[NFC] ASTGen: Extract ParamDecl and ParameterList translation into a new file

Author: AnthonyLatsis

include/swift/AST/CASTBridging.h

@@ -321,8 +321,7 @@ struct BridgedFuncDecl
 FuncDecl_create(BridgedASTContext cContext, BridgedDeclContext cDeclContext,
                 BridgedSourceLoc cStaticLoc, BridgedSourceLoc cFuncKeywordLoc,
                 BridgedIdentifier cName, BridgedSourceLoc cNameLoc,
-                BridgedSourceLoc cLeftParenLoc, BridgedArrayRef params,
-                BridgedSourceLoc cRightParenLoc, BridgedSourceLoc cAsyncLoc,
+                void *opaqueParameterList, BridgedSourceLoc cAsyncLoc,
                 BridgedSourceLoc cThrowsLoc, void *_Nullable opaqueReturnType);
 void FuncDecl_setBody(void *fn, void *body);
 
@@ -371,6 +370,11 @@ void *GenericTypeParamDecl_create(BridgedASTContext cContext,
 void GenericTypeParamDecl_setInheritedType(BridgedASTContext cContext,
                                            void *Param, void *ty);
 
+void *ParameterList_create(BridgedASTContext cContext,
+                           BridgedSourceLoc cLeftParenLoc,
+                           BridgedArrayRef cParameters,
+                           BridgedSourceLoc cRightParenLoc);
+
 BridgedTypeAttrKind TypeAttrKind_fromString(BridgedString cStr);
 BridgedTypeAttributes TypeAttributes_create(void);
 void TypeAttributes_addSimpleAttr(BridgedTypeAttributes cAttributes,

lib/AST/CASTBridging.cpp

@@ -424,14 +424,11 @@ BridgedFuncDecl
 FuncDecl_create(BridgedASTContext cContext, BridgedDeclContext cDeclContext,
                 BridgedSourceLoc cStaticLoc, BridgedSourceLoc cFuncKeywordLoc,
                 BridgedIdentifier cName, BridgedSourceLoc cNameLoc,
-                BridgedSourceLoc cLeftParenLoc, BridgedArrayRef params,
-                BridgedSourceLoc cRightParenLoc, BridgedSourceLoc cAsyncLoc,
+                void *opaqueParameterList, BridgedSourceLoc cAsyncLoc,
                 BridgedSourceLoc cThrowsLoc, void *_Nullable opaqueReturnType) {
   ASTContext &context = convertASTContext(cContext);
 
-  auto *paramList = ParameterList::create(
-      context, convertSourceLoc(cLeftParenLoc),
-      convertArrayRef<ParamDecl *>(params), convertSourceLoc(cRightParenLoc));
+  auto *paramList = static_cast<ParameterList *>(opaqueParameterList);
   auto declName = DeclName(context, convertIdentifier(cName), paramList);
   auto asyncLoc = convertSourceLoc(cAsyncLoc);
   auto throwsLoc = convertSourceLoc(cThrowsLoc);
@@ -833,6 +830,16 @@ void GenericTypeParamDecl_setInheritedType(BridgedASTContext cContext,
   ((GenericTypeParamDecl *)param)->setInherited(entries);
 }
 
+void *ParameterList_create(BridgedASTContext cContext,
+                           BridgedSourceLoc cLeftParenLoc,
+                           BridgedArrayRef cParameters,
+                           BridgedSourceLoc cRightParenLoc) {
+  ASTContext &context = convertASTContext(cContext);
+  return ParameterList::create(context, convertSourceLoc(cLeftParenLoc),
+                               convertArrayRef<ParamDecl *>(cParameters),
+                               convertSourceLoc(cRightParenLoc));
+}
+
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
 

lib/ASTGen/CMakeLists.txt

@@ -15,6 +15,7 @@ add_pure_swift_host_library(swiftASTGen STATIC
   Sources/ASTGen/Generics.swift
   Sources/ASTGen/Literals.swift
   Sources/ASTGen/Macros.swift
+  Sources/ASTGen/ParameterClause.swift
   Sources/ASTGen/PluginHost.swift
   Sources/ASTGen/SourceFile.swift
   Sources/ASTGen/SourceManager.swift

