//===- Reader.cpp - Code to read bytecode files ---------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This library implements the functionality defined in llvm/Bytecode/Reader.h
//
// Note that this library should be as fast as possible, reentrant, and
// threadsafe!!
//
// TODO: Allow passing in an option to ignore the symbol table
//
//===----------------------------------------------------------------------===//
#include "Reader.h"
#include "llvm/Bytecode/BytecodeHandler.h"
#include "llvm/BasicBlock.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/SymbolTable.h"
#include "llvm/Bytecode/Format.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "Support/StringExtras.h"
#include <sstream>
using namespace llvm;
namespace {
/// @brief A class for maintaining the slot number definition
/// as a placeholder for the actual definition for forward constants defs.
class ConstantPlaceHolder : public ConstantExpr {
unsigned ID;
ConstantPlaceHolder(); // DO NOT IMPLEMENT
void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
public:
ConstantPlaceHolder(const Type *Ty, unsigned id)
: ConstantExpr(Instruction::UserOp1, Constant::getNullValue(Ty), Ty),
ID(id) {}
unsigned getID() { return ID; }
};
}
// Provide some details on error
inline void BytecodeReader::error(std::string err) {
err += " (Vers=" ;
err += itostr(RevisionNum) ;
err += ", Pos=" ;
err += itostr(At-MemStart);
err += ")";
throw err;
}
//===----------------------------------------------------------------------===//
// Bytecode Reading Methods
//===----------------------------------------------------------------------===//
/// Determine if the current block being read contains any more data.
inline bool BytecodeReader::moreInBlock() {
return At < BlockEnd;
}
/// Throw an error if we've read past the end of the current block
inline void BytecodeReader::checkPastBlockEnd(const char * block_name) {
if (At > BlockEnd)
error(std::string("Attempt to read past the end of ") + block_name + " block.");
}
/// Align the buffer position to a 32 bit boundary
inline void BytecodeReader::align32() {
BufPtr Save = At;
At = (const unsigned char *)((unsigned long)(At+3) & (~3UL));
if (At > Save)
if (Handler) Handler->handleAlignment(At - Save);
if (At > BlockEnd)
error("Ran out of data while aligning!");
}
/// Read a whole unsigned integer
inline unsigned BytecodeReader::read_uint() {
if (At+4 > BlockEnd)
error("Ran out of data reading uint!");
At += 4;
return At[-4] | (At[-3] << 8) | (At[-2] << 16) | (At[-1] << 24);
}
/// Read a variable-bit-rate encoded unsigned integer
inline unsigned BytecodeReader::read_vbr_uint() {
unsigned Shift = 0;
unsigned Result = 0;
BufPtr Save = At;
do {
if (At == BlockEnd)
error("Ran out of data reading vbr_uint!");
Result |= (unsigned)((*At++) & 0x7F) << Shift;
Shift += 7;
} while (At[-1] & 0x80);
if (Handler) Handler->handleVBR32(At-Save);
return Result;
}
/// Read a variable-bit-rate encoded unsigned 64-bit integer.
inline uint64_t BytecodeReader::read_vbr_uint64() {
unsigned Shift = 0;
uint64_t Result = 0;
BufPtr Save = At;
do {
if (At == BlockEnd)
error("Ran out of data reading vbr_uint64!");
Result |= (uint64_t)((*At++) & 0x7F) << Shift;
Shift += 7;
} while (At[-1] & 0x80);
if (Handler) Handler->handleVBR64(At-Save);
return Result;
}
/// Read a variable-bit-rate encoded signed 64-bit integer.
inline int64_t BytecodeReader::read_vbr_int64() {
uint64_t R = read_vbr_uint64();
if (R & 1) {
if (R != 1)
return -(int64_t)(R >> 1);
else // There is no such thing as -0 with integers. "-0" really means
// 0x8000000000000000.
return 1LL << 63;
} else
return (int64_t)(R >> 1);
}
/// Read a pascal-style string (length followed by text)
inline std::string BytecodeReader::read_str() {
unsigned Size = read_vbr_uint();
const unsigned char *OldAt = At;
At += Size;
if (At > BlockEnd) // Size invalid?
error("Ran out of data reading a string!");
return std::string((char*)OldAt, Size);
}
/// Read an arbitrary block of data
inline void BytecodeReader::read_data(void *Ptr, void *End) {
unsigned char *Start = (unsigned char *)Ptr;
unsigned Amount = (unsigned char *)End - Start;
if (At+Amount > BlockEnd)
error("Ran out of data!");
std::copy(At, At+Amount, Start);
At += Amount;
}
/// Read a float value in little-endian order
inline void BytecodeReader::read_float(float& FloatVal) {
/// FIXME: This isn't optimal, it has size problems on some platforms
/// where FP is not IEEE.
union {
float f;
uint32_t i;
} FloatUnion;
FloatUnion.i = At[0] | (At[1] << 8) | (At[2] << 16) | (At[3] << 24);
At+=sizeof(uint32_t);
FloatVal = FloatUnion.f;
}
/// Read a double value in little-endian order
inline void BytecodeReader::read_double(double& DoubleVal) {
/// FIXME: This isn't optimal, it has size problems on some platforms
/// where FP is not IEEE.
union {
double d;
uint64_t i;
} DoubleUnion;
DoubleUnion.i = At[0] | (At[1] << 8) | (At[2] << 16) | (At[3] << 24) |
(uint64_t(At[4]) << 32) | (uint64_t(At[5]) << 40) |
(uint64_t(At[6]) << 48) | (uint64_t(At[7]) << 56);
At+=sizeof(uint64_t);
DoubleVal = DoubleUnion.d;
}
/// Read a block header and obtain its type and size
inline void BytecodeReader::read_block(unsigned &Type, unsigned &Size) {
if ( hasLongBlockHeaders ) {
Type = read_uint();
Size = read_uint();
switch (Type) {
case BytecodeFormat::Reserved_DoNotUse :
error("Reserved_DoNotUse used as Module Type?");
Type = BytecodeFormat::Module; break;
case BytecodeFormat::Module:
Type = BytecodeFormat::ModuleBlockID; break;
case BytecodeFormat::Function:
Type = BytecodeFormat::FunctionBlockID; break;
case BytecodeFormat::ConstantPool:
Type = BytecodeFormat::ConstantPoolBlockID; break;
case BytecodeFormat::SymbolTable:
Type = BytecodeFormat::SymbolTableBlockID; break;
case BytecodeFormat::ModuleGlobalInfo:
Type = BytecodeFormat::ModuleGlobalInfoBlockID; break;
case BytecodeFormat::GlobalTypePlane:
Type = BytecodeFormat::GlobalTypePlaneBlockID; break;
case BytecodeFormat::InstructionList:
Type = BytecodeFormat::InstructionListBlockID; break;
case BytecodeFormat::CompactionTable:
Type = BytecodeFormat::CompactionTableBlockID; break;
case BytecodeFormat::BasicBlock:
/// This block type isn't used after version 1.1. However, we have to
/// still allow the value in case this is an old bc format file.
/// We just let its value creep thru.
break;
default:
error("Invalid module type found: " + utostr(Type));
break;
}
} else {
Size = read_uint();
Type = Size & 0x1F; // mask low order five bits
Size >>= 5; // get rid of five low order bits, leaving high 27
}
BlockStart = At;
if (At + Size > BlockEnd)
error("Attempt to size a block past end of memory");
BlockEnd = At + Size;
if (Handler) Handler->handleBlock(Type, BlockStart, Size);
}
/// In LLVM 1.2 and before, Types were derived from Value and so they were
/// written as part of the type planes along with any other Value. In LLVM
/// 1.3 this changed so that Type does not derive from Value. Consequently,
/// the BytecodeReader's containers for Values can't contain Types because
/// there's no inheritance relationship. This means that the "Type Type"
/// plane is defunct along with the Type::TypeTyID TypeID. In LLVM 1.3
/// whenever a bytecode construct must have both types and values together,
/// the types are always read/written first and then the Values. Furthermore
/// since Type::TypeTyID no longer exists, its value (12) now corresponds to
/// Type::LabelTyID. In order to overcome this we must "sanitize" all the
/// type TypeIDs we encounter. For LLVM 1.3 bytecode files, there's no change.
/// For LLVM 1.2 and before, this function will decrement the type id by
/// one to account for the missing Type::TypeTyID enumerator if the value is
/// larger than 12 (Type::LabelTyID). If the value is exactly 12, then this
/// function returns true, otherwise false. This helps detect situations
/// where the pre 1.3 bytecode is indicating that what follows is a type.
/// @returns true iff type id corresponds to pre 1.3 "type type"
inline bool BytecodeReader::sanitizeTypeId(unsigned &TypeId) {
if (hasTypeDerivedFromValue) { /// do nothing if 1.3 or later
if (TypeId == Type::LabelTyID) {
TypeId = Type::VoidTyID; // sanitize it
return true; // indicate we got TypeTyID in pre 1.3 bytecode
} else if (TypeId > Type::LabelTyID)
--TypeId; // shift all planes down because type type plane is missing
}
return false;
}
/// Reads a vbr uint to read in a type id and does the necessary
/// conversion on it by calling sanitizeTypeId.
