/// <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);
// Construct a loop expression.
// var enumerator = TypeUtilities.EnumeratePropertyNames(rhs).GetEnumerator();
// while (true) {
// continue-target:
// if (enumerator.MoveNext() == false)
// goto break-target;
// lhs = enumerator.Current;
//
// <body statements>
// }
// break-target:
// Call IEnumerable<string> EnumeratePropertyNames(ScriptEngine engine, object obj)
EmitHelpers.LoadScriptEngine(generator);
this.TargetObject.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.TargetObject.ResultType);
generator.Call(ReflectionHelpers.TypeUtilities_EnumeratePropertyNames);
// Call IEnumerable<string>.GetEnumerator()
generator.Call(ReflectionHelpers.IEnumerable_GetEnumerator);
// Store the enumerator in a temporary variable.
var enumerator = generator.CreateTemporaryVariable(typeof(IEnumerator<string>));
generator.StoreVariable(enumerator);
var breakTarget = generator.CreateLabel();
var continueTarget = generator.DefineLabelPosition();
// Emit debugging information.
if (optimizationInfo.DebugDocument != null)
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.VariableDebugInfo);
// if (enumerator.MoveNext() == false)
// goto break-target;
generator.LoadVariable(enumerator);
generator.Call(ReflectionHelpers.IEnumerator_MoveNext);
generator.BranchIfFalse(breakTarget);
// lhs = enumerator.Current;
generator.LoadVariable(enumerator);
generator.Call(ReflectionHelpers.IEnumerator_Current);
this.Variable.GenerateSet(generator, optimizationInfo, PrimitiveType.String, false);
// Emit the body statement(s).
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget, continueTarget, labelledOnly: false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
generator.Branch(continueTarget);
generator.DefineLabelPosition(breakTarget);
// 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);
if (this.ContributesToEvalResult == true && optimizationInfo.EvalResult != null)
{
// Emit the expression.
this.Expression.GenerateCode(generator, optimizationInfo);
// Store the result.
EmitConversion.ToAny(generator, this.Expression.ResultType);
generator.StoreVariable(optimizationInfo.EvalResult);
}
else
{
// Emit the expression.
this.Expression.GenerateCode(generator, optimizationInfo);
generator.Pop();
}
// 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);
// Create the scope.
this.Scope.GenerateScopeCreation(generator, optimizationInfo);
// Make sure the scope is reverted even if an exception is thrown.
generator.BeginExceptionBlock();
// 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;
// Generate code for the body statements.
this.Body.GenerateCode(generator, optimizationInfo);
// Reset the InsideTryCatchOrFinally flag.
optimizationInfo.InsideTryCatchOrFinally = previousInsideTryCatchOrFinally;
// Revert the scope.
generator.BeginFinallyBlock();
this.Scope.GenerateScopeDestruction(generator, optimizationInfo);
generator.EndExceptionBlock();
// 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);
// 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);
// 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);
// Emit an unconditional branch.
// Note: the continue statement might be branching from inside a try { } or finally { }
// block to outside. EmitLongJump() handles this.
optimizationInfo.EmitLongJump(generator, optimizationInfo.GetContinueTarget(this.Label));
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates CIL for the end of every 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>
/// <param name="locals"> Variables common to both GenerateStartOfStatement() and GenerateEndOfStatement(). </param>
public void GenerateEndOfStatement(ILGenerator generator, OptimizationInfo optimizationInfo, StatementLocals locals)
{
if (locals.NonDefaultBreakStatementBehavior == false && this.HasLabels == true)
{
// Revert the information needed by the break statement.
generator.DefineLabelPosition(locals.EndOfStatement);
optimizationInfo.PopBreakOrContinueInfo();
}
#if DEBUG && !SILVERLIGHT && !XBOX
// Check that the stack count is zero.
if (generator is DynamicILGenerator && ((DynamicILGenerator)generator).StackSize != locals.OriginalStackSize)
throw new InvalidOperationException("Encountered unexpected stack imbalance.");
#endif
}
/// <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);
// Inserts a breakpoint into the IL.
generator.Breakpoint();
// When the debugger stops, it stops at the first instruction after the breakpoint. By
// inserting a no-op operation the debugger will highlight the "debugger" statement
// instead of the statement after the "debugger" statement.
generator.NoOperation();
// 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);
// Emit code to throw the given value.
this.Value.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.Value.ResultType);
generator.LoadInt32(0);
generator.LoadNull();
generator.NewObject(ReflectionHelpers.JavaScriptException_Constructor_Object);
generator.Throw();
// 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);
// Emit the return value.
