llvm/unittests/MC/DwarfLineTableHeaders.cpp

   1 //===- llvm/unittest/MC/DwarfLineTableHeaders.cpp -------------------------===//
   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 #include "llvm/ADT/STLExtras.h"
  10 #include "llvm/BinaryFormat/Dwarf.h"
  11 #include "llvm/MC/MCAsmBackend.h"
  12 #include "llvm/MC/MCAsmInfo.h"
  13 #include "llvm/MC/MCAssembler.h"
  14 #include "llvm/MC/MCCodeEmitter.h"
  15 #include "llvm/MC/MCContext.h"
  16 #include "llvm/MC/MCDwarf.h"
  17 #include "llvm/MC/MCInstrInfo.h"
  18 #include "llvm/MC/MCObjectStreamer.h"
  19 #include "llvm/MC/MCObjectWriter.h"
  20 #include "llvm/MC/MCRegisterInfo.h"
  21 #include "llvm/MC/MCStreamer.h"
  22 #include "llvm/MC/MCSubtargetInfo.h"
  23 #include "llvm/MC/MCTargetOptions.h"
  24 #include "llvm/MC/TargetRegistry.h"
  25 #include "llvm/Object/Binary.h"
  26 #include "llvm/Object/ELFObjectFile.h"
  27 #include "llvm/Support/FileSystem.h"
  28 #include "llvm/Support/MemoryBuffer.h"
  29 #include "llvm/Support/TargetSelect.h"
  30 #include "llvm/Support/ToolOutputFile.h"
  31 #include "gtest/gtest.h"
  32
  33 using namespace llvm;
  34
  35 namespace {
  36
  37 class DwarfLineTableHeaders : public ::testing::Test {
  38 public:
  39   const char *TripleName = "x86_64-pc-linux";
  40   std::unique_ptr<MCRegisterInfo> MRI;
  41   std::unique_ptr<MCAsmInfo> MAI;
  42   std::unique_ptr<const MCSubtargetInfo> STI;
  43   const Target *TheTarget;
  44
  45   struct StreamerContext {
  46     std::unique_ptr<MCObjectFileInfo> MOFI;
  47     std::unique_ptr<MCContext> Ctx;
  48     std::unique_ptr<const MCInstrInfo> MII;
  49     std::unique_ptr<MCStreamer> Streamer;
  50   };
  51
  52   DwarfLineTableHeaders() {
  53     llvm::InitializeAllTargetInfos();
  54     llvm::InitializeAllTargetMCs();
  55     llvm::InitializeAllDisassemblers();
  56
  57     // If we didn't build x86, do not run the test.
  58     std::string Error;
  59     TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
  60     if (!TheTarget)
  61       return;
  62
  63     MRI.reset(TheTarget->createMCRegInfo(TripleName));
  64     MCTargetOptions MCOptions;
  65     MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
  66     STI.reset(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
  67   }
  68
  69   /// Create all data structures necessary to operate an assembler
  70   StreamerContext createStreamer(raw_pwrite_stream &OS) {
  71     StreamerContext Res;
  72     Res.Ctx =
  73         std::make_unique<MCContext>(Triple(TripleName), MAI.get(), MRI.get(),
  74                                     /*MSTI=*/nullptr);
  75     Res.MOFI.reset(TheTarget->createMCObjectFileInfo(*Res.Ctx,
  76                                                      /*PIC=*/false));
  77     Res.Ctx->setObjectFileInfo(Res.MOFI.get());
  78
  79     Res.MII.reset(TheTarget->createMCInstrInfo());
  80     MCCodeEmitter *MCE = TheTarget->createMCCodeEmitter(*Res.MII, *Res.Ctx);
  81     MCAsmBackend *MAB =
  82         TheTarget->createMCAsmBackend(*STI, *MRI, MCTargetOptions());
  83     std::unique_ptr<MCObjectWriter> OW = MAB->createObjectWriter(OS);
  84     Res.Streamer.reset(TheTarget->createMCObjectStreamer(
  85         Triple(TripleName), *Res.Ctx, std::unique_ptr<MCAsmBackend>(MAB),
  86         std::move(OW), std::unique_ptr<MCCodeEmitter>(MCE), *STI));
  87     return Res;
  88   }
  89
  90   /// Emit a .debug_line section with the given context parameters
  91   void emitDebugLineSection(StreamerContext &C) {
  92     MCContext &Ctx = *C.Ctx;
  93     MCStreamer *TheStreamer = C.Streamer.get();
  94     MCAssembler &Assembler =
  95         static_cast<MCObjectStreamer *>(TheStreamer)->getAssembler();
  96     TheStreamer->initSections(false, *STI);
  97
  98     // Create a mock function
  99     MCSection *Section = C.MOFI->getTextSection();
 100     Section->setHasInstructions(true);
 101     TheStreamer->switchSection(Section);
 102     TheStreamer->emitCFIStartProc(true);
 103
 104     // Create a mock dwarfloc
 105     Ctx.setCurrentDwarfLoc(/*FileNo=*/0, /*Line=*/1, /*Column=*/1, /*Flags=*/0,
 106                            /*Isa=*/0, /*Discriminator=*/0);
 107     MCDwarfLoc Loc = Ctx.getCurrentDwarfLoc();
 108     MCSymbol *LineSym = Ctx.createTempSymbol();
 109     // Set the value of the symbol to use for the MCDwarfLineEntry.
