src/dex_instruction.cc - platform/art - Gitiles

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "dex_instruction.h"

 #include "dex_file.h"
 #include <iomanip>

 namespace art {

 const char* const Instruction::kInstructionNames[] = {
 #define INSTRUCTION_NAME(o, c, pname, f, r, i, a, v) pname,
 #include "dex_instruction_list.h"
   DEX_INSTRUCTION_LIST(INSTRUCTION_NAME)
 #undef DEX_INSTRUCTION_LIST
 #undef INSTRUCTION_NAME
 };

 Instruction::Format const Instruction::kInstructionFormats[] = {
 #define INSTRUCTION_FORMAT(o, c, p, format, r, i, a, v) format,
 #include "dex_instruction_list.h"
   DEX_INSTRUCTION_LIST(INSTRUCTION_FORMAT)
 #undef DEX_INSTRUCTION_LIST
 #undef INSTRUCTION_FORMAT
 };

 int const Instruction::kInstructionFlags[] = {
 #define INSTRUCTION_FLAGS(o, c, p, f, r, i, flags, v) flags,
 #include "dex_instruction_list.h"
   DEX_INSTRUCTION_LIST(INSTRUCTION_FLAGS)
 #undef DEX_INSTRUCTION_LIST
 #undef INSTRUCTION_FLAGS
 };

 int const Instruction::kInstructionVerifyFlags[] = {
 #define INSTRUCTION_VERIFY_FLAGS(o, c, p, f, r, i, a, vflags) vflags,
 #include "dex_instruction_list.h"
   DEX_INSTRUCTION_LIST(INSTRUCTION_VERIFY_FLAGS)
 #undef DEX_INSTRUCTION_LIST
 #undef INSTRUCTION_VERIFY_FLAGS
 };

 /*
  * Handy macros for helping decode instructions.
  */
 #define FETCH(_offset)      (insns[(_offset)])
 #define FETCH_u4(_offset)   (fetch_u4_impl((_offset), insns))
 #define INST_A(_insn)       (((uint16_t)(_insn) >> 8) & 0x0f)
 #define INST_B(_insn)       ((uint16_t)(_insn) >> 12)
 #define INST_AA(_insn)      ((_insn) >> 8)

 /* Helper for FETCH_u4, above. */
 static inline uint32_t fetch_u4_impl(uint32_t offset, const uint16_t* insns) {
   return insns[offset] | ((uint32_t) insns[offset+1] << 16);
 }

 void Instruction::Decode(uint32_t &vA, uint32_t &vB, uint64_t &vB_wide, uint32_t &vC, uint32_t arg[]) const {
   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
   uint16_t insn = *insns;
   int opcode = insn & 0xFF;

