Address feedback from config binding gen PR to improve enum parsing

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Emitter.cs

@@ -13,6 +13,9 @@ private sealed partial class Emitter
  private readonly InterceptorInfo _interceptorInfo;
  private readonly BindingHelperInfo _bindingHelperInfo;
  private readonly TypeIndex _typeIndex;
+ private readonly bool _emitEnumParseMethod;
+ private readonly bool _emitGenericParseEnum;
+ private readonly bool _emitThrowIfNullMethod;
 
  private readonly SourceWriter _writer = new();
 
@@ -21,6 +24,9 @@ public Emitter(SourceGenerationSpec sourceGenSpec)
  _interceptorInfo = sourceGenSpec.InterceptorInfo;
  _bindingHelperInfo = sourceGenSpec.BindingHelperInfo;
  _typeIndex = new TypeIndex(sourceGenSpec.ConfigTypes);
+ _emitEnumParseMethod = sourceGenSpec.EmitEnumParseMethod;
+ _emitGenericParseEnum = sourceGenSpec.EmitGenericParseEnum;
+ _emitThrowIfNullMethod = sourceGenSpec.EmitThrowIfNullMethod;
  }
 
  public void Emit(SourceProductionContext context)

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/ConfigurationBindingGenerator.Parser.cs

@@ -26,6 +26,8 @@ internal sealed partial class Parser(CompilationData compilationData)
 
  private readonly InterceptorInfo.Builder _interceptorInfoBuilder = new();
  private BindingHelperInfo.Builder? _helperInfoBuilder; // Init'ed with type index when registering interceptors, after creating type specs.
+ private bool _emitEnumParseMethod;
+ private bool _emitGenericParseEnum;
 
  public List<DiagnosticInfo>? Diagnostics { get; private set; }
 
@@ -45,12 +47,16 @@ internal sealed partial class Parser(CompilationData compilationData)
  ParseInvocations(invocations);
  CreateTypeSpecs(cancellationToken);
  RegisterInterceptors();
+ CheckIfToEmitParseEnumMethod();
 
  return new SourceGenerationSpec
  {
  InterceptorInfo = _interceptorInfoBuilder.ToIncrementalValue(),
  BindingHelperInfo = _helperInfoBuilder!.ToIncrementalValue(),
  ConfigTypes = _createdTypeSpecs.Values.OrderBy(s => s.TypeRef.FullyQualifiedName).ToImmutableEquatableArray(),
+ EmitEnumParseMethod = _emitEnumParseMethod,
+ EmitGenericParseEnum = _emitGenericParseEnum,
+ EmitThrowIfNullMethod = IsThrowIfNullMethodToBeEmitted()
  };
  }
 
@@ -842,6 +848,45 @@ private void RecordDiagnostic(DiagnosticDescriptor descriptor, Location trimmedL
  Diagnostics ??= new List<DiagnosticInfo>();
  Diagnostics.Add(DiagnosticInfo.Create(descriptor, trimmedLocation, messageArgs));
  }
+
+ private void CheckIfToEmitParseEnumMethod()
+ {
+ foreach (var typeSymbol in _createdTypeSpecs.Keys)
+ {
+ if (IsEnum(typeSymbol))
+ {
+ _emitEnumParseMethod = true;
+ _emitGenericParseEnum = _typeSymbols.Enum.GetMembers("Parse").Any(m => m is IMethodSymbol methodSymbol && methodSymbol.IsGenericMethod);
+ return;
+ }
+ }
+ }
+
+ private bool IsThrowIfNullMethodToBeEmitted()
+ {
+ if (_typeSymbols.ArgumentNullException is not null)
+ {
+ var throwIfNullMethods = _typeSymbols.ArgumentNullException.GetMembers("ThrowIfNull");
+
+ foreach (var throwIfNullMethod in throwIfNullMethods)
+ {
+ if (throwIfNullMethod is IMethodSymbol throwIfNullMethodSymbol && throwIfNullMethodSymbol.IsStatic && throwIfNullMethodSymbol.Parameters.Length == 2)
+ {
+ var parameters = throwIfNullMethodSymbol.Parameters;
+ var firstParam = parameters[0];
+ var secondParam = parameters[1];
+
+ if (firstParam.Name == "argument" && firstParam.Type.SpecialType == SpecialType.System_Object
+ && secondParam.Name == "paramName" && secondParam.Type.Equals(_typeSymbols.String, SymbolEqualityComparer.Default))
+ {
+ return true;
+ }
+ }
+ }
+ }
+
+ return false;
+ }
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/ConfigurationBinder.cs

@@ -144,8 +144,8 @@ void EmitMethods(ImmutableEquatableArray<TypedInterceptorInvocationInfo>? interc
  Debug.Assert(!type.IsValueType);
  string binderOptionsArg = configureOptions ? $"{Identifier.GetBinderOptions}({Identifier.configureOptions})" : $"{Identifier.binderOptions}: null";
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  _writer.WriteLine($$"""
  var {{Identifier.typedObj}} = ({{type.DisplayString}}){{Identifier.instance}};
  {{nameof(MethodsToGen_CoreBindingHelper.BindCore)}}({{configExpression}}, ref {{Identifier.typedObj}}, defaultValueIfNotFound: false, {{binderOptionsArg}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/CoreBindingHelpers.cs

