|
public GenerateSet ( |
||
| generator | The generator to output the CIL to. | |
| optimizationInfo | Information about any optimizations that should be performed. | |
| valueType | PrimitiveType | The primitive type of the value that is on the top of the stack. |
| throwIfUnresolvable | bool | |
| return | void | |
/// <summary>
/// Generates code that initializes the variable and function declarations.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
internal virtual void GenerateDeclarations(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Initialize the declared variables and functions.
foreach (var variable in this.variables.Values)
{
// Emit the initialization code.
if (this is ObjectScope)
{
// Determine the property attributes.
var attributes = Library.PropertyAttributes.Enumerable;
if (variable.Writable == true)
{
attributes |= Library.PropertyAttributes.Writable;
}
if (variable.Deletable == true)
{
attributes |= Library.PropertyAttributes.Configurable;
}
if (variable.ValueAtTopOfScope == null)
{
// void InitializeMissingProperty(object key, PropertyAttributes attributes)
EmitHelpers.LoadScope(generator);
generator.CastClass(typeof(ObjectScope));
generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
generator.LoadString(variable.Name);
generator.LoadInt32((int)attributes);
generator.Call(ReflectionHelpers.ObjectInstance_InitializeMissingProperty);
}
else
{
// bool DefineProperty(string propertyName, PropertyDescriptor descriptor, bool throwOnError)
EmitHelpers.LoadScope(generator);
generator.CastClass(typeof(ObjectScope));
generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
generator.LoadString(variable.Name);
variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
EmitConversion.Convert(generator, variable.ValueAtTopOfScope.ResultType, PrimitiveType.Any, optimizationInfo);
generator.LoadInt32((int)attributes);
generator.NewObject(ReflectionHelpers.PropertyDescriptor_Constructor2);
generator.LoadBoolean(false);
generator.Call(ReflectionHelpers.ObjectInstance_DefineProperty);
generator.Pop();
}
}
else if (variable.ValueAtTopOfScope != null)
{
variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
var name = new NameExpression(this, variable.Name);
name.GenerateSet(generator, optimizationInfo, variable.ValueAtTopOfScope.ResultType, false);
}
}
}
/// <summary>
/// Generates code that initializes the variable and function declarations.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
internal void GenerateHoistedDeclarations(ILGenerator generator, OptimizationInfo optimizationInfo)
{
if (this.hoistedFunctions != null)
{
foreach (var nameAndValue in this.hoistedFunctions)
{
// Make sure the scope is valid.
nameAndValue.Value.Scope.GenerateScopeCreation(generator, optimizationInfo);
// Create the function.
nameAndValue.Value.GenerateCode(generator, optimizationInfo);
// Assign it to the variable.
var name = new NameExpression(this, nameAndValue.Key);
name.GenerateSet(generator, optimizationInfo, nameAndValue.Value.ResultType);
}
// In case GenerateHoistedDeclarations() is called twice.
this.hoistedFunctions = null;
}
}
/// <summary>
/// Generates IL for the script.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
protected override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Method signature: object FunctionDelegate(Compiler.Scope scope, object thisObject, Library.FunctionInstance functionObject, object[] arguments)
// Initialize the scope (note: the initial scope for a function is always declarative).
this.InitialScope.GenerateScopeCreation(generator, optimizationInfo);
// Verify the scope is correct.
VerifyScope(generator);
// In ES3 the "this" value must be an object. See 10.4.3 in the spec.
if (this.StrictMode == false && this.MethodOptimizationHints.HasThis == true)
{
// if (thisObject == null || thisObject == Null.Value || thisObject == Undefined.Value)
EmitHelpers.LoadThis(generator);
generator.LoadNull();
generator.CompareEqual();
EmitHelpers.LoadThis(generator);
EmitHelpers.EmitNull(generator);
generator.CompareEqual();
generator.BitwiseOr();
EmitHelpers.LoadThis(generator);
EmitHelpers.EmitUndefined(generator);
generator.CompareEqual();
generator.BitwiseOr();
// {
var startOfFalse = generator.CreateLabel();
generator.BranchIfFalse(startOfFalse);
// thisObject = engine.Global;
EmitHelpers.LoadScriptEngine(generator);
generator.Call(ReflectionHelpers.ScriptEngine_Global);
// } else {
var endOfIf = generator.CreateLabel();
generator.Branch(endOfIf);
generator.DefineLabelPosition(startOfFalse);
// thisObject = TypeConverter.ToObject(thisObject);
EmitHelpers.LoadThis(generator);
EmitConversion.ToObject(generator, PrimitiveType.Any, optimizationInfo);
// }
generator.DefineLabelPosition(endOfIf);
EmitHelpers.StoreThis(generator);
}
// Transfer the function name into the scope.
if (string.IsNullOrEmpty(this.Name) == false &&
this.IncludeNameInScope == true &&
this.ArgumentNames.Contains(this.Name) == false &&
optimizationInfo.MethodOptimizationHints.HasVariable(this.Name))
{
EmitHelpers.LoadFunction(generator);
var functionName = new NameExpression(this.InitialScope, this.Name);
functionName.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
// Transfer the arguments object into the scope.
if (this.MethodOptimizationHints.HasArguments == true && this.ArgumentNames.Contains("arguments") == false)
{
// prototype
EmitHelpers.LoadScriptEngine(generator);
generator.Call(ReflectionHelpers.ScriptEngine_Object);
generator.Call(ReflectionHelpers.FunctionInstance_InstancePrototype);
// callee
EmitHelpers.LoadFunction(generator);
generator.CastClass(typeof(Library.UserDefinedFunction));
// scope
EmitHelpers.LoadScope(generator);
generator.CastClass(typeof(DeclarativeScope));
// argumentValues
EmitHelpers.LoadArgumentsArray(generator);
generator.NewObject(ReflectionHelpers.Arguments_Constructor);
var arguments = new NameExpression(this.InitialScope, "arguments");
arguments.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
// Transfer the argument values into the scope.
