/// <summary>
/// Rewrite an async method into a state machine class.
/// </summary>
/// <param name="body">The original body of the method</param>
/// <param name="method">The method's identity</param>
/// <param name="compilationState">The collection of generated methods that result from this transformation and which must be emitted</param>
/// <param name="diagnostics">Diagnostic bag for diagnostics.</param>
/// <param name="generateDebugInfo"></param>
/// <param name="stateMachineType"></param>
internal static BoundStatement Rewrite(
BoundStatement body,
MethodSymbol method,
TypeCompilationState compilationState,
DiagnosticBag diagnostics,
bool generateDebugInfo,
out AsyncStateMachine stateMachineType)
{
if (!method.IsAsync)
{
stateMachineType = null;
return(body);
}
// The CLR doesn't support adding fields to structs, so in order to enable EnC in an async method we need to generate a class.
var typeKind = compilationState.Compilation.Options.EnableEditAndContinue ? TypeKind.Class : TypeKind.Struct;
var bodyWithAwaitLifted = AwaitLiftingRewriter.Rewrite(body, method, compilationState, diagnostics);
stateMachineType = new AsyncStateMachine(method, typeKind);
compilationState.ModuleBuilderOpt.CompilationState.SetStateMachineType(method, stateMachineType);
var rewriter = new AsyncRewriter(bodyWithAwaitLifted, method, stateMachineType, compilationState, diagnostics, generateDebugInfo);
if (!rewriter.constructedSuccessfully)
{
return(body);
}
return(rewriter.Rewrite());
}
/// <summary>
/// Rewrite an async method into a state machine class.
/// </summary>
/// <param name="body">The original body of the method</param>
/// <param name="method">The method's identity</param>
/// <param name="compilationState">The collection of generated methods that result from this transformation and which must be emitted</param>
/// <param name="diagnostics">Diagnostic bag for diagnostics.</param>
/// <param name="generateDebugInfo"></param>
internal static BoundStatement Rewrite(
BoundStatement body,
MethodSymbol method,
TypeCompilationState compilationState,
DiagnosticBag diagnostics,
bool generateDebugInfo)
{
if (!method.IsAsync)
{
return(body);
}
var bodyWithAwaitLifted = AwaitLiftingRewriter.Rewrite(body, method, compilationState, diagnostics);
var rewriter = new AsyncRewriter2(bodyWithAwaitLifted, method, ((SourceMethodSymbol)method).AsyncStateMachineType, compilationState, diagnostics, generateDebugInfo);
if (!rewriter.constructedSuccessfully)
{
return(body);
}
var bodyReplacement = rewriter.Rewrite();
return(bodyReplacement);
}