if (this.Value == null)
EmitHelpers.EmitUndefined(generator);
else
{
this.Value.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.Value.ResultType);
}
// Determine if this is the last statement in the function.
bool lastStatement = optimizationInfo.AbstractSyntaxTree is BlockStatement &&
((BlockStatement)optimizationInfo.AbstractSyntaxTree).Statements.Count > 0 &&
((BlockStatement)optimizationInfo.AbstractSyntaxTree).Statements[((BlockStatement)optimizationInfo.AbstractSyntaxTree).Statements.Count - 1] == this;
// The first return statement initializes the variable that holds the return value.
if (optimizationInfo.ReturnVariable == null)
optimizationInfo.ReturnVariable = generator.DeclareVariable(typeof(object), "returnValue");
// Store the return value in a variable.
generator.StoreVariable(optimizationInfo.ReturnVariable);
// There is no need to jump to the end of the function if this is the last statement.
if (lastStatement == false)
{
// The first return statement that needs to branch creates the return label. This is
// defined in FunctionmethodGenerator.GenerateCode() at the end of the function.
if (optimizationInfo.ReturnTarget == null)
optimizationInfo.ReturnTarget = generator.CreateLabel();
// Branch to the end of the function. Note: the return statement might be branching
// from inside a try { } or finally { } block to outside. EmitLongJump() handles this.
optimizationInfo.EmitLongJump(generator, optimizationInfo.ReturnTarget);
}
// 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);
// Generate code for the condition and coerce to a boolean.
this.Condition.GenerateCode(generator, optimizationInfo);
EmitConversion.ToBool(generator, this.Condition.ResultType);
// We will need a label at the end of the if statement.
var endOfEverything = generator.CreateLabel();
if (this.ElseClause == null)
{
// Jump to the end if the condition is false.
generator.BranchIfFalse(endOfEverything);
// Generate code for the if clause.
this.IfClause.GenerateCode(generator, optimizationInfo);
}
else
{
// Branch to the else clause if the condition is false.
var startOfElseClause = generator.CreateLabel();
generator.BranchIfFalse(startOfElseClause);
// Generate code for the if clause.
this.IfClause.GenerateCode(generator, optimizationInfo);
// Branch to the end of the if statement.
generator.Branch(endOfEverything);
// Generate code for the else clause.
generator.DefineLabelPosition(startOfElseClause);
this.ElseClause.GenerateCode(generator, optimizationInfo);
}
// Define the label at the end of the if statement.
generator.DefineLabelPosition(endOfEverything);
// 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);
foreach (var declaration in this.Declarations)
{
if (declaration.InitExpression != null)
{
// Create a new assignment expression and generate code for it.
var initializationStatement = new ExpressionStatement(
new AssignmentExpression(this.Scope, declaration.VariableName, declaration.InitExpression));
initializationStatement.SourceSpan = declaration.SourceSpan;
initializationStatement.GenerateCode(generator, optimizationInfo);
}
}
// 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);
foreach (var declaration in this.Declarations)
{
if (declaration.InitExpression != null)
{
// Create a new assignment expression and generate code for it.
if (optimizationInfo.DebugDocument != null)
generator.MarkSequencePoint(optimizationInfo.DebugDocument, declaration.DebugInfo);
var initializationStatement = new ExpressionStatement(
new AssignmentExpression(this.Scope, declaration.VariableName, declaration.InitExpression));
initializationStatement.GenerateCode(generator, optimizationInfo);
}
}
// 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() { NonDefaultBreakStatementBehavior = true };
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// We need a label for each case clause and one for the default case.
var jumpTargets = new ILLabel[this.CaseClauses.Count];
int defaultIndex = -1;
ILLabel endOfSwitch = generator.CreateLabel();
// Generate code for the switch value.
var startOfSwitch = generator.CreateLabel();
this.Value.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.Value.ResultType);
// Save the switch value in a variable.
var switchValue = generator.CreateTemporaryVariable(typeof(object));
generator.StoreVariable(switchValue);
for (int i = 0; i < this.CaseClauses.Count; i ++)
{
var caseClause = this.CaseClauses[i];
// Create a label for each clause.
jumpTargets[i] = generator.CreateLabel();
if (caseClause.Value == null)
{
// This is a default clause.
defaultIndex = i;
continue;
}
// TypeComparer.StrictEquals(switchValue, caseValue)
generator.LoadVariable(switchValue);
caseClause.Value.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, caseClause.Value.ResultType);
generator.Call(ReflectionHelpers.TypeComparer_StrictEquals);
// if (TypeComparer.StrictEquals(switchValue, caseValue) == true)
// goto case i
generator.BranchIfTrue(jumpTargets[i]);
}
// None of the cases matched, jump to the default clause or the end of the switch.
