public void Rewriter_that_changes_node_returns_new_tree()
{
var subject = InfoGroup().AddRules(Rule("rule1"), Rule("rule2"));
var result = LambdaRewriter.Visit(subject, node => node switch
{
RuleNode r => r.WithName(r.Name + r.Name),
_ => node
});
// Internal for testing
internal string Parse(string code, IReadOnlyCollection<Type> moduleTypes, IEnumerable<string> namespaces)
{
// Rewrite the lambda shorthand expressions
SyntaxTree syntaxTree = CSharpSyntaxTree.ParseText(code, new CSharpParseOptions(kind: SourceCodeKind.Script));
LambdaRewriter lambdaRewriter = new LambdaRewriter(moduleTypes.Select(x => x.Name));
SyntaxNode syntaxNode = lambdaRewriter.Visit(syntaxTree.GetRoot());
// "Lift" class and method declarations
LiftingWalker liftingWalker = new LiftingWalker();
liftingWalker.Visit(syntaxNode);
// Get the using statements
string usingStatements = string.Join(Environment.NewLine, namespaces.Select(x => "using " + x + ";"));
// Get the methods to instantiate each module
Dictionary<string, string> moduleNames = new Dictionary<string, string>();
string moduleMethods = string.Join(Environment.NewLine,
moduleTypes.Select(x => GenerateModuleConstructorMethods(x, moduleNames)));
// Return the fully parsed script
return
$@"// Generated: bring all module namespaces in scope
{usingStatements}
// Input: using directives
{liftingWalker.UsingDirectives}
public class {ScriptClassName} : ScriptBase
{{
public {ScriptClassName}(Engine engine) : base(engine) {{ }}
public override void Run()
{{
// Input: script code
{liftingWalker.ScriptCode}
}}
// Input: lifted methods
{liftingWalker.MethodDeclarations}
// Generated: methods for module instantiation
{moduleMethods}
}}
// Input: lifted object declarations
{liftingWalker.TypeDeclarations}
public static class ScriptExtensionMethods
{{
// Input: lifted extension methods
{liftingWalker.ExtensionMethodDeclarations}
}}";
}
internal override void GenerateMethodBody(TypeCompilationState compilationState, DiagnosticBag diagnostics)
{
ImmutableArray <LocalSymbol> declaredLocalsArray;
var body = _generateMethodBody(this, diagnostics, out declaredLocalsArray);
var compilation = compilationState.Compilation;
_lazyReturnType = CalculateReturnType(compilation, body);
// Can't do this until the return type has been computed.
TypeParameterChecker.Check(this, _allTypeParameters);
if (diagnostics.HasAnyErrors())
{
return;
}
DiagnosticsPass.IssueDiagnostics(compilation, body, diagnostics, this);
if (diagnostics.HasAnyErrors())
{
return;
}
// Check for use-site diagnostics (e.g. missing types in the signature).
DiagnosticInfo useSiteDiagnosticInfo = null;
this.CalculateUseSiteDiagnostic(ref useSiteDiagnosticInfo);
if (useSiteDiagnosticInfo != null && useSiteDiagnosticInfo.Severity == DiagnosticSeverity.Error)
{
diagnostics.Add(useSiteDiagnosticInfo, this.Locations[0]);
return;
}
try
{
var declaredLocals = PooledHashSet <LocalSymbol> .GetInstance();
try
{
// Rewrite local declaration statement.
body = (BoundStatement)LocalDeclarationRewriter.Rewrite(compilation, _container, declaredLocals, body, declaredLocalsArray);
// Verify local declaration names.
foreach (var local in declaredLocals)
{
Debug.Assert(local.Locations.Length > 0);
var name = local.Name;
if (name.StartsWith("$", StringComparison.Ordinal))
{
diagnostics.Add(ErrorCode.ERR_UnexpectedCharacter, local.Locations[0], name[0]);
return;
}
}
// Rewrite references to placeholder "locals".
body = (BoundStatement)PlaceholderLocalRewriter.Rewrite(compilation, _container, declaredLocals, body, diagnostics);
if (diagnostics.HasAnyErrors())
{
return;
}
}
finally
{
declaredLocals.Free();
}
var syntax = body.Syntax;
var statementsBuilder = ArrayBuilder <BoundStatement> .GetInstance();
statementsBuilder.Add(body);
// Insert an implicit return statement if necessary.
