/* src/vm/utf.c - utf functions

   Copyright (C) 1996-2005 R. Grafl, A. Krall, C. Kruegel, C. Oates,
   R. Obermaisser, M. Platter, M. Probst, S. Ring, E. Steiner,
   C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich, J. Wenninger,
   Institut f. Computersprachen - TU Wien

   This file is part of CACAO.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
   02111-1307, USA.

   Contact: cacao@complang.tuwien.ac.at

   Authors: Reinhard Grafl

   Changes: Mark Probst
            Andreas Krall
            Christian Thalinger

   $Id: utf8.c 2061 2005-03-23 11:10:33Z twisti $

*/


#include <string.h>

#include "mm/memory.h"
#include "vm/exceptions.h"
#include "vm/options.h"
#include "vm/statistics.h"
#include "vm/tables.h"
#include "vm/utf8.h"


hashtable utf_hash;                     /* hashtable for utf8-symbols         */


/* utf-symbols for pointer comparison of frequently used strings **************/

utf *utf_java_lang_Object;              /* java/lang/Object                   */

utf *utf_java_lang_Class;
utf *utf_java_lang_ClassLoader;
utf *utf_java_lang_Cloneable;
utf *utf_java_lang_SecurityManager;
utf *utf_java_lang_String;
utf *utf_java_lang_System;
utf *utf_java_io_Serializable;

utf *utf_java_lang_Throwable;
utf *utf_java_lang_VMThrowable;
utf *utf_java_lang_Exception;
utf *utf_java_lang_Error;
utf *utf_java_lang_OutOfMemoryError;

utf* utf_java_lang_Void;
utf* utf_java_lang_Boolean;
utf* utf_java_lang_Byte;
utf* utf_java_lang_Character;
utf* utf_java_lang_Short;
utf* utf_java_lang_Integer;
utf* utf_java_lang_Long;
utf* utf_java_lang_Float;
utf* utf_java_lang_Double;

utf *utf_java_util_Vector;

utf *utf_InnerClasses;                  /* InnerClasses                       */
utf *utf_ConstantValue;                 /* ConstantValue                      */
utf *utf_Code;                          /* Code                               */
utf *utf_Exceptions;                    /* Exceptions                         */
utf *utf_LineNumberTable;               /* LineNumberTable                    */
utf *utf_SourceFile;                    /* SourceFile                         */

utf *utf_init;                          /* <init>                             */
utf *utf_clinit;                        /* <clinit>                           */
utf *utf_finalize;                      /* finalize                           */

utf *utf_printStackTrace;
utf *utf_fillInStackTrace;
utf *utf_loadClass;

utf *utf_void__void;                    /* ()V                                */
utf *utf_boolean__void;                 /* (Z)V                               */
utf *utf_byte__void;                    /* (B)V                               */
utf *utf_char__void;                    /* (C)V                               */
utf *utf_short__void;                   /* (S)V                               */
utf *utf_int__void;                     /* (I)V                               */
utf *utf_long__void;                    /* (J)V                               */
utf *utf_float__void;                   /* (F)V                               */
utf *utf_double__void;                  /* (D)V                               */
utf *utf_void__java_lang_Throwable;     /* ()Ljava/lang/Throwable;            */
utf *utf_java_lang_String__void;        /* (Ljava/lang/String;)V              */
utf *utf_java_lang_String__java_lang_Class;
utf *utf_java_lang_Throwable__void;     /* (Ljava/lang/Throwable;)V           */

utf *array_packagename;


/* utf_init ********************************************************************

   Initializes the utf8 subsystem.

*******************************************************************************/

void utf8_init(void)
{
	/* create utf-symbols for pointer comparison of frequently used strings */

	utf_java_lang_Object           = utf_new_char("java/lang/Object");

	utf_java_lang_Class            = utf_new_char("java/lang/Class");
	utf_java_lang_ClassLoader      = utf_new_char("java/lang/ClassLoader");
	utf_java_lang_Cloneable        = utf_new_char("java/lang/Cloneable");
	utf_java_lang_SecurityManager  = utf_new_char("java/lang/SecurityManager");
	utf_java_lang_String           = utf_new_char("java/lang/String");
	utf_java_lang_System           = utf_new_char("java/lang/System");
	utf_java_io_Serializable       = utf_new_char("java/io/Serializable");

