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Merged
rekhoff merged 4 commits into from
Mar 20, 2026
Merged

fix(csharp-codegen): escape C# reserved keywords in generated identifiers #4535

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b41d294
fix(csharp-codegen): escape C# reserved keywords in generated identif…
stablegenius49 Mar 3, 2026
e49364a
Fix C# codegen keyword escaping (#4529)
stablegenius49 Mar 3, 2026
667db18
Merge branch 'master' into fix/csharp-escape-keywords-4529
rekhoff Mar 16, 2026
1c437e0
Corrected `IEquatable`, `ReadOnlyAccessor`, duplicate accessor names,…
rekhoff Mar 17, 2026
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36 changes: 22 additions & 14 deletions crates/bindings-csharp/BSATN.Codegen/Type.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -422,6 +422,8 @@ public MemberDeclaration(ISymbol member, ITypeSymbol type, DiagReporter diag)
public MemberDeclaration(IFieldSymbol field, DiagReporter diag)
: this(field, field.Type, diag) { }

public string Identifier => EscapeIdentifier(Name);

public static string GenerateBsatnFields(
Accessibility visibility,
IEnumerable<MemberDeclaration> members
Expand All @@ -431,7 +433,7 @@ IEnumerable<MemberDeclaration> members
return string.Join(
"\n ",
members.Select(m =>
$"{visStr} static readonly {m.Type.ToBSATNString()} {m.Name}{TypeUse.BsatnFieldSuffix} = new();"
$"{visStr} static readonly {m.Type.ToBSATNString()} {m.Identifier}{TypeUse.BsatnFieldSuffix} = new();"
)
);
}
Expand All @@ -442,7 +444,7 @@ public static string GenerateDefs(IEnumerable<MemberDeclaration> members) =>
// we can't use nameof(m.Type.BsatnFieldName) because the bsatn field name differs from the logical name
// assigned in the type.
members.Select(m =>
$"new(\"{m.Name}\", {m.Name}{TypeUse.BsatnFieldSuffix}.GetAlgebraicType(registrar))"
$"new(\"{m.Name}\", {m.Identifier}{TypeUse.BsatnFieldSuffix}.GetAlgebraicType(registrar))"
)
);
}
Expand All @@ -462,6 +464,12 @@ public abstract record BaseTypeDeclaration<M>
public readonly TypeKind Kind;
public readonly EquatableArray<M> Members;

/// <summary>
/// Returns the escaped version of ShortName for use in generated C# code where the type name
/// appears as an identifier (e.g., in IEquatable&lt;T&gt; or as a base type reference).
/// </summary>
public string ShortNameIdentifier => EscapeIdentifier(ShortName);

protected abstract M ConvertMember(int index, IFieldSymbol field, DiagReporter diag);

public BaseTypeDeclaration(GeneratorAttributeSyntaxContext context, DiagReporter diag)
Expand Down Expand Up @@ -557,7 +565,7 @@ public Scope.Extensions ToExtensions()

var bsatnDecls = Members.Cast<MemberDeclaration>();

extensions.BaseTypes.Add($"System.IEquatable<{ShortName}>");
extensions.BaseTypes.Add($"System.IEquatable<{ShortNameIdentifier}>");

if (Kind is TypeKind.Sum)
{
Expand All @@ -569,10 +577,10 @@ public Scope.Extensions ToExtensions()
// To avoid this, we append an underscore to the field name.
// In most cases the field name shouldn't matter anyway as you'll idiomatically use pattern matching to extract the value.
$$"""
public sealed record {{m.Name}}({{m.Type.Name}} {{m.Name}}_) : {{ShortName}}
public sealed record {{m.Identifier}}({{m.Type.Name}} {{m.Identifier}}_) : {{ShortNameIdentifier}}
{
public override string ToString() =>
$"{{m.Name}}({ SpacetimeDB.BSATN.StringUtil.GenericToString({{m.Name}}_) })";
$"{{m.Name}}({ SpacetimeDB.BSATN.StringUtil.GenericToString({{m.Identifier}}_) })";
}

