1//===--- BreakableToken.cpp - Format C++ code -----------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// Contains implementation of BreakableToken class and classes derived
11/// from it.
12///
13//===----------------------------------------------------------------------===//
14
15#include "BreakableToken.h"
16#include "ContinuationIndenter.h"
17#include "clang/Basic/CharInfo.h"
18#include "clang/Format/Format.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/Support/Debug.h"
21#include <algorithm>
22
23#define DEBUG_TYPE "format-token-breaker"
24
25namespace clang {
26namespace format {
27
28static constexpr StringRef Blanks = " \t\v\f\r";
29static bool IsBlank(char C) {
30 switch (C) {
31 case ' ':
32 case '\t':
33 case '\v':
34 case '\f':
35 case '\r':
36 return true;
37 default:
38 return false;
39 }
40}
41
42static StringRef getLineCommentIndentPrefix(StringRef Comment,
43 const FormatStyle &Style) {
44 static constexpr StringRef KnownCStylePrefixes[] = {"///<", "//!<", "///",
45 "//!", "//:", "//"};
46 static constexpr StringRef KnownTextProtoPrefixes[] = {"####", "###", "##",
47 "//", "#"};
48 ArrayRef<StringRef> KnownPrefixes(KnownCStylePrefixes);
49 if (Style.Language == FormatStyle::LK_TextProto)
50 KnownPrefixes = KnownTextProtoPrefixes;
51
52 assert(
53 llvm::is_sorted(KnownPrefixes, [](StringRef Lhs, StringRef Rhs) noexcept {
54 return Lhs.size() > Rhs.size();
55 }));
56
57 for (StringRef KnownPrefix : KnownPrefixes) {
58 if (Comment.starts_with(Prefix: KnownPrefix)) {
59 const auto PrefixLength =
60 Comment.find_first_not_of(C: ' ', From: KnownPrefix.size());
61 return Comment.substr(Start: 0, N: PrefixLength);
62 }
63 }
64 return {};
65}
66
67static BreakableToken::Split
68getCommentSplit(StringRef Text, unsigned ContentStartColumn,
69 unsigned ColumnLimit, unsigned TabWidth,
70 encoding::Encoding Encoding, const FormatStyle &Style,
71 bool DecorationEndsWithStar = false) {
72 LLVM_DEBUG(llvm::dbgs() << "Comment split: \"" << Text
73 << "\", Column limit: " << ColumnLimit
74 << ", Content start: " << ContentStartColumn << "\n");
75 if (ColumnLimit <= ContentStartColumn + 1)
76 return BreakableToken::Split(StringRef::npos, 0);
77
78 unsigned MaxSplit = ColumnLimit - ContentStartColumn + 1;
79 unsigned MaxSplitBytes = 0;
80
81 for (unsigned NumChars = 0;
82 NumChars < MaxSplit && MaxSplitBytes < Text.size();) {
83 unsigned BytesInChar =
84 encoding::getCodePointNumBytes(FirstChar: Text[MaxSplitBytes], Encoding);
85 NumChars += encoding::columnWidthWithTabs(
86 Text: Text.substr(Start: MaxSplitBytes, N: BytesInChar), StartColumn: ContentStartColumn + NumChars,
87 TabWidth, Encoding);
88 MaxSplitBytes += BytesInChar;
89 }
90
91 // In JavaScript, some @tags can be followed by {, and machinery that parses
92 // these comments will fail to understand the comment if followed by a line
93 // break. So avoid ever breaking before a {.
94 if (Style.isJavaScript()) {
95 StringRef::size_type SpaceOffset =
96 Text.find_first_of(Chars: Blanks, From: MaxSplitBytes);
97 if (SpaceOffset != StringRef::npos && SpaceOffset + 1 < Text.size() &&
98 Text[SpaceOffset + 1] == '{') {
99 MaxSplitBytes = SpaceOffset + 1;
100 }
101 }
102
103 StringRef::size_type SpaceOffset = Text.find_last_of(Chars: Blanks, From: MaxSplitBytes);
104
105 static const auto kNumberedListRegexp = llvm::Regex("^[1-9][0-9]?\\.");
106 // Some spaces are unacceptable to break on, rewind past them.
107 while (SpaceOffset != StringRef::npos) {
108 // If a line-comment ends with `\`, the next line continues the comment,
109 // whether or not it starts with `//`. This is confusing and triggers
110 // -Wcomment.
111 // Avoid introducing multiline comments by not allowing a break right
112 // after '\'.
113 if (Style.isCpp()) {
114 StringRef::size_type LastNonBlank =
115 Text.find_last_not_of(Chars: Blanks, From: SpaceOffset);
116 if (LastNonBlank != StringRef::npos && Text[LastNonBlank] == '\\') {
117 SpaceOffset = Text.find_last_of(Chars: Blanks, From: LastNonBlank);
118 continue;
119 }
120 }
121
122 // Do not split before a number followed by a dot: this would be interpreted
123 // as a numbered list, which would prevent re-flowing in subsequent passes.
124 if (kNumberedListRegexp.match(String: Text.substr(Start: SpaceOffset).ltrim(Chars: Blanks))) {
125 SpaceOffset = Text.find_last_of(Chars: Blanks, From: SpaceOffset);
126 continue;
127 }
128
129 // Avoid ever breaking before a @tag or a { in JavaScript.
130 if (Style.isJavaScript() && SpaceOffset + 1 < Text.size() &&
131 (Text[SpaceOffset + 1] == '{' || Text[SpaceOffset + 1] == '@')) {
132 SpaceOffset = Text.find_last_of(Chars: Blanks, From: SpaceOffset);
133 continue;
134 }
135
136 break;
137 }
138
139 if (SpaceOffset == StringRef::npos ||
140 // Don't break at leading whitespace.
141 Text.find_last_not_of(Chars: Blanks, From: SpaceOffset) == StringRef::npos) {
142 // Make sure that we don't break at leading whitespace that
143 // reaches past MaxSplit.
144 StringRef::size_type FirstNonWhitespace = Text.find_first_not_of(Chars: Blanks);
145 if (FirstNonWhitespace == StringRef::npos) {
146 // If the comment is only whitespace, we cannot split.
147 return BreakableToken::Split(StringRef::npos, 0);
148 }
149 SpaceOffset = Text.find_first_of(
150 Chars: Blanks, From: std::max<unsigned>(a: MaxSplitBytes, b: FirstNonWhitespace));
151 }
152 if (SpaceOffset != StringRef::npos && SpaceOffset != 0) {
153 // adaptStartOfLine will break after lines starting with /** if the comment
154 // is broken anywhere. Avoid emitting this break twice here.
155 // Example: in /** longtextcomesherethatbreaks */ (with ColumnLimit 20) will
156 // insert a break after /**, so this code must not insert the same break.
157 if (SpaceOffset == 1 && Text[SpaceOffset - 1] == '*')
158 return BreakableToken::Split(StringRef::npos, 0);
159 StringRef BeforeCut = Text.substr(Start: 0, N: SpaceOffset).rtrim(Chars: Blanks);
160 StringRef AfterCut = Text.substr(Start: SpaceOffset);
161 // Don't trim the leading blanks if it would create a */ after the break.
