[wasm][interpreter][eh] Implement catch_all

R=clemensb@chromium.org

Bug: v8:8091
Change-Id: I512db4c4a6dce56c06f6d222f75029eebeaa4f66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2691046
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72700}

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

@@ -95,6 +95,38 @@ WASM_EXEC_TEST(TryMultiCatchThrow) {
   }
 }
 
+WASM_EXEC_TEST(TryCatchAllThrow) {
+  TestSignatures sigs;
+  EXPERIMENTAL_FLAG_SCOPE(eh);
+  WasmRunner<uint32_t, uint32_t> r(execution_tier);
+  uint32_t except1 = r.builder().AddException(sigs.v_v());
+  uint32_t except2 = r.builder().AddException(sigs.v_v());
+  constexpr uint32_t kResult0 = 23;
+  constexpr uint32_t kResult1 = 42;
+  constexpr uint32_t kResult2 = 51;
+
+  // Build the main test function.
+  BUILD(
+      r, kExprTry, static_cast<byte>((kWasmI32).value_type_code()),
+      WASM_STMTS(WASM_I32V(kResult2),
+                 WASM_IF(WASM_I32_EQZ(WASM_LOCAL_GET(0)), WASM_THROW(except1)),
+                 WASM_IF(WASM_I32_EQ(WASM_LOCAL_GET(0), WASM_I32V(1)),
+                         WASM_THROW(except2))),
+      kExprCatch, except1, WASM_STMTS(WASM_I32V(kResult0)), kExprElse,
+      WASM_STMTS(WASM_I32V(kResult1)), kExprEnd);
+
+  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);
+    r.CheckCallViaJS(kResult2, 2);
+  } else {
+    CHECK_EQ(kResult0, r.CallInterpreter(0));
+    CHECK_EQ(kResult1, r.CallInterpreter(1));
+    CHECK_EQ(kResult2, r.CallInterpreter(2));
+  }
+}
+
 WASM_EXEC_TEST(TryCatchCallDirect) {
   TestSignatures sigs;
   EXPERIMENTAL_FLAG_SCOPE(eh);

test/common/wasm/wasm-interpreter.cc

@@ -560,6 +560,7 @@ int64_t ExecuteI64ReinterpretF64(WasmValue a) {
 }
 
 constexpr int32_t kCatchInArity = 1;
+constexpr int32_t kCatchAllExceptionIndex = -1;
 
 }  // namespace
 
@@ -810,20 +811,39 @@ class SideTable : public ZoneObject {
           break;
         }
         case kExprElse: {
-          // TODO(thibaudm): implement catch_all.
+          // Alias for catch_all if the current block is a try.
           Control* c = &control_stack.back();
-          copy_unreachable();
-          TRACE("control @%u: Else\n", i.pc_offset());
-          if (!unreachable) {
-            c->end_label->Ref(i.pc(), stack_height);
+          if (*c->pc == kExprIf) {
+            copy_unreachable();
+            TRACE("control @%u: Else\n", i.pc_offset());
+            if (!unreachable) {
+              c->end_label->Ref(i.pc(), stack_height);
+            }
+            DCHECK_NOT_NULL(c->else_label);
+            c->else_label->Bind(i.pc() + 1);
+            c->else_label->Finish(&map_, code->start);
+            stack_height = c->else_label->target_stack_height;
+            c->else_label = nullptr;
+            DCHECK_IMPLIES(!unreachable,
+                           stack_height >= c->end_label->target_stack_height);
+          } else {
+            DCHECK_EQ(*c->pc, kExprTry);
+            if (!exception_stack.empty() &&
+                exception_stack.back() == control_stack.size() - 1) {
+              // Only pop the exception stack if this is the only catch handler.
+              exception_stack.pop_back();
+            }
+            copy_unreachable();
+            TRACE("control @%u: CatchAll\n", i.pc_offset());
+            if (!unreachable) {
+              c->end_label->Ref(i.pc(), stack_height);
+            }
+            DCHECK_NOT_NULL(c->else_label);
+            c->else_label->Bind(i.pc() + 1, kCatchAllExceptionIndex);
+            DCHECK_IMPLIES(!unreachable,
+                           stack_height >= c->end_label->target_stack_height);
+            stack_height = c->end_label->target_stack_height;
           }
-          DCHECK_NOT_NULL(c->else_label);
-          c->else_label->Bind(i.pc() + 1);
-          c->else_label->Finish(&map_, code->start);
-          stack_height = c->else_label->target_stack_height;
-          c->else_label = nullptr;
-          DCHECK_IMPLIES(!unreachable,
-                         stack_height >= c->end_label->target_stack_height);
           break;
         }
         case kExprTry: {
@@ -1346,7 +1366,12 @@ class WasmInterpreterInternals {
     auto it = code->side_table->map_.catch_map.find(*pc);
     DCHECK_NE(it, code->side_table->map_.catch_map.end());
     for (auto& entry : it->second) {
-      if (MatchingExceptionTag(exception_object, entry.exception_index)) {
+      if (entry.exception_index == kCatchAllExceptionIndex) {
+        ResetStack(StackHeight() - entry.sp_diff);
+        *pc += entry.pc_diff;
+        return true;
+      } else if (MatchingExceptionTag(exception_object,
+                                      entry.exception_index)) {
         const WasmException* exception =
             &module()->exceptions[entry.exception_index];
         const FunctionSig* sig = exception->sig;