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llvm/bolt/include/bolt/Core/BinaryFunction.h
Vladislav Khmelevsky 425dda76e9 [BOLT][AArch64] Handle gold linker veneers 
The gold linker veneers are written between functions without symbols,
so we to handle it specially in BOLT.

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Differential Revision: https://reviews.llvm.org/D128082
2022-06-28 16:14:05 +03:00

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//===- bolt/Core/BinaryFunction.h - Low-level function ----------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the BinaryFunction class. It represents
// a function at the lowest IR level. Typically, a BinaryFunction represents a
// function object in a compiled and linked binary file. However, a
// BinaryFunction can also be constructed manually, e.g. for injecting into a
// binary file.
//
// A BinaryFunction could be in one of the several states described in
// BinaryFunction::State. While in the disassembled state, it will contain a
// list of instructions with their offsets. In the CFG state, it will contain a
// list of BinaryBasicBlocks that form a control-flow graph. This state is best
// suited for binary analysis and optimizations. However, sometimes it's
// impossible to build the precise CFG due to the ambiguity of indirect
// branches.
//
//===----------------------------------------------------------------------===//
#ifndef BOLT_CORE_BINARY_FUNCTION_H
#define BOLT_CORE_BINARY_FUNCTION_H
#include "bolt/Core/BinaryBasicBlock.h"
#include "bolt/Core/BinaryContext.h"
#include "bolt/Core/BinaryLoop.h"
#include "bolt/Core/BinarySection.h"
#include "bolt/Core/DebugData.h"
#include "bolt/Core/JumpTable.h"
#include "bolt/Core/MCPlus.h"
#include "bolt/Utils/NameResolver.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <limits>
#include <unordered_map>
#include <unordered_set>
#include <vector>
using namespace llvm::object;
namespace llvm {
class DWARFUnit;
namespace bolt {
using InputOffsetToAddressMapTy = std::unordered_multimap<uint64_t, uint64_t>;
/// Types of macro-fusion alignment corrections.
enum MacroFusionType { MFT_NONE, MFT_HOT, MFT_ALL };
enum IndirectCallPromotionType : char {
ICP_NONE, /// Don't perform ICP.
ICP_CALLS, /// Perform ICP on indirect calls.
ICP_JUMP_TABLES, /// Perform ICP on jump tables.
ICP_ALL /// Perform ICP on calls and jump tables.
};
/// Information on a single indirect call to a particular callee.
struct IndirectCallProfile {
MCSymbol *Symbol;
uint32_t Offset;
uint64_t Count;
uint64_t Mispreds;
IndirectCallProfile(MCSymbol *Symbol, uint64_t Count, uint64_t Mispreds,
uint32_t Offset = 0)
: Symbol(Symbol), Offset(Offset), Count(Count), Mispreds(Mispreds) {}
bool operator==(const IndirectCallProfile &Other) const {
return Symbol == Other.Symbol && Offset == Other.Offset;
}
};
/// Aggregated information for an indirect call site.
using IndirectCallSiteProfile = SmallVector<IndirectCallProfile, 4>;
inline raw_ostream &operator<<(raw_ostream &OS,
const bolt::IndirectCallSiteProfile &ICSP) {
std::string TempString;
raw_string_ostream SS(TempString);
const char *Sep = "\n ";
uint64_t TotalCount = 0;
uint64_t TotalMispreds = 0;
for (const IndirectCallProfile &CSP : ICSP) {
SS << Sep << "{ " << (CSP.Symbol ? CSP.Symbol->getName() : "<unknown>")
<< ": " << CSP.Count << " (" << CSP.Mispreds << " misses) }";
Sep = ",\n ";
TotalCount += CSP.Count;
TotalMispreds += CSP.Mispreds;
}
SS.flush();
OS << TotalCount << " (" << TotalMispreds << " misses) :" << TempString;
return OS;
}
/// BinaryFunction is a representation of machine-level function.
///
/// In the input binary, an instance of BinaryFunction can represent a fragment
/// of a function if the higher-level function was split, e.g. into hot and cold
/// parts. The fragment containing the main entry point is called a parent
/// or the main fragment.
class BinaryFunction {
public:
enum class State : char {
Empty = 0, /// Function body is empty.
Disassembled, /// Function have been disassembled.
CFG, /// Control flow graph has been built.
CFG_Finalized, /// CFG is finalized. No optimizations allowed.
EmittedCFG, /// Instructions have been emitted to output.
Emitted, /// Same as above plus CFG is destroyed.
};
/// Types of profile the function can use. Could be a combination.
enum {
PF_NONE = 0, /// No profile.
PF_LBR = 1, /// Profile is based on last branch records.
PF_SAMPLE = 2, /// Non-LBR sample-based profile.
PF_MEMEVENT = 4, /// Profile has mem events.
};
/// Struct for tracking exception handling ranges.
struct CallSite {
const MCSymbol *Start;
const MCSymbol *End;
const MCSymbol *LP;
uint64_t Action;
};
using CallSitesType = SmallVector<CallSite, 0>;
using IslandProxiesType =
std::map<BinaryFunction *, std::map<const MCSymbol *, MCSymbol *>>;
struct IslandInfo {
/// Temporary holder of offsets that are data markers (used in AArch)
/// It is possible to have data in code sections. To ease the identification
/// of data in code sections, the ABI requires the symbol table to have
/// symbols named "$d" identifying the start of data inside code and "$x"
/// identifying the end of a chunk of data inside code. DataOffsets contain
/// all offsets of $d symbols and CodeOffsets all offsets of $x symbols.
std::set<uint64_t> DataOffsets;
std::set<uint64_t> CodeOffsets;
/// List of relocations associated with data in the constant island
std::map<uint64_t, Relocation> Relocations;
/// Offsets in function that are data values in a constant island identified
/// after disassembling
std::map<uint64_t, MCSymbol *> Offsets;
SmallPtrSet<MCSymbol *, 4> Symbols;
DenseMap<const MCSymbol *, BinaryFunction *> ProxySymbols;
DenseMap<const MCSymbol *, MCSymbol *> ColdSymbols;
/// Keeps track of other functions we depend on because there is a reference
/// to the constant islands in them.
IslandProxiesType Proxies, ColdProxies;
SmallPtrSet<BinaryFunction *, 1> Dependency; // The other way around
mutable MCSymbol *FunctionConstantIslandLabel{nullptr};
mutable MCSymbol *FunctionColdConstantIslandLabel{nullptr};
// Returns constant island alignment
uint16_t getAlignment() const { return sizeof(uint64_t); }
};
static constexpr uint64_t COUNT_NO_PROFILE =
BinaryBasicBlock::COUNT_NO_PROFILE;
/// We have to use at least 2-byte alignment for functions because of C++ ABI.
static constexpr unsigned MinAlign = 2;
static const char TimerGroupName[];
static const char TimerGroupDesc[];
using BasicBlockOrderType = SmallVector<BinaryBasicBlock *, 0>;
/// Mark injected functions
bool IsInjected = false;
using LSDATypeTableTy = SmallVector<uint64_t, 0>;
/// List of DWARF CFI instructions. Original CFI from the binary must be
/// sorted w.r.t. offset that it appears. We rely on this to replay CFIs
/// if needed (to fix state after reordering BBs).
using CFIInstrMapType = SmallVector<MCCFIInstruction, 0>;
using cfi_iterator = CFIInstrMapType::iterator;
using const_cfi_iterator = CFIInstrMapType::const_iterator;
private:
/// Current state of the function.
State CurrentState{State::Empty};
/// A list of symbols associated with the function entry point.
///
/// Multiple symbols would typically result from identical code-folding
/// optimization.
typedef SmallVector<MCSymbol *, 1> SymbolListTy;
SymbolListTy Symbols;
/// The list of names this function is known under. Used for fuzzy-matching
/// the function to its name in a profile, command line, etc.
SmallVector<std::string, 0> Aliases;
/// Containing section in the input file.
BinarySection *OriginSection = nullptr;
/// Address of the function in memory. Also could be an offset from
/// base address for position independent binaries.
uint64_t Address;
/// Original size of the function.
uint64_t Size;
/// Address of the function in output.
uint64_t OutputAddress{0};
/// Size of the function in the output file.
uint64_t OutputSize{0};
/// Offset in the file.
uint64_t FileOffset{0};
/// Maximum size this function is allowed to have.
uint64_t MaxSize{std::numeric_limits<uint64_t>::max()};
/// Alignment requirements for the function.
uint16_t Alignment{2};
/// Maximum number of bytes used for alignment of hot part of the function.
uint16_t MaxAlignmentBytes{0};
/// Maximum number of bytes used for alignment of cold part of the function.
uint16_t MaxColdAlignmentBytes{0};
const MCSymbol *PersonalityFunction{nullptr};
uint8_t PersonalityEncoding{dwarf::DW_EH_PE_sdata4 | dwarf::DW_EH_PE_pcrel};
BinaryContext &BC;
std::unique_ptr<BinaryLoopInfo> BLI;
/// All labels in the function that are referenced via relocations from
/// data objects. Typically these are jump table destinations and computed
/// goto labels.
std::set<uint64_t> ExternallyReferencedOffsets;
/// Offsets of indirect branches with unknown destinations.
std::set<uint64_t> UnknownIndirectBranchOffsets;
/// A set of local and global symbols corresponding to secondary entry points.
/// Each additional function entry point has a corresponding entry in the map.
/// The key is a local symbol corresponding to a basic block and the value
/// is a global symbol corresponding to an external entry point.
DenseMap<const MCSymbol *, MCSymbol *> SecondaryEntryPoints;
/// False if the function is too complex to reconstruct its control
/// flow graph.
/// In relocation mode we still disassemble and re-assemble such functions.
bool IsSimple{true};
/// Indication that the function should be ignored for optimization purposes.
/// If we can skip emission of some functions, then ignored functions could
/// be not fully disassembled and will not be emitted.
bool IsIgnored{false};
/// Pseudo functions should not be disassembled or emitted.
bool IsPseudo{false};
/// True if the original function code has all necessary relocations to track
/// addresses of functions emitted to new locations. Typically set for
/// functions that we are not going to emit.
bool HasExternalRefRelocations{false};
/// True if the function has an indirect branch with unknown destination.
bool HasUnknownControlFlow{false};
/// The code from inside the function references one of the code locations
/// from the same function as a data, i.e. it's possible the label is used
/// inside an address calculation or could be referenced from outside.
bool HasInternalLabelReference{false};
/// In AArch64, preserve nops to maintain code equal to input (assuming no
/// optimizations are done).
bool PreserveNops{false};
/// Indicate if this function has associated exception handling metadata.
bool HasEHRanges{false};
/// True if the function uses DW_CFA_GNU_args_size CFIs.
bool UsesGnuArgsSize{false};
/// True if the function might have a profile available externally.
