BridgeJS: Fix issue with multiple stack-based parameters that require reversed order and intermediate properties

Author: krodak

Plugins/BridgeJS/Sources/BridgeJSCore/ExportSwift.swift

@@ -1667,6 +1667,7 @@ public class ExportSwift {
         }
 
         func call(name: String, returnType: BridgeType) {
+            generateParameterLifting()
             let item = renderCallStatement(callee: "\(raw: name)", returnType: returnType)
             append(item)
         }
@@ -1694,6 +1695,7 @@ public class ExportSwift {
 
         func callMethod(klassName: String, methodName: String, returnType: BridgeType) {
             let (_, selfExpr) = removeFirstLiftedParameter()
+            generateParameterLifting()
             let item = renderCallStatement(
                 callee: "\(raw: selfExpr).\(raw: methodName)",
                 returnType: returnType
@@ -1827,6 +1829,29 @@ public class ExportSwift {
         func returnSignature() -> String {
             return abiReturnType?.swiftType ?? "Void"
         }
+
+        /// Generates intermediate variables for stack-using parameters if needed for LIFO compatibility
+        private func generateParameterLifting() {
+            let stackParamIndices = parameters.enumerated().compactMap { index, param -> Int? in
+                switch param.type {
+                case .optional(.associatedValueEnum):
+                    return index
+                default:
+                    return nil
+                }
+            }
+
+            guard stackParamIndices.count > 1 else { return }
+
+            for index in stackParamIndices.reversed() {
+                let param = parameters[index]
+                let expr = liftedParameterExprs[index]
+                let varName = "_tmp_\(param.name)"
+
+                append("let \(raw: varName) = \(expr)")
+                liftedParameterExprs[index] = ExprSyntax(DeclReferenceExprSyntax(baseName: .identifier(varName)))
+            }
+        }
     }
 
     private struct ClosureCodegen {

Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/EnumAssociatedValue.swift

@@ -45,7 +45,7 @@ enum Utilities {
     case failure(String, Int)
 }
 
-@JS func roundTripOptionalNetworkingResult(result: NetworkingResult?) -> NetworkingResult? 
+@JS func roundTripOptionalNetworkingResult(result: NetworkingResult?) -> NetworkingResult?
 
 @JS
 enum APIOptionalResult {

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/ExportSwiftTests/EnumAssociatedValue.swift

@@ -612,7 +612,9 @@ public func _bjs_roundTripOptionalAPIOptionalResult(resultIsSome: Int32, resultC
 @_cdecl("bjs_compareAPIResults")
 public func _bjs_compareAPIResults(result1IsSome: Int32, result1CaseId: Int32, result2IsSome: Int32, result2CaseId: Int32) -> Void {
     #if arch(wasm32)
-    let ret = compareAPIResults(result1: Optional<APIOptionalResult>.bridgeJSLiftParameter(result1IsSome, result1CaseId), result2: Optional<APIOptionalResult>.bridgeJSLiftParameter(result2IsSome, result2CaseId))
+    let _tmp_result2 = Optional<APIOptionalResult>.bridgeJSLiftParameter(result2IsSome, result2CaseId)
+    let _tmp_result1 = Optional<APIOptionalResult>.bridgeJSLiftParameter(result1IsSome, result1CaseId)
+    let ret = compareAPIResults(result1: _tmp_result1, result2: _tmp_result2)
     return ret.bridgeJSLowerReturn()
     #else
     fatalError("Only available on WebAssembly")

