1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
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   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_RUNTIME_SIGNATURE_HPP
  26 #define SHARE_RUNTIME_SIGNATURE_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "oops/method.hpp"
  30 
  31 // SignatureIterators iterate over a Java signature (or parts of it).
  32 // (Syntax according to: "The Java Virtual Machine Specification" by
  33 // Tim Lindholm & Frank Yellin; section 4.3 Descriptors; p. 89ff.)
  34 //
  35 // Example: Iterating over ([Lfoo;D)I using
  36 //                         0123456789
  37 //
  38 // iterate_parameters() calls: do_array(2, 7); do_double();
  39 // iterate_returntype() calls:                              do_int();
  40 // iterate()            calls: do_array(2, 7); do_double(); do_int();
  41 //
  42 // is_return_type()        is: false         ; false      ; true
  43 //
  44 // NOTE: The new optimizer has an alternate, for-loop based signature
  45 // iterator implemented in opto/type.cpp, TypeTuple::make().
  46 
  47 class SignatureIterator: public ResourceObj {
  48  protected:
  49   Symbol*      _signature;             // the signature to iterate over
  50   int          _index;                 // the current character index (only valid during iteration)
  51   int          _parameter_index;       // the current parameter index (0 outside iteration phase)
  52   BasicType    _return_type;
  53 
  54   void expect(char c);
  55   int  parse_type();                   // returns the parameter size in words (0 for void)
  56   void check_signature_end();
  57 
  58  public:
  59   // Definitions used in generating and iterating the
  60   // bit field form of the signature generated by the
  61   // Fingerprinter.
  62   enum {
  63     static_feature_size    = 1,
  64     is_static_bit          = 1,
  65 
  66     result_feature_size    = 4,
  67     result_feature_mask    = 0xF,
  68     parameter_feature_size = 4,
  69     parameter_feature_mask = 0xF,
  70 
  71       bool_parm            = 1,
  72       byte_parm            = 2,
  73       char_parm            = 3,
  74       short_parm           = 4,
  75       int_parm             = 5,
  76       long_parm            = 6,
  77       float_parm           = 7,
  78       double_parm          = 8,
  79       obj_parm             = 9,
  80       done_parm            = 10,  // marker for end of parameters
  81 
  82     // max parameters is wordsize minus
  83     //    The sign bit, termination field, the result and static bit fields
  84     max_size_of_parameters = (BitsPerLong-1 -
  85                               result_feature_size - parameter_feature_size -
  86                               static_feature_size) / parameter_feature_size
  87   };
  88 
  89   // Constructors
  90   SignatureIterator(Symbol* signature);
  91 
  92   // Iteration
  93   void dispatch_field();               // dispatches once for field signatures
  94   void iterate_parameters();           // iterates over parameters only
  95   void iterate_parameters( uint64_t fingerprint );
  96   void iterate_returntype();           // iterates over returntype only
  97   void iterate();                      // iterates over whole signature
  98   // Returns the word index of the current parameter;
  99   int  parameter_index() const         { return _parameter_index; }
 100   bool is_return_type() const          { return parameter_index() < 0; }
 101   BasicType get_ret_type() const       { return _return_type; }
 102 
 103   // Basic types
 104   virtual void do_bool  ()             = 0;
 105   virtual void do_char  ()             = 0;
 106   virtual void do_float ()             = 0;
 107   virtual void do_double()             = 0;
 108   virtual void do_byte  ()             = 0;
 109   virtual void do_short ()             = 0;
 110   virtual void do_int   ()             = 0;
 111   virtual void do_long  ()             = 0;
 112   virtual void do_void  ()             = 0;
 113 
 114   // Object types (begin indexes the first character of the entry, end indexes the first character after the entry)
 115   virtual void do_object(int begin, int end) = 0;
 116   virtual void do_array (int begin, int end) = 0;
 117 
 118   static bool is_static(uint64_t fingerprint) {
 119     assert(fingerprint != (uint64_t)CONST64(-1), "invalid fingerprint");
 120     return fingerprint & is_static_bit;
 121   }
 122   static BasicType return_type(uint64_t fingerprint) {
 123     assert(fingerprint != (uint64_t)CONST64(-1), "invalid fingerprint");
 124     return (BasicType) ((fingerprint >> static_feature_size) & result_feature_mask);
 125   }
 126 };
 127 
 128 
 129 // Specialized SignatureIterators: Used to compute signature specific values.
