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//===- llvm/unittest/MC/DwarfLineTableHeaders.cpp -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/STLExtras.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/ToolOutputFile.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
class DwarfLineTableHeaders : public ::testing::Test {
public:
const char *TripleName = "x86_64-pc-linux";
std::unique_ptr<MCRegisterInfo> MRI;
std::unique_ptr<MCAsmInfo> MAI;
std::unique_ptr<const MCSubtargetInfo> STI;
const Target *TheTarget;
struct StreamerContext {
std::unique_ptr<MCObjectFileInfo> MOFI;
std::unique_ptr<MCContext> Ctx;
std::unique_ptr<const MCInstrInfo> MII;
std::unique_ptr<MCStreamer> Streamer;
};
DwarfLineTableHeaders() {
llvm::InitializeAllTargetInfos();
llvm::InitializeAllTargetMCs();
llvm::InitializeAllDisassemblers();
// If we didn't build x86, do not run the test.
std::string Error;
TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
if (!TheTarget)
return;
MRI.reset(TheTarget->createMCRegInfo(TripleName));
MCTargetOptions MCOptions;
MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
STI.reset(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
}
/// Create all data structures necessary to operate an assembler
StreamerContext createStreamer(raw_pwrite_stream &OS) {
StreamerContext Res;
Res.Ctx =
std::make_unique<MCContext>(Triple(TripleName), MAI.get(), MRI.get(),
/*MSTI=*/nullptr);
Res.MOFI.reset(TheTarget->createMCObjectFileInfo(*Res.Ctx,
/*PIC=*/false));
Res.Ctx->setObjectFileInfo(Res.MOFI.get());
Res.MII.reset(TheTarget->createMCInstrInfo());
MCCodeEmitter *MCE = TheTarget->createMCCodeEmitter(*Res.MII, *Res.Ctx);
MCAsmBackend *MAB =
TheTarget->createMCAsmBackend(*STI, *MRI, MCTargetOptions());
std::unique_ptr<MCObjectWriter> OW = MAB->createObjectWriter(OS);
Res.Streamer.reset(TheTarget->createMCObjectStreamer(
Triple(TripleName), *Res.Ctx, std::unique_ptr<MCAsmBackend>(MAB),
std::move(OW), std::unique_ptr<MCCodeEmitter>(MCE), *STI));
return Res;
}
/// Emit a .debug_line section with the given context parameters
void emitDebugLineSection(StreamerContext &C) {
MCContext &Ctx = *C.Ctx;
MCStreamer *TheStreamer = C.Streamer.get();
MCAssembler &Assembler =
static_cast<MCObjectStreamer *>(TheStreamer)->getAssembler();
TheStreamer->initSections(false, *STI);
// Create a mock function
MCSection *Section = C.MOFI->getTextSection();
Section->setHasInstructions(true);
TheStreamer->switchSection(Section);
TheStreamer->emitCFIStartProc(true);
// Create a mock dwarfloc
Ctx.setCurrentDwarfLoc(/*FileNo=*/0, /*Line=*/1, /*Column=*/1, /*Flags=*/0,
/*Isa=*/0, /*Discriminator=*/0);
MCDwarfLoc Loc = Ctx.getCurrentDwarfLoc();
MCSymbol *LineSym = Ctx.createTempSymbol();
// Set the value of the symbol to use for the MCDwarfLineEntry.
TheStreamer->emitLabel(LineSym);
TheStreamer->emitNops(4, 1, SMLoc(), *STI);
TheStreamer->emitCFIEndProc();
// Start emission of .debug_line
TheStreamer->switchSection(C.MOFI->getDwarfLineSection());
MCDwarfLineTableHeader Header;
MCDwarfLineTableParams Params = Assembler.getDWARFLinetableParams();
std::optional<MCDwarfLineStr> LineStr(std::nullopt);
if (Ctx.getDwarfVersion() >= 5) {
LineStr.emplace(Ctx);
Header.setRootFile("dir", "file", std::nullopt, std::nullopt);
}
MCSymbol *LineEndSym = Header.Emit(TheStreamer, Params, LineStr).second;
// Put out the line tables.
