Hexagon.cpp

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//===--- Hexagon.cpp - Hexagon 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 "Hexagon.h"
#include "clang/Driver/CommonArgs.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Driver.h"
#include "clang/Driver/InputInfo.h"
#include "clang/Driver/MultilibBuilder.h"
#include "clang/Driver/SanitizerArgs.h"
#include "clang/Options/Options.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/VirtualFileSystem.h"
 
using namespace clang::driver;
using namespace clang::driver::tools;
using namespace clang::driver::toolchains;
using namespace clang;
using namespace llvm::opt;
 
// Default hvx-length for various versions.
static StringRef getDefaultHvxLength(StringRef HvxVer) {
  return llvm::StringSwitch<StringRef>(HvxVer)
      .Case("v60", "64b")
      .Case("v62", "64b")
      .Case("v65", "64b")
      .Default("128b");
}
 
static void handleHVXWarnings(const Driver &D, const ArgList &Args) {
  // Handle the unsupported values passed to mhvx-length.
  if (Arg *A = Args.getLastArg(options::OPT_mhexagon_hvx_length_EQ)) {
    StringRef Val = A->getValue();
    if (!Val.equals_insensitive("64b") && !Val.equals_insensitive("128b"))
      D.Diag(diag::err_drv_unsupported_option_argument)
          << A->getSpelling() << Val;
  }
}
 
// Handle hvx target features explicitly.
static void handleHVXTargetFeatures(const Driver &D, const ArgList &Args,
                                    std::vector<StringRef> &Features,
                                    StringRef Cpu, bool &HasHVX) {
  // Handle HVX warnings.
  handleHVXWarnings(D, Args);
 
  auto makeFeature = [&Args](Twine T, bool Enable) -> StringRef {
    const std::string &S = T.str();
    StringRef Opt(S);
    Opt.consume_back("=");
    if (Opt.starts_with("mno-"))
      Opt = Opt.drop_front(4);
    else if (Opt.starts_with("m"))
      Opt = Opt.drop_front(1);
    return Args.MakeArgString(Twine(Enable ? "+" : "-") + Twine(Opt));
  };
 
  auto withMinus = [](StringRef S) -> std::string {
    return "-" + S.str();
  };
 
  std::optional<std::string> HvxVer =
      toolchains::HexagonToolChain::GetHVXVersion(Args);
  HasHVX = HvxVer.has_value();
  if (HasHVX)
    Features.push_back(makeFeature(Twine("hvx") + *HvxVer, true));
  else {
    if (Arg *A = Args.getLastArg(options::OPT_mno_hexagon_hvx)) {
      // If there was an explicit -mno-hvx, add -hvx to target features.
      Features.push_back(makeFeature(A->getOption().getName(), false));
    }
  }
 
  StringRef HvxLen =
      getDefaultHvxLength(HasHVX ? StringRef(*HvxVer) : StringRef(""));
 
  // Handle -mhvx-length=.
  if (Arg *A = Args.getLastArg(options::OPT_mhexagon_hvx_length_EQ)) {
    // These flags are valid only if HVX in enabled.
    if (!HasHVX)
      D.Diag(diag::err_drv_needs_hvx) << withMinus(A->getOption().getName());
    else if (A->getOption().matches(options::OPT_mhexagon_hvx_length_EQ))
      HvxLen = A->getValue();
  }
 
  if (HasHVX) {
    StringRef L = makeFeature(Twine("hvx-length") + HvxLen.lower(), true);
    Features.push_back(L);
  }
 
  unsigned HvxVerNum = 0;
  // getAsInteger returns 'true' on error.
  if (HasHVX) {
    StringRef HvxVerRef(*HvxVer);
    if (HvxVerRef.size() <= 1 ||
        HvxVerRef.drop_front(1).getAsInteger(10, HvxVerNum))
      HvxVerNum = 0;
  }
 
  // Handle HVX floating point flags.
  auto checkFlagHvxVersion =
      [&](auto FlagOn, auto FlagOnWithModes, auto FlagOff, bool CheckMode,
          unsigned MinVerNum) -> std::optional<StringRef> {
    // Return an std::optional<StringRef>:
    // - std::nullopt indicates a verification failure, or that the flag was not
    //   present in Args.
    // - Otherwise the returned value is that name of the feature to add
    //   to Features.
    Arg *A = Args.getLastArg(FlagOn, FlagOnWithModes, FlagOff);
    if (!A)
      return std::nullopt;
 