/// @returns true iff \p TypeId read corresponds to a pre 1.3 "type type"
/// @see sanitizeTypeId
inline bool BytecodeReader::read_typeid(unsigned &TypeId) {
TypeId = read_vbr_uint();
if ( !has32BitTypes )
if ( TypeId == 0x00FFFFFF )
TypeId = read_vbr_uint();
return sanitizeTypeId(TypeId);
}
//===----------------------------------------------------------------------===//
// IR Lookup Methods
//===----------------------------------------------------------------------===//
/// Determine if a type id has an implicit null value
inline bool BytecodeReader::hasImplicitNull(unsigned TyID) {
if (!hasExplicitPrimitiveZeros)
return TyID != Type::LabelTyID && TyID != Type::VoidTyID;
return TyID >= Type::FirstDerivedTyID;
}
/// Obtain a type given a typeid and account for things like compaction tables,
/// function level vs module level, and the offsetting for the primitive types.
const Type *BytecodeReader::getType(unsigned ID) {
if (ID < Type::FirstDerivedTyID)
if (const Type *T = Type::getPrimitiveType((Type::TypeID)ID))
return T; // Asked for a primitive type...
// Otherwise, derived types need offset...
ID -= Type::FirstDerivedTyID;
if (!CompactionTypes.empty()) {
if (ID >= CompactionTypes.size())
error("Type ID out of range for compaction table!");
return CompactionTypes[ID];
}
// Is it a module-level type?
if (ID < ModuleTypes.size())
return ModuleTypes[ID].get();
// Nope, is it a function-level type?
ID -= ModuleTypes.size();
if (ID < FunctionTypes.size())
return FunctionTypes[ID].get();
error("Illegal type reference!");
return Type::VoidTy;
}
/// Get a sanitized type id. This just makes sure that the \p ID
/// is both sanitized and not the "type type" of pre-1.3 bytecode.
/// @see sanitizeTypeId
inline const Type* BytecodeReader::getSanitizedType(unsigned& ID) {
if (sanitizeTypeId(ID))
error("Invalid type id encountered");
return getType(ID);
}
/// This method just saves some coding. It uses read_typeid to read
/// in a sanitized type id, errors that its not the type type, and
/// then calls getType to return the type value.
inline const Type* BytecodeReader::readSanitizedType() {
unsigned ID;
if (read_typeid(ID))
error("Invalid type id encountered");
return getType(ID);
}
/// Get the slot number associated with a type accounting for primitive
/// types, compaction tables, and function level vs module level.
unsigned BytecodeReader::getTypeSlot(const Type *Ty) {
if (Ty->isPrimitiveType())
return Ty->getTypeID();
// Scan the compaction table for the type if needed.
if (!CompactionTypes.empty()) {
std::vector<const Type*>::const_iterator I =
find(CompactionTypes.begin(), CompactionTypes.end(), Ty);
if (I == CompactionTypes.end())
error("Couldn't find type specified in compaction table!");
return Type::FirstDerivedTyID + (&*I - &CompactionTypes[0]);
}
// Check the function level types first...
TypeListTy::iterator I = find(FunctionTypes.begin(), FunctionTypes.end(), Ty);
if (I != FunctionTypes.end())
return Type::FirstDerivedTyID + ModuleTypes.size() +
(&*I - &FunctionTypes[0]);
// Check the module level types now...
I = find(ModuleTypes.begin(), ModuleTypes.end(), Ty);
if (I == ModuleTypes.end())
error("Didn't find type in ModuleTypes.");
return Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
}
/// This is just like getType, but when a compaction table is in use, it is
/// ignored. It also ignores function level types.
/// @see getType
const Type *BytecodeReader::getGlobalTableType(unsigned Slot) {
if (Slot < Type::FirstDerivedTyID) {
const Type *Ty = Type::getPrimitiveType((Type::TypeID)Slot);
if (!Ty)
error("Not a primitive type ID?");
return Ty;
}
Slot -= Type::FirstDerivedTyID;
if (Slot >= ModuleTypes.size())
error("Illegal compaction table type reference!");
return ModuleTypes[Slot];
}
/// This is just like getTypeSlot, but when a compaction table is in use, it
/// is ignored. It also ignores function level types.
unsigned BytecodeReader::getGlobalTableTypeSlot(const Type *Ty) {
if (Ty->isPrimitiveType())
return Ty->getTypeID();
TypeListTy::iterator I = find(ModuleTypes.begin(),
ModuleTypes.end(), Ty);
if (I == ModuleTypes.end())
error("Didn't find type in ModuleTypes.");
return Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
}
/// Retrieve a value of a given type and slot number, possibly creating
/// it if it doesn't already exist.
Value * BytecodeReader::getValue(unsigned type, unsigned oNum, bool Create) {
assert(type != Type::LabelTyID && "getValue() cannot get blocks!");
unsigned Num = oNum;
// If there is a compaction table active, it defines the low-level numbers.
// If not, the module values define the low-level numbers.
if (CompactionValues.size() > type && !CompactionValues[type].empty()) {
if (Num < CompactionValues[type].size())
return CompactionValues[type][Num];
Num -= CompactionValues[type].size();
} else {
// By default, the global type id is the type id passed in
unsigned GlobalTyID = type;
// If the type plane was compactified, figure out the global type ID
// by adding the derived type ids and the distance.
if (!CompactionTypes.empty() && type >= Type::FirstDerivedTyID) {
const Type *Ty = CompactionTypes[type-Type::FirstDerivedTyID];
TypeListTy::iterator I =
find(ModuleTypes.begin(), ModuleTypes.end(), Ty);
assert(I != ModuleTypes.end());
GlobalTyID = Type::FirstDerivedTyID + (&*I - &ModuleTypes[0]);
}
if (hasImplicitNull(GlobalTyID)) {
if (Num == 0)
return Constant::getNullValue(getType(type));
--Num;
}
if (GlobalTyID < ModuleValues.size() && ModuleValues[GlobalTyID]) {
if (Num < ModuleValues[GlobalTyID]->size())
return ModuleValues[GlobalTyID]->getOperand(Num);
Num -= ModuleValues[GlobalTyID]->size();
}
}
if (FunctionValues.size() > type &&
FunctionValues[type] &&
Num < FunctionValues[type]->size())
return FunctionValues[type]->getOperand(Num);
if (!Create) return 0; // Do not create a placeholder?
std::pair<unsigned,unsigned> KeyValue(type, oNum);
ForwardReferenceMap::iterator I = ForwardReferences.lower_bound(KeyValue);
if (I != ForwardReferences.end() && I->first == KeyValue)
return I->second; // We have already created this placeholder
Value *Val = new Argument(getType(type));
ForwardReferences.insert(I, std::make_pair(KeyValue, Val));
return Val;
}
/// This is just like getValue, but when a compaction table is in use, it
/// is ignored. Also, no forward references or other fancy features are
/// supported.
Value* BytecodeReader::getGlobalTableValue(const Type *Ty, unsigned SlotNo) {
// FIXME: getTypeSlot is inefficient!
unsigned TyID = getGlobalTableTypeSlot(Ty);
if (TyID != Type::LabelTyID) {
if (SlotNo == 0)
return Constant::getNullValue(Ty);
--SlotNo;
}
if (TyID >= ModuleValues.size() || ModuleValues[TyID] == 0 ||
SlotNo >= ModuleValues[TyID]->size()) {
error("Corrupt compaction table entry!"
+ utostr(TyID) + ", " + utostr(SlotNo) + ": "
+ utostr(ModuleValues.size()) + ", "
+ utohexstr(intptr_t((void*)ModuleValues[TyID])) + ", "
+ utostr(ModuleValues[TyID]->size()));
}
return ModuleValues[TyID]->getOperand(SlotNo);
}
/// Just like getValue, except that it returns a null pointer
/// only on error. It always returns a constant (meaning that if the value is
/// defined, but is not a constant, that is an error). If the specified
/// constant hasn't been parsed yet, a placeholder is defined and used.
/// Later, after the real value is parsed, the placeholder is eliminated.