if (defaultIndex >= 0)
generator.Branch(jumpTargets[defaultIndex]);
else
generator.Branch(endOfSwitch);
for (int i = 0; i < this.CaseClauses.Count; i++)
{
// Define a label at the start of the case clause.
generator.DefineLabelPosition(jumpTargets[i]);
// Set up the information needed by the break statement.
optimizationInfo.PushBreakOrContinueInfo(this.Labels, endOfSwitch, null, labelledOnly: false);
// Emit the case clause statements.
foreach (var statement in this.CaseClauses[i].BodyStatements)
statement.GenerateCode(generator, optimizationInfo);
// Revert the information needed by the break statement.
optimizationInfo.PopBreakOrContinueInfo();
}
// Define a label for the end of the switch statement.
generator.DefineLabelPosition(endOfSwitch);
// Release the switch value variable for use elsewhere.
generator.ReleaseTemporaryVariable(switchValue);
// 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()
{
NonDefaultBreakStatementBehavior = true, NonDefaultSourceSpanBehavior = true
};
GenerateStartOfStatement(generator, optimizationInfo, statementLocals);
// Construct a loop expression.
// var iterator = TypeUtilities.GetIterator(obj);
// while (true) {
// continue-target:
// if (enumerator.MoveNext() == false)
// goto break-target;
// lhs = enumerator.Current;
//
// <body statements>
// }
// break-target:
// Call: ObjectInstance GetIterator(ScriptEngine engine, ObjectInstance iterable)
// Then call: IEnumerable<object> Iterate(ScriptEngine engine, ObjectInstance iterator)
optimizationInfo.MarkSequencePoint(generator, this.TargetObjectSourceSpan);
EmitHelpers.LoadScriptEngine(generator);
this.TargetObject.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, this.TargetObject.ResultType);
generator.Call(ReflectionHelpers.TypeUtilities_ForOf);
// Call IEnumerable<object>.GetEnumerator()
generator.Call(ReflectionHelpers.IEnumerable_Object_GetEnumerator);
// Store the enumerator in a temporary variable.
var enumerator = generator.CreateTemporaryVariable(typeof(IEnumerator <object>));
generator.StoreVariable(enumerator);
var breakTarget = generator.CreateLabel();
var continueTarget = generator.DefineLabelPosition();
// Generate the scope variable if necessary.
this.Scope.GenerateScopeCreation(generator, optimizationInfo);
// Emit debugging information.
if (optimizationInfo.DebugDocument != null)
{
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.VariableSourceSpan);
}
// if (enumerator.MoveNext() == false)
// goto break-target;
generator.LoadVariable(enumerator);
generator.Call(ReflectionHelpers.IEnumerator_MoveNext);
generator.BranchIfFalse(breakTarget);
// lhs = enumerator.Current;
this.Variable.GenerateReference(generator, optimizationInfo);
generator.LoadVariable(enumerator);
generator.Call(ReflectionHelpers.IEnumerator_Object_Current);
this.Variable.GenerateSet(generator, optimizationInfo, PrimitiveType.Any);
// Emit the body statement(s).
optimizationInfo.PushBreakOrContinueInfo(this.Labels, breakTarget, continueTarget, labelledOnly: false);
this.Body.GenerateCode(generator, optimizationInfo);
optimizationInfo.PopBreakOrContinueInfo();
generator.Branch(continueTarget);
generator.DefineLabelPosition(breakTarget);
// Generate code for the end of the statement.
GenerateEndOfStatement(generator, optimizationInfo, statementLocals);
}
/// <summary>
/// Generates CIL for the start of every 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>
/// <param name="locals"> Variables common to both GenerateStartOfStatement() and GenerateEndOfStatement(). </param>
public void GenerateStartOfStatement(ILGenerator generator, OptimizationInfo optimizationInfo, StatementLocals locals)
{
#if DEBUG && !SILVERLIGHT
// Statements must not produce or consume any values on the stack.
if (generator is DynamicILGenerator)
locals.OriginalStackSize = ((DynamicILGenerator)generator).StackSize;
#endif
if (locals.NonDefaultBreakStatementBehavior == false && this.HasLabels == true)
{
// Set up the information needed by the break statement.
locals.EndOfStatement = generator.CreateLabel();
optimizationInfo.PushBreakOrContinueInfo(this.Labels, locals.EndOfStatement, null, labelledOnly: true);
}
// Emit debugging information.
if (locals.NonDefaultDebugInfoBehavior == false && optimizationInfo.DebugDocument != null && this.DebugInfo != null)
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.DebugInfo);
}
/// <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() { 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);
}
