
203   }
204 };
205 
206 template <>
207 struct ScalarEnumerationTraits<FormatStyle::SpaceBeforeParensOptions> {
208   static void enumeration(IO &IO,
209                           FormatStyle::SpaceBeforeParensOptions &Value) {
210     IO.enumCase(Value, "Never", FormatStyle::SBPO_Never);
211     IO.enumCase(Value, "ControlStatements",
212                 FormatStyle::SBPO_ControlStatements);
213     IO.enumCase(Value, "Always", FormatStyle::SBPO_Always);
214 
215     // For backward compatibility.
216     IO.enumCase(Value, "false", FormatStyle::SBPO_Never);
217     IO.enumCase(Value, "true", FormatStyle::SBPO_ControlStatements);
218   }
219 };
220 
221 template <> struct MappingTraits<FormatStyle> {
222   static void mapping(IO &IO, FormatStyle &Style) {
223     // When reading, read the language first, we need it for getPredefinedStyle.
224     IO.mapOptional("Language", Style.Language);
225 
226     if (IO.outputting()) {
227       StringRef StylesArray[] = {"LLVM",    "Google", "Chromium",
228                                  "Mozilla", "WebKit", "GNU"};
229       ArrayRef<StringRef> Styles(StylesArray);
230       for (size_t i = 0, e = Styles.size(); i < e; ++i) {
231         StringRef StyleName(Styles[i]);
232         FormatStyle PredefinedStyle;
233         if (getPredefinedStyle(StyleName, Style.Language, &PredefinedStyle) &&
234             Style == PredefinedStyle) {
235           IO.mapOptional("# BasedOnStyle", StyleName);
236           break;
237         }
238       }
239     } else {
240       StringRef BasedOnStyle;
241       IO.mapOptional("BasedOnStyle", BasedOnStyle);
242       if (!BasedOnStyle.empty()) {
243         FormatStyle::LanguageKind OldLanguage = Style.Language;
244         FormatStyle::LanguageKind Language =
245             ((FormatStyle *)IO.getContext())->Language;
246         if (!getPredefinedStyle(BasedOnStyle, Language, &Style)) {
247           IO.setError(Twine("Unknown value for BasedOnStyle: ", BasedOnStyle));
248           return;
249         }
250         Style.Language = OldLanguage;
251       }
252     }
253 
254     // For backward compatibility.
255     if (!IO.outputting()) {
256       IO.mapOptional("AlignEscapedNewlinesLeft", Style.AlignEscapedNewlines);
257       IO.mapOptional("DerivePointerBinding", Style.DerivePointerAlignment);
258       IO.mapOptional("IndentFunctionDeclarationAfterType",
259                      Style.IndentWrappedFunctionNames);
260       IO.mapOptional("PointerBindsToType", Style.PointerAlignment);
261       IO.mapOptional("SpaceAfterControlStatementKeyword",
262                      Style.SpaceBeforeParens);
263     }
264 
265     IO.mapOptional("AccessModifierOffset", Style.AccessModifierOffset);
266     IO.mapOptional("AlignAfterOpenBracket", Style.AlignAfterOpenBracket);
267     IO.mapOptional("AlignConsecutiveAssignments",
268                    Style.AlignConsecutiveAssignments);
269     IO.mapOptional("AlignConsecutiveDeclarations",
270                    Style.AlignConsecutiveDeclarations);
271     IO.mapOptional("AlignEscapedNewlines", Style.AlignEscapedNewlines);
272     IO.mapOptional("AlignOperands", Style.AlignOperands);
273     IO.mapOptional("AlignTrailingComments", Style.AlignTrailingComments);
274     IO.mapOptional("AllowAllParametersOfDeclarationOnNextLine",
275                    Style.AllowAllParametersOfDeclarationOnNextLine);
276     IO.mapOptional("AllowShortBlocksOnASingleLine",
277                    Style.AllowShortBlocksOnASingleLine);
278     IO.mapOptional("AllowShortCaseLabelsOnASingleLine",
279                    Style.AllowShortCaseLabelsOnASingleLine);
280     IO.mapOptional("AllowShortFunctionsOnASingleLine",
281                    Style.AllowShortFunctionsOnASingleLine);
282     IO.mapOptional("AllowShortIfStatementsOnASingleLine",
283                    Style.AllowShortIfStatementsOnASingleLine);
284     IO.mapOptional("AllowShortLoopsOnASingleLine",
285                    Style.AllowShortLoopsOnASingleLine);
286     IO.mapOptional("AlwaysBreakAfterDefinitionReturnType",
287                    Style.AlwaysBreakAfterDefinitionReturnType);
288     IO.mapOptional("AlwaysBreakAfterReturnType",
289                    Style.AlwaysBreakAfterReturnType);
290     // If AlwaysBreakAfterDefinitionReturnType was specified but
291     // AlwaysBreakAfterReturnType was not, initialize the latter from the
292     // former for backwards compatibility.
293     if (Style.AlwaysBreakAfterDefinitionReturnType != FormatStyle::DRTBS_None &&
294         Style.AlwaysBreakAfterReturnType == FormatStyle::RTBS_None) {
295       if (Style.AlwaysBreakAfterDefinitionReturnType == FormatStyle::DRTBS_All)
296         Style.AlwaysBreakAfterReturnType = FormatStyle::RTBS_AllDefinitions;
297       else if (Style.AlwaysBreakAfterDefinitionReturnType ==
298                FormatStyle::DRTBS_TopLevel)
299         Style.AlwaysBreakAfterReturnType =
300             FormatStyle::RTBS_TopLevelDefinitions;
301     }
302 
303     IO.mapOptional("AlwaysBreakBeforeMultilineStrings",
304                    Style.AlwaysBreakBeforeMultilineStrings);
305     IO.mapOptional("AlwaysBreakTemplateDeclarations",
306                    Style.AlwaysBreakTemplateDeclarations);
307     IO.mapOptional("BinPackArguments", Style.BinPackArguments);
308     IO.mapOptional("BinPackParameters", Style.BinPackParameters);
309     IO.mapOptional("BraceWrapping", Style.BraceWrapping);
310     IO.mapOptional("BreakBeforeBinaryOperators",
311                    Style.BreakBeforeBinaryOperators);
312     IO.mapOptional("BreakBeforeBraces", Style.BreakBeforeBraces);
313     IO.mapOptional("BreakBeforeTernaryOperators",
314                    Style.BreakBeforeTernaryOperators);
315 
316     bool BreakConstructorInitializersBeforeComma = false;
317     IO.mapOptional("BreakConstructorInitializersBeforeComma",
318                    BreakConstructorInitializersBeforeComma);
319     IO.mapOptional("BreakConstructorInitializers",
320                    Style.BreakConstructorInitializers);
321     // If BreakConstructorInitializersBeforeComma was specified but
322     // BreakConstructorInitializers was not, initialize the latter from the
323     // former for backwards compatibility.
324     if (BreakConstructorInitializersBeforeComma &&
325         Style.BreakConstructorInitializers == FormatStyle::BCIS_BeforeColon)
326       Style.BreakConstructorInitializers = FormatStyle::BCIS_BeforeComma;
327 
328     IO.mapOptional("BreakAfterJavaFieldAnnotations",
329                    Style.BreakAfterJavaFieldAnnotations);
330     IO.mapOptional("BreakStringLiterals", Style.BreakStringLiterals);
331     IO.mapOptional("ColumnLimit", Style.ColumnLimit);
332     IO.mapOptional("CommentPragmas", Style.CommentPragmas);
333     IO.mapOptional("BreakBeforeInheritanceComma",
334                    Style.BreakBeforeInheritanceComma);
335     IO.mapOptional("ConstructorInitializerAllOnOneLineOrOnePerLine",
336                    Style.ConstructorInitializerAllOnOneLineOrOnePerLine);
337     IO.mapOptional("ConstructorInitializerIndentWidth",
338                    Style.ConstructorInitializerIndentWidth);
339     IO.mapOptional("ContinuationIndentWidth", Style.ContinuationIndentWidth);
340     IO.mapOptional("Cpp11BracedListStyle", Style.Cpp11BracedListStyle);
341     IO.mapOptional("DerivePointerAlignment", Style.DerivePointerAlignment);
342     IO.mapOptional("DisableFormat", Style.DisableFormat);
343     IO.mapOptional("ExperimentalAutoDetectBinPacking",
344                    Style.ExperimentalAutoDetectBinPacking);
345     IO.mapOptional("FixNamespaceComments", Style.FixNamespaceComments);
346     IO.mapOptional("ForEachMacros", Style.ForEachMacros);
347     IO.mapOptional("IncludeCategories", Style.IncludeCategories);
348     IO.mapOptional("IncludeIsMainRegex", Style.IncludeIsMainRegex);
349     IO.mapOptional("IndentCaseLabels", Style.IndentCaseLabels);
350     IO.mapOptional("IndentWidth", Style.IndentWidth);
351     IO.mapOptional("IndentWrappedFunctionNames",
352                    Style.IndentWrappedFunctionNames);
353     IO.mapOptional("JavaScriptQuotes", Style.JavaScriptQuotes);
354     IO.mapOptional("JavaScriptWrapImports", Style.JavaScriptWrapImports);
355     IO.mapOptional("KeepEmptyLinesAtTheStartOfBlocks",
356                    Style.KeepEmptyLinesAtTheStartOfBlocks);
357     IO.mapOptional("MacroBlockBegin", Style.MacroBlockBegin);
358     IO.mapOptional("MacroBlockEnd", Style.MacroBlockEnd);
359     IO.mapOptional("MaxEmptyLinesToKeep", Style.MaxEmptyLinesToKeep);
360     IO.mapOptional("NamespaceIndentation", Style.NamespaceIndentation);
361     IO.mapOptional("ObjCBlockIndentWidth", Style.ObjCBlockIndentWidth);
362     IO.mapOptional("ObjCSpaceAfterProperty", Style.ObjCSpaceAfterProperty);
363     IO.mapOptional("ObjCSpaceBeforeProtocolList",
364                    Style.ObjCSpaceBeforeProtocolList);
365     IO.mapOptional("PenaltyBreakAssignment",
366                    Style.PenaltyBreakAssignment);
367     IO.mapOptional("PenaltyBreakBeforeFirstCallParameter",
368                    Style.PenaltyBreakBeforeFirstCallParameter);
369     IO.mapOptional("PenaltyBreakComment", Style.PenaltyBreakComment);
370     IO.mapOptional("PenaltyBreakFirstLessLess",
371                    Style.PenaltyBreakFirstLessLess);
372     IO.mapOptional("PenaltyBreakString", Style.PenaltyBreakString);
373     IO.mapOptional("PenaltyExcessCharacter", Style.PenaltyExcessCharacter);
374     IO.mapOptional("PenaltyReturnTypeOnItsOwnLine",
375                    Style.PenaltyReturnTypeOnItsOwnLine);
376     IO.mapOptional("PointerAlignment", Style.PointerAlignment);
377     IO.mapOptional("ReflowComments", Style.ReflowComments);
378     IO.mapOptional("SortIncludes", Style.SortIncludes);
379     IO.mapOptional("SpaceAfterCStyleCast", Style.SpaceAfterCStyleCast);
380     IO.mapOptional("SpaceAfterTemplateKeyword", Style.SpaceAfterTemplateKeyword);
381     IO.mapOptional("SpaceBeforeAssignmentOperators",
382                    Style.SpaceBeforeAssignmentOperators);
383     IO.mapOptional("SpaceBeforeParens", Style.SpaceBeforeParens);
384     IO.mapOptional("SpaceInEmptyParentheses", Style.SpaceInEmptyParentheses);
385     IO.mapOptional("SpacesBeforeTrailingComments",
386                    Style.SpacesBeforeTrailingComments);
387     IO.mapOptional("SpacesInAngles", Style.SpacesInAngles);
388     IO.mapOptional("SpacesInContainerLiterals",
389                    Style.SpacesInContainerLiterals);
390     IO.mapOptional("SpacesInCStyleCastParentheses",
391                    Style.SpacesInCStyleCastParentheses);
392     IO.mapOptional("SpacesInParentheses", Style.SpacesInParentheses);
393     IO.mapOptional("SpacesInSquareBrackets", Style.SpacesInSquareBrackets);
394     IO.mapOptional("Standard", Style.Standard);
395     IO.mapOptional("TabWidth", Style.TabWidth);
396     IO.mapOptional("UseTab", Style.UseTab);
397   }
398 };
399 
400 template <> struct MappingTraits<FormatStyle::BraceWrappingFlags> {
401   static void mapping(IO &IO, FormatStyle::BraceWrappingFlags &Wrapping) {
402     IO.mapOptional("AfterClass", Wrapping.AfterClass);
403     IO.mapOptional("AfterControlStatement", Wrapping.AfterControlStatement);
404     IO.mapOptional("AfterEnum", Wrapping.AfterEnum);
405     IO.mapOptional("AfterFunction", Wrapping.AfterFunction);
406     IO.mapOptional("AfterNamespace", Wrapping.AfterNamespace);
407     IO.mapOptional("AfterObjCDeclaration", Wrapping.AfterObjCDeclaration);
408     IO.mapOptional("AfterStruct", Wrapping.AfterStruct);
409     IO.mapOptional("AfterUnion", Wrapping.AfterUnion);
410     IO.mapOptional("BeforeCatch", Wrapping.BeforeCatch);
411     IO.mapOptional("BeforeElse", Wrapping.BeforeElse);
412     IO.mapOptional("IndentBraces", Wrapping.IndentBraces);
413   }
414 };
415 
416 template <> struct MappingTraits<FormatStyle::IncludeCategory> {
417   static void mapping(IO &IO, FormatStyle::IncludeCategory &Category) {
418     IO.mapOptional("Regex", Category.Regex);
419     IO.mapOptional("Priority", Category.Priority);
420   }
421 };
422 
423 // Allows to read vector<FormatStyle> while keeping default values.