Constant* BytecodeReader::getConstantValue(unsigned TypeSlot, unsigned Slot) {
if (Value *V = getValue(TypeSlot, Slot, false))
if (Constant *C = dyn_cast<Constant>(V))
return C; // If we already have the value parsed, just return it
else
error("Value for slot " + utostr(Slot) +
" is expected to be a constant!");
const Type *Ty = getType(TypeSlot);
std::pair<const Type*, unsigned> Key(Ty, Slot);
ConstantRefsType::iterator I = ConstantFwdRefs.lower_bound(Key);
if (I != ConstantFwdRefs.end() && I->first == Key) {
return I->second;
} else {
// Create a placeholder for the constant reference and
// keep track of the fact that we have a forward ref to recycle it
Constant *C = new ConstantPlaceHolder(Ty, Slot);
// Keep track of the fact that we have a forward ref to recycle it
ConstantFwdRefs.insert(I, std::make_pair(Key, C));
return C;
}
}
//===----------------------------------------------------------------------===//
// IR Construction Methods
//===----------------------------------------------------------------------===//
/// As values are created, they are inserted into the appropriate place
/// with this method. The ValueTable argument must be one of ModuleValues
/// or FunctionValues data members of this class.
unsigned BytecodeReader::insertValue(Value *Val, unsigned type,
ValueTable &ValueTab) {
assert((!isa<Constant>(Val) || !cast<Constant>(Val)->isNullValue()) ||
!hasImplicitNull(type) &&
"Cannot read null values from bytecode!");
if (ValueTab.size() <= type)
ValueTab.resize(type+1);
if (!ValueTab[type]) ValueTab[type] = new ValueList();
ValueTab[type]->push_back(Val);
bool HasOffset = hasImplicitNull(type);
return ValueTab[type]->size()-1 + HasOffset;
}
/// Insert the arguments of a function as new values in the reader.
void BytecodeReader::insertArguments(Function* F) {
const FunctionType *FT = F->getFunctionType();
Function::aiterator AI = F->abegin();
for (FunctionType::param_iterator It = FT->param_begin();
It != FT->param_end(); ++It, ++AI)
insertValue(AI, getTypeSlot(AI->getType()), FunctionValues);
}
//===----------------------------------------------------------------------===//
// Bytecode Parsing Methods
//===----------------------------------------------------------------------===//
/// This method parses a single instruction. The instruction is
/// inserted at the end of the \p BB provided. The arguments of
/// the instruction are provided in the \p Args vector.
void BytecodeReader::ParseInstruction(std::vector<unsigned> &Oprnds,
BasicBlock* BB) {
BufPtr SaveAt = At;
// Clear instruction data
Oprnds.clear();
unsigned iType = 0;
unsigned Opcode = 0;
unsigned Op = read_uint();
// bits Instruction format: Common to all formats
// --------------------------
// 01-00: Opcode type, fixed to 1.
// 07-02: Opcode
Opcode = (Op >> 2) & 63;
Oprnds.resize((Op >> 0) & 03);
// Extract the operands
switch (Oprnds.size()) {
case 1:
// bits Instruction format:
// --------------------------
// 19-08: Resulting type plane
// 31-20: Operand #1 (if set to (2^12-1), then zero operands)
//
iType = (Op >> 8) & 4095;
Oprnds[0] = (Op >> 20) & 4095;
if (Oprnds[0] == 4095) // Handle special encoding for 0 operands...
Oprnds.resize(0);
break;
case 2:
// bits Instruction format:
// --------------------------
// 15-08: Resulting type plane
// 23-16: Operand #1
// 31-24: Operand #2
//
iType = (Op >> 8) & 255;
Oprnds[0] = (Op >> 16) & 255;
Oprnds[1] = (Op >> 24) & 255;
break;
case 3:
// bits Instruction format:
// --------------------------
// 13-08: Resulting type plane
// 19-14: Operand #1
// 25-20: Operand #2
// 31-26: Operand #3
//
iType = (Op >> 8) & 63;
Oprnds[0] = (Op >> 14) & 63;
Oprnds[1] = (Op >> 20) & 63;
Oprnds[2] = (Op >> 26) & 63;
break;
case 0:
At -= 4; // Hrm, try this again...
Opcode = read_vbr_uint();
Opcode >>= 2;
iType = read_vbr_uint();
unsigned NumOprnds = read_vbr_uint();
Oprnds.resize(NumOprnds);
if (NumOprnds == 0)
error("Zero-argument instruction found; this is invalid.");
for (unsigned i = 0; i != NumOprnds; ++i)
Oprnds[i] = read_vbr_uint();
align32();
break;
}
const Type *InstTy = getSanitizedType(iType);
// We have enough info to inform the handler now.
if (Handler) Handler->handleInstruction(Opcode, InstTy, Oprnds, At-SaveAt);
// Declare the resulting instruction we'll build.
Instruction *Result = 0;
// Handle binary operators
if (Opcode >= Instruction::BinaryOpsBegin &&
Opcode < Instruction::BinaryOpsEnd && Oprnds.size() == 2)
Result = BinaryOperator::create((Instruction::BinaryOps)Opcode,
getValue(iType, Oprnds[0]),
getValue(iType, Oprnds[1]));
switch (Opcode) {
default:
if (Result == 0)
error("Illegal instruction read!");
break;
case Instruction::VAArg:
Result = new VAArgInst(getValue(iType, Oprnds[0]),
getSanitizedType(Oprnds[1]));
break;
case Instruction::VANext:
Result = new VANextInst(getValue(iType, Oprnds[0]),
getSanitizedType(Oprnds[1]));
break;
case Instruction::Cast:
Result = new CastInst(getValue(iType, Oprnds[0]),
getSanitizedType(Oprnds[1]));
break;
case Instruction::Select:
Result = new SelectInst(getValue(Type::BoolTyID, Oprnds[0]),
getValue(iType, Oprnds[1]),
getValue(iType, Oprnds[2]));
break;
case Instruction::PHI: {
if (Oprnds.size() == 0 || (Oprnds.size() & 1))
error("Invalid phi node encountered!");
PHINode *PN = new PHINode(InstTy);
PN->op_reserve(Oprnds.size());
for (unsigned i = 0, e = Oprnds.size(); i != e; i += 2)
PN->addIncoming(getValue(iType, Oprnds[i]), getBasicBlock(Oprnds[i+1]));
Result = PN;
break;
}
case Instruction::Shl:
case Instruction::Shr:
Result = new ShiftInst((Instruction::OtherOps)Opcode,
getValue(iType, Oprnds[0]),
getValue(Type::UByteTyID, Oprnds[1]));
break;
case Instruction::Ret:
if (Oprnds.size() == 0)
Result = new ReturnInst();
else if (Oprnds.size() == 1)
Result = new ReturnInst(getValue(iType, Oprnds[0]));
else
error("Unrecognized instruction!");
break;
case Instruction::Br:
if (Oprnds.size() == 1)
Result = new BranchInst(getBasicBlock(Oprnds[0]));
else if (Oprnds.size() == 3)
Result = new BranchInst(getBasicBlock(Oprnds[0]),
getBasicBlock(Oprnds[1]), getValue(Type::BoolTyID , Oprnds[2]));
else
error("Invalid number of operands for a 'br' instruction!");
break;
case Instruction::Switch: {
if (Oprnds.size() & 1)
error("Switch statement with odd number of arguments!");
SwitchInst *I = new SwitchInst(getValue(iType, Oprnds[0]),
getBasicBlock(Oprnds[1]));
for (unsigned i = 2, e = Oprnds.size(); i != e; i += 2)
I->addCase(cast<Constant>(getValue(iType, Oprnds[i])),
getBasicBlock(Oprnds[i+1]));
Result = I;
break;
}
case Instruction::Call: {
if (Oprnds.size() == 0)
error("Invalid call instruction encountered!");
Value *F = getValue(iType, Oprnds[0]);
// Check to make sure we have a pointer to function type
const PointerType *PTy = dyn_cast<PointerType>(F->getType());
if (PTy == 0) error("Call to non function pointer value!");
const FunctionType *FTy = dyn_cast<FunctionType>(PTy->getElementType());
if (FTy == 0) error("Call to non function pointer value!");
std::vector<Value *> Params;
if (!FTy->isVarArg()) {
FunctionType::param_iterator It = FTy->param_begin();
for (unsigned i = 1, e = Oprnds.size(); i != e; ++i) {
if (It == FTy->param_end())
error("Invalid call instruction!");
Params.push_back(getValue(getTypeSlot(*It++), Oprnds[i]));
}
if (It != FTy->param_end())
error("Invalid call instruction!");
} else {
Oprnds.erase(Oprnds.begin(), Oprnds.begin()+1);
unsigned FirstVariableOperand;
if (Oprnds.size() < FTy->getNumParams())
error("Call instruction missing operands!");
// Read all of the fixed arguments
for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
Params.push_back(getValue(getTypeSlot(FTy->getParamType(i)),Oprnds[i]));
FirstVariableOperand = FTy->getNumParams();
if ((Oprnds.size()-FirstVariableOperand) & 1) // Must be pairs of type/value
error("Invalid call instruction!");
for (unsigned i = FirstVariableOperand, e = Oprnds.size();
i != e; i += 2)
Params.push_back(getValue(Oprnds[i], Oprnds[i+1]));
}
Result = new CallInst(F, Params);
break;
}
case Instruction::Invoke: {
if (Oprnds.size() < 3)
error("Invalid invoke instruction!");
Value *F = getValue(iType, Oprnds[0]);
// Check to make sure we have a pointer to function type
const PointerType *PTy = dyn_cast<PointerType>(F->getType());
if (PTy == 0)
error("Invoke to non function pointer value!");
const FunctionType *FTy = dyn_cast<FunctionType>(PTy->getElementType());
if (FTy == 0)
error("Invoke to non function pointer value!");
std::vector<Value *> Params;
BasicBlock *Normal, *Except;
if (!FTy->isVarArg()) {
Normal = getBasicBlock(Oprnds[1]);
Except = getBasicBlock(Oprnds[2]);
FunctionType::param_iterator It = FTy->param_begin();
for (unsigned i = 3, e = Oprnds.size(); i != e; ++i) {
if (It == FTy->param_end())
error("Invalid invoke instruction!");
Params.push_back(getValue(getTypeSlot(*It++), Oprnds[i]));
}
if (It != FTy->param_end())
error("Invalid invoke instruction!");
} else {
Oprnds.erase(Oprnds.begin(), Oprnds.begin()+1);
Normal = getBasicBlock(Oprnds[0]);
Except = getBasicBlock(Oprnds[1]);
unsigned FirstVariableArgument = FTy->getNumParams()+2;
for (unsigned i = 2; i != FirstVariableArgument; ++i)
Params.push_back(getValue(getTypeSlot(FTy->getParamType(i-2)),
Oprnds[i]));
if (Oprnds.size()-FirstVariableArgument & 1) // Must be type/value pairs
error("Invalid invoke instruction!");
for (unsigned i = FirstVariableArgument; i < Oprnds.size(); i += 2)
Params.push_back(getValue(Oprnds[i], Oprnds[i+1]));
}
Result = new InvokeInst(F, Normal, Except, Params);
break;
}
case Instruction::Malloc:
if (Oprnds.size() > 2)
error("Invalid malloc instruction!");
if (!isa<PointerType>(InstTy))
error("Invalid malloc instruction!");
Result = new MallocInst(cast<PointerType>(InstTy)->getElementType(),
Oprnds.size() ? getValue(Type::UIntTyID,
Oprnds[0]) : 0);
break;
case Instruction::Alloca:
if (Oprnds.size() > 2)
error("Invalid alloca instruction!");
if (!isa<PointerType>(InstTy))
error("Invalid alloca instruction!");
Result = new AllocaInst(cast<PointerType>(InstTy)->getElementType(),
Oprnds.size() ? getValue(Type::UIntTyID,
Oprnds[0]) :0);
break;
case Instruction::Free:
if (!isa<PointerType>(InstTy))
error("Invalid free instruction!");
Result = new FreeInst(getValue(iType, Oprnds[0]));
break;
case Instruction::GetElementPtr: {
if (Oprnds.size() == 0 || !isa<PointerType>(InstTy))
error("Invalid getelementptr instruction!");
std::vector<Value*> Idx;
const Type *NextTy = InstTy;
for (unsigned i = 1, e = Oprnds.size(); i != e; ++i) {
const CompositeType *TopTy = dyn_cast_or_null<CompositeType>(NextTy);
if (!TopTy)
error("Invalid getelementptr instruction!");
unsigned ValIdx = Oprnds[i];
unsigned IdxTy = 0;
if (!hasRestrictedGEPTypes) {
// Struct indices are always uints, sequential type indices can be any
// of the 32 or 64-bit integer types. The actual choice of type is
// encoded in the low two bits of the slot number.
