[KT-63275] Prepare SirAsSwiftSourcesPrinter for non-empty bodies

native/swift/sir-printer/src/org/jetbrains/sir/printer/SirAsSwiftSourcesPrinter.kt

@@ -10,8 +10,6 @@ import org.jetbrains.kotlin.sir.visitors.SirVisitorVoid
 import org.jetbrains.kotlin.utils.SmartPrinter
 import org.jetbrains.kotlin.utils.withIndent
 
-private const val DEFAULT_INDENT: String = "    "
-
 public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVisitorVoid() {
 
     public constructor() : this(SmartPrinter(StringBuilder()))
@@ -31,26 +29,43 @@ public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVi
     }
 
     override fun visitFunction(function: SirFunction): Unit = with(printer) {
-        println(
-            listOfNotNull(
-                function.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " },
-                "func ",
-                function.name.swiftIdentifier,
-                function.parameters.takeIf { it.isNotEmpty() }
-                    ?.joinToString(prefix = "(\n", postfix = "\n)", separator = ",\n") {
-                        it.swift.prependIndent(DEFAULT_INDENT)
-                    } ?: "()",
-                " -> ",
-                function.returnType.swift,
-                " { fatalError() }",
-            ).joinToString(separator = ""),
+        print(
+            function.visibility.takeIf { it != SirVisibility.INTERNAL }?.let { "${it.swift} " } ?: "",
+            "func ",
+            function.name.swiftIdentifier,
+            "("
         )
+        if (function.parameters.isNotEmpty()) {
+            println()
+            withIndent {
+                function.parameters.forEachIndexed { index, sirParameter ->
+                    print(sirParameter.swift)
+                    if (index != function.parameters.lastIndex) {
+                        println(",")
+                    } else {
+                        println()
+                    }
+                }
+            }
+        }
+        print(
+            ")",
+            " -> ",
+            function.returnType.swift,
+        )
+        println(" {")
+        withIndent {
+            printFunctionBody(function).forEach {
+                println(it)
+            }
+        }
+        println("}")
     }
 
     override fun visitEnum(enum: SirEnum): Unit = with(printer) {
         println("enum ${enum.name.swiftIdentifier} {")
         withIndent {
-            enum.acceptChildren(SirAsSwiftSourcesPrinter(printer))
+            enum.acceptChildren(this@SirAsSwiftSourcesPrinter)
         }
         println("}")
     }
@@ -62,6 +77,10 @@ public class SirAsSwiftSourcesPrinter(private val printer: SmartPrinter) : SirVi
     }
 }
 
+private fun printFunctionBody(function: SirFunction): List<String> {
+    return listOf("fatalError()")
+}
+
 private val SirVisibility.swift
     get(): String = when (this) {
         SirVisibility.PRIVATE -> "private"

native/swift/sir-printer/testData/all_types_argument.golden.swift

@@ -6,4 +6,6 @@ public func foo(
     arg5: Swift.Int64,
     arg6: Swift.Double,
     arg7: Swift.Float
-) -> Swift.Bool { fatalError() }
+) -> Swift.Bool {
+    fatalError()
+}

native/swift/sir-printer/testData/simple_function.golden.swift

@@ -1 +1,3 @@
-public func foo() -> Swift.Bool { fatalError() }
+public func foo() -> Swift.Bool {
+    fatalError()
+}

native/swift/sir-printer/testData/simple_multiple_function.golden.swift

@@ -1,3 +1,7 @@
-public func foo1() -> Swift.Bool { fatalError() }
+public func foo1() -> Swift.Bool {
+    fatalError()
+}
 
-public func foo2() -> Swift.Bool { fatalError() }
+public func foo2() -> Swift.Bool {
+    fatalError()
+}

native/swift/sir-printer/testData/single_argument.golden.swift

@@ -1,3 +1,5 @@
 public func foo(
     arg1: Swift.Int32
-) -> Swift.Bool { fatalError() }
+) -> Swift.Bool {
+    fatalError()
+}

native/swift/sir-printer/testData/two_arguments.golden.swift

@@ -1,4 +1,6 @@
 public func foo(
     arg1: Swift.Int32,
     arg2: Swift.Double
-) -> Swift.Bool { fatalError() }
+) -> Swift.Bool {
+    fatalError()
+}

plugins/swift-export/testData/simple.golden.swift

@@ -1,10 +1,16 @@
 enum namespace1 {
     enum main {
-        public func foobar() -> Swift.Int32 { fatalError() }
+        public func foobar() -> Swift.Int32 {
+            fatalError()
+        }
+    }
+    public func foo() -> Swift.Int32 {
+        fatalError()
     }
-    public func foo() -> Swift.Int32 { fatalError() }
 }
 
 enum namespace2 {
-    public func bar() -> Swift.Int32 { fatalError() }
+    public func bar() -> Swift.Int32 {
+        fatalError()
+    }
 }