|
public PushBreakOrContinueInfo ( IList |
||
| labelNames | IList |
The label names associated with the break or continue target.
/// Can be |
| breakTarget | ILLabel | The IL label to jump to if a break statement is encountered. |
| continueTarget | ILLabel | The IL label to jump to if a continue statement is
/// encountered. Can be |
| labelledOnly | bool | |
| return | void | |
/// <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.NonDefaultSourceSpanBehavior == false)
{
optimizationInfo.MarkSequencePoint(generator, this.SourceSpan);
}
}
/// <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()
{
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();
// 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, 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()
{
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, 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 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, 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();
#if !XBOX
// Emit debugging information.
if (optimizationInfo.DebugDocument != null)
generator.MarkSequencePoint(optimizationInfo.DebugDocument, this.VariableDebugInfo);
#endif
// 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() { 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()
{
NonDefaultBreakStatementBehavior = true, NonDefaultSourceSpanBehavior = 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)
optimizationInfo.MarkSequencePoint(generator, this.TargetObjectSourceSpan);
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_String_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();
// Generate the scope variable if necessary.
this.Scope.GenerateScopeCreation(generator, optimizationInfo);
// 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_String_Current);
this.Variable.GenerateSet(generator, optimizationInfo, PrimitiveType.String);
// 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);
}