UnwrappedLineFormatter.cpp source code [clang_source_code/lib/Format/UnwrappedLineFormatter.cpp]

1	//===--- UnwrappedLineFormatter.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	#include "UnwrappedLineFormatter.h"
10	#include "NamespaceEndCommentsFixer.h"
11	#include "WhitespaceManager.h"
12	#include "llvm/Support/Debug.h"
13	#include <queue>
14
15	#define DEBUG_TYPE "format-formatter"
16
17	namespace clang {
18	namespace format {
19
20	namespace {
21
22	bool startsExternCBlock(const AnnotatedLine &Line) {
23	const FormatToken *Next = Line.First->getNextNonComment();
24	const FormatToken *NextNext = Next ? Next->getNextNonComment() : nullptr;
25	return Line.startsWith(tok::kw_extern) && Next && Next->isStringLiteral() &&
26	NextNext && NextNext->is(tok::l_brace);
27	}
28
29	/// Tracks the indent level of \c AnnotatedLines across levels.
30	///
31	/// \c nextLine must be called for each \c AnnotatedLine, after which \c
32	/// getIndent() will return the indent for the last line \c nextLine was called
33	/// with.
34	/// If the line is not formatted (and thus the indent does not change), calling
35	/// \c adjustToUnmodifiedLine after the call to \c nextLine will cause
36	/// subsequent lines on the same level to be indented at the same level as the
37	/// given line.
38	class LevelIndentTracker {
39	public:
40	LevelIndentTracker(const FormatStyle &Style,
41	const AdditionalKeywords &Keywords, unsigned StartLevel,
42	int AdditionalIndent)
43	: Style(Style), Keywords(Keywords), AdditionalIndent(AdditionalIndent) {
44	for (unsigned i = 0; i != StartLevel; ++i)
45	IndentForLevel.push_back(Style.IndentWidth * i + AdditionalIndent);
46	}
47
48	/// Returns the indent for the current line.
49	unsigned getIndent() const { return Indent; }
50
51	/// Update the indent state given that \p Line is going to be formatted
52	/// next.
53	void nextLine(const AnnotatedLine &Line) {
54	Offset = getIndentOffset(*Line.First);
55	// Update the indent level cache size so that we can rely on it
56	// having the right size in adjustToUnmodifiedline.
57	while (IndentForLevel.size() <= Line.Level)
58	IndentForLevel.push_back(-1);
59	if (Line.InPPDirective) {
60	Indent = Line.Level * Style.IndentWidth + AdditionalIndent;
61	} else {
62	IndentForLevel.resize(Line.Level + 1);
63	Indent = getIndent(IndentForLevel, Line.Level);
64	}
65	if (static_cast<int>(Indent) + Offset >= 0)
66	Indent += Offset;
67	}
68
69	/// Update the indent state given that \p Line indent should be
70	/// skipped.
71	void skipLine(const AnnotatedLine &Line) {
72	while (IndentForLevel.size() <= Line.Level)
73	IndentForLevel.push_back(Indent);
74	}
75
76	/// Update the level indent to adapt to the given \p Line.
77	///
78	/// When a line is not formatted, we move the subsequent lines on the same
79	/// level to the same indent.
80	/// Note that \c nextLine must have been called before this method.
81	void adjustToUnmodifiedLine(const AnnotatedLine &Line) {
82	unsigned LevelIndent = Line.First->OriginalColumn;
83	if (static_cast<int>(LevelIndent) - Offset >= 0)
84	LevelIndent -= Offset;
85	if ((!Line.First->is(tok::comment) \|\| IndentForLevel[Line.Level] == -1) &&
86	!Line.InPPDirective)
87	IndentForLevel[Line.Level] = LevelIndent;
88	}
89
90	private:
91	/// Get the offset of the line relatively to the level.
92	///
93	/// For example, 'public:' labels in classes are offset by 1 or 2
94	/// characters to the left from their level.
95	int getIndentOffset(const FormatToken &RootToken) {
96	if (Style.Language == FormatStyle::LK_Java \|\|
97	Style.Language == FormatStyle::LK_JavaScript \|\| Style.isCSharp())
98	return 0;
99	if (RootToken.isAccessSpecifier(false) \|\|
100	RootToken.isObjCAccessSpecifier() \|\|
101	(RootToken.isOneOf(Keywords.kw_signals, Keywords.kw_qsignals) &&
102	RootToken.Next && RootToken.Next->is(tok::colon)))
103	return Style.AccessModifierOffset;
104	return 0;
105	}
106
107	/// Get the indent of \p Level from \p IndentForLevel.
108	///
109	/// \p IndentForLevel must contain the indent for the level \c l
110	/// at \p IndentForLevel[l], or a value < 0 if the indent for
111	/// that level is unknown.
112	unsigned getIndent(ArrayRef<int> IndentForLevel, unsigned Level) {
113	if (IndentForLevel[Level] != -1)
114	return IndentForLevel[Level];
115	if (Level == 0)
116	return 0;
117	return getIndent(IndentForLevel, Level - 1) + Style.IndentWidth;
118	}
119
120	const FormatStyle &Style;
121	const AdditionalKeywords &Keywords;
122	const unsigned AdditionalIndent;
123
124	/// The indent in characters for each level.
125	std::vector<int> IndentForLevel;
126
127	/// Offset of the current line relative to the indent level.
128	///
129	/// For example, the 'public' keywords is often indented with a negative
130	/// offset.
131	int Offset = 0;
132
133	/// The current line's indent.
134	unsigned Indent = 0;
135	};
136
137	bool isNamespaceDeclaration(const AnnotatedLine *Line) {
138	const FormatToken *NamespaceTok = Line->First;
139	return NamespaceTok && NamespaceTok->getNamespaceToken();
140	}
141
142	bool isEndOfNamespace(const AnnotatedLine *Line,
143	const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines) {
144	if (!Line->startsWith(tok::r_brace))
145	return false;
146	size_t StartLineIndex = Line->MatchingOpeningBlockLineIndex;
147	if (StartLineIndex == UnwrappedLine::kInvalidIndex)
148	return false;
149	assert(StartLineIndex < AnnotatedLines.size());
150	return isNamespaceDeclaration(AnnotatedLines[StartLineIndex]);
151	}
152
153	class LineJoiner {
154	public:
155	LineJoiner(const FormatStyle &Style, const AdditionalKeywords &Keywords,
156	const SmallVectorImpl<AnnotatedLine *> &Lines)
157	: Style(Style), Keywords(Keywords), End(Lines.end()), Next(Lines.begin()),
158	AnnotatedLines(Lines) {}
159
160	/// Returns the next line, merging multiple lines into one if possible.
