llvm-project/llvm/lib/Bitcode/Reader/BitcodeReader.h

255 lines
8.4 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 BITCODE_READER_H
#define BITCODE_READER_H
#include "llvm/ModuleProvider.h"
#include "llvm/Attributes.h"
#include "llvm/Type.h"
#include "llvm/OperandTraits.h"
#include "llvm/Bitcode/BitstreamReader.h"
#include "llvm/Bitcode/LLVMBitCodes.h"
#include "llvm/ADT/DenseMap.h"
#include <vector>
namespace llvm {
class MemoryBuffer;
//===----------------------------------------------------------------------===//
// BitcodeReaderValueList Class
//===----------------------------------------------------------------------===//
class BitcodeReaderValueList : public User {
unsigned Capacity;
/// 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;
public:
BitcodeReaderValueList() : User(Type::VoidTy, Value::ArgumentVal, 0, 0)
, Capacity(0) {}
~BitcodeReaderValueList() {
assert(ResolveConstants.empty() && "Constants not resolved?");
}
/// Provide fast operand accessors
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
// vector compatibility methods
unsigned size() const { return getNumOperands(); }
void resize(unsigned);
void push_back(Value *V) {
unsigned OldOps(NumOperands), NewOps(NumOperands + 1);
resize(NewOps);
NumOperands = NewOps;
OperandList[OldOps] = V;
}
void clear() {
assert(ResolveConstants.empty() && "Constants not resolved?");
if (OperandList) dropHungoffUses(OperandList);
Capacity = 0;
}
Value *operator[](unsigned i) const { return getOperand(i); }
Value *back() const { return getOperand(size() - 1); }
void pop_back() { setOperand(size() - 1, 0); --NumOperands; }
bool empty() const { return NumOperands == 0; }
void shrinkTo(unsigned N) {
assert(N <= NumOperands && "Invalid shrinkTo request!");
while (NumOperands > N)
pop_back();
}
virtual void print(std::ostream&) const {}
Constant *getConstantFwdRef(unsigned Idx, const Type *Ty);
Value *getValueFwdRef(unsigned Idx, const Type *Ty);
void AssignValue(Value *V, unsigned Idx) {
if (Idx == size()) {
push_back(V);
} else if (Value *OldV = getOperand(Idx)) {
// Handle constants and non-constants (e.g. instrs) differently for
// efficiency.
if (Constant *PHC = dyn_cast<Constant>(OldV)) {
ResolveConstants.push_back(std::make_pair(PHC, Idx));
setOperand(Idx, V);
} else {
// If there was a forward reference to this value, replace it.
setOperand(Idx, V);
OldV->replaceAllUsesWith(V);
delete OldV;
}
} else {
initVal(Idx, V);
}
}
/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
/// resolves any forward references.
void ResolveConstantForwardRefs();
private:
void initVal(unsigned Idx, Value *V) {
if (Idx >= size()) {
// Insert a bunch of null values.
resize(Idx * 2 + 1);
}
assert(getOperand(Idx) == 0 && "Cannot init an already init'd Use!");
OperandList[Idx] = V;
}
};
template <>
struct OperandTraits<BitcodeReaderValueList>
: HungoffOperandTraits</*16 FIXME*/> {
};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BitcodeReaderValueList, Value)
class BitcodeReader : public ModuleProvider {
MemoryBuffer *Buffer;
BitstreamReader Stream;
const char *ErrorString;
std::vector<PATypeHolder> TypeList;
BitcodeReaderValueList ValueList;
std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
/// 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<AttrListPtr> MAttributes;
/// 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;
// After the module header has been read, the FunctionsWithBodies list is
// reversed. This keeps track of whether we've done this yet.
bool HasReversedFunctionsWithBodies;
/// DeferredFunctionInfo - When function bodies are initially scanned, this
/// map contains info about where to find deferred function body (in the
/// stream) and what linkage the original function had.
DenseMap<Function*, std::pair<uint64_t, unsigned> > DeferredFunctionInfo;
public:
explicit BitcodeReader(MemoryBuffer *buffer)
: Buffer(buffer), ErrorString(0) {
HasReversedFunctionsWithBodies = false;
}
~BitcodeReader() {
FreeState();
}
void FreeState();
/// releaseMemoryBuffer - This causes the reader to completely forget about
/// the memory buffer it contains, which prevents the buffer from being
/// destroyed when it is deleted.
void releaseMemoryBuffer() {
Buffer = 0;
}
virtual bool materializeFunction(Function *F, std::string *ErrInfo = 0);
virtual Module *materializeModule(std::string *ErrInfo = 0);
virtual void dematerializeFunction(Function *F);
virtual Module *releaseModule(std::string *ErrInfo = 0);
bool Error(const char *Str) {
ErrorString = Str;
return true;
}
const char *getErrorString() const { return ErrorString; }
/// @brief Main interface to parsing a bitcode buffer.
/// @returns true if an error occurred.
bool ParseBitcode();
private:
const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
Value *getFnValueByID(unsigned ID, const Type *Ty) {
return ValueList.getValueFwdRef(ID, Ty);
}
BasicBlock *getBasicBlock(unsigned ID) const {
if (ID >= FunctionBBs.size()) return 0; // Invalid ID
return FunctionBBs[ID];
}
AttrListPtr getAttributes(unsigned i) const {
if (i-1 < MAttributes.size())
return MAttributes[i-1];
return AttrListPtr();
}
/// 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(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
unsigned InstNum, Value *&ResVal) {
if (Slot == Record.size()) return true;
unsigned ValNo = (unsigned)Record[Slot++];
if (ValNo < InstNum) {
// If this is not a forward reference, just return the value we already
// have.
ResVal = getFnValueByID(ValNo, 0);
return ResVal == 0;
} else if (Slot == Record.size()) {
return true;
}
unsigned TypeNo = (unsigned)Record[Slot++];
ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
return ResVal == 0;
}
bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
const Type *Ty, Value *&ResVal) {
if (Slot == Record.size()) return true;
unsigned ValNo = (unsigned)Record[Slot++];
ResVal = getFnValueByID(ValNo, Ty);
return ResVal == 0;
}
bool ParseModule(const std::string &ModuleID);
bool ParseAttributeBlock();
bool ParseTypeTable();
bool ParseTypeSymbolTable();
bool ParseValueSymbolTable();
bool ParseConstants();
bool RememberAndSkipFunctionBody();
bool ParseFunctionBody(Function *F);
bool ResolveGlobalAndAliasInits();
};
} // End llvm namespace
#endif