//===-- ExecutionEngine.cpp - Common Implementation shared by EEs ---------===//
//
// 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 file defines the common interface used by the various execution engine
// subclasses.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "jit"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MutexGuard.h"
#include "llvm/System/DynamicLibrary.h"
#include "llvm/Target/TargetData.h"
using namespace llvm;
namespace {
Statistic NumInitBytes("lli", "Number of bytes of global vars initialized");
Statistic NumGlobals ("lli", "Number of global vars initialized");
}
ExecutionEngine::EECtorFn ExecutionEngine::JITCtor = 0;
ExecutionEngine::EECtorFn ExecutionEngine::InterpCtor = 0;
ExecutionEngine::ExecutionEngine(ModuleProvider *P) {
LazyCompilationDisabled = false;
Modules.push_back(P);
assert(P && "ModuleProvider is null?");
}
ExecutionEngine::ExecutionEngine(Module *M) {
LazyCompilationDisabled = false;
assert(M && "Module is null?");
Modules.push_back(new ExistingModuleProvider(M));
}
ExecutionEngine::~ExecutionEngine() {
for (unsigned i = 0, e = Modules.size(); i != e; ++i)
delete Modules[i];
}
/// FindFunctionNamed - Search all of the active modules to find the one that
/// defines FnName. This is very slow operation and shouldn't be used for
/// general code.
Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
if (Function *F = Modules[i]->getModule()->getNamedFunction(FnName))
return F;
}
return 0;
}
/// addGlobalMapping - Tell the execution engine that the specified global is
/// at the specified location. This is used internally as functions are JIT'd
/// and as global variables are laid out in memory. It can and should also be
/// used by clients of the EE that want to have an LLVM global overlay
/// existing data in memory.
void ExecutionEngine::addGlobalMapping(const GlobalValue *GV, void *Addr) {
MutexGuard locked(lock);
void *&CurVal = state.getGlobalAddressMap(locked)[GV];
assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
CurVal = Addr;
// If we are using the reverse mapping, add it too
if (!state.getGlobalAddressReverseMap(locked).empty()) {
const GlobalValue *&V = state.getGlobalAddressReverseMap(locked)[Addr];
assert((V == 0 || GV == 0) && "GlobalMapping already established!");
V = GV;
}
}
/// clearAllGlobalMappings - Clear all global mappings and start over again
/// use in dynamic compilation scenarios when you want to move globals
void ExecutionEngine::clearAllGlobalMappings() {
MutexGuard locked(lock);
state.getGlobalAddressMap(locked).clear();
state.getGlobalAddressReverseMap(locked).clear();
}
/// updateGlobalMapping - Replace an existing mapping for GV with a new
/// address. This updates both maps as required. If "Addr" is null, the
/// entry for the global is removed from the mappings.
void ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
MutexGuard locked(lock);
// Deleting from the mapping?
if (Addr == 0) {
state.getGlobalAddressMap(locked).erase(GV);
if (!state.getGlobalAddressReverseMap(locked).empty())
state.getGlobalAddressReverseMap(locked).erase(Addr);
return;
}
void *&CurVal = state.getGlobalAddressMap(locked)[GV];
if (CurVal && !state.getGlobalAddressReverseMap(locked).empty())
state.getGlobalAddressReverseMap(locked).erase(CurVal);
CurVal = Addr;
// If we are using the reverse mapping, add it too
if (!state.getGlobalAddressReverseMap(locked).empty()) {
const GlobalValue *&V = state.getGlobalAddressReverseMap(locked)[Addr];
assert((V == 0 || GV == 0) && "GlobalMapping already established!");
V = GV;
}
}
/// getPointerToGlobalIfAvailable - This returns the address of the specified
/// global value if it is has already been codegen'd, otherwise it returns null.
///
void *ExecutionEngine::getPointerToGlobalIfAvailable(const GlobalValue *GV) {
MutexGuard locked(lock);
std::map<const GlobalValue*, void*>::iterator I =
state.getGlobalAddressMap(locked).find(GV);
return I != state.getGlobalAddressMap(locked).end() ? I->second : 0;
}
/// getGlobalValueAtAddress - Return the LLVM global value object that starts
/// at the specified address.
