Instrumenter Class Reference

Finds and instruments individual LLVM IR instructions. More...

#include <IRDynamicChecks.cpp>

Inheritance diagram for Instrumenter:

Public Member Functions
	Instrumenter (llvm::Module &module, std::shared_ptr< UtilityFunction > checker_function)
	Constructor.
virtual	~Instrumenter ()=default
bool	Inspect (llvm::Function &function)
	Inspect a function to find instructions to instrument.
bool	Instrument ()
	Instrument all the instructions found by Inspect()

Protected Types
typedef std::vector< llvm::Instruction * >	InstVector
typedef InstVector::iterator	InstIterator

Protected Member Functions
virtual bool	InstrumentInstruction (llvm::Instruction *inst)=0
	Add instrumentation to a single instruction.
void	RegisterInstruction (llvm::Instruction &inst)
	Register a single instruction to be instrumented.
virtual bool	InspectInstruction (llvm::Instruction &i)
	Determine whether a single instruction is interesting to instrument, and, if so, call RegisterInstruction.
virtual bool	InspectBasicBlock (llvm::BasicBlock &bb)
	Scan a basic block to see if any instructions are interesting.
virtual bool	InspectFunction (llvm::Function &f)
	Scan a function to see if any instructions are interesting.
llvm::FunctionCallee	BuildObjectCheckerFunc (lldb::addr_t start_address)
	Build a function pointer for a function with signature void (*)(uint8_t*, uint8_t*) with a given address.
PointerType *	GetI8PtrTy ()
IntegerType *	GetIntptrTy ()

Protected Attributes
InstVector	m_to_instrument
	List of instructions the inspector found.
llvm::Module &	m_module
	The module which is being instrumented.
std::shared_ptr< UtilityFunction >	m_checker_function
	The dynamic checker function for the process.

Private Attributes
PointerType *	m_i8ptr_ty = nullptr
IntegerType *	m_intptr_ty = nullptr

Detailed Description

Finds and instruments individual LLVM IR instructions.

When instrumenting LLVM IR, it is frequently desirable to first search for instructions, and then later modify them. This way iterators remain intact, and multiple passes can look at the same code base without treading on each other's toes.

The Instrumenter class implements this functionality. A client first calls Inspect on a function, which populates a list of instructions to be instrumented. Then, later, when all passes' Inspect functions have been called, the client calls Instrument, which adds the desired instrumentation.

A subclass of Instrumenter must override InstrumentInstruction, which is responsible for adding whatever instrumentation is necessary.

A subclass of Instrumenter may override:

• InspectInstruction [default: does nothing]
• InspectBasicBlock [default: iterates through the instructions in a basic block calling InspectInstruction]
• InspectFunction [default: iterates through the basic blocks in a function calling InspectBasicBlock]

Definition at line 116 of file IRDynamicChecks.cpp.

Member Typedef Documentation

InstIterator

typedef InstVector::iterator Instrumenter::InstIterator

protected

Definition at line 256 of file IRDynamicChecks.cpp.

InstVector

typedef std::vector<llvm::Instruction *> Instrumenter::InstVector

protected

Definition at line 255 of file IRDynamicChecks.cpp.

Constructor & Destructor Documentation

Instrumenter()

Instrumenter::Instrumenter ( llvm::Module & module, std::shared_ptr< UtilityFunction > checker_function )

inline

Constructor.

Parameters

[in]

module

The module being instrumented.

Definition at line 122 of file IRDynamicChecks.cpp.

References m_checker_function, and m_module.

Referenced by ObjcObjectChecker::ObjcObjectChecker().

~Instrumenter()

virtual Instrumenter::~Instrumenter ( )

virtualdefault

Member Function Documentation

BuildObjectCheckerFunc()

llvm::FunctionCallee Instrumenter::BuildObjectCheckerFunc ( lldb::addr_t start_address )

inlineprotected

Build a function pointer for a function with signature void (*)(uint8_t*, uint8_t*) with a given address.

Parameters

[in]

start_address

The address of the function.

Returns

The function pointer, for use in a CallInst.

Definition at line 222 of file IRDynamicChecks.cpp.

References GetI8PtrTy(), GetIntptrTy(), and m_module.

Referenced by ObjcObjectChecker::InstrumentInstruction().

GetI8PtrTy()

PointerType * Instrumenter::GetI8PtrTy ( )

inlineprotected

Definition at line 238 of file IRDynamicChecks.cpp.

