Revert "Reapply "LTO: add API to set strategy for -internalize""

[oota-llvm.git] / lib / Transforms / IPO / Internalize.cpp

diff --git a/lib/Transforms/IPO/Internalize.cpp b/lib/Transforms/IPO/Internalize.cpp
index f2feacc0b636e24f6a567577c1131699fcd3cf5e..c1fe01cebcd18fea2957cd82f9332e575530e12b 100644 (file)
--- a/lib/Transforms/IPO/Internalize.cpp
+++ b/lib/Transforms/IPO/Internalize.cpp
@@ -11,6 +11,12 @@
 // 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"
@@ -23,6 +29,7 @@
 #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>
@@ -52,11 +59,11 @@ namespace {
     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
@@ -65,8 +72,7 @@ char InternalizePass::ID = 0;
 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());
@@ -74,7 +80,7 @@ InternalizePass::InternalizePass()
 }
 
 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++) {
@@ -108,6 +114,10 @@ static bool shouldInternalize(const GlobalValue &GV,
   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;
@@ -120,7 +130,8 @@ static bool shouldInternalize(const GlobalValue &GV,
 }
 
 bool InternalizePass::runOnModule(Module &M) {
-  CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
+  CallGraphWrapperPass *CGPass = getAnalysisIfAvailable<CallGraphWrapperPass>();
+  CallGraph *CG = CGPass ? &CGPass->getCallGraph() : 0;
   CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
   bool Changed = false;
 
@@ -143,7 +154,6 @@ bool InternalizePass::runOnModule(Module &M) {
   }
 
   // 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;
@@ -179,7 +189,6 @@ bool InternalizePass::runOnModule(Module &M) {
 
   // 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))
@@ -206,9 +215,7 @@ bool InternalizePass::runOnModule(Module &M) {
   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);