cling/lib/Interpreter/Value.cpp

274 lines
9.0 KiB
C++

//------------------------------------------------------------------------------
// CLING - the C++ LLVM-based InterpreterG :)
// author: Axel Naumann <axel@cern.ch>
//
// This file is dual-licensed: you can choose to license it under the University
// of Illinois Open Source License or the GNU Lesser General Public License. See
// LICENSE.TXT for details.
//------------------------------------------------------------------------------
#include "cling/Interpreter/Value.h"
#include "cling/Interpreter/Interpreter.h"
#include "cling/Interpreter/Transaction.h"
#include "cling/Utils/AST.h"
#include "cling/Utils/Output.h"
#include "cling/Utils/UTF8.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CanonicalType.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/Type.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Sema/Lookup.h"
#include "clang/Sema/Overload.h"
#include "clang/Sema/Sema.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/raw_os_ostream.h"
namespace {
///\brief The allocation starts with this layout; it is followed by the
/// value's object at m_Payload. This class does not inherit from
/// llvm::RefCountedBase because deallocation cannot use this type but must
/// free the character array.
class AllocatedValue {
public:
typedef void (*DtorFunc_t)(void*);
private:
///\brief The reference count - once 0, this object will be deallocated.
mutable unsigned m_RefCnt;
///\brief The destructor function.
DtorFunc_t m_DtorFunc;
///\brief The size of the allocation (for arrays)
unsigned long m_AllocSize;
///\brief The number of elements in the array
unsigned long m_NElements;
///\brief The start of the allocation.
char m_Payload[1];
static DtorFunc_t PtrToFunc(void* ptr) {
union {
void* m_Ptr;
DtorFunc_t m_Func;
};
m_Ptr = ptr;
return m_Func;
}
public:
///\brief Initialize the storage management part of the allocated object.
/// The allocator is referencing it, thus initialize m_RefCnt with 1.
///\param [in] dtorFunc - the function to be called before deallocation.
AllocatedValue(void* dtorFunc, size_t allocSize, size_t nElements):
m_RefCnt(1), m_DtorFunc(PtrToFunc(dtorFunc)), m_AllocSize(allocSize),
m_NElements(nElements)
{}
char* getPayload() { return m_Payload; }
static unsigned getPayloadOffset() {
static const AllocatedValue Dummy(0,0,0);
return Dummy.m_Payload - (const char*)&Dummy;
}
static AllocatedValue* getFromPayload(void* payload) {
return
reinterpret_cast<AllocatedValue*>((char*)payload - getPayloadOffset());
}
void Retain() { ++m_RefCnt; }
///\brief This object must be allocated as a char array. Deallocate it as
/// such.
void Release() {
assert (m_RefCnt > 0 && "Reference count is already zero.");
if (--m_RefCnt == 0) {
if (m_DtorFunc) {
char* payload = getPayload();
for (size_t el = 0; el < m_NElements; ++el)
(*m_DtorFunc)(payload + el * m_AllocSize / m_NElements);
}
delete [] (char*)this;
}
}
};
}
namespace cling {
Value::Value(const Value& other):
m_Storage(other.m_Storage), m_StorageType(other.m_StorageType),
m_Type(other.m_Type), m_Interpreter(other.m_Interpreter) {
if (other.needsManagedAllocation())
AllocatedValue::getFromPayload(m_Storage.m_Ptr)->Retain();
}
Value::Value(clang::QualType clangTy, Interpreter& Interp):
m_StorageType(determineStorageType(clangTy)),
m_Type(clangTy.getAsOpaquePtr()),
m_Interpreter(&Interp) {
if (needsManagedAllocation())
ManagedAllocate();
}
Value& Value::operator =(const Value& other) {
// Release old value.
if (needsManagedAllocation())
AllocatedValue::getFromPayload(m_Storage.m_Ptr)->Release();
// Retain new one.
m_Type = other.m_Type;
m_Storage = other.m_Storage;
m_StorageType = other.m_StorageType;
m_Interpreter = other.m_Interpreter;
if (needsManagedAllocation())
AllocatedValue::getFromPayload(m_Storage.m_Ptr)->Retain();
return *this;
}
Value& Value::operator =(Value&& other) {
// Release old value.
if (needsManagedAllocation())
AllocatedValue::getFromPayload(m_Storage.m_Ptr)->Release();
// Move new one.
m_Type = other.m_Type;
m_Storage = other.m_Storage;
m_StorageType = other.m_StorageType;
m_Interpreter = other.m_Interpreter;
// Invalidate other so it will not release.
