The C# syntax tree's name accessors (ParameterDeclaration.Name, GotoStatement.Label,
catch variable, query continuations, ...) are convenience strings over a backing Identifier
token. Names that may be absent are now typed string? and read as null when absent, instead of
a non-null empty-string sentinel; required names stay non-null string. The backing token slot's
nullability follows, and an empty or null assignment clears the token (empty == absent).
Because the property type now carries optionality, the separate [NameSlot] attribute and its
nullOnEmpty flag are redundant: a [Slot] on a string property is a name (child slots are
AstNode-typed, so the type disambiguates), and the generator infers optionality from the
declared nullable annotation -- which a string? declaration already requires #nullable for. The
repeated empty-to-null setter body becomes Identifier.CreateIfNotEmpty. To make the annotation
readable, #nullable enable is turned on across the syntax node files (the directive the inferred
optionality depends on), with the attendant local nullability fixups. Consumers that feed a name
into a non-null slot assert it where the variable structurally has a name.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Nodes use nullable reference types now, so the generated null-object
node and its hasNullNode / NeedsNullNode / NullNodeBaseCtorParamCount
plumbing are dead. Drop them and reword the affected comments.
The 124 concrete node classes that are neither a base of another node nor a
host for a generated PatternPlaceholder subclass are now sealed, so the JIT can
devirtualize the slot dispatch (GetChild, GetChildCount, GetChildSlotInfo,
GetChildNodes, AcceptVisitor) when the static type is the sealed leaf. Identifier's
constructor becomes private (protected is meaningless and an error in a sealed
type). Abstract bases, base classes (PreProcessorDirective, the EntityDeclaration/
AstType/Statement/Expression hierarchy roots), and pattern-placeholder hosts stay
open.
Assisted-by: Claude:claude-opus-4-8:Claude Code
The [Slot] and [NameSlot] string argument only feeds SlotKind derivation, which
takes the last dotted segment and strips a trailing "Role", so the Roles.
qualifier and the Role suffix were dead decoration. Rewrite each to the bare
SlotKind it already produces, so the attribute reads as exactly the kind.
Collapse the runs of consecutive blank lines that removing the hand-written
constructors, fields and properties left between the remaining members.
Assisted-by: Claude:claude-opus-4-8:Claude Code
The decompiler never emits "delegate () {}" (an explicit empty parameter
list) -- it produces "delegate {}" when there are no parameters and
"delegate (...) {}" when there are -- so HasParameterList always equalled
Parameters.Any(). Drop the property, its backing field and the two setter
calls, and read Parameters.Any() directly at the printer and the
resolve-result builder.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Scalar value properties that merely forwarded to a private backing field
(IsAsync, Operator and the operator-type enums, Format, ClassType, Variance,
ParameterModifier, the parameter bool flags, and similar) become
auto-properties, formatted on a single line. Behavior is identical;
PrimitiveExpression's constructor sets the property instead of the dropped
field.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Each concrete node's constructors are now emitted by the source generator
from its members in source order: single and collection [Slot] children,
the [NameSlot] string, and settable enum scalars (Operator, FieldDirection,
...). It emits the empty ctor (for object initializers), a required-prefix
ctor, one ending at each collection, and the full ctor, with later ctors
forwarding to shorter ones via this(...) and a params[] overload alongside
each IEnumerable<T> one. The hand-written ctors the generator now produces
are removed; scalar/location/Identifier convenience overloads that it cannot
express are kept (e.g. AssignmentExpression(left, right), SimpleType(Identifier),
the string+TextLocation overloads).
Because ctor parameters follow source order, BinaryOperatorExpression and
AssignmentExpression declare Operator between Left and Right so the generated
ctor is the expected (left, op, right). Pure-scalar nodes whose state is not
in slots (e.g. PrimitiveExpression's literal value) are left untouched.
Assisted-by: Claude:claude-opus-4-8:Claude Code
TokenRole was a printer-side descriptor whose only jobs were holding a token's
text and giving the writers an identity to single out specific tokens. The text
becomes plain const strings on the nodes, and the few identity checks are
reexpressed as node-stack context: interpolation braces are recognized by an
Interpolation on the writer's stack, record class versus struct coloring keys
off TypeDeclaration.ClassType, and the accessor/this/base/override cases fall
out of the surrounding node. WriteKeyword/WriteToken drop the descriptor
parameter. The constants are named for what the token is: a keyword, a symbol
token, or a modifier.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Slot identity already lived in node.Slot/CSharpSlotInfo/SlotKind after
the storage flip, so the parallel Role/Role<T> child model was redundant.
