mjc2wsl.java

   1 import java.io.*;
   2 import java.util.*;
   3
   4 /**
   5  * This program converts file from compiled MicroJava bytecode (a subset used
   6  * in Compiler Construction courses by H. Moessenboeck, not "Java ME")
   7  * to WSL language which is a part of the FermaT Transformation system.
   8  *
   9  * @author Doni Pracner, http://perun.dmi.rs/pracner http://quemaster.com
  10  */
  11 public class mjc2wsl{
  12         public static String versionN = "0.1";
  13
  14         //regular comments from the original file
  15         //OC when original code is inserted in the file, next to the translations
  16         //SPEC special messages from the translator
  17         //ERR error messages from the transnlator
  18         public static final char C_REG = ' ', C_OC = '#', C_SPEC = '&', C_ERR = '!';
  19
  20
  21                 /** instruction code */
  22                 public static final int
  23                 load        =  1,
  24                 load_0      =  2,
  25                 load_1      =  3,
  26                 load_2      =  4,
  27                 load_3      =  5,
  28                 store       =  6,
  29                 store_n     =  7,
  30                 getstatic   = 11,
  31                 putstatic   = 12,
  32                 getfield    = 13,
  33                 putfield    = 14,
  34                 const_0     = 15,
  35                 const_1     = 16,
  36                 const_2     = 17,
  37                 const_3     = 18,
  38                 const_4     = 19,
  39                 const_5     = 20,
  40                 const_m1    = 21,
  41                 const_      = 22,
  42                 add         = 23,
  43                 sub         = 24,
  44                 mul         = 25,
  45                 div         = 26,
  46                 rem         = 27,
  47                 neg         = 28,
  48                 shl         = 29,
  49                 shr         = 30,
  50                 inc         = 31,
  51                 new_        = 32,
  52                 newarray    = 33,
  53                 aload       = 34,
  54                 astore      = 35,
  55                 baload      = 36,
  56                 bastore     = 37,
  57                 arraylength = 38,
  58                 pop         = 39,
  59                 dup         = 40,
  60                 dup2        = 41,
  61                 jmp         = 42,
  62                 jcc         = 43,
  63                 call        = 49,
  64                 return_     = 50,
  65                 enter       = 51,
  66                 exit        = 52,
  67                 read        = 53,
  68                 print       = 54,
  69                 bread       = 55,
  70                 bprint      = 56,
  71                 trap            = 57;
  72
  73         public String getStandardStart(){
  74                 String ret ="C:\" This file automatically converted from microjava bytecode\";\n"
  75                         +"C:\" with mjc2wsl v "+versionN+"\";\n";
  76                 ret +="VAR < tempa := 0, tempb := 0, tempres :=0,\n"+
  77                 "       stack := < >, t_e_m_p := 0 > :\n";
  78
  79                 return ret;
  80         }
  81
  82         public String getStandardEnd(){
  83                 return "SKIP\nENDVAR";
  84         }
  85
  86         private InputStream mainIn;
  87         private PrintStream out = System.out;
  88
  89         private void pr(int i){
  90                         out.print(i);
  91         }
  92
  93         private void pr(char i){
  94                         out.print(i);
  95         }
  96
  97         private void pr(String i){
  98                         out.print(i);
  99         }
 100
 101         private void prl(String i){
 102                         out.println(i);
 103         }
 104
 105         private int get() {
 106                         int res = -1;
 107                         try{
 108                                         res = mainIn.read();
 109                                         if (res>=0) res = res<<24>>>24;
 110                         }catch (IOException ex){
 111                                 ex.printStackTrace();
 112                         }
 113                         return res;
 114         }
 115
 116         private int get2() {
 117                 return (get()*256 + get())<<16>>16;
 118         }
 119
 120         private int get4() {
 121                 return (get2()<<16) + (get2()<<16>>>16);
 122         }
 123
 124         /**
 125          * Creates a WSL comment with care to quote chars.
 126          */
 127         public static String createComment(String str){
 128                 return createComment(str, C_REG);
 129         }
 130
 131         /**
 132          * Creates a WSL comment with care to quote chars, of the
 133          * given type.  Types are given as char constants. They can be
 134          * default comments, comments that contain the original code
 135          * in them, or additional comments regarding the translation
 136          * process.
