| /* |
| * Copyright (c) 2003, 2014, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_CLASSFILE_VERIFICATIONTYPE_HPP |
| #define SHARE_VM_CLASSFILE_VERIFICATIONTYPE_HPP |
| |
| #include "classfile/systemDictionary.hpp" |
| #include "memory/allocation.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "oops/symbol.hpp" |
| #include "runtime/handles.hpp" |
| #include "runtime/signature.hpp" |
| |
| enum { |
| // As specifed in the JVM spec |
| ITEM_Top = 0, |
| ITEM_Integer = 1, |
| ITEM_Float = 2, |
| ITEM_Double = 3, |
| ITEM_Long = 4, |
| ITEM_Null = 5, |
| ITEM_UninitializedThis = 6, |
| ITEM_Object = 7, |
| ITEM_Uninitialized = 8, |
| ITEM_Bogus = (uint)-1 |
| }; |
| |
| class ClassVerifier; |
| |
| class VerificationType VALUE_OBJ_CLASS_SPEC { |
| private: |
| // Least significant bits of _handle are always 0, so we use these as |
| // the indicator that the _handle is valid. Otherwise, the _data field |
| // contains encoded data (as specified below). Should the VM change |
| // and the lower bits on oops aren't 0, the assert in the constructor |
| // will catch this and we'll have to add a descriminator tag to this |
| // structure. |
| union { |
| Symbol* _sym; |
| uintptr_t _data; |
| } _u; |
| |
| enum { |
| // These rest are not found in classfiles, but used by the verifier |
| ITEM_Boolean = 9, ITEM_Byte, ITEM_Short, ITEM_Char, |
| ITEM_Long_2nd, ITEM_Double_2nd |
| }; |
| |
| // Enum for the _data field |
| enum { |
| // Bottom two bits determine if the type is a reference, primitive, |
| // uninitialized or a query-type. |
| TypeMask = 0x00000003, |
| |
| // Topmost types encoding |
| Reference = 0x0, // _sym contains the name |
| Primitive = 0x1, // see below for primitive list |
| Uninitialized = 0x2, // 0x00ffff00 contains bci |
| TypeQuery = 0x3, // Meta-types used for category testing |
| |
| // Utility flags |
| ReferenceFlag = 0x00, // For reference query types |
| Category1Flag = 0x01, // One-word values |
| Category2Flag = 0x02, // First word of a two-word value |
| Category2_2ndFlag = 0x04, // Second word of a two-word value |
| |
| // special reference values |
| Null = 0x00000000, // A reference with a 0 sym is null |
| |
| // Primitives categories (the second byte determines the category) |
| Category1 = (Category1Flag << 1 * BitsPerByte) | Primitive, |
| Category2 = (Category2Flag << 1 * BitsPerByte) | Primitive, |
| Category2_2nd = (Category2_2ndFlag << 1 * BitsPerByte) | Primitive, |
| |
| // Primitive values (type descriminator stored in most-signifcant bytes) |
| Bogus = (ITEM_Bogus << 2 * BitsPerByte) | Category1, |
| Boolean = (ITEM_Boolean << 2 * BitsPerByte) | Category1, |
| Byte = (ITEM_Byte << 2 * BitsPerByte) | Category1, |
| Short = (ITEM_Short << 2 * BitsPerByte) | Category1, |
| Char = (ITEM_Char << 2 * BitsPerByte) | Category1, |
| Integer = (ITEM_Integer << 2 * BitsPerByte) | Category1, |
| Float = (ITEM_Float << 2 * BitsPerByte) | Category1, |
| Long = (ITEM_Long << 2 * BitsPerByte) | Category2, |
| Double = (ITEM_Double << 2 * BitsPerByte) | Category2, |
| Long_2nd = (ITEM_Long_2nd << 2 * BitsPerByte) | Category2_2nd, |
| Double_2nd = (ITEM_Double_2nd << 2 * BitsPerByte) | Category2_2nd, |
| |
| // Used by Uninitialized (second and third bytes hold the bci) |
| BciMask = 0xffff << 1 * BitsPerByte, |
| BciForThis = ((u2)-1), // A bci of -1 is an Unintialized-This |
| |
| // Query values |
| ReferenceQuery = (ReferenceFlag << 1 * BitsPerByte) | TypeQuery, |
| Category1Query = (Category1Flag << 1 * BitsPerByte) | TypeQuery, |
| Category2Query = (Category2Flag << 1 * BitsPerByte) | TypeQuery, |
| Category2_2ndQuery = (Category2_2ndFlag << 1 * BitsPerByte) | TypeQuery |
| }; |
| |
| VerificationType(uintptr_t raw_data) { |
| _u._data = raw_data; |
| } |
| |
| public: |
| |
| VerificationType() { *this = bogus_type(); } |
| |
| // Create verification types |
| static VerificationType bogus_type() { return VerificationType(Bogus); } |
| static VerificationType top_type() { return bogus_type(); } // alias |
