Swift AST: add GenericSignature

and add `var Type.invocationGenericSignatureOfFunctionType`

Author: eeckstein

SwiftCompilerSources/Sources/AST/CMakeLists.txt

@@ -12,6 +12,7 @@ add_swift_compiler_module(AST
   SOURCES
     Declarations.swift
     Conformance.swift
+    GenericSignature.swift
     Registration.swift
     SubstitutionMap.swift
     Type.swift)

SwiftCompilerSources/Sources/AST/GenericSignature.swift

@@ -0,0 +1,28 @@
+//===--- GenericSignature.swift -------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import Basic
+import ASTBridging
+
+/// Describes the generic signature of a particular declaration, including both the generic type
+/// parameters and the requirements placed on those generic parameters.
+public struct GenericSignature: CustomStringConvertible, NoReflectionChildren {
+  public let bridged: BridgedGenericSignature
+
+  public init(bridged: BridgedGenericSignature) {
+    self.bridged = bridged
+  }
+  
+  public var description: String {
+    return String(taking: bridged.getDebugDescription())
+  }
+}

SwiftCompilerSources/Sources/AST/Type.swift

@@ -97,6 +97,9 @@ extension TypeProperties {
   public var representationOfMetatype: AST.`Type`.MetatypeRepresentation {
     type.bridged.getRepresentationOfMetatype().representation
   }
+  public var invocationGenericSignatureOfFunctionType: GenericSignature {
+    GenericSignature(bridged: type.bridged.getInvocationGenericSignatureOfFunctionType())
+  }
 
   public var canBeClass: Type.TraitResult { type.bridged.canBeClass().result }
 

include/swift/AST/ASTBridging.h

@@ -49,6 +49,8 @@ enum class DifferentiabilityKind : uint8_t;
 class Fingerprint;
 class Identifier;
 class IfConfigClauseRangeInfo;
+class GenericSignature;
+class GenericSignatureImpl;
 struct LabeledStmtInfo;
 class LayoutConstraint;
 class LayoutConstraintInfo;
@@ -75,6 +77,7 @@ struct BridgedASTType;
 class BridgedCanType;
 class BridgedASTContext;
 struct BridgedSubstitutionMap;
+struct BridgedGenericSignature;
 struct BridgedConformance;
 class BridgedParameterList;
 enum BridgedPlatformKind : size_t;
@@ -3015,6 +3018,7 @@ struct BridgedASTType {
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE OptionalBridgedDeclObj getAnyNominal() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType getInstanceTypeOfMetatype() const;
   BRIDGED_INLINE MetatypeRepresentation getRepresentationOfMetatype() const;
+  SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedGenericSignature getInvocationGenericSignatureOfFunctionType() const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType subst(BridgedSubstitutionMap substMap) const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTType subst(BridgedASTType fromType, BridgedASTType toType) const;
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedConformance checkConformance(BridgedDeclObj proto) const;  
@@ -3078,6 +3082,13 @@ struct BridgedSubstitutionMap {
   SWIFT_IMPORT_UNSAFE BRIDGED_INLINE BridgedASTTypeArray getReplacementTypes() const;
 };
 
+struct BridgedGenericSignature {
+  const swift::GenericSignatureImpl * _Nullable impl;
+
+  BRIDGED_INLINE swift::GenericSignature unbridged() const;
+  BridgedOwnedString getDebugDescription() const;
+};
+
 struct BridgedFingerprint {
   uint64_t v1;
   uint64_t v2;

include/swift/AST/ASTBridgingImpl.h

@@ -19,6 +19,7 @@
 #include "swift/AST/ConformanceLookup.h"
 #include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
+#include "swift/AST/GenericSignature.h"
 #include "swift/AST/IfConfigClauseRangeInfo.h"
 #include "swift/AST/MacroDeclaration.h"
 #include "swift/AST/ProtocolConformance.h"
@@ -453,6 +454,10 @@ BridgedASTType::MetatypeRepresentation BridgedASTType::getRepresentationOfMetaty
   return MetatypeRepresentation(unbridged()->getAs<swift::AnyMetatypeType>()->getRepresentation());
 }
 
+BridgedGenericSignature BridgedASTType::getInvocationGenericSignatureOfFunctionType() const {
+  return {unbridged()->castTo<swift::SILFunctionType>()->getInvocationGenericSignature().getPointer()};
+}
+
 BridgedASTType BridgedASTType::subst(BridgedSubstitutionMap substMap) const {
   return {unbridged().subst(substMap.unbridged()).getPointer()};
 }
@@ -660,6 +665,14 @@ BridgedASTTypeArray BridgedSubstitutionMap::getReplacementTypes() const {
   return {unbridged().getReplacementTypes()};
 }
 
+//===----------------------------------------------------------------------===//
+// MARK: BridgedGenericSignature
+//===----------------------------------------------------------------------===//
+
+swift::GenericSignature BridgedGenericSignature::unbridged() const {
+  return swift::GenericSignature(impl);
+}
+
 //===----------------------------------------------------------------------===//
 // MARK: BridgedFingerprint
 //===----------------------------------------------------------------------===//

lib/AST/Bridging/MiscBridging.cpp

@@ -121,3 +121,14 @@ BridgedOwnedString BridgedSubstitutionMap::getDebugDescription() const {
   unbridged().dump(os);
   return BridgedOwnedString(str);
 }
+
+//===----------------------------------------------------------------------===//
+// MARK: GenericSignature
+//===----------------------------------------------------------------------===//
+
+BridgedOwnedString BridgedGenericSignature::getDebugDescription() const {
+  std::string str;
+  llvm::raw_string_ostream os(str);
+  unbridged().print(os);
+  return BridgedOwnedString(str);
+}