JDK14/Java14源码在线阅读
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#ifndef SHARE_OOPS_CONSTANTPOOL_HPP
#define SHARE_OOPS_CONSTANTPOOL_HPP
#include "memory/allocation.hpp"
#include "oops/arrayOop.hpp"
#include "oops/cpCache.hpp"
#include "oops/objArrayOop.hpp"
#include "oops/oopHandle.hpp"
#include "oops/symbol.hpp"
#include "oops/typeArrayOop.hpp"
#include "runtime/handles.hpp"
#include "utilities/align.hpp"
#include "utilities/bytes.hpp"
#include "utilities/constantTag.hpp"
// A ConstantPool is an array containing class constants as described in the
// class file.
//
// Most of the constant pool entries are written during class parsing, which
// is safe. For klass types, the constant pool entry is
// modified when the entry is resolved. If a klass constant pool
// entry is read without a lock, only the resolved state guarantees that
// the entry in the constant pool is a klass object and not a Symbol*.
class SymbolHashMap;
class CPSlot {
friend class ConstantPool;
intptr_t _ptr;
enum TagBits {_pseudo_bit = 1};
public:
CPSlot(intptr_t ptr): _ptr(ptr) {}
CPSlot(Symbol* ptr, int tag_bits = 0): _ptr((intptr_t)ptr | tag_bits) {}
intptr_t value() { return _ptr; }
bool is_pseudo_string() { return (_ptr & _pseudo_bit) != 0; }
Symbol* get_symbol() {
return (Symbol*)(_ptr & ~_pseudo_bit);
}
};
// This represents a JVM_CONSTANT_Class, JVM_CONSTANT_UnresolvedClass, or
// JVM_CONSTANT_UnresolvedClassInError slot in the constant pool.
class CPKlassSlot {
// cp->symbol_at(_name_index) gives the name of the class.
int _name_index;
// cp->_resolved_klasses->at(_resolved_klass_index) gives the Klass* for the class.
int _resolved_klass_index;
public:
enum {
// This is used during constant pool merging where the resolved klass index is
// not yet known, and will be computed at a later stage (during a call to
// initialize_unresolved_klasses()).
_temp_resolved_klass_index = 0xffff
};
CPKlassSlot(int n, int rk) {
_name_index = n;
_resolved_klass_index = rk;
}
int name_index() const {
return _name_index;
}
int resolved_klass_index() const {
assert(_resolved_klass_index != _temp_resolved_klass_index, "constant pool merging was incomplete");
return _resolved_klass_index;
}
};
class KlassSizeStats;
class ConstantPool : public Metadata {
friend class VMStructs;
friend class JVMCIVMStructs;
friend class BytecodeInterpreter; // Directly extracts a klass in the pool for fast instanceof/checkcast
friend class Universe; // For null constructor
private:
// If you add a new field that points to any metaspace object, you
// must add this field to ConstantPool::metaspace_pointers_do().
Array<u1>* _tags; // the tag array describing the constant pool's contents
ConstantPoolCache* _cache; // the cache holding interpreter runtime information
InstanceKlass* _pool_holder; // the corresponding class
Array<u2>* _operands; // for variable-sized (InvokeDynamic) nodes, usually empty
// Consider using an array of compressed klass pointers to
// save space on 64-bit platforms.