 130 
 131 class SignatureTypeNames : public SignatureIterator {
 132  protected:
 133   virtual void type_name(const char* name)   = 0;
 134 
 135   void do_bool()                       { type_name("jboolean"); }
 136   void do_char()                       { type_name("jchar"   ); }
 137   void do_float()                      { type_name("jfloat"  ); }
 138   void do_double()                     { type_name("jdouble" ); }
 139   void do_byte()                       { type_name("jbyte"   ); }
 140   void do_short()                      { type_name("jshort"  ); }
 141   void do_int()                        { type_name("jint"    ); }
 142   void do_long()                       { type_name("jlong"   ); }
 143   void do_void()                       { type_name("void"    ); }
 144   void do_object(int begin, int end)   { type_name("jobject" ); }
 145   void do_array (int begin, int end)   { type_name("jobject" ); }
 146 
 147  public:
 148   SignatureTypeNames(Symbol* signature) : SignatureIterator(signature) {}
 149 };
 150 
 151 
 152 class SignatureInfo: public SignatureIterator {
 153  protected:
 154   bool      _has_iterated;             // need this because iterate cannot be called in constructor (set is virtual!)
 155   bool      _has_iterated_return;
 156   int       _size;
 157 
 158   void lazy_iterate_parameters()       { if (!_has_iterated) { iterate_parameters(); _has_iterated = true; } }
 159   void lazy_iterate_return()           { if (!_has_iterated_return) { iterate_returntype(); _has_iterated_return = true; } }
 160 
 161   virtual void set(int size, BasicType type) = 0;
 162 
 163   void do_bool  ()                     { set(T_BOOLEAN_size, T_BOOLEAN); }
 164   void do_char  ()                     { set(T_CHAR_size   , T_CHAR   ); }
 165   void do_float ()                     { set(T_FLOAT_size  , T_FLOAT  ); }
 166   void do_double()                     { set(T_DOUBLE_size , T_DOUBLE ); }
 167   void do_byte  ()                     { set(T_BYTE_size   , T_BYTE   ); }
 168   void do_short ()                     { set(T_SHORT_size  , T_SHORT  ); }
 169   void do_int   ()                     { set(T_INT_size    , T_INT    ); }
 170   void do_long  ()                     { set(T_LONG_size   , T_LONG   ); }
 171   void do_void  ()                     { set(T_VOID_size   , T_VOID   ); }
 172   void do_object(int begin, int end)   { set(T_OBJECT_size , T_OBJECT ); }
 173   void do_array (int begin, int end)   { set(T_ARRAY_size  , T_ARRAY  ); }
 174 
 175  public:
 176   SignatureInfo(Symbol* signature) : SignatureIterator(signature) {
 177     _has_iterated = _has_iterated_return = false;
 178     _size         = 0;
 179     _return_type  = T_ILLEGAL;
 180   }
 181 
 182 };
 183 
 184 
 185 // Specialized SignatureIterator: Used to compute the argument size.
 186 
 187 class ArgumentSizeComputer: public SignatureInfo {
 188  private:
 189   void set(int size, BasicType type)   { _size += size; }
 190  public:
 191   ArgumentSizeComputer(Symbol* signature) : SignatureInfo(signature) {}
 192 
 193   int       size()                     { lazy_iterate_parameters(); return _size; }
 194 };
 195 
 196 
 197 class ArgumentCount: public SignatureInfo {
 198  private:
 199   void set(int size, BasicType type)   { _size ++; }
 200  public:
 201   ArgumentCount(Symbol* signature) : SignatureInfo(signature) {}
 202 
 203   int       size()                     { lazy_iterate_parameters(); return _size; }
 204 };
 205 
 206 
 207 // Specialized SignatureIterator: Used to compute the result type.
 208 
 209 class ResultTypeFinder: public SignatureInfo {
 210  private:
 211   void set(int size, BasicType type)   { _return_type = type; }
 212  public:
 213   BasicType type()                     { lazy_iterate_return(); return _return_type; }
 214 
 215   ResultTypeFinder(Symbol* signature) : SignatureInfo(signature) {}
 216 };
 217 
 218 
 219 // Fingerprinter computes a unique ID for a given method. The ID
 220 // is a bitvector characterizing the methods signature (incl. the receiver).
