src/hotspot/share/classfile/vmSymbols.cpp - toolchain/jdk/jdk21 - Git at Google

 /*
  * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */

 #include "precompiled.hpp"
 #include "classfile/symbolTable.hpp"
 #include "classfile/vmSymbols.hpp"
 #include "compiler/compilerDirectives.hpp"
 #include "jvm.h"
 #include "memory/allocation.inline.hpp"
 #include "memory/oopFactory.hpp"
 #include "memory/metaspaceClosure.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/signature.hpp"
 #include "utilities/tribool.hpp"
 #include "utilities/xmlstream.hpp"


 Symbol* vmSymbols::_type_signatures[T_VOID+1] = { nullptr /*, nullptr...*/ };

 inline int compare_symbol(const Symbol* a, const Symbol* b) {
   if (a == b)  return 0;
   // follow the natural address order:
   return (address)a > (address)b ? +1 : -1;
 }

 static vmSymbolID vm_symbol_index[vmSymbols::number_of_symbols()];
 extern "C" {
   static int compare_vmsymbol_sid(const void* void_a, const void* void_b) {
     const Symbol* a = Symbol::vm_symbol_at(*((vmSymbolID*) void_a));
     const Symbol* b = Symbol::vm_symbol_at(*((vmSymbolID*) void_b));
     return compare_symbol(a, b);
   }
 }

 #ifdef ASSERT
 #define VM_SYMBOL_ENUM_NAME_BODY(name, string) #name "\0"
 static const char* vm_symbol_enum_names =
   VM_SYMBOLS_DO(VM_SYMBOL_ENUM_NAME_BODY, VM_ALIAS_IGNORE)
   "\0";
 static const char* vm_symbol_enum_name(vmSymbolID sid) {
   const char* string = &vm_symbol_enum_names[0];
   int skip = vmSymbols::as_int(sid) - vmSymbols::as_int(vmSymbolID::FIRST_SID);
   for (; skip != 0; skip--) {
     size_t skiplen = strlen(string);
     if (skiplen == 0)  return "<unknown>";  // overflow
     string += skiplen+1;
   }
   return string;
 }
 #endif //ASSERT

 // Put all the VM symbol strings in one place.
 // Makes for a more compact libjvm.
 #define VM_SYMBOL_BODY(name, string) string "\0"
 static const char* vm_symbol_bodies = VM_SYMBOLS_DO(VM_SYMBOL_BODY, VM_ALIAS_IGNORE);

 void vmSymbols::initialize() {
   assert(SID_LIMIT <= (1<<log2_SID_LIMIT), "must fit in this bitfield");
   assert(SID_LIMIT*5 > (1<<log2_SID_LIMIT), "make the bitfield smaller, please");
   assert(vmIntrinsics::FLAG_LIMIT <= (1 << vmIntrinsics::log2_FLAG_LIMIT), "must fit in this bitfield");

   if (!UseSharedSpaces) {
     const char* string = &vm_symbol_bodies[0];
     for (auto index : EnumRange<vmSymbolID>{}) {
       Symbol* sym = SymbolTable::new_permanent_symbol(string);
       Symbol::_vm_symbols[as_int(index)] = sym;
       string += strlen(string); // skip string body
       string += 1;              // skip trailing null
     }

     _type_signatures[T_BYTE]    = byte_signature();
     _type_signatures[T_CHAR]    = char_signature();
     _type_signatures[T_DOUBLE]  = double_signature();
     _type_signatures[T_FLOAT]   = float_signature();
     _type_signatures[T_INT]     = int_signature();
     _type_signatures[T_LONG]    = long_signature();
     _type_signatures[T_SHORT]   = short_signature();
     _type_signatures[T_BOOLEAN] = bool_signature();
     _type_signatures[T_VOID]    = void_signature();
 #ifdef ASSERT
     for (int i = (int)T_BOOLEAN; i < (int)T_VOID+1; i++) {
       Symbol* s = _type_signatures[i];
       if (s == nullptr)  continue;
       SignatureStream ss(s, false);
       assert(ss.type() == i, "matching signature");
       assert(!ss.is_reference(), "no single-char signature for T_OBJECT, etc.");
     }
 #endif
   }

 #ifdef ASSERT
   // Check for duplicates:

   for (auto i1 : EnumRange<vmSymbolID>{}) {
     Symbol* sym = symbol_at(i1);
     for (auto i2 : EnumRange<vmSymbolID>{vmSymbolID::FIRST_SID, i1}) {
       if (i2 != i1 && symbol_at(i2) == sym) {
         tty->print("*** Duplicate VM symbol SIDs %s(%d) and %s(%d): \"",
                    vm_symbol_enum_name(i2), as_int(i2),
                    vm_symbol_enum_name(i1), as_int(i1));
         sym->print_symbol_on(tty);
         tty->print_cr("\"");
       }
     }
   }
 #endif //ASSERT