	utf_java_lang_Throwable        = utf_new_char("java/lang/Throwable");
	utf_java_lang_VMThrowable      = utf_new_char("java/lang/VMThrowable");
	utf_java_lang_Exception        = utf_new_char("java/lang/Exception");
	utf_java_lang_Error            = utf_new_char("java/lang/Error");
	utf_java_lang_OutOfMemoryError = utf_new_char("java/lang/OutOfMemoryError");

	utf_java_lang_Void             = utf_new_char("java/lang/Void");
	utf_java_lang_Boolean          = utf_new_char("java/lang/Boolean");
	utf_java_lang_Byte             = utf_new_char("java/lang/Byte");
	utf_java_lang_Character        = utf_new_char("java/lang/Character");
	utf_java_lang_Short            = utf_new_char("java/lang/Short");
	utf_java_lang_Integer          = utf_new_char("java/lang/Integer");
	utf_java_lang_Long             = utf_new_char("java/lang/Long");
	utf_java_lang_Float            = utf_new_char("java/lang/Float");
	utf_java_lang_Double           = utf_new_char("java/lang/Double");

	utf_java_util_Vector           = utf_new_char("java/util/Vector");

	utf_InnerClasses               = utf_new_char("InnerClasses");
	utf_ConstantValue              = utf_new_char("ConstantValue");
	utf_Code                       = utf_new_char("Code");
	utf_Exceptions	               = utf_new_char("Exceptions");
	utf_LineNumberTable            = utf_new_char("LineNumberTable");
	utf_SourceFile                 = utf_new_char("SourceFile");

	utf_init	                   = utf_new_char("<init>");
	utf_clinit	                   = utf_new_char("<clinit>");
	utf_finalize	               = utf_new_char("finalize");

	utf_printStackTrace            = utf_new_char("printStackTrace");
	utf_fillInStackTrace           = utf_new_char("fillInStackTrace");
	utf_loadClass                  = utf_new_char("loadClass");

	utf_void__void                 = utf_new_char("()V");
	utf_boolean__void              = utf_new_char("(Z)V");
	utf_byte__void                 = utf_new_char("(B)V");
	utf_char__void                 = utf_new_char("(C)V");
	utf_short__void                = utf_new_char("(S)V");
	utf_int__void                  = utf_new_char("(I)V");
	utf_long__void                 = utf_new_char("(J)V");
	utf_float__void                = utf_new_char("(F)V");
	utf_double__void               = utf_new_char("(D)V");
	utf_void__java_lang_Throwable  = utf_new_char("()Ljava/lang/Throwable;");
	utf_java_lang_String__void     = utf_new_char("(Ljava/lang/String;)V");

	utf_java_lang_String__java_lang_Class =
		utf_new_char("(Ljava/lang/String;)Ljava/lang/Class;");

	utf_java_lang_Throwable__void  = utf_new_char("(Ljava/lang/Throwable;)V");
	array_packagename              = utf_new_char("<the array package>");
}


/* utf_hashkey *****************************************************************

   The hashkey is computed from the utf-text by using up to 8
   characters.  For utf-symbols longer than 15 characters 3 characters
   are taken from the beginning and the end, 2 characters are taken
   from the middle.

*******************************************************************************/

#define nbs(val) ((u4) *(++text) << val) /* get next byte, left shift by val  */
#define fbs(val) ((u4) *(  text) << val) /* get first byte, left shift by val */

u4 utf_hashkey(const char *text, u4 length)
{
	const char *start_pos = text;       /* pointer to utf text                */
	u4 a;

	switch (length) {
	case 0: /* empty string */
		return 0;

	case 1: return fbs(0);
	case 2: return fbs(0) ^ nbs(3);
	case 3: return fbs(0) ^ nbs(3) ^ nbs(5);
	case 4: return fbs(0) ^ nbs(2) ^ nbs(4) ^ nbs(6);
	case 5: return fbs(0) ^ nbs(2) ^ nbs(3) ^ nbs(4) ^ nbs(6);
	case 6: return fbs(0) ^ nbs(1) ^ nbs(2) ^ nbs(3) ^ nbs(5) ^ nbs(6);
	case 7: return fbs(0) ^ nbs(1) ^ nbs(2) ^ nbs(3) ^ nbs(4) ^ nbs(5) ^ nbs(6);
	case 8: return fbs(0) ^ nbs(1) ^ nbs(2) ^ nbs(3) ^ nbs(4) ^ nbs(5) ^ nbs(6) ^ nbs(7);