 221 class Fingerprinter: public SignatureIterator {
 222  private:
 223   uint64_t _fingerprint;
 224   int _shift_count;
 225   methodHandle mh;
 226 
 227  public:
 228 
 229   void do_bool()    { _fingerprint |= (((uint64_t)bool_parm) << _shift_count); _shift_count += parameter_feature_size; }
 230   void do_char()    { _fingerprint |= (((uint64_t)char_parm) << _shift_count); _shift_count += parameter_feature_size; }
 231   void do_byte()    { _fingerprint |= (((uint64_t)byte_parm) << _shift_count); _shift_count += parameter_feature_size; }
 232   void do_short()   { _fingerprint |= (((uint64_t)short_parm) << _shift_count); _shift_count += parameter_feature_size; }
 233   void do_int()     { _fingerprint |= (((uint64_t)int_parm) << _shift_count); _shift_count += parameter_feature_size; }
 234   void do_long()    { _fingerprint |= (((uint64_t)long_parm) << _shift_count); _shift_count += parameter_feature_size; }
 235   void do_float()   { _fingerprint |= (((uint64_t)float_parm) << _shift_count); _shift_count += parameter_feature_size; }
 236   void do_double()  { _fingerprint |= (((uint64_t)double_parm) << _shift_count); _shift_count += parameter_feature_size; }
 237 
 238   void do_object(int begin, int end)  { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; }
 239   void do_array (int begin, int end)  { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; }
 240 
 241   void do_void()    { ShouldNotReachHere(); }
 242 
 243   Fingerprinter(const methodHandle& method) : SignatureIterator(method->signature()) {
 244     mh = method;
 245     _fingerprint = 0;
 246   }
 247 
 248   uint64_t fingerprint() {
 249     // See if we fingerprinted this method already
 250     if (mh->constMethod()->fingerprint() != CONST64(0)) {
 251       return mh->constMethod()->fingerprint();
 252     }
 253 
 254     if (mh->size_of_parameters() > max_size_of_parameters ) {
 255       _fingerprint = (uint64_t)CONST64(-1);
 256       mh->constMethod()->set_fingerprint(_fingerprint);
 257       return _fingerprint;
 258     }
 259 
 260     assert( (int)mh->result_type() <= (int)result_feature_mask, "bad result type");
 261     _fingerprint = mh->result_type();
 262     _fingerprint <<= static_feature_size;
 263     if (mh->is_static())  _fingerprint |= 1;
 264     _shift_count = result_feature_size + static_feature_size;
 265     iterate_parameters();
 266     _fingerprint |= ((uint64_t)done_parm) << _shift_count;// mark end of sig
 267     mh->constMethod()->set_fingerprint(_fingerprint);
 268     return _fingerprint;
 269   }
 270 };
 271 
 272 
 273 // Specialized SignatureIterator: Used for native call purposes
 274 
 275 class NativeSignatureIterator: public SignatureIterator {
 276  private:
 277   methodHandle _method;
 278 // We need separate JNI and Java offset values because in 64 bit mode,
 279 // the argument offsets are not in sync with the Java stack.
 280 // For example a long takes up 1 "C" stack entry but 2 Java stack entries.
 281   int          _offset;                // The java stack offset
 282   int          _prepended;             // number of prepended JNI parameters (1 JNIEnv, plus 1 mirror if static)
 283   int          _jni_offset;            // the current parameter offset, starting with 0
 284 
 285   void do_bool  ()                     { pass_int();    _jni_offset++; _offset++;       }
 286   void do_char  ()                     { pass_int();    _jni_offset++; _offset++;       }
 287   void do_float ()                     { pass_float();  _jni_offset++; _offset++;       }
 288 #ifdef _LP64
 289   void do_double()                     { pass_double(); _jni_offset++; _offset += 2;    }
 290 #else
 291   void do_double()                     { pass_double(); _jni_offset += 2; _offset += 2; }
 292 #endif
 293   void do_byte  ()                     { pass_int();    _jni_offset++; _offset++;       }
 294   void do_short ()                     { pass_int();    _jni_offset++; _offset++;       }
 295   void do_int   ()                     { pass_int();    _jni_offset++; _offset++;       }
 296 #ifdef _LP64
 297   void do_long  ()                     { pass_long();   _jni_offset++; _offset += 2;    }
 298 #else
 299   void do_long  ()                     { pass_long();   _jni_offset += 2; _offset += 2; }
 300 #endif
 301   void do_void  ()                     { ShouldNotReachHere();                               }
 302   void do_object(int begin, int end)   { pass_object(); _jni_offset++; _offset++;        }
 303   void do_array (int begin, int end)   { pass_object(); _jni_offset++; _offset++;        }
 304 
 305  public:
 306   methodHandle method() const          { return _method; }
 307   int          offset() const          { return _offset; }
 308   int      jni_offset() const          { return _jni_offset + _prepended; }
 309 //  int     java_offset() const          { return method()->size_of_parameters() - _offset - 1; }
 310   bool      is_static() const          { return method()->is_static(); }
 311   virtual void pass_int()              = 0;
 312   virtual void pass_long()             = 0;
 313   virtual void pass_object()           = 0;
 314   virtual void pass_float()            = 0;
 315 #ifdef _LP64
 316   virtual void pass_double()           = 0;
 317 #else
 318   virtual void pass_double()           { pass_long(); }  // may be same as long
 319 #endif
 320 
 321   NativeSignatureIterator(const methodHandle& method) : SignatureIterator(method->signature()) {
 322     _method = method;
 323     _offset = 0;
 324     _jni_offset = 0;
 325 
 326     const int JNIEnv_words = 1;
 327     const int mirror_words = 1;
 328     _prepended = !is_static() ? JNIEnv_words : JNIEnv_words + mirror_words;
 329   }
 330 
 331   // iterate() calles the 2 virtual methods according to the following invocation syntax:
 332   //
 333   // {pass_int | pass_long | pass_object}
 334   //
 335   // Arguments are handled from left to right (receiver first, if any).
