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         //regular comments from the original file
  16         //OC when original code is inserted in the file, next to the translations
  17         //SPEC special messages from the translator
  18         //ERR error messages from the translator
  19         public static final char C_REG = ' ', C_OC = '#', C_SPEC = '&', C_ERR = '!';
  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_0     =  7,
  30                 store_1     =  8,
  31                 store_2     =  9,
  32                 store_3     = 10,
  33                 getstatic   = 11,
  34                 putstatic   = 12,
  35                 getfield    = 13,
  36                 putfield    = 14,
  37                 const_0     = 15,
  38                 const_1     = 16,
  39                 const_2     = 17,
  40                 const_3     = 18,
  41                 const_4     = 19,
  42                 const_5     = 20,
  43                 const_m1    = 21,
  44                 const_      = 22,
  45                 add         = 23,
  46                 sub         = 24,
  47                 mul         = 25,
  48                 div         = 26,
  49                 rem         = 27,
  50                 neg         = 28,
  51                 shl         = 29,
  52                 shr         = 30,
  53                 inc         = 31,
  54                 new_        = 32,
  55                 newarray    = 33,
  56                 aload       = 34,
  57                 astore      = 35,
  58                 baload      = 36,
  59                 bastore     = 37,
  60                 arraylength = 38,
  61                 pop         = 39,
  62                 dup         = 40,
  63                 dup2        = 41,
  64                 jmp         = 42,
  65                 jeq         = 43,
  66                 jne         = 44,
  67                 jlt         = 45,
  68                 jle         = 46,
  69                 jgt         = 47,
  70                 jge         = 48,
  71                 call        = 49,
  72                 return_     = 50,
  73                 enter       = 51,
  74                 exit        = 52,
  75                 read        = 53,
  76                 print       = 54,
  77                 bread       = 55,
  78                 bprint      = 56,
  79                 trap            = 57;
  80
  81         public String getStandardStart(){
  82                 StringBuilder ret = new StringBuilder(
  83                         "C:\" This file automatically converted from microjava bytecode\";\n"
  84                         +"C:\" with mjc2wsl v "+versionN+"\";\n");
  85
  86                 ret.append("VAR < tempa := 0, tempb := 0, tempres :=0,\n");
  87                 for (int i = 0; i <= 3; i++)
  88                         ret.append("loc" + i + " := 0, ");
  89                 ret.append("\n  estack := < >, t_e_m_p := 0 > :");
  90
  91                 return ret.toString();
  92         }
  93
  94         public String getStandardEnd(){
  95                 return "SKIP\nENDVAR";
  96         }
  97
  98         private boolean originalInComments = false;
  99
 100         private InputStream mainIn;
 101         private PrintWriter out = null;
 102         private int counter = -1;
 103
 104         private void pr(int i){
 105                         out.print(i);
 106         }
 107
 108         private void pr(char i){
 109                         out.print(i);
 110         }
 111
 112         private void pr(String i){
 113                         out.print(i);
 114         }
 115
 116         private void prl(String i){
 117                         out.println(i);
 118         }
 119
 120         private int get() {
 121                 int res = -1;
 122                 try {
 123                         res = mainIn.read();
 124                         if (res >= 0)
 125                                 res = res << 24 >>> 24;
 126                 } catch (IOException ex) {
 127                         ex.printStackTrace();
 128                 }
 129                 counter++;
 130                 return res;
 131         }
 132
 133         private int get2() {
 134                 return (get() * 256 + get()) << 16 >> 16;
 135         }
 136
 137         private int get4() {
 138                 return (get2() << 16) + (get2() << 16 >>> 16);
 139         }
 140
 141         private String loc(int i){
 142                 return "loc" + i;
 143         }
 144
 145         /**
 146          * Creates a WSL comment with care to quote chars.
