[wasm][eh] Remove unwind instruction

Relevant links:
https://github.com/WebAssembly/exception-handling/issues/153
https://github.com/WebAssembly/exception-handling/pull/156

R=clemensb@chromium.org

Bug: v8:8091
Change-Id: I0deeb9665c6648e643d0aa4f310b7676e1c2fa32
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2959624
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75135}

src/wasm/baseline/liftoff-compiler.cc

@@ -1226,8 +1226,7 @@ class LiftoffCompiler {
   }
 
   void CatchAll(FullDecoder* decoder, Control* block) {
-    DCHECK(block->is_try_catchall() || block->is_try_catch() ||
-           block->is_try_unwind());
+    DCHECK(block->is_try_catchall() || block->is_try_catch());
     DCHECK_EQ(decoder->control_at(0), block);
 
     // The catch block is unreachable if no possible throws in the try block
@@ -1333,7 +1332,7 @@ class LiftoffCompiler {
   }
 
   void FinishTry(FullDecoder* decoder, Control* c) {
-    DCHECK(c->is_try_catch() || c->is_try_catchall() || c->is_try_unwind());
+    DCHECK(c->is_try_catch() || c->is_try_catchall());
     if (!c->end_merge.reached) {
       if (c->try_info->catch_reached) {
         // Drop the implicit exception ref.
@@ -1357,8 +1356,7 @@ class LiftoffCompiler {
     if (c->is_onearmed_if()) {
       // Special handling for one-armed ifs.
       FinishOneArmedIf(decoder, c);
-    } else if (c->is_try_catch() || c->is_try_catchall() ||
-               c->is_try_unwind()) {
+    } else if (c->is_try_catch() || c->is_try_catchall()) {
       FinishTry(decoder, c);
     } else if (c->end_merge.reached) {
       // There is a merge already. Merge our state into that, then continue with
@@ -3128,8 +3126,7 @@ class LiftoffCompiler {
                           ? next_control->stack_depth + __ num_locals() +
                                 next_control->num_exceptions
                           : __ cache_state()->stack_height();
-      bool exception = control->is_try_catch() || control->is_try_catchall() ||
-                       control->is_try_unwind();
+      bool exception = control->is_try_catch() || control->is_try_catchall();
       for (; index < end_index; ++index) {
         auto& slot = stack_state[index];
         auto& value = values[index];

src/wasm/function-body-decoder-impl.h

@@ -843,7 +843,6 @@ enum ControlKind : uint8_t {
   kControlTry,
   kControlTryCatch,
   kControlTryCatchAll,
-  kControlTryUnwind
 };
 
 enum Reachability : uint8_t {
@@ -905,10 +904,8 @@ struct ControlBase : public PcForErrors<validate> {
   bool is_incomplete_try() const { return kind == kControlTry; }
   bool is_try_catch() const { return kind == kControlTryCatch; }
   bool is_try_catchall() const { return kind == kControlTryCatchAll; }
-  bool is_try_unwind() const { return kind == kControlTryUnwind; }
   bool is_try() const {
-    return is_incomplete_try() || is_try_catch() || is_try_catchall() ||
-           is_try_unwind();
+    return is_incomplete_try() || is_try_catch() || is_try_catchall();
   }
 
   Merge<Value>* br_merge() {
@@ -1629,7 +1626,6 @@ class WasmDecoder : public Decoder {
       case kExprDrop:
       case kExprSelect:
       case kExprCatchAll:
-      case kExprUnwind:
         return 1;
       case kExprSelectWithType: {
         SelectTypeImmediate<validate> imm(WasmFeatures::All(), decoder, pc + 1,
@@ -1972,7 +1968,6 @@ class WasmDecoder : public Decoder {
       case kExprCatch:
       case kExprCatchAll:
       case kExprDelegate:
-      case kExprUnwind:
       case kExprRethrow:
       case kExprNop:
       case kExprNopForTestingUnsupportedInLiftoff:
@@ -2328,7 +2323,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           case kControlIfElse:
           case kControlTryCatch:
           case kControlTryCatchAll:
-          case kControlTryUnwind:
           case kControlLet:  // TODO(7748): Implement
             break;
         }
@@ -2452,10 +2446,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->DecodeError("catch after catch-all for try");
       return 0;
     }
-    if (!VALIDATE(!c->is_try_unwind())) {
-      this->DecodeError("catch after unwind for try");
-      return 0;
-    }
     FallThrough();
     c->kind = kControlTryCatch;
     // TODO(jkummerow): Consider moving the stack manipulation after the
@@ -2492,8 +2482,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
           "delegate target must be a try block or the function block");
       return 0;
     }
-    if (target->is_try_catch() || target->is_try_catchall() ||
-        target->is_try_unwind()) {
+    if (target->is_try_catch() || target->is_try_catchall()) {
       this->DecodeError(
           "cannot delegate inside the catch handler of the target");
       return 0;
@@ -2518,10 +2507,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
       this->error("catch-all already present for try");
       return 0;
     }
-    if (!VALIDATE(!c->is_try_unwind())) {
-      this->error("cannot have catch-all after unwind");
-      return 0;
-    }
     FallThrough();
     c->kind = kControlTryCatchAll;
     c->reachability = control_at(1)->innerReachability();
@@ -2532,29 +2517,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return 1;
   }
 