Array<Klass*>* _resolved_klasses;
enum {
_has_preresolution = 1, // Flags
_on_stack = 2,
_is_shared = 4,
_has_dynamic_constant = 8
};
int _flags; // old fashioned bit twiddling
int _length; // number of elements in the array
union {
// set for CDS to restore resolved references
int _resolved_reference_length;
// keeps version number for redefined classes (used in backtrace)
int _version;
} _saved;
void set_tags(Array<u1>* tags) { _tags = tags; }
void tag_at_put(int which, jbyte t) { tags()->at_put(which, t); }
void release_tag_at_put(int which, jbyte t) { tags()->release_at_put(which, t); }
u1* tag_addr_at(int which) const { return tags()->adr_at(which); }
void set_operands(Array<u2>* operands) { _operands = operands; }
int flags() const { return _flags; }
void set_flags(int f) { _flags = f; }
private:
intptr_t* base() const { return (intptr_t*) (((char*) this) + sizeof(ConstantPool)); }
CPSlot slot_at(int which) const;
void slot_at_put(int which, CPSlot s) const {
assert(is_within_bounds(which), "index out of bounds");
assert(s.value() != 0, "Caught something");
*(intptr_t*)&base()[which] = s.value();
}
intptr_t* obj_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (intptr_t*) &base()[which];
}
jint* int_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jint*) &base()[which];
}
jlong* long_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jlong*) &base()[which];
}
jfloat* float_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jfloat*) &base()[which];
}
jdouble* double_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (jdouble*) &base()[which];
}
ConstantPool(Array<u1>* tags);
ConstantPool() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); }
public:
static ConstantPool* allocate(ClassLoaderData* loader_data, int length, TRAPS);
bool is_constantPool() const volatile { return true; }
Array<u1>* tags() const { return _tags; }
Array<u2>* operands() const { return _operands; }
bool has_preresolution() const { return (_flags & _has_preresolution) != 0; }
void set_has_preresolution() {
assert(!is_shared(), "should never be called on shared ConstantPools");
_flags |= _has_preresolution;
}
// Redefine classes support. If a method refering to this constant pool
// is on the executing stack, or as a handle in vm code, this constant pool
// can't be removed from the set of previous versions saved in the instance
// class.
bool on_stack() const { return (_flags &_on_stack) != 0; }
void set_on_stack(const bool value);
// Faster than MetaspaceObj::is_shared() - used by set_on_stack()
bool is_shared() const { return (_flags & _is_shared) != 0; }
bool has_dynamic_constant() const { return (_flags & _has_dynamic_constant) != 0; }
void set_has_dynamic_constant() { _flags |= _has_dynamic_constant; }
// Klass holding pool
InstanceKlass* pool_holder() const { return _pool_holder; }
void set_pool_holder(InstanceKlass* k) { _pool_holder = k; }
InstanceKlass** pool_holder_addr() { return &_pool_holder; }
// Interpreter runtime support
ConstantPoolCache* cache() const { return _cache; }
void set_cache(ConstantPoolCache* cache){ _cache = cache; }
virtual void metaspace_pointers_do(MetaspaceClosure* iter);
virtual MetaspaceObj::Type type() const { return ConstantPoolType; }
// Create object cache in the constant pool
void initialize_resolved_references(ClassLoaderData* loader_data,
const intStack& reference_map,
int constant_pool_map_length,
TRAPS);
// resolved strings, methodHandles and callsite objects from the constant pool
objArrayOop resolved_references() const;
objArrayOop resolved_references_or_null() const;
// mapping resolved object array indexes to cp indexes and back.
int object_to_cp_index(int index) { return reference_map()->at(index); }
int cp_to_object_index(int index);
void set_resolved_klasses(Array<Klass*>* rk) { _resolved_klasses = rk; }
Array<Klass*>* resolved_klasses() const { return _resolved_klasses; }
void allocate_resolved_klasses(ClassLoaderData* loader_data, int num_klasses, TRAPS);
void initialize_unresolved_klasses(ClassLoaderData* loader_data, TRAPS);
// Invokedynamic indexes.
// They must look completely different from normal indexes.
// The main reason is that byte swapping is sometimes done on normal indexes.
// Finally, it is helpful for debugging to tell the two apart.
static bool is_invokedynamic_index(int i) { return (i < 0); }
static int decode_invokedynamic_index(int i) { assert(is_invokedynamic_index(i), ""); return ~i; }
static int encode_invokedynamic_index(int i) { assert(!is_invokedynamic_index(i), ""); return ~i; }
// The invokedynamic points at a CP cache entry. This entry points back
// at the original CP entry (CONSTANT_InvokeDynamic) and also (via f2) at an entry
// in the resolved_references array (which provides the appendix argument).
int invokedynamic_cp_cache_index(int indy_index) const {
assert(is_invokedynamic_index(indy_index), "should be a invokedynamic index");
int cache_index = decode_invokedynamic_index(indy_index);
return cache_index;
}
ConstantPoolCacheEntry* invokedynamic_cp_cache_entry_at(int indy_index) const {
// decode index that invokedynamic points to.
int cp_cache_index = invokedynamic_cp_cache_index(indy_index);
return cache()->entry_at(cp_cache_index);
}
// Given the per-instruction index of an indy instruction, report the
// main constant pool entry for its bootstrap specifier.