/// Used to check if processing of the function is required under certain
/// conditions.
bool HasProfileAvailable{false};
bool HasMemoryProfile{false};
/// Execution halts whenever this function is entered.
bool TrapsOnEntry{false};
/// True if the function had an indirect branch with a fixed internal
/// destination.
bool HasFixedIndirectBranch{false};
/// True if the function is a fragment of another function. This means that
/// this function could only be entered via its parent or one of its sibling
/// fragments. It could be entered at any basic block. It can also return
/// the control to any basic block of its parent or its sibling.
bool IsFragment{false};
/// Indicate that the function body has SDT marker
bool HasSDTMarker{false};
/// Indicate that the function body has Pseudo Probe
bool HasPseudoProbe{BC.getUniqueSectionByName(".pseudo_probe_desc") &&
BC.getUniqueSectionByName(".pseudo_probe")};
/// True if the original entry point was patched.
bool IsPatched{false};
/// True if the function contains jump table with entries pointing to
/// locations in fragments.
bool HasSplitJumpTable{false};
/// True if there are no control-flow edges with successors in other functions
/// (i.e. if tail calls have edges to function-local basic blocks).
/// Set to false by SCTC. Dynostats can't be reliably computed for
/// functions with non-canonical CFG.
/// This attribute is only valid when hasCFG() == true.
bool HasCanonicalCFG{true};
/// The address for the code for this function in codegen memory.
/// Used for functions that are emitted in a dedicated section with a fixed
/// address. E.g. for functions that are overwritten in-place.
uint64_t ImageAddress{0};
/// The size of the code in memory.
uint64_t ImageSize{0};
/// Name for the section this function code should reside in.
std::string CodeSectionName;
/// Name for the corresponding cold code section.
std::string ColdCodeSectionName;
/// Parent function fragment for split function fragments.
SmallPtrSet<BinaryFunction *, 1> ParentFragments;
/// Indicate if the function body was folded into another function.
/// Used by ICF optimization.
BinaryFunction *FoldedIntoFunction{nullptr};
/// All fragments for a parent function.
SmallPtrSet<BinaryFunction *, 1> Fragments;
/// The profile data for the number of times the function was executed.
uint64_t ExecutionCount{COUNT_NO_PROFILE};
/// Profile match ratio.
float ProfileMatchRatio{0.0f};
/// Raw branch count for this function in the profile
uint64_t RawBranchCount{0};
/// Indicates the type of profile the function is using.
uint16_t ProfileFlags{PF_NONE};
/// For functions with mismatched profile we store all call profile
/// information at a function level (as opposed to tying it to
/// specific call sites).
IndirectCallSiteProfile AllCallSites;
/// Score of the function (estimated number of instructions executed,
/// according to profile data). -1 if the score has not been calculated yet.
mutable int64_t FunctionScore{-1};
/// Original LSDA address for the function.
uint64_t LSDAAddress{0};
/// Containing compilation unit for the function.
DWARFUnit *DwarfUnit{nullptr};
/// Last computed hash value. Note that the value could be recomputed using
/// different parameters by every pass.
mutable uint64_t Hash{0};
/// For PLT functions it contains a symbol associated with a function
/// reference. It is nullptr for non-PLT functions.
const MCSymbol *PLTSymbol{nullptr};
/// Function order for streaming into the destination binary.
uint32_t Index{-1U};
/// Get basic block index assuming it belongs to this function.
unsigned getIndex(const BinaryBasicBlock *BB) const {
assert(BB->getIndex() < BasicBlocks.size());
return BB->getIndex();
}
/// Return basic block that originally contained offset \p Offset
/// from the function start.
BinaryBasicBlock *getBasicBlockContainingOffset(uint64_t Offset);
const BinaryBasicBlock *getBasicBlockContainingOffset(uint64_t Offset) const {
return const_cast<BinaryFunction *>(this)->getBasicBlockContainingOffset(
Offset);
}
/// Return basic block that started at offset \p Offset.
BinaryBasicBlock *getBasicBlockAtOffset(uint64_t Offset) {
BinaryBasicBlock *BB = getBasicBlockContainingOffset(Offset);
return BB && BB->getOffset() == Offset ? BB : nullptr;
}
/// Release memory taken by the list.
template <typename T> BinaryFunction &clearList(T &List) {
T TempList;
TempList.swap(List);
return *this;
}
/// Update the indices of all the basic blocks starting at StartIndex.
void updateBBIndices(const unsigned StartIndex);
/// Annotate each basic block entry with its current CFI state. This is
/// run right after the construction of CFG while basic blocks are in their
/// original order.
void annotateCFIState();
/// Associate DW_CFA_GNU_args_size info with invoke instructions
/// (call instructions with non-empty landing pad).
void propagateGnuArgsSizeInfo(MCPlusBuilder::AllocatorIdTy AllocId);
/// Synchronize branch instructions with CFG.
void postProcessBranches();
/// The address offset where we emitted the constant island, that is, the
/// chunk of data in the function code area (AArch only)
int64_t OutputDataOffset{0};
int64_t OutputColdDataOffset{0};
/// Map labels to corresponding basic blocks.
DenseMap<const MCSymbol *, BinaryBasicBlock *> LabelToBB;
using BranchListType = SmallVector<std::pair<uint32_t, uint32_t>, 0>;
BranchListType TakenBranches; /// All local taken branches.
BranchListType IgnoredBranches; /// Branches ignored by CFG purposes.
/// Map offset in the function to a label.
/// Labels are used for building CFG for simple functions. For non-simple
/// function in relocation mode we need to emit them for relocations
/// referencing function internals to work (e.g. jump tables).
using LabelsMapType = std::map<uint32_t, MCSymbol *>;
LabelsMapType Labels;
/// Temporary holder of instructions before CFG is constructed.
/// Map offset in the function to MCInst.
using InstrMapType = std::map<uint32_t, MCInst>;
InstrMapType Instructions;
/// We don't decode Call Frame Info encoded in DWARF program state
/// machine. Instead we define a "CFI State" - a frame information that
/// is a result of executing FDE CFI program up to a given point. The
/// program consists of opaque Call Frame Instructions:
///
/// CFI #0
/// CFI #1
/// ....
/// CFI #N
///
/// When we refer to "CFI State K" - it corresponds to a row in an abstract
/// Call Frame Info table. This row is reached right before executing CFI #K.
///
/// At any point of execution in a function we are in any one of (N + 2)
/// states described in the original FDE program. We can't have more states
/// without intelligent processing of CFIs.
///
/// When the final layout of basic blocks is known, and we finalize CFG,
/// we modify the original program to make sure the same state could be
/// reached even when basic blocks containing CFI instructions are executed
/// in a different order.
CFIInstrMapType FrameInstructions;
/// A map of restore state CFI instructions to their equivalent CFI
/// instructions that produce the same state, in order to eliminate
/// remember-restore CFI instructions when rewriting CFI.
DenseMap<int32_t, SmallVector<int32_t, 4>> FrameRestoreEquivalents;
// For tracking exception handling ranges.
CallSitesType CallSites;
CallSitesType ColdCallSites;
/// Binary blobs representing action, type, and type index tables for this
/// function' LSDA (exception handling).
ArrayRef<uint8_t> LSDAActionTable;
ArrayRef<uint8_t> LSDATypeIndexTable;
/// Vector of addresses of types referenced by LSDA.
LSDATypeTableTy LSDATypeTable;
/// Vector of addresses of entries in LSDATypeTable used for indirect
/// addressing.
LSDATypeTableTy LSDATypeAddressTable;
/// Marking for the beginning of language-specific data area for the function.
MCSymbol *LSDASymbol{nullptr};
MCSymbol *ColdLSDASymbol{nullptr};
/// Map to discover which CFIs are attached to a given instruction offset.
/// Maps an instruction offset into a FrameInstructions offset.
/// This is only relevant to the buildCFG phase and is discarded afterwards.
std::multimap<uint32_t, uint32_t> OffsetToCFI;
/// List of CFI instructions associated with the CIE (common to more than one
/// function and that apply before the entry basic block).
CFIInstrMapType CIEFrameInstructions;
/// All compound jump tables for this function. This duplicates what's stored
/// in the BinaryContext, but additionally it gives quick access for all
/// jump tables used by this function.
///
/// <OriginalAddress> -> <JumpTable *>
std::map<uint64_t, JumpTable *> JumpTables;
/// All jump table sites in the function before CFG is built.
SmallVector<std::pair<uint64_t, uint64_t>, 0> JTSites;
/// List of relocations in this function.
std::map<uint64_t, Relocation> Relocations;
/// Information on function constant islands.
std::unique_ptr<IslandInfo> Islands;
// Blocks are kept sorted in the layout order. If we need to change the
// layout (if BasicBlocksLayout stores a different order than BasicBlocks),
// the terminating instructions need to be modified.
using BasicBlockListType = SmallVector<BinaryBasicBlock *, 0>;
BasicBlockListType BasicBlocks;
BasicBlockListType DeletedBasicBlocks;
BasicBlockOrderType BasicBlocksLayout;
/// Previous layout replaced by modifyLayout
BasicBlockOrderType BasicBlocksPreviousLayout;
bool ModifiedLayout{false};
/// BasicBlockOffsets are used during CFG construction to map from code
/// offsets to BinaryBasicBlocks. Any modifications made to the CFG
/// after initial construction are not reflected in this data structure.
using BasicBlockOffset = std::pair<uint64_t, BinaryBasicBlock *>;
struct CompareBasicBlockOffsets {
bool operator()(const BasicBlockOffset &A,
const BasicBlockOffset &B) const {
return A.first < B.first;
}
};
SmallVector<BasicBlockOffset, 0> BasicBlockOffsets;
MCSymbol *ColdSymbol{nullptr};
/// Symbol at the end of the function.
mutable MCSymbol *FunctionEndLabel{nullptr};
/// Symbol at the end of the cold part of split function.
mutable MCSymbol *FunctionColdEndLabel{nullptr};
/// Unique number associated with the function.
uint64_t FunctionNumber;
/// Count the number of functions created.
static uint64_t Count;
/// Map offsets of special instructions to addresses in the output.
InputOffsetToAddressMapTy InputOffsetToAddressMap;
/// Register alternative function name.
void addAlternativeName(std::string NewName) {
Aliases.push_back(std::move(NewName));
}
/// Return a label at a given \p Address in the function. If the label does
/// not exist - create it. Assert if the \p Address does not belong to
/// the function. If \p CreatePastEnd is true, then return the function
/// end label when the \p Address points immediately past the last byte
/// of the function.
/// NOTE: the function always returns a local (temp) symbol, even if there's
/// a global symbol that corresponds to an entry at this address.
MCSymbol *getOrCreateLocalLabel(uint64_t Address, bool CreatePastEnd = false);
/// Register an data entry at a given \p Offset into the function.
void markDataAtOffset(uint64_t Offset) {
if (!Islands)
Islands = std::make_unique<IslandInfo>();
Islands->DataOffsets.emplace(Offset);
}
/// Register an entry point at a given \p Offset into the function.
void markCodeAtOffset(uint64_t Offset) {
if (!Islands)
Islands = std::make_unique<IslandInfo>();
Islands->CodeOffsets.emplace(Offset);
}
/// Register secondary entry point at a given \p Offset into the function.
/// Return global symbol for use by extern function references.