   switch (FormatOf(Opcode())) {
     case k10x:       // op
       /* nothing to do; copy the AA bits out for the verifier */
       vA = INST_AA(insn);
       break;
     case k12x:       // op vA, vB
       vA = INST_A(insn);
       vB = INST_B(insn);
       break;
     case k11n:       // op vA, #+B
       vA = INST_A(insn);
       vB = (int32_t) (INST_B(insn) << 28) >> 28; // sign extend 4-bit value
       break;
     case k11x:       // op vAA
       vA = INST_AA(insn);
       break;
     case k10t:       // op +AA
       vA = (int8_t) INST_AA(insn);              // sign-extend 8-bit value
       break;
     case k20t:       // op +AAAA
       vA = (int16_t) FETCH(1);                   // sign-extend 16-bit value
       break;
     case k20bc:      // op AA, kind@BBBB
     case k21c:       // op vAA, thing@BBBB
     case k22x:       // op vAA, vBBBB
       vA = INST_AA(insn);
       vB = FETCH(1);
       break;
     case k21s:       // op vAA, #+BBBB
     case k21t:       // op vAA, +BBBB
       vA = INST_AA(insn);
       vB = (int16_t) FETCH(1);                   // sign-extend 16-bit value
       break;
     case k21h:       // op vAA, #+BBBB0000[00000000]
       vA = INST_AA(insn);
       /*
        * The value should be treated as right-zero-extended, but we don't
        * actually do that here. Among other things, we don't know if it's
        * the top bits of a 32- or 64-bit value.
        */
       vB = FETCH(1);
       break;
     case k23x:       // op vAA, vBB, vCC
       vA = INST_AA(insn);
       vB = FETCH(1) & 0xff;
       vC = FETCH(1) >> 8;
       break;
     case k22b:       // op vAA, vBB, #+CC
       vA = INST_AA(insn);
       vB = FETCH(1) & 0xff;
       vC = (int8_t) (FETCH(1) >> 8);            // sign-extend 8-bit value
       break;
     case k22s:       // op vA, vB, #+CCCC
     case k22t:       // op vA, vB, +CCCC
       vA = INST_A(insn);
       vB = INST_B(insn);
       vC = (int16_t) FETCH(1);                   // sign-extend 16-bit value
       break;
     case k22c:       // op vA, vB, thing@CCCC
       vA = INST_A(insn);
       vB = INST_B(insn);
       vC = FETCH(1);
       break;
     case k30t:       // op +AAAAAAAA
       vA = FETCH_u4(1);                     // signed 32-bit value
       break;
     case k31t:       // op vAA, +BBBBBBBB
     case k31c:       // op vAA, string@BBBBBBBB
       vA = INST_AA(insn);
       vB = FETCH_u4(1);                     // 32-bit value
       break;
     case k32x:       // op vAAAA, vBBBB
       vA = FETCH(1);
       vB = FETCH(2);
       break;
     case k31i:       // op vAA, #+BBBBBBBB
       vA = INST_AA(insn);
       vB = FETCH_u4(1);                     // signed 32-bit value
       break;
     case k35c:       // op {vC, vD, vE, vF, vG}, thing@BBBB
       {
         /*
          * Note that the fields mentioned in the spec don't appear in
          * their "usual" positions here compared to most formats. This
          * was done so that the field names for the argument count and
          * reference index match between this format and the corresponding
          * range formats (3rc and friends).
          *
          * Bottom line: The argument count is always in vA, and the
          * method constant (or equivalent) is always in vB.
          */
         uint16_t regList;
         int count;

         vA = INST_B(insn); // This is labeled A in the spec.
         vB = FETCH(1);
         regList = FETCH(2);

         count = vA;

         /*
          * Copy the argument registers into the arg[] array, and
          * also copy the first argument (if any) into vC. (The
          * DecodedInstruction structure doesn't have separate
          * fields for {vD, vE, vF, vG}, so there's no need to make
          * copies of those.) Note that cases 5..2 fall through.
          */
         switch (count) {
         case 5: arg[4] = INST_A(insn);
         case 4: arg[3] = (regList >> 12) & 0x0f;
         case 3: arg[2] = (regList >> 8) & 0x0f;
         case 2: arg[1] = (regList >> 4) & 0x0f;
         case 1: vC = arg[0] = regList & 0x0f; break;
         case 0: break; // Valid, but no need to do anything.
         default:
           LOG(ERROR) << "Invalid arg count in 35c (" << count << ")";
           return;
         }
       }
       break;
     case k3rc:       // op {vCCCC .. v(CCCC+AA-1)}, meth@BBBB
       vA = INST_AA(insn);
       vB = FETCH(1);
       vC = FETCH(2);
         break;
     case k51l:       // op vAA, #+BBBBBBBBBBBBBBBB
       vA = INST_AA(insn);
       vB_wide = FETCH_u4(1) | ((uint64_t) FETCH_u4(3) << 32);
       break;
     default:
       LOG(ERROR) << "Can't decode unexpected format " << static_cast<int>(FormatOf(Opcode())) << " (op=" << opcode << ")";
       return;
   }
 }