@@ -92,7 +92,7 @@ private void EmitGetCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, Action<{Identifier.BinderOptions}>? {Identifier.configureOptions})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
 
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -178,7 +178,7 @@ private void EmitGetValueCoreMethod()
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static object? {nameof(MethodsToGen_CoreBindingHelper.GetValueCore)}(this {Identifier.IConfiguration} {Identifier.configuration}, Type {Identifier.type}, string {Identifier.key})");
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.configuration);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configuration, _emitThrowIfNullMethod);
  _writer.WriteLine($@"{Identifier.IConfigurationSection} {Identifier.section} = {GetSectionFromConfigurationExpression(Identifier.key, addQuotes: false)};");
  _writer.WriteLine();
 
@@ -224,7 +224,7 @@ private void EmitBindCoreMainMethod()
 
  EmitBlankLineIfRequired();
  EmitStartBlock($"public static void {nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}({Identifier.IConfiguration} {Identifier.configuration}, object {Identifier.instance}, Type {Identifier.type}, {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions})");
- EmitCheckForNullArgument_WithBlankLine(Identifier.instance, voidReturn: true);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.instance, _emitThrowIfNullMethod, voidReturn: true);
  EmitIConfigurationHasValueOrChildrenCheck(voidReturn: true);
  _writer.WriteLine($"{Identifier.BinderOptions}? {Identifier.binderOptions} = {Identifier.GetBinderOptions}({Identifier.configureOptions});");
  _writer.WriteLine();
@@ -475,24 +475,20 @@ private void EmitHelperMethods()
  EmitGetBinderOptionsHelper();
  }
 
- if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ if (_emitEnumParseMethod)
  {
- bool enumTypeExists = false;
+ _writer.WriteLine();
+ EmitEnumParseMethod();
+ _emitBlankLineBeforeNextStatement = true;
+ }
 
+ if (_bindingHelperInfo.TypesForGen_ParsePrimitive is { Count: not 0 } stringParsableTypes)
+ {
  foreach (ParsableFromStringSpec type in stringParsableTypes)
  {
- EmitBlankLineIfRequired();
-
- if (type.StringParsableTypeKind == StringParsableTypeKind.Enum)
- {
- if (!enumTypeExists)
- {
- EmitEnumParseMethod();
- enumTypeExists = true;
- }
- }
- else
+ if (type.StringParsableTypeKind is not StringParsableTypeKind.Enum)
  {
+ EmitBlankLineIfRequired();
  EmitPrimitiveParseMethod(type);
  }
  }
@@ -585,16 +581,13 @@ private void EmitEnumParseMethod()
  {
  string exceptionArg1 = string.Format(ExceptionMessages.FailedBinding, $"{{{Identifier.getPath}()}}", $"{{typeof(T)}}");
 
+ string parseEnumCall = _emitGenericParseEnum ? "Enum.Parse<T>(value, ignoreCase: true)" : "(T)Enum.Parse(typeof(T), value, ignoreCase: true)";
  _writer.WriteLine($$"""
  public static T ParseEnum<T>(string value, Func<string?> getPath) where T : struct
  {
  try
  {
- #if NETFRAMEWORK || NETSTANDARD2_0
- return (T)Enum.Parse(typeof(T), value, ignoreCase: true);
- #else
- return Enum.Parse<T>(value, ignoreCase: true);
- #endif
+ return {{parseEnumCall}};
  }
  catch ({{Identifier.Exception}} {{Identifier.exception}})
  {
@@ -614,8 +607,6 @@ private void EmitPrimitiveParseMethod(ParsableFromStringSpec type)
 
  switch (typeKind)
  {
- case StringParsableTypeKind.Enum:
- return;
  case StringParsableTypeKind.ByteArray:
  {
  parsedValueExpr = $"Convert.FromBase64String({Identifier.value})";

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/Helpers.cs

@@ -229,18 +229,30 @@ private void EmitBlankLineIfRequired()
  _emitBlankLineBeforeNextStatement = true;
  }
 
- private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool voidReturn = false)
+ private void EmitCheckForNullArgument_WithBlankLine(string paramName, bool useThrowIfNullMethod, bool voidReturn = false)
  {
- string returnExpr = voidReturn
- ? "return"
- : $"throw new ArgumentNullException(nameof({paramName}))";
-
- _writer.WriteLine($$"""
+ if (voidReturn)
+ {
+ _writer.WriteLine($$"""
  if ({{paramName}} is null)
  {
-{{returnExpr}};
+return;
  }
  """);
+ }
+ else
+ {
+ string throwIfNullExpr = useThrowIfNullMethod
+ ? $"ArgumentNullException.ThrowIfNull({paramName});"
+ : $$"""
+ if ({{paramName}} is null)
+ {
+ throw new ArgumentNullException(nameof({{paramName}}));
+ }
+ """;
+
+ _writer.WriteLine(throwIfNullExpr);
+ }
 
