1 //===--- AffectedRangeManager.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 /// This file implements AffectRangeManager class.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "AffectedRangeManager.h"
15 
16 #include "FormatToken.h"
17 #include "TokenAnnotator.h"
18 
19 namespace clang {
20 namespace format {
21 
22 bool AffectedRangeManager::computeAffectedLines(
23     SmallVectorImpl<AnnotatedLine *> &Lines) {
24   SmallVectorImpl<AnnotatedLine *>::iterator I = Lines.begin();
25   SmallVectorImpl<AnnotatedLine *>::iterator E = Lines.end();
26   bool SomeLineAffected = false;
27   const AnnotatedLine *PreviousLine = nullptr;
28   while (I != E) {
29     AnnotatedLine *Line = *I;
30     Line->LeadingEmptyLinesAffected = affectsLeadingEmptyLines(*Line->First);
31 
32     // If a line is part of a preprocessor directive, it needs to be formatted
33     // if any token within the directive is affected.
34     if (Line->InPPDirective) {
35       FormatToken *Last = Line->Last;
36       SmallVectorImpl<AnnotatedLine *>::iterator PPEnd = I + 1;
37       while (PPEnd != E && !(*PPEnd)->First->HasUnescapedNewline) {
38         Last = (*PPEnd)->Last;
39         ++PPEnd;
40       }
41 
42       if (affectsTokenRange(*Line->First, *Last,
43                             /*IncludeLeadingNewlines=*/false)) {
44         SomeLineAffected = true;
45         markAllAsAffected(I, PPEnd);
46       }
47       I = PPEnd;
48       continue;
49     }
50 
51     if (nonPPLineAffected(Line, PreviousLine, Lines))
52       SomeLineAffected = true;
53 
54     PreviousLine = Line;
55     ++I;
56   }
57   return SomeLineAffected;
58 }
59 
60 bool AffectedRangeManager::affectsCharSourceRange(
61     const CharSourceRange &Range) {
62   for (SmallVectorImpl<CharSourceRange>::const_iterator I = Ranges.begin(),
63                                                         E = Ranges.end();
64        I != E; ++I) {
65     if (!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(), I->getBegin()) &&
66         !SourceMgr.isBeforeInTranslationUnit(I->getEnd(), Range.getBegin()))
67       return true;
68   }
69   return false;
70 }
71 
72 bool AffectedRangeManager::affectsTokenRange(const FormatToken &First,
73                                              const FormatToken &Last,
74                                              bool IncludeLeadingNewlines) {
75   SourceLocation Start = First.WhitespaceRange.getBegin();
76   if (!IncludeLeadingNewlines)
77     Start = Start.getLocWithOffset(First.LastNewlineOffset);
78   SourceLocation End = Last.getStartOfNonWhitespace();
79   End = End.getLocWithOffset(Last.TokenText.size());
80   CharSourceRange Range = CharSourceRange::getCharRange(Start, End);
81   return affectsCharSourceRange(Range);
82 }
83 
84 bool AffectedRangeManager::affectsLeadingEmptyLines(const FormatToken &Tok) {
85   CharSourceRange EmptyLineRange = CharSourceRange::getCharRange(
86       Tok.WhitespaceRange.getBegin(),
87       Tok.WhitespaceRange.getBegin().getLocWithOffset(Tok.LastNewlineOffset));
88   return affectsCharSourceRange(EmptyLineRange);
89 }
90 
91 void AffectedRangeManager::markAllAsAffected(
92     SmallVectorImpl<AnnotatedLine *>::iterator I,
93     SmallVectorImpl<AnnotatedLine *>::iterator E) {
94   while (I != E) {
95     (*I)->Affected = true;
96     markAllAsAffected((*I)->Children.begin(), (*I)->Children.end());
97     ++I;
98   }
99 }
100 
101 bool AffectedRangeManager::nonPPLineAffected(
102     AnnotatedLine *Line, const AnnotatedLine *PreviousLine,
103     SmallVectorImpl<AnnotatedLine *> &Lines) {
104   bool SomeLineAffected = false;
105   Line->ChildrenAffected = computeAffectedLines(Line->Children);
106   if (Line->ChildrenAffected)
107     SomeLineAffected = true;
108 
109   // Stores whether one of the line's tokens is directly affected.
110   bool SomeTokenAffected = false;
111   // Stores whether we need to look at the leading newlines of the next token
112   // in order to determine whether it was affected.
113   bool IncludeLeadingNewlines = false;
114 
115   // Stores whether the first child line of any of this line's tokens is
116   // affected.
117   bool SomeFirstChildAffected = false;
118 
119   for (FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
120     // Determine whether 'Tok' was affected.
121     if (affectsTokenRange(*Tok, *Tok, IncludeLeadingNewlines))
122       SomeTokenAffected = true;
123 
124     // Determine whether the first child of 'Tok' was affected.
125     if (!Tok->Children.empty() && Tok->Children.front()->Affected)
126       SomeFirstChildAffected = true;
127 
128     IncludeLeadingNewlines = Tok->Children.empty();
129   }
130 
131   // Was this line moved, i.e. has it previously been on the same line as an
132   // affected line?
133   bool LineMoved = PreviousLine && PreviousLine->Affected &&
134                    Line->First->NewlinesBefore == 0;
135 
136   bool IsContinuedComment =
137       Line->First->is(tok::comment) && Line->First->Next == nullptr &&
138       Line->First->NewlinesBefore < 2 && PreviousLine &&
139       PreviousLine->Affected && PreviousLine->Last->is(tok::comment);
140 
141   bool IsAffectedClosingBrace =
142       Line->First->is(tok::r_brace) &&
143       Line->MatchingOpeningBlockLineIndex != UnwrappedLine::kInvalidIndex &&
144       Lines[Line->MatchingOpeningBlockLineIndex]->Affected;
145 
146   if (SomeTokenAffected || SomeFirstChildAffected || LineMoved ||
147       IsContinuedComment || IsAffectedClosingBrace) {
148     Line->Affected = true;
149     SomeLineAffected = true;
150   }
151   return SomeLineAffected;
152 }
153 
154 } // namespace format
155 } // namespace clang
156