scintilla/lexers/LexDiff.cxx

   1 // Scintilla source code edit control
   2 /** @file LexDiff.cxx
   3  ** Lexer for diff results.
   4  **/
   5 // Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
   6 // The License.txt file describes the conditions under which this software may be distributed.
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <stdio.h>
  11 #include <stdarg.h>
  12 #include <assert.h>
  13 #include <ctype.h>
  14
  15 #include "ILexer.h"
  16 #include "Scintilla.h"
  17 #include "SciLexer.h"
  18
  19 #include "WordList.h"
  20 #include "LexAccessor.h"
  21 #include "Accessor.h"
  22 #include "StyleContext.h"
  23 #include "CharacterSet.h"
  24 #include "LexerModule.h"
  25
  26 #ifdef SCI_NAMESPACE
  27 using namespace Scintilla;
  28 #endif
  29
  30 static inline bool AtEOL(Accessor &styler, Sci_PositionU i) {
  31         return (styler[i] == '\n') ||
  32                ((styler[i] == '\r') && (styler.SafeGetCharAt(i + 1) != '\n'));
  33 }
  34
  35 #define DIFF_BUFFER_START_SIZE 16
  36 // Note that ColouriseDiffLine analyzes only the first DIFF_BUFFER_START_SIZE
  37 // characters of each line to classify the line.
  38
  39 static void ColouriseDiffLine(char *lineBuffer, Sci_Position endLine, Accessor &styler) {
  40         // It is needed to remember the current state to recognize starting
  41         // comment lines before the first "diff " or "--- ". If a real
  42         // difference starts then each line starting with ' ' is a whitespace
  43         // otherwise it is considered a comment (Only in..., Binary file...)
  44         if (0 == strncmp(lineBuffer, "diff ", 5)) {
  45                 styler.ColourTo(endLine, SCE_DIFF_COMMAND);
  46         } else if (0 == strncmp(lineBuffer, "Index: ", 7)) {  // For subversion's diff
  47                 styler.ColourTo(endLine, SCE_DIFF_COMMAND);
  48         } else if (0 == strncmp(lineBuffer, "---", 3) && lineBuffer[3] != '-') {
  49                 // In a context diff, --- appears in both the header and the position markers
  50                 if (lineBuffer[3] == ' ' && atoi(lineBuffer + 4) && !strchr(lineBuffer, '/'))
  51                         styler.ColourTo(endLine, SCE_DIFF_POSITION);
  52                 else if (lineBuffer[3] == '\r' || lineBuffer[3] == '\n')
  53                         styler.ColourTo(endLine, SCE_DIFF_POSITION);
  54                 else if (lineBuffer[3] == ' ')
  55                         styler.ColourTo(endLine, SCE_DIFF_HEADER);
  56                 else
  57                         styler.ColourTo(endLine, SCE_DIFF_DELETED);
  58         } else if (0 == strncmp(lineBuffer, "+++ ", 4)) {
  59                 // I don't know of any diff where "+++ " is a position marker, but for
  60                 // consistency, do the same as with "--- " and "*** ".
  61                 if (atoi(lineBuffer+4) && !strchr(lineBuffer, '/'))
  62                         styler.ColourTo(endLine, SCE_DIFF_POSITION);
  63                 else
  64                         styler.ColourTo(endLine, SCE_DIFF_HEADER);
  65         } else if (0 == strncmp(lineBuffer, "====", 4)) {  // For p4's diff
  66                 styler.ColourTo(endLine, SCE_DIFF_HEADER);
  67         } else if (0 == strncmp(lineBuffer, "***", 3)) {
  68                 // In a context diff, *** appears in both the header and the position markers.
  69                 // Also ******** is a chunk header, but here it's treated as part of the
  70                 // position marker since there is no separate style for a chunk header.
