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llvm-mirror/lib/Bitcode/Reader/BitcodeReader.h
Rafael Espindola 20325e7adb Be lazy about loading metadata in IRObjectFile.
This speeds up llvm-ar building lib64/libclangSema.a with debug IR files
from 8.658015807 seconds to just 0.351036519 seconds :-)

llvm-svn: 232221
2015-03-13 21:54:20 +00:00

384 lines
14 KiB
C++

//===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header defines the BitcodeReader class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_BITCODE_READER_BITCODEREADER_H
#define LLVM_LIB_BITCODE_READER_BITCODEREADER_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include "llvm/Bitcode/LLVMBitCodes.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/GVMaterializer.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/OperandTraits.h"
#include "llvm/IR/TrackingMDRef.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/ValueHandle.h"
#include <deque>
#include <system_error>
#include <vector>
namespace llvm {
class Comdat;
class MemoryBuffer;
class LLVMContext;
//===----------------------------------------------------------------------===//
// BitcodeReaderValueList Class
//===----------------------------------------------------------------------===//
class BitcodeReaderValueList {
std::vector<WeakVH> ValuePtrs;
/// ResolveConstants - As we resolve forward-referenced constants, we add
/// information about them to this vector. This allows us to resolve them in
/// bulk instead of resolving each reference at a time. See the code in
/// ResolveConstantForwardRefs for more information about this.
///
/// The key of this vector is the placeholder constant, the value is the slot
/// number that holds the resolved value.
typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
ResolveConstantsTy ResolveConstants;
LLVMContext &Context;
public:
BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
~BitcodeReaderValueList() {
assert(ResolveConstants.empty() && "Constants not resolved?");
}
// vector compatibility methods
unsigned size() const { return ValuePtrs.size(); }
void resize(unsigned N) { ValuePtrs.resize(N); }
void push_back(Value *V) {
ValuePtrs.push_back(V);
}
void clear() {
assert(ResolveConstants.empty() && "Constants not resolved?");
ValuePtrs.clear();
}
Value *operator[](unsigned i) const {
assert(i < ValuePtrs.size());
return ValuePtrs[i];
}
Value *back() const { return ValuePtrs.back(); }
void pop_back() { ValuePtrs.pop_back(); }
bool empty() const { return ValuePtrs.empty(); }
void shrinkTo(unsigned N) {
assert(N <= size() && "Invalid shrinkTo request!");
ValuePtrs.resize(N);
}
Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
Value *getValueFwdRef(unsigned Idx, Type *Ty);
void AssignValue(Value *V, unsigned Idx);
/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
/// resolves any forward references.
void ResolveConstantForwardRefs();
};
//===----------------------------------------------------------------------===//
// BitcodeReaderMDValueList Class
//===----------------------------------------------------------------------===//
class BitcodeReaderMDValueList {
unsigned NumFwdRefs;
bool AnyFwdRefs;
unsigned MinFwdRef;
unsigned MaxFwdRef;
std::vector<TrackingMDRef> MDValuePtrs;
LLVMContext &Context;
public:
BitcodeReaderMDValueList(LLVMContext &C)
: NumFwdRefs(0), AnyFwdRefs(false), Context(C) {}
// vector compatibility methods
unsigned size() const { return MDValuePtrs.size(); }
void resize(unsigned N) { MDValuePtrs.resize(N); }
void push_back(Metadata *MD) { MDValuePtrs.emplace_back(MD); }
void clear() { MDValuePtrs.clear(); }
Metadata *back() const { return MDValuePtrs.back(); }
void pop_back() { MDValuePtrs.pop_back(); }
bool empty() const { return MDValuePtrs.empty(); }
Metadata *operator[](unsigned i) const {
assert(i < MDValuePtrs.size());
return MDValuePtrs[i];
}
void shrinkTo(unsigned N) {
assert(N <= size() && "Invalid shrinkTo request!");
MDValuePtrs.resize(N);
}
Metadata *getValueFwdRef(unsigned Idx);
void AssignValue(Metadata *MD, unsigned Idx);
void tryToResolveCycles();
};
class BitcodeReader : public GVMaterializer {
LLVMContext &Context;
DiagnosticHandlerFunction DiagnosticHandler;
Module *TheModule;
std::unique_ptr<MemoryBuffer> Buffer;
std::unique_ptr<BitstreamReader> StreamFile;
BitstreamCursor Stream;
DataStreamer *LazyStreamer;
uint64_t NextUnreadBit;
bool SeenValueSymbolTable;
std::vector<Type*> TypeList;
BitcodeReaderValueList ValueList;
BitcodeReaderMDValueList MDValueList;
std::vector<Comdat *> ComdatList;
SmallVector<Instruction *, 64> InstructionList;
std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
std::vector<std::pair<Function*, unsigned> > FunctionPrefixes;
std::vector<std::pair<Function*, unsigned> > FunctionPrologues;
SmallVector<Instruction*, 64> InstsWithTBAATag;
/// MAttributes - The set of attributes by index. Index zero in the
/// file is for null, and is thus not represented here. As such all indices
/// are off by one.
