llvm/lib/CodeGen/MachineCheckDebugify.cpp

   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 }