///
const GlobalValue *ExecutionEngine::getGlobalValueAtAddress(void *Addr) {
MutexGuard locked(lock);
// If we haven't computed the reverse mapping yet, do so first.
if (state.getGlobalAddressReverseMap(locked).empty()) {
for (std::map<const GlobalValue*, void *>::iterator
I = state.getGlobalAddressMap(locked).begin(),
E = state.getGlobalAddressMap(locked).end(); I != E; ++I)
state.getGlobalAddressReverseMap(locked).insert(std::make_pair(I->second,
I->first));
}
std::map<void *, const GlobalValue*>::iterator I =
state.getGlobalAddressReverseMap(locked).find(Addr);
return I != state.getGlobalAddressReverseMap(locked).end() ? I->second : 0;
}
// CreateArgv - Turn a vector of strings into a nice argv style array of
// pointers to null terminated strings.
//
static void *CreateArgv(ExecutionEngine *EE,
const std::vector<std::string> &InputArgv) {
unsigned PtrSize = EE->getTargetData()->getPointerSize();
char *Result = new char[(InputArgv.size()+1)*PtrSize];
DOUT << "ARGV = " << (void*)Result << "\n";
const Type *SBytePtr = PointerType::get(Type::SByteTy);
for (unsigned i = 0; i != InputArgv.size(); ++i) {
unsigned Size = InputArgv[i].size()+1;
char *Dest = new char[Size];
DOUT << "ARGV[" << i << "] = " << (void*)Dest << "\n";
std::copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
Dest[Size-1] = 0;
// Endian safe: Result[i] = (PointerTy)Dest;
EE->StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Result+i*PtrSize),
SBytePtr);
}
// Null terminate it
EE->StoreValueToMemory(PTOGV(0),
(GenericValue*)(Result+InputArgv.size()*PtrSize),
SBytePtr);
return Result;
}
/// runStaticConstructorsDestructors - This method is used to execute all of
/// the static constructors or destructors for a program, depending on the
/// value of isDtors.
void ExecutionEngine::runStaticConstructorsDestructors(bool isDtors) {
const char *Name = isDtors ? "llvm.global_dtors" : "llvm.global_ctors";
// Execute global ctors/dtors for each module in the program.
for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
GlobalVariable *GV = Modules[m]->getModule()->getNamedGlobal(Name);
// If this global has internal linkage, or if it has a use, then it must be
// an old-style (llvmgcc3) static ctor with __main linked in and in use. If
// this is the case, don't execute any of the global ctors, __main will do
// it.
if (!GV || GV->isExternal() || GV->hasInternalLinkage()) continue;
// Should be an array of '{ int, void ()* }' structs. The first value is
// the init priority, which we ignore.
ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
if (!InitList) continue;
for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
if (ConstantStruct *CS =
dyn_cast<ConstantStruct>(InitList->getOperand(i))) {
if (CS->getNumOperands() != 2) break; // Not array of 2-element structs.
Constant *FP = CS->getOperand(1);
if (FP->isNullValue())
break; // Found a null terminator, exit.
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
if (CE->isCast())
FP = CE->getOperand(0);
if (Function *F = dyn_cast<Function>(FP)) {
// Execute the ctor/dtor function!
runFunction(F, std::vector<GenericValue>());
}
}
}
}
/// runFunctionAsMain - This is a helper function which wraps runFunction to
/// handle the common task of starting up main with the specified argc, argv,
/// and envp parameters.
int ExecutionEngine::runFunctionAsMain(Function *Fn,
const std::vector<std::string> &argv,
const char * const * envp) {
std::vector<GenericValue> GVArgs;
GenericValue GVArgc;
GVArgc.IntVal = argv.size();
unsigned NumArgs = Fn->getFunctionType()->getNumParams();
if (NumArgs) {
GVArgs.push_back(GVArgc); // Arg #0 = argc.
if (NumArgs > 1) {
GVArgs.push_back(PTOGV(CreateArgv(this, argv))); // Arg #1 = argv.
assert(((char **)GVTOP(GVArgs[1]))[0] &&
"argv[0] was null after CreateArgv");
if (NumArgs > 2) {
std::vector<std::string> EnvVars;
for (unsigned i = 0; envp[i]; ++i)
EnvVars.push_back(envp[i]);
GVArgs.push_back(PTOGV(CreateArgv(this, EnvVars))); // Arg #2 = envp.