424 // IO.getContext() should contain a pointer to the FormatStyle structure, that
425 // will be used to get default values for missing keys.
426 // If the first element has no Language specified, it will be treated as the
427 // default one for the following elements.
428 template <> struct DocumentListTraits<std::vector<FormatStyle>> {
429   static size_t size(IO &IO, std::vector<FormatStyle> &Seq) {
430     return Seq.size();
431   }
432   static FormatStyle &element(IO &IO, std::vector<FormatStyle> &Seq,
433                               size_t Index) {
434     if (Index >= Seq.size()) {
435       assert(Index == Seq.size());
436       FormatStyle Template;
437       if (Seq.size() > 0 && Seq[0].Language == FormatStyle::LK_None) {
438         Template = Seq[0];
439       } else {
440         Template = *((const FormatStyle *)IO.getContext());
441         Template.Language = FormatStyle::LK_None;
442       }
443       Seq.resize(Index + 1, Template);
444     }
445     return Seq[Index];
446   }
447 };
448 } // namespace yaml
449 } // namespace llvm
450 
451 namespace clang {
452 namespace format {
453 
454 const std::error_category &getParseCategory() {
455   static ParseErrorCategory C;
456   return C;
457 }
458 std::error_code make_error_code(ParseError e) {
459   return std::error_code(static_cast<int>(e), getParseCategory());
460 }
461 
462 inline llvm::Error make_string_error(const llvm::Twine &Message) {
463   return llvm::make_error<llvm::StringError>(Message,
464                                              llvm::inconvertibleErrorCode());
465 }
466 
467 const char *ParseErrorCategory::name() const noexcept {
468   return "clang-format.parse_error";
469 }
470 
471 std::string ParseErrorCategory::message(int EV) const {
472   switch (static_cast<ParseError>(EV)) {
473   case ParseError::Success:
474     return "Success";
475   case ParseError::Error:
476     return "Invalid argument";
477   case ParseError::Unsuitable:
478     return "Unsuitable";
479   }
480   llvm_unreachable("unexpected parse error");
481 }
482 
483 static FormatStyle expandPresets(const FormatStyle &Style) {
484   if (Style.BreakBeforeBraces == FormatStyle::BS_Custom)
485     return Style;
486   FormatStyle Expanded = Style;
487   Expanded.BraceWrapping = {false, false, false, false, false, false,
488                             false, false, false, false, false};
489   switch (Style.BreakBeforeBraces) {
490   case FormatStyle::BS_Linux:
491     Expanded.BraceWrapping.AfterClass = true;
492     Expanded.BraceWrapping.AfterFunction = true;
493     Expanded.BraceWrapping.AfterNamespace = true;
494     break;
495   case FormatStyle::BS_Mozilla:
496     Expanded.BraceWrapping.AfterClass = true;
497     Expanded.BraceWrapping.AfterEnum = true;
498     Expanded.BraceWrapping.AfterFunction = true;
499     Expanded.BraceWrapping.AfterStruct = true;
500     Expanded.BraceWrapping.AfterUnion = true;
501     break;
502   case FormatStyle::BS_Stroustrup:
503     Expanded.BraceWrapping.AfterFunction = true;
504     Expanded.BraceWrapping.BeforeCatch = true;
505     Expanded.BraceWrapping.BeforeElse = true;
506     break;
507   case FormatStyle::BS_Allman:
508     Expanded.BraceWrapping.AfterClass = true;
509     Expanded.BraceWrapping.AfterControlStatement = true;
510     Expanded.BraceWrapping.AfterEnum = true;
511     Expanded.BraceWrapping.AfterFunction = true;
512     Expanded.BraceWrapping.AfterNamespace = true;
513     Expanded.BraceWrapping.AfterObjCDeclaration = true;
514     Expanded.BraceWrapping.AfterStruct = true;
515     Expanded.BraceWrapping.BeforeCatch = true;
516     Expanded.BraceWrapping.BeforeElse = true;
517     break;
518   case FormatStyle::BS_GNU:
519     Expanded.BraceWrapping = {true, true, true, true, true, true,
520                               true, true, true, true, true};
521     break;
522   case FormatStyle::BS_WebKit:
523     Expanded.BraceWrapping.AfterFunction = true;
524     break;
525   default:
526     break;
527   }
528   return Expanded;
529 }
530 
531 FormatStyle getLLVMStyle() {
532   FormatStyle LLVMStyle;
533   LLVMStyle.Language = FormatStyle::LK_Cpp;
534   LLVMStyle.AccessModifierOffset = -2;
535   LLVMStyle.AlignEscapedNewlines = FormatStyle::ENAS_Right;
536   LLVMStyle.AlignAfterOpenBracket = FormatStyle::BAS_Align;
537   LLVMStyle.AlignOperands = true;
538   LLVMStyle.AlignTrailingComments = true;
539   LLVMStyle.AlignConsecutiveAssignments = false;
540   LLVMStyle.AlignConsecutiveDeclarations = false;
541   LLVMStyle.AllowAllParametersOfDeclarationOnNextLine = true;
542   LLVMStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_All;
543   LLVMStyle.AllowShortBlocksOnASingleLine = false;
544   LLVMStyle.AllowShortCaseLabelsOnASingleLine = false;
545   LLVMStyle.AllowShortIfStatementsOnASingleLine = false;
546   LLVMStyle.AllowShortLoopsOnASingleLine = false;
547   LLVMStyle.AlwaysBreakAfterReturnType = FormatStyle::RTBS_None;
548   LLVMStyle.AlwaysBreakAfterDefinitionReturnType = FormatStyle::DRTBS_None;
549   LLVMStyle.AlwaysBreakBeforeMultilineStrings = false;
550   LLVMStyle.AlwaysBreakTemplateDeclarations = false;
551   LLVMStyle.BinPackParameters = true;
552   LLVMStyle.BinPackArguments = true;
553   LLVMStyle.BreakBeforeBinaryOperators = FormatStyle::BOS_None;
554   LLVMStyle.BreakBeforeTernaryOperators = true;
555   LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
556   LLVMStyle.BraceWrapping = {false, false, false, false, false, false,
557                              false, false, false, false, false};
558   LLVMStyle.BreakAfterJavaFieldAnnotations = false;
559   LLVMStyle.BreakConstructorInitializers = FormatStyle::BCIS_BeforeColon;
560   LLVMStyle.BreakBeforeInheritanceComma = false;
561   LLVMStyle.BreakStringLiterals = true;
562   LLVMStyle.ColumnLimit = 80;
563   LLVMStyle.CommentPragmas = "^ IWYU pragma:";
564   LLVMStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = false;
565   LLVMStyle.ConstructorInitializerIndentWidth = 4;
566   LLVMStyle.ContinuationIndentWidth = 4;
567   LLVMStyle.Cpp11BracedListStyle = true;
568   LLVMStyle.DerivePointerAlignment = false;
569   LLVMStyle.ExperimentalAutoDetectBinPacking = false;
570   LLVMStyle.FixNamespaceComments = true;
571   LLVMStyle.ForEachMacros.push_back("foreach");
572   LLVMStyle.ForEachMacros.push_back("Q_FOREACH");
573   LLVMStyle.ForEachMacros.push_back("BOOST_FOREACH");
574   LLVMStyle.IncludeCategories = {{"^\"(llvm|llvm-c|clang|clang-c)/", 2},
575                                  {"^(<|\"(gtest|isl|json)/)", 3},
576                                  {".*", 1}};
577   LLVMStyle.IncludeIsMainRegex = "$";
578   LLVMStyle.IndentCaseLabels = false;
579   LLVMStyle.IndentWrappedFunctionNames = false;
580   LLVMStyle.IndentWidth = 2;
581   LLVMStyle.JavaScriptQuotes = FormatStyle::JSQS_Leave;
582   LLVMStyle.JavaScriptWrapImports = true;
583   LLVMStyle.TabWidth = 8;
584   LLVMStyle.MaxEmptyLinesToKeep = 1;
585   LLVMStyle.KeepEmptyLinesAtTheStartOfBlocks = true;
586   LLVMStyle.NamespaceIndentation = FormatStyle::NI_None;
587   LLVMStyle.ObjCBlockIndentWidth = 2;
588   LLVMStyle.ObjCSpaceAfterProperty = false;
589   LLVMStyle.ObjCSpaceBeforeProtocolList = true;
590   LLVMStyle.PointerAlignment = FormatStyle::PAS_Right;
591   LLVMStyle.SpacesBeforeTrailingComments = 1;
592   LLVMStyle.Standard = FormatStyle::LS_Cpp11;
593   LLVMStyle.UseTab = FormatStyle::UT_Never;
594   LLVMStyle.ReflowComments = true;
595   LLVMStyle.SpacesInParentheses = false;
596   LLVMStyle.SpacesInSquareBrackets = false;
597   LLVMStyle.SpaceInEmptyParentheses = false;
598   LLVMStyle.SpacesInContainerLiterals = true;
599   LLVMStyle.SpacesInCStyleCastParentheses = false;
600   LLVMStyle.SpaceAfterCStyleCast = false;
601   LLVMStyle.SpaceAfterTemplateKeyword = true;
602   LLVMStyle.SpaceBeforeParens = FormatStyle::SBPO_ControlStatements;
603   LLVMStyle.SpaceBeforeAssignmentOperators = true;
604   LLVMStyle.SpacesInAngles = false;
605 
606   LLVMStyle.PenaltyBreakAssignment = prec::Assignment;
607   LLVMStyle.PenaltyBreakComment = 300;
608   LLVMStyle.PenaltyBreakFirstLessLess = 120;
609   LLVMStyle.PenaltyBreakString = 1000;
610   LLVMStyle.PenaltyExcessCharacter = 1000000;
611   LLVMStyle.PenaltyReturnTypeOnItsOwnLine = 60;
612   LLVMStyle.PenaltyBreakBeforeFirstCallParameter = 19;
613 
614   LLVMStyle.DisableFormat = false;
615   LLVMStyle.SortIncludes = true;
616 
617   return LLVMStyle;
618 }
619 
620 FormatStyle getGoogleStyle(FormatStyle::LanguageKind Language) {
621   FormatStyle GoogleStyle = getLLVMStyle();
622   GoogleStyle.Language = Language;
623 
624   GoogleStyle.AccessModifierOffset = -1;
625   GoogleStyle.AlignEscapedNewlines = FormatStyle::ENAS_Left;
