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/MachineBasicBlock.h"
14#include "llvm/CodeGen/MachineFunction.h"
15#include "llvm/CodeGen/MachineModuleInfo.h"
16#include "llvm/CodeGen/Passes.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
23using namespace llvm;
24
25namespace {
26cl::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(Val: true));
31
32struct StripDebugMachineModule : public ModulePass {
33 bool runOnModule(Module &M) override {
34 if (OnlyDebugified) {
35 NamedMDNode *DebugifyMD = M.getNamedMetadata(Name: "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 (MachineInstr &MI : llvm::make_early_inc_range(Range: MBB.instrs())) {
54 if (MI.isDebugInstr()) {
55 // FIXME: We should remove all of them. However, AArch64 emits an
56 // invalid `DBG_VALUE $lr` with only one operand instead of
57 // the usual three and has a test that depends on it's
58 // preservation. Preserve it for now.
59 if (MI.getNumOperands() > 1) {
60 LLVM_DEBUG(dbgs() << "Removing debug instruction " << MI);
61 MBB.erase(I: &MI);
62 Changed |= true;
63 continue;
64 }
65 }
66 if (MI.getDebugLoc()) {
67 LLVM_DEBUG(dbgs() << "Removing location " << MI);
68 MI.setDebugLoc(DebugLoc());
69 Changed |= true;
70 continue;
71 }
72 LLVM_DEBUG(dbgs() << "Keeping " << MI);
73 }
74 }
75 }
76
77 Changed |= stripDebugifyMetadata(M);
78
79 return Changed;
80 }
81
82 StripDebugMachineModule() : StripDebugMachineModule(OnlyDebugifiedDefault) {}
83 StripDebugMachineModule(bool OnlyDebugified)
84 : ModulePass(ID), OnlyDebugified(OnlyDebugified) {}
85
86 void getAnalysisUsage(AnalysisUsage &AU) const override {
87 AU.addRequired<MachineModuleInfoWrapperPass>();
88 AU.addPreserved<MachineModuleInfoWrapperPass>();
89 AU.setPreservesCFG();
90 }
91
92 static char ID; // Pass identification.
93
94protected:
95 bool OnlyDebugified;
96};
97char StripDebugMachineModule::ID = 0;
98
99} // end anonymous namespace
100
101INITIALIZE_PASS_BEGIN(StripDebugMachineModule, DEBUG_TYPE,
102 "Machine Strip Debug Module", false, false)
103INITIALIZE_PASS_END(StripDebugMachineModule, DEBUG_TYPE,
104 "Machine Strip Debug Module", false, false)
105
106ModulePass *llvm::createStripDebugMachineModulePass(bool OnlyDebugified) {
107 return new StripDebugMachineModule(OnlyDebugified);
108}
109