MCSymbol *addEntryPointAtOffset(uint64_t Offset);
/// Register an internal offset in a function referenced from outside.
void registerReferencedOffset(uint64_t Offset) {
ExternallyReferencedOffsets.emplace(Offset);
}
/// True if there are references to internals of this function from data,
/// e.g. from jump tables.
bool hasInternalReference() const {
return !ExternallyReferencedOffsets.empty();
}
/// Return an entry ID corresponding to a symbol known to belong to
/// the function.
///
/// Prefer to use BinaryContext::getFunctionForSymbol(EntrySymbol, &ID)
/// instead of calling this function directly.
uint64_t getEntryIDForSymbol(const MCSymbol *EntrySymbol) const;
/// If the function represents a secondary split function fragment, set its
/// parent fragment to \p BF.
void addParentFragment(BinaryFunction &BF) {
assert(this != &BF);
assert(IsFragment && "function must be a fragment to have a parent");
ParentFragments.insert(&BF);
}
/// Register a child fragment for the main fragment of a split function.
void addFragment(BinaryFunction &BF) {
assert(this != &BF);
Fragments.insert(&BF);
}
void addInstruction(uint64_t Offset, MCInst &&Instruction) {
Instructions.emplace(Offset, std::forward<MCInst>(Instruction));
}
/// Convert CFI instructions to a standard form (remove remember/restore).
void normalizeCFIState();
/// Analyze and process indirect branch \p Instruction before it is
/// added to Instructions list.
IndirectBranchType processIndirectBranch(MCInst &Instruction, unsigned Size,
uint64_t Offset,
uint64_t &TargetAddress);
BinaryFunction &operator=(const BinaryFunction &) = delete;
BinaryFunction(const BinaryFunction &) = delete;
friend class MachORewriteInstance;
friend class RewriteInstance;
friend class BinaryContext;
friend class DataReader;
friend class DataAggregator;
static std::string buildCodeSectionName(StringRef Name,
const BinaryContext &BC);
static std::string buildColdCodeSectionName(StringRef Name,
const BinaryContext &BC);
/// Creation should be handled by RewriteInstance or BinaryContext
BinaryFunction(const std::string &Name, BinarySection &Section,
uint64_t Address, uint64_t Size, BinaryContext &BC)
: OriginSection(&Section), Address(Address), Size(Size), BC(BC),
CodeSectionName(buildCodeSectionName(Name, BC)),
ColdCodeSectionName(buildColdCodeSectionName(Name, BC)),
FunctionNumber(++Count) {
Symbols.push_back(BC.Ctx->getOrCreateSymbol(Name));
}
/// This constructor is used to create an injected function
BinaryFunction(const std::string &Name, BinaryContext &BC, bool IsSimple)
: Address(0), Size(0), BC(BC), IsSimple(IsSimple),
CodeSectionName(buildCodeSectionName(Name, BC)),
ColdCodeSectionName(buildColdCodeSectionName(Name, BC)),
FunctionNumber(++Count) {
Symbols.push_back(BC.Ctx->getOrCreateSymbol(Name));
IsInjected = true;
}
/// Create a basic block at a given \p Offset in the function and append it
/// to the end of list of blocks. Used during CFG construction only.
BinaryBasicBlock *addBasicBlockAt(uint64_t Offset, MCSymbol *Label) {
assert(CurrentState == State::Disassembled &&
"Cannot add block with an offset in non-disassembled state.");
assert(!getBasicBlockAtOffset(Offset) &&
"Basic block already exists at the offset.");
BasicBlocks.emplace_back(createBasicBlock(Label).release());
BinaryBasicBlock *BB = BasicBlocks.back();
BB->setIndex(BasicBlocks.size() - 1);
BB->setOffset(Offset);
BasicBlockOffsets.emplace_back(Offset, BB);
assert(llvm::is_sorted(BasicBlockOffsets, CompareBasicBlockOffsets()) &&
llvm::is_sorted(blocks()));
return BB;
}
/// Clear state of the function that could not be disassembled or if its
/// disassembled state was later invalidated.
void clearDisasmState();
/// Release memory allocated for CFG and instructions.
/// We still keep basic blocks for address translation/mapping purposes.
void releaseCFG() {
for (BinaryBasicBlock *BB : BasicBlocks)
BB->releaseCFG();
for (BinaryBasicBlock *BB : DeletedBasicBlocks)
BB->releaseCFG();
clearList(CallSites);
clearList(ColdCallSites);
clearList(LSDATypeTable);
clearList(LSDATypeAddressTable);
clearList(LabelToBB);
if (!isMultiEntry())
clearList(Labels);
clearList(FrameInstructions);
clearList(FrameRestoreEquivalents);
}
public:
BinaryFunction(BinaryFunction &&) = default;
using iterator = pointee_iterator<BasicBlockListType::iterator>;
using const_iterator = pointee_iterator<BasicBlockListType::const_iterator>;
using reverse_iterator =
pointee_iterator<BasicBlockListType::reverse_iterator>;
using const_reverse_iterator =
pointee_iterator<BasicBlockListType::const_reverse_iterator>;
typedef BasicBlockOrderType::iterator order_iterator;
typedef BasicBlockOrderType::const_iterator const_order_iterator;
typedef BasicBlockOrderType::reverse_iterator reverse_order_iterator;
typedef BasicBlockOrderType::const_reverse_iterator
const_reverse_order_iterator;
// CFG iterators.
iterator begin() { return BasicBlocks.begin(); }
const_iterator begin() const { return BasicBlocks.begin(); }
iterator end () { return BasicBlocks.end(); }
const_iterator end () const { return BasicBlocks.end(); }
reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
reverse_iterator rend () { return BasicBlocks.rend(); }
const_reverse_iterator rend () const { return BasicBlocks.rend(); }
size_t size() const { return BasicBlocks.size();}
bool empty() const { return BasicBlocks.empty(); }
const BinaryBasicBlock &front() const { return *BasicBlocks.front(); }
BinaryBasicBlock &front() { return *BasicBlocks.front(); }
const BinaryBasicBlock & back() const { return *BasicBlocks.back(); }
BinaryBasicBlock & back() { return *BasicBlocks.back(); }
inline iterator_range<iterator> blocks() {
return iterator_range<iterator>(begin(), end());
}
inline iterator_range<const_iterator> blocks() const {
return iterator_range<const_iterator>(begin(), end());
}
// Iterators by pointer.
BasicBlockListType::iterator pbegin() { return BasicBlocks.begin(); }
BasicBlockListType::iterator pend() { return BasicBlocks.end(); }
order_iterator layout_begin() { return BasicBlocksLayout.begin(); }
const_order_iterator layout_begin() const
{ return BasicBlocksLayout.begin(); }
order_iterator layout_end() { return BasicBlocksLayout.end(); }
const_order_iterator layout_end() const
{ return BasicBlocksLayout.end(); }
reverse_order_iterator layout_rbegin()
{ return BasicBlocksLayout.rbegin(); }
const_reverse_order_iterator layout_rbegin() const
{ return BasicBlocksLayout.rbegin(); }
reverse_order_iterator layout_rend()
{ return BasicBlocksLayout.rend(); }
const_reverse_order_iterator layout_rend() const
{ return BasicBlocksLayout.rend(); }
size_t layout_size() const { return BasicBlocksLayout.size(); }
bool layout_empty() const { return BasicBlocksLayout.empty(); }
const BinaryBasicBlock *layout_front() const
{ return BasicBlocksLayout.front(); }
BinaryBasicBlock *layout_front() { return BasicBlocksLayout.front(); }
const BinaryBasicBlock *layout_back() const
{ return BasicBlocksLayout.back(); }
BinaryBasicBlock *layout_back() { return BasicBlocksLayout.back(); }
inline iterator_range<order_iterator> layout() {
return iterator_range<order_iterator>(BasicBlocksLayout.begin(),
BasicBlocksLayout.end());
}
inline iterator_range<const_order_iterator> layout() const {
return iterator_range<const_order_iterator>(BasicBlocksLayout.begin(),
BasicBlocksLayout.end());
}
inline iterator_range<reverse_order_iterator> rlayout() {
return iterator_range<reverse_order_iterator>(BasicBlocksLayout.rbegin(),
BasicBlocksLayout.rend());
}
inline iterator_range<const_reverse_order_iterator> rlayout() const {
return iterator_range<const_reverse_order_iterator>(
BasicBlocksLayout.rbegin(), BasicBlocksLayout.rend());
}
cfi_iterator cie_begin() { return CIEFrameInstructions.begin(); }
const_cfi_iterator cie_begin() const { return CIEFrameInstructions.begin(); }
cfi_iterator cie_end() { return CIEFrameInstructions.end(); }
const_cfi_iterator cie_end() const { return CIEFrameInstructions.end(); }
bool cie_empty() const { return CIEFrameInstructions.empty(); }
inline iterator_range<cfi_iterator> cie() {
return iterator_range<cfi_iterator>(cie_begin(), cie_end());
}
inline iterator_range<const_cfi_iterator> cie() const {
return iterator_range<const_cfi_iterator>(cie_begin(), cie_end());
}
/// Iterate over all jump tables associated with this function.
iterator_range<std::map<uint64_t, JumpTable *>::const_iterator>
jumpTables() const {
return make_range(JumpTables.begin(), JumpTables.end());
}
/// Return relocation associated with a given \p Offset in the function,
/// or nullptr if no such relocation exists.
const Relocation *getRelocationAt(uint64_t Offset) const {
assert(CurrentState == State::Empty &&
"Relocations unavailable in the current function state.");
auto RI = Relocations.find(Offset);
return (RI == Relocations.end()) ? nullptr : &RI->second;
}
/// Return the first relocation in the function that starts at an address in
/// the [StartOffset, EndOffset) range. Return nullptr if no such relocation
/// exists.
const Relocation *getRelocationInRange(uint64_t StartOffset,
uint64_t EndOffset) const {
assert(CurrentState == State::Empty &&
"Relocations unavailable in the current function state.");
auto RI = Relocations.lower_bound(StartOffset);
if (RI != Relocations.end() && RI->first < EndOffset)
return &RI->second;
return nullptr;
}
/// Returns the raw binary encoding of this function.
ErrorOr<ArrayRef<uint8_t>> getData() const;
BinaryFunction &updateState(BinaryFunction::State State) {
CurrentState = State;
return *this;
}
/// Update layout of basic blocks used for output.
void updateBasicBlockLayout(BasicBlockOrderType &NewLayout) {
BasicBlocksPreviousLayout = BasicBlocksLayout;
if (NewLayout != BasicBlocksLayout) {
ModifiedLayout = true;
BasicBlocksLayout.clear();
BasicBlocksLayout.swap(NewLayout);
}
}
/// Recompute landing pad information for the function and all its blocks.
void recomputeLandingPads();
/// Return current basic block layout.
const BasicBlockOrderType &getLayout() const { return BasicBlocksLayout; }
/// Return a list of basic blocks sorted using DFS and update layout indices
/// using the same order. Does not modify the current layout.