 110     TheStreamer->emitLabel(LineSym);
 111     TheStreamer->emitNops(4, 1, SMLoc(), *STI);
 112     TheStreamer->emitCFIEndProc();
 113
 114     // Start emission of .debug_line
 115     TheStreamer->switchSection(C.MOFI->getDwarfLineSection());
 116     MCDwarfLineTableHeader Header;
 117     MCDwarfLineTableParams Params = Assembler.getDWARFLinetableParams();
 118     std::optional<MCDwarfLineStr> LineStr(std::nullopt);
 119     if (Ctx.getDwarfVersion() >= 5) {
 120       LineStr.emplace(Ctx);
 121       Header.setRootFile("dir", "file", std::nullopt, std::nullopt);
 122     }
 123     MCSymbol *LineEndSym = Header.Emit(TheStreamer, Params, LineStr).second;
 124
 125     // Put out the line tables.
 126     MCLineSection::MCDwarfLineEntryCollection LineEntries;
 127     MCDwarfLineEntry LineEntry(LineSym, Loc);
 128     LineEntries.push_back(LineEntry);
 129     MCDwarfLineTable::emitOne(TheStreamer, Section, LineEntries);
 130     TheStreamer->emitLabel(LineEndSym);
 131     if (LineStr) {
 132       SmallString<0> Data = LineStr->getFinalizedData();
 133       TheStreamer->switchSection(TheStreamer->getContext()
 134                                      .getObjectFileInfo()
 135                                      ->getDwarfLineStrSection());
 136       TheStreamer->emitBinaryData(Data.str());
 137     }
 138   }
 139
 140   /// Check contents of .debug_line section
 141   void verifyDebugLineContents(const llvm::object::ObjectFile &E,
 142                                ArrayRef<uint8_t> ExpectedEncoding) {
 143     for (const llvm::object::SectionRef &Section : E.sections()) {
 144       Expected<StringRef> SectionNameOrErr = Section.getName();
 145       ASSERT_TRUE(static_cast<bool>(SectionNameOrErr));
 146       StringRef SectionName = *SectionNameOrErr;
 147       if (SectionName.empty() || SectionName != ".debug_line")
 148         continue;
 149       Expected<StringRef> ContentsOrErr = Section.getContents();
 150       ASSERT_TRUE(static_cast<bool>(ContentsOrErr));
 151       StringRef Contents = *ContentsOrErr;
 152       ASSERT_TRUE(Contents.size() > ExpectedEncoding.size());
 153       EXPECT_EQ(
 154           arrayRefFromStringRef(Contents.slice(0, ExpectedEncoding.size())),
 155           ExpectedEncoding);
 156       return;
 157     }
 158     llvm_unreachable(".debug_line not found");
 159   }
 160
 161   /// Check contents of .debug_line_str section
 162   void verifyDebugLineStrContents(const llvm::object::ObjectFile &E) {
 163     for (const llvm::object::SectionRef &Section : E.sections()) {
 164       Expected<StringRef> SectionNameOrErr = Section.getName();
 165       ASSERT_TRUE(static_cast<bool>(SectionNameOrErr));
 166       StringRef SectionName = *SectionNameOrErr;
 167       if (SectionName.empty() || SectionName != ".debug_line_str")
 168         continue;
 169       Expected<StringRef> ContentsOrErr = Section.getContents();
 170       ASSERT_TRUE(static_cast<bool>(ContentsOrErr));