 size_t Instruction::SizeInCodeUnits() const {
   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
   if (*insns == Instruction::kPackedSwitchSignature) {
     return (4 + insns[1] * 2);
   } else if (*insns == Instruction::kSparseSwitchSignature) {
     return (2 + insns[1] * 4);
   } else if (*insns == kArrayDataSignature) {
     uint16_t element_size = insns[1];
     uint32_t length = insns[2] | (((uint32_t)insns[3]) << 16);
     // The plus 1 is to round up for odd size and width.
     return (4 + (element_size * length + 1) / 2);
   } else {
     switch (FormatOf(Opcode())) {
       case k10x:
       case k12x:
       case k11n:
       case k11x:
       case k10t:
         return 1;
       case k20bc:
       case k20t:
       case k22x:
       case k21t:
       case k21s:
       case k21h:
       case k21c:
       case k23x:
       case k22b:
       case k22t:
       case k22s:
       case k22c:
         return 2;
       case k32x:
       case k30t:
       case k31t:
       case k31i:
       case k31c:
       case k35c:
       case k3rc:
         return 3;
       case k51l:
         return 5;
       default:
         LOG(FATAL) << "Unreachable";
     }
   }
   return 0;
 }

 Instruction::Code Instruction::Opcode() const {
   const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
   int opcode = *insns & 0xFF;
   return static_cast<Code>(opcode);
 }

 const Instruction* Instruction::Next() const {
   size_t current_size_in_bytes = SizeInCodeUnits() * sizeof(uint16_t);
   const uint8_t* ptr = reinterpret_cast<const uint8_t*>(this);
   return reinterpret_cast<const Instruction*>(ptr + current_size_in_bytes);
 }

 std::string Instruction::DumpHex(size_t code_units) const {
   size_t inst_length = SizeInCodeUnits();
   if (inst_length > code_units) {
     inst_length = code_units;
   }
   std::ostringstream os;
   const uint16_t* insn = reinterpret_cast<const uint16_t*>(this);
   for (size_t i = 0; i < inst_length; i++) {
     os << StringPrintf("0x%04x", insn[i]) << " ";
   }
   for (size_t i = inst_length; i < code_units; i++) {
     os << "       ";
   }
   return os.str();
 }

 std::string Instruction::DumpString(const DexFile* file) const {
   DecodedInstruction insn(this);
   std::ostringstream os;
   const char* opcode = kInstructionNames[insn.opcode];
   switch (FormatOf(Opcode())) {
     case k10x:  os << opcode; break;
     case k12x:  os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
     case k11n:  os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
     case k11x:  os << StringPrintf("%s v%d", opcode, insn.vA); break;
     case k10t:  os << StringPrintf("%s %+d", opcode, insn.vA); break;
     case k20bc: os << StringPrintf("%s %d, kind@%d", opcode, insn.vA, insn.vB); break;
     case k20t:  os << StringPrintf("%s %+d", opcode, insn.vA); break;
     case k22x:  os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
     case k21t:  os << StringPrintf("%s v%d, %+d", opcode, insn.vA, insn.vB); break;
     case k21s:  os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
     case k21h:  os << StringPrintf("%s v%d, #%+d00000[00000000]", opcode, insn.vA, insn.vB); break;
     case k21c:  os << StringPrintf("%s v%d, thing@%d", opcode, insn.vA, insn.vB); break;
     case k23x:  os << StringPrintf("%s v%d, v%d, v%d", opcode, insn.vA, insn.vB, insn.vC); break;
     case k22b:  os << StringPrintf("%s v%d, v%d, #%+d", opcode, insn.vA, insn.vB, insn.vC); break;
     case k22t:  os << StringPrintf("%s v%d, v%d, %+d", opcode, insn.vA, insn.vB, insn.vC); break;
     case k22s:  os << StringPrintf("%s v%d, v%d, #%+d", opcode, insn.vA, insn.vB, insn.vC); break;
     case k22c:  os << StringPrintf("%s v%d, v%d, thing@%d", opcode, insn.vA, insn.vB, insn.vC); break;
     case k32x:  os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
     case k30t:  os << StringPrintf("%s %+d", opcode, insn.vA); break;
     case k31t:  os << StringPrintf("%s v%d, %+d", opcode, insn.vA, insn.vB); break;
     case k31i:  os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
     case k31c:  os << StringPrintf("%s v%d, thing@%d", opcode, insn.vA, insn.vB); break;
     case k35c: {
       switch (insn.opcode) {
         case INVOKE_VIRTUAL:
         case INVOKE_SUPER:
         case INVOKE_DIRECT:
         case INVOKE_STATIC:
         case INVOKE_INTERFACE:
           if (file != NULL) {
             const DexFile::MethodId& meth_id = file->GetMethodId(insn.vB);
             os << opcode << " {";
             for (size_t i = 0; i < insn.vA; ++i) {
               if (i != 0) {
                 os << ", ";
               }
               os << "v" << insn.arg[i];
             }
             os << "}, "
                << file->GetMethodDeclaringClassDescriptor(meth_id) << "."
                << file->GetMethodName(meth_id) << file->GetMethodSignature(meth_id)
                << " // method@" << insn.vB;
             break;
           }  // else fall-through
         default:
           os << opcode << " {v" << insn.arg[0] << ", v" << insn.arg[1] << ", v" << insn.arg[2]
                        << ", v" << insn.arg[3] << ", v" << insn.arg[4] << "}, thing@" << insn.vB;
           break;
       }
       break;
     }
     case k3rc: os << StringPrintf("%s, {v%d .. v%d}, method@%d", opcode, insn.vC, (insn.vC + insn.vA - 1), insn.vB); break;
     case k51l: os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
     default: os << " unknown format (" << DumpHex(5) << ")"; break;
   }
   return os.str();
 }