// Note: the arguments array can be smaller than expected.
if (this.ArgumentNames.Count > 0)
{
var endOfArguments = generator.CreateLabel();
for (int i = 0; i < this.ArgumentNames.Count; i++)
{
// Check if a duplicate argument name exists.
bool duplicate = false;
for (int j = i + 1; j < this.ArgumentNames.Count; j++)
{
if (this.ArgumentNames[i] == this.ArgumentNames[j])
{
duplicate = true;
break;
}
}
if (duplicate == true)
{
continue;
}
// Check if an array element exists.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadArrayLength();
generator.LoadInt32(i);
generator.BranchIfLessThanOrEqual(endOfArguments);
// Store the array element in the scope.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadInt32(i);
generator.LoadArrayElement(typeof(object));
var argument = new NameExpression(this.InitialScope, this.ArgumentNames[i]);
argument.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
generator.DefineLabelPosition(endOfArguments);
}
// Initialize any declarations.
this.InitialScope.GenerateDeclarations(generator, optimizationInfo);
//EmitHelpers.LoadScope(generator);
//EmitConversion.ToObject(generator, PrimitiveType.Any);
//generator.Pop();
// Generate code for the body of the function.
this.AbstractSyntaxTree.GenerateCode(generator, optimizationInfo);
// Define the return target - this is where the return statement jumps to.
// ReturnTarget can be null if there were no return statements.
if (optimizationInfo.ReturnTarget != null)
{
generator.DefineLabelPosition(optimizationInfo.ReturnTarget);
}
// Load the return value. If the variable is null, there were no return statements.
if (optimizationInfo.ReturnVariable != null)
{
// Return the value stored in the variable. Will be null if execution hits the end
// of the function without encountering any return statements.
generator.LoadVariable(optimizationInfo.ReturnVariable);
}
else
{
// There were no return statements - return null.
generator.LoadNull();
}
}
/// <summary>
/// Generates CIL for the statement.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Generate code for the start of the statement.
var statementLocals = new StatementLocals() { NonDefaultSourceSpanBehavior = true };
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// Unlike in .NET, in javascript there are no restrictions on what can appear inside
// try, catch and finally blocks. The one restriction which causes problems is the
// inability to jump out of .NET finally blocks. This is required when break, continue
// or return statements appear inside of a finally block. To work around this, when
// inside a finally block these instructions throw an exception instead.
// Setting the InsideTryCatchOrFinally flag converts BR instructions into LEAVE
// instructions so that the finally block is executed correctly.
var previousInsideTryCatchOrFinally = optimizationInfo.InsideTryCatchOrFinally;
optimizationInfo.InsideTryCatchOrFinally = true;
// Finally requires two exception nested blocks.
if (this.FinallyBlock != null)
generator.BeginExceptionBlock();
// Begin the exception block.
generator.BeginExceptionBlock();
// Generate code for the try block.
this.TryBlock.GenerateCode(generator, optimizationInfo);
// Generate code for the catch block.
if (this.CatchBlock != null)
{
// Begin a catch block. The exception is on the top of the stack.
generator.BeginCatchBlock(typeof(JavaScriptException));
// Create a new DeclarativeScope.
this.CatchScope.GenerateScopeCreation(generator, optimizationInfo);
// Store the error object in the variable provided.
generator.Call(ReflectionHelpers.JavaScriptException_ErrorObject);
var catchVariable = new NameExpression(this.CatchScope, this.CatchVariableName);
catchVariable.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
// Make sure the scope is reverted even if an exception is thrown.
generator.BeginExceptionBlock();
// Emit code for the statements within the catch block.
this.CatchBlock.GenerateCode(generator, optimizationInfo);
// Revert the scope.
generator.BeginFinallyBlock();
this.CatchScope.GenerateScopeDestruction(generator, optimizationInfo);
generator.EndExceptionBlock();
}
// Generate code for the finally block.
if (this.FinallyBlock != null)
{
generator.BeginFinallyBlock();
var branches = new List<ILLabel>();
var previousStackSize = optimizationInfo.LongJumpStackSizeThreshold;
optimizationInfo.LongJumpStackSizeThreshold = optimizationInfo.BreakOrContinueStackSize;
var previousCallback = optimizationInfo.LongJumpCallback;
optimizationInfo.LongJumpCallback = (generator2, label) =>
{
// It is not possible to branch out of a finally block - therefore instead of
// generating LEAVE instructions we throw an exception then catch it to transfer
// control out of the finally block.
generator2.LoadInt32(branches.Count);
generator2.NewObject(ReflectionHelpers.LongJumpException_Constructor);
generator2.Throw();
// Record any branches that are made within the finally code.