626   GoogleStyle.AllowShortIfStatementsOnASingleLine = true;
627   GoogleStyle.AllowShortLoopsOnASingleLine = true;
628   GoogleStyle.AlwaysBreakBeforeMultilineStrings = true;
629   GoogleStyle.AlwaysBreakTemplateDeclarations = true;
630   GoogleStyle.ConstructorInitializerAllOnOneLineOrOnePerLine = true;
631   GoogleStyle.DerivePointerAlignment = true;
632   GoogleStyle.IncludeCategories = {{"^<.*\\.h>", 1}, {"^<.*", 2}, {".*", 3}};
633   GoogleStyle.IncludeIsMainRegex = "([-_](test|unittest))?$";
634   GoogleStyle.IndentCaseLabels = true;
635   GoogleStyle.KeepEmptyLinesAtTheStartOfBlocks = false;
636   GoogleStyle.ObjCSpaceAfterProperty = false;
637   GoogleStyle.ObjCSpaceBeforeProtocolList = false;
638   GoogleStyle.PointerAlignment = FormatStyle::PAS_Left;
639   GoogleStyle.SpacesBeforeTrailingComments = 2;
640   GoogleStyle.Standard = FormatStyle::LS_Auto;
641 
642   GoogleStyle.PenaltyReturnTypeOnItsOwnLine = 200;
643   GoogleStyle.PenaltyBreakBeforeFirstCallParameter = 1;
644 
645   if (Language == FormatStyle::LK_Java) {
646     GoogleStyle.AlignAfterOpenBracket = FormatStyle::BAS_DontAlign;
647     GoogleStyle.AlignOperands = false;
648     GoogleStyle.AlignTrailingComments = false;
649     GoogleStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_Empty;
650     GoogleStyle.AllowShortIfStatementsOnASingleLine = false;
651     GoogleStyle.AlwaysBreakBeforeMultilineStrings = false;
652     GoogleStyle.BreakBeforeBinaryOperators = FormatStyle::BOS_NonAssignment;
653     GoogleStyle.ColumnLimit = 100;
654     GoogleStyle.SpaceAfterCStyleCast = true;
655     GoogleStyle.SpacesBeforeTrailingComments = 1;
656   } else if (Language == FormatStyle::LK_JavaScript) {
657     GoogleStyle.AlignAfterOpenBracket = FormatStyle::BAS_AlwaysBreak;
658     GoogleStyle.AlignOperands = false;
659     GoogleStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_Empty;
660     GoogleStyle.AlwaysBreakBeforeMultilineStrings = false;
661     GoogleStyle.BreakBeforeTernaryOperators = false;
662     // taze:, triple slash directives (`/// <...`), @tag followed by { for a lot
663     // of JSDoc tags, and @see, which is commonly followed by overlong URLs.
664     GoogleStyle.CommentPragmas =
665         "(taze:|^/[ \t]*<|(@[A-Za-z_0-9-]+[ \\t]*{)|@see)";
666     GoogleStyle.MaxEmptyLinesToKeep = 3;
667     GoogleStyle.NamespaceIndentation = FormatStyle::NI_All;
668     GoogleStyle.SpacesInContainerLiterals = false;
669     GoogleStyle.JavaScriptQuotes = FormatStyle::JSQS_Single;
670     GoogleStyle.JavaScriptWrapImports = false;
671   } else if (Language == FormatStyle::LK_Proto) {
672     GoogleStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_None;
673     GoogleStyle.SpacesInContainerLiterals = false;
674   } else if (Language == FormatStyle::LK_ObjC) {
675     GoogleStyle.ColumnLimit = 100;
676   }
677 
678   return GoogleStyle;
679 }
680 
681 FormatStyle getChromiumStyle(FormatStyle::LanguageKind Language) {
682   FormatStyle ChromiumStyle = getGoogleStyle(Language);
683   if (Language == FormatStyle::LK_Java) {
684     ChromiumStyle.AllowShortIfStatementsOnASingleLine = true;
685     ChromiumStyle.BreakAfterJavaFieldAnnotations = true;
686     ChromiumStyle.ContinuationIndentWidth = 8;
687     ChromiumStyle.IndentWidth = 4;
688   } else if (Language == FormatStyle::LK_JavaScript) {
689     ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
690     ChromiumStyle.AllowShortLoopsOnASingleLine = false;
691   } else {
692     ChromiumStyle.AllowAllParametersOfDeclarationOnNextLine = false;
693     ChromiumStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_Inline;
694     ChromiumStyle.AllowShortIfStatementsOnASingleLine = false;
695     ChromiumStyle.AllowShortLoopsOnASingleLine = false;
696     ChromiumStyle.BinPackParameters = false;
697     ChromiumStyle.DerivePointerAlignment = false;
698     if (Language == FormatStyle::LK_ObjC)
699       ChromiumStyle.ColumnLimit = 80;
700   }
701   return ChromiumStyle;
702 }
703 
704 FormatStyle getMozillaStyle() {
705   FormatStyle MozillaStyle = getLLVMStyle();
706   MozillaStyle.AllowAllParametersOfDeclarationOnNextLine = false;
707   MozillaStyle.AllowShortFunctionsOnASingleLine = FormatStyle::SFS_Inline;
708   MozillaStyle.AlwaysBreakAfterReturnType =
709       FormatStyle::RTBS_TopLevel;
710   MozillaStyle.AlwaysBreakAfterDefinitionReturnType =
711       FormatStyle::DRTBS_TopLevel;
712   MozillaStyle.AlwaysBreakTemplateDeclarations = true;
713   MozillaStyle.BinPackParameters = false;
714   MozillaStyle.BinPackArguments = false;
715   MozillaStyle.BreakBeforeBraces = FormatStyle::BS_Mozilla;
716   MozillaStyle.BreakConstructorInitializers = FormatStyle::BCIS_BeforeComma;
717   MozillaStyle.BreakBeforeInheritanceComma = true;
718   MozillaStyle.ConstructorInitializerIndentWidth = 2;
719   MozillaStyle.ContinuationIndentWidth = 2;
720   MozillaStyle.Cpp11BracedListStyle = false;
721   MozillaStyle.FixNamespaceComments = false;
722   MozillaStyle.IndentCaseLabels = true;
723   MozillaStyle.ObjCSpaceAfterProperty = true;
724   MozillaStyle.ObjCSpaceBeforeProtocolList = false;
725   MozillaStyle.PenaltyReturnTypeOnItsOwnLine = 200;
726   MozillaStyle.PointerAlignment = FormatStyle::PAS_Left;
727   MozillaStyle.SpaceAfterTemplateKeyword = false;
728   return MozillaStyle;
729 }
730 
731 FormatStyle getWebKitStyle() {
732   FormatStyle Style = getLLVMStyle();
733   Style.AccessModifierOffset = -4;
734   Style.AlignAfterOpenBracket = FormatStyle::BAS_DontAlign;
735   Style.AlignOperands = false;
736   Style.AlignTrailingComments = false;
737   Style.BreakBeforeBinaryOperators = FormatStyle::BOS_All;
738   Style.BreakBeforeBraces = FormatStyle::BS_WebKit;
739   Style.BreakConstructorInitializers = FormatStyle::BCIS_BeforeComma;
740   Style.Cpp11BracedListStyle = false;
741   Style.ColumnLimit = 0;
742   Style.FixNamespaceComments = false;
743   Style.IndentWidth = 4;
744   Style.NamespaceIndentation = FormatStyle::NI_Inner;
745   Style.ObjCBlockIndentWidth = 4;
746   Style.ObjCSpaceAfterProperty = true;
747   Style.PointerAlignment = FormatStyle::PAS_Left;
748   return Style;
749 }
750 
751 FormatStyle getGNUStyle() {
752   FormatStyle Style = getLLVMStyle();
753   Style.AlwaysBreakAfterDefinitionReturnType = FormatStyle::DRTBS_All;
754   Style.AlwaysBreakAfterReturnType = FormatStyle::RTBS_AllDefinitions;
755   Style.BreakBeforeBinaryOperators = FormatStyle::BOS_All;
756   Style.BreakBeforeBraces = FormatStyle::BS_GNU;
757   Style.BreakBeforeTernaryOperators = true;
758   Style.Cpp11BracedListStyle = false;
759   Style.ColumnLimit = 79;
760   Style.FixNamespaceComments = false;
761   Style.SpaceBeforeParens = FormatStyle::SBPO_Always;
762   Style.Standard = FormatStyle::LS_Cpp03;
763   return Style;
764 }
765 
766 FormatStyle getNoStyle() {
767   FormatStyle NoStyle = getLLVMStyle();
768   NoStyle.DisableFormat = true;
769   NoStyle.SortIncludes = false;
770   return NoStyle;
771 }
772 
773 bool getPredefinedStyle(StringRef Name, FormatStyle::LanguageKind Language,
774                         FormatStyle *Style) {
775   if (Name.equals_lower("llvm")) {
776     *Style = getLLVMStyle();
777   } else if (Name.equals_lower("chromium")) {
778     *Style = getChromiumStyle(Language);
779   } else if (Name.equals_lower("mozilla")) {
780     *Style = getMozillaStyle();
781   } else if (Name.equals_lower("google")) {
782     *Style = getGoogleStyle(Language);
783   } else if (Name.equals_lower("webkit")) {
784     *Style = getWebKitStyle();
785   } else if (Name.equals_lower("gnu")) {
786     *Style = getGNUStyle();
787   } else if (Name.equals_lower("none")) {
788     *Style = getNoStyle();
789   } else {
790     return false;
791   }
792 
793   Style->Language = Language;
794   return true;
795 }
796 
797 std::error_code parseConfiguration(StringRef Text, FormatStyle *Style) {
798   assert(Style);
799   FormatStyle::LanguageKind Language = Style->Language;
800   assert(Language != FormatStyle::LK_None);
801   if (Text.trim().empty())
802     return make_error_code(ParseError::Error);
803 
804   std::vector<FormatStyle> Styles;
805   llvm::yaml::Input Input(Text);
806   // DocumentListTraits<vector<FormatStyle>> uses the context to get default
807   // values for the fields, keys for which are missing from the configuration.
808   // Mapping also uses the context to get the language to find the correct
809   // base style.
810   Input.setContext(Style);
811   Input >> Styles;
812   if (Input.error())
813     return Input.error();
814 
815   for (unsigned i = 0; i < Styles.size(); ++i) {
816     // Ensures that only the first configuration can skip the Language option.
