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).
  14  *
  15  * You should have received a copy of the GNU General Public License version
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  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_VM_OOPS_CONSTMETHODOOP_HPP
  26 #define SHARE_VM_OOPS_CONSTMETHODOOP_HPP
  27 
  28 #include "oops/oop.hpp"
  29 
  30 // An ConstMethod represents portions of a Java method which are not written to after
  31 // the classfile is parsed(*see below).  This part of the method can be shared across
  32 // processes in a read-only section with Class Data Sharing (CDS).  It's important
  33 // that this class doesn't have virtual functions because the vptr cannot be shared
  34 // with CDS.
  35 //
  36 // Note that most applications load thousands of methods, so keeping the size of this
  37 // structure small has a big impact on footprint.
  38 
  39 // The actual bytecodes are inlined after the end of the ConstMethod struct.
  40 //
  41 // The line number table is compressed and inlined following the byte codes. It is
  42 // found as the first byte following the byte codes.  Note that accessing the line
  43 // number and local variable tables is not performance critical at all.
  44 //
  45 // The checked exceptions table and the local variable table are inlined after the
  46 // line number table, and indexed from the end of the method. We do not compress the
  47 // checked exceptions table since the average length is less than 2, and it is used
  48 // by reflection so access should be fast.  We do not bother to compress the local
  49 // variable table either since it is mostly absent.
  50 //
  51 //
  52 //  ConstMethod embedded field layout (after declared fields):
  53 //    [EMBEDDED byte codes]
  54 //    [EMBEDDED compressed linenumber table]
  55 //     (see class CompressedLineNumberReadStream)
  56 //     (note that length is unknown until decompressed)
  57 //     (access flags bit tells whether table is present)
  58 //     (indexed from start of ConstMethod)
  59 //     (elements not necessarily sorted!)
  60 //    [EMBEDDED localvariable table elements + length (length last)]
  61 //     (length is u2, elements are 6-tuples of u2)
  62 //     (see class LocalVariableTableElement)
  63 //     (access flags bit tells whether table is present)
  64 //     (indexed from end of ConstMethod*)
  65 //    [EMBEDDED exception table + length (length last)]
  66 //     (length is u2, elements are 4-tuples of u2)
  67 //     (see class ExceptionTableElement)
  68 //     (access flags bit tells whether table is present)
  69 //     (indexed from end of ConstMethod*)
  70 //    [EMBEDDED checked exceptions elements + length (length last)]
  71 //     (length is u2, elements are u2)
  72 //     (see class CheckedExceptionElement)
  73 //     (access flags bit tells whether table is present)
  74 //     (indexed from end of ConstMethod*)
  75 //    [EMBEDDED method parameters elements + length (length last)]
  76 //     (length is u2, elements are u2, u4 structures)
  77 //     (see class MethodParametersElement)
  78 //     (access flags bit tells whether table is present)
  79 //     (indexed from end of ConstMethod*)
  80 //    [EMBEDDED generic signature index (u2)]
  81 //     (indexed from end of constMethodOop)
  82 //    [EMBEDDED annotations arrays - method, parameter, type, default]
  83 //      pointer to Array<u1> if annotation is present
  84 //
  85 // IMPORTANT: If anything gets added here, there need to be changes to
  86 // ensure that ServicabilityAgent doesn't get broken as a result!
  87 
  88 
  89 // Utility class describing elements in checked exceptions table inlined in Method*.
  90 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC {
  91  public:
  92   u2 class_cp_index;
  93 };
  94 
  95 
  96 // Utility class describing elements in local variable table inlined in Method*.