// From there, uncached_name/signature_ref_at will get the name/type.
int invokedynamic_bootstrap_ref_index_at(int indy_index) const {
return invokedynamic_cp_cache_entry_at(indy_index)->constant_pool_index();
}
// Assembly code support
static int tags_offset_in_bytes() { return offset_of(ConstantPool, _tags); }
static int cache_offset_in_bytes() { return offset_of(ConstantPool, _cache); }
static int pool_holder_offset_in_bytes() { return offset_of(ConstantPool, _pool_holder); }
static int resolved_klasses_offset_in_bytes() { return offset_of(ConstantPool, _resolved_klasses); }
// Storing constants
// For temporary use while constructing constant pool
void klass_index_at_put(int which, int name_index) {
tag_at_put(which, JVM_CONSTANT_ClassIndex);
*int_at_addr(which) = name_index;
}
// Unsafe anonymous class support:
void klass_at_put(int class_index, int name_index, int resolved_klass_index, Klass* k, Symbol* name);
void klass_at_put(int class_index, Klass* k);
void unresolved_klass_at_put(int which, int name_index, int resolved_klass_index) {
release_tag_at_put(which, JVM_CONSTANT_UnresolvedClass);
assert((name_index & 0xffff0000) == 0, "must be");
assert((resolved_klass_index & 0xffff0000) == 0, "must be");
*int_at_addr(which) =
build_int_from_shorts((jushort)resolved_klass_index, (jushort)name_index);
}
void method_handle_index_at_put(int which, int ref_kind, int ref_index) {
tag_at_put(which, JVM_CONSTANT_MethodHandle);
*int_at_addr(which) = ((jint) ref_index<<16) | ref_kind;
}
void method_type_index_at_put(int which, int ref_index) {
tag_at_put(which, JVM_CONSTANT_MethodType);
*int_at_addr(which) = ref_index;
}
void dynamic_constant_at_put(int which, int bsms_attribute_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_Dynamic);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
}
void invoke_dynamic_at_put(int which, int bsms_attribute_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_InvokeDynamic);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | bsms_attribute_index;
}
void unresolved_string_at_put(int which, Symbol* s) {
release_tag_at_put(which, JVM_CONSTANT_String);
slot_at_put(which, CPSlot(s));
}
void int_at_put(int which, jint i) {
tag_at_put(which, JVM_CONSTANT_Integer);
*int_at_addr(which) = i;
}
void long_at_put(int which, jlong l) {
tag_at_put(which, JVM_CONSTANT_Long);
// *long_at_addr(which) = l;
Bytes::put_native_u8((address)long_at_addr(which), *((u8*) &l));
}
void float_at_put(int which, jfloat f) {
tag_at_put(which, JVM_CONSTANT_Float);
*float_at_addr(which) = f;
}
void double_at_put(int which, jdouble d) {
tag_at_put(which, JVM_CONSTANT_Double);
// *double_at_addr(which) = d;
// u8 temp = *(u8*) &d;
Bytes::put_native_u8((address) double_at_addr(which), *((u8*) &d));
}
Symbol** symbol_at_addr(int which) const {
assert(is_within_bounds(which), "index out of bounds");
return (Symbol**) &base()[which];
}
void symbol_at_put(int which, Symbol* s) {
assert(s->refcount() != 0, "should have nonzero refcount");
tag_at_put(which, JVM_CONSTANT_Utf8);
*symbol_at_addr(which) = s;
}
void string_at_put(int which, int obj_index, oop str);
// For temporary use while constructing constant pool
void string_index_at_put(int which, int string_index) {
tag_at_put(which, JVM_CONSTANT_StringIndex);
*int_at_addr(which) = string_index;
}
void field_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_Fieldref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
}
void method_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_Methodref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index;
}
void interface_method_at_put(int which, int class_index, int name_and_type_index) {
tag_at_put(which, JVM_CONSTANT_InterfaceMethodref);
*int_at_addr(which) = ((jint) name_and_type_index<<16) | class_index; // Not so nice
}
void name_and_type_at_put(int which, int name_index, int signature_index) {
tag_at_put(which, JVM_CONSTANT_NameAndType);
*int_at_addr(which) = ((jint) signature_index<<16) | name_index; // Not so nice
}
// Tag query
constantTag tag_at(int which) const { return (constantTag)tags()->at_acquire(which); }
// Fetching constants
Klass* klass_at(int which, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return klass_at_impl(h_this, which, true, THREAD);
}
// Version of klass_at that doesn't save the resolution error, called during deopt
Klass* klass_at_ignore_error(int which, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return klass_at_impl(h_this, which, false, THREAD);
}
CPKlassSlot klass_slot_at(int which) const {
assert(tag_at(which).is_unresolved_klass() || tag_at(which).is_klass(),
"Corrupted constant pool");
int value = *int_at_addr(which);
int name_index = extract_high_short_from_int(value);
int resolved_klass_index = extract_low_short_from_int(value);
return CPKlassSlot(name_index, resolved_klass_index);
}
Symbol* klass_name_at(int which) const; // Returns the name, w/o resolving.
