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* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#include <memory>
#include <sstream>
#include <vector>
#include "base/arena_allocator.h"
#include "base/macros.h"
#include "base/scoped_arena_containers.h"
#include "base/stl_util.h"
#include "base/value_object.h"
#include "dex_file.h"
#include "handle.h"
#include "instruction_flags.h"
#include "method_reference.h"
#include "register_line.h"
#include "reg_type_cache.h"
namespace art {
class CompilerCallbacks;
class Instruction;
struct ReferenceMap2Visitor;
class Thread;
class VariableIndentationOutputStream;
namespace verifier {
class MethodVerifier;
class RegisterLine;
using RegisterLineArenaUniquePtr = std::unique_ptr<RegisterLine, RegisterLineArenaDelete>;
class RegType;
* "Direct" and "virtual" methods are stored independently. The type of call used to invoke the
* method determines which list we search, and whether we travel up into superclasses.
* (<clinit>, <init>, and methods declared "private" or "static" are stored in the "direct" list.
* All others are stored in the "virtual" list.)
enum MethodType {
METHOD_DIRECT, // <init>, private
METHOD_STATIC, // static
METHOD_VIRTUAL, // virtual
METHOD_SUPER, // super
std::ostream& operator<<(std::ostream& os, const MethodType& rhs);
* An enumeration of problems that can turn up during verification.
* the entire class to be rejected. However, VERIFY_ERROR_BAD_CLASS_SOFT denotes a soft failure
* that can potentially be corrected, and the verifier will try again at runtime.
* VERIFY_ERROR_BAD_CLASS_HARD denotes a hard failure that can't be corrected, and will cause
* the class to remain uncompiled. Other errors denote verification errors that cause bytecode
* to be rewritten to fail at runtime.
enum VerifyError {
VERIFY_ERROR_BAD_CLASS_HARD = 1, // VerifyError; hard error that skips compilation.
VERIFY_ERROR_BAD_CLASS_SOFT = 2, // VerifyError; soft error that verifies again at runtime.
VERIFY_ERROR_NO_CLASS = 4, // NoClassDefFoundError.
VERIFY_ERROR_NO_FIELD = 8, // NoSuchFieldError.
VERIFY_ERROR_NO_METHOD = 16, // NoSuchMethodError.
VERIFY_ERROR_ACCESS_CLASS = 32, // IllegalAccessError.
VERIFY_ERROR_ACCESS_FIELD = 64, // IllegalAccessError.
VERIFY_ERROR_ACCESS_METHOD = 128, // IllegalAccessError.
VERIFY_ERROR_CLASS_CHANGE = 256, // IncompatibleClassChangeError.
VERIFY_ERROR_INSTANTIATION = 512, // InstantiationError.
// For opcodes that don't have complete verifier support (such as lambda opcodes),
// we need a way to continue execution at runtime without attempting to re-verify
// (since we know it will fail no matter what). Instead, run as the interpreter
// in a special "do access checks" mode which will perform verifier-like checking
// on the fly.
// TODO: Once all new opcodes have implemented full verifier support, this can be removed.
VERIFY_ERROR_FORCE_INTERPRETER = 1024, // Skip the verification phase at runtime;
// force the interpreter to do access checks.
// (sets a soft fail at compile time).
VERIFY_ERROR_LOCKING = 2048, // Could not guarantee balanced locking. This should be
// punted to the interpreter with access checks.
std::ostream& operator<<(std::ostream& os, const VerifyError& rhs);
// We don't need to store the register data for many instructions, because we either only need
// it at branch points (for verification) or GC points and branches (for verification +
// type-precise register analysis).
enum RegisterTrackingMode {
// A mapping from a dex pc to the register line statuses as they are immediately prior to the
// execution of that instruction.
class PcToRegisterLineTable {
explicit PcToRegisterLineTable(ScopedArenaAllocator& arena);
// Initialize the RegisterTable. Every instruction address can have a different set of information
// about what's in which register, but for verification purposes we only need to store it at
// branch target addresses (because we merge into that).
