#include "BPF.h"
#include "BPFCORE.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsBPF.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"

Macros
#define	DEBUG_TYPE "bpf-preserve-static-offset"

Functions
static bool	isIntrinsicCall (Value *I, Intrinsic::ID Id)

static bool	isPreserveStaticOffsetCall (Value *I)

static CallInst *	isGEPAndLoad (Value *I)

static CallInst *	isGEPAndStore (Value *I)

template<class T = Instruction>
static DebugLoc	mergeDebugLocs (SmallVector< T * > &Insns)

static CallInst *	makeIntrinsicCall (Module M, Intrinsic::BPFIntrinsics Intrinsic, ArrayRef< Type > Types, ArrayRef< Value * > Args)

static void	setParamElementType (CallInst Call, unsigned ArgNo, Type Type)

static void	setParamReadNone (CallInst *Call, unsigned ArgNo)

static void	setParamReadOnly (CallInst *Call, unsigned ArgNo)

static void	setParamWriteOnly (CallInst *Call, unsigned ArgNo)

template<class T = std::disjunction<LoadInst, StoreInst>>
static void	fillCommonArgs (LLVMContext &C, SmallVector< Value * > &Args, GEPChainInfo &GEP, T *Insn)

static Instruction *	makeGEPAndLoad (Module M, GEPChainInfo &GEP, LoadInst Load)

static Instruction *	makeGEPAndStore (Module M, GEPChainInfo &GEP, StoreInst Store)

static unsigned	getOperandAsUnsigned (CallInst *Call, unsigned ArgNo)

static GetElementPtrInst *	reconstructGEP (CallInst *Call, int Delta)

template<class T = std::disjunction<LoadInst, StoreInst>>
static void	reconstructCommon (CallInst Call, GetElementPtrInst GEP, T *Insn, int Delta)

static bool	isZero (Value *V)

static bool	foldGEPChainAsStructAccess (SmallVector< GetElementPtrInst * > &GEPs, GEPChainInfo &Info)

static bool	foldGEPChainAsU8Access (SmallVector< GetElementPtrInst * > &GEPs, GEPChainInfo &Info)

static void	reportNonStaticGEPChain (Instruction *Insn)

static bool	allZeroIndices (SmallVector< GetElementPtrInst * > &GEPs)

static bool	tryToReplaceWithGEPBuiltin (Instruction LoadOrStoreTemplate, SmallVector< GetElementPtrInst > &GEPs, Instruction *InsnToReplace)

static bool	isPointerOperand (Value I, User U)

static bool	isInlineableCall (User *U)

static void	rewriteAccessChain (Instruction Insn, SmallVector< GetElementPtrInst > &GEPs, SmallVector< Instruction * > &Visited, bool AllowPatial, bool &StillUsed)

static void	rewriteUses (Instruction Insn, SmallVector< GetElementPtrInst > &GEPs, SmallVector< Instruction * > &Visited, bool AllowPatial, bool &StillUsed)

static void	removeMarkerCall (Instruction *Marker)

static bool	rewriteAccessChain (Instruction Marker, bool AllowPatial, SmallPtrSetImpl< Instruction > &RemovedMarkers)

static std::vector< Instruction * >	collectPreserveStaticOffsetCalls (Function &F)

bool	isPreserveArrayIndex (Value *V)

bool	isPreserveStructIndex (Value *V)

bool	isPreserveUnionIndex (Value *V)

static void	removePAICalls (Instruction *Marker)

static bool	rewriteFunction (Function &F, bool AllowPartial)

Variables
static const unsigned	GepAndLoadFirstIdxArg = 6

static const unsigned	GepAndStoreFirstIdxArg = 7

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "bpf-preserve-static-offset"

Definition at line 121 of file BPFPreserveStaticOffset.cpp.

Function Documentation

◆ allZeroIndices()

static bool allZeroIndices ( SmallVector< GetElementPtrInst * > & GEPs )

static

Definition at line 403 of file BPFPreserveStaticOffset.cpp.

