tags.c

nedit 是一款linux下的开发源码的功能强大的编辑器

        else
            Rcs[bucket] = newrcs;
            
        newstr = newrcs->string;
    }

    RcsStats.tbytes += len;
    return newstr;
}

/*
** Decrease the reference count on a shared string.  When the reference
** count reaches zero, free the master string.
*/

static void rcs_free(const char *rcs_str)
{
    int bucket;
    struct rcs *rp;
    struct rcs *prev = NULL;

    if (rcs_str == NULL)
        return;
        
    bucket = hashAddr(rcs_str) % RCS_SIZE;

    /* find it in hash */
    for (rp = Rcs[bucket]; rp; rp = rp->next)
    {
        if (rcs_str == rp->string)
            break;
        prev = rp;
    }

    if (rp)  /* It's a shared string, decrease ref count */
    {
        rp->usage--;
        
        if (rp->usage < 0) /* D'OH! */
        {
            fprintf(stderr, "NEdit: internal error deallocating shared string.");
            return;
        }

        if (rp->usage == 0)  /* Last one- free the storage */
        {
            free(rp->string);
            if (prev)
                prev->next = rp->next;
            else
                Rcs[bucket] = rp->next;
            free(rp);
        }
    }
    else    /* Doesn't appear to be a shared string */
    {
        fprintf(stderr, "NEdit: attempt to free a non-shared string.");
        return;
    }
}

/********************************************************************
 *           Functions for loading Calltips files                   *
 ********************************************************************/

enum tftoken_types { TF_EOF, TF_BLOCK, TF_VERSION, TF_INCLUDE, TF_LANGUAGE, 
                     TF_ALIAS, TF_ERROR, TF_ERROR_EOF };

/* A wrapper for SearchString */
static int searchLine(char *line, const char *regex) {
    int dummy1, dummy2;
    return SearchString(line, regex, SEARCH_FORWARD, SEARCH_REGEX,
                             False, 0, &dummy1, &dummy2, NULL, NULL, NULL);
}

/* Check if a line has non-ws characters */
static Boolean lineEmpty(const char *line) {
    while (*line && *line != '\n') {
        if (*line != ' ' && *line != '\t')
            return False;
        ++line;
    }
    return True;
}

/* Remove trailing whitespace from a line */
static void rstrip( char *dst, const char *src ) {
    int wsStart, dummy2;
    /* Strip trailing whitespace */
    if(SearchString(src, "\\s*\\n", SEARCH_FORWARD, SEARCH_REGEX,
                         False, 0, &wsStart, &dummy2, NULL, NULL, NULL)) {
        if(dst != src)
            memcpy(dst, src, wsStart);
        dst[wsStart] = 0;
    } else
        if(dst != src)
            strcpy(dst, src);
}

/* 
** Get the next block from a tips file.  A block is a \n\n+ delimited set of
** lines in a calltips file.  All of the parameters except <fp> are return
** values, and most have different roles depending on the type of block
** that is found.  
**      header:     Depends on the block type
**      body:       Depends on the block type.  Used to return a new 
**                  dynamically allocated string.
**      blkLine:    Returns the line number of the first line of the block
**                  after the "* xxxx *" line. 
**      currLine:   Used to keep track of the current line in the file.
*/
static int nextTFBlock(FILE *fp, char *header, char **body, int *blkLine, 
        int *currLine) 
{
    /* These are the different kinds of tokens */
    const char *commenTF_regex = "^\\s*\\* comment \\*\\s*$";
    const char *version_regex  = "^\\s*\\* version \\*\\s*$";
    const char *include_regex  = "^\\s*\\* include \\*\\s*$";
    const char *language_regex = "^\\s*\\* language \\*\\s*$";
    const char *alias_regex    = "^\\s*\\* alias \\*\\s*$";
    char line[MAXLINE], *status;
    int dummy1;
    int code;
    
    /* Skip blank lines and comments */
    while(1) {
        /* Skip blank lines */
        while((status=fgets(line, MAXLINE, fp))) {
            ++(*currLine);
            if(!lineEmpty( line )) 
                break;
        }

        /* Check for error or EOF */
        if(!status) 
            return TF_EOF;

        /* We've got a non-blank line -- is it a comment block? */
        if( !searchLine(line, commenTF_regex) ) 
            break;
        