BasicBlockOrderType dfs() const;
/// Find the loops in the CFG of the function and store information about
/// them.
void calculateLoopInfo();
/// Calculate missed macro-fusion opportunities and update BinaryContext
/// stats.
void calculateMacroOpFusionStats();
/// Returns if loop detection has been run for this function.
bool hasLoopInfo() const { return BLI != nullptr; }
const BinaryLoopInfo &getLoopInfo() { return *BLI.get(); }
bool isLoopFree() {
if (!hasLoopInfo())
calculateLoopInfo();
return BLI->empty();
}
/// Print loop information about the function.
void printLoopInfo(raw_ostream &OS) const;
/// View CFG in graphviz program
void viewGraph() const;
/// Dump CFG in graphviz format
void dumpGraph(raw_ostream &OS) const;
/// Dump CFG in graphviz format to file.
void dumpGraphToFile(std::string Filename) const;
/// Dump CFG in graphviz format to a file with a filename that is derived
/// from the function name and Annotation strings. Useful for dumping the
/// CFG after an optimization pass.
void dumpGraphForPass(std::string Annotation = "") const;
/// Return BinaryContext for the function.
const BinaryContext &getBinaryContext() const { return BC; }
/// Return BinaryContext for the function.
BinaryContext &getBinaryContext() { return BC; }
/// Attempt to validate CFG invariants.
bool validateCFG() const;
BinaryBasicBlock *getBasicBlockForLabel(const MCSymbol *Label) {
auto I = LabelToBB.find(Label);
return I == LabelToBB.end() ? nullptr : I->second;
}
const BinaryBasicBlock *getBasicBlockForLabel(const MCSymbol *Label) const {
auto I = LabelToBB.find(Label);
return I == LabelToBB.end() ? nullptr : I->second;
}
/// Returns the basic block after the given basic block in the layout or
/// nullptr the last basic block is given.
const BinaryBasicBlock *getBasicBlockAfter(const BinaryBasicBlock *BB,
bool IgnoreSplits = true) const {
return const_cast<BinaryFunction *>(this)->getBasicBlockAfter(BB,
IgnoreSplits);
}
BinaryBasicBlock *getBasicBlockAfter(const BinaryBasicBlock *BB,
bool IgnoreSplits = true) {
for (auto I = layout_begin(), E = layout_end(); I != E; ++I) {
auto Next = std::next(I);
if (*I == BB && Next != E) {
return (IgnoreSplits || (*I)->isCold() == (*Next)->isCold()) ? *Next
: nullptr;
}
}
return nullptr;
}
/// Retrieve the landing pad BB associated with invoke instruction \p Invoke
/// that is in \p BB. Return nullptr if none exists
BinaryBasicBlock *getLandingPadBBFor(const BinaryBasicBlock &BB,
const MCInst &InvokeInst) const {
assert(BC.MIB->isInvoke(InvokeInst) && "must be invoke instruction");
const Optional<MCPlus::MCLandingPad> LP = BC.MIB->getEHInfo(InvokeInst);
if (LP && LP->first) {
BinaryBasicBlock *LBB = BB.getLandingPad(LP->first);
assert(LBB && "Landing pad should be defined");
return LBB;
}
return nullptr;
}
/// Return instruction at a given offset in the function. Valid before
/// CFG is constructed or while instruction offsets are available in CFG.
MCInst *getInstructionAtOffset(uint64_t Offset);
const MCInst *getInstructionAtOffset(uint64_t Offset) const {
return const_cast<BinaryFunction *>(this)->getInstructionAtOffset(Offset);
}
/// Return offset for the first instruction. If there is data at the
/// beginning of a function then offset of the first instruction could
/// be different from 0
uint64_t getFirstInstructionOffset() const {
if (Instructions.empty())
return 0;
return Instructions.begin()->first;
}
/// Return jump table that covers a given \p Address in memory.
JumpTable *getJumpTableContainingAddress(uint64_t Address) {
auto JTI = JumpTables.upper_bound(Address);
if (JTI == JumpTables.begin())
return nullptr;
--JTI;
if (JTI->first + JTI->second->getSize() > Address)
return JTI->second;
if (JTI->second->getSize() == 0 && JTI->first == Address)
return JTI->second;
return nullptr;
}
const JumpTable *getJumpTableContainingAddress(uint64_t Address) const {
return const_cast<BinaryFunction *>(this)->getJumpTableContainingAddress(
Address);
}
/// Return the name of the function if the function has just one name.
/// If the function has multiple names - return one followed
/// by "(*#<numnames>)".
///
/// We should use getPrintName() for diagnostics and use
/// hasName() to match function name against a given string.
///
/// NOTE: for disambiguating names of local symbols we use the following
/// naming schemes:
/// primary: <function>/<id>
/// alternative: <function>/<file>/<id2>
std::string getPrintName() const {
const size_t NumNames = Symbols.size() + Aliases.size();
return NumNames == 1
? getOneName().str()
: (getOneName().str() + "(*" + std::to_string(NumNames) + ")");
}
/// The function may have many names. For that reason, we avoid having
/// getName() method as most of the time the user needs a different
/// interface, such as forEachName(), hasName(), hasNameRegex(), etc.
/// In some cases though, we need just a name uniquely identifying
/// the function, and that's what this method is for.
StringRef getOneName() const { return Symbols[0]->getName(); }
/// Return the name of the function as getPrintName(), but also trying
/// to demangle it.
std::string getDemangledName() const;
/// Call \p Callback for every name of this function as long as the Callback
/// returns false. Stop if Callback returns true or all names have been used.
/// Return the name for which the Callback returned true if any.
template <typename FType>
Optional<StringRef> forEachName(FType Callback) const {
for (MCSymbol *Symbol : Symbols)
if (Callback(Symbol->getName()))
return Symbol->getName();
for (const std::string &Name : Aliases)
if (Callback(StringRef(Name)))
return StringRef(Name);
return NoneType();
}
/// Check if (possibly one out of many) function name matches the given
/// string. Use this member function instead of direct name comparison.
bool hasName(const std::string &FunctionName) const {
auto Res =
forEachName([&](StringRef Name) { return Name == FunctionName; });
return Res.hasValue();
}
/// Check if any of function names matches the given regex.
Optional<StringRef> hasNameRegex(const StringRef NameRegex) const;
/// Check if any of restored function names matches the given regex.
/// Restored name means stripping BOLT-added suffixes like "/1",
Optional<StringRef> hasRestoredNameRegex(const StringRef NameRegex) const;
/// Return a vector of all possible names for the function.
const std::vector<StringRef> getNames() const {
std::vector<StringRef> AllNames;
forEachName([&AllNames](StringRef Name) {
AllNames.push_back(Name);
return false;
});
return AllNames;
}
/// Return a state the function is in (see BinaryFunction::State definition
/// for description).
State getState() const { return CurrentState; }
/// Return true if function has a control flow graph available.
bool hasCFG() const {
return getState() == State::CFG || getState() == State::CFG_Finalized ||
getState() == State::EmittedCFG;
}
/// Return true if the function state implies that it includes instructions.
bool hasInstructions() const {
return getState() == State::Disassembled || hasCFG();
}
bool isEmitted() const {
return getState() == State::EmittedCFG || getState() == State::Emitted;
}
/// Return the section in the input binary this function originated from or
/// nullptr if the function did not originate from the file.
BinarySection *getOriginSection() const { return OriginSection; }
void setOriginSection(BinarySection *Section) { OriginSection = Section; }
/// Return true if the function did not originate from the primary input file.
bool isInjected() const { return IsInjected; }
/// Return original address of the function (or offset from base for PIC).
uint64_t getAddress() const { return Address; }
uint64_t getOutputAddress() const { return OutputAddress; }
uint64_t getOutputSize() const { return OutputSize; }
/// Does this function have a valid streaming order index?
bool hasValidIndex() const { return Index != -1U; }
/// Get the streaming order index for this function.
uint32_t getIndex() const { return Index; }
/// Set the streaming order index for this function.
void setIndex(uint32_t Idx) {
assert(!hasValidIndex());
Index = Idx;
}
/// Return offset of the function body in the binary file.
uint64_t getFileOffset() const { return FileOffset; }
/// Return (original) byte size of the function.
uint64_t getSize() const { return Size; }
/// Return the maximum size the body of the function could have.
uint64_t getMaxSize() const { return MaxSize; }
/// Return the number of emitted instructions for this function.
uint32_t getNumNonPseudos() const {
uint32_t N = 0;
for (BinaryBasicBlock *const &BB : layout())
N += BB->getNumNonPseudos();
return N;
}
/// Return MC symbol associated with the function.
/// All references to the function should use this symbol.
MCSymbol *getSymbol() { return Symbols[0]; }
/// Return MC symbol associated with the function (const version).
/// All references to the function should use this symbol.
const MCSymbol *getSymbol() const { return Symbols[0]; }
/// Return a list of symbols associated with the main entry of the function.
SymbolListTy &getSymbols() { return Symbols; }
const SymbolListTy &getSymbols() const { return Symbols; }
/// If a local symbol \p BBLabel corresponds to a basic block that is a
/// secondary entry point into the function, then return a global symbol
/// that represents the secondary entry point. Otherwise return nullptr.
MCSymbol *getSecondaryEntryPointSymbol(const MCSymbol *BBLabel) const {
auto I = SecondaryEntryPoints.find(BBLabel);
if (I == SecondaryEntryPoints.end())
return nullptr;
return I->second;
}
/// If the basic block serves as a secondary entry point to the function,
/// return a global symbol representing the entry. Otherwise return nullptr.
MCSymbol *getSecondaryEntryPointSymbol(const BinaryBasicBlock &BB) const {
return getSecondaryEntryPointSymbol(BB.getLabel());
}
/// Return true if the basic block is an entry point into the function
/// (either primary or secondary).
bool isEntryPoint(const BinaryBasicBlock &BB) const {
if (&BB == BasicBlocks.front())
return true;
return getSecondaryEntryPointSymbol(BB);
}
/// Return MC symbol corresponding to an enumerated entry for multiple-entry
/// functions.
MCSymbol *getSymbolForEntryID(uint64_t EntryNum);
const MCSymbol *getSymbolForEntryID(uint64_t EntryNum) const {
return const_cast<BinaryFunction *>(this)->getSymbolForEntryID(EntryNum);
}
using EntryPointCallbackTy = function_ref<bool(uint64_t, const MCSymbol *)>;
/// Invoke \p Callback function for every entry point in the function starting
/// with the main entry and using entries in the ascending address order.
/// Stop calling the function after false is returned by the callback.
///
/// Pass an offset of the entry point in the input binary and a corresponding
/// global symbol to the callback function.
///
/// Return true of all callbacks returned true, false otherwise.
bool forEachEntryPoint(EntryPointCallbackTy Callback) const;
MCSymbol *getColdSymbol() {
if (ColdSymbol)
return ColdSymbol;
ColdSymbol = BC.Ctx->getOrCreateSymbol(
NameResolver::append(getSymbol()->getName(), ".cold.0"));
return ColdSymbol;
}
/// Return MC symbol associated with the end of the function.