 147          */
 148         public static String createComment(String str){
 149                 return createComment(str, C_REG);
 150         }
 151
 152         /**
 153          * Creates a WSL comment with care to quote chars, of the
 154          * given type.  Types are given as char constants. They can be
 155          * default comments, comments that contain the original code
 156          * in them, or additional comments regarding the translation
 157          * process.
 158          */
 159         public static String createComment(String str, char type) {
 160                 return "C:\"" + type + str.replace("\"", "''") + "\";";
 161         }
 162
 163         private String cmdToEStack(int i) {
 164                 return "estack := <" + i + " > ++ estack;";
 165         }
 166
 167         private String cmdToEStack(String i) {
 168                 return "estack := <" + i + " > ++ estack;";
 169         }
 170
 171         private String cmdFromEStack(String st) {
 172                 return st + " := HEAD(estack); estack := TAIL(estack);";
 173         }
 174
 175         private String getTopTwo(){
 176                 return cmdFromEStack("tempa") + "\n" + cmdFromEStack("tempb");
 177         }
 178
 179         private String getTop() {
 180                 return cmdFromEStack("tempa");
 181         }
 182
 183         public void convertStream(InputStream ins){
 184                 mainIn = ins;
 185                 //skip start TODO make better
 186                 for (int i = 0; i < 14; i++)
 187                         get();
 188
 189                 prl(getStandardStart());
 190                 prl("SKIP;\n ACTIONS A_S_start:\n A_S_start == CALL a14 END");
 191                 int op = get();
 192                 while (op >= 0) {
 193                         if (originalInComments)
 194                                 prl(createComment("" + op, C_OC));
 195                         prl("a" + counter + " == ");
 196                         switch (op) {
 197                         case load: {
 198                                 prl(cmdToEStack(loc(get())));
 199                                 break;
 200                         }
 201                         case load_0:
 202                         case load_1:
 203                         case load_2:
 204                         case load_3: {
 205                                 prl(cmdToEStack(loc(op - load_0)));
 206                                 break;
 207                         }
 208                         case store: {
 209                                 prl(cmdFromEStack(loc(get())));
 210                                 break;
 211                         }
 212                         case store_0:
 213                         case store_1:
 214                         case store_2:
 215                         case store_3: {
 216                                 prl(cmdFromEStack(loc(op - store_0)));
 217                                 break;
 218                         }
 219                         case const_: {
 220                                 prl(cmdToEStack(get4()));
 221                                 break;
 222                         }
 223
 224                         case const_0:
 225                         case const_1:
 226                         case const_2:
 227                         case const_3:
 228                         case const_4:
 229                         case const_5: {
 230                                 prl(cmdToEStack(op - const_0));
 231                                 break;
 232                         }
 233
 234                         case jmp: {
 235                                 prl("CALL a" + (counter + get2()) + ";");
 236                                 break;
 237                         }
 238
 239                         case jeq:
 240                         case jne:
 241                         case jlt:
 242                         case jle:
 243                         case jgt:
 244                         case jge: {
 245                                 prl(getTopTwo());
 246                                 prl("IF tempb >= tempa THEN CALL a" + (counter + get2())
 247                                                 + " FI;");
 248                                 break;
 249                         }
 250
 251                         case add: {
 252                                 prl(getTopTwo());
 253                                 prl("tempres := tempb + tempa;");
 254                                 prl(cmdToEStack("tempres"));
 255                                 break;
 256                         }
 257                         case div: {
 258                                 prl(getTopTwo());
 259                                 prl("tempres := tempb / tempa;");
 260                                 prl(cmdToEStack("tempres"));
 261                                 break;
 262                         }
 263
 264                         case enter: {
 265                                 prl(createComment("enter not fully procesed yet"));
 266                                 get();
 267                                 get();
 268                                 break;
 269                         }
 270                         case return_: {
 271                                 prl(createComment("return not fully procesed yet"));
 272                                 break;
 273                         }
 274                         case exit: {
 275                                 prl(createComment("exit not fully procesed yet"));
 276                                 break;