}
}
}
return runFunction(Fn, GVArgs).IntVal;
}
/// If possible, create a JIT, unless the caller specifically requests an
/// Interpreter or there's an error. If even an Interpreter cannot be created,
/// NULL is returned.
///
ExecutionEngine *ExecutionEngine::create(ModuleProvider *MP,
bool ForceInterpreter) {
ExecutionEngine *EE = 0;
// Unless the interpreter was explicitly selected, try making a JIT.
if (!ForceInterpreter && JITCtor)
EE = JITCtor(MP);
// If we can't make a JIT, make an interpreter instead.
if (EE == 0 && InterpCtor)
EE = InterpCtor(MP);
if (EE) {
// Make sure we can resolve symbols in the program as well. The zero arg
// to the function tells DynamicLibrary to load the program, not a library.
try {
sys::DynamicLibrary::LoadLibraryPermanently(0);
} catch (...) {
}
}
return EE;
}
/// getPointerToGlobal - This returns the address of the specified global
/// value. This may involve code generation if it's a function.
///
void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
return getPointerToFunction(F);
MutexGuard locked(lock);
void *p = state.getGlobalAddressMap(locked)[GV];
if (p)
return p;
// Global variable might have been added since interpreter started.
if (GlobalVariable *GVar =
const_cast<GlobalVariable *>(dyn_cast<GlobalVariable>(GV)))
EmitGlobalVariable(GVar);
else
assert("Global hasn't had an address allocated yet!");
return state.getGlobalAddressMap(locked)[GV];
}
/// This function converts a Constant* into a GenericValue. The interesting
/// part is if C is a ConstantExpr.
/// @brief Get a GenericValue for a Constnat*
GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
// Declare the result as garbage.
GenericValue Result;
// If its undefined, return the garbage.
if (isa<UndefValue>(C)) return Result;
// If the value is a ConstantExpr
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
switch (CE->getOpcode()) {
case Instruction::GetElementPtr: {
// Compute the index
Result = getConstantValue(CE->getOperand(0));
std::vector<Value*> Indexes(CE->op_begin()+1, CE->op_end());
uint64_t Offset =
TD->getIndexedOffset(CE->getOperand(0)->getType(), Indexes);
if (getTargetData()->getPointerSize() == 4)
Result.IntVal += Offset;
else
Result.LongVal += Offset;
return Result;
}
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
break;
case Instruction::PtrToInt: {
Constant *Op = CE->getOperand(0);
GenericValue GV = getConstantValue(Op);
return GV;
}
case Instruction::BitCast: {
// Bit casts are no-ops but we can only return the GV of the operand if
// they are the same basic type (pointer->pointer, packed->packed, etc.)
Constant *Op = CE->getOperand(0);
GenericValue GV = getConstantValue(Op);
if (Op->getType()->getTypeID() == C->getType()->getTypeID())
return GV;
break;
}
case Instruction::IntToPtr: {
// IntToPtr casts are just so special. Cast to intptr_t first.