	case 9:
		a = fbs(0);
		a ^= nbs(1);
		a ^= nbs(2);
		text++;
		return a ^ nbs(4) ^ nbs(5) ^ nbs(6) ^ nbs(7) ^ nbs(8);

	case 10:
		a = fbs(0);
		text++;
		a ^= nbs(2);
		a ^= nbs(3);
		a ^= nbs(4);
		text++;
		return a ^ nbs(6) ^ nbs(7) ^ nbs(8) ^ nbs(9);

	case 11:
		a = fbs(0);
		text++;
		a ^= nbs(2);
		a ^= nbs(3);
		a ^= nbs(4);
		text++;
		return a ^ nbs(6) ^ nbs(7) ^ nbs(8) ^ nbs(9) ^ nbs(10);

	case 12:
		a = fbs(0);
		text += 2;
		a ^= nbs(2);
		a ^= nbs(3);
		text++;
		a ^= nbs(5);
		a ^= nbs(6);
		a ^= nbs(7);
		text++;
		return a ^ nbs(9) ^ nbs(10);

	case 13:
		a = fbs(0);
		a ^= nbs(1);
		text++;
		a ^= nbs(3);
		a ^= nbs(4);
		text += 2;	
		a ^= nbs(7);
		a ^= nbs(8);
		text += 2;
		return a ^ nbs(9) ^ nbs(10);

	case 14:
		a = fbs(0);
		text += 2;	
		a ^= nbs(3);
		a ^= nbs(4);
		text += 2;	
		a ^= nbs(7);
		a ^= nbs(8);
		text += 2;
		return a ^ nbs(9) ^ nbs(10) ^ nbs(11);

	case 15:
		a = fbs(0);
		text += 2;	
		a ^= nbs(3);
		a ^= nbs(4);
		text += 2;	
		a ^= nbs(7);
		a ^= nbs(8);
		text += 2;
		return a ^ nbs(9) ^ nbs(10) ^ nbs(11);

	default:  /* 3 characters from beginning */
		a = fbs(0);
		text += 2;
		a ^= nbs(3);
		a ^= nbs(4);

		/* 2 characters from middle */
		text = start_pos + (length / 2);
		a ^= fbs(5);
		text += 2;
		a ^= nbs(6);	

		/* 3 characters from end */
		text = start_pos + length - 4;

		a ^= fbs(7);
		text++;

		return a ^ nbs(10) ^ nbs(11);
    }
}


/* utf_hashkey *****************************************************************

   Compute the hashkey of a unicode string.

*******************************************************************************/

u4 unicode_hashkey(u2 *text, u2 len)
{
	return utf_hashkey((char *) text, len);
}


/* utf_new *********************************************************************

   Creates a new utf-symbol, the text of the symbol is passed as a
   u1-array. The function searches the utf-hashtable for a utf-symbol
   with this text. On success the element returned, otherwise a new
   hashtable element is created.

   If the number of entries in the hashtable exceeds twice the size of
   the hashtable slots a reorganization of the hashtable is done and
   the utf symbols are copied to a new hashtable with doubled size.

*******************************************************************************/

utf *utf_new_intern(const char *text, u2 length);

utf *utf_new(const char *text, u2 length)
{
    utf *r;

#if defined(USE_THREADS) && defined(NATIVE_THREADS)
    tables_lock();
#endif

    r = utf_new_intern(text, length);

#if defined(USE_THREADS) && defined(NATIVE_THREADS)
    tables_unlock();
#endif

    return r;
}


utf *utf_new_intern(const char *text, u2 length)
{
	u4 key;                             /* hashkey computed from utf-text     */
	u4 slot;                            /* slot in hashtable                  */
	utf *u;                             /* hashtable element                  */
	u2 i;

#ifdef STATISTICS
	if (opt_stat)
		count_utf_new++;
#endif

	key  = utf_hashkey(text, length);
	slot = key & (utf_hash.size - 1);
	u    = utf_hash.ptr[slot];

	/* search external hash chain for utf-symbol */
	while (u) {
		if (u->blength == length) {

			/* compare text of hashtable elements */
			for (i = 0; i < length; i++)
				if (text[i] != u->text[i]) goto nomatch;
			
