/// <summary>
/// Declares the data layout of the given type if it was not declared already.
/// An LLVM type that corresponds to the declaration is returned.
/// </summary>
/// <param name="Type">The type to declare.</param>
/// <returns>An LLVM type.</returns>
public LLVMTypeRef DeclareDataLayout(LLVMType Type)
{
LLVMTypeRef result;
if (!declaredDataLayouts.TryGetValue(Type, out result))
{
if (Type.GetIsValueType() || Type.GetIsEnum() || Type.IsRuntimeImplementedDelegate)
{
// The layout of some types can be computed naively.
result = Type.DefineLayout(this);
declaredDataLayouts[Type] = result;
}
else
{
// Reference types cannot have their layout computed naively, because
// they might refer to themselves. To get around this, we first declare
// a named struct, then figure out what its layout should look like and
// finally fill it out.
result = StructCreateNamed(GetGlobalContext(), Type.FullName.ToString());
declaredDataLayouts[Type] = result;
var layout = Type.DefineLayout(this);
StructSetBody(result, GetStructElementTypes(layout), IsPackedStruct(layout));
}
}
return(result);
}
public ITypeBuilder DeclareType(ITypeSignatureTemplate Template)
{
var childType = new LLVMType(this, Template);
declaredTypes.Add(childType);
return(childType);
}
private LLVMBasicBlockRef WriteReturnBlock(
LLVMType Type,
LLVMMethod Implementation,
LLVMModuleBuilder Module)
{
return(WriteReturnBlock(Type.Name.ToString(), Module.DeclareVirtual(Implementation)));
}
/// <summary>
/// Gets the vtable global for the given type.
/// </summary>
/// <param name="Type">The type to get the vtable of.</param>
/// <returns>A vtable global.</returns>
public VTableInstance GetVTable(IType Type)
{
VTableInstance vtable;
if (!declaredVTables.TryGetValue(Type, out vtable))
{
if (Type is LLVMType)
{
vtable = ((LLVMType)Type).DefineVTable(this);
}
else
{
vtable = new VTableInstance(
LLVMType.DefineVTableGlobal(this, Type, new LLVMValueRef[] { }),
new LLVMMethod[] { });
}
declaredVTables[Type] = vtable;
}
return(vtable);
}
public LLVMField(LLVMType DeclaringType, IFieldSignatureTemplate Template, int FieldIndex)
: base(DeclaringType)
{
this.templateInstance = new FieldSignatureInstance(Template, this);
this.FieldIndex = FieldIndex;
}
public LLVMSymbolTypeMember(LLVMType DeclaringType, LLVMAbi Abi)
{
this.ParentType = DeclaringType;
this.abiVal = Abi.AsLazyAbi();
}
public LLVMSymbolTypeMember(LLVMType DeclaringType)
{
this.ParentType = DeclaringType;
this.abiVal = new Lazy <LLVMAbi>(PickLLVMAbi);
}
public LLVMMethod(LLVMType DeclaringType, IMethodSignatureTemplate Template, LLVMAbi Abi)
: base(DeclaringType, Abi)
{
this.templateInstance = new MethodSignatureInstance(Template, this);
this.allInterfaceImpls = new Lazy <HashSet <LLVMMethod> >(LookupAllInterfaceImpls);
}
/// <summary>
/// Generates code that runs the given type's static constructors.
/// </summary>
/// <param name="BasicBlock">The basic block to extend.</param>
/// <param name="Type">The type whose static constructors are to be run.</param>
/// <returns>A basic block builder.</returns>
public BasicBlockBuilder EmitRunStaticConstructors(BasicBlockBuilder BasicBlock, LLVMType Type)
{
if (Type.StaticConstructors.Count == 0)
{
return(BasicBlock);
}
// Get or create the lock triple for the type. A lock triple consists of:
//
// * A global Boolean flag that tells if all static constructors for
// the type have been run.
//
// * A global Boolean flag that tells if the static constructors for
// the type are in the process of being run.
//
// * A thread-local Boolean flag that tells if the static constructors
// for the type are in the process of being run **by the current
// thread.**
//
// * A common metadata node per thread-local variable that is used to
// group loads/stores to that variable in an '!invariant.group'.
//
Tuple <LLVMValueRef, LLVMValueRef, LLVMValueRef, LLVMValueRef> lockQuad;
if (!staticConstructorLocks.TryGetValue(Type, out lockQuad))
{
string typeName = Type.Namespace.Assembly.Abi.Mangler.Mangle(Type, true);
var hasRunGlobal = AddGlobal(module, Int8Type(), typeName + "__has_run_cctor");
hasRunGlobal.SetInitializer(ConstInt(Int8Type(), 0, false));
hasRunGlobal.SetLinkage(LLVMLinkage.LLVMInternalLinkage);
var isRunningGlobal = AddGlobal(module, Int8Type(), typeName + "__is_running_cctor");
isRunningGlobal.SetInitializer(ConstInt(Int8Type(), 0, false));
isRunningGlobal.SetLinkage(LLVMLinkage.LLVMInternalLinkage);
var isRunningHereGlobal = AddGlobal(module, Int1Type(), typeName + "__is_running_cctor_here");
isRunningHereGlobal.SetInitializer(ConstInt(Int1Type(), 0, false));
isRunningHereGlobal.SetLinkage(LLVMLinkage.LLVMInternalLinkage);
isRunningHereGlobal.SetThreadLocal(true);
var mdNode = MDNode(new LLVMValueRef[] { MDString(typeName + "__is_running_cctor_here") });
lockQuad = new Tuple <LLVMValueRef, LLVMValueRef, LLVMValueRef, LLVMValueRef>(
hasRunGlobal, isRunningGlobal, isRunningHereGlobal, mdNode);
staticConstructorLocks[Type] = lockQuad;
}
// A type's static constructors need to be run *before* any of its static fields
// are accessed. Also, we need to ensure that a type's static constructors are
// run only *once* in both single-threaded and multi-threaded environments.
