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      1 //===--- AffectedRangeManager.cpp - Format C++ code -----------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 ///
     10 /// \file
     11 /// \brief This file implements AffectRangeManager class.
     12 ///
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "AffectedRangeManager.h"
     16 
     17 #include "FormatToken.h"
     18 #include "TokenAnnotator.h"
     19 
     20 namespace clang {
     21 namespace format {
     22 
     23 bool AffectedRangeManager::computeAffectedLines(
     24     SmallVectorImpl<AnnotatedLine *>::iterator I,
     25     SmallVectorImpl<AnnotatedLine *>::iterator E) {
     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))
     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   bool SomeLineAffected = false;
    104   Line->ChildrenAffected =
    105       computeAffectedLines(Line->Children.begin(), Line->Children.end());
    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   if (SomeTokenAffected || SomeFirstChildAffected || LineMoved ||
    142       IsContinuedComment) {
    143     Line->Affected = true;
    144     SomeLineAffected = true;
    145   }
    146   return SomeLineAffected;
    147 }
    148 
    149 } // namespace format
    150 } // namespace clang
    151