References llvm::all_of(), llvm::SmallVectorBase< Size_T >::empty(), and GEP.

Referenced by rewriteAccessChain().

◆ collectPreserveStaticOffsetCalls()

static std::vector< Instruction * > collectPreserveStaticOffsetCalls ( Function & F )

static

Definition at line 589 of file BPFPreserveStaticOffset.cpp.

References F, instructions, and isPreserveStaticOffsetCall().

Referenced by rewriteFunction().

◆ fillCommonArgs()

template<class T = std::disjunction<LoadInst, StoreInst>>

static void fillCommonArgs	(	LLVMContext &	C,
		SmallVector< Value * > &	Args,
		GEPChainInfo &	GEP,
		T *	Insn
	)

static

Definition at line 207 of file BPFPreserveStaticOffset.cpp.

References llvm::CallingConv::C, GEP, llvm::Type::getInt1Ty(), llvm::Type::getInt8Ty(), and llvm::Log2_64().

Referenced by makeGEPAndLoad(), and makeGEPAndStore().

◆ foldGEPChainAsStructAccess()

static bool foldGEPChainAsStructAccess	(	SmallVector< GetElementPtrInst * > &	GEPs,
		GEPChainInfo &	Info
	)

static

Definition at line 329 of file BPFPreserveStaticOffset.cpp.

References llvm::all_of(), llvm::drop_begin(), llvm::SmallVectorBase< Size_T >::empty(), llvm::First, GEP, Info, and isZero().

Referenced by tryToReplaceWithGEPBuiltin().

◆ foldGEPChainAsU8Access()

static bool foldGEPChainAsU8Access	(	SmallVector< GetElementPtrInst * > &	GEPs,
		GEPChainInfo &	Info
	)

static

Definition at line 368 of file BPFPreserveStaticOffset.cpp.

References llvm::CallingConv::C, DL, llvm::SmallVectorBase< Size_T >::empty(), llvm::First, GEP, llvm::Type::getInt8Ty(), Info, and llvm::Offset.

Referenced by tryToReplaceWithGEPBuiltin().

◆ getOperandAsUnsigned()

static unsigned getOperandAsUnsigned	(	CallInst *	Call,
		unsigned	ArgNo
	)

static

Definition at line 265 of file BPFPreserveStaticOffset.cpp.

References Int, and llvm::report_fatal_error().

Referenced by reconstructCommon(), and reconstructGEP().

◆ isGEPAndLoad()

static CallInst * isGEPAndLoad ( Value * I )

static

Definition at line 139 of file BPFPreserveStaticOffset.cpp.

References I, and isIntrinsicCall().

Referenced by isPointerOperand(), and rewriteAccessChain().

◆ isGEPAndStore()

static CallInst * isGEPAndStore ( Value * I )

static

Definition at line 145 of file BPFPreserveStaticOffset.cpp.

References I, and isIntrinsicCall().

Referenced by isPointerOperand(), and rewriteAccessChain().

◆ isInlineableCall()

static bool isInlineableCall ( User * U )

static

Definition at line 445 of file BPFPreserveStaticOffset.cpp.

Referenced by rewriteAccessChain(), and rewriteUses().

◆ isIntrinsicCall()

static bool isIntrinsicCall	(	Value *	I,
		Intrinsic::ID	Id
	)

static

Definition at line 128 of file BPFPreserveStaticOffset.cpp.

References I.

Referenced by isGEPAndLoad(), isGEPAndStore(), and isPreserveStaticOffsetCall().

◆ isPointerOperand()

static bool isPointerOperand	(	Value *	I,
		User *	U
	)

static

Definition at line 431 of file BPFPreserveStaticOffset.cpp.

References GEP, I, isGEPAndLoad(), and isGEPAndStore().

Referenced by isInterestingPointerComparison(), isInterestingPointerSubtraction(), and rewriteUses().