   // Create an index for find_id:
   {
     for (auto index : EnumRange<vmSymbolID>{}) {
       vm_symbol_index[as_int(index)] = index;
     }
     int num_sids = SID_LIMIT-FIRST_SID;
     qsort(&vm_symbol_index[FIRST_SID], num_sids, sizeof(vm_symbol_index[0]),
           compare_vmsymbol_sid);
   }

 #ifdef ASSERT
   {
     // Spot-check correspondence between strings, symbols, and enums:
     assert(Symbol::_vm_symbols[NO_SID] == nullptr, "must be");
     const char* str = "java/lang/Object";
     TempNewSymbol jlo = SymbolTable::new_permanent_symbol(str);
     assert(strncmp(str, (char*)jlo->base(), jlo->utf8_length()) == 0, "");
     assert(jlo == java_lang_Object(), "");
     vmSymbolID sid = VM_SYMBOL_ENUM_NAME(java_lang_Object);
     assert(find_sid(jlo) == sid, "");
     assert(symbol_at(sid) == jlo, "");

     // Make sure find_sid produces the right answer in each case.
     for (auto index : EnumRange<vmSymbolID>{}) {
       Symbol* sym = symbol_at(index);
       sid = find_sid(sym);
       assert(sid == index, "symbol index works");
       // Note:  If there are duplicates, this assert will fail.
       // A "Duplicate VM symbol" message will have already been printed.
     }

     // The string "format" happens (at the moment) not to be a vmSymbol,
     // though it is a method name in java.lang.String.
     str = "format";
     TempNewSymbol fmt = SymbolTable::new_permanent_symbol(str);
     sid = find_sid(fmt);
     assert(sid == vmSymbolID::NO_SID, "symbol index works (negative test)");
   }
 #endif
 }


 #ifndef PRODUCT
 const char* vmSymbols::name_for(vmSymbolID sid) {
   if (sid == vmSymbolID::NO_SID)
     return "NO_SID";
   const char* string = &vm_symbol_bodies[0];
   for (auto index : EnumRange<vmSymbolID>{}) {
     if (index == sid)
       return string;
     string += strlen(string); // skip string body
     string += 1;              // skip trailing null
   }
   return "BAD_SID";
 }
 #endif


 void vmSymbols::symbols_do(SymbolClosure* f) {
   for (auto index : EnumRange<vmSymbolID>{}) {
     f->do_symbol(&Symbol::_vm_symbols[as_int(index)]);
   }
   for (int i = 0; i < T_VOID+1; i++) {
     f->do_symbol(&_type_signatures[i]);
   }
 }

 void vmSymbols::metaspace_pointers_do(MetaspaceClosure *closure) {
   for (auto index : EnumRange<vmSymbolID>{}) {
     closure->push(&Symbol::_vm_symbols[as_int(index)]);
   }
   for (int i = 0; i < T_VOID+1; i++) {
     closure->push(&_type_signatures[i]);
   }
 }

 void vmSymbols::serialize(SerializeClosure* soc) {
   soc->do_region((u_char*)&Symbol::_vm_symbols[FIRST_SID],
                  (SID_LIMIT - FIRST_SID) * sizeof(Symbol::_vm_symbols[0]));
   soc->do_region((u_char*)_type_signatures, sizeof(_type_signatures));
 }

 #ifndef PRODUCT
 static int find_sid_calls, find_sid_probes;
 // (Typical counts are calls=7000 and probes=17000.)
 #endif

