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  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 #ifdef INTERPRETER
  19
  20 #pragma interface
  21
  22 #include <java/lang/Class.h>
  23 #include <java/lang/ClassLoader.h>
  24 #include <java/lang/reflect/Modifier.h>
  25 #include <java/lang/Thread.h>
  26 #include <gnu/gcj/RawData.h>
  27
  28 // Define this to get the direct-threaded interpreter.  If undefined,
  29 // we revert to a basic bytecode interpreter.  The former is faster
  30 // but uses more memory.
  31 #define DIRECT_THREADED
  32
  33 #include <ffi.h>
  34
  35 struct _Jv_ResolvedMethod;
  36
  37 void _Jv_InitInterpreter ();
  38 void _Jv_DefineClass (jclass, jbyteArray, jint, jint,
  39                       java::security::ProtectionDomain *,
  40                       _Jv_Utf8Const **);
  41
  42 void _Jv_InitField (jobject, jclass, int);
  43 void * _Jv_AllocMethodInvocation (jsize size);
  44 int  _Jv_count_arguments (_Jv_Utf8Const *signature,
  45                           jboolean staticp = true);
  46 void _Jv_VerifyMethod (_Jv_InterpMethod *method);
  47 void _Jv_CompileMethod (_Jv_InterpMethod* method);
  48 int _Jv_init_cif (_Jv_Utf8Const* signature,
  49                   int arg_count,
  50                   jboolean staticp,
  51                   ffi_cif *cif,
  52                   ffi_type **arg_types,
  53                   ffi_type **rtype_p);
  54
  55 /* the interpreter is written in C++, primarily because it makes it easy for
  56  * the entire thing to be "friend" with class Class. */
  57
  58 class _Jv_InterpClass;
  59 class _Jv_InterpMethod;
  60
  61 // Before a method is "compiled" we store values as the bytecode PC,
  62 // an int.  Afterwards we store them as pointers into the prepared
  63 // code itself.
  64 union _Jv_InterpPC
  65 {
  66   int i;
  67   void *p;
  68 };
  69
  70 class _Jv_InterpException
  71 {
  72   _Jv_InterpPC start_pc;
  73   _Jv_InterpPC end_pc;
  74   _Jv_InterpPC handler_pc;
  75   _Jv_InterpPC handler_type;
  76
  77   friend class _Jv_ClassReader;
  78   friend class _Jv_InterpMethod;
  79   friend class _Jv_BytecodeVerifier;
  80 };
  81
  82 // Base class for method representations.  Subclasses are interpreted
  83 // and JNI methods.
  84 class _Jv_MethodBase
  85 {
  86 protected:
  87   // The class which defined this method.
  88   jclass defining_class;
  89
  90   // The method description.
  91   _Jv_Method *self;
  92
  93   // Size of raw arguments.
  94   _Jv_ushort args_raw_size;
  95
  96   friend class _Jv_InterpreterEngine;
  97
  98 public:
  99   _Jv_Method *get_method ()
 100   {
 101     return self;
 102   }
 103 };
 104
 105 // The type of the PC depends on whether we're doing direct threading
 106 // or a more ordinary bytecode interpreter.
 107 #ifdef DIRECT_THREADED
 108 // Slot in the "compiled" form of the bytecode.
 109 union insn_slot
 110 {
 111   // Address of code.
 112   void *insn;
 113   // An integer value used by an instruction.
 114   jint int_val;
 115   // A pointer value used by an instruction.
 116   void *datum;
 117 };
 118
 119 typedef insn_slot *pc_t;
 120 #else
 121 typedef unsigned char *pc_t;
 122 #endif
 123
 124
 125 // This structure holds the bytecode pc and corresponding source code
 126 // line number.  An array (plus length field) of this structure is put
 127 // in each _Jv_InterpMethod and used to resolve the (internal) program
 128 // counter of the interpreted method to an actual java source file
 129 // line.
