//===--- ZOS.cpp - z/OS ToolChain Implementations ---------------*- 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 "ZOS.h"

#include "CommonArgs.h"

#include "clang/Driver/Compilation.h"

#include "clang/Driver/Options.h"

#include "llvm/Option/ArgList.h"

#include "llvm/Support/FileSystem.h"

#include "llvm/Support/VirtualFileSystem.h"

#include "llvm/Support/WithColor.h"

using namespace clang;

using namespace clang::driver;

using namespace clang::driver::tools;

using namespace clang::driver::toolchains;

using namespace llvm;

using namespace llvm::opt;

using namespace llvm::sys;

ZOS::ZOS(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)

    : ToolChain(D, Triple, Args) {}

ZOS::~ZOS() {}

void ZOS::addClangTargetOptions(const ArgList &DriverArgs,

                                ArgStringList &CC1Args,

                                Action::OffloadKind DeviceOffloadKind) const {

  // Pass "-faligned-alloc-unavailable" only when the user hasn't manually

  // enabled or disabled aligned allocations.

  if (!DriverArgs.hasArgNoClaim(options::OPT_faligned_allocation,

                                options::OPT_fno_aligned_allocation))

    CC1Args.push_back("-faligned-alloc-unavailable");

}

void zos::Assembler::ConstructJob(Compilation &C, const JobAction &JA,

                                  const InputInfo &Output,

                                  const InputInfoList &Inputs,

                                  const ArgList &Args,

                                  const char *LinkingOutput) const {

  ArgStringList CmdArgs;

  Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);

  // Specify assembler output file.

  assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");

  if (Output.isFilename()) {

    CmdArgs.push_back("-o");

    CmdArgs.push_back(Output.getFilename());

  }

  // Specify assembler input file.

  // The system assembler on z/OS takes exactly one input file. The driver is

  // expected to invoke as(1) separately for each assembler source input file.

  if (Inputs.size() != 1)

    llvm_unreachable("Invalid number of input files.");

  const InputInfo &II = Inputs[0];

  assert((II.isFilename() || II.isNothing()) && "Invalid input.");

  if (II.isFilename())

    CmdArgs.push_back(II.getFilename());

  const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));

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

                                         Exec, CmdArgs, Inputs));

}

static std::string getLEHLQ(const ArgList &Args) {

  if (Args.hasArg(options::OPT_mzos_hlq_le_EQ)) {

    Arg *LEHLQArg = Args.getLastArg(options::OPT_mzos_hlq_le_EQ);

    StringRef HLQ = LEHLQArg->getValue();

    if (!HLQ.empty())

      return HLQ.str();

  }

  return "CEE";

}

static std::string getClangHLQ(const ArgList &Args) {

  if (Args.hasArg(options::OPT_mzos_hlq_clang_EQ)) {

    Arg *ClangHLQArg = Args.getLastArg(options::OPT_mzos_hlq_clang_EQ);

    StringRef HLQ = ClangHLQArg->getValue();

    if (!HLQ.empty())

      return HLQ.str();

  }

  return getLEHLQ(Args);

}

static std::string getCSSHLQ(const ArgList &Args) {

  if (Args.hasArg(options::OPT_mzos_hlq_csslib_EQ)) {

    Arg *CsslibHLQArg = Args.getLastArg(options::OPT_mzos_hlq_csslib_EQ);

    StringRef HLQ = CsslibHLQArg->getValue();

    if (!HLQ.empty())

      return HLQ.str();

  }

  return "SYS1";

}

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

                               const InputInfo &Output,

                               const InputInfoList &Inputs, const ArgList &Args,

                               const char *LinkingOutput) const {

  const ZOS &ToolChain = static_cast<const ZOS &>(getToolChain());

  ArgStringList CmdArgs;

  const bool IsSharedLib =

      Args.hasFlag(options::OPT_shared, options::OPT_static, false);

  assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");

  if (Output.isFilename()) {

    CmdArgs.push_back("-o");

