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  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 extern "C" {
  27 #include <ffi.h>
  28 }
  29
  30 extern inline jboolean
  31 _Jv_IsInterpretedClass (jclass c)
  32 {
  33   return (c->accflags & java::lang::reflect::Modifier::INTERPRETED) != 0;
  34 }
  35
  36 struct _Jv_ResolvedMethod;
  37
  38 void _Jv_InitInterpreter ();
  39 void _Jv_DefineClass (jclass, jbyteArray, jint, jint);
  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 /* FIXME: this should really be defined in some more generic place */
  48 #define ROUND(V, A) (((((unsigned) (V))-1) | ((A)-1))+1)
  49
  50 /* the interpreter is written in C++, primarily because it makes it easy for
  51  * the entire thing to be "friend" with class Class. */
  52
  53 class _Jv_InterpClass;
  54 class _Jv_InterpMethod;
  55
  56 // Before a method is "compiled" we store values as the bytecode PC,
  57 // an int.  Afterwards we store them as pointers into the prepared
  58 // code itself.
  59 union _Jv_InterpPC
  60 {
  61   int i;
  62   void *p;
  63 };
  64
  65 class _Jv_InterpException
  66 {
  67   _Jv_InterpPC start_pc;
  68   _Jv_InterpPC end_pc;
  69   _Jv_InterpPC handler_pc;
  70   _Jv_InterpPC handler_type;
  71
  72   friend class _Jv_ClassReader;
  73   friend class _Jv_InterpMethod;
  74   friend class _Jv_BytecodeVerifier;
  75 };
  76
  77 // Base class for method representations.  Subclasses are interpreted
  78 // and JNI methods.
  79 class _Jv_MethodBase
  80 {
  81 protected:
  82   // The class which defined this method.
  83   jclass defining_class;
  84
  85   // The method description.
  86   _Jv_Method *self;
  87
  88   // Size of raw arguments.
  89   _Jv_ushort args_raw_size;
  90
  91   // Chain of addresses to fill in.  See _Jv_Defer_Resolution.
  92   void *deferred;
  93
  94   friend void _Jv_Defer_Resolution (void *cl, _Jv_Method *meth, void **);
  95   friend void _Jv_PrepareClass(jclass);
  96
  97 public:
  98   _Jv_Method *get_method ()
  99   {
 100     return self;
 101   }
 102 };
 103
 104 class _Jv_InterpMethod : public _Jv_MethodBase
 105 {
 106   _Jv_ushort       max_stack;
 107   _Jv_ushort       max_locals;
 108   int              code_length;
 109
 110   _Jv_ushort       exc_count;
 111
 112   void *prepared;
 113
 114   unsigned char* bytecode ()
 115   {
 116     return
 117       ((unsigned char*)this)
 118       + ROUND((sizeof (_Jv_InterpMethod)
 119                + exc_count*sizeof (_Jv_InterpException)), 4);
 120   }
 121
 122   _Jv_InterpException * exceptions ()
 123   {
 124     return (_Jv_InterpException*) (this+1);
 125   }
 126
 127   static size_t size (int exc_count, int code_length)
 128   {
 129     return
 130       ROUND ((sizeof (_Jv_InterpMethod)
 131               + (exc_count * sizeof (_Jv_InterpException))), 4)
 132       + code_length;
 133   }
 134
 135   // return the method's invocation pointer (a stub).
