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
19namespace clang {
20namespace format {
21
22bool 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    assert(Line->First);
31    Line->LeadingEmptyLinesAffected = affectsLeadingEmptyLines(*Line->First);
32
33    // If a line is part of a preprocessor directive, it needs to be formatted
34    // if any token within the directive is affected.
35    if (Line->InPPDirective) {
36      FormatToken *Last = Line->Last;
37      SmallVectorImpl<AnnotatedLine *>::iterator PPEnd = I + 1;
38      while (PPEnd != E && !(*PPEnd)->First->HasUnescapedNewline) {
39        Last = (*PPEnd)->Last;
40        ++PPEnd;
41      }
42
43      if (affectsTokenRange(*Line->First, *Last,
44                            /*IncludeLeadingNewlines=*/false)) {
45        SomeLineAffected = true;
46        markAllAsAffected(I, PPEnd);
47      }
48      I = PPEnd;
49      continue;
50    }
51
52    if (nonPPLineAffected(Line, PreviousLine, Lines))
53      SomeLineAffected = true;
54
55    PreviousLine = Line;
56    ++I;
57  }
58  return SomeLineAffected;
59}
60
61bool AffectedRangeManager::affectsCharSourceRange(
62    const CharSourceRange &Range) {
63  for (const CharSourceRange &R : Ranges) {
64    if (!SourceMgr.isBeforeInTranslationUnit(Range.getEnd(), R.getBegin()) &&
65        !SourceMgr.isBeforeInTranslationUnit(R.getEnd(), Range.getBegin())) {
66      return true;
67    }
68  }
69  return false;
70}
71
72bool 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
84bool 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
91void 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
101bool 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  assert(Line->First);
120  for (FormatToken *Tok = Line->First; Tok; Tok = Tok->Next) {
121    // Determine whether 'Tok' was affected.
122    if (affectsTokenRange(*Tok, *Tok, IncludeLeadingNewlines))
123      SomeTokenAffected = true;
124
125    // Determine whether the first child of 'Tok' was affected.
126    if (!Tok->Children.empty() && Tok->Children.front()->Affected)
127      SomeFirstChildAffected = true;
128
129    IncludeLeadingNewlines = Tok->Children.empty();
130  }
131
132  // Was this line moved, i.e. has it previously been on the same line as an
133  // affected line?
134  bool LineMoved = PreviousLine && PreviousLine->Affected &&
135                   Line->First->NewlinesBefore == 0;
136
137  bool IsContinuedComment =
138      Line->First->is(tok::comment) && !Line->First->Next &&
139      Line->First->NewlinesBefore < 2 && PreviousLine &&
140      PreviousLine->Affected && PreviousLine->Last->is(tok::comment);
141
142  bool IsAffectedClosingBrace =
143      Line->First->is(tok::r_brace) &&
144      Line->MatchingOpeningBlockLineIndex != UnwrappedLine::kInvalidIndex &&
145      Lines[Line->MatchingOpeningBlockLineIndex]->Affected;
146
147  if (SomeTokenAffected || SomeFirstChildAffected || LineMoved ||
148      IsContinuedComment || IsAffectedClosingBrace) {
149    Line->Affected = true;
150    SomeLineAffected = true;
151  }
152  return SomeLineAffected;
153}
154
155} // namespace format
156} // namespace clang
157