162 if (!DecorationEndsWithStar || AfterCut.size() <= 1 || AfterCut[1] != '/')
163 AfterCut = AfterCut.ltrim(Chars: Blanks);
164 return BreakableToken::Split(BeforeCut.size(),
165 AfterCut.begin() - BeforeCut.end());
166 }
167 return BreakableToken::Split(StringRef::npos, 0);
168}
169
170static BreakableToken::Split
171getStringSplit(StringRef Text, unsigned UsedColumns, unsigned ColumnLimit,
172 unsigned TabWidth, encoding::Encoding Encoding) {
173 // FIXME: Reduce unit test case.
174 if (Text.empty())
175 return BreakableToken::Split(StringRef::npos, 0);
176 if (ColumnLimit <= UsedColumns)
177 return BreakableToken::Split(StringRef::npos, 0);
178 unsigned MaxSplit = ColumnLimit - UsedColumns;
179 StringRef::size_type SpaceOffset = 0;
180 StringRef::size_type SlashOffset = 0;
181 StringRef::size_type WordStartOffset = 0;
182 StringRef::size_type SplitPoint = 0;
183 for (unsigned Chars = 0;;) {
184 unsigned Advance;
185 if (Text[0] == '\\') {
186 Advance = encoding::getEscapeSequenceLength(Text);
187 Chars += Advance;
188 } else {
189 Advance = encoding::getCodePointNumBytes(FirstChar: Text[0], Encoding);
190 Chars += encoding::columnWidthWithTabs(
191 Text: Text.substr(Start: 0, N: Advance), StartColumn: UsedColumns + Chars, TabWidth, Encoding);
192 }
193
194 if (Chars > MaxSplit || Text.size() <= Advance)
195 break;
196
197 if (IsBlank(C: Text[0]))
198 SpaceOffset = SplitPoint;
199 if (Text[0] == '/')
200 SlashOffset = SplitPoint;
201 if (Advance == 1 && !isAlphanumeric(c: Text[0]))
202 WordStartOffset = SplitPoint;
203
204 SplitPoint += Advance;
205 Text = Text.substr(Start: Advance);
206 }
207
208 if (SpaceOffset != 0)
209 return BreakableToken::Split(SpaceOffset + 1, 0);
210 if (SlashOffset != 0)
211 return BreakableToken::Split(SlashOffset + 1, 0);
212 if (WordStartOffset != 0)
213 return BreakableToken::Split(WordStartOffset + 1, 0);
214 if (SplitPoint != 0)
215 return BreakableToken::Split(SplitPoint, 0);
216 return BreakableToken::Split(StringRef::npos, 0);
217}
218
219bool switchesFormatting(const FormatToken &Token) {
220 assert((Token.is(TT_BlockComment) || Token.is(TT_LineComment)) &&
221 "formatting regions are switched by comment tokens");
222 StringRef Content = Token.TokenText.substr(Start: 2).ltrim();
223 return Content.starts_with(Prefix: "clang-format on") ||
224 Content.starts_with(Prefix: "clang-format off");
225}
226
227unsigned
228BreakableToken::getLengthAfterCompression(unsigned RemainingTokenColumns,
229 Split Split) const {
230 // Example: consider the content
231 // lala lala
232 // - RemainingTokenColumns is the original number of columns, 10;
233 // - Split is (4, 2), denoting the two spaces between the two words;
234 //
235 // We compute the number of columns when the split is compressed into a single
236 // space, like:
237 // lala lala
238 //
239 // FIXME: Correctly measure the length of whitespace in Split.second so it
240 // works with tabs.
241 return RemainingTokenColumns + 1 - Split.second;
242}
243
244unsigned BreakableStringLiteral::getLineCount() const { return 1; }
245
246unsigned BreakableStringLiteral::getRangeLength(unsigned LineIndex,
247 unsigned Offset,
248 StringRef::size_type Length,
249 unsigned StartColumn) const {
250 llvm_unreachable("Getting the length of a part of the string literal "
251 "indicates that the code tries to reflow it.");
252}
253
254unsigned
255BreakableStringLiteral::getRemainingLength(unsigned LineIndex, unsigned Offset,
256 unsigned StartColumn) const {
257 return UnbreakableTailLength + Postfix.size() +
258 encoding::columnWidthWithTabs(Text: Line.substr(Start: Offset), StartColumn,
259 TabWidth: Style.TabWidth, Encoding);
260}
261
262unsigned BreakableStringLiteral::getContentStartColumn(unsigned LineIndex,
263 bool Break) const {
264 return StartColumn + Prefix.size();
265}
266
267BreakableStringLiteral::BreakableStringLiteral(
268 const FormatToken &Tok, unsigned StartColumn, StringRef Prefix,
269 StringRef Postfix, unsigned UnbreakableTailLength, bool InPPDirective,
270 encoding::Encoding Encoding, const FormatStyle &Style)
271 : BreakableToken(Tok, InPPDirective, Encoding, Style),
272 StartColumn(StartColumn), Prefix(Prefix), Postfix(Postfix),
273 UnbreakableTailLength(UnbreakableTailLength) {
274 assert(Tok.TokenText.starts_with(Prefix) && Tok.TokenText.ends_with(Postfix));
275 Line = Tok.TokenText.substr(
276 Start: Prefix.size(), N: Tok.TokenText.size() - Prefix.size() - Postfix.size());
277}
278
279BreakableToken::Split BreakableStringLiteral::getSplit(
280 unsigned LineIndex, unsigned TailOffset, unsigned ColumnLimit,
281 unsigned ContentStartColumn, const llvm::Regex &CommentPragmasRegex) const {
282 return getStringSplit(Text: Line.substr(Start: TailOffset), UsedColumns: ContentStartColumn,
283 ColumnLimit: ColumnLimit - Postfix.size(), TabWidth: Style.TabWidth, Encoding);
284}
285
286void BreakableStringLiteral::insertBreak(unsigned LineIndex,
287 unsigned TailOffset, Split Split,
288 unsigned ContentIndent,
289 WhitespaceManager &Whitespaces) const {
290 Whitespaces.replaceWhitespaceInToken(
291 Tok, Offset: Prefix.size() + TailOffset + Split.first, ReplaceChars: Split.second, PreviousPostfix: Postfix,
292 CurrentPrefix: Prefix, InPPDirective, Newlines: 1, Spaces: StartColumn);
293}
294
295BreakableStringLiteralUsingOperators::BreakableStringLiteralUsingOperators(
296 const FormatToken &Tok, QuoteStyleType QuoteStyle, bool UnindentPlus,
297 unsigned StartColumn, unsigned UnbreakableTailLength, bool InPPDirective,
298 encoding::Encoding Encoding, const FormatStyle &Style)
299 : BreakableStringLiteral(
300 Tok, StartColumn, /*Prefix=*/QuoteStyle == SingleQuotes ? "'"
301 : QuoteStyle == AtDoubleQuotes ? "@\""
302 : "\"",
303 /*Postfix=*/QuoteStyle == SingleQuotes ? "'" : "\"",
304 UnbreakableTailLength, InPPDirective, Encoding, Style),
305 BracesNeeded(Tok.isNot(Kind: TT_StringInConcatenation)),
306 QuoteStyle(QuoteStyle) {
307 // Find the replacement text for inserting braces and quotes and line breaks.
308 // We don't create an allocated string concatenated from parts here because it
309 // has to outlive the BreakableStringliteral object. The brace replacements
310 // include a quote so that WhitespaceManager can tell it apart from whitespace
311 // replacements between the string and surrounding tokens.
312
313 // The option is not implemented in JavaScript.
