src/mjc2wsl.java

   1 import java.io.*;
   2 import java.util.*;
   3
   4 /**
   5  * This program converts file from compiled MicroJava bytecode to WSL language
   6  * which is a part of the FermaT Transformation system. MicroJava is a subset
   7  * used in Compiler Construction courses by Hanspeter Moessenboeck, not
   8  * "Java ME".
   9  *
  10  * @author Doni Pracner, http://perun.dmi.rs/pracner http://quemaster.com
  11  */
  12 public class mjc2wsl{
  13         public static String versionN = "0.1.2";
  14
  15         /** Constant used for marking a regular comment from the original file */
  16         public static final char C_REG = ' ';
  17         /**
  18          * Constant used for marking when original code is inserted in the file,
  19          * next to the translations
  20          */
  21         public static final char C_OC = '#';
  22         /** Constant used for marking special messages from the translator */
  23         public static final char C_SPEC = '&';
  24         /** Constant used for marking error messages from the translator */
  25         public static final char C_ERR = '!';
  26
  27         /** instruction code in MicroJava bytecode. */
  28         public static final int
  29                 load        =  1,
  30                 load_0      =  2,
  31                 load_1      =  3,
  32                 load_2      =  4,
  33                 load_3      =  5,
  34                 store       =  6,
  35                 store_0     =  7,
  36                 store_1     =  8,
  37                 store_2     =  9,
  38                 store_3     = 10,
  39                 getstatic   = 11,
  40                 putstatic   = 12,
  41                 getfield    = 13,
  42                 putfield    = 14,
  43                 const_0     = 15,
  44                 const_1     = 16,
  45                 const_2     = 17,
  46                 const_3     = 18,
  47                 const_4     = 19,
  48                 const_5     = 20,
  49                 const_m1    = 21,
  50                 const_      = 22,
  51                 add         = 23,
  52                 sub         = 24,
  53                 mul         = 25,
  54                 div         = 26,
  55                 rem         = 27,
  56                 neg         = 28,
  57                 shl         = 29,
  58                 shr         = 30,
  59                 inc         = 31,
  60                 new_        = 32,
  61                 newarray    = 33,
  62                 aload       = 34,
  63                 astore      = 35,
  64                 baload      = 36,
  65                 bastore     = 37,
  66                 arraylength = 38,
  67                 pop         = 39,
  68                 dup         = 40,
  69                 dup2        = 41,
  70                 jmp         = 42,
  71                 jeq         = 43,
  72                 jne         = 44,
  73                 jlt         = 45,
  74                 jle         = 46,
  75                 jgt         = 47,
  76                 jge         = 48,
  77                 call        = 49,
  78                 return_     = 50,
  79                 enter       = 51,
  80                 exit        = 52,
  81                 read        = 53,
  82                 print       = 54,
  83                 bread       = 55,
  84                 bprint      = 56,
  85                 trap            = 57;
  86
  87         public String getStandardStart(){
  88                 StringBuilder ret = new StringBuilder(
  89                         "C:\" This file automatically converted from microjava bytecode\";\n"
  90                         +"C:\" with mjc2wsl v "+versionN+"\";\n");
  91
  92                 ret.append("VAR < tempa := 0, tempb := 0, tempres :=0,\n");
  93                 for (int i = 0; i <= 3; i++)
  94                         ret.append("loc" + i + " := 0, ");
  95                 ret.append("\n  estack := < >, t_e_m_p := 0 > :");
  96
  97                 return ret.toString();
  98         }
  99
 100         public String getStandardEnd(){
 101                 return "SKIP\nENDVAR";
 102         }
 103
 104         private boolean originalInComments = false;
 105
 106         private InputStream mainIn;
 107         private PrintWriter out = null;
 108         private int counter = -1;
 109
 110         private void pr(int i){
 111                         out.print(i);
 112         }
 113
 114         private void pr(char i){
 115                         out.print(i);
 116         }
 117
 118         private void pr(String i){
 119                         out.print(i);
 120         }
 121
 122         private void prl(String i){
 123                         out.println(i);
 124         }
 125
 126         private int get() {
 127                 int res = -1;
 128                 try {
 129                         res = mainIn.read();
 130                         if (res >= 0)
 131                                 res = res << 24 >>> 24;
 132                 } catch (IOException ex) {
 133                         ex.printStackTrace();
 134                 }
 135                 counter++;
 136                 return res;
 137         }
 138
 139         private int get2() {
 140                 return (get() * 256 + get()) << 16 >> 16;
 141         }
 142
 143         private int get4() {
 144                 return (get2() << 16) + (get2() << 16 >>> 16);
 145         }
 146
 147         private String loc(int i){
 148                 return "loc" + i;
 149         }
 150
 151         /**
 152          * Creates a WSL comment with care to quote chars.