int klass_name_index_at(int which) const {
return klass_slot_at(which).name_index();
}
Klass* resolved_klass_at(int which) const; // Used by Compiler
// RedefineClasses() API support:
Symbol* klass_at_noresolve(int which) { return klass_name_at(which); }
void temp_unresolved_klass_at_put(int which, int name_index) {
// Used only during constant pool merging for class redefinition. The resolved klass index
// will be initialized later by a call to initialize_unresolved_klasses().
unresolved_klass_at_put(which, name_index, CPKlassSlot::_temp_resolved_klass_index);
}
jint int_at(int which) {
assert(tag_at(which).is_int(), "Corrupted constant pool");
return *int_at_addr(which);
}
jlong long_at(int which) {
assert(tag_at(which).is_long(), "Corrupted constant pool");
// return *long_at_addr(which);
u8 tmp = Bytes::get_native_u8((address)&base()[which]);
return *((jlong*)&tmp);
}
jfloat float_at(int which) {
assert(tag_at(which).is_float(), "Corrupted constant pool");
return *float_at_addr(which);
}
jdouble double_at(int which) {
assert(tag_at(which).is_double(), "Corrupted constant pool");
u8 tmp = Bytes::get_native_u8((address)&base()[which]);
return *((jdouble*)&tmp);
}
Symbol* symbol_at(int which) const {
assert(tag_at(which).is_utf8(), "Corrupted constant pool");
return *symbol_at_addr(which);
}
oop string_at(int which, int obj_index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return string_at_impl(h_this, which, obj_index, THREAD);
}
oop string_at(int which, TRAPS) {
int obj_index = cp_to_object_index(which);
return string_at(which, obj_index, THREAD);
}
// Version that can be used before string oop array is created.
oop uncached_string_at(int which, TRAPS);
// A "pseudo-string" is an non-string oop that has found its way into
// a String entry.
// This can happen if the user patches a live
// object into a CONSTANT_String entry of an unsafe anonymous class.
// Method oops internally created for method handles may also
// use pseudo-strings to link themselves to related metaobjects.
bool is_pseudo_string_at(int which);
oop pseudo_string_at(int which, int obj_index);
oop pseudo_string_at(int which);
void pseudo_string_at_put(int which, int obj_index, oop x) {
assert(tag_at(which).is_string(), "Corrupted constant pool");
Symbol* sym = unresolved_string_at(which);
slot_at_put(which, CPSlot(sym, CPSlot::_pseudo_bit));
string_at_put(which, obj_index, x); // this works just fine
}
// only called when we are sure a string entry is already resolved (via an
// earlier string_at call.
oop resolved_string_at(int which) {
assert(tag_at(which).is_string(), "Corrupted constant pool");
// Must do an acquire here in case another thread resolved the klass
// behind our back, lest we later load stale values thru the oop.
// we might want a volatile_obj_at in ObjArrayKlass.
int obj_index = cp_to_object_index(which);
return resolved_references()->obj_at(obj_index);
}
Symbol* unresolved_string_at(int which) {
assert(tag_at(which).is_string(), "Corrupted constant pool");
Symbol* sym = slot_at(which).get_symbol();
return sym;
}
// Returns an UTF8 for a CONSTANT_String entry at a given index.
