//===-- cc1as_main.cpp - Clang Assembler ---------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This is the entry point to the clang -cc1as functionality, which implements
// the direct interface to the LLVM MC based assembler.
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Driver/DriverDiagnostic.h"
#include "clang/Driver/Options.h"
#include "clang/Frontend/FrontendDiagnostic.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"
#include "clang/Frontend/Utils.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCParser/MCAsmParser.h"
#include "llvm/MC/MCParser/MCTargetAsmParser.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Support/Timer.h"
#include "llvm/Support/raw_ostream.h"
#include <memory>
#include <system_error>
using namespace clang;
using namespace clang::driver;
using namespace clang::driver::options;
using namespace llvm;
using namespace llvm::opt;
namespace {
/// Helper class for representing a single invocation of the assembler.
struct AssemblerInvocation {
/// @name Target Options
/// @{
/// The name of the target triple to assemble for.
std::string Triple;
/// If given, the name of the target CPU to determine which instructions
/// are legal.
std::string CPU;
/// The list of target specific features to enable or disable -- this should
/// be a list of strings starting with '+' or '-'.
std::vector<std::string> Features;
/// The list of symbol definitions.
std::vector<std::string> SymbolDefs;
/// @}
/// @name Language Options
/// @{
std::vector<std::string> IncludePaths;
unsigned NoInitialTextSection : 1;
unsigned SaveTemporaryLabels : 1;
unsigned GenDwarfForAssembly : 1;
unsigned RelaxELFRelocations : 1;
unsigned Dwarf64 : 1;
unsigned DwarfVersion;
std::string DwarfDebugFlags;
std::string DwarfDebugProducer;
std::string DebugCompilationDir;
std::map<const std::string, const std::string> DebugPrefixMap;
llvm::DebugCompressionType CompressDebugSections =
llvm::DebugCompressionType::None;
std::string MainFileName;
std::string SplitDwarfOutput;
/// @}
/// @name Frontend Options
/// @{
std::string InputFile;
std::vector<std::string> LLVMArgs;
std::string OutputPath;
enum FileType {
FT_Asm, ///< Assembly (.s) output, transliterate mode.
FT_Null, ///< No output, for timing purposes.
FT_Obj ///< Object file output.
};
FileType OutputType;
unsigned ShowHelp : 1;
unsigned ShowVersion : 1;
/// @}
/// @name Transliterate Options
/// @{
unsigned OutputAsmVariant;
unsigned ShowEncoding : 1;
unsigned ShowInst : 1;
/// @}
/// @name Assembler Options
/// @{
unsigned RelaxAll : 1;
unsigned NoExecStack : 1;
unsigned FatalWarnings : 1;
unsigned NoWarn : 1;
unsigned IncrementalLinkerCompatible : 1;
unsigned EmbedBitcode : 1;
/// The name of the relocation model to use.
std::string RelocationModel;
/// The ABI targeted by the backend. Specified using -target-abi. Empty
/// otherwise.
std::string TargetABI;
/// @}
public:
AssemblerInvocation() {
Triple = "";
NoInitialTextSection = 0;
InputFile = "-";
OutputPath = "-";
OutputType = FT_Asm;
OutputAsmVariant = 0;
ShowInst = 0;
ShowEncoding = 0;
RelaxAll = 0;
NoExecStack = 0;
FatalWarnings = 0;
NoWarn = 0;
IncrementalLinkerCompatible = 0;
Dwarf64 = 0;
DwarfVersion = 0;
EmbedBitcode = 0;
}
static bool CreateFromArgs(AssemblerInvocation &Res,
ArrayRef<const char *> Argv,
DiagnosticsEngine &Diags);
};
}
bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
ArrayRef<const char *> Argv,
DiagnosticsEngine &Diags) {
bool Success = true;
// Parse the arguments.
const OptTable &OptTbl = getDriverOptTable();
const unsigned IncludedFlagsBitmask = options::CC1AsOption;
unsigned MissingArgIndex, MissingArgCount;
InputArgList Args = OptTbl.ParseArgs(Argv, MissingArgIndex, MissingArgCount,
IncludedFlagsBitmask);
// Check for missing argument error.
if (MissingArgCount) {
Diags.Report(diag::err_drv_missing_argument)
<< Args.getArgString(MissingArgIndex) << MissingArgCount;
Success = false;
}
// Issue errors on unknown arguments.
for (const Arg *A : Args.filtered(OPT_UNKNOWN)) {
auto ArgString = A->getAsString(Args);
std::string Nearest;
if (OptTbl.findNearest(ArgString, Nearest, IncludedFlagsBitmask) > 1)
Diags.Report(diag::err_drv_unknown_argument) << ArgString;
else
Diags.Report(diag::err_drv_unknown_argument_with_suggestion)
<< ArgString << Nearest;
Success = false;
}
// Construct the invocation.
