1 //===- MachineStripDebug.cpp - Strip debug info ---------------------------===// 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 /// \file This removes debug info from everything. It can be used to ensure 10 /// tests can be debugified without affecting the output MIR. 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/CodeGen/MachineFunctionPass.h" 14 #include "llvm/CodeGen/MachineModuleInfo.h" 15 #include "llvm/CodeGen/Passes.h" 16 #include "llvm/IR/DebugInfo.h" 17 #include "llvm/InitializePasses.h" 18 #include "llvm/Support/CommandLine.h" 19 #include "llvm/Transforms/Utils/Debugify.h" 20 21 #define DEBUG_TYPE "mir-strip-debug" 22 23 using namespace llvm; 24 25 namespace { 26 cl::opt<bool> 27 OnlyDebugifiedDefault("mir-strip-debugify-only", 28 cl::desc("Should mir-strip-debug only strip debug " 29 "info from debugified modules by default"), 30 cl::init(true)); 31 32 struct StripDebugMachineModule : public ModulePass { 33 bool runOnModule(Module &M) override { 34 if (OnlyDebugified) { 35 NamedMDNode *DebugifyMD = M.getNamedMetadata("llvm.debugify"); 36 if (!DebugifyMD) { 37 LLVM_DEBUG(dbgs() << "Not stripping debug info" 38 " (debugify metadata not found)?\n"); 39 return false; 40 } 41 } 42 43 MachineModuleInfo &MMI = 44 getAnalysis<MachineModuleInfoWrapperPass>().getMMI(); 45 46 bool Changed = false; 47 for (Function &F : M.functions()) { 48 MachineFunction *MaybeMF = MMI.getMachineFunction(F); 49 if (!MaybeMF) 50 continue; 51 MachineFunction &MF = *MaybeMF; 52 for (MachineBasicBlock &MBB : MF) { 53 for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); 54 I != E;) { 55 if (I->isDebugInstr()) { 56 // FIXME: We should remove all of them. However, AArch64 emits an 57 // invalid `DBG_VALUE $lr` with only one operand instead of 58 // the usual three and has a test that depends on it's 59 // preservation. Preserve it for now. 60 if (I->getNumOperands() > 1) { 61 LLVM_DEBUG(dbgs() << "Removing debug instruction " << *I); 62 I = MBB.erase(I); 63 Changed |= true; 64 continue; 65 } 66 } 67 if (I->getDebugLoc()) { 68 LLVM_DEBUG(dbgs() << "Removing location " << *I); 69 I->setDebugLoc(DebugLoc()); 70 Changed |= true; 71 ++I; 72 continue; 73 } 74 LLVM_DEBUG(dbgs() << "Keeping " << *I); 75 ++I; 76 } 77 } 78 } 79 80 Changed |= stripDebugifyMetadata(M); 81 82 return Changed; 83 } 84 85 StripDebugMachineModule() : StripDebugMachineModule(OnlyDebugifiedDefault) {} 86 StripDebugMachineModule(bool OnlyDebugified) 87 : ModulePass(ID), OnlyDebugified(OnlyDebugified) {} 88 89 void getAnalysisUsage(AnalysisUsage &AU) const override { 90 AU.addRequired<MachineModuleInfoWrapperPass>(); 91 AU.addPreserved<MachineModuleInfoWrapperPass>(); 92 AU.setPreservesCFG(); 93 } 94 95 static char ID; // Pass identification. 96 97 protected: 98 bool OnlyDebugified; 99 }; 100 char StripDebugMachineModule::ID = 0; 101 102 } // end anonymous namespace 103 104 INITIALIZE_PASS_BEGIN(StripDebugMachineModule, DEBUG_TYPE, 105 "Machine Strip Debug Module", false, false) 106 INITIALIZE_PASS_END(StripDebugMachineModule, DEBUG_TYPE, 107 "Machine Strip Debug Module", false, false) 108 109 ModulePass *llvm::createStripDebugMachineModulePass(bool OnlyDebugified) { 110 return new StripDebugMachineModule(OnlyDebugified); 111 } 112