Add helper for ultimate aliasee resoltion
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48255 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/GlobalAlias.h b/include/llvm/GlobalAlias.h
index 572de67..1dee041 100644
--- a/include/llvm/GlobalAlias.h
+++ b/include/llvm/GlobalAlias.h
@@ -78,7 +78,12 @@
/// getAliasedGlobal() - Aliasee can be either global or bitcast of
/// global. This method retrives the global for both aliasee flavours.
const GlobalValue* getAliasedGlobal() const;
-
+
+ /// resolveAliasedGlobal() - This method tries to ultimately resolve alias by
+ /// going through aliasing chain and trying to find the very last
+ /// global. Return NULL is cycle was found.
+ const GlobalValue* resolveAliasedGlobal() const;
+
// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const GlobalAlias *) { return true; }
static inline bool classof(const Value *V) {
diff --git a/lib/VMCore/Globals.cpp b/lib/VMCore/Globals.cpp
index dae22e4..d66d351 100644
--- a/lib/VMCore/Globals.cpp
+++ b/lib/VMCore/Globals.cpp
@@ -17,6 +17,7 @@
#include "llvm/GlobalAlias.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Support/LeakDetector.h"
using namespace llvm;
@@ -230,3 +231,18 @@
return 0;
}
+const GlobalValue *GlobalAlias::resolveAliasedGlobal() const {
+ SmallPtrSet<const GlobalValue*, 1> Visited;
+
+ const GlobalValue *GV = getAliasedGlobal();
+ Visited.insert(GV);
+
+ while (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV)) {
+ GV = GA->getAliasedGlobal();
+
+ if (!Visited.insert(GV))
+ return NULL;
+ }
+
+ return GV;
+}