| static VerificationType null_type() { return VerificationType(Null); } |
| static VerificationType integer_type() { return VerificationType(Integer); } |
| static VerificationType float_type() { return VerificationType(Float); } |
| static VerificationType long_type() { return VerificationType(Long); } |
| static VerificationType long2_type() { return VerificationType(Long_2nd); } |
| static VerificationType double_type() { return VerificationType(Double); } |
| static VerificationType boolean_type() { return VerificationType(Boolean); } |
| static VerificationType byte_type() { return VerificationType(Byte); } |
| static VerificationType char_type() { return VerificationType(Char); } |
| static VerificationType short_type() { return VerificationType(Short); } |
| static VerificationType double2_type() |
| { return VerificationType(Double_2nd); } |
| |
| // "check" types are used for queries. A "check" type is not assignable |
| // to anything, but the specified types are assignable to a "check". For |
| // example, any category1 primitive is assignable to category1_check and |
| // any reference is assignable to reference_check. |
| static VerificationType reference_check() |
| { return VerificationType(ReferenceQuery); } |
| static VerificationType category1_check() |
| { return VerificationType(Category1Query); } |
| static VerificationType category2_check() |
| { return VerificationType(Category2Query); } |
| static VerificationType category2_2nd_check() |
| { return VerificationType(Category2_2ndQuery); } |
| |
| // For reference types, store the actual Symbol |
| static VerificationType reference_type(Symbol* sh) { |
| assert(((uintptr_t)sh & 0x3) == 0, "Symbols must be aligned"); |
| // If the above assert fails in the future because oop* isn't aligned, |
| // then this type encoding system will have to change to have a tag value |
| // to descriminate between oops and primitives. |
| return VerificationType((uintptr_t)sh); |
| } |
| static VerificationType uninitialized_type(u2 bci) |
| { return VerificationType(bci << 1 * BitsPerByte | Uninitialized); } |
| static VerificationType uninitialized_this_type() |
| { return uninitialized_type(BciForThis); } |
| |
| // Create based on u1 read from classfile |
| static VerificationType from_tag(u1 tag); |
| |
| bool is_bogus() const { return (_u._data == Bogus); } |
| bool is_null() const { return (_u._data == Null); } |
| bool is_boolean() const { return (_u._data == Boolean); } |
| bool is_byte() const { return (_u._data == Byte); } |
| bool is_char() const { return (_u._data == Char); } |
| bool is_short() const { return (_u._data == Short); } |
| bool is_integer() const { return (_u._data == Integer); } |
| bool is_long() const { return (_u._data == Long); } |
| bool is_float() const { return (_u._data == Float); } |
| bool is_double() const { return (_u._data == Double); } |
| bool is_long2() const { return (_u._data == Long_2nd); } |
| bool is_double2() const { return (_u._data == Double_2nd); } |
| bool is_reference() const { return ((_u._data & TypeMask) == Reference); } |
| bool is_category1() const { |
| // This should return true for all one-word types, which are category1 |
| // primitives, and references (including uninitialized refs). Though |
| // the 'query' types should technically return 'false' here, if we |
| // allow this to return true, we can perform the test using only |
| // 2 operations rather than 8 (3 masks, 3 compares and 2 logical 'ands'). |
| // Since noone should call this on a query type anyway, this is ok. |
| assert(!is_check(), "Must not be a check type (wrong value returned)"); |
| return ((_u._data & Category1) != Primitive); |
| // should only return false if it's a primitive, and the category1 flag |
| // is not set. |
| } |
| bool is_category2() const { return ((_u._data & Category2) == Category2); } |
| bool is_category2_2nd() const { |
| return ((_u._data & Category2_2nd) == Category2_2nd); |
| } |