◆ isPreserveArrayIndex()

bool isPreserveArrayIndex ( Value * V )

Definition at line 597 of file BPFPreserveStaticOffset.cpp.

References isIntrinsicCall().

Referenced by removePAICalls().

◆ isPreserveStaticOffsetCall()

static bool isPreserveStaticOffsetCall ( Value * I )

static

Definition at line 135 of file BPFPreserveStaticOffset.cpp.

References I, and isIntrinsicCall().

Referenced by collectPreserveStaticOffsetCalls(), removePAICalls(), rewriteAccessChain(), and rewriteUses().

◆ isPreserveStructIndex()

bool isPreserveStructIndex ( Value * V )

Definition at line 601 of file BPFPreserveStaticOffset.cpp.

References isIntrinsicCall().

Referenced by removePAICalls().

◆ isPreserveUnionIndex()

bool isPreserveUnionIndex ( Value * V )

Definition at line 605 of file BPFPreserveStaticOffset.cpp.

References isIntrinsicCall().

Referenced by removePAICalls().

◆ isZero()

static bool isZero ( Value * V )

static

Definition at line 321 of file BPFPreserveStaticOffset.cpp.

◆ makeGEPAndLoad()

static Instruction * makeGEPAndLoad	(	Module *	M,
		GEPChainInfo &	GEP,
		LoadInst *	Load
	)

static

Definition at line 222 of file BPFPreserveStaticOffset.cpp.

References fillCommonArgs(), GEP, GepAndLoadFirstIdxArg, I, makeIntrinsicCall(), mergeDebugLocs(), setParamElementType(), and setParamReadOnly().

Referenced by tryToReplaceWithGEPBuiltin().

◆ makeGEPAndStore()

static Instruction * makeGEPAndStore	(	Module *	M,
		GEPChainInfo &	GEP,
		StoreInst *	Store
	)

static

Definition at line 242 of file BPFPreserveStaticOffset.cpp.

References fillCommonArgs(), GEP, GepAndStoreFirstIdxArg, getType(), I, makeIntrinsicCall(), mergeDebugLocs(), setParamElementType(), setParamReadNone(), and setParamWriteOnly().

Referenced by tryToReplaceWithGEPBuiltin().

◆ makeIntrinsicCall()

static CallInst * makeIntrinsicCall	(	Module *	M,
		Intrinsic::BPFIntrinsics	Intrinsic,
		ArrayRef< Type * >	Types,
		ArrayRef< Value * >	Args
	)

static

Definition at line 159 of file BPFPreserveStaticOffset.cpp.

References llvm::CallInst::Create(), and llvm::Intrinsic::getOrInsertDeclaration().

Referenced by makeGEPAndLoad(), and makeGEPAndStore().

◆ mergeDebugLocs()

template<class T = Instruction>

static DebugLoc mergeDebugLocs ( SmallVector< T * > & Insns )

static

Definition at line 152 of file BPFPreserveStaticOffset.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::begin(), getDebugLoc(), llvm::DebugLoc::getMergedLocation(), and I.

Referenced by makeGEPAndLoad(), and makeGEPAndStore().

◆ reconstructCommon()

template<class T = std::disjunction<LoadInst, StoreInst>>

static void reconstructCommon	(	CallInst *	Call,
		GetElementPtrInst *	GEP,
		T *	Insn,
		int	Delta
	)

static

Definition at line 288 of file BPFPreserveStaticOffset.cpp.

References GEP, and getOperandAsUnsigned().

Referenced by llvm::BPFPreserveStaticOffsetPass::reconstructLoad(), and llvm::BPFPreserveStaticOffsetPass::reconstructStore().

◆ reconstructGEP()

static GetElementPtrInst * reconstructGEP	(	CallInst *	Call,
		int	Delta
	)

static

Definition at line 275 of file BPFPreserveStaticOffset.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::GetElementPtrInst::Create(), GEP, and getOperandAsUnsigned().