161	const AnnotatedLine *getNextMergedLine(bool DryRun,
162	LevelIndentTracker &IndentTracker) {
163	if (Next == End)
164	return nullptr;
165	const AnnotatedLine Current = Next;
166	IndentTracker.nextLine(*Current);
167	unsigned MergedLines = tryFitMultipleLinesInOne(IndentTracker, Next, End);
168	if (MergedLines > 0 && Style.ColumnLimit == 0)
169	// Disallow line merging if there is a break at the start of one of the
170	// input lines.
171	for (unsigned i = 0; i < MergedLines; ++i)
172	if (Next[i + 1]->First->NewlinesBefore > 0)
173	MergedLines = 0;
174	if (!DryRun)
175	for (unsigned i = 0; i < MergedLines; ++i)
176	join(Next[0], Next[i + 1]);
177	Next = Next + MergedLines + 1;
178	return Current;
179	}
180
181	private:
182	/// Calculates how many lines can be merged into 1 starting at \p I.
183	unsigned
184	tryFitMultipleLinesInOne(LevelIndentTracker &IndentTracker,
185	SmallVectorImpl<AnnotatedLine *>::const_iterator I,
186	SmallVectorImpl<AnnotatedLine *>::const_iterator E) {
187	const unsigned Indent = IndentTracker.getIndent();
188
189	// Can't join the last line with anything.
190	if (I + 1 == E)
191	return 0;
192	// We can never merge stuff if there are trailing line comments.
193	const AnnotatedLine TheLine = I;
194	if (TheLine->Last->is(TT_LineComment))
195	return 0;
196	if (I[1]->Type == LT_Invalid \|\| I[1]->First->MustBreakBefore)
197	return 0;
198	if (TheLine->InPPDirective &&
199	(!I[1]->InPPDirective \|\| I[1]->First->HasUnescapedNewline))
200	return 0;
201
202	if (Style.ColumnLimit > 0 && Indent > Style.ColumnLimit)
203	return 0;
204
205	unsigned Limit =
206	Style.ColumnLimit == 0 ? UINT_MAX : Style.ColumnLimit - Indent;
207	// If we already exceed the column limit, we set 'Limit' to 0. The different
208	// tryMerge..() functions can then decide whether to still do merging.
209	Limit = TheLine->Last->TotalLength > Limit
210	? 0
211	: Limit - TheLine->Last->TotalLength;
212
213	if (TheLine->Last->is(TT_FunctionLBrace) &&
214	TheLine->First == TheLine->Last &&
215	!Style.BraceWrapping.SplitEmptyFunction &&
216	I[1]->First->is(tok::r_brace))
217	return tryMergeSimpleBlock(I, E, Limit);
218
219	// Handle empty record blocks where the brace has already been wrapped
220	if (TheLine->Last->is(tok::l_brace) && TheLine->First == TheLine->Last &&
221	I != AnnotatedLines.begin()) {
222	bool EmptyBlock = I[1]->First->is(tok::r_brace);
223
224	const FormatToken *Tok = I[-1]->First;
225	if (Tok && Tok->is(tok::comment))
226	Tok = Tok->getNextNonComment();
227
228	if (Tok && Tok->getNamespaceToken())
229	return !Style.BraceWrapping.SplitEmptyNamespace && EmptyBlock
230	? tryMergeSimpleBlock(I, E, Limit)
231	: 0;
232
233	if (Tok && Tok->is(tok::kw_typedef))
234	Tok = Tok->getNextNonComment();
235	if (Tok && Tok->isOneOf(tok::kw_class, tok::kw_struct, tok::kw_union,
236	tok::kw_extern, Keywords.kw_interface))
237	return !Style.BraceWrapping.SplitEmptyRecord && EmptyBlock
238	? tryMergeSimpleBlock(I, E, Limit)
239	: 0;
240	}
241
242	// FIXME: TheLine->Level != 0 might or might not be the right check to do.
243	// If necessary, change to something smarter.
244	bool MergeShortFunctions =
245	Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_All \|\|
246	(Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
247	I[1]->First->is(tok::r_brace)) \|\|
248	(Style.AllowShortFunctionsOnASingleLine & FormatStyle::SFS_InlineOnly &&
249	TheLine->Level != 0);
250
251	if (Style.CompactNamespaces) {
252	if (isNamespaceDeclaration(TheLine)) {
253	int i = 0;
254	unsigned closingLine = TheLine->MatchingClosingBlockLineIndex - 1;
255	for (; I + 1 + i != E && isNamespaceDeclaration(I[i + 1]) &&
256	closingLine == I[i + 1]->MatchingClosingBlockLineIndex &&
257	I[i + 1]->Last->TotalLength < Limit;
258	i++, closingLine--) {
259	// No extra indent for compacted namespaces
260	IndentTracker.skipLine(*I[i + 1]);
261
262	Limit -= I[i + 1]->Last->TotalLength;
263	}
264	return i;
265	}
266
267	if (isEndOfNamespace(TheLine, AnnotatedLines)) {
268	int i = 0;
269	unsigned openingLine = TheLine->MatchingOpeningBlockLineIndex - 1;
270	for (; I + 1 + i != E && isEndOfNamespace(I[i + 1], AnnotatedLines) &&
271	openingLine == I[i + 1]->MatchingOpeningBlockLineIndex;
272	i++, openingLine--) {
273	// No space between consecutive braces
274	I[i + 1]->First->SpacesRequiredBefore = !I[i]->Last->is(tok::r_brace);
275
276	// Indent like the outer-most namespace
277	IndentTracker.nextLine(*I[i + 1]);
278	}
279	return i;
280	}
281	}
282
283	// Try to merge a function block with left brace unwrapped
284	if (TheLine->Last->is(TT_FunctionLBrace) &&
285	TheLine->First != TheLine->Last) {
286	return MergeShortFunctions ? tryMergeSimpleBlock(I, E, Limit) : 0;
287	}
288	// Try to merge a control statement block with left brace unwrapped
289	if (TheLine->Last->is(tok::l_brace) && TheLine->First != TheLine->Last &&
290	TheLine->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
291	return Style.AllowShortBlocksOnASingleLine
292	? tryMergeSimpleBlock(I, E, Limit)
293	: 0;
294	}
295	// Try to merge a control statement block with left brace wrapped
296	if (I[1]->First->is(tok::l_brace) &&
297	TheLine->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
298	return Style.BraceWrapping.AfterControlStatement
299	? tryMergeSimpleBlock(I, E, Limit)
300	: 0;
301	}
302	// Try to merge either empty or one-line block if is precedeed by control
303	// statement token
304	if (TheLine->First->is(tok::l_brace) && TheLine->First == TheLine->Last &&
305	I != AnnotatedLines.begin() &&
306	I[-1]->First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_for)) {
307	unsigned MergedLines = 0;
308	if (Style.AllowShortBlocksOnASingleLine) {
309	MergedLines = tryMergeSimpleBlock(I - 1, E, Limit);
310	// If we managed to merge the block, discard the first merged line
311	// since we are merging starting from I.