// UTF8 char* representation was chosen to avoid conversion of
// java_lang_Strings at resolved entries into Symbol*s
// or vice versa.
char* string_at_noresolve(int which);
jint name_and_type_at(int which) {
assert(tag_at(which).is_name_and_type(), "Corrupted constant pool");
return *int_at_addr(which);
}
int method_handle_ref_kind_at(int which) {
assert(tag_at(which).is_method_handle() ||
tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
return extract_low_short_from_int(*int_at_addr(which)); // mask out unwanted ref_index bits
}
int method_handle_index_at(int which) {
assert(tag_at(which).is_method_handle() ||
tag_at(which).is_method_handle_in_error(), "Corrupted constant pool");
return extract_high_short_from_int(*int_at_addr(which)); // shift out unwanted ref_kind bits
}
int method_type_index_at(int which) {
assert(tag_at(which).is_method_type() ||
tag_at(which).is_method_type_in_error(), "Corrupted constant pool");
return *int_at_addr(which);
}
// Derived queries:
Symbol* method_handle_name_ref_at(int which) {
int member = method_handle_index_at(which);
return impl_name_ref_at(member, true);
}
Symbol* method_handle_signature_ref_at(int which) {
int member = method_handle_index_at(which);
return impl_signature_ref_at(member, true);
}
int method_handle_klass_index_at(int which) {
int member = method_handle_index_at(which);
return impl_klass_ref_index_at(member, true);
}
Symbol* method_type_signature_at(int which) {
int sym = method_type_index_at(which);
return symbol_at(sym);
}
int bootstrap_name_and_type_ref_index_at(int which) {
assert(tag_at(which).has_bootstrap(), "Corrupted constant pool");
return extract_high_short_from_int(*int_at_addr(which));
}
int bootstrap_methods_attribute_index(int which) {
assert(tag_at(which).has_bootstrap(), "Corrupted constant pool");
return extract_low_short_from_int(*int_at_addr(which));
}
int bootstrap_operand_base(int which) {
int bsms_attribute_index = bootstrap_methods_attribute_index(which);
return operand_offset_at(operands(), bsms_attribute_index);
}
// The first part of the operands array consists of an index into the second part.
// Extract a 32-bit index value from the first part.
static int operand_offset_at(Array<u2>* operands, int bsms_attribute_index) {
int n = (bsms_attribute_index * 2);
assert(n >= 0 && n+2 <= operands->length(), "oob");
// The first 32-bit index points to the beginning of the second part
// of the operands array. Make sure this index is in the first part.
DEBUG_ONLY(int second_part = build_int_from_shorts(operands->at(0),
operands->at(1)));
assert(second_part == 0 || n+2 <= second_part, "oob (2)");
int offset = build_int_from_shorts(operands->at(n+0),
operands->at(n+1));
// The offset itself must point into the second part of the array.
assert(offset == 0 || offset >= second_part && offset <= operands->length(), "oob (3)");
return offset;
}
static void operand_offset_at_put(Array<u2>* operands, int bsms_attribute_index, int offset) {
int n = bsms_attribute_index * 2;
assert(n >= 0 && n+2 <= operands->length(), "oob");
operands->at_put(n+0, extract_low_short_from_int(offset));
operands->at_put(n+1, extract_high_short_from_int(offset));
}
static int operand_array_length(Array<u2>* operands) {
if (operands == NULL || operands->length() == 0) return 0;
int second_part = operand_offset_at(operands, 0);
return (second_part / 2);
}
#ifdef ASSERT
// operand tuples fit together exactly, end to end
static int operand_limit_at(Array<u2>* operands, int bsms_attribute_index) {
int nextidx = bsms_attribute_index + 1;
if (nextidx == operand_array_length(operands))
return operands->length();
else
return operand_offset_at(operands, nextidx);
}
int bootstrap_operand_limit(int which) {
int bsms_attribute_index = bootstrap_methods_attribute_index(which);
return operand_limit_at(operands(), bsms_attribute_index);
}
#endif //ASSERT
// Layout of InvokeDynamic and Dynamic bootstrap method specifier
// data in second part of operands array. This encodes one record in
// the BootstrapMethods attribute. The whole specifier also includes
// the name and type information from the main constant pool entry.
