1 /* 2 * Copyright (c) 2003, 2019, 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_CLASSFILE_STACKMAPFRAME_HPP 26 #define SHARE_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 ResourceObj(cp), 67 _offset(cp._offset), _locals_size(cp._locals_size), 68 _stack_size(cp._stack_size), _stack_mark(cp._stack_mark), 69 _max_locals(cp._max_locals), _max_stack(cp._max_stack), 70 _flags(cp._flags) { 71 _locals = NEW_RESOURCE_ARRAY(VerificationType, _max_locals); 72 for (int i = 0; i < _max_locals; ++i) { 73 if (i < _locals_size) { 74 _locals[i] = cp._locals[i]; 75 } else { 76 _locals[i] = VerificationType::bogus_type(); 77 } 78 } 79 int ss = MAX2(_stack_size, _stack_mark); 80 _stack = NEW_RESOURCE_ARRAY(VerificationType, _max_stack); 81 for (int i = 0; i < _max_stack; ++i) { 82 if (i < ss) { 83 _stack[i] = cp._stack[i]; 84 } else { 85 _stack[i] = VerificationType::bogus_type(); 86 } 87 } 88 _verifier = NULL; 89 } 90 91 public: 92 // constructors 93 94 // This constructor is used by the type checker to allocate frames 95 // in type state, which have _max_locals and _max_stack array elements 96 // in _locals and _stack. 97 StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* verifier); 98 99 // This constructor is used to initialize stackmap frames in stackmap table, 100 // 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)101 StackMapFrame(int32_t offset, 102 u1 flags, 103 u2 locals_size, 104 u2 stack_size, 105 u2 max_locals, 106 u2 max_stack, 107 VerificationType* locals, 108 VerificationType* stack, 109 ClassVerifier* v) : _offset(offset), 110 _locals_size(locals_size), 111 _stack_size(stack_size), 112 _stack_mark(-1), 113 _max_locals(max_locals), 114 _max_stack(max_stack), _flags(flags), 115 _locals(locals), _stack(stack), 116 _verifier(v) { } 117 copy(StackMapFrame * smf)118 static StackMapFrame* copy(StackMapFrame* smf) { 119 return new StackMapFrame(*smf); 120 } 121 set_offset(int32_t offset)122 inline void set_offset(int32_t offset) { _offset = offset; } set_verifier(ClassVerifier * v)123 inline void set_verifier(ClassVerifier* v) { _verifier = v; } set_flags(u1 flags)124 inline void set_flags(u1 flags) { _flags = flags; } set_locals_size(u2 locals_size)125 inline void set_locals_size(u2 locals_size) { _locals_size = locals_size; } set_stack_size(u2 stack_size)126 inline void set_stack_size(u2 stack_size) { _stack_size = _stack_mark = stack_size; } clear_stack()127 inline void clear_stack() { _stack_size = 0; } offset() const128 inline int32_t offset() const { return _offset; } verifier() const129 inline ClassVerifier* verifier() const { return _verifier; } flags() const130 inline u1 flags() const { return _flags; } locals_size() const131 inline int32_t locals_size() const { return _locals_size; } locals() const132 inline VerificationType* locals() const { return _locals; } stack_size() const133 inline int32_t stack_size() const { return _stack_size; } stack() const134 inline VerificationType* stack() const { return _stack; } max_locals() const135 inline int32_t max_locals() const { return _max_locals; } max_stack() const136 inline int32_t max_stack() const { return _max_stack; } flag_this_uninit() const137 inline bool flag_this_uninit() const { return _flags & FLAG_THIS_UNINIT; } 138 139 // Set locals and stack types to bogus reset()140 inline void reset() { 141 int32_t i; 142 for (i = 0; i < _max_locals; i++) { 143 _locals[i] = VerificationType::bogus_type(); 144 } 145 for (i = 0; i < _max_stack; i++) { 146 _stack[i] = VerificationType::bogus_type(); 147 } 148 } 149 150 // Return a StackMapFrame with the same local variable array and empty stack. 151 // Stack array is allocate with unused one element. 152 StackMapFrame* frame_in_exception_handler(u1 flags); 153 154 // Set local variable type array based on m's signature. 155 VerificationType set_locals_from_arg( 156 const methodHandle& m, VerificationType thisKlass, TRAPS); 157 158 // Search local variable type array and stack type array. 159 // Set every element with type of old_object to new_object. 160 void initialize_object( 161 VerificationType old_object, VerificationType new_object); 162 163 // Copy local variable type array in src into this local variable type array. 164 void copy_locals(const StackMapFrame* src); 165 166 // Copy stack type array in src into this stack type array. 167 void copy_stack(const StackMapFrame* src); 168 169 // Return true if this stack map frame is assignable to target. 