312	if (MergedLines > 0)
313	--MergedLines;
314	}
315	return MergedLines;
316	}
317	// Don't merge block with left brace wrapped after ObjC special blocks
318	if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
319	I[-1]->First->is(tok::at) && I[-1]->First->Next) {
320	tok::ObjCKeywordKind kwId = I[-1]->First->Next->Tok.getObjCKeywordID();
321	if (kwId == clang::tok::objc_autoreleasepool \|\|
322	kwId == clang::tok::objc_synchronized)
323	return 0;
324	}
325	// Don't merge block with left brace wrapped after case labels
326	if (TheLine->First->is(tok::l_brace) && I != AnnotatedLines.begin() &&
327	I[-1]->First->isOneOf(tok::kw_case, tok::kw_default))
328	return 0;
329	// Try to merge a block with left brace wrapped that wasn't yet covered
330	if (TheLine->Last->is(tok::l_brace)) {
331	return !Style.BraceWrapping.AfterFunction \|\|
332	(I[1]->First->is(tok::r_brace) &&
333	!Style.BraceWrapping.SplitEmptyRecord)
334	? tryMergeSimpleBlock(I, E, Limit)
335	: 0;
336	}
337	// Try to merge a function block with left brace wrapped
338	if (I[1]->First->is(TT_FunctionLBrace) &&
339	Style.BraceWrapping.AfterFunction) {
340	if (I[1]->Last->is(TT_LineComment))
341	return 0;
342
343	// Check for Limit <= 2 to account for the " {".
344	if (Limit <= 2 \|\| (Style.ColumnLimit == 0 && containsMustBreak(TheLine)))
345	return 0;
346	Limit -= 2;
347
348	unsigned MergedLines = 0;
349	if (MergeShortFunctions \|\|
350	(Style.AllowShortFunctionsOnASingleLine >= FormatStyle::SFS_Empty &&
351	I[1]->First == I[1]->Last && I + 2 != E &&
352	I[2]->First->is(tok::r_brace))) {
353	MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
354	// If we managed to merge the block, count the function header, which is
355	// on a separate line.
356	if (MergedLines > 0)
357	++MergedLines;
358	}
359	return MergedLines;
360	}
361	if (TheLine->First->is(tok::kw_if)) {
362	return Style.AllowShortIfStatementsOnASingleLine
363	? tryMergeSimpleControlStatement(I, E, Limit)
364	: 0;
365	}
366	if (TheLine->First->isOneOf(tok::kw_for, tok::kw_while)) {
367	return Style.AllowShortLoopsOnASingleLine
368	? tryMergeSimpleControlStatement(I, E, Limit)
369	: 0;
370	}
371	if (TheLine->First->isOneOf(tok::kw_case, tok::kw_default)) {
372	return Style.AllowShortCaseLabelsOnASingleLine
373	? tryMergeShortCaseLabels(I, E, Limit)
374	: 0;
375	}
376	if (TheLine->InPPDirective &&
377	(TheLine->First->HasUnescapedNewline \|\| TheLine->First->IsFirst)) {
378	return tryMergeSimplePPDirective(I, E, Limit);
379	}
380	return 0;
381	}
382
383	unsigned
384	tryMergeSimplePPDirective(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
385	SmallVectorImpl<AnnotatedLine *>::const_iterator E,
386	unsigned Limit) {
387	if (Limit == 0)
388	return 0;
389	if (I + 2 != E && I[2]->InPPDirective && !I[2]->First->HasUnescapedNewline)
390	return 0;
391	if (1 + I[1]->Last->TotalLength > Limit)
392	return 0;
393	return 1;
394	}
395
396	unsigned tryMergeSimpleControlStatement(
397	SmallVectorImpl<AnnotatedLine *>::const_iterator I,
398	SmallVectorImpl<AnnotatedLine *>::const_iterator E, unsigned Limit) {
399	if (Limit == 0)
400	return 0;
401	if (Style.BraceWrapping.AfterControlStatement &&
402	(I[1]->First->is(tok::l_brace) && !Style.AllowShortBlocksOnASingleLine))
403	return 0;
404	if (I[1]->InPPDirective != (*I)->InPPDirective \|\|
405	(I[1]->InPPDirective && I[1]->First->HasUnescapedNewline))
406	return 0;
407	Limit = limitConsideringMacros(I + 1, E, Limit);
408	AnnotatedLine &Line = **I;
409	if (Line.Last->isNot(tok::r_paren))
410	return 0;
411	if (1 + I[1]->Last->TotalLength > Limit)
412	return 0;
413	if (I[1]->First->isOneOf(tok::semi, tok::kw_if, tok::kw_for, tok::kw_while,
414	TT_LineComment))
415	return 0;
416	// Only inline simple if's (no nested if or else), unless specified
417	if (Style.AllowShortIfStatementsOnASingleLine != FormatStyle::SIS_Always) {
418	if (I + 2 != E && Line.startsWith(tok::kw_if) &&
419	I[2]->First->is(tok::kw_else))
420	return 0;
421	}
422	return 1;
423	}
424
425	unsigned
426	tryMergeShortCaseLabels(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
427	SmallVectorImpl<AnnotatedLine *>::const_iterator E,
428	unsigned Limit) {
429	if (Limit == 0 \|\| I + 1 == E \|\|
430	I[1]->First->isOneOf(tok::kw_case, tok::kw_default))
431	return 0;
432	if (I[0]->Last->is(tok::l_brace) \|\| I[1]->First->is(tok::l_brace))
433	return 0;
434	unsigned NumStmts = 0;
435	unsigned Length = 0;
436	bool EndsWithComment = false;
437	bool InPPDirective = I[0]->InPPDirective;
438	const unsigned Level = I[0]->Level;
439	for (; NumStmts < 3; ++NumStmts) {
440	if (I + 1 + NumStmts == E)
441	break;
442	const AnnotatedLine *Line = I[1 + NumStmts];
443	if (Line->InPPDirective != InPPDirective)
444	break;
445	if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
446	break;
447	if (Line->First->isOneOf(tok::kw_if, tok::kw_for, tok::kw_switch,
448	tok::kw_while) \|\|
449	EndsWithComment)
450	return 0;
451	if (Line->First->is(tok::comment)) {
452	if (Level != Line->Level)
453	return 0;
454	SmallVectorImpl<AnnotatedLine *>::const_iterator J = I + 2 + NumStmts;
455	for (; J != E; ++J) {
456	Line = *J;
457	if (Line->InPPDirective != InPPDirective)
458	break;
459	if (Line->First->isOneOf(tok::kw_case, tok::kw_default, tok::r_brace))
460	break;
461	if (Line->First->isNot(tok::comment) \|\| Level != Line->Level)
462	return 0;
463	}
464	break;
465	}
466	if (Line->Last->is(tok::comment))
467	EndsWithComment = true;
468	Length += I[1 + NumStmts]->Last->TotalLength + 1; // 1 for the space.
469	}
470	if (NumStmts == 0 \|\| NumStmts == 3 \|\| Length > Limit)
471	return 0;
472	return NumStmts;
473	}
474
475	unsigned
476	tryMergeSimpleBlock(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
477	SmallVectorImpl<AnnotatedLine *>::const_iterator E,
478	unsigned Limit) {
479	AnnotatedLine &Line = **I;
480
481	// Don't merge ObjC @ keywords and methods.
