From bbaf070bd90f32d913afa4298041a598956c09e9 Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Mon, 6 Sep 2010 17:01:44 -0700
Subject: [PATCH] compiler.cfg.write-barrier: fix soundness issue with ##copy
 that never came up but probably should've been fixed anyway

---
 .../write-barrier/write-barrier-tests.factor  | 61 +++++++++++++++++++
 .../cfg/write-barrier/write-barrier.factor    |  2 +-
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/basis/compiler/cfg/write-barrier/write-barrier-tests.factor b/basis/compiler/cfg/write-barrier/write-barrier-tests.factor
index 136324ba47..b11ffa8716 100644
--- a/basis/compiler/cfg/write-barrier/write-barrier-tests.factor
+++ b/basis/compiler/cfg/write-barrier/write-barrier-tests.factor
@@ -91,3 +91,64 @@ IN: compiler.cfg.write-barrier.tests
         T{ ##write-barrier-imm f 1 }
     } write-barriers-step
 ] unit-test
+
+! ##copy instructions
+[
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##set-slot-imm f 3 1 }
+        T{ ##write-barrier-imm f 2 }
+    }
+] [
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##set-slot-imm f 3 1 }
+        T{ ##write-barrier-imm f 2 }
+    } write-barriers-step
+] unit-test
+
+[
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##set-slot-imm f 3 2 }
+        T{ ##write-barrier-imm f 1 }
+    }
+] [
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##set-slot-imm f 3 2 }
+        T{ ##write-barrier-imm f 1 }
+    } write-barriers-step
+] unit-test
+
+[
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##copy f 3 2 }
+        T{ ##set-slot-imm f 3 1 }
+        T{ ##write-barrier-imm f 2 }
+    }
+] [
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##copy f 3 2 }
+        T{ ##set-slot-imm f 3 1 }
+        T{ ##write-barrier-imm f 2 }
+    } write-barriers-step
+] unit-test
+
+[
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##copy f 3 2 }
+        T{ ##set-slot-imm f 4 1 }
+        T{ ##write-barrier-imm f 3 }
+    }
+] [
+    V{
+        T{ ##copy f 2 1 }
+        T{ ##copy f 3 2 }
+        T{ ##set-slot-imm f 4 1 }
+        T{ ##write-barrier-imm f 3 }
+    } write-barriers-step
+] unit-test
diff --git a/basis/compiler/cfg/write-barrier/write-barrier.factor b/basis/compiler/cfg/write-barrier/write-barrier.factor
index 95562eadca..6f8e437aa9 100644
--- a/basis/compiler/cfg/write-barrier/write-barrier.factor
+++ b/basis/compiler/cfg/write-barrier/write-barrier.factor
@@ -50,7 +50,7 @@ M: gc-map-insn eliminate-write-barrier
     fresh-allocations get clear-assoc ;
 
 M: ##copy eliminate-write-barrier
-    [ src>> ] [ dst>> ] bi copies get set-at t ;
+    [ src>> resolve-copy ] [ dst>> ] bi copies get set-at t ;
 
 M: insn eliminate-write-barrier drop t ;