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