482	// FIXME: If an option to allow short exception handling clauses on a single
483	// line is added, change this to not return for @try and friends.
484	if (Style.Language != FormatStyle::LK_Java &&
485	Line.First->isOneOf(tok::at, tok::minus, tok::plus))
486	return 0;
487
488	// Check that the current line allows merging. This depends on whether we
489	// are in a control flow statements as well as several style flags.
490	if (Line.First->isOneOf(tok::kw_else, tok::kw_case) \|\|
491	(Line.First->Next && Line.First->Next->is(tok::kw_else)))
492	return 0;
493	// default: in switch statement
494	if (Line.First->is(tok::kw_default)) {
495	const FormatToken *Tok = Line.First->getNextNonComment();
496	if (Tok && Tok->is(tok::colon))
497	return 0;
498	}
499	if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
500	tok::kw___try, tok::kw_catch, tok::kw___finally,
501	tok::kw_for, tok::r_brace, Keywords.kw___except)) {
502	if (!Style.AllowShortBlocksOnASingleLine)
503	return 0;
504	// Don't merge when we can't except the case when
505	// the control statement block is empty
506	if (!Style.AllowShortIfStatementsOnASingleLine &&
507	Line.startsWith(tok::kw_if) &&
508	!Style.BraceWrapping.AfterControlStatement &&
509	!I[1]->First->is(tok::r_brace))
510	return 0;
511	if (!Style.AllowShortIfStatementsOnASingleLine &&
512	Line.startsWith(tok::kw_if) &&
513	Style.BraceWrapping.AfterControlStatement && I + 2 != E &&
514	!I[2]->First->is(tok::r_brace))
515	return 0;
516	if (!Style.AllowShortLoopsOnASingleLine &&
517	Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for) &&
518	!Style.BraceWrapping.AfterControlStatement &&
519	!I[1]->First->is(tok::r_brace))
520	return 0;
521	if (!Style.AllowShortLoopsOnASingleLine &&
522	Line.First->isOneOf(tok::kw_while, tok::kw_do, tok::kw_for) &&
523	Style.BraceWrapping.AfterControlStatement && I + 2 != E &&
524	!I[2]->First->is(tok::r_brace))
525	return 0;
526	// FIXME: Consider an option to allow short exception handling clauses on
527	// a single line.
528	// FIXME: This isn't covered by tests.
529	// FIXME: For catch, __except, __finally the first token on the line
530	// is '}', so this isn't correct here.
531	if (Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
532	Keywords.kw___except, tok::kw___finally))
533	return 0;
534	}
535
536	if (Line.Last->is(tok::l_brace)) {
537	FormatToken *Tok = I[1]->First;
538	if (Tok->is(tok::r_brace) && !Tok->MustBreakBefore &&
539	(Tok->getNextNonComment() == nullptr \|\|
540	Tok->getNextNonComment()->is(tok::semi))) {
541	// We merge empty blocks even if the line exceeds the column limit.
542	Tok->SpacesRequiredBefore = 0;
543	Tok->CanBreakBefore = true;
544	return 1;
545	} else if (Limit != 0 && !Line.startsWithNamespace() &&
546	!startsExternCBlock(Line)) {
547	// We don't merge short records.
548	FormatToken *RecordTok = Line.First;
549	// Skip record modifiers.
550	while (RecordTok->Next &&
551	RecordTok->isOneOf(tok::kw_typedef, tok::kw_export,
552	Keywords.kw_declare, Keywords.kw_abstract,
553	tok::kw_default))
554	RecordTok = RecordTok->Next;
555	if (RecordTok &&
556	RecordTok->isOneOf(tok::kw_class, tok::kw_union, tok::kw_struct,
557	Keywords.kw_interface))
558	return 0;
559
560	// Check that we still have three lines and they fit into the limit.
561	if (I + 2 == E \|\| I[2]->Type == LT_Invalid)
562	return 0;
563	Limit = limitConsideringMacros(I + 2, E, Limit);
564
565	if (!nextTwoLinesFitInto(I, Limit))
566	return 0;
567
568	// Second, check that the next line does not contain any braces - if it
569	// does, readability declines when putting it into a single line.
570	if (I[1]->Last->is(TT_LineComment))
571	return 0;
572	do {
573	if (Tok->is(tok::l_brace) && Tok->BlockKind != BK_BracedInit)
574	return 0;
575	Tok = Tok->Next;
576	} while (Tok);
577
578	// Last, check that the third line starts with a closing brace.
579	Tok = I[2]->First;
580	if (Tok->isNot(tok::r_brace))
581	return 0;
582
583	// Don't merge "if (a) { .. } else {".
584	if (Tok->Next && Tok->Next->is(tok::kw_else))
585	return 0;
586
587	return 2;
588	}
589	} else if (I[1]->First->is(tok::l_brace)) {
590	if (I[1]->Last->is(TT_LineComment))
591	return 0;
592
593	// Check for Limit <= 2 to account for the " {".
594	if (Limit <= 2 \|\| (Style.ColumnLimit == 0 && containsMustBreak(*I)))
595	return 0;
596	Limit -= 2;
597	unsigned MergedLines = 0;
598	if (Style.AllowShortBlocksOnASingleLine \|\|
599	(I[1]->First == I[1]->Last && I + 2 != E &&
600	I[2]->First->is(tok::r_brace))) {
601	MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
602	// If we managed to merge the block, count the statement header, which
603	// is on a separate line.
604	if (MergedLines > 0)
605	++MergedLines;
606	}
607	return MergedLines;
608	}
609	return 0;
610	}
611
612	/// Returns the modified column limit for \p I if it is inside a macro and
613	/// needs a trailing '\'.