-  DECODE(Unwind) {
-    CHECK_PROTOTYPE_OPCODE(eh);
-    DCHECK(!control_.empty());
-    Control* c = &control_.back();
-    if (!VALIDATE(c->is_try())) {
-      this->DecodeError("unwind does not match a try");
-      return 0;
-    }
-    if (!VALIDATE(!c->is_try_catch() && !c->is_try_catchall() &&
-                  !c->is_try_unwind())) {
-      this->error("catch, catch-all or unwind already present for try");
-      return 0;
-    }
-    FallThrough();
-    c->kind = kControlTryUnwind;
-    c->reachability = control_at(1)->innerReachability();
-    current_catch_ = c->previous_catch;  // Pop try scope.
-    CALL_INTERFACE_IF_OK_AND_PARENT_REACHABLE(CatchAll, c);
-    stack_end_ = stack_ + c->stack_depth;
-    current_code_reachable_and_ok_ = this->ok() && c->reachable();
-    return 1;
-  }
-
   DECODE(BrOnNull) {
     CHECK_PROTOTYPE_OPCODE(typed_funcref);
     BranchDepthImmediate<validate> imm(this, this->pc_ + 1);
@@ -2738,11 +2700,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     if (c->is_onearmed_if()) {
       if (!VALIDATE(TypeCheckOneArmedIf(c))) return 0;
     }
-    if (c->is_try_unwind()) {
-      // Unwind implicitly rethrows at the end.
-      CALL_INTERFACE_IF_OK_AND_REACHABLE(Rethrow, c);
-      EndControl();
-    }
 
     if (c->is_let()) {
       CALL_INTERFACE_IF_OK_AND_REACHABLE(DeallocateLocals, c->locals_count);
@@ -3344,7 +3301,6 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     DECODE_IMPL(Catch);
     DECODE_IMPL(Delegate);
     DECODE_IMPL(CatchAll);
-    DECODE_IMPL(Unwind);
     DECODE_IMPL(BrOnNull);
     DECODE_IMPL(BrOnNonNull);
     DECODE_IMPL(Let);

src/wasm/function-body-decoder.cc

@@ -191,7 +191,7 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
     }
     if (line_numbers) line_numbers->push_back(i.position());
     if (opcode == kExprElse || opcode == kExprCatch ||
-        opcode == kExprCatchAll || opcode == kExprUnwind) {
+        opcode == kExprCatchAll) {
       control_depth--;
     }
 
@@ -241,7 +241,6 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
       case kExprElse:
       case kExprCatch:
       case kExprCatchAll:
-      case kExprUnwind:
         os << " @" << i.pc_offset();
         control_depth++;
         break;

src/wasm/graph-builder-interface.cc

@@ -721,8 +721,7 @@ class WasmGraphBuildingInterface {
   }
 
   void Rethrow(FullDecoder* decoder, Control* block) {
-    DCHECK(block->is_try_catchall() || block->is_try_catch() ||
-           block->is_try_unwind());
+    DCHECK(block->is_try_catchall() || block->is_try_catch());
     TFNode* exception = block->try_info->exception;
     DCHECK_NOT_NULL(exception);
     CheckForException(decoder, builder_->Rethrow(exception));
@@ -808,8 +807,7 @@ class WasmGraphBuildingInterface {
   }
 
   void CatchAll(FullDecoder* decoder, Control* block) {
-    DCHECK(block->is_try_catchall() || block->is_try_catch() ||
-           block->is_try_unwind());
+    DCHECK(block->is_try_catchall() || block->is_try_catch());
     DCHECK_EQ(decoder->control_at(0), block);
 
