[GUFA] Fix call.without.effects's handling of the last parameter (#5111)

The last parameter is the function to call, and we treated it like a normal parameter.
This is mostly only an issue during debugging, but in theory sending this extra value
could cause us to optimize less later (since it gets added to what the local of that
index can contain).

Also add assertions which would have caught this before.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/ir/possible-contents.cpp b/src/ir/possible-contents.cpp
index 1b5c5ae0d..7c69121e6 100644
--- a/src/ir/possible-contents.cpp
+++ b/src/ir/possible-contents.cpp
@@ -590,9 +590,11 @@ struct InfoCollector
     handleCall(
       curr,
       [&](Index i) {
+        assert(i <= target->getParams().size());
         return LocalLocation{target, i, 0};
       },
       [&](Index i) {
+        assert(i <= target->getResults().size());
         return ResultLocation{target, i};
       });
   }
@@ -600,9 +602,11 @@ struct InfoCollector
     handleCall(
       curr,
       [&](Index i) {
+        assert(i <= targetType.getSignature().params.size());
         return SignatureParamLocation{targetType, i};
       },
       [&](Index i) {
+        assert(i <= targetType.getSignature().results.size());
         return SignatureResultLocation{targetType, i};
       });
   }
@@ -630,6 +634,11 @@ struct InfoCollector
     // makes us ignore the function ref that flows to an import, so we are not
     // aware that it is actually called.)
     auto* target = curr->operands.back();
+
+    // We must ignore the last element when handling the call - the target is
+    // used to perform the call, and not sent during the call.
+    curr->operands.pop_back();
+
     if (auto* refFunc = target->dynCast<RefFunc>()) {
       // We can see exactly where this goes.
       handleDirectCall(curr, refFunc->func);
@@ -642,6 +651,9 @@ struct InfoCollector
       // a workaround.)
       handleIndirectCall(curr, target->type);
     }
+
+    // Restore the target.
+    curr->operands.push_back(target);
   }
   void visitCallIndirect(CallIndirect* curr) {
     // TODO: the table identity could also be used here