"""
Expand All @@ -585,7 +593,7 @@ public override string ToString() =>
{{string.Join(
"\n ",
bsatnDecls.Select((m, i) =>
$"{i} => new {m.Name}({m.Name}{TypeUse.BsatnFieldSuffix}.Read(reader)),"
$"{i} => new {m.Identifier}({m.Identifier}{TypeUse.BsatnFieldSuffix}.Read(reader)),"
)
)}}
_ => throw new System.InvalidOperationException("Invalid tag value, this state should be unreachable.")
Expand All @@ -597,9 +605,9 @@ public override string ToString() =>
{{string.Join(
"\n",
bsatnDecls.Select((m, i) => $"""
case {m.Name}(var inner):
case {m.Identifier}(var inner):
writer.Write((byte){i});
{m.Name}{TypeUse.BsatnFieldSuffix}.Write(writer, inner);
{m.Identifier}{TypeUse.BsatnFieldSuffix}.Write(writer, inner);
break;
"""))}}
}
Expand All @@ -615,7 +623,7 @@ public override string ToString() =>
var hashName = $"___hash{member.Name}";

return $"""
case {member.Name}(var inner):
case {member.Identifier}(var inner):
{member.Type.GetHashCodeStatement("inner", hashName)}
return {hashName};
""";
Expand All @@ -634,14 +642,14 @@ public override string ToString() =>
public void ReadFields(System.IO.BinaryReader reader) {
{{string.Join(
"\n",
bsatnDecls.Select(m => $" {m.Name} = BSATN.{m.Name}{TypeUse.BsatnFieldSuffix}.Read(reader);")
bsatnDecls.Select(m => $" {m.Identifier} = BSATN.{m.Identifier}{TypeUse.BsatnFieldSuffix}.Read(reader);")
)}}
}

public void WriteFields(System.IO.BinaryWriter writer) {
{{string.Join(
"\n",
bsatnDecls.Select(m => $" BSATN.{m.Name}{TypeUse.BsatnFieldSuffix}.Write(writer, {m.Name});")
bsatnDecls.Select(m => $" BSATN.{m.Identifier}{TypeUse.BsatnFieldSuffix}.Write(writer, {m.Identifier});")
)}}
}

Expand All @@ -661,7 +669,7 @@ object SpacetimeDB.BSATN.IStructuralReadWrite.GetSerializer() {
public override string ToString() =>
$"{{ShortName}} {{start}} {{string.Join(
", ",
bsatnDecls.Select(m => $$"""{{m.Name}} = {SpacetimeDB.BSATN.StringUtil.GenericToString({{m.Name}})}""")
bsatnDecls.Select(m => $$"""{{m.Name}} = {SpacetimeDB.BSATN.StringUtil.GenericToString({{m.Identifier}})}""")
)}} {{end}}";
"""
);
Expand All @@ -680,7 +688,7 @@ public override string ToString() =>
var declHashName = (MemberDeclaration decl) => $"___hash{decl.Name}";

getHashCode = $$"""
{{string.Join("\n", bsatnDecls.Select(decl => decl.Type.GetHashCodeStatement(decl.Name, declHashName(decl))))}}
{{string.Join("\n", bsatnDecls.Select(decl => decl.Type.GetHashCodeStatement(decl.Identifier, declHashName(decl))))}}
return {{JoinOrValue(
" ^\n ",
bsatnDecls.Select(declHashName),
Expand Down Expand Up @@ -735,7 +743,7 @@ public override int GetHashCode()
public bool Equals({{fullNameMaybeRef}} that)
{
{{(Scope.IsStruct ? "" : "if (((object?)that) == null) { return false; }\n ")}}
{{string.Join("\n", bsatnDecls.Select(decl => decl.Type.EqualsStatement($"this.{decl.Name}", $"that.{decl.Name}", declEqualsName(decl))))}}
{{string.Join("\n", bsatnDecls.Select(decl => decl.Type.EqualsStatement($"this.{decl.Identifier}", $"that.{decl.Identifier}", declEqualsName(decl))))}}
return {{JoinOrValue(
" &&\n ",
bsatnDecls.Select(declEqualsName),
Expand Down
13 changes: 13 additions & 0 deletions crates/bindings-csharp/BSATN.Codegen/Utils.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -33,13 +33,26 @@ public readonly record struct EquatableArray<T>(ImmutableArray<T> Array) : IEnum
.AddMemberOptions(SymbolDisplayMemberOptions.IncludeContainingType)
.AddMiscellaneousOptions(
SymbolDisplayMiscellaneousOptions.IncludeNullableReferenceTypeModifier
| SymbolDisplayMiscellaneousOptions.EscapeKeywordIdentifiers
);