 vmSymbolID vmSymbols::find_sid(const Symbol* symbol) {
   static int mid_hint = FIRST_SID+1;
   // Handle the majority of misses by a bounds check.
   // Then, use a binary search over the index.
   // Expected trip count is less than log2_SID_LIMIT, about eight.
   // This is slow but acceptable, given that calls are not
   // dynamically common.  (Method*::intrinsic_id has a cache.)
   NOT_PRODUCT(find_sid_calls++);
   int min = FIRST_SID, max = SID_LIMIT - 1;
   vmSymbolID sid = vmSymbolID::NO_SID, sid1;
   int cmp1;
   sid1 = vm_symbol_index[min];
   cmp1 = compare_symbol(symbol, Symbol::vm_symbol_at(sid1));
   if (cmp1 <= 0) {              // before the first
     if (cmp1 == 0)  sid = sid1;
   } else {
     sid1 = vm_symbol_index[max];
     cmp1 = compare_symbol(symbol, symbol_at(sid1));
     if (cmp1 >= 0) {            // after the last
       if (cmp1 == 0)  sid = sid1;
     } else {
       // After checking the extremes, do a binary search.
       ++min; --max;             // endpoints are done
       int mid = mid_hint;       // start at previous success
       while (max >= min) {
         assert(mid >= min && mid <= max, "");
         NOT_PRODUCT(find_sid_probes++);
         sid1 = vm_symbol_index[mid];
         cmp1 = compare_symbol(symbol, symbol_at(sid1));
         if (cmp1 == 0) {
           mid_hint = mid;
           sid = sid1;
           break;
         }
         if (cmp1 < 0)
           max = mid - 1;        // symbol < symbol_at(sid)
         else
           min = mid + 1;

         // Pick a new probe point:
         mid = (max + min) / 2;
       }
     }
   }

 #ifdef ASSERT
   if (sid == vmSymbolID::NO_SID) {
     return sid;
   }

   // Perform the exhaustive self-check the first 1000 calls,
   // and every 100 calls thereafter.
   static int find_sid_check_count = -2000;
   if ((uint)++find_sid_check_count > (uint)100) {
     if (find_sid_check_count > 0)  find_sid_check_count = 0;

     // Make sure this is the right answer, using linear search.
     // (We have already proven that there are no duplicates in the list.)
     vmSymbolID sid2 = vmSymbolID::NO_SID;
     for (auto index : EnumRange<vmSymbolID>{}) {
       Symbol* sym2 = symbol_at(index);
       if (sym2 == symbol) {
         sid2 = index;
         break;
       }
     }
     // Unless it's a duplicate, assert that the sids are the same.
     if (Symbol::_vm_symbols[as_int(sid)] != Symbol::_vm_symbols[as_int(sid2)]) {
       assert(sid == sid2, "binary same as linear search");
     }
   }
 #endif //ASSERT

   return sid;
 }

 vmSymbolID vmSymbols::find_sid(const char* symbol_name) {
   Symbol* symbol = SymbolTable::probe(symbol_name, (int) strlen(symbol_name));
   if (symbol == nullptr)  return vmSymbolID::NO_SID;
   return find_sid(symbol);
 }
	/*
	* Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	#include "precompiled.hpp"
	#include "classfile/symbolTable.hpp"
	#include "classfile/vmSymbols.hpp"
	#include "compiler/compilerDirectives.hpp"
	#include "jvm.h"
	#include "memory/allocation.inline.hpp"
	#include "memory/oopFactory.hpp"
	#include "memory/metaspaceClosure.hpp"
	#include "oops/oop.inline.hpp"
	#include "runtime/handles.inline.hpp"
	#include "runtime/signature.hpp"
	#include "utilities/tribool.hpp"
	#include "utilities/xmlstream.hpp"


	Symbol* vmSymbols::_type_signatures[T_VOID+1] = { nullptr /, nullptr.../ };

	inline int compare_symbol(const Symbol* a, const Symbol* b) {
	if (a == b) return 0;
	// follow the natural address order:
	return (address)a > (address)b ? +1 : -1;
	}

	static vmSymbolID vm_symbol_index[vmSymbols::number_of_symbols()];
	extern "C" {
	static int compare_vmsymbol_sid(const void* void_a, const void* void_b) {
	const Symbol* a = Symbol::vm_symbol_at(((vmSymbolID) void_a));
	const Symbol* b = Symbol::vm_symbol_at(((vmSymbolID) void_b));
	return compare_symbol(a, b);
	}
	}

	#ifdef ASSERT
	#define VM_SYMBOL_ENUM_NAME_BODY(name, string) #name "\0"
	static const char* vm_symbol_enum_names =
	VM_SYMBOLS_DO(VM_SYMBOL_ENUM_NAME_BODY, VM_ALIAS_IGNORE)
	"\0";
	static const char* vm_symbol_enum_name(vmSymbolID sid) {
	const char* string = &vm_symbol_enum_names[0];
	int skip = vmSymbols::as_int(sid) - vmSymbols::as_int(vmSymbolID::FIRST_SID);
	for (; skip != 0; skip--) {
	size_t skiplen = strlen(string);
	if (skiplen == 0) return "<unknown>"; // overflow
	string += skiplen+1;
	}
	return string;
	}
	#endif //ASSERT