branches.Add(label);
};
// Emit code for the finally block.
this.FinallyBlock.GenerateCode(generator, optimizationInfo);
// End the main exception block.
generator.EndExceptionBlock();
// Begin a catch block to catch any LongJumpExceptions. The exception object is on
// the top of the stack.
generator.BeginCatchBlock(typeof(LongJumpException));
if (branches.Count > 0)
{
// switch (exception.RouteID)
// {
// case 0: goto label1;
// case 1: goto label2;
// }
ILLabel[] switchLabels = new ILLabel[branches.Count];
for (int i = 0; i < branches.Count; i++)
switchLabels[i] = generator.CreateLabel();
generator.Call(ReflectionHelpers.LongJumpException_RouteID);
generator.Switch(switchLabels);
for (int i = 0; i < branches.Count; i++)
{
generator.DefineLabelPosition(switchLabels[i]);
generator.Leave(branches[i]);
}
}
// Reset the state we clobbered.
optimizationInfo.LongJumpStackSizeThreshold = previousStackSize;
optimizationInfo.LongJumpCallback = previousCallback;
}
// End the exception block.
generator.EndExceptionBlock();
// Reset the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates CIL for the statement.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Generate code for the start of the statement.
var statementLocals = new StatementLocals() { NonDefaultSourceSpanBehavior = true };
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// Unlike in .NET, in javascript there are no restrictions on what can appear inside
// try, catch and finally blocks. The one restriction which causes problems is the
// inability to jump out of .NET finally blocks. This is required when break, continue
// or return statements appear inside of a finally block. To work around this, when
// inside a finally block these instructions throw an exception instead.
// Setting the InsideTryCatchOrFinally flag converts BR instructions into LEAVE
// instructions so that the finally block is executed correctly.
var previousInsideTryCatchOrFinally = optimizationInfo.InsideTryCatchOrFinally;
optimizationInfo.InsideTryCatchOrFinally = true;
// Finally requires two exception nested blocks.
if (this.FinallyBlock != null)
generator.BeginExceptionBlock();
// Begin the exception block.
generator.BeginExceptionBlock();
// Generate code for the try block.
this.TryBlock.GenerateCode(generator, optimizationInfo);
// Generate code for the catch block.
ILLocalVariable skipFinallyBlock = null;
// Begin a catch block. The exception is on the top of the stack.
generator.BeginCatchBlock(typeof(Exception));
// Check the exception is catchable by calling CanCatchException(ex).
// We need to handle the case where JS code calls into .NET code which then throws
// a JavaScriptException from a different ScriptEngine.
// If CatchBlock is null, we need to rethrow the exception in every case.
var endOfIfLabel = generator.CreateLabel();
generator.Duplicate(); // ex
var exceptionTemporary = generator.CreateTemporaryVariable(typeof(Exception));
generator.StoreVariable(exceptionTemporary);
EmitHelpers.LoadScriptEngine(generator);
generator.LoadVariable(exceptionTemporary);
generator.ReleaseTemporaryVariable(exceptionTemporary);
generator.Call(ReflectionHelpers.ScriptEngine_CanCatchException);
generator.BranchIfTrue(endOfIfLabel);
if (this.FinallyBlock != null)
{
generator.LoadBoolean(true);
skipFinallyBlock = generator.DeclareVariable(typeof(bool), "skipFinallyBlock");
generator.StoreVariable(skipFinallyBlock);
}
if (this.CatchBlock == null)
generator.DefineLabelPosition(endOfIfLabel);
generator.Rethrow();
if (this.CatchBlock != null)
generator.DefineLabelPosition(endOfIfLabel);
if (this.CatchBlock != null) {
// Create a new DeclarativeScope.
this.CatchScope.GenerateScopeCreation(generator, optimizationInfo);
// Store the error object in the variable provided.
generator.Call(ReflectionHelpers.JavaScriptException_ErrorObject);
var catchVariable = new NameExpression(this.CatchScope, this.CatchVariableName);
catchVariable.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
// Make sure the scope is reverted even if an exception is thrown.
generator.BeginExceptionBlock();
// Emit code for the statements within the catch block.
this.CatchBlock.GenerateCode(generator, optimizationInfo);
// Revert the scope.
generator.BeginFinallyBlock();
this.CatchScope.GenerateScopeDestruction(generator, optimizationInfo);
generator.EndExceptionBlock();
}
// Generate code for the finally block.
if (this.FinallyBlock != null)
{
generator.BeginFinallyBlock();
// If an exception was thrown that wasn't handled by the catch block, then don't
// run the finally block either. This prevents user code from being run when a
// ThreadAbortException is thrown.
var endOfFinallyBlock = generator.CreateLabel();
generator.LoadVariable(skipFinallyBlock);
generator.BranchIfTrue(endOfFinallyBlock);
var branches = new List<ILLabel>();
var previousStackSize = optimizationInfo.LongJumpStackSizeThreshold;
optimizationInfo.LongJumpStackSizeThreshold = optimizationInfo.BreakOrContinueStackSize;
var previousCallback = optimizationInfo.LongJumpCallback;
optimizationInfo.LongJumpCallback = (generator2, label) =>
{
// It is not possible to branch out of a finally block - therefore instead of
// generating LEAVE instructions we throw an exception then catch it to transfer
// control out of the finally block.