314 bool SignOnNewLine =
315 !Style.isJavaScript() &&
316 Style.BreakBeforeBinaryOperators != FormatStyle::BOS_None;
317
318 if (Style.isVerilog()) {
319 // In Verilog, all strings are quoted by double quotes, joined by commas,
320 // and wrapped in braces. The comma is always before the newline.
321 assert(QuoteStyle == DoubleQuotes);
322 LeftBraceQuote = Style.Cpp11BracedListStyle ? "{\"" : "{ \"";
323 RightBraceQuote = Style.Cpp11BracedListStyle ? "\"}" : "\" }";
324 Postfix = "\",";
325 Prefix = "\"";
326 } else {
327 // The plus sign may be on either line. And also C# and JavaScript have
328 // several quoting styles.
329 if (QuoteStyle == SingleQuotes) {
330 LeftBraceQuote = Style.SpacesInParensOptions.Other ? "( '" : "('";
331 RightBraceQuote = Style.SpacesInParensOptions.Other ? "' )" : "')";
332 Postfix = SignOnNewLine ? "'" : "' +";
333 Prefix = SignOnNewLine ? "+ '" : "'";
334 } else {
335 if (QuoteStyle == AtDoubleQuotes) {
336 LeftBraceQuote = Style.SpacesInParensOptions.Other ? "( @" : "(@";
337 Prefix = SignOnNewLine ? "+ @\"" : "@\"";
338 } else {
339 LeftBraceQuote = Style.SpacesInParensOptions.Other ? "( \"" : "(\"";
340 Prefix = SignOnNewLine ? "+ \"" : "\"";
341 }
342 RightBraceQuote = Style.SpacesInParensOptions.Other ? "\" )" : "\")";
343 Postfix = SignOnNewLine ? "\"" : "\" +";
344 }
345 }
346
347 // Following lines are indented by the width of the brace and space if any.
348 ContinuationIndent = BracesNeeded ? LeftBraceQuote.size() - 1 : 0;
349 // The plus sign may need to be unindented depending on the style.
350 // FIXME: Add support for DontAlign.
351 if (!Style.isVerilog() && SignOnNewLine && !BracesNeeded && UnindentPlus &&
352 Style.AlignOperands == FormatStyle::OAS_AlignAfterOperator) {
353 ContinuationIndent -= 2;
354 }
355}
356
357unsigned BreakableStringLiteralUsingOperators::getRemainingLength(
358 unsigned LineIndex, unsigned Offset, unsigned StartColumn) const {
359 return UnbreakableTailLength + (BracesNeeded ? RightBraceQuote.size() : 1) +
360 encoding::columnWidthWithTabs(Text: Line.substr(Start: Offset), StartColumn,
361 TabWidth: Style.TabWidth, Encoding);
362}
363
364unsigned
365BreakableStringLiteralUsingOperators::getContentStartColumn(unsigned LineIndex,
366 bool Break) const {
367 return std::max(
368 a: 0,
369 b: static_cast<int>(StartColumn) +
370 (Break ? ContinuationIndent + static_cast<int>(Prefix.size())
371 : (BracesNeeded ? static_cast<int>(LeftBraceQuote.size()) - 1
372 : 0) +
373 (QuoteStyle == AtDoubleQuotes ? 2 : 1)));
374}
375
376void BreakableStringLiteralUsingOperators::insertBreak(
377 unsigned LineIndex, unsigned TailOffset, Split Split,
378 unsigned ContentIndent, WhitespaceManager &Whitespaces) const {
379 Whitespaces.replaceWhitespaceInToken(
380 Tok, /*Offset=*/(QuoteStyle == AtDoubleQuotes ? 2 : 1) + TailOffset +
381 Split.first,
382 /*ReplaceChars=*/Split.second, /*PreviousPostfix=*/Postfix,
383 /*CurrentPrefix=*/Prefix, InPPDirective, /*NewLines=*/Newlines: 1,
384 /*Spaces=*/
385 std::max(a: 0, b: static_cast<int>(StartColumn) + ContinuationIndent));
386}
387
388void BreakableStringLiteralUsingOperators::updateAfterBroken(
389 WhitespaceManager &Whitespaces) const {
390 // Add the braces required for breaking the token if they are needed.
391 if (!BracesNeeded)
392 return;
393
394 // To add a brace or parenthesis, we replace the quote (or the at sign) with a
395 // brace and another quote. This is because the rest of the program requires
396 // one replacement for each source range. If we replace the empty strings
397 // around the string, it may conflict with whitespace replacements between the
398 // string and adjacent tokens.
399 Whitespaces.replaceWhitespaceInToken(
400 Tok, /*Offset=*/0, /*ReplaceChars=*/1, /*PreviousPostfix=*/"",
401 /*CurrentPrefix=*/LeftBraceQuote, InPPDirective, /*NewLines=*/Newlines: 0,
402 /*Spaces=*/0);
403 Whitespaces.replaceWhitespaceInToken(
404 Tok, /*Offset=*/Tok.TokenText.size() - 1, /*ReplaceChars=*/1,
405 /*PreviousPostfix=*/RightBraceQuote,
406 /*CurrentPrefix=*/"", InPPDirective, /*NewLines=*/Newlines: 0, /*Spaces=*/0);
407}
408
409BreakableComment::BreakableComment(const FormatToken &Token,
410 unsigned StartColumn, bool InPPDirective,
411 encoding::Encoding Encoding,
412 const FormatStyle &Style)
413 : BreakableToken(Token, InPPDirective, Encoding, Style),
414 StartColumn(StartColumn) {}
415
416unsigned BreakableComment::getLineCount() const { return Lines.size(); }
417
418BreakableToken::Split
419BreakableComment::getSplit(unsigned LineIndex, unsigned TailOffset,
420 unsigned ColumnLimit, unsigned ContentStartColumn,
421 const llvm::Regex &CommentPragmasRegex) const {
422 // Don't break lines matching the comment pragmas regex.
423 if (CommentPragmasRegex.match(String: Content[LineIndex]))
424 return Split(StringRef::npos, 0);
425 return getCommentSplit(Text: Content[LineIndex].substr(Start: TailOffset),
426 ContentStartColumn, ColumnLimit, TabWidth: Style.TabWidth,
427 Encoding, Style);
428}
429
430void BreakableComment::compressWhitespace(
431 unsigned LineIndex, unsigned TailOffset, Split Split,
432 WhitespaceManager &Whitespaces) const {
433 StringRef Text = Content[LineIndex].substr(Start: TailOffset);
434 // Text is relative to the content line, but Whitespaces operates relative to
435 // the start of the corresponding token, so compute the start of the Split
436 // that needs to be compressed into a single space relative to the start of
437 // its token.
438 unsigned BreakOffsetInToken =
439 Text.data() - tokenAt(LineIndex).TokenText.data() + Split.first;
440 unsigned CharsToRemove = Split.second;
441 Whitespaces.replaceWhitespaceInToken(
442 Tok: tokenAt(LineIndex), Offset: BreakOffsetInToken, ReplaceChars: CharsToRemove, PreviousPostfix: "", CurrentPrefix: "",
443 /*InPPDirective=*/false, /*Newlines=*/0, /*Spaces=*/1);
444}
445
446const FormatToken &BreakableComment::tokenAt(unsigned LineIndex) const {
447 return Tokens[LineIndex] ? *Tokens[LineIndex] : Tok;
448}
449
450static bool mayReflowContent(StringRef Content) {
451 Content = Content.trim(Chars: Blanks);
452 // Lines starting with '@' or '\' commonly have special meaning.