    CmdArgs.push_back(Output.getFilename());

  }

  SmallString<128> LinkerOptions;

  LinkerOptions = "AMODE=";

  LinkerOptions += "64";

  LinkerOptions += ",LIST";

  LinkerOptions += ",DYNAM=DLL";

  LinkerOptions += ",MSGLEVEL=4";

  LinkerOptions += ",CASE=MIXED";

  LinkerOptions += ",REUS=RENT";

  CmdArgs.push_back("-b");

  CmdArgs.push_back(Args.MakeArgString(LinkerOptions));

  if (!IsSharedLib) {

    CmdArgs.push_back("-e");

    CmdArgs.push_back("CELQSTRT");

    CmdArgs.push_back("-O");

    CmdArgs.push_back("CELQSTRT");

    CmdArgs.push_back("-u");

    CmdArgs.push_back("CELQMAIN");

  }

  // Generate side file if -shared option is present.

  if (IsSharedLib) {

    StringRef OutputName = Output.getFilename();

    // Strip away the last file suffix in presence from output name and add

    // a new .x suffix.

    size_t Suffix = OutputName.find_last_of('.');

    const char *SideDeckName =

        Args.MakeArgString(OutputName.substr(0, Suffix) + ".x");

    CmdArgs.push_back("-x");

    CmdArgs.push_back(SideDeckName);

  } else {

    // We need to direct side file to /dev/null to suppress linker warning when

    // the object file contains exported symbols, and -shared or

    // -Wl,-x<sidedeck>.x is not specified.

    CmdArgs.push_back("-x");

    CmdArgs.push_back("/dev/null");

  }

  // Add archive library search paths.

  Args.addAllArgs(CmdArgs, {options::OPT_L, options::OPT_u});

  ToolChain.AddFilePathLibArgs(Args, CmdArgs);

  // Specify linker input file(s)

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

  //  z/OS tool chain depends on LE data sets and the CSSLIB data set.

  //  These data sets can have different high level qualifiers (HLQs)

  //  as each installation can define them differently.

  std::string LEHLQ = getLEHLQ(Args);

  std::string CsslibHLQ = getCSSHLQ(Args);

  StringRef ld_env_var = StringRef(getenv("_LD_SYSLIB")).trim();

  if (ld_env_var.empty()) {

    CmdArgs.push_back("-S");

    CmdArgs.push_back(Args.MakeArgString("//'" + LEHLQ + ".SCEEBND2'"));

    CmdArgs.push_back("-S");

    CmdArgs.push_back(Args.MakeArgString("//'" + CsslibHLQ + ".CSSLIB'"));

  }

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

    ld_env_var = StringRef(getenv("_LD_SIDE_DECKS")).trim();

    if (ld_env_var.empty()) {

      CmdArgs.push_back(

          Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS001)'"));

      CmdArgs.push_back(

          Args.MakeArgString("//'" + LEHLQ + ".SCEELIB(CELQS003)'"));

    } else {

      SmallVector<StringRef> ld_side_deck;

      ld_env_var.split(ld_side_deck, ":");

      for (StringRef ld_loc : ld_side_deck) {

        CmdArgs.push_back((ld_loc.str()).c_str());

      }

    }

  }

  // Link libc++ library

  if (ToolChain.ShouldLinkCXXStdlib(Args)) {

    ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);

  }

  // Specify compiler-rt library path for linker

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

    AddRunTimeLibs(ToolChain, ToolChain.getDriver(), CmdArgs, Args);

  const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());

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

                                         Exec, CmdArgs, Inputs));

}

ToolChain::RuntimeLibType ZOS::GetDefaultRuntimeLibType() const {

  return ToolChain::RLT_CompilerRT;

}

ToolChain::CXXStdlibType ZOS::GetDefaultCXXStdlibType() const {

  return ToolChain::CST_Libcxx;