817     if (Styles[i].Language == FormatStyle::LK_None && i != 0)
818       return make_error_code(ParseError::Error);
819     // Ensure that each language is configured at most once.
820     for (unsigned j = 0; j < i; ++j) {
821       if (Styles[i].Language == Styles[j].Language) {
822         DEBUG(llvm::dbgs()
823               << "Duplicate languages in the config file on positions " << j
824               << " and " << i << "\n");
825         return make_error_code(ParseError::Error);
826       }
827     }
828   }
829   // Look for a suitable configuration starting from the end, so we can
830   // find the configuration for the specific language first, and the default
831   // configuration (which can only be at slot 0) after it.
832   for (int i = Styles.size() - 1; i >= 0; --i) {
833     if (Styles[i].Language == Language ||
834         Styles[i].Language == FormatStyle::LK_None) {
835       *Style = Styles[i];
836       Style->Language = Language;
837       return make_error_code(ParseError::Success);
838     }
839   }
840   return make_error_code(ParseError::Unsuitable);
841 }
842 
843 std::string configurationAsText(const FormatStyle &Style) {
844   std::string Text;
845   llvm::raw_string_ostream Stream(Text);
846   llvm::yaml::Output Output(Stream);
847   // We use the same mapping method for input and output, so we need a non-const
848   // reference here.
849   FormatStyle NonConstStyle = expandPresets(Style);
850   Output << NonConstStyle;
851   return Stream.str();
852 }
853 
854 namespace {
855 
856 class JavaScriptRequoter : public TokenAnalyzer {
857 public:
858   JavaScriptRequoter(const Environment &Env, const FormatStyle &Style)
859       : TokenAnalyzer(Env, Style) {}
860 
861   tooling::Replacements
862   analyze(TokenAnnotator &Annotator,
863           SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
864           FormatTokenLexer &Tokens) override {
865     AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
866                                           AnnotatedLines.end());
867     tooling::Replacements Result;
868     requoteJSStringLiteral(AnnotatedLines, Result);
869     return Result;
870   }
871 
872 private:
873   // Replaces double/single-quoted string literal as appropriate, re-escaping
874   // the contents in the process.
875   void requoteJSStringLiteral(SmallVectorImpl<AnnotatedLine *> &Lines,
876                               tooling::Replacements &Result) {
877     for (AnnotatedLine *Line : Lines) {
878       requoteJSStringLiteral(Line->Children, Result);
879       if (!Line->Affected)
880         continue;
881       for (FormatToken *FormatTok = Line->First; FormatTok;
882            FormatTok = FormatTok->Next) {
883         StringRef Input = FormatTok->TokenText;
884         if (FormatTok->Finalized || !FormatTok->isStringLiteral() ||
885             // NB: testing for not starting with a double quote to avoid
886             // breaking `template strings`.
887             (Style.JavaScriptQuotes == FormatStyle::JSQS_Single &&
888              !Input.startswith("\"")) ||
889             (Style.JavaScriptQuotes == FormatStyle::JSQS_Double &&
890              !Input.startswith("\'")))
891           continue;
892 
893         // Change start and end quote.
894         bool IsSingle = Style.JavaScriptQuotes == FormatStyle::JSQS_Single;
895         SourceLocation Start = FormatTok->Tok.getLocation();
896         auto Replace = [&](SourceLocation Start, unsigned Length,
897                            StringRef ReplacementText) {
898           auto Err = Result.add(tooling::Replacement(
899               Env.getSourceManager(), Start, Length, ReplacementText));
900           // FIXME: handle error. For now, print error message and skip the
901           // replacement for release version.
902           if (Err) {
903             llvm::errs() << llvm::toString(std::move(Err)) << "\n";
904             assert(false);
905           }
906         };
907         Replace(Start, 1, IsSingle ? "'" : "\"");
908         Replace(FormatTok->Tok.getEndLoc().getLocWithOffset(-1), 1,
909                 IsSingle ? "'" : "\"");
910 
911         // Escape internal quotes.
912         bool Escaped = false;
913         for (size_t i = 1; i < Input.size() - 1; i++) {
914           switch (Input[i]) {
915           case '\\':
916             if (!Escaped && i + 1 < Input.size() &&
917                 ((IsSingle && Input[i + 1] == '"') ||
918                  (!IsSingle && Input[i + 1] == '\''))) {
919               // Remove this \, it's escaping a " or ' that no longer needs
920               // escaping
921               Replace(Start.getLocWithOffset(i), 1, "");
922               continue;
923             }
924             Escaped = !Escaped;
925             break;
926           case '\"':
927           case '\'':
928             if (!Escaped && IsSingle == (Input[i] == '\'')) {
929               // Escape the quote.
930               Replace(Start.getLocWithOffset(i), 0, "\\");
931             }
932             Escaped = false;
933             break;
934           default:
935             Escaped = false;
936             break;
937           }
938         }
939       }
940     }
941   }
942 };
943 
944 class Formatter : public TokenAnalyzer {
945 public:
946   Formatter(const Environment &Env, const FormatStyle &Style,
947             FormattingAttemptStatus *Status)
948       : TokenAnalyzer(Env, Style), Status(Status) {}
949 
950   tooling::Replacements
951   analyze(TokenAnnotator &Annotator,
952           SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
953           FormatTokenLexer &Tokens) override {
954     tooling::Replacements Result;
955     deriveLocalStyle(AnnotatedLines);
956     AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
957                                           AnnotatedLines.end());
958     for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
959       Annotator.calculateFormattingInformation(*AnnotatedLines[i]);
960     }
961     Annotator.setCommentLineLevels(AnnotatedLines);
962 
963     WhitespaceManager Whitespaces(
964         Env.getSourceManager(), Style,
965         inputUsesCRLF(Env.getSourceManager().getBufferData(Env.getFileID())));
966     ContinuationIndenter Indenter(Style, Tokens.getKeywords(),
967                                   Env.getSourceManager(), Whitespaces, Encoding,
968                                   BinPackInconclusiveFunctions);
969     UnwrappedLineFormatter(&Indenter, &Whitespaces, Style, Tokens.getKeywords(),
970                            Env.getSourceManager(), Status)
971         .format(AnnotatedLines);
972     for (const auto &R : Whitespaces.generateReplacements())
973       if (Result.add(R))
974         return Result;
975     return Result;
976   }
977 
978 private:
979 
980   static bool inputUsesCRLF(StringRef Text) {
981     return Text.count('\r') * 2 > Text.count('\n');
982   }
983 
984   bool
985   hasCpp03IncompatibleFormat(const SmallVectorImpl<AnnotatedLine *> &Lines) {
986     for (const AnnotatedLine *Line : Lines) {
987       if (hasCpp03IncompatibleFormat(Line->Children))
988         return true;
989       for (FormatToken *Tok = Line->First->Next; Tok; Tok = Tok->Next) {
990         if (Tok->WhitespaceRange.getBegin() == Tok->WhitespaceRange.getEnd()) {
991           if (Tok->is(tok::coloncolon) && Tok->Previous->is(TT_TemplateOpener))
992             return true;
993           if (Tok->is(TT_TemplateCloser) &&
994               Tok->Previous->is(TT_TemplateCloser))
995             return true;
996         }
997       }
998     }
999     return false;
1000   }
1001 
1002   int countVariableAlignments(const SmallVectorImpl<AnnotatedLine *> &Lines) {
1003     int AlignmentDiff = 0;
1004     for (const AnnotatedLine *Line : Lines) {
1005       AlignmentDiff += countVariableAlignments(Line->Children);
1006       for (FormatToken *Tok = Line->First; Tok && Tok->Next; Tok = Tok->Next) {
1007         if (!Tok->is(TT_PointerOrReference))
1008           continue;
1009         bool SpaceBefore =
1010             Tok->WhitespaceRange.getBegin() != Tok->WhitespaceRange.getEnd();
1011         bool SpaceAfter = Tok->Next->WhitespaceRange.getBegin() !=
1012                           Tok->Next->WhitespaceRange.getEnd();
1013         if (SpaceBefore && !SpaceAfter)
1014           ++AlignmentDiff;
1015         if (!SpaceBefore && SpaceAfter)
1016           --AlignmentDiff;
1017       }
1018     }
1019     return AlignmentDiff;
1020   }
1021 
1022   void
1023   deriveLocalStyle(const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
1024     bool HasBinPackedFunction = false;
1025     bool HasOnePerLineFunction = false;
1026     for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
1027       if (!AnnotatedLines[i]->First->Next)
1028         continue;
1029       FormatToken *Tok = AnnotatedLines[i]->First->Next;
1030       while (Tok->Next) {
1031         if (Tok->PackingKind == PPK_BinPacked)
1032           HasBinPackedFunction = true;
1033         if (Tok->PackingKind == PPK_OnePerLine)
1034           HasOnePerLineFunction = true;
1035 
1036         Tok = Tok->Next;
1037       }
1038     }
1039     if (Style.DerivePointerAlignment)
1040       Style.PointerAlignment = countVariableAlignments(AnnotatedLines) <= 0
1041                                    ? FormatStyle::PAS_Left
1042                                    : FormatStyle::PAS_Right;
1043     if (Style.Standard == FormatStyle::LS_Auto)
1044       Style.Standard = hasCpp03IncompatibleFormat(AnnotatedLines)
1045                            ? FormatStyle::LS_Cpp11
1046                            : FormatStyle::LS_Cpp03;
1047     BinPackInconclusiveFunctions =
1048         HasBinPackedFunction || !HasOnePerLineFunction;
1049   }
1050 
1051   bool BinPackInconclusiveFunctions;
1052   FormattingAttemptStatus *Status;
1053 };
1054 
1055 // This class clean up the erroneous/redundant code around the given ranges in
1056 // file.
1057 class Cleaner : public TokenAnalyzer {
1058 public:
1059   Cleaner(const Environment &Env, const FormatStyle &Style)
1060       : TokenAnalyzer(Env, Style),
1061         DeletedTokens(FormatTokenLess(Env.getSourceManager())) {}
1062 
1063   // FIXME: eliminate unused parameters.
1064   tooling::Replacements
1065   analyze(TokenAnnotator &Annotator,
1066           SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
1067           FormatTokenLexer &Tokens) override {
1068     // FIXME: in the current implementation the granularity of affected range
1069     // is an annotated line. However, this is not sufficient. Furthermore,
1070     // redundant code introduced by replacements does not necessarily
1071     // intercept with ranges of replacements that result in the redundancy.
1072     // To determine if some redundant code is actually introduced by
1073     // replacements(e.g. deletions), we need to come up with a more
1074     // sophisticated way of computing affected ranges.
1075     AffectedRangeMgr.computeAffectedLines(AnnotatedLines.begin(),
1076                                           AnnotatedLines.end());
1077 
1078     checkEmptyNamespace(AnnotatedLines);
1079 
1080     for (auto &Line : AnnotatedLines) {
1081       if (Line->Affected) {
1082         cleanupRight(Line->First, tok::comma, tok::comma);
1083         cleanupRight(Line->First, TT_CtorInitializerColon, tok::comma);
1084         cleanupRight(Line->First, tok::l_paren, tok::comma);
1085         cleanupLeft(Line->First, tok::comma, tok::r_paren);
1086         cleanupLeft(Line->First, TT_CtorInitializerComma, tok::l_brace);
1087         cleanupLeft(Line->First, TT_CtorInitializerColon, tok::l_brace);
1088         cleanupLeft(Line->First, TT_CtorInitializerColon, tok::equal);
1089       }
1090     }
1091 
1092     return generateFixes();
1093   }
1094 
1095 private:
1096   bool containsOnlyComments(const AnnotatedLine &Line) {
1097     for (FormatToken *Tok = Line.First; Tok != nullptr; Tok = Tok->Next) {
1098       if (Tok->isNot(tok::comment))
1099         return false;
1100     }
1101     return true;
1102   }
1103 
1104   // Iterate through all lines and remove any empty (nested) namespaces.