453 // Lines starting with '-', '-#', '+' or '*' are bulleted/numbered lists.
454 bool hasSpecialMeaningPrefix = false;
455 for (StringRef Prefix :
456 {"@", "\\", "TODO", "FIXME", "XXX", "-# ", "- ", "+ ", "* "}) {
457 if (Content.starts_with(Prefix)) {
458 hasSpecialMeaningPrefix = true;
459 break;
460 }
461 }
462
463 // Numbered lists may also start with a number followed by '.'
464 // To avoid issues if a line starts with a number which is actually the end
465 // of a previous line, we only consider numbers with up to 2 digits.
466 static const auto kNumberedListRegexp = llvm::Regex("^[1-9][0-9]?\\. ");
467 hasSpecialMeaningPrefix =
468 hasSpecialMeaningPrefix || kNumberedListRegexp.match(String: Content);
469
470 // Simple heuristic for what to reflow: content should contain at least two
471 // characters and either the first or second character must be
472 // non-punctuation.
473 return Content.size() >= 2 && !hasSpecialMeaningPrefix &&
474 !Content.ends_with(Suffix: "\\") &&
475 // Note that this is UTF-8 safe, since if isPunctuation(Content[0]) is
476 // true, then the first code point must be 1 byte long.
477 (!isPunctuation(c: Content[0]) || !isPunctuation(c: Content[1]));
478}
479
480BreakableBlockComment::BreakableBlockComment(
481 const FormatToken &Token, unsigned StartColumn,
482 unsigned OriginalStartColumn, bool FirstInLine, bool InPPDirective,
483 encoding::Encoding Encoding, const FormatStyle &Style, bool UseCRLF)
484 : BreakableComment(Token, StartColumn, InPPDirective, Encoding, Style),
485 DelimitersOnNewline(false),
486 UnbreakableTailLength(Token.UnbreakableTailLength) {
487 assert(Tok.is(TT_BlockComment) &&
488 "block comment section must start with a block comment");
489
490 StringRef TokenText(Tok.TokenText);
491 assert(TokenText.starts_with("/*") && TokenText.ends_with("*/"));
492 TokenText.substr(Start: 2, N: TokenText.size() - 4)
493 .split(A&: Lines, Separator: UseCRLF ? "\r\n" : "\n");
494
495 int IndentDelta = StartColumn - OriginalStartColumn;
496 Content.resize(N: Lines.size());
497 Content[0] = Lines[0];
498 ContentColumn.resize(N: Lines.size());
499 // Account for the initial '/*'.
500 ContentColumn[0] = StartColumn + 2;
501 Tokens.resize(N: Lines.size());
502 for (size_t i = 1; i < Lines.size(); ++i)
503 adjustWhitespace(LineIndex: i, IndentDelta);
504
505 // Align decorations with the column of the star on the first line,
506 // that is one column after the start "/*".
507 DecorationColumn = StartColumn + 1;
508
509 // Account for comment decoration patterns like this:
510 //
511 // /*
512 // ** blah blah blah
513 // */
514 if (Lines.size() >= 2 && Content[1].starts_with(Prefix: "**") &&
515 static_cast<unsigned>(ContentColumn[1]) == StartColumn) {
516 DecorationColumn = StartColumn;
517 }
518
519 Decoration = "* ";
520 if (Lines.size() == 1 && !FirstInLine) {
521 // Comments for which FirstInLine is false can start on arbitrary column,
522 // and available horizontal space can be too small to align consecutive
523 // lines with the first one.
524 // FIXME: We could, probably, align them to current indentation level, but
525 // now we just wrap them without stars.
526 Decoration = "";
527 }
528 for (size_t i = 1, e = Content.size(); i < e && !Decoration.empty(); ++i) {
529 const StringRef &Text = Content[i];
530 if (i + 1 == e) {
531 // If the last line is empty, the closing "*/" will have a star.
532 if (Text.empty())
533 break;
534 } else if (!Text.empty() && Decoration.starts_with(Prefix: Text)) {
535 continue;
536 }
537 while (!Text.starts_with(Prefix: Decoration))
538 Decoration = Decoration.drop_back(N: 1);
539 }
540
541 LastLineNeedsDecoration = true;
542 IndentAtLineBreak = ContentColumn[0] + 1;
543 for (size_t i = 1, e = Lines.size(); i < e; ++i) {
544 if (Content[i].empty()) {
545 if (i + 1 == e) {
546 // Empty last line means that we already have a star as a part of the
547 // trailing */. We also need to preserve whitespace, so that */ is
548 // correctly indented.
549 LastLineNeedsDecoration = false;
550 // Align the star in the last '*/' with the stars on the previous lines.
551 if (e >= 2 && !Decoration.empty())
552 ContentColumn[i] = DecorationColumn;
553 } else if (Decoration.empty()) {
554 // For all other lines, set the start column to 0 if they're empty, so
555 // we do not insert trailing whitespace anywhere.
556 ContentColumn[i] = 0;
557 }
558 continue;
559 }
560
561 // The first line already excludes the star.
562 // The last line excludes the star if LastLineNeedsDecoration is false.
563 // For all other lines, adjust the line to exclude the star and
564 // (optionally) the first whitespace.
565 unsigned DecorationSize = Decoration.starts_with(Prefix: Content[i])
566 ? Content[i].size()
567 : Decoration.size();
568 if (DecorationSize)
569 ContentColumn[i] = DecorationColumn + DecorationSize;
570 Content[i] = Content[i].substr(Start: DecorationSize);
571 if (!Decoration.starts_with(Prefix: Content[i])) {
572 IndentAtLineBreak =
573 std::min<int>(a: IndentAtLineBreak, b: std::max(a: 0, b: ContentColumn[i]));
574 }
575 }
576 IndentAtLineBreak = std::max<unsigned>(a: IndentAtLineBreak, b: Decoration.size());
577
578 // Detect a multiline jsdoc comment and set DelimitersOnNewline in that case.
579 if (Style.isJavaScript() || Style.Language == FormatStyle::LK_Java) {
580 if ((Lines[0] == "*" || Lines[0].starts_with(Prefix: "* ")) && Lines.size() > 1) {
581 // This is a multiline jsdoc comment.
582 DelimitersOnNewline = true;
583 } else if (Lines[0].starts_with(Prefix: "* ") && Lines.size() == 1) {
584 // Detect a long single-line comment, like:
585 // /** long long long */
586 // Below, '2' is the width of '*/'.
587 unsigned EndColumn =
588 ContentColumn[0] +
589 encoding::columnWidthWithTabs(Text: Lines[0], StartColumn: ContentColumn[0],
590 TabWidth: Style.TabWidth, Encoding) +
591 2;
592 DelimitersOnNewline = EndColumn > Style.ColumnLimit;
593 }
594 }
595
596 LLVM_DEBUG({
597 llvm::dbgs() << "IndentAtLineBreak " << IndentAtLineBreak << "\n";
598 llvm::dbgs() << "DelimitersOnNewline " << DelimitersOnNewline << "\n";
599 for (size_t i = 0; i < Lines.size(); ++i) {
600 llvm::dbgs() << i << " |" << Content[i] << "| "
601 << "CC=" << ContentColumn[i] << "| "
602 << "IN=" << (Content[i].data() - Lines[i].data()) << "\n";
603 }
604 });
605}
606
607BreakableToken::Split BreakableBlockComment::getSplit(
608 unsigned LineIndex, unsigned TailOffset, unsigned ColumnLimit,
609 unsigned ContentStartColumn, const llvm::Regex &CommentPragmasRegex) const {
610 // Don't break lines matching the comment pragmas regex.
