text: // Scintilla source code edit control
  /** @file LexAsm.cxx
   ** Lexer for Assembler, just for the MASM syntax
   ** Written by The Black Horus
   ** Enhancements and NASM stuff by Kein-Hong Man, 2003-10
   ** SCE_ASM_COMMENTBLOCK and SCE_ASM_CHARACTER are for future GNU as colouring
   ** Converted to lexer object and added further folding features/properties by "Udo Lechner" <dlchnr(at)gmx(dot)net>
   **/
  // Copyright 1998-2003 by Neil Hodgson <neilh@scintilla.org>
  // The License.txt file describes the conditions under which this software may be distributed.
  
  #include <stdlib.h>
  #include <string.h>
  #include <stdio.h>
  #include <stdarg.h>
  #include <assert.h>
  #include <ctype.h>
  
  #include <string>
  #include <map>
  #include <set>
  
  #include "ILexer.h"
  #include "Scintilla.h"
  #include "SciLexer.h"
  
  #include "WordList.h"
  #include "LexAccessor.h"
  #include "StyleContext.h"
  #include "CharacterSet.h"
  #include "LexerModule.h"
  #include "OptionSet.h"
  #include "DefaultLexer.h"
  
  #ifdef SCI_NAMESPACE
  using namespace Scintilla;
  #endif
  
  static inline bool IsAWordChar(const int ch) {
  	return (ch < 0x80) && (isalnum(ch) || ch == '.' ||
  		ch == '_' || ch == '?');
  }
  
  static inline bool IsAWordStart(const int ch) {
  	return (ch < 0x80) && (isalnum(ch) || ch == '_' || ch == '.' ||
  		ch == '%' || ch == '@' || ch == '$' || ch == '?');
  }
  
  static inline bool IsAsmOperator(const int ch) {
  	if ((ch < 0x80) && (isalnum(ch)))
  		return false;
  	// '.' left out as it is used to make up numbers
  	if (ch == '*' || ch == '/' || ch == '-' || ch == '+' ||
  		ch == '(' || ch == ')' || ch == '=' || ch == '^' ||
  		ch == '[' || ch == ']' || ch == '<' || ch == '&' ||
  		ch == '>' || ch == ',' || ch == '|' || ch == '~' ||
  		ch == '%' || ch == ':')
  		return true;
  	return false;
  }
  
  static bool IsStreamCommentStyle(int style) {
  	return style == SCE_ASM_COMMENTDIRECTIVE || style == SCE_ASM_COMMENTBLOCK;
  }
  
  static inline int LowerCase(int c) {
  	if (c >= 'A' && c <= 'Z')
  		return 'a' + c - 'A';
  	return c;
  }
  
  // An individual named option for use in an OptionSet
  
  // Options used for LexerAsm
  struct OptionsAsm {
  	std::string delimiter;
  	bool fold;
  	bool foldSyntaxBased;
  	bool foldCommentMultiline;
  	bool foldCommentExplicit;
  	std::string foldExplicitStart;
  	std::string foldExplicitEnd;
  	bool foldExplicitAnywhere;
  	bool foldCompact;
  	OptionsAsm() {
  		delimiter = "";
  		fold = false;
  		foldSyntaxBased = true;
  		foldCommentMultiline = false;
  		foldCommentExplicit = false;
  		foldExplicitStart = "";
  		foldExplicitEnd   = "";
  		foldExplicitAnywhere = false;
  		foldCompact = true;
  	}
  };
  
  static const char * const asmWordListDesc[] = {
  	"CPU instructions",
  	"FPU instructions",
  	"Registers",
  	"Directives",
  	"Directive operands",
  	"Extended instructions",
  	"Directives4Foldstart",
  	"Directives4Foldend",
  	0
  };
  
  struct OptionSetAsm : public OptionSet<OptionsAsm> {
  	OptionSetAsm() {
  		DefineProperty("lexer.asm.comment.delimiter", &OptionsAsm::delimiter,
  			"Character used for COMMENT directive's delimiter, replacing the standard \"~\".");
  
  		DefineProperty("fold", &OptionsAsm::fold);
  
  		DefineProperty("fold.asm.syntax.based", &OptionsAsm::foldSyntaxBased,
  			"Set this property to 0 to disable syntax based folding.");
  
  		DefineProperty("fold.asm.comment.multiline", &OptionsAsm::foldCommentMultiline,
  			"Set this property to 1 to enable folding multi-line comments.");
  
  		DefineProperty("fold.asm.comment.explicit", &OptionsAsm::foldCommentExplicit,
  			"This option enables folding explicit fold points when using the Asm lexer. "
  			"Explicit fold points allows adding extra folding by placing a ;{ comment at the start and a ;} "
  			"at the end of a section that should fold.");
  