}

void ZOS::AddCXXStdlibLibArgs(const llvm::opt::ArgList &Args,

                              llvm::opt::ArgStringList &CmdArgs) const {

  switch (GetCXXStdlibType(Args)) {

  case ToolChain::CST_Libstdcxx:

    llvm::report_fatal_error("linking libstdc++ is unimplemented on z/OS");

    break;

  case ToolChain::CST_Libcxx: {

    std::string ClangHLQ = getClangHLQ(Args);

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXE)'"));

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXS)'"));

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXP)'"));

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQCXA)'"));

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQXLA)'"));

    CmdArgs.push_back(

        Args.MakeArgString("//'" + ClangHLQ + ".SCEELIB(CRTDQUNW)'"));

  } break;

  }

}

auto ZOS::buildAssembler() const -> Tool * { return new zos::Assembler(*this); }

auto ZOS::buildLinker() const -> Tool * { return new zos::Linker(*this); }

void ZOS::AddClangSystemIncludeArgs(const ArgList &DriverArgs,

                                    ArgStringList &CC1Args) const {

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

    return;

  const Driver &D = getDriver();

  // resolve ResourceDir

  std::string ResourceDir(D.ResourceDir);

  // zos_wrappers must take highest precedence

  // - <clang>/lib/clang/<ver>/include/zos_wrappers

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

    SmallString<128> P(ResourceDir);

    path::append(P, "include", "zos_wrappers");

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

    // - <clang>/lib/clang/<ver>/include

    SmallString<128> P2(ResourceDir);

    path::append(P2, "include");

    addSystemInclude(DriverArgs, CC1Args, P2.str());

  }

  // - /usr/include

  if (Arg *SysIncludeArg =

          DriverArgs.getLastArg(options::OPT_mzos_sys_include_EQ)) {

    StringRef SysInclude = SysIncludeArg->getValue();

    // fall back to the default include path

    if (!SysInclude.empty()) {

      // -mzos-sys-include opton can have colon separated

      // list of paths, so we need to parse the value.

      StringRef PathLE(SysInclude);

      size_t Colon = PathLE.find(':');

      if (Colon == StringRef::npos) {

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

        return;

      }

      while (Colon != StringRef::npos) {

        SmallString<128> P = PathLE.substr(0, Colon);

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

        PathLE = PathLE.substr(Colon + 1);

        Colon = PathLE.find(':');

      }

      if (PathLE.size())

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

      return;

    }

  }

  addSystemInclude(DriverArgs, CC1Args, "/usr/include");

}

void ZOS::TryAddIncludeFromPath(llvm::SmallString<128> Path,

                                const llvm::opt::ArgList &DriverArgs,

                                llvm::opt::ArgStringList &CC1Args) const {

  if (!getVFS().exists(Path)) {

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

      WithColor::warning(errs(), "Clang")

          << "ignoring nonexistent directory \"" << Path << "\"\n";

    if (!DriverArgs.hasArg(options::OPT__HASH_HASH_HASH))

      return;

  }

  addSystemInclude(DriverArgs, CC1Args, Path);

}

void ZOS::AddClangCXXStdlibIncludeArgs(

    const llvm::opt::ArgList &DriverArgs,

    llvm::opt::ArgStringList &CC1Args) const {

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

      DriverArgs.hasArg(options::OPT_nostdincxx) ||

      DriverArgs.hasArg(options::OPT_nostdlibinc))

    return;

  switch (GetCXXStdlibType(DriverArgs)) {

  case ToolChain::CST_Libcxx: {

    // <install>/bin/../include/c++/v1

    llvm::SmallString<128> InstallBin =

        llvm::StringRef(getDriver().getInstalledDir());

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

    TryAddIncludeFromPath(InstallBin, DriverArgs, CC1Args);

    break;

  }

  case ToolChain::CST_Libstdcxx:

    llvm::report_fatal_error(

        "picking up libstdc++ headers is unimplemented on z/OS");

    break;

  }

}