[NFC] BridgeJS: Use consistent codegen helper for @_extern decl

Author: kateinoigakukun

Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift

@@ -46,17 +46,16 @@ public struct ClosureCodegen {
 
         // Generate extern declaration using CallJSEmission
         let externDecl = builder.renderImportDecl()
-
-        let makeClosureExternDecl: DeclSyntax = """
-            #if arch(wasm32)
-            @_extern(wasm, module: "bjs", name: "make_swift_closure_\(raw: signature.moduleName)_\(raw: signature.mangleName)")
-            fileprivate func make_swift_closure_\(raw: signature.moduleName)_\(raw: signature.mangleName)(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
-            #else
-            fileprivate func make_swift_closure_\(raw: signature.moduleName)_\(raw: signature.mangleName)(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
-                fatalError("Only available on WebAssembly")
-            }
-            #endif
-            """
+        let externABIName = "make_swift_closure_\(signature.moduleName)_\(signature.mangleName)"
+        let externDeclPrinter = CodeFragmentPrinter()
+        SwiftCodePattern.buildExternFunctionDecl(
+            printer: externDeclPrinter,
+            moduleName: "bjs",
+            abiName: externABIName,
+            functionName: externABIName,
+            signature: "(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32"
+        )
+        let makeClosureExternDecl: DeclSyntax = "\(raw: externDeclPrinter.lines.joined(separator: "\n"))"
 
         let helperEnumDeclPrinter = CodeFragmentPrinter()
         helperEnumDeclPrinter.write("private enum \(helperName) {")
@@ -98,7 +97,7 @@ public struct ClosureCodegen {
             extension JSTypedClosure where Signature == \(raw: swiftClosureType) {
                 init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping \(raw: swiftClosureType)) {
                     self.init(
-                        makeClosure: make_swift_closure_\(raw: signature.moduleName)_\(raw: signature.mangleName),
+                        makeClosure: \(raw: externABIName),
                         body: body,
                         fileID: fileID,
                         line: line

Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift

@@ -701,26 +701,12 @@ public class ExportSwift {
         )
 
         let externDeclPrinter = CodeFragmentPrinter()
-        SwiftCodePattern.buildWasmConditionalCompilationDecls(
+        SwiftCodePattern.buildExternFunctionDecl(
             printer: externDeclPrinter,
-            wasmDecl: { printer in
-                SwiftCodePattern.buildExternFunctionDecl(
-                    printer: printer,
-                    moduleName: moduleName,
-                    abiName: externFunctionName,
-                    functionName: wrapFunctionName,
-                    signature: funcSignature
-                )
-            },
-            elseDecl: { printer in
-                printer.write(
-                    multilineString: """
-                        fileprivate func \(wrapFunctionName)\(funcSignature) {
-                            fatalError("Only available on WebAssembly")
-                        }
-                        """
-                )
-            }
+            moduleName: moduleName,
+            abiName: externFunctionName,
+            functionName: wrapFunctionName,
+            signature: funcSignature
         )
         let externDecl: DeclSyntax = "\(raw: externDeclPrinter.lines.joined(separator: "\n"))"
         return [extensionDecl, externDecl]
@@ -1297,26 +1283,12 @@ struct StructCodegen {
         functionName: String,
         signature: String
     ) {
-        SwiftCodePattern.buildWasmConditionalCompilationDecls(
+        SwiftCodePattern.buildExternFunctionDecl(
             printer: printer,
-            wasmDecl: { printer in
-                SwiftCodePattern.buildExternFunctionDecl(
-                    printer: printer,
-                    moduleName: "bjs",
-                    abiName: externName,
-                    functionName: functionName,
-                    signature: signature
-                )
-            },
-            elseDecl: { printer in
-                printer.write(
-                    multilineString: """
-                        fileprivate func \(functionName)\(signature) {
-                            fatalError("Only available on WebAssembly")
-                        }
-                        """
-                )
-            }
+            moduleName: "bjs",
+            abiName: externName,
+            functionName: functionName,
+            signature: signature
         )
     }
 

Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift

@@ -228,26 +228,12 @@ public struct ImportTS {
             )
 
             let printer = CodeFragmentPrinter()
-            SwiftCodePattern.buildWasmConditionalCompilationDecls(
+            SwiftCodePattern.buildExternFunctionDecl(
                 printer: printer,
-                wasmDecl: { printer in
-                    SwiftCodePattern.buildExternFunctionDecl(
-                        printer: printer,
-                        moduleName: moduleName,
-                        abiName: abiName,
-                        functionName: abiName,
-                        signature: signature
-                    )
-                },
-                elseDecl: { printer in
-                    printer.write(
-                        multilineString: """
-                            fileprivate func \(abiName)\(signature) {
-                                fatalError("Only available on WebAssembly")
-                            }
-                            """
-                    )
-                }
+                moduleName: moduleName,
+                abiName: abiName,
+                functionName: abiName,
+                signature: signature
             )
             return "\(raw: printer.lines.joined(separator: "\n"))"
         }
@@ -658,8 +644,20 @@ enum SwiftCodePattern {
         functionName: String,
         signature: String
     ) {
-        printer.write(buildExternAttribute(moduleName: moduleName, abiName: abiName))
-        printer.write("fileprivate func \(functionName)\(signature)")
+        buildWasmConditionalCompilationDecls(
+            printer: printer,
+            wasmDecl: { printer in
+                printer.write(buildExternAttribute(moduleName: moduleName, abiName: abiName))
+                printer.write("fileprivate func \(functionName)\(signature)")
+            },
+            elseDecl: { printer in
+                printer.write("fileprivate func \(functionName)\(signature) {")
+                printer.indent {
+                    printer.write("fatalError(\"Only available on WebAssembly\")")
+                }
+                printer.write("}")
+            }
+        )
     }
 
     /// Builds the standard @_expose and @_cdecl attributes for WebAssembly-exposed functions