     // The catch block is unreachable if no possible throws in the try block

src/wasm/wasm-opcodes-inl.h

@@ -197,7 +197,6 @@ constexpr const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_OP(Throw, "throw")
     CASE_OP(Rethrow, "rethrow")
     CASE_OP(CatchAll, "catch-all")
-    CASE_OP(Unwind, "unwind")
 
     // asm.js-only opcodes.
     CASE_F64_OP(Acos, "acos")

src/wasm/wasm-opcodes.h

@@ -42,7 +42,6 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
   V(Catch, 0x07, _ /* eh_prototype */)          \
   V(Throw, 0x08, _ /* eh_prototype */)          \
   V(Rethrow, 0x09, _ /* eh_prototype */)        \
-  V(Unwind, 0x0a, _ /* eh_prototype */)         \
   V(End, 0x0b, _)                               \
   V(Br, 0x0c, _)                                \
   V(BrIf, 0x0d, _)                              \

test/cctest/wasm/test-run-wasm-exceptions.cc

@@ -211,43 +211,11 @@ WASM_EXEC_TEST(TryDelegate) {
   }
 }
 
-WASM_EXEC_TEST(TryUnwind) {
-  TestSignatures sigs;
-  EXPERIMENTAL_FLAG_SCOPE(eh);
-  WasmRunner<uint32_t, uint32_t> r(execution_tier);
-  byte except = r.builder().AddException(sigs.v_v());
-  constexpr uint32_t kResult0 = 23;
-  constexpr uint32_t kResult1 = 42;
-
-  // Build the main test function.
-  BUILD(r, WASM_TRY_CATCH_T(
-               kWasmI32,
-               WASM_TRY_UNWIND_T(
-                   kWasmI32,
-                   WASM_TRY_DELEGATE_T(
-                       kWasmI32,
-                       WASM_STMTS(WASM_I32V(kResult1),
-                                  WASM_IF(WASM_I32_EQZ(WASM_LOCAL_GET(0)),
-                                          WASM_THROW(except))),
-                       0),
-                   kExprNop),
-               WASM_I32V(kResult0), except));
-
-  if (execution_tier != TestExecutionTier::kInterpreter) {
-    // Need to call through JS to allow for creation of stack traces.
-    r.CheckCallViaJS(kResult0, 0);
-    r.CheckCallViaJS(kResult1, 1);
-  } else {
-    CHECK_EQ(kResult0, r.CallInterpreter(0));
-    CHECK_EQ(kResult1, r.CallInterpreter(1));
-  }
-}
-
 WASM_EXEC_TEST(TestCatchlessTry) {
   TestSignatures sigs;
   EXPERIMENTAL_FLAG_SCOPE(eh);
   WasmRunner<uint32_t> r(execution_tier);
-  uint32_t except = r.builder().AddException(sigs.v_i());
+  byte except = r.builder().AddException(sigs.v_i());
   BUILD(r,
         WASM_TRY_CATCH_T(
             kWasmI32,
@@ -706,17 +674,16 @@ TEST(Regress1186795) {
   EXPERIMENTAL_FLAG_SCOPE(eh);
   WasmRunner<uint32_t> r(TestExecutionTier::kInterpreter);
   byte except = r.builder().AddException(sigs.v_i());
-  BUILD(r, WASM_TRY_CATCH_T(
-               kWasmI32,
-               WASM_STMTS(
-                   WASM_I32V(0), WASM_I32V(0), WASM_I32V(0), WASM_I32V(0),
-                   WASM_I32V(0), WASM_I32V(0), WASM_I32V(0),
-                   WASM_TRY_UNWIND_T(
-                       kWasmI32, WASM_STMTS(WASM_I32V(0), WASM_THROW(except)),
-                       WASM_I32V(0)),
-                   WASM_DROP, WASM_DROP, WASM_DROP, WASM_DROP, WASM_DROP,
-                   WASM_DROP, WASM_DROP),
-               WASM_NOP, except));
+  BUILD(r,
+        WASM_TRY_CATCH_T(
+            kWasmI32,
+            WASM_STMTS(WASM_I32V(0), WASM_I32V(0), WASM_I32V(0), WASM_I32V(0),
+                       WASM_I32V(0), WASM_I32V(0), WASM_I32V(0),
+                       WASM_TRY_T(kWasmI32,
+                                  WASM_STMTS(WASM_I32V(0), WASM_THROW(except))),
+                       WASM_DROP, WASM_DROP, WASM_DROP, WASM_DROP, WASM_DROP,
+                       WASM_DROP, WASM_DROP),
+            WASM_NOP, except));
   CHECK_EQ(0, r.CallInterpreter());
 }
 