614	unsigned
615	limitConsideringMacros(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
616	SmallVectorImpl<AnnotatedLine *>::const_iterator E,
617	unsigned Limit) {
618	if (I[0]->InPPDirective && I + 1 != E &&
619	!I[1]->First->HasUnescapedNewline && !I[1]->First->is(tok::eof)) {
620	return Limit < 2 ? 0 : Limit - 2;
621	}
622	return Limit;
623	}
624
625	bool nextTwoLinesFitInto(SmallVectorImpl<AnnotatedLine *>::const_iterator I,
626	unsigned Limit) {
627	if (I[1]->First->MustBreakBefore \|\| I[2]->First->MustBreakBefore)
628	return false;
629	return 1 + I[1]->Last->TotalLength + 1 + I[2]->Last->TotalLength <= Limit;
630	}
631
632	bool containsMustBreak(const AnnotatedLine *Line) {
633	for (const FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
634	if (Tok->MustBreakBefore)
635	return true;
636	}
637	return false;
638	}
639
640	void join(AnnotatedLine &A, const AnnotatedLine &B) {
641	Next", "/home/seafit/code_projects/clang_source/clang/lib/Format/UnwrappedLineFormatter.cpp", 641, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!A.Last->Next);
642	Previous", "/home/seafit/code_projects/clang_source/clang/lib/Format/UnwrappedLineFormatter.cpp", 642, __PRETTY_FUNCTION__))" file_link="../../../include/assert.h.html#88" macro="true">assert(!B.First->Previous);
643	if (B.Affected)
644	A.Affected = true;
645	A.Last->Next = B.First;
646	B.First->Previous = A.Last;
647	B.First->CanBreakBefore = true;
648	unsigned LengthA = A.Last->TotalLength + B.First->SpacesRequiredBefore;
649	for (FormatToken *Tok = B.First; Tok; Tok = Tok->Next) {
650	Tok->TotalLength += LengthA;
651	A.Last = Tok;
652	}
653	}
654
655	const FormatStyle &Style;
656	const AdditionalKeywords &Keywords;
657	const SmallVectorImpl<AnnotatedLine *>::const_iterator End;
658
659	SmallVectorImpl<AnnotatedLine *>::const_iterator Next;
660	const SmallVectorImpl<AnnotatedLine *> &AnnotatedLines;
661	};
662
663	static void markFinalized(FormatToken *Tok) {
664	for (; Tok; Tok = Tok->Next) {
665	Tok->Finalized = true;
666	for (AnnotatedLine *Child : Tok->Children)
667	markFinalized(Child->First);
668	}
669	}
670
671	#ifndef NDEBUG
672	static void printLineState(const LineState &State) {
673	llvm::dbgs() << "State: ";
674	for (const ParenState &P : State.Stack) {
675	llvm::dbgs() << (P.Tok ? P.Tok->TokenText : "F") << "\|" << P.Indent << "\|"
676	<< P.LastSpace << "\|" << P.NestedBlockIndent << " ";
677	}
678	llvm::dbgs() << State.NextToken->TokenText << "\n";
679	}
680	#endif
681
682	/// Base class for classes that format one \c AnnotatedLine.
683	class LineFormatter {
684	public:
685	LineFormatter(ContinuationIndenter Indenter, WhitespaceManager Whitespaces,
686	const FormatStyle &Style,
687	UnwrappedLineFormatter *BlockFormatter)
688	: Indenter(Indenter), Whitespaces(Whitespaces), Style(Style),
689	BlockFormatter(BlockFormatter) {}
690	virtual ~LineFormatter() {}
691
692	/// Formats an \c AnnotatedLine and returns the penalty.
693	///
694	/// If \p DryRun is \c false, directly applies the changes.
695	virtual unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
696	unsigned FirstStartColumn, bool DryRun) = 0;
697
698	protected:
699	/// If the \p State's next token is an r_brace closing a nested block,
700	/// format the nested block before it.
701	///
702	/// Returns \c true if all children could be placed successfully and adapts
703	/// \p Penalty as well as \p State. If \p DryRun is false, also directly
704	/// creates changes using \c Whitespaces.
705	///
706	/// The crucial idea here is that children always get formatted upon
707	/// encountering the closing brace right after the nested block. Now, if we
708	/// are currently trying to keep the "}" on the same line (i.e. \p NewLine is
709	/// \c false), the entire block has to be kept on the same line (which is only
710	/// possible if it fits on the line, only contains a single statement, etc.
711	///
712	/// If \p NewLine is true, we format the nested block on separate lines, i.e.
713	/// break after the "{", format all lines with correct indentation and the put
714	/// the closing "}" on yet another new line.
715	///
716	/// This enables us to keep the simple structure of the
717	/// \c UnwrappedLineFormatter, where we only have two options for each token:
718	/// break or don't break.
719	bool formatChildren(LineState &State, bool NewLine, bool DryRun,
720	unsigned &Penalty) {
721	const FormatToken *LBrace = State.NextToken->getPreviousNonComment();
722	FormatToken &Previous = *State.NextToken->Previous;
723	if (!LBrace \|\| LBrace->isNot(tok::l_brace) \|\|
724	LBrace->BlockKind != BK_Block \|\| Previous.Children.size() == 0)
725	// The previous token does not open a block. Nothing to do. We don't
726	// assert so that we can simply call this function for all tokens.
727	return true;
728
729	if (NewLine) {
730	int AdditionalIndent = State.Stack.back().Indent -
731	Previous.Children[0]->Level * Style.IndentWidth;
732
733	Penalty +=
734	BlockFormatter->format(Previous.Children, DryRun, AdditionalIndent,
735	/FixBadIndentation=/true);
736	return true;
737	}
738
739	if (Previous.Children[0]->First->MustBreakBefore)
740	return false;
741
742	// Cannot merge into one line if this line ends on a comment.
743	if (Previous.is(tok::comment))
744	return false;
745
746	// Cannot merge multiple statements into a single line.
747	if (Previous.Children.size() > 1)
748	return false;
749
750	const AnnotatedLine *Child = Previous.Children[0];
751	// We can't put the closing "}" on a line with a trailing comment.
752	if (Child->Last->isTrailingComment())
753	return false;
754
755	// If the child line exceeds the column limit, we wouldn't want to merge it.
756	// We add +2 for the trailing " }".
757	if (Style.ColumnLimit > 0 &&
758	Child->Last->TotalLength + State.Column + 2 > Style.ColumnLimit)
759	return false;
760
761	if (!DryRun) {
762	Whitespaces->replaceWhitespace(
763	Child->First, /Newlines=/0, /Spaces=*/1,
764	/StartOfTokenColumn=/State.Column, State.Line->InPPDirective);
765	}
766	Penalty +=
767	formatLine(Child, State.Column + 1, /FirstStartColumn=*/0, DryRun);
768
769	State.Column += 1 + Child->Last->TotalLength;
770	return true;
771	}
772
773	ContinuationIndenter *Indenter;
774
775	private:
776	WhitespaceManager *Whitespaces;
777	const FormatStyle &Style;
778	UnwrappedLineFormatter *BlockFormatter;
779	};
780
781	/// Formatter that keeps the existing line breaks.