The Role-keyed mutation/query API is reexpressed over SlotKind, and the
role-index packing on AstNode flags is gone.
Because a node's Slot is now derived from its index in its parent rather
than stored on the child, the located-AST reattach in
InsertMissingTokensDecorator must capture the child's slot kind before
Remove() detaches it.
Assisted-by: Claude:claude-opus-4-8:Claude Code
The grammar-production doc comments were transcribed in ANTLR style and
often copied the C# spec verbatim, including sub-rules the AST does not
model. Rewrite them as W3C EBNF (::=, ?, *, +), unroll sub-productions
that are not themselves AST nodes (e.g. anonymous_function_modifier ->
'async'), and shape each production to the node's actual members. Render
top-level alternations of node productions as multi-line <code> blocks;
keep operator and keyword token lists inline.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Each concrete syntax node now carries, in an XML-doc <remarks> block, the
matching production from the C# language specification grammar (ECMA/Microsoft,
ANTLR notation), quoted verbatim. Aggregate nodes (e.g. BinaryOperatorExpression,
ComposedType, TypeDeclaration) list every production they span; lexical/trivia
nodes (Comment, the preprocessor directives, Identifier) cite the lexical rule.
Nodes with no spec production -- ErrorExpression, UndocumentedExpression,
InvocationAstType, TypeReferenceExpression, NamedExpression, DocumentationReference,
and the C# 14 ExtensionDeclaration -- carry a hand-written EBNF plus a note
explaining why no official production exists.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Comments and preprocessor directives were positional children interleaved
into the child list, and punctuation, keywords and operators were token-node
children. Add a leading/trailing trivia side-channel for comments and
directives, emit it from the output visitor, and re-home every comment
receiver onto it (including inside-block comments as comment-only empty
statements and undecodable attribute arguments as an ErrorExpression). With
locations and sequence points no longer sourced from token nodes, stop
reconstructing them on the locations path and delete CSharpTokenNode,
CSharpModifierToken and InsertSpecialsDecorator. The AST no longer carries
token children or positional comments; output is byte-identical.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Each child of a C# AST node is declared as a [Slot] partial property, and the
source generator emits the accessor bodies and an ordered slot schema
(SlotCount/GetSlotRole/IsCollectionSlot) from them. Generating the schema
keeps slot order from being mis-stated by hand and lets a DEBUG invariant
check declared slot order against document order on every decompile. The node
hierarchy is converted family by family; the EntityDeclaration leaves flatten
their inherited Attributes/ReturnType/NameToken into each leaf's ordered slot
set. Storage stays the NRefactory linked list at this stage, so only the
declaration model changes and output is unchanged.
Assisted-by: Claude:claude-opus-4-8:Claude Code
The generator emits the IAstVisitor interface, the AcceptVisitor overloads,
and the null-node and pattern-placeholder nodes from [DecompilerAstNode]
declarations, so drop the hand-written equivalents across the C# AST: per-node
AcceptVisitor/DoMatch, the #region Null / #region PatternPlaceholder blocks,
IAstVisitor.cs, and now-dead usings. Also adds AccessorKind and moves
IdentifierExpressionBackreference into the PatternMatching folder.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Introduce a Roslyn source generator that emits the visitor boilerplate for
the C# AST from [DecompilerAstNode]-tagged node declarations: the
IAstVisitor interface, the AcceptVisitor overloads, the pattern-placeholder
nodes, and the initial DoMatch support. AccessorKind lets an accessor's
keyword be chosen independently of its role, an early step toward shedding
the NRefactory role model.
The C# AST inherited NRefactory's freezable model (IFreezable, Freeze,
IsFrozen, a frozen flag bit, and ThrowIfFrozen guards on every mutator),
but the decompiler never uses it: nothing calls Freeze(), not even the
generated null-node singletons, so every IsFrozen guard only ever
evaluated false. The decompiler is single-threaded and never shares or
freezes nodes. Remove the whole apparatus as preparation for the
slot-based AST rewrite, which has no place for it. Roles are untouched
here, so the flags word keeps its role index; only the freed frozen bit
goes away.
Siegfried Pammer
Peter Crabtree
dotnet format
Christoph Wille