void Init(RegisterTrackingMode mode, InstructionFlags* flags, uint32_t insns_size,
uint16_t registers_size, MethodVerifier* verifier);
RegisterLine* GetLine(size_t idx) const {
return register_lines_[idx].get();
ScopedArenaVector<RegisterLineArenaUniquePtr> register_lines_;
// The verifier
class MethodVerifier {
enum FailureKind {
/* Verify a class. Returns "kNoFailure" on success. */
static FailureKind VerifyClass(Thread* self,
mirror::Class* klass,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
bool log_hard_failures,
std::string* error)
static FailureKind VerifyClass(Thread* self,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef* class_def,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
bool log_hard_failures,
std::string* error)
static MethodVerifier* VerifyMethodAndDump(Thread* self,
VariableIndentationOutputStream* vios,
uint32_t method_idx,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef* class_def,
const DexFile::CodeItem* code_item, ArtMethod* method,
uint32_t method_access_flags)
uint8_t EncodePcToReferenceMapData() const;
uint32_t DexFileVersion() const {
return dex_file_->GetVersion();
RegTypeCache* GetRegTypeCache() {
return &reg_types_;
// Log a verification failure.
std::ostream& Fail(VerifyError error);
// Log for verification information.
std::ostream& LogVerifyInfo();
// Dump the failures encountered by the verifier.
std::ostream& DumpFailures(std::ostream& os);
// Dump the state of the verifier, namely each instruction, what flags are set on it, register
// information
void Dump(std::ostream& os) SHARED_REQUIRES(Locks::mutator_lock_);
void Dump(VariableIndentationOutputStream* vios) SHARED_REQUIRES(Locks::mutator_lock_);
// Fills 'monitor_enter_dex_pcs' with the dex pcs of the monitor-enter instructions corresponding
// to the locks held at 'dex_pc' in method 'm'.
static void FindLocksAtDexPc(ArtMethod* m, uint32_t dex_pc,
std::vector<uint32_t>* monitor_enter_dex_pcs)
// Returns the accessed field corresponding to the quick instruction's field
// offset at 'dex_pc' in method 'm'.
static ArtField* FindAccessedFieldAtDexPc(ArtMethod* m, uint32_t dex_pc)
// Returns the invoked method corresponding to the quick instruction's vtable
// index at 'dex_pc' in method 'm'.
static ArtMethod* FindInvokedMethodAtDexPc(ArtMethod* m, uint32_t dex_pc)
static void Init() SHARED_REQUIRES(Locks::mutator_lock_);
static void Shutdown();
bool CanLoadClasses() const {
return can_load_classes_;
// Run verification on the method. Returns true if verification completes and false if the input
// has an irrecoverable corruption.
bool Verify() SHARED_REQUIRES(Locks::mutator_lock_);
// Describe VRegs at the given dex pc.
std::vector<int32_t> DescribeVRegs(uint32_t dex_pc);
static void VisitStaticRoots(RootVisitor* visitor)
void VisitRoots(RootVisitor* visitor, const RootInfo& roots)
// Accessors used by the compiler via CompilerCallback
const DexFile::CodeItem* CodeItem() const;
RegisterLine* GetRegLine(uint32_t dex_pc);
ALWAYS_INLINE const InstructionFlags& GetInstructionFlags(size_t index) const;
ALWAYS_INLINE InstructionFlags& GetInstructionFlags(size_t index);
mirror::ClassLoader* GetClassLoader() SHARED_REQUIRES(Locks::mutator_lock_);
mirror::DexCache* GetDexCache() SHARED_REQUIRES(Locks::mutator_lock_);
ArtMethod* GetMethod() const SHARED_REQUIRES(Locks::mutator_lock_);
MethodReference GetMethodReference() const;
uint32_t GetAccessFlags() const;
bool HasCheckCasts() const;
bool HasVirtualOrInterfaceInvokes() const;
bool HasFailures() const;
bool HasInstructionThatWillThrow() const {
return have_any_pending_runtime_throw_failure_;
const RegType& ResolveCheckedClass(uint32_t class_idx)
// Returns the method of a quick invoke or null if it cannot be found.
ArtMethod* GetQuickInvokedMethod(const Instruction* inst, RegisterLine* reg_line,
bool is_range, bool allow_failure)
// Returns the access field of a quick field access (iget/iput-quick) or null
// if it cannot be found.