1105   void checkEmptyNamespace(SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
1106     std::set<unsigned> DeletedLines;
1107     for (unsigned i = 0, e = AnnotatedLines.size(); i != e; ++i) {
1108       auto &Line = *AnnotatedLines[i];
1109       if (Line.startsWith(tok::kw_namespace) ||
1110           Line.startsWith(tok::kw_inline, tok::kw_namespace)) {
1111         checkEmptyNamespace(AnnotatedLines, i, i, DeletedLines);
1112       }
1113     }
1114 
1115     for (auto Line : DeletedLines) {
1116       FormatToken *Tok = AnnotatedLines[Line]->First;
1117       while (Tok) {
1118         deleteToken(Tok);
1119         Tok = Tok->Next;
1120       }
1121     }
1122   }
1123 
1124   // The function checks if the namespace, which starts from \p CurrentLine, and
1125   // its nested namespaces are empty and delete them if they are empty. It also
1126   // sets \p NewLine to the last line checked.
1127   // Returns true if the current namespace is empty.
1128   bool checkEmptyNamespace(SmallVectorImpl<AnnotatedLine *> &AnnotatedLines,
1129                            unsigned CurrentLine, unsigned &NewLine,
1130                            std::set<unsigned> &DeletedLines) {
1131     unsigned InitLine = CurrentLine, End = AnnotatedLines.size();
1132     if (Style.BraceWrapping.AfterNamespace) {
1133       // If the left brace is in a new line, we should consume it first so that
1134       // it does not make the namespace non-empty.
1135       // FIXME: error handling if there is no left brace.
1136       if (!AnnotatedLines[++CurrentLine]->startsWith(tok::l_brace)) {
1137         NewLine = CurrentLine;
1138         return false;
1139       }
1140     } else if (!AnnotatedLines[CurrentLine]->endsWith(tok::l_brace)) {
1141       return false;
1142     }
1143     while (++CurrentLine < End) {
1144       if (AnnotatedLines[CurrentLine]->startsWith(tok::r_brace))
1145         break;
1146 
1147       if (AnnotatedLines[CurrentLine]->startsWith(tok::kw_namespace) ||
1148           AnnotatedLines[CurrentLine]->startsWith(tok::kw_inline,
1149                                                   tok::kw_namespace)) {
1150         if (!checkEmptyNamespace(AnnotatedLines, CurrentLine, NewLine,
1151                                  DeletedLines))
1152           return false;
1153         CurrentLine = NewLine;
1154         continue;
1155       }
1156 
1157       if (containsOnlyComments(*AnnotatedLines[CurrentLine]))
1158         continue;
1159 
1160       // If there is anything other than comments or nested namespaces in the
1161       // current namespace, the namespace cannot be empty.
1162       NewLine = CurrentLine;
1163       return false;
1164     }
1165 
1166     NewLine = CurrentLine;
1167     if (CurrentLine >= End)
1168       return false;
1169 
1170     // Check if the empty namespace is actually affected by changed ranges.
1171     if (!AffectedRangeMgr.affectsCharSourceRange(CharSourceRange::getCharRange(
1172             AnnotatedLines[InitLine]->First->Tok.getLocation(),
1173             AnnotatedLines[CurrentLine]->Last->Tok.getEndLoc())))
1174       return false;
1175 
1176     for (unsigned i = InitLine; i <= CurrentLine; ++i) {
1177       DeletedLines.insert(i);
1178     }
1179 
1180     return true;
1181   }
1182 
1183   // Checks pairs {start, start->next},..., {end->previous, end} and deletes one
1184   // of the token in the pair if the left token has \p LK token kind and the
1185   // right token has \p RK token kind. If \p DeleteLeft is true, the left token
1186   // is deleted on match; otherwise, the right token is deleted.
1187   template <typename LeftKind, typename RightKind>
1188   void cleanupPair(FormatToken *Start, LeftKind LK, RightKind RK,
1189                    bool DeleteLeft) {
1190     auto NextNotDeleted = [this](const FormatToken &Tok) -> FormatToken * {
1191       for (auto *Res = Tok.Next; Res; Res = Res->Next)
1192         if (!Res->is(tok::comment) &&
1193             DeletedTokens.find(Res) == DeletedTokens.end())
1194           return Res;
1195       return nullptr;
1196     };
1197     for (auto *Left = Start; Left;) {
1198       auto *Right = NextNotDeleted(*Left);
1199       if (!Right)
1200         break;
1201       if (Left->is(LK) && Right->is(RK)) {
1202         deleteToken(DeleteLeft ? Left : Right);
1203         for (auto *Tok = Left->Next; Tok && Tok != Right; Tok = Tok->Next)
1204           deleteToken(Tok);
1205         // If the right token is deleted, we should keep the left token
1206         // unchanged and pair it with the new right token.
1207         if (!DeleteLeft)
1208           continue;
1209       }
1210       Left = Right;
1211     }
1212   }
1213 
1214   template <typename LeftKind, typename RightKind>
1215   void cleanupLeft(FormatToken *Start, LeftKind LK, RightKind RK) {
1216     cleanupPair(Start, LK, RK, /*DeleteLeft=*/true);
1217   }
1218 
1219   template <typename LeftKind, typename RightKind>
1220   void cleanupRight(FormatToken *Start, LeftKind LK, RightKind RK) {
1221     cleanupPair(Start, LK, RK, /*DeleteLeft=*/false);
1222   }
1223 
1224   // Delete the given token.
1225   inline void deleteToken(FormatToken *Tok) {
1226     if (Tok)
1227       DeletedTokens.insert(Tok);
1228   }
1229 
1230   tooling::Replacements generateFixes() {
1231     tooling::Replacements Fixes;
1232     std::vector<FormatToken *> Tokens;
1233     std::copy(DeletedTokens.begin(), DeletedTokens.end(),
1234               std::back_inserter(Tokens));
1235 
1236     // Merge multiple continuous token deletions into one big deletion so that
1237     // the number of replacements can be reduced. This makes computing affected
1238     // ranges more efficient when we run reformat on the changed code.
1239     unsigned Idx = 0;
1240     while (Idx < Tokens.size()) {
1241       unsigned St = Idx, End = Idx;
1242       while ((End + 1) < Tokens.size() &&
1243              Tokens[End]->Next == Tokens[End + 1]) {
1244         End++;
1245       }
1246       auto SR = CharSourceRange::getCharRange(Tokens[St]->Tok.getLocation(),
1247                                               Tokens[End]->Tok.getEndLoc());
1248       auto Err =
1249           Fixes.add(tooling::Replacement(Env.getSourceManager(), SR, ""));
1250       // FIXME: better error handling. for now just print error message and skip
1251       // for the release version.
1252       if (Err) {
1253         llvm::errs() << llvm::toString(std::move(Err)) << "\n";
1254         assert(false && "Fixes must not conflict!");
1255       }
1256       Idx = End + 1;
1257     }
1258 
1259     return Fixes;
1260   }
1261 
1262   // Class for less-than inequality comparason for the set `RedundantTokens`.
1263   // We store tokens in the order they appear in the translation unit so that
1264   // we do not need to sort them in `generateFixes()`.
1265   struct FormatTokenLess {
1266     FormatTokenLess(const SourceManager &SM) : SM(SM) {}
1267 
1268     bool operator()(const FormatToken *LHS, const FormatToken *RHS) const {
1269       return SM.isBeforeInTranslationUnit(LHS->Tok.getLocation(),
1270                                           RHS->Tok.getLocation());
1271     }
1272     const SourceManager &SM;
1273   };
1274 
1275   // Tokens to be deleted.
1276   std::set<FormatToken *, FormatTokenLess> DeletedTokens;
1277 };
1278 
1279 struct IncludeDirective {
1280   StringRef Filename;
1281   StringRef Text;
1282   unsigned Offset;
1283   int Category;
1284 };
1285 
1286 } // end anonymous namespace
1287 
1288 // Determines whether 'Ranges' intersects with ('Start', 'End').
1289 static bool affectsRange(ArrayRef<tooling::Range> Ranges, unsigned Start,
1290                          unsigned End) {
1291   for (auto Range : Ranges) {
1292     if (Range.getOffset() < End &&
1293         Range.getOffset() + Range.getLength() > Start)
1294       return true;
1295   }
1296   return false;
1297 }
1298 
1299 // Returns a pair (Index, OffsetToEOL) describing the position of the cursor
1300 // before sorting/deduplicating. Index is the index of the include under the
1301 // cursor in the original set of includes. If this include has duplicates, it is
1302 // the index of the first of the duplicates as the others are going to be
1303 // removed. OffsetToEOL describes the cursor's position relative to the end of
1304 // its current line.
1305 // If `Cursor` is not on any #include, `Index` will be UINT_MAX.
1306 static std::pair<unsigned, unsigned>
1307 FindCursorIndex(const SmallVectorImpl<IncludeDirective> &Includes,
1308                 const SmallVectorImpl<unsigned> &Indices, unsigned Cursor) {
1309   unsigned CursorIndex = UINT_MAX;
1310   unsigned OffsetToEOL = 0;
1311   for (int i = 0, e = Includes.size(); i != e; ++i) {
1312     unsigned Start = Includes[Indices[i]].Offset;
1313     unsigned End = Start + Includes[Indices[i]].Text.size();
1314     if (!(Cursor >= Start && Cursor < End))
1315       continue;
1316     CursorIndex = Indices[i];
1317     OffsetToEOL = End - Cursor;
1318     // Put the cursor on the only remaining #include among the duplicate
1319     // #includes.
1320     while (--i >= 0 && Includes[CursorIndex].Text == Includes[Indices[i]].Text)
1321       CursorIndex = i;
1322     break;
1323   }
1324   return std::make_pair(CursorIndex, OffsetToEOL);
1325 }
1326 
1327 // Sorts and deduplicate a block of includes given by 'Includes' alphabetically
1328 // adding the necessary replacement to 'Replaces'. 'Includes' must be in strict
1329 // source order.
1330 // #include directives with the same text will be deduplicated, and only the
1331 // first #include in the duplicate #includes remains. If the `Cursor` is
1332 // provided and put on a deleted #include, it will be moved to the remaining
1333 // #include in the duplicate #includes.
1334 static void sortCppIncludes(const FormatStyle &Style,
1335                             const SmallVectorImpl<IncludeDirective> &Includes,
1336                             ArrayRef<tooling::Range> Ranges, StringRef FileName,
1337                             tooling::Replacements &Replaces, unsigned *Cursor) {
1338   unsigned IncludesBeginOffset = Includes.front().Offset;
1339   unsigned IncludesEndOffset =
1340       Includes.back().Offset + Includes.back().Text.size();
1341   unsigned IncludesBlockSize = IncludesEndOffset - IncludesBeginOffset;
1342   if (!affectsRange(Ranges, IncludesBeginOffset, IncludesEndOffset))
1343     return;
1344   SmallVector<unsigned, 16> Indices;
1345   for (unsigned i = 0, e = Includes.size(); i != e; ++i)
1346     Indices.push_back(i);
1347   std::stable_sort(
1348       Indices.begin(), Indices.end(), [&](unsigned LHSI, unsigned RHSI) {
1349         return std::tie(Includes[LHSI].Category, Includes[LHSI].Filename) <
1350                std::tie(Includes[RHSI].Category, Includes[RHSI].Filename);
1351       });
1352   // The index of the include on which the cursor will be put after
1353   // sorting/deduplicating.
