clang/lib/Format/AffectedRangeManager.cpp

   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     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
  61 bool 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
  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   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