BoundsChecking.cpp File Reference

#include "llvm/Transforms/Instrumentation/BoundsChecking.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Analysis/TargetFolder.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Value.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdint>
#include <vector>

Include dependency graph for BoundsChecking.cpp:

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "bounds-checking"

Typedefs
using	BuilderTy = IRBuilder< TargetFolder >

Functions
	STATISTIC (ChecksAdded, "Bounds checks added")
	STATISTIC (ChecksSkipped, "Bounds checks skipped")
	STATISTIC (ChecksUnable, "Bounds checks unable to add")
static Value *	getBoundsCheckCond (Value *Ptr, Value *InstVal, const DataLayout &DL, TargetLibraryInfo &TLI, ObjectSizeOffsetEvaluator &ObjSizeEval, BuilderTy &IRB, ScalarEvolution &SE)
	Gets the conditions under which memory accessing instructions will overflow. More...
template<typename GetTrapBBT >
static void	insertBoundsCheck (Value *Or, BuilderTy IRB, GetTrapBBT GetTrapBB)
	Adds run-time bounds checks to memory accessing instructions. More...
static bool	addBoundsChecking (Function &F, TargetLibraryInfo &TLI, ScalarEvolution &SE)
	INITIALIZE_PASS_BEGIN (BoundsCheckingLegacyPass, "bounds-checking", "Run-time bounds checking", false, false) INITIALIZE_PASS_END(BoundsCheckingLegacyPass

Variables
static cl::opt< bool >	SingleTrapBB ("bounds-checking-single-trap", cl::desc("Use one trap block per function"))
bounds	checking
bounds Run time bounds	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "bounds-checking"

Definition at line 39 of file BoundsChecking.cpp.

Typedef Documentation

BuilderTy

using BuilderTy = IRBuilder<TargetFolder>

Definition at line 48 of file BoundsChecking.cpp.

Function Documentation

addBoundsChecking()

static bool addBoundsChecking ( Function &  F, TargetLibraryInfo &  TLI, ScalarEvolution &  SE  )

static

Definition at line 143 of file BoundsChecking.cpp.

References llvm::BasicBlock::Create(), getBoundsCheckCond(), llvm::Function::getContext(), llvm::Module::getDataLayout(), llvm::Intrinsic::getDeclaration(), llvm::Instruction::getParent(), llvm::GlobalValue::getParent(), I, insertBoundsCheck(), llvm::instructions(), llvm::CallBase::setDoesNotReturn(), SI, SingleTrapBB, and llvm::Intrinsic::trap.

Referenced by llvm::BoundsCheckingPass::run().

getBoundsCheckCond()

static Value* getBoundsCheckCond ( Value *  Ptr, Value *  InstVal, const DataLayout &  DL, TargetLibraryInfo &  TLI, ObjectSizeOffsetEvaluator &  ObjSizeEval, BuilderTy &  IRB, ScalarEvolution &  SE  )

static

Gets the conditions under which memory accessing instructions will overflow.

Ptr is the pointer that will be read/written, and InstVal is either the result from the load or the value being stored. It is used to determine the size of memory block that is touched.

Returns the condition under which the access will overflow.

Definition at line 57 of file BoundsChecking.cpp.

References llvm::ObjectSizeOffsetEvaluator::bothKnown(), llvm::ObjectSizeOffsetEvaluator::compute(), llvm::IRBuilder< T, Inserter >::CreateICmpSLT(), llvm::IRBuilder< T, Inserter >::CreateICmpULT(), llvm::IRBuilder< T, Inserter >::CreateOr(), llvm::IRBuilder< T, Inserter >::CreateSub(), llvm::dbgs(), llvm::dyn_cast(), llvm::ConstantInt::get(), llvm::Value::getContext(), llvm::ConstantInt::getFalse(), llvm::DataLayout::getIntPtrType(), llvm::ScalarEvolution::getSCEV(), llvm::Value::getType(), llvm::DataLayout::getTypeStoreSize(), llvm::ScalarEvolution::getUnsignedRange(), llvm::ConstantInt::getValue(), LLVM_DEBUG, Size, and llvm::APInt::slt().

Referenced by addBoundsChecking().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	BoundsCheckingLegacyPass	,
		"bounds-checking"	,
		"Run-time bounds checking"	,
		false	,
		false
	)

Referenced by llvm::BoundsCheckingPass::run().

insertBoundsCheck()

template<typename GetTrapBBT >

static void insertBoundsCheck ( Value *  Or, BuilderTy  IRB, GetTrapBBT  GetTrapBB  )

static

Adds run-time bounds checks to memory accessing instructions.

Or is the condition that should guard the trap.

GetTrapBB is a callable that returns the trap BB to use on failure.

Definition at line 115 of file BoundsChecking.cpp.

References C, llvm::BranchInst::Create(), llvm::Instruction::eraseFromParent(), llvm::IRBuilderBase::GetInsertPoint(), llvm::BasicBlock::getTerminator(), llvm::ConstantInt::getZExtValue(), and llvm::BasicBlock::splitBasicBlock().

Referenced by addBoundsChecking().

STATISTIC() [1/3]

STATISTIC	(	ChecksAdded	,
		"Bounds checks added"
	)

STATISTIC() [2/3]

STATISTIC	(	ChecksSkipped	,
		"Bounds checks skipped"
	)

STATISTIC() [3/3]

STATISTIC	(	ChecksUnable	,
		"Bounds checks unable to add"
	)

Variable Documentation

checking

bounds Run time bounds checking

Definition at line 243 of file BoundsChecking.cpp.

false

bounds Run time bounds false

Definition at line 243 of file BoundsChecking.cpp.

SingleTrapBB

cl::opt<bool> SingleTrapBB("bounds-checking-single-trap", cl::desc("Use one trap block per function"))

static

Referenced by addBoundsChecking().