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