    StringRef OptName = A->getOption().getName();
    if (A->getOption().matches(FlagOff))
      return makeFeature(OptName, false);
 
    if (!HasHVX) {
      D.Diag(diag::err_drv_needs_hvx) << withMinus(OptName);
      return std::nullopt;
    }
    if (HvxVerNum < MinVerNum) {
      D.Diag(diag::err_drv_needs_hvx_version)
          << withMinus(OptName) << ("v" + std::to_string(HvxVerNum));
      return std::nullopt;
    }
 
    if (CheckMode && A->getOption().matches(FlagOnWithModes)) {
      bool ValidMode =
          llvm::StringSwitch<bool>(StringRef(A->getValue()).lower())
              .Cases({"strict-ieee", "ieee", "lossy", "legacy"}, true)
              .Default(false);
      if (!ValidMode)
        D.Diag(diag::err_drv_invalid_value)
            << A->getAsString(Args) << A->getValue();
    }
    return makeFeature(OptName, true);
  };
 
  if (auto F = checkFlagHvxVersion(
          options::OPT_mhexagon_hvx_qfloat, options::OPT_mhexagon_hvx_qfloat_EQ,
          options::OPT_mno_hexagon_hvx_qfloat, /*CheckMode=*/true, 68)) {
    Features.push_back(*F);
  }
  if (auto F = checkFlagHvxVersion(
          options::OPT_mhexagon_hvx_ieee_fp, options::OPT_mhexagon_hvx_ieee_fp,
          options::OPT_mno_hexagon_hvx_ieee_fp, /*CheckMode=*/false, 68)) {
    Features.push_back(*F);
  }
 
  // On v79 and above, there is no IEEE hardware. Treat -mhvx-ieee-fp
  // as "qfloat mode ieee".
  if (HvxVerNum >= 79 && Args.getLastArg(options::OPT_mhexagon_hvx_ieee_fp))
    Features.push_back("+hvx-qfloat");
}
 
// Hexagon target features.
void hexagon::getHexagonTargetFeatures(const Driver &D,
                                       const llvm::Triple &Triple,
                                       const ArgList &Args,
                                       std::vector<StringRef> &Features) {
  handleTargetFeaturesGroup(D, Triple, Args, Features,
                            options::OPT_m_hexagon_Features_Group);
 
  bool UseLongCalls = false;
  if (Arg *A = Args.getLastArg(options::OPT_mlong_calls,
                               options::OPT_mno_long_calls)) {
    if (A->getOption().matches(options::OPT_mlong_calls))
      UseLongCalls = true;
  }
 
  Features.push_back(UseLongCalls ? "+long-calls" : "-long-calls");
 
  bool HasHVX = false;
  StringRef Cpu(toolchains::HexagonToolChain::GetTargetCPUVersion(Args));
  // 't' in Cpu denotes tiny-core micro-architecture. For now, the co-processors
  // have no dependency on micro-architecture.
  const bool TinyCore = Cpu.contains('t');
 
  if (TinyCore)
    Cpu = Cpu.take_front(Cpu.size() - 1);
 
  handleHVXTargetFeatures(D, Args, Features, Cpu, HasHVX);
 
  if (HexagonToolChain::isAutoHVXEnabled(Args) && !HasHVX)
    D.Diag(diag::warn_drv_needs_hvx) << "auto-vectorization";
}
 
// Hexagon tools start.
void hexagon::Assembler::RenderExtraToolArgs(const JobAction &JA,
                                             ArgStringList &CmdArgs) const {
}
 
void hexagon::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                      const InputInfo &Output,
                                      const InputInfoList &Inputs,
                                      const ArgList &Args,
                                      const char *LinkingOutput) const {
  claimNoWarnArgs(Args);
 
  auto &HTC = static_cast<const toolchains::HexagonToolChain&>(getToolChain());
  const Driver &D = HTC.getDriver();
  ArgStringList CmdArgs;
 
  CmdArgs.push_back("--arch=hexagon");
 