611 if (CommentPragmasRegex.match(String: Content[LineIndex]))
612 return Split(StringRef::npos, 0);
613 return getCommentSplit(Text: Content[LineIndex].substr(Start: TailOffset),
614 ContentStartColumn, ColumnLimit, TabWidth: Style.TabWidth,
615 Encoding, Style, DecorationEndsWithStar: Decoration.ends_with(Suffix: "*"));
616}
617
618void BreakableBlockComment::adjustWhitespace(unsigned LineIndex,
619 int IndentDelta) {
620 // When in a preprocessor directive, the trailing backslash in a block comment
621 // is not needed, but can serve a purpose of uniformity with necessary escaped
622 // newlines outside the comment. In this case we remove it here before
623 // trimming the trailing whitespace. The backslash will be re-added later when
624 // inserting a line break.
625 size_t EndOfPreviousLine = Lines[LineIndex - 1].size();
626 if (InPPDirective && Lines[LineIndex - 1].ends_with(Suffix: "\\"))
627 --EndOfPreviousLine;
628
629 // Calculate the end of the non-whitespace text in the previous line.
630 EndOfPreviousLine =
631 Lines[LineIndex - 1].find_last_not_of(Chars: Blanks, From: EndOfPreviousLine);
632 if (EndOfPreviousLine == StringRef::npos)
633 EndOfPreviousLine = 0;
634 else
635 ++EndOfPreviousLine;
636 // Calculate the start of the non-whitespace text in the current line.
637 size_t StartOfLine = Lines[LineIndex].find_first_not_of(Chars: Blanks);
638 if (StartOfLine == StringRef::npos)
639 StartOfLine = Lines[LineIndex].size();
640
641 StringRef Whitespace = Lines[LineIndex].substr(Start: 0, N: StartOfLine);
642 // Adjust Lines to only contain relevant text.
643 size_t PreviousContentOffset =
644 Content[LineIndex - 1].data() - Lines[LineIndex - 1].data();
645 Content[LineIndex - 1] = Lines[LineIndex - 1].substr(
646 Start: PreviousContentOffset, N: EndOfPreviousLine - PreviousContentOffset);
647 Content[LineIndex] = Lines[LineIndex].substr(Start: StartOfLine);
648
649 // Adjust the start column uniformly across all lines.
650 ContentColumn[LineIndex] =
651 encoding::columnWidthWithTabs(Text: Whitespace, StartColumn: 0, TabWidth: Style.TabWidth, Encoding) +
652 IndentDelta;
653}
654
655unsigned BreakableBlockComment::getRangeLength(unsigned LineIndex,
656 unsigned Offset,
657 StringRef::size_type Length,
658 unsigned StartColumn) const {
659 return encoding::columnWidthWithTabs(
660 Text: Content[LineIndex].substr(Start: Offset, N: Length), StartColumn, TabWidth: Style.TabWidth,
661 Encoding);
662}
663
664unsigned BreakableBlockComment::getRemainingLength(unsigned LineIndex,
665 unsigned Offset,
666 unsigned StartColumn) const {
667 unsigned LineLength =
668 UnbreakableTailLength +
669 getRangeLength(LineIndex, Offset, Length: StringRef::npos, StartColumn);
670 if (LineIndex + 1 == Lines.size()) {
671 LineLength += 2;
672 // We never need a decoration when breaking just the trailing "*/" postfix.
673 bool HasRemainingText = Offset < Content[LineIndex].size();
674 if (!HasRemainingText) {
675 bool HasDecoration = Lines[LineIndex].ltrim().starts_with(Prefix: Decoration);
676 if (HasDecoration)
677 LineLength -= Decoration.size();
678 }
679 }
680 return LineLength;
681}
682
683unsigned BreakableBlockComment::getContentStartColumn(unsigned LineIndex,
684 bool Break) const {
685 if (Break)
686 return IndentAtLineBreak;
687 return std::max(a: 0, b: ContentColumn[LineIndex]);
688}
689
690const llvm::StringSet<>
691 BreakableBlockComment::ContentIndentingJavadocAnnotations = {
692 "@param", "@return", "@returns", "@throws", "@type", "@template",
693 "@see", "@deprecated", "@define", "@exports", "@mods", "@private",
694};
695
696unsigned BreakableBlockComment::getContentIndent(unsigned LineIndex) const {
697 if (Style.Language != FormatStyle::LK_Java && !Style.isJavaScript())
698 return 0;
699 // The content at LineIndex 0 of a comment like:
700 // /** line 0 */
701 // is "* line 0", so we need to skip over the decoration in that case.
702 StringRef ContentWithNoDecoration = Content[LineIndex];
703 if (LineIndex == 0 && ContentWithNoDecoration.starts_with(Prefix: "*"))
704 ContentWithNoDecoration = ContentWithNoDecoration.substr(Start: 1).ltrim(Chars: Blanks);
705 StringRef FirstWord = ContentWithNoDecoration.substr(
706 Start: 0, N: ContentWithNoDecoration.find_first_of(Chars: Blanks));
707 if (ContentIndentingJavadocAnnotations.contains(key: FirstWord))
708 return Style.ContinuationIndentWidth;
709 return 0;
710}
711
712void BreakableBlockComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
713 Split Split, unsigned ContentIndent,
714 WhitespaceManager &Whitespaces) const {
715 StringRef Text = Content[LineIndex].substr(Start: TailOffset);
716 StringRef Prefix = Decoration;
717 // We need this to account for the case when we have a decoration "* " for all
718 // the lines except for the last one, where the star in "*/" acts as a
719 // decoration.
720 unsigned LocalIndentAtLineBreak = IndentAtLineBreak;
721 if (LineIndex + 1 == Lines.size() &&
722 Text.size() == Split.first + Split.second) {
723 // For the last line we need to break before "*/", but not to add "* ".
724 Prefix = "";
725 if (LocalIndentAtLineBreak >= 2)
726 LocalIndentAtLineBreak -= 2;
727 }
728 // The split offset is from the beginning of the line. Convert it to an offset
729 // from the beginning of the token text.
730 unsigned BreakOffsetInToken =
731 Text.data() - tokenAt(LineIndex).TokenText.data() + Split.first;
732 unsigned CharsToRemove = Split.second;
733 assert(LocalIndentAtLineBreak >= Prefix.size());
734 std::string PrefixWithTrailingIndent = std::string(Prefix);
735 PrefixWithTrailingIndent.append(n: ContentIndent, c: ' ');
736 Whitespaces.replaceWhitespaceInToken(
737 Tok: tokenAt(LineIndex), Offset: BreakOffsetInToken, ReplaceChars: CharsToRemove, PreviousPostfix: "",
738 CurrentPrefix: PrefixWithTrailingIndent, InPPDirective, /*Newlines=*/1,
739 /*Spaces=*/LocalIndentAtLineBreak + ContentIndent -
740 PrefixWithTrailingIndent.size());
741}
742
743BreakableToken::Split BreakableBlockComment::getReflowSplit(
744 unsigned LineIndex, const llvm::Regex &CommentPragmasRegex) const {
745 if (!mayReflow(LineIndex, CommentPragmasRegex))
746 return Split(StringRef::npos, 0);
747
748 // If we're reflowing into a line with content indent, only reflow the next
749 // line if its starting whitespace matches the content indent.