Referenced by llvm::BPFPreserveStaticOffsetPass::reconstructLoad(), and llvm::BPFPreserveStaticOffsetPass::reconstructStore().

◆ removeMarkerCall()

static void removeMarkerCall ( Instruction * Marker )

static

Definition at line 564 of file BPFPreserveStaticOffset.cpp.

References llvm::Instruction::eraseFromParent(), llvm::User::getOperand(), and llvm::Value::replaceAllUsesWith().

Referenced by rewriteAccessChain(), and rewriteFunction().

◆ removePAICalls()

static void removePAICalls ( Instruction * Marker )

static

Definition at line 609 of file BPFPreserveStaticOffset.cpp.

References llvm::SmallVectorBase< Size_T >::empty(), GEP, isPreserveArrayIndex(), isPreserveStaticOffsetCall(), isPreserveStructIndex(), isPreserveUnionIndex(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::BPFCoreSharedInfo::removeArrayAccessCall(), llvm::BPFCoreSharedInfo::removeStructAccessCall(), and llvm::BPFCoreSharedInfo::removeUnionAccessCall().

Referenced by rewriteFunction().

◆ reportNonStaticGEPChain()

static void reportNonStaticGEPChain ( Instruction * Insn )

static

Definition at line 392 of file BPFPreserveStaticOffset.cpp.

References llvm::concat(), llvm::LLVMContext::diagnose(), llvm::DS_Warning, llvm::Value::getContext(), llvm::Instruction::getDebugLoc(), and llvm::Instruction::getFunction().

Referenced by rewriteAccessChain().

◆ rewriteAccessChain() [1/2]

static void rewriteAccessChain	(	Instruction *	Insn,
		SmallVector< GetElementPtrInst * > &	GEPs,
		SmallVector< Instruction * > &	Visited,
		bool	AllowPatial,
		bool &	StillUsed
	)

static

Definition at line 497 of file BPFPreserveStaticOffset.cpp.

References allZeroIndices(), llvm::concat(), GEP, isGEPAndLoad(), isGEPAndStore(), isInlineableCall(), isPreserveStaticOffsetCall(), llvm::SmallVectorTemplateBase< T, bool >::pop_back(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::BPFPreserveStaticOffsetPass::reconstructLoad(), llvm::BPFPreserveStaticOffsetPass::reconstructStore(), llvm::report_fatal_error(), reportNonStaticGEPChain(), rewriteUses(), and tryToReplaceWithGEPBuiltin().

Referenced by rewriteFunction(), and rewriteUses().

◆ rewriteAccessChain() [2/2]

static bool rewriteAccessChain	(	Instruction *	Marker,
		bool	AllowPatial,
		SmallPtrSetImpl< Instruction * > &	RemovedMarkers
	)

static

Definition at line 569 of file BPFPreserveStaticOffset.cpp.

References llvm::SmallPtrSetImpl< PtrType >::insert(), isPreserveStaticOffsetCall(), llvm::SmallVectorTemplateCommon< T, typename >::rbegin(), removeMarkerCall(), llvm::SmallVectorTemplateCommon< T, typename >::rend(), and rewriteUses().

◆ rewriteFunction()

static bool rewriteFunction	(	Function &	F,
		bool	AllowPartial
	)

static

Definition at line 644 of file BPFPreserveStaticOffset.cpp.

References collectPreserveStaticOffsetCalls(), llvm::SmallPtrSetImpl< PtrType >::contains(), llvm::dbgs(), F, LLVM_DEBUG, removeMarkerCall(), removePAICalls(), and rewriteAccessChain().

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

◆ rewriteUses()

static void rewriteUses	(	Instruction *	Insn,
		SmallVector< GetElementPtrInst * > &	GEPs,
		SmallVector< Instruction * > &	Visited,
		bool	AllowPatial,
		bool &	StillUsed
	)