// Target Options
Opts.Triple = llvm::Triple::normalize(Args.getLastArgValue(OPT_triple));
Opts.CPU = std::string(Args.getLastArgValue(OPT_target_cpu));
Opts.Features = Args.getAllArgValues(OPT_target_feature);
// Use the default target triple if unspecified.
if (Opts.Triple.empty())
Opts.Triple = llvm::sys::getDefaultTargetTriple();
// Language Options
Opts.IncludePaths = Args.getAllArgValues(OPT_I);
Opts.NoInitialTextSection = Args.hasArg(OPT_n);
Opts.SaveTemporaryLabels = Args.hasArg(OPT_msave_temp_labels);
// Any DebugInfoKind implies GenDwarfForAssembly.
Opts.GenDwarfForAssembly = Args.hasArg(OPT_debug_info_kind_EQ);
if (const Arg *A = Args.getLastArg(OPT_compress_debug_sections_EQ)) {
Opts.CompressDebugSections =
llvm::StringSwitch<llvm::DebugCompressionType>(A->getValue())
.Case("none", llvm::DebugCompressionType::None)
.Case("zlib", llvm::DebugCompressionType::Z)
.Case("zlib-gnu", llvm::DebugCompressionType::GNU)
.Default(llvm::DebugCompressionType::None);
}
Opts.RelaxELFRelocations = Args.hasArg(OPT_mrelax_relocations);
if (auto *DwarfFormatArg = Args.getLastArg(OPT_gdwarf64, OPT_gdwarf32))
Opts.Dwarf64 = DwarfFormatArg->getOption().matches(OPT_gdwarf64);
Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
Opts.DwarfDebugFlags =
std::string(Args.getLastArgValue(OPT_dwarf_debug_flags));
Opts.DwarfDebugProducer =
std::string(Args.getLastArgValue(OPT_dwarf_debug_producer));
if (const Arg *A = Args.getLastArg(options::OPT_ffile_compilation_dir_EQ,
options::OPT_fdebug_compilation_dir_EQ))
Opts.DebugCompilationDir = A->getValue();
Opts.MainFileName = std::string(Args.getLastArgValue(OPT_main_file_name));
for (const auto &Arg : Args.getAllArgValues(OPT_fdebug_prefix_map_EQ)) {
auto Split = StringRef(Arg).split('=');
Opts.DebugPrefixMap.insert(
{std::string(Split.first), std::string(Split.second)});
}
// Frontend Options
if (Args.hasArg(OPT_INPUT)) {
bool First = true;
for (const Arg *A : Args.filtered(OPT_INPUT)) {
if (First) {
Opts.InputFile = A->getValue();
First = false;
} else {
Diags.Report(diag::err_drv_unknown_argument) << A->getAsString(Args);
Success = false;
}
}
}
Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
Opts.OutputPath = std::string(Args.getLastArgValue(OPT_o));
Opts.SplitDwarfOutput =
std::string(Args.getLastArgValue(OPT_split_dwarf_output));
if (Arg *A = Args.getLastArg(OPT_filetype)) {
StringRef Name = A->getValue();
unsigned OutputType = StringSwitch<unsigned>(Name)
.Case("asm", FT_Asm)
.Case("null", FT_Null)
.Case("obj", FT_Obj)
.Default(~0U);
if (OutputType == ~0U) {
Diags.Report(diag::err_drv_invalid_value) << A->getAsString(Args) << Name;
Success = false;
} else
Opts.OutputType = FileType(OutputType);
}
Opts.ShowHelp = Args.hasArg(OPT_help);
Opts.ShowVersion = Args.hasArg(OPT_version);
// Transliterate Options
Opts.OutputAsmVariant =
getLastArgIntValue(Args, OPT_output_asm_variant, 0, Diags);
Opts.ShowEncoding = Args.hasArg(OPT_show_encoding);
Opts.ShowInst = Args.hasArg(OPT_show_inst);
// Assemble Options
Opts.RelaxAll = Args.hasArg(OPT_mrelax_all);
Opts.NoExecStack = Args.hasArg(OPT_mno_exec_stack);
Opts.FatalWarnings = Args.hasArg(OPT_massembler_fatal_warnings);
Opts.NoWarn = Args.hasArg(OPT_massembler_no_warn);
Opts.RelocationModel =
std::string(Args.getLastArgValue(OPT_mrelocation_model, "pic"));
Opts.TargetABI = std::string(Args.getLastArgValue(OPT_target_abi));
Opts.IncrementalLinkerCompatible =
Args.hasArg(OPT_mincremental_linker_compatible);
Opts.SymbolDefs = Args.getAllArgValues(OPT_defsym);
// EmbedBitcode Option. If -fembed-bitcode is enabled, set the flag.
