runtime/verifier/register_line.h - platform/art - Git at Google

 /*
  * Copyright (C) 2012 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.
  */

 #ifndef ART_RUNTIME_VERIFIER_REGISTER_LINE_H_
 #define ART_RUNTIME_VERIFIER_REGISTER_LINE_H_

 #include <memory>
 #include <vector>

 #include "dex_instruction.h"
 #include "reg_type.h"
 #include "safe_map.h"

 namespace art {
 namespace verifier {

 class MethodVerifier;

 /*
  * Register type categories, for type checking.
  *
  * The spec says category 1 includes boolean, byte, char, short, int, float, reference, and
  * returnAddress. Category 2 includes long and double.
  *
  * We treat object references separately, so we have "category1nr". We don't support jsr/ret, so
  * there is no "returnAddress" type.
  */
 enum TypeCategory {
   kTypeCategoryUnknown = 0,
   kTypeCategory1nr = 1,         // boolean, byte, char, short, int, float
   kTypeCategory2 = 2,           // long, double
   kTypeCategoryRef = 3,         // object reference
 };

 // During verification, we associate one of these with every "interesting" instruction. We track
 // the status of all registers, and (if the method has any monitor-enter instructions) maintain a
 // stack of entered monitors (identified by code unit offset).
 class RegisterLine {
  public:
   static RegisterLine* Create(size_t num_regs, MethodVerifier* verifier) {
     void* memory = operator new(sizeof(RegisterLine) + (num_regs * sizeof(uint16_t)));
     RegisterLine* rl = new (memory) RegisterLine(num_regs, verifier);
     return rl;
   }

   // Implement category-1 "move" instructions. Copy a 32-bit value from "vsrc" to "vdst".
   void CopyRegister1(uint32_t vdst, uint32_t vsrc, TypeCategory cat)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Implement category-2 "move" instructions. Copy a 64-bit value from "vsrc" to "vdst". This
   // copies both halves of the register.
   void CopyRegister2(uint32_t vdst, uint32_t vsrc)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Implement "move-result". Copy the category-1 value from the result register to another
   // register, and reset the result register.
   void CopyResultRegister1(uint32_t vdst, bool is_reference)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Implement "move-result-wide". Copy the category-2 value from the result register to another
   // register, and reset the result register.
   void CopyResultRegister2(uint32_t vdst)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Set the invisible result register to unknown
   void SetResultTypeToUnknown() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Set the type of register N, verifying that the register is valid.  If "newType" is the "Lo"
   // part of a 64-bit value, register N+1 will be set to "newType+1".
   // The register index was validated during the static pass, so we don't need to check it here.
   bool SetRegisterType(uint32_t vdst, RegType& new_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   bool SetRegisterTypeWide(uint32_t vdst, RegType& new_type1, RegType& new_type2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /* Set the type of the "result" register. */
   void SetResultRegisterType(RegType& new_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void SetResultRegisterTypeWide(RegType& new_type1, RegType& new_type2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Get the type of register vsrc.
   RegType& GetRegisterType(uint32_t vsrc) const;

   bool VerifyRegisterType(uint32_t vsrc, RegType& check_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   bool VerifyRegisterTypeWide(uint32_t vsrc, RegType& check_type1, RegType& check_type2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CopyFromLine(const RegisterLine* src) {
     DCHECK_EQ(num_regs_, src->num_regs_);
     memcpy(&line_, &src->line_, num_regs_ * sizeof(uint16_t));
     monitors_ = src->monitors_;
     reg_to_lock_depths_ = src->reg_to_lock_depths_;
   }

   std::string Dump() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void FillWithGarbage() {
     memset(&line_, 0xf1, num_regs_ * sizeof(uint16_t));
     while (!monitors_.empty()) {
       monitors_.pop_back();
     }
     reg_to_lock_depths_.clear();
   }

