/*
* Copyright (c) 1997, 2022, 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 "asm/assembler.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
#include "memory/oopFactory.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.hpp"
#include "oops/instanceKlass.hpp"
#include "oops/klass.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "oops/typeArrayKlass.hpp"
#include "runtime/fieldDescriptor.inline.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/safepointVerifiers.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/signature.hpp"
#include "runtime/sharedRuntime.hpp"
// Implementation of SignatureIterator
// Signature syntax:
//
// Signature = "(" {Parameter} ")" ReturnType.
// Parameter = FieldType.
// ReturnType = FieldType | "V".
// FieldType = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "[" FieldType.
// ClassName = string.
// The ClassName string can be any JVM-style UTF8 string except:
// - an empty string (the empty string is never a name of any kind)
// - a string which begins or ends with slash '/' (the package separator)
// - a string which contains adjacent slashes '//' (no empty package names)
// - a string which contains a semicolon ';' (the end-delimiter)
// - a string which contains a left bracket '[' (the array marker)
// - a string which contains a dot '.' (the external package separator)
//
// Other "meta-looking" characters, such as '(' and '<' and '+',
// are perfectly legitimate within a class name, for the JVM.
// Class names which contain double slashes ('a//b') and non-initial
// brackets ('a[b]') are reserved for possible enrichment of the
// type language.
void SignatureIterator::set_fingerprint(fingerprint_t fingerprint) {
if (!fp_is_valid(fingerprint)) {
_fingerprint = fingerprint;
_return_type = T_ILLEGAL;
} else if (fingerprint != _fingerprint) {
assert(_fingerprint == zero_fingerprint(), "consistent fingerprint values");
_fingerprint = fingerprint;
_return_type = fp_return_type(fingerprint);
}
}
BasicType SignatureIterator::return_type() {
if (_return_type == T_ILLEGAL) {
SignatureStream ss(_signature);
ss.skip_to_return_type();
_return_type = ss.type();
assert(_return_type != T_ILLEGAL, "illegal return type");
}
return _return_type;
}
bool SignatureIterator::fp_is_valid_type(BasicType type, bool for_return_type) {
assert(type != (BasicType)fp_parameters_done, "fingerprint is incorrectly at done");
assert(((int)type & ~fp_parameter_feature_mask) == 0, "fingerprint feature mask yielded non-zero value");
return (is_java_primitive(type) ||
is_reference_type(type) ||
(for_return_type && type == T_VOID));
}
ArgumentSizeComputer::ArgumentSizeComputer(Symbol* signature)
: SignatureIterator(signature)
{
_size = 0;
do_parameters_on(this); // non-virtual template execution
}
ArgumentCount::ArgumentCount(Symbol* signature)
: SignatureIterator(signature)
{
_size = 0;
do_parameters_on(this); // non-virtual template execution
}
ReferenceArgumentCount::ReferenceArgumentCount(Symbol* signature)
: SignatureIterator(signature)
{
_refs = 0;
do_parameters_on(this); // non-virtual template execution
}
#if !defined(_LP64) || defined(ZERO) || defined(ASSERT)
static int compute_num_stack_arg_slots(Symbol* signature, int sizeargs, bool is_static) {
ResourceMark rm;
BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
int sig_index = 0;
if (!is_static) {
sig_bt[sig_index++] = T_OBJECT; // 'this'
}
for (SignatureStream ss(signature); !ss.at_return_type(); ss.next()) {
BasicType t = ss.type();
assert(type2size[t] == 1 || type2size[t] == 2, "size is 1 or 2");
sig_bt[sig_index++] = t;
if (type2size[t] == 2) {
sig_bt[sig_index++] = T_VOID;
}
}
assert(sig_index == sizeargs, "sig_index: %d sizeargs: %d", sig_index, sizeargs);
return SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs);
}
#endif
void Fingerprinter::compute_fingerprint_and_return_type(bool static_flag) {
// See if we fingerprinted this method already
if (_method != NULL) {
assert(!static_flag, "must not be passed by caller");
static_flag = _method->is_static();
_fingerprint = _method->constMethod()->fingerprint();
if (_fingerprint != zero_fingerprint()) {
_return_type = _method->result_type();
assert(is_java_type(_return_type), "return type must be a java type");
return;
}
if (_method->size_of_parameters() > fp_max_size_of_parameters) {
_fingerprint = overflow_fingerprint();
_method->constMethod()->set_fingerprint(_fingerprint);
// as long as we are here compute the return type:
_return_type = ResultTypeFinder(_method->signature()).type();
assert(is_java_type(_return_type), "return type must be a java type");
return;
}
}
// Note: This will always take the slow path, since _fp==zero_fp.