if (body.Kind != BoundKind.ReturnStatement)
{
statementsBuilder.Add(new BoundReturnStatement(syntax, RefKind.None, expressionOpt: null));
}
var localsBuilder = ArrayBuilder <LocalSymbol> .GetInstance();
var localsSet = PooledHashSet <LocalSymbol> .GetInstance();
foreach (var local in this.LocalsForBinding)
{
Debug.Assert(!localsSet.Contains(local));
localsBuilder.Add(local);
localsSet.Add(local);
}
foreach (var local in this.Locals)
{
if (!localsSet.Contains(local))
{
Debug.Assert(!localsSet.Contains(local));
localsBuilder.Add(local);
localsSet.Add(local);
}
}
localsSet.Free();
body = new BoundBlock(syntax, localsBuilder.ToImmutableAndFree(), statementsBuilder.ToImmutableAndFree())
{
WasCompilerGenerated = true
};
Debug.Assert(!diagnostics.HasAnyErrors());
Debug.Assert(!body.HasErrors);
bool sawLambdas;
bool sawLocalFunctions;
bool sawAwaitInExceptionHandler;
ImmutableArray <SourceSpan> dynamicAnalysisSpans = ImmutableArray <SourceSpan> .Empty;
body = LocalRewriter.Rewrite(
compilation: this.DeclaringCompilation,
method: this,
methodOrdinal: _methodOrdinal,
containingType: _container,
statement: body,
compilationState: compilationState,
previousSubmissionFields: null,
allowOmissionOfConditionalCalls: false,
instrumentForDynamicAnalysis: false,
debugDocumentProvider: null,
dynamicAnalysisSpans: ref dynamicAnalysisSpans,
diagnostics: diagnostics,
sawLambdas: out sawLambdas,
sawLocalFunctions: out sawLocalFunctions,
sawAwaitInExceptionHandler: out sawAwaitInExceptionHandler);
Debug.Assert(!sawAwaitInExceptionHandler);
Debug.Assert(dynamicAnalysisSpans.Length == 0);
if (body.HasErrors)
{
return;
}
// Variables may have been captured by lambdas in the original method
// or in the expression, and we need to preserve the existing values of
// those variables in the expression. This requires rewriting the variables
// in the expression based on the closure classes from both the original
// method and the expression, and generating a preamble that copies
// values into the expression closure classes.
//
// Consider the original method:
// static void M()
// {
// int x, y, z;
// ...
// F(() => x + y);
// }
// and the expression in the EE: "F(() => x + z)".
//
// The expression is first rewritten using the closure class and local <1>
// from the original method: F(() => <1>.x + z)
// Then lambda rewriting introduces a new closure class that includes
// the locals <1> and z, and a corresponding local <2>: F(() => <2>.<1>.x + <2>.z)
// And a preamble is added to initialize the fields of <2>:
// <2> = new <>c__DisplayClass0();
// <2>.<1> = <1>;
// <2>.z = z;
// Rewrite "this" and "base" references to parameter in this method.
// Rewrite variables within body to reference existing display classes.
body = (BoundStatement)CapturedVariableRewriter.Rewrite(
this.SubstitutedSourceMethod.IsStatic ? null : _parameters[0],
compilation.Conversions,
_displayClassVariables,
body,
diagnostics);
if (body.HasErrors)
{
Debug.Assert(false, "Please add a test case capturing whatever caused this assert.");
return;
}
if (diagnostics.HasAnyErrors())
{
return;
}
if (sawLambdas || sawLocalFunctions)
{
var closureDebugInfoBuilder = ArrayBuilder <ClosureDebugInfo> .GetInstance();
var lambdaDebugInfoBuilder = ArrayBuilder <LambdaDebugInfo> .GetInstance();
body = LambdaRewriter.Rewrite(
loweredBody: body,
thisType: this.SubstitutedSourceMethod.ContainingType,
thisParameter: _thisParameter,
method: this,
methodOrdinal: _methodOrdinal,
substitutedSourceMethod: this.SubstitutedSourceMethod.OriginalDefinition,
closureDebugInfoBuilder: closureDebugInfoBuilder,
lambdaDebugInfoBuilder: lambdaDebugInfoBuilder,
slotAllocatorOpt: null,
compilationState: compilationState,
diagnostics: diagnostics,
assignLocals: true);
// we don't need this information:
closureDebugInfoBuilder.Free();
lambdaDebugInfoBuilder.Free();
}
// Insert locals from the original method,
// followed by any new locals.
var block = (BoundBlock)body;
var localBuilder = ArrayBuilder <LocalSymbol> .GetInstance();
foreach (var local in this.Locals)
{
Debug.Assert(!(local is EELocalSymbol) || (((EELocalSymbol)local).Ordinal == localBuilder.Count));
localBuilder.Add(local);
}
foreach (var local in block.Locals)
{
var oldLocal = local as EELocalSymbol;
if (oldLocal != null)
{
Debug.Assert(localBuilder[oldLocal.Ordinal] == oldLocal);
continue;
}
localBuilder.Add(local);
}
body = block.Update(localBuilder.ToImmutableAndFree(), block.LocalFunctions, block.Statements);
TypeParameterChecker.Check(body, _allTypeParameters);
compilationState.AddSynthesizedMethod(this, body);
}
catch (BoundTreeVisitor.CancelledByStackGuardException ex)
{
ex.AddAnError(diagnostics);
}
}