References m_i8ptr_ty, and m_module.

Referenced by BuildObjectCheckerFunc().

GetIntptrTy()

IntegerType * Instrumenter::GetIntptrTy ( )

inlineprotected

Definition at line 245 of file IRDynamicChecks.cpp.

References m_intptr_ty, and m_module.

Referenced by BuildObjectCheckerFunc().

Inspect()

bool Instrumenter::Inspect ( llvm::Function & function )

inline

Inspect a function to find instructions to instrument.

Parameters

[in]

function

The function to inspect.

Returns

True on success; false on error.

Definition at line 135 of file IRDynamicChecks.cpp.

References InspectFunction().

Referenced by lldb_private::IRDynamicChecks::runOnModule().

InspectBasicBlock()

virtual bool Instrumenter::InspectBasicBlock ( llvm::BasicBlock & bb )

inlineprotectedvirtual

Scan a basic block to see if any instructions are interesting.

Parameters

[in]

bb

The basic block to be inspected.

Returns

False if there was an error scanning; true otherwise.

Definition at line 187 of file IRDynamicChecks.cpp.

References InspectInstruction().

Referenced by InspectFunction().

InspectFunction()

virtual bool Instrumenter::InspectFunction ( llvm::Function & f )

inlineprotectedvirtual

Scan a function to see if any instructions are interesting.

Parameters

[in]

f

The function to be inspected.

Returns

False if there was an error scanning; true otherwise.

Definition at line 204 of file IRDynamicChecks.cpp.

References InspectBasicBlock().

Referenced by Inspect().

InspectInstruction()

virtual bool Instrumenter::InspectInstruction ( llvm::Instruction & i )

inlineprotectedvirtual

Determine whether a single instruction is interesting to instrument, and, if so, call RegisterInstruction.

Parameters

[in]

i

The instruction to be inspected.

Returns

False if there was an error scanning; true otherwise.

Reimplemented in ObjcObjectChecker.

Definition at line 178 of file IRDynamicChecks.cpp.

Referenced by InspectBasicBlock().

Instrument()

bool Instrumenter::Instrument ( )

inline

Instrument all the instructions found by Inspect()

Returns

True on success; false on error.

Definition at line 141 of file IRDynamicChecks.cpp.

References InstrumentInstruction(), and m_to_instrument.

Referenced by lldb_private::IRDynamicChecks::runOnModule().

InstrumentInstruction()

virtual bool Instrumenter::InstrumentInstruction ( llvm::Instruction * inst )

protectedpure virtual

Add instrumentation to a single instruction.

Parameters

[in]

inst

The instruction to be instrumented.

Returns

True on success; false otherwise.

Implemented in ObjcObjectChecker.

Referenced by Instrument().

RegisterInstruction()

void Instrumenter::RegisterInstruction ( llvm::Instruction & inst )

inlineprotected

Register a single instruction to be instrumented.

Parameters

[in]

inst

The instruction to be instrumented.

Definition at line 166 of file IRDynamicChecks.cpp.

References m_to_instrument.

Referenced by ObjcObjectChecker::InspectInstruction().

Member Data Documentation

m_checker_function

std::shared_ptr<UtilityFunction> Instrumenter::m_checker_function

protected

The dynamic checker function for the process.

Definition at line 261 of file IRDynamicChecks.cpp.

Referenced by Instrumenter(), and ObjcObjectChecker::InstrumentInstruction().

m_i8ptr_ty

PointerType* Instrumenter::m_i8ptr_ty = nullptr

private

Definition at line 264 of file IRDynamicChecks.cpp.

Referenced by GetI8PtrTy().

m_intptr_ty

IntegerType* Instrumenter::m_intptr_ty = nullptr

private

Definition at line 265 of file IRDynamicChecks.cpp.

Referenced by GetIntptrTy().

m_module

llvm::Module& Instrumenter::m_module

protected

The module which is being instrumented.

Definition at line 259 of file IRDynamicChecks.cpp.

Referenced by BuildObjectCheckerFunc(), GetI8PtrTy(), GetIntptrTy(), and Instrumenter().

m_to_instrument

InstVector Instrumenter::m_to_instrument

protected

List of instructions the inspector found.

Definition at line 258 of file IRDynamicChecks.cpp.

Referenced by Instrument(), and RegisterInstruction().

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The documentation for this class was generated from the following file:

• IRDynamicChecks.cpp