 DecodedInstruction::DecodedInstruction(const Instruction* inst) {
   inst->Decode(vA, vB, vB_wide, vC, arg);
   opcode = inst->Opcode();
 }

 }  // namespace art
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "dex_instruction.h"

	#include "dex_file.h"
	#include <iomanip>

	namespace art {

	const char* const Instruction::kInstructionNames[] = {
	#define INSTRUCTION_NAME(o, c, pname, f, r, i, a, v) pname,
	#include "dex_instruction_list.h"
	DEX_INSTRUCTION_LIST(INSTRUCTION_NAME)
	#undef DEX_INSTRUCTION_LIST
	#undef INSTRUCTION_NAME
	};

	Instruction::Format const Instruction::kInstructionFormats[] = {
	#define INSTRUCTION_FORMAT(o, c, p, format, r, i, a, v) format,
	#include "dex_instruction_list.h"
	DEX_INSTRUCTION_LIST(INSTRUCTION_FORMAT)
	#undef DEX_INSTRUCTION_LIST
	#undef INSTRUCTION_FORMAT
	};

	int const Instruction::kInstructionFlags[] = {
	#define INSTRUCTION_FLAGS(o, c, p, f, r, i, flags, v) flags,
	#include "dex_instruction_list.h"
	DEX_INSTRUCTION_LIST(INSTRUCTION_FLAGS)
	#undef DEX_INSTRUCTION_LIST
	#undef INSTRUCTION_FLAGS
	};

	int const Instruction::kInstructionVerifyFlags[] = {
	#define INSTRUCTION_VERIFY_FLAGS(o, c, p, f, r, i, a, vflags) vflags,
	#include "dex_instruction_list.h"
	DEX_INSTRUCTION_LIST(INSTRUCTION_VERIFY_FLAGS)
	#undef DEX_INSTRUCTION_LIST
	#undef INSTRUCTION_VERIFY_FLAGS
	};

	/*
	* Handy macros for helping decode instructions.
	*/
	#define FETCH(_offset) (insns[(_offset)])
	#define FETCH_u4(_offset) (fetch_u4_impl((_offset), insns))
	#define INST_A(_insn) (((uint16_t)(_insn) >> 8) & 0x0f)
	#define INST_B(_insn) ((uint16_t)(_insn) >> 12)
	#define INST_AA(_insn) ((_insn) >> 8)