test/common/wasm/wasm-interpreter.cc

@@ -690,9 +690,6 @@ class SideTable : public ZoneObject {
       // Track whether this block was already left, i.e. all further
       // instructions are unreachable.
       bool unreachable = false;
-      // Whether this is a try...unwind...end block. Needed to handle the
-      // implicit rethrow when we reach the end of the block.
-      bool unwind = false;
 
       Control(const byte* pc, CLabel* end_label, CLabel* else_label,
               uint32_t exit_arity)
@@ -865,27 +862,6 @@ class SideTable : public ZoneObject {
           stack_height = c->end_label->target_stack_height;
           break;
         }
-        case kExprUnwind: {
-          TRACE("control @%u: Unwind\n", i.pc_offset());
-          Control* c = &control_stack.back();
-          DCHECK_EQ(*c->pc, kExprTry);
-          DCHECK(!exception_stack.empty());
-          DCHECK_EQ(exception_stack.back(), control_stack.size() - 1);
-          exception_stack.pop_back();
-          copy_unreachable();
-          if (!unreachable) c->end_label->Ref(i.pc(), stack_height);
-          DCHECK_NOT_NULL(c->else_label);
-          int control_index = static_cast<int>(control_stack.size()) - 1;
-          c->else_label->Bind(i.pc() + 1, kCatchAllExceptionIndex,
-                              control_index);
-          c->else_label->Finish(&map_, code->start);
-          c->else_label = nullptr;
-          c->unwind = true;
-          DCHECK_IMPLIES(!unreachable,
-                         stack_height >= c->end_label->target_stack_height);
-          stack_height = c->end_label->target_stack_height;
-          break;
-        }
         case kExprTry: {
           BlockTypeImmediate<Decoder::kNoValidation> imm(
               WasmFeatures::All(), &i, i.pc() + 1, module);
@@ -968,13 +944,6 @@ class SideTable : public ZoneObject {
                 stack_height = c->else_label->target_stack_height;
                 rethrow = !unreachable;
               }
-            } else if (c->unwind) {
-              DCHECK_EQ(*c->pc, kExprTry);
-              rethrow_map_.emplace(i.pc() - i.start(),
-                                   static_cast<int>(control_stack.size()) - 1);
-              if (!exception_stack.empty()) {
-                rethrow = !unreachable;
-              }
             }
             c->end_label->Bind(i.pc() + 1);
           }
@@ -3415,7 +3384,6 @@ class WasmInterpreterInternals {
           break;
         }
         case kExprElse:
-        case kExprUnwind:
         case kExprCatch:
         case kExprCatchAll: {
           len = LookupTargetDelta(code, pc);
@@ -3512,19 +3480,6 @@ class WasmInterpreterInternals {
           break;
         }
         case kExprEnd: {
-          if (code->side_table->rethrow_map_.count(pc)) {
-            // Implicit rethrow after unwind.
-            HandleScope scope(isolate_);
-            DCHECK(!frames_.back().caught_exception_stack.is_null());
-            int index = code->side_table->rethrow_map_[pc];
-            Handle<Object> exception = handle(
-                frames_.back().caught_exception_stack->get(index), isolate_);
-            DCHECK(!exception->IsTheHole());
-            CommitPc(pc);  // Needed for local unwinding.
-            if (!DoRethrowException(exception)) return;
-            ReloadFromFrameOnException(&decoder, &code, &pc, &limit);
-            continue;  // Do not bump pc.
-          }
           break;
         }
         case kExprI32Const: {

test/common/wasm/wasm-macro-gen.h

@@ -199,9 +199,6 @@
 #define WASM_TRY_DELEGATE_T(t, trystmt, depth)                                \
   kExprTry, static_cast<byte>((t).value_type_code()), trystmt, kExprDelegate, \
       depth
-#define WASM_TRY_UNWIND_T(t, trystmt, unwindstmt)                           \
-  kExprTry, static_cast<byte>((t).value_type_code()), trystmt, kExprUnwind, \
-      unwindstmt, kExprEnd
 