other.m_StorageType = kUnsupportedType;
return *this;
}
Value::~Value() {
if (needsManagedAllocation())
AllocatedValue::getFromPayload(m_Storage.m_Ptr)->Release();
}
clang::QualType Value::getType() const {
return clang::QualType::getFromOpaquePtr(m_Type);
}
clang::ASTContext& Value::getASTContext() const {
return m_Interpreter->getCI()->getASTContext();
}
bool Value::isValid() const { return !getType().isNull(); }
bool Value::isVoid() const {
const clang::ASTContext& Ctx = getASTContext();
return isValid() && Ctx.hasSameType(getType(), Ctx.VoidTy);
}
size_t Value::GetNumberOfElements() const {
if (const clang::ConstantArrayType* ArrTy
= llvm::dyn_cast<clang::ConstantArrayType>(getType())) {
llvm::APInt arrSize(sizeof(size_t)*8, 1);
do {
arrSize *= ArrTy->getSize();
ArrTy = llvm::dyn_cast<clang::ConstantArrayType>(ArrTy->getElementType()
.getTypePtr());
} while (ArrTy);
return static_cast<size_t>(arrSize.getZExtValue());
}
return 1;
}
Value::EStorageType Value::determineStorageType(clang::QualType QT) {
const clang::Type* desugCanon = QT.getCanonicalType().getTypePtr();
if (desugCanon->isSignedIntegerOrEnumerationType())
return kSignedIntegerOrEnumerationType;
else if (desugCanon->isUnsignedIntegerOrEnumerationType())
return kUnsignedIntegerOrEnumerationType;
else if (desugCanon->isRealFloatingType()) {
const clang::BuiltinType* BT = desugCanon->getAs<clang::BuiltinType>();
if (BT->getKind() == clang::BuiltinType::Double)
return kDoubleType;
else if (BT->getKind() == clang::BuiltinType::Float)
return kFloatType;
else if (BT->getKind() == clang::BuiltinType::LongDouble)
return kLongDoubleType;
} else if (desugCanon->isPointerType() || desugCanon->isObjectType()
|| desugCanon->isReferenceType()) {
if (desugCanon->isRecordType() || desugCanon->isConstantArrayType()
|| desugCanon->isMemberPointerType())
return kManagedAllocation;
return kPointerType;
}
return kUnsupportedType;
}
void Value::ManagedAllocate() {
assert(needsManagedAllocation() && "Does not need managed allocation");
void* dtorFunc = 0;
clang::QualType DtorType = getType();
// For arrays we destruct the elements.
if (const clang::ConstantArrayType* ArrTy
= llvm::dyn_cast<clang::ConstantArrayType>(DtorType.getTypePtr())) {
DtorType = ArrTy->getElementType();
}
if (const clang::RecordType* RTy = DtorType->getAs<clang::RecordType>())
dtorFunc = m_Interpreter->compileDtorCallFor(RTy->getDecl());
const clang::ASTContext& ctx = getASTContext();
unsigned payloadSize = ctx.getTypeSizeInChars(getType()).getQuantity();
char* alloc = new char[AllocatedValue::getPayloadOffset() + payloadSize];
AllocatedValue* allocVal = new (alloc) AllocatedValue(dtorFunc, payloadSize,
GetNumberOfElements());
m_Storage.m_Ptr = allocVal->getPayload();
}
void Value::AssertOnUnsupportedTypeCast() const {
assert("unsupported type in Value, cannot cast simplistically!" && 0);
}
namespace valuePrinterInternal {
std::string printTypeInternal(const Value& V);
std::string printValueInternal(const Value& V);
} // end namespace valuePrinterInternal
void Value::print(llvm::raw_ostream& Out, bool Escape) const {
// Get the default type string representation
Out << cling::valuePrinterInternal::printTypeInternal(*this) << ' ';
// Get the value string representation, by printValue() method overloading
const std::string Val = cling::valuePrinterInternal::printValueInternal(*this);
if (Escape) {
const char* Data = Val.data();
const size_t N = Val.size();
switch (N ? Data[0] : 0) {
case 'u': case 'U': case 'L':
if (N < 3 || Data[1] != '\"')
break;
// Unicode string, encoded as Utf-8
case '\"':
if (N > 2 && Data[N-1] == '\"') {
// Drop the terminating " so Utf-8 errors can be detected ("\xeA")
Out << utils::utf8::EscapeSequence().encode(Data, N-1) << "\"\n";
return;
}
default:
break;
}
}
Out << Val << '\n';
}
void Value::dump(bool Escape) const {
print(cling::outs(), Escape);
}
} // end namespace cling