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