1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "dex_instruction-inl.h"
18 
19 #include <inttypes.h>
20 
21 #include <iomanip>
22 #include <sstream>
23 
24 #include "android-base/stringprintf.h"
25 
26 #include "dex_file-inl.h"
27 #include "utf.h"
28 
29 namespace art {
30 
31 using android::base::StringPrintf;
32 
33 const char* const Instruction::kInstructionNames[] = {
34 #define INSTRUCTION_NAME(o, c, pname, f, i, a, e, v) pname,
35 #include "dex_instruction_list.h"
36   DEX_INSTRUCTION_LIST(INSTRUCTION_NAME)
37 #undef DEX_INSTRUCTION_LIST
38 #undef INSTRUCTION_NAME
39 };
40 
41 static_assert(sizeof(Instruction::InstructionDescriptor) == 8u, "Unexpected descriptor size");
42 
InstructionSizeInCodeUnitsByOpcode(Instruction::Code opcode,Instruction::Format format)43 static constexpr int8_t InstructionSizeInCodeUnitsByOpcode(Instruction::Code opcode,
44                                                            Instruction::Format format) {
45   if (opcode == Instruction::Code::NOP) {
46     return -1;
47   } else if ((format >= Instruction::Format::k10x) && (format <= Instruction::Format::k10t)) {
48     return 1;
49   } else if ((format >= Instruction::Format::k20t) && (format <= Instruction::Format::k22c)) {
50     return 2;
51   } else if ((format >= Instruction::Format::k32x) && (format <= Instruction::Format::k3rc)) {
52     return 3;
53   } else if ((format >= Instruction::Format::k45cc) && (format <= Instruction::Format::k4rcc)) {
54     return 4;
55   } else if (format == Instruction::Format::k51l) {
56     return 5;
57   } else {
58     return -1;
59   }
60 }
61 
62 Instruction::InstructionDescriptor const Instruction::kInstructionDescriptors[] = {
63 #define INSTRUCTION_DESCR(opcode, c, p, format, index, flags, eflags, vflags) \
64     { vflags, \
65       format, \
66       index, \
67       flags, \
68       InstructionSizeInCodeUnitsByOpcode((c), (format)), \
69     },
70 #include "dex_instruction_list.h"
71   DEX_INSTRUCTION_LIST(INSTRUCTION_DESCR)
72 #undef DEX_INSTRUCTION_LIST
73 #undef INSTRUCTION_DESCR
74 };
75 
GetTargetOffset() const76 int32_t Instruction::GetTargetOffset() const {
77   switch (FormatOf(Opcode())) {
78     // Cases for conditional branches follow.
79     case k22t: return VRegC_22t();
80     case k21t: return VRegB_21t();
81     // Cases for unconditional branches follow.
82     case k10t: return VRegA_10t();
83     case k20t: return VRegA_20t();
84     case k30t: return VRegA_30t();
85     default: LOG(FATAL) << "Tried to access the branch offset of an instruction " << Name() <<
86         " which does not have a target operand.";
87   }
88   UNREACHABLE();
89 }
90 
CanFlowThrough() const91 bool Instruction::CanFlowThrough() const {
92   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
93   uint16_t insn = *insns;
94   Code opcode = static_cast<Code>(insn & 0xFF);
95   return  FlagsOf(opcode) & Instruction::kContinue;
96 }
97 
SizeInCodeUnitsComplexOpcode() const98 size_t Instruction::SizeInCodeUnitsComplexOpcode() const {
99   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
100   // Handle special NOP encoded variable length sequences.
101   switch (*insns) {
102     case kPackedSwitchSignature:
103       return (4 + insns[1] * 2);
104     case kSparseSwitchSignature:
105       return (2 + insns[1] * 4);
106     case kArrayDataSignature: {
107       uint16_t element_size = insns[1];
108       uint32_t length = insns[2] | (((uint32_t)insns[3]) << 16);
109       // The plus 1 is to round up for odd size and width.
110       return (4 + (element_size * length + 1) / 2);
111     }
112     default:
113       if ((*insns & 0xFF) == 0) {
114         return 1;  // NOP.
115       } else {
116         LOG(FATAL) << "Unreachable: " << DumpString(nullptr);
117         UNREACHABLE();
118       }
119   }
120 }
121 
CodeUnitsRequiredForSizeOfComplexOpcode() const122 size_t Instruction::CodeUnitsRequiredForSizeOfComplexOpcode() const {
123   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
124   // Handle special NOP encoded variable length sequences.