initialize_accumulator();
initialize_calling_convention(static_flag);
do_parameters_on(this);
assert(fp_is_valid_type(_return_type, true), "bad result type");
// Fill in the return type and static bits:
_accumulator |= _return_type << fp_static_feature_size;
if (static_flag) {
_accumulator |= fp_is_static_bit;
} else {
_param_size += 1; // this is the convention for Method::compute_size_of_parameters
}
#if defined(_LP64) && !defined(ZERO)
_stack_arg_slots = align_up(_stack_arg_slots, 2);
#ifdef ASSERT
int dbg_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
assert(_stack_arg_slots == dbg_stack_arg_slots, "fingerprinter: %d full: %d", _stack_arg_slots, dbg_stack_arg_slots);
#endif
#else
// Fallback: computed _stack_arg_slots is unreliable, compute directly.
_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
#endif
// Detect overflow. (We counted _param_size correctly.)
if (_method == NULL && _param_size > fp_max_size_of_parameters) {
// We did a one-pass computation of argument size, return type,
// and fingerprint.
_fingerprint = overflow_fingerprint();
return;
}
assert(_shift_count < BitsPerLong,
"shift count overflow %d (%d vs. %d): %s",
_shift_count, _param_size, fp_max_size_of_parameters,
_signature->as_C_string());
assert((_accumulator >> _shift_count) == fp_parameters_done, "must be zero");
// This is the result, along with _return_type:
_fingerprint = _accumulator;
// Cache the result on the method itself:
if (_method != NULL) {
_method->constMethod()->set_fingerprint(_fingerprint);
}
}
void Fingerprinter::initialize_calling_convention(bool static_flag) {
_int_args = 0;
_fp_args = 0;
if (!static_flag) { // `this` takes up an int register
_int_args++;
}
}
void Fingerprinter::do_type_calling_convention(BasicType type) {
// We compute the number of slots for stack-passed arguments in compiled calls.
// TODO: SharedRuntime::java_calling_convention is the shared code that knows all details
// about the platform-specific calling conventions. This method tries to compute the stack
// args number... poorly, at least for 32-bit ports and for zero. Current code has the fallback
// that recomputes the stack args number from SharedRuntime::java_calling_convention.