  97 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC {
  98  public:
  99   u2 start_bci;
 100   u2 length;
 101   u2 name_cp_index;
 102   u2 descriptor_cp_index;
 103   u2 signature_cp_index;
 104   u2 slot;
 105 };
 106 
 107 // Utility class describing elements in exception table
 108 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC {
 109  public:
 110   u2 start_pc;
 111   u2 end_pc;
 112   u2 handler_pc;
 113   u2 catch_type_index;
 114 };
 115 
 116 // Utility class describing elements in method parameters
 117 class MethodParametersElement VALUE_OBJ_CLASS_SPEC {
 118  public:
 119   u2 name_cp_index;
 120   u2 flags;
 121 };
 122 
 123 class KlassSizeStats;
 124 class AdapterHandlerEntry;
 125 
 126 // Class to collect the sizes of ConstMethod inline tables
 127 #define INLINE_TABLES_DO(do_element)            \
 128   do_element(localvariable_table_length)        \
 129   do_element(compressed_linenumber_size)        \
 130   do_element(exception_table_length)            \
 131   do_element(checked_exceptions_length)         \
 132   do_element(method_parameters_length)          \
 133   do_element(generic_signature_index)           \
 134   do_element(method_annotations_length)         \
 135   do_element(parameter_annotations_length)      \
 136   do_element(type_annotations_length)           \
 137   do_element(default_annotations_length)
 138 
 139 #define INLINE_TABLE_DECLARE(sym)    int _##sym;
 140 #define INLINE_TABLE_PARAM(sym)      int sym,
 141 #define INLINE_TABLE_INIT(sym)       _##sym(sym),
 142 #define INLINE_TABLE_NULL(sym)       _##sym(0),
 143 #define INLINE_TABLE_ACCESSOR(sym)   int sym() const { return _##sym; }
 144 
 145 class InlineTableSizes : StackObj {
 146   // declarations
 147   INLINE_TABLES_DO(INLINE_TABLE_DECLARE)
 148   int _end;
 149  public:
 150   InlineTableSizes(
 151       INLINE_TABLES_DO(INLINE_TABLE_PARAM)
 152       int end) :
 153       INLINE_TABLES_DO(INLINE_TABLE_INIT)
 154       _end(end) {}
 155 
 156   // Default constructor for no inlined tables
 157   InlineTableSizes() :
 158       INLINE_TABLES_DO(INLINE_TABLE_NULL)
 159       _end(0) {}
 160 
 161   // Accessors
 162   INLINE_TABLES_DO(INLINE_TABLE_ACCESSOR)
 163 };
 164 #undef INLINE_TABLE_ACCESSOR
 165 #undef INLINE_TABLE_NULL
 166 #undef INLINE_TABLE_INIT
 167 #undef INLINE_TABLE_PARAM
 168 #undef INLINE_TABLE_DECLARE
 169 
 170 class ConstMethod : public MetaspaceObj {
 171   friend class VMStructs;
 172   friend class JVMCIVMStructs;
 173 
 174 public:
 175   typedef enum { NORMAL, OVERPASS } MethodType;
 176 
 177 private:
 178   enum {
 179     _has_linenumber_table = 0x0001,
 180     _has_checked_exceptions = 0x0002,
 181     _has_localvariable_table = 0x0004,
 182     _has_exception_table = 0x0008,
 183     _has_generic_signature = 0x0010,
 184     _has_method_parameters = 0x0020,
 185     _is_overpass = 0x0040,
 186     _has_method_annotations = 0x0080,
 187     _has_parameter_annotations = 0x0100,
 188     _has_type_annotations = 0x0200,
 189     _has_default_annotations = 0x0400
 190   };
 191 
 192   // Bit vector of signature
 193   // Callers interpret 0=not initialized yet and
 194   // -1=too many args to fix, must parse the slow way.
 195   // The real initial value is special to account for nonatomicity of 64 bit
 196   // loads and stores.  This value may updated and read without a lock by
 197   // multiple threads, so is volatile.
 198   volatile uint64_t _fingerprint;
 199 
 200   ConstantPool*     _constants;                  // Constant pool
 201 
 202   // Raw stackmap data for the method
 203   Array<u1>*        _stackmap_data;
 204 
 205   // Adapter blob (i2c/c2i) for this Method*. Set once when method is linked.
 206   union {
 207     AdapterHandlerEntry* _adapter;
 208     AdapterHandlerEntry** _adapter_trampoline;
 209   };
 210 
 211   int               _constMethod_size;
 212   u2                _flags;
 213 
 214   // Size of Java bytecodes allocated immediately after Method*.
 215   u2                _code_size;
 216   u2                _name_index;                 // Method name (index in constant pool)
 217   u2                _signature_index;            // Method signature (index in constant pool)
 218   u2                _method_idnum;               // unique identification number for the method within the class
 219                                                  // initially corresponds to the index into the methods array.
