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