[Wasm] Add compiler flag to disable exception handling proposal

Fail with unreachable instead of throwing an exception

Merge-request: KT-MR-11481
Merged-by: Svyatoslav Kuzmich <svyatoslav.kuzmich@jetbrains.com>

wasm/wasm.ir/src/org/jetbrains/kotlin/wasm/ir/convertors/WasmIrToBinary.kt

@@ -123,9 +123,11 @@ class WasmIrToBinary(
             }
 
             // tag section
-            appendSection(WasmBinary.Section.TAG) {
-                appendVectorSize(tags.size)
-                tags.forEach { appendTag(it) }
+            if (tags.isNotEmpty()) {
+                appendSection(WasmBinary.Section.TAG) {
+                    appendVectorSize(tags.size)
+                    tags.forEach { appendTag(it) }
+                }
             }
 
             appendSection(WasmBinary.Section.GLOBAL) {
@@ -607,7 +609,7 @@ abstract class ByteWriter {
     fun writeUByte(v: UByte) {
         writeByte(v.toByte())
     }
-    
+
     fun writeUInt32(v: UInt) {
         writeByte(v.toByte())
         writeByte((v shr 8).toByte())

wasm/wasm.tests/test/org/jetbrains/kotlin/wasm/test/handlers/WasmBoxRunner.kt

@@ -11,6 +11,7 @@ import org.jetbrains.kotlin.js.JavaScript
 import org.jetbrains.kotlin.test.DebugMode
 import org.jetbrains.kotlin.test.InTextDirectivesUtils
 import org.jetbrains.kotlin.test.directives.WasmEnvironmentConfigurationDirectives
+import org.jetbrains.kotlin.test.directives.WasmEnvironmentConfigurationDirectives.DISABLE_WASM_EXCEPTION_HANDLING
 import org.jetbrains.kotlin.test.directives.WasmEnvironmentConfigurationDirectives.RUN_UNIT_TESTS
 import org.jetbrains.kotlin.test.model.TestFile
 import org.jetbrains.kotlin.test.services.TestServices
@@ -191,6 +192,8 @@ class WasmBoxRunner(
             val testFileText = originalFile.readText()
             val failsIn: List<String> = InTextDirectivesUtils.findListWithPrefixes(testFileText, "// WASM_FAILS_IN: ")
 
+            val disableExceptions = DISABLE_WASM_EXCEPTION_HANDLING in testServices.moduleStructure.allDirectives
+
             val exceptions = listOf(WasmVM.V8, WasmVM.SpiderMonkey).mapNotNull map@{ vm ->
                 try {
                     if (debugMode >= DebugMode.DEBUG) {
@@ -199,7 +202,8 @@ class WasmBoxRunner(
                     vm.run(
                         "./${entryMjs}",
                         jsFilePaths,
-                        workingDirectory = dir
+                        workingDirectory = dir,
+                        disableExceptionHandlingIfPossible = disableExceptions
                     )
                     if (vm.shortName in failsIn) {
                         return@map AssertionError("The test expected to fail in ${vm.name}. Please update the testdata.")

wasm/wasm.tests/test/org/jetbrains/kotlin/wasm/test/tools/WasmVM.kt

@@ -17,10 +17,10 @@ internal sealed class WasmVM(val shortName: String) {
     val name: String = javaClass.simpleName
     protected val tool = ExternalTool(System.getProperty("javascript.engine.path.$name"))
 
-    abstract fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?)
+    abstract fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?, disableExceptionHandlingIfPossible: Boolean = false)
 
     object V8 : WasmVM("V8") {
-        override fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?) {
+        override fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?, disableExceptionHandlingIfPossible: Boolean) {
             tool.run(
                 "--experimental-wasm-gc",
                 "--wasm-final-types",
@@ -34,10 +34,11 @@ internal sealed class WasmVM(val shortName: String) {
     }
 
     object SpiderMonkey : WasmVM("SM") {
-        override fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?) {
+        override fun run(entryMjs: String, jsFiles: List<String>, workingDirectory: File?, disableExceptionHandlingIfPossible: Boolean) {
             tool.run(
                 "--wasm-verbose",
                 "--wasm-gc",
+                *if (disableExceptionHandlingIfPossible) arrayOf("--no-wasm-exceptions") else emptyArray(),
                 "--wasm-function-references",
                 *jsFiles.flatMap { listOf("-f", it) }.toTypedArray(),
                 "--module=$entryMjs",

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenWasmJsInteropTestGenerated.java

@@ -139,6 +139,12 @@ public class FirWasmCodegenWasmJsInteropTestGenerated extends AbstractFirWasmCod
         runTest("compiler/testData/codegen/boxWasmJsInterop/nameClash.kt");
     }
 
+    @Test
+    @TestMetadata("noExceptions.kt")
+    public void testNoExceptions() throws Exception {
+        runTest("compiler/testData/codegen/boxWasmJsInterop/noExceptions.kt");
+    }
+
     @Test
     @TestMetadata("nullableExternRefs.kt")
     public void testNullableExternRefs() throws Exception {

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenWasmJsInteropTestGenerated.java

@@ -139,6 +139,12 @@ public class K1WasmCodegenWasmJsInteropTestGenerated extends AbstractK1WasmCodeg
         runTest("compiler/testData/codegen/boxWasmJsInterop/nameClash.kt");
     }
 
+    @Test
+    @TestMetadata("noExceptions.kt")
+    public void testNoExceptions() throws Exception {
+        runTest("compiler/testData/codegen/boxWasmJsInterop/noExceptions.kt");
+    }
+
     @Test
     @TestMetadata("nullableExternRefs.kt")
     public void testNullableExternRefs() throws Exception {