generator2.LoadInt32(branches.Count);
generator2.NewObject(ReflectionHelpers.LongJumpException_Constructor);
generator2.Throw();
// Record any branches that are made within the finally code.
branches.Add(label);
};
// Emit code for the finally block.
this.FinallyBlock.GenerateCode(generator, optimizationInfo);
// Define the position at the end of the finally block.
generator.DefineLabelPosition(endOfFinallyBlock);
// End the main exception block.
generator.EndExceptionBlock();
// Begin a catch block to catch any LongJumpExceptions. The exception object is on
// the top of the stack.
generator.BeginCatchBlock(typeof(LongJumpException));
if (branches.Count > 0)
{
// switch (exception.RouteID)
// {
// case 0: goto label1;
// case 1: goto label2;
// }
ILLabel[] switchLabels = new ILLabel[branches.Count];
for (int i = 0; i < branches.Count; i++)
switchLabels[i] = generator.CreateLabel();
generator.Call(ReflectionHelpers.LongJumpException_RouteID);
generator.Switch(switchLabels);
for (int i = 0; i < branches.Count; i++)
{
generator.DefineLabelPosition(switchLabels[i]);
generator.Leave(branches[i]);
}
}
// Reset the state we clobbered.
optimizationInfo.LongJumpStackSizeThreshold = previousStackSize;
optimizationInfo.LongJumpCallback = previousCallback;
}
// End the exception block.
generator.EndExceptionBlock();
// Reset the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates IL for the script.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
protected override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Method signature: object FunctionDelegate(Compiler.Scope scope, object thisObject, Library.FunctionInstance functionObject, object[] arguments)
// Initialize the scope (note: the initial scope for a function is always declarative).
this.BaseScope.GenerateScopeCreation(generator, optimizationInfo);
// In ES3 the "this" value must be an object. See 10.4.3 in the spec.
if (this.StrictMode == false && this.MethodOptimizationHints.HasThis == true)
{
// context.ConvertThisToObject();
EmitHelpers.LoadExecutionContext(generator);
generator.Call(ReflectionHelpers.ExecutionContext_ConvertThisToObject);
}
// Transfer the function name into the scope.
if (Name.HasStaticName && !Name.IsGetter && !Name.IsSetter &&
this.Arguments.Any(a => a.Name == Name.StaticName) == false &&
optimizationInfo.MethodOptimizationHints.HasVariable(Name.StaticName))
{
EmitHelpers.LoadFunction(generator);
var functionName = new NameExpression(this.BaseScope, Name.StaticName);
functionName.GenerateSet(generator, optimizationInfo, PrimitiveType.Any);
}
// Transfer the arguments object into the scope.
if (this.MethodOptimizationHints.HasArguments == true && this.Arguments.Any(a => a.Name == "arguments") == false)
{
// executionContext.CreateArgumentsInstance(object[] arguments)
EmitHelpers.LoadExecutionContext(generator);
this.BaseScope.GenerateReference(generator, optimizationInfo);
EmitHelpers.LoadArgumentsArray(generator);
generator.Call(ReflectionHelpers.ExecutionContext_CreateArgumentsInstance);
var arguments = new NameExpression(this.BaseScope, "arguments");
arguments.GenerateSet(generator, optimizationInfo, PrimitiveType.Any);
}
// Transfer the argument values into the scope.
// Note: the arguments array can be smaller than expected.
if (this.Arguments.Count > 0)
{
for (int i = 0; i < this.Arguments.Count; i++)
{
// Check if a duplicate argument name exists.
bool duplicate = false;
for (int j = i + 1; j < this.Arguments.Count; j++)
{
if (this.Arguments[i].Name == this.Arguments[j].Name)
{
duplicate = true;
break;
}
}
if (duplicate == true)
{
continue;
}
var loadDefaultValue = generator.CreateLabel();
var storeValue = generator.CreateLabel();
// Check if an array element exists.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadArrayLength();
generator.LoadInt32(i);
generator.BranchIfLessThanOrEqual(loadDefaultValue);
// Load the parameter value from the parameters array.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadInt32(i);
generator.LoadArrayElement(typeof(object));
if (this.Arguments[i].DefaultValue == null)
{
// Branch to the part where it stores the value.
generator.Branch(storeValue);
// Load undefined.
generator.DefineLabelPosition(loadDefaultValue);
EmitHelpers.EmitUndefined(generator);
generator.ReinterpretCast(typeof(object));
}
else
{
// Check if it's undefined.
generator.Duplicate();
EmitHelpers.EmitUndefined(generator);
generator.ReinterpretCast(typeof(object));
generator.BranchIfNotEqual(storeValue);
generator.Pop();
// Load the default value.
generator.DefineLabelPosition(loadDefaultValue);
this.Arguments[i].DefaultValue.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.Arguments[i].DefaultValue.ResultType);
}
// Store the value in the scope.
generator.DefineLabelPosition(storeValue);
var argument = new NameExpression(this.BaseScope, this.Arguments[i].Name);
argument.GenerateSet(generator, optimizationInfo, PrimitiveType.Any);
}
}
// Initialize any declarations.
this.BaseScope.GenerateHoistedDeclarations(generator, optimizationInfo);
// Generate code for the body of the function.
this.AbstractSyntaxTree.GenerateCode(generator, optimizationInfo);
// Define the return target - this is where the return statement jumps to.
