wasm-interp: Implement EHv4

WebAssembly · Oct 8, 2024 · ad9a8a6 · ad9a8a6
1 parent 9fe9fad
commit ad9a8a6
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Showing 10 changed files with 158 additions and 70 deletions.
diff --git a/include/wabt/interp/interp.h b/include/wabt/interp/interp.h
@@ -295,6 +295,7 @@ struct LocalDesc {
 struct CatchDesc {
   Index tag_index;
   u32 offset;
+  bool ref = false;
 };
 
 // Handlers for a catch-less `try` or `try-catch` block are included in the
@@ -313,6 +314,7 @@ struct HandlerDesc {
   // Local stack heights at the handler site that need to be restored.
   u32 values;
   u32 exceptions;
+  bool catch_all_ref = false;
 };
 
 struct FuncDesc {

diff --git a/include/wabt/shared-validator.h b/include/wabt/shared-validator.h
@@ -213,7 +213,7 @@ class SharedValidator {
   Result OnThrow(const Location&, Var tag_var);
   Result OnThrowRef(const Location&);
   Result OnTry(const Location&, Type sig_type);
-  Result BeginTryTable(const Location&);
+  Result BeginTryTable(const Location&, Type sig_type);
   Result OnTryTableCatch(const Location&, const TableCatch&);
   Result EndTryTable(const Location&, Type sig_type);
   Result OnUnary(const Location&, Opcode);

diff --git a/include/wabt/type-checker.h b/include/wabt/type-checker.h
@@ -131,8 +131,9 @@ class TypeChecker {
   Result OnThrowRef();
   Result OnTry(const TypeVector& param_types, const TypeVector& result_types);
   Result OnTryTableCatch(const TypeVector& sig, Index);
-  Result OnTryTable(const TypeVector& param_types,
-                    const TypeVector& result_types);
+  Result BeginTryTable(const TypeVector& param_types);
+  Result EndTryTable(const TypeVector& param_types,
+                     const TypeVector& result_types);
   Result OnUnary(Opcode);
   Result OnUnreachable();
   Result EndFunction();

diff --git a/src/interp/binary-reader-interp.cc b/src/interp/binary-reader-interp.cc
@@ -649,7 +649,7 @@ Result BinaryReaderInterp::BeginInitExpr(FuncDesc* func) {
   label_stack_.clear();
   func_ = func;
   func_->code_offset = istream_.end();
-  Type type = func->type.results[0];
+  Type type = func_->type.results[0];
   CHECK_RESULT(validator_.BeginInitExpr(GetLocation(), type));
   // Push implicit init func label (equivalent to return).
   PushLabel(LabelKind::Try, Istream::kInvalidOffset, Istream::kInvalidOffset);
@@ -1068,6 +1068,11 @@ Result BinaryReaderInterp::OnEndExpr() {
     HandlerDesc& desc = func_->handlers[local_label->handler_desc_index];
     desc.try_end_offset = istream_.end();
     assert(desc.catches.size() == 0);
+  } else if (label_type == LabelType::TryTable) {
+    // TryTable blocks need a try_end_offset
+    Label* local_label = TopLabel();
+    HandlerDesc& desc = func_->handlers[local_label->handler_desc_index];
+    desc.try_end_offset = istream_.end();
   } else if (label_type == LabelType::Catch) {
     istream_.EmitCatchDrop(1);
   }
@@ -1553,63 +1558,77 @@ Result BinaryReaderInterp::OnTryExpr(Type sig_type) {
 