782	class NoColumnLimitLineFormatter : public LineFormatter {
783	public:
784	NoColumnLimitLineFormatter(ContinuationIndenter *Indenter,
785	WhitespaceManager *Whitespaces,
786	const FormatStyle &Style,
787	UnwrappedLineFormatter *BlockFormatter)
788	: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
789
790	/// Formats the line, simply keeping all of the input's line breaking
791	/// decisions.
792	unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
793	unsigned FirstStartColumn, bool DryRun) override {
794	assert(!DryRun);
795	LineState State = Indenter->getInitialState(FirstIndent, FirstStartColumn,
796	&Line, /DryRun=/false);
797	while (State.NextToken) {
798	bool Newline =
799	Indenter->mustBreak(State) \|\|
800	(Indenter->canBreak(State) && State.NextToken->NewlinesBefore > 0);
801	unsigned Penalty = 0;
802	formatChildren(State, Newline, /DryRun=/false, Penalty);
803	Indenter->addTokenToState(State, Newline, /DryRun=/false);
804	}
805	return 0;
806	}
807	};
808
809	/// Formatter that puts all tokens into a single line without breaks.
810	class NoLineBreakFormatter : public LineFormatter {
811	public:
812	NoLineBreakFormatter(ContinuationIndenter *Indenter,
813	WhitespaceManager *Whitespaces, const FormatStyle &Style,
814	UnwrappedLineFormatter *BlockFormatter)
815	: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
816
817	/// Puts all tokens into a single line.
818	unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
819	unsigned FirstStartColumn, bool DryRun) override {
820	unsigned Penalty = 0;
821	LineState State =
822	Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
823	while (State.NextToken) {
824	formatChildren(State, /Newline=/false, DryRun, Penalty);
825	Indenter->addTokenToState(
826	State, /Newline=/State.NextToken->MustBreakBefore, DryRun);
827	}
828	return Penalty;
829	}
830	};
831
832	/// Finds the best way to break lines.
833	class OptimizingLineFormatter : public LineFormatter {
834	public:
835	OptimizingLineFormatter(ContinuationIndenter *Indenter,
836	WhitespaceManager *Whitespaces,
837	const FormatStyle &Style,
838	UnwrappedLineFormatter *BlockFormatter)
839	: LineFormatter(Indenter, Whitespaces, Style, BlockFormatter) {}
840
841	/// Formats the line by finding the best line breaks with line lengths
842	/// below the column limit.
843	unsigned formatLine(const AnnotatedLine &Line, unsigned FirstIndent,
844	unsigned FirstStartColumn, bool DryRun) override {
845	LineState State =
846	Indenter->getInitialState(FirstIndent, FirstStartColumn, &Line, DryRun);
847
848	// If the ObjC method declaration does not fit on a line, we should format
849	// it with one arg per line.
850	if (State.Line->Type == LT_ObjCMethodDecl)
851	State.Stack.back().BreakBeforeParameter = true;
852
853	// Find best solution in solution space.
854	return analyzeSolutionSpace(State, DryRun);
855	}
856
857	private:
858	struct CompareLineStatePointers {
859	bool operator()(LineState obj1, LineState obj2) const {
860	return obj1 < obj2;
861	}
862	};
863
864	/// A pair of <penalty, count> that is used to prioritize the BFS on.
865	///
866	/// In case of equal penalties, we want to prefer states that were inserted
867	/// first. During state generation we make sure that we insert states first
868	/// that break the line as late as possible.
869	typedef std::pair<unsigned, unsigned> OrderedPenalty;
870
871	/// An edge in the solution space from \c Previous->State to \c State,
872	/// inserting a newline dependent on the \c NewLine.
873	struct StateNode {
874	StateNode(const LineState &State, bool NewLine, StateNode *Previous)
875	: State(State), NewLine(NewLine), Previous(Previous) {}
876	LineState State;
877	bool NewLine;
878	StateNode *Previous;
879	};
880
881	/// An item in the prioritized BFS search queue. The \c StateNode's
882	/// \c State has the given \c OrderedPenalty.
883	typedef std::pair<OrderedPenalty, StateNode *> QueueItem;
884
885	/// The BFS queue type.
886	typedef std::priority_queue<QueueItem, std::vector<QueueItem>,
887	std::greater<QueueItem>>
888	QueueType;
889
890	/// Analyze the entire solution space starting from \p InitialState.
891	///
892	/// This implements a variant of Dijkstra's algorithm on the graph that spans
893	/// the solution space (\c LineStates are the nodes). The algorithm tries to
894	/// find the shortest path (the one with lowest penalty) from \p InitialState
895	/// to a state where all tokens are placed. Returns the penalty.
896	///
897	/// If \p DryRun is \c false, directly applies the changes.
898	unsigned analyzeSolutionSpace(LineState &InitialState, bool DryRun) {
899	std::set<LineState *, CompareLineStatePointers> Seen;
900
901	// Increasing count of \c StateNode items we have created. This is used to
902	// create a deterministic order independent of the container.
903	unsigned Count = 0;
904	QueueType Queue;
905
906	// Insert start element into queue.
907	StateNode *Node =
908	new (Allocator.Allocate()) StateNode(InitialState, false, nullptr);
909	Queue.push(QueueItem(OrderedPenalty(0, Count), Node));
910	++Count;
911
912	unsigned Penalty = 0;
913
914	// While not empty, take first element and follow edges.
915	while (!Queue.empty()) {
916	Penalty = Queue.top().first.first;
917	StateNode *Node = Queue.top().second;
918	if (!Node->State.NextToken) {
919	LLVM_DEBUG(llvm::dbgs()
920	<< "\n---\nPenalty for line: " << Penalty << "\n");
921	break;
922	}
923	Queue.pop();
924
925	// Cut off the analysis of certain solutions if the analysis gets too
926	// complex. See description of IgnoreStackForComparison.
927	if (Count > 50000)
928	Node->State.IgnoreStackForComparison = true;
929
930	if (!Seen.insert(&Node->State).second)
931	// State already examined with lower penalty.
932	continue;
933
934	FormatDecision LastFormat = Node->State.NextToken->Decision;
935	if (LastFormat == FD_Unformatted \|\| LastFormat == FD_Continue)
936	addNextStateToQueue(Penalty, Node, /NewLine=/false, &Count, &Queue);
937	if (LastFormat == FD_Unformatted \|\| LastFormat == FD_Break)
938	addNextStateToQueue(Penalty, Node, /NewLine=/true, &Count, &Queue);
939	}
940
941	if (Queue.empty()) {
942	// We were unable to find a solution, do nothing.