125   switch (*insns) {
126     case kPackedSwitchSignature:
127       FALLTHROUGH_INTENDED;
128     case kSparseSwitchSignature:
129       return 2;
130     case kArrayDataSignature:
131       return 4;
132     default:
133       if ((*insns & 0xFF) == 0) {
134         return 1;  // NOP.
135       } else {
136         LOG(FATAL) << "Unreachable: " << DumpString(nullptr);
137         UNREACHABLE();
138       }
139   }
140 }
141 
DumpHex(size_t code_units) const142 std::string Instruction::DumpHex(size_t code_units) const {
143   size_t inst_length = SizeInCodeUnits();
144   if (inst_length > code_units) {
145     inst_length = code_units;
146   }
147   std::ostringstream os;
148   const uint16_t* insn = reinterpret_cast<const uint16_t*>(this);
149   for (size_t i = 0; i < inst_length; i++) {
150     os << StringPrintf("0x%04x", insn[i]) << " ";
151   }
152   for (size_t i = inst_length; i < code_units; i++) {
153     os << "       ";
154   }
155   return os.str();
156 }
157 
DumpHexLE(size_t instr_code_units) const158 std::string Instruction::DumpHexLE(size_t instr_code_units) const {
159   size_t inst_length = SizeInCodeUnits();
160   if (inst_length > instr_code_units) {
161     inst_length = instr_code_units;
162   }
163   std::ostringstream os;
164   const uint16_t* insn = reinterpret_cast<const uint16_t*>(this);
165   for (size_t i = 0; i < inst_length; i++) {
166     os << StringPrintf("%02x%02x", static_cast<uint8_t>(insn[i] & 0x00FF),
167                        static_cast<uint8_t>((insn[i] & 0xFF00) >> 8)) << " ";
168   }
169   for (size_t i = inst_length; i < instr_code_units; i++) {
170     os << "     ";
171   }
172   return os.str();
173 }
174 
DumpString(const DexFile * file) const175 std::string Instruction::DumpString(const DexFile* file) const {
176   std::ostringstream os;
177   const char* opcode = kInstructionNames[Opcode()];
178   switch (FormatOf(Opcode())) {
179     case k10x:  os << opcode; break;
180     case k12x:  os << StringPrintf("%s v%d, v%d", opcode, VRegA_12x(), VRegB_12x()); break;
181     case k11n:  os << StringPrintf("%s v%d, #%+d", opcode, VRegA_11n(), VRegB_11n()); break;
182     case k11x:  os << StringPrintf("%s v%d", opcode, VRegA_11x()); break;
183     case k10t:  os << StringPrintf("%s %+d", opcode, VRegA_10t()); break;
184     case k20t:  os << StringPrintf("%s %+d", opcode, VRegA_20t()); break;
185     case k22x:  os << StringPrintf("%s v%d, v%d", opcode, VRegA_22x(), VRegB_22x()); break;
186     case k21t:  os << StringPrintf("%s v%d, %+d", opcode, VRegA_21t(), VRegB_21t()); break;
187     case k21s:  os << StringPrintf("%s v%d, #%+d", opcode, VRegA_21s(), VRegB_21s()); break;
188     case k21h: {
189         // op vAA, #+BBBB0000[00000000]
190         if (Opcode() == CONST_HIGH16) {
191           uint32_t value = VRegB_21h() << 16;
192           os << StringPrintf("%s v%d, #int %+d // 0x%x", opcode, VRegA_21h(), value, value);
193         } else {
194           uint64_t value = static_cast<uint64_t>(VRegB_21h()) << 48;
195           os << StringPrintf("%s v%d, #long %+" PRId64 " // 0x%" PRIx64, opcode, VRegA_21h(),
196                              value, value);
197         }
198       }
199       break;
200     case k21c: {
201       switch (Opcode()) {
202         case CONST_STRING:
203           if (file != nullptr) {
204             uint32_t string_idx = VRegB_21c();
205             if (string_idx < file->NumStringIds()) {
206               os << StringPrintf(
207                   "const-string v%d, %s // string@%d",
208                   VRegA_21c(),
209                   PrintableString(file->StringDataByIdx(dex::StringIndex(string_idx))).c_str(),
210                   string_idx);
211             } else {
212               os << StringPrintf("const-string v%d, <<invalid-string-idx-%d>> // string@%d",
213                                  VRegA_21c(),
214                                  string_idx,
215                                  string_idx);
216             }
217             break;
218           }
219           FALLTHROUGH_INTENDED;
220         case CHECK_CAST:
221         case CONST_CLASS:
222         case NEW_INSTANCE:
223           if (file != nullptr) {
224             dex::TypeIndex type_idx(VRegB_21c());