 130 struct  _Jv_LineTableEntry
 131 {
 132   union
 133   {
 134     pc_t pc;
 135     int bytecode_pc;
 136   };
 137   int line;
 138 };
 139
 140 class _Jv_InterpMethod : public _Jv_MethodBase
 141 {
 142   // Breakpoint instruction
 143   static pc_t breakpoint_insn;
 144 #ifdef DIRECT_THREADED
 145   static insn_slot bp_insn_slot;
 146 #else
 147   static unsigned char bp_insn_opcode;
 148 #endif
 149
 150   _Jv_ushort       max_stack;
 151   _Jv_ushort       max_locals;
 152   int              code_length;
 153
 154   _Jv_ushort       exc_count;
 155   bool             is_15;
 156
 157   // Length of the line_table - when this is zero then line_table is NULL.
 158   int line_table_len;
 159   _Jv_LineTableEntry *line_table;
 160
 161   pc_t prepared;
 162   int number_insn_slots;
 163
 164   unsigned char* bytecode ()
 165   {
 166     return
 167       ((unsigned char*)this)
 168       + ROUND((sizeof (_Jv_InterpMethod)
 169                + exc_count*sizeof (_Jv_InterpException)), 4);
 170   }
 171
 172   _Jv_InterpException * exceptions ()
 173   {
 174     return (_Jv_InterpException*) (this+1);
 175   }
 176
 177   static size_t size (int exc_count, int code_length)
 178   {
 179     return
 180       ROUND ((sizeof (_Jv_InterpMethod)
 181               + (exc_count * sizeof (_Jv_InterpException))), 4)
 182       + code_length;
 183   }
 184
 185   // return the method's invocation pointer (a stub).
 186   void *ncode ();
 187   void compile (const void * const *);
 188
 189   static void run_normal (ffi_cif*, void*, ffi_raw*, void*);
 190   static void run_synch_object (ffi_cif*, void*, ffi_raw*, void*);
 191   static void run_class (ffi_cif*, void*, ffi_raw*, void*);
 192   static void run_synch_class (ffi_cif*, void*, ffi_raw*, void*);
 193
 194   static void run_normal_debug (ffi_cif*, void*, ffi_raw*, void*);
 195   static void run_synch_object_debug (ffi_cif*, void*, ffi_raw*, void*);
 196   static void run_class_debug (ffi_cif*, void*, ffi_raw*, void*);
 197   static void run_synch_class_debug (ffi_cif*, void*, ffi_raw*, void*);
 198
 199   static void run (void *, ffi_raw *, _Jv_InterpMethod *);
 200   static void run_debug (void *, ffi_raw *, _Jv_InterpMethod *);
 201
 202
 203
 204   // Returns source file line number for given PC value, or -1 if line
 205   // number info is unavailable.
 206   int get_source_line(pc_t mpc);
 207
 208   // Convenience function for indexing bytecode PC/insn slots in
 209   // line tables for JDWP
 210   jlong insn_index (pc_t pc);
 211
 212    public:
 213
 214   /* Get the line table for this method.