Constant *Op = CE->getOperand(0);
GenericValue GV = getConstantValue(Op);
switch (Op->getType()->getTypeID()) {
case Type::BoolTyID: return PTOGV((void*)(uintptr_t)GV.BoolVal);
case Type::SByteTyID: return PTOGV((void*)( intptr_t)GV.SByteVal);
case Type::UByteTyID: return PTOGV((void*)(uintptr_t)GV.UByteVal);
case Type::ShortTyID: return PTOGV((void*)( intptr_t)GV.ShortVal);
case Type::UShortTyID: return PTOGV((void*)(uintptr_t)GV.UShortVal);
case Type::IntTyID: return PTOGV((void*)( intptr_t)GV.IntVal);
case Type::UIntTyID: return PTOGV((void*)(uintptr_t)GV.UIntVal);
case Type::LongTyID: return PTOGV((void*)( intptr_t)GV.LongVal);
case Type::ULongTyID: return PTOGV((void*)(uintptr_t)GV.ULongVal);
default: assert(0 && "Unknown integral type!");
}
break;
}
case Instruction::Add:
switch (CE->getOperand(0)->getType()->getTypeID()) {
default: assert(0 && "Bad add type!"); abort();
case Type::LongTyID:
case Type::ULongTyID:
Result.LongVal = getConstantValue(CE->getOperand(0)).LongVal +
getConstantValue(CE->getOperand(1)).LongVal;
break;
case Type::IntTyID:
case Type::UIntTyID:
Result.IntVal = getConstantValue(CE->getOperand(0)).IntVal +
getConstantValue(CE->getOperand(1)).IntVal;
break;
case Type::ShortTyID:
case Type::UShortTyID:
Result.ShortVal = getConstantValue(CE->getOperand(0)).ShortVal +
getConstantValue(CE->getOperand(1)).ShortVal;
break;
case Type::SByteTyID:
case Type::UByteTyID:
Result.SByteVal = getConstantValue(CE->getOperand(0)).SByteVal +
getConstantValue(CE->getOperand(1)).SByteVal;
break;
case Type::FloatTyID:
Result.FloatVal = getConstantValue(CE->getOperand(0)).FloatVal +
getConstantValue(CE->getOperand(1)).FloatVal;
break;
case Type::DoubleTyID:
Result.DoubleVal = getConstantValue(CE->getOperand(0)).DoubleVal +
getConstantValue(CE->getOperand(1)).DoubleVal;
break;
}
return Result;
default:
break;
}
cerr << "ConstantExpr not handled as global var init: " << *CE << "\n";
abort();
}
switch (C->getType()->getTypeID()) {
#define GET_CONST_VAL(TY, CTY, CLASS, GETMETH) \
case Type::TY##TyID: Result.TY##Val = (CTY)cast<CLASS>(C)->GETMETH(); break
GET_CONST_VAL(Bool , bool , ConstantBool, getValue);
GET_CONST_VAL(UByte , unsigned char , ConstantInt, getZExtValue);
GET_CONST_VAL(SByte , signed char , ConstantInt, getSExtValue);
GET_CONST_VAL(UShort , unsigned short, ConstantInt, getZExtValue);
GET_CONST_VAL(Short , signed short , ConstantInt, getSExtValue);
GET_CONST_VAL(UInt , unsigned int , ConstantInt, getZExtValue);
GET_CONST_VAL(Int , signed int , ConstantInt, getSExtValue);
GET_CONST_VAL(ULong , uint64_t , ConstantInt, getZExtValue);
GET_CONST_VAL(Long , int64_t , ConstantInt, getSExtValue);
GET_CONST_VAL(Float , float , ConstantFP, getValue);
GET_CONST_VAL(Double , double , ConstantFP, getValue);
#undef GET_CONST_VAL
case Type::PointerTyID:
if (isa<ConstantPointerNull>(C))
Result.PointerVal = 0;
else if (const Function *F = dyn_cast<Function>(C))
Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
else if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
else
assert(0 && "Unknown constant pointer type!");
break;
default:
cerr << "ERROR: Constant unimp for type: " << *C->getType() << "\n";
abort();
}
return Result;
}
/// StoreValueToMemory - Stores the data in Val of type Ty at address Ptr. Ptr
/// is the address of the memory at which to store Val, cast to GenericValue *.
/// It is not a pointer to a GenericValue containing the address at which to
/// store Val.