   /*
    * We're creating a new instance of class C at address A. Any registers holding instances
    * previously created at address A must be initialized by now. If not, we mark them as "conflict"
    * to prevent them from being used (otherwise, MarkRefsAsInitialized would mark the old ones and
    * the new ones at the same time).
    */
   void MarkUninitRefsAsInvalid(RegType& uninit_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Update all registers holding "uninit_type" to instead hold the corresponding initialized
    * reference type. This is called when an appropriate constructor is invoked -- all copies of
    * the reference must be marked as initialized.
    */
   void MarkRefsAsInitialized(RegType& uninit_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Update all registers to be Conflict except vsrc.
    */
   void MarkAllRegistersAsConflicts();
   void MarkAllRegistersAsConflictsExcept(uint32_t vsrc);
   void MarkAllRegistersAsConflictsExceptWide(uint32_t vsrc);

   /*
    * Check constraints on constructor return. Specifically, make sure that the "this" argument got
    * initialized.
    * The "this" argument to <init> uses code offset kUninitThisArgAddr, which puts it at the start
    * of the list in slot 0. If we see a register with an uninitialized slot 0 reference, we know it
    * somehow didn't get initialized.
    */
   bool CheckConstructorReturn() const;

   // Compare two register lines. Returns 0 if they match.
   // Using this for a sort is unwise, since the value can change based on machine endianness.
   int CompareLine(const RegisterLine* line2) const {
     DCHECK(monitors_ == line2->monitors_);
     // TODO: DCHECK(reg_to_lock_depths_ == line2->reg_to_lock_depths_);
     return memcmp(&line_, &line2->line_, num_regs_ * sizeof(uint16_t));
   }

   size_t NumRegs() const {
     return num_regs_;
   }

   /*
    * Get the "this" pointer from a non-static method invocation. This returns the RegType so the
    * caller can decide whether it needs the reference to be initialized or not. (Can also return
    * kRegTypeZero if the reference can only be zero at this point.)
    *
    * The argument count is in vA, and the first argument is in vC, for both "simple" and "range"
    * versions. We just need to make sure vA is >= 1 and then return vC.
    */
   RegType& GetInvocationThis(const Instruction* inst, bool is_range)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Verify types for a simple two-register instruction (e.g. "neg-int").
    * "dst_type" is stored into vA, and "src_type" is verified against vB.
    */
   void CheckUnaryOp(const Instruction* inst, RegType& dst_type,
                     RegType& src_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckUnaryOpWide(const Instruction* inst,
                         RegType& dst_type1, RegType& dst_type2,
                         RegType& src_type1, RegType& src_type2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckUnaryOpToWide(const Instruction* inst,
                           RegType& dst_type1, RegType& dst_type2,
                           RegType& src_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckUnaryOpFromWide(const Instruction* inst,
                             RegType& dst_type,
                             RegType& src_type1, RegType& src_type2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Verify types for a simple three-register instruction (e.g. "add-int").
    * "dst_type" is stored into vA, and "src_type1"/"src_type2" are verified
    * against vB/vC.
    */
   void CheckBinaryOp(const Instruction* inst,
                      RegType& dst_type, RegType& src_type1, RegType& src_type2,
                      bool check_boolean_op)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckBinaryOpWide(const Instruction* inst,
                          RegType& dst_type1, RegType& dst_type2,
                          RegType& src_type1_1, RegType& src_type1_2,
                          RegType& src_type2_1, RegType& src_type2_2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckBinaryOpWideShift(const Instruction* inst,
                               RegType& long_lo_type, RegType& long_hi_type,
                               RegType& int_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Verify types for a binary "2addr" operation. "src_type1"/"src_type2"
    * are verified against vA/vB, then "dst_type" is stored into vA.
    */
   void CheckBinaryOp2addr(const Instruction* inst,
                           RegType& dst_type,
                           RegType& src_type1, RegType& src_type2,
                           bool check_boolean_op)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckBinaryOp2addrWide(const Instruction* inst,
                               RegType& dst_type1, RegType& dst_type2,
                               RegType& src_type1_1, RegType& src_type1_2,
                               RegType& src_type2_1, RegType& src_type2_2)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   void CheckBinaryOp2addrWideShift(const Instruction* inst,
                                    RegType& long_lo_type, RegType& long_hi_type,
                                    RegType& int_type)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   /*
    * Verify types for A two-register instruction with a literal constant (e.g. "add-int/lit8").
    * "dst_type" is stored into vA, and "src_type" is verified against vB.
    *
    * If "check_boolean_op" is set, we use the constant value in vC.
    */
   void CheckLiteralOp(const Instruction* inst,
                       RegType& dst_type, RegType& src_type,
                       bool check_boolean_op, bool is_lit16)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Verify/push monitor onto the monitor stack, locking the value in reg_idx at location insn_idx.
   void PushMonitor(uint32_t reg_idx, int32_t insn_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Verify/pop monitor from monitor stack ensuring that we believe the monitor is locked
   void PopMonitor(uint32_t reg_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   // Stack of currently held monitors and where they were locked
   size_t MonitorStackDepth() const {
     return monitors_.size();
   }