	/* Helper for FETCH_u4, above. */
	static inline uint32_t fetch_u4_impl(uint32_t offset, const uint16_t* insns) {
	return insns[offset] \| ((uint32_t) insns[offset+1] << 16);
	}

	void Instruction::Decode(uint32_t &vA, uint32_t &vB, uint64_t &vB_wide, uint32_t &vC, uint32_t arg[]) const {
	const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
	uint16_t insn = *insns;
	int opcode = insn & 0xFF;

	switch (FormatOf(Opcode())) {
	case k10x: // op
	/* nothing to do; copy the AA bits out for the verifier */
	vA = INST_AA(insn);
	break;
	case k12x: // op vA, vB
	vA = INST_A(insn);
	vB = INST_B(insn);
	break;
	case k11n: // op vA, #+B
	vA = INST_A(insn);
	vB = (int32_t) (INST_B(insn) << 28) >> 28; // sign extend 4-bit value
	break;
	case k11x: // op vAA
	vA = INST_AA(insn);
	break;
	case k10t: // op +AA
	vA = (int8_t) INST_AA(insn); // sign-extend 8-bit value
	break;
	case k20t: // op +AAAA
	vA = (int16_t) FETCH(1); // sign-extend 16-bit value
	break;
	case k20bc: // op AA, kind@BBBB
	case k21c: // op vAA, thing@BBBB
	case k22x: // op vAA, vBBBB
	vA = INST_AA(insn);
	vB = FETCH(1);
	break;
	case k21s: // op vAA, #+BBBB
	case k21t: // op vAA, +BBBB
	vA = INST_AA(insn);
	vB = (int16_t) FETCH(1); // sign-extend 16-bit value
	break;
	case k21h: // op vAA, #+BBBB0000[00000000]
	vA = INST_AA(insn);
	/*
	* The value should be treated as right-zero-extended, but we don't
	* actually do that here. Among other things, we don't know if it's
	* the top bits of a 32- or 64-bit value.
	*/
	vB = FETCH(1);
	break;
	case k23x: // op vAA, vBB, vCC
	vA = INST_AA(insn);
	vB = FETCH(1) & 0xff;
	vC = FETCH(1) >> 8;
	break;
	case k22b: // op vAA, vBB, #+CC
	vA = INST_AA(insn);
	vB = FETCH(1) & 0xff;
	vC = (int8_t) (FETCH(1) >> 8); // sign-extend 8-bit value
	break;
	case k22s: // op vA, vB, #+CCCC
	case k22t: // op vA, vB, +CCCC
	vA = INST_A(insn);
	vB = INST_B(insn);
	vC = (int16_t) FETCH(1); // sign-extend 16-bit value
	break;
	case k22c: // op vA, vB, thing@CCCC
	vA = INST_A(insn);
	vB = INST_B(insn);
	vC = FETCH(1);
	break;
	case k30t: // op +AAAAAAAA
	vA = FETCH_u4(1); // signed 32-bit value
	break;
	case k31t: // op vAA, +BBBBBBBB
	case k31c: // op vAA, string@BBBBBBBB
	vA = INST_AA(insn);
	vB = FETCH_u4(1); // 32-bit value
	break;
	case k32x: // op vAAAA, vBBBB
	vA = FETCH(1);
	vB = FETCH(2);
	break;
	case k31i: // op vAA, #+BBBBBBBB
	vA = INST_AA(insn);
	vB = FETCH_u4(1); // signed 32-bit value
	break;
	case k35c: // op {vC, vD, vE, vF, vG}, thing@BBBB
	{
	/*
	* Note that the fields mentioned in the spec don't appear in
	* their "usual" positions here compared to most formats. This
	* was done so that the field names for the argument count and
	* reference index match between this format and the corresponding
	* range formats (3rc and friends).
	*
	* Bottom line: The argument count is always in vA, and the
	* method constant (or equivalent) is always in vB.
	*/
	uint16_t regList;
	int count;

	vA = INST_B(insn); // This is labeled A in the spec.
	vB = FETCH(1);
	regList = FETCH(2);

	count = vA;