///
void ExecutionEngine::StoreValueToMemory(GenericValue Val, GenericValue *Ptr,
const Type *Ty) {
if (getTargetData()->isLittleEndian()) {
switch (Ty->getTypeID()) {
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID: Ptr->Untyped[0] = Val.UByteVal; break;
case Type::UShortTyID:
case Type::ShortTyID: Ptr->Untyped[0] = Val.UShortVal & 255;
Ptr->Untyped[1] = (Val.UShortVal >> 8) & 255;
break;
Store4BytesLittleEndian:
case Type::FloatTyID:
case Type::UIntTyID:
case Type::IntTyID: Ptr->Untyped[0] = Val.UIntVal & 255;
Ptr->Untyped[1] = (Val.UIntVal >> 8) & 255;
Ptr->Untyped[2] = (Val.UIntVal >> 16) & 255;
Ptr->Untyped[3] = (Val.UIntVal >> 24) & 255;
break;
case Type::PointerTyID: if (getTargetData()->getPointerSize() == 4)
goto Store4BytesLittleEndian;
case Type::DoubleTyID:
case Type::ULongTyID:
case Type::LongTyID:
Ptr->Untyped[0] = (unsigned char)(Val.ULongVal );
Ptr->Untyped[1] = (unsigned char)(Val.ULongVal >> 8);
Ptr->Untyped[2] = (unsigned char)(Val.ULongVal >> 16);
Ptr->Untyped[3] = (unsigned char)(Val.ULongVal >> 24);
Ptr->Untyped[4] = (unsigned char)(Val.ULongVal >> 32);
Ptr->Untyped[5] = (unsigned char)(Val.ULongVal >> 40);
Ptr->Untyped[6] = (unsigned char)(Val.ULongVal >> 48);
Ptr->Untyped[7] = (unsigned char)(Val.ULongVal >> 56);
break;
default:
cerr << "Cannot store value of type " << *Ty << "!\n";
}
} else {
switch (Ty->getTypeID()) {
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID: Ptr->Untyped[0] = Val.UByteVal; break;
case Type::UShortTyID:
case Type::ShortTyID: Ptr->Untyped[1] = Val.UShortVal & 255;
Ptr->Untyped[0] = (Val.UShortVal >> 8) & 255;
break;
Store4BytesBigEndian:
case Type::FloatTyID:
case Type::UIntTyID:
case Type::IntTyID: Ptr->Untyped[3] = Val.UIntVal & 255;
Ptr->Untyped[2] = (Val.UIntVal >> 8) & 255;
Ptr->Untyped[1] = (Val.UIntVal >> 16) & 255;
Ptr->Untyped[0] = (Val.UIntVal >> 24) & 255;
break;
case Type::PointerTyID: if (getTargetData()->getPointerSize() == 4)
goto Store4BytesBigEndian;
case Type::DoubleTyID:
case Type::ULongTyID:
case Type::LongTyID:
Ptr->Untyped[7] = (unsigned char)(Val.ULongVal );
Ptr->Untyped[6] = (unsigned char)(Val.ULongVal >> 8);
Ptr->Untyped[5] = (unsigned char)(Val.ULongVal >> 16);
Ptr->Untyped[4] = (unsigned char)(Val.ULongVal >> 24);
Ptr->Untyped[3] = (unsigned char)(Val.ULongVal >> 32);
Ptr->Untyped[2] = (unsigned char)(Val.ULongVal >> 40);
Ptr->Untyped[1] = (unsigned char)(Val.ULongVal >> 48);
Ptr->Untyped[0] = (unsigned char)(Val.ULongVal >> 56);
break;
default:
cerr << "Cannot store value of type " << *Ty << "!\n";
}
}
}
/// FIXME: document
///
GenericValue ExecutionEngine::LoadValueFromMemory(GenericValue *Ptr,
const Type *Ty) {
GenericValue Result;
if (getTargetData()->isLittleEndian()) {
switch (Ty->getTypeID()) {
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID: Result.UByteVal = Ptr->Untyped[0]; break;
case Type::UShortTyID:
case Type::ShortTyID: Result.UShortVal = (unsigned)Ptr->Untyped[0] |
((unsigned)Ptr->Untyped[1] << 8);
break;
Load4BytesLittleEndian:
case Type::FloatTyID:
case Type::UIntTyID:
case Type::IntTyID: Result.UIntVal = (unsigned)Ptr->Untyped[0] |
((unsigned)Ptr->Untyped[1] << 8) |
((unsigned)Ptr->Untyped[2] << 16) |
((unsigned)Ptr->Untyped[3] << 24);
break;