   // We expect no monitors to be held at certain points, such a method returns. Verify the stack
   // is empty, failing and returning false if not.
   bool VerifyMonitorStackEmpty() const;

   bool MergeRegisters(const RegisterLine* incoming_line)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

   size_t GetMaxNonZeroReferenceReg(size_t max_ref_reg) {
     size_t i = static_cast<int>(max_ref_reg) < 0 ? 0 : max_ref_reg;
     for (; i < num_regs_; i++) {
       if (GetRegisterType(i).IsNonZeroReferenceTypes()) {
         max_ref_reg = i;
       }
     }
     return max_ref_reg;
   }

   // Write a bit at each register location that holds a reference
   void WriteReferenceBitMap(std::vector<uint8_t>& data, size_t max_bytes);

   size_t GetMonitorEnterCount() {
     return monitors_.size();
   }

   uint32_t GetMonitorEnterDexPc(size_t i) {
     return monitors_[i];
   }

  private:
   void CopyRegToLockDepth(size_t dst, size_t src) {
     auto it = reg_to_lock_depths_.find(src);
     if (it != reg_to_lock_depths_.end()) {
       reg_to_lock_depths_.Put(dst, it->second);
     }
   }

   bool IsSetLockDepth(size_t reg, size_t depth) {
     auto it = reg_to_lock_depths_.find(reg);
     if (it != reg_to_lock_depths_.end()) {
       return (it->second & (1 << depth)) != 0;
     } else {
       return false;
     }
   }

   void SetRegToLockDepth(size_t reg, size_t depth) {
     CHECK_LT(depth, 32u);
     DCHECK(!IsSetLockDepth(reg, depth));
     auto it = reg_to_lock_depths_.find(reg);
     if (it == reg_to_lock_depths_.end()) {
       reg_to_lock_depths_.Put(reg, 1 << depth);
     } else {
       it->second |= (1 << depth);
     }
   }

   void ClearRegToLockDepth(size_t reg, size_t depth) {
     CHECK_LT(depth, 32u);
     DCHECK(IsSetLockDepth(reg, depth));
     auto it = reg_to_lock_depths_.find(reg);
     DCHECK(it != reg_to_lock_depths_.end());
     uint32_t depths = it->second ^ (1 << depth);
     if (depths != 0) {
       it->second = depths;
     } else {
       reg_to_lock_depths_.erase(it);
     }
   }

   void ClearAllRegToLockDepths(size_t reg) {
     reg_to_lock_depths_.erase(reg);
   }

   RegisterLine(size_t num_regs, MethodVerifier* verifier)
       : verifier_(verifier), num_regs_(num_regs) {
     memset(&line_, 0, num_regs_ * sizeof(uint16_t));
     SetResultTypeToUnknown();
   }

   // Storage for the result register's type, valid after an invocation
   uint16_t result_[2];

   // Back link to the verifier
   MethodVerifier* verifier_;

   // Length of reg_types_
   const uint32_t num_regs_;
   // A stack of monitor enter locations
   std::vector<uint32_t, TrackingAllocator<uint32_t, kAllocatorTagVerifier>> monitors_;
   // A map from register to a bit vector of indices into the monitors_ stack. As we pop the monitor
   // stack we verify that monitor-enter/exit are correctly nested. That is, if there was a
   // monitor-enter on v5 and then on v6, we expect the monitor-exit to be on v6 then on v5
   AllocationTrackingSafeMap<uint32_t, uint32_t, kAllocatorTagVerifier> reg_to_lock_depths_;

   // An array of RegType Ids associated with each dex register.
   uint16_t line_[0];
 };
 std::ostream& operator<<(std::ostream& os, const RegisterLine& rhs);