public static string SymbolToName(ISymbol symbol)
{
return symbol.ToDisplayString(SymbolFormat);
}

public static string EscapeIdentifier(string name)
{
if (name.Length > 0 && name[0] == '@')
{
return name;
}

var kind = SyntaxFacts.GetKeywordKind(name);
var contextualKind = SyntaxFacts.GetContextualKeywordKind(name);
return kind != SyntaxKind.None || contextualKind != SyntaxKind.None ? $"@{name}" : name;
}

public static void RegisterSourceOutputs(
this IncrementalValuesProvider<Scope.Extensions> methods,
IncrementalGeneratorInitializationContext context
Expand Down
81 changes: 81 additions & 0 deletions crates/bindings-csharp/Codegen.Tests/Tests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -256,6 +256,87 @@ public static async Task SettingsAndExplicitNames()
AssertGeneratedCodeDoesNotUseInternalBound(compilationAfterGen);
}

[Fact]
public static async Task CSharpKeywordIdentifiersAreEscapedInGeneratedCode()
{
var fixture = await Fixture.Compile("server");

const string source = """
using SpacetimeDB;

[SpacetimeDB.Table]
public partial struct KeywordTable
{
[SpacetimeDB.PrimaryKey]
public ulong @class;

public int @params;
}

[SpacetimeDB.Table(Accessor = "event")]
public partial struct AccessorKeywordTable
{
[SpacetimeDB.PrimaryKey]
[SpacetimeDB.Index.BTree(Accessor = "params")]
public int Id;
}

[SpacetimeDB.Table]
public partial struct @class
{
[SpacetimeDB.PrimaryKey]
public int Id;
}

public static partial class KeywordApis
{
[SpacetimeDB.Reducer]
public static void KeywordReducer(ReducerContext ctx, int @params, string @class)
{
_ = @params;
_ = @class;
}

[SpacetimeDB.Reducer]
public static void @class(ReducerContext ctx)
{
}

[SpacetimeDB.Procedure]
public static int KeywordProcedure(ProcedureContext ctx, int @params, int @class)
{
return @params + @class;
}

[SpacetimeDB.Procedure]
public static void @params(ProcedureContext ctx)
{
}
}
""";

var parseOptions = new CSharpParseOptions(fixture.SampleCompilation.LanguageVersion);
var tree = CSharpSyntaxTree.ParseText(source, parseOptions, path: "KeywordNames.cs");
var compilation = fixture.SampleCompilation.AddSyntaxTrees(tree);

var driver = CSharpGeneratorDriver.Create(
[
new SpacetimeDB.Codegen.Type().AsSourceGenerator(),
new SpacetimeDB.Codegen.Module().AsSourceGenerator(),
],
driverOptions: new(
disabledOutputs: IncrementalGeneratorOutputKind.None,
trackIncrementalGeneratorSteps: true
),
parseOptions: parseOptions
);

var runResult = driver.RunGenerators(compilation).GetRunResult();
var compilationAfterGen = compilation.AddSyntaxTrees(runResult.GeneratedTrees);

Assert.Empty(GetCompilationErrors(compilationAfterGen));
}

[Fact]
public static async Task TestDiagnostics()
{
Expand Down
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