750 size_t Trimmed = Content[LineIndex].find_first_not_of(Chars: Blanks);
751 if (LineIndex) {
752 unsigned PreviousContentIndent = getContentIndent(LineIndex: LineIndex - 1);
753 if (PreviousContentIndent && Trimmed != StringRef::npos &&
754 Trimmed != PreviousContentIndent) {
755 return Split(StringRef::npos, 0);
756 }
757 }
758
759 return Split(0, Trimmed != StringRef::npos ? Trimmed : 0);
760}
761
762bool BreakableBlockComment::introducesBreakBeforeToken() const {
763 // A break is introduced when we want delimiters on newline.
764 return DelimitersOnNewline &&
765 Lines[0].substr(Start: 1).find_first_not_of(Chars: Blanks) != StringRef::npos;
766}
767
768void BreakableBlockComment::reflow(unsigned LineIndex,
769 WhitespaceManager &Whitespaces) const {
770 StringRef TrimmedContent = Content[LineIndex].ltrim(Chars: Blanks);
771 // Here we need to reflow.
772 assert(Tokens[LineIndex - 1] == Tokens[LineIndex] &&
773 "Reflowing whitespace within a token");
774 // This is the offset of the end of the last line relative to the start of
775 // the token text in the token.
776 unsigned WhitespaceOffsetInToken = Content[LineIndex - 1].data() +
777 Content[LineIndex - 1].size() -
778 tokenAt(LineIndex).TokenText.data();
779 unsigned WhitespaceLength = TrimmedContent.data() -
780 tokenAt(LineIndex).TokenText.data() -
781 WhitespaceOffsetInToken;
782 Whitespaces.replaceWhitespaceInToken(
783 Tok: tokenAt(LineIndex), Offset: WhitespaceOffsetInToken,
784 /*ReplaceChars=*/WhitespaceLength, /*PreviousPostfix=*/"",
785 /*CurrentPrefix=*/ReflowPrefix, InPPDirective, /*Newlines=*/0,
786 /*Spaces=*/0);
787}
788
789void BreakableBlockComment::adaptStartOfLine(
790 unsigned LineIndex, WhitespaceManager &Whitespaces) const {
791 if (LineIndex == 0) {
792 if (DelimitersOnNewline) {
793 // Since we're breaking at index 1 below, the break position and the
794 // break length are the same.
795 // Note: this works because getCommentSplit is careful never to split at
796 // the beginning of a line.
797 size_t BreakLength = Lines[0].substr(Start: 1).find_first_not_of(Chars: Blanks);
798 if (BreakLength != StringRef::npos) {
799 insertBreak(LineIndex, TailOffset: 0, Split: Split(1, BreakLength), /*ContentIndent=*/0,
800 Whitespaces);
801 }
802 }
803 return;
804 }
805 // Here no reflow with the previous line will happen.
806 // Fix the decoration of the line at LineIndex.
807 StringRef Prefix = Decoration;
808 if (Content[LineIndex].empty()) {
809 if (LineIndex + 1 == Lines.size()) {
810 if (!LastLineNeedsDecoration) {
811 // If the last line was empty, we don't need a prefix, as the */ will
812 // line up with the decoration (if it exists).
813 Prefix = "";
814 }
815 } else if (!Decoration.empty()) {
816 // For other empty lines, if we do have a decoration, adapt it to not
817 // contain a trailing whitespace.
818 Prefix = Prefix.substr(Start: 0, N: 1);
819 }
820 } else if (ContentColumn[LineIndex] == 1) {
821 // This line starts immediately after the decorating *.
822 Prefix = Prefix.substr(Start: 0, N: 1);
823 }
824 // This is the offset of the end of the last line relative to the start of the
825 // token text in the token.
826 unsigned WhitespaceOffsetInToken = Content[LineIndex - 1].data() +
827 Content[LineIndex - 1].size() -
828 tokenAt(LineIndex).TokenText.data();
829 unsigned WhitespaceLength = Content[LineIndex].data() -
830 tokenAt(LineIndex).TokenText.data() -
831 WhitespaceOffsetInToken;
832 Whitespaces.replaceWhitespaceInToken(
833 Tok: tokenAt(LineIndex), Offset: WhitespaceOffsetInToken, ReplaceChars: WhitespaceLength, PreviousPostfix: "", CurrentPrefix: Prefix,
834 InPPDirective, /*Newlines=*/1, Spaces: ContentColumn[LineIndex] - Prefix.size());
835}
836
837BreakableToken::Split
838BreakableBlockComment::getSplitAfterLastLine(unsigned TailOffset) const {
839 if (DelimitersOnNewline) {
840 // Replace the trailing whitespace of the last line with a newline.
841 // In case the last line is empty, the ending '*/' is already on its own
842 // line.
843 StringRef Line = Content.back().substr(Start: TailOffset);
844 StringRef TrimmedLine = Line.rtrim(Chars: Blanks);
845 if (!TrimmedLine.empty())
846 return Split(TrimmedLine.size(), Line.size() - TrimmedLine.size());
847 }
848 return Split(StringRef::npos, 0);
849}
850
851bool BreakableBlockComment::mayReflow(
852 unsigned LineIndex, const llvm::Regex &CommentPragmasRegex) const {
853 // Content[LineIndex] may exclude the indent after the '*' decoration. In that
854 // case, we compute the start of the comment pragma manually.
855 StringRef IndentContent = Content[LineIndex];
856 if (Lines[LineIndex].ltrim(Chars: Blanks).starts_with(Prefix: "*"))
857 IndentContent = Lines[LineIndex].ltrim(Chars: Blanks).substr(Start: 1);
858 return LineIndex > 0 && !CommentPragmasRegex.match(String: IndentContent) &&
859 mayReflowContent(Content: Content[LineIndex]) && !Tok.Finalized &&
860 !switchesFormatting(Token: tokenAt(LineIndex));
861}
862
863BreakableLineCommentSection::BreakableLineCommentSection(
864 const FormatToken &Token, unsigned StartColumn, bool InPPDirective,
865 encoding::Encoding Encoding, const FormatStyle &Style)
866 : BreakableComment(Token, StartColumn, InPPDirective, Encoding, Style) {
867 assert(Tok.is(TT_LineComment) &&
868 "line comment section must start with a line comment");
869 FormatToken *LineTok = nullptr;
870 const int Minimum = Style.SpacesInLineCommentPrefix.Minimum;
871 // How many spaces we changed in the first line of the section, this will be
872 // applied in all following lines
873 int FirstLineSpaceChange = 0;
874 for (const FormatToken *CurrentTok = &Tok;
875 CurrentTok && CurrentTok->is(TT: TT_LineComment);
876 CurrentTok = CurrentTok->Next) {
877 LastLineTok = LineTok;
878 StringRef TokenText(CurrentTok->TokenText);
879 assert((TokenText.starts_with("//") || TokenText.starts_with("#")) &&
880 "unsupported line comment prefix, '//' and '#' are supported");
881 size_t FirstLineIndex = Lines.size();
882 TokenText.split(A&: Lines, Separator: "\n");
883 Content.resize(N: Lines.size());
884 ContentColumn.resize(N: Lines.size());
885 PrefixSpaceChange.resize(N: Lines.size());
886 Tokens.resize(N: Lines.size());
887 Prefix.resize(N: Lines.size());
888 OriginalPrefix.resize(N: Lines.size());
889 for (size_t i = FirstLineIndex, e = Lines.size(); i < e; ++i) {
890 Lines[i] = Lines[i].ltrim(Chars: Blanks);
891 StringRef IndentPrefix = getLineCommentIndentPrefix(Comment: Lines[i], Style);
892 OriginalPrefix[i] = IndentPrefix;
893 const int SpacesInPrefix = llvm::count(Range&: IndentPrefix, Element: ' ');
894
895 // This lambda also considers multibyte character that is not handled in
896 // functions like isPunctuation provided by CharInfo.
