DwarfEHPrepare.cpp File Reference

#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/DomTreeUpdater.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/RuntimeLibcalls.h"
#include "llvm/CodeGen/StackProtector.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/EHPersonalities.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include <cstddef>

Include dependency graph for DwarfEHPrepare.cpp:

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "dwarfehprepare"

Functions
	STATISTIC (NumResumesLowered, "Number of resume calls lowered")
	STATISTIC (NumCleanupLandingPadsUnreachable, "Number of cleanup landing pads found unreachable")
	STATISTIC (NumCleanupLandingPadsRemaining, "Number of cleanup landing pads remaining")
	STATISTIC (NumNoUnwind, "Number of functions with nounwind")
	STATISTIC (NumUnwind, "Number of functions with unwind")
static void	addCleanupResumeToLandingPad (BasicBlock &BB, DomTreeUpdater *DTU)
	If a landingpad block doesn't already have a cleanup case, add one that feeds directly into a resume instruction.
static BasicBlock *	createCleanupResumeBB (Function &F, Type *LandingPadTy)
	Create a basic block that has a landingpad instruction feeding directly into a resume.
static void	changeCallToInvokeResume (CallInst &CI, BasicBlock *CleanupResumeBB, DomTreeUpdater *DTU)
	Convert a call that might throw into an invoke that unwinds to the specified simple landingpad/resume block.
static void	addCleanupPathsForStackProtector (Function &F, DomTreeUpdater *DTU)
	Ensure that any call in this function that might throw has an associated cleanup/resume that the stack protector can instrument later.
static bool	prepareDwarfEH (CodeGenOpt::Level OptLevel, Function &F, const TargetLowering &TLI, DominatorTree *DT, const TargetTransformInfo *TTI, const Triple &TargetTriple)
	INITIALIZE_PASS_BEGIN (DwarfEHPrepareLegacyPass, DEBUG_TYPE, "Prepare DWARF exceptions", false, false) INITIALIZE_PASS_END(DwarfEHPrepareLegacyPass

Variables
	DEBUG_TYPE
Prepare DWARF	exceptions
Prepare DWARF	false

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "dwarfehprepare"

Definition at line 47 of file DwarfEHPrepare.cpp.

Function Documentation

addCleanupPathsForStackProtector()

static void addCleanupPathsForStackProtector ( Function &  F, DomTreeUpdater *  DTU  )

static

Ensure that any call in this function that might throw has an associated cleanup/resume that the stack protector can instrument later.

Existing invokes will get an added cleanup clause if needed, calls will be converted to an invoke with trivial unwind followup.

Definition at line 256 of file DwarfEHPrepare.cpp.

References addCleanupResumeToLandingPad(), changeCallToInvokeResume(), createCleanupResumeBB(), llvm::CallBase::doesNotThrow(), F, llvm::BasicBlock::getLandingPadInst(), I, and llvm::CallInst::isTailCall().

addCleanupResumeToLandingPad()

static void addCleanupResumeToLandingPad ( BasicBlock &  BB, DomTreeUpdater *  DTU  )

static

If a landingpad block doesn't already have a cleanup case, add one that feeds directly into a resume instruction.

Definition at line 174 of file DwarfEHPrepare.cpp.

References llvm::DomTreeUpdater::applyUpdates(), B, llvm::BasicBlock::Create(), llvm::ResumeInst::Create(), llvm::Instruction::eraseFromParent(), F, llvm::ConstantInt::get(), llvm::BasicBlock::getLandingPadInst(), llvm::ilist_node_with_parent< NodeTy, ParentTy, Options >::getNextNode(), llvm::BasicBlock::getParent(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), llvm::LandingPadInst::isCleanup(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::LandingPadInst::setCleanup(), and llvm::SplitBlock().

Referenced by addCleanupPathsForStackProtector().

changeCallToInvokeResume()

static void changeCallToInvokeResume ( CallInst &  CI, BasicBlock *  CleanupResumeBB, DomTreeUpdater *  DTU  )

static

Convert a call that might throw into an invoke that unwinds to the specified simple landingpad/resume block.

Definition at line 226 of file DwarfEHPrepare.cpp.

References llvm::DomTreeUpdater::applyUpdates(), llvm::CallBase::args(), B, llvm::Instruction::copyMetadata(), llvm::Instruction::eraseFromParent(), llvm::CallBase::getAttributes(), llvm::CallBase::getCalledOperand(), llvm::CallBase::getCallingConv(), llvm::CallBase::getFunctionType(), llvm::Value::getName(), llvm::CallBase::getOperandBundlesAsDefs(), llvm::Instruction::getParent(), llvm::BasicBlock::getTerminator(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::Value::replaceAllUsesWith(), llvm::CallBase::setAttributes(), llvm::CallBase::setCallingConv(), and llvm::SplitBlock().

Referenced by addCleanupPathsForStackProtector().

createCleanupResumeBB()

static BasicBlock * createCleanupResumeBB ( Function &  F, Type *  LandingPadTy  )

static

Create a basic block that has a landingpad instruction feeding directly into a resume.

Will be set to the unwind destination of a new invoke.

Definition at line 207 of file DwarfEHPrepare.cpp.

References B, llvm::BasicBlock::Create(), F, llvm::IntegerType::get(), llvm::StructType::get(), llvm::Type::getInt8PtrTy(), and llvm::LandingPadInst::setCleanup().

Referenced by addCleanupPathsForStackProtector().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	DwarfEHPrepareLegacyPass	,
		DEBUG_TYPE	,
		"Prepare DWARF exceptions"	,
		false	,
		false
	)

prepareDwarfEH()

static bool prepareDwarfEH ( CodeGenOpt::Level  OptLevel, Function &  F, const TargetLowering &  TLI, DominatorTree *  DT, const TargetTransformInfo *  TTI, const Triple &  TargetTriple  )

static

Definition at line 444 of file DwarfEHPrepare.cpp.

References F.

STATISTIC() [1/5]

STATISTIC	(	NumCleanupLandingPadsRemaining	,
		"Number of cleanup landing pads remaining"
	)

STATISTIC() [2/5]

STATISTIC	(	NumCleanupLandingPadsUnreachable	,
		"Number of cleanup landing pads found unreachable"
	)

STATISTIC() [3/5]

STATISTIC	(	NumNoUnwind	,
		"Number of functions with nounwind"
	)

STATISTIC() [4/5]

STATISTIC	(	NumResumesLowered	,
		"Number of resume calls lowered"
	)

STATISTIC() [5/5]

STATISTIC	(	NumUnwind	,
		"Number of functions with unwind"
	)

References F.

Variable Documentation

DEBUG_TYPE

DEBUG_TYPE

Definition at line 507 of file DwarfEHPrepare.cpp.

exceptions

Prepare DWARF exceptions

Definition at line 508 of file DwarfEHPrepare.cpp.

false

Prepare DWARF false

Definition at line 508 of file DwarfEHPrepare.cpp.