// EmbedBitcode behaves the same for all embed options for assembly files.
if (auto *A = Args.getLastArg(OPT_fembed_bitcode_EQ)) {
Opts.EmbedBitcode = llvm::StringSwitch<unsigned>(A->getValue())
.Case("all", 1)
.Case("bitcode", 1)
.Case("marker", 1)
.Default(0);
}
return Success;
}
static std::unique_ptr<raw_fd_ostream>
getOutputStream(StringRef Path, DiagnosticsEngine &Diags, bool Binary) {
// Make sure that the Out file gets unlinked from the disk if we get a
// SIGINT.
if (Path != "-")
sys::RemoveFileOnSignal(Path);
std::error_code EC;
auto Out = std::make_unique<raw_fd_ostream>(
Path, EC, (Binary ? sys::fs::OF_None : sys::fs::OF_TextWithCRLF));
if (EC) {
Diags.Report(diag::err_fe_unable_to_open_output) << Path << EC.message();
return nullptr;
}
return Out;
}
static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
DiagnosticsEngine &Diags) {
// Get the target specific parser.
std::string Error;
const Target *TheTarget = TargetRegistry::lookupTarget(Opts.Triple, Error);
if (!TheTarget)
return Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
ErrorOr<std::unique_ptr<MemoryBuffer>> Buffer =
MemoryBuffer::getFileOrSTDIN(Opts.InputFile, /*IsText=*/true);
if (std::error_code EC = Buffer.getError()) {
Error = EC.message();
return Diags.Report(diag::err_fe_error_reading) << Opts.InputFile;
}
SourceMgr SrcMgr;
// Tell SrcMgr about this buffer, which is what the parser will pick up.
unsigned BufferIndex = SrcMgr.AddNewSourceBuffer(std::move(*Buffer), SMLoc());
// Record the location of the include directories so that the lexer can find
// it later.
SrcMgr.setIncludeDirs(Opts.IncludePaths);
std::unique_ptr<MCRegisterInfo> MRI(TheTarget->createMCRegInfo(Opts.Triple));
assert(MRI && "Unable to create target register info!");
MCTargetOptions MCOptions;
std::unique_ptr<MCAsmInfo> MAI(
TheTarget->createMCAsmInfo(*MRI, Opts.Triple, MCOptions));
assert(MAI && "Unable to create target asm info!");
// Ensure MCAsmInfo initialization occurs before any use, otherwise sections
// may be created with a combination of default and explicit settings.
MAI->setCompressDebugSections(Opts.CompressDebugSections);
MAI->setRelaxELFRelocations(Opts.RelaxELFRelocations);
bool IsBinary = Opts.OutputType == AssemblerInvocation::FT_Obj;
if (Opts.OutputPath.empty())
Opts.OutputPath = "-";
std::unique_ptr<raw_fd_ostream> FDOS =
getOutputStream(Opts.OutputPath, Diags, IsBinary);
if (!FDOS)
return true;
std::unique_ptr<raw_fd_ostream> DwoOS;
if (!Opts.SplitDwarfOutput.empty())
DwoOS = getOutputStream(Opts.SplitDwarfOutput, Diags, IsBinary);
// Build up the feature string from the target feature list.
std::string FS = llvm::join(Opts.Features, ",");
std::unique_ptr<MCSubtargetInfo> STI(
TheTarget->createMCSubtargetInfo(Opts.Triple, Opts.CPU, FS));
assert(STI && "Unable to create subtarget info!");
MCContext Ctx(Triple(Opts.Triple), MAI.get(), MRI.get(), STI.get(), &SrcMgr,
&MCOptions);
bool PIC = false;
if (Opts.RelocationModel == "static") {
PIC = false;
} else if (Opts.RelocationModel == "pic") {
PIC = true;
} else {
assert(Opts.RelocationModel == "dynamic-no-pic" &&
"Invalid PIC model!");
PIC = false;
}
// FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
// MCObjectFileInfo needs a MCContext reference in order to initialize itself.
