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