//===----------------------------------------------------------------------===//
#include "llvm/Transforms/IPO/GlobalDCE.h"
-#include "llvm/Analysis/CallGraph.h"
#include "llvm/Module.h"
#include "llvm/Function.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Analysis/CallGraph.h"
#include "Support/DepthFirstIterator.h"
static bool RemoveUnreachableFunctions(Module *M, CallGraph &CallGraph) {
return true;
}
+static bool RemoveUnreachableGlobalVariables(Module *M) {
+ bool Changed = false;
+ // Eliminate all global variables that are unused, and that are internal, or
+ // do not have an initializer.
+ //
+ for (Module::giterator I = M->gbegin(); I != M->gend(); )
+ if (!(*I)->use_empty() ||
+ ((*I)->hasExternalLinkage() && (*I)->hasInitializer()))
+ ++I; // Cannot eliminate global variable
+ else {
+ delete M->getGlobalList().remove(I);
+ Changed = true;
+ }
+ return Changed;
+}
+
namespace {
struct GlobalDCE : public Pass {
const char *getPassName() const { return "Dead Global Elimination"; }
// the specified callgraph to reflect the changes.
//
bool run(Module *M) {
- return RemoveUnreachableFunctions(M, getAnalysis<CallGraph>());
+ return RemoveUnreachableFunctions(M, getAnalysis<CallGraph>()) |
+ RemoveUnreachableGlobalVariables(M);
}
// getAnalysisUsage - This function works on the call graph of a module.