 }  // namespace verifier
 }  // namespace art

 #endif  // ART_RUNTIME_VERIFIER_REGISTER_LINE_H_
	/*
	* Copyright (C) 2012 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.
	*/

	#ifndef ART_RUNTIME_VERIFIER_REGISTER_LINE_H_
	#define ART_RUNTIME_VERIFIER_REGISTER_LINE_H_

	#include <memory>
	#include <vector>

	#include "dex_instruction.h"
	#include "reg_type.h"
	#include "safe_map.h"

	namespace art {
	namespace verifier {

	class MethodVerifier;

	/*
	* Register type categories, for type checking.
	*
	* The spec says category 1 includes boolean, byte, char, short, int, float, reference, and
	* returnAddress. Category 2 includes long and double.
	*
	* We treat object references separately, so we have "category1nr". We don't support jsr/ret, so
	* there is no "returnAddress" type.
	*/
	enum TypeCategory {
	kTypeCategoryUnknown = 0,
	kTypeCategory1nr = 1, // boolean, byte, char, short, int, float
	kTypeCategory2 = 2, // long, double
	kTypeCategoryRef = 3, // object reference
	};

	// During verification, we associate one of these with every "interesting" instruction. We track
	// the status of all registers, and (if the method has any monitor-enter instructions) maintain a
	// stack of entered monitors (identified by code unit offset).
	class RegisterLine {
	public:
	static RegisterLine* Create(size_t num_regs, MethodVerifier* verifier) {
	void* memory = operator new(sizeof(RegisterLine) + (num_regs * sizeof(uint16_t)));
	RegisterLine* rl = new (memory) RegisterLine(num_regs, verifier);
	return rl;
	}

	// Implement category-1 "move" instructions. Copy a 32-bit value from "vsrc" to "vdst".
	void CopyRegister1(uint32_t vdst, uint32_t vsrc, TypeCategory cat)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Implement category-2 "move" instructions. Copy a 64-bit value from "vsrc" to "vdst". This
	// copies both halves of the register.
	void CopyRegister2(uint32_t vdst, uint32_t vsrc)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Implement "move-result". Copy the category-1 value from the result register to another
	// register, and reset the result register.
	void CopyResultRegister1(uint32_t vdst, bool is_reference)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Implement "move-result-wide". Copy the category-2 value from the result register to another
	// register, and reset the result register.
	void CopyResultRegister2(uint32_t vdst)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Set the invisible result register to unknown
	void SetResultTypeToUnknown() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Set the type of register N, verifying that the register is valid. If "newType" is the "Lo"
	// part of a 64-bit value, register N+1 will be set to "newType+1".
	// The register index was validated during the static pass, so we don't need to check it here.
	bool SetRegisterType(uint32_t vdst, RegType& new_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	bool SetRegisterTypeWide(uint32_t vdst, RegType& new_type1, RegType& new_type2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/* Set the type of the "result" register. */
	void SetResultRegisterType(RegType& new_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void SetResultRegisterTypeWide(RegType& new_type1, RegType& new_type2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Get the type of register vsrc.
	RegType& GetRegisterType(uint32_t vsrc) const;

	bool VerifyRegisterType(uint32_t vsrc, RegType& check_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	bool VerifyRegisterTypeWide(uint32_t vsrc, RegType& check_type1, RegType& check_type2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CopyFromLine(const RegisterLine* src) {
	DCHECK_EQ(num_regs_, src->num_regs_);
	memcpy(&line_, &src->line_, num_regs_ * sizeof(uint16_t));
	monitors_ = src->monitors_;
	reg_to_lock_depths_ = src->reg_to_lock_depths_;
	}

	std::string Dump() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void FillWithGarbage() {
	memset(&line_, 0xf1, num_regs_ * sizeof(uint16_t));
	while (!monitors_.empty()) {
	monitors_.pop_back();
	}
	reg_to_lock_depths_.clear();
	}

	/*
	* We're creating a new instance of class C at address A. Any registers holding instances
	* previously created at address A must be initialized by now. If not, we mark them as "conflict"
	* to prevent them from being used (otherwise, MarkRefsAsInitialized would mark the old ones and
	* the new ones at the same time).
	*/
	void MarkUninitRefsAsInvalid(RegType& uninit_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Update all registers holding "uninit_type" to instead hold the corresponding initialized
	* reference type. This is called when an appropriate constructor is invoked -- all copies of
	* the reference must be marked as initialized.
	*/
	void MarkRefsAsInitialized(RegType& uninit_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Update all registers to be Conflict except vsrc.
	*/
	void MarkAllRegistersAsConflicts();
	void MarkAllRegistersAsConflictsExcept(uint32_t vsrc);
	void MarkAllRegistersAsConflictsExceptWide(uint32_t vsrc);

