libjava/include/java-interp.h

   1 // java-interp.h - Header file for the bytecode interpreter.  -*- c++ -*-
   2
   3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 #ifndef __JAVA_INTERP_H__
  12 #define __JAVA_INTERP_H__
  13
  14 #include <jvm.h>
  15 #include <java-cpool.h>
  16 #include <gnu/gcj/runtime/NameFinder.h>
  17
  18 enum _Jv_FrameType
  19 {
  20   frame_native,
  21   frame_interpreter,
  22   frame_proxy
  23 };
  24
  25 #ifdef INTERPRETER
  26
  27 #pragma interface
  28
  29 #include <java/lang/Class.h>
  30 #include <java/lang/ClassLoader.h>
  31 #include <java/lang/reflect/Modifier.h>
  32 #include <java/lang/Thread.h>
  33 #include <gnu/gcj/RawData.h>
  34
  35 // Define this to get the direct-threaded interpreter.  If undefined,
  36 // we revert to a basic bytecode interpreter.  The former is faster
  37 // but uses more memory.
  38 #define DIRECT_THREADED
  39
  40 #include <ffi.h>
  41
  42 struct _Jv_ResolvedMethod;
  43
  44 void _Jv_InitInterpreter ();
  45 void _Jv_DefineClass (jclass, jbyteArray, jint, jint,
  46                       java::security::ProtectionDomain *,
  47                       _Jv_Utf8Const **);
  48
  49 void _Jv_InitField (jobject, jclass, int);
  50 void * _Jv_AllocMethodInvocation (jsize size);
  51 int  _Jv_count_arguments (_Jv_Utf8Const *signature,
  52                           jboolean staticp = true);
  53 void _Jv_VerifyMethod (_Jv_InterpMethod *method);
  54 void _Jv_CompileMethod (_Jv_InterpMethod* method);
  55 int _Jv_init_cif (_Jv_Utf8Const* signature,
  56                   int arg_count,
  57                   jboolean staticp,
  58                   ffi_cif *cif,
  59                   ffi_type **arg_types,
  60                   ffi_type **rtype_p);
  61
  62 /* the interpreter is written in C++, primarily because it makes it easy for
  63  * the entire thing to be "friend" with class Class. */
  64
  65 class _Jv_InterpClass;
  66 class _Jv_InterpMethod;
  67
  68 // Before a method is "compiled" we store values as the bytecode PC,
  69 // an int.  Afterwards we store them as pointers into the prepared
  70 // code itself.
  71 union _Jv_InterpPC
  72 {
  73   int i;
  74   void *p;
  75 };
  76
  77 class _Jv_InterpException
  78 {
  79   _Jv_InterpPC start_pc;
  80   _Jv_InterpPC end_pc;
  81   _Jv_InterpPC handler_pc;
  82   _Jv_InterpPC handler_type;
  83
  84   friend class _Jv_ClassReader;
  85   friend class _Jv_InterpMethod;
  86   friend class _Jv_BytecodeVerifier;
  87 };
  88
  89 // Base class for method representations.  Subclasses are interpreted
  90 // and JNI methods.
  91 class _Jv_MethodBase
  92 {
  93 protected:
  94   // The class which defined this method.
  95   jclass defining_class;
  96
  97   // The method description.
  98   _Jv_Method *self;
  99
 100   // Size of raw arguments.
 101   _Jv_ushort args_raw_size;
 102
 103   friend class _Jv_InterpreterEngine;
 104
 105 public:
 106   _Jv_Method *get_method ()
 107   {
 108     return self;
 109   }
 110 };
 111
 112 // The type of the PC depends on whether we're doing direct threading
 113 // or a more ordinary bytecode interpreter.
 114 #ifdef DIRECT_THREADED
 115 // Slot in the "compiled" form of the bytecode.
 116 union insn_slot
 117 {
 118   // Address of code.
 119   void *insn;
 120   // An integer value used by an instruction.
 121   jint int_val;
 122   // A pointer value used by an instruction.