// ReturnTarget can be null if there were no return statements.
if (optimizationInfo.ReturnTarget != null)
{
generator.DefineLabelPosition(optimizationInfo.ReturnTarget);
}
// Load the return value. If the variable is null, there were no return statements.
if (optimizationInfo.ReturnVariable != null)
{
// Return the value stored in the variable. Will be null if execution hits the end
// of the function without encountering any return statements.
generator.LoadVariable(optimizationInfo.ReturnVariable);
}
else
{
// There were no return statements - return null.
generator.LoadNull();
}
}
/// <summary>
/// Generates IL for the script.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
protected override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Method signature: object FunctionDelegate(Compiler.Scope scope, object thisObject, Library.FunctionInstance functionObject, object[] arguments)
// Initialize the scope (note: the initial scope for a function is always declarative).
this.InitialScope.GenerateScopeCreation(generator, optimizationInfo);
// Verify the scope is correct.
VerifyScope(generator);
// In ES3 the "this" value must be an object. See 10.4.3 in the spec.
if (this.StrictMode == false && this.MethodOptimizationHints.HasThis == true)
{
// if (thisObject == null || thisObject == Null.Value || thisObject == Undefined.Value)
EmitHelpers.LoadThis(generator);
generator.LoadNull();
generator.CompareEqual();
EmitHelpers.LoadThis(generator);
EmitHelpers.EmitNull(generator);
generator.CompareEqual();
generator.BitwiseOr();
EmitHelpers.LoadThis(generator);
EmitHelpers.EmitUndefined(generator);
generator.CompareEqual();
generator.BitwiseOr();
// {
var startOfFalse = generator.CreateLabel();
generator.BranchIfFalse(startOfFalse);
// thisObject = engine.Global;
EmitHelpers.LoadScriptEngine(generator);
generator.Call(ReflectionHelpers.ScriptEngine_Global);
// } else {
var endOfIf = generator.CreateLabel();
generator.Branch(endOfIf);
generator.DefineLabelPosition(startOfFalse);
// thisObject = TypeConverter.ToObject(thisObject);
EmitHelpers.LoadThis(generator);
EmitConversion.ToObject(generator, PrimitiveType.Any);
// }
generator.DefineLabelPosition(endOfIf);
EmitHelpers.StoreThis(generator);
}
// Transfer the function name into the scope.
if (string.IsNullOrEmpty(this.Name) == false &&
this.ArgumentNames.Contains(this.Name) == false &&
optimizationInfo.MethodOptimizationHints.HasVariable(this.Name))
{
EmitHelpers.LoadFunction(generator);
var functionName = new NameExpression(this.InitialScope, this.Name);
functionName.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
// Transfer the arguments object into the scope.
if (this.MethodOptimizationHints.HasArguments == true && this.ArgumentNames.Contains("arguments") == false)
{
// prototype
EmitHelpers.LoadScriptEngine(generator);
generator.Call(ReflectionHelpers.ScriptEngine_Object);
generator.Call(ReflectionHelpers.FunctionInstance_InstancePrototype);
// callee
EmitHelpers.LoadFunction(generator);
generator.CastClass(typeof(Library.UserDefinedFunction));
// scope
EmitHelpers.LoadScope(generator);
generator.CastClass(typeof(DeclarativeScope));
// argumentValues
EmitHelpers.LoadArgumentsArray(generator);
generator.NewObject(ReflectionHelpers.Arguments_Constructor);
var arguments = new NameExpression(this.InitialScope, "arguments");
arguments.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
// Transfer the argument values into the scope.
// Note: the arguments array can be smaller than expected.
if (this.ArgumentNames.Count > 0)
{
var endOfArguments = generator.CreateLabel();
for (int i = 0; i < this.ArgumentNames.Count; i++)
{
// Check if a duplicate argument name exists.
bool duplicate = false;
for (int j = i + 1; j < this.ArgumentNames.Count; j++)
if (this.ArgumentNames[i] == this.ArgumentNames[j])
{
duplicate = true;
break;
}
if (duplicate == true)
continue;
// Check if an array element exists.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadArrayLength();
generator.LoadInt32(i);
generator.BranchIfLessThanOrEqual(endOfArguments);
// Store the array element in the scope.
EmitHelpers.LoadArgumentsArray(generator);
generator.LoadInt32(i);
generator.LoadArrayElement(typeof(object));
var argument = new NameExpression(this.InitialScope, this.ArgumentNames[i]);
argument.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
}
generator.DefineLabelPosition(endOfArguments);
}
// Initialize any declarations.
this.InitialScope.GenerateDeclarations(generator, optimizationInfo);
//EmitHelpers.LoadScope(generator);
//EmitConversion.ToObject(generator, PrimitiveType.Any);
//generator.Pop();
// Generate code for the body of the function.
this.AbstractSyntaxTree.GenerateCode(generator, optimizationInfo);
// Define the return target - this is where the return statement jumps to.