1354   unsigned CursorIndex;
1355   // The offset from cursor to the end of line.
1356   unsigned CursorToEOLOffset;
1357   if (Cursor)
1358     std::tie(CursorIndex, CursorToEOLOffset) =
1359         FindCursorIndex(Includes, Indices, *Cursor);
1360 
1361   // Deduplicate #includes.
1362   Indices.erase(std::unique(Indices.begin(), Indices.end(),
1363                             [&](unsigned LHSI, unsigned RHSI) {
1364                               return Includes[LHSI].Text == Includes[RHSI].Text;
1365                             }),
1366                 Indices.end());
1367 
1368   // If the #includes are out of order, we generate a single replacement fixing
1369   // the entire block. Otherwise, no replacement is generated.
1370   if (Indices.size() == Includes.size() &&
1371       std::is_sorted(Indices.begin(), Indices.end()))
1372     return;
1373 
1374   std::string result;
1375   for (unsigned Index : Indices) {
1376     if (!result.empty())
1377       result += "\n";
1378     result += Includes[Index].Text;
1379     if (Cursor && CursorIndex == Index)
1380       *Cursor = IncludesBeginOffset + result.size() - CursorToEOLOffset;
1381   }
1382 
1383   auto Err = Replaces.add(tooling::Replacement(
1384       FileName, Includes.front().Offset, IncludesBlockSize, result));
1385   // FIXME: better error handling. For now, just skip the replacement for the
1386   // release version.
1387   if (Err) {
1388     llvm::errs() << llvm::toString(std::move(Err)) << "\n";
1389     assert(false);
1390   }
1391 }
1392 
1393 namespace {
1394 
1395 // This class manages priorities of #include categories and calculates
1396 // priorities for headers.
1397 class IncludeCategoryManager {
1398 public:
1399   IncludeCategoryManager(const FormatStyle &Style, StringRef FileName)
1400       : Style(Style), FileName(FileName) {
1401     FileStem = llvm::sys::path::stem(FileName);
1402     for (const auto &Category : Style.IncludeCategories)
1403       CategoryRegexs.emplace_back(Category.Regex);
1404     IsMainFile = FileName.endswith(".c") || FileName.endswith(".cc") ||
1405                  FileName.endswith(".cpp") || FileName.endswith(".c++") ||
1406                  FileName.endswith(".cxx") || FileName.endswith(".m") ||
1407                  FileName.endswith(".mm");
1408   }
1409 
1410   // Returns the priority of the category which \p IncludeName belongs to.
1411   // If \p CheckMainHeader is true and \p IncludeName is a main header, returns
1412   // 0. Otherwise, returns the priority of the matching category or INT_MAX.
1413   int getIncludePriority(StringRef IncludeName, bool CheckMainHeader) {
1414     int Ret = INT_MAX;
1415     for (unsigned i = 0, e = CategoryRegexs.size(); i != e; ++i)
1416       if (CategoryRegexs[i].match(IncludeName)) {
1417         Ret = Style.IncludeCategories[i].Priority;
1418         break;
1419       }
1420     if (CheckMainHeader && IsMainFile && Ret > 0 && isMainHeader(IncludeName))
1421       Ret = 0;
1422     return Ret;
1423   }
1424 
1425 private:
1426   bool isMainHeader(StringRef IncludeName) const {
1427     if (!IncludeName.startswith("\""))
1428       return false;
1429     StringRef HeaderStem =
1430         llvm::sys::path::stem(IncludeName.drop_front(1).drop_back(1));
1431     if (FileStem.startswith(HeaderStem)) {
1432       llvm::Regex MainIncludeRegex(
1433           (HeaderStem + Style.IncludeIsMainRegex).str());
1434       if (MainIncludeRegex.match(FileStem))
1435         return true;
1436     }
1437     return false;
1438   }
1439 
1440   const FormatStyle &Style;
1441   bool IsMainFile;
1442   StringRef FileName;
1443   StringRef FileStem;
1444   SmallVector<llvm::Regex, 4> CategoryRegexs;
1445 };
1446 
1447 const char IncludeRegexPattern[] =
1448     R"(^[\t\ ]*#[\t\ ]*(import|include)[^"<]*(["<][^">]*[">]))";
1449 
1450 } // anonymous namespace
1451 
1452 tooling::Replacements sortCppIncludes(const FormatStyle &Style, StringRef Code,
1453                                       ArrayRef<tooling::Range> Ranges,
1454                                       StringRef FileName,
1455                                       tooling::Replacements &Replaces,
1456                                       unsigned *Cursor) {
1457   unsigned Prev = 0;
1458   unsigned SearchFrom = 0;
1459   llvm::Regex IncludeRegex(IncludeRegexPattern);
1460   SmallVector<StringRef, 4> Matches;
1461   SmallVector<IncludeDirective, 16> IncludesInBlock;
1462 
1463   // In compiled files, consider the first #include to be the main #include of
1464   // the file if it is not a system #include. This ensures that the header
1465   // doesn't have hidden dependencies
1466   // (http://llvm.org/docs/CodingStandards.html#include-style).
1467   //
1468   // FIXME: Do some sanity checking, e.g. edit distance of the base name, to fix
1469   // cases where the first #include is unlikely to be the main header.
1470   IncludeCategoryManager Categories(Style, FileName);
1471   bool FirstIncludeBlock = true;
1472   bool MainIncludeFound = false;
1473   bool FormattingOff = false;
1474 
1475   for (;;) {
1476     auto Pos = Code.find('\n', SearchFrom);
1477     StringRef Line =
1478         Code.substr(Prev, (Pos != StringRef::npos ? Pos : Code.size()) - Prev);
1479 
1480     StringRef Trimmed = Line.trim();
1481     if (Trimmed == "// clang-format off")
1482       FormattingOff = true;
1483     else if (Trimmed == "// clang-format on")
1484       FormattingOff = false;
1485 
1486     if (!FormattingOff && !Line.endswith("\\")) {
1487       if (IncludeRegex.match(Line, &Matches)) {
1488         StringRef IncludeName = Matches[2];
1489         int Category = Categories.getIncludePriority(
1490             IncludeName,
1491             /*CheckMainHeader=*/!MainIncludeFound && FirstIncludeBlock);
1492         if (Category == 0)
1493           MainIncludeFound = true;
1494         IncludesInBlock.push_back({IncludeName, Line, Prev, Category});
1495       } else if (!IncludesInBlock.empty()) {
1496         sortCppIncludes(Style, IncludesInBlock, Ranges, FileName, Replaces,
1497                         Cursor);
1498         IncludesInBlock.clear();
1499         FirstIncludeBlock = false;
1500       }
1501       Prev = Pos + 1;
1502     }
1503     if (Pos == StringRef::npos || Pos + 1 == Code.size())
1504       break;
1505     SearchFrom = Pos + 1;
1506   }
1507   if (!IncludesInBlock.empty())
1508     sortCppIncludes(Style, IncludesInBlock, Ranges, FileName, Replaces, Cursor);
1509   return Replaces;
1510 }
1511 
1512 bool isMpegTS(StringRef Code) {
1513   // MPEG transport streams use the ".ts" file extension. clang-format should
1514   // not attempt to format those. MPEG TS' frame format starts with 0x47 every
1515   // 189 bytes - detect that and return.
1516   return Code.size() > 188 && Code[0] == 0x47 && Code[188] == 0x47;
1517 }
1518 
1519 tooling::Replacements sortIncludes(const FormatStyle &Style, StringRef Code,
1520                                    ArrayRef<tooling::Range> Ranges,
1521                                    StringRef FileName, unsigned *Cursor) {
1522   tooling::Replacements Replaces;
1523   if (!Style.SortIncludes)
1524     return Replaces;
1525   if (Style.Language == FormatStyle::LanguageKind::LK_JavaScript &&
1526       isMpegTS(Code))
1527     return Replaces;
1528   if (Style.Language == FormatStyle::LanguageKind::LK_JavaScript)
1529     return sortJavaScriptImports(Style, Code, Ranges, FileName);
1530   sortCppIncludes(Style, Code, Ranges, FileName, Replaces, Cursor);
1531   return Replaces;
1532 }
1533 
1534 template <typename T>
1535 static llvm::Expected<tooling::Replacements>
1536 processReplacements(T ProcessFunc, StringRef Code,
1537                     const tooling::Replacements &Replaces,
1538                     const FormatStyle &Style) {
1539   if (Replaces.empty())
1540     return tooling::Replacements();
1541 
1542   auto NewCode = applyAllReplacements(Code, Replaces);
1543   if (!NewCode)
1544     return NewCode.takeError();
1545   std::vector<tooling::Range> ChangedRanges = Replaces.getAffectedRanges();
1546   StringRef FileName = Replaces.begin()->getFilePath();
1547 
1548   tooling::Replacements FormatReplaces =
1549       ProcessFunc(Style, *NewCode, ChangedRanges, FileName);
1550 
1551   return Replaces.merge(FormatReplaces);
1552 }
1553 
1554 llvm::Expected<tooling::Replacements>
1555 formatReplacements(StringRef Code, const tooling::Replacements &Replaces,
1556                    const FormatStyle &Style) {
1557   // We need to use lambda function here since there are two versions of
1558   // `sortIncludes`.
1559   auto SortIncludes = [](const FormatStyle &Style, StringRef Code,
1560                          std::vector<tooling::Range> Ranges,
1561                          StringRef FileName) -> tooling::Replacements {
1562     return sortIncludes(Style, Code, Ranges, FileName);
1563   };
1564   auto SortedReplaces =
1565       processReplacements(SortIncludes, Code, Replaces, Style);
1566   if (!SortedReplaces)
1567     return SortedReplaces.takeError();
1568 
1569   // We need to use lambda function here since there are two versions of
1570   // `reformat`.
1571   auto Reformat = [](const FormatStyle &Style, StringRef Code,
1572                      std::vector<tooling::Range> Ranges,
1573                      StringRef FileName) -> tooling::Replacements {
1574     return reformat(Style, Code, Ranges, FileName);
1575   };
1576   return processReplacements(Reformat, Code, *SortedReplaces, Style);
1577 }
1578 
1579 namespace {
1580 
1581 inline bool isHeaderInsertion(const tooling::Replacement &Replace) {
1582   return Replace.getOffset() == UINT_MAX && Replace.getLength() == 0 &&
1583          llvm::Regex(IncludeRegexPattern).match(Replace.getReplacementText());
1584 }
1585 
1586 inline bool isHeaderDeletion(const tooling::Replacement &Replace) {
1587   return Replace.getOffset() == UINT_MAX && Replace.getLength() == 1;
1588 }
1589 
1590 // Returns the offset after skipping a sequence of tokens, matched by \p
1591 // GetOffsetAfterSequence, from the start of the code.
1592 // \p GetOffsetAfterSequence should be a function that matches a sequence of
1593 // tokens and returns an offset after the sequence.
1594 unsigned getOffsetAfterTokenSequence(
1595     StringRef FileName, StringRef Code, const FormatStyle &Style,
1596     llvm::function_ref<unsigned(const SourceManager &, Lexer &, Token &)>
1597         GetOffsetAfterSequence) {
1598   std::unique_ptr<Environment> Env =
1599       Environment::CreateVirtualEnvironment(Code, FileName, /*Ranges=*/{});
1600   const SourceManager &SourceMgr = Env->getSourceManager();
1601   Lexer Lex(Env->getFileID(), SourceMgr.getBuffer(Env->getFileID()), SourceMgr,
1602             getFormattingLangOpts(Style));
1603   Token Tok;
1604   // Get the first token.