 123   void *datum;
 124 };
 125
 126 typedef insn_slot *pc_t;
 127 #else
 128 typedef unsigned char *pc_t;
 129 #endif
 130
 131
 132 // This structure holds the bytecode pc and corresponding source code
 133 // line number.  An array (plus length field) of this structure is put
 134 // in each _Jv_InterpMethod and used to resolve the (internal) program
 135 // counter of the interpreted method to an actual java source file
 136 // line.
 137 struct  _Jv_LineTableEntry
 138 {
 139   union
 140   {
 141     pc_t pc;
 142     int bytecode_pc;
 143   };
 144   int line;
 145 };
 146
 147 // This structure holds local variable information.
 148 // Like _Jv_LineTableEntry above, it is remapped when the method is
 149 // compiled for direct threading.
 150 struct _Jv_LocalVarTableEntry
 151 {
 152   // First PC value at which variable is live
 153   union
 154   {
 155     pc_t pc;
 156     int bytecode_pc;
 157   };
 158
 159   // length of visibility of variable
 160   int length;
 161
 162   // variable name
 163   char *name;
 164
 165   // type description
 166   char *descriptor;
 167
 168   // stack slot number (long and double occupy slot and slot + 1)
 169   int slot;
 170 };
 171
 172 class _Jv_InterpMethod : public _Jv_MethodBase
 173 {
 174   // Breakpoint instruction
 175   static pc_t breakpoint_insn;
 176 #ifdef DIRECT_THREADED
 177   static insn_slot bp_insn_slot;
 178 #else
 179   static unsigned char bp_insn_opcode;
 180 #endif
 181
 182   _Jv_ushort       max_stack;
 183   _Jv_ushort       max_locals;
 184   int              code_length;
 185
 186   _Jv_ushort       exc_count;
 187   bool             is_15;
 188
 189   // Length of the line_table - when this is zero then line_table is NULL.
 190   int line_table_len;
 191   _Jv_LineTableEntry *line_table;
 192
 193   // The local variable table length and the table itself
 194   int local_var_table_len;
 195   _Jv_LocalVarTableEntry *local_var_table;
 196
 197   pc_t prepared;
 198   int number_insn_slots;
 199
 200   unsigned char* bytecode ()
 201   {
 202     return
 203       ((unsigned char*)this)
 204       + ROUND((sizeof (_Jv_InterpMethod)
 205                + exc_count*sizeof (_Jv_InterpException)), 4);
 206   }
 207
 208   _Jv_InterpException * exceptions ()
 209   {
 210     return (_Jv_InterpException*) (this+1);
 211   }
 212
 213   static size_t size (int exc_count, int code_length)
 214   {
 215     return
 216       ROUND ((sizeof (_Jv_InterpMethod)
 217               + (exc_count * sizeof (_Jv_InterpException))), 4)
 218       + code_length;
 219   }
 220
 221   // return the method's invocation pointer (a stub).
 222   void *ncode (jclass);
 223   void compile (const void * const *);
 224
 225 #if FFI_NATIVE_RAW_API
 226 #  define INTERP_FFI_RAW_TYPE ffi_raw
 227 #else
 228 #  define INTERP_FFI_RAW_TYPE ffi_java_raw
 229 #endif
 230
 231   static void run_normal (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 232   static void run_synch_object (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 233   static void run_class (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 234   static void run_synch_class (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 235
 236   static void run_normal_debug (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 237   static void run_synch_object_debug (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*,
 238                                       void*);
 239   static void run_class_debug (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*, void*);
 240   static void run_synch_class_debug (ffi_cif*, void*, INTERP_FFI_RAW_TYPE*,
 241                                      void*);
 242
 243   static void run (void *, INTERP_FFI_RAW_TYPE *, _Jv_InterpMethod *);
 244   static void run_debug (void *, INTERP_FFI_RAW_TYPE *, _Jv_InterpMethod *);
 245
 246
 247
 248   // Returns source file line number for given PC value, or -1 if line
 249   // number info is unavailable.
 250   int get_source_line(pc_t mpc);
 251
 252    public:
 253
 254   // Convenience function for indexing bytecode PC/insn slots in
 255   // line tables for JDWP
 256   jlong insn_index (pc_t pc);
 257
 258   // Helper function used to check if there is a handler for an exception
 259   // present at this code index
 260   jboolean check_handler (pc_t *pc, _Jv_InterpMethod *meth,
 261                      java::lang::Throwable *ex);
 262
 263   /* Get the line table for this method.
