// If the function or variable is not in the list of external names given to
// the pass it is marked as internal.
//
+// This transformation would not be legal in a regular compilation, but it gets
+// extra information from the linker about what is safe.
+//
+// For example: Internalizing a function with external linkage. Only if we are
+// told it is only used from within this module, it is safe to do it.
+//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "internalize"
#include "llvm/Transforms/IPO.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Utils/GlobalStatus.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"
#include <fstream>
#include <set>
using namespace llvm;
+#define DEBUG_TYPE "internalize"
+
STATISTIC(NumAliases , "Number of aliases internalized");
STATISTIC(NumFunctions, "Number of functions internalized");
STATISTIC(NumGlobals , "Number of global vars internalized");
explicit InternalizePass();
explicit InternalizePass(ArrayRef<const char *> ExportList);
void LoadFile(const char *Filename);
- virtual bool runOnModule(Module &M);
+ bool runOnModule(Module &M) override;
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
- AU.addPreserved<CallGraph>();
+ AU.addPreserved<CallGraphWrapperPass>();
}
};
} // end anonymous namespace
INITIALIZE_PASS(InternalizePass, "internalize",
"Internalize Global Symbols", false, false)
-InternalizePass::InternalizePass()
- : ModulePass(ID) {
+InternalizePass::InternalizePass() : ModulePass(ID) {
initializeInternalizePassPass(*PassRegistry::getPassRegistry());
if (!APIFile.empty()) // If a filename is specified, use it.
LoadFile(APIFile.c_str());
}
InternalizePass::InternalizePass(ArrayRef<const char *> ExportList)
- : ModulePass(ID){
+ : ModulePass(ID) {
initializeInternalizePassPass(*PassRegistry::getPassRegistry());
for(ArrayRef<const char *>::const_iterator itr = ExportList.begin();
itr != ExportList.end(); itr++) {
if (GV.hasAvailableExternallyLinkage())
return false;
+ // Assume that dllexported symbols are referenced elsewhere
+ if (GV.hasDLLExportStorageClass())
+ return false;
+
// Already has internal linkage
if (GV.hasLocalLinkage())
return false;
}
bool InternalizePass::runOnModule(Module &M) {
- CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
- CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
+ CallGraphWrapperPass *CGPass = getAnalysisIfAvailable<CallGraphWrapperPass>();
+ CallGraph *CG = CGPass ? &CGPass->getCallGraph() : nullptr;
+ CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : nullptr;
bool Changed = false;
SmallPtrSet<GlobalValue *, 8> Used;
// we don't see references from function local inline assembly. To be
// conservative, we internalize symbols in llvm.compiler.used, but we
// keep llvm.compiler.used so that the symbol is not deleted by llvm.
- for (SmallPtrSet<GlobalValue *, 8>::iterator I = Used.begin(), E = Used.end();
- I != E; ++I) {
- GlobalValue *V = *I;
+ for (GlobalValue *V : Used) {
ExternalNames.insert(V->getName());
}
// Mark all functions not in the api as internal.
- // FIXME: maybe use private linkage?
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
if (!shouldInternalize(*I, ExternalNames))
continue;
+ I->setVisibility(GlobalValue::DefaultVisibility);
I->setLinkage(GlobalValue::InternalLinkage);
if (ExternalNode)
// Mark all global variables with initializers that are not in the api as
// internal as well.
- // FIXME: maybe use private linkage?
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
if (!shouldInternalize(*I, ExternalNames))
continue;
+ I->setVisibility(GlobalValue::DefaultVisibility);
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumGlobals;
if (!shouldInternalize(*I, ExternalNames))
continue;
+ I->setVisibility(GlobalValue::DefaultVisibility);
I->setLinkage(GlobalValue::InternalLinkage);
Changed = true;
++NumAliases;
return Changed;
}
-ModulePass *llvm::createInternalizePass() {
- return new InternalizePass();
-}
+ModulePass *llvm::createInternalizePass() { return new InternalizePass(); }
ModulePass *llvm::createInternalizePass(ArrayRef<const char *> ExportList) {
return new InternalizePass(ExportList);