if (isa<StructType>(TopTy))
IdxTy = Type::UIntTyID;
else {
switch (ValIdx & 3) {
default:
case 0: IdxTy = Type::UIntTyID; break;
case 1: IdxTy = Type::IntTyID; break;
case 2: IdxTy = Type::ULongTyID; break;
case 3: IdxTy = Type::LongTyID; break;
}
ValIdx >>= 2;
}
} else {
IdxTy = isa<StructType>(TopTy) ? Type::UByteTyID : Type::LongTyID;
}
Idx.push_back(getValue(IdxTy, ValIdx));
// Convert ubyte struct indices into uint struct indices.
if (isa<StructType>(TopTy) && hasRestrictedGEPTypes)
if (ConstantUInt *C = dyn_cast<ConstantUInt>(Idx.back()))
Idx[Idx.size()-1] = ConstantExpr::getCast(C, Type::UIntTy);
NextTy = GetElementPtrInst::getIndexedType(InstTy, Idx, true);
}
Result = new GetElementPtrInst(getValue(iType, Oprnds[0]), Idx);
break;
}
case 62: // volatile load
case Instruction::Load:
if (Oprnds.size() != 1 || !isa<PointerType>(InstTy))
error("Invalid load instruction!");
Result = new LoadInst(getValue(iType, Oprnds[0]), "", Opcode == 62);
break;
case 63: // volatile store
case Instruction::Store: {
if (!isa<PointerType>(InstTy) || Oprnds.size() != 2)
error("Invalid store instruction!");
Value *Ptr = getValue(iType, Oprnds[1]);
const Type *ValTy = cast<PointerType>(Ptr->getType())->getElementType();
Result = new StoreInst(getValue(getTypeSlot(ValTy), Oprnds[0]), Ptr,
Opcode == 63);
break;
}
case Instruction::Unwind:
if (Oprnds.size() != 0)
error("Invalid unwind instruction!");
Result = new UnwindInst();
break;
} // end switch(Opcode)
unsigned TypeSlot;
if (Result->getType() == InstTy)
TypeSlot = iType;
else
TypeSlot = getTypeSlot(Result->getType());
insertValue(Result, TypeSlot, FunctionValues);
BB->getInstList().push_back(Result);
}
/// Get a particular numbered basic block, which might be a forward reference.
/// This works together with ParseBasicBlock to handle these forward references
/// in a clean manner. This function is used when constructing phi, br, switch,
/// and other instructions that reference basic blocks. Blocks are numbered
/// sequentially as they appear in the function.
BasicBlock *BytecodeReader::getBasicBlock(unsigned ID) {
// Make sure there is room in the table...
if (ParsedBasicBlocks.size() <= ID) ParsedBasicBlocks.resize(ID+1);
// First check to see if this is a backwards reference, i.e., ParseBasicBlock
// has already created this block, or if the forward reference has already
// been created.
if (ParsedBasicBlocks[ID])
return ParsedBasicBlocks[ID];
// Otherwise, the basic block has not yet been created. Do so and add it to
// the ParsedBasicBlocks list.
return ParsedBasicBlocks[ID] = new BasicBlock();
}
/// In LLVM 1.0 bytecode files, we used to output one basicblock at a time.
/// This method reads in one of the basicblock packets. This method is not used
/// for bytecode files after LLVM 1.0
/// @returns The basic block constructed.
BasicBlock *BytecodeReader::ParseBasicBlock(unsigned BlockNo) {
if (Handler) Handler->handleBasicBlockBegin(BlockNo);
BasicBlock *BB = 0;
if (ParsedBasicBlocks.size() == BlockNo)
ParsedBasicBlocks.push_back(BB = new BasicBlock());
else if (ParsedBasicBlocks[BlockNo] == 0)
BB = ParsedBasicBlocks[BlockNo] = new BasicBlock();
else
BB = ParsedBasicBlocks[BlockNo];
std::vector<unsigned> Operands;
while (moreInBlock())
ParseInstruction(Operands, BB);
if (Handler) Handler->handleBasicBlockEnd(BlockNo);
return BB;
}
/// Parse all of the BasicBlock's & Instruction's in the body of a function.
/// In post 1.0 bytecode files, we no longer emit basic block individually,
/// in order to avoid per-basic-block overhead.
/// @returns Rhe number of basic blocks encountered.
unsigned BytecodeReader::ParseInstructionList(Function* F) {
unsigned BlockNo = 0;
std::vector<unsigned> Args;
while (moreInBlock()) {
if (Handler) Handler->handleBasicBlockBegin(BlockNo);
BasicBlock *BB;
if (ParsedBasicBlocks.size() == BlockNo)
ParsedBasicBlocks.push_back(BB = new BasicBlock());
else if (ParsedBasicBlocks[BlockNo] == 0)
BB = ParsedBasicBlocks[BlockNo] = new BasicBlock();
else
BB = ParsedBasicBlocks[BlockNo];
++BlockNo;
F->getBasicBlockList().push_back(BB);
// Read instructions into this basic block until we get to a terminator
while (moreInBlock() && !BB->getTerminator())
ParseInstruction(Args, BB);
if (!BB->getTerminator())
error("Non-terminated basic block found!");
if (Handler) Handler->handleBasicBlockEnd(BlockNo-1);
}
return BlockNo;
}
/// Parse a symbol table. This works for both module level and function
/// level symbol tables. For function level symbol tables, the CurrentFunction
/// parameter must be non-zero and the ST parameter must correspond to
/// CurrentFunction's symbol table. For Module level symbol tables, the
/// CurrentFunction argument must be zero.
void BytecodeReader::ParseSymbolTable(Function *CurrentFunction,
SymbolTable *ST) {
if (Handler) Handler->handleSymbolTableBegin(CurrentFunction,ST);
// Allow efficient basic block lookup by number.
std::vector<BasicBlock*> BBMap;
if (CurrentFunction)
for (Function::iterator I = CurrentFunction->begin(),
E = CurrentFunction->end(); I != E; ++I)
BBMap.push_back(I);
/// In LLVM 1.3 we write types separately from values so
/// The types are always first in the symbol table. This is
/// because Type no longer derives from Value.
if (!hasTypeDerivedFromValue) {
// Symtab block header: [num entries]
unsigned NumEntries = read_vbr_uint();
for (unsigned i = 0; i < NumEntries; ++i) {
// Symtab entry: [def slot #][name]
unsigned slot = read_vbr_uint();
std::string Name = read_str();
const Type* T = getType(slot);
ST->insert(Name, T);
}
}
while (moreInBlock()) {
// Symtab block header: [num entries][type id number]
unsigned NumEntries = read_vbr_uint();
unsigned Typ = 0;
bool isTypeType = read_typeid(Typ);
const Type *Ty = getType(Typ);
for (unsigned i = 0; i != NumEntries; ++i) {
// Symtab entry: [def slot #][name]
unsigned slot = read_vbr_uint();
std::string Name = read_str();
// if we're reading a pre 1.3 bytecode file and the type plane
// is the "type type", handle it here
if (isTypeType) {
const Type* T = getType(slot);
if (T == 0)
error("Failed type look-up for name '" + Name + "'");
ST->insert(Name, T);
continue; // code below must be short circuited
} else {
Value *V = 0;
if (Typ == Type::LabelTyID) {
if (slot < BBMap.size())
V = BBMap[slot];
} else {
V = getValue(Typ, slot, false); // Find mapping...