 264    * start  is the lowest index in the method
 265    * end    is the  highest index in the method
 266    * line_numbers is an array to hold the list of source line numbers
 267    * code_indices is an array to hold the corresponding list of code indices
 268    */
 269   void get_line_table (jlong& start, jlong& end, jintArray& line_numbers,
 270                        jlongArray& code_indices);
 271
 272   int get_max_locals ()
 273   {
 274     return static_cast<int> (max_locals);
 275   }
 276
 277   /* Get info for a local variable of this method.
 278    * If there is no loca_var_table for this method it will return -1.
 279    * table_slot  indicates which slot in the local_var_table to get, if there is
 280    * no variable at this location it will return 0.
 281    * Otherwise, it will return the number of table slots after the selected
 282    * slot, indexed from 0.
 283    *
 284    * Example: there are 5 slots in the table, you request slot 0 so it will
 285    * return 4.
 286    */
 287   int get_local_var_table (char **name, char **sig, char **generic_sig,
 288                            jlong *startloc, jint *length, jint *slot,
 289                            int table_slot);
 290
 291   /* Installs a break instruction at the given code index. Returns
 292      the pc_t of the breakpoint or NULL if index is invalid. */
 293   pc_t install_break (jlong index);
 294
 295   // Gets the instruction at the given index
 296   pc_t get_insn (jlong index);
 297
 298   /* Writes the given instruction at the given code index. Returns
 299      the insn or NULL if index is invalid. */
 300   pc_t set_insn (jlong index, pc_t insn);
 301
 302   // Is the given location in this method a breakpoint?
 303   bool breakpoint_at (jlong index);
 304
 305 #ifdef DIRECT_THREADED
 306   friend void _Jv_CompileMethod (_Jv_InterpMethod*);
 307 #endif
 308
 309   friend class _Jv_ClassReader;
 310   friend class _Jv_BytecodeVerifier;
 311   friend class _Jv_StackTrace;
 312   friend class _Jv_InterpreterEngine;
 313
 314 #ifdef JV_MARKOBJ_DECL
 315   friend JV_MARKOBJ_DECL;
 316 #endif
 317 };
 318
 319 class _Jv_InterpClass
 320 {
 321   _Jv_MethodBase **interpreted_methods;
 322   _Jv_ushort     *field_initializers;
 323   jstring source_file_name;
 324   _Jv_ClosureList **closures;
 325
 326   friend class _Jv_ClassReader;
 327   friend class _Jv_InterpMethod;
 328   friend class _Jv_StackTrace;
 329   friend class _Jv_InterpreterEngine;
 330
 331   friend void  _Jv_InitField (jobject, jclass, int);
 332 #ifdef JV_MARKOBJ_DECL
 333   friend JV_MARKOBJ_DECL;
 334 #endif
 335
 336   friend _Jv_MethodBase ** _Jv_GetFirstMethod (_Jv_InterpClass *klass);
 337   friend jstring _Jv_GetInterpClassSourceFile (jclass);
 338 };
 339
 340 extern inline _Jv_MethodBase **
 341 _Jv_GetFirstMethod (_Jv_InterpClass *klass)
 342 {
 343   return klass->interpreted_methods;
 344 }
 345
 346 struct _Jv_ResolvedMethod
 347 {
 348   jint            stack_item_count;
 349   jclass          klass;
 350   _Jv_Method*     method;
 351
 352   // a resolved method holds the cif in-line, so that _Jv_MarkObj just needs
 353   // to mark the resolved method to hold on to the cif.  Some memory could be
 354   // saved by keeping a cache of cif's, since many will be the same.
 355   ffi_cif         cif;
 356   ffi_type *      arg_types[0];
 357 };
 358
 359 class _Jv_JNIMethod : public _Jv_MethodBase
 360 {
 361   // The underlying function.  If NULL we have to look for the
 362   // function.
 363   void *function;
 364
 365   // This is the CIF used by the JNI function.
 366   ffi_cif jni_cif;
 367
 368   // These are the argument types used by the JNI function.