#ifdef STATISTICS
			if (opt_stat)
				count_utf_new_found++;
#endif

			/* symbol found in hashtable */
			return u;
		}
	nomatch:
		u = u->hashlink; /* next element in external chain */
	}

#ifdef STATISTICS
	if (opt_stat)
		count_utf_len += sizeof(utf) + length;
#endif

	/* location in hashtable found, create new utf element */
	u = NEW(utf);
	u->blength  = length;               /* length in bytes of utfstring       */
	u->hashlink = utf_hash.ptr[slot];   /* link in external hashchain         */
	u->text     = mem_alloc(length + 1);/* allocate memory for utf-text       */
	memcpy(u->text, text, length);      /* copy utf-text                      */
	u->text[length] = '\0';
	utf_hash.ptr[slot] = u;             /* insert symbol into table           */

	utf_hash.entries++;                 /* update number of entries           */

	if (utf_hash.entries > (utf_hash.size * 2)) {

        /* reorganization of hashtable, average length of 
           the external chains is approx. 2                */  

		u4 i;
		utf *u;
		hashtable newhash; /* the new hashtable */

		/* create new hashtable, double the size */
		init_hashtable(&newhash, utf_hash.size * 2);
		newhash.entries = utf_hash.entries;

#ifdef STATISTICS
		if (opt_stat)
			count_utf_len += sizeof(utf*) * utf_hash.size;
#endif

		/* transfer elements to new hashtable */
		for (i = 0; i < utf_hash.size; i++) {
			u = (utf *) utf_hash.ptr[i];
			while (u) {
				utf *nextu = u->hashlink;
				u4 slot = utf_hashkey(u->text, u->blength) & (newhash.size - 1);
						
				u->hashlink = (utf *) newhash.ptr[slot];
				newhash.ptr[slot] = u;

				/* follow link in external hash chain */
				u = nextu;
			}
		}
	
		/* dispose old table */
		MFREE(utf_hash.ptr, void*, utf_hash.size);
		utf_hash = newhash;
	}

	return u;
}


/* utf_new_u2 ******************************************************************

   Make utf symbol from u2 array, if isclassname is true '.' is
   replaced by '/'.

*******************************************************************************/

utf *utf_new_u2(u2 *unicode_pos, u4 unicode_length, bool isclassname)
{
	char *buffer;                   /* memory buffer for  unicode characters  */
	char *pos;                      /* pointer to current position in buffer  */
	u4 left;                        /* unicode characters left                */
	u4 buflength;                   /* utf length in bytes of the u2 array    */
	utf *result;                    /* resulting utf-string                   */
	int i;    	

	/* determine utf length in bytes and allocate memory */

	buflength = u2_utflength(unicode_pos, unicode_length); 
	buffer    = MNEW(char, buflength);
 
	left = buflength;
	pos  = buffer;

	for (i = 0; i++ < unicode_length; unicode_pos++) {
		/* next unicode character */
		u2 c = *unicode_pos;
		
		if ((c != 0) && (c < 0x80)) {
			/* 1 character */	
			left--;
	    	if ((int) left < 0) break;
			/* convert classname */
			if (isclassname && c == '.')
				*pos++ = '/';
			else
				*pos++ = (char) c;

		} else if (c < 0x800) { 	    
			/* 2 characters */				
	    	unsigned char high = c >> 6;
	    	unsigned char low  = c & 0x3F;
			left = left - 2;
	    	if ((int) left < 0) break;
	    	*pos++ = high | 0xC0; 
	    	*pos++ = low  | 0x80;	  

		} else {	 
	    	/* 3 characters */				
	    	char low  = c & 0x3f;
	    	char mid  = (c >> 6) & 0x3F;
	    	char high = c >> 12;
			left = left - 3;
	    	if ((int) left < 0) break;
	    	*pos++ = high | 0xE0; 
	    	*pos++ = mid  | 0x80;  
	    	*pos++ = low  | 0x80;   
		}
	}
	
	/* insert utf-string into symbol-table */
	result = utf_new(buffer,buflength);

	MFREE(buffer, char, buflength);

	return result;
}


/* utf_new_char ****************************************************************

   Creates a new utf symbol, the text for this symbol is passed as a
   c-string ( = char* ).