}
if (V == 0)
error("Failed value look-up for name '" + Name + "'");
V->setName(Name, ST);
}
}
}
checkPastBlockEnd("Symbol Table");
if (Handler) Handler->handleSymbolTableEnd();
}
/// Read in the types portion of a compaction table.
void BytecodeReader::ParseCompactionTypes(unsigned NumEntries) {
for (unsigned i = 0; i != NumEntries; ++i) {
unsigned TypeSlot = 0;
if (read_typeid(TypeSlot))
error("Invalid type in compaction table: type type");
const Type *Typ = getGlobalTableType(TypeSlot);
CompactionTypes.push_back(Typ);
if (Handler) Handler->handleCompactionTableType(i, TypeSlot, Typ);
}
}
/// Parse a compaction table.
void BytecodeReader::ParseCompactionTable() {
// Notify handler that we're beginning a compaction table.
if (Handler) Handler->handleCompactionTableBegin();
// In LLVM 1.3 Type no longer derives from Value. So,
// we always write them first in the compaction table
// because they can't occupy a "type plane" where the
// Values reside.
if (! hasTypeDerivedFromValue) {
unsigned NumEntries = read_vbr_uint();
ParseCompactionTypes(NumEntries);
}
// Compaction tables live in separate blocks so we have to loop
// until we've read the whole thing.
while (moreInBlock()) {
// Read the number of Value* entries in the compaction table
unsigned NumEntries = read_vbr_uint();
unsigned Ty = 0;
unsigned isTypeType = false;
// Decode the type from value read in. Most compaction table
// planes will have one or two entries in them. If that's the
// case then the length is encoded in the bottom two bits and
// the higher bits encode the type. This saves another VBR value.
if ((NumEntries & 3) == 3) {
// In this case, both low-order bits are set (value 3). This
// is a signal that the typeid follows.
NumEntries >>= 2;
isTypeType = read_typeid(Ty);
} else {
// In this case, the low-order bits specify the number of entries
// and the high order bits specify the type.
Ty = NumEntries >> 2;
isTypeType = sanitizeTypeId(Ty);
NumEntries &= 3;
}
// if we're reading a pre 1.3 bytecode file and the type plane
// is the "type type", handle it here
if (isTypeType) {
ParseCompactionTypes(NumEntries);
} else {
// Make sure we have enough room for the plane
if (Ty >= CompactionValues.size())
CompactionValues.resize(Ty+1);
// Make sure the plane is empty or we have some kind of error
if (!CompactionValues[Ty].empty())
error("Compaction table plane contains multiple entries!");
// Notify handler about the plane
if (Handler) Handler->handleCompactionTablePlane(Ty, NumEntries);
// Convert the type slot to a type
const Type *Typ = getType(Ty);
// Push the implicit zero
CompactionValues[Ty].push_back(Constant::getNullValue(Typ));
// Read in each of the entries, put them in the compaction table
// and notify the handler that we have a new compaction table value.
for (unsigned i = 0; i != NumEntries; ++i) {
unsigned ValSlot = read_vbr_uint();
Value *V = getGlobalTableValue(Typ, ValSlot);
CompactionValues[Ty].push_back(V);
if (Handler) Handler->handleCompactionTableValue(i, Ty, ValSlot, Typ);
}
}
}
// Notify handler that the compaction table is done.
if (Handler) Handler->handleCompactionTableEnd();
}
// Parse a single type. The typeid is read in first. If its a primitive type
// then nothing else needs to be read, we know how to instantiate it. If its
// a derived type, then additional data is read to fill out the type
// definition.
const Type *BytecodeReader::ParseType() {
unsigned PrimType = 0;
if (read_typeid(PrimType))
error("Invalid type (type type) in type constants!");
const Type *Result = 0;
if ((Result = Type::getPrimitiveType((Type::TypeID)PrimType)))
return Result;
switch (PrimType) {
case Type::FunctionTyID: {
const Type *RetType = readSanitizedType();
unsigned NumParams = read_vbr_uint();
std::vector<const Type*> Params;
while (NumParams--)
Params.push_back(readSanitizedType());
bool isVarArg = Params.size() && Params.back() == Type::VoidTy;
if (isVarArg) Params.pop_back();
Result = FunctionType::get(RetType, Params, isVarArg);
break;
}
case Type::ArrayTyID: {
const Type *ElementType = readSanitizedType();
unsigned NumElements = read_vbr_uint();
Result = ArrayType::get(ElementType, NumElements);
break;
}
case Type::StructTyID: {
std::vector<const Type*> Elements;
unsigned Typ = 0;
if (read_typeid(Typ))
error("Invalid element type (type type) for structure!");
while (Typ) { // List is terminated by void/0 typeid
Elements.push_back(getType(Typ));
if (read_typeid(Typ))
error("Invalid element type (type type) for structure!");
}
Result = StructType::get(Elements);
break;
}
case Type::PointerTyID: {
Result = PointerType::get(readSanitizedType());
break;
}
case Type::OpaqueTyID: {
Result = OpaqueType::get();
break;
}
default:
error("Don't know how to deserialize primitive type " + utostr(PrimType));
break;
}
if (Handler) Handler->handleType(Result);
return Result;
}
// ParseType - We have to use this weird code to handle recursive
// types. We know that recursive types will only reference the current slab of
// values in the type plane, but they can forward reference types before they
// have been read. For example, Type #0 might be '{ Ty#1 }' and Type #1 might
// be 'Ty#0*'. When reading Type #0, type number one doesn't exist. To fix
// this ugly problem, we pessimistically insert an opaque type for each type we
// are about to read. This means that forward references will resolve to
// something and when we reread the type later, we can replace the opaque type
// with a new resolved concrete type.
//
void BytecodeReader::ParseTypes(TypeListTy &Tab, unsigned NumEntries){
assert(Tab.size() == 0 && "should not have read type constants in before!");
// Insert a bunch of opaque types to be resolved later...
Tab.reserve(NumEntries);
for (unsigned i = 0; i != NumEntries; ++i)
Tab.push_back(OpaqueType::get());
// Loop through reading all of the types. Forward types will make use of the
// opaque types just inserted.
//
for (unsigned i = 0; i != NumEntries; ++i) {
const Type* NewTy = ParseType();
const Type* OldTy = Tab[i].get();
if (NewTy == 0)
error("Couldn't parse type!");
// Don't directly push the new type on the Tab. Instead we want to replace
// the opaque type we previously inserted with the new concrete value. This
// approach helps with forward references to types. The refinement from the
// abstract (opaque) type to the new type causes all uses of the abstract
// type to use the concrete type (NewTy). This will also cause the opaque
// type to be deleted.
cast<DerivedType>(const_cast<Type*>(OldTy))->refineAbstractTypeTo(NewTy);
// This should have replaced the old opaque type with the new type in the
// value table... or with a preexisting type that was already in the system.
// Let's just make sure it did.
assert(Tab[i] != OldTy && "refineAbstractType didn't work!");
}
}
/// Parse a single constant value
Constant *BytecodeReader::ParseConstantValue(unsigned TypeID) {
// We must check for a ConstantExpr before switching by type because
// a ConstantExpr can be of any type, and has no explicit value.
//
// 0 if not expr; numArgs if is expr
unsigned isExprNumArgs = read_vbr_uint();
if (isExprNumArgs) {
// FIXME: Encoding of constant exprs could be much more compact!
