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 #include <gnu/gcj/runtime/StackTrace.h>
  26
  27 extern "C" {
  28 #include <ffi.h>
  29 }
  30
  31 extern inline jboolean
  32 _Jv_IsInterpretedClass (jclass c)
  33 {
  34   return (c->accflags & java::lang::reflect::Modifier::INTERPRETED) != 0;
  35 }
  36
  37 struct _Jv_ResolvedMethod;
  38
  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   _Jv_InterpClass *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   friend void _Jv_PrepareClass(jclass);
 155
 156 #ifdef JV_MARKOBJ_DECL
 157   friend JV_MARKOBJ_DECL;
 158 #endif
 159 };
 160
 161 class _Jv_InterpClass : public java::lang::Class
 162 {
 163   _Jv_MethodBase **interpreted_methods;
 164   _Jv_ushort        *field_initializers;
 165
 166   friend class _Jv_ClassReader;
 167   friend class _Jv_InterpMethod;
 168   friend void  _Jv_PrepareClass(jclass);
 169   friend void  _Jv_PrepareMissingMethods (jclass base2, jclass iface_class);
 170   friend void  _Jv_InitField (jobject, jclass, int);
 171 #ifdef JV_MARKOBJ_DECL
 172   friend JV_MARKOBJ_DECL;
 173 #endif
 174
 175   friend _Jv_MethodBase ** _Jv_GetFirstMethod (_Jv_InterpClass *klass);
 176   friend void _Jv_Defer_Resolution (void *cl, _Jv_Method *meth, void **);
 177 };
 178
 179 // We have an interpreted class CL and we're trying to find the
 180 // address of the ncode of a method METH.  That interpreted class
 181 // hasn't yet been prepared, so we defer fixups until they are ready.
 182 // To do this, we create a chain of fixups that will be resolved by
 183 // _Jv_PrepareClass.
 184 extern inline void
 185 _Jv_Defer_Resolution (void *cl, _Jv_Method *meth, void **address)
 186 {
 187   int i;
 188   _Jv_InterpClass *self = (_Jv_InterpClass *)cl;
 189   for (i = 0; i < self->method_count; i++)
 190     {
 191       _Jv_Method *m = &self->methods[i];
 192       if (m == meth)
 193         {
 194           _Jv_MethodBase *imeth = self->interpreted_methods[i];
 195           *address = imeth->deferred;
 196           imeth->deferred = address;
 197           return;
 198         }
 199     }
 200   return;
 201 }
 202
 203 extern inline _Jv_MethodBase **
 204 _Jv_GetFirstMethod (_Jv_InterpClass *klass)
 205 {
 206   return klass->interpreted_methods;
 207 }
 208
 209 struct _Jv_ResolvedMethod {
 210   jint            stack_item_count;
 211   jint            vtable_index;
 212   jclass          klass;
 213   _Jv_Method*     method;
 214
 215   // a resolved method holds the cif in-line, so that _Jv_MarkObj just needs
 216   // to mark the resolved method to hold on to the cif.  Some memory could be
 217   // saved by keeping a cache of cif's, since many will be the same.
 218   ffi_cif         cif;
 219   ffi_type *      arg_types[0];
 220 };
 221
 222 class _Jv_JNIMethod : public _Jv_MethodBase
 223 {
 224   // The underlying function.  If NULL we have to look for the
 225   // function.
 226   void *function;
 227
 228   // This is the CIF used by the JNI function.
 229   ffi_cif jni_cif;
 230
 231   // These are the argument types used by the JNI function.
 232   ffi_type **jni_arg_types;
 233
 234   // This function is used when making a JNI call from the interpreter.
 235   static void call (ffi_cif *, void *, ffi_raw *, void *);
 236
 237   void *ncode ();
 238
 239   friend class _Jv_ClassReader;
 240   friend void _Jv_PrepareClass(jclass);
 241
 242 public:
 243   // FIXME: this is ugly.
 244   void set_function (void *f)
 245   {
 246     function = f;
 247   }
 248 };
 249
 250 // A structure of this type is used to link together interpreter
 251 // invocations on the stack.
 252 struct _Jv_MethodChain
 253 {
 254   const _Jv_InterpMethod *self;
 255   _Jv_MethodChain **ptr;
 256   _Jv_MethodChain *next;
 257
 258   _Jv_MethodChain (const _Jv_InterpMethod *s, _Jv_MethodChain **n)
 259   {
 260     self = s;
 261     ptr = n;
 262     next = *n;
 263     *n = this;
 264   }
 265
 266   ~_Jv_MethodChain ()
 267   {
 268     *ptr = next;
 269   }
 270 };
 271
 272 #endif /* INTERPRETER */
 273
 274 #endif /* __JAVA_INTERP_H__ */