C++ GlobalAlias::getName方法代码示例

static void convertAliasToDeclaration(GlobalAlias &GA, Module &M) {
  GlobalValue *GVal = GA.getBaseObject();
  GlobalValue *NewGV;
  if (auto *GVar = dyn_cast<GlobalVariable>(GVal)) {
    GlobalVariable *NewGVar = new GlobalVariable(
        M, GVar->getType()->getElementType(), GVar->isConstant(),
        GVar->getLinkage(), /*init*/ nullptr, GA.getName(), GVar,
        GVar->getThreadLocalMode(), GVar->getType()->getAddressSpace());
    NewGV = NewGVar;
    NewGV->copyAttributesFrom(GVar);
  } else {
    auto *F = dyn_cast<Function>(GVal);
    assert(F);
    Function *NewF = Function::Create(F->getFunctionType(), F->getLinkage(),
                                      GA.getName(), &M);
    NewGV = NewF;
    NewGV->copyAttributesFrom(F);
  }
  GA.replaceAllUsesWith(ConstantExpr::getBitCast(NewGV, GA.getType()));
  GA.eraseFromParent();
}

// Replace G with an alias to F and delete G.
void MergeFunctions::writeAlias(Function *F, Function *G) {
  Constant *BitcastF = ConstantExpr::getBitCast(F, G->getType());
  GlobalAlias *GA = new GlobalAlias(G->getType(), G->getLinkage(), "",
                                    BitcastF, G->getParent());
  F->setAlignment(std::max(F->getAlignment(), G->getAlignment()));
  GA->takeName(G);
  GA->setVisibility(G->getVisibility());
  removeUsers(G);
  G->replaceAllUsesWith(GA);
  G->eraseFromParent();

  DEBUG(dbgs() << "writeAlias: " << GA->getName() << '\n');
  ++NumAliasesWritten;
}

Module * llvmutil_extractmodule(Module * OrigMod, TargetMachine * TM, std::vector<Function*> * livefns, std::vector<std::string> * symbolnames) {
        assert(symbolnames == NULL || livefns->size() == symbolnames->size());
        ValueToValueMapTy VMap;
        Module * M = CloneModule(OrigMod, VMap);
        PassManager * MPM = new PassManager();
        
        llvmutil_addtargetspecificpasses(MPM, TM);
        
        std::vector<const char *> names;
        for(size_t i = 0; i < livefns->size(); i++) {
            Function * fn = cast<Function>(VMap[(*livefns)[i]]);
            const char * name;
            if(symbolnames) {
                GlobalAlias * ga = new GlobalAlias(fn->getType(), Function::ExternalLinkage, (*symbolnames)[i], fn, M);
                name = copyName(ga->getName());
            } else {
                name = copyName(fn->getName());
            }
            names.push_back(name); //internalize pass has weird interface, so we need to copy the names here
        }
        
        //at this point we run optimizations on the module
        //first internalize all functions not mentioned in "names" using an internalize pass and then perform 
        //standard optimizations
        
        MPM->add(createVerifierPass()); //make sure we haven't messed stuff up yet
        MPM->add(createInternalizePass(names));
        MPM->add(createGlobalDCEPass()); //run this early since anything not in the table of exported functions is still in this module
                                         //this will remove dead functions
        
        //clean up the name list
        for(size_t i = 0; i < names.size(); i++) {
            free((char*)names[i]);
            names[i] = NULL;
        }
        
        PassManagerBuilder PMB;
        PMB.OptLevel = 3;
        PMB.DisableUnrollLoops = true;
        
        PMB.populateModulePassManager(*MPM);
        //PMB.populateLTOPassManager(*MPM, false, false); //no need to re-internalize, we already did it
    