  71                 if (lineBuffer[3] == ' ' && atoi(lineBuffer+4) && !strchr(lineBuffer, '/'))
  72                         styler.ColourTo(endLine, SCE_DIFF_POSITION);
  73                 else if (lineBuffer[3] == '*')
  74                         styler.ColourTo(endLine, SCE_DIFF_POSITION);
  75                 else
  76                         styler.ColourTo(endLine, SCE_DIFF_HEADER);
  77         } else if (0 == strncmp(lineBuffer, "? ", 2)) {    // For difflib
  78                 styler.ColourTo(endLine, SCE_DIFF_HEADER);
  79         } else if (lineBuffer[0] == '@') {
  80                 styler.ColourTo(endLine, SCE_DIFF_POSITION);
  81         } else if (lineBuffer[0] >= '0' && lineBuffer[0] <= '9') {
  82                 styler.ColourTo(endLine, SCE_DIFF_POSITION);
  83         } else if (lineBuffer[0] == '-' || lineBuffer[0] == '<') {
  84                 styler.ColourTo(endLine, SCE_DIFF_DELETED);
  85         } else if (lineBuffer[0] == '+' || lineBuffer[0] == '>') {
  86                 styler.ColourTo(endLine, SCE_DIFF_ADDED);
  87         } else if (lineBuffer[0] == '!') {
  88                 styler.ColourTo(endLine, SCE_DIFF_CHANGED);
  89         } else if (lineBuffer[0] != ' ') {
  90                 styler.ColourTo(endLine, SCE_DIFF_COMMENT);
  91         } else {
  92                 styler.ColourTo(endLine, SCE_DIFF_DEFAULT);
  93         }
  94 }
  95
  96 static void ColouriseDiffDoc(Sci_PositionU startPos, Sci_Position length, int, WordList *[], Accessor &styler) {
  97         char lineBuffer[DIFF_BUFFER_START_SIZE] = "";
  98         styler.StartAt(startPos);
  99         styler.StartSegment(startPos);
 100         Sci_PositionU linePos = 0;
 101         for (Sci_PositionU i = startPos; i < startPos + length; i++) {
 102                 if (AtEOL(styler, i)) {
 103                         if (linePos < DIFF_BUFFER_START_SIZE) {
 104                                 lineBuffer[linePos] = 0;
 105                         }
 106                         ColouriseDiffLine(lineBuffer, i, styler);
 107                         linePos = 0;
 108                 } else if (linePos < DIFF_BUFFER_START_SIZE - 1) {
 109                         lineBuffer[linePos++] = styler[i];
 110                 } else if (linePos == DIFF_BUFFER_START_SIZE - 1) {
 111                         lineBuffer[linePos++] = 0;
 112                 }
 113         }
 114         if (linePos > 0) {      // Last line does not have ending characters
 115                 if (linePos < DIFF_BUFFER_START_SIZE) {
 116                         lineBuffer[linePos] = 0;
 117                 }
 118                 ColouriseDiffLine(lineBuffer, startPos + length - 1, styler);
 119         }
 120 }
 121
 122 static void FoldDiffDoc(Sci_PositionU startPos, Sci_Position length, int, WordList *[], Accessor &styler) {
 123         Sci_Position curLine = styler.GetLine(startPos);
 124         Sci_Position curLineStart = styler.LineStart(curLine);
 125         int prevLevel = curLine > 0 ? styler.LevelAt(curLine - 1) : SC_FOLDLEVELBASE;
 126         int nextLevel;
 127
 128         do {
 129                 const int lineType = styler.StyleAt(curLineStart);
 130                 if (lineType == SCE_DIFF_COMMAND)
 131                         nextLevel = SC_FOLDLEVELBASE | SC_FOLDLEVELHEADERFLAG;
 132                 else if (lineType == SCE_DIFF_HEADER)
 133                         nextLevel = (SC_FOLDLEVELBASE + 1) | SC_FOLDLEVELHEADERFLAG;
 134                 else if (lineType == SCE_DIFF_POSITION && styler[curLineStart] != '-')
 135                         nextLevel = (SC_FOLDLEVELBASE + 2) | SC_FOLDLEVELHEADERFLAG;
 136                 else if (prevLevel & SC_FOLDLEVELHEADERFLAG)
 137                         nextLevel = (prevLevel & SC_FOLDLEVELNUMBERMASK) + 1;
 138                 else
 139                         nextLevel = prevLevel;
 140
 141                 if ((nextLevel & SC_FOLDLEVELHEADERFLAG) && (nextLevel == prevLevel))
 142                         styler.SetLevel(curLine-1, prevLevel & ~SC_FOLDLEVELHEADERFLAG);
 143
 144                 styler.SetLevel(curLine, nextLevel);
 145                 prevLevel = nextLevel;
 146
 147                 curLineStart = styler.LineStart(++curLine);
 148         } while (static_cast<Sci_Position>(startPos)+length > curLineStart);
 149 }
 150
 151 static const char *const emptyWordListDesc[] = {
 152         0
 153 };
 154
 155 LexerModule lmDiff(SCLEX_DIFF, ColouriseDiffDoc, "diff", FoldDiffDoc, emptyWordListDesc);