1605   Lex.LexFromRawLexer(Tok);
1606   return GetOffsetAfterSequence(SourceMgr, Lex, Tok);
1607 }
1608 
1609 // Check if a sequence of tokens is like "#<Name> <raw_identifier>". If it is,
1610 // \p Tok will be the token after this directive; otherwise, it can be any token
1611 // after the given \p Tok (including \p Tok).
1612 bool checkAndConsumeDirectiveWithName(Lexer &Lex, StringRef Name, Token &Tok) {
1613   bool Matched = Tok.is(tok::hash) && !Lex.LexFromRawLexer(Tok) &&
1614                  Tok.is(tok::raw_identifier) &&
1615                  Tok.getRawIdentifier() == Name && !Lex.LexFromRawLexer(Tok) &&
1616                  Tok.is(tok::raw_identifier);
1617   if (Matched)
1618     Lex.LexFromRawLexer(Tok);
1619   return Matched;
1620 }
1621 
1622 void skipComments(Lexer &Lex, Token &Tok) {
1623   while (Tok.is(tok::comment))
1624     if (Lex.LexFromRawLexer(Tok))
1625       return;
1626 }
1627 
1628 // Returns the offset after header guard directives and any comments
1629 // before/after header guards. If no header guard presents in the code, this
1630 // will returns the offset after skipping all comments from the start of the
1631 // code.
1632 unsigned getOffsetAfterHeaderGuardsAndComments(StringRef FileName,
1633                                                StringRef Code,
1634                                                const FormatStyle &Style) {
1635   return getOffsetAfterTokenSequence(
1636       FileName, Code, Style,
1637       [](const SourceManager &SM, Lexer &Lex, Token Tok) {
1638         skipComments(Lex, Tok);
1639         unsigned InitialOffset = SM.getFileOffset(Tok.getLocation());
1640         if (checkAndConsumeDirectiveWithName(Lex, "ifndef", Tok)) {
1641           skipComments(Lex, Tok);
1642           if (checkAndConsumeDirectiveWithName(Lex, "define", Tok))
1643             return SM.getFileOffset(Tok.getLocation());
1644         }
1645         return InitialOffset;
1646       });
1647 }
1648 
1649 // Check if a sequence of tokens is like
1650 //    "#include ("header.h" | <header.h>)".
1651 // If it is, \p Tok will be the token after this directive; otherwise, it can be
1652 // any token after the given \p Tok (including \p Tok).
1653 bool checkAndConsumeInclusiveDirective(Lexer &Lex, Token &Tok) {
1654   auto Matched = [&]() {
1655     Lex.LexFromRawLexer(Tok);
1656     return true;
1657   };
1658   if (Tok.is(tok::hash) && !Lex.LexFromRawLexer(Tok) &&
1659       Tok.is(tok::raw_identifier) && Tok.getRawIdentifier() == "include") {
1660     if (Lex.LexFromRawLexer(Tok))
1661       return false;
1662     if (Tok.is(tok::string_literal))
1663       return Matched();
1664     if (Tok.is(tok::less)) {
1665       while (!Lex.LexFromRawLexer(Tok) && Tok.isNot(tok::greater)) {
1666       }
1667       if (Tok.is(tok::greater))
1668         return Matched();
1669     }
1670   }
1671   return false;
1672 }
1673 
1674 // Returns the offset of the last #include directive after which a new
1675 // #include can be inserted. This ignores #include's after the #include block(s)
1676 // in the beginning of a file to avoid inserting headers into code sections
1677 // where new #include's should not be added by default.
1678 // These code sections include:
1679 //      - raw string literals (containing #include).
1680 //      - #if blocks.
1681 //      - Special #include's among declarations (e.g. functions).
1682 //
1683 // If no #include after which a new #include can be inserted, this returns the
1684 // offset after skipping all comments from the start of the code.
1685 // Inserting after an #include is not allowed if it comes after code that is not
1686 // #include (e.g. pre-processing directive that is not #include, declarations).
1687 unsigned getMaxHeaderInsertionOffset(StringRef FileName, StringRef Code,
1688                                      const FormatStyle &Style) {
1689   return getOffsetAfterTokenSequence(
1690       FileName, Code, Style,
1691       [](const SourceManager &SM, Lexer &Lex, Token Tok) {
1692         skipComments(Lex, Tok);
1693         unsigned MaxOffset = SM.getFileOffset(Tok.getLocation());
1694         while (checkAndConsumeInclusiveDirective(Lex, Tok))
1695           MaxOffset = SM.getFileOffset(Tok.getLocation());
1696         return MaxOffset;
1697       });
1698 }
1699 
1700 bool isDeletedHeader(llvm::StringRef HeaderName,
1701                      const std::set<llvm::StringRef> &HeadersToDelete) {
1702   return HeadersToDelete.count(HeaderName) ||
1703          HeadersToDelete.count(HeaderName.trim("\"<>"));
1704 }
1705 
1706 // FIXME: insert empty lines between newly created blocks.
1707 tooling::Replacements
1708 fixCppIncludeInsertions(StringRef Code, const tooling::Replacements &Replaces,
1709                         const FormatStyle &Style) {
1710   if (!Style.isCpp())
1711     return Replaces;
1712 
1713   tooling::Replacements HeaderInsertions;
1714   std::set<llvm::StringRef> HeadersToDelete;
1715   tooling::Replacements Result;
1716   for (const auto &R : Replaces) {
1717     if (isHeaderInsertion(R)) {
1718       // Replacements from \p Replaces must be conflict-free already, so we can
1719       // simply consume the error.
1720       llvm::consumeError(HeaderInsertions.add(R));
1721     } else if (isHeaderDeletion(R)) {
1722       HeadersToDelete.insert(R.getReplacementText());
1723     } else if (R.getOffset() == UINT_MAX) {
1724       llvm::errs() << "Insertions other than header #include insertion are "
1725                       "not supported! "
1726                    << R.getReplacementText() << "\n";
1727     } else {
1728       llvm::consumeError(Result.add(R));
1729     }
1730   }
1731   if (HeaderInsertions.empty() && HeadersToDelete.empty())
1732     return Replaces;
1733 
1734   llvm::Regex IncludeRegex(IncludeRegexPattern);
1735   llvm::Regex DefineRegex(R"(^[\t\ ]*#[\t\ ]*define[\t\ ]*[^\\]*$)");
1736   SmallVector<StringRef, 4> Matches;
1737 
1738   StringRef FileName = Replaces.begin()->getFilePath();
1739   IncludeCategoryManager Categories(Style, FileName);
1740 
1741   // Record the offset of the end of the last include in each category.
1742   std::map<int, int> CategoryEndOffsets;
1743   // All possible priorities.
1744   // Add 0 for main header and INT_MAX for headers that are not in any category.
1745   std::set<int> Priorities = {0, INT_MAX};
1746   for (const auto &Category : Style.IncludeCategories)
1747     Priorities.insert(Category.Priority);
1748   int FirstIncludeOffset = -1;
1749   // All new headers should be inserted after this offset.
1750   unsigned MinInsertOffset =
1751       getOffsetAfterHeaderGuardsAndComments(FileName, Code, Style);
1752   StringRef TrimmedCode = Code.drop_front(MinInsertOffset);
1753   // Max insertion offset in the original code.
1754   unsigned MaxInsertOffset =
1755       MinInsertOffset +
1756       getMaxHeaderInsertionOffset(FileName, TrimmedCode, Style);
1757   SmallVector<StringRef, 32> Lines;
1758   TrimmedCode.split(Lines, '\n');
1759   unsigned Offset = MinInsertOffset;
1760   unsigned NextLineOffset;
1761   std::set<StringRef> ExistingIncludes;
1762   for (auto Line : Lines) {
1763     NextLineOffset = std::min(Code.size(), Offset + Line.size() + 1);
1764     if (IncludeRegex.match(Line, &Matches)) {
1765       // The header name with quotes or angle brackets.
1766       StringRef IncludeName = Matches[2];
1767       ExistingIncludes.insert(IncludeName);
1768       // Only record the offset of current #include if we can insert after it.
1769       if (Offset <= MaxInsertOffset) {
1770         int Category = Categories.getIncludePriority(
1771             IncludeName, /*CheckMainHeader=*/FirstIncludeOffset < 0);
1772         CategoryEndOffsets[Category] = NextLineOffset;
1773         if (FirstIncludeOffset < 0)
1774           FirstIncludeOffset = Offset;
1775       }
1776       if (isDeletedHeader(IncludeName, HeadersToDelete)) {
1777         // If this is the last line without trailing newline, we need to make
1778         // sure we don't delete across the file boundary.
1779         unsigned Length = std::min(Line.size() + 1, Code.size() - Offset);
1780         llvm::Error Err =
1781             Result.add(tooling::Replacement(FileName, Offset, Length, ""));
1782         if (Err) {
1783           // Ignore the deletion on conflict.
1784           llvm::errs() << "Failed to add header deletion replacement for "
1785                        << IncludeName << ": " << llvm::toString(std::move(Err))
1786                        << "\n";
1787         }
1788       }
1789     }
1790     Offset = NextLineOffset;
1791   }
1792 
1793   // Populate CategoryEndOfssets:
1794   // - Ensure that CategoryEndOffset[Highest] is always populated.
1795   // - If CategoryEndOffset[Priority] isn't set, use the next higher value that
1796   //   is set, up to CategoryEndOffset[Highest].
1797   auto Highest = Priorities.begin();
1798   if (CategoryEndOffsets.find(*Highest) == CategoryEndOffsets.end()) {
1799     if (FirstIncludeOffset >= 0)
1800       CategoryEndOffsets[*Highest] = FirstIncludeOffset;
1801     else
1802       CategoryEndOffsets[*Highest] = MinInsertOffset;
1803   }
1804   // By this point, CategoryEndOffset[Highest] is always set appropriately:
1805   //  - to an appropriate location before/after existing #includes, or
1806   //  - to right after the header guard, or
1807   //  - to the beginning of the file.
1808   for (auto I = ++Priorities.begin(), E = Priorities.end(); I != E; ++I)
1809     if (CategoryEndOffsets.find(*I) == CategoryEndOffsets.end())
1810       CategoryEndOffsets[*I] = CategoryEndOffsets[*std::prev(I)];
1811 
1812   bool NeedNewLineAtEnd = !Code.empty() && Code.back() != '\n';
1813   for (const auto &R : HeaderInsertions) {
1814     auto IncludeDirective = R.getReplacementText();
1815     bool Matched = IncludeRegex.match(IncludeDirective, &Matches);
1816     assert(Matched && "Header insertion replacement must have replacement text "
1817                       "'#include ...'");
1818     (void)Matched;
1819     auto IncludeName = Matches[2];
1820     if (ExistingIncludes.find(IncludeName) != ExistingIncludes.end()) {
1821       DEBUG(llvm::dbgs() << "Skip adding existing include : " << IncludeName
1822                          << "\n");
1823       continue;
1824     }
1825     int Category =
1826         Categories.getIncludePriority(IncludeName, /*CheckMainHeader=*/true);
1827     Offset = CategoryEndOffsets[Category];
1828     std::string NewInclude = !IncludeDirective.endswith("\n")
1829                                  ? (IncludeDirective + "\n").str()
1830                                  : IncludeDirective.str();
1831     // When inserting headers at end of the code, also append '\n' to the code
1832     // if it does not end with '\n'.