	/*
	* Copy the argument registers into the arg[] array, and
	* also copy the first argument (if any) into vC. (The
	* DecodedInstruction structure doesn't have separate
	* fields for {vD, vE, vF, vG}, so there's no need to make
	* copies of those.) Note that cases 5..2 fall through.
	*/
	switch (count) {
	case 5: arg[4] = INST_A(insn);
	case 4: arg[3] = (regList >> 12) & 0x0f;
	case 3: arg[2] = (regList >> 8) & 0x0f;
	case 2: arg[1] = (regList >> 4) & 0x0f;
	case 1: vC = arg[0] = regList & 0x0f; break;
	case 0: break; // Valid, but no need to do anything.
	default:
	LOG(ERROR) << "Invalid arg count in 35c (" << count << ")";
	return;
	}
	}
	break;
	case k3rc: // op {vCCCC .. v(CCCC+AA-1)}, meth@BBBB
	vA = INST_AA(insn);
	vB = FETCH(1);
	vC = FETCH(2);
	break;
	case k51l: // op vAA, #+BBBBBBBBBBBBBBBB
	vA = INST_AA(insn);
	vB_wide = FETCH_u4(1) \| ((uint64_t) FETCH_u4(3) << 32);
	break;
	default:
	LOG(ERROR) << "Can't decode unexpected format " << static_cast<int>(FormatOf(Opcode())) << " (op=" << opcode << ")";
	return;
	}
	}

	size_t Instruction::SizeInCodeUnits() const {
	const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
	if (*insns == Instruction::kPackedSwitchSignature) {
	return (4 + insns[1] * 2);
	} else if (*insns == Instruction::kSparseSwitchSignature) {
	return (2 + insns[1] * 4);
	} else if (*insns == kArrayDataSignature) {
	uint16_t element_size = insns[1];
	uint32_t length = insns[2] \| (((uint32_t)insns[3]) << 16);
	// The plus 1 is to round up for odd size and width.
	return (4 + (element_size * length + 1) / 2);
	} else {
	switch (FormatOf(Opcode())) {
	case k10x:
	case k12x:
	case k11n:
	case k11x:
	case k10t:
	return 1;
	case k20bc:
	case k20t:
	case k22x:
	case k21t:
	case k21s:
	case k21h:
	case k21c:
	case k23x:
	case k22b:
	case k22t:
	case k22s:
	case k22c:
	return 2;
	case k32x:
	case k30t:
	case k31t:
	case k31i:
	case k31c:
	case k35c:
	case k3rc:
	return 3;
	case k51l:
	return 5;
	default:
	LOG(FATAL) << "Unreachable";
	}
	}
	return 0;
	}

	Instruction::Code Instruction::Opcode() const {
	const uint16_t* insns = reinterpret_cast<const uint16_t*>(this);
	int opcode = *insns & 0xFF;
	return static_cast<Code>(opcode);
	}

	const Instruction* Instruction::Next() const {
	size_t current_size_in_bytes = SizeInCodeUnits() * sizeof(uint16_t);
	const uint8_t* ptr = reinterpret_cast<const uint8_t*>(this);
	return reinterpret_cast<const Instruction*>(ptr + current_size_in_bytes);
	}

	std::string Instruction::DumpHex(size_t code_units) const {
	size_t inst_length = SizeInCodeUnits();
	if (inst_length > code_units) {
	inst_length = code_units;
	}
	std::ostringstream os;
	const uint16_t* insn = reinterpret_cast<const uint16_t*>(this);
	for (size_t i = 0; i < inst_length; i++) {
	os << StringPrintf("0x%04x", insn[i]) << " ";
	}
	for (size_t i = inst_length; i < code_units; i++) {
	os << " ";
	}
	return os.str();
	}

