//===-- BareMetal.cpp - Bare Metal ToolChain --------------------*- C++ -*-===//

//

// 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 "BareMetal.h"

#include "CommonArgs.h"

#include "InputInfo.h"

#include "Gnu.h"

#include "Arch/RISCV.h"

#include "clang/Driver/Compilation.h"

#include "clang/Driver/Driver.h"

#include "clang/Driver/DriverDiagnostic.h"

#include "clang/Driver/Options.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/VirtualFileSystem.h"

#include "llvm/Support/raw_ostream.h"

using namespace llvm::opt;

using namespace clang;

using namespace clang::driver;

using namespace clang::driver::tools;

using namespace clang::driver::toolchains;

static Multilib makeMultilib(StringRef commonSuffix) {

  return Multilib(commonSuffix, commonSuffix, commonSuffix);

}

static bool findRISCVMultilibs(const Driver &D,

                               const llvm::Triple &TargetTriple,

                               const ArgList &Args, DetectedMultilibs &Result) {

  Multilib::flags_list Flags;

  StringRef Arch = riscv::getRISCVArch(Args, TargetTriple);

  StringRef Abi = tools::riscv::getRISCVABI(Args, TargetTriple);

  if (TargetTriple.getArch() == llvm::Triple::riscv64) {

    Multilib Imac = makeMultilib("").flag("+march=rv64imac").flag("+mabi=lp64");

    Multilib Imafdc = makeMultilib("/rv64imafdc/lp64d")

                          .flag("+march=rv64imafdc")

                          .flag("+mabi=lp64d");

    // Multilib reuse

    bool UseImafdc =

        (Arch == "rv64imafdc") || 
(Arch == "rv64gc")54
; // gc => imafdc

    addMultilibFlag((Arch == "rv64imac"), "march=rv64imac", Flags);

    addMultilibFlag(UseImafdc, "march=rv64imafdc", Flags);

    addMultilibFlag(Abi == "lp64", "mabi=lp64", Flags);

    addMultilibFlag(Abi == "lp64d", "mabi=lp64d", Flags);

    Result.Multilibs = MultilibSet().Either(Imac, Imafdc);

    return Result.Multilibs.select(Flags, Result.SelectedMultilib);

  }

  if (TargetTriple.getArch() == llvm::Triple::riscv32) {

    Multilib Imac =

        makeMultilib("").flag("+march=rv32imac").flag("+mabi=ilp32");

    Multilib I =

        makeMultilib("/rv32i/ilp32").flag("+march=rv32i").flag("+mabi=ilp32");

    Multilib Im =

        makeMultilib("/rv32im/ilp32").flag("+march=rv32im").flag("+mabi=ilp32");

    Multilib Iac = makeMultilib("/rv32iac/ilp32")

                       .flag("+march=rv32iac")

                       .flag("+mabi=ilp32");

    Multilib Imafc = makeMultilib("/rv32imafc/ilp32f")

                         .flag("+march=rv32imafc")

                         .flag("+mabi=ilp32f");

    // Multilib reuse

    bool UseI = (Arch == "rv32i") || 
(Arch == "rv32ic")109
;    // ic => i

    bool UseIm = (Arch == "rv32im") || 
(Arch == "rv32imc")111
; // imc => im

    bool UseImafc = (Arch == "rv32imafc") || 
(Arch == "rv32imafdc")111
 ||

                    (Arch == "rv32gc"); // imafdc,gc => imafc

    addMultilibFlag(UseI, "march=rv32i", Flags);

    addMultilibFlag(UseIm, "march=rv32im", Flags);

    addMultilibFlag((Arch == "rv32iac"), "march=rv32iac", Flags);

    addMultilibFlag((Arch == "rv32imac"), "march=rv32imac", Flags);

    addMultilibFlag(UseImafc, "march=rv32imafc", Flags);

    addMultilibFlag(Abi == "ilp32", "mabi=ilp32", Flags);

    addMultilibFlag(Abi == "ilp32f", "mabi=ilp32f", Flags);

    Result.Multilibs = MultilibSet().Either(I, Im, Iac, Imac, Imafc);

    return Result.Multilibs.select(Flags, Result.SelectedMultilib);

  }

  return false;

}

BareMetal::BareMetal(const Driver &D, const llvm::Triple &Triple,

                           const ArgList &Args)