MCSymbol *getFunctionEndLabel() const {
assert(BC.Ctx && "cannot be called with empty context");
if (!FunctionEndLabel) {
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
FunctionEndLabel = BC.Ctx->createNamedTempSymbol("func_end");
}
return FunctionEndLabel;
}
/// Return MC symbol associated with the end of the cold part of the function.
MCSymbol *getFunctionColdEndLabel() const {
if (!FunctionColdEndLabel) {
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
FunctionColdEndLabel = BC.Ctx->createNamedTempSymbol("func_cold_end");
}
return FunctionColdEndLabel;
}
/// Return a label used to identify where the constant island was emitted
/// (AArch only). This is used to update the symbol table accordingly,
/// emitting data marker symbols as required by the ABI.
MCSymbol *getFunctionConstantIslandLabel() const {
assert(Islands && "function expected to have constant islands");
if (!Islands->FunctionConstantIslandLabel) {
Islands->FunctionConstantIslandLabel =
BC.Ctx->createNamedTempSymbol("func_const_island");
}
return Islands->FunctionConstantIslandLabel;
}
MCSymbol *getFunctionColdConstantIslandLabel() const {
assert(Islands && "function expected to have constant islands");
if (!Islands->FunctionColdConstantIslandLabel) {
Islands->FunctionColdConstantIslandLabel =
BC.Ctx->createNamedTempSymbol("func_cold_const_island");
}
return Islands->FunctionColdConstantIslandLabel;
}
/// Return true if this is a function representing a PLT entry.
bool isPLTFunction() const { return PLTSymbol != nullptr; }
/// Return PLT function reference symbol for PLT functions and nullptr for
/// non-PLT functions.
const MCSymbol *getPLTSymbol() const { return PLTSymbol; }
/// Set function PLT reference symbol for PLT functions.
void setPLTSymbol(const MCSymbol *Symbol) {
assert(Size == 0 && "function size should be 0 for PLT functions");
PLTSymbol = Symbol;
IsPseudo = true;
}
/// Update output values of the function based on the final \p Layout.
void updateOutputValues(const MCAsmLayout &Layout);
/// Return mapping of input to output addresses. Most users should call
/// translateInputToOutputAddress() for address translation.
InputOffsetToAddressMapTy &getInputOffsetToAddressMap() {
assert(isEmitted() && "cannot use address mapping before code emission");
return InputOffsetToAddressMap;
}
void addRelocationAArch64(uint64_t Offset, MCSymbol *Symbol, uint64_t RelType,
uint64_t Addend, uint64_t Value, bool IsCI) {
std::map<uint64_t, Relocation> &Rels =
(IsCI) ? Islands->Relocations : Relocations;
switch (RelType) {
case ELF::R_AARCH64_ABS64:
case ELF::R_AARCH64_ABS32:
case ELF::R_AARCH64_ABS16:
case ELF::R_AARCH64_ADD_ABS_LO12_NC:
case ELF::R_AARCH64_ADR_GOT_PAGE:
case ELF::R_AARCH64_ADR_PREL_LO21:
case ELF::R_AARCH64_ADR_PREL_PG_HI21:
case ELF::R_AARCH64_ADR_PREL_PG_HI21_NC:
case ELF::R_AARCH64_LD64_GOT_LO12_NC:
case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
case ELF::R_AARCH64_TLSDESC_ADD_LO12:
case ELF::R_AARCH64_TLSDESC_ADR_PAGE21:
case ELF::R_AARCH64_TLSDESC_ADR_PREL21:
case ELF::R_AARCH64_TLSDESC_LD64_LO12:
case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21:
case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
case ELF::R_AARCH64_MOVW_UABS_G0:
case ELF::R_AARCH64_MOVW_UABS_G0_NC:
case ELF::R_AARCH64_MOVW_UABS_G1:
case ELF::R_AARCH64_MOVW_UABS_G1_NC:
case ELF::R_AARCH64_MOVW_UABS_G2:
case ELF::R_AARCH64_MOVW_UABS_G2_NC:
case ELF::R_AARCH64_MOVW_UABS_G3:
case ELF::R_AARCH64_PREL16:
case ELF::R_AARCH64_PREL32:
case ELF::R_AARCH64_PREL64:
Rels[Offset] = Relocation{Offset, Symbol, RelType, Addend, Value};
return;
case ELF::R_AARCH64_CALL26:
case ELF::R_AARCH64_JUMP26:
case ELF::R_AARCH64_TSTBR14:
case ELF::R_AARCH64_CONDBR19:
case ELF::R_AARCH64_TLSDESC_CALL:
case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12:
case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC:
return;
default:
llvm_unreachable("Unexpected AArch64 relocation type in code");
}
}
void addRelocationX86(uint64_t Offset, MCSymbol *Symbol, uint64_t RelType,
uint64_t Addend, uint64_t Value) {
switch (RelType) {
case ELF::R_X86_64_8:
case ELF::R_X86_64_16:
case ELF::R_X86_64_32:
case ELF::R_X86_64_32S:
case ELF::R_X86_64_64:
case ELF::R_X86_64_PC8:
case ELF::R_X86_64_PC32:
case ELF::R_X86_64_PC64:
case ELF::R_X86_64_GOTPCRELX:
case ELF::R_X86_64_REX_GOTPCRELX:
Relocations[Offset] = Relocation{Offset, Symbol, RelType, Addend, Value};
return;
case ELF::R_X86_64_PLT32:
case ELF::R_X86_64_GOTPCREL:
case ELF::R_X86_64_TPOFF32:
case ELF::R_X86_64_GOTTPOFF:
return;
default:
llvm_unreachable("Unexpected x86 relocation type in code");
}
}
/// Register relocation type \p RelType at a given \p Address in the function
/// against \p Symbol.
/// Assert if the \p Address is not inside this function.
void addRelocation(uint64_t Address, MCSymbol *Symbol, uint64_t RelType,
uint64_t Addend, uint64_t Value) {
assert(Address >= getAddress() && Address < getAddress() + getMaxSize() &&
"address is outside of the function");
uint64_t Offset = Address - getAddress();
if (BC.isAArch64()) {
return addRelocationAArch64(Offset, Symbol, RelType, Addend, Value,
isInConstantIsland(Address));
}
return addRelocationX86(Offset, Symbol, RelType, Addend, Value);
}
/// Return the name of the section this function originated from.
Optional<StringRef> getOriginSectionName() const {
if (!OriginSection)
return NoneType();
return OriginSection->getName();
}
/// Return internal section name for this function.
StringRef getCodeSectionName() const { return StringRef(CodeSectionName); }
/// Assign a code section name to the function.
void setCodeSectionName(StringRef Name) {
CodeSectionName = std::string(Name);
}
/// Get output code section.
ErrorOr<BinarySection &> getCodeSection() const {
return BC.getUniqueSectionByName(getCodeSectionName());
}
/// Return cold code section name for the function.
StringRef getColdCodeSectionName() const {
return StringRef(ColdCodeSectionName);
}
/// Assign a section name for the cold part of the function.
void setColdCodeSectionName(StringRef Name) {
ColdCodeSectionName = std::string(Name);
}
/// Get output code section for cold code of this function.
ErrorOr<BinarySection &> getColdCodeSection() const {
return BC.getUniqueSectionByName(getColdCodeSectionName());
}
/// Return true iif the function will halt execution on entry.
bool trapsOnEntry() const { return TrapsOnEntry; }
/// Make the function always trap on entry. Other than the trap instruction,
/// the function body will be empty.
void setTrapOnEntry();
/// Return true if the function could be correctly processed.
bool isSimple() const { return IsSimple; }
/// Return true if the function should be ignored for optimization purposes.
bool isIgnored() const { return IsIgnored; }
/// Return true if the function should not be disassembled, emitted, or
/// otherwise processed.
bool isPseudo() const { return IsPseudo; }
/// Return true if the function contains a jump table with entries pointing
/// to split fragments.
bool hasSplitJumpTable() const { return HasSplitJumpTable; }
/// Return true if all CFG edges have local successors.
bool hasCanonicalCFG() const { return HasCanonicalCFG; }
/// Return true if the original function code has all necessary relocations
/// to track addresses of functions emitted to new locations.
bool hasExternalRefRelocations() const { return HasExternalRefRelocations; }
/// Return true if the function has instruction(s) with unknown control flow.
bool hasUnknownControlFlow() const { return HasUnknownControlFlow; }
/// Return true if the function body is non-contiguous.
bool isSplit() const {
return isSimple() && layout_size() &&
layout_front()->isCold() != layout_back()->isCold();
}
bool shouldPreserveNops() const { return PreserveNops; }
/// Return true if the function has exception handling tables.
bool hasEHRanges() const { return HasEHRanges; }
/// Return true if the function uses DW_CFA_GNU_args_size CFIs.
bool usesGnuArgsSize() const { return UsesGnuArgsSize; }
/// Return true if the function has more than one entry point.
bool isMultiEntry() const { return !SecondaryEntryPoints.empty(); }
/// Return true if the function might have a profile available externally,
/// but not yet populated into the function.
bool hasProfileAvailable() const { return HasProfileAvailable; }
bool hasMemoryProfile() const { return HasMemoryProfile; }
/// Return true if the body of the function was merged into another function.
bool isFolded() const { return FoldedIntoFunction != nullptr; }
/// If this function was folded, return the function it was folded into.
BinaryFunction *getFoldedIntoFunction() const { return FoldedIntoFunction; }
/// Return true if the function uses jump tables.
bool hasJumpTables() const { return !JumpTables.empty(); }
/// Return true if the function has SDT marker
bool hasSDTMarker() const { return HasSDTMarker; }
/// Return true if the function has Pseudo Probe
bool hasPseudoProbe() const { return HasPseudoProbe; }
/// Return true if the original entry point was patched.
bool isPatched() const { return IsPatched; }
const JumpTable *getJumpTable(const MCInst &Inst) const {
const uint64_t Address = BC.MIB->getJumpTable(Inst);
return getJumpTableContainingAddress(Address);
}
JumpTable *getJumpTable(const MCInst &Inst) {
const uint64_t Address = BC.MIB->getJumpTable(Inst);
return getJumpTableContainingAddress(Address);
}
const MCSymbol *getPersonalityFunction() const { return PersonalityFunction; }
uint8_t getPersonalityEncoding() const { return PersonalityEncoding; }
const CallSitesType &getCallSites() const { return CallSites; }
const CallSitesType &getColdCallSites() const { return ColdCallSites; }
const ArrayRef<uint8_t> getLSDAActionTable() const { return LSDAActionTable; }
const LSDATypeTableTy &getLSDATypeTable() const { return LSDATypeTable; }
const LSDATypeTableTy &getLSDATypeAddressTable() const {
return LSDATypeAddressTable;
}
const ArrayRef<uint8_t> getLSDATypeIndexTable() const {
return LSDATypeIndexTable;
}
const LabelsMapType &getLabels() const { return Labels; }
IslandInfo &getIslandInfo() {
assert(Islands && "function expected to have constant islands");
return *Islands;
}
const IslandInfo &getIslandInfo() const {
assert(Islands && "function expected to have constant islands");
return *Islands;
}
/// Return true if the function has CFI instructions
bool hasCFI() const {
return !FrameInstructions.empty() || !CIEFrameInstructions.empty();
}
/// Return unique number associated with the function.
uint64_t getFunctionNumber() const { return FunctionNumber; }
/// Return true if the given address \p PC is inside the function body.
bool containsAddress(uint64_t PC, bool UseMaxSize = false) const {
if (UseMaxSize)
return Address <= PC && PC < Address + MaxSize;
return Address <= PC && PC < Address + Size;
}
/// Create a basic block in the function. The new block is *NOT* inserted
/// into the CFG. The caller must use insertBasicBlocks() to add any new
/// blocks to the CFG.
std::unique_ptr<BinaryBasicBlock>
createBasicBlock(MCSymbol *Label = nullptr) {
if (!Label) {
std::unique_lock<std::shared_timed_mutex> Lock(BC.CtxMutex);
Label = BC.Ctx->createNamedTempSymbol("BB");
}
auto BB =
std::unique_ptr<BinaryBasicBlock>(new BinaryBasicBlock(this, Label));
LabelToBB[Label] = BB.get();
return BB;
}
/// Create a new basic block with an optional \p Label and add it to the list
/// of basic blocks of this function.