 369   ffi_type **jni_arg_types;
 370
 371   // This function is used when making a JNI call from the interpreter.
 372   static void call (ffi_cif *, void *, INTERP_FFI_RAW_TYPE *, void *);
 373
 374   void *ncode (jclass);
 375
 376   friend class _Jv_ClassReader;
 377   friend class _Jv_InterpreterEngine;
 378
 379 #ifdef JV_MARKOBJ_DECL
 380   friend JV_MARKOBJ_DECL;
 381 #endif
 382
 383 public:
 384   // FIXME: this is ugly.
 385   void set_function (void *f)
 386   {
 387     function = f;
 388   }
 389 };
 390
 391 //  The composite call stack as represented by a linked list of frames
 392 class _Jv_Frame
 393 {
 394 public:
 395   java::lang::Thread *thread;
 396
 397   union
 398   {
 399     _Jv_MethodBase *self;
 400     void *meth;
 401     _Jv_Method *proxyMethod;
 402   };
 403
 404   //The full list of frames, JNI and interpreted
 405   _Jv_Frame *next;
 406   _Jv_FrameType frame_type;
 407
 408   _Jv_Frame (_Jv_MethodBase *s, java::lang::Thread *thr, _Jv_FrameType type)
 409   {
 410     self = s;
 411     frame_type = type;
 412     next = (_Jv_Frame *) thr->frame;
 413     thr->frame = (gnu::gcj::RawData *) this;
 414     thread = thr;
 415   }
 416
 417   ~_Jv_Frame ()
 418   {
 419     thread->frame = (gnu::gcj::RawData *) next;
 420   }
 421
 422   int depth ()
 423   {
 424     int depth = 0;
 425     struct _Jv_Frame *f;
 426     for (f = this; f != NULL; f = f->next)
 427       ++depth;
 428
 429     return depth;
 430   }
 431 };
 432
 433 // An interpreted frame in the call stack
 434 class _Jv_InterpFrame : public _Jv_Frame
 435 {
 436 public:
 437
 438   // Keep the purely interpreted list around so as not to break backtraces
 439   _Jv_InterpFrame *next_interp;
 440
 441   union
 442   {
 443     pc_t pc;
 444     jclass proxyClass;
 445   };
 446
 447   // Pointer to the actual pc value.
 448   pc_t *pc_ptr;
 449
 450   //Debug info for local variables.
 451   _Jv_word *locals;
 452   char *locals_type;
 453
 454   // Object pointer for this frame ("this")
 455   jobject obj_ptr;
 456
 457   _Jv_InterpFrame (void *meth, java::lang::Thread *thr, jclass proxyCls = NULL,
 458                    pc_t *pc = NULL)
 459   : _Jv_Frame (reinterpret_cast<_Jv_MethodBase *> (meth), thr,
 460                      frame_interpreter)
 461   {
 462     next_interp = (_Jv_InterpFrame *) thr->interp_frame;
 463     proxyClass = proxyCls;
 464     thr->interp_frame = (gnu::gcj::RawData *) this;
 465     obj_ptr = NULL;
 466     pc_ptr = pc;
 467   }
 468
 469   ~_Jv_InterpFrame ()
 470   {
 471     thread->interp_frame = (gnu::gcj::RawData *) next_interp;
 472   }
 473
 474   jobject get_this_ptr ()
 475   {
 476     return obj_ptr;
 477   }
 478
 479   pc_t get_pc ()
 480   {
 481     pc_t pc;
 482
 483     // If the PC_PTR is NULL, we are not debugging.
 484     if (pc_ptr == NULL)
 485       pc = 0;
 486     else
 487       pc = *pc_ptr - 1;
 488
 489     return pc;
 490   }
 491 };
 492
 493 // A native frame in the call stack really just a placeholder
 494 class _Jv_NativeFrame : public _Jv_Frame
 495 {
 496 public:
 497
 498   _Jv_NativeFrame (_Jv_JNIMethod *s, java::lang::Thread *thr)
 499   : _Jv_Frame (s, thr, frame_native)
 500   {
 501   }
 502 };
 503
 504 #endif /* INTERPRETER */
 505
 506 #endif /* __JAVA_INTERP_H__ */