  		DefineProperty("fold.asm.explicit.start", &OptionsAsm::foldExplicitStart,
  			"The string to use for explicit fold start points, replacing the standard ;{.");
  
  		DefineProperty("fold.asm.explicit.end", &OptionsAsm::foldExplicitEnd,
  			"The string to use for explicit fold end points, replacing the standard ;}.");
  
  		DefineProperty("fold.asm.explicit.anywhere", &OptionsAsm::foldExplicitAnywhere,
  			"Set this property to 1 to enable explicit fold points anywhere, not just in line comments.");
  
  		DefineProperty("fold.compact", &OptionsAsm::foldCompact);
  
  		DefineWordListSets(asmWordListDesc);
  	}
  };
  
  class LexerAsm : public DefaultLexer {
  	WordList cpuInstruction;
  	WordList mathInstruction;
  	WordList registers;
  	WordList directive;
  	WordList directiveOperand;
  	WordList extInstruction;
  	WordList directives4foldstart;
  	WordList directives4foldend;
  	OptionsAsm options;
  	OptionSetAsm osAsm;
  	int commentChar;
  public:
  	LexerAsm(int commentChar_) {
  		commentChar = commentChar_;
  	}
  	virtual ~LexerAsm() {
  	}
  	void SCI_METHOD Release() override {
  		delete this;
  	}
  	int SCI_METHOD Version() const override {
  		return lvRelease4;
  	}
  	const char * SCI_METHOD PropertyNames() override {
  		return osAsm.PropertyNames();
  	}
  	int SCI_METHOD PropertyType(const char *name) override {
  		return osAsm.PropertyType(name);
  	}
  	const char * SCI_METHOD DescribeProperty(const char *name) override {
  		return osAsm.DescribeProperty(name);
  	}
  	Sci_Position SCI_METHOD PropertySet(const char *key, const char *val) override;
  	const char * SCI_METHOD DescribeWordListSets() override {
  		return osAsm.DescribeWordListSets();
  	}
  	Sci_Position SCI_METHOD WordListSet(int n, const char *wl) override;
  	void SCI_METHOD Lex(Sci_PositionU startPos, Sci_Position length, int initStyle, IDocument *pAccess) override;
  	void SCI_METHOD Fold(Sci_PositionU startPos, Sci_Position length, int initStyle, IDocument *pAccess) override;
  
  	void * SCI_METHOD PrivateCall(int, void *) override {
  		return 0;
  	}
  
  	static ILexer4 *LexerFactoryAsm() {
  		return new LexerAsm(';');
  	}
  
  	static ILexer4 *LexerFactoryAs() {
  		return new LexerAsm('#');
  	}
  };
  
  Sci_Position SCI_METHOD LexerAsm::PropertySet(const char *key, const char *val) {
  	if (osAsm.PropertySet(&options, key, val)) {
  		return 0;
  	}
  	return -1;
  }
  
  Sci_Position SCI_METHOD LexerAsm::WordListSet(int n, const char *wl) {
  	WordList *wordListN = 0;
  	switch (n) {
  	case 0:
  		wordListN = &cpuInstruction;
  		break;
  	case 1:
  		wordListN = &mathInstruction;
  		break;
  	case 2:
  		wordListN = &registers;
  		break;
  	case 3:
  		wordListN = &directive;
  		break;
  	case 4:
  		wordListN = &directiveOperand;
  		break;
  	case 5:
  		wordListN = &extInstruction;
  		break;
  	case 6:
  		wordListN = &directives4foldstart;
  		break;
  	case 7:
  		wordListN = &directives4foldend;
  		break;
  	}
  	Sci_Position firstModification = -1;
  	if (wordListN) {
  		WordList wlNew;
  		wlNew.Set(wl);
  		if (*wordListN != wlNew) {
  			wordListN->Set(wl);
  			firstModification = 0;
  		}
  	}
  	return firstModification;
  }
  
  void SCI_METHOD LexerAsm::Lex(Sci_PositionU startPos, Sci_Position length, int initStyle, IDocument *pAccess) {
  	LexAccessor styler(pAccess);
  
  	// Do not leak onto next line
  	if (initStyle == SCE_ASM_STRINGEOL)
  		initStyle = SCE_ASM_DEFAULT;
  
  	StyleContext sc(startPos, length, initStyle, styler);
  
  	for (; sc.More(); sc.Forward())
  	{
  
  		// Prevent SCE_ASM_STRINGEOL from leaking back to previous line
  		if (sc.atLineStart && (sc.state == SCE_ASM_STRING)) {
  			sc.SetState(SCE_ASM_STRING);
  		} else if (sc.atLineStart && (sc.state == SCE_ASM_CHARACTER)) {
  			sc.SetState(SCE_ASM_CHARACTER);
  		}
  