*******************************************************************************/

utf *utf_new_char(const char *text)
{
	return utf_new(text, strlen(text));
}


/* utf_new_char_classname ******************************************************

   Creates a new utf symbol, the text for this symbol is passed as a
   c-string ( = char* ) "." characters are going to be replaced by
   "/". Since the above function is used often, this is a separte
   function, instead of an if.

*******************************************************************************/

utf *utf_new_char_classname(const char *text)
{
	if (strchr(text, '.')) {
		char *txt = strdup(text);
		char *end = txt + strlen(txt);
		char *c;
		utf *tmpRes;

		for (c = txt; c < end; c++)
			if (*c == '.') *c = '/';

		tmpRes = utf_new(txt, strlen(txt));
		FREE(txt, 0);

		return tmpRes;

	} else
		return utf_new(text, strlen(text));
}


/* utf_nextu2 ******************************************************************

   Read the next unicode character from the utf string and increment
   the utf-string pointer accordingly.

*******************************************************************************/

u2 utf_nextu2(char **utf_ptr)
{
    /* uncompressed unicode character */
    u2 unicode_char = 0;
    /* current position in utf text */	
    unsigned char *utf = (unsigned char *) (*utf_ptr);
    /* bytes representing the unicode character */
    unsigned char ch1, ch2, ch3;
    /* number of bytes used to represent the unicode character */
    int len = 0;
	
    switch ((ch1 = utf[0]) >> 4) {
	default: /* 1 byte */
		(*utf_ptr)++;
		return (u2) ch1;
	case 0xC: 
	case 0xD: /* 2 bytes */
		if (((ch2 = utf[1]) & 0xC0) == 0x80) {
			unsigned char high = ch1 & 0x1F;
			unsigned char low  = ch2 & 0x3F;
			unicode_char = (high << 6) + low;
			len = 2;
		}
		break;

	case 0xE: /* 2 or 3 bytes */
		if (((ch2 = utf[1]) & 0xC0) == 0x80) {
			if (((ch3 = utf[2]) & 0xC0) == 0x80) {
				unsigned char low  = ch3 & 0x3f;
				unsigned char mid  = ch2 & 0x3f;
				unsigned char high = ch1 & 0x0f;
				unicode_char = (((high << 6) + mid) << 6) + low;
				len = 3;
			} else
				len = 2;					   
		}
		break;
    }

    /* update position in utf-text */
    *utf_ptr = (char *) (utf + len);

    return unicode_char;
}


/* utf_strlen ******************************************************************

   Determine number of unicode characters in the utf string.

*******************************************************************************/

u4 utf_strlen(utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */
	u4 len = 0;                         /* number of unicode characters       */

	if (!u) {
		*exceptionptr = new_nullpointerexception();
		return 0;
	}

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) {
		len++;
		/* next unicode character */
		utf_nextu2(&utf_ptr);
	}

	if (utf_ptr != endpos)
		/* string ended abruptly */
		throw_cacao_exception_exit(string_java_lang_InternalError,
								   "Illegal utf8 string");

	return len;
}


/* u2_utflength ****************************************************************

   Returns the utf length in bytes of a u2 array.

*******************************************************************************/

u4 u2_utflength(u2 *text, u4 u2_length)
{
	u4 result_len = 0;                  /* utf length in bytes                */
	u2 ch;                              /* current unicode character          */
	u4 len;
	
	for (len = 0; len < u2_length; len++) {
		/* next unicode character */
		ch = *text++;
	  
		/* determine bytes required to store unicode character as utf */
		if (ch && (ch < 0x80)) 
			result_len++;
		else if (ch < 0x800)
			result_len += 2;	
		else 
			result_len += 3;	
	}

    return result_len;
}


/* utf_display *****************************************************************

   Write utf symbol to stdout (for debugging purposes).

*******************************************************************************/

void utf_display(utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */

	if (!u) {
		printf("NULL");
		fflush(stdout);
		return;
	}

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) {
		/* read next unicode character */                
		u2 c = utf_nextu2(&utf_ptr);
		if (c >= 32 && c <= 127) printf("%c", c);
		else printf("?");
	}

	fflush(stdout);
}


/* utf_display_classname *******************************************************

   Write utf symbol to stdout with `/' converted to `.' (for debugging
   purposes).