ArtField* GetQuickFieldAccess(const Instruction* inst, RegisterLine* reg_line)
uint32_t GetEncounteredFailureTypes() {
return encountered_failure_types_;
bool IsInstanceConstructor() const {
return IsConstructor() && !IsStatic();
ScopedArenaAllocator& GetArena() {
return arena_;
MethodVerifier(Thread* self,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef* class_def,
const DexFile::CodeItem* code_item,
uint32_t method_idx,
ArtMethod* method,
uint32_t access_flags,
bool can_load_classes,
bool allow_soft_failures,
bool need_precise_constants,
bool verify_to_dump,
bool allow_thread_suspension)
void UninstantiableError(const char* descriptor);
static bool IsInstantiableOrPrimitive(mirror::Class* klass) SHARED_REQUIRES(Locks::mutator_lock_);
// Is the method being verified a constructor? See the comment on the field.
bool IsConstructor() const {
return is_constructor_;
// Is the method verified static?
bool IsStatic() const {
return (method_access_flags_ & kAccStatic) != 0;
// Adds the given string to the beginning of the last failure message.
void PrependToLastFailMessage(std::string);
// Adds the given string to the end of the last failure message.
void AppendToLastFailMessage(std::string);
// Verification result for method(s). Includes a (maximum) failure kind, and (the union of)
// all failure types.
struct FailureData : ValueObject {
FailureKind kind = kNoFailure;
uint32_t types = 0U;
// Merge src into this. Uses the most severe failure kind, and the union of types.
void Merge(const FailureData& src);
// Verify all direct or virtual methods of a class. The method assumes that the iterator is
// positioned correctly, and the iterator will be updated.
template <bool kDirect>
static FailureData VerifyMethods(Thread* self,
ClassLinker* linker,
const DexFile* dex_file,
const DexFile::ClassDef* class_def,
ClassDataItemIterator* it,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
bool log_hard_failures,
bool need_precise_constants,
std::string* error_string)
* Perform verification on a single method.
* We do this in three passes:
* (1) Walk through all code units, determining instruction locations,
* widths, and other characteristics.
* (2) Walk through all code units, performing static checks on
* operands.
* (3) Iterate through the method, checking type safety and looking
* for code flow problems.
static FailureData VerifyMethod(Thread* self, uint32_t method_idx,
const DexFile* dex_file,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader,
const DexFile::ClassDef* class_def_idx,
const DexFile::CodeItem* code_item,
ArtMethod* method,
uint32_t method_access_flags,
CompilerCallbacks* callbacks,
bool allow_soft_failures,
bool log_hard_failures,
bool need_precise_constants,
std::string* hard_failure_msg)
void FindLocksAtDexPc() SHARED_REQUIRES(Locks::mutator_lock_);
ArtField* FindAccessedFieldAtDexPc(uint32_t dex_pc)
ArtMethod* FindInvokedMethodAtDexPc(uint32_t dex_pc)
SafeMap<uint32_t, std::set<uint32_t>>& FindStringInitMap()
* Compute the width of the instruction at each address in the instruction stream, and store it in
* insn_flags_. Addresses that are in the middle of an instruction, or that are part of switch
* table data, are not touched (so the caller should probably initialize "insn_flags" to zero).
* The "new_instance_count_" and "monitor_enter_count_" fields in vdata are also set.
* Performs some static checks, notably:
* - opcode of first instruction begins at index 0
* - only documented instructions may appear
* - each instruction follows the last
* - last byte of last instruction is at (code_length-1)
* Logs an error and returns "false" on failure.
bool ComputeWidthsAndCountOps();
* Set the "in try" flags for all instructions protected by "try" statements. Also sets the
* "branch target" flags for exception handlers.
* Call this after widths have been set in "insn_flags".
* Returns "false" if something in the exception table looks fishy, but we're expecting the
* exception table to be somewhat sane.
bool ScanTryCatchBlocks() SHARED_REQUIRES(Locks::mutator_lock_);
* Perform static verification on all instructions in a method.
* Walks through instructions in a method calling VerifyInstruction on each.
bool VerifyInstructions();
* Perform static verification on an instruction.
* As a side effect, this sets the "branch target" flags in InsnFlags.