#if defined(_LP64) && !defined(ZERO)
switch (type) {
case T_VOID:
break;
case T_BOOLEAN:
case T_CHAR:
case T_BYTE:
case T_SHORT:
case T_INT:
#if defined(PPC64) || defined(S390)
if (_int_args < Argument::n_int_register_parameters_j) {
_int_args++;
} else {
_stack_arg_slots += 1;
}
break;
#endif // defined(PPC64) || defined(S390)
case T_LONG:
case T_OBJECT:
case T_ARRAY:
case T_ADDRESS:
if (_int_args < Argument::n_int_register_parameters_j) {
_int_args++;
} else {
PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
_stack_arg_slots += 2;
}
break;
case T_FLOAT:
#if defined(PPC64) || defined(S390)
if (_fp_args < Argument::n_float_register_parameters_j) {
_fp_args++;
} else {
_stack_arg_slots += 1;
}
break;
#endif // defined(PPC64) || defined(S390)
case T_DOUBLE:
if (_fp_args < Argument::n_float_register_parameters_j) {
_fp_args++;
} else {
PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
_stack_arg_slots += 2;
}
break;
default:
ShouldNotReachHere();
break;
}
#endif
}
// Implementation of SignatureStream
static inline BasicType decode_signature_char(int ch) {
switch (ch) {
#define EACH_SIG(ch, bt, ignore) \
case ch: return bt;
SIGNATURE_TYPES_DO(EACH_SIG, ignore)
#undef EACH_SIG
}
return (BasicType)0;
}
SignatureStream::SignatureStream(const Symbol* signature,
bool is_method) {
assert(!is_method || signature->starts_with(JVM_SIGNATURE_FUNC),
"method signature required");
_signature = signature;
_limit = signature->utf8_length();
int oz = (is_method ? _s_method : _s_field);
_state = oz;
_begin = _end = oz; // skip first '(' in method signatures
_array_prefix = 0; // just for definiteness
// assigning java/lang/Object to _previous_name means we can
// avoid a number of NULL checks in the parser
_previous_name = vmSymbols::java_lang_Object();
_names = NULL;
next();
}
SignatureStream::~SignatureStream() {
if (_previous_name == vmSymbols::java_lang_Object()) {
// no names were created
assert(_names == NULL, "_names unexpectedly created");
return;
}
// decrement refcount for names created during signature parsing
_previous_name->decrement_refcount();
if (_names != NULL) {
for (int i = 0; i < _names->length(); i++) {
_names->at(i)->decrement_refcount();
}
}
}
inline int SignatureStream::scan_type(BasicType type) {
const u1* base = _signature->bytes();
int end = _end;
int limit = _limit;
const u1* tem;
switch (type) {
case T_OBJECT:
tem = (const u1*) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
return (tem == NULL ? limit : tem + 1 - base);
case T_ARRAY:
while ((end < limit) && ((char)base[end] == JVM_SIGNATURE_ARRAY)) { end++; }
// If we discovered only the string of '[', this means something is wrong.
if (end >= limit) {
assert(false, "Invalid type detected");
return limit;
}
_array_prefix = end - _end; // number of '[' chars just skipped
if (Signature::has_envelope(base[end])) {
tem = (const u1 *) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
return (tem == NULL ? limit : tem + 1 - base);
}
// Skipping over a single character for a primitive type.
assert(is_java_primitive(decode_signature_char(base[end])), "only primitives expected");
return end + 1;
default:
// Skipping over a single character for a primitive type (or void).
assert(!is_reference_type(type), "only primitives or void expected");
return end + 1;
}
}
void SignatureStream::next() {
const Symbol* sig = _signature;
int len = _limit;
if (_end >= len) { set_done(); return; }
_begin = _end;
int ch = sig->char_at(_begin);
if (ch == JVM_SIGNATURE_ENDFUNC) {
assert(_state == _s_method, "must be in method");
_state = _s_method_return;
_begin = ++_end;
if (_end >= len) { set_done(); return; }
ch = sig->char_at(_begin);
}
BasicType bt = decode_signature_char(ch);
assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
_type = bt;
_end = scan_type(bt);
}
int SignatureStream::skip_whole_array_prefix() {
assert(_type == T_ARRAY, "must be");
// we are stripping all levels of T_ARRAY,
// so we must decode the next character
int whole_array_prefix = _array_prefix;
int new_begin = _begin + whole_array_prefix;
_begin = new_begin;
int ch = _signature->char_at(new_begin);
BasicType bt = decode_signature_char(ch);
assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
_type = bt;
assert(bt != T_VOID && bt != T_ARRAY, "bad signature type");
// Don't bother to re-scan, since it won't change the value of _end.
