8157181: Compilers accept modification of final fields outside initializer methods
Summary: Track initialized final field updates; disable constant folding if an update is detected. Enforce final field update rules introduced by JVMS-7 (but only for JDK 9).
Reviewed-by: vlivanov, dnsimon, forax, never, kvn, coleenp
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#ifndef SHARE_VM_UTILITIES_ACCESSFLAGS_HPP
#define SHARE_VM_UTILITIES_ACCESSFLAGS_HPP
#include "memory/allocation.hpp"
#include "prims/jvm.h"
#include "utilities/macros.hpp"
// AccessFlags is an abstraction over Java access flags.
enum {
// See jvm.h for shared JVM_ACC_XXX access flags
// HotSpot-specific access flags
// flags actually put in .class file
JVM_ACC_WRITTEN_FLAGS = 0x00007FFF,
// Method* flags
JVM_ACC_MONITOR_MATCH = 0x10000000, // True if we know that monitorenter/monitorexit bytecodes match
JVM_ACC_HAS_MONITOR_BYTECODES = 0x20000000, // Method contains monitorenter/monitorexit bytecodes
JVM_ACC_HAS_LOOPS = 0x40000000, // Method has loops
JVM_ACC_LOOPS_FLAG_INIT = (int)0x80000000,// The loop flag has been initialized
JVM_ACC_QUEUED = 0x01000000, // Queued for compilation
JVM_ACC_NOT_C2_COMPILABLE = 0x02000000,
JVM_ACC_NOT_C1_COMPILABLE = 0x04000000,
JVM_ACC_NOT_C2_OSR_COMPILABLE = 0x08000000,
JVM_ACC_HAS_LINE_NUMBER_TABLE = 0x00100000,
JVM_ACC_HAS_CHECKED_EXCEPTIONS = 0x00400000,
JVM_ACC_HAS_JSRS = 0x00800000,
JVM_ACC_IS_OLD = 0x00010000, // RedefineClasses() has replaced this method
JVM_ACC_IS_OBSOLETE = 0x00020000, // RedefineClasses() has made method obsolete
JVM_ACC_IS_PREFIXED_NATIVE = 0x00040000, // JVMTI has prefixed this native method
JVM_ACC_ON_STACK = 0x00080000, // RedefineClasses() was used on the stack
JVM_ACC_IS_DELETED = 0x00008000, // RedefineClasses() has deleted this method
// Klass* flags
JVM_ACC_HAS_MIRANDA_METHODS = 0x10000000, // True if this class has miranda methods in it's vtable
JVM_ACC_HAS_VANILLA_CONSTRUCTOR = 0x20000000, // True if klass has a vanilla default constructor
JVM_ACC_HAS_FINALIZER = 0x40000000, // True if klass has a non-empty finalize() method
JVM_ACC_IS_CLONEABLE_FAST = (int)0x80000000,// True if klass implements the Cloneable interface and can be optimized in generated code
JVM_ACC_HAS_FINAL_METHOD = 0x01000000, // True if klass has final method
// Klass* and Method* flags
JVM_ACC_HAS_LOCAL_VARIABLE_TABLE= 0x00200000,
JVM_ACC_PROMOTED_FLAGS = 0x00200000, // flags promoted from methods to the holding klass
// field flags
// Note: these flags must be defined in the low order 16 bits because
// InstanceKlass only stores a ushort worth of information from the
// AccessFlags value.
// These bits must not conflict with any other field-related access flags
// (e.g., ACC_ENUM).
// Note that the class-related ACC_ANNOTATION bit conflicts with these flags.
JVM_ACC_FIELD_ACCESS_WATCHED = 0x00002000, // field access is watched by JVMTI
JVM_ACC_FIELD_MODIFICATION_WATCHED = 0x00008000, // field modification is watched by JVMTI
JVM_ACC_FIELD_INTERNAL = 0x00000400, // internal field, same as JVM_ACC_ABSTRACT
JVM_ACC_FIELD_STABLE = 0x00000020, // @Stable field, same as JVM_ACC_SYNCHRONIZED and JVM_ACC_SUPER
JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE = 0x00000100, // (static) final field updated outside (class) initializer, same as JVM_ACC_NATIVE
JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE = 0x00000800, // field has generic signature
JVM_ACC_FIELD_INTERNAL_FLAGS = JVM_ACC_FIELD_ACCESS_WATCHED |
JVM_ACC_FIELD_MODIFICATION_WATCHED |
JVM_ACC_FIELD_INTERNAL |
JVM_ACC_FIELD_STABLE |
JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE,
// flags accepted by set_field_flags()
JVM_ACC_FIELD_FLAGS = JVM_RECOGNIZED_FIELD_MODIFIERS | JVM_ACC_FIELD_INTERNAL_FLAGS
};
class AccessFlags VALUE_OBJ_CLASS_SPEC {
friend class VMStructs;
private:
jint _flags;
public:
AccessFlags() : _flags(0) {}