 Result BinaryReaderInterp::OnTryTableExpr(Type sig_type,
                                           const RawCatchVector& catches) {
-  CHECK_RESULT(validator_.BeginTryTable(GetLocation()));
-
-  assert(false && "NYI");
-
-  //// from loop
-  // PushLabel(LabelKind::Block, istream_.end());
-  // return Result::Ok;
-
-  //// from brtable
-  // Index drop_count, keep_count, catch_drop_count;
-  // istream_.Emit(Opcode::BrTable, num_targets);
-
-  // for (Index i = 0; i < num_targets; ++i) {
-  //   Index depth = target_depths[i];
-  //   CHECK_RESULT(
-  //       validator_.OnBrTableTarget(GetLocation(), Var(depth,
-  //       GetLocation())));
-  //   CHECK_RESULT(GetBrDropKeepCount(depth, &drop_count, &keep_count));
-  //   CHECK_RESULT(validator_.GetCatchCount(depth, &catch_drop_count));
-  //   // Emit DropKeep directly (instead of using EmitDropKeep) so the
-  //   // instruction has a fixed size. Same for CatchDrop as well.
-  //   istream_.Emit(Opcode::InterpDropKeep, drop_count, keep_count);
-  //   istream_.Emit(Opcode::InterpCatchDrop, catch_drop_count);
-  //   EmitBr(depth, 0, 0, 0);
-  // }
-  // CHECK_RESULT(validator_.OnBrTableTarget(
-  //     GetLocation(), Var(default_target_depth, GetLocation())));
-  // CHECK_RESULT(
-  //     GetBrDropKeepCount(default_target_depth, &drop_count, &keep_count));
-  // CHECK_RESULT(
-  //     validator_.GetCatchCount(default_target_depth, &catch_drop_count));
-  //// The default case doesn't need a fixed size, since it is never jumped
-  /// over.
-  // istream_.EmitDropKeep(drop_count, keep_count);
-  // istream_.Emit(Opcode::InterpCatchDrop, catch_drop_count);
-  // EmitBr(default_target_depth, 0, 0, 0);
-
-  // CHECK_RESULT(validator_.EndBrTable(GetLocation()));
-  // return Result::Ok;
-
-  //// from try
-  // u32 exn_stack_height;
-  // CHECK_RESULT(
-  //     validator_.GetCatchCount(label_stack_.size() - 1, &exn_stack_height));
-  // u32 value_stack_height = validator_.type_stack_size();
-  // CHECK_RESULT(validator_.OnTry(GetLocation(), sig_type));
-  //// Push a label that tracks mapping of exn -> catch
-  // PushLabel(LabelKind::Try, Istream::kInvalidOffset, Istream::kInvalidOffset,
-  //           func_->handlers.size());
-  // func_->handlers.push_back(HandlerDesc{HandlerKind::Catch,
-  //                                       istream_.end(),
-  //                                       Istream::kInvalidOffset,
-  //                                       {},
-  //                                       {Istream::kInvalidOffset},
-  //                                       value_stack_height,
-  //                                       exn_stack_height});
-  return Result::Error;
+  // we can just emit the catch handlers beforehand, so long as we skip over
+  // them when entering the try.
+  CHECK_RESULT(validator_.BeginTryTable(GetLocation(), sig_type));
+
+  u32 exn_stack_height;
+  CHECK_RESULT(
+      validator_.GetCatchCount(label_stack_.size() - 1, &exn_stack_height));
+  // NOTE: *NOT* GetLocalCount. we don't count the parameters, as they're not
+  // part of the frame.
+  u32 value_stack_height = validator_.type_stack_size() + local_count_;
+
+  HandlerDesc desc = HandlerDesc{HandlerKind::Catch,
+                                 Istream::kInvalidOffset,
+                                 Istream::kInvalidOffset,
+                                 {},
+                                 {Istream::kInvalidOffset},
+                                 value_stack_height,
+                                 exn_stack_height};
+
+  istream_.Emit(Opcode::Br);
+  auto offset = istream_.EmitFixupU32();
+
+  bool has_catch_all = false;
+  for (const auto& raw_catch : catches) {
+    TableCatch catch_;
+    catch_.kind = raw_catch.kind;
+    catch_.tag = Var(raw_catch.tag, GetLocation());
+    catch_.target = Var(raw_catch.depth, GetLocation());
+    CHECK_RESULT(validator_.OnTryTableCatch(GetLocation(), catch_));
+    // stop emitting handlers after catch_all - but we must still validate the
+    // handlers we don't emit
+    if (has_catch_all) {
+      continue;
+    }
+    if (catch_.IsCatchAll()) {
+      has_catch_all = true;
+      desc.catch_all_ref = catch_.IsRef();
+      desc.catch_all_offset = istream_.end();
+    } else {
+      desc.catches.push_back(CatchDesc{raw_catch.tag, istream_.end(), catch_.IsRef()});
+    }
+    // we can't use GetBrDropKeepCount because we're not in a real block.
+    SharedValidator::Label* vlabel;
+    CHECK_RESULT(validator_.GetLabel(raw_catch.depth, &vlabel));
+    // we keep the exception's results.
+    // (this has already been validated, above)
+    Index keep_count = vlabel->br_types().size();
+    // we drop everything between the current block and the br target.
+    // (we have already taken the TryTable block parameters into account, in
+    // BeginTryTable)
+    Index drop_count = validator_.type_stack_size() - vlabel->type_stack_limit;
+    Index catch_drop_count;
+    // we use the regular catch count
+    CHECK_RESULT(validator_.GetCatchCount(raw_catch.depth, &catch_drop_count));
+    // but increment, as we are semantically in a catch
+    catch_drop_count++;
+    EmitBr(raw_catch.depth, drop_count, keep_count, catch_drop_count);
+  }
+
+  CHECK_RESULT(validator_.EndTryTable(GetLocation(), sig_type));
+
+  desc.try_start_offset = istream_.end();
+
+  // as usual, the label is pushed after the catch handlers
+  PushLabel(LabelKind::Try, Istream::kInvalidOffset, Istream::kInvalidOffset,
+            func_->handlers.size());
+  func_->handlers.push_back(std::move(desc));
+
+  istream_.ResolveFixupU32(offset);
+
+  return Result::Ok;
 }
 