 220                                                  // but this may change with redefinition
 221   u2                _max_stack;                  // Maximum number of entries on the expression stack
 222   u2                _max_locals;                 // Number of local variables used by this method
 223   u2                _size_of_parameters;         // size of the parameter block (receiver + arguments) in words
 224   u2                _orig_method_idnum;          // Original unique identification number for the method
 225 
 226   // Constructor
 227   ConstMethod(int byte_code_size,
 228               InlineTableSizes* sizes,
 229               MethodType is_overpass,
 230               int size);
 231 public:
 232 
 233   static ConstMethod* allocate(ClassLoaderData* loader_data,
 234                                int byte_code_size,
 235                                InlineTableSizes* sizes,
 236                                MethodType mt,
 237                                TRAPS);
 238 
 239   bool is_constMethod() const { return true; }
 240 
 241   // Inlined tables
 242   void set_inlined_tables_length(InlineTableSizes* sizes);
 243 
 244   bool has_generic_signature() const
 245     { return (_flags & _has_generic_signature) != 0; }
 246 
 247   bool has_linenumber_table() const
 248     { return (_flags & _has_linenumber_table) != 0; }
 249 
 250   bool has_checked_exceptions() const
 251     { return (_flags & _has_checked_exceptions) != 0; }
 252 
 253   bool has_localvariable_table() const
 254     { return (_flags & _has_localvariable_table) != 0; }
 255 
 256   bool has_exception_handler() const
 257     { return (_flags & _has_exception_table) != 0; }
 258 
 259   bool has_method_parameters() const
 260     { return (_flags & _has_method_parameters) != 0; }
 261 
 262   MethodType method_type() const {
 263     return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
 264   }
 265 
 266   void set_method_type(MethodType mt) {
 267     if (mt == NORMAL) {
 268       _flags &= ~(_is_overpass);
 269     } else {
 270       _flags |= _is_overpass;
 271     }
 272   }
 273 
 274   // constant pool
 275   ConstantPool* constants() const        { return _constants; }
 276   void set_constants(ConstantPool* c)    { _constants = c; }
 277 
 278   Method* method() const;
 279 
 280   // stackmap table data
 281   Array<u1>* stackmap_data() const { return _stackmap_data; }
 282   void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
 283   void copy_stackmap_data(ClassLoaderData* loader_data, u1* sd, int length, TRAPS);
 284   bool has_stackmap_table() const { return _stackmap_data != NULL; }
 285 
 286   // adapter
 287   void set_adapter_entry(AdapterHandlerEntry* adapter) {
 288     assert(!is_shared(), "shared methods have fixed adapter_trampoline");
 289     _adapter = adapter;
 290   }
 291   void set_adapter_trampoline(AdapterHandlerEntry** trampoline) {
 292     assert(DumpSharedSpaces, "must be");
 293     assert(*trampoline == NULL, "must be NULL during dump time, to be initialized at run time");
 294     _adapter_trampoline = trampoline;
 295   }
 296   void update_adapter_trampoline(AdapterHandlerEntry* adapter) {
 297     assert(is_shared(), "must be");
 298     *_adapter_trampoline = adapter;
 299     assert(this->adapter() == adapter, "must be");
 300   }
 301   AdapterHandlerEntry* adapter() {
 302     if (is_shared()) {
 303       return *_adapter_trampoline;
 304     } else {
 305       return _adapter;
 306     }
 307   }
 308 
 309   void init_fingerprint() {
 310     const uint64_t initval = UCONST64(0x8000000000000000);
 311     _fingerprint = initval;
 312   }
 313 
 314   uint64_t fingerprint() const                   {
 315     // Since reads aren't atomic for 64 bits, if any of the high or low order
 316     // word is the initial value, return 0.  See init_fingerprint for initval.
 317     uint high_fp = (uint)(_fingerprint >> 32);
 318     if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
 319       return 0L;
 320     } else {
 321       return _fingerprint;
 322     }
 323   }
 324 
 325   uint64_t set_fingerprint(uint64_t new_fingerprint) {
 326 #ifdef ASSERT
 327     // Assert only valid if complete/valid 64 bit _fingerprint value is read.
