// 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>

#ifdef _MSC_VER
#pragma warning(disable: 4786)
#endif

#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"

#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 ILexer {
    WordList cpuInstruction;
    WordList mathInstruction;
    WordList registers;
    WordList directive;
    WordList directiveOperand;
    WordList extInstruction;
    WordList directives4foldstart;
    WordList directives4foldend;
    OptionsAsm options;
    OptionSetAsm osAsm;
public:
    LexerAsm() {
    }
    ~LexerAsm() {
    }
    void SCI_METHOD Release() {
        delete this;
    }
    int SCI_METHOD Version() const {
        return lvOriginal;
    }
    const char * SCI_METHOD PropertyNames() {
        return osAsm.PropertyNames();
    }
    int SCI_METHOD PropertyType(const char *name) {
        return osAsm.PropertyType(name);
    }
    const char * SCI_METHOD DescribeProperty(const char *name) {
        return osAsm.DescribeProperty(name);
    }
    int SCI_METHOD PropertySet(const char *key, const char *val);
    const char * SCI_METHOD DescribeWordListSets() {
        return osAsm.DescribeWordListSets();
    }
    int SCI_METHOD WordListSet(int n, const char *wl);
    void SCI_METHOD Lex(unsigned int startPos, int length, int initStyle, IDocument *pAccess);
    void SCI_METHOD Fold(unsigned int startPos, int length, int initStyle, IDocument *pAccess);

    void * SCI_METHOD PrivateCall(int, void *) {
        return 0;
    }

    static ILexer *LexerFactoryAsm() {
        return new LexerAsm();
    }
};

int SCI_METHOD LexerAsm::PropertySet(const char *key, const char *val) {
    if (osAsm.PropertySet(&options, key, val)) {
        return 0;
    }
    return -1;
}

int 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;
    }
    int firstModification = -1;
    if (wordListN) {
        WordList wlNew;
        wlNew.Set(wl);
        if (*wordListN != wlNew) {
            wordListN->Set(wl);
            firstModification = 0;
        }
    }
    return firstModification;
}

void SCI_METHOD LexerAsm::Lex(unsigned int startPos, int 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 == ';'){
                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(unsigned int startPos, int length, int initStyle, IDocument *pAccess) {

    if (!options.fold)
        return;

    LexAccessor styler(pAccess);

    unsigned int endPos = startPos + length;
    int visibleChars = 0;
    int 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 (unsigned int 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<unsigned int>(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);