 Result BinaryReaderInterp::OnCatchExpr(Index tag_index) {

diff --git a/src/interp/interp.cc b/src/interp/interp.cc
@@ -2609,6 +2609,7 @@ RunResult Thread::DoThrow(Exception::Ptr exn) {
   Tag::Ptr exn_tag{store_, exn->tag()};
   bool popped_frame = false;
   bool had_catch_all = false;
+  bool target_exnref = false;
 
   // DoThrow is responsible for unwinding the stack at the point at which an
   // exception is thrown, and also branching to the appropriate catch within
@@ -2646,6 +2647,7 @@ RunResult Thread::DoThrow(Exception::Ptr exn) {
             target_offset = _catch.offset;
             target_values = (*iter).values;
             target_exceptions = (*iter).exceptions;
+	    target_exnref = _catch.ref;
             goto found_handler;
           }
         }
@@ -2654,6 +2656,7 @@ RunResult Thread::DoThrow(Exception::Ptr exn) {
           target_values = (*iter).values;
           target_exceptions = (*iter).exceptions;
           had_catch_all = true;
+	  target_exnref = handler.catch_all_ref;
           goto found_handler;
         }
       }
@@ -2691,6 +2694,9 @@ RunResult Thread::DoThrow(Exception::Ptr exn) {
   if (!had_catch_all) {
     PushValues(exn_tag->type().signature, exn->args());
   }
+  if (target_exnref) {
+    Push(exn.ref());
+  }
   return RunResult::Ok;
 }
 

diff --git a/src/shared-validator.cc b/src/shared-validator.cc
@@ -1211,8 +1211,12 @@ Result SharedValidator::OnTry(const Location& loc, Type sig_type) {
   return result;
 }
 
-Result SharedValidator::BeginTryTable(const Location& loc) {
+Result SharedValidator::BeginTryTable(const Location& loc, Type sig_type) {
   Result result = CheckInstr(Opcode::TryTable, loc);
+  TypeVector param_types, result_types;
+  result |= CheckBlockSignature(loc, Opcode::TryTable, sig_type, &param_types,
+                                &result_types);
+  result |= typechecker_.BeginTryTable(param_types);
   return result;
 }
 
@@ -1237,7 +1241,7 @@ Result SharedValidator::EndTryTable(const Location& loc, Type sig_type) {
   TypeVector param_types, result_types;
   result |= CheckBlockSignature(loc, Opcode::TryTable, sig_type, &param_types,
                                 &result_types);
-  result |= typechecker_.OnTryTable(param_types, result_types);
+  result |= typechecker_.EndTryTable(param_types, result_types);
   return result;
 }
 

diff --git a/src/type-checker.cc b/src/type-checker.cc
@@ -890,6 +890,11 @@ Result TypeChecker::OnTry(const TypeVector& param_types,
   return result;
 }
 
+Result TypeChecker::BeginTryTable(const TypeVector& param_types) {
+  Result result = PopAndCheckSignature(param_types, "try_table");
+  return result;
+}
+
 Result TypeChecker::OnTryTableCatch(const TypeVector& sig, Index depth) {
   Result result = Result::Ok;
   Label* label;
@@ -903,12 +908,11 @@ Result TypeChecker::OnTryTableCatch(const TypeVector& sig, Index depth) {
   return result;
 }
 
-Result TypeChecker::OnTryTable(const TypeVector& param_types,
-                               const TypeVector& result_types) {
-  Result result = PopAndCheckSignature(param_types, "try_table");
+Result TypeChecker::EndTryTable(const TypeVector& param_types,
+                                const TypeVector& result_types) {
   PushLabel(LabelType::TryTable, param_types, result_types);
   PushTypes(param_types);
-  return result;
+  return Result::Ok;
 }
 
 Result TypeChecker::OnUnary(Opcode opcode) {

diff --git a/src/validator.cc b/src/validator.cc
@@ -568,7 +568,7 @@ Result Validator::EndTryExpr(TryExpr* expr) {
 }
 
