Implement review feedback

llvm-svn: 36564

3 files changed, 30 insertions, 9 deletions

diff --git a/llvm/lib/VMCore/AsmWriter.cpp b/llvm/lib/VMCore/AsmWriter.cpp
index 656a7bed74e..ac68e8d32fb 100644
--- a/llvm/lib/VMCore/AsmWriter.cpp
+++ b/llvm/lib/VMCore/AsmWriter.cpp
@@ -926,8 +926,7 @@ void AssemblyWriter::printAlias(const GlobalAlias *GA) {
    assert(0 && "Invalid alias linkage");
   }
   
-  const Constant *Aliasee = dyn_cast_or_null<Constant>(GA->getAliasee());
-  assert(Aliasee && "Aliasee cannot be null");
+  const Constant *Aliasee = GA->getAliasee();
     
   if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Aliasee)) {
     printType(GV->getType());
diff --git a/llvm/lib/VMCore/Globals.cpp b/llvm/lib/VMCore/Globals.cpp
index 88a8c0b2a7a..aeb34f43715 100644
--- a/llvm/lib/VMCore/Globals.cpp
+++ b/llvm/lib/VMCore/Globals.cpp
@@ -12,6 +12,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Constants.h"
 #include "llvm/GlobalVariable.h"
 #include "llvm/GlobalAlias.h"
 #include "llvm/DerivedTypes.h"
@@ -193,16 +194,36 @@ void GlobalAlias::eraseFromParent() {
 }
 
 bool GlobalAlias::isDeclaration() const {
-  const GlobalValue* AV = dyn_cast_or_null<const GlobalValue>(getAliasee());
-  return (AV && AV->isDeclaration());
+  const GlobalValue* AV = getAliasedGlobal();
+  if (AV)
+    return AV->isDeclaration();
+  else
+    return false;
 }
 
 void GlobalAlias::setAliasee(Constant *Aliasee) 
 {
-  if (Aliasee) {
-    assert(Aliasee->getType() == getType() && 
+  if (Aliasee)
+    assert(Aliasee->getType() == getType() &&
            "Alias and aliasee types should match!");
-    setOperand(0, Aliasee);
-  }
+  
+  setOperand(0, Aliasee);
+}
+
+const GlobalValue *GlobalAlias::getAliasedGlobal() const  {
+  const Constant *C = getAliasee();
+  if (C) {
+    if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
+      return GV;
+    else {
+      const ConstantExpr *CE = 0;
+      if ((CE = dyn_cast<ConstantExpr>(Aliasee)) &&
+          (CE->getOpcode() == Instruction::BitCast))
+        return cast<GlobalValue>(CE->getOperand(0));
+      else
+        assert(0 && "Unsupported aliasee");
+    }
+  } else
+    return 0;
 }
 
diff --git a/llvm/lib/VMCore/Verifier.cpp b/llvm/lib/VMCore/Verifier.cpp
index c580e70d84e..8e632e2f8da 100644
--- a/llvm/lib/VMCore/Verifier.cpp
+++ b/llvm/lib/VMCore/Verifier.cpp
@@ -321,7 +321,8 @@ void Verifier::visitGlobalAlias(GlobalAlias &GA) {
   
   if (!isa<GlobalValue>(GA.getAliasee())) {
     const ConstantExpr *CE = dyn_cast<ConstantExpr>(GA.getAliasee());
-    Assert1(CE && CE->getOpcode() == Instruction::BitCast,
+    Assert1(CE && CE->getOpcode() == Instruction::BitCast &&
+            isa<GlobalValue>(CE->getOperand(0)),
             "Aliasee should be either GlobalValue or bitcast of GlobalValue",
             &GA);
   }