 136   void *ncode ();
 137   void compile (const void * const *);
 138
 139   static void run_normal (ffi_cif*, void*, ffi_raw*, void*);
 140   static void run_synch_object (ffi_cif*, void*, ffi_raw*, void*);
 141   static void run_class (ffi_cif*, void*, ffi_raw*, void*);
 142   static void run_synch_class (ffi_cif*, void*, ffi_raw*, void*);
 143
 144   void run (void*, ffi_raw *);
 145
 146  public:
 147   static void dump_object(jobject o);
 148
 149   friend class _Jv_ClassReader;
 150   friend class _Jv_BytecodeVerifier;
 151   friend class gnu::gcj::runtime::NameFinder;
 152   friend class gnu::gcj::runtime::StackTrace;
 153
 154
 155   friend void _Jv_PrepareClass(jclass);
 156
 157 #ifdef JV_MARKOBJ_DECL
 158   friend JV_MARKOBJ_DECL;
 159 #endif
 160 };
 161
 162 class _Jv_InterpClass
 163 {
 164   _Jv_MethodBase **interpreted_methods;
 165   _Jv_ushort        *field_initializers;
 166
 167   friend class _Jv_ClassReader;
 168   friend class _Jv_InterpMethod;
 169   friend void  _Jv_PrepareClass(jclass);
 170   friend void  _Jv_PrepareMissingMethods (jclass base2, jclass iface_class);
 171   friend void  _Jv_InitField (jobject, jclass, int);
 172 #ifdef JV_MARKOBJ_DECL
 173   friend JV_MARKOBJ_DECL;
 174 #endif
 175
 176   friend _Jv_MethodBase ** _Jv_GetFirstMethod (_Jv_InterpClass *klass);
 177   friend void _Jv_Defer_Resolution (void *cl, _Jv_Method *meth, void **);
 178 };
 179
 180 // We have an interpreted class CL and we're trying to find the
 181 // address of the ncode of a method METH.  That interpreted class
 182 // hasn't yet been prepared, so we defer fixups until they are ready.
 183 // To do this, we create a chain of fixups that will be resolved by
 184 // _Jv_PrepareClass.
 185 extern inline void
 186 _Jv_Defer_Resolution (void *cl, _Jv_Method *meth, void **address)
 187 {
 188   int i;
 189   jclass self = (jclass) cl;
 190   _Jv_InterpClass *interp_cl = (_Jv_InterpClass*) self->aux_info;
 191
 192   for (i = 0; i < self->method_count; i++)
 193     {
 194       _Jv_Method *m = &self->methods[i];
 195       if (m == meth)
 196         {
 197           _Jv_MethodBase *imeth = interp_cl->interpreted_methods[i];
 198           *address = imeth->deferred;
 199           imeth->deferred = address;
 200           return;
 201         }
 202     }
 203   return;
 204 }
 205
 206 extern inline _Jv_MethodBase **
 207 _Jv_GetFirstMethod (_Jv_InterpClass *klass)
 208 {
 209   return klass->interpreted_methods;
 210 }
 211
 212 struct _Jv_ResolvedMethod {
 213   jint            stack_item_count;
 214   jint            vtable_index;
 215   jclass          klass;
 216   _Jv_Method*     method;
 217
 218   // a resolved method holds the cif in-line, so that _Jv_MarkObj just needs
 219   // to mark the resolved method to hold on to the cif.  Some memory could be
 220   // saved by keeping a cache of cif's, since many will be the same.
 221   ffi_cif         cif;
 222   ffi_type *      arg_types[0];
 223 };
 224
 225 class _Jv_JNIMethod : public _Jv_MethodBase
 226 {
 227   // The underlying function.  If NULL we have to look for the
 228   // function.
 229   void *function;
 230
 231   // This is the CIF used by the JNI function.
 232   ffi_cif jni_cif;
 233
 234   // These are the argument types used by the JNI function.
 235   ffi_type **jni_arg_types;
 236
 237   // This function is used when making a JNI call from the interpreter.
 238   static void call (ffi_cif *, void *, ffi_raw *, void *);
 239
 240   void *ncode ();
 241
 242   friend class _Jv_ClassReader;
 243   friend void _Jv_PrepareClass(jclass);
 244
 245 public:
 246   // FIXME: this is ugly.
 247   void set_function (void *f)
 248   {
 249     function = f;
 250   }
 251 };
 252
 253 // A structure of this type is used to link together interpreter
 254 // invocations on the stack.
 255 struct _Jv_MethodChain
 256 {
 257   const _Jv_InterpMethod *self;
 258   _Jv_MethodChain **ptr;
 259   _Jv_MethodChain *next;
 260
 261   _Jv_MethodChain (const _Jv_InterpMethod *s, _Jv_MethodChain **n)
 262   {
 263     self = s;
 264     ptr = n;
 265     next = *n;
 266     *n = this;
 267   }
 268
 269   ~_Jv_MethodChain ()
 270   {
 271     *ptr = next;
 272   }
 273 };
 274
 275 #endif /* INTERPRETER */
 276
 277 #endif /* __JAVA_INTERP_H__ */