case Type::PointerTyID: if (getTargetData()->getPointerSize() == 4)
goto Load4BytesLittleEndian;
case Type::DoubleTyID:
case Type::ULongTyID:
case Type::LongTyID: Result.ULongVal = (uint64_t)Ptr->Untyped[0] |
((uint64_t)Ptr->Untyped[1] << 8) |
((uint64_t)Ptr->Untyped[2] << 16) |
((uint64_t)Ptr->Untyped[3] << 24) |
((uint64_t)Ptr->Untyped[4] << 32) |
((uint64_t)Ptr->Untyped[5] << 40) |
((uint64_t)Ptr->Untyped[6] << 48) |
((uint64_t)Ptr->Untyped[7] << 56);
break;
default:
cerr << "Cannot load value of type " << *Ty << "!\n";
abort();
}
} else {
switch (Ty->getTypeID()) {
case Type::BoolTyID:
case Type::UByteTyID:
case Type::SByteTyID: Result.UByteVal = Ptr->Untyped[0]; break;
case Type::UShortTyID:
case Type::ShortTyID: Result.UShortVal = (unsigned)Ptr->Untyped[1] |
((unsigned)Ptr->Untyped[0] << 8);
break;
Load4BytesBigEndian:
case Type::FloatTyID:
case Type::UIntTyID:
case Type::IntTyID: Result.UIntVal = (unsigned)Ptr->Untyped[3] |
((unsigned)Ptr->Untyped[2] << 8) |
((unsigned)Ptr->Untyped[1] << 16) |
((unsigned)Ptr->Untyped[0] << 24);
break;
case Type::PointerTyID: if (getTargetData()->getPointerSize() == 4)
goto Load4BytesBigEndian;
case Type::DoubleTyID:
case Type::ULongTyID:
case Type::LongTyID: Result.ULongVal = (uint64_t)Ptr->Untyped[7] |
((uint64_t)Ptr->Untyped[6] << 8) |
((uint64_t)Ptr->Untyped[5] << 16) |
((uint64_t)Ptr->Untyped[4] << 24) |
((uint64_t)Ptr->Untyped[3] << 32) |
((uint64_t)Ptr->Untyped[2] << 40) |
((uint64_t)Ptr->Untyped[1] << 48) |
((uint64_t)Ptr->Untyped[0] << 56);
break;
default:
cerr << "Cannot load value of type " << *Ty << "!\n";
abort();
}
}
return Result;
}
// InitializeMemory - Recursive function to apply a Constant value into the
// specified memory location...
//
void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
if (isa<UndefValue>(Init)) {
return;
} else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(Init)) {
unsigned ElementSize =
getTargetData()->getTypeSize(CP->getType()->getElementType());
for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
InitializeMemory(CP->getOperand(i), (char*)Addr+i*ElementSize);
return;
} else if (Init->getType()->isFirstClassType()) {
GenericValue Val = getConstantValue(Init);
StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
return;
} else if (isa<ConstantAggregateZero>(Init)) {
memset(Addr, 0, (size_t)getTargetData()->getTypeSize(Init->getType()));
return;
}
switch (Init->getType()->getTypeID()) {
case Type::ArrayTyID: {
const ConstantArray *CPA = cast<ConstantArray>(Init);
unsigned ElementSize =
getTargetData()->getTypeSize(CPA->getType()->getElementType());
for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
return;
}
case Type::StructTyID: {
const ConstantStruct *CPS = cast<ConstantStruct>(Init);
const StructLayout *SL =
getTargetData()->getStructLayout(cast<StructType>(CPS->getType()));
for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->MemberOffsets[i]);
return;
}
default:
cerr << "Bad Type: " << *Init->getType() << "\n";
assert(0 && "Unknown constant type to initialize memory with!");
}
}
/// EmitGlobals - Emit all of the global variables to memory, storing their
/// addresses into GlobalAddress. This must make sure to copy the contents of
/// their initializers into the memory.