Tests/BridgeJSRuntimeTests/ExportAPITests.swift

@@ -528,6 +528,32 @@ typealias OptionalAge = Int?
     return value
 }
 
+@JS func compareAPIResults(_ r1: APIResult?, _ r2: APIResult?) -> String {
+    let r1Str: String
+    switch r1 {
+    case .none: r1Str = "nil"
+    case .some(.success(let msg)): r1Str = "success:\(msg)"
+    case .some(.failure(let code)): r1Str = "failure:\(code)"
+    case .some(.info): r1Str = "info"
+    case .some(.flag(let b)): r1Str = "flag:\(b)"
+    case .some(.rate(let r)): r1Str = "rate:\(r)"
+    case .some(.precise(let p)): r1Str = "precise:\(p)"
+    }
+
+    let r2Str: String
+    switch r2 {
+    case .none: r2Str = "nil"
+    case .some(.success(let msg)): r2Str = "success:\(msg)"
+    case .some(.failure(let code)): r2Str = "failure:\(code)"
+    case .some(.info): r2Str = "info"
+    case .some(.flag(let b)): r2Str = "flag:\(b)"
+    case .some(.rate(let r)): r2Str = "rate:\(r)"
+    case .some(.precise(let p)): r2Str = "precise:\(p)"
+    }
+
+    return "r1:\(r1Str),r2:\(r2Str)"
+}
+
 @JS func roundTripOptionalComplexResult(_ result: ComplexResult?) -> ComplexResult? {
     return result
 }

Tests/BridgeJSRuntimeTests/Generated/BridgeJS.ExportSwift.swift

@@ -3079,6 +3079,19 @@ public func _bjs_roundTripOptionalAPIResult(valueIsSome: Int32, valueCaseId: Int
     #endif
 }
 
+@_expose(wasm, "bjs_compareAPIResults")
+@_cdecl("bjs_compareAPIResults")
+public func _bjs_compareAPIResults(r1IsSome: Int32, r1CaseId: Int32, r2IsSome: Int32, r2CaseId: Int32) -> Void {
+    #if arch(wasm32)
+    let _tmp_r2 = Optional<APIResult>.bridgeJSLiftParameter(r2IsSome, r2CaseId)
+    let _tmp_r1 = Optional<APIResult>.bridgeJSLiftParameter(r1IsSome, r1CaseId)
+    let ret = compareAPIResults(_: _tmp_r1, _: _tmp_r2)
+    return ret.bridgeJSLowerReturn()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
 @_expose(wasm, "bjs_roundTripOptionalComplexResult")
 @_cdecl("bjs_roundTripOptionalComplexResult")
 public func _bjs_roundTripOptionalComplexResult(resultIsSome: Int32, resultCaseId: Int32) -> Void {

Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.ExportSwift.json

@@ -6826,6 +6826,48 @@
         }
       }
     },
+    {
+      "abiName" : "bjs_compareAPIResults",
+      "effects" : {
+        "isAsync" : false,
+        "isStatic" : false,
+        "isThrows" : false
+      },
+      "name" : "compareAPIResults",
+      "parameters" : [
+        {
+          "label" : "_",
+          "name" : "r1",
+          "type" : {
+            "optional" : {
+              "_0" : {
+                "associatedValueEnum" : {
+                  "_0" : "APIResult"
+                }
+              }
+            }
+          }
+        },
+        {
+          "label" : "_",
+          "name" : "r2",
+          "type" : {
+            "optional" : {
+              "_0" : {
+                "associatedValueEnum" : {
+                  "_0" : "APIResult"
+                }
+              }
+            }
+          }
+        }
+      ],
+      "returnType" : {
+        "string" : {
+
+        }
+      }
+    },
     {
       "abiName" : "bjs_roundTripOptionalComplexResult",
       "effects" : {

Tests/prelude.mjs

@@ -571,6 +571,15 @@ function BridgeJSRuntimeTests_runJsWorks(instance, exports) {
     assert.deepEqual(exports.roundTripOptionalAPIResult(p1), p1);
     assert.deepEqual(exports.roundTripOptionalComplexResult(cl1), cl1);
 
+    const apiSuccess = { tag: exports.APIResult.Tag.Success, param0: "test success" };
+    const apiFailure = { tag: exports.APIResult.Tag.Failure, param0: 404 };
+    const apiInfo = { tag: exports.APIResult.Tag.Info };
+   
+    assert.equal(exports.compareAPIResults(apiSuccess, apiFailure), "r1:success:test success,r2:failure:404");
+    assert.equal(exports.compareAPIResults(null, apiInfo), "r1:nil,r2:info");
+    assert.equal(exports.compareAPIResults(apiFailure, null), "r1:failure:404,r2:nil");
+    assert.equal(exports.compareAPIResults(null, null), "r1:nil,r2:nil");
+
     const optionalGreeter = new exports.Greeter("Schrödinger");
     const optionalGreeter2 = exports.roundTripOptionalClass(optionalGreeter);
     assert.equal(optionalGreeter2?.greet() ?? "", "Hello, Schrödinger!");