897 const auto NoSpaceBeforeFirstCommentChar = [&]() {
898 assert(Lines[i].size() > IndentPrefix.size());
899 const char FirstCommentChar = Lines[i][IndentPrefix.size()];
900 const unsigned FirstCharByteSize =
901 encoding::getCodePointNumBytes(FirstChar: FirstCommentChar, Encoding);
902 if (encoding::columnWidth(
903 Text: Lines[i].substr(Start: IndentPrefix.size(), N: FirstCharByteSize),
904 Encoding) != 1) {
905 return false;
906 }
907 // In C-like comments, add a space before #. For example this is useful
908 // to preserve the relative indentation when commenting out code with
909 // #includes.
910 //
911 // In languages using # as the comment leader such as proto, don't
912 // add a space to support patterns like:
913 // #########
914 // # section
915 // #########
916 if (FirstCommentChar == '#' && !TokenText.starts_with(Prefix: "#"))
917 return false;
918 return FirstCommentChar == '\\' || isPunctuation(c: FirstCommentChar) ||
919 isHorizontalWhitespace(c: FirstCommentChar);
920 };
921
922 // On the first line of the comment section we calculate how many spaces
923 // are to be added or removed, all lines after that just get only the
924 // change and we will not look at the maximum anymore. Additionally to the
925 // actual first line, we calculate that when the non space Prefix changes,
926 // e.g. from "///" to "//".
927 if (i == 0 || OriginalPrefix[i].rtrim(Chars: Blanks) !=
928 OriginalPrefix[i - 1].rtrim(Chars: Blanks)) {
929 if (SpacesInPrefix < Minimum && Lines[i].size() > IndentPrefix.size() &&
930 !NoSpaceBeforeFirstCommentChar()) {
931 FirstLineSpaceChange = Minimum - SpacesInPrefix;
932 } else if (static_cast<unsigned>(SpacesInPrefix) >
933 Style.SpacesInLineCommentPrefix.Maximum) {
934 FirstLineSpaceChange =
935 Style.SpacesInLineCommentPrefix.Maximum - SpacesInPrefix;
936 } else {
937 FirstLineSpaceChange = 0;
938 }
939 }
940
941 if (Lines[i].size() != IndentPrefix.size()) {
942 PrefixSpaceChange[i] = FirstLineSpaceChange;
943
944 if (SpacesInPrefix + PrefixSpaceChange[i] < Minimum) {
945 PrefixSpaceChange[i] +=
946 Minimum - (SpacesInPrefix + PrefixSpaceChange[i]);
947 }
948
949 assert(Lines[i].size() > IndentPrefix.size());
950 const auto FirstNonSpace = Lines[i][IndentPrefix.size()];
951 const bool IsFormatComment = LineTok && switchesFormatting(Token: *LineTok);
952 const bool LineRequiresLeadingSpace =
953 !NoSpaceBeforeFirstCommentChar() ||
954 (FirstNonSpace == '}' && FirstLineSpaceChange != 0);
955 const bool AllowsSpaceChange =
956 !IsFormatComment &&
957 (SpacesInPrefix != 0 || LineRequiresLeadingSpace);
958
959 if (PrefixSpaceChange[i] > 0 && AllowsSpaceChange) {
960 Prefix[i] = IndentPrefix.str();
961 Prefix[i].append(n: PrefixSpaceChange[i], c: ' ');
962 } else if (PrefixSpaceChange[i] < 0 && AllowsSpaceChange) {
963 Prefix[i] = IndentPrefix
964 .drop_back(N: std::min<std::size_t>(
965 a: -PrefixSpaceChange[i], b: SpacesInPrefix))
966 .str();
967 } else {
968 Prefix[i] = IndentPrefix.str();
969 }
970 } else {
971 // If the IndentPrefix is the whole line, there is no content and we
972 // drop just all space
973 Prefix[i] = IndentPrefix.drop_back(N: SpacesInPrefix).str();
974 }
975
976 Tokens[i] = LineTok;
977 Content[i] = Lines[i].substr(Start: IndentPrefix.size());
978 ContentColumn[i] =
979 StartColumn + encoding::columnWidthWithTabs(Text: Prefix[i], StartColumn,
980 TabWidth: Style.TabWidth, Encoding);
981
982 // Calculate the end of the non-whitespace text in this line.
983 size_t EndOfLine = Content[i].find_last_not_of(Chars: Blanks);
984 if (EndOfLine == StringRef::npos)
985 EndOfLine = Content[i].size();
986 else
987 ++EndOfLine;
988 Content[i] = Content[i].substr(Start: 0, N: EndOfLine);
989 }
990 LineTok = CurrentTok->Next;
991 if (CurrentTok->Next && !CurrentTok->Next->ContinuesLineCommentSection) {
992 // A line comment section needs to broken by a line comment that is
993 // preceded by at least two newlines. Note that we put this break here
994 // instead of breaking at a previous stage during parsing, since that
995 // would split the contents of the enum into two unwrapped lines in this
996 // example, which is undesirable:
997 // enum A {
998 // a, // comment about a
999 //
1000 // // comment about b
1001 // b
1002 // };
1003 //
1004 // FIXME: Consider putting separate line comment sections as children to
1005 // the unwrapped line instead.
1006 break;
1007 }
1008 }
1009}
1010
1011unsigned
1012BreakableLineCommentSection::getRangeLength(unsigned LineIndex, unsigned Offset,
1013 StringRef::size_type Length,
1014 unsigned StartColumn) const {
1015 return encoding::columnWidthWithTabs(
1016 Text: Content[LineIndex].substr(Start: Offset, N: Length), StartColumn, TabWidth: Style.TabWidth,
1017 Encoding);
1018}
1019
1020unsigned
1021BreakableLineCommentSection::getContentStartColumn(unsigned LineIndex,
1022 bool /*Break*/) const {
1023 return ContentColumn[LineIndex];
1024}
1025
1026void BreakableLineCommentSection::insertBreak(
1027 unsigned LineIndex, unsigned TailOffset, Split Split,
1028 unsigned ContentIndent, WhitespaceManager &Whitespaces) const {
1029 StringRef Text = Content[LineIndex].substr(Start: TailOffset);
1030 // Compute the offset of the split relative to the beginning of the token
1031 // text.