 153          */
 154         public static String createComment(String str){
 155                 return createComment(str, C_REG);
 156         }
 157
 158         /**
 159          * Creates a WSL comment with care to quote chars, of the
 160          * given type.  Types are given as char constants. They can be
 161          * default comments, comments that contain the original code
 162          * in them, or additional comments regarding the translation
 163          * process.
 164          */
 165         public static String createComment(String str, char type) {
 166                 return "C:\"" + type + str.replace("\"", "''") + "\";";
 167         }
 168
 169         private String cmdToEStack(int i) {
 170                 return "estack := <" + i + " > ++ estack;";
 171         }
 172
 173         private String cmdToEStack(String i) {
 174                 return "estack := <" + i + " > ++ estack;";
 175         }
 176
 177         private String cmdFromEStack(String st) {
 178                 return st + " := HEAD(estack); estack := TAIL(estack);";
 179         }
 180
 181         private String getTopTwo(){
 182                 return cmdFromEStack("tempa") + "\n" + cmdFromEStack("tempb");
 183         }
 184
 185         private String getTop() {
 186                 return cmdFromEStack("tempa");
 187         }
 188
 189         private String getRelationFor(int opcode) throws Exception {
 190                         switch (opcode) {
 191                                         case jeq: return "=";
 192                                         case jne: return "<>";
 193                                         case jlt: return "<";
 194                                         case jle: return "<=";
 195                                         case jgt: return ">";
 196                                         case jge: return ">=";
 197                         }
 198                         throw new Exception("Wrong opcode for a relation");
 199         }
 200
 201         public void convertStream(InputStream ins) throws Exception{
 202                 mainIn = ins;
 203                 //skip start TODO make better
 204                 for (int i = 0; i < 14; i++)
 205                         get();
 206
 207                 prl(getStandardStart());
 208                 prl("SKIP;\n ACTIONS A_S_start:\n A_S_start == CALL a14 END");
 209                 int op = get();
 210                 while (op >= 0) {
 211                         if (originalInComments)
 212                                 prl(createComment("" + op, C_OC));
 213                         prl("a" + counter + " == ");
 214                         switch (op) {
 215                         case load: {
 216                                 prl(cmdToEStack(loc(get())));
 217                                 break;
 218                         }
 219                         case load_0:
 220                         case load_1:
 221                         case load_2:
 222                         case load_3: {
 223                                 prl(cmdToEStack(loc(op - load_0)));
 224                                 break;
 225                         }
 226                         case store: {
 227                                 prl(cmdFromEStack(loc(get())));
 228                                 break;
 229                         }
 230                         case store_0:
 231                         case store_1:
 232                         case store_2:
 233                         case store_3: {
 234                                 prl(cmdFromEStack(loc(op - store_0)));
 235                                 break;
 236                         }
 237                         case const_: {
 238                                 prl(cmdToEStack(get4()));
 239                                 break;
 240                         }
 241
 242                         case const_0:
 243                         case const_1:
 244                         case const_2:
 245                         case const_3:
 246                         case const_4:
 247                         case const_5: {
 248                                 prl(cmdToEStack(op - const_0));
 249                                 break;
 250                         }
 251
 252                         case jmp: {
 253                                 prl("CALL a" + (counter + get2()) + ";");
 254                                 break;
 255                         }
 256
 257                         case jeq:
 258                         case jne:
 259                         case jlt:
 260                         case jle:
 261                         case jgt:
 262                         case jge: {
 263                                 prl(getTopTwo());
 264                                 prl("IF tempb "+ getRelationFor(op)
 265                                                 +" tempa THEN CALL a" + (counter + get2())
 266                                                 + " FI;");
 267                                 break;
 268                         }
 269
 270                         case add: {
 271                                 prl(getTopTwo());
 272                                 prl("tempres := tempb + tempa;");
 273                                 prl(cmdToEStack("tempres"));
 274                                 break;
 275                         }
 276                         case sub: {
 277                                 prl(getTopTwo());
 278                                 prl("tempres := tempb - tempa;");
 279                                 prl(cmdToEStack("tempres"));
 280                                 break;
 281                         }
 282                         case mul: {
 283                                 prl(getTopTwo());
 284                                 prl("tempres := tempb * tempa;");
 285                                 prl(cmdToEStack("tempres"));
 286                                 break;
 287                         }
 288                         case div: {
 289                                 prl(getTopTwo());
 290                                 prl("IF tempa = 0 THEN ERROR(\"division by zero\") FI;");
 291                                 prl("tempres := tempb DIV tempa;");
 292                                 prl(cmdToEStack("tempres"));
 293                                 break;
 294                         }
 295                         case rem: {
 296                                 prl(getTopTwo());
 297                                 prl("IF tempa = 0 THEN ERROR(\"division by zero\") FI;");
