Unreachability fixes for inlining (#5492)

We must refinalize as inlining unreachable code can lead to
more things becoming unreachable.

We also must uniquify label names before refinalizing, as the
IR must be valid at that time, so that code is moved.

This causes some minor changes to existing test code (some
label changes, and refinalization makes more things
unreachable), but only the two new tests show actual problems
that needed to be fixed.

1 files changed, 10 insertions, 5 deletions

diff --git a/src/passes/Inlining.cpp b/src/passes/Inlining.cpp
index 4475db7b0..7df5c8f29 100644
--- a/src/passes/Inlining.cpp
+++ b/src/passes/Inlining.cpp
@@ -413,6 +413,16 @@ static Expression* doInlining(Module* module,
     // Make the block reachable by adding a break to it
     block->list.push_back(builder.makeBreak(block->name));
   }
+  // Anything we inlined into may now have non-unique label names, fix it up.
+  // Note that we must do this before refinalization, as otherwise duplicate
+  // block labels can lead to errors (the IR must be valid before we
+  // refinalize).
+  wasm::UniqueNameMapper::uniquify(into->body);
+  // Inlining unreachable contents can make things in the function we inlined
+  // into unreachable.
+  ReFinalize().walkFunctionInModule(into, module);
+  // New locals we added may require fixups for nondefaultability.
+  // FIXME Is this not done automatically?
   TypeUpdating::handleNonDefaultableLocals(into, *module);
   return block;
 }
@@ -1039,11 +1049,6 @@ struct Inlining : public Pass {
         assert(inlinedUses[inlinedName] <= infos[inlinedName].refs);
       }
     }
-    for (auto func : inlinedInto) {
-      // Anything we inlined into may now have non-unique label names, fix it
-      // up.
-      wasm::UniqueNameMapper::uniquify(func->body);
-    }
     if (optimize && inlinedInto.size() > 0) {
       OptUtils::optimizeAfterInlining(inlinedInto, module, getPassRunner());
     }