  		// Handle line continuation generically.
  		if (sc.ch == '\\') {
  			if (sc.chNext == '\n' || sc.chNext == '\r') {
  				sc.Forward();
  				if (sc.ch == '\r' && sc.chNext == '\n') {
  					sc.Forward();
  				}
  				continue;
  			}
  		}
  
  		// Determine if the current state should terminate.
  		if (sc.state == SCE_ASM_OPERATOR) {
  			if (!IsAsmOperator(sc.ch)) {
  			    sc.SetState(SCE_ASM_DEFAULT);
  			}
  		} else if (sc.state == SCE_ASM_NUMBER) {
  			if (!IsAWordChar(sc.ch)) {
  				sc.SetState(SCE_ASM_DEFAULT);
  			}
  		} else if (sc.state == SCE_ASM_IDENTIFIER) {
  			if (!IsAWordChar(sc.ch) ) {
  				char s[100];
  				sc.GetCurrentLowered(s, sizeof(s));
  				bool IsDirective = false;
  
  				if (cpuInstruction.InList(s)) {
  					sc.ChangeState(SCE_ASM_CPUINSTRUCTION);
  				} else if (mathInstruction.InList(s)) {
  					sc.ChangeState(SCE_ASM_MATHINSTRUCTION);
  				} else if (registers.InList(s)) {
  					sc.ChangeState(SCE_ASM_REGISTER);
  				}  else if (directive.InList(s)) {
  					sc.ChangeState(SCE_ASM_DIRECTIVE);
  					IsDirective = true;
  				} else if (directiveOperand.InList(s)) {
  					sc.ChangeState(SCE_ASM_DIRECTIVEOPERAND);
  				} else if (extInstruction.InList(s)) {
  					sc.ChangeState(SCE_ASM_EXTINSTRUCTION);
  				}
  				sc.SetState(SCE_ASM_DEFAULT);
  				if (IsDirective && !strcmp(s, "comment")) {
  					char delimiter = options.delimiter.empty() ? '~' : options.delimiter.c_str()[0];
  					while (IsASpaceOrTab(sc.ch) && !sc.atLineEnd) {
  						sc.ForwardSetState(SCE_ASM_DEFAULT);
  					}
  					if (sc.ch == delimiter) {
  						sc.SetState(SCE_ASM_COMMENTDIRECTIVE);
  					}
  				}
  			}
  		} else if (sc.state == SCE_ASM_COMMENTDIRECTIVE) {
  			char delimiter = options.delimiter.empty() ? '~' : options.delimiter.c_str()[0];
  			if (sc.ch == delimiter) {
  				while (!sc.atLineEnd) {
  					sc.Forward();
  				}
  				sc.SetState(SCE_ASM_DEFAULT);
  			}
  		} else if (sc.state == SCE_ASM_COMMENT ) {
  			if (sc.atLineEnd) {
  				sc.SetState(SCE_ASM_DEFAULT);
  			}
  		} else if (sc.state == SCE_ASM_STRING) {
  			if (sc.ch == '\\') {
  				if (sc.chNext == '\"' || sc.chNext == '\'' || sc.chNext == '\\') {
  					sc.Forward();
  				}
  			} else if (sc.ch == '\"') {
  				sc.ForwardSetState(SCE_ASM_DEFAULT);
  			} else if (sc.atLineEnd) {
  				sc.ChangeState(SCE_ASM_STRINGEOL);
  				sc.ForwardSetState(SCE_ASM_DEFAULT);
  			}
  		} else if (sc.state == SCE_ASM_CHARACTER) {
  			if (sc.ch == '\\') {
  				if (sc.chNext == '\"' || sc.chNext == '\'' || sc.chNext == '\\') {
  					sc.Forward();
  				}
  			} else if (sc.ch == '\'') {
  				sc.ForwardSetState(SCE_ASM_DEFAULT);
  			} else if (sc.atLineEnd) {
  				sc.ChangeState(SCE_ASM_STRINGEOL);
  				sc.ForwardSetState(SCE_ASM_DEFAULT);
  			}
  		}
  