std::vector<AttributeSet> MAttributes;
/// \brief The set of attribute groups.
std::map<unsigned, AttributeSet> MAttributeGroups;
/// FunctionBBs - While parsing a function body, this is a list of the basic
/// blocks for the function.
std::vector<BasicBlock*> FunctionBBs;
// When reading the module header, this list is populated with functions that
// have bodies later in the file.
std::vector<Function*> FunctionsWithBodies;
// When intrinsic functions are encountered which require upgrading they are
// stored here with their replacement function.
typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
UpgradedIntrinsicMap UpgradedIntrinsics;
// Map the bitcode's custom MDKind ID to the Module's MDKind ID.
DenseMap<unsigned, unsigned> MDKindMap;
// Several operations happen after the module header has been read, but
// before function bodies are processed. This keeps track of whether
// we've done this yet.
bool SeenFirstFunctionBody;
/// DeferredFunctionInfo - When function bodies are initially scanned, this
/// map contains info about where to find deferred function body in the
/// stream.
DenseMap<Function*, uint64_t> DeferredFunctionInfo;
/// When Metadata block is initially scanned when parsing the module, we may
/// choose to defer parsing of the metadata. This vector contains info about
/// which Metadata blocks are deferred.
std::vector<uint64_t> DeferredMetadataInfo;
/// These are basic blocks forward-referenced by block addresses. They are
/// inserted lazily into functions when they're loaded. The basic block ID is
/// its index into the vector.
DenseMap<Function *, std::vector<BasicBlock *>> BasicBlockFwdRefs;
std::deque<Function *> BasicBlockFwdRefQueue;
/// UseRelativeIDs - Indicates that we are using a new encoding for
/// instruction operands where most operands in the current
/// FUNCTION_BLOCK are encoded relative to the instruction number,
/// for a more compact encoding. Some instruction operands are not
/// relative to the instruction ID: basic block numbers, and types.
/// Once the old style function blocks have been phased out, we would
/// not need this flag.
bool UseRelativeIDs;
/// True if all functions will be materialized, negating the need to process
/// (e.g.) blockaddress forward references.
bool WillMaterializeAllForwardRefs;
/// Functions that have block addresses taken. This is usually empty.
SmallPtrSet<const Function *, 4> BlockAddressesTaken;
/// True if any Metadata block has been materialized.
bool IsMetadataMaterialized;
public:
std::error_code Error(BitcodeError E, const Twine &Message);
std::error_code Error(BitcodeError E);
std::error_code Error(const Twine &Message);
explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
DiagnosticHandlerFunction DiagnosticHandler);
explicit BitcodeReader(DataStreamer *streamer, LLVMContext &C,
DiagnosticHandlerFunction DiagnosticHandler);
~BitcodeReader() { FreeState(); }
std::error_code materializeForwardReferencedFunctions();
void FreeState();
void releaseBuffer();
bool isDematerializable(const GlobalValue *GV) const override;
std::error_code materialize(GlobalValue *GV) override;
std::error_code MaterializeModule(Module *M) override;
std::vector<StructType *> getIdentifiedStructTypes() const override;
void Dematerialize(GlobalValue *GV) override;
/// @brief Main interface to parsing a bitcode buffer.
/// @returns true if an error occurred.
std::error_code ParseBitcodeInto(Module *M,
bool ShouldLazyLoadMetadata = false);
/// @brief Cheap mechanism to just extract module triple
/// @returns true if an error occurred.