943	// FIXME: Add diagnostic?
944	LLVM_DEBUG(llvm::dbgs() << "Could not find a solution.\n");
945	return 0;
946	}
947
948	// Reconstruct the solution.
949	if (!DryRun)
950	reconstructPath(InitialState, Queue.top().second);
951
952	LLVM_DEBUG(llvm::dbgs()
953	<< "Total number of analyzed states: " << Count << "\n");
954	LLVM_DEBUG(llvm::dbgs() << "---\n");
955
956	return Penalty;
957	}
958
959	/// Add the following state to the analysis queue \c Queue.
960	///
961	/// Assume the current state is \p PreviousNode and has been reached with a
962	/// penalty of \p Penalty. Insert a line break if \p NewLine is \c true.
963	void addNextStateToQueue(unsigned Penalty, StateNode *PreviousNode,
964	bool NewLine, unsigned Count, QueueType Queue) {
965	if (NewLine && !Indenter->canBreak(PreviousNode->State))
966	return;
967	if (!NewLine && Indenter->mustBreak(PreviousNode->State))
968	return;
969
970	StateNode *Node = new (Allocator.Allocate())
971	StateNode(PreviousNode->State, NewLine, PreviousNode);
972	if (!formatChildren(Node->State, NewLine, /DryRun=/true, Penalty))
973	return;
974
975	Penalty += Indenter->addTokenToState(Node->State, NewLine, true);
976
977	Queue->push(QueueItem(OrderedPenalty(Penalty, *Count), Node));
978	++(*Count);
979	}
980
981	/// Applies the best formatting by reconstructing the path in the
982	/// solution space that leads to \c Best.
983	void reconstructPath(LineState &State, StateNode *Best) {
984	std::deque<StateNode *> Path;
985	// We do not need a break before the initial token.
986	while (Best->Previous) {
987	Path.push_front(Best);
988	Best = Best->Previous;
989	}
990	for (auto I = Path.begin(), E = Path.end(); I != E; ++I) {
991	unsigned Penalty = 0;
992	formatChildren(State, (I)->NewLine, /DryRun=*/false, Penalty);
993	Penalty += Indenter->addTokenToState(State, (*I)->NewLine, false);
994
995	LLVM_DEBUG({
996	printLineState((*I)->Previous->State);
997	if ((*I)->NewLine) {
998	llvm::dbgs() << "Penalty for placing "
999	<< (*I)->Previous->State.NextToken->Tok.getName()
1000	<< " on a new line: " << Penalty << "\n";
1001	}
1002	});
1003	}
1004	}
1005
1006	llvm::SpecificBumpPtrAllocator<StateNode> Allocator;
1007	};
1008
1009	} // anonymous namespace
1010
1011	unsigned UnwrappedLineFormatter::format(
1012	const SmallVectorImpl<AnnotatedLine *> &Lines, bool DryRun,
1013	int AdditionalIndent, bool FixBadIndentation, unsigned FirstStartColumn,
1014	unsigned NextStartColumn, unsigned LastStartColumn) {
1015	LineJoiner Joiner(Style, Keywords, Lines);
1016
1017	// Try to look up already computed penalty in DryRun-mode.
1018	std::pair<const SmallVectorImpl<AnnotatedLine > , unsigned> CacheKey(
1019	&Lines, AdditionalIndent);
1020	auto CacheIt = PenaltyCache.find(CacheKey);
1021	if (DryRun && CacheIt != PenaltyCache.end())
1022	return CacheIt->second;
1023
1024	assert(!Lines.empty());
1025	unsigned Penalty = 0;
1026	LevelIndentTracker IndentTracker(Style, Keywords, Lines[0]->Level,
1027	AdditionalIndent);
1028	const AnnotatedLine *PreviousLine = nullptr;
1029	const AnnotatedLine *NextLine = nullptr;
1030
1031	// The minimum level of consecutive lines that have been formatted.
1032	unsigned RangeMinLevel = UINT_MAX;
1033
1034	bool FirstLine = true;
1035	for (const AnnotatedLine *Line =
1036	Joiner.getNextMergedLine(DryRun, IndentTracker);
1037	Line; Line = NextLine, FirstLine = false) {
1038	const AnnotatedLine &TheLine = *Line;
1039	unsigned Indent = IndentTracker.getIndent();
1040
1041	// We continue formatting unchanged lines to adjust their indent, e.g. if a
1042	// scope was added. However, we need to carefully stop doing this when we
1043	// exit the scope of affected lines to prevent indenting a the entire
1044	// remaining file if it currently missing a closing brace.
1045	bool PreviousRBrace =
1046	PreviousLine && PreviousLine->startsWith(tok::r_brace);
1047	bool ContinueFormatting =
1048	TheLine.Level > RangeMinLevel \|\|
1049	(TheLine.Level == RangeMinLevel && !PreviousRBrace &&
1050	!TheLine.startsWith(tok::r_brace));
1051
1052	bool FixIndentation = (FixBadIndentation \|\| ContinueFormatting) &&
1053	Indent != TheLine.First->OriginalColumn;
1054	bool ShouldFormat = TheLine.Affected \|\| FixIndentation;
1055	// We cannot format this line; if the reason is that the line had a
1056	// parsing error, remember that.
1057	if (ShouldFormat && TheLine.Type == LT_Invalid && Status) {
1058	Status->FormatComplete = false;
1059	Status->Line =
1060	SourceMgr.getSpellingLineNumber(TheLine.First->Tok.getLocation());
1061	}
1062
1063	if (ShouldFormat && TheLine.Type != LT_Invalid) {
1064	if (!DryRun) {
1065	bool LastLine = Line->First->is(tok::eof);
1066	formatFirstToken(TheLine, PreviousLine, Lines, Indent,
1067	LastLine ? LastStartColumn : NextStartColumn + Indent);
1068	}
1069
1070	NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
1071	unsigned ColumnLimit = getColumnLimit(TheLine.InPPDirective, NextLine);
1072	bool FitsIntoOneLine =
1073	TheLine.Last->TotalLength + Indent <= ColumnLimit \|\|
1074	(TheLine.Type == LT_ImportStatement &&
1075	(Style.Language != FormatStyle::LK_JavaScript \|\|
1076	!Style.JavaScriptWrapImports)) \|\|
1077	(Style.isCSharp() &&
1078	TheLine.InPPDirective); // don't split #regions in C#
1079	if (Style.ColumnLimit == 0)
1080	NoColumnLimitLineFormatter(Indenter, Whitespaces, Style, this)
1081	.formatLine(TheLine, NextStartColumn + Indent,
1082	FirstLine ? FirstStartColumn : 0, DryRun);
1083	else if (FitsIntoOneLine)
1084	Penalty += NoLineBreakFormatter(Indenter, Whitespaces, Style, this)
1085	.formatLine(TheLine, NextStartColumn + Indent,
1086	FirstLine ? FirstStartColumn : 0, DryRun);
1087	else
1088	Penalty += OptimizingLineFormatter(Indenter, Whitespaces, Style, this)
1089	.formatLine(TheLine, NextStartColumn + Indent,
1090	FirstLine ? FirstStartColumn : 0, DryRun);
1091	RangeMinLevel = std::min(RangeMinLevel, TheLine.Level);
1092	} else {
1093	// If no token in the current line is affected, we still need to format
1094	// affected children.