BinaryBasicBlock *addBasicBlock(MCSymbol *Label = nullptr) {
assert(CurrentState == State::CFG && "Can only add blocks in CFG state");
BasicBlocks.emplace_back(createBasicBlock(Label).release());
BinaryBasicBlock *BB = BasicBlocks.back();
BB->setIndex(BasicBlocks.size() - 1);
BB->setLayoutIndex(layout_size());
BasicBlocksLayout.emplace_back(BB);
return BB;
}
/// Add basic block \BB as an entry point to the function. Return global
/// symbol associated with the entry.
MCSymbol *addEntryPoint(const BinaryBasicBlock &BB);
/// Mark all blocks that are unreachable from a root (entry point
/// or landing pad) as invalid.
void markUnreachableBlocks();
/// Rebuilds BBs layout, ignoring dead BBs. Returns the number of removed
/// BBs and the removed number of bytes of code.
std::pair<unsigned, uint64_t> eraseInvalidBBs();
/// Get the relative order between two basic blocks in the original
/// layout. The result is > 0 if B occurs before A and < 0 if B
/// occurs after A. If A and B are the same block, the result is 0.
signed getOriginalLayoutRelativeOrder(const BinaryBasicBlock *A,
const BinaryBasicBlock *B) const {
return getIndex(A) - getIndex(B);
}
/// Insert the BBs contained in NewBBs into the basic blocks for this
/// function. Update the associated state of all blocks as needed, i.e.
/// BB offsets and BB indices. The new BBs are inserted after Start.
/// This operation could affect fallthrough branches for Start.
///
void
insertBasicBlocks(BinaryBasicBlock *Start,
std::vector<std::unique_ptr<BinaryBasicBlock>> &&NewBBs,
const bool UpdateLayout = true,
const bool UpdateCFIState = true,
const bool RecomputeLandingPads = true);
iterator insertBasicBlocks(
iterator StartBB, std::vector<std::unique_ptr<BinaryBasicBlock>> &&NewBBs,
const bool UpdateLayout = true, const bool UpdateCFIState = true,
const bool RecomputeLandingPads = true);
/// Update the basic block layout for this function. The BBs from
/// [Start->Index, Start->Index + NumNewBlocks) are inserted into the
/// layout after the BB indicated by Start.
void updateLayout(BinaryBasicBlock *Start, const unsigned NumNewBlocks);
/// Make sure basic blocks' indices match the current layout.
void updateLayoutIndices() const {
unsigned Index = 0;
for (BinaryBasicBlock *BB : layout())
BB->setLayoutIndex(Index++);
}
/// Recompute the CFI state for NumNewBlocks following Start after inserting
/// new blocks into the CFG. This must be called after updateLayout.
void updateCFIState(BinaryBasicBlock *Start, const unsigned NumNewBlocks);
/// Return true if we detected ambiguous jump tables in this function, which
/// happen when one JT is used in more than one indirect jumps. This precludes
/// us from splitting edges for this JT unless we duplicate the JT (see
/// disambiguateJumpTables).
bool checkForAmbiguousJumpTables();
/// Detect when two distinct indirect jumps are using the same jump table and
/// duplicate it, allocating a separate JT for each indirect branch. This is
/// necessary for code transformations on the CFG that change an edge induced
/// by an indirect branch, e.g.: instrumentation or shrink wrapping. However,
/// this is only possible if we are not updating jump tables in place, but are
/// writing it to a new location (moving them).
void disambiguateJumpTables(MCPlusBuilder::AllocatorIdTy AllocId);
/// Change \p OrigDest to \p NewDest in the jump table used at the end of
/// \p BB. Returns false if \p OrigDest couldn't be find as a valid target
/// and no replacement took place.
bool replaceJumpTableEntryIn(BinaryBasicBlock *BB, BinaryBasicBlock *OldDest,
BinaryBasicBlock *NewDest);
/// Split the CFG edge <From, To> by inserting an intermediate basic block.
/// Returns a pointer to this new intermediate basic block. BB "From" will be
/// updated to jump to the intermediate block, which in turn will have an
/// unconditional branch to BB "To".
/// User needs to manually call fixBranches(). This function only creates the
/// correct CFG edges.
BinaryBasicBlock *splitEdge(BinaryBasicBlock *From, BinaryBasicBlock *To);
/// We may have built an overly conservative CFG for functions with calls
/// to functions that the compiler knows will never return. In this case,
/// clear all successors from these blocks.
void deleteConservativeEdges();
/// Determine direction of the branch based on the current layout.
/// Callee is responsible of updating basic block indices prior to using
/// this function (e.g. by calling BinaryFunction::updateLayoutIndices()).
static bool isForwardBranch(const BinaryBasicBlock *From,
const BinaryBasicBlock *To) {
assert(From->getFunction() == To->getFunction() &&
"basic blocks should be in the same function");
return To->getLayoutIndex() > From->getLayoutIndex();
}
/// Determine direction of the call to callee symbol relative to the start
/// of this function.
/// Note: this doesn't take function splitting into account.
bool isForwardCall(const MCSymbol *CalleeSymbol) const;
/// Dump function information to debug output. If \p PrintInstructions
/// is true - include instruction disassembly.
void dump(bool PrintInstructions = true) const;
/// Print function information to the \p OS stream.
void print(raw_ostream &OS, std::string Annotation = "",
bool PrintInstructions = true) const;
/// Print all relocations between \p Offset and \p Offset + \p Size in
/// this function.
void printRelocations(raw_ostream &OS, uint64_t Offset, uint64_t Size) const;
/// Return true if function has a profile, even if the profile does not
/// match CFG 100%.
bool hasProfile() const { return ExecutionCount != COUNT_NO_PROFILE; }
/// Return true if function profile is present and accurate.
bool hasValidProfile() const {
return ExecutionCount != COUNT_NO_PROFILE && ProfileMatchRatio == 1.0f;
}
/// Mark this function as having a valid profile.
void markProfiled(uint16_t Flags) {
if (ExecutionCount == COUNT_NO_PROFILE)
ExecutionCount = 0;
ProfileFlags = Flags;
ProfileMatchRatio = 1.0f;
}
/// Return flags describing a profile for this function.
uint16_t getProfileFlags() const { return ProfileFlags; }
void addCFIInstruction(uint64_t Offset, MCCFIInstruction &&Inst) {
assert(!Instructions.empty());
// Fix CFI instructions skipping NOPs. We need to fix this because changing
// CFI state after a NOP, besides being wrong and inaccurate, makes it
// harder for us to recover this information, since we can create empty BBs
// with NOPs and then reorder it away.
// We fix this by moving the CFI instruction just before any NOPs.
auto I = Instructions.lower_bound(Offset);
if (Offset == getSize()) {
assert(I == Instructions.end() && "unexpected iterator value");
// Sometimes compiler issues restore_state after all instructions
// in the function (even after nop).
--I;
Offset = I->first;
}
assert(I->first == Offset && "CFI pointing to unknown instruction");
if (I == Instructions.begin()) {
CIEFrameInstructions.emplace_back(std::forward<MCCFIInstruction>(Inst));
return;
}
--I;
while (I != Instructions.begin() && BC.MIB->isNoop(I->second)) {
Offset = I->first;
--I;
}
OffsetToCFI.emplace(Offset, FrameInstructions.size());
FrameInstructions.emplace_back(std::forward<MCCFIInstruction>(Inst));
return;
}
BinaryBasicBlock::iterator addCFIInstruction(BinaryBasicBlock *BB,
BinaryBasicBlock::iterator Pos,
MCCFIInstruction &&Inst) {
size_t Idx = FrameInstructions.size();
FrameInstructions.emplace_back(std::forward<MCCFIInstruction>(Inst));
return addCFIPseudo(BB, Pos, Idx);
}
/// Insert a CFI pseudo instruction in a basic block. This pseudo instruction
/// is a placeholder that refers to a real MCCFIInstruction object kept by
/// this function that will be emitted at that position.
BinaryBasicBlock::iterator addCFIPseudo(BinaryBasicBlock *BB,
BinaryBasicBlock::iterator Pos,
uint32_t Offset) {
MCInst CFIPseudo;
BC.MIB->createCFI(CFIPseudo, Offset);
return BB->insertPseudoInstr(Pos, CFIPseudo);
}
/// Retrieve the MCCFIInstruction object associated with a CFI pseudo.
const MCCFIInstruction *getCFIFor(const MCInst &Instr) const {
if (!BC.MIB->isCFI(Instr))
return nullptr;
uint32_t Offset = Instr.getOperand(0).getImm();
assert(Offset < FrameInstructions.size() && "Invalid CFI offset");
return &FrameInstructions[Offset];
}
void setCFIFor(const MCInst &Instr, MCCFIInstruction &&CFIInst) {
assert(BC.MIB->isCFI(Instr) &&
"attempting to change CFI in a non-CFI inst");
uint32_t Offset = Instr.getOperand(0).getImm();
assert(Offset < FrameInstructions.size() && "Invalid CFI offset");
FrameInstructions[Offset] = std::move(CFIInst);
}
void mutateCFIRegisterFor(const MCInst &Instr, MCPhysReg NewReg);
const MCCFIInstruction *mutateCFIOffsetFor(const MCInst &Instr,
int64_t NewOffset);
BinaryFunction &setFileOffset(uint64_t Offset) {
FileOffset = Offset;
return *this;
}
BinaryFunction &setSize(uint64_t S) {
Size = S;
return *this;
}
BinaryFunction &setMaxSize(uint64_t Size) {
MaxSize = Size;
return *this;
}
BinaryFunction &setOutputAddress(uint64_t Address) {
OutputAddress = Address;
return *this;
}
BinaryFunction &setOutputSize(uint64_t Size) {
OutputSize = Size;
return *this;
}
BinaryFunction &setSimple(bool Simple) {
IsSimple = Simple;
return *this;
}
void setPseudo(bool Pseudo) { IsPseudo = Pseudo; }
BinaryFunction &setUsesGnuArgsSize(bool Uses = true) {
UsesGnuArgsSize = Uses;
return *this;
}
BinaryFunction &setHasProfileAvailable(bool V = true) {
HasProfileAvailable = V;
return *this;
}
/// Mark function that should not be emitted.
