xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/MachineCheckDebugify.cpp (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 
27 using namespace llvm;
28 
29 namespace {
30 
31 struct CheckDebugMachineModule : public ModulePass {
32   bool runOnModule(Module &M) override {
33     NamedMDNode *NMD = M.getNamedMetadata("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>(NMD->getOperand(Idx)->getOperand(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(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(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(LocalVar->getName(), Var, 10);
86           assert(Var <= NumVars && "Unexpected name for DILocalVariable");
87           MissingVars.reset(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 };
117 char CheckDebugMachineModule::ID = 0;
118 
119 } // end anonymous namespace
120 
121 INITIALIZE_PASS_BEGIN(CheckDebugMachineModule, DEBUG_TYPE,
122                       "Machine Check Debug Module", false, false)
123 INITIALIZE_PASS_END(CheckDebugMachineModule, DEBUG_TYPE,
124                     "Machine Check Debug Module", false, false)
125 
126 ModulePass *llvm::createCheckDebugMachineModulePass() {
127   return new CheckDebugMachineModule();
128 }
129