 #define WASM_SELECT(tval, fval, cond) tval, fval, cond, kExprSelect
 #define WASM_SELECT_I(tval, fval, cond) \

test/fuzzer/wasm-compile.cc

@@ -215,7 +215,6 @@ class WasmGenerator {
     // Allow one more target than there are enclosing try blocks, for delegating
     // to the caller.
     uint8_t delegate_target = data->get<uint8_t>() % (try_blocks_.size() + 1);
-    bool is_unwind = num_catch == 0 && !has_catch_all && !is_delegate;
 
     Vector<const ValueType> return_type_vec = return_type.kind() == kVoid
                                                   ? Vector<ValueType>{}
@@ -249,10 +248,6 @@ class WasmGenerator {
       builder_->EmitWithU32V(kExprDelegate, delegate_depth);
     }
     catch_blocks_.pop_back();
-    if (is_unwind) {
-      builder_->Emit(kExprUnwind);
-      Generate(return_type, data);
-    }
   }
 
   template <ValueKind T>

test/mjsunit/wasm/exceptions.js

@@ -79,17 +79,9 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
         kExprCatchAll,
         kExprEnd
       ]).exportFunc();
-  builder.addFunction('unreachable_in_try_unwind', kSig_v_v)
-      .addBody([
-        kExprTry, kWasmVoid,
-          kExprUnreachable,
-        kExprUnwind,
-        kExprEnd
-      ]).exportFunc();
   let instance = builder.instantiate();
 
   assertTraps(kTrapUnreachable, () => instance.exports.unreachable_in_try());
-  assertTraps(kTrapUnreachable, () => instance.exports.unreachable_in_try_unwind());
 })();
 
 (function TestTrapInCalleeNotCaught() {
@@ -110,21 +102,10 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
-  builder.addFunction('trap_in_callee_unwind', kSig_i_ii)
-      .addBody([
-        kExprTry, kWasmI32,
-          kExprLocalGet, 0,
-          kExprLocalGet, 1,
-          kExprCallFunction, func_div.index,
-        kExprUnwind,
-          kExprI32Const, 11,
-        kExprEnd
-      ]).exportFunc();
   let instance = builder.instantiate();
 
   assertEquals(3, instance.exports.trap_in_callee(7, 2));
   assertTraps(kTrapDivByZero, () => instance.exports.trap_in_callee(1, 0));
-  assertTraps(kTrapDivByZero, () => instance.exports.trap_in_callee_unwind(1, 0));
 })();
 
 (function TestTrapViaJSNotCaught() {
@@ -145,14 +126,6 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
-  builder.addFunction('call_import_unwind', kSig_i_v)
-      .addBody([
-        kExprTry, kWasmI32,
-          kExprCallFunction, imp,
-        kExprUnwind,
-          kExprI32Const, 11,
-        kExprEnd
-      ]).exportFunc();
   let exception = undefined;
   let instance;
   function js_import() {
@@ -175,18 +148,6 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
   assertSame(exception, caught);
   assertInstanceof(exception, WebAssembly.RuntimeError);
   assertEquals(exception.message, kTrapMsgs[kTrapDivByZero]);
-
-  // Same test with unwind instead of catch_all.
-  caught = undefined;
-  try {
-    let res = instance.exports.call_import_unwind();
-    assertUnreachable('call_import_unwind should trap, but returned with ' + res);
-  } catch (e) {
-    caught = e;
-  }
-  assertSame(exception, caught);
-  assertInstanceof(exception, WebAssembly.RuntimeError);
-  assertEquals(exception.message, kTrapMsgs[kTrapDivByZero]);
 })();
 