1032 unsigned BreakOffsetInToken =
1033 Text.data() - tokenAt(LineIndex).TokenText.data() + Split.first;
1034 unsigned CharsToRemove = Split.second;
1035 Whitespaces.replaceWhitespaceInToken(
1036 Tok: tokenAt(LineIndex), Offset: BreakOffsetInToken, ReplaceChars: CharsToRemove, PreviousPostfix: "",
1037 CurrentPrefix: Prefix[LineIndex], InPPDirective, /*Newlines=*/1,
1038 /*Spaces=*/ContentColumn[LineIndex] - Prefix[LineIndex].size());
1039}
1040
1041BreakableComment::Split BreakableLineCommentSection::getReflowSplit(
1042 unsigned LineIndex, const llvm::Regex &CommentPragmasRegex) const {
1043 if (!mayReflow(LineIndex, CommentPragmasRegex))
1044 return Split(StringRef::npos, 0);
1045
1046 size_t Trimmed = Content[LineIndex].find_first_not_of(Chars: Blanks);
1047
1048 // In a line comment section each line is a separate token; thus, after a
1049 // split we replace all whitespace before the current line comment token
1050 // (which does not need to be included in the split), plus the start of the
1051 // line up to where the content starts.
1052 return Split(0, Trimmed != StringRef::npos ? Trimmed : 0);
1053}
1054
1055void BreakableLineCommentSection::reflow(unsigned LineIndex,
1056 WhitespaceManager &Whitespaces) const {
1057 if (LineIndex > 0 && Tokens[LineIndex] != Tokens[LineIndex - 1]) {
1058 // Reflow happens between tokens. Replace the whitespace between the
1059 // tokens by the empty string.
1060 Whitespaces.replaceWhitespace(
1061 Tok&: *Tokens[LineIndex], /*Newlines=*/0, /*Spaces=*/0,
1062 /*StartOfTokenColumn=*/StartColumn, /*IsAligned=*/true,
1063 /*InPPDirective=*/false);
1064 } else if (LineIndex > 0) {
1065 // In case we're reflowing after the '\' in:
1066 //
1067 // // line comment \
1068 // // line 2
1069 //
1070 // the reflow happens inside the single comment token (it is a single line
1071 // comment with an unescaped newline).
1072 // Replace the whitespace between the '\' and '//' with the empty string.
1073 //
1074 // Offset points to after the '\' relative to start of the token.
1075 unsigned Offset = Lines[LineIndex - 1].data() +
1076 Lines[LineIndex - 1].size() -
1077 tokenAt(LineIndex: LineIndex - 1).TokenText.data();
1078 // WhitespaceLength is the number of chars between the '\' and the '//' on
1079 // the next line.
1080 unsigned WhitespaceLength =
1081 Lines[LineIndex].data() - tokenAt(LineIndex).TokenText.data() - Offset;
1082 Whitespaces.replaceWhitespaceInToken(Tok: *Tokens[LineIndex], Offset,
1083 /*ReplaceChars=*/WhitespaceLength,
1084 /*PreviousPostfix=*/"",
1085 /*CurrentPrefix=*/"",
1086 /*InPPDirective=*/false,
1087 /*Newlines=*/0,
1088 /*Spaces=*/0);
1089 }
1090 // Replace the indent and prefix of the token with the reflow prefix.
1091 unsigned Offset =
1092 Lines[LineIndex].data() - tokenAt(LineIndex).TokenText.data();
1093 unsigned WhitespaceLength =
1094 Content[LineIndex].data() - Lines[LineIndex].data();
1095 Whitespaces.replaceWhitespaceInToken(Tok: *Tokens[LineIndex], Offset,
1096 /*ReplaceChars=*/WhitespaceLength,
1097 /*PreviousPostfix=*/"",
1098 /*CurrentPrefix=*/ReflowPrefix,
1099 /*InPPDirective=*/false,
1100 /*Newlines=*/0,
1101 /*Spaces=*/0);
1102}
1103
1104void BreakableLineCommentSection::adaptStartOfLine(
1105 unsigned LineIndex, WhitespaceManager &Whitespaces) const {
1106 // If this is the first line of a token, we need to inform Whitespace Manager
1107 // about it: either adapt the whitespace range preceding it, or mark it as an
1108 // untouchable token.
1109 // This happens for instance here:
1110 // // line 1 \
1111 // // line 2
1112 if (LineIndex > 0 && Tokens[LineIndex] != Tokens[LineIndex - 1]) {
1113 // This is the first line for the current token, but no reflow with the
1114 // previous token is necessary. However, we still may need to adjust the
1115 // start column. Note that ContentColumn[LineIndex] is the expected
1116 // content column after a possible update to the prefix, hence the prefix
1117 // length change is included.
1118 unsigned LineColumn =
1119 ContentColumn[LineIndex] -
1120 (Content[LineIndex].data() - Lines[LineIndex].data()) +
1121 (OriginalPrefix[LineIndex].size() - Prefix[LineIndex].size());
1122
1123 // We always want to create a replacement instead of adding an untouchable
1124 // token, even if LineColumn is the same as the original column of the
1125 // token. This is because WhitespaceManager doesn't align trailing
1126 // comments if they are untouchable.
1127 Whitespaces.replaceWhitespace(Tok&: *Tokens[LineIndex],
1128 /*Newlines=*/1,
1129 /*Spaces=*/LineColumn,
1130 /*StartOfTokenColumn=*/LineColumn,
1131 /*IsAligned=*/true,
1132 /*InPPDirective=*/false);
1133 }
1134 if (OriginalPrefix[LineIndex] != Prefix[LineIndex]) {
1135 // Adjust the prefix if necessary.
1136 const auto SpacesToRemove = -std::min(a: PrefixSpaceChange[LineIndex], b: 0);
1137 const auto SpacesToAdd = std::max(a: PrefixSpaceChange[LineIndex], b: 0);
1138 Whitespaces.replaceWhitespaceInToken(
1139 Tok: tokenAt(LineIndex), Offset: OriginalPrefix[LineIndex].size() - SpacesToRemove,
1140 /*ReplaceChars=*/SpacesToRemove, PreviousPostfix: "", CurrentPrefix: "", /*InPPDirective=*/false,
1141 /*Newlines=*/0, /*Spaces=*/SpacesToAdd);
1142 }
1143}
1144
1145void BreakableLineCommentSection::updateNextToken(LineState &State) const {
1146 if (LastLineTok)
1147 State.NextToken = LastLineTok->Next;
1148}
1149
1150bool BreakableLineCommentSection::mayReflow(
1151 unsigned LineIndex, const llvm::Regex &CommentPragmasRegex) const {
1152 // Line comments have the indent as part of the prefix, so we need to
1153 // recompute the start of the line.
1154 StringRef IndentContent = Content[LineIndex];
1155 if (Lines[LineIndex].starts_with(Prefix: "//"))
1156 IndentContent = Lines[LineIndex].substr(Start: 2);
1157 // FIXME: Decide whether we want to reflow non-regular indents:
1158 // Currently, we only reflow when the OriginalPrefix[LineIndex] matches the
1159 // OriginalPrefix[LineIndex-1]. That means we don't reflow
1160 // // text that protrudes
1161 // // into text with different indent
1162 // We do reflow in that case in block comments.
1163 return LineIndex > 0 && !CommentPragmasRegex.match(String: IndentContent) &&
1164 mayReflowContent(Content: Content[LineIndex]) && !Tok.Finalized &&
1165 !switchesFormatting(Token: tokenAt(LineIndex)) &&
1166 OriginalPrefix[LineIndex] == OriginalPrefix[LineIndex - 1];
1167}
1168
1169} // namespace format
1170} // namespace clang
1171

source code of clang/lib/Format/BreakableToken.cpp