// ReturnTarget can be null if there were no return statements.
if (optimizationInfo.ReturnTarget != null)
generator.DefineLabelPosition(optimizationInfo.ReturnTarget);
// Load the return value. If the variable is null, there were no return statements.
if (optimizationInfo.ReturnVariable != null)
// Return the value stored in the variable. Will be null if execution hits the end
// of the function without encountering any return statements.
generator.LoadVariable(optimizationInfo.ReturnVariable);
else
// There were no return statements - return null.
generator.LoadNull();
}
/// <summary>
/// Generates CIL for the statement.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Generate code for the start of the statement.
var statementLocals = new StatementLocals()
{
NonDefaultBreakStatementBehavior = true, NonDefaultDebugInfoBehavior = true
};
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// <initializer>
// if (<condition>)
// {
// <loop body>
// <increment>
// while (true) {
// if (<condition> == false)
// break;
//
// <body statements>
//
// continue-target:
// <increment>
// }
// }
// break-target:
// Set up some labels.
var continueTarget = generator.CreateLabel();
var breakTarget1 = generator.CreateLabel();
var breakTarget2 = generator.CreateLabel();
// Emit the initialization statement.
if (this.InitStatement != null)
{
this.InitStatement.GenerateCode(generator, optimizationInfo);
}
// Check the condition and jump to the end if it is false.
if (this.CheckConditionAtEnd == false && this.ConditionStatement != null)
{
#if !XBOX
if (optimizationInfo.DebugDocument != null)
{
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.ConditionStatement.DebugInfo);
}
#endif
this.Condition.GenerateCode(generator, optimizationInfo);
EmitConversion.ToBool(generator, this.Condition.ResultType);
generator.BranchIfFalse(breakTarget1);
}
// Emit the loop body.
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget1, continueTarget, false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
// Increment the loop variable.
if (this.IncrementStatement != null)
{
this.IncrementStatement.GenerateCode(generator, optimizationInfo);
}
// Strengthen the variable types.
List <KeyValuePair <Scope.DeclaredVariable, RevertInfo> > previousVariableTypes = null;
var previousInsideTryCatchOrFinally = optimizationInfo.InsideTryCatchOrFinally;
if (optimizationInfo.OptimizeInferredTypes == true)
{
// Keep a record of the variable types before strengthening.
previousVariableTypes = new List <KeyValuePair <Scope.DeclaredVariable, RevertInfo> >();
var typedVariables = FindTypedVariables();
foreach (var variableAndType in typedVariables)
{
var variable = variableAndType.Key;
var variableInfo = variableAndType.Value;
if (variableInfo.Conditional == false && variableInfo.Type != variable.Type)
{
// Save the previous type so we can restore it later.
var previousType = variable.Type;
previousVariableTypes.Add(new KeyValuePair <Scope.DeclaredVariable, RevertInfo>(variable, new RevertInfo()
{
Type = previousType, Variable = variable.Store
}));
// Load the existing value.
var nameExpression = new NameExpression(variable.Scope, variable.Name);
nameExpression.GenerateGet(generator, optimizationInfo, false);
// Store the typed value.
variable.Store = generator.DeclareVariable(variableInfo.Type);
variable.Type = variableInfo.Type;
nameExpression.GenerateSet(generator, optimizationInfo, previousType, false);
}
}
// The variables must be reverted even in the presence of exceptions.
if (previousVariableTypes.Count > 0)
{
generator.BeginExceptionBlock();
// Setting the InsideTryCatchOrFinally flag converts BR instructions into LEAVE
// instructions so that the finally block is executed correctly.
optimizationInfo.InsideTryCatchOrFinally = true;
}
}
// The inner loop starts here.
var startOfLoop = generator.DefineLabelPosition();
// Check the condition and jump to the end if it is false.
if (this.ConditionStatement != null)
{
#if !XBOX
if (optimizationInfo.DebugDocument != null)
{
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.ConditionStatement.DebugInfo);
}
#endif
this.Condition.GenerateCode(generator, optimizationInfo);
EmitConversion.ToBool(generator, this.Condition.ResultType);
generator.BranchIfFalse(breakTarget2);
}
// Emit the loop body.
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget2, continueTarget, labelledOnly: false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
// The continue statement jumps here.
generator.DefineLabelPosition(continueTarget);
// Increment the loop variable.
if (this.IncrementStatement != null)
{
this.IncrementStatement.GenerateCode(generator, optimizationInfo);
}
// Unconditionally branch back to the start of the loop.
generator.Branch(startOfLoop);
// Define the end of the loop (actually just after).
generator.DefineLabelPosition(breakTarget2);
// Revert the variable types.
if (previousVariableTypes != null && previousVariableTypes.Count > 0)
{
// Revert the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Revert the variable types within a finally block.
generator.BeginFinallyBlock();
foreach (var previousVariableAndType in previousVariableTypes)
{
var variable = previousVariableAndType.Key;
var variableRevertInfo = previousVariableAndType.Value;
// Load the existing value.
var nameExpression = new NameExpression(variable.Scope, variable.Name);
nameExpression.GenerateGet(generator, optimizationInfo, false);
// Store the typed value.
var previousType = variable.Type;
variable.Store = variableRevertInfo.Variable;
variable.Type = variableRevertInfo.Type;
nameExpression.GenerateSet(generator, optimizationInfo, previousType, false);
}
// End the exception block.
generator.EndExceptionBlock();
}
// Define the end of the loop (actually just after).
