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 {
runOnModule__anonab875b320111::StripDebugMachineModule33 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
StripDebugMachineModule__anonab875b320111::StripDebugMachineModule85 StripDebugMachineModule() : StripDebugMachineModule(OnlyDebugifiedDefault) {}
StripDebugMachineModule__anonab875b320111::StripDebugMachineModule86 StripDebugMachineModule(bool OnlyDebugified)
87 : ModulePass(ID), OnlyDebugified(OnlyDebugified) {}
88
getAnalysisUsage__anonab875b320111::StripDebugMachineModule89 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
createStripDebugMachineModulePass(bool OnlyDebugified)109 ModulePass *llvm::createStripDebugMachineModulePass(bool OnlyDebugified) {
110 return new StripDebugMachineModule(OnlyDebugified);
111 }
112