225             os << opcode << " v" << static_cast<int>(VRegA_21c()) << ", "
226                << file->PrettyType(type_idx) << " // type@" << type_idx;
227             break;
228           }
229           FALLTHROUGH_INTENDED;
230         case SGET:
231         case SGET_WIDE:
232         case SGET_OBJECT:
233         case SGET_BOOLEAN:
234         case SGET_BYTE:
235         case SGET_CHAR:
236         case SGET_SHORT:
237           if (file != nullptr) {
238             uint32_t field_idx = VRegB_21c();
239             os << opcode << "  v" << static_cast<int>(VRegA_21c()) << ", " << file->PrettyField(field_idx, true)
240                << " // field@" << field_idx;
241             break;
242           }
243           FALLTHROUGH_INTENDED;
244         case SPUT:
245         case SPUT_WIDE:
246         case SPUT_OBJECT:
247         case SPUT_BOOLEAN:
248         case SPUT_BYTE:
249         case SPUT_CHAR:
250         case SPUT_SHORT:
251           if (file != nullptr) {
252             uint32_t field_idx = VRegB_21c();
253             os << opcode << " v" << static_cast<int>(VRegA_21c()) << ", " << file->PrettyField(field_idx, true)
254                << " // field@" << field_idx;
255             break;
256           }
257           FALLTHROUGH_INTENDED;
258         default:
259           os << StringPrintf("%s v%d, thing@%d", opcode, VRegA_21c(), VRegB_21c());
260           break;
261       }
262       break;
263     }
264     case k23x:  os << StringPrintf("%s v%d, v%d, v%d", opcode, VRegA_23x(), VRegB_23x(), VRegC_23x()); break;
265     case k22b:  os << StringPrintf("%s v%d, v%d, #%+d", opcode, VRegA_22b(), VRegB_22b(), VRegC_22b()); break;
266     case k22t:  os << StringPrintf("%s v%d, v%d, %+d", opcode, VRegA_22t(), VRegB_22t(), VRegC_22t()); break;
267     case k22s:  os << StringPrintf("%s v%d, v%d, #%+d", opcode, VRegA_22s(), VRegB_22s(), VRegC_22s()); break;
268     case k22c: {
269       switch (Opcode()) {
270         case IGET:
271         case IGET_WIDE:
272         case IGET_OBJECT:
273         case IGET_BOOLEAN:
274         case IGET_BYTE:
275         case IGET_CHAR:
276         case IGET_SHORT:
277           if (file != nullptr) {
278             uint32_t field_idx = VRegC_22c();
279             os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
280                << file->PrettyField(field_idx, true) << " // field@" << field_idx;
281             break;
282           }
283           FALLTHROUGH_INTENDED;
284         case IPUT:
285         case IPUT_WIDE:
286         case IPUT_OBJECT:
287         case IPUT_BOOLEAN:
288         case IPUT_BYTE:
289         case IPUT_CHAR:
290         case IPUT_SHORT:
291           if (file != nullptr) {
292             uint32_t field_idx = VRegC_22c();
293             os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v" << static_cast<int>(VRegB_22c()) << ", "
294                << file->PrettyField(field_idx, true) << " // field@" << field_idx;
295             break;
296           }
297           FALLTHROUGH_INTENDED;
298         case INSTANCE_OF:
299           if (file != nullptr) {
300             dex::TypeIndex type_idx(VRegC_22c());
301             os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v"
302                << static_cast<int>(VRegB_22c()) << ", " << file->PrettyType(type_idx)
303                << " // type@" << type_idx.index_;
304             break;
305           }
306           FALLTHROUGH_INTENDED;
307         case NEW_ARRAY:
308           if (file != nullptr) {
309             dex::TypeIndex type_idx(VRegC_22c());
310             os << opcode << " v" << static_cast<int>(VRegA_22c()) << ", v"
311                << static_cast<int>(VRegB_22c()) << ", " << file->PrettyType(type_idx)
312                << " // type@" << type_idx.index_;
313             break;
314           }
315           FALLTHROUGH_INTENDED;
316         default:
317           os << StringPrintf("%s v%d, v%d, thing@%d", opcode, VRegA_22c(), VRegB_22c(), VRegC_22c());
318           break;
319       }
320       break;
321     }
322     case k32x:  os << StringPrintf("%s v%d, v%d", opcode, VRegA_32x(), VRegB_32x()); break;
323     case k30t:  os << StringPrintf("%s %+d", opcode, VRegA_30t()); break;