generator.DefineLabelPosition(breakTarget1);
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates code that initializes the variable and function declarations.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
internal virtual void GenerateDeclarations(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Initialize the declared variables and functions.
foreach (var variable in this.variables.Values)
{
// When a scope is reused, i.e. with an eval(), do not reinitialize the variables.
if (variable.Initialized == true)
continue;
if (variable.ValueAtTopOfScope != null)
{
// Emit the initialization code.
if (this is ObjectScope)
{
// Determine the property attributes.
var attributes = Library.PropertyAttributes.Enumerable;
if (variable.Writable == true)
attributes |= Library.PropertyAttributes.Writable;
if (variable.Deletable == true)
attributes |= Library.PropertyAttributes.Configurable;
// bool DefineProperty(string propertyName, PropertyDescriptor descriptor, bool throwOnError)
EmitHelpers.LoadScope(generator);
generator.CastClass(typeof(ObjectScope));
generator.Call(ReflectionHelpers.ObjectScope_ScopeObject);
generator.LoadString(variable.Name);
variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
EmitConversion.Convert(generator, variable.ValueAtTopOfScope.ResultType, PrimitiveType.Any, optimizationInfo);
generator.LoadInt32((int)attributes);
generator.NewObject(ReflectionHelpers.PropertyDescriptor_Constructor2);
generator.LoadBoolean(false);
generator.Call(ReflectionHelpers.ObjectInstance_DefineProperty);
generator.Pop();
}
else
{
variable.ValueAtTopOfScope.GenerateCode(generator, optimizationInfo);
var name = new NameExpression(this, variable.Name);
name.GenerateSet(generator, optimizationInfo, variable.ValueAtTopOfScope.ResultType, false);
}
// Mark the variable as having been initialized.
variable.Initialized = true;
}
}
}
/// <summary>
/// Generates CIL for the statement.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Generate code for the start of the statement.
var statementLocals = new StatementLocals() { NonDefaultBreakStatementBehavior = true, NonDefaultSourceSpanBehavior = true };
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// <initializer>
// if (<condition>)
// {
// <loop body>
// <increment>
// while (true) {
// if (<condition> == false)
// break;
//
// <body statements>
//
// continue-target:
// <increment>
// }
// }
// break-target:
// Set up some labels.
var continueTarget = generator.CreateLabel();
var breakTarget1 = generator.CreateLabel();
var breakTarget2 = generator.CreateLabel();
// Emit the initialization statement.
if (this.InitStatement != null)
this.InitStatement.GenerateCode(generator, optimizationInfo);
// Check the condition and jump to the end if it is false.
if (this.CheckConditionAtEnd == false && this.ConditionStatement != null)
{
optimizationInfo.MarkSequencePoint(generator, this.ConditionStatement.SourceSpan);
this.Condition.GenerateCode(generator, optimizationInfo);
EmitConversion.ToBool(generator, this.Condition.ResultType);
generator.BranchIfFalse(breakTarget1);
}
// Emit the loop body.
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget1, continueTarget, false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
// Increment the loop variable.
if (this.IncrementStatement != null)
this.IncrementStatement.GenerateCode(generator, optimizationInfo);
// Strengthen the variable types.
List<KeyValuePair<Scope.DeclaredVariable, RevertInfo>> previousVariableTypes = null;
var previousInsideTryCatchOrFinally = optimizationInfo.InsideTryCatchOrFinally;
if (optimizationInfo.OptimizeInferredTypes == true)
{
// Keep a record of the variable types before strengthening.
previousVariableTypes = new List<KeyValuePair<Scope.DeclaredVariable, RevertInfo>>();
var typedVariables = FindTypedVariables();
foreach (var variableAndType in typedVariables)
{
var variable = variableAndType.Key;
var variableInfo = variableAndType.Value;
if (variableInfo.Conditional == false && variableInfo.Type != variable.Type)
{
// Save the previous type so we can restore it later.
var previousType = variable.Type;
previousVariableTypes.Add(new KeyValuePair<Scope.DeclaredVariable, RevertInfo>(variable, new RevertInfo() { Type = previousType, Variable = variable.Store }));
// Load the existing value.
var nameExpression = new NameExpression(variable.Scope, variable.Name);
nameExpression.GenerateGet(generator, optimizationInfo, false);
// Store the typed value.
variable.Store = generator.DeclareVariable(variableInfo.Type);
variable.Type = variableInfo.Type;
nameExpression.GenerateSet(generator, optimizationInfo, previousType, false);
}
}
// The variables must be reverted even in the presence of exceptions.
if (previousVariableTypes.Count > 0)
{
generator.BeginExceptionBlock();
// Setting the InsideTryCatchOrFinally flag converts BR instructions into LEAVE
// instructions so that the finally block is executed correctly.
optimizationInfo.InsideTryCatchOrFinally = true;
}
}
// The inner loop starts here.
var startOfLoop = generator.DefineLabelPosition();
// Check the condition and jump to the end if it is false.
if (this.ConditionStatement != null)
{
optimizationInfo.MarkSequencePoint(generator, this.ConditionStatement.SourceSpan);
this.Condition.GenerateCode(generator, optimizationInfo);
EmitConversion.ToBool(generator, this.Condition.ResultType);
generator.BranchIfFalse(breakTarget2);
}
// Emit the loop body.
