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         public static final int M_ERR = 2, M_WAR = 1;
  16
  17         private int printLevel = 0;
  18
  19         private int[] messageCounters = new int[M_ERR+1];
  20
  21         private void message(String mes, int level){
  22                         if (level>printLevel)
  23                                         System.out.println(mes);
  24                         messageCounters[level]++;
  25         }
  26
  27         private void printMessageCounters(){
  28                         printMessageCounters(System.out);
  29         }
  30
  31         private void printMessageCounters(PrintStream out){
  32                         out.println("total errors:"+messageCounters[M_ERR]+" warnings:"+messageCounters[M_WAR]);
  33         }
  34
  35         /** Constant used for marking a regular comment from the original file */
  36         public static final char C_REG = ' ';
  37         /**
  38          * Constant used for marking when original code is inserted in the file,
  39          * next to the translations
  40          */
  41         public static final char C_OC = '#';
  42         /** Constant used for marking special messages from the translator */
  43         public static final char C_SPEC = '&';
  44         /** Constant used for marking error messages from the translator */
  45         public static final char C_ERR = '!';
  46
  47         /** instruction code in MicroJava bytecode. */
  48         public static final int
  49                 load        =  1,
  50                 load_0      =  2,
  51                 load_1      =  3,
  52                 load_2      =  4,
  53                 load_3      =  5,
  54                 store       =  6,
  55                 store_0     =  7,
  56                 store_1     =  8,
  57                 store_2     =  9,
  58                 store_3     = 10,
  59                 getstatic   = 11,
  60                 putstatic   = 12,
  61                 getfield    = 13,
  62                 putfield    = 14,
  63                 const_0     = 15,
  64                 const_1     = 16,
  65                 const_2     = 17,
  66                 const_3     = 18,
  67                 const_4     = 19,
  68                 const_5     = 20,
  69                 const_m1    = 21,
  70                 const_      = 22,
  71                 add         = 23,
  72                 sub         = 24,
  73                 mul         = 25,
  74                 div         = 26,
  75                 rem         = 27,
  76                 neg         = 28,
  77                 shl         = 29,
  78                 shr         = 30,
  79                 inc         = 31,
  80                 new_        = 32,
  81                 newarray    = 33,
  82                 aload       = 34,
  83                 astore      = 35,
  84                 baload      = 36,
  85                 bastore     = 37,
  86                 arraylength = 38,
  87                 pop         = 39,
  88                 dup         = 40,
  89                 dup2        = 41,
  90                 jmp         = 42,
  91                 jeq         = 43,
  92                 jne         = 44,
  93                 jlt         = 45,
  94                 jle         = 46,
  95                 jgt         = 47,
  96                 jge         = 48,
  97                 call        = 49,
  98                 return_     = 50,
  99                 enter       = 51,
 100                 exit        = 52,
 101                 read        = 53,
 102                 print       = 54,
 103                 bread       = 55,
 104                 bprint      = 56,
 105                 trap            = 57;
 106
 107         public String getStandardStart(){
 108                 StringBuilder ret = new StringBuilder(
 109                         "C:\" This file automatically converted from microjava bytecode\";\n"
 110                         +"C:\" with mjc2wsl v "+versionN+"\";\n");
 111
 112                 ret.append("VAR < tempa := 0, tempb := 0, tempres :=0,\n");
 113                 for (int i = 0; i <= 3; i++)
 114                         ret.append("loc" + i + " := 0, ");
 115                 ret.append("\n  estack := < >, t_e_m_p := 0 > :");
 116
 117                 return ret.toString();
 118         }
 119
 120         public String getStandardEnd(){
 121                 return "SKIP\nENDVAR";
 122         }
 123
 124         private boolean originalInComments = false;
 125
 126         private InputStream mainIn;
 127         private PrintWriter out = null;
 128         private int counter = -1;
 129
 130         private void pr(int i){
 131                         out.print(i);
 132         }
 133
 134         private void pr(char i){
 135                         out.print(i);
 136         }
 137
 138         private void pr(String i){
 139                         out.print(i);
 140         }
 141
 142         private void prl(String i){
 143                         out.println(i);
 144         }
 145
 146         private int get() {
 147                 int res = -1;
 148                 try {
 149                         res = mainIn.read();
 150                         if (res >= 0)
 151                                 res = res << 24 >>> 24;
 152                 } catch (IOException ex) {
 153                         ex.printStackTrace();
 154                 }
 155                 counter++;
 156                 return res;
 157         }
 158
 159         private int get2() {
 160                 return (get() * 256 + get()) << 16 >> 16;
 161         }
 162
 163         private int get4() {
 164                 return (get2() << 16) + (get2() << 16 >>> 16);
 165         }
 166
 167         private String loc(int i){
 168                 return "loc" + i;
 169         }
 170
 171         /**
 172          * Creates a WSL comment with care to quote chars.
