From 7b4011aa609ee69915c6d7573954bc88032654d4 Mon Sep 17 00:00:00 2001
From: NikVolf <nikvolf@gmail.com>
Date: Tue, 9 May 2017 18:10:24 +0300
Subject: [PATCH] global opt 2

---
 src/optimizer.rs | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/src/optimizer.rs b/src/optimizer.rs
index ef49ca9..728c2db 100644
--- a/src/optimizer.rs
+++ b/src/optimizer.rs
@@ -452,4 +452,47 @@ mod tests {
             "There should 1 (one) global entry in the optimized module, since _call function uses it"
         );         
     }
+
+    /// @spec 2
+    /// Imagine there is one exported function in unoptimized module, `_call`, that we specify as the one
+    /// to stay during the optimization. The code of this function uses one global during the execution,
+    /// but we have a bunch of other unused globals in the code. Last globals should not survive the optimization,
+    /// while the former should. 
+    #[test]
+    fn globals_2() {
+        let mut module = builder::module()
+            .global()
+                .value_type().i32()
+                .build()
+            .global()
+                .value_type().i64()
+                .build()
+            .global()
+                .value_type().f32()
+                .build()                                
+            .function()
+                .signature().param().i32().build()
+                .body()
+                    .with_opcodes(elements::Opcodes::new(
+                        vec![
+                            elements::Opcode::GetGlobal(1),
+                            elements::Opcode::End
+                        ]
+                    ))
+                    .build()
+                .build()
+            .export()
+                .field("_call")
+                .internal().func(0).build()
+            .build();
+
+        optimize(&mut module, vec!["_call"]).expect("optimizer to succeed");
+
+        assert_eq!(
+            1,
+            module.global_section().expect("global section to be generated").entries().len(),
+            "There should 1 (one) global entry in the optimized module, since _call function uses only one"
+        );         
+    }
+
 }
\ No newline at end of file