324     case k31t:  os << StringPrintf("%s v%d, %+d", opcode, VRegA_31t(), VRegB_31t()); break;
325     case k31i:  os << StringPrintf("%s v%d, #%+d", opcode, VRegA_31i(), VRegB_31i()); break;
326     case k31c:
327       if (Opcode() == CONST_STRING_JUMBO) {
328         uint32_t string_idx = VRegB_31c();
329         if (file != nullptr) {
330           if (string_idx < file->NumStringIds()) {
331             os << StringPrintf(
332                 "%s v%d, %s // string@%d",
333                 opcode,
334                 VRegA_31c(),
335                 PrintableString(file->StringDataByIdx(dex::StringIndex(string_idx))).c_str(),
336                 string_idx);
337           } else {
338             os << StringPrintf("%s v%d, <<invalid-string-idx-%d>> // string@%d",
339                                opcode,
340                                VRegA_31c(),
341                                string_idx,
342                                string_idx);
343           }
344         } else {
345           os << StringPrintf("%s v%d, string@%d", opcode, VRegA_31c(), string_idx);
346         }
347       } else {
348         os << StringPrintf("%s v%d, thing@%d", opcode, VRegA_31c(), VRegB_31c()); break;
349       }
350       break;
351     case k35c: {
352       uint32_t arg[kMaxVarArgRegs];
353       GetVarArgs(arg);
354       auto DumpArgs = [&](size_t count) {
355         for (size_t i = 0; i < count; ++i) {
356           if (i != 0) {
357             os << ", ";
358           }
359           os << "v" << arg[i];
360         }
361       };
362       switch (Opcode()) {
363         case FILLED_NEW_ARRAY:
364         {
365           os << opcode << " {";
366           DumpArgs(VRegA_35c());
367           os << "}, type@" << VRegB_35c();
368         }
369         break;
370 
371         case INVOKE_VIRTUAL:
372         case INVOKE_SUPER:
373         case INVOKE_DIRECT:
374         case INVOKE_STATIC:
375         case INVOKE_INTERFACE:
376           if (file != nullptr) {
377             os << opcode << " {";
378             uint32_t method_idx = VRegB_35c();
379             DumpArgs(VRegA_35c());
380             os << "}, " << file->PrettyMethod(method_idx) << " // method@" << method_idx;
381             break;
382           }
383           FALLTHROUGH_INTENDED;
384         case INVOKE_CUSTOM:
385           if (file != nullptr) {
386             os << opcode << " {";
387             uint32_t call_site_idx = VRegB_35c();
388             DumpArgs(VRegA_35c());
389             os << "},  // call_site@" << call_site_idx;
390             break;
391           }
392           FALLTHROUGH_INTENDED;
393         default:
394           os << opcode << " {";
395           DumpArgs(VRegA_35c());
396           os << "}, thing@" << VRegB_35c();
397           break;
398       }
399       break;
400     }
401     case k3rc: {
402       uint16_t first_reg = VRegC_3rc();
403       uint16_t last_reg =  VRegC_3rc() + VRegA_3rc() - 1;
404       switch (Opcode()) {
405         case INVOKE_VIRTUAL_RANGE:
406         case INVOKE_SUPER_RANGE:
407         case INVOKE_DIRECT_RANGE:
408         case INVOKE_STATIC_RANGE:
409         case INVOKE_INTERFACE_RANGE:
410           if (file != nullptr) {
411             uint32_t method_idx = VRegB_3rc();
412             os << StringPrintf("%s, {v%d .. v%d}, ", opcode, first_reg, last_reg)
413                << file->PrettyMethod(method_idx) << " // method@" << method_idx;
414             break;
415           }
416           FALLTHROUGH_INTENDED;
417         case INVOKE_CUSTOM_RANGE:
418           if (file != nullptr) {
419             uint32_t call_site_idx = VRegB_3rc();
420             os << StringPrintf("%s, {v%d .. v%d}, ", opcode, first_reg, last_reg)
421                << "// call_site@" << call_site_idx;
422             break;
423           }
424           FALLTHROUGH_INTENDED;
425         default:
426           os << StringPrintf("%s, {v%d .. v%d}, ", opcode, first_reg, last_reg)
427              << "thing@" << VRegB_3rc();
428           break;
429       }
430       break;
431     }
432     case k45cc: {
433       uint32_t arg[kMaxVarArgRegs];
434       GetVarArgs(arg);
435       uint16_t method_idx = VRegB_45cc();
436       dex::ProtoIndex proto_idx(VRegH_45cc());
437       os << opcode << " {";