 Result Validator::BeginTryTableExpr(TryTableExpr* expr) {
-  result_ |= validator_.BeginTryTable(expr->loc);
+  result_ |= validator_.BeginTryTable(expr->loc, GetDeclarationType(expr->block.decl));
   for (const TableCatch& catch_ : expr->catches) {
     result_ |= validator_.OnTryTableCatch(expr->loc, catch_);
   }

diff --git a/test/spec/exception-handling/throw_ref.txt b/test/spec/exception-handling/throw_ref.txt
@@ -1,4 +1,19 @@
 ;;; TOOL: run-interp-spec
 ;;; STDIN_FILE: third_party/testsuite/proposals/exception-handling/throw_ref.wast
 ;;; ARGS*: --enable-exceptions
-;;; SKIP: NYI
+(;; STDOUT ;;;
+out/test/spec/exception-handling/throw_ref.wast:99: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:101: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:104: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:106: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:108: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:109: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:115: assert_exception passed
+out/test/spec/exception-handling/throw_ref.wast:117: assert_invalid passed:
+  out/test/spec/exception-handling/throw_ref/throw_ref.1.wasm:0000018: error: type mismatch in throw_ref, expected [exnref] but got []
+  0000018: error: OnThrowRefExpr callback failed
+out/test/spec/exception-handling/throw_ref.wast:118: assert_invalid passed:
+  out/test/spec/exception-handling/throw_ref/throw_ref.2.wasm:000001a: error: type mismatch in throw_ref, expected [exnref] but got []
+  000001a: error: OnThrowRefExpr callback failed
+15/15 tests passed.
+;;; STDOUT ;;)
diff --git a/test/spec/exception-handling/try_table.txt b/test/spec/exception-handling/try_table.txt
@@ -1,4 +1,41 @@
 ;;; TOOL: run-interp-spec
 ;;; STDIN_FILE: third_party/testsuite/proposals/exception-handling/try_table.wast
 ;;; ARGS*: --enable-exceptions --enable-tail-call
-;;; SKIP: NYI
+(;; STDOUT ;;;
+out/test/spec/exception-handling/try_table.wast:246: assert_trap passed: unreachable executed
+out/test/spec/exception-handling/try_table.wast:249: assert_trap passed: integer divide by zero
+out/test/spec/exception-handling/try_table.wast:253: assert_exception passed
+out/test/spec/exception-handling/try_table.wast:257: assert_exception passed
+out/test/spec/exception-handling/try_table.wast:294: assert_exception passed
+out/test/spec/exception-handling/try_table.wast:295: assert_exception passed
+out/test/spec/exception-handling/try_table.wast:322: assert_malformed passed:
+  out/test/spec/exception-handling/try_table/try_table.3.wat:1:16: error: unexpected token "catch_all", expected an instr.
+  (module (func (catch_all)))
+                 ^^^^^^^^^
+out/test/spec/exception-handling/try_table.wast:327: assert_malformed passed:
+  out/test/spec/exception-handling/try_table/try_table.4.wat:1:25: error: unexpected token "catch", expected an instr.
+  (module (tag $e) (func (catch $e)))
+                          ^^^^^
+out/test/spec/exception-handling/try_table.wast:342: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.6.wasm:000001c: error: type mismatch in try table, expected [i32] but got []
+  000001c: error: OnEndExpr callback failed
+out/test/spec/exception-handling/try_table.wast:346: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.7.wasm:000001e: error: type mismatch in try table, expected [i32] but got [i64]
+  000001e: error: OnEndExpr callback failed
+out/test/spec/exception-handling/try_table.wast:351: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.8.wasm:0000022: error: catch signature doesn't match target: expected [exnref], got []
+  0000022: error: OnTryTableExpr callback failed
+out/test/spec/exception-handling/try_table.wast:355: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.9.wasm:0000026: error: catch signature doesn't match target: expected [], got [exnref]
+  0000026: error: OnTryTableExpr callback failed
+out/test/spec/exception-handling/try_table.wast:359: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.10.wasm:000001c: error: catch signature doesn't match target: expected [exnref], got []
+  000001c: error: OnTryTableExpr callback failed
+out/test/spec/exception-handling/try_table.wast:363: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.11.wasm:000001d: error: catch signature doesn't match target: expected [], got [exnref]
+  000001d: error: OnTryTableExpr callback failed
+out/test/spec/exception-handling/try_table.wast:367: assert_invalid passed:
+  out/test/spec/exception-handling/try_table/try_table.12.wasm:0000028: error: catch signature doesn't match target: expected [i64, exnref], got [i32, exnref]
+  0000028: error: OnTryTableExpr callback failed
+51/51 tests passed.
+;;; STDOUT ;;)