 336   // The offset() values refer to the Java stack offsets but are 0 based and increasing.
 337   // The java_offset() values count down to 0, and refer to the Java TOS.
 338   // The jni_offset() values increase from 1 or 2, and refer to C arguments.
 339 
 340   void iterate() { iterate(Fingerprinter(method()).fingerprint());
 341   }
 342 
 343 
 344   // Optimized path if we have the bitvector form of signature
 345   void iterate( uint64_t fingerprint ) {
 346 
 347     if (!is_static()) {
 348       // handle receiver (not handled by iterate because not in signature)
 349       pass_object(); _jni_offset++; _offset++;
 350     }
 351 
 352     SignatureIterator::iterate_parameters( fingerprint );
 353   }
 354 };
 355 
 356 
 357 // Handy stream for iterating over signature
 358 
 359 class SignatureStream : public StackObj {
 360  private:
 361   Symbol*      _signature;
 362   int          _begin;
 363   int          _end;
 364   BasicType    _type;
 365   bool         _at_return_type;
 366   GrowableArray<Symbol*>* _names;  // symbols created while parsing signature
 367 
 368  public:
 369   bool at_return_type() const                    { return _at_return_type; }
 370   bool is_done() const;
 371   void next_non_primitive(int t);
 372   void next() {
 373     Symbol* sig = _signature;
 374     int len = sig->utf8_length();
 375     if (_end >= len) {
 376       _end = len + 1;
 377       return;
 378     }
 379 
 380     _begin = _end;
 381     int t = sig->char_at(_begin);
 382     switch (t) {
 383       case 'B': _type = T_BYTE;    break;
 384       case 'C': _type = T_CHAR;    break;
 385       case 'D': _type = T_DOUBLE;  break;
 386       case 'F': _type = T_FLOAT;   break;
 387       case 'I': _type = T_INT;     break;
 388       case 'J': _type = T_LONG;    break;
 389       case 'S': _type = T_SHORT;   break;
 390       case 'Z': _type = T_BOOLEAN; break;
 391       case 'V': _type = T_VOID;    break;
 392       default : next_non_primitive(t);
 393                 return;
 394     }
 395     _end++;
 396   }
 397 
 398   SignatureStream(Symbol* signature, bool is_method = true);
 399   ~SignatureStream();
 400 
 401   bool is_object() const;                        // True if this argument is an object
 402   bool is_array() const;                         // True if this argument is an array
 403   BasicType type() const                         { return _type; }
 404   Symbol* as_symbol(TRAPS);
 405   enum FailureMode { ReturnNull, CNFException, NCDFError };
 406   Klass* as_klass(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
 407   oop as_java_mirror(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
 408   const u1* raw_bytes()  { return _signature->bytes() + _begin; }
 409   int       raw_length() { return _end - _begin; }
 410 
 411   // return same as_symbol except allocation of new symbols is avoided.
 412   Symbol* as_symbol_or_null();
 413 
 414   // count the number of references in the signature
 415   int reference_parameter_count();
 416 };
 417 
 418 class SignatureVerifier : public StackObj {
 419   public:
 420     // Returns true if the symbol is valid method or type signature
 421     static bool is_valid_signature(Symbol* sig);
 422 
 423     static bool is_valid_method_signature(Symbol* sig);
 424     static bool is_valid_type_signature(Symbol* sig);
 425   private:
 426 
 427     static ssize_t is_valid_type(const char*, ssize_t);
 428     static bool invalid_name_char(char);
 429 };
 430 
 431 #endif // SHARE_RUNTIME_SIGNATURE_HPP