src/highlighter.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2016 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "highlighter.h"

HighlighterData* new_highlighter_data() {
    HighlighterData* hd = malloc(sizeof(HighlighterData));
    if (hd == NULL) {
        return NULL;
    } else {
        hd->multiline_comment = 0;
        hd->primary_buffer = ucx_buffer_new(NULL, 256, UCX_BUFFER_AUTOEXTEND);
        hd->secondary_buffer = ucx_buffer_new(NULL, 32, UCX_BUFFER_AUTOEXTEND);
        return hd;
    }
}

void free_highlighter_data(HighlighterData *hd) {
    ucx_buffer_free(hd->primary_buffer);
    ucx_buffer_free(hd->secondary_buffer);
    free(hd);
}

static void put_htmlescaped(UcxBuffer *dest, char c) {
    if (c == '>') {
        ucx_buffer_puts(dest, "&gt;");
    } else if (c == '<') {
        ucx_buffer_puts(dest, "&lt;");
    } else {
        ucx_buffer_putc(dest, c);
    }
}

static void put_htmlescapedstr(UcxBuffer *dest, sstr_t s) {
    for (int i = 0 ; i < s.length ; i++) {
        put_htmlescaped(dest, s.ptr[i]);
    }
}

static int check_keyword(sstr_t word, const char** keywords) {
    for (int i = 0 ; keywords[i] ; i++) {
        if (sstrcmp(word, sstr((char*)keywords[i])) == 0) {
            return 1;
        }
    }
    return 0;
}

static int check_capsonly(sstr_t word) {
    for (size_t i = 0 ; i < word.length ; i++) {
        if (!isupper(word.ptr[i]) && !isdigit(word.ptr[i])
                && word.ptr[i] != '_') {
            return 0;
        }
    }
    return 1;
}

/* Plaintext Highlighter */

void plain_highlighter(char *src, UcxBuffer *dest, HighlighterData *hd) {
    while (*src && *src != '\n') {
        put_htmlescaped(dest, *src);
        src++;
    }
    ucx_buffer_putc(dest, '\n');
}

/* C Highlighter */

static const char* ckeywords[] = {
    "auto", "break", "case", "char", "const", "continue", "default", "do",
    "double", "else", "enum", "extern", "float", "for", "goto", "if", "int",
    "long", "register", "return", "short", "signed", "sizeof", "static",
    "struct", "switch", "typedef", "union", "unsigned", "void", "volatile",
    "while", NULL
};

void c_highlighter(char *src, UcxBuffer *dest, HighlighterData *hd) {
    /* reset buffers without clearing them */
    hd->primary_buffer->size = hd->primary_buffer->pos = 0;
    hd->secondary_buffer->size = hd->secondary_buffer->pos = 0;
    
    /* alias the buffers for better handling */
    UcxBuffer *wbuf = hd->primary_buffer;
    UcxBuffer *ifilebuf = hd->secondary_buffer;
    
    /* local information */
    size_t sp = (size_t)-1;
    int isstring = 0, iscomment = 0, isinclude = 0, parseinclude = 0;
    char quote = '\0';
    int isescaping = 0;
    
    /* continue a multi line comment highlighting */
    if (hd->multiline_comment) {
        iscomment = 1;
        ucx_buffer_puts(dest, "<span class=\"c2html-comment\">");
    }

    char c;
    do {
        c = src[++sp];
        if (!c) {
            /* TODO: might cause problems if code file does not end with NL */
            break;
        }
        
        /* comments */
        if (!isstring && c == '/') {
            if (hd->multiline_comment && sp > 0 && src[sp-1] == '*') {
                iscomment = 0;
                hd->multiline_comment = 0;
                ucx_buffer_puts(dest, "/</span>");
                continue;
            } else if (!iscomment && (src[sp+1] == '/' || src[sp+1] == '*')) {
                iscomment = 1;
                hd->multiline_comment = (src[sp+1] == '*');
                ucx_buffer_puts(dest, "<span class=\"c2html-comment\">");
            }
        }

        if (iscomment) {
            if (c == '\n') {
                ucx_buffer_puts(dest, "</span>\n");
            } else {
                put_htmlescaped(dest, c);
            }
        } else if (isinclude) {
            if (c == '<') {
                ucx_buffer_puts(dest,
                        "<span class=\"c2html-stdinclude\">&lt;");
            } else if (c == '\"') {
                if (parseinclude) {
                    ucx_buffer_puts(dest, "\">");
                    ucx_buffer_write(ifilebuf->space, 1, ifilebuf->size, dest);
                    ucx_buffer_puts(dest, "\"</a>");
                    parseinclude = 0;
                } else {
                    ucx_buffer_puts(dest,
                            "<a class=\"c2html-userinclude\" href=\"");
                    ucx_buffer_putc(ifilebuf, '\"');
                    parseinclude = 1;
                }
            } else if (c == '>') {
                ucx_buffer_puts(dest,  "&gt;</span>");
            } else {
                if (parseinclude) {
                    ucx_buffer_putc(ifilebuf, c);
                }
                put_htmlescaped(dest, c);
            }
        } else {
            /* strings */
            if (!isescaping && (c == '\'' || c == '\"')) {
                if (isstring) {
                    put_htmlescaped(dest, c);
                    if (c == quote) {
                        isstring = 0;
                        ucx_buffer_puts(dest, "</span>");
                    } else {
                        put_htmlescaped(dest, c);
                    }
                } else {
                    isstring = 1;
                    quote = c;
                    ucx_buffer_puts(dest, "<span class=\"c2html-string\">");
                    put_htmlescaped(dest, c);
                }
            } else {
                if (isstring) {
                    put_htmlescaped(dest, c);
                } else if (!isalnum(c) && c!='_' && c!='#') {
                    /* write buffered word, if any */
                    if (wbuf->size > 0) {
                        sstr_t word = sstrn(wbuf->space, wbuf->size);
                        int closespan = 1;
                        sstr_t typesuffix = ST("_t");
                        if (check_keyword(word, ckeywords)) {
                            ucx_buffer_puts(dest,
                                    "<span class=\"c2html-keyword\">");
                        } else if (sstrsuffix(word, typesuffix)) {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-type\">");
                        } else if (word.ptr[0] == '#') {
                            isinclude = !sstrcmp(word, S("#include"));
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-directive\">");
                        } else if (check_capsonly(word)) {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-macroconst\">");
                        } else {
                            closespan = 0;
                        }
                        put_htmlescapedstr(dest, word);
                        if (closespan) {
                            ucx_buffer_puts(dest, "</span>");
                        }
                    }
                    wbuf->pos = wbuf->size = 0; /* reset word buffer */
                    
