//
//===----------------------------------------------------------------------===//
-#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 {
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("");
// Visit the GlobalVariables.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
- if (I->hasLocalLinkage())
- I->setVisibility(GlobalValue::HiddenVisibility);
- I->setLinkage(GlobalValue::ExternalLinkage);
- if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration())
- I->setInitializer(0);
+ bool Delete =
+ deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
+ if (!Delete) {
+ if (I->hasAvailableExternallyLinkage())
+ continue;
+ if (I->getName() == "llvm.global_ctors")
+ continue;
+ }
+
+ makeVisible(*I, Delete);
+
+ if (Delete)
+ I->setInitializer(nullptr);
}
// Visit the Functions.
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
- if (I->hasLocalLinkage())
- I->setVisibility(GlobalValue::HiddenVisibility);
- I->setLinkage(GlobalValue::ExternalLinkage);
- if (deleteStuff == (bool)Named.count(I) && !I->isDeclaration())
+ bool Delete =
+ deleteStuff == (bool)Named.count(I) && !I->isDeclaration();
+ if (!Delete) {
+ if (I->hasAvailableExternallyLinkage())
+ continue;
+ }
+
+ makeVisible(*I, Delete);
+
+ if (Delete)
I->deleteBody();
}
+ // Visit the Aliases.
+ for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
+ I != E;) {
+ Module::alias_iterator CurI = I;
+ ++I;
+
+ bool Delete = deleteStuff == (bool)Named.count(CurI);
+ makeVisible(*CurI, Delete);
+
+ if (Delete) {
+ Type *Ty = CurI->getType()->getElementType();
+
+ CurI->removeFromParent();
+ llvm::Value *Declaration;
+ if (FunctionType *FTy = dyn_cast<FunctionType>(Ty)) {
+ Declaration = Function::Create(FTy, GlobalValue::ExternalLinkage,
+ CurI->getName(), &M);
+
+ } else {
+ Declaration =
+ new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage,
+ nullptr, CurI->getName());
+
+ }
+ CurI->replaceAllUsesWith(Declaration);
+ delete CurI;
+ }
+ }
+
return true;
}
};