1 /* 2 * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CLASSFILE_STACKMAPFRAME_HPP 26 #define SHARE_VM_CLASSFILE_STACKMAPFRAME_HPP 27 28 #include "classfile/verificationType.hpp" 29 #include "classfile/verifier.hpp" 30 #include "oops/method.hpp" 31 #include "runtime/handles.hpp" 32 #include "runtime/signature.hpp" 33 #include "utilities/exceptions.hpp" 34 35 // A StackMapFrame represents one frame in the stack map attribute. 36 37 class TypeContext; 38 39 enum { 40 FLAG_THIS_UNINIT = 0x01 41 }; 42 43 class StackMapFrame : public ResourceObj { 44 private: 45 int32_t _offset; 46 47 // See comment in StackMapTable about _frame_count about why these 48 // fields are int32_t instead of u2. 49 int32_t _locals_size; // number of valid type elements in _locals 50 int32_t _stack_size; // number of valid type elements in _stack 51 52 int32_t _stack_mark; // Records the size of the stack prior to an 53 // instruction modification, to allow rewinding 54 // when/if an error occurs. 55 56 int32_t _max_locals; 57 int32_t _max_stack; 58 59 u1 _flags; 60 VerificationType* _locals; // local variable type array 61 VerificationType* _stack; // operand stack type array 62 63 ClassVerifier* _verifier; // the verifier verifying this method 64 StackMapFrame(const StackMapFrame & cp)65 StackMapFrame(const StackMapFrame& cp) : 66 _offset(cp._offset), _locals_size(cp._locals_size), 67 _stack_size(cp._stack_size), _stack_mark(cp._stack_mark), 68 _max_locals(cp._max_locals), _max_stack(cp._max_stack), 69 _flags(cp._flags) { 70 _locals = NEW_RESOURCE_ARRAY(VerificationType, _max_locals); 71 for (int i = 0; i < _max_locals; ++i) { 72 if (i < _locals_size) { 73 _locals[i] = cp._locals[i]; 74 } else { 75 _locals[i] = VerificationType::bogus_type(); 76 } 77 } 78 int ss = MAX2(_stack_size, _stack_mark); 79 _stack = NEW_RESOURCE_ARRAY(VerificationType, _max_stack); 80 for (int i = 0; i < _max_stack; ++i) { 81 if (i < ss) { 82 _stack[i] = cp._stack[i]; 83 } else { 84 _stack[i] = VerificationType::bogus_type(); 85 } 86 } 87 _verifier = NULL; 88 } 89 90 public: 91 // constructors 92 93 // This constructor is used by the type checker to allocate frames 94 // in type state, which have _max_locals and _max_stack array elements 95 // in _locals and _stack. 96 StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* verifier); 97 98 // This constructor is used to initialize stackmap frames in stackmap table, 99 // which have _locals_size and _stack_size array elements in _locals and _stack. StackMapFrame(int32_t offset,u1 flags,u2 locals_size,u2 stack_size,u2 max_locals,u2 max_stack,VerificationType * locals,VerificationType * stack,ClassVerifier * v)100 StackMapFrame(int32_t offset, 101 u1 flags, 102 u2 locals_size, 103 u2 stack_size, 104 u2 max_locals, 105 u2 max_stack, 106 VerificationType* locals, 107 VerificationType* stack, 108 ClassVerifier* v) : _offset(offset), _flags(flags), 109 _locals_size(locals_size), 110 _stack_size(stack_size), 111 _stack_mark(-1), 112 _max_locals(max_locals), 113 _max_stack(max_stack), 114 _locals(locals), _stack(stack), 115 _verifier(v) { } 116 copy(StackMapFrame * smf)117 static StackMapFrame* copy(StackMapFrame* smf) { 118 return new StackMapFrame(*smf); 119 } 120 set_offset(int32_t offset)121 inline void set_offset(int32_t offset) { _offset = offset; } set_verifier(ClassVerifier * v)122 inline void set_verifier(ClassVerifier* v) { _verifier = v; } set_flags(u1 flags)123 inline void set_flags(u1 flags) { _flags = flags; } set_locals_size(u2 locals_size)124 inline void set_locals_size(u2 locals_size) { _locals_size = locals_size; } set_stack_size(u2 stack_size)125 inline void set_stack_size(u2 stack_size) { _stack_size = _stack_mark = stack_size; } clear_stack()126 inline void clear_stack() { _stack_size = 0; } offset() const127 inline int32_t offset() const { return _offset; } verifier() const128 inline ClassVerifier* verifier() const { return _verifier; } flags() const129 inline u1 flags() const { return _flags; } locals_size() const130 inline int32_t locals_size() const { return _locals_size; } locals() const131 inline VerificationType* locals() const { return _locals; } stack_size() const132 inline int32_t stack_size() const { return _stack_size; } stack() const133 inline VerificationType* stack() const { return _stack; } max_locals() const134 inline int32_t max_locals() const { return _max_locals; } max_stack() const135 inline int32_t max_stack() const { return _max_stack; } flag_this_uninit() const136 inline bool flag_this_uninit() const { return _flags & FLAG_THIS_UNINIT; } 137 138 // Set locals and stack types to bogus reset()139 inline void reset() { 140 int32_t i; 141 for (i = 0; i < _max_locals; i++) { 142 _locals[i] = VerificationType::bogus_type(); 143 } 144 for (i = 0; i < _max_stack; i++) { 145 _stack[i] = VerificationType::bogus_type(); 146 } 147 } 148 149 // Return a StackMapFrame with the same local variable array and empty stack. 150 // Stack array is allocate with unused one element. 151 StackMapFrame* frame_in_exception_handler(u1 flags); 152 153 // Set local variable type array based on m's signature. 