 (function TestManuallyThrownRuntimeErrorCaught() {
@@ -201,21 +162,12 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
-  builder.addFunction('call_import_unwind', kSig_i_v)
-      .addBody([
-        kExprTry, kWasmI32,
-          kExprCallFunction, imp,
-        kExprUnwind,
-          kExprI32Const, 11,
-        kExprEnd
-      ]).exportFunc();
   function throw_exc() {
     throw new WebAssembly.RuntimeError('My user text');
   }
   let instance = builder.instantiate({imp: {ort: throw_exc}});
 
   assertEquals(11, instance.exports.call_import());
-  assertThrows(instance.exports.call_import_unwind, WebAssembly.RuntimeError, "My user text");
 })();
 
 (function TestExnWithWasmProtoNotCaught() {
@@ -1041,18 +993,8 @@ d8.file.execute("test/mjsunit/wasm/exceptions-utils.js");
         kExprCatchAll,
         kExprEnd
       ]).exportFunc();
-  builder.addFunction('test_unwind', kSig_v_v)
-      .addBody([
-        kExprTry, kWasmVoid,
-          kExprTry, kWasmVoid,
-            kExprThrow, except,
-          kExprDelegate, 1,
-        kExprUnwind,
-        kExprEnd
-      ]).exportFunc();
   instance = builder.instantiate();
   assertTraps(WebAssembly.RuntimeError, () => instance.exports.test());
-  assertTraps(WebAssembly.RuntimeError, () => instance.exports.test_unwind());
 })();
 
 (function TestThrowBeforeUnreachable() {

test/mjsunit/wasm/wasm-module-builder.js

@@ -228,7 +228,6 @@ const kWasmOpcodes = {
   'Throw': 0x08,
   'Rethrow': 0x09,
   'CatchAll': 0x19,
-  'Unwind': 0x0a,
   'End': 0x0b,
   'Br': 0x0c,
   'BrIf': 0x0d,

test/unittests/wasm/function-body-decoder-unittest.cc

@@ -2967,21 +2967,6 @@ TEST_F(FunctionBodyDecoderTest, TryCatch) {
                 "catch does not match a try");
 }
 
-TEST_F(FunctionBodyDecoderTest, TryUnwind) {
-  WASM_FEATURE_SCOPE(eh);
-  byte ex = builder.AddException(sigs.v_v());
-  ExpectValidates(sigs.v_v(), {WASM_TRY_OP, kExprUnwind, kExprEnd});
-  ExpectFailure(sigs.v_v(),
-                {WASM_TRY_OP, kExprUnwind, kExprCatch, ex, kExprEnd},
-                kAppendEnd, "catch after unwind for try");
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprCatchAll, kExprUnwind, kExprEnd},
-                kAppendEnd,
-                "catch, catch-all or unwind already present for try");
-  ExpectFailure(
-      sigs.v_v(), {WASM_TRY_OP, kExprCatch, ex, kExprUnwind, kExprEnd},
-      kAppendEnd, "catch, catch-all or unwind already present for try");
-}
-
 TEST_F(FunctionBodyDecoderTest, Rethrow) {
   WASM_FEATURE_SCOPE(eh);
   ExpectValidates(sigs.v_v(),
@@ -2993,9 +2978,6 @@ TEST_F(FunctionBodyDecoderTest, Rethrow) {
                 "rethrow not targeting catch or catch-all");
   ExpectFailure(sigs.v_v(), {kExprRethrow, 0}, kAppendEnd,
                 "rethrow not targeting catch or catch-all");
-  ExpectFailure(sigs.v_v(),
-                {WASM_TRY_OP, kExprUnwind, kExprRethrow, 0, kExprEnd},
-                kAppendEnd, "rethrow not targeting catch or catch-all");
 }
 
 TEST_F(FunctionBodyDecoderTest, TryDelegate) {
@@ -3021,11 +3003,6 @@ TEST_F(FunctionBodyDecoderTest, TryDelegate) {
                  WASM_TRY_DELEGATE(WASM_STMTS(kExprThrow, ex), 0), kExprEnd},
                 kAppendEnd,
                 "cannot delegate inside the catch handler of the target");
-  ExpectFailure(sigs.v_v(),
-                {WASM_TRY_OP, kExprUnwind,
-                 WASM_TRY_DELEGATE(WASM_STMTS(kExprThrow, ex), 0), kExprEnd},
-                kAppendEnd,
-                "cannot delegate inside the catch handler of the target");
   ExpectFailure(
       sigs.v_v(),
       {WASM_BLOCK(WASM_TRY_OP, WASM_TRY_DELEGATE(WASM_STMTS(kExprThrow, ex), 3),