170 bool is_assignable_to( 171 const StackMapFrame* target, ErrorContext* ctx, TRAPS) const; 172 set_mark()173 inline void set_mark() { 174 #ifdef ASSERT 175 // Put bogus type to indicate it's no longer valid. 176 if (_stack_mark != -1) { 177 for (int i = _stack_mark - 1; i >= _stack_size; --i) { 178 _stack[i] = VerificationType::bogus_type(); 179 } 180 } 181 #endif // def ASSERT 182 _stack_mark = _stack_size; 183 } 184 185 // Used when an error occurs and we want to reset the stack to the state 186 // it was before operands were popped off. restore()187 void restore() { 188 if (_stack_mark != -1) { 189 _stack_size = _stack_mark; 190 } 191 } 192 193 // Push type into stack type array. push_stack(VerificationType type,TRAPS)194 inline void push_stack(VerificationType type, TRAPS) { 195 assert(!type.is_check(), "Must be a real type"); 196 if (_stack_size >= _max_stack) { 197 verifier()->verify_error( 198 ErrorContext::stack_overflow(_offset, this), 199 "Operand stack overflow"); 200 return; 201 } 202 _stack[_stack_size++] = type; 203 } 204 push_stack_2(VerificationType type1,VerificationType type2,TRAPS)205 inline void push_stack_2( 206 VerificationType type1, VerificationType type2, TRAPS) { 207 assert(type1.is_long() || type1.is_double(), "must be long/double"); 208 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 209 if (_stack_size >= _max_stack - 1) { 210 verifier()->verify_error( 211 ErrorContext::stack_overflow(_offset, this), 212 "Operand stack overflow"); 213 return; 214 } 215 _stack[_stack_size++] = type1; 216 _stack[_stack_size++] = type2; 217 } 218 219 // Pop and return the top type on stack without verifying. pop_stack(TRAPS)220 inline VerificationType pop_stack(TRAPS) { 221 if (_stack_size <= 0) { 222 verifier()->verify_error( 223 ErrorContext::stack_underflow(_offset, this), 224 "Operand stack underflow"); 225 return VerificationType::bogus_type(); 226 } 227 VerificationType top = _stack[--_stack_size]; 228 return top; 229 } 230 231 // Pop and return the top type on stack type array after verifying it 232 // is assignable to type. pop_stack(VerificationType type,TRAPS)233 inline VerificationType pop_stack(VerificationType type, TRAPS) { 234 if (_stack_size != 0) { 235 VerificationType top = _stack[_stack_size - 1]; 236 bool subtype = type.is_assignable_from( 237 top, verifier(), false, CHECK_(VerificationType::bogus_type())); 238 if (subtype) { 239 --_stack_size; 240 return top; 241 } 242 } 243 return pop_stack_ex(type, THREAD); 244 } 245 pop_stack_2(VerificationType type1,VerificationType type2,TRAPS)246 inline void pop_stack_2( 247 VerificationType type1, VerificationType type2, TRAPS) { 248 assert(type1.is_long2() || type1.is_double2(), "must be long/double"); 249 assert(type2.is_long() || type2.is_double(), "must be long/double_2"); 250 if (_stack_size >= 2) { 251 VerificationType top1 = _stack[_stack_size - 1]; 252 bool subtype1 = type1.is_assignable_from(top1, verifier(), false, CHECK); 253 VerificationType top2 = _stack[_stack_size - 2]; 254 bool subtype2 = type2.is_assignable_from(top2, verifier(), false, CHECK); 255 if (subtype1 && subtype2) { 256 _stack_size -= 2; 257 return; 258 } 259 } 260 pop_stack_ex(type1, THREAD); 261 pop_stack_ex(type2, THREAD); 262 } 263 local_at(int index)264 VerificationType local_at(int index) { 265 return _locals[index]; 266 } 267 stack_at(int index)268 VerificationType stack_at(int index) { 269 return _stack[index]; 270 } 271 272 // Uncommon case that throws exceptions. 273 VerificationType pop_stack_ex(VerificationType type, TRAPS); 274 275 // Return the type at index in local variable array after verifying 276 // it is assignable to type. 277 VerificationType get_local(int32_t index, VerificationType type, TRAPS); 278 // For long/double. 279 void get_local_2( 280 int32_t index, VerificationType type1, VerificationType type2, TRAPS); 281 282 // Set element at index in local variable array to type. 283 void set_local(int32_t index, VerificationType type, TRAPS); 284 // For long/double. 285 void set_local_2( 286 int32_t index, VerificationType type1, VerificationType type2, TRAPS); 287 288 // Private auxiliary method used only in is_assignable_to(StackMapFrame). 289 // Returns true if src is assignable to target. 290 int is_assignable_to( 291 VerificationType* src, VerificationType* target, int32_t len, TRAPS) const; 292 293 TypeOrigin stack_top_ctx(); 294 295 void print_on(outputStream* str) const; 296 }; 297 298 #endif // SHARE_CLASSFILE_STACKMAPFRAME_HPP 299