        /* Skip the comment (non-blank lines) */
        while((status=fgets(line, MAXLINE, fp))) {
            ++(*currLine);
            if(lineEmpty( line )) 
                break;
        }
        
        if(!status) 
            return TF_EOF;
    }
    
    /* Now we know it's a meaningful block */
    dummy1 = searchLine(line, include_regex);
    if( dummy1 || searchLine(line, alias_regex) ) {
        /* INCLUDE or ALIAS block */
        int incLen, incPos, i, incLines;
        
        /* fprintf(stderr, "Starting include/alias at line %i\n", *currLine); */
        if(dummy1)
            code = TF_INCLUDE;
        else {
            code = TF_ALIAS;
            /* Need to read the header line for an alias */
            status=fgets(line, MAXLINE, fp);
            ++(*currLine);
            if (!status) 
                return TF_ERROR_EOF;
            if (lineEmpty( line )) {
                fprintf( stderr, "nedit: Warning: empty '* alias *' "
                        "block in calltips file.\n" );
                return TF_ERROR;
            }
            rstrip(header, line);
        }
        incPos = ftell(fp);
        *blkLine = *currLine + 1; /* Line of first actual filename/alias */
        if (incPos < 0) 
            return TF_ERROR;
        /* Figure out how long the block is */
        while((status=fgets(line, MAXLINE, fp))) {
            ++(*currLine);
            if(lineEmpty( line )) 
                break;
        }
        incLen = ftell(fp) - incPos;
        incLines = *currLine - *blkLine;
        /* Correct currLine for the empty line it read at the end */
        --(*currLine);
        if (incLines == 0) {
            fprintf( stderr, "nedit: Warning: empty '* include *' or"
                    " '* alias *' block in calltips file.\n" );
            return TF_ERROR;
        }
        /* Make space for the filenames/alias sources */
        *body = (char *)malloc(incLen+1);
        if (!*body) 
            return TF_ERROR;
        *body[0]=0;
        if (fseek(fp, incPos, SEEK_SET) != 0) {
            free (*body);
            return TF_ERROR;
        }
        /* Read all the lines in the block */
        /* fprintf(stderr, "Copying lines\n"); */
        for (i=0; i<incLines; i++) {
            status = fgets(line, MAXLINE, fp);
            if (!status) {
                free (*body);
                return TF_ERROR_EOF;
            }
            rstrip(line,line);
            if(i) 
                strcat(*body, ":");
            strcat(*body, line);
        }
        /* fprintf(stderr, "Finished include/alias at line %i\n", *currLine); */
    }
    
    else if( searchLine(line, language_regex) ) {
        /* LANGUAGE block */
        status=fgets(line, MAXLINE, fp);
        ++(*currLine);
        if (!status) 
            return TF_ERROR_EOF;
        if (lineEmpty( line )) {
            fprintf( stderr, "nedit: Warning: empty '* language *' block in calltips file.\n" );
            return TF_ERROR;
        }
        *blkLine = *currLine;
        rstrip(header, line);
        code = TF_LANGUAGE;
    }

    else if( searchLine(line, version_regex) ) {
        /* VERSION block */
        status=fgets(line, MAXLINE, fp);
        ++(*currLine);
        if (!status) 
            return TF_ERROR_EOF;
        if (lineEmpty( line )) {
            fprintf( stderr, "nedit: Warning: empty '* version *' block in calltips file.\n" );
            return TF_ERROR;
        }
        *blkLine = *currLine;
        rstrip(header, line);
        code = TF_VERSION;
    }

    else {
        /* Calltip block */
        /*  The first line is the key, the rest is the tip. 
            Strip trailing whitespace. */
        rstrip(header, line);
        
        status=fgets(line, MAXLINE, fp);
        ++(*currLine);
        if (!status) 
            return TF_ERROR_EOF;
        if (lineEmpty( line )) {
            fprintf( stderr, "nedit: Warning: empty calltip block:\n"
                     "   \"%s\"\n", header);
            return TF_ERROR;
        }
        *blkLine = *currLine;
        *body = strdup(line);
        code = TF_BLOCK;
    }
    
    /* Skip the rest of the block */
    dummy1 = *currLine;
    while(fgets(line, MAXLINE, fp)) {
        ++(*currLine);
        if (lineEmpty( line )) 
            break;
    }
    