 171       StringRef Contents = *ContentsOrErr;
 172       ASSERT_TRUE(Contents.contains("dir"));
 173       ASSERT_TRUE(Contents.contains("file"));
 174       ASSERT_TRUE(Contents.size() == 9);
 175       return;
 176     }
 177     llvm_unreachable(".debug_line_str not found");
 178   }
 179
 180   ///  Open ObjFileData as an object file and read its .debug_line section
 181   void readAndCheckDebugContents(StringRef ObjFileData,
 182                                      ArrayRef<uint8_t> Expected, uint8_t DwarfVersion) {
 183     std::unique_ptr<MemoryBuffer> MB =
 184         MemoryBuffer::getMemBuffer(ObjFileData, "", false);
 185     std::unique_ptr<object::Binary> Bin =
 186         cantFail(llvm::object::createBinary(MB->getMemBufferRef()));
 187     if (auto *E = dyn_cast<llvm::object::ELFObjectFileBase>(&*Bin)) {
 188       verifyDebugLineContents(*E, Expected);
 189       if (DwarfVersion >= 5)
 190         verifyDebugLineStrContents(*E);
 191       return;
 192     }
 193     llvm_unreachable("ELF object file not found");
 194   }
 195 };
 196 } // namespace
 197
 198 TEST_F(DwarfLineTableHeaders, TestDWARF4HeaderEmission) {
 199   if (!MRI)
 200     GTEST_SKIP();
 201
 202   SmallString<0> EmittedBinContents;
 203   raw_svector_ostream VecOS(EmittedBinContents);
 204   StreamerContext C = createStreamer(VecOS);
 205   constexpr uint8_t DwarfVersion = 4;
 206   C.Ctx->setDwarfVersion(DwarfVersion);
 207   emitDebugLineSection(C);
 208   C.Streamer->finish();
 209   readAndCheckDebugContents(
 210       EmittedBinContents.str(),
 211       {/*    Total length=*/0x30, 0, 0, 0,
 212        /*   DWARF version=*/DwarfVersion, 0,
 213        /* Prologue length=*/0x14, 0, 0, 0,
 214        /* min_inst_length=*/1,
 215        /*max_ops_per_inst=*/1,
 216        /* default_is_stmt=*/DWARF2_LINE_DEFAULT_IS_STMT,
 217        /*       line_base=*/static_cast<uint8_t>(-5),
 218        /*      line_range=*/14,
 219        /*     opcode_base=*/13}, DwarfVersion);
 220 }
 221
 222 TEST_F(DwarfLineTableHeaders, TestDWARF5HeaderEmission) {
 223   if (!MRI)
 224     GTEST_SKIP();
 225
 226   SmallString<0> EmittedBinContents;
 227   raw_svector_ostream VecOS(EmittedBinContents);
 228   StreamerContext C = createStreamer(VecOS);
 229   constexpr uint8_t DwarfVersion = 5;
 230   C.Ctx->setDwarfVersion(DwarfVersion);
 231   emitDebugLineSection(C);
 232   C.Streamer->finish();
 233   readAndCheckDebugContents(
 234       EmittedBinContents.str(),
 235       {/*    Total length=*/0x43, 0, 0, 0,
 236        /*   DWARF version=*/DwarfVersion, 0,
 237        /*        ptr size=*/8,
 238        /*         segment=*/0,
 239        /* Prologue length=*/0x25, 0, 0, 0,
 240        /* min_inst_length=*/1,
 241        /*max_ops_per_inst=*/1,
 242        /* default_is_stmt=*/DWARF2_LINE_DEFAULT_IS_STMT,
 243        /*       line_base=*/static_cast<uint8_t>(-5),
 244        /*      line_range=*/14,
 245        /*     opcode_base=*/13}, DwarfVersion);
 246 }