return whole_array_prefix;
}
bool Signature::is_valid_array_signature(const Symbol* sig) {
assert(sig->utf8_length() > 1, "this should already have been checked");
assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked");
// The first character is already checked
int i = 1;
int len = sig->utf8_length();
// First skip all '['s
while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++;
// Check type
switch(sig->char_at(i)) {
case JVM_SIGNATURE_BYTE:
case JVM_SIGNATURE_CHAR:
case JVM_SIGNATURE_DOUBLE:
case JVM_SIGNATURE_FLOAT:
case JVM_SIGNATURE_INT:
case JVM_SIGNATURE_LONG:
case JVM_SIGNATURE_SHORT:
case JVM_SIGNATURE_BOOLEAN:
// If it is an array, the type is the last character
return (i + 1 == len);
case JVM_SIGNATURE_CLASS:
// If it is an object, the last character must be a ';'
return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS;
}
return false;
}
BasicType Signature::basic_type(int ch) {
BasicType btcode = decode_signature_char(ch);
if (btcode == 0) return T_ILLEGAL;
return btcode;
}
Symbol* Signature::strip_envelope(const Symbol* signature) {
assert(has_envelope(signature), "precondition");
return SymbolTable::new_symbol((char*) signature->bytes() + 1,
signature->utf8_length() - 2);
}
static const int jl_len = 10, object_len = 6, jl_object_len = jl_len + object_len;
static const char jl_str[] = "java/lang/";
#ifdef ASSERT
static bool signature_symbols_sane() {
static bool done;
if (done) return true;
done = true;
// test some tense code that looks for common symbol names:
assert(vmSymbols::java_lang_Object()->utf8_length() == jl_object_len &&
vmSymbols::java_lang_Object()->starts_with(jl_str, jl_len) &&
vmSymbols::java_lang_Object()->ends_with("Object", object_len) &&
vmSymbols::java_lang_Object()->is_permanent() &&
vmSymbols::java_lang_String()->utf8_length() == jl_object_len &&
vmSymbols::java_lang_String()->starts_with(jl_str, jl_len) &&
vmSymbols::java_lang_String()->ends_with("String", object_len) &&
vmSymbols::java_lang_String()->is_permanent(),
"sanity");
return true;
}
#endif //ASSERT
// returns a symbol; the caller is responsible for decrementing it
Symbol* SignatureStream::find_symbol() {
// Create a symbol from for string _begin _end
int begin = raw_symbol_begin();
int end = raw_symbol_end();
const char* symbol_chars = (const char*)_signature->base() + begin;
int len = end - begin;
// Quick check for common symbols in signatures
assert(signature_symbols_sane(), "incorrect signature sanity check");
if (len == jl_object_len &&
memcmp(symbol_chars, jl_str, jl_len) == 0) {
if (memcmp("String", symbol_chars + jl_len, object_len) == 0) {
return vmSymbols::java_lang_String();
} else if (memcmp("Object", symbol_chars + jl_len, object_len) == 0) {
return vmSymbols::java_lang_Object();
}
}
Symbol* name = _previous_name;
if (name->equals(symbol_chars, len)) {
return name;
}
// Save names for cleaning up reference count at the end of
// SignatureStream scope.
name = SymbolTable::new_symbol(symbol_chars, len);
// Only allocate the GrowableArray for the _names buffer if more than
// one name is being processed in the signature.
if (!_previous_name->is_permanent()) {
if (_names == NULL) {
_names = new GrowableArray<Symbol*>(10);
}
_names->push(_previous_name);
}
_previous_name = name;
return name;
}
Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
FailureMode failure_mode, TRAPS) {
if (!is_reference()) {
return NULL;
}
Symbol* name = as_symbol();
Klass* k = NULL;
if (failure_mode == ReturnNull) {
// Note: SD::resolve_or_null returns NULL for most failure modes,
// but not all. Circularity errors, invalid PDs, etc., throw.
k = SystemDictionary::resolve_or_null(name, class_loader, protection_domain, CHECK_NULL);
} else if (failure_mode == CachedOrNull) {
NoSafepointVerifier nsv; // no loading, now, we mean it!
assert(!HAS_PENDING_EXCEPTION, "");
k = SystemDictionary::find_instance_klass(THREAD, name, class_loader, protection_domain);
// SD::find does not trigger loading, so there should be no throws
// Still, bad things can happen, so we CHECK_NULL and ask callers
// to do likewise.
return k;
} else {
// The only remaining failure mode is NCDFError.