enum {
_indy_bsm_offset = 0, // CONSTANT_MethodHandle bsm
_indy_argc_offset = 1, // u2 argc
_indy_argv_offset = 2 // u2 argv[argc]
};
// These functions are used in RedefineClasses for CP merge
int operand_offset_at(int bsms_attribute_index) {
assert(0 <= bsms_attribute_index &&
bsms_attribute_index < operand_array_length(operands()),
"Corrupted CP operands");
return operand_offset_at(operands(), bsms_attribute_index);
}
int operand_bootstrap_method_ref_index_at(int bsms_attribute_index) {
int offset = operand_offset_at(bsms_attribute_index);
return operands()->at(offset + _indy_bsm_offset);
}
int operand_argument_count_at(int bsms_attribute_index) {
int offset = operand_offset_at(bsms_attribute_index);
int argc = operands()->at(offset + _indy_argc_offset);
return argc;
}
int operand_argument_index_at(int bsms_attribute_index, int j) {
int offset = operand_offset_at(bsms_attribute_index);
return operands()->at(offset + _indy_argv_offset + j);
}
int operand_next_offset_at(int bsms_attribute_index) {
int offset = operand_offset_at(bsms_attribute_index) + _indy_argv_offset
+ operand_argument_count_at(bsms_attribute_index);
return offset;
}
// Compare a bootstrap specifier data in the operands arrays
bool compare_operand_to(int bsms_attribute_index1, const constantPoolHandle& cp2,
int bsms_attribute_index2, TRAPS);
// Find a bootstrap specifier data in the operands array
int find_matching_operand(int bsms_attribute_index, const constantPoolHandle& search_cp,
int operands_cur_len, TRAPS);
// Resize the operands array with delta_len and delta_size
void resize_operands(int delta_len, int delta_size, TRAPS);
// Extend the operands array with the length and size of the ext_cp operands
void extend_operands(const constantPoolHandle& ext_cp, TRAPS);
// Shrink the operands array to a smaller array with new_len length
void shrink_operands(int new_len, TRAPS);
int bootstrap_method_ref_index_at(int which) {
assert(tag_at(which).has_bootstrap(), "Corrupted constant pool");
int op_base = bootstrap_operand_base(which);
return operands()->at(op_base + _indy_bsm_offset);
}
int bootstrap_argument_count_at(int which) {
assert(tag_at(which).has_bootstrap(), "Corrupted constant pool");
int op_base = bootstrap_operand_base(which);
int argc = operands()->at(op_base + _indy_argc_offset);
DEBUG_ONLY(int end_offset = op_base + _indy_argv_offset + argc;
int next_offset = bootstrap_operand_limit(which));
assert(end_offset == next_offset, "matched ending");
return argc;
}
int bootstrap_argument_index_at(int which, int j) {
int op_base = bootstrap_operand_base(which);
DEBUG_ONLY(int argc = operands()->at(op_base + _indy_argc_offset));
assert((uint)j < (uint)argc, "oob");
return operands()->at(op_base + _indy_argv_offset + j);
}
// The following methods (name/signature/klass_ref_at, klass_ref_at_noresolve,
// name_and_type_ref_index_at) all expect to be passed indices obtained
// directly from the bytecode.
// If the indices are meant to refer to fields or methods, they are
// actually rewritten constant pool cache indices.
// The routine remap_instruction_operand_from_cache manages the adjustment
// of these values back to constant pool indices.
// There are also "uncached" versions which do not adjust the operand index; see below.
// FIXME: Consider renaming these with a prefix "cached_" to make the distinction clear.
// In a few cases (the verifier) there are uses before a cpcache has been built,
// which are handled by a dynamic check in remap_instruction_operand_from_cache.
// FIXME: Remove the dynamic check, and adjust all callers to specify the correct mode.