 328     uint64_t oldfp = fingerprint();
 329 #endif // ASSERT
 330     _fingerprint = new_fingerprint;
 331     assert(oldfp == 0L || new_fingerprint == oldfp,
 332            "fingerprint cannot change");
 333     assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
 334            "fingerprint should call init to set initial value");
 335     return new_fingerprint;
 336   }
 337 
 338   // name
 339   int name_index() const                         { return _name_index; }
 340   void set_name_index(int index)                 { _name_index = index; }
 341 
 342   // signature
 343   int signature_index() const                    { return _signature_index; }
 344   void set_signature_index(int index)            { _signature_index = index; }
 345 
 346   // generics support
 347   int generic_signature_index() const            {
 348     if (has_generic_signature()) {
 349       return *generic_signature_index_addr();
 350     } else {
 351       return 0;
 352     }
 353   }
 354   void set_generic_signature_index(u2 index)    {
 355     assert(has_generic_signature(), "");
 356     u2* addr = generic_signature_index_addr();
 357     *addr = index;
 358   }
 359 
 360   // Sizing
 361   static int header_size() { return sizeof(ConstMethod)/wordSize; }
 362 
 363   // Size needed
 364   static int size(int code_size, InlineTableSizes* sizes);
 365 
 366   int size() const                    { return _constMethod_size;}
 367   void set_constMethod_size(int size)     { _constMethod_size = size; }
 368 #if INCLUDE_SERVICES
 369   void collect_statistics(KlassSizeStats *sz) const;
 370 #endif
 371 
 372   // code size
 373   int code_size() const                          { return _code_size; }
 374   void set_code_size(int size) {
 375     assert(max_method_code_size < (1 << 16),
 376            "u2 is too small to hold method code size in general");
 377     assert(0 <= size && size <= max_method_code_size, "invalid code size");
 378     _code_size = size;
 379   }
 380 
 381   // linenumber table - note that length is unknown until decompression,
 382   // see class CompressedLineNumberReadStream.
 383   u_char* compressed_linenumber_table() const;         // not preserved by gc
 384   u2* generic_signature_index_addr() const;
 385   u2* checked_exceptions_length_addr() const;
 386   u2* localvariable_table_length_addr() const;
 387   u2* exception_table_length_addr() const;
 388   u2* method_parameters_length_addr() const;
 389 
 390   // checked exceptions
 391   int checked_exceptions_length() const;
 392   CheckedExceptionElement* checked_exceptions_start() const;
 393 
 394   // localvariable table
 395   int localvariable_table_length() const;
 396   LocalVariableTableElement* localvariable_table_start() const;
 397 
 398   // exception table
 399   int exception_table_length() const;
 400   ExceptionTableElement* exception_table_start() const;
 401 
 402   // method parameters table
 403 
 404   // This returns -1 if no parameters are present, a non-negative
 405   // value otherwise.  Note: sometimes, there are 0-length parameters
 406   // attributes that must be reported up to the reflection API all the
 407   // same.
 408   int method_parameters_length() const;
 409   MethodParametersElement* method_parameters_start() const;
 410 
 411   // method annotations
 412   bool has_method_annotations() const
 413     { return (_flags & _has_method_annotations) != 0; }
 414 
 415   bool has_parameter_annotations() const
 416     { return (_flags & _has_parameter_annotations) != 0; }
 417 
 418   bool has_type_annotations() const
 419     { return (_flags & _has_type_annotations) != 0; }
 420 
 421   bool has_default_annotations() const
 422     { return (_flags & _has_default_annotations) != 0; }
 423 
 424 
 425   AnnotationArray** method_annotations_addr() const;
 426   AnnotationArray* method_annotations() const  {
 427     return has_method_annotations() ? *(method_annotations_addr()) : NULL;
 428   }
 429   void set_method_annotations(AnnotationArray* anno) {
 430     *(method_annotations_addr()) = anno;
 431   }
 432 
 433   AnnotationArray** parameter_annotations_addr() const;
 434   AnnotationArray* parameter_annotations() const {
 435     return has_parameter_annotations() ? *(parameter_annotations_addr()) : NULL;
 436   }
 437   void set_parameter_annotations(AnnotationArray* anno) {
 438     *(parameter_annotations_addr()) = anno;
 439   }
 440 
 441   AnnotationArray** type_annotations_addr() const;