* "(CF)" items are handled during code-flow analysis.
* v3 4.10.1
* - target of each jump and branch instruction must be valid
* - targets of switch statements must be valid
* - operands referencing constant pool entries must be valid
* - (CF) operands of getfield, putfield, getstatic, putstatic must be valid
* - (CF) operands of method invocation instructions must be valid
* - (CF) only invoke-direct can call a method starting with '<'
* - (CF) <clinit> must never be called explicitly
* - operands of instanceof, checkcast, new (and variants) must be valid
* - new-array[-type] limited to 255 dimensions
* - can't use "new" on an array class
* - (?) limit dimensions in multi-array creation
* - local variable load/store register values must be in valid range
* v3
* - branches must be within the bounds of the code array
* - targets of all control-flow instructions are the start of an instruction
* - register accesses fall within range of allocated registers
* - (N/A) access to constant pool must be of appropriate type
* - code does not end in the middle of an instruction
* - execution cannot fall off the end of the code
* - (earlier) for each exception handler, the "try" area must begin and
* end at the start of an instruction (end can be at the end of the code)
* - (earlier) for each exception handler, the handler must start at a valid
* instruction
bool VerifyInstruction(const Instruction* inst, uint32_t code_offset);
/* Ensure that the register index is valid for this code item. */
bool CheckRegisterIndex(uint32_t idx);
/* Ensure that the wide register index is valid for this code item. */
bool CheckWideRegisterIndex(uint32_t idx);
// Perform static checks on a field Get or set instruction. All we do here is ensure that the
// field index is in the valid range.
bool CheckFieldIndex(uint32_t idx);
// Perform static checks on a method invocation instruction. All we do here is ensure that the
// method index is in the valid range.
bool CheckMethodIndex(uint32_t idx);
// Perform static checks on a "new-instance" instruction. Specifically, make sure the class
// reference isn't for an array class.
bool CheckNewInstance(uint32_t idx);
/* Ensure that the string index is in the valid range. */
bool CheckStringIndex(uint32_t idx);
// Perform static checks on an instruction that takes a class constant. Ensure that the class
// index is in the valid range.
bool CheckTypeIndex(uint32_t idx);
// Perform static checks on a "new-array" instruction. Specifically, make sure they aren't
// creating an array of arrays that causes the number of dimensions to exceed 255.
bool CheckNewArray(uint32_t idx);
// Verify an array data table. "cur_offset" is the offset of the fill-array-data instruction.
bool CheckArrayData(uint32_t cur_offset);
// Verify that the target of a branch instruction is valid. We don't expect code to jump directly
// into an exception handler, but it's valid to do so as long as the target isn't a
// "move-exception" instruction. We verify that in a later stage.
// The dex format forbids certain instructions from branching to themselves.
// Updates "insn_flags_", setting the "branch target" flag.
bool CheckBranchTarget(uint32_t cur_offset);
// Verify a switch table. "cur_offset" is the offset of the switch instruction.
// Updates "insn_flags_", setting the "branch target" flag.
bool CheckSwitchTargets(uint32_t cur_offset);
// Check the register indices used in a "vararg" instruction, such as invoke-virtual or
// filled-new-array.
// - vA holds word count (0-5), args[] have values.
// There are some tests we don't do here, e.g. we don't try to verify that invoking a method that
// takes a double is done with consecutive registers. This requires parsing the target method
// signature, which we will be doing later on during the code flow analysis.
bool CheckVarArgRegs(uint32_t vA, uint32_t arg[]);
// Check the register indices used in a "vararg/range" instruction, such as invoke-virtual/range
// or filled-new-array/range.
// - vA holds word count, vC holds index of first reg.
bool CheckVarArgRangeRegs(uint32_t vA, uint32_t vC);
// Extract the relative offset from a branch instruction.
// Returns "false" on failure (e.g. this isn't a branch instruction).
bool GetBranchOffset(uint32_t cur_offset, int32_t* pOffset, bool* pConditional,
bool* selfOkay);
/* Perform detailed code-flow analysis on a single method. */
bool VerifyCodeFlow() SHARED_REQUIRES(Locks::mutator_lock_);
// Set the register types for the first instruction in the method based on the method signature.
// This has the side-effect of validating the signature.
bool SetTypesFromSignature() SHARED_REQUIRES(Locks::mutator_lock_);
* Perform code flow on a method.
* The basic strategy is as outlined in v3 set the "changed" bit on the first
* instruction, process it (setting additional "changed" bits), and repeat until there are no
* more.
* v3
* - (N/A) operand stack is always the same size
* - operand stack [registers] contain the correct types of values
* - local variables [registers] contain the correct types of values
* - methods are invoked with the appropriate arguments
* - fields are assigned using values of appropriate types
* - opcodes have the correct type values in operand registers
* - there is never an uninitialized class instance in a local variable in code protected by an
* exception handler (operand stack is okay, because the operand stack is discarded when an
* exception is thrown) [can't know what's a local var w/o the debug info -- should fall out of
* register typing]
* v3
* - execution cannot fall off the end of the code
* (We also do many of the items described in the "static checks" sections, because it's easier to
* do them here.)
* We need an array of RegType values, one per register, for every instruction. If the method uses
* monitor-enter, we need extra data for every register, and a stack for every "interesting"
* instruction. In theory this could become quite large -- up to several megabytes for a monster
* function.
* The spec forbids backward branches when there's an uninitialized reference in a register. The
* idea is to prevent something like this:
* loop:
* move r1, r0
* new-instance r0, MyClass
* ...
* if-eq rN, loop // once
* initialize r0
* This leaves us with two different instances, both allocated by the same instruction, but only
* one is initialized. The scheme outlined in v3 wouldn't catch this, so they work around
* it by preventing backward branches. We achieve identical results without restricting code
* reordering by specifying that you can't execute the new-instance instruction if a register
* contains an uninitialized instance created by that same instruction.
bool CodeFlowVerifyMethod() SHARED_REQUIRES(Locks::mutator_lock_);
* Perform verification for a single instruction.
* This requires fully decoding the instruction to determine the effect it has on registers.
* Finds zero or more following instructions and sets the "changed" flag if execution at that
* point needs to be (re-)evaluated. Register changes are merged into "reg_types_" at the target
* addresses. Does not set or clear any other flags in "insn_flags_".
bool CodeFlowVerifyInstruction(uint32_t* start_guess)
// Perform verification of a new array instruction
void VerifyNewArray(const Instruction* inst, bool is_filled, bool is_range)
// Helper to perform verification on puts of primitive type.
void VerifyPrimitivePut(const RegType& target_type, const RegType& insn_type,
const uint32_t vregA) SHARED_REQUIRES(Locks::mutator_lock_);
// Perform verification of an aget instruction. The destination register's type will be set to
// be that of component type of the array unless the array type is unknown, in which case a
// bottom type inferred from the type of instruction is used. is_primitive is false for an
// aget-object.
void VerifyAGet(const Instruction* inst, const RegType& insn_type,
bool is_primitive) SHARED_REQUIRES(Locks::mutator_lock_);
// Perform verification of an aput instruction.
void VerifyAPut(const Instruction* inst, const RegType& insn_type,
bool is_primitive) SHARED_REQUIRES(Locks::mutator_lock_);
// Lookup instance field and fail for resolution violations
ArtField* GetInstanceField(const RegType& obj_type, int field_idx)
// Lookup static field and fail for resolution violations
ArtField* GetStaticField(int field_idx) SHARED_REQUIRES(Locks::mutator_lock_);
// Perform verification of an iget/sget/iput/sput instruction.
enum class FieldAccessType { // private
template <FieldAccessType kAccType>
void VerifyISFieldAccess(const Instruction* inst, const RegType& insn_type,
bool is_primitive, bool is_static)
template <FieldAccessType kAccType>
void VerifyQuickFieldAccess(const Instruction* inst, const RegType& insn_type, bool is_primitive)
// Resolves a class based on an index and performs access checks to ensure the referrer can
// access the resolved class.
const RegType& ResolveClassAndCheckAccess(uint32_t class_idx)
* For the "move-exception" instruction at "work_insn_idx_", which must be at an exception handler
* address, determine the Join of all exceptions that can land here. Fails if no matching
* exception handler can be found or if the Join of exception types fails.
const RegType& GetCaughtExceptionType()
* Resolves a method based on an index and performs access checks to ensure
* the referrer can access the resolved method.
