Files
swift-mirror/lib/IRGen/GenInit.cpp
2014-02-22 01:45:40 +00:00

122 lines
3.8 KiB
C++

//===--- GenInit.cpp - IR Generation for Initialization -------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements IR generation for the initialization of
// local and global variables.
//
//
//===----------------------------------------------------------------------===//
#include "swift/Basic/Optional.h"
#include "swift/AST/Pattern.h"
#include "swift/SIL/SILDeclRef.h"
#include "swift/SIL/SILGlobalVariable.h"
#include "llvm/IR/GlobalVariable.h"
#include "Explosion.h"
#include "GenHeap.h"
#include "GenTuple.h"
#include "IRGenFunction.h"
#include "IRGenModule.h"
#include "FixedTypeInfo.h"
using namespace swift;
using namespace irgen;
/// Emit a global variable.
Address IRGenModule::emitSILGlobalVariable(SILGlobalVariable *var) {
auto &type = getTypeInfo(var->getLoweredType());
// If the variable is empty, don't actually emit it; just return undef.
if (type.isKnownEmpty()) {
return type.getUndefAddress();
}
/// Get the global variable.
Address addr = getAddrOfSILGlobalVariable(var, ForDefinition);
/// Add a zero initializer.
auto gvar = cast<llvm::GlobalVariable>(addr.getAddress());
gvar->setInitializer(llvm::Constant::getNullValue(type.getStorageType()));
return addr;
}
/// Emit a global variable.
///
/// FIXME: Combine into emitSILGlobalVariable.
Address IRGenModule::emitGlobalVariable(VarDecl *var,
const TypeInfo &type) {
// If the variable is empty, don't actually emit it; just return undef.
// FIXME: global destructors?
if (type.isKnownEmpty()) {
return type.getUndefAddress();
}
/// Get the global variable.
Address addr = getAddrOfGlobalVariable(var, ForDefinition);
// Add a zero-initializer.
llvm::GlobalVariable *gvar = cast<llvm::GlobalVariable>(addr.getAddress());
gvar->setInitializer(llvm::Constant::getNullValue(type.getStorageType()));
return addr;
}
ContainedAddress FixedTypeInfo::allocateStack(IRGenFunction &IGF, CanType T,
const Twine &name) const {
// If the type is known to be empty, don't actually allocate anything.
if (isKnownEmpty()) {
auto addr = getUndefAddress();
return { addr, addr };
}
Address alloca =
IGF.createAlloca(getStorageType(), getFixedAlignment(), name);
// TODO: lifetime intrinsics?
return { alloca, alloca };
}
void FixedTypeInfo::deallocateStack(IRGenFunction &IGF, Address addr,
CanType T) const {
// TODO: lifetime intrinsics?
}
/// Allocate an object with fixed layout.
OwnedAddress FixedTypeInfo::allocateBox(IRGenFunction &IGF, CanType T,
const Twine &name) const {
// If the type is known to be empty, don't actually allocate anything.
if (isKnownEmpty())
return OwnedAddress(getUndefAddress(), IGF.IGM.RefCountedNull);
// Lay out the type as a heap object.
HeapLayout layout(IGF.IGM, LayoutStrategy::Optimal, T, this);
assert(!layout.isKnownEmpty() && "non-empty type had empty layout?");
auto &elt = layout.getElements()[0];
// Allocate a new object.
// TODO: lifetime intrinsics?
llvm::Value *allocation = IGF.emitUnmanagedAlloc(layout, name + ".alloc");
// FIXME: provide non-fixed offsets
NonFixedOffsets offsets = Nothing;
// Cast and GEP down to the element.
Address rawAddr = layout.emitCastTo(IGF, allocation);
rawAddr = elt.project(IGF, rawAddr, offsets, name);
OwnedAddress addr(rawAddr, allocation);
return addr;
}