 137          */
 138         public static String createComment(String str, char type){
 139                 return "C:\""+type+str.replace("\"", "''")+"\";";
 140         }
 141
 142         private String cmdToStack(int i){
 143                         return "stack := <"+i+" > ++ stack;";
 144         }
 145
 146         private String cmdToStack(String i){
 147                         return "stack := <"+i+" > ++ stack;";
 148         }
 149
 150         private String cmdFromStack(String st){
 151                         return st+" := HEAD(stack); stack := TAIL(stack);";
 152         }
 153
 154         private String getTopTwo(){
 155                  return cmdFromStack("tempa")+cmdFromStack("tempb");
 156         }
 157
 158         private String getTop(){
 159                  return cmdFromStack("tempa");
 160         }
 161
 162         public void convertStream(InputStream ins){
 163                 mainIn = ins;
 164                 //skip start TODO make better
 165                 for (int i=0;i<14;i++) get();
 166
 167                 prl(getStandardStart());
 168
 169                 int op = get();
 170                 while (op>=0){
 171                                 switch(op) {
 172                                         case load: {
 173                                                 prl(cmdToStack(get()));
 174                                                 break;
 175                                         }
 176                                         case load_0: {
 177                                                 prl(cmdToStack(0));
 178                                                 break;
 179                                         }
 180                                         case const_: {
 181                                                 prl(cmdToStack(get4()));
 182                                                 break;
 183                                         }
 184                                         case const_0: {
 185                                                 prl(cmdToStack(0));
 186                                                 break;
 187                                         }
 188                                         case const_1: {
 189                                                 prl(cmdToStack(1));
 190                                                 break;
 191                                         }
 192                                         case const_2: {
 193                                                 prl(cmdToStack(2));
 194                                                 break;
 195                                         }
 196                                         case const_3: {
 197                                                 prl(cmdToStack(3));
 198                                                 break;
 199                                         }
 200                                         case const_4: {
 201                                                 prl(cmdToStack(4));
 202                                                 break;
 203                                         }
 204
 205                                         case const_5: {
 206                                                 prl(cmdToStack(5));
 207                                                 break;
 208                                         }
 209
 210                                         case div: {
 211                                                 prl(getTopTwo());
 212                                                 prl("tempr = tempa / tempb;");
 213                                                 prl(cmdToStack("tempr"));
 214                                                 break;
 215                                         }
 216
 217                                         case enter: {
 218                                                 prl(createComment("enter"));
 219                                                 get();get();
 220                                                 break;
 221                                         }
 222
 223                                         //the prints
 224                                         case bprint: {
 225                                                                         prl(getTop());
 226                                                                         prl("PRINT(tempa);");
 227                                                                         break;
 228                                         }
 229                                         case print: {
 230                                                                         //TODO need to make it a char
 231                                                                         prl(getTop());
 232                                                                         prl("PRINT(tempa);");
 233                                                                         break;
 234                                         }
 235
 236                                         default: prl(createComment("unknown op error: "+op,C_ERR)); break;
 237                                 }
 238                                 op = get();
 239                 }
 240                 prl(getStandardEnd());
 241
 242         }
 243
 244         public void convertFile(File f){
 245                         try{
 246                                         convertStream(new FileInputStream(f));
 247                         }catch (Exception ex){
 248                                         ex.printStackTrace();
 249                         }
 250         }
 251
 252         public void run(String[] args){
 253                 if (args.length == 0){
 254                         System.out.println("MicroJava bytecode to WSL converter. v "+versionN+", by Doni Pracner");
 255                         System.out.println("usage:\n\t mjc2wsl  filename");
 256                 }else{
 257                         File f = new File(args[0]);
 258                         if (f.exists()){
 259                                 Calendar now = Calendar.getInstance();
 260                                 convertFile(f);
 261                                 long mili = Calendar.getInstance().getTimeInMillis() - now.getTimeInMillis();
 262                                 System.out.println("conversion time:"+mili+" ms");
 263                         }else
 264                                 System.out.println("file does not exist");
 265                 }
 266         }
 267
 268         public static void main(String[] args){
 269                         new mjc2wsl().run(args);
 270         }
 271 }