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget2, continueTarget, labelledOnly: false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
// The continue statement jumps here.
generator.DefineLabelPosition(continueTarget);
// Increment the loop variable.
if (this.IncrementStatement != null)
this.IncrementStatement.GenerateCode(generator, optimizationInfo);
// Unconditionally branch back to the start of the loop.
generator.Branch(startOfLoop);
// Define the end of the loop (actually just after).
generator.DefineLabelPosition(breakTarget2);
// Revert the variable types.
if (previousVariableTypes != null && previousVariableTypes.Count > 0)
{
// Revert the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Revert the variable types within a finally block.
generator.BeginFinallyBlock();
foreach (var previousVariableAndType in previousVariableTypes)
{
var variable = previousVariableAndType.Key;
var variableRevertInfo = previousVariableAndType.Value;
// Load the existing value.
var nameExpression = new NameExpression(variable.Scope, variable.Name);
nameExpression.GenerateGet(generator, optimizationInfo, false);
// Store the typed value.
var previousType = variable.Type;
variable.Store = variableRevertInfo.Variable;
variable.Type = variableRevertInfo.Type;
nameExpression.GenerateSet(generator, optimizationInfo, previousType, false);
}
// End the exception block.
generator.EndExceptionBlock();
}
// Define the end of the loop (actually just after).
generator.DefineLabelPosition(breakTarget1);
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates CIL for the statement.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
public override void GenerateCode(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Generate code for the start of the statement.
var statementLocals = new StatementLocals();
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// Unlike in .NET, in javascript there are no restrictions on what can appear inside
// try, catch and finally blocks. The one restriction which causes problems is the
// inability to jump out of .NET finally blocks. This is required when break, continue
// or return statements appear inside of a finally block. To work around this, when
// inside a finally block these instructions throw an exception instead.
// Setting the InsideTryCatchOrFinally flag converts BR instructions into LEAVE
// instructions so that the finally block is executed correctly.
var previousInsideTryCatchOrFinally = optimizationInfo.InsideTryCatchOrFinally;
optimizationInfo.InsideTryCatchOrFinally = true;
// Finally requires two exception nested blocks.
if (this.FinallyBlock != null)
{
generator.BeginExceptionBlock();
}
// Begin the exception block.
generator.BeginExceptionBlock();
// Generate code for the try block.
this.TryBlock.GenerateCode(generator, optimizationInfo);
// Generate code for the catch block.
if (this.CatchBlock != null)
{
// Begin a catch block. The exception is on the top of the stack.
generator.BeginCatchBlock(typeof(JavaScriptException));
// Create a new DeclarativeScope.
this.CatchScope.GenerateScopeCreation(generator, optimizationInfo);
// Store the error object in the variable provided.
generator.Call(ReflectionHelpers.JavaScriptException_ErrorObject);
var catchVariable = new NameExpression(this.CatchScope, this.CatchVariableName);
catchVariable.GenerateSet(generator, optimizationInfo, PrimitiveType.Any, false);
// Make sure the scope is reverted even if an exception is thrown.
generator.BeginExceptionBlock();
// Emit code for the statements within the catch block.
this.CatchBlock.GenerateCode(generator, optimizationInfo);
// Revert the scope.
generator.BeginFinallyBlock();
this.CatchScope.GenerateScopeDestruction(generator, optimizationInfo);
generator.EndExceptionBlock();
}
// Generate code for the finally block.
if (this.FinallyBlock != null)
{
generator.BeginFinallyBlock();
var branches = new List <ILLabel>();
var previousStackSize = optimizationInfo.LongJumpStackSizeThreshold;
optimizationInfo.LongJumpStackSizeThreshold = optimizationInfo.BreakOrContinueStackSize;
var previousCallback = optimizationInfo.LongJumpCallback;
optimizationInfo.LongJumpCallback = (generator2, label) =>
{
// It is not possible to branch out of a finally block - therefore instead of
// generating LEAVE instructions we throw an exception then catch it to transfer
// control out of the finally block.
generator2.LoadInt32(branches.Count);
generator2.NewObject(ReflectionHelpers.LongJumpException_Constructor);
generator2.Throw();
// Record any branches that are made within the finally code.
branches.Add(label);
};
// Emit code for the finally block.
this.FinallyBlock.GenerateCode(generator, optimizationInfo);
// End the main exception block.
generator.EndExceptionBlock();
// Begin a catch block to catch any LongJumpExceptions. The exception object is on
// the top of the stack.
generator.BeginCatchBlock(typeof(LongJumpException));
if (branches.Count > 0)
{
// switch (exception.RouteID)
// {
// case 0: goto label1;
// case 1: goto label2;
// }
ILLabel[] switchLabels = new ILLabel[branches.Count];
for (int i = 0; i < branches.Count; i++)
{
switchLabels[i] = generator.CreateLabel();
}
generator.Call(ReflectionHelpers.LongJumpException_RouteID);
generator.Switch(switchLabels);
for (int i = 0; i < branches.Count; i++)
{
generator.DefineLabelPosition(switchLabels[i]);
generator.Leave(branches[i]);
}
}
// Reset the state we clobbered.
optimizationInfo.LongJumpStackSizeThreshold = previousStackSize;
optimizationInfo.LongJumpCallback = previousCallback;
}
// End the exception block.
generator.EndExceptionBlock();
// Reset the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}