	std::string Instruction::DumpString(const DexFile* file) const {
	DecodedInstruction insn(this);
	std::ostringstream os;
	const char* opcode = kInstructionNames[insn.opcode];
	switch (FormatOf(Opcode())) {
	case k10x: os << opcode; break;
	case k12x: os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
	case k11n: os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
	case k11x: os << StringPrintf("%s v%d", opcode, insn.vA); break;
	case k10t: os << StringPrintf("%s %+d", opcode, insn.vA); break;
	case k20bc: os << StringPrintf("%s %d, kind@%d", opcode, insn.vA, insn.vB); break;
	case k20t: os << StringPrintf("%s %+d", opcode, insn.vA); break;
	case k22x: os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
	case k21t: os << StringPrintf("%s v%d, %+d", opcode, insn.vA, insn.vB); break;
	case k21s: os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
	case k21h: os << StringPrintf("%s v%d, #%+d00000[00000000]", opcode, insn.vA, insn.vB); break;
	case k21c: os << StringPrintf("%s v%d, thing@%d", opcode, insn.vA, insn.vB); break;
	case k23x: os << StringPrintf("%s v%d, v%d, v%d", opcode, insn.vA, insn.vB, insn.vC); break;
	case k22b: os << StringPrintf("%s v%d, v%d, #%+d", opcode, insn.vA, insn.vB, insn.vC); break;
	case k22t: os << StringPrintf("%s v%d, v%d, %+d", opcode, insn.vA, insn.vB, insn.vC); break;
	case k22s: os << StringPrintf("%s v%d, v%d, #%+d", opcode, insn.vA, insn.vB, insn.vC); break;
	case k22c: os << StringPrintf("%s v%d, v%d, thing@%d", opcode, insn.vA, insn.vB, insn.vC); break;
	case k32x: os << StringPrintf("%s v%d, v%d", opcode, insn.vA, insn.vB); break;
	case k30t: os << StringPrintf("%s %+d", opcode, insn.vA); break;
	case k31t: os << StringPrintf("%s v%d, %+d", opcode, insn.vA, insn.vB); break;
	case k31i: os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
	case k31c: os << StringPrintf("%s v%d, thing@%d", opcode, insn.vA, insn.vB); break;
	case k35c: {
	switch (insn.opcode) {
	case INVOKE_VIRTUAL:
	case INVOKE_SUPER:
	case INVOKE_DIRECT:
	case INVOKE_STATIC:
	case INVOKE_INTERFACE:
	if (file != NULL) {
	const DexFile::MethodId& meth_id = file->GetMethodId(insn.vB);
	os << opcode << " {";
	for (size_t i = 0; i < insn.vA; ++i) {
	if (i != 0) {
	os << ", ";
	}
	os << "v" << insn.arg[i];
	}
	os << "}, "
	<< file->GetMethodDeclaringClassDescriptor(meth_id) << "."
	<< file->GetMethodName(meth_id) << file->GetMethodSignature(meth_id)
	<< " // method@" << insn.vB;
	break;
	} // else fall-through
	default:
	os << opcode << " {v" << insn.arg[0] << ", v" << insn.arg[1] << ", v" << insn.arg[2]
	<< ", v" << insn.arg[3] << ", v" << insn.arg[4] << "}, thing@" << insn.vB;
	break;
	}
	break;
	}
	case k3rc: os << StringPrintf("%s, {v%d .. v%d}, method@%d", opcode, insn.vC, (insn.vC + insn.vA - 1), insn.vB); break;
	case k51l: os << StringPrintf("%s v%d, #%+d", opcode, insn.vA, insn.vB); break;
	default: os << " unknown format (" << DumpHex(5) << ")"; break;
	}
	return os.str();
	}

	DecodedInstruction::DecodedInstruction(const Instruction* inst) {
	inst->Decode(vA, vB, vB_wide, vC, arg);
	opcode = inst->Opcode();
	}

	} // namespace art