From: Matt Arsenault <Matthew.Arsenault@amd.com>
Date: Sat, 20 Jul 2013 17:46:05 +0000 (+0000)
Subject: Disallow global aliases to bitcast between address spaces
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5f53c3be6fce77d494e82f23d5ea0b6a0144eb5d;p=oota-llvm.git

Disallow global aliases to bitcast between address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186767 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp
index 6e04dfeef68..fa53a4ee694 100644
--- a/lib/IR/Verifier.cpp
+++ b/lib/IR/Verifier.cpp
@@ -498,18 +498,29 @@ void Verifier::visitGlobalAlias(GlobalAlias &GA) {
           "Alias and aliasee types should match!", &GA);
   Assert1(!GA.hasUnnamedAddr(), "Alias cannot have unnamed_addr!", &GA);
 
-  if (!isa<GlobalValue>(GA.getAliasee())) {
-    const ConstantExpr *CE = dyn_cast<ConstantExpr>(GA.getAliasee());
+  Constant *Aliasee = GA.getAliasee();
+
+  if (!isa<GlobalValue>(Aliasee)) {
+    ConstantExpr *CE = dyn_cast<ConstantExpr>(Aliasee);
     Assert1(CE &&
             (CE->getOpcode() == Instruction::BitCast ||
              CE->getOpcode() == Instruction::GetElementPtr) &&
             isa<GlobalValue>(CE->getOperand(0)),
             "Aliasee should be either GlobalValue or bitcast of GlobalValue",
             &GA);
+
+    if (CE->getOpcode() == Instruction::BitCast) {
+      unsigned SrcAS = CE->getOperand(0)->getType()->getPointerAddressSpace();
+      unsigned DstAS = CE->getType()->getPointerAddressSpace();
+
+      Assert1(SrcAS == DstAS,
+              "Alias bitcasts cannot be between different address spaces",
+              &GA);
+    }
   }
 
-  const GlobalValue* Aliasee = GA.resolveAliasedGlobal(/*stopOnWeak*/ false);
-  Assert1(Aliasee,
+  const GlobalValue* Resolved = GA.resolveAliasedGlobal(/*stopOnWeak*/ false);
+  Assert1(Resolved,
           "Aliasing chain should end with function or global variable", &GA);
 
   visitGlobalValue(GA);
diff --git a/test/Verifier/bitcast-alias-address-space.ll b/test/Verifier/bitcast-alias-address-space.ll
new file mode 100644
index 00000000000..9cad8ab3779
--- /dev/null
+++ b/test/Verifier/bitcast-alias-address-space.ll
@@ -0,0 +1,8 @@
+; RUN: not llvm-as -verify -disable-output %s
+
+target datalayout = "e-p:32:32:32-p1:16:16:16-p2:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n8:16:32"
+
+
+@data = addrspace(2) global i32 27
+
+@illegal_alias_data = alias bitcast (i32 addrspace(2)* @data to i32 addrspace(1)*)