std::vector<Constant*> ArgVec;
ArgVec.reserve(isExprNumArgs);
unsigned Opcode = read_vbr_uint();
// Read the slot number and types of each of the arguments
for (unsigned i = 0; i != isExprNumArgs; ++i) {
unsigned ArgValSlot = read_vbr_uint();
unsigned ArgTypeSlot = 0;
if (read_typeid(ArgTypeSlot))
error("Invalid argument type (type type) for constant value");
// Get the arg value from its slot if it exists, otherwise a placeholder
ArgVec.push_back(getConstantValue(ArgTypeSlot, ArgValSlot));
}
// Construct a ConstantExpr of the appropriate kind
if (isExprNumArgs == 1) { // All one-operand expressions
if (Opcode != Instruction::Cast)
error("Only Cast instruction has one argument for ConstantExpr");
Constant* Result = ConstantExpr::getCast(ArgVec[0], getType(TypeID));
if (Handler) Handler->handleConstantExpression(Opcode, ArgVec, Result);
return Result;
} else if (Opcode == Instruction::GetElementPtr) { // GetElementPtr
std::vector<Constant*> IdxList(ArgVec.begin()+1, ArgVec.end());
if (hasRestrictedGEPTypes) {
const Type *BaseTy = ArgVec[0]->getType();
generic_gep_type_iterator<std::vector<Constant*>::iterator>
GTI = gep_type_begin(BaseTy, IdxList.begin(), IdxList.end()),
E = gep_type_end(BaseTy, IdxList.begin(), IdxList.end());
for (unsigned i = 0; GTI != E; ++GTI, ++i)
if (isa<StructType>(*GTI)) {
if (IdxList[i]->getType() != Type::UByteTy)
error("Invalid index for getelementptr!");
IdxList[i] = ConstantExpr::getCast(IdxList[i], Type::UIntTy);
}
}
Constant* Result = ConstantExpr::getGetElementPtr(ArgVec[0], IdxList);
if (Handler) Handler->handleConstantExpression(Opcode, ArgVec, Result);
return Result;
} else if (Opcode == Instruction::Select) {
if (ArgVec.size() != 3)
error("Select instruction must have three arguments.");
Constant* Result = ConstantExpr::getSelect(ArgVec[0], ArgVec[1],
ArgVec[2]);
if (Handler) Handler->handleConstantExpression(Opcode, ArgVec, Result);
return Result;
} else { // All other 2-operand expressions
Constant* Result = ConstantExpr::get(Opcode, ArgVec[0], ArgVec[1]);
if (Handler) Handler->handleConstantExpression(Opcode, ArgVec, Result);
return Result;
}
}
// Ok, not an ConstantExpr. We now know how to read the given type...
const Type *Ty = getType(TypeID);
switch (Ty->getTypeID()) {
case Type::BoolTyID: {
unsigned Val = read_vbr_uint();
if (Val != 0 && Val != 1)
error("Invalid boolean value read.");
Constant* Result = ConstantBool::get(Val == 1);
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::UByteTyID: // Unsigned integer types...
case Type::UShortTyID:
case Type::UIntTyID: {
unsigned Val = read_vbr_uint();
if (!ConstantUInt::isValueValidForType(Ty, Val))
error("Invalid unsigned byte/short/int read.");
Constant* Result = ConstantUInt::get(Ty, Val);
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::ULongTyID: {
Constant* Result = ConstantUInt::get(Ty, read_vbr_uint64());
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::SByteTyID: // Signed integer types...
case Type::ShortTyID:
case Type::IntTyID: {
case Type::LongTyID:
int64_t Val = read_vbr_int64();
if (!ConstantSInt::isValueValidForType(Ty, Val))
error("Invalid signed byte/short/int/long read.");
Constant* Result = ConstantSInt::get(Ty, Val);
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::FloatTyID: {
float Val;
read_float(Val);
Constant* Result = ConstantFP::get(Ty, Val);
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::DoubleTyID: {
double Val;
read_double(Val);
Constant* Result = ConstantFP::get(Ty, Val);
if (Handler) Handler->handleConstantValue(Result);
return Result;
}
case Type::ArrayTyID: {
const ArrayType *AT = cast<ArrayType>(Ty);
unsigned NumElements = AT->getNumElements();
unsigned TypeSlot = getTypeSlot(AT->getElementType());
std::vector<Constant*> Elements;
Elements.reserve(NumElements);
while (NumElements--) // Read all of the elements of the constant.
Elements.push_back(getConstantValue(TypeSlot,
read_vbr_uint()));
Constant* Result = ConstantArray::get(AT, Elements);
if (Handler) Handler->handleConstantArray(AT, Elements, TypeSlot, Result);
return Result;
}
case Type::StructTyID: {
const StructType *ST = cast<StructType>(Ty);
std::vector<Constant *> Elements;
Elements.reserve(ST->getNumElements());
for (unsigned i = 0; i != ST->getNumElements(); ++i)
Elements.push_back(getConstantValue(ST->getElementType(i),
read_vbr_uint()));
Constant* Result = ConstantStruct::get(ST, Elements);
if (Handler) Handler->handleConstantStruct(ST, Elements, Result);
return Result;
}
case Type::PointerTyID: { // ConstantPointerRef value...
const PointerType *PT = cast<PointerType>(Ty);
unsigned Slot = read_vbr_uint();
// Check to see if we have already read this global variable...
Value *Val = getValue(TypeID, Slot, false);
GlobalValue *GV;
if (Val) {
if (!(GV = dyn_cast<GlobalValue>(Val)))
error("GlobalValue not in ValueTable!");
} else {
error("Forward references are not allowed here.");
}
if (Handler) Handler->handleConstantPointer(PT, Slot, GV );
return GV;
}
default:
error("Don't know how to deserialize constant value of type '" +
Ty->getDescription());
break;
}
return 0;
}
/// Resolve references for constants. This function resolves the forward
/// referenced constants in the ConstantFwdRefs map. It uses the
/// replaceAllUsesWith method of Value class to substitute the placeholder
/// instance with the actual instance.
void BytecodeReader::ResolveReferencesToConstant(Constant *NewV, unsigned Slot){
ConstantRefsType::iterator I =
ConstantFwdRefs.find(std::make_pair(NewV->getType(), Slot));
if (I == ConstantFwdRefs.end()) return; // Never forward referenced?
Value *PH = I->second; // Get the placeholder...
PH->replaceAllUsesWith(NewV);
delete PH; // Delete the old placeholder
ConstantFwdRefs.erase(I); // Remove the map entry for it
}
/// Parse the constant strings section.
void BytecodeReader::ParseStringConstants(unsigned NumEntries, ValueTable &Tab){
for (; NumEntries; --NumEntries) {
unsigned Typ = 0;
if (read_typeid(Typ))
error("Invalid type (type type) for string constant");
const Type *Ty = getType(Typ);
if (!isa<ArrayType>(Ty))
error("String constant data invalid!");
const ArrayType *ATy = cast<ArrayType>(Ty);
if (ATy->getElementType() != Type::SByteTy &&
ATy->getElementType() != Type::UByteTy)
error("String constant data invalid!");
// Read character data. The type tells us how long the string is.
char Data[ATy->getNumElements()];
read_data(Data, Data+ATy->getNumElements());
std::vector<Constant*> Elements(ATy->getNumElements());
if (ATy->getElementType() == Type::SByteTy)
for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
Elements[i] = ConstantSInt::get(Type::SByteTy, (signed char)Data[i]);
else
for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i)
Elements[i] = ConstantUInt::get(Type::UByteTy, (unsigned char)Data[i]);
// Create the constant, inserting it as needed.
Constant *C = ConstantArray::get(ATy, Elements);
unsigned Slot = insertValue(C, Typ, Tab);
ResolveReferencesToConstant(C, Slot);
if (Handler) Handler->handleConstantString(cast<ConstantArray>(C));
}
}
/// Parse the constant pool.
void BytecodeReader::ParseConstantPool(ValueTable &Tab,
TypeListTy &TypeTab,
bool isFunction) {
if (Handler) Handler->handleGlobalConstantsBegin();
/// In LLVM 1.3 Type does not derive from Value so the types
/// do not occupy a plane. Consequently, we read the types
/// first in the constant pool.
if (isFunction && !hasTypeDerivedFromValue) {
unsigned NumEntries = read_vbr_uint();
ParseTypes(TypeTab, NumEntries);
}
while (moreInBlock()) {
unsigned NumEntries = read_vbr_uint();
unsigned Typ = 0;
bool isTypeType = read_typeid(Typ);
/// In LLVM 1.2 and before, Types were written to the
/// bytecode file in the "Type Type" plane (#12).
/// In 1.3 plane 12 is now the label plane. Handle this here.
if (isTypeType) {
ParseTypes(TypeTab, NumEntries);
} else if (Typ == Type::VoidTyID) {
/// Use of Type::VoidTyID is a misnomer. It actually means
/// that the following plane is constant strings
assert(&Tab == &ModuleValues && "Cannot read strings in functions!");
ParseStringConstants(NumEntries, Tab);
} else {
for (unsigned i = 0; i < NumEntries; ++i) {
Constant *C = ParseConstantValue(Typ);
assert(C && "ParseConstantValue returned NULL!");
unsigned Slot = insertValue(C, Typ, Tab);
// If we are reading a function constant table, make sure that we adjust
// the slot number to be the real global constant number.