154 VerificationType set_locals_from_arg( 155 const methodHandle& m, VerificationType thisKlass, TRAPS); 156 157 // Search local variable type array and stack type array. 158 // Set every element with type of old_object to new_object. 159 void initialize_object( 160 VerificationType old_object, VerificationType new_object); 161 162 // Copy local variable type array in src into this local variable type array. 163 void copy_locals(const StackMapFrame* src); 164 165 // Copy stack type array in src into this stack type array. 166 void copy_stack(const StackMapFrame* src); 167 168 // Return true if this stack map frame is assignable to target. 169 bool is_assignable_to( 170 const StackMapFrame* target, ErrorContext* ctx, TRAPS) const; 171 set_mark()172 inline void set_mark() { 173 #ifdef ASSERT 174 // Put bogus type to indicate it's no longer valid. 175 if (_stack_mark != -1) { 176 for (int i = _stack_mark - 1; i >= _stack_size; --i) { 177 _stack[i] = VerificationType::bogus_type(); 178 } 179 } 180 #endif // def ASSERT 181 _stack_mark = _stack_size; 182 } 183 184 // Used when an error occurs and we want to reset the stack to the state 185 // it was before operands were popped off. restore()186 void restore() { 187 if (_stack_mark != -1) { 188 _stack_size = _stack_mark; 189 } 190 } 191 192 // Push type into stack type array. push_stack(VerificationType type,TRAPS)193 inline void push_stack(VerificationType type, TRAPS) { 194 assert(!type.is_check(), "Must be a real type"); 195 if (_stack_size >= _max_stack) { 196 verifier()->verify_error( 197 ErrorContext::stack_overflow(_offset, this), 198 "Operand stack overflow"); 199 return; 200 } 201 _stack[_stack_size++] = type; 202 } 203 push_stack_2(VerificationType type1,VerificationType type2,TRAPS)204 inline void push_stack_2( 205 VerificationType type1, VerificationType type2, TRAPS) { 206 assert(type1.is_long() || type1.is_double(), "must be long/double"); 207 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 208 if (_stack_size >= _max_stack - 1) { 209 verifier()->verify_error( 210 ErrorContext::stack_overflow(_offset, this), 211 "Operand stack overflow"); 212 return; 213 } 214 _stack[_stack_size++] = type1; 215 _stack[_stack_size++] = type2; 216 } 217 218 // Pop and return the top type on stack without verifying. pop_stack(TRAPS)219 inline VerificationType pop_stack(TRAPS) { 220 if (_stack_size <= 0) { 221 verifier()->verify_error( 222 ErrorContext::stack_underflow(_offset, this), 223 "Operand stack underflow"); 224 return VerificationType::bogus_type(); 225 } 226 VerificationType top = _stack[--_stack_size]; 227 return top; 228 } 229 230 // Pop and return the top type on stack type array after verifying it 231 // is assignable to type. pop_stack(VerificationType type,TRAPS)232 inline VerificationType pop_stack(VerificationType type, TRAPS) { 233 if (_stack_size != 0) { 234 VerificationType top = _stack[_stack_size - 1]; 235 bool subtype = type.is_assignable_from( 236 top, verifier(), false, CHECK_(VerificationType::bogus_type())); 237 if (subtype) { 238 --_stack_size; 239 return top; 240 } 241 } 242 return pop_stack_ex(type, THREAD); 243 } 244 pop_stack_2(VerificationType type1,VerificationType type2,TRAPS)245 inline void pop_stack_2( 246 VerificationType type1, VerificationType type2, TRAPS) { 247 assert(type1.is_long2() || type1.is_double2(), "must be long/double"); 248 assert(type2.is_long() || type2.is_double(), "must be long/double_2"); 249 if (_stack_size >= 2) { 250 VerificationType top1 = _stack[_stack_size - 1]; 251 bool subtype1 = type1.is_assignable_from(top1, verifier(), false, CHECK); 252 VerificationType top2 = _stack[_stack_size - 2]; 253 bool subtype2 = type2.is_assignable_from(top2, verifier(), false, CHECK); 254 if (subtype1 && subtype2) { 255 _stack_size -= 2; 256 return; 257 } 258 } 259 pop_stack_ex(type1, THREAD); 260 pop_stack_ex(type2, THREAD); 261 } 262 local_at(int index)263 VerificationType local_at(int index) { 264 return _locals[index]; 265 } 266 stack_at(int index)267 VerificationType stack_at(int index) { 268 return _stack[index]; 269 } 270 271 // Uncommon case that throws exceptions. 272 VerificationType pop_stack_ex(VerificationType type, TRAPS); 273 274 // Return the type at index in local variable array after verifying 275 // it is assignable to type. 276 VerificationType get_local(int32_t index, VerificationType type, TRAPS); 277 // For long/double. 278 void get_local_2( 279 int32_t index, VerificationType type1, VerificationType type2, TRAPS); 280 281 // Set element at index in local variable array to type. 282 void set_local(int32_t index, VerificationType type, TRAPS); 283 // For long/double. 284 void set_local_2( 285 int32_t index, VerificationType type1, VerificationType type2, TRAPS); 286 287 // Private auxiliary method used only in is_assignable_to(StackMapFrame). 288 // Returns true if src is assignable to target. 289 int is_assignable_to( 290 VerificationType* src, VerificationType* target, int32_t len, TRAPS) const; 291 292 TypeOrigin stack_top_ctx(); 293 294 void print_on(outputStream* str) const; 295 }; 296 297 #endif // SHARE_VM_CLASSFILE_STACKMAPFRAME_HPP 298