// Lookup for entries consisting of (klass_index, name_and_type index)
Klass* klass_ref_at(int which, TRAPS);
Symbol* klass_ref_at_noresolve(int which);
Symbol* name_ref_at(int which) { return impl_name_ref_at(which, false); }
Symbol* signature_ref_at(int which) { return impl_signature_ref_at(which, false); }
int klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, false); }
int name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, false); }
int remap_instruction_operand_from_cache(int operand); // operand must be biased by CPCACHE_INDEX_TAG
constantTag tag_ref_at(int cp_cache_index) { return impl_tag_ref_at(cp_cache_index, false); }
// Lookup for entries consisting of (name_index, signature_index)
int name_ref_index_at(int which_nt); // == low-order jshort of name_and_type_at(which_nt)
int signature_ref_index_at(int which_nt); // == high-order jshort of name_and_type_at(which_nt)
BasicType basic_type_for_signature_at(int which) const;
// Resolve string constants (to prevent allocation during compilation)
void resolve_string_constants(TRAPS) {
constantPoolHandle h_this(THREAD, this);
resolve_string_constants_impl(h_this, CHECK);
}
// CDS support
void archive_resolved_references(Thread *THREAD) NOT_CDS_JAVA_HEAP_RETURN;
void resolve_class_constants(TRAPS) NOT_CDS_JAVA_HEAP_RETURN;
void remove_unshareable_info();
void restore_unshareable_info(TRAPS);
// The ConstantPool vtable is restored by this call when the ConstantPool is
// in the shared archive. See patch_klass_vtables() in metaspaceShared.cpp for
// all the gory details. SA, dtrace and pstack helpers distinguish metadata
// by their vtable.
void restore_vtable() { guarantee(is_constantPool(), "vtable restored by this call"); }
private:
enum { _no_index_sentinel = -1, _possible_index_sentinel = -2 };
public:
// Get the tag for a constant, which may involve a constant dynamic
constantTag constant_tag_at(int which);
// Get the basic type for a constant, which may involve a constant dynamic
BasicType basic_type_for_constant_at(int which);
// Resolve late bound constants.
oop resolve_constant_at(int index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, index, _no_index_sentinel, NULL, THREAD);
}
oop resolve_cached_constant_at(int cache_index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, _no_index_sentinel, cache_index, NULL, THREAD);
}
oop resolve_possibly_cached_constant_at(int pool_index, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, NULL, THREAD);
}
oop find_cached_constant_at(int pool_index, bool& found_it, TRAPS) {
constantPoolHandle h_this(THREAD, this);
return resolve_constant_at_impl(h_this, pool_index, _possible_index_sentinel, &found_it, THREAD);
}
void copy_bootstrap_arguments_at(int index,
int start_arg, int end_arg,
objArrayHandle info, int pos,
bool must_resolve, Handle if_not_available, TRAPS) {
constantPoolHandle h_this(THREAD, this);
copy_bootstrap_arguments_at_impl(h_this, index, start_arg, end_arg,
info, pos, must_resolve, if_not_available, THREAD);
}
// Klass name matches name at offset
bool klass_name_at_matches(const InstanceKlass* k, int which);
// Sizing
int length() const { return _length; }
void set_length(int length) { _length = length; }
// Tells whether index is within bounds.
bool is_within_bounds(int index) const {
return 0 <= index && index < length();
}
// Sizing (in words)
static int header_size() {
return align_up((int)sizeof(ConstantPool), wordSize) / wordSize;
}
static int size(int length) { return align_metadata_size(header_size() + length); }
int size() const { return size(length()); }
#if INCLUDE_SERVICES
void collect_statistics(KlassSizeStats *sz) const;
#endif
// ConstantPools should be stored in the read-only region of CDS archive.
static bool is_read_only_by_default() { return true; }
friend class ClassFileParser;
friend class SystemDictionary;
// Used by CDS. These classes need to access the private ConstantPool() constructor.
template <class T> friend class CppVtableTesterA;
template <class T> friend class CppVtableTesterB;
template <class T> friend class CppVtableCloner;
// Used by compiler to prevent classloading.
static Method* method_at_if_loaded (const constantPoolHandle& this_cp, int which);
static bool has_appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
static oop appendix_at_if_loaded (const constantPoolHandle& this_cp, int which);
static bool has_local_signature_at_if_loaded (const constantPoolHandle& this_cp, int which);
static Klass* klass_at_if_loaded (const constantPoolHandle& this_cp, int which);
// Routines currently used for annotations (only called by jvm.cpp) but which might be used in the
// future by other Java code. These take constant pool indices rather than
// constant pool cache indices as do the peer methods above.