 215    * start  is the lowest index in the method
 216    * end    is the  highest index in the method
 217    * line_numbers is an array to hold the list of source line numbers
 218    * code_indices is an array to hold the corresponding list of code indices
 219    */
 220   void get_line_table (jlong& start, jlong& end, jintArray& line_numbers,
 221                        jlongArray& code_indices);
 222
 223   /* Installs a break instruction at the given code index. Returns
 224      the pc_t of the breakpoint or NULL if index is invalid. */
 225   pc_t install_break (jlong index);
 226
 227   // Gets the instruction at the given index
 228   pc_t get_insn (jlong index);
 229
 230   /* Writes the given instruction at the given code index. Returns
 231      the insn or NULL if index is invalid. */
 232   pc_t set_insn (jlong index, pc_t insn);
 233
 234 #ifdef DIRECT_THREADED
 235   friend void _Jv_CompileMethod (_Jv_InterpMethod*);
 236 #endif
 237
 238   friend class _Jv_ClassReader;
 239   friend class _Jv_BytecodeVerifier;
 240   friend class _Jv_StackTrace;
 241   friend class _Jv_InterpreterEngine;
 242
 243 #ifdef JV_MARKOBJ_DECL
 244   friend JV_MARKOBJ_DECL;
 245 #endif
 246 };
 247
 248 class _Jv_InterpClass
 249 {
 250   _Jv_MethodBase **interpreted_methods;
 251   _Jv_ushort     *field_initializers;
 252   jstring source_file_name;
 253
 254   friend class _Jv_ClassReader;
 255   friend class _Jv_InterpMethod;
 256   friend class _Jv_StackTrace;
 257   friend class _Jv_InterpreterEngine;
 258
 259   friend void  _Jv_InitField (jobject, jclass, int);
 260 #ifdef JV_MARKOBJ_DECL
 261   friend JV_MARKOBJ_DECL;
 262 #endif
 263
 264   friend _Jv_MethodBase ** _Jv_GetFirstMethod (_Jv_InterpClass *klass);
 265 };
 266
 267 extern inline _Jv_MethodBase **
 268 _Jv_GetFirstMethod (_Jv_InterpClass *klass)
 269 {
 270   return klass->interpreted_methods;
 271 }
 272
 273 struct _Jv_ResolvedMethod
 274 {
 275   jint            stack_item_count;
 276   jclass          klass;
 277   _Jv_Method*     method;
 278
 279   // a resolved method holds the cif in-line, so that _Jv_MarkObj just needs
 280   // to mark the resolved method to hold on to the cif.  Some memory could be
 281   // saved by keeping a cache of cif's, since many will be the same.
 282   ffi_cif         cif;
 283   ffi_type *      arg_types[0];
 284 };
 285
 286 class _Jv_JNIMethod : public _Jv_MethodBase
 287 {
 288   // The underlying function.  If NULL we have to look for the
 289   // function.
 290   void *function;
 291
 292   // This is the CIF used by the JNI function.
 293   ffi_cif jni_cif;
 294
 295   // These are the argument types used by the JNI function.
 296   ffi_type **jni_arg_types;
 297
 298   // This function is used when making a JNI call from the interpreter.
 299   static void call (ffi_cif *, void *, ffi_raw *, void *);
 300
 301   void *ncode ();
 302
 303   friend class _Jv_ClassReader;
 304   friend class _Jv_InterpreterEngine;
 305
 306 #ifdef JV_MARKOBJ_DECL
 307   friend JV_MARKOBJ_DECL;
 308 #endif
 309
 310 public:
 311   // FIXME: this is ugly.
 312   void set_function (void *f)
 313   {
 314     function = f;
 315   }
 316 };
 317
 318 // The interpreted call stack, represented by a linked list of frames.
 319 struct _Jv_InterpFrame
 320 {
 321   union
 322   {
 323     void *meth;
 324     _Jv_InterpMethod *self;
 325     _Jv_Method *proxyMethod;
 326   };
 327   java::lang::Thread *thread;
 328   _Jv_InterpFrame *next;
 329   union
 330   {
 331     pc_t pc;
 332     jclass proxyClass;
 333   };
 334
 335   _Jv_InterpFrame (void *meth, java::lang::Thread *thr, jclass proxyClass = NULL)
 336   {
 337     this->meth = meth;
 338     thread = thr;
 339     next = (_Jv_InterpFrame *) thr->interp_frame;
 340     thr->interp_frame = (gnu::gcj::RawData *) this;
 341     this->proxyClass = proxyClass;
 342   }
 343
 344   ~_Jv_InterpFrame ()
 345   {
 346     thread->interp_frame = (gnu::gcj::RawData *) next;
 347   }
 348 };
 349
 350 #endif /* INTERPRETER */
 351
 352 #endif /* __JAVA_INTERP_H__ */