BoundsChecking.cpp File Reference

#include "llvm/Transforms/Instrumentation/BoundsChecking.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.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/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <utility>

Go to the source code of this file.

Classes
class	BuilderTy

Macros
#define	DEBUG_TYPE   "bounds-checking"

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.
static CallInst *	InsertTrap (BuilderTy &IRB, bool DebugTrapBB, std::optional< int8_t > GuardKind)
static CallInst *	InsertCall (BuilderTy &IRB, bool MayReturn, StringRef Name)
template<typename GetTrapBBT>
static void	insertBoundsCheck (Value *Or, BuilderTy &IRB, GetTrapBBT GetTrapBB)
	Adds run-time bounds checks to memory accessing instructions.
static std::string	getRuntimeCallName (const BoundsCheckingPass::Options::Runtime &Opts)
static bool	addBoundsChecking (Function &F, TargetLibraryInfo &TLI, ScalarEvolution &SE, const BoundsCheckingPass::Options &Opts)

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

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "bounds-checking"

Definition at line 35 of file BoundsChecking.cpp.

Function Documentation

addBoundsChecking()

bool addBoundsChecking ( Function & F, TargetLibraryInfo & TLI, ScalarEvolution & SE, const BoundsCheckingPass::Options & Opts )

static

Definition at line 184 of file BoundsChecking.cpp.

References llvm::CallBase::addFnAttr(), llvm::BasicBlock::Create(), llvm::IRBuilderBase::CreateAnd(), llvm::IRBuilderBase::CreateIntrinsic(), DL, llvm::dyn_cast(), llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::ObjectSizeOpts::EvalMode, llvm::ObjectSizeOpts::ExactUnderlyingSizeAndOffset, F, getBoundsCheckCond(), llvm::Function::getContext(), llvm::IRBuilderBase::getInt1Ty(), llvm::GlobalValue::getParent(), llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent(), getRuntimeCallName(), llvm::BoundsCheckingPass::Options::GuardKind, I, insertBoundsCheck(), InsertCall(), InsertTrap(), instructions, llvm::BoundsCheckingPass::Options::Merge, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::ObjectSizeOpts::RoundToAlign, llvm::BoundsCheckingPass::Options::Rt, llvm::Instruction::setDebugLoc(), llvm::CallBase::setDoesNotReturn(), llvm::CallBase::setDoesNotThrow(), and SingleTrapBB.

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

getBoundsCheckCond()

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 59 of file BoundsChecking.cpp.

References llvm::SizeOffsetType< T, C >::bothKnown(), llvm::ObjectSizeOffsetEvaluator::compute(), llvm::IRBuilderBase::CreateICmpSLT(), llvm::IRBuilderBase::CreateICmpULT(), llvm::IRBuilderBase::CreateOr(), llvm::IRBuilderBase::CreateSub(), llvm::IRBuilderBase::CreateTypeSize(), llvm::dbgs(), DL, llvm::dyn_cast(), llvm::ConstantInt::getFalse(), llvm::ScalarEvolution::getSCEV(), llvm::Value::getType(), llvm::ScalarEvolution::getUnsignedRange(), llvm::ConstantInt::getValue(), LLVM_DEBUG, llvm::Offset, llvm::SizeOffsetType< T, C >::Offset, Ptr, Size, llvm::SizeOffsetType< T, C >::Size, and llvm::APInt::slt().

Referenced by addBoundsChecking().

getRuntimeCallName()

std::string getRuntimeCallName ( const BoundsCheckingPass::Options::Runtime & Opts )

static

Definition at line 175 of file BoundsChecking.cpp.

References llvm::BoundsCheckingPass::Options::Runtime::MayReturn, and llvm::BoundsCheckingPass::Options::Runtime::MinRuntime.

Referenced by addBoundsChecking().

insertBoundsCheck()

template<typename GetTrapBBT>

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 144 of file BoundsChecking.cpp.

References llvm::CallingConv::C, llvm::BranchInst::Create(), llvm::dyn_cast_or_null(), llvm::Instruction::eraseFromParent(), llvm::IRBuilderBase::GetInsertPoint(), llvm::BasicBlock::getParent(), llvm::BasicBlock::getTerminator(), and llvm::BasicBlock::splitBasicBlock().

Referenced by addBoundsChecking().

InsertCall()

CallInst * InsertCall ( BuilderTy & IRB, bool MayReturn, StringRef Name )

static

Definition at line 124 of file BoundsChecking.cpp.

References B(), llvm::IRBuilderBase::CreateCall(), llvm::Function::getContext(), llvm::IRBuilderBase::GetInsertBlock(), llvm::Module::getOrInsertFunction(), llvm::BasicBlock::getParent(), llvm::GlobalValue::getParent(), and llvm::Type::getVoidTy().

Referenced by addBoundsChecking().

InsertTrap()

CallInst * InsertTrap ( BuilderTy & IRB, bool DebugTrapBB, std::optional< int8_t > GuardKind )

static

Definition at line 111 of file BoundsChecking.cpp.

References llvm::IRBuilderBase::CreateIntrinsic(), llvm::IRBuilderBase::GetInsertBlock(), llvm::IRBuilderBase::getInt8Ty(), llvm::BasicBlock::getParent(), and llvm::Function::size().

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

SingleTrapBB

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

static

Referenced by addBoundsChecking().