[wasm][eh] Update catch_all encoding

'catch_all' and 'else' use distinct opcodes now.

R=clemensb@chromium.org

Bug: v8:8091
Change-Id: If07e46b9ea23068953db1765d10c7e3746d21d99
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2699258
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72810}

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

@@ -1747,6 +1747,7 @@ class WasmDecoder : public Decoder {
       case kExprReturnCallRef:
       case kExprDrop:
       case kExprSelect:
+      case kExprCatchAll:
       case kExprUnwind:
         return 1;
       case kExprSelectWithType: {
@@ -2073,6 +2074,7 @@ class WasmDecoder : public Decoder {
       case kExprElse:
       case kExprTry:
       case kExprCatch:
+      case kExprCatchAll:
       case kExprDelegate:
       case kExprUnwind:
       case kExprRethrow:
@@ -2575,6 +2577,31 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return 1 + imm.length;
   }
 
+  DECODE(CatchAll) {
+    CHECK_PROTOTYPE_OPCODE(eh);
+    DCHECK(!control_.empty());
+    Control* c = &control_.back();
+    if (!VALIDATE(c->is_try())) {
+      this->DecodeError("catch-all does not match a try");
+      return 0;
+    }
+    if (!VALIDATE(!c->is_try_catchall())) {
+      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;
+    }
+    FallThruTo(c);
+    c->kind = kControlTryCatchAll;
+    stack_end_ = stack_ + c->stack_depth;
+    c->reachability = control_at(1)->innerReachability();
+    CALL_INTERFACE_IF_PARENT_REACHABLE(CatchAll, c);
+    current_code_reachable_ = this->ok() && c->reachable();
+    return 1;
+  }
+
   DECODE(Unwind) {
     CHECK_PROTOTYPE_OPCODE(eh);
     DCHECK(!control_.empty());
@@ -2692,42 +2719,23 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     return 1 + imm.length;
   }
 
-  // Alias for "catch_all" if the current block is a try.
   DECODE(Else) {
     DCHECK(!control_.empty());
     Control* c = &control_.back();
-    if (!VALIDATE(c->is_if() || c->is_try())) {
-      this->DecodeError("else/catch_all does not match an if/try");
+    if (!VALIDATE(c->is_if())) {
+      this->DecodeError("else does not match an if");
       return 0;
     }
-    if (c->is_if()) {
-      if (!VALIDATE(c->is_onearmed_if())) {
-        this->DecodeError("else already present for if");
-        return 0;
-      }
-      if (!TypeCheckFallThru()) return 0;
-      c->kind = kControlIfElse;
-      CALL_INTERFACE_IF_PARENT_REACHABLE(Else, c);
-      if (c->reachable()) c->end_merge.reached = true;
-      PushMergeValues(c, &c->start_merge);
-      c->reachability = control_at(1)->innerReachability();
-    } else {
-      CHECK_PROTOTYPE_OPCODE(eh);
-      DCHECK(c->is_try());
-      if (!VALIDATE(!c->is_try_catchall())) {
-        this->error("catch-all already present for try");
-        return 0;
-      }
-      if (!VALIDATE(!c->is_try_unwind())) {
-        this->error("cannot have a catch-all after unwind");
-        return 0;
-      }
-      c->kind = kControlTryCatchAll;
-      FallThruTo(c);
-      stack_end_ = stack_ + c->stack_depth;
-      c->reachability = control_at(1)->innerReachability();
-      CALL_INTERFACE_IF_PARENT_REACHABLE(CatchAll, c);
+    if (!VALIDATE(c->is_onearmed_if())) {
+      this->DecodeError("else already present for if");
+      return 0;
     }
+    if (!TypeCheckFallThru()) return 0;
+    c->kind = kControlIfElse;
+    CALL_INTERFACE_IF_PARENT_REACHABLE(Else, c);
+    if (c->reachable()) c->end_merge.reached = true;
+    PushMergeValues(c, &c->start_merge);
+    c->reachability = control_at(1)->innerReachability();
     current_code_reachable_ = this->ok() && c->reachable();
     return 1;
   }
@@ -3329,6 +3337,7 @@ class WasmFullDecoder : public WasmDecoder<validate> {
     DECODE_IMPL(Try);
     DECODE_IMPL(Catch);
     DECODE_IMPL(Delegate);
+    DECODE_IMPL(CatchAll);
     DECODE_IMPL(Unwind);
     DECODE_IMPL(BrOnNull);
     DECODE_IMPL(Let);

src/wasm/function-body-decoder.cc

@@ -190,7 +190,8 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
       offset = 2;
     }
     if (line_numbers) line_numbers->push_back(i.position());
-    if (opcode == kExprElse || opcode == kExprCatch || opcode == kExprUnwind) {
+    if (opcode == kExprElse || opcode == kExprCatch ||
+        opcode == kExprCatchAll || opcode == kExprUnwind) {
       control_depth--;
     }
 