//
if (&Tab != &ModuleValues && Typ < ModuleValues.size() &&
ModuleValues[Typ])
Slot += ModuleValues[Typ]->size();
ResolveReferencesToConstant(C, Slot);
}
}
}
checkPastBlockEnd("Constant Pool");
if (Handler) Handler->handleGlobalConstantsEnd();
}
/// Parse the contents of a function. Note that this function can be
/// called lazily by materializeFunction
/// @see materializeFunction
void BytecodeReader::ParseFunctionBody(Function* F) {
unsigned FuncSize = BlockEnd - At;
GlobalValue::LinkageTypes Linkage = GlobalValue::ExternalLinkage;
unsigned LinkageType = read_vbr_uint();
switch (LinkageType) {
case 0: Linkage = GlobalValue::ExternalLinkage; break;
case 1: Linkage = GlobalValue::WeakLinkage; break;
case 2: Linkage = GlobalValue::AppendingLinkage; break;
case 3: Linkage = GlobalValue::InternalLinkage; break;
case 4: Linkage = GlobalValue::LinkOnceLinkage; break;
default:
error("Invalid linkage type for Function.");
Linkage = GlobalValue::InternalLinkage;
break;
}
F->setLinkage(Linkage);
if (Handler) Handler->handleFunctionBegin(F,FuncSize);
// Keep track of how many basic blocks we have read in...
unsigned BlockNum = 0;
bool InsertedArguments = false;
BufPtr MyEnd = BlockEnd;
while (At < MyEnd) {
unsigned Type, Size;
BufPtr OldAt = At;
read_block(Type, Size);
switch (Type) {
case BytecodeFormat::ConstantPoolBlockID:
if (!InsertedArguments) {
// Insert arguments into the value table before we parse the first basic
// block in the function, but after we potentially read in the
// compaction table.
insertArguments(F);
InsertedArguments = true;
}
ParseConstantPool(FunctionValues, FunctionTypes, true);
break;
case BytecodeFormat::CompactionTableBlockID:
ParseCompactionTable();
break;
case BytecodeFormat::BasicBlock: {
if (!InsertedArguments) {
// Insert arguments into the value table before we parse the first basic
// block in the function, but after we potentially read in the
// compaction table.
insertArguments(F);
InsertedArguments = true;
}
BasicBlock *BB = ParseBasicBlock(BlockNum++);
F->getBasicBlockList().push_back(BB);
break;
}
case BytecodeFormat::InstructionListBlockID: {
// Insert arguments into the value table before we parse the instruction
// list for the function, but after we potentially read in the compaction
// table.
if (!InsertedArguments) {
insertArguments(F);
InsertedArguments = true;
}
if (BlockNum)
error("Already parsed basic blocks!");
BlockNum = ParseInstructionList(F);
break;
}
case BytecodeFormat::SymbolTableBlockID:
ParseSymbolTable(F, &F->getSymbolTable());
break;
default:
At += Size;
if (OldAt > At)
error("Wrapped around reading bytecode.");
break;
}
BlockEnd = MyEnd;
// Malformed bc file if read past end of block.
align32();
}
// Make sure there were no references to non-existant basic blocks.
if (BlockNum != ParsedBasicBlocks.size())
error("Illegal basic block operand reference");
ParsedBasicBlocks.clear();
// Resolve forward references. Replace any uses of a forward reference value
// with the real value.
// replaceAllUsesWith is very inefficient for instructions which have a LARGE
// number of operands. PHI nodes often have forward references, and can also
// often have a very large number of operands.
//
// FIXME: REEVALUATE. replaceAllUsesWith is _much_ faster now, and this code
// should be simplified back to using it!
//
std::map<Value*, Value*> ForwardRefMapping;
for (std::map<std::pair<unsigned,unsigned>, Value*>::iterator
I = ForwardReferences.begin(), E = ForwardReferences.end();
I != E; ++I)
ForwardRefMapping[I->second] = getValue(I->first.first, I->first.second,
false);
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
if (Argument *A = dyn_cast<Argument>(I->getOperand(i))) {
std::map<Value*, Value*>::iterator It = ForwardRefMapping.find(A);
if (It != ForwardRefMapping.end()) I->setOperand(i, It->second);
}
while (!ForwardReferences.empty()) {
std::map<std::pair<unsigned,unsigned>, Value*>::iterator I =
ForwardReferences.begin();
Value *PlaceHolder = I->second;
ForwardReferences.erase(I);
// Now that all the uses are gone, delete the placeholder...
// If we couldn't find a def (error case), then leak a little
// memory, because otherwise we can't remove all uses!
delete PlaceHolder;
}
// Clear out function-level types...
FunctionTypes.clear();
CompactionTypes.clear();
CompactionValues.clear();
freeTable(FunctionValues);
if (Handler) Handler->handleFunctionEnd(F);
}
/// This function parses LLVM functions lazily. It obtains the type of the
/// function and records where the body of the function is in the bytecode
/// buffer. The caller can then use the ParseNextFunction and
/// ParseAllFunctionBodies to get handler events for the functions.
void BytecodeReader::ParseFunctionLazily() {
if (FunctionSignatureList.empty())
error("FunctionSignatureList empty!");
Function *Func = FunctionSignatureList.back();
FunctionSignatureList.pop_back();
// Save the information for future reading of the function
LazyFunctionLoadMap[Func] = LazyFunctionInfo(BlockStart, BlockEnd);
// Pretend we've `parsed' this function
At = BlockEnd;
}
/// The ParserFunction method lazily parses one function. Use this method to
/// casue the parser to parse a specific function in the module. Note that
/// this will remove the function from what is to be included by
/// ParseAllFunctionBodies.
/// @see ParseAllFunctionBodies
/// @see ParseBytecode
void BytecodeReader::ParseFunction(Function* Func) {
// Find {start, end} pointers and slot in the map. If not there, we're done.
LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.find(Func);
// Make sure we found it
if (Fi == LazyFunctionLoadMap.end()) {
error("Unrecognized function of type " + Func->getType()->getDescription());
return;
}
BlockStart = At = Fi->second.Buf;
BlockEnd = Fi->second.EndBuf;
assert(Fi->first == Func && "Found wrong function?");
LazyFunctionLoadMap.erase(Fi);
this->ParseFunctionBody(Func);
}
/// The ParseAllFunctionBodies method parses through all the previously
/// unparsed functions in the bytecode file. If you want to completely parse
/// a bytecode file, this method should be called after Parsebytecode because
/// Parsebytecode only records the locations in the bytecode file of where
/// the function definitions are located. This function uses that information
/// to materialize the functions.
/// @see ParseBytecode
void BytecodeReader::ParseAllFunctionBodies() {
LazyFunctionMap::iterator Fi = LazyFunctionLoadMap.begin();
LazyFunctionMap::iterator Fe = LazyFunctionLoadMap.end();
while (Fi != Fe) {
Function* Func = Fi->first;
BlockStart = At = Fi->second.Buf;
BlockEnd = Fi->second.EndBuf;
this->ParseFunctionBody(Func);
++Fi;
}
}
/// Parse the global type list
void BytecodeReader::ParseGlobalTypes() {
// Read the number of types
unsigned NumEntries = read_vbr_uint();
// Ignore the type plane identifier for types if the bc file is pre 1.3
if (hasTypeDerivedFromValue)
read_vbr_uint();
ParseTypes(ModuleTypes, NumEntries);
}
/// Parse the Global info (types, global vars, constants)
void BytecodeReader::ParseModuleGlobalInfo() {
if (Handler) Handler->handleModuleGlobalsBegin();
// Read global variables...
unsigned VarType = read_vbr_uint();
while (VarType != Type::VoidTyID) { // List is terminated by Void
// VarType Fields: bit0 = isConstant, bit1 = hasInitializer, bit2,3,4 =
// Linkage, bit4+ = slot#
unsigned SlotNo = VarType >> 5;
if (sanitizeTypeId(SlotNo))
error("Invalid type (type type) for global var!");
unsigned LinkageID = (VarType >> 2) & 7;
bool isConstant = VarType & 1;
bool hasInitializer = VarType & 2;
GlobalValue::LinkageTypes Linkage;
switch (LinkageID) {
case 0: Linkage = GlobalValue::ExternalLinkage; break;
case 1: Linkage = GlobalValue::WeakLinkage; break;
case 2: Linkage = GlobalValue::AppendingLinkage; break;
case 3: Linkage = GlobalValue::InternalLinkage; break;
case 4: Linkage = GlobalValue::LinkOnceLinkage; break;
default:
error("Unknown linkage type: " + utostr(LinkageID));
Linkage = GlobalValue::InternalLinkage;
break;
}
const Type *Ty = getType(SlotNo);
if (!Ty) {
error("Global has no type! SlotNo=" + utostr(SlotNo));
}
if (!isa<PointerType>(Ty)) {
error("Global not a pointer type! Ty= " + Ty->getDescription());
}
const Type *ElTy = cast<PointerType>(Ty)->getElementType();
// Create the global variable...
GlobalVariable *GV = new GlobalVariable(ElTy, isConstant, Linkage,
0, "", TheModule);
insertValue(GV, SlotNo, ModuleValues);
unsigned initSlot = 0;
if (hasInitializer) {
initSlot = read_vbr_uint();
GlobalInits.push_back(std::make_pair(GV, initSlot));
}
// Notify handler about the global value.
if (Handler) Handler->handleGlobalVariable(ElTy, isConstant, Linkage, SlotNo, initSlot);
// Get next item
VarType = read_vbr_uint();
}
// Read the function objects for all of the functions that are coming
unsigned FnSignature = 0;
if (read_typeid(FnSignature))
error("Invalid function type (type type) found");
while (FnSignature != Type::VoidTyID) { // List is terminated by Void
const Type *Ty = getType(FnSignature);
if (!isa<PointerType>(Ty) ||
!isa<FunctionType>(cast<PointerType>(Ty)->getElementType())) {
error("Function not a pointer to function type! Ty = " +
Ty->getDescription());
// FIXME: what should Ty be if handler continues?