	// Put all the VM symbol strings in one place.
	// Makes for a more compact libjvm.
	#define VM_SYMBOL_BODY(name, string) string "\0"
	static const char* vm_symbol_bodies = VM_SYMBOLS_DO(VM_SYMBOL_BODY, VM_ALIAS_IGNORE);

	void vmSymbols::initialize() {
	assert(SID_LIMIT <= (1<<log2_SID_LIMIT), "must fit in this bitfield");
	assert(SID_LIMIT*5 > (1<<log2_SID_LIMIT), "make the bitfield smaller, please");
	assert(vmIntrinsics::FLAG_LIMIT <= (1 << vmIntrinsics::log2_FLAG_LIMIT), "must fit in this bitfield");

	if (!UseSharedSpaces) {
	const char* string = &vm_symbol_bodies[0];
	for (auto index : EnumRange<vmSymbolID>{}) {
	Symbol* sym = SymbolTable::new_permanent_symbol(string);
	Symbol::_vm_symbols[as_int(index)] = sym;
	string += strlen(string); // skip string body
	string += 1; // skip trailing null
	}

	_type_signatures[T_BYTE] = byte_signature();
	_type_signatures[T_CHAR] = char_signature();
	_type_signatures[T_DOUBLE] = double_signature();
	_type_signatures[T_FLOAT] = float_signature();
	_type_signatures[T_INT] = int_signature();
	_type_signatures[T_LONG] = long_signature();
	_type_signatures[T_SHORT] = short_signature();
	_type_signatures[T_BOOLEAN] = bool_signature();
	_type_signatures[T_VOID] = void_signature();
	#ifdef ASSERT
	for (int i = (int)T_BOOLEAN; i < (int)T_VOID+1; i++) {
	Symbol* s = _type_signatures[i];
	if (s == nullptr) continue;
	SignatureStream ss(s, false);
	assert(ss.type() == i, "matching signature");
	assert(!ss.is_reference(), "no single-char signature for T_OBJECT, etc.");
	}
	#endif
	}

	#ifdef ASSERT
	// Check for duplicates:

	for (auto i1 : EnumRange<vmSymbolID>{}) {
	Symbol* sym = symbol_at(i1);
	for (auto i2 : EnumRange<vmSymbolID>{vmSymbolID::FIRST_SID, i1}) {
	if (i2 != i1 && symbol_at(i2) == sym) {
	tty->print("*** Duplicate VM symbol SIDs %s(%d) and %s(%d): \"",
	vm_symbol_enum_name(i2), as_int(i2),
	vm_symbol_enum_name(i1), as_int(i1));
	sym->print_symbol_on(tty);
	tty->print_cr("\"");
	}
	}
	}
	#endif //ASSERT

	// Create an index for find_id:
	{
	for (auto index : EnumRange<vmSymbolID>{}) {
	vm_symbol_index[as_int(index)] = index;
	}
	int num_sids = SID_LIMIT-FIRST_SID;
	qsort(&vm_symbol_index[FIRST_SID], num_sids, sizeof(vm_symbol_index[0]),
	compare_vmsymbol_sid);
	}

	#ifdef ASSERT
	{
	// Spot-check correspondence between strings, symbols, and enums:
	assert(Symbol::_vm_symbols[NO_SID] == nullptr, "must be");
	const char* str = "java/lang/Object";
	TempNewSymbol jlo = SymbolTable::new_permanent_symbol(str);
	assert(strncmp(str, (char*)jlo->base(), jlo->utf8_length()) == 0, "");
	assert(jlo == java_lang_Object(), "");
	vmSymbolID sid = VM_SYMBOL_ENUM_NAME(java_lang_Object);
	assert(find_sid(jlo) == sid, "");
	assert(symbol_at(sid) == jlo, "");

	// Make sure find_sid produces the right answer in each case.
	for (auto index : EnumRange<vmSymbolID>{}) {
	Symbol* sym = symbol_at(index);
	sid = find_sid(sym);
	assert(sid == index, "symbol index works");
	// Note: If there are duplicates, this assert will fail.
	// A "Duplicate VM symbol" message will have already been printed.
	}

	// The string "format" happens (at the moment) not to be a vmSymbol,
	// though it is a method name in java.lang.String.
	str = "format";
	TempNewSymbol fmt = SymbolTable::new_permanent_symbol(str);
	sid = find_sid(fmt);
	assert(sid == vmSymbolID::NO_SID, "symbol index works (negative test)");
	}
	#endif
	}