ErrorOr<std::string> parseTriple();
static uint64_t decodeSignRotatedValue(uint64_t V);
/// Materialize any deferred Metadata block.
std::error_code materializeMetadata() override;
private:
std::vector<StructType *> IdentifiedStructTypes;
StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
StructType *createIdentifiedStructType(LLVMContext &Context);
Type *getTypeByID(unsigned ID);
Value *getFnValueByID(unsigned ID, Type *Ty) {
if (Ty && Ty->isMetadataTy())
return MetadataAsValue::get(Ty->getContext(), getFnMetadataByID(ID));
return ValueList.getValueFwdRef(ID, Ty);
}
Metadata *getFnMetadataByID(unsigned ID) {
return MDValueList.getValueFwdRef(ID);
}
BasicBlock *getBasicBlock(unsigned ID) const {
if (ID >= FunctionBBs.size()) return nullptr; // Invalid ID
return FunctionBBs[ID];
}
AttributeSet getAttributes(unsigned i) const {
if (i-1 < MAttributes.size())
return MAttributes[i-1];
return AttributeSet();
}
/// getValueTypePair - Read a value/type pair out of the specified record from
/// slot 'Slot'. Increment Slot past the number of slots used in the record.
/// Return true on failure.
bool getValueTypePair(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
unsigned InstNum, Value *&ResVal) {
if (Slot == Record.size()) return true;
unsigned ValNo = (unsigned)Record[Slot++];
// Adjust the ValNo, if it was encoded relative to the InstNum.
if (UseRelativeIDs)
ValNo = InstNum - ValNo;
if (ValNo < InstNum) {
// If this is not a forward reference, just return the value we already
// have.
ResVal = getFnValueByID(ValNo, nullptr);
return ResVal == nullptr;
} else if (Slot == Record.size()) {
return true;
}
unsigned TypeNo = (unsigned)Record[Slot++];
ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
return ResVal == nullptr;
}
/// popValue - Read a value out of the specified record from slot 'Slot'.
/// Increment Slot past the number of slots used by the value in the record.
/// Return true if there is an error.
bool popValue(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
unsigned InstNum, Type *Ty, Value *&ResVal) {
if (getValue(Record, Slot, InstNum, Ty, ResVal))
return true;
// All values currently take a single record slot.
++Slot;
return false;
}
/// getValue -- Like popValue, but does not increment the Slot number.
bool getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
unsigned InstNum, Type *Ty, Value *&ResVal) {
ResVal = getValue(Record, Slot, InstNum, Ty);
return ResVal == nullptr;
}
/// getValue -- Version of getValue that returns ResVal directly,
/// or 0 if there is an error.
Value *getValue(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
unsigned InstNum, Type *Ty) {
if (Slot == Record.size()) return nullptr;
unsigned ValNo = (unsigned)Record[Slot];
// Adjust the ValNo, if it was encoded relative to the InstNum.
if (UseRelativeIDs)
ValNo = InstNum - ValNo;
return getFnValueByID(ValNo, Ty);
}
/// getValueSigned -- Like getValue, but decodes signed VBRs.
Value *getValueSigned(SmallVectorImpl<uint64_t> &Record, unsigned Slot,
unsigned InstNum, Type *Ty) {
if (Slot == Record.size()) return nullptr;
unsigned ValNo = (unsigned)decodeSignRotatedValue(Record[Slot]);
// Adjust the ValNo, if it was encoded relative to the InstNum.
if (UseRelativeIDs)
ValNo = InstNum - ValNo;
return getFnValueByID(ValNo, Ty);
}
/// Converts alignment exponent (i.e. power of two (or zero)) to the
/// corresponding alignment to use. If alignment is too large, returns
/// a corresponding error code.
std::error_code parseAlignmentValue(uint64_t Exponent, unsigned &Alignment);
std::error_code ParseAttrKind(uint64_t Code, Attribute::AttrKind *Kind);
std::error_code ParseModule(bool Resume, bool ShouldLazyLoadMetadata = false);
std::error_code ParseAttributeBlock();
std::error_code ParseAttributeGroupBlock();
std::error_code ParseTypeTable();
std::error_code ParseTypeTableBody();
std::error_code ParseValueSymbolTable();
std::error_code ParseConstants();
std::error_code RememberAndSkipFunctionBody();
/// Save the positions of the Metadata blocks and skip parsing the blocks.
std::error_code rememberAndSkipMetadata();
std::error_code ParseFunctionBody(Function *F);
std::error_code GlobalCleanup();
std::error_code ResolveGlobalAndAliasInits();
std::error_code ParseMetadata();
std::error_code ParseMetadataAttachment();
ErrorOr<std::string> parseModuleTriple();
std::error_code ParseUseLists();
std::error_code InitStream();
std::error_code InitStreamFromBuffer();
std::error_code InitLazyStream();
std::error_code FindFunctionInStream(
Function *F,
DenseMap<Function *, uint64_t>::iterator DeferredFunctionInfoIterator);
};
} // End llvm namespace
#endif