    : ToolChain(D, Triple, Args) {

  getProgramPaths().push_back(getDriver().getInstalledDir());

  if (getDriver().getInstalledDir() != getDriver().Dir)

    getProgramPaths().push_back(getDriver().Dir);

  findMultilibs(D, Triple, Args);

  SmallString<128> SysRoot(computeSysRoot());

  if (!SysRoot.empty()) {

    llvm::sys::path::append(SysRoot, "lib");

    getFilePaths().push_back(std::string(SysRoot));

  }

}

/// Is the triple {arm,thumb}-none-none-{eabi,eabihf} ?

static bool isARMBareMetal(const llvm::Triple &Triple) {

  if (Triple.getArch() != llvm::Triple::arm &&

      Triple.getArch() != llvm::Triple::thumb)

    return false;

  if (Triple.getVendor() != llvm::Triple::UnknownVendor)

    return false;

  if (Triple.getOS() != llvm::Triple::UnknownOS)

    return false;

  if (Triple.getEnvironment() != llvm::Triple::EABI &&

      Triple.getEnvironment() != llvm::Triple::EABIHF)

    return false;

  return true;

}

static bool isRISCVBareMetal(const llvm::Triple &Triple) {

  if (Triple.getArch() != llvm::Triple::riscv32 &&

      Triple.getArch() != llvm::Triple::riscv64)

    return false;

  if (Triple.getVendor() != llvm::Triple::UnknownVendor)

    return false;

  if (Triple.getOS() != llvm::Triple::UnknownOS)

    return false;

  return Triple.getEnvironmentName() == "elf";

}

void BareMetal::findMultilibs(const Driver &D, const llvm::Triple &Triple,

                              const ArgList &Args) {

  DetectedMultilibs Result;

  if (isRISCVBareMetal(Triple)) {

    if (findRISCVMultilibs(D, Triple, Args, Result)) {

      SelectedMultilib = Result.SelectedMultilib;

      Multilibs = Result.Multilibs;

    }

  }

}

bool BareMetal::handlesTarget(const llvm::Triple &Triple) {

  return isARMBareMetal(Triple) || 
isRISCVBareMetal(Triple)11.3k
;

}

Tool *BareMetal::buildLinker() const {

  return new tools::baremetal::Linker(*this);

}

std::string BareMetal::getCompilerRTPath() const { return getRuntimesDir(); }

std::string BareMetal::getCompilerRTBasename(const llvm::opt::ArgList &,

                                             StringRef, FileType, bool) const {

  return ("libclang_rt.builtins-" + getTriple().getArchName() + ".a").str();

}

std::string BareMetal::getRuntimesDir() const {

  SmallString<128> Dir(getDriver().ResourceDir);

  llvm::sys::path::append(Dir, "lib", "baremetal");

  Dir += SelectedMultilib.gccSuffix();

  return std::string(Dir.str());

}

std::string BareMetal::computeSysRoot() const {

  if (!getDriver().SysRoot.empty())

    return getDriver().SysRoot + SelectedMultilib.osSuffix();

  SmallString<128> SysRootDir;

  llvm::sys::path::append(SysRootDir, getDriver().Dir, "../lib/clang-runtimes",

                          getDriver().getTargetTriple());

  SysRootDir += SelectedMultilib.osSuffix();

  return std::string(SysRootDir);

}

void BareMetal::AddClangSystemIncludeArgs(const ArgList &DriverArgs,

                                          ArgStringList &CC1Args) const {

  if (DriverArgs.hasArg(options::OPT_nostdinc))

    return;

  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {

    SmallString<128> Dir(getDriver().ResourceDir);

    llvm::sys::path::append(Dir, "include");

    addSystemInclude(DriverArgs, CC1Args, Dir.str());

  }

  if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {

    SmallString<128> Dir(computeSysRoot());

    if (!Dir.empty()) {

      llvm::sys::path::append(Dir, "include");

      addSystemInclude(DriverArgs, CC1Args, Dir.str());

    }

  }

}

void BareMetal::addClangTargetOptions(const ArgList &DriverArgs,

                                      ArgStringList &CC1Args,

                                      Action::OffloadKind) const {

  CC1Args.push_back("-nostdsysteminc");