  		// Determine if a new state should be entered.
  		if (sc.state == SCE_ASM_DEFAULT) {
  			if (sc.ch == commentChar){
  				sc.SetState(SCE_ASM_COMMENT);
  			} else if (IsASCII(sc.ch) && (isdigit(sc.ch) || (sc.ch == '.' && IsASCII(sc.chNext) && isdigit(sc.chNext)))) {
  				sc.SetState(SCE_ASM_NUMBER);
  			} else if (IsAWordStart(sc.ch)) {
  				sc.SetState(SCE_ASM_IDENTIFIER);
  			} else if (sc.ch == '\"') {
  				sc.SetState(SCE_ASM_STRING);
  			} else if (sc.ch == '\'') {
  				sc.SetState(SCE_ASM_CHARACTER);
  			} else if (IsAsmOperator(sc.ch)) {
  				sc.SetState(SCE_ASM_OPERATOR);
  			}
  		}
  
  	}
  	sc.Complete();
  }
  
  // Store both the current line's fold level and the next lines in the
  // level store to make it easy to pick up with each increment
  // and to make it possible to fiddle the current level for "else".
  
  void SCI_METHOD LexerAsm::Fold(Sci_PositionU startPos, Sci_Position length, int initStyle, IDocument *pAccess) {
  
  	if (!options.fold)
  		return;
  
  	LexAccessor styler(pAccess);
  
  	Sci_PositionU endPos = startPos + length;
  	int visibleChars = 0;
  	Sci_Position lineCurrent = styler.GetLine(startPos);
  	int levelCurrent = SC_FOLDLEVELBASE;
  	if (lineCurrent > 0)
  		levelCurrent = styler.LevelAt(lineCurrent-1) >> 16;
  	int levelNext = levelCurrent;
  	char chNext = styler[startPos];
  	int styleNext = styler.StyleAt(startPos);
  	int style = initStyle;
  	char word[100];
  	int wordlen = 0;
  	const bool userDefinedFoldMarkers = !options.foldExplicitStart.empty() && !options.foldExplicitEnd.empty();
  	for (Sci_PositionU i = startPos; i < endPos; i++) {
  		char ch = chNext;
  		chNext = styler.SafeGetCharAt(i + 1);
  		int stylePrev = style;
  		style = styleNext;
  		styleNext = styler.StyleAt(i + 1);
  		bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
  		if (options.foldCommentMultiline && IsStreamCommentStyle(style)) {
  			if (!IsStreamCommentStyle(stylePrev)) {
  				levelNext++;
  			} else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
  				// Comments don't end at end of line and the next character may be unstyled.
  				levelNext--;
  			}
  		}
  		if (options.foldCommentExplicit && ((style == SCE_ASM_COMMENT) || options.foldExplicitAnywhere)) {
  			if (userDefinedFoldMarkers) {
  				if (styler.Match(i, options.foldExplicitStart.c_str())) {
   					levelNext++;
  				} else if (styler.Match(i, options.foldExplicitEnd.c_str())) {
   					levelNext--;
   				}
  			} else {
  				if (ch == ';') {
  					if (chNext == '{') {
  						levelNext++;
  					} else if (chNext == '}') {
  						levelNext--;
  					}
  				}
   			}
   		}
  		if (options.foldSyntaxBased && (style == SCE_ASM_DIRECTIVE)) {
  			word[wordlen++] = static_cast<char>(LowerCase(ch));
  			if (wordlen == 100) {                   // prevent overflow
  				word[0] = '\0';
  				wordlen = 1;
  			}
  			if (styleNext != SCE_ASM_DIRECTIVE) {   // reading directive ready
  				word[wordlen] = '\0';
  				wordlen = 0;
  				if (directives4foldstart.InList(word)) {
  					levelNext++;
  				} else if (directives4foldend.InList(word)){
  					levelNext--;
  				}
  			}
  		}
  		if (!IsASpace(ch))
  			visibleChars++;
  		if (atEOL || (i == endPos-1)) {
  			int levelUse = levelCurrent;
  			int lev = levelUse | levelNext << 16;
  			if (visibleChars == 0 && options.foldCompact)
  				lev |= SC_FOLDLEVELWHITEFLAG;
  			if (levelUse < levelNext)
  				lev |= SC_FOLDLEVELHEADERFLAG;
  			if (lev != styler.LevelAt(lineCurrent)) {
  				styler.SetLevel(lineCurrent, lev);
  			}
  			lineCurrent++;
  			levelCurrent = levelNext;
  			if (atEOL && (i == static_cast<Sci_PositionU>(styler.Length() - 1))) {
  				// There is an empty line at end of file so give it same level and empty
  				styler.SetLevel(lineCurrent, (levelCurrent | levelCurrent << 16) | SC_FOLDLEVELWHITEFLAG);
  			}
  			visibleChars = 0;
  		}
  	}
  }
  
  LexerModule lmAsm(SCLEX_ASM, LexerAsm::LexerFactoryAsm, "asm", asmWordListDesc);
  LexerModule lmAs(SCLEX_AS, LexerAsm::LexerFactoryAs, "as", asmWordListDesc);
  
  