 173          */
 174         public static String createComment(String str){
 175                 return createComment(str, C_REG);
 176         }
 177
 178         /**
 179          * Creates a WSL comment with care to quote chars, of the
 180          * given type.  Types are given as char constants. They can be
 181          * default comments, comments that contain the original code
 182          * in them, or additional comments regarding the translation
 183          * process.
 184          */
 185         public static String createComment(String str, char type) {
 186                 return "C:\"" + type + str.replace("\"", "''") + "\";";
 187         }
 188
 189         private String cmdToEStack(int i) {
 190                 return "estack := <" + i + " > ++ estack;";
 191         }
 192
 193         private String cmdToEStack(String i) {
 194                 return "estack := <" + i + " > ++ estack;";
 195         }
 196
 197         private String cmdFromEStack(String st) {
 198                 return st + " := HEAD(estack); estack := TAIL(estack);";
 199         }
 200
 201         private String getTopTwo(){
 202                 return cmdFromEStack("tempa") + "\n" + cmdFromEStack("tempb");
 203         }
 204
 205         private String getTop() {
 206                 return cmdFromEStack("tempa");
 207         }
 208
 209         private String getRelationFor(int opcode) throws Exception {
 210                         switch (opcode) {
 211                                         case jeq: return "=";
 212                                         case jne: return "<>";
 213                                         case jlt: return "<";
 214                                         case jle: return "<=";
 215                                         case jgt: return ">";
 216                                         case jge: return ">=";
 217                         }
 218                         throw new Exception("Wrong opcode for a relation");
 219         }
 220
 221         public void convertStream(InputStream ins) throws Exception{
 222                 mainIn = ins;
 223                 //skip start TODO make better
 224                 for (int i = 0; i < 14; i++)
 225                         get();
 226
 227                 prl(getStandardStart());
 228                 prl("SKIP;\n ACTIONS A_S_start:\n A_S_start == CALL a14 END");
 229                 int op = get();
 230                 while (op >= 0) {
 231                         if (originalInComments)
 232                                 prl(createComment("" + op, C_OC));
 233                         prl("a" + counter + " == ");
 234                         switch (op) {
 235                         case load: {
 236                                 prl(cmdToEStack(loc(get())));
 237                                 break;
 238                         }
 239                         case load_0:
 240                         case load_1:
 241                         case load_2:
 242                         case load_3: {
 243                                 prl(cmdToEStack(loc(op - load_0)));
 244                                 break;
 245                         }
 246                         case store: {
 247                                 prl(cmdFromEStack(loc(get())));
 248                                 break;
 249                         }
 250                         case store_0:
 251                         case store_1:
 252                         case store_2:
 253                         case store_3: {
 254                                 prl(cmdFromEStack(loc(op - store_0)));
 255                                 break;
 256                         }
 257                         case const_: {
 258                                 prl(cmdToEStack(get4()));
 259                                 break;
 260                         }
 261
 262                         case const_0:
 263                         case const_1:
 264                         case const_2:
 265                         case const_3:
 266                         case const_4:
 267                         case const_5: {
 268                                 prl(cmdToEStack(op - const_0));
 269                                 break;
 270                         }
 271
 272                         case jmp: {
 273                                 prl("CALL a" + (counter + get2()) + ";");
 274                                 break;
 275                         }
 276
 277                         case jeq:
 278                         case jne:
 279                         case jlt:
 280                         case jle:
 281                         case jgt:
 282                         case jge: {
 283                                 prl(getTopTwo());
 284                                 prl("IF tempb "+ getRelationFor(op)
 285                                                 +" tempa THEN CALL a" + (counter + get2())
 286                                                 + " FI;");
 287                                 break;
 288                         }
 289
 290                         case add: {
 291                                 prl(getTopTwo());
 292                                 prl("tempres := tempb + tempa;");
 293                                 prl(cmdToEStack("tempres"));
 294                                 break;
 295                         }
 296                         case sub: {
 297                                 prl(getTopTwo());
 298                                 prl("tempres := tempb - tempa;");
 299                                 prl(cmdToEStack("tempres"));
 300                                 break;
 301                         }
 302                         case mul: {
 303                                 prl(getTopTwo());
 304                                 prl("tempres := tempb * tempa;");
 305                                 prl(cmdToEStack("tempres"));
 306                                 break;
 307                         }
 308                         case div: {
 309                                 prl(getTopTwo());
 310                                 prl("IF tempa = 0 THEN ERROR(\"division by zero\") FI;");
 311                                 prl("tempres := tempb DIV tempa;");
 312                                 prl(cmdToEStack("tempres"));
 313                                 break;
 314                         }
 315                         case rem: {
 316                                 prl(getTopTwo());
 317                                 prl("IF tempa = 0 THEN ERROR(\"division by zero\") FI;");
 318                                 prl("tempres := tempb MOD tempa;");
 319                                 prl(cmdToEStack("tempres"));
 320                                 break;