	/*
	* Check constraints on constructor return. Specifically, make sure that the "this" argument got
	* initialized.
	* The "this" argument to <init> uses code offset kUninitThisArgAddr, which puts it at the start
	* of the list in slot 0. If we see a register with an uninitialized slot 0 reference, we know it
	* somehow didn't get initialized.
	*/
	bool CheckConstructorReturn() const;

	// Compare two register lines. Returns 0 if they match.
	// Using this for a sort is unwise, since the value can change based on machine endianness.
	int CompareLine(const RegisterLine* line2) const {
	DCHECK(monitors_ == line2->monitors_);
	// TODO: DCHECK(reg_to_lock_depths_ == line2->reg_to_lock_depths_);
	return memcmp(&line_, &line2->line_, num_regs_ * sizeof(uint16_t));
	}

	size_t NumRegs() const {
	return num_regs_;
	}

	/*
	* Get the "this" pointer from a non-static method invocation. This returns the RegType so the
	* caller can decide whether it needs the reference to be initialized or not. (Can also return
	* kRegTypeZero if the reference can only be zero at this point.)
	*
	* The argument count is in vA, and the first argument is in vC, for both "simple" and "range"
	* versions. We just need to make sure vA is >= 1 and then return vC.
	*/
	RegType& GetInvocationThis(const Instruction* inst, bool is_range)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Verify types for a simple two-register instruction (e.g. "neg-int").
	* "dst_type" is stored into vA, and "src_type" is verified against vB.
	*/
	void CheckUnaryOp(const Instruction* inst, RegType& dst_type,
	RegType& src_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckUnaryOpWide(const Instruction* inst,
	RegType& dst_type1, RegType& dst_type2,
	RegType& src_type1, RegType& src_type2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckUnaryOpToWide(const Instruction* inst,
	RegType& dst_type1, RegType& dst_type2,
	RegType& src_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckUnaryOpFromWide(const Instruction* inst,
	RegType& dst_type,
	RegType& src_type1, RegType& src_type2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Verify types for a simple three-register instruction (e.g. "add-int").
	* "dst_type" is stored into vA, and "src_type1"/"src_type2" are verified
	* against vB/vC.
	*/
	void CheckBinaryOp(const Instruction* inst,
	RegType& dst_type, RegType& src_type1, RegType& src_type2,
	bool check_boolean_op)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckBinaryOpWide(const Instruction* inst,
	RegType& dst_type1, RegType& dst_type2,
	RegType& src_type1_1, RegType& src_type1_2,
	RegType& src_type2_1, RegType& src_type2_2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckBinaryOpWideShift(const Instruction* inst,
	RegType& long_lo_type, RegType& long_hi_type,
	RegType& int_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Verify types for a binary "2addr" operation. "src_type1"/"src_type2"
	* are verified against vA/vB, then "dst_type" is stored into vA.
	*/
	void CheckBinaryOp2addr(const Instruction* inst,
	RegType& dst_type,
	RegType& src_type1, RegType& src_type2,
	bool check_boolean_op)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckBinaryOp2addrWide(const Instruction* inst,
	RegType& dst_type1, RegType& dst_type2,
	RegType& src_type1_1, RegType& src_type1_2,
	RegType& src_type2_1, RegType& src_type2_2)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	void CheckBinaryOp2addrWideShift(const Instruction* inst,
	RegType& long_lo_type, RegType& long_hi_type,
	RegType& int_type)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	/*
	* Verify types for A two-register instruction with a literal constant (e.g. "add-int/lit8").
	* "dst_type" is stored into vA, and "src_type" is verified against vB.
	*
	* If "check_boolean_op" is set, we use the constant value in vC.
	*/
	void CheckLiteralOp(const Instruction* inst,
	RegType& dst_type, RegType& src_type,
	bool check_boolean_op, bool is_lit16)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Verify/push monitor onto the monitor stack, locking the value in reg_idx at location insn_idx.
	void PushMonitor(uint32_t reg_idx, int32_t insn_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Verify/pop monitor from monitor stack ensuring that we believe the monitor is locked
	void PopMonitor(uint32_t reg_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	// Stack of currently held monitors and where they were locked
	size_t MonitorStackDepth() const {
	return monitors_.size();
	}