| bool is_reference_check() const { return _u._data == ReferenceQuery; } |
| bool is_category1_check() const { return _u._data == Category1Query; } |
| bool is_category2_check() const { return _u._data == Category2Query; } |
| bool is_category2_2nd_check() const { return _u._data == Category2_2ndQuery; } |
| bool is_check() const { return (_u._data & TypeQuery) == TypeQuery; } |
| |
| bool is_x_array(char sig) const { |
| return is_null() || (is_array() && (name()->byte_at(1) == sig)); |
| } |
| bool is_int_array() const { return is_x_array('I'); } |
| bool is_byte_array() const { return is_x_array('B'); } |
| bool is_bool_array() const { return is_x_array('Z'); } |
| bool is_char_array() const { return is_x_array('C'); } |
| bool is_short_array() const { return is_x_array('S'); } |
| bool is_long_array() const { return is_x_array('J'); } |
| bool is_float_array() const { return is_x_array('F'); } |
| bool is_double_array() const { return is_x_array('D'); } |
| bool is_object_array() const { return is_x_array('L'); } |
| bool is_array_array() const { return is_x_array('['); } |
| bool is_reference_array() const |
| { return is_object_array() || is_array_array(); } |
| bool is_object() const |
| { return (is_reference() && !is_null() && name()->utf8_length() >= 1 && |
| name()->byte_at(0) != '['); } |
| bool is_array() const |
| { return (is_reference() && !is_null() && name()->utf8_length() >= 2 && |
| name()->byte_at(0) == '['); } |
| bool is_uninitialized() const |
| { return ((_u._data & Uninitialized) == Uninitialized); } |
| bool is_uninitialized_this() const |
| { return is_uninitialized() && bci() == BciForThis; } |
| |
| VerificationType to_category2_2nd() const { |
| assert(is_category2(), "Must be a double word"); |
| return VerificationType(is_long() ? Long_2nd : Double_2nd); |
| } |
| |
| u2 bci() const { |
| assert(is_uninitialized(), "Must be uninitialized type"); |
| return ((_u._data & BciMask) >> 1 * BitsPerByte); |
| } |
| |
| Symbol* name() const { |
| assert(is_reference() && !is_null(), "Must be a non-null reference"); |
| return _u._sym; |
| } |
| |
| bool equals(const VerificationType& t) const { |
| return (_u._data == t._u._data || |
| (is_reference() && t.is_reference() && !is_null() && !t.is_null() && |
| name() == t.name())); |
| } |
| |
| bool operator ==(const VerificationType& t) const { |
| return equals(t); |
| } |
| |
| bool operator !=(const VerificationType& t) const { |
| return !equals(t); |
| } |
| |
| // The whole point of this type system - check to see if one type |
| // is assignable to another. Returns true if one can assign 'from' to |
| // this. |
| bool is_assignable_from( |
| const VerificationType& from, ClassVerifier* context, |
| bool from_field_is_protected, TRAPS) const { |
| if (equals(from) || is_bogus()) { |
| return true; |
| } else { |
| switch(_u._data) { |
| case Category1Query: |
| return from.is_category1(); |
| case Category2Query: |
| return from.is_category2(); |
| case Category2_2ndQuery: |
| return from.is_category2_2nd(); |
| case ReferenceQuery: |
| return from.is_reference() || from.is_uninitialized(); |
| case Boolean: |
| case Byte: |
| case Char: |
| case Short: |
| // An int can be assigned to boolean, byte, char or short values. |
| return from.is_integer(); |
| default: |
| if (is_reference() && from.is_reference()) { |
| return is_reference_assignable_from(from, context, |
| from_field_is_protected, |
| CHECK_false); |
| } else { |
| return false; |
| } |
| } |
| } |
| } |
| |
| VerificationType get_component(ClassVerifier* context, TRAPS) const; |
| |
| int dimensions() const { |
| assert(is_array(), "Must be an array"); |
| int index = 0; |
| while (name()->byte_at(index) == '[') index++; |
| return index; |
| } |
| |
| void print_on(outputStream* st) const; |
| |
| private: |
| |
| bool is_reference_assignable_from( |
| const VerificationType&, ClassVerifier*, bool from_field_is_protected, |
| TRAPS) const; |
| }; |
| |
| #endif // SHARE_VM_CLASSFILE_VERIFICATIONTYPE_HPP |