@@ -240,6 +241,7 @@ bool PrintRawWasmCode(AccountingAllocator* allocator, const FunctionBody& body,
     switch (opcode) {
       case kExprElse:
       case kExprCatch:
+      case kExprCatchAll:
       case kExprUnwind:
         os << " @" << i.pc_offset();
         control_depth++;

src/wasm/wasm-opcodes-inl.h

@@ -188,6 +188,7 @@ constexpr const char* WasmOpcodes::OpcodeName(WasmOpcode opcode) {
     CASE_OP(Delegate, "delegate")
     CASE_OP(Throw, "throw")
     CASE_OP(Rethrow, "rethrow")
+    CASE_OP(CatchAll, "catch-all")
     CASE_OP(Unwind, "unwind")
 
     // asm.js-only opcodes.

src/wasm/wasm-opcodes.h

@@ -46,8 +46,9 @@ bool V8_EXPORT_PRIVATE IsJSCompatibleSignature(const FunctionSig* sig,
   V(Return, 0x0f, _)                            \
   V(Let, 0x17, _ /* typed_funcref prototype */) \
   V(Delegate, 0x18, _ /* eh_prototype */)       \
+  V(CatchAll, 0x19, _ /* eh_prototype */)       \
   V(BrOnNull, 0xd4, _ /* gc prototype */)       \
-  V(NopForTestingUnsupportedInLiftoff, 0x19, _)
+  V(NopForTestingUnsupportedInLiftoff, 0x16, _)
 
 // Constants, locals, globals, and calls.
 #define FOREACH_MISC_OPCODE(V)                            \

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

@@ -112,7 +112,7 @@ WASM_EXEC_TEST(TryCatchAllThrow) {
                  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,
+      kExprCatch, except1, WASM_STMTS(WASM_I32V(kResult0)), kExprCatchAll,
       WASM_STMTS(WASM_I32V(kResult1)), kExprEnd);
 
   if (execution_tier != TestExecutionTier::kInterpreter) {

test/common/wasm/wasm-interpreter.cc

@@ -825,49 +825,50 @@ class SideTable : public ZoneObject {
           break;
         }
         case kExprElse: {
-          // Alias for catch_all if the current block is a try.
+          TRACE("control @%u: Else\n", i.pc_offset());
           Control* c = &control_stack.back();
-          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);
-            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;
-            DCHECK_IMPLIES(!unreachable,
-                           stack_height >= c->end_label->target_stack_height);
-            stack_height = c->end_label->target_stack_height;
+          DCHECK_EQ(*c->pc, kExprIf);
+          copy_unreachable();
+          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);
+          break;
+        }
+        case kExprCatchAll: {
+          TRACE("control @%u: CatchAll\n", i.pc_offset());
+          Control* c = &control_stack.back();
+          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();
+          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;
+          DCHECK_IMPLIES(!unreachable,
+                         stack_height >= c->end_label->target_stack_height);
+          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();
-          TRACE("control @%u: Unwind\n", i.pc_offset());
           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;
@@ -3472,7 +3473,8 @@ class WasmInterpreterInternals {
         }
         case kExprElse:
         case kExprUnwind:
-        case kExprCatch: {
+        case kExprCatch:
+        case kExprCatchAll: {
           len = LookupTargetDelta(code, pc);
           TRACE("  end => @%zu\n", pc + len);
           break;

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

@@ -189,8 +189,8 @@
       except1, catchstmt1, kExprCatch, except2, catchstmt2, kExprEnd
 #define WASM_TRY_CATCH_R(t, trystmt, catchstmt) \
   kExprTry, WASM_REF_TYPE(t), trystmt, kExprCatch, catchstmt, kExprEnd
-#define WASM_TRY_CATCH_ALL_T(t, trystmt, catchstmt)                       \
-  kExprTry, static_cast<byte>((t).value_type_code()), trystmt, kExprElse, \
+#define WASM_TRY_CATCH_ALL_T(t, trystmt, catchstmt)                           \
+  kExprTry, static_cast<byte>((t).value_type_code()), trystmt, kExprCatchAll, \
       catchstmt, kExprEnd
 #define WASM_TRY_DELEGATE(trystmt, depth) \
   kExprTry, kVoidCode, trystmt, kExprDelegate, depth

test/debugger/debug/wasm/debug-enabled-tier-down-wasm-unsupported-liftoff.js

@@ -11,7 +11,7 @@ load('test/mjsunit/wasm/wasm-module-builder.js');
 
 // Create a simple Wasm module.
 function create_builder(i) {
-  const kExprNopForTestingUnsupportedInLiftoff = 0x19;
+  const kExprNopForTestingUnsupportedInLiftoff = 0x16;
   const builder = new WasmModuleBuilder();
   builder.addFunction('main', kSig_i_i)
       .addBody([

test/mjsunit/regress/regress-9832.js

@@ -21,7 +21,7 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
           kExprCallFunction, f.index,
           kExprCallFunction, f.index,
           kExprLocalSet, 0,
-        kExprElse,
+        kExprCatchAll,
           kExprLocalGet, 0,
           kExprCallFunction, f.index,
           kExprLocalSet, 0,