1095	if (TheLine.ChildrenAffected)
1096	for (const FormatToken *Tok = TheLine.First; Tok; Tok = Tok->Next)
1097	if (!Tok->Children.empty())
1098	format(Tok->Children, DryRun);
1099
1100	// Adapt following lines on the current indent level to the same level
1101	// unless the current \c AnnotatedLine is not at the beginning of a line.
1102	bool StartsNewLine =
1103	TheLine.First->NewlinesBefore > 0 \|\| TheLine.First->IsFirst;
1104	if (StartsNewLine)
1105	IndentTracker.adjustToUnmodifiedLine(TheLine);
1106	if (!DryRun) {
1107	bool ReformatLeadingWhitespace =
1108	StartsNewLine && ((PreviousLine && PreviousLine->Affected) \|\|
1109	TheLine.LeadingEmptyLinesAffected);
1110	// Format the first token.
1111	if (ReformatLeadingWhitespace)
1112	formatFirstToken(TheLine, PreviousLine, Lines,
1113	TheLine.First->OriginalColumn,
1114	TheLine.First->OriginalColumn);
1115	else
1116	Whitespaces->addUntouchableToken(*TheLine.First,
1117	TheLine.InPPDirective);
1118
1119	// Notify the WhitespaceManager about the unchanged whitespace.
1120	for (FormatToken *Tok = TheLine.First->Next; Tok; Tok = Tok->Next)
1121	Whitespaces->addUntouchableToken(*Tok, TheLine.InPPDirective);
1122	}
1123	NextLine = Joiner.getNextMergedLine(DryRun, IndentTracker);
1124	RangeMinLevel = UINT_MAX;
1125	}
1126	if (!DryRun)
1127	markFinalized(TheLine.First);
1128	PreviousLine = &TheLine;
1129	}
1130	PenaltyCache[CacheKey] = Penalty;
1131	return Penalty;
1132	}
1133
1134	void UnwrappedLineFormatter::formatFirstToken(
1135	const AnnotatedLine &Line, const AnnotatedLine *PreviousLine,
1136	const SmallVectorImpl<AnnotatedLine *> &Lines, unsigned Indent,
1137	unsigned NewlineIndent) {
1138	FormatToken &RootToken = *Line.First;
1139	if (RootToken.is(tok::eof)) {
1140	unsigned Newlines = std::min(RootToken.NewlinesBefore, 1u);
1141	unsigned TokenIndent = Newlines ? NewlineIndent : 0;
1142	Whitespaces->replaceWhitespace(RootToken, Newlines, TokenIndent,
1143	TokenIndent);
1144	return;
1145	}
1146	unsigned Newlines =
1147	std::min(RootToken.NewlinesBefore, Style.MaxEmptyLinesToKeep + 1);
1148	// Remove empty lines before "}" where applicable.
1149	if (RootToken.is(tok::r_brace) &&
1150	(!RootToken.Next \|\|
1151	(RootToken.Next->is(tok::semi) && !RootToken.Next->Next)) &&
1152	// Do not remove empty lines before namespace closing "}".
1153	!getNamespaceToken(&Line, Lines))
1154	Newlines = std::min(Newlines, 1u);
1155	// Remove empty lines at the start of nested blocks (lambdas/arrow functions)
1156	if (PreviousLine == nullptr && Line.Level > 0)
1157	Newlines = std::min(Newlines, 1u);
1158	if (Newlines == 0 && !RootToken.IsFirst)
1159	Newlines = 1;
1160	if (RootToken.IsFirst && !RootToken.HasUnescapedNewline)
1161	Newlines = 0;
1162
1163	// Remove empty lines after "{".
1164	if (!Style.KeepEmptyLinesAtTheStartOfBlocks && PreviousLine &&
1165	PreviousLine->Last->is(tok::l_brace) &&
1166	!PreviousLine->startsWithNamespace() &&
1167	!startsExternCBlock(*PreviousLine))
1168	Newlines = 1;
1169
1170	// Insert extra new line before access specifiers.
1171	if (PreviousLine && PreviousLine->Last->isOneOf(tok::semi, tok::r_brace) &&
1172	RootToken.isAccessSpecifier() && RootToken.NewlinesBefore == 1)
1173	++Newlines;
1174
1175	// Remove empty lines after access specifiers.
1176	if (PreviousLine && PreviousLine->First->isAccessSpecifier() &&
1177	(!PreviousLine->InPPDirective \|\| !RootToken.HasUnescapedNewline))
1178	Newlines = std::min(1u, Newlines);
1179
1180	if (Newlines)
1181	Indent = NewlineIndent;
1182
1183	// Preprocessor directives get indented before the hash only if specified
1184	if (Style.IndentPPDirectives != FormatStyle::PPDIS_BeforeHash &&
1185	(Line.Type == LT_PreprocessorDirective \|\|
1186	Line.Type == LT_ImportStatement))
1187	Indent = 0;
1188
1189	Whitespaces->replaceWhitespace(RootToken, Newlines, Indent, Indent,
1190	Line.InPPDirective &&
1191	!RootToken.HasUnescapedNewline);
1192	}
1193
1194	unsigned
1195	UnwrappedLineFormatter::getColumnLimit(bool InPPDirective,
1196	const AnnotatedLine *NextLine) const {
1197	// In preprocessor directives reserve two chars for trailing " \" if the
1198	// next line continues the preprocessor directive.
1199	bool ContinuesPPDirective =
1200	InPPDirective &&
1201	// If there is no next line, this is likely a child line and the parent
1202	// continues the preprocessor directive.
1203	(!NextLine \|\|
1204	(NextLine->InPPDirective &&
1205	// If there is an unescaped newline between this line and the next, the
1206	// next line starts a new preprocessor directive.
1207	!NextLine->First->HasUnescapedNewline));
1208	return Style.ColumnLimit - (ContinuesPPDirective ? 2 : 0);
1209	}
1210
1211	} // namespace format
1212	} // namespace clang
1213

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