	#ifndef PRODUCT
	const char* vmSymbols::name_for(vmSymbolID sid) {
	if (sid == vmSymbolID::NO_SID)
	return "NO_SID";
	const char* string = &vm_symbol_bodies[0];
	for (auto index : EnumRange<vmSymbolID>{}) {
	if (index == sid)
	return string;
	string += strlen(string); // skip string body
	string += 1; // skip trailing null
	}
	return "BAD_SID";
	}
	#endif



	void vmSymbols::symbols_do(SymbolClosure* f) {
	for (auto index : EnumRange<vmSymbolID>{}) {
	f->do_symbol(&Symbol::_vm_symbols[as_int(index)]);
	}
	for (int i = 0; i < T_VOID+1; i++) {
	f->do_symbol(&_type_signatures[i]);
	}
	}

	void vmSymbols::metaspace_pointers_do(MetaspaceClosure *closure) {
	for (auto index : EnumRange<vmSymbolID>{}) {
	closure->push(&Symbol::_vm_symbols[as_int(index)]);
	}
	for (int i = 0; i < T_VOID+1; i++) {
	closure->push(&_type_signatures[i]);
	}
	}

	void vmSymbols::serialize(SerializeClosure* soc) {
	soc->do_region((u_char*)&Symbol::_vm_symbols[FIRST_SID],
	(SID_LIMIT - FIRST_SID) * sizeof(Symbol::_vm_symbols[0]));
	soc->do_region((u_char*)_type_signatures, sizeof(_type_signatures));
	}

	#ifndef PRODUCT
	static int find_sid_calls, find_sid_probes;
	// (Typical counts are calls=7000 and probes=17000.)
	#endif

	vmSymbolID vmSymbols::find_sid(const Symbol* symbol) {
	static int mid_hint = FIRST_SID+1;
	// Handle the majority of misses by a bounds check.
	// Then, use a binary search over the index.
	// Expected trip count is less than log2_SID_LIMIT, about eight.
	// This is slow but acceptable, given that calls are not
	// dynamically common. (Method*::intrinsic_id has a cache.)
	NOT_PRODUCT(find_sid_calls++);
	int min = FIRST_SID, max = SID_LIMIT - 1;
	vmSymbolID sid = vmSymbolID::NO_SID, sid1;
	int cmp1;
	sid1 = vm_symbol_index[min];
	cmp1 = compare_symbol(symbol, Symbol::vm_symbol_at(sid1));
	if (cmp1 <= 0) { // before the first
	if (cmp1 == 0) sid = sid1;
	} else {
	sid1 = vm_symbol_index[max];
	cmp1 = compare_symbol(symbol, symbol_at(sid1));
	if (cmp1 >= 0) { // after the last
	if (cmp1 == 0) sid = sid1;
	} else {
	// After checking the extremes, do a binary search.
	++min; --max; // endpoints are done
	int mid = mid_hint; // start at previous success
	while (max >= min) {
	assert(mid >= min && mid <= max, "");
	NOT_PRODUCT(find_sid_probes++);
	sid1 = vm_symbol_index[mid];
	cmp1 = compare_symbol(symbol, symbol_at(sid1));
	if (cmp1 == 0) {
	mid_hint = mid;
	sid = sid1;
	break;
	}
	if (cmp1 < 0)
	max = mid - 1; // symbol < symbol_at(sid)
	else
	min = mid + 1;

	// Pick a new probe point:
	mid = (max + min) / 2;
	}
	}
	}

	#ifdef ASSERT
	if (sid == vmSymbolID::NO_SID) {
	return sid;
	}

	// Perform the exhaustive self-check the first 1000 calls,
	// and every 100 calls thereafter.
	static int find_sid_check_count = -2000;
	if ((uint)++find_sid_check_count > (uint)100) {
	if (find_sid_check_count > 0) find_sid_check_count = 0;

	// Make sure this is the right answer, using linear search.
	// (We have already proven that there are no duplicates in the list.)
	vmSymbolID sid2 = vmSymbolID::NO_SID;
	for (auto index : EnumRange<vmSymbolID>{}) {
	Symbol* sym2 = symbol_at(index);
	if (sym2 == symbol) {
	sid2 = index;
	break;
	}
	}
	// Unless it's a duplicate, assert that the sids are the same.
	if (Symbol::_vm_symbols[as_int(sid)] != Symbol::_vm_symbols[as_int(sid2)]) {
	assert(sid == sid2, "binary same as linear search");
	}
	}
	#endif //ASSERT

	return sid;
	}

	vmSymbolID vmSymbols::find_sid(const char* symbol_name) {
	Symbol* symbol = SymbolTable::probe(symbol_name, (int) strlen(symbol_name));
	if (symbol == nullptr) return vmSymbolID::NO_SID;
	return find_sid(symbol);
	}