lib/ASTGen/Sources/ASTGen/Decls.swift

@@ -85,50 +85,20 @@ extension ASTGenVisitor {
     )
   }
 
-  public func visit(_ node: FunctionParameterSyntax) -> ASTNode {
-    // FIXME: This location should be derived from the type repr.
-    let specifierLoc: BridgedSourceLoc = nil
-
-    let firstName: BridgedIdentifier
-    if node.firstName.text != "_" {
-      // Swift AST represents "_" as nil.
-      firstName = node.firstName.bridgedIdentifier(in: self)
-    } else {
-      firstName = nil
-    }
-    let (secondName, secondNameLoc) = node.secondName.bridgedIdentifierAndSourceLoc(in: self)
-
-    return .decl(
-      ParamDecl_create(
-        self.ctx,
-        self.declContext,
-        specifierLoc,
-        firstName,
-        self.bridgedSourceLoc(for: node.firstName),
-        secondName,
-        secondNameLoc,
-        self.visit(node.type).rawValue
-      )
-    )
-  }
-
   public func visit(_ node: FunctionDeclSyntax) -> ASTNode {
     // FIXME: Compute this location
     let staticLoc: BridgedSourceLoc = nil
 
     let (name, nameLoc) = node.name.bridgedIdentifierAndSourceLoc(in: self)
 
-    let parameters = node.signature.parameterClause.parameters.lazy.map { visit($0).rawValue }
     let out = FuncDecl_create(
       self.ctx,
       self.declContext,
       staticLoc,
       self.bridgedSourceLoc(for: node.funcKeyword),
       name,
       nameLoc,
-      self.bridgedSourceLoc(for: node.signature.parameterClause.leftParen),
-      parameters.bridgedArray(in: self),
-      self.bridgedSourceLoc(for: node.signature.parameterClause.rightParen),
+      self.visit(node.signature.parameterClause).rawValue,
       self.bridgedSourceLoc(for: node.signature.effectSpecifiers?.asyncSpecifier),
       self.bridgedSourceLoc(for: node.signature.effectSpecifiers?.throwsSpecifier),
       self.visit(node.signature.returnClause?.type)?.rawValue

lib/ASTGen/Sources/ASTGen/ParameterClause.swift

@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2023 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 CASTBridging
+
+// Needed to use SyntaxTransformVisitor's visit method.
+@_spi(SyntaxTransformVisitor)
+import SwiftSyntax
+
+// MARK: - ParamDecl
+
+extension ASTGenVisitor {
+  func visit(_ node: FunctionParameterSyntax) -> ASTNode {
+    // FIXME: This location should be derived from the type repr.
+    let specifierLoc: BridgedSourceLoc = nil
+
+    let firstName: BridgedIdentifier
+    if node.firstName.tokenKind != .wildcard {
+      // Swift AST represents "_" as nil.
+      firstName = node.firstName.bridgedIdentifier(in: self)
+    } else {
+      firstName = nil
+    }
+    let (secondName, secondNameLoc) = node.secondName.bridgedIdentifierAndSourceLoc(in: self)
+
+    return .decl(
+      ParamDecl_create(
+        self.ctx,
+        self.declContext,
+        specifierLoc,
+        firstName,
+        self.bridgedSourceLoc(for: node.firstName),
+        secondName,
+        secondNameLoc,
+        self.visit(node.type).rawValue
+      )
+    )
+  }
+}
+
+// MARK: - ParameterList
+
+extension ASTGenVisitor {
+  func visit(_ node: FunctionParameterClauseSyntax) -> ASTNode {
+    .misc(
+      ParameterList_create(
+        self.ctx,
+        self.bridgedSourceLoc(for: node.leftParen),
+        self.visit(node.parameters),
+        self.bridgedSourceLoc(for: node.rightParen)
+      )
+    )
+  }
+
+  @inline(__always)
+  func visit(_ node: FunctionParameterListSyntax) -> BridgedArrayRef {
+    node.lazy.map { self.visit($0).rawValue }.bridgedArray(in: self)
+  }
+}