	// We expect no monitors to be held at certain points, such a method returns. Verify the stack
	// is empty, failing and returning false if not.
	bool VerifyMonitorStackEmpty() const;

	bool MergeRegisters(const RegisterLine* incoming_line)
	SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);

	size_t GetMaxNonZeroReferenceReg(size_t max_ref_reg) {
	size_t i = static_cast<int>(max_ref_reg) < 0 ? 0 : max_ref_reg;
	for (; i < num_regs_; i++) {
	if (GetRegisterType(i).IsNonZeroReferenceTypes()) {
	max_ref_reg = i;
	}
	}
	return max_ref_reg;
	}

	// Write a bit at each register location that holds a reference
	void WriteReferenceBitMap(std::vector<uint8_t>& data, size_t max_bytes);

	size_t GetMonitorEnterCount() {
	return monitors_.size();
	}

	uint32_t GetMonitorEnterDexPc(size_t i) {
	return monitors_[i];
	}

	private:
	void CopyRegToLockDepth(size_t dst, size_t src) {
	auto it = reg_to_lock_depths_.find(src);
	if (it != reg_to_lock_depths_.end()) {
	reg_to_lock_depths_.Put(dst, it->second);
	}
	}

	bool IsSetLockDepth(size_t reg, size_t depth) {
	auto it = reg_to_lock_depths_.find(reg);
	if (it != reg_to_lock_depths_.end()) {
	return (it->second & (1 << depth)) != 0;
	} else {
	return false;
	}
	}

	void SetRegToLockDepth(size_t reg, size_t depth) {
	CHECK_LT(depth, 32u);
	DCHECK(!IsSetLockDepth(reg, depth));
	auto it = reg_to_lock_depths_.find(reg);
	if (it == reg_to_lock_depths_.end()) {
	reg_to_lock_depths_.Put(reg, 1 << depth);
	} else {
	it->second \|= (1 << depth);
	}
	}

	void ClearRegToLockDepth(size_t reg, size_t depth) {
	CHECK_LT(depth, 32u);
	DCHECK(IsSetLockDepth(reg, depth));
	auto it = reg_to_lock_depths_.find(reg);
	DCHECK(it != reg_to_lock_depths_.end());
	uint32_t depths = it->second ^ (1 << depth);
	if (depths != 0) {
	it->second = depths;
	} else {
	reg_to_lock_depths_.erase(it);
	}
	}

	void ClearAllRegToLockDepths(size_t reg) {
	reg_to_lock_depths_.erase(reg);
	}

	RegisterLine(size_t num_regs, MethodVerifier* verifier)
	: verifier_(verifier), num_regs_(num_regs) {
	memset(&line_, 0, num_regs_ * sizeof(uint16_t));
	SetResultTypeToUnknown();
	}

	// Storage for the result register's type, valid after an invocation
	uint16_t result_[2];

	// Back link to the verifier
	MethodVerifier* verifier_;

	// Length of reg_types_
	const uint32_t num_regs_;
	// A stack of monitor enter locations
	std::vector<uint32_t, TrackingAllocator<uint32_t, kAllocatorTagVerifier>> monitors_;
	// A map from register to a bit vector of indices into the monitors_ stack. As we pop the monitor
	// stack we verify that monitor-enter/exit are correctly nested. That is, if there was a
	// monitor-enter on v5 and then on v6, we expect the monitor-exit to be on v6 then on v5
	AllocationTrackingSafeMap<uint32_t, uint32_t, kAllocatorTagVerifier> reg_to_lock_depths_;

	// An array of RegType Ids associated with each dex register.
	uint16_t line_[0];
	};
	std::ostream& operator<<(std::ostream& os, const RegisterLine& rhs);

	} // namespace verifier
	} // namespace art

	#endif // ART_RUNTIME_VERIFIER_REGISTER_LINE_H_