}

void BareMetal::AddClangCXXStdlibIncludeArgs(

    const ArgList &DriverArgs, ArgStringList &CC1Args) const {

  if (DriverArgs.hasArg(options::OPT_nostdinc) ||

      DriverArgs.hasArg(options::OPT_nostdlibinc) ||

      DriverArgs.hasArg(options::OPT_nostdincxx))

    return;

  std::string SysRoot(computeSysRoot());

  if (SysRoot.empty())

    return;

  switch (GetCXXStdlibType(DriverArgs)) {

  case ToolChain::CST_Libcxx: {

    SmallString<128> Dir(SysRoot);

    llvm::sys::path::append(Dir, "include", "c++", "v1");

    addSystemInclude(DriverArgs, CC1Args, Dir.str());

    break;

  }

  case ToolChain::CST_Libstdcxx: {

    SmallString<128> Dir(SysRoot);

    llvm::sys::path::append(Dir, "include", "c++");

    std::error_code EC;

    Generic_GCC::GCCVersion Version = {"", -1, -1, -1, "", "", ""};

    // Walk the subdirs, and find the one with the newest gcc version:

    for (llvm::vfs::directory_iterator

             LI = getDriver().getVFS().dir_begin(Dir.str(), EC),

             LE;

         !EC && LI != LE; 
LI = LI.increment(EC)5
) {

      StringRef VersionText = llvm::sys::path::filename(LI->path());

      auto CandidateVersion = Generic_GCC::GCCVersion::Parse(VersionText);

      if (CandidateVersion.Major == -1)

        continue;

      if (CandidateVersion <= Version)

        continue;

      Version = CandidateVersion;

    }

    if (Version.Major == -1)

      return;

    llvm::sys::path::append(Dir, Version.Text);

    addSystemInclude(DriverArgs, CC1Args, Dir.str());

    break;

  }

  }

}

void BareMetal::AddCXXStdlibLibArgs(const ArgList &Args,

                                    ArgStringList &CmdArgs) const {

  switch (GetCXXStdlibType(Args)) {

  case ToolChain::CST_Libcxx:

    CmdArgs.push_back("-lc++");

    CmdArgs.push_back("-lc++abi");

    break;

  case ToolChain::CST_Libstdcxx:

    CmdArgs.push_back("-lstdc++");

    CmdArgs.push_back("-lsupc++");

    break;

  }

  CmdArgs.push_back("-lunwind");

}

void BareMetal::AddLinkRuntimeLib(const ArgList &Args,

                                  ArgStringList &CmdArgs) const {

  ToolChain::RuntimeLibType RLT = GetRuntimeLibType(Args);

  switch (RLT) {

  case ToolChain::RLT_CompilerRT:

    CmdArgs.push_back(

        Args.MakeArgString("-lclang_rt.builtins-" + getTriple().getArchName()));

    return;

  case ToolChain::RLT_Libgcc:

    CmdArgs.push_back("-lgcc");

    return;

  }

  llvm_unreachable("Unhandled RuntimeLibType.");

}

void baremetal::Linker::ConstructJob(Compilation &C, const JobAction &JA,

                                     const InputInfo &Output,

                                     const InputInfoList &Inputs,

                                     const ArgList &Args,

                                     const char *LinkingOutput) const {

  ArgStringList CmdArgs;

  auto &TC = static_cast<const toolchains::BareMetal&>(getToolChain());

  AddLinkerInputs(TC, Inputs, Args, CmdArgs, JA);

  CmdArgs.push_back("-Bstatic");

  CmdArgs.push_back(Args.MakeArgString("-L" + TC.getRuntimesDir()));

  TC.AddFilePathLibArgs(Args, CmdArgs);

  Args.AddAllArgs(CmdArgs, {options::OPT_L, options::OPT_T_Group,

                            options::OPT_e, options::OPT_s, options::OPT_t,

                            options::OPT_Z_Flag, options::OPT_r});

  if (TC.ShouldLinkCXXStdlib(Args))

    TC.AddCXXStdlibLibArgs(Args, CmdArgs);

  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {

    CmdArgs.push_back("-lc");

    CmdArgs.push_back("-lm");

    TC.AddLinkRuntimeLib(Args, CmdArgs);

  }

  CmdArgs.push_back("-o");

  CmdArgs.push_back(Output.getFilename());

  C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),

                                         Args.MakeArgString(TC.GetLinkerPath()),

                                         CmdArgs, Inputs, Output));

}