        MPM->run(*M);
        
        delete MPM;
        MPM = NULL;
    
        return M;
}

static void
computeAliasSummary(ModuleSummaryIndex &Index, const GlobalAlias &A,
                    DenseSet<GlobalValue::GUID> &CantBePromoted) {
  bool NonRenamableLocal = isNonRenamableLocal(A);
  GlobalValueSummary::GVFlags Flags(A.getLinkage(), NonRenamableLocal,
                                    /* LiveRoot = */ false);
  auto AS = llvm::make_unique<AliasSummary>(Flags, ArrayRef<ValueInfo>{});
  auto *Aliasee = A.getBaseObject();
  auto *AliaseeSummary = Index.getGlobalValueSummary(*Aliasee);
  assert(AliaseeSummary && "Alias expects aliasee summary to be parsed");
  AS->setAliasee(AliaseeSummary);
  if (NonRenamableLocal)
    CantBePromoted.insert(A.getGUID());
  Index.addGlobalValueSummary(A.getName(), std::move(AS));
}

// destructively move the contents of src into dest
// this assumes that the targets of the two modules are the same
// including the DataLayout and ModuleFlags (for example)
// and that there is no module-level assembly
static void jl_merge_module(Module *dest, std::unique_ptr<Module> src)
{
    assert(dest != src.get());
    for (Module::global_iterator I = src->global_begin(), E = src->global_end(); I != E;) {
        GlobalVariable *sG = &*I;
        GlobalValue *dG = dest->getNamedValue(sG->getName());
        ++I;
        // Replace a declaration with the definition:
        if (dG) {
            if (sG->isDeclaration()) {
                sG->replaceAllUsesWith(dG);
                sG->eraseFromParent();
                continue;
            }
            else {
                dG->replaceAllUsesWith(sG);
                dG->eraseFromParent();
            }
        }
        // Reparent the global variable:
        sG->removeFromParent();
        dest->getGlobalList().push_back(sG);
        // Comdat is owned by the Module, recreate it in the new parent:
        addComdat(sG);
    }

    for (Module::iterator I = src->begin(), E = src->end(); I != E;) {
        Function *sG = &*I;
        GlobalValue *dG = dest->getNamedValue(sG->getName());
        ++I;
        // Replace a declaration with the definition:
        if (dG) {
            if (sG->isDeclaration()) {
                sG->replaceAllUsesWith(dG);
                sG->eraseFromParent();
                continue;
            }
            else {
                dG->replaceAllUsesWith(sG);
                dG->eraseFromParent();
            }
        }
        // Reparent the global variable:
        sG->removeFromParent();
        dest->getFunctionList().push_back(sG);
        // Comdat is owned by the Module, recreate it in the new parent:
        addComdat(sG);
    }

    for (Module::alias_iterator I = src->alias_begin(), E = src->alias_end(); I != E;) {
        GlobalAlias *sG = &*I;
        GlobalValue *dG = dest->getNamedValue(sG->getName());
        ++I;
        if (dG) {
            if (!dG->isDeclaration()) { // aliases are always definitions, so this test is reversed from the above two
                sG->replaceAllUsesWith(dG);
                sG->eraseFromParent();
                continue;
            }
            else {
                dG->replaceAllUsesWith(sG);
                dG->eraseFromParent();
            }
        }
        sG->removeFromParent();
        dest->getAliasList().push_back(sG);
    }

    // metadata nodes need to be explicitly merged not just copied
    // so there are special passes here for each known type of metadata
    NamedMDNode *sNMD = src->getNamedMetadata("llvm.dbg.cu");
    if (sNMD) {
        NamedMDNode *dNMD = dest->getOrInsertNamedMetadata("llvm.dbg.cu");
#ifdef LLVM35
        for (NamedMDNode::op_iterator I = sNMD->op_begin(), E = sNMD->op_end(); I != E; ++I) {
            dNMD->addOperand(*I);
        }
#else
        for (unsigned i = 0, l = sNMD->getNumOperands(); i < l; i++) {
            dNMD->addOperand(sNMD->getOperand(i));
        }
#endif
    }
}