void setIgnored();
void setIsPatched(bool V) { IsPatched = V; }
void setHasSplitJumpTable(bool V) { HasSplitJumpTable = V; }
void setHasCanonicalCFG(bool V) { HasCanonicalCFG = V; }
void setFolded(BinaryFunction *BF) { FoldedIntoFunction = BF; }
BinaryFunction &setPersonalityFunction(uint64_t Addr) {
assert(!PersonalityFunction && "can't set personality function twice");
PersonalityFunction = BC.getOrCreateGlobalSymbol(Addr, "FUNCat");
return *this;
}
BinaryFunction &setPersonalityEncoding(uint8_t Encoding) {
PersonalityEncoding = Encoding;
return *this;
}
BinaryFunction &setAlignment(uint16_t Align) {
Alignment = Align;
return *this;
}
uint16_t getAlignment() const { return Alignment; }
BinaryFunction &setMaxAlignmentBytes(uint16_t MaxAlignBytes) {
MaxAlignmentBytes = MaxAlignBytes;
return *this;
}
uint16_t getMaxAlignmentBytes() const { return MaxAlignmentBytes; }
BinaryFunction &setMaxColdAlignmentBytes(uint16_t MaxAlignBytes) {
MaxColdAlignmentBytes = MaxAlignBytes;
return *this;
}
uint16_t getMaxColdAlignmentBytes() const { return MaxColdAlignmentBytes; }
BinaryFunction &setImageAddress(uint64_t Address) {
ImageAddress = Address;
return *this;
}
/// Return the address of this function' image in memory.
uint64_t getImageAddress() const { return ImageAddress; }
BinaryFunction &setImageSize(uint64_t Size) {
ImageSize = Size;
return *this;
}
/// Return the size of this function' image in memory.
uint64_t getImageSize() const { return ImageSize; }
/// Return true if the function is a secondary fragment of another function.
bool isFragment() const { return IsFragment; }
/// Returns if the given function is a parent fragment of this function.
bool isParentFragment(BinaryFunction *Parent) const {
return ParentFragments.count(Parent);
}
/// Set the profile data for the number of times the function was called.
BinaryFunction &setExecutionCount(uint64_t Count) {
ExecutionCount = Count;
return *this;
}
/// Adjust execution count for the function by a given \p Count. The value
/// \p Count will be subtracted from the current function count.
///
/// The function will proportionally adjust execution count for all
/// basic blocks and edges in the control flow graph.
void adjustExecutionCount(uint64_t Count);
/// Set LSDA address for the function.
BinaryFunction &setLSDAAddress(uint64_t Address) {
LSDAAddress = Address;
return *this;
}
/// Set LSDA symbol for the function.
BinaryFunction &setLSDASymbol(MCSymbol *Symbol) {
LSDASymbol = Symbol;
return *this;
}
/// Return the profile information about the number of times
/// the function was executed.
///
/// Return COUNT_NO_PROFILE if there's no profile info.
uint64_t getExecutionCount() const { return ExecutionCount; }
/// Return the raw profile information about the number of branch
/// executions corresponding to this function.
uint64_t getRawBranchCount() const { return RawBranchCount; }
/// Return the execution count for functions with known profile.
/// Return 0 if the function has no profile.
uint64_t getKnownExecutionCount() const {
return ExecutionCount == COUNT_NO_PROFILE ? 0 : ExecutionCount;
}
/// Return original LSDA address for the function or NULL.
uint64_t getLSDAAddress() const { return LSDAAddress; }
/// Return symbol pointing to function's LSDA.
MCSymbol *getLSDASymbol() {
if (LSDASymbol)
return LSDASymbol;
if (CallSites.empty())
return nullptr;
LSDASymbol = BC.Ctx->getOrCreateSymbol(
Twine("GCC_except_table") + Twine::utohexstr(getFunctionNumber()));
return LSDASymbol;
}
/// Return symbol pointing to function's LSDA for the cold part.
MCSymbol *getColdLSDASymbol() {
if (ColdLSDASymbol)
return ColdLSDASymbol;
if (ColdCallSites.empty())
return nullptr;
ColdLSDASymbol = BC.Ctx->getOrCreateSymbol(
Twine("GCC_cold_except_table") + Twine::utohexstr(getFunctionNumber()));
return ColdLSDASymbol;
}
void setOutputDataAddress(uint64_t Address) { OutputDataOffset = Address; }
uint64_t getOutputDataAddress() const { return OutputDataOffset; }
void setOutputColdDataAddress(uint64_t Address) {
OutputColdDataOffset = Address;
}
uint64_t getOutputColdDataAddress() const { return OutputColdDataOffset; }
/// If \p Address represents an access to a constant island managed by this
/// function, return a symbol so code can safely refer to it. Otherwise,
/// return nullptr. First return value is the symbol for reference in the
/// hot code area while the second return value is the symbol for reference
/// in the cold code area, as when the function is split the islands are
/// duplicated.
MCSymbol *getOrCreateIslandAccess(uint64_t Address) {
if (!Islands)
return nullptr;
MCSymbol *Symbol;
if (!isInConstantIsland(Address))
return nullptr;
// Register our island at global namespace
Symbol = BC.getOrCreateGlobalSymbol(Address, "ISLANDat");
// Internal bookkeeping
const uint64_t Offset = Address - getAddress();
assert((!Islands->Offsets.count(Offset) ||
Islands->Offsets[Offset] == Symbol) &&
"Inconsistent island symbol management");
if (!Islands->Offsets.count(Offset)) {
Islands->Offsets[Offset] = Symbol;
Islands->Symbols.insert(Symbol);
}
return Symbol;
}
/// Called by an external function which wishes to emit references to constant
/// island symbols of this function. We create a proxy for it, so we emit
/// separate symbols when emitting our constant island on behalf of this other
/// function.
MCSymbol *getOrCreateProxyIslandAccess(uint64_t Address,
BinaryFunction &Referrer) {
MCSymbol *Symbol = getOrCreateIslandAccess(Address);
if (!Symbol)
return nullptr;
MCSymbol *Proxy;
if (!Islands->Proxies[&Referrer].count(Symbol)) {
Proxy = BC.Ctx->getOrCreateSymbol(Symbol->getName() + ".proxy.for." +
Referrer.getPrintName());
Islands->Proxies[&Referrer][Symbol] = Proxy;
Islands->Proxies[&Referrer][Proxy] = Symbol;
}
Proxy = Islands->Proxies[&Referrer][Symbol];
return Proxy;
}
/// Make this function depend on \p BF because we have a reference to its
/// constant island. When emitting this function, we will also emit
// \p BF's constants. This only happens in custom AArch64 assembly code.
void createIslandDependency(MCSymbol *Island, BinaryFunction *BF) {
if (!Islands)
Islands = std::make_unique<IslandInfo>();
Islands->Dependency.insert(BF);
Islands->ProxySymbols[Island] = BF;
}
/// Detects whether \p Address is inside a data region in this function
/// (constant islands).
bool isInConstantIsland(uint64_t Address) const {
if (!Islands)
return false;
if (Address < getAddress())
return false;
uint64_t Offset = Address - getAddress();
if (Offset >= getMaxSize())
return false;
auto DataIter = Islands->DataOffsets.upper_bound(Offset);
if (DataIter == Islands->DataOffsets.begin())
return false;
DataIter = std::prev(DataIter);
auto CodeIter = Islands->CodeOffsets.upper_bound(Offset);
if (CodeIter == Islands->CodeOffsets.begin())
return true;
return *std::prev(CodeIter) <= *DataIter;
}
uint16_t getConstantIslandAlignment() const {
return Islands ? Islands->getAlignment() : 1;
}
uint64_t
estimateConstantIslandSize(const BinaryFunction *OnBehalfOf = nullptr) const {
if (!Islands)
return 0;
uint64_t Size = 0;
for (auto DataIter = Islands->DataOffsets.begin();
DataIter != Islands->DataOffsets.end(); ++DataIter) {
auto NextData = std::next(DataIter);
auto CodeIter = Islands->CodeOffsets.lower_bound(*DataIter);
if (CodeIter == Islands->CodeOffsets.end() &&
NextData == Islands->DataOffsets.end()) {
Size += getMaxSize() - *DataIter;
continue;
}
uint64_t NextMarker;
if (CodeIter == Islands->CodeOffsets.end())
NextMarker = *NextData;
else if (NextData == Islands->DataOffsets.end())
NextMarker = *CodeIter;
else
NextMarker = (*CodeIter > *NextData) ? *NextData : *CodeIter;
Size += NextMarker - *DataIter;
}
if (!OnBehalfOf) {
for (BinaryFunction *ExternalFunc : Islands->Dependency) {
Size = alignTo(Size, ExternalFunc->getConstantIslandAlignment());
Size += ExternalFunc->estimateConstantIslandSize(this);
}
}
return Size;
}
bool hasIslandsInfo() const { return !!Islands; }
bool hasConstantIsland() const {
return Islands && !Islands->DataOffsets.empty();
}
/// Return true iff the symbol could be seen inside this function otherwise
/// it is probably another function.
bool isSymbolValidInScope(const SymbolRef &Symbol, uint64_t SymbolSize) const;
/// Disassemble function from raw data.
/// If successful, this function will populate the list of instructions
/// for this function together with offsets from the function start
/// in the input. It will also populate Labels with destinations for
/// local branches, and TakenBranches with [from, to] info.
///
/// The Function should be properly initialized before this function
/// is called. I.e. function address and size should be set.
///
/// Returns true on successful disassembly, and updates the current
/// state to State:Disassembled.
///
/// Returns false if disassembly failed.
bool disassemble();
/// Scan function for references to other functions. In relocation mode,
/// add relocations for external references.
///
/// Return true on success.
bool scanExternalRefs();
/// Return the size of a data object located at \p Offset in the function.
/// Return 0 if there is no data object at the \p Offset.
size_t getSizeOfDataInCodeAt(uint64_t Offset) const;
/// Verify that starting at \p Offset function contents are filled with
/// zero-value bytes.
bool isZeroPaddingAt(uint64_t Offset) const;
/// Check that entry points have an associated instruction at their
/// offsets after disassembly.
void postProcessEntryPoints();
/// Post-processing for jump tables after disassembly. Since their
/// boundaries are not known until all call sites are seen, we need this
/// extra pass to perform any final adjustments.
void postProcessJumpTables();
/// Builds a list of basic blocks with successor and predecessor info.
///
/// The function should in Disassembled state prior to call.