//
// We'll generate something along the lines of this when a type's static
// constructors need to be run:
//
// if (!is_running_cctor_here && !has_run_cctor)
// {
// while (!Interlocked.CompareExchange(ref is_running_cctor, false, true)) { }
// if (!has_run_cctor)
// {
// cctor();
// has_run_cctor = true;
// }
// is_running_cctors = false;
// }
//
// Or, using gotos:
//
// if (is_running_cctors_here) goto after_cctor;
// else goto check_has_run_cctor;
//
// check_has_run_cctor:
// is_running_cctors_here = true;
// if (has_run_cctor) goto after_cctor;
// else goto wait_for_cctor_lock;
//
// wait_for_cctor_lock:
// has_exchanged = Interlocked.CompareExchange(ref is_running_cctos, false, true);
// if (has_exchanged) goto maybe_run_cctor;
// else goto wait_for_cctor_lock;
//
// maybe_run_cctor:
// if (has_run_cctor) goto reset_lock;
// else goto run_cctor;
//
// run_cctor:
// cctor();
// has_run_cctor = true;
// goto reset_lock;
//
// reset_lock:
// is_running_cctors = false;
// goto after_cctor;
//
// after_cctor:
// ...
var hasRunPtr = lockQuad.Item1;
var isRunningPtr = lockQuad.Item2;
var isRunningHerePtr = lockQuad.Item3;
var invariantGroup = lockQuad.Item4;
var invariantGroupMdId = GetMDKindID("invariant.group");
var checkHasRunBlock = BasicBlock.CreateChildBlock("check_has_run_cctor");
var waitForLockBlock = BasicBlock.CreateChildBlock("wait_for_cctor_lock");
var maybeRunBlock = BasicBlock.CreateChildBlock("maybe_run_cctor");
var runBlock = BasicBlock.CreateChildBlock("run_cctor");
var resetLockBlock = BasicBlock.CreateChildBlock("reset_lock");
var afterBlock = BasicBlock.CreateChildBlock("after_cctor");
// Implement the entry basic block.
BuildCondBr(
BasicBlock.Builder,
WithMetadata(
BuildLoad(BasicBlock.Builder, isRunningHerePtr, "is_running_cctor_here"),
invariantGroupMdId,
invariantGroup),
afterBlock.Block,
checkHasRunBlock.Block);
// Implement the `check_has_run_cctor` block.
WithMetadata(
BuildStore(checkHasRunBlock.Builder, ConstInt(Int1Type(), 1, false), isRunningHerePtr),
invariantGroupMdId,
invariantGroup);
BuildCondBr(
checkHasRunBlock.Builder,
IntToBoolean(
checkHasRunBlock.Builder,
BuildAtomicLoad(checkHasRunBlock.Builder, hasRunPtr, "has_run_cctor")),
afterBlock.Block,
waitForLockBlock.Block);
// Implement the `wait_for_cctor_lock` block.
var cmpxhg = BuildAtomicCmpXchg(
waitForLockBlock.Builder,
isRunningPtr,
ConstInt(Int8Type(), 0, false),
ConstInt(Int8Type(), 1, false),
LLVMAtomicOrdering.LLVMAtomicOrderingSequentiallyConsistent,
LLVMAtomicOrdering.LLVMAtomicOrderingMonotonic,
false);
cmpxhg.SetValueName("is_running_cctor_cmpxhg");
BuildCondBr(
waitForLockBlock.Builder,
BuildExtractValue(
waitForLockBlock.Builder,
cmpxhg,
1,
"has_exchanged"),
maybeRunBlock.Block,
waitForLockBlock.Block);
// Implement the `maybe_run_cctor` block.
BuildCondBr(
maybeRunBlock.Builder,
IntToBoolean(
maybeRunBlock.Builder,
BuildAtomicLoad(maybeRunBlock.Builder, hasRunPtr, "has_run_cctor")),
resetLockBlock.Block,
runBlock.Block);
// Implement the `run_cctor` block.
for (int i = 0; i < Type.StaticConstructors.Count; i++)
{
BuildCall(runBlock.Builder, Declare(Type.StaticConstructors[i]), new LLVMValueRef[] { }, "");
}
BuildAtomicStore(runBlock.Builder, ConstInt(Int8Type(), 1, false), hasRunPtr);
BuildBr(runBlock.Builder, resetLockBlock.Block);
// Implement the `reset_lock` block.
BuildAtomicStore(resetLockBlock.Builder, ConstInt(Int8Type(), 0, false), isRunningPtr);
BuildBr(resetLockBlock.Builder, afterBlock.Block);
return(afterBlock);
}
public LLVMProperty(LLVMType ParentType, IPropertySignatureTemplate Template)
{
this.ParentType = ParentType;
this.templateInstance = new PropertySignatureInstance(Template, this);
this.declaredAccessors = new List <LLVMAccessor>();
}
/// <summary>
/// Registers the given method as the implementation for the given type.
/// </summary>
/// <param name="Type">The type that implements the method.</param>
/// <param name="Method">The implementation method.</param>
public void Implement(LLVMType Type, LLVMMethod Method)
{
impls.Add(Type, Method);
}