 321                         }
 322
 323                         case enter: {
 324                                 prl(createComment("enter not fully procesed yet"));
 325                                 message("enter not fully procesed yet", M_WAR);
 326                                 get();
 327                                 get();
 328                                 break;
 329                         }
 330                         case return_: {
 331                                 prl(createComment("return not fully procesed yet"));
 332                                 message("return not fully procesed yet", M_WAR);
 333                                 break;
 334                         }
 335                         case exit: {
 336                                 prl(createComment("exit not fully procesed yet"));
 337                                 message("exit not fully procesed yet", M_WAR);
 338                                 break;
 339                         }
 340
 341                         // the prints
 342                         case bprint: {
 343                                 prl(getTopTwo());
 344                                 prl("PRINT(tempb);");
 345                                 break;
 346                         }
 347                         case print: {
 348                                 // TODO need to make it a char
 349                                 prl(getTopTwo());
 350                                 prl("PRINT(tempb);");
 351                                 break;
 352                         }
 353                         default:
 354                                 prl(createComment("unknown op error: " + op, C_ERR));
 355                                 message("unknown op error: "+ op, M_ERR);
 356                                 break;
 357                         }
 358
 359                         op = get();
 360                         if (op >= 0)
 361                                 prl("CALL a" + counter + " END");
 362                 }
 363                 prl("CALL Z;\nSKIP END\nENDACTIONS;\n");
 364                 prl(getStandardEnd());
 365
 366         }
 367
 368         public void convertFile(File f) {
 369                 try {
 370                         convertStream(new FileInputStream(f));
 371                 } catch (Exception ex) {
 372                         ex.printStackTrace();
 373                 }
 374         }
 375
 376         public void printHelp() {
 377                 System.out.println("MicroJava bytecode to WSL converter. v " + versionN
 378                                 + ", by Doni Pracner");
 379                 System.out.println("usage:\n\t {options} mjc2wsl  filename [outfile]");
 380                 System.out.println("options:\n\t--screen print output to screen");
 381                 System.out.println("\t-o --oc include original code in comments");
 382         }
 383
 384         public String makeDefaultOutName(String inname){
 385                 String rez = inname;
 386                 if (inname.endsWith(".obj"))
 387                         rez = rez.substring(0, rez.length() - 4);
 388                 return rez + ".wsl";
 389         }
 390
 391         public void run(String[] args) {
 392                 if (args.length == 0) {
 393                         printHelp();
 394                 } else {
 395                         int i = 0;
 396                         while (i < args.length && args[i].charAt(0) == '-') {
 397                                 if (args[i].compareTo("-h") == 0) {
 398                                         printHelp();
 399                                         return;
 400                                 } else if (args[i].compareTo("-o") == 0
 401                                                 || args[i].startsWith("--oc")) {
 402                                         if (args[i].length() == 2)
 403                                                 originalInComments = true;
 404                                         else if (args[i].length() == 5)
 405                                                 originalInComments = args[i].charAt(4) == '+';
 406                                         else
 407                                                 originalInComments = true;
 408                                 } else if (args[i].startsWith("--screen")) {
 409                                         out = new PrintWriter(System.out);
 410                                 }
 411                                 i++;
 412                         }
 413
 414                         if (i >= args.length) {
 415                                 System.out.println("no filename supplied");
 416                                 System.exit(2);
 417                         }
 418                         File f = new File(args[i]);
 419
 420                         if (i + 1 < args.length) {
 421                                 try {
 422                                         out = new PrintWriter(args[i + 1]);
 423                                 } catch (Exception e) {
 424                                         System.err.println("error in opening out file:");
 425                                         e.printStackTrace();
 426                                 }
 427                         }
 428                         if (out == null) {
 429                                 // if not set to screen, or a file, make a default filename
 430                                 try {
 431                                         out = new PrintWriter(makeDefaultOutName(args[i]));
 432                                 } catch (Exception e) {
 433                                         System.err.println("error in opening out file:");
 434                                         e.printStackTrace();
 435                                 }
 436                         }
 437                         if (f.exists()) {
 438                                 Calendar now = Calendar.getInstance();
 439                                 printLevel=10;
 440                                 convertFile(f);
 441                                 long mili = Calendar.getInstance().getTimeInMillis()
 442                                                 - now.getTimeInMillis();
 443                                 System.out.println("conversion time:" + mili + " ms");
 444                                 printMessageCounters();
 445                                 out.close();
 446                         } else
 447                                 System.out.println("file does not exist");
 448                 }
 449         }
 450
 451         public static void main(String[] args) {
 452                 new mjc2wsl().run(args);
 453         }
 454 }