 298                                 prl("tempres := tempb MOD tempa;");
 299                                 prl(cmdToEStack("tempres"));
 300                                 break;
 301                         }
 302
 303                         case enter: {
 304                                 prl(createComment("enter not fully procesed yet"));
 305                                 get();
 306                                 get();
 307                                 break;
 308                         }
 309                         case return_: {
 310                                 prl(createComment("return not fully procesed yet"));
 311                                 break;
 312                         }
 313                         case exit: {
 314                                 prl(createComment("exit not fully procesed yet"));
 315                                 break;
 316                         }
 317
 318                         // the prints
 319                         case bprint: {
 320                                 prl(getTopTwo());
 321                                 prl("PRINT(tempb);");
 322                                 break;
 323                         }
 324                         case print: {
 325                                 // TODO need to make it a char
 326                                 prl(getTopTwo());
 327                                 prl("PRINT(tempb);");
 328                                 break;
 329                         }
 330                         default:
 331                                 prl(createComment("unknown op error: " + op, C_ERR));
 332                                 break;
 333                         }
 334
 335                         op = get();
 336                         if (op >= 0)
 337                                 prl("CALL a" + counter + " END");
 338                 }
 339                 prl("CALL Z;\nSKIP END\nENDACTIONS;\n");
 340                 prl(getStandardEnd());
 341
 342         }
 343
 344         public void convertFile(File f) {
 345                 try {
 346                         convertStream(new FileInputStream(f));
 347                 } catch (Exception ex) {
 348                         ex.printStackTrace();
 349                 }
 350         }
 351
 352         public void printHelp() {
 353                 System.out.println("MicroJava bytecode to WSL converter. v " + versionN
 354                                 + ", by Doni Pracner");
 355                 System.out.println("usage:\n\t {options} mjc2wsl  filename [outfile]");
 356                 System.out.println("options:\n\t--screen print output to screen");
 357                 System.out.println("\t-o --oc include original code in comments");
 358         }
 359
 360         public String makeDefaultOutName(String inname){
 361                 String rez = inname;
 362                 if (inname.endsWith(".obj"))
 363                         rez = rez.substring(0, rez.length() - 4);
 364                 return rez + ".wsl";
 365         }
 366
 367         public void run(String[] args) {
 368                 if (args.length == 0) {
 369                         printHelp();
 370                 } else {
 371                         int i = 0;
 372                         while (i < args.length && args[i].charAt(0) == '-') {
 373                                 if (args[i].compareTo("-h") == 0) {
 374                                         printHelp();
 375                                         return;
 376                                 } else if (args[i].compareTo("-o") == 0
 377                                                 || args[i].startsWith("--oc")) {
 378                                         if (args[i].length() == 2)
 379                                                 originalInComments = true;
 380                                         else if (args[i].length() == 5)
 381                                                 originalInComments = args[i].charAt(4) == '+';
 382                                         else
 383                                                 originalInComments = true;
 384                                 } else if (args[i].startsWith("--screen")) {
 385                                         out = new PrintWriter(System.out);
 386                                 }
 387                                 i++;
 388                         }
 389
 390                         if (i >= args.length) {
 391                                 System.out.println("no filename supplied");
 392                                 System.exit(2);
 393                         }
 394                         File f = new File(args[i]);
 395
 396                         if (i + 1 < args.length) {
 397                                 try {
 398                                         out = new PrintWriter(args[i + 1]);
 399                                 } catch (Exception e) {
 400                                         System.err.println("error in opening out file:");
 401                                         e.printStackTrace();
 402                                 }
 403                         }
 404                         if (out == null) {
 405                                 // if not set to screen, or a file, make a default filename
 406                                 try {
 407                                         out = new PrintWriter(makeDefaultOutName(args[i]));
 408                                 } catch (Exception e) {
 409                                         System.err.println("error in opening out file:");
 410                                         e.printStackTrace();
 411                                 }
 412                         }
 413                         if (f.exists()) {
 414                                 Calendar now = Calendar.getInstance();
 415                                 convertFile(f);
 416                                 long mili = Calendar.getInstance().getTimeInMillis()
 417                                                 - now.getTimeInMillis();
 418                                 System.out.println("conversion time:" + mili + " ms");
 419                                 out.close();
 420                         } else
 421                                 System.out.println("file does not exist");
 422                 }
 423         }
 424
 425         public static void main(String[] args) {
 426                 new mjc2wsl().run(args);
 427         }
 428 }