 277                         }
 278
 279                         // the prints
 280                         case bprint: {
 281                                 prl(getTopTwo());
 282                                 prl("PRINT(tempb);");
 283                                 break;
 284                         }
 285                         case print: {
 286                                 // TODO need to make it a char
 287                                 prl(getTopTwo());
 288                                 prl("PRINT(tempb);");
 289                                 break;
 290                         }
 291                         default:
 292                                 prl(createComment("unknown op error: " + op, C_ERR));
 293                                 break;
 294                         }
 295
 296                         op = get();
 297                         if (op >= 0)
 298                                 prl("CALL a" + counter + " END");
 299                 }
 300                 prl("CALL Z;\nSKIP END\nENDACTIONS;\n");
 301                 prl(getStandardEnd());
 302
 303         }
 304
 305         public void convertFile(File f) {
 306                 try {
 307                         convertStream(new FileInputStream(f));
 308                 } catch (Exception ex) {
 309                         ex.printStackTrace();
 310                 }
 311         }
 312
 313         public void printHelp() {
 314                 System.out.println("MicroJava bytecode to WSL converter. v " + versionN
 315                                 + ", by Doni Pracner");
 316                 System.out.println("usage:\n\t {options} mjc2wsl  filename [outfile]");
 317                 System.out.println("options:\n\t--screen print output to screen");
 318                 System.out.println("\t-o --oc include original code in comments");
 319         }
 320
 321         public String makeDefaultOutName(String inname){
 322                 String rez = inname;
 323                 if (inname.endsWith(".obj"))
 324                         rez = rez.substring(0, rez.length() - 4);
 325                 return rez + ".wsl";
 326         }
 327
 328         public void run(String[] args) {
 329                 if (args.length == 0) {
 330                         printHelp();
 331                 } else {
 332                         int i = 0;
 333                         while (i < args.length && args[i].charAt(0) == '-') {
 334                                 if (args[i].compareTo("-h") == 0) {
 335                                         printHelp();
 336                                         return;
 337                                 } else if (args[i].compareTo("-o") == 0
 338                                                 || args[i].startsWith("--oc")) {
 339                                         if (args[i].length() == 2)
 340                                                 originalInComments = true;
 341                                         else if (args[i].length() == 5)
 342                                                 originalInComments = args[i].charAt(4) == '+';
 343                                         else
 344                                                 originalInComments = true;
 345                                 } else if (args[i].startsWith("--screen")) {
 346                                         out = new PrintWriter(System.out);
 347                                 }
 348                                 i++;
 349                         }
 350
 351                         if (i >= args.length) {
 352                                 System.out.println("no filename supplied");
 353                                 System.exit(2);
 354                         }
 355                         File f = new File(args[i]);
 356
 357                         if (i + 1 < args.length) {
 358                                 try {
 359                                         out = new PrintWriter(args[i + 1]);
 360                                 } catch (Exception e) {
 361                                         System.err.println("error in opening out file:");
 362                                         e.printStackTrace();
 363                                 }
 364                         }
 365                         if (out == null) {
 366                                 // if not set to screen, or a file, make a default filename
 367                                 try {
 368                                         out = new PrintWriter(makeDefaultOutName(args[i]));
 369                                 } catch (Exception e) {
 370                                         System.err.println("error in opening out file:");
 371                                         e.printStackTrace();
 372                                 }
 373                         }
 374                         if (f.exists()) {
 375                                 Calendar now = Calendar.getInstance();
 376                                 convertFile(f);
 377                                 long mili = Calendar.getInstance().getTimeInMillis()
 378                                                 - now.getTimeInMillis();
 379                                 System.out.println("conversion time:" + mili + " ms");
 380                                 out.close();
 381                         } else
 382                                 System.out.println("file does not exist");
 383                 }
 384         }
 385
 386         public static void main(String[] args) {
 387                 new mjc2wsl().run(args);
 388         }
 389 }