Symbol* uncached_klass_ref_at_noresolve(int which);
Symbol* uncached_name_ref_at(int which) { return impl_name_ref_at(which, true); }
Symbol* uncached_signature_ref_at(int which) { return impl_signature_ref_at(which, true); }
int uncached_klass_ref_index_at(int which) { return impl_klass_ref_index_at(which, true); }
int uncached_name_and_type_ref_index_at(int which) { return impl_name_and_type_ref_index_at(which, true); }
// Sharing
int pre_resolve_shared_klasses(TRAPS);
// Debugging
const char* printable_name_at(int which) PRODUCT_RETURN0;
#ifdef ASSERT
enum { CPCACHE_INDEX_TAG = 0x10000 }; // helps keep CP cache indices distinct from CP indices
#else
enum { CPCACHE_INDEX_TAG = 0 }; // in product mode, this zero value is a no-op
#endif //ASSERT
static int decode_cpcache_index(int raw_index, bool invokedynamic_ok = false) {
if (invokedynamic_ok && is_invokedynamic_index(raw_index))
return decode_invokedynamic_index(raw_index);
else
return raw_index - CPCACHE_INDEX_TAG;
}
private:
void set_resolved_references(OopHandle s) { _cache->set_resolved_references(s); }
Array<u2>* reference_map() const { return (_cache == NULL) ? NULL : _cache->reference_map(); }
void set_reference_map(Array<u2>* o) { _cache->set_reference_map(o); }
// patch JSR 292 resolved references after the class is linked.
void patch_resolved_references(GrowableArray<Handle>* cp_patches);
Symbol* impl_name_ref_at(int which, bool uncached);
Symbol* impl_signature_ref_at(int which, bool uncached);
int impl_klass_ref_index_at(int which, bool uncached);
int impl_name_and_type_ref_index_at(int which, bool uncached);
constantTag impl_tag_ref_at(int which, bool uncached);
// Used while constructing constant pool (only by ClassFileParser)
jint klass_index_at(int which) {
assert(tag_at(which).is_klass_index(), "Corrupted constant pool");
return *int_at_addr(which);
}
jint string_index_at(int which) {
assert(tag_at(which).is_string_index(), "Corrupted constant pool");
return *int_at_addr(which);
}
// Performs the LinkResolver checks
static void verify_constant_pool_resolve(const constantPoolHandle& this_cp, Klass* klass, TRAPS);
// Implementation of methods that needs an exposed 'this' pointer, in order to
// handle GC while executing the method
static Klass* klass_at_impl(const constantPoolHandle& this_cp, int which,
bool save_resolution_error, TRAPS);
static oop string_at_impl(const constantPoolHandle& this_cp, int which, int obj_index, TRAPS);
static void trace_class_resolution(const constantPoolHandle& this_cp, Klass* k);
// Resolve string constants (to prevent allocation during compilation)
static void resolve_string_constants_impl(const constantPoolHandle& this_cp, TRAPS);
static oop resolve_constant_at_impl(const constantPoolHandle& this_cp, int index, int cache_index,
bool* status_return, TRAPS);
static void copy_bootstrap_arguments_at_impl(const constantPoolHandle& this_cp, int index,
int start_arg, int end_arg,
objArrayHandle info, int pos,
bool must_resolve, Handle if_not_available, TRAPS);
// Exception handling
static Symbol* exception_message(const constantPoolHandle& this_cp, int which, constantTag tag, oop pending_exception);
static void save_and_throw_exception(const constantPoolHandle& this_cp, int which, constantTag tag, TRAPS);
public:
// Exception handling
static void throw_resolution_error(const constantPoolHandle& this_cp, int which, TRAPS);
// Merging ConstantPool* support:
bool compare_entry_to(int index1, const constantPoolHandle& cp2, int index2, TRAPS);
void copy_cp_to(int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS) {
constantPoolHandle h_this(THREAD, this);
copy_cp_to_impl(h_this, start_i, end_i, to_cp, to_i, THREAD);
}
static void copy_cp_to_impl(const constantPoolHandle& from_cp, int start_i, int end_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
static void copy_entry_to(const constantPoolHandle& from_cp, int from_i, const constantPoolHandle& to_cp, int to_i, TRAPS);
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