From aa724846f6a5947864ed49f00219f260def1f757 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Wed, 1 Nov 2017 11:25:22 -0700
Subject: [PATCH] Clear the wasm operand stack at the end of a function.

This preserves an invariant that the stack is empty between function
body translations.
---
 lib/wasm/src/func_translator.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/wasm/src/func_translator.rs b/lib/wasm/src/func_translator.rs
index 9723f22ca5..aad791c9ac 100644
--- a/lib/wasm/src/func_translator.rs
+++ b/lib/wasm/src/func_translator.rs
@@ -215,6 +215,10 @@ fn parse_function_body<FE: FuncEnvironment + ?Sized>(
         builder.ins().return_(&state.stack);
     }
 
+    // Discard any remaining values on the stack. Either we just returned them,
+    // or the end of the function is unreachable.
+    state.stack.clear();
+
     debug_assert!(reader.eof());
 
     Ok(())