*******************************************************************************/

void utf_display_classname(utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */

	if (!u) {
		printf("NULL");
		fflush(stdout);
		return;
	}

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) {
		/* read next unicode character */                
		u2 c = utf_nextu2(&utf_ptr);
		if (c == '/') c = '.';
		if (c >= 32 && c <= 127) printf("%c", c);
		else printf("?");
	}

	fflush(stdout);
}


/* utf_sprint ******************************************************************
	
   Write utf symbol into c-string (for debugging purposes).

*******************************************************************************/

void utf_sprint(char *buffer, utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */
	u2 pos = 0;                         /* position in c-string               */

	if (!u) {
		memcpy(buffer, "NULL", 5);      /* 4 chars + terminating \0           */
		return;
	}

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) 
		/* copy next unicode character */       
		buffer[pos++] = utf_nextu2(&utf_ptr);

	/* terminate string */
	buffer[pos] = '\0';
}


/* utf_sprint_classname ********************************************************
	
   Write utf symbol into c-string with `/' converted to `.' (for debugging
   purposes).

*******************************************************************************/

void utf_sprint_classname(char *buffer, utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */
	u2 pos = 0;                         /* position in c-string               */

	if (!u) {
		memcpy(buffer, "NULL", 5);      /* 4 chars + terminating \0           */
		return;
	}

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) {
		/* copy next unicode character */       
		u2 c = utf_nextu2(&utf_ptr);
		if (c == '/') c = '.';
		buffer[pos++] = c;
	}

	/* terminate string */
	buffer[pos] = '\0';
}


/* utf_fprint ******************************************************************
	
   Write utf symbol into file.

*******************************************************************************/

void utf_fprint(FILE *file, utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */

	if (!u)
		return;

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) { 
		/* read next unicode character */                
		u2 c = utf_nextu2(&utf_ptr);				

		if (c >= 32 && c <= 127) fprintf(file, "%c", c);
		else fprintf(file, "?");
	}
}


/* utf_fprint_classname ********************************************************
	
   Write utf symbol into file with `/' converted to `.'.

*******************************************************************************/

void utf_fprint_classname(FILE *file, utf *u)
{
	char *endpos;                       /* points behind utf string           */
	char *utf_ptr;                      /* current position in utf text       */

    if (!u)
		return;

	endpos = utf_end(u);
	utf_ptr = u->text;

	while (utf_ptr < endpos) { 
		/* read next unicode character */                
		u2 c = utf_nextu2(&utf_ptr);				
		if (c == '/') c = '.';

		if (c >= 32 && c <= 127) fprintf(file, "%c", c);
		else fprintf(file, "?");
	}
}


/* is_valid_utf ****************************************************************

   Return true if the given string is a valid UTF-8 string.

   utf_ptr...points to first character
   end_pos...points after last character

*******************************************************************************/

static unsigned long min_codepoint[6] = {0,1L<<7,1L<<11,1L<<16,1L<<21,1L<<26};

bool is_valid_utf(char *utf_ptr, char *end_pos)
{
	int bytes;
	int len,i;
	char c;
	unsigned long v;

	if (end_pos < utf_ptr) return false;
	bytes = end_pos - utf_ptr;
	while (bytes--) {
		c = *utf_ptr++;

		if (!c) return false;                     /* 0x00 is not allowed */
		if ((c & 0x80) == 0) continue;            /* ASCII */

		if      ((c & 0xe0) == 0xc0) len = 1;     /* 110x xxxx */
		else if ((c & 0xf0) == 0xe0) len = 2;     /* 1110 xxxx */
		else if ((c & 0xf8) == 0xf0) len = 3;     /* 1111 0xxx */
		else if ((c & 0xfc) == 0xf8) len = 4;     /* 1111 10xx */
		else if ((c & 0xfe) == 0xfc) len = 5;     /* 1111 110x */
		else return false;                        /* invalid leading byte */

		if (len > 2) return false;                /* Java limitation */

		v = (unsigned long)c & (0x3f >> len);
		
		if ((bytes -= len) < 0) return false;     /* missing bytes */

		for (i = len; i--; ) {
			c = *utf_ptr++;
			if ((c & 0xc0) != 0x80)               /* 10xx xxxx */
				return false;
			v = (v << 6) | (c & 0x3f);
		}

		if (v == 0) {
			if (len != 1) return false;           /* Java special */

		} else {
			/* Sun Java seems to allow overlong UTF-8 encodings */
			
			if (v < min_codepoint[len]) { /* overlong UTF-8 */
				if (!opt_liberalutf)
					fprintf(stderr,"WARNING: Overlong UTF-8 sequence found.\n");
				/* XXX change this to panic? */
			}
		}

