1//===- MachineCheckDebugify.cpp - Check 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 checks debug info after mir-debugify (+ pass-to-test). Currently
10/// it simply checks the integrity of line info in DILocation and
11/// DILocalVariable which mir-debugifiy generated before.
12//===----------------------------------------------------------------------===//
13
14#include "llvm/ADT/StringExtras.h"
15#include "llvm/CodeGen/MachineBasicBlock.h"
16#include "llvm/CodeGen/MachineFunction.h"
17#include "llvm/CodeGen/MachineModuleInfo.h"
18#include "llvm/CodeGen/Passes.h"
19#include "llvm/IR/Constants.h"
20#include "llvm/IR/DebugInfoMetadata.h"
21#include "llvm/IR/Module.h"
22#include "llvm/InitializePasses.h"
23#include "llvm/Pass.h"
24
25#define DEBUG_TYPE "mir-check-debugify"
26
27using namespace llvm;
28
29namespace {
30
31struct CheckDebugMachineModule : public ModulePass {
32 bool runOnModule(Module &M) override {
33 NamedMDNode *NMD = M.getNamedMetadata(Name: "llvm.mir.debugify");
34 if (!NMD) {
35 errs() << "WARNING: Please run mir-debugify to generate "
36 "llvm.mir.debugify metadata first.\n";
37 return false;
38 }
39
40 MachineModuleInfo &MMI =
41 getAnalysis<MachineModuleInfoWrapperPass>().getMMI();
42
43 auto getDebugifyOperand = [&](unsigned Idx) -> unsigned {
44 return mdconst::extract<ConstantInt>(MD: NMD->getOperand(i: Idx)->getOperand(I: 0))
45 ->getZExtValue();
46 };
47 assert(NMD->getNumOperands() == 2 &&
48 "llvm.mir.debugify should have exactly 2 operands!");
49 unsigned NumLines = getDebugifyOperand(0);
50 unsigned NumVars = getDebugifyOperand(1);
51 BitVector MissingLines{NumLines, true};
52 BitVector MissingVars{NumVars, true};
53
54 for (Function &F : M.functions()) {
55 MachineFunction *MF = MMI.getMachineFunction(F);
56 if (!MF)
57 continue;
58 for (MachineBasicBlock &MBB : *MF) {
59 // Find missing lines.
60 // TODO: Avoid meta instructions other than dbg_val.
61 for (MachineInstr &MI : MBB) {
62 if (MI.isDebugValue())
63 continue;
64 const DebugLoc DL = MI.getDebugLoc();
65 if (DL && DL.getLine() != 0) {
66 MissingLines.reset(Idx: DL.getLine() - 1);
67 continue;
68 }
69
70 if (!DL) {
71 errs() << "WARNING: Instruction with empty DebugLoc in function ";
72 errs() << F.getName() << " --";
73 MI.print(OS&: errs());
74 }
75 }
76
77 // Find missing variables.
78 // TODO: Handle DBG_INSTR_REF which is under an experimental option now.
79 for (MachineInstr &MI : MBB) {
80 if (!MI.isDebugValue())
81 continue;
82 const DILocalVariable *LocalVar = MI.getDebugVariable();
83 unsigned Var = ~0U;
84
85 (void)to_integer(S: LocalVar->getName(), Num&: Var, Base: 10);
86 assert(Var <= NumVars && "Unexpected name for DILocalVariable");
87 MissingVars.reset(Idx: Var - 1);
88 }
89 }
90 }
91
92 bool Fail = false;
93 for (unsigned Idx : MissingLines.set_bits()) {
94 errs() << "WARNING: Missing line " << Idx + 1 << "\n";
95 Fail = true;
96 }
97
98 for (unsigned Idx : MissingVars.set_bits()) {
99 errs() << "WARNING: Missing variable " << Idx + 1 << "\n";
100 Fail = true;
101 }
102 errs() << "Machine IR debug info check: ";
103 errs() << (Fail ? "FAIL" : "PASS") << "\n";
104
105 return false;
106 }
107
108 CheckDebugMachineModule() : ModulePass(ID) {}
109
110 void getAnalysisUsage(AnalysisUsage &AU) const override {
111 AU.addRequired<MachineModuleInfoWrapperPass>();
112 AU.setPreservesAll();
113 }
114
115 static char ID; // Pass identification.
116};
117char CheckDebugMachineModule::ID = 0;
118
119} // end anonymous namespace
120
121INITIALIZE_PASS_BEGIN(CheckDebugMachineModule, DEBUG_TYPE,
122 "Machine Check Debug Module", false, false)
123INITIALIZE_PASS_END(CheckDebugMachineModule, DEBUG_TYPE,
124 "Machine Check Debug Module", false, false)
125
126ModulePass *llvm::createCheckDebugMachineModulePass() {
127 return new CheckDebugMachineModule();
128}
129