  _writer.WriteLine();
  }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsBuilderConfigurationExtensions.cs

@@ -43,7 +43,7 @@ private void EmitBindMethods_Extensions_OptionsBuilder()
  paramList + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureBinder}",
  documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
 
  _writer.WriteLine($$"""
  {{Identifier.Configure}}<{{Identifier.TOptions}}>({{Identifier.optionsBuilder}}.{{Identifier.Services}}, {{Identifier.optionsBuilder}}.Name, {{Identifier.config}}, {{Identifier.configureBinder}});
@@ -65,11 +65,11 @@ private void EmitBindConfigurationMethod()
 
  EmitMethodStartBlock(MethodsToGen.OptionsBuilderExt_BindConfiguration, "BindConfiguration", paramList, documentation);
 
- EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder);
- EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.optionsBuilder, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.configSectionPath, _emitThrowIfNullMethod);
 
  EmitStartBlock($"{Identifier.optionsBuilder}.{Identifier.Configure}<{Identifier.IConfiguration}>(({Identifier.instance}, {Identifier.config}) =>");
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  {{Identifier.IConfiguration}} {{Identifier.section}} = string.Equals(string.Empty, {{Identifier.configSectionPath}}, StringComparison.OrdinalIgnoreCase) ? {{Identifier.config}} : {{Identifier.config}}.{{Identifier.GetSection}}({{Identifier.configSectionPath}});
  {{nameof(MethodsToGen_CoreBindingHelper.BindCoreMain)}}({{Identifier.section}}, {{Identifier.instance}}, typeof({{Identifier.TOptions}}), {{Identifier.configureBinder}});

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Emitter/OptionsConfigurationServiceCollectionExtensions.cs

@@ -53,8 +53,8 @@ private void EmitConfigureMethods()
  // Like the others, it is public API that could be called directly by users.
  // So, it is always generated whenever a Configure overload is called.
  EmitStartMethod(MethodsToGen.ServiceCollectionExt_Configure_T_name_BinderOptions, paramList: $"string? {Identifier.name}, " + configParam + $", {TypeDisplayString.NullableActionOfBinderOptions} {Identifier.configureOptions}");
- EmitCheckForNullArgument_WithBlankLine(Identifier.services);
- EmitCheckForNullArgument_WithBlankLine(Identifier.config);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.services, _emitThrowIfNullMethod);
+ EmitCheckForNullArgument_WithBlankLine(Identifier.config, _emitThrowIfNullMethod);
  _writer.WriteLine($$"""
  OptionsServiceCollectionExtensions.AddOptions({{Identifier.services}});
  {{Identifier.services}}.{{Identifier.AddSingleton}}<{{Identifier.IOptionsChangeTokenSource}}<{{Identifier.TOptions}}>>(new {{Identifier.ConfigurationChangeTokenSource}}<{{Identifier.TOptions}}>({{Identifier.name}}, {{Identifier.config}}));

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Parser/KnownTypeSymbols.cs

@@ -56,6 +56,8 @@ internal sealed class KnownTypeSymbols
  public INamedTypeSymbol? ISet_Unbound { get; }
  public INamedTypeSymbol? ISet { get; }
  public INamedTypeSymbol? List { get; }
+ public INamedTypeSymbol Enum { get; }
+ public INamedTypeSymbol? ArgumentNullException { get; }
 
  public KnownTypeSymbols(CSharpCompilation compilation)
  {
@@ -113,6 +115,12 @@ public KnownTypeSymbols(CSharpCompilation compilation)
  IReadOnlyList_Unbound = compilation.GetBestTypeByMetadataName(typeof(IReadOnlyList<>))?.ConstructUnboundGenericType();
  IReadOnlySet_Unbound = compilation.GetBestTypeByMetadataName("System.Collections.Generic.IReadOnlySet`1")?.ConstructUnboundGenericType();
  ISet_Unbound = ISet?.ConstructUnboundGenericType();
+
+ // needed to be able to know if a member exist inside the compilation unit
+ Enum = compilation.GetSpecialType(SpecialType.System_Enum);
+ ArgumentNullException = compilation.GetBestTypeByMetadataName(typeof(ArgumentNullException));
+
+ String = compilation.GetBestTypeByMetadataName(typeof(string));
  }
  }
 }

src/libraries/Microsoft.Extensions.Configuration.Binder/gen/Specs/SourceGenerationSpec.cs

@@ -10,5 +10,8 @@ public sealed record SourceGenerationSpec
  public required InterceptorInfo InterceptorInfo { get; init; }
  public required BindingHelperInfo BindingHelperInfo { get; init; }
  public required ImmutableEquatableArray<TypeSpec> ConfigTypes { get; init; }
+ public required bool EmitEnumParseMethod { get; set; }
+ public required bool EmitGenericParseEnum { get; set; }
+ public required bool EmitThrowIfNullMethod { get; set; }
  }
 }