		/* surrogates in UTF-8 seem to be allowed in Java classfiles */
		/* if (v >= 0xd800 && v <= 0xdfff) return false; */ /* surrogates */

		/* even these seem to be allowed */
		/* if (v == 0xfffe || v == 0xffff) return false; */ /* invalid codepoints */
	}

	return true;
}


/* is_valid_name ***************************************************************

   Return true if the given string may be used as a class/field/method
   name. (Currently this only disallows empty strings and control
   characters.)

   NOTE: The string is assumed to have passed is_valid_utf!

   utf_ptr...points to first character
   end_pos...points after last character

*******************************************************************************/

bool is_valid_name(char *utf_ptr, char *end_pos)
{
	if (end_pos <= utf_ptr) return false; /* disallow empty names */

	while (utf_ptr < end_pos) {
		unsigned char c = *utf_ptr++;

		if (c < 0x20) return false; /* disallow control characters */
		if (c == 0xc0 && (unsigned char) *utf_ptr == 0x80)  /* disallow zero */
			return false;
	}

	return true;
}

bool is_valid_name_utf(utf *u)
{
	return is_valid_name(u->text,utf_end(u));
}


/* utf_show ********************************************************************

   Writes the utf symbols in the utfhash to stdout and displays the
   number of external hash chains grouped according to the chainlength
   (for debugging purposes).

*******************************************************************************/

void utf_show(void)
{

#define CHAIN_LIMIT 20               /* limit for seperated enumeration */

	u4 chain_count[CHAIN_LIMIT]; /* numbers of chains */
	u4 max_chainlength = 0;      /* maximum length of the chains */
	u4 sum_chainlength = 0;      /* sum of the chainlengths */
	u4 beyond_limit = 0;         /* number of utf-symbols in chains with length>=CHAIN_LIMIT-1 */
	u4 i;

	printf ("UTF-HASH:\n");

	/* show element of utf-hashtable */
	for (i=0; i<utf_hash.size; i++) {
		utf *u = utf_hash.ptr[i];
		if (u) {
			printf ("SLOT %d: ", (int) i);
			while (u) {
				printf ("'");
				utf_display (u);
				printf ("' ");
				u = u->hashlink;
			}	
			printf ("\n");
		}
		
	}

	printf ("UTF-HASH: %d slots for %d entries\n", 
			(int) utf_hash.size, (int) utf_hash.entries );


	if (utf_hash.entries == 0)
		return;

	printf("chains:\n  chainlength    number of chains    %% of utfstrings\n");

	for (i=0;i<CHAIN_LIMIT;i++)
		chain_count[i]=0;

	/* count numbers of hashchains according to their length */
	for (i=0; i<utf_hash.size; i++) {
		  
		utf *u = (utf*) utf_hash.ptr[i];
		u4 chain_length = 0;

		/* determine chainlength */
		while (u) {
			u = u->hashlink;
			chain_length++;
		}

		/* update sum of all chainlengths */
		sum_chainlength+=chain_length;

		/* determine the maximum length of the chains */
		if (chain_length>max_chainlength)
			max_chainlength = chain_length;

		/* update number of utf-symbols in chains with length>=CHAIN_LIMIT-1 */
		if (chain_length>=CHAIN_LIMIT) {
			beyond_limit+=chain_length;
			chain_length=CHAIN_LIMIT-1;
		}

		/* update number of hashchains of current length */
		chain_count[chain_length]++;
	}

	/* display results */  
	for (i=1;i<CHAIN_LIMIT-1;i++) 
		printf("       %2d %17d %18.2f%%\n",i,chain_count[i],(((float) chain_count[i]*i*100)/utf_hash.entries));
	  
	printf("     >=%2d %17d %18.2f%%\n",CHAIN_LIMIT-1,chain_count[CHAIN_LIMIT-1],((float) beyond_limit*100)/utf_hash.entries);


	printf("max. chainlength:%5d\n",max_chainlength);

	/* avg. chainlength = sum of chainlengths / number of chains */
	printf("avg. chainlength:%5.2f\n",(float) sum_chainlength / (utf_hash.size-chain_count[0]));
}


/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 */