                    /* write current character */
                    put_htmlescaped(dest, c);
                } else {
                    /* buffer the current word */
                    ucx_buffer_putc(wbuf, c);
                }
            }

            isescaping = !isescaping & (c == '\\');
        }
    } while (c != '\n');
}

/* Java Highlighter */

static const char* jkeywords[] = {
    "abstract", "continue", "for", "new", "switch", "assert", "default", "goto",
    "package", "synchronized", "boolean", "do", "if", "private", "this",
    "break", "double", "implements", "protected", "throw", "byte", "else",
    "import", "public", "throws", "case", "enum", "instanceof", "return",
    "transient", "catch", "extends", "int", "short", "try", "char", "final",
    "interface", "static", "void", "class", "finally", "long", "strictfp",
    "volatile", "const", "float", "native", "super", "while", NULL
};

void java_highlighter(char *src, UcxBuffer *dest, HighlighterData *hd) {
    /* reset buffers without clearing them */
    hd->primary_buffer->size = hd->primary_buffer->pos = 0;
    hd->secondary_buffer->size = hd->secondary_buffer->pos = 0;

    /* alias the buffers for better handling */
    UcxBuffer *wbuf = hd->primary_buffer;
    
    /* local information */
    size_t sp = (size_t)-1;
    int isstring = 0, iscomment = 0, isimport = 0;
    char quote = '\0';
    int isescaping = 0;

    if (hd->multiline_comment) {
        iscomment = 1;
        ucx_buffer_puts(dest, "<span class=\"c2html-comment\">");
    }

    char c;
    do {
        c = src[++sp];
        if (!c) {
            /* TODO: might cause problems if code file does not end with NL */
            break;
        }
        
        /* comments */
        if (!isstring && c == '/') {
            if (hd->multiline_comment && sp > 0 && src[sp-1] == '*') {
                iscomment = 0;
                hd->multiline_comment = 0;
                ucx_buffer_puts(dest, "/</span>");
                continue;
            } else if (!iscomment && (src[sp+1] == '/' || src[sp+1] == '*')) {
                iscomment = 1;
                hd->multiline_comment = (src[sp+1] == '*');
                ucx_buffer_puts(dest, "<span class=\"c2html-comment\">");
            }
        }

        if (iscomment) {
            if (c == '\n') {
                ucx_buffer_puts(dest, "</span>\n");
            } else {
                put_htmlescaped(dest, c);
            }
        } else if (isimport) {
            /* TODO: local imports */
        } else {
            /* strings */
            if (!isescaping && (c == '\'' || c == '\"')) {
                if (isstring) {
                    put_htmlescaped(dest, c);
                    if (c == quote) {
                        isstring = 0;
                        ucx_buffer_puts(dest, "</span>");
                    } else {
                        put_htmlescaped(dest, c);
                    }
                } else {
                    isstring = 1;
                    quote = c;
                    ucx_buffer_puts(dest,
                        "<span class=\"c2html-string\">");
                    put_htmlescaped(dest, c);
                }
            } else {
                if (isstring) {
                    put_htmlescaped(dest, c);
                } else if (!isalnum(c) && c!='_' && c!='@') {
                    /* write buffered word, if any */
                    if (wbuf->size > 0) {
                        sstr_t word = sstrn(wbuf->space, wbuf->size);
                        int closespan = 1;
                        if (check_keyword(word, jkeywords)) {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-keyword\">");
                        } else if (isupper(word.ptr[0])) {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-type\">");
                        } else if (word.ptr[0] == '@') {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-directive\">");
                        } else if (check_capsonly(word)) {
                            ucx_buffer_puts(dest,
                                "<span class=\"c2html-macroconst\">");
                        } else {
                            closespan = 0;
                        }
                        put_htmlescapedstr(dest, word);
                        
                        if (closespan) {
                            ucx_buffer_puts(dest, "</span>");
                        }
                    }
                    wbuf->pos = wbuf->size = 0; /* reset buffer */
                    
                    /* write current character */
                    put_htmlescaped(dest, c);
                } else {
                    /* buffer the current word */
                    ucx_buffer_putc(wbuf, c);
                }
            }

            isescaping = !isescaping & (c == '\\');
        }
    } while (c != '\n');
}