[EH] Support assert_exception (#5684)

`assert_exception` is similar to `assert_trap` but for exceptions, which
is supported in the interpreter of the EH proposal
(https://github.com/WebAssembly/exception-handling/tree/main/interpreter).

We've been using `assert_trap` for both traps and exceptions, but this
PR distinguishes them.

2 files changed, 26 insertions, 10 deletions

diff --git a/src/tools/wasm-shell.cpp b/src/tools/wasm-shell.cpp
index 70f52a038..29ccc6c7f 100644
--- a/src/tools/wasm-shell.cpp
+++ b/src/tools/wasm-shell.cpp
@@ -35,6 +35,7 @@ using namespace wasm;
 
 Name ASSERT_RETURN("assert_return");
 Name ASSERT_TRAP("assert_trap");
+Name ASSERT_EXCEPTION("assert_exception");
 Name ASSERT_INVALID("assert_invalid");
 Name ASSERT_MALFORMED("assert_malformed");
 Name ASSERT_UNLINKABLE("assert_unlinkable");
@@ -114,6 +115,8 @@ protected:
       parseAssertReturn(s);
     } else if (id == ASSERT_TRAP) {
       parseAssertTrap(s);
+    } else if (id == ASSERT_EXCEPTION) {
+      parseAssertException(s);
     } else if ((id == ASSERT_INVALID) || (id == ASSERT_MALFORMED)) {
       parseModuleAssertion(s);
     }
@@ -203,11 +206,24 @@ protected:
       parseOperation(inner);
     } catch (const TrapException&) {
       trapped = true;
+    }
+    assert(trapped);
+  }
+
+  void parseAssertException(Element& s) {
+    [[maybe_unused]] bool thrown = false;
+    auto& inner = *s[1];
+    if (inner[0]->str() == MODULE) {
+      return parseModuleAssertion(s);
+    }
+
+    try {
+      parseOperation(inner);
     } catch (const WasmException& e) {
       std::cout << "[exception thrown: " << e << "]" << std::endl;
-      trapped = true;
+      thrown = true;
     }
-    assert(trapped);
+    assert(thrown);
   }
 
   void parseAssertReturn(Element& s) {
@@ -284,7 +300,7 @@ protected:
       ModuleUtils::iterImportedMemories(wasm, reportUnknownImport);
     }
 
-    if (!invalid && id == ASSERT_TRAP) {
+    if (!invalid && (id == ASSERT_TRAP || id == ASSERT_EXCEPTION)) {
       try {
         instantiate(&wasm);
       } catch (const TrapException&) {
diff --git a/test/spec/exception-handling.wast b/test/spec/exception-handling.wast
index 4b817a81d..5ec78dfed 100644
--- a/test/spec/exception-handling.wast
+++ b/test/spec/exception-handling.wast
@@ -285,23 +285,23 @@
   )
 )
 
-(assert_trap (invoke "throw_single_value"))
-(assert_trap (invoke "throw_multiple_values"))
+(assert_exception (invoke "throw_single_value"))
+(assert_exception (invoke "throw_multiple_values"))
 (assert_return (invoke "try_nothrow") (i32.const 3))
 (assert_return (invoke "try_throw_catch") (i32.const 3))
-(assert_trap (invoke "try_throw_nocatch"))
+(assert_exception (invoke "try_throw_nocatch"))
 (assert_return (invoke "try_throw_catchall") (i32.const 3))
 (assert_return (invoke "try_call_catch") (i32.const 5))
 (assert_return (invoke "try_throw_multivalue_catch") (i32.const 5))
-(assert_trap (invoke "try_throw_rethrow"))
-(assert_trap (invoke "try_call_rethrow"))
+(assert_exception (invoke "try_throw_rethrow"))
+(assert_exception (invoke "try_call_rethrow"))
 (assert_return (invoke "rethrow_target_test1") (i32.const 2))
 (assert_return (invoke "rethrow_target_test2") (i32.const 1))
 (assert_return (invoke "rethrow_target_test3") (i32.const 1))
 (assert_return (invoke "try_delegate_caught") (i32.const 3))
-(assert_trap (invoke "try_delegate_to_catchless_try"))
+(assert_exception (invoke "try_delegate_to_catchless_try"))
 (assert_return (invoke "try_delegate_to_delegate") (i32.const 3))
-(assert_trap (invoke "try_delegate_to_caller"))
+(assert_exception (invoke "try_delegate_to_caller"))
 
 (assert_invalid
   (module