Imported Upstream version 5.18.0.167

Former-commit-id: 289509151e0fee68a1b591a20c9f109c3c789d3a

external/llvm/lib/Transforms/IPO/ExtractGV.cpp

@@ -1,161 +0,0 @@
-//===-- ExtractGV.cpp - Global Value extraction pass ----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass extracts global values
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/SetVector.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Transforms/IPO.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 global values and their dependencies.
-  class GVExtractorPass : public ModulePass {
-    SetVector<GlobalValue *> Named;
-    bool deleteStuff;
-  public:
-    static char ID; // Pass identification, replacement for typeid
-
-    /// If deleteS is true, this pass deletes the specified global values.
-    /// Otherwise, it deletes as much of the module as possible, except for the
-    /// global values specified.
-    explicit GVExtractorPass(std::vector<GlobalValue*> &GVs,
-                             bool deleteS = true)
-      : ModulePass(ID), Named(GVs.begin(), GVs.end()), deleteStuff(deleteS) {}
-
-    bool runOnModule(Module &M) override {
-      if (skipModule(M))
-        return false;
-
-      // Visit the global inline asm.
-      if (!deleteStuff)
-        M.setModuleInlineAsm("");
-
-      // For simplicity, just give all GlobalValues ExternalLinkage. A trickier
-      // implementation could figure out which GlobalValues are actually
-      // referenced by the Named set, and which GlobalValues in the rest of
-      // the module are referenced by the NamedSet, and get away with leaving
-      // more internal and private things internal and private. But for now,
-      // be conservative and simple.
-
-      // Visit the GlobalVariables.
-      for (Module::global_iterator I = M.global_begin(), E = M.global_end();
-           I != E; ++I) {
-        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) {
-          // Make this a declaration and drop it's comdat.
-          I->setInitializer(nullptr);
-          I->setComdat(nullptr);
-        }
-      }
-
-      // Visit the Functions.
-      for (Function &F : M) {
-        bool Delete =
-            deleteStuff == (bool)Named.count(&F) && !F.isDeclaration();
-        if (!Delete) {
-          if (F.hasAvailableExternallyLinkage())
-            continue;
-        }
-
-        makeVisible(F, Delete);
-
-        if (Delete) {
-          // Make this a declaration and drop it's comdat.
-          F.deleteBody();
-          F.setComdat(nullptr);
-        }
-      }
-
-      // 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->getValueType();
-
-          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;
-    }
-  };
-
-  char GVExtractorPass::ID = 0;
-}
-
-ModulePass *llvm::createGVExtractionPass(std::vector<GlobalValue *> &GVs,
-                                         bool deleteFn) {
-  return new GVExtractorPass(GVs, deleteFn);
-}