Basic EH instrucion support for the new spec (#3487)

This updates `try`-`catch`-`catch_all` and `rethrow` instructions to
match the new spec. `delegate` is not included. Now `Try` contains not a
single `catchBody` expression but a vector of catch
bodies and events.

This updates most existing routines, optimizations, and tests modulo the
interpreter and the CFG traversal. Because the interpreter has not been
updated yet, the EH spec test is temporarily disabled in check.py. Also,
because the CFG traversal for EH is not yet updated, several EH tests in
`rse_all-features.wast`, which uses CFG traversal, are temporarily
commented out.

Also added a few more tests in existing EH test functions in
test/passes. In the previous spec, `catch` was catching all exceptions
so it was assumed that anything `try` body throws is caught by its
`catch`, but now we can assume the same only if there is a `catch_all`.
Newly added tests test cases when there is a `catch_all` and cases there
are only `catch`es separately.

1 files changed, 20 insertions, 14 deletions

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index b0fc4d9c8..064a151c3 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -2026,21 +2026,28 @@ void FunctionValidator::visitTry(Try* curr) {
       curr->type,
       curr->body,
       "try's type does not match try body's type");
-    shouldBeSubTypeOrFirstIsUnreachable(
-      curr->catchBody->type,
-      curr->type,
-      curr->catchBody,
-      "try's type does not match catch's body type");
+    for (auto catchBody : curr->catchBodies) {
+      shouldBeSubTypeOrFirstIsUnreachable(
+        catchBody->type,
+        curr->type,
+        catchBody,
+        "try's type does not match catch's body type");
+    }
   } else {
     shouldBeEqual(curr->body->type,
                   Type(Type::unreachable),
                   curr,
                   "unreachable try-catch must have unreachable try body");
-    shouldBeEqual(curr->catchBody->type,
-                  Type(Type::unreachable),
-                  curr,
-                  "unreachable try-catch must have unreachable catch body");
+    for (auto catchBody : curr->catchBodies) {
+      shouldBeEqual(catchBody->type,
+                    Type(Type::unreachable),
+                    curr,
+                    "unreachable try-catch must have unreachable catch body");
+    }
   }
+  shouldBeTrue(curr->catchBodies.size() - curr->catchEvents.size() <= 1,
+               curr,
+               "the number of catch blocks and events do not match");
 }
 
 void FunctionValidator::visitThrow(Throw* curr) {
@@ -2084,11 +2091,10 @@ void FunctionValidator::visitRethrow(Rethrow* curr) {
                 Type(Type::unreachable),
                 curr,
                 "rethrow's type must be unreachable");
-  shouldBeSubTypeOrFirstIsUnreachable(
-    curr->exnref->type,
-    Type::exnref,
-    curr->exnref,
-    "rethrow's argument must be exnref type or its subtype");
+  // TODO Allow non-zero depths and Validate the depth field. The current LLVM
+  // toolchain only generates depth 0 for C++ support.
+  shouldBeEqual(
+    curr->depth, (Index)0, curr, "rethrow only support depth 0 at the moment");
 }
 
 void FunctionValidator::visitBrOnExn(BrOnExn* curr) {