// The test here allows for an additional mode CNFException
// if callers need to request the reflective error instead.
bool throw_error = (failure_mode == NCDFError);
k = SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, CHECK_NULL);
}
return k;
}
oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain,
FailureMode failure_mode, TRAPS) {
if (!is_reference()) {
return Universe::java_mirror(type());
}
Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL);
if (klass == NULL) {
return NULL;
}
return klass->java_mirror();
}
void SignatureStream::skip_to_return_type() {
while (!at_return_type()) {
next();
}
}
ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature,
Handle class_loader,
Handle protection_domain,
bool is_method)
: SignatureStream(signature, is_method),
_class_loader(class_loader), _protection_domain(protection_domain)
{
initialize_load_origin(NULL);
}
ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method)
: SignatureStream(signature, is_method)
{
assert(load_origin != NULL, "");
initialize_load_origin(load_origin);
}
ResolvingSignatureStream::ResolvingSignatureStream(const Method* method)
: SignatureStream(method->signature(), true)
{
initialize_load_origin(method->method_holder());
}
void ResolvingSignatureStream::cache_handles() {
assert(_load_origin != NULL, "");
JavaThread* current = JavaThread::current();
_class_loader = Handle(current, _load_origin->class_loader());
_protection_domain = Handle(current, _load_origin->protection_domain());
}
#ifdef ASSERT
extern bool signature_constants_sane(); // called from basic_types_init()
bool signature_constants_sane() {
// for the lookup table, test every 8-bit code point, and then some:
for (int i = -256; i <= 256; i++) {
int btcode = 0;
switch (i) {
#define EACH_SIG(ch, bt, ignore) \
case ch: { btcode = bt; break; }
SIGNATURE_TYPES_DO(EACH_SIG, ignore)
#undef EACH_SIG
}
int btc = decode_signature_char(i);
assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode);
}
return true;
}
bool SignatureVerifier::is_valid_method_signature(Symbol* sig) {
const char* method_sig = (const char*)sig->bytes();
ssize_t len = sig->utf8_length();
ssize_t index = 0;
if (method_sig != NULL && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
++index;
while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
ssize_t res = is_valid_type(&method_sig[index], len - index);
if (res == -1) {
return false;
} else {
index += res;
}
}
if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
// check the return type
++index;
return (is_valid_type(&method_sig[index], len - index) == (len - index));
}
}
return false;
}
bool SignatureVerifier::is_valid_type_signature(Symbol* sig) {
const char* type_sig = (const char*)sig->bytes();
ssize_t len = sig->utf8_length();
return (type_sig != NULL && len >= 1 &&
(is_valid_type(type_sig, len) == len));
}
// Checks to see if the type (not to go beyond 'limit') refers to a valid type.
// Returns -1 if it is not, or the index of the next character that is not part
// of the type. The type encoding may end before 'limit' and that's ok.
ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
ssize_t index = 0;
// Iterate over any number of array dimensions
while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
if (index >= limit) {
return -1;
}
switch (type[index]) {
case JVM_SIGNATURE_BYTE:
case JVM_SIGNATURE_CHAR:
case JVM_SIGNATURE_FLOAT:
case JVM_SIGNATURE_DOUBLE:
case JVM_SIGNATURE_INT:
case JVM_SIGNATURE_LONG:
case JVM_SIGNATURE_SHORT:
case JVM_SIGNATURE_BOOLEAN:
case JVM_SIGNATURE_VOID:
return index + 1;
case JVM_SIGNATURE_CLASS:
for (index = index + 1; index < limit; ++index) {
char c = type[index];
switch (c) {
case JVM_SIGNATURE_ENDCLASS:
return index + 1;
case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
return -1;
default: ; // fall through
}
}
// fall through
default: ; // fall through
}
return -1;
}
#endif // ASSERT
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