///
/// Returns true on success and update the current function state to
/// State::CFG. Returns false if CFG cannot be built.
bool buildCFG(MCPlusBuilder::AllocatorIdTy);
/// Perform post-processing of the CFG.
void postProcessCFG();
/// Verify that any assumptions we've made about indirect branches were
/// correct and also make any necessary changes to unknown indirect branches.
///
/// Catch-22: we need to know indirect branch targets to build CFG, and
/// in order to determine the value for indirect branches we need to know CFG.
///
/// As such, the process of decoding indirect branches is broken into 2 steps:
/// first we make our best guess about a branch without knowing the CFG,
/// and later after we have the CFG for the function, we verify our earlier
/// assumptions and also do our best at processing unknown indirect branches.
///
/// Return true upon successful processing, or false if the control flow
/// cannot be statically evaluated for any given indirect branch.
bool postProcessIndirectBranches(MCPlusBuilder::AllocatorIdTy AllocId);
/// Return all call site profile info for this function.
IndirectCallSiteProfile &getAllCallSites() { return AllCallSites; }
const IndirectCallSiteProfile &getAllCallSites() const {
return AllCallSites;
}
/// Walks the list of basic blocks filling in missing information about
/// edge frequency for fall-throughs.
///
/// Assumes the CFG has been built and edge frequency for taken branches
/// has been filled with LBR data.
void inferFallThroughCounts();
/// Clear execution profile of the function.
void clearProfile();
/// Converts conditional tail calls to unconditional tail calls. We do this to
/// handle conditional tail calls correctly and to give a chance to the
/// simplify conditional tail call pass to decide whether to re-optimize them
/// using profile information.
void removeConditionalTailCalls();
// Convert COUNT_NO_PROFILE to 0
void removeTagsFromProfile();
/// Computes a function hotness score: the sum of the products of BB frequency
/// and size.
uint64_t getFunctionScore() const;
/// Return true if the layout has been changed by basic block reordering,
/// false otherwise.
bool hasLayoutChanged() const;
/// Get the edit distance of the new layout with respect to the previous
/// layout after basic block reordering.
uint64_t getEditDistance() const;
/// Get the number of instructions within this function.
uint64_t getInstructionCount() const;
const CFIInstrMapType &getFDEProgram() const { return FrameInstructions; }
void moveRememberRestorePair(BinaryBasicBlock *BB);
bool replayCFIInstrs(int32_t FromState, int32_t ToState,
BinaryBasicBlock *InBB,
BinaryBasicBlock::iterator InsertIt);
/// unwindCFIState is used to unwind from a higher to a lower state number
/// without using remember-restore instructions. We do that by keeping track
/// of what values have been changed from state A to B and emitting
/// instructions that undo this change.
SmallVector<int32_t, 4> unwindCFIState(int32_t FromState, int32_t ToState,
BinaryBasicBlock *InBB,
BinaryBasicBlock::iterator &InsertIt);
/// After reordering, this function checks the state of CFI and fixes it if it
/// is corrupted. If it is unable to fix it, it returns false.
bool finalizeCFIState();
/// Return true if this function needs an address-transaltion table after
/// its code emission.
bool requiresAddressTranslation() const;
/// Adjust branch instructions to match the CFG.
///
/// As it comes to internal branches, the CFG represents "the ultimate source
/// of truth". Transformations on functions and blocks have to update the CFG
/// and fixBranches() would make sure the correct branch instructions are
/// inserted at the end of basic blocks.
///
/// We do require a conditional branch at the end of the basic block if
/// the block has 2 successors as CFG currently lacks the conditional
/// code support (it will probably stay that way). We only use this
/// branch instruction for its conditional code, the destination is
/// determined by CFG - first successor representing true/taken branch,
/// while the second successor - false/fall-through branch.
///
/// When we reverse the branch condition, the CFG is updated accordingly.
void fixBranches();
/// Mark function as finalized. No further optimizations are permitted.
void setFinalized() { CurrentState = State::CFG_Finalized; }
void setEmitted(bool KeepCFG = false) {
CurrentState = State::EmittedCFG;
if (!KeepCFG) {
releaseCFG();
CurrentState = State::Emitted;
}
}
/// Process LSDA information for the function.
void parseLSDA(ArrayRef<uint8_t> LSDAData, uint64_t LSDAAddress);
/// Update exception handling ranges for the function.
void updateEHRanges();
/// Traverse cold basic blocks and replace references to constants in islands
/// with a proxy symbol for the duplicated constant island that is going to be
/// emitted in the cold region.
void duplicateConstantIslands();
/// Merge profile data of this function into those of the given
/// function. The functions should have been proven identical with
/// isIdenticalWith.
void mergeProfileDataInto(BinaryFunction &BF) const;
/// Returns the last computed hash value of the function.
size_t getHash() const { return Hash; }
using OperandHashFuncTy =
function_ref<typename std::string(const MCOperand &)>;
/// Compute the hash value of the function based on its contents.
///
/// If \p UseDFS is set, process basic blocks in DFS order. Otherwise, use
/// the existing layout order.
///
/// By default, instruction operands are ignored while calculating the hash.
/// The caller can change this via passing \p OperandHashFunc function.
/// The return result of this function will be mixed with internal hash.
size_t computeHash(
bool UseDFS = false,
OperandHashFuncTy OperandHashFunc = [](const MCOperand &) {
return std::string();
}) const;
void setDWARFUnit(DWARFUnit *Unit) { DwarfUnit = Unit; }
/// Return DWARF compile unit for this function.
DWARFUnit *getDWARFUnit() const { return DwarfUnit; }
/// Return line info table for this function.
const DWARFDebugLine::LineTable *getDWARFLineTable() const {
return getDWARFUnit() ? BC.DwCtx->getLineTableForUnit(getDWARFUnit())
: nullptr;
}
/// Finalize profile for the function.
void postProcessProfile();
/// Returns an estimate of the function's hot part after splitting.
/// This is a very rough estimate, as with C++ exceptions there are
/// blocks we don't move, and it makes no attempt at estimating the size
/// of the added/removed branch instructions.
/// Note that this size is optimistic and the actual size may increase
/// after relaxation.
size_t estimateHotSize(const bool UseSplitSize = true) const {
size_t Estimate = 0;
if (UseSplitSize && isSplit()) {
for (const BinaryBasicBlock *BB : BasicBlocksLayout)
if (!BB->isCold())
Estimate += BC.computeCodeSize(BB->begin(), BB->end());
} else {
for (const BinaryBasicBlock *BB : BasicBlocksLayout)
if (BB->getKnownExecutionCount() != 0)
Estimate += BC.computeCodeSize(BB->begin(), BB->end());
}
return Estimate;
}
size_t estimateColdSize() const {
if (!isSplit())
return estimateSize();
size_t Estimate = 0;
for (const BinaryBasicBlock *BB : BasicBlocksLayout)
if (BB->isCold())
Estimate += BC.computeCodeSize(BB->begin(), BB->end());
return Estimate;
}
size_t estimateSize() const {
size_t Estimate = 0;
for (const BinaryBasicBlock *BB : BasicBlocksLayout)
Estimate += BC.computeCodeSize(BB->begin(), BB->end());
return Estimate;
}
/// Return output address ranges for a function.
DebugAddressRangesVector getOutputAddressRanges() const;
/// Given an address corresponding to an instruction in the input binary,
/// return an address of this instruction in output binary.
///
/// Return 0 if no matching address could be found or the instruction was
/// removed.
uint64_t translateInputToOutputAddress(uint64_t Address) const;
/// Take address ranges corresponding to the input binary and translate
/// them to address ranges in the output binary.
DebugAddressRangesVector translateInputToOutputRanges(
const DWARFAddressRangesVector &InputRanges) const;
/// Similar to translateInputToOutputRanges() but operates on location lists
/// and moves associated data to output location lists.
DebugLocationsVector
translateInputToOutputLocationList(const DebugLocationsVector &InputLL) const;
/// Return true if the function is an AArch64 linker inserted veneer
bool isAArch64Veneer() const;
virtual ~BinaryFunction();
/// Info for fragmented functions.
class FragmentInfo {
private:
uint64_t Address{0};
uint64_t ImageAddress{0};
uint64_t ImageSize{0};
uint64_t FileOffset{0};
public:
uint64_t getAddress() const { return Address; }
uint64_t getImageAddress() const { return ImageAddress; }
uint64_t getImageSize() const { return ImageSize; }
uint64_t getFileOffset() const { return FileOffset; }
void setAddress(uint64_t VAddress) { Address = VAddress; }
void setImageAddress(uint64_t Address) { ImageAddress = Address; }
void setImageSize(uint64_t Size) { ImageSize = Size; }
void setFileOffset(uint64_t Offset) { FileOffset = Offset; }
};
/// Cold fragment of the function.
FragmentInfo ColdFragment;
FragmentInfo &cold() { return ColdFragment; }
const FragmentInfo &cold() const { return ColdFragment; }
};
inline raw_ostream &operator<<(raw_ostream &OS,
const BinaryFunction &Function) {
OS << Function.getPrintName();
return OS;
}
} // namespace bolt
// GraphTraits specializations for function basic block graphs (CFGs)
template <>
struct GraphTraits<bolt::BinaryFunction *>
: public GraphTraits<bolt::BinaryBasicBlock *> {
static NodeRef getEntryNode(bolt::BinaryFunction *F) {
return *F->layout_begin();
}
using nodes_iterator = pointer_iterator<bolt::BinaryFunction::iterator>;
static nodes_iterator nodes_begin(bolt::BinaryFunction *F) {
llvm_unreachable("Not implemented");
return nodes_iterator(F->begin());
}
static nodes_iterator nodes_end(bolt::BinaryFunction *F) {
llvm_unreachable("Not implemented");
return nodes_iterator(F->end());
}
static size_t size(bolt::BinaryFunction *F) { return F->size(); }
};
template <>
struct GraphTraits<const bolt::BinaryFunction *>
: public GraphTraits<const bolt::BinaryBasicBlock *> {
static NodeRef getEntryNode(const bolt::BinaryFunction *F) {
return *F->layout_begin();
}
using nodes_iterator = pointer_iterator<bolt::BinaryFunction::const_iterator>;
static nodes_iterator nodes_begin(const bolt::BinaryFunction *F) {
llvm_unreachable("Not implemented");
return nodes_iterator(F->begin());
}
static nodes_iterator nodes_end(const bolt::BinaryFunction *F) {
llvm_unreachable("Not implemented");
return nodes_iterator(F->end());
}
static size_t size(const bolt::BinaryFunction *F) { return F->size(); }
};
template <>
struct GraphTraits<Inverse<bolt::BinaryFunction *>>
: public GraphTraits<Inverse<bolt::BinaryBasicBlock *>> {
static NodeRef getEntryNode(Inverse<bolt::BinaryFunction *> G) {
return *G.Graph->layout_begin();
}
};
template <>
struct GraphTraits<Inverse<const bolt::BinaryFunction *>>
: public GraphTraits<Inverse<const bolt::BinaryBasicBlock *>> {
static NodeRef getEntryNode(Inverse<const bolt::BinaryFunction *> G) {
return *G.Graph->layout_begin();
}
};
} // namespace llvm
#endif
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