1833     if (NeedNewLineAtEnd && Offset == Code.size()) {
1834       NewInclude = "\n" + NewInclude;
1835       NeedNewLineAtEnd = false;
1836     }
1837     auto NewReplace = tooling::Replacement(FileName, Offset, 0, NewInclude);
1838     auto Err = Result.add(NewReplace);
1839     if (Err) {
1840       llvm::consumeError(std::move(Err));
1841       unsigned NewOffset = Result.getShiftedCodePosition(Offset);
1842       NewReplace = tooling::Replacement(FileName, NewOffset, 0, NewInclude);
1843       Result = Result.merge(tooling::Replacements(NewReplace));
1844     }
1845   }
1846   return Result;
1847 }
1848 
1849 } // anonymous namespace
1850 
1851 llvm::Expected<tooling::Replacements>
1852 cleanupAroundReplacements(StringRef Code, const tooling::Replacements &Replaces,
1853                           const FormatStyle &Style) {
1854   // We need to use lambda function here since there are two versions of
1855   // `cleanup`.
1856   auto Cleanup = [](const FormatStyle &Style, StringRef Code,
1857                     std::vector<tooling::Range> Ranges,
1858                     StringRef FileName) -> tooling::Replacements {
1859     return cleanup(Style, Code, Ranges, FileName);
1860   };
1861   // Make header insertion replacements insert new headers into correct blocks.
1862   tooling::Replacements NewReplaces =
1863       fixCppIncludeInsertions(Code, Replaces, Style);
1864   return processReplacements(Cleanup, Code, NewReplaces, Style);
1865 }
1866 
1867 tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
1868                                ArrayRef<tooling::Range> Ranges,
1869                                StringRef FileName,
1870                                FormattingAttemptStatus *Status) {
1871   FormatStyle Expanded = expandPresets(Style);
1872   if (Expanded.DisableFormat)
1873     return tooling::Replacements();
1874   if (Expanded.Language == FormatStyle::LK_JavaScript && isMpegTS(Code))
1875     return tooling::Replacements();
1876   auto Env = Environment::CreateVirtualEnvironment(Code, FileName, Ranges);
1877 
1878   auto reformatAfterApplying = [&] (TokenAnalyzer& Fixer) {
1879     tooling::Replacements Fixes = Fixer.process();
1880     if (!Fixes.empty()) {
1881       auto NewCode = applyAllReplacements(Code, Fixes);
1882       if (NewCode) {
1883         auto NewEnv = Environment::CreateVirtualEnvironment(
1884             *NewCode, FileName,
1885             tooling::calculateRangesAfterReplacements(Fixes, Ranges));
1886         Formatter Format(*NewEnv, Expanded, Status);
1887         return Fixes.merge(Format.process());
1888       }
1889     }
1890     Formatter Format(*Env, Expanded, Status);
1891     return Format.process();
1892   };
1893 
1894   if (Style.Language == FormatStyle::LK_Cpp &&
1895       Style.FixNamespaceComments) {
1896     NamespaceEndCommentsFixer CommentsFixer(*Env, Expanded);
1897     return reformatAfterApplying(CommentsFixer);
1898   }
1899 
1900   if (Style.Language == FormatStyle::LK_JavaScript &&
1901       Style.JavaScriptQuotes != FormatStyle::JSQS_Leave) {
1902     JavaScriptRequoter Requoter(*Env, Expanded);
1903     return reformatAfterApplying(Requoter);
1904   }
1905 
1906   Formatter Format(*Env, Expanded, Status);
1907   return Format.process();
1908 }
1909 
1910 tooling::Replacements cleanup(const FormatStyle &Style, StringRef Code,
1911                               ArrayRef<tooling::Range> Ranges,
1912                               StringRef FileName) {
1913   // cleanups only apply to C++ (they mostly concern ctor commas etc.)
1914   if (Style.Language != FormatStyle::LK_Cpp)
1915     return tooling::Replacements();
1916   std::unique_ptr<Environment> Env =
1917       Environment::CreateVirtualEnvironment(Code, FileName, Ranges);
1918   Cleaner Clean(*Env, Style);
1919   return Clean.process();
1920 }
1921 
1922 tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
1923                                ArrayRef<tooling::Range> Ranges,
1924                                StringRef FileName, bool *IncompleteFormat) {
1925   FormattingAttemptStatus Status;
1926   auto Result = reformat(Style, Code, Ranges, FileName, &Status);
1927   if (!Status.FormatComplete)
1928     *IncompleteFormat = true;
1929   return Result;
1930 }
1931 
1932 tooling::Replacements fixNamespaceEndComments(const FormatStyle &Style,
1933                                               StringRef Code,
1934                                               ArrayRef<tooling::Range> Ranges,
1935                                               StringRef FileName) {
1936   std::unique_ptr<Environment> Env =
1937       Environment::CreateVirtualEnvironment(Code, FileName, Ranges);
1938   NamespaceEndCommentsFixer Fix(*Env, Style);
1939   return Fix.process();
1940 }
1941 
1942 LangOptions getFormattingLangOpts(const FormatStyle &Style) {
1943   LangOptions LangOpts;
1944   LangOpts.CPlusPlus = 1;
1945   LangOpts.CPlusPlus11 = Style.Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
1946   LangOpts.CPlusPlus14 = Style.Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
1947   LangOpts.CPlusPlus1z = Style.Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
1948   LangOpts.LineComment = 1;
1949   bool AlternativeOperators = Style.isCpp();
1950   LangOpts.CXXOperatorNames = AlternativeOperators ? 1 : 0;
1951   LangOpts.Bool = 1;
1952   LangOpts.ObjC1 = 1;
1953   LangOpts.ObjC2 = 1;
1954   LangOpts.MicrosoftExt = 1;    // To get kw___try, kw___finally.
1955   LangOpts.DeclSpecKeyword = 1; // To get __declspec.
1956   return LangOpts;
1957 }
1958 
1959 const char *StyleOptionHelpDescription =
1960     "Coding style, currently supports:\n"
1961     "  LLVM, Google, Chromium, Mozilla, WebKit.\n"
1962     "Use -style=file to load style configuration from\n"
1963     ".clang-format file located in one of the parent\n"
1964     "directories of the source file (or current\n"
1965     "directory for stdin).\n"
1966     "Use -style=\"{key: value, ...}\" to set specific\n"
1967     "parameters, e.g.:\n"
1968     "  -style=\"{BasedOnStyle: llvm, IndentWidth: 8}\"";
1969 
1970 static FormatStyle::LanguageKind getLanguageByFileName(StringRef FileName) {
1971   if (FileName.endswith(".java"))
1972     return FormatStyle::LK_Java;
1973   if (FileName.endswith_lower(".js") || FileName.endswith_lower(".ts"))
1974     return FormatStyle::LK_JavaScript; // JavaScript or TypeScript.
1975   if (FileName.endswith(".m") || FileName.endswith(".mm"))
1976     return FormatStyle::LK_ObjC;
1977   if (FileName.endswith_lower(".proto") ||
1978       FileName.endswith_lower(".protodevel"))
1979     return FormatStyle::LK_Proto;
1980   if (FileName.endswith_lower(".td"))
1981     return FormatStyle::LK_TableGen;
1982   return FormatStyle::LK_Cpp;
1983 }
1984 
1985 llvm::Expected<FormatStyle> getStyle(StringRef StyleName, StringRef FileName,
1986                                      StringRef FallbackStyleName,
1987                                      StringRef Code, vfs::FileSystem *FS) {
1988   if (!FS) {
1989     FS = vfs::getRealFileSystem().get();
1990   }
1991   FormatStyle Style = getLLVMStyle();
1992   Style.Language = getLanguageByFileName(FileName);
1993 
1994   // This is a very crude detection of whether a header contains ObjC code that
1995   // should be improved over time and probably be done on tokens, not one the
1996   // bare content of the file.
1997   if (Style.Language == FormatStyle::LK_Cpp && FileName.endswith(".h") &&
1998       (Code.contains("\n- (") || Code.contains("\n+ (")))
1999     Style.Language = FormatStyle::LK_ObjC;
2000 
2001   FormatStyle FallbackStyle = getNoStyle();
2002   if (!getPredefinedStyle(FallbackStyleName, Style.Language, &FallbackStyle))
2003     return make_string_error("Invalid fallback style \"" + FallbackStyleName);
2004 
2005   if (StyleName.startswith("{")) {
2006     // Parse YAML/JSON style from the command line.
2007     if (std::error_code ec = parseConfiguration(StyleName, &Style))
2008       return make_string_error("Error parsing -style: " + ec.message());
2009     return Style;
2010   }
2011 
2012   if (!StyleName.equals_lower("file")) {
2013     if (!getPredefinedStyle(StyleName, Style.Language, &Style))
2014       return make_string_error("Invalid value for -style");
2015     return Style;
2016   }
2017 
2018   // Look for .clang-format/_clang-format file in the file's parent directories.
2019   SmallString<128> UnsuitableConfigFiles;
2020   SmallString<128> Path(FileName);
2021   if (std::error_code EC = FS->makeAbsolute(Path))
2022     return make_string_error(EC.message());
2023 
2024   for (StringRef Directory = Path; !Directory.empty();
2025        Directory = llvm::sys::path::parent_path(Directory)) {
2026 
2027     auto Status = FS->status(Directory);
2028     if (!Status ||
2029         Status->getType() != llvm::sys::fs::file_type::directory_file) {
2030       continue;
2031     }
2032 
2033     SmallString<128> ConfigFile(Directory);
2034 
2035     llvm::sys::path::append(ConfigFile, ".clang-format");
2036     DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
2037 
2038     Status = FS->status(ConfigFile.str());
2039     bool FoundConfigFile =
2040         Status && (Status->getType() == llvm::sys::fs::file_type::regular_file);
2041     if (!FoundConfigFile) {
2042       // Try _clang-format too, since dotfiles are not commonly used on Windows.
2043       ConfigFile = Directory;
2044       llvm::sys::path::append(ConfigFile, "_clang-format");
2045       DEBUG(llvm::dbgs() << "Trying " << ConfigFile << "...\n");
2046       Status = FS->status(ConfigFile.str());
2047       FoundConfigFile = Status && (Status->getType() ==
2048                                    llvm::sys::fs::file_type::regular_file);
2049     }
2050 
2051     if (FoundConfigFile) {
2052       llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Text =
2053           FS->getBufferForFile(ConfigFile.str());
2054       if (std::error_code EC = Text.getError())
2055         return make_string_error(EC.message());
2056       if (std::error_code ec =
2057               parseConfiguration(Text.get()->getBuffer(), &Style)) {
2058         if (ec == ParseError::Unsuitable) {
2059           if (!UnsuitableConfigFiles.empty())
2060             UnsuitableConfigFiles.append(", ");
2061           UnsuitableConfigFiles.append(ConfigFile);
2062           continue;
2063         }
2064         return make_string_error("Error reading " + ConfigFile + ": " +
2065                                  ec.message());
2066       }
2067       DEBUG(llvm::dbgs() << "Using configuration file " << ConfigFile << "\n");
2068       return Style;
2069     }
2070   }
2071   if (!UnsuitableConfigFiles.empty())
2072     return make_string_error("Configuration file(s) do(es) not support " +
2073                              getLanguageName(Style.Language) + ": " +
2074                              UnsuitableConfigFiles);
2075   return FallbackStyle;
2076 }
2077 
2078 } // namespace format
2079 } // namespace clang
2080