test/mjsunit/wasm/exceptions-rethrow.js

@@ -49,7 +49,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
       .addBody([
         kExprTry, kWasmStmt,
           kExprThrow, except,
-        kExprElse,
+        kExprCatchAll,
           kExprRethrow, 0,
         kExprEnd,
   ]).exportFunc();
@@ -57,7 +57,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
       .addBody([
         kExprTry, kWasmI32,
           kExprThrow, except,
-        kExprElse,
+        kExprCatchAll,
           kExprLocalGet, 0,
           kExprI32Eqz,
           kExprIf, kWasmStmt,

test/mjsunit/wasm/exceptions.js

@@ -76,7 +76,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
       .addBody([
         kExprTry, kWasmStmt,
           kExprUnreachable,
-        kExprElse,
+        kExprCatchAll,
         kExprEnd
       ]).exportFunc();
   builder.addFunction('unreachable_in_try_unwind', kSig_v_v)
@@ -106,7 +106,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
           kExprLocalGet, 0,
           kExprLocalGet, 1,
           kExprCallFunction, func_div.index,
-        kExprElse,
+        kExprCatchAll,
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
@@ -141,7 +141,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
       .addBody([
         kExprTry, kWasmI32,
           kExprCallFunction, imp,
-        kExprElse,
+        kExprCatchAll,
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
@@ -197,7 +197,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
       .addBody([
         kExprTry, kWasmI32,
           kExprCallFunction, imp,
-        kExprElse,
+        kExprCatchAll,
           kExprI32Const, 11,
         kExprEnd
       ]).exportFunc();
@@ -1016,7 +1016,7 @@ load("test/mjsunit/wasm/exceptions-utils.js");
           kExprTry, kWasmStmt,
             kExprThrow, except,
           kExprDelegate, 1,
-        kExprElse,
+        kExprCatchAll,
         kExprEnd
       ]).exportFunc();
   builder.addFunction('test_unwind', kSig_v_v)

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

@@ -216,6 +216,7 @@ const kWasmOpcodes = {
   'Catch': 0x07,
   'Throw': 0x08,
   'Rethrow': 0x09,
+  'CatchAll': 0x19,
   'Unwind': 0x0a,
   'End': 0x0b,
   'Br': 0x0c,

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

@@ -2872,12 +2872,17 @@ TEST_F(FunctionBodyDecoderTest, TryCatch) {
   byte ex = builder.AddException(sigs.v_v());
   ExpectValidates(sigs.v_v(), {WASM_TRY_OP, kExprCatch, ex, kExprEnd});
   ExpectValidates(sigs.v_v(),
-                  {WASM_TRY_OP, kExprCatch, ex, kExprElse, kExprEnd});
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprElse, kExprCatch, ex, kExprEnd});
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprElse, kExprElse, kExprEnd});
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprEnd});    // Missing catch.
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprCatch, ex});  // Missing end.
-  ExpectFailure(sigs.v_v(), {kExprCatch, kExprEnd});     // Missing try.
+                  {WASM_TRY_OP, kExprCatch, ex, kExprCatchAll, kExprEnd});
+  ExpectFailure(sigs.v_v(),
+                {WASM_TRY_OP, kExprCatchAll, kExprCatch, ex, kExprEnd},
+                kAppendEnd, "catch after catch-all for try");
+  ExpectFailure(sigs.v_v(),
+                {WASM_TRY_OP, kExprCatchAll, kExprCatchAll, kExprEnd},
+                kAppendEnd, "catch-all already present for try");
+  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprEnd}, kAppendEnd,
+                "missing catch or catch-all in try");
+  ExpectFailure(sigs.v_v(), {kExprCatch, ex, kExprEnd}, kAppendEnd,
+                "catch does not match a try");
 }
 
 TEST_F(FunctionBodyDecoderTest, TryUnwind) {
@@ -2885,16 +2890,20 @@ TEST_F(FunctionBodyDecoderTest, TryUnwind) {
   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});
-  ExpectFailure(sigs.v_v(), {WASM_TRY_OP, kExprElse, kExprUnwind, kExprEnd});
-  ExpectFailure(sigs.v_v(),
-                {WASM_TRY_OP, kExprCatch, ex, kExprUnwind, kExprEnd});
+                {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(),
-                  {WASM_TRY_OP, kExprElse, kExprRethrow, 0, kExprEnd});
+                  {WASM_TRY_OP, kExprCatchAll, kExprRethrow, 0, kExprEnd});
   ExpectFailure(sigs.v_v(),
                 {WASM_TRY_OP, kExprRethrow, 0, kExprCatch, kExprEnd},
                 kAppendEnd, "rethrow not targeting catch or catch-all");
@@ -2941,7 +2950,7 @@ TEST_F(FunctionBodyDecoderTest, TryDelegate) {
       kAppendEnd, "delegate does not match a try");
   ExpectFailure(
       sigs.v_v(),
-      {WASM_TRY_OP, WASM_TRY_OP, kExprElse, kExprDelegate, 1, kExprEnd},
+      {WASM_TRY_OP, WASM_TRY_OP, kExprCatchAll, kExprDelegate, 1, kExprEnd},
       kAppendEnd, "delegate does not match a try");
 }