std::unique_ptr<MCObjectFileInfo> MOFI(
TheTarget->createMCObjectFileInfo(Ctx, PIC));
Ctx.setObjectFileInfo(MOFI.get());
if (Opts.SaveTemporaryLabels)
Ctx.setAllowTemporaryLabels(false);
if (Opts.GenDwarfForAssembly)
Ctx.setGenDwarfForAssembly(true);
if (!Opts.DwarfDebugFlags.empty())
Ctx.setDwarfDebugFlags(StringRef(Opts.DwarfDebugFlags));
if (!Opts.DwarfDebugProducer.empty())
Ctx.setDwarfDebugProducer(StringRef(Opts.DwarfDebugProducer));
if (!Opts.DebugCompilationDir.empty())
Ctx.setCompilationDir(Opts.DebugCompilationDir);
else {
// If no compilation dir is set, try to use the current directory.
SmallString<128> CWD;
if (!sys::fs::current_path(CWD))
Ctx.setCompilationDir(CWD);
}
if (!Opts.DebugPrefixMap.empty())
for (const auto &KV : Opts.DebugPrefixMap)
Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
if (!Opts.MainFileName.empty())
Ctx.setMainFileName(StringRef(Opts.MainFileName));
Ctx.setDwarfFormat(Opts.Dwarf64 ? dwarf::DWARF64 : dwarf::DWARF32);
Ctx.setDwarfVersion(Opts.DwarfVersion);
if (Opts.GenDwarfForAssembly)
Ctx.setGenDwarfRootFile(Opts.InputFile,
SrcMgr.getMemoryBuffer(BufferIndex)->getBuffer());
std::unique_ptr<MCStreamer> Str;
std::unique_ptr<MCInstrInfo> MCII(TheTarget->createMCInstrInfo());
assert(MCII && "Unable to create instruction info!");
raw_pwrite_stream *Out = FDOS.get();
std::unique_ptr<buffer_ostream> BOS;
MCOptions.MCNoWarn = Opts.NoWarn;
MCOptions.MCFatalWarnings = Opts.FatalWarnings;
MCOptions.ABIName = Opts.TargetABI;
// FIXME: There is a bit of code duplication with addPassesToEmitFile.
if (Opts.OutputType == AssemblerInvocation::FT_Asm) {
MCInstPrinter *IP = TheTarget->createMCInstPrinter(
llvm::Triple(Opts.Triple), Opts.OutputAsmVariant, *MAI, *MCII, *MRI);
std::unique_ptr<MCCodeEmitter> CE;
if (Opts.ShowEncoding)
CE.reset(TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
std::unique_ptr<MCAsmBackend> MAB(
TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
auto FOut = std::make_unique<formatted_raw_ostream>(*Out);
Str.reset(TheTarget->createAsmStreamer(
Ctx, std::move(FOut), /*asmverbose*/ true,
/*useDwarfDirectory*/ true, IP, std::move(CE), std::move(MAB),
Opts.ShowInst));
} else if (Opts.OutputType == AssemblerInvocation::FT_Null) {
Str.reset(createNullStreamer(Ctx));
} else {
assert(Opts.OutputType == AssemblerInvocation::FT_Obj &&
"Invalid file type!");
if (!FDOS->supportsSeeking()) {
BOS = std::make_unique<buffer_ostream>(*FDOS);
Out = BOS.get();
}
std::unique_ptr<MCCodeEmitter> CE(
TheTarget->createMCCodeEmitter(*MCII, *MRI, Ctx));
std::unique_ptr<MCAsmBackend> MAB(
TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
assert(MAB && "Unable to create asm backend!");
std::unique_ptr<MCObjectWriter> OW =
DwoOS ? MAB->createDwoObjectWriter(*Out, *DwoOS)
: MAB->createObjectWriter(*Out);
Triple T(Opts.Triple);
Str.reset(TheTarget->createMCObjectStreamer(
T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI,
Opts.RelaxAll, Opts.IncrementalLinkerCompatible,
/*DWARFMustBeAtTheEnd*/ true));
Str.get()->InitSections(Opts.NoExecStack);
}
// When -fembed-bitcode is passed to clang_as, a 1-byte marker
// is emitted in __LLVM,__asm section if the object file is MachO format.
if (Opts.EmbedBitcode && Ctx.getObjectFileType() == MCContext::IsMachO) {
MCSection *AsmLabel = Ctx.getMachOSection(
"__LLVM", "__asm", MachO::S_REGULAR, 4, SectionKind::getReadOnly());
Str.get()->SwitchSection(AsmLabel);
Str.get()->emitZeros(1);
}
// Assembly to object compilation should leverage assembly info.
