Reformat partially, where I touched for whitespace changes.

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

diff --git a/lib/Transforms/IPO/ExtractGV.cpp b/lib/Transforms/IPO/ExtractGV.cpp
index 57c2f6d410d1a5687e5bc7b4996b4c1c7799a665..2f8c7d9349b9ccae813789497edcd9313ebe9b61 100644 (file)
--- a/lib/Transforms/IPO/ExtractGV.cpp
+++ b/lib/Transforms/IPO/ExtractGV.cpp
@@ -11,16 +11,47 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Instructions.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Constants.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/ADT/SetVector.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
 #include <algorithm>
 using namespace llvm;
 
+/// Make sure GV is visible from both modules. Delete is true if it is
+/// being deleted from this module.
+/// This also makes sure GV cannot be dropped so that references from
+/// the split module remain valid.
+static void makeVisible(GlobalValue &GV, bool Delete) {
+  bool Local = GV.hasLocalLinkage();
+  if (Local || Delete) {
+    GV.setLinkage(GlobalValue::ExternalLinkage);
+    if (Local)
+      GV.setVisibility(GlobalValue::HiddenVisibility);
+    return;
+  }
+
+  if (!GV.hasLinkOnceLinkage()) {
+    assert(!GV.isDiscardableIfUnused());
+    return;
+  }
+
+  // Map linkonce* to weak* so that llvm doesn't drop this GV.
+  switch(GV.getLinkage()) {
+  default:
+    llvm_unreachable("Unexpected linkage");
+  case GlobalValue::LinkOnceAnyLinkage:
+    GV.setLinkage(GlobalValue::WeakAnyLinkage);
+    return;
+  case GlobalValue::LinkOnceODRLinkage:
+    GV.setLinkage(GlobalValue::WeakODRLinkage);
+    return;
+  }
+}
+
 namespace {
   /// @brief A pass to extract specific functions and their dependencies.
   class GVExtractorPass : public ModulePass {
@@ -36,7 +67,7 @@ namespace {
     explicit GVExtractorPass(std::vector<GlobalValue*>& GVs, bool deleteS = true)
       : ModulePass(ID), Named(GVs.begin(), GVs.end()), deleteStuff(deleteS) {}
 
-    bool runOnModule(Module &M) {
+    bool runOnModule(Module &M) override {
       // Visit the global inline asm.
       if (!deleteStuff)
         M.setModuleInlineAsm("");
@@ -51,32 +82,34 @@ namespace {
       // Visit the GlobalVariables.
       for (Module::global_iterator I = M.global_begin(), E = M.global_end();
            I != E; ++I) {
-        if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration()) {
-          I->setInitializer(0);
-        } else {
+        bool Delete =
+          deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
+        if (!Delete) {
           if (I->hasAvailableExternallyLinkage())
             continue;
           if (I->getName() == "llvm.global_ctors")
             continue;
         }
 
-        if (I->hasLocalLinkage())
-          I->setVisibility(GlobalValue::HiddenVisibility);
-        I->setLinkage(GlobalValue::ExternalLinkage);
+        makeVisible(*I, Delete);
+
+        if (Delete)
+          I->setInitializer(nullptr);
       }
 
       // Visit the Functions.
       for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
-        if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration()) {
-          I->deleteBody();
-        } else {
+        bool Delete =
+          deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
+        if (!Delete) {
           if (I->hasAvailableExternallyLinkage())
             continue;
         }
 
-        if (I->hasLocalLinkage())
-          I->setVisibility(GlobalValue::HiddenVisibility);
-        I->setLinkage(GlobalValue::ExternalLinkage);
+        makeVisible(*I, Delete);
+
+        if (Delete)
+          I->deleteBody();
       }
 
       // Visit the Aliases.
@@ -85,11 +118,10 @@ namespace {
         Module::alias_iterator CurI = I;
         ++I;
 
-        if (CurI->hasLocalLinkage())
-          CurI->setVisibility(GlobalValue::HiddenVisibility);
-        CurI->setLinkage(GlobalValue::ExternalLinkage);
+        bool Delete = deleteStuff == (bool)Named.count(CurI);
+        makeVisible(*CurI, Delete);
 
-        if (deleteStuff == (bool)Named.count(CurI)) {
+        if (Delete) {
           Type *Ty =  CurI->getType()->getElementType();
 
           CurI->removeFromParent();
@@ -101,7 +133,7 @@ namespace {
           } else {
             Declaration =
               new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage,
-                                 0, CurI->getName());
+                                 nullptr, CurI->getName());
 
           }
           CurI->replaceAllUsesWith(Declaration);
@@ -116,7 +148,7 @@ namespace {
   char GVExtractorPass::ID = 0;
 }
 
-ModulePass *llvm::createGVExtractionPass(std::vector<GlobalValue*>& GVs, 
+ModulePass *llvm::createGVExtractionPass(std::vector<GlobalValue *> &GVs,
                                          bool deleteFn) {
   return new GVExtractorPass(GVs, deleteFn);
 }