Allow plain `try` with no `catch` or `delegate` (#1676)

Matches recent changes in the exception handling spec that allowed
this case to reduce special cases in the syntax:

  https://github.com/WebAssembly/exception-handling/pull/157

5 files changed, 56 insertions, 36 deletions

diff --git a/test/dump/try.txt b/test/dump/try.txt
index 672dc2a9..33ec7c3d 100644
--- a/test/dump/try.txt
+++ b/test/dump/try.txt
@@ -3,6 +3,9 @@
 (module
   (tag $e (param i32))
   (func
+    try
+      nop
+    end
     try $try1 (result i32)
       nop
       i32.const 7
@@ -55,22 +58,26 @@
 0000021: 00                                        ; func body size (guess)
 0000022: 00                                        ; local decl count
 0000023: 06                                        ; try
-0000024: 7f                                        ; i32
+0000024: 40                                        ; void
 0000025: 01                                        ; nop
-0000026: 41                                        ; i32.const
-0000027: 07                                        ; i32 literal
-0000028: 07                                        ; catch
-0000029: 00                                        ; catch tag
-000002a: 1a                                        ; drop
-000002b: 41                                        ; i32.const
-000002c: 08                                        ; i32 literal
-000002d: 0b                                        ; end
+0000026: 0b                                        ; end
+0000027: 06                                        ; try
+0000028: 7f                                        ; i32
+0000029: 01                                        ; nop
+000002a: 41                                        ; i32.const
+000002b: 07                                        ; i32 literal
+000002c: 07                                        ; catch
+000002d: 00                                        ; catch tag
 000002e: 1a                                        ; drop
-000002f: 0b                                        ; end
-0000021: 0e                                        ; FIXUP func body size
-000001f: 10                                        ; FIXUP section size
-; move data: [1e, 30) -> [1b, 2d)
-; truncate to 45 (0x2d)
+000002f: 41                                        ; i32.const
+0000030: 08                                        ; i32 literal
+0000031: 0b                                        ; end
+0000032: 1a                                        ; drop
+0000033: 0b                                        ; end
+0000021: 12                                        ; FIXUP func body size
+000001f: 14                                        ; FIXUP section size
+; move data: [1e, 34) -> [1b, 31)
+; truncate to 49 (0x31)
 ;;; STDERR ;;)
 (;; STDOUT ;;;
 
@@ -79,13 +86,16 @@ try.wasm:	file format wasm 0x1
 Code Disassembly:
 
 00001f func[0]:
- 000020: 06 7f                      | try i32
+ 000020: 06 40                      | try
  000022: 01                         |   nop
- 000023: 41 07                      |   i32.const 7
- 000025: 07 00                      | catch 0
- 000027: 1a                         |   drop
- 000028: 41 08                      |   i32.const 8
- 00002a: 0b                         | end
- 00002b: 1a                         | drop
- 00002c: 0b                         | end
+ 000023: 0b                         | end
+ 000024: 06 7f                      | try i32
+ 000026: 01                         |   nop
+ 000027: 41 07                      |   i32.const 7
+ 000029: 07 00                      | catch 0
+ 00002b: 1a                         |   drop
+ 00002c: 41 08                      |   i32.const 8
+ 00002e: 0b                         | end
+ 00002f: 1a                         | drop
+ 000030: 0b                         | end
 ;;; STDOUT ;;)
diff --git a/test/parse/expr/bad-try-clause.txt b/test/parse/expr/bad-try-clause.txt
new file mode 100644
index 00000000..f8575c8c
--- /dev/null
+++ b/test/parse/expr/bad-try-clause.txt
@@ -0,0 +1,10 @@
+;;; TOOL: wat2wasm
+;;; ARGS: --enable-exceptions
+;;; ERROR: 1
+(module
+  (func (try (do) (foo)))
+(;; STDERR ;;;
+out/test/parse/expr/bad-try-clause.txt:5:20: error: unexpected token "foo", expected catch, catch_all or delegate.
+  (func (try (do) (foo)))
+                   ^^^
+;;; STDERR ;;)
diff --git a/test/parse/expr/bad-try-no-catch.txt b/test/parse/expr/bad-try-no-catch.txt
deleted file mode 100644
index c85756fb..00000000
--- a/test/parse/expr/bad-try-no-catch.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-;;; TOOL: wat2wasm
-;;; ARGS: --enable-exceptions
-;;; ERROR: 1
-(module
-  (func try nop end)
-  (func (try (do nop))))
-(;; STDERR ;;;
-out/test/parse/expr/bad-try-no-catch.txt:5:17: error: unexpected token "end", expected catch, catch_all or delegate.
-  (func try nop end)
-                ^^^
-out/test/parse/expr/bad-try-no-catch.txt:6:22: error: unexpected token ), expected (.
-  (func (try (do nop))))
-                     ^
-;;; STDERR ;;)
diff --git a/test/parse/expr/try.txt b/test/parse/expr/try.txt
index c10eebc2..51ed83b5 100644
--- a/test/parse/expr/try.txt
+++ b/test/parse/expr/try.txt
@@ -3,6 +3,12 @@
 (module
   (tag (param i32))
 
+  ;; no catch
+  (func
+    try
+      nop
+    end)
+
   ;; bare
   (func
     try
diff --git a/test/roundtrip/fold-try.txt b/test/roundtrip/fold-try.txt
index d33dbbe2..412e34ca 100644
--- a/test/roundtrip/fold-try.txt
+++ b/test/roundtrip/fold-try.txt
@@ -3,6 +3,10 @@
 (module
   (func (result i32)
     try (result i32)
+      i32.const 6
+    end
+    drop
+    try (result i32)
       nop
       i32.const 7
     catch_all
@@ -14,6 +18,10 @@
 (module
   (type (;0;) (func (result i32)))
   (func (;0;) (type 0) (result i32)
+    (drop
+      (try (result i32)  ;; label = @1
+        (do
+          (i32.const 6))))
     (try (result i32)  ;; label = @1
       (do
         (nop)