* Does not throw exceptions.
ArtMethod* ResolveMethodAndCheckAccess(uint32_t method_idx, MethodType method_type)
* Verify the arguments to a method. We're executing in "method", making
* a call to the method reference in vB.
* If this is a "direct" invoke, we allow calls to <init>. For calls to
* <init>, the first argument may be an uninitialized reference. Otherwise,
* calls to anything starting with '<' will be rejected, as will any
* uninitialized reference arguments.
* For non-static method calls, this will verify that the method call is
* appropriate for the "this" argument.
* The method reference is in vBBBB. The "is_range" parameter determines
* whether we use 0-4 "args" values or a range of registers defined by
* vAA and vCCCC.
* Widening conversions on integers and references are allowed, but
* narrowing conversions are not.
* Returns the resolved method on success, null on failure (with *failure
* set appropriately).
ArtMethod* VerifyInvocationArgs(const Instruction* inst, MethodType method_type, bool is_range)
// Similar checks to the above, but on the proto. Will be used when the method cannot be
// resolved.
void VerifyInvocationArgsUnresolvedMethod(const Instruction* inst, MethodType method_type,
bool is_range)
template <class T>
ArtMethod* VerifyInvocationArgsFromIterator(T* it, const Instruction* inst,
MethodType method_type, bool is_range,
ArtMethod* res_method)
ArtMethod* VerifyInvokeVirtualQuickArgs(const Instruction* inst, bool is_range)
* Verify that the target instruction is not "move-exception". It's important that the only way
* to execute a move-exception is as the first instruction of an exception handler.
* Returns "true" if all is well, "false" if the target instruction is move-exception.
bool CheckNotMoveException(const uint16_t* insns, int insn_idx);
* Verify that the target instruction is not "move-result". It is important that we cannot
* branch to move-result instructions, but we have to make this a distinct check instead of
* adding it to CheckNotMoveException, because it is legal to continue into "move-result"
* instructions - as long as the previous instruction was an invoke, which is checked elsewhere.
bool CheckNotMoveResult(const uint16_t* insns, int insn_idx);
* Verify that the target instruction is not "move-result" or "move-exception". This is to
* be used when checking branch and switch instructions, but not instructions that can
* continue.
bool CheckNotMoveExceptionOrMoveResult(const uint16_t* insns, int insn_idx);
* Control can transfer to "next_insn". Merge the registers from merge_line into the table at
* next_insn, and set the changed flag on the target address if any of the registers were changed.
* In the case of fall-through, update the merge line on a change as its the working line for the
* next instruction.
* Returns "false" if an error is encountered.
bool UpdateRegisters(uint32_t next_insn, RegisterLine* merge_line, bool update_merge_line)
// Return the register type for the method.
const RegType& GetMethodReturnType() SHARED_REQUIRES(Locks::mutator_lock_);
// Get a type representing the declaring class of the method.
const RegType& GetDeclaringClass() SHARED_REQUIRES(Locks::mutator_lock_);
InstructionFlags* CurrentInsnFlags();
const RegType& DetermineCat1Constant(int32_t value, bool precise)
// Try to create a register type from the given class. In case a precise type is requested, but
// the class is not instantiable, a soft error (of type NO_CLASS) will be enqueued and a
// non-precise reference will be returned.
// Note: we reuse NO_CLASS as this will throw an exception at runtime, when the failing class is
// actually touched.
const RegType& FromClass(const char* descriptor, mirror::Class* klass, bool precise)
// The thread we're verifying on.
Thread* const self_;
// Arena allocator.
ArenaStack arena_stack_;
ScopedArenaAllocator arena_;
RegTypeCache reg_types_;
PcToRegisterLineTable reg_table_;
// Storage for the register status we're currently working on.
RegisterLineArenaUniquePtr work_line_;
// The address of the instruction we're currently working on, note that this is in 2 byte
// quantities
uint32_t work_insn_idx_;
// Storage for the register status we're saving for later.
RegisterLineArenaUniquePtr saved_line_;
const uint32_t dex_method_idx_; // The method we're working on.
// Its object representation if known.
ArtMethod* mirror_method_ GUARDED_BY(Locks::mutator_lock_);
const uint32_t method_access_flags_; // Method's access flags.
const RegType* return_type_; // Lazily computed return type of the method.
const DexFile* const dex_file_; // The dex file containing the method.
// The dex_cache for the declaring class of the method.
Handle<mirror::DexCache> dex_cache_ GUARDED_BY(Locks::mutator_lock_);
// The class loader for the declaring class of the method.
Handle<mirror::ClassLoader> class_loader_ GUARDED_BY(Locks::mutator_lock_);
const DexFile::ClassDef* const class_def_; // The class def of the declaring class of the method.
const DexFile::CodeItem* const code_item_; // The code item containing the code for the method.
const RegType* declaring_class_; // Lazily computed reg type of the method's declaring class.
// Instruction widths and flags, one entry per code unit.
// Owned, but not unique_ptr since insn_flags_ are allocated in arenas.
ArenaUniquePtr<InstructionFlags[]> insn_flags_;
// The dex PC of a FindLocksAtDexPc request, -1 otherwise.
uint32_t interesting_dex_pc_;
// The container into which FindLocksAtDexPc should write the registers containing held locks,
// null if we're not doing FindLocksAtDexPc.
std::vector<uint32_t>* monitor_enter_dex_pcs_;
// The types of any error that occurs.
std::vector<VerifyError> failures_;
// Error messages associated with failures.
std::vector<std::ostringstream*> failure_messages_;
// Is there a pending hard failure?
bool have_pending_hard_failure_;
// Is there a pending runtime throw failure? A runtime throw failure is when an instruction
// would fail at runtime throwing an exception. Such an instruction causes the following code
// to be unreachable. This is set by Fail and used to ensure we don't process unreachable
// instructions that would hard fail the verification.
// Note: this flag is reset after processing each instruction.
bool have_pending_runtime_throw_failure_;
// Is there a pending experimental failure?
bool have_pending_experimental_failure_;
// A version of the above that is not reset and thus captures if there were *any* throw failures.
bool have_any_pending_runtime_throw_failure_;
// Info message log use primarily for verifier diagnostics.
std::ostringstream info_messages_;
// The number of occurrences of specific opcodes.
size_t new_instance_count_;
size_t monitor_enter_count_;
// Bitset of the encountered failure types. Bits are according to the values in VerifyError.
uint32_t encountered_failure_types_;
const bool can_load_classes_;
// Converts soft failures to hard failures when false. Only false when the compiler isn't
// running and the verifier is called from the class linker.
const bool allow_soft_failures_;
// An optimization where instead of generating unique RegTypes for constants we use imprecise
// constants that cover a range of constants. This isn't good enough for deoptimization that
// avoids loading from registers in the case of a constant as the dex instruction set lost the
// notion of whether a value should be in a floating point or general purpose register file.
const bool need_precise_constants_;
// Indicates the method being verified contains at least one check-cast or aput-object
// instruction. Aput-object operations implicitly check for array-store exceptions, similar to
// check-cast.
bool has_check_casts_;
// Indicates the method being verified contains at least one invoke-virtual/range
// or invoke-interface/range.
bool has_virtual_or_interface_invokes_;
// Indicates whether we verify to dump the info. In that case we accept quickened instructions
// even though we might detect to be a compiler. Should only be set when running
// VerifyMethodAndDump.
const bool verify_to_dump_;
// Whether or not we call AllowThreadSuspension periodically, we want a way to disable this for
// thread dumping checkpoints since we may get thread suspension at an inopportune time due to
// FindLocksAtDexPC, resulting in deadlocks.
const bool allow_thread_suspension_;
// Whether the method seems to be a constructor. Note that this field exists as we can't trust
// the flags in the dex file. Some older code does not mark methods named "<init>" and "<clinit>"
// correctly.
// Note: this flag is only valid once Verify() has started.
bool is_constructor_;
// Link, for the method verifier root linked list.
MethodVerifier* link_;
friend class art::Thread;
std::ostream& operator<<(std::ostream& os, const MethodVerifier::FailureKind& rhs);
} // namespace verifier
} // namespace art