 442   AnnotationArray* type_annotations() const {
 443     return has_type_annotations() ? *(type_annotations_addr()) : NULL;
 444   }
 445   void set_type_annotations(AnnotationArray* anno) {
 446     *(type_annotations_addr()) = anno;
 447   }
 448 
 449   AnnotationArray** default_annotations_addr() const;
 450   AnnotationArray* default_annotations() const {
 451     return has_default_annotations() ? *(default_annotations_addr()) : NULL;
 452   }
 453   void set_default_annotations(AnnotationArray* anno) {
 454     *(default_annotations_addr()) = anno;
 455   }
 456 
 457   int method_annotations_length() const {
 458     return has_method_annotations() ? method_annotations()->length() : 0;
 459   }
 460   int parameter_annotations_length() const {
 461     return has_parameter_annotations() ? parameter_annotations()->length() : 0;
 462   }
 463   int type_annotations_length() const {
 464     return has_type_annotations() ? type_annotations()->length() : 0;
 465   }
 466   int default_annotations_length() const {
 467     return has_default_annotations() ? default_annotations()->length() : 0;
 468   }
 469 
 470   // Copy annotations from other ConstMethod
 471   void copy_annotations_from(ConstMethod* cm);
 472 
 473   // byte codes
 474   void    set_code(address code) {
 475     if (code_size() > 0) {
 476       memcpy(code_base(), code, code_size());
 477     }
 478   }
 479   address code_base() const            { return (address) (this+1); }
 480   address code_end() const             { return code_base() + code_size(); }
 481   bool    contains(address bcp) const  { return code_base() <= bcp
 482                                                      && bcp < code_end(); }
 483   // Offset to bytecodes
 484   static ByteSize codes_offset()
 485                             { return in_ByteSize(sizeof(ConstMethod)); }
 486 
 487   static ByteSize constants_offset()
 488                             { return byte_offset_of(ConstMethod, _constants); }
 489 
 490   static ByteSize max_stack_offset()
 491                             { return byte_offset_of(ConstMethod, _max_stack); }
 492   static ByteSize size_of_locals_offset()
 493                             { return byte_offset_of(ConstMethod, _max_locals); }
 494   static ByteSize size_of_parameters_offset()
 495                             { return byte_offset_of(ConstMethod, _size_of_parameters); }
 496 
 497 
 498   // Unique id for the method
 499   static const u2 MAX_IDNUM;
 500   static const u2 UNSET_IDNUM;
 501   u2 method_idnum() const                        { return _method_idnum; }
 502   void set_method_idnum(u2 idnum)                { _method_idnum = idnum; }
 503 
 504   u2 orig_method_idnum() const                   { return _orig_method_idnum; }
 505   void set_orig_method_idnum(u2 idnum)           { _orig_method_idnum = idnum; }
 506 
 507   // max stack
 508   int  max_stack() const                         { return _max_stack; }
 509   void set_max_stack(int size)                   { _max_stack = size; }
 510 
 511   // max locals
 512   int  max_locals() const                        { return _max_locals; }
 513   void set_max_locals(int size)                  { _max_locals = size; }
 514 
 515   // size of parameters
 516   int  size_of_parameters() const                { return _size_of_parameters; }
 517   void set_size_of_parameters(int size)          { _size_of_parameters = size; }
 518 
 519   // Deallocation for RedefineClasses
 520   void deallocate_contents(ClassLoaderData* loader_data);
 521   bool is_klass() const { return false; }
 522   DEBUG_ONLY(bool on_stack() { return false; })
 523 
 524 private:
 525   // Since the size of the compressed line number table is unknown, the
 526   // offsets of the other variable sized sections are computed backwards
 527   // from the end of the ConstMethod*.
 528 
 529   // First byte after ConstMethod*
 530   address constMethod_end() const
 531                           { return (address)((intptr_t*)this + _constMethod_size); }
 532 
 533   // Last short in ConstMethod*
 534   u2* last_u2_element() const;
 535 
 536  public:
 537   // Printing
 538   void print_on      (outputStream* st) const;
 539   void print_value_on(outputStream* st) const;
 540 
 541   const char* internal_name() const { return "{constMethod}"; }
 542 
 543   // Verify
 544   void verify_on(outputStream* st);
 545 };
 546 
 547 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP