fix

Author: kripken

src/passes/Vacuum.cpp

@@ -22,6 +22,7 @@
 #include <ir/branch-hints.h>
 #include <ir/drop.h>
 #include <ir/effects.h>
+#include <ir/eh-utils.h>
 #include <ir/find_all.h>
 #include <ir/intrinsics.h>
 #include <ir/iteration.h>
@@ -38,8 +39,18 @@ struct Vacuum : public WalkerPass<ExpressionStackWalker<Vacuum>> {
 
   std::unique_ptr<Pass> create() override { return std::make_unique<Vacuum>(); }
 
+  // Track whether we need to fix up pops at the end: adding a block in a Try
+  // can require that.
+  bool hasTry = false;
+  bool addedBlocks = false;
+
   void doWalkFunction(Function* func) {
     walk(func->body);
+
+    if (hasTry && addedBlocks) {
+      EHUtils::handleBlockNestedPops(func, *getModule());
+    }
+
     ReFinalize().walkFunctionInModule(func, getModule());
   }
 
@@ -122,6 +133,7 @@ struct Vacuum : public WalkerPass<ExpressionStackWalker<Vacuum>> {
       if (curr->type.isDefaultable()) {
         auto* dummy = Builder(*getModule())
                         .makeConstantExpression(Literal::makeZeros(curr->type));
+        addedBlocks = true;
         return getDroppedChildrenAndAppend(
           curr, *getModule(), getPassOptions(), dummy);
       }
@@ -438,6 +450,8 @@ struct Vacuum : public WalkerPass<ExpressionStackWalker<Vacuum>> {
   }
 
   void visitTry(Try* curr) {
+    hasTry = true;
+
     // If try's body does not throw, the whole try-catch can be replaced with
     // the try's body.
     if (!EffectAnalyzer(getPassOptions(), *getModule(), curr->body).throws()) {

test/lit/passes/vacuum-eh-legacy.wast

@@ -293,4 +293,56 @@
       (catch_all)
     )
   )
+
+  ;; CHECK:      (func $add-block-in-catch-pop (type $void)
+  ;; CHECK-NEXT:  (local $temp i32)
+  ;; CHECK-NEXT:  (local $1 i32)
+  ;; CHECK-NEXT:  (try
+  ;; CHECK-NEXT:   (do
+  ;; CHECK-NEXT:    (call $add-block-in-catch-pop)
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:   (catch $e
+  ;; CHECK-NEXT:    (local.set $1
+  ;; CHECK-NEXT:     (pop i32)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:    (block
+  ;; CHECK-NEXT:     (block
+  ;; CHECK-NEXT:      (drop
+  ;; CHECK-NEXT:       (local.get $1)
+  ;; CHECK-NEXT:      )
+  ;; CHECK-NEXT:      (drop
+  ;; CHECK-NEXT:       (local.tee $temp
+  ;; CHECK-NEXT:        (i32.const 0)
+  ;; CHECK-NEXT:       )
+  ;; CHECK-NEXT:      )
+  ;; CHECK-NEXT:     )
+  ;; CHECK-NEXT:     (call $add-block-in-catch-pop)
+  ;; CHECK-NEXT:    )
+  ;; CHECK-NEXT:   )
+  ;; CHECK-NEXT:  )
+  ;; CHECK-NEXT: )
+  (func $add-block-in-catch-pop
+    (local $temp i32)
+    (try
+      (do
+        ;; We need a call so the try does not vanish entirely.
+        (call $add-block-in-catch-pop)
+      )
+      (catch $e
+        (drop
+          ;; This select will be removed, and a block appear, which must be handled
+          ;; for the pop.
+          (select
+            (pop i32)
+            (local.tee $temp
+              (i32.const 0)
+            )
+            (i32.const 0)
+          )
+        )
+        ;; Needed to avoid the catch being trivial.
+        (call $add-block-in-catch-pop)
+      )
+    )
+  )
 )