}
// We create functions by passing the underlying FunctionType to create...
const FunctionType* FTy =
cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
// Insert the place hodler
Function* Func = new Function(FTy, GlobalValue::InternalLinkage,
"", TheModule);
insertValue(Func, FnSignature, ModuleValues);
// Save this for later so we know type of lazily instantiated functions
FunctionSignatureList.push_back(Func);
if (Handler) Handler->handleFunctionDeclaration(Func);
// Get Next function signature
if (read_typeid(FnSignature))
error("Invalid function type (type type) found");
}
// Now that the function signature list is set up, reverse it so that we can
// remove elements efficiently from the back of the vector.
std::reverse(FunctionSignatureList.begin(), FunctionSignatureList.end());
// If this bytecode format has dependent library information in it ..
if (!hasNoDependentLibraries) {
// Read in the number of dependent library items that follow
unsigned num_dep_libs = read_vbr_uint();
std::string dep_lib;
while( num_dep_libs-- ) {
dep_lib = read_str();
TheModule->addLibrary(dep_lib);
}
// Read target triple and place into the module
std::string triple = read_str();
TheModule->setTargetTriple(triple);
}
if (hasInconsistentModuleGlobalInfo)
align32();
// This is for future proofing... in the future extra fields may be added that
// we don't understand, so we transparently ignore them.
//
At = BlockEnd;
if (Handler) Handler->handleModuleGlobalsEnd();
}
/// Parse the version information and decode it by setting flags on the
/// Reader that enable backward compatibility of the reader.
void BytecodeReader::ParseVersionInfo() {
unsigned Version = read_vbr_uint();
// Unpack version number: low four bits are for flags, top bits = version
Module::Endianness Endianness;
Module::PointerSize PointerSize;
Endianness = (Version & 1) ? Module::BigEndian : Module::LittleEndian;
PointerSize = (Version & 2) ? Module::Pointer64 : Module::Pointer32;
bool hasNoEndianness = Version & 4;
bool hasNoPointerSize = Version & 8;
RevisionNum = Version >> 4;
// Default values for the current bytecode version
hasInconsistentModuleGlobalInfo = false;
hasExplicitPrimitiveZeros = false;
hasRestrictedGEPTypes = false;
hasTypeDerivedFromValue = false;
hasLongBlockHeaders = false;
has32BitTypes = false;
hasNoDependentLibraries = false;
switch (RevisionNum) {
case 0: // LLVM 1.0, 1.1 release version
// Base LLVM 1.0 bytecode format.
hasInconsistentModuleGlobalInfo = true;
hasExplicitPrimitiveZeros = true;
// FALL THROUGH
case 1: // LLVM 1.2 release version
// LLVM 1.2 added explicit support for emitting strings efficiently.
// Also, it fixed the problem where the size of the ModuleGlobalInfo block
// included the size for the alignment at the end, where the rest of the
// blocks did not.
// LLVM 1.2 and before required that GEP indices be ubyte constants for
// structures and longs for sequential types.
hasRestrictedGEPTypes = true;
// LLVM 1.2 and before had the Type class derive from Value class. This
// changed in release 1.3 and consequently LLVM 1.3 bytecode files are
// written differently because Types can no longer be part of the
// type planes for Values.
hasTypeDerivedFromValue = true;
// FALL THROUGH
case 2: /// 1.2.5 (mid-release) version
/// LLVM 1.2 and earlier had two-word block headers. This is a bit wasteful,
/// especially for small files where the 8 bytes per block is a large fraction
/// of the total block size. In LLVM 1.3, the block type and length are
/// compressed into a single 32-bit unsigned integer. 27 bits for length, 5
/// bits for block type.
hasLongBlockHeaders = true;
/// LLVM 1.2 and earlier wrote type slot numbers as vbr_uint32. In LLVM 1.3
/// this has been reduced to vbr_uint24. It shouldn't make much difference
/// since we haven't run into a module with > 24 million types, but for safety
/// the 24-bit restriction has been enforced in 1.3 to free some bits in
/// various places and to ensure consistency.
has32BitTypes = true;
/// LLVM 1.2 and earlier did not provide a target triple nor a list of
/// libraries on which the bytecode is dependent. LLVM 1.3 provides these
/// features, for use in future versions of LLVM.
hasNoDependentLibraries = true;
// FALL THROUGH
case 3: // LLVM 1.3 release version
break;
default:
error("Unknown bytecode version number: " + itostr(RevisionNum));
}
if (hasNoEndianness) Endianness = Module::AnyEndianness;
if (hasNoPointerSize) PointerSize = Module::AnyPointerSize;
TheModule->setEndianness(Endianness);
TheModule->setPointerSize(PointerSize);
if (Handler) Handler->handleVersionInfo(RevisionNum, Endianness, PointerSize);
}
/// Parse a whole module.
void BytecodeReader::ParseModule() {
unsigned Type, Size;
FunctionSignatureList.clear(); // Just in case...
// Read into instance variables...
ParseVersionInfo();
align32();
bool SeenModuleGlobalInfo = false;
bool SeenGlobalTypePlane = false;
BufPtr MyEnd = BlockEnd;
while (At < MyEnd) {
BufPtr OldAt = At;
read_block(Type, Size);
switch (Type) {
case BytecodeFormat::GlobalTypePlaneBlockID:
if (SeenGlobalTypePlane)
error("Two GlobalTypePlane Blocks Encountered!");
ParseGlobalTypes();
SeenGlobalTypePlane = true;
break;
case BytecodeFormat::ModuleGlobalInfoBlockID:
if (SeenModuleGlobalInfo)
error("Two ModuleGlobalInfo Blocks Encountered!");
ParseModuleGlobalInfo();
SeenModuleGlobalInfo = true;
break;
case BytecodeFormat::ConstantPoolBlockID:
ParseConstantPool(ModuleValues, ModuleTypes,false);
break;
case BytecodeFormat::FunctionBlockID:
ParseFunctionLazily();
break;
case BytecodeFormat::SymbolTableBlockID:
ParseSymbolTable(0, &TheModule->getSymbolTable());
break;
default:
At += Size;
if (OldAt > At) {
error("Unexpected Block of Type #" + utostr(Type) + " encountered!");
}
break;
}
BlockEnd = MyEnd;
align32();
}
// After the module constant pool has been read, we can safely initialize
// global variables...
while (!GlobalInits.empty()) {
GlobalVariable *GV = GlobalInits.back().first;
unsigned Slot = GlobalInits.back().second;
GlobalInits.pop_back();
// Look up the initializer value...
// FIXME: Preserve this type ID!
const llvm::PointerType* GVType = GV->getType();
unsigned TypeSlot = getTypeSlot(GVType->getElementType());
if (Constant *CV = getConstantValue(TypeSlot, Slot)) {
if (GV->hasInitializer())
error("Global *already* has an initializer?!");
if (Handler) Handler->handleGlobalInitializer(GV,CV);
GV->setInitializer(CV);
} else
error("Cannot find initializer value.");
}
/// Make sure we pulled them all out. If we didn't then there's a declaration
/// but a missing body. That's not allowed.
if (!FunctionSignatureList.empty())
error("Function declared, but bytecode stream ended before definition");
}
/// This function completely parses a bytecode buffer given by the \p Buf
/// and \p Length parameters.
void BytecodeReader::ParseBytecode(BufPtr Buf, unsigned Length,
const std::string &ModuleID,
bool processFunctions) {
try {
At = MemStart = BlockStart = Buf;
MemEnd = BlockEnd = Buf + Length;
// Create the module
TheModule = new Module(ModuleID);
if (Handler) Handler->handleStart(TheModule, Length);
// Read and check signature...
unsigned Sig = read_uint();
if (Sig != ('l' | ('l' << 8) | ('v' << 16) | ('m' << 24))) {
error("Invalid bytecode signature: " + utostr(Sig));
}
// Tell the handler we're starting a module
if (Handler) Handler->handleModuleBegin(ModuleID);
// Get the module block and size and verify. This is handled specially
// because the module block/size is always written in long format. Other
// blocks are written in short format so the read_block method is used.
unsigned Type, Size;
Type = read_uint();
Size = read_uint();
if (Type != BytecodeFormat::ModuleBlockID) {
error("Expected Module Block! Type:" + utostr(Type) + ", Size:"
+ utostr(Size));
}
if (At + Size != MemEnd) {
error("Invalid Top Level Block Length! Type:" + utostr(Type)
+ ", Size:" + utostr(Size));
}
// Parse the module contents
this->ParseModule();
// Check for missing functions
if (hasFunctions())
error("Function expected, but bytecode stream ended!");
// Process all the function bodies now, if requested
if (processFunctions)
ParseAllFunctionBodies();
// Tell the handler we're done with the module
if (Handler)
Handler->handleModuleEnd(ModuleID);
// Tell the handler we're finished the parse
if (Handler) Handler->handleFinish();
} catch (std::string& errstr) {
if (Handler) Handler->handleError(errstr);
freeState();
delete TheModule;
TheModule = 0;
throw;
} catch (...) {
std::string msg("Unknown Exception Occurred");
if (Handler) Handler->handleError(msg);
freeState();
delete TheModule;
TheModule = 0;
throw msg;
}
}
//===----------------------------------------------------------------------===//
//=== Default Implementations of Handler Methods
//===----------------------------------------------------------------------===//
BytecodeHandler::~BytecodeHandler() {}
// vim: sw=2