Track current exception (#4701)

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/CAdapterGenerator.kt

@@ -461,7 +461,7 @@ private class ExportedElement(val kind: ElementKind,
                     "result", cfunction[0], Direction.KOTLIN_TO_C, builder)
             builder.append("  return $result;\n")
         }
-        builder.append("   } catch (ExceptionObjHolder& e) { TerminateWithUnhandledException(e.obj()); } \n")
+        builder.append("   } catch (ExceptionObjHolder& e) { TerminateWithUnhandledException(e.GetExceptionObject()); } \n")
 
         builder.append("}\n")
 
@@ -905,7 +905,6 @@ internal class CAdapterGenerator(val context: Context) : DeclarationDescriptorVi
         |#define RUNTIME_NORETURN __attribute__((noreturn))
         |
         |extern "C" {
-        |void UpdateHeapRef(KObjHeader**, const KObjHeader*) RUNTIME_NOTHROW;
         |void UpdateStackRef(KObjHeader**, const KObjHeader*) RUNTIME_NOTHROW;
         |KObjHeader* AllocInstance(const KTypeInfo*, KObjHeader**) RUNTIME_NOTHROW;
         |KObjHeader* DerefStablePointer(void*, KObjHeader**) RUNTIME_NOTHROW;
@@ -951,16 +950,10 @@ internal class CAdapterGenerator(val context: Context) : DeclarationDescriptorVi
         |};
         |
         |class ExceptionObjHolder {
-        | public:
-        |  explicit ExceptionObjHolder(const KObjHeader* obj): obj_(nullptr) {
-        |    ::UpdateHeapRef(&obj_, obj);
-        |  }
-        |  ~ExceptionObjHolder() {
-        |    UpdateHeapRef(&obj_, nullptr);
-        |  }
-        |  KObjHeader* obj() { return obj_; }
-        | private:
-        |  KObjHeader* obj_;
+        |public:
+        |    virtual ~ExceptionObjHolder() = default;
+        |
+        |    KObjHeader* GetExceptionObject() noexcept;
         |};
         |
         |static void DisposeStablePointerImpl(${prefix}_KNativePtr ptr) {

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt

@@ -862,14 +862,10 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
         val beginCatch = context.llvm.cxaBeginCatchFunction
         val exceptionRawPtr = call(beginCatch, listOf(exceptionRecord))
 
-        // Pointer to KotlinException instance:
-        val exceptionPtrPtr = bitcast(codegen.kObjHeaderPtrPtr, exceptionRawPtr, "")
-
         // Pointer to Kotlin exception object:
-        // We do need a slot here, as otherwise exception instance could be freed by _cxa_end_catch.
-        val exceptionPtr = loadSlot(exceptionPtrPtr, true, "exception")
+        val exceptionPtr = call(context.llvm.Kotlin_getExceptionObject, listOf(exceptionRawPtr), Lifetime.GLOBAL)
 
-        // __cxa_end_catch performs some C++ cleanup, including calling `KotlinException` class destructor.
+        // __cxa_end_catch performs some C++ cleanup, including calling `ExceptionObjHolder` class destructor.
         val endCatch = context.llvm.cxaEndCatchFunction
         call(endCatch, listOf())
 

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt

@@ -516,6 +516,7 @@ internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
     val checkLifetimesConstraint = importRtFunction("CheckLifetimesConstraint")
     val freezeSubgraph = importRtFunction("FreezeSubgraph")
     val checkGlobalsAccessible = importRtFunction("CheckGlobalsAccessible")
+    val Kotlin_getExceptionObject = importRtFunction("Kotlin_getExceptionObject")
 
     val kRefSharedHolderInitLocal = importRtFunction("KRefSharedHolder_initLocal")
     val kRefSharedHolderInit = importRtFunction("KRefSharedHolder_init")

kotlin-native/backend.native/tests/build.gradle

@@ -2545,6 +2545,16 @@ standaloneTest("exception_in_global_init") {
     outputChecker = { s -> s.contains("Uncaught Kotlin exception: kotlin.IllegalStateException: FAIL") && !s.contains("in kotlin main") }
 }
 
+task rethrow_exception(type: KonanLocalTest) {
+    enabled = (project.testTarget != 'wasm32') // Uses exceptions.
+    source = "runtime/exceptions/rethrow.kt"
+}
+
+task throw_from_catch(type: KonanLocalTest) {
+    enabled = (project.testTarget != 'wasm32') // Uses exceptions.
+    source = "runtime/exceptions/throw_from_catch.kt"
+}
+
 standaloneTest("runtime_math_exceptions") {
     enabled = (project.testTarget != 'wasm32')
     source = "stdlib_external/numbers/MathExceptionTest.kt"

kotlin-native/backend.native/tests/runtime/exceptions/rethrow.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+package runtime.exceptions.rethtow
+
+import kotlin.test.*
+
+@Test
+fun runTest() {
+    assertFailsWith<IllegalStateException>("My error") {
+        try {
+            error("My error")
+        } catch (e: Throwable) {
+            throw e
+        }
+    }
+}

kotlin-native/backend.native/tests/runtime/exceptions/throw_from_catch.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+package runtime.exceptions.throw_from_catch
+
+import kotlin.test.*
+
+@Test
+fun runTest() {
+    assertFailsWith<IllegalStateException>("My another error") {
+        try {
+            error("My error")
+        } catch (e: Throwable) {
+            error("My another error")
+        }
+    }
+}