438       for (uint32_t i = 0; i < VRegA_45cc(); ++i) {
439         if (i != 0) {
440           os << ", ";
441         }
442         os << "v" << arg[i];
443       }
444       os << "}";
445       if (file != nullptr) {
446         os << ", " << file->PrettyMethod(method_idx)
447            << ", " << file->GetShorty(proto_idx)
448            << " // ";
449       } else {
450         os << ", ";
451       }
452       os << "method@" << method_idx << ", proto@" << proto_idx;
453       break;
454     }
455     case k4rcc:
456       switch (Opcode()) {
457         case INVOKE_POLYMORPHIC_RANGE: {
458           if (file != nullptr) {
459             uint16_t method_idx = VRegB_4rcc();
460             dex::ProtoIndex proto_idx(VRegH_4rcc());
461             os << opcode << ", {v" << VRegC_4rcc() << " .. v" << (VRegC_4rcc() + VRegA_4rcc())
462                << "}, " << file->PrettyMethod(method_idx)
463                << ", " << file->GetShorty(dex::ProtoIndex(proto_idx))
464                << " // method@" << method_idx << ", proto@" << proto_idx;
465             break;
466           }
467         }
468         FALLTHROUGH_INTENDED;
469         default: {
470           uint16_t method_idx = VRegB_4rcc();
471           dex::ProtoIndex proto_idx(VRegH_4rcc());
472           os << opcode << ", {v" << VRegC_4rcc() << " .. v" << (VRegC_4rcc() + VRegA_4rcc())
473              << "}, method@" << method_idx << ", proto@" << proto_idx;
474         }
475       }
476       break;
477     case k51l: os << StringPrintf("%s v%d, #%+" PRId64, opcode, VRegA_51l(), VRegB_51l()); break;
478     case kInvalidFormat: os << "<invalid-opcode-format>";
479   }
480   return os.str();
481 }
482 
483 // Add some checks that ensure the flags make sense. We need a subclass to be in the context of
484 // Instruction. Otherwise the flags from the instruction list don't work.
485 struct InstructionStaticAsserts : private Instruction {
486   #define IMPLIES(a, b) (!(a) || (b))
487 
488   #define VAR_ARGS_CHECK(o, c, pname, f, i, a, e, v) \
489     static_assert(IMPLIES((f) == k35c || (f) == k45cc, \
490                           ((v) & (kVerifyVarArg | kVerifyVarArgNonZero)) != 0), \
491                   "Missing var-arg verification");
492   #include "dex_instruction_list.h"
493     DEX_INSTRUCTION_LIST(VAR_ARGS_CHECK)
494   #undef DEX_INSTRUCTION_LIST
495   #undef VAR_ARGS_CHECK
496 
497   #define VAR_ARGS_RANGE_CHECK(o, c, pname, f, i, a, e, v) \
498     static_assert(IMPLIES((f) == k3rc || (f) == k4rcc, \
499                           ((v) & (kVerifyVarArgRange | kVerifyVarArgRangeNonZero)) != 0), \
500                   "Missing var-arg verification");
501   #include "dex_instruction_list.h"
502     DEX_INSTRUCTION_LIST(VAR_ARGS_RANGE_CHECK)
503   #undef DEX_INSTRUCTION_LIST
504   #undef VAR_ARGS_RANGE_CHECK
505 
506   #define EXPERIMENTAL_CHECK(o, c, pname, f, i, a, e, v) \
507     static_assert(kHaveExperimentalInstructions || (((a) & kExperimental) == 0), \
508                   "Unexpected experimental instruction.");
509     #include "dex_instruction_list.h"
510   DEX_INSTRUCTION_LIST(EXPERIMENTAL_CHECK)
511   #undef DEX_INSTRUCTION_LIST
512   #undef EXPERIMENTAL_CHECK
513 };
514 
operator <<(std::ostream & os,Instruction::Code code)515 std::ostream& operator<<(std::ostream& os, Instruction::Code code) {
516   return os << Instruction::Name(code);
517 }
518 
GetOperand(size_t operand_index) const519 uint32_t RangeInstructionOperands::GetOperand(size_t operand_index) const {
520   DCHECK_LT(operand_index, GetNumberOfOperands());
521   return first_operand_ + operand_index;
522 }
523 
GetOperand(size_t operand_index) const524 uint32_t VarArgsInstructionOperands::GetOperand(size_t operand_index) const {
525   DCHECK_LT(operand_index, GetNumberOfOperands());
526   return operands_[operand_index];
527 }
528 
GetOperand(size_t operand_index) const529 uint32_t NoReceiverInstructionOperands::GetOperand(size_t operand_index) const {
530   DCHECK_LT(GetNumberOfOperands(), inner_->GetNumberOfOperands());
531   // The receiver is the first operand and since we're skipping it, we need to
532   // add 1 to the operand_index.
533   return inner_->GetOperand(operand_index + 1);
534 }
535 
536 }  // namespace art
537