explicit AccessFlags(jint flags) : _flags(flags) {}
// Java access flags
bool is_public () const { return (_flags & JVM_ACC_PUBLIC ) != 0; }
bool is_private () const { return (_flags & JVM_ACC_PRIVATE ) != 0; }
bool is_protected () const { return (_flags & JVM_ACC_PROTECTED ) != 0; }
bool is_static () const { return (_flags & JVM_ACC_STATIC ) != 0; }
bool is_final () const { return (_flags & JVM_ACC_FINAL ) != 0; }
bool is_synchronized() const { return (_flags & JVM_ACC_SYNCHRONIZED) != 0; }
bool is_super () const { return (_flags & JVM_ACC_SUPER ) != 0; }
bool is_volatile () const { return (_flags & JVM_ACC_VOLATILE ) != 0; }
bool is_transient () const { return (_flags & JVM_ACC_TRANSIENT ) != 0; }
bool is_native () const { return (_flags & JVM_ACC_NATIVE ) != 0; }
bool is_interface () const { return (_flags & JVM_ACC_INTERFACE ) != 0; }
bool is_abstract () const { return (_flags & JVM_ACC_ABSTRACT ) != 0; }
bool is_strict () const { return (_flags & JVM_ACC_STRICT ) != 0; }
// Attribute flags
bool is_synthetic () const { return (_flags & JVM_ACC_SYNTHETIC ) != 0; }
// Method* flags
bool is_monitor_matching () const { return (_flags & JVM_ACC_MONITOR_MATCH ) != 0; }
bool has_monitor_bytecodes () const { return (_flags & JVM_ACC_HAS_MONITOR_BYTECODES ) != 0; }
bool has_loops () const { return (_flags & JVM_ACC_HAS_LOOPS ) != 0; }
bool loops_flag_init () const { return (_flags & JVM_ACC_LOOPS_FLAG_INIT ) != 0; }
bool queued_for_compilation () const { return (_flags & JVM_ACC_QUEUED ) != 0; }
bool is_not_c1_compilable () const { return (_flags & JVM_ACC_NOT_C1_COMPILABLE ) != 0; }
bool is_not_c2_compilable () const { return (_flags & JVM_ACC_NOT_C2_COMPILABLE ) != 0; }
bool is_not_c2_osr_compilable() const { return (_flags & JVM_ACC_NOT_C2_OSR_COMPILABLE ) != 0; }
bool has_linenumber_table () const { return (_flags & JVM_ACC_HAS_LINE_NUMBER_TABLE ) != 0; }
bool has_checked_exceptions () const { return (_flags & JVM_ACC_HAS_CHECKED_EXCEPTIONS ) != 0; }
bool has_jsrs () const { return (_flags & JVM_ACC_HAS_JSRS ) != 0; }
bool is_old () const { return (_flags & JVM_ACC_IS_OLD ) != 0; }
bool is_obsolete () const { return (_flags & JVM_ACC_IS_OBSOLETE ) != 0; }
bool is_deleted () const { return (_flags & JVM_ACC_IS_DELETED ) != 0; }
bool is_prefixed_native () const { return (_flags & JVM_ACC_IS_PREFIXED_NATIVE ) != 0; }
// Klass* flags
bool has_miranda_methods () const { return (_flags & JVM_ACC_HAS_MIRANDA_METHODS ) != 0; }
bool has_vanilla_constructor () const { return (_flags & JVM_ACC_HAS_VANILLA_CONSTRUCTOR) != 0; }
bool has_finalizer () const { return (_flags & JVM_ACC_HAS_FINALIZER ) != 0; }
bool has_final_method () const { return (_flags & JVM_ACC_HAS_FINAL_METHOD ) != 0; }
bool is_cloneable_fast () const { return (_flags & JVM_ACC_IS_CLONEABLE_FAST ) != 0; }
// Klass* and Method* flags
bool has_localvariable_table () const { return (_flags & JVM_ACC_HAS_LOCAL_VARIABLE_TABLE) != 0; }
void set_has_localvariable_table() { atomic_set_bits(JVM_ACC_HAS_LOCAL_VARIABLE_TABLE); }
void clear_has_localvariable_table() { atomic_clear_bits(JVM_ACC_HAS_LOCAL_VARIABLE_TABLE); }
// field flags
bool is_field_access_watched() const { return (_flags & JVM_ACC_FIELD_ACCESS_WATCHED) != 0; }
bool is_field_modification_watched() const
{ return (_flags & JVM_ACC_FIELD_MODIFICATION_WATCHED) != 0; }
bool has_field_initialized_final_update() const
{ return (_flags & JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE) != 0; }
bool on_stack() const { return (_flags & JVM_ACC_ON_STACK) != 0; }
bool is_internal() const { return (_flags & JVM_ACC_FIELD_INTERNAL) != 0; }
bool is_stable() const { return (_flags & JVM_ACC_FIELD_STABLE) != 0; }
bool field_has_generic_signature() const
{ return (_flags & JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE) != 0; }
// get .class file flags
jint get_flags () const { return (_flags & JVM_ACC_WRITTEN_FLAGS); }
