1 //===- DXILFinalizeLinkage.cpp - Finalize linkage of functions ------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "DXILFinalizeLinkage.h" 10 #include "DirectX.h" 11 #include "llvm/IR/Function.h" 12 #include "llvm/IR/GlobalValue.h" 13 #include "llvm/IR/Metadata.h" 14 #include "llvm/IR/Module.h" 15 16 #define DEBUG_TYPE "dxil-finalize-linkage" 17 18 using namespace llvm; 19 20 static bool finalizeLinkage(Module &M) { 21 bool MadeChange = false; 22 23 // Convert private global variables to internal linkage. 24 for (GlobalVariable &GV : M.globals()) { 25 if (GV.hasPrivateLinkage()) { 26 GV.setLinkage(GlobalValue::InternalLinkage); 27 MadeChange = true; 28 } 29 } 30 31 SmallVector<Function *> Funcs; 32 33 // Collect non-entry and non-exported functions to set to internal linkage. 34 for (Function &EF : M.functions()) { 35 if (EF.isIntrinsic()) 36 continue; 37 if (EF.hasExternalLinkage() && EF.hasDefaultVisibility()) 38 continue; 39 if (EF.hasFnAttribute("hlsl.shader")) 40 continue; 41 Funcs.push_back(&EF); 42 } 43 44 for (Function *F : Funcs) { 45 if (F->getLinkage() == GlobalValue::ExternalLinkage) { 46 F->setLinkage(GlobalValue::InternalLinkage); 47 MadeChange = true; 48 } 49 if (F->isDefTriviallyDead()) { 50 M.getFunctionList().erase(F); 51 MadeChange = true; 52 } 53 } 54 55 return MadeChange; 56 } 57 58 PreservedAnalyses DXILFinalizeLinkage::run(Module &M, 59 ModuleAnalysisManager &AM) { 60 if (finalizeLinkage(M)) 61 return PreservedAnalyses::none(); 62 return PreservedAnalyses::all(); 63 } 64 65 bool DXILFinalizeLinkageLegacy::runOnModule(Module &M) { 66 return finalizeLinkage(M); 67 } 68 69 char DXILFinalizeLinkageLegacy::ID = 0; 70 71 INITIALIZE_PASS_BEGIN(DXILFinalizeLinkageLegacy, DEBUG_TYPE, 72 "DXIL Finalize Linkage", false, false) 73 INITIALIZE_PASS_END(DXILFinalizeLinkageLegacy, DEBUG_TYPE, 74 "DXIL Finalize Linkage", false, false) 75 76 ModulePass *llvm::createDXILFinalizeLinkageLegacyPass() { 77 return new DXILFinalizeLinkageLegacy(); 78 } 79