Str->setUseAssemblerInfoForParsing(true);
bool Failed = false;
std::unique_ptr<MCAsmParser> Parser(
createMCAsmParser(SrcMgr, Ctx, *Str.get(), *MAI));
// FIXME: init MCTargetOptions from sanitizer flags here.
std::unique_ptr<MCTargetAsmParser> TAP(
TheTarget->createMCAsmParser(*STI, *Parser, *MCII, MCOptions));
if (!TAP)
Failed = Diags.Report(diag::err_target_unknown_triple) << Opts.Triple;
// Set values for symbols, if any.
for (auto &S : Opts.SymbolDefs) {
auto Pair = StringRef(S).split('=');
auto Sym = Pair.first;
auto Val = Pair.second;
int64_t Value;
// We have already error checked this in the driver.
Val.getAsInteger(0, Value);
Ctx.setSymbolValue(Parser->getStreamer(), Sym, Value);
}
if (!Failed) {
Parser->setTargetParser(*TAP.get());
Failed = Parser->Run(Opts.NoInitialTextSection);
}
return Failed;
}
static bool ExecuteAssembler(AssemblerInvocation &Opts,
DiagnosticsEngine &Diags) {
bool Failed = ExecuteAssemblerImpl(Opts, Diags);
// Delete output file if there were errors.
if (Failed) {
if (Opts.OutputPath != "-")
sys::fs::remove(Opts.OutputPath);
if (!Opts.SplitDwarfOutput.empty() && Opts.SplitDwarfOutput != "-")
sys::fs::remove(Opts.SplitDwarfOutput);
}
return Failed;
}
static void LLVMErrorHandler(void *UserData, const std::string &Message,
bool GenCrashDiag) {
DiagnosticsEngine &Diags = *static_cast<DiagnosticsEngine*>(UserData);
Diags.Report(diag::err_fe_error_backend) << Message;
// We cannot recover from llvm errors.
sys::Process::Exit(1);
}
int cc1as_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
// Initialize targets and assembly printers/parsers.
InitializeAllTargetInfos();
InitializeAllTargetMCs();
InitializeAllAsmParsers();
// Construct our diagnostic client.
IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
TextDiagnosticPrinter *DiagClient
= new TextDiagnosticPrinter(errs(), &*DiagOpts);
DiagClient->setPrefix("clang -cc1as");
IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
DiagnosticsEngine Diags(DiagID, &*DiagOpts, DiagClient);
// Set an error handler, so that any LLVM backend diagnostics go through our
// error handler.
ScopedFatalErrorHandler FatalErrorHandler
(LLVMErrorHandler, static_cast<void*>(&Diags));
// Parse the arguments.
AssemblerInvocation Asm;
if (!AssemblerInvocation::CreateFromArgs(Asm, Argv, Diags))
return 1;
if (Asm.ShowHelp) {
getDriverOptTable().printHelp(
llvm::outs(), "clang -cc1as [options] file...",
"Clang Integrated Assembler",
/*Include=*/driver::options::CC1AsOption, /*Exclude=*/0,
/*ShowAllAliases=*/false);
return 0;
}
// Honor -version.
//
// FIXME: Use a better -version message?
if (Asm.ShowVersion) {
llvm::cl::PrintVersionMessage();
return 0;
}
// Honor -mllvm.
//
// FIXME: Remove this, one day.
if (!Asm.LLVMArgs.empty()) {
unsigned NumArgs = Asm.LLVMArgs.size();
auto Args = std::make_unique<const char*[]>(NumArgs + 2);
Args[0] = "clang (LLVM option parsing)";
for (unsigned i = 0; i != NumArgs; ++i)
Args[i + 1] = Asm.LLVMArgs[i].c_str();
Args[NumArgs + 1] = nullptr;
llvm::cl::ParseCommandLineOptions(NumArgs + 1, Args.get());
}
// Execute the invocation, unless there were parsing errors.
bool Failed = Diags.hasErrorOccurred() || ExecuteAssembler(Asm, Diags);
// If any timers were active but haven't been destroyed yet, print their
// results now.
TimerGroup::printAll(errs());
TimerGroup::clearAll();
return !!Failed;
}