    /* Warn about any unneeded extra lines (which are ignored). */
    if (dummy1+1 < *currLine && code != TF_BLOCK) {
        fprintf( stderr, "nedit: Warning: extra lines in language or version block ignored.\n" );
    }
    
    return code;
}

/* A struct for describing a calltip alias */
typedef struct _alias {
    char *dest;
    char *sources;
    struct _alias *next;
} tf_alias;

/*
** Allocate a new alias, copying dest and stealing sources.  This may
** seem strange but that's the way it's called 
*/
static tf_alias *new_alias(const char *dest, char *sources) {
    tf_alias *alias;
    
    /* fprintf(stderr, "new_alias: %s <- %s\n", dest, sources); */
    /* Allocate the alias */
    alias = (tf_alias *)malloc( sizeof(tf_alias) );
    if(!alias) 
        return NULL;

    /* Fill it in */
    alias->dest = (char*)malloc( strlen(dest)+1 );
    if(!(alias->dest))
        return NULL;
    strcpy( alias->dest, dest );
    alias->sources = sources;
    return alias;
}

/* Deallocate a linked-list of aliases */
static void free_alias_list(tf_alias *alias) {
    tf_alias *tmp_alias;
    while(alias) {
        tmp_alias = alias->next;
        free(alias->dest);
        free(alias->sources);
        free(alias);
        alias = tmp_alias;
    }
}

/*
** Load a calltips file and insert all of the entries into the global tips
** database.  Each tip is essentially stored as its filename and the line
** at which it appears--the exact same way ctags indexes source-code.  That's
** why calltips and tags share so much code.
*/
static int loadTipsFile(const char *tipsFile, int index, int recLevel)
{
    FILE *fp = NULL;
    char header[MAXLINE];
    char *body, *tipIncFile;
    char tipPath[MAXPATHLEN];
    char resolvedTipsFile[MAXPATHLEN+1];
    int nTipsAdded=0, langMode = PLAIN_LANGUAGE_MODE, oldLangMode;
    int currLine=0, code, blkLine;
    tf_alias *aliases=NULL, *tmp_alias;
    
    if(recLevel > MAX_TAG_INCLUDE_RECURSION_LEVEL) {
        fprintf(stderr, "nedit: Warning: Reached recursion limit before loading calltips file:\n\t%s\n", tipsFile);
        return 0;
    }
    
    /* find the tips file */
#ifndef VMS
    /* Allow ~ in Unix filenames */
    strncpy(tipPath, tipsFile, MAXPATHLEN);    /* ExpandTilde is destructive */
    ExpandTilde(tipPath);
    if(!ResolvePath(tipPath, resolvedTipsFile))
        return 0;
#else
    if(!ResolvePath(tipsFile, resolvedTipsFile))
        return 0;
#endif

    /* Get the path to the tips file */
    ParseFilename(resolvedTipsFile, NULL, tipPath);

    /* Open the file */
    if ((fp = fopen(resolvedTipsFile, "r")) == NULL)
       return 0;

    while( 1 ) {
        code = nextTFBlock(fp, header, &body, &blkLine, &currLine);
        if( code == TF_ERROR_EOF ) {
            fprintf(stderr,"nedit: Warning: unexpected EOF in calltips file.\n");
            break;
        }
        if( code == TF_EOF ) 
            break;
        
        switch (code) {
            case TF_BLOCK:
                /* Add the calltip to the global hash table.
                    For the moment I'm just using line numbers because I don't
                    want to have to deal with adding escape characters for
                    regex metacharacters that might appear in the string */
                nTipsAdded += addTag(header, resolvedTipsFile, langMode, "", 
                        blkLine, tipPath, index);
                free( body );
                break;
            case TF_INCLUDE:
                /* nextTFBlock returns a colon-separated list of tips files
                    in body */
                for(tipIncFile=strtok(body,":"); tipIncFile; 
                        tipIncFile=strtok(NULL,":")) {
                    /* fprintf(stderr,
                        "nedit: DEBUG: including tips file '%s'\n",
                        tipIncFile); */
                    nTipsAdded += loadTipsFile( tipIncFile, index, recLevel+1);
                }
                free( body );