// Initialization
void add_promoted_flags(jint flags) { _flags |= (flags & JVM_ACC_PROMOTED_FLAGS); }
void set_field_flags(jint flags) {
assert((flags & JVM_ACC_FIELD_FLAGS) == flags, "only recognized flags");
_flags = (flags & JVM_ACC_FIELD_FLAGS);
}
void set_flags(jint flags) { _flags = (flags & JVM_ACC_WRITTEN_FLAGS); }
void set_queued_for_compilation() { atomic_set_bits(JVM_ACC_QUEUED); }
void clear_queued_for_compilation() { atomic_clear_bits(JVM_ACC_QUEUED); }
// Atomic update of flags
void atomic_set_bits(jint bits);
void atomic_clear_bits(jint bits);
private:
friend class Method;
friend class Klass;
friend class ClassFileParser;
// the functions below should only be called on the _access_flags inst var directly,
// otherwise they are just changing a copy of the flags
// attribute flags
void set_is_synthetic() { atomic_set_bits(JVM_ACC_SYNTHETIC); }
// Method* flags
void set_monitor_matching() { atomic_set_bits(JVM_ACC_MONITOR_MATCH); }
void set_has_monitor_bytecodes() { atomic_set_bits(JVM_ACC_HAS_MONITOR_BYTECODES); }
void set_has_loops() { atomic_set_bits(JVM_ACC_HAS_LOOPS); }
void set_loops_flag_init() { atomic_set_bits(JVM_ACC_LOOPS_FLAG_INIT); }
void set_not_c1_compilable() { atomic_set_bits(JVM_ACC_NOT_C1_COMPILABLE); }
void set_not_c2_compilable() { atomic_set_bits(JVM_ACC_NOT_C2_COMPILABLE); }
void set_not_c2_osr_compilable() { atomic_set_bits(JVM_ACC_NOT_C2_OSR_COMPILABLE); }
void set_has_linenumber_table() { atomic_set_bits(JVM_ACC_HAS_LINE_NUMBER_TABLE); }
void set_has_checked_exceptions() { atomic_set_bits(JVM_ACC_HAS_CHECKED_EXCEPTIONS); }
void set_has_jsrs() { atomic_set_bits(JVM_ACC_HAS_JSRS); }
void set_is_old() { atomic_set_bits(JVM_ACC_IS_OLD); }
void set_is_obsolete() { atomic_set_bits(JVM_ACC_IS_OBSOLETE); }
void set_is_deleted() { atomic_set_bits(JVM_ACC_IS_DELETED); }
void set_is_prefixed_native() { atomic_set_bits(JVM_ACC_IS_PREFIXED_NATIVE); }
void clear_not_c1_compilable() { atomic_clear_bits(JVM_ACC_NOT_C1_COMPILABLE); }
void clear_not_c2_compilable() { atomic_clear_bits(JVM_ACC_NOT_C2_COMPILABLE); }
void clear_not_c2_osr_compilable() { atomic_clear_bits(JVM_ACC_NOT_C2_OSR_COMPILABLE); }
// Klass* flags
void set_has_vanilla_constructor() { atomic_set_bits(JVM_ACC_HAS_VANILLA_CONSTRUCTOR); }
void set_has_finalizer() { atomic_set_bits(JVM_ACC_HAS_FINALIZER); }
void set_has_final_method() { atomic_set_bits(JVM_ACC_HAS_FINAL_METHOD); }
void set_is_cloneable_fast() { atomic_set_bits(JVM_ACC_IS_CLONEABLE_FAST); }
void set_has_miranda_methods() { atomic_set_bits(JVM_ACC_HAS_MIRANDA_METHODS); }
public:
// field flags
void set_is_field_access_watched(const bool value)
{
if (value) {
atomic_set_bits(JVM_ACC_FIELD_ACCESS_WATCHED);
} else {
atomic_clear_bits(JVM_ACC_FIELD_ACCESS_WATCHED);
}
}
void set_is_field_modification_watched(const bool value)
{
if (value) {
atomic_set_bits(JVM_ACC_FIELD_MODIFICATION_WATCHED);
} else {
atomic_clear_bits(JVM_ACC_FIELD_MODIFICATION_WATCHED);
}
}
void set_has_field_initialized_final_update(const bool value) {
if (value) {
atomic_set_bits(JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE);
} else {
atomic_clear_bits(JVM_ACC_FIELD_INITIALIZED_FINAL_UPDATE);
}
}
void set_field_has_generic_signature()
{
atomic_set_bits(JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE);
}
void set_on_stack(const bool value)
{
if (value) {
atomic_set_bits(JVM_ACC_ON_STACK);
} else {
atomic_clear_bits(JVM_ACC_ON_STACK);
}
}
// Conversion
jshort as_short() const { return (jshort)_flags; }
jint as_int() const { return _flags; }
inline friend AccessFlags accessFlags_from(jint flags);
// Printing/debugging
#if INCLUDE_JVMTI
void print_on(outputStream* st) const;
#else
void print_on(outputStream* st) const PRODUCT_RETURN;
#endif
};
inline AccessFlags accessFlags_from(jint flags) {
AccessFlags af;
af._flags = flags;
return af;
}
#endif // SHARE_VM_UTILITIES_ACCESSFLAGS_HPP