///
void ExecutionEngine::emitGlobals() {
const TargetData *TD = getTargetData();
// Loop over all of the global variables in the program, allocating the memory
// to hold them. If there is more than one module, do a prepass over globals
// to figure out how the different modules should link together.
//
std::map<std::pair<std::string, const Type*>,
const GlobalValue*> LinkedGlobalsMap;
if (Modules.size() != 1) {
for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
Module &M = *Modules[m]->getModule();
for (Module::const_global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I) {
const GlobalValue *GV = I;
if (GV->hasInternalLinkage() || GV->isExternal() ||
GV->hasAppendingLinkage() || !GV->hasName())
continue;// Ignore external globals and globals with internal linkage.
const GlobalValue *&GVEntry =
LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
// If this is the first time we've seen this global, it is the canonical
// version.
if (!GVEntry) {
GVEntry = GV;
continue;
}
// If the existing global is strong, never replace it.
if (GVEntry->hasExternalLinkage() ||
GVEntry->hasDLLImportLinkage() ||
GVEntry->hasDLLExportLinkage())
continue;
// Otherwise, we know it's linkonce/weak, replace it if this is a strong
// symbol.
if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
GVEntry = GV;
}
}
}
std::vector<const GlobalValue*> NonCanonicalGlobals;
for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
Module &M = *Modules[m]->getModule();
for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
// In the multi-module case, see what this global maps to.
if (!LinkedGlobalsMap.empty()) {
if (const GlobalValue *GVEntry =
LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
// If something else is the canonical global, ignore this one.
if (GVEntry != &*I) {
NonCanonicalGlobals.push_back(I);
continue;
}
}
}
if (!I->isExternal()) {
// Get the type of the global.
const Type *Ty = I->getType()->getElementType();
// Allocate some memory for it!
unsigned Size = TD->getTypeSize(Ty);
addGlobalMapping(I, new char[Size]);
} else {
// External variable reference. Try to use the dynamic loader to
// get a pointer to it.
if (void *SymAddr =
sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName().c_str()))
addGlobalMapping(I, SymAddr);
else {
cerr << "Could not resolve external global address: "
<< I->getName() << "\n";
abort();
}
}
}
// If there are multiple modules, map the non-canonical globals to their
// canonical location.
if (!NonCanonicalGlobals.empty()) {
for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
const GlobalValue *GV = NonCanonicalGlobals[i];
const GlobalValue *CGV =
LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
void *Ptr = getPointerToGlobalIfAvailable(CGV);
assert(Ptr && "Canonical global wasn't codegen'd!");
addGlobalMapping(GV, getPointerToGlobalIfAvailable(CGV));
}
}
// Now that all of the globals are set up in memory, loop through them all and
// initialize their contents.
for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
if (!I->isExternal()) {
if (!LinkedGlobalsMap.empty()) {
if (const GlobalValue *GVEntry =
LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())])
if (GVEntry != &*I) // Not the canonical variable.
continue;
}
EmitGlobalVariable(I);
}
}
}
}
// EmitGlobalVariable - This method emits the specified global variable to the
// address specified in GlobalAddresses, or allocates new memory if it's not
// already in the map.
void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
void *GA = getPointerToGlobalIfAvailable(GV);
DOUT << "Global '" << GV->getName() << "' -> " << GA << "\n";
const Type *ElTy = GV->getType()->getElementType();
size_t GVSize = (size_t)getTargetData()->getTypeSize(ElTy);
if (GA == 0) {
// If it's not already specified, allocate memory for the global.
GA = new char[GVSize];
addGlobalMapping(GV, GA);
}
InitializeMemory(GV->getInitializer(), GA);
NumInitBytes += (unsigned)GVSize;
++NumGlobals;
}