MCLineSection::MCDwarfLineEntryCollection LineEntries;
MCDwarfLineEntry LineEntry(LineSym, Loc);
LineEntries.push_back(LineEntry);
MCDwarfLineTable::emitOne(TheStreamer, Section, LineEntries);
TheStreamer->emitLabel(LineEndSym);
if (LineStr) {
SmallString<0> Data = LineStr->getFinalizedData();
TheStreamer->switchSection(TheStreamer->getContext()
.getObjectFileInfo()
->getDwarfLineStrSection());
TheStreamer->emitBinaryData(Data.str());
}
}
/// Check contents of .debug_line section
void verifyDebugLineContents(const llvm::object::ObjectFile &E,
ArrayRef<uint8_t> ExpectedEncoding) {
for (const llvm::object::SectionRef &Section : E.sections()) {
Expected<StringRef> SectionNameOrErr = Section.getName();
ASSERT_TRUE(static_cast<bool>(SectionNameOrErr));
StringRef SectionName = *SectionNameOrErr;
if (SectionName.empty() || SectionName != ".debug_line")
continue;
Expected<StringRef> ContentsOrErr = Section.getContents();
ASSERT_TRUE(static_cast<bool>(ContentsOrErr));
StringRef Contents = *ContentsOrErr;
ASSERT_TRUE(Contents.size() > ExpectedEncoding.size());
EXPECT_EQ(
arrayRefFromStringRef(Contents.slice(0, ExpectedEncoding.size())),
ExpectedEncoding);
return;
}
llvm_unreachable(".debug_line not found");
}
/// Check contents of .debug_line_str section
void verifyDebugLineStrContents(const llvm::object::ObjectFile &E) {
for (const llvm::object::SectionRef &Section : E.sections()) {
Expected<StringRef> SectionNameOrErr = Section.getName();
ASSERT_TRUE(static_cast<bool>(SectionNameOrErr));
StringRef SectionName = *SectionNameOrErr;
if (SectionName.empty() || SectionName != ".debug_line_str")
continue;
Expected<StringRef> ContentsOrErr = Section.getContents();
ASSERT_TRUE(static_cast<bool>(ContentsOrErr));
StringRef Contents = *ContentsOrErr;
ASSERT_TRUE(Contents.contains("dir"));
ASSERT_TRUE(Contents.contains("file"));
ASSERT_TRUE(Contents.size() == 9);
return;
}
llvm_unreachable(".debug_line_str not found");
}
/// Open ObjFileData as an object file and read its .debug_line section
void readAndCheckDebugContents(StringRef ObjFileData,
ArrayRef<uint8_t> Expected, uint8_t DwarfVersion) {
std::unique_ptr<MemoryBuffer> MB =
MemoryBuffer::getMemBuffer(ObjFileData, "", false);
std::unique_ptr<object::Binary> Bin =
cantFail(llvm::object::createBinary(MB->getMemBufferRef()));
if (auto *E = dyn_cast<llvm::object::ELFObjectFileBase>(&*Bin)) {
verifyDebugLineContents(*E, Expected);
if (DwarfVersion >= 5)
verifyDebugLineStrContents(*E);
return;
}
llvm_unreachable("ELF object file not found");
}
};
} // namespace
TEST_F(DwarfLineTableHeaders, TestDWARF4HeaderEmission) {
if (!MRI)
GTEST_SKIP();
SmallString<0> EmittedBinContents;
raw_svector_ostream VecOS(EmittedBinContents);
StreamerContext C = createStreamer(VecOS);
constexpr uint8_t DwarfVersion = 4;
C.Ctx->setDwarfVersion(DwarfVersion);
emitDebugLineSection(C);
C.Streamer->finish();
readAndCheckDebugContents(
EmittedBinContents.str(),
{/* Total length=*/0x30, 0, 0, 0,
/* DWARF version=*/DwarfVersion, 0,
/* Prologue length=*/0x14, 0, 0, 0,
/* min_inst_length=*/1,
/*max_ops_per_inst=*/1,
/* default_is_stmt=*/DWARF2_LINE_DEFAULT_IS_STMT,
/* line_base=*/static_cast<uint8_t>(-5),
/* line_range=*/14,
/* opcode_base=*/13}, DwarfVersion);
}
TEST_F(DwarfLineTableHeaders, TestDWARF5HeaderEmission) {
if (!MRI)
GTEST_SKIP();
SmallString<0> EmittedBinContents;
raw_svector_ostream VecOS(EmittedBinContents);
StreamerContext C = createStreamer(VecOS);
constexpr uint8_t DwarfVersion = 5;
C.Ctx->setDwarfVersion(DwarfVersion);
emitDebugLineSection(C);
C.Streamer->finish();
readAndCheckDebugContents(
EmittedBinContents.str(),
{/* Total length=*/0x43, 0, 0, 0,
/* DWARF version=*/DwarfVersion, 0,
/* ptr size=*/8,
/* segment=*/0,
/* Prologue length=*/0x25, 0, 0, 0,
/* min_inst_length=*/1,
/*max_ops_per_inst=*/1,
/* default_is_stmt=*/DWARF2_LINE_DEFAULT_IS_STMT,
/* line_base=*/static_cast<uint8_t>(-5),
/* line_range=*/14,
/* opcode_base=*/13}, DwarfVersion);
}
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