  RenderExtraToolArgs(JA, CmdArgs);
 
  const char *AsName = "llvm-mc";
  CmdArgs.push_back("-filetype=obj");
  CmdArgs.push_back(Args.MakeArgString(
      "-mcpu=hexagon" +
      toolchains::HexagonToolChain::GetTargetCPUVersion(Args)));
 
  if (std::get<0>(ParsePICArgs(HTC, Args)) == llvm::Reloc::PIC_)
    CmdArgs.push_back("-position-independent");
 
  addSanitizerRuntimes(HTC, Args, CmdArgs, C);
 
  assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");
  if (Output.isFilename()) {
    CmdArgs.push_back("-o");
    CmdArgs.push_back(Output.getFilename());
  } else {
    CmdArgs.push_back("-fsyntax-only");
  }
 
  if (Arg *A = Args.getLastArg(options::OPT_mhexagon_hvx_ieee_fp,
                               options::OPT_mno_hexagon_hvx_ieee_fp)) {
    if (A->getOption().matches(options::OPT_mhexagon_hvx_ieee_fp))
      CmdArgs.push_back("-mhvx-ieee-fp");
  }
 
  if (auto G = toolchains::HexagonToolChain::getSmallDataThreshold(Args)) {
    CmdArgs.push_back(Args.MakeArgString("-gpsize=" + Twine(*G)));
  }
 
  Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA, options::OPT_Xassembler);
 
  // Only pass -x if gcc will understand it; otherwise hope gcc
  // understands the suffix correctly. The main use case this would go
  // wrong in is for linker inputs if they happened to have an odd
  // suffix; really the only way to get this to happen is a command
  // like '-x foobar a.c' which will treat a.c like a linker input.
  //
  // FIXME: For the linker case specifically, can we safely convert
  // inputs into '-Wl,' options?
  for (const auto &II : Inputs) {
    // Don't try to pass LLVM or AST inputs to a generic gcc.
    if (types::isLLVMIR(II.getType()))
      D.Diag(clang::diag::err_drv_no_linker_llvm_support)
          << HTC.getTripleString();
    else if (II.getType() == types::TY_AST)
      D.Diag(clang::diag::err_drv_no_ast_support)
          << HTC.getTripleString();
    else if (II.getType() == types::TY_ModuleFile)
      D.Diag(diag::err_drv_no_module_support)
          << HTC.getTripleString();
 
    if (II.isFilename())
      CmdArgs.push_back(II.getFilename());
    else
      // Don't render as input, we need gcc to do the translations.
      // FIXME: What is this?
      II.getInputArg().render(Args, CmdArgs);
  }
 
  auto *Exec = Args.MakeArgString(HTC.GetProgramPath(AsName));
  C.addCommand(std::make_unique<Command>(JA, *this,
                                         ResponseFileSupport::AtFileCurCP(),
                                         Exec, CmdArgs, Inputs, Output));
}
 
void hexagon::Linker::RenderExtraToolArgs(const JobAction &JA,
                                          ArgStringList &CmdArgs) const {
}
 
static void
constructHexagonLinkArgs(Compilation &C, const JobAction &JA,
                         const toolchains::HexagonToolChain &HTC,
                         const InputInfo &Output, const InputInfoList &Inputs,
                         const ArgList &Args, ArgStringList &CmdArgs,
                         const char *LinkingOutput) {
 
  const Driver &D = HTC.getDriver();
 
  //----------------------------------------------------------------------------
  //
  //----------------------------------------------------------------------------
  bool IsStatic = Args.hasArg(options::OPT_static);
  bool IsShared = Args.hasArg(options::OPT_shared);
  bool IsPIE = Args.hasFlag(options::OPT_pie, options::OPT_no_pie,
                            HTC.isPIEDefault(Args));
  bool IncStdLib = !Args.hasArg(options::OPT_nostdlib);
  bool IncStartFiles = !Args.hasArg(options::OPT_nostartfiles);
  bool IncDefLibs = !Args.hasArg(options::OPT_nodefaultlibs);
  bool UseLLD = false;
  const char *Exec = Args.MakeArgString(HTC.GetLinkerPath(&UseLLD));
  UseLLD = UseLLD || llvm::sys::path::filename(Exec).ends_with("ld.lld") ||
           llvm::sys::path::stem(Exec).ends_with("ld.lld");
  bool UseShared = IsShared && !IsStatic;
  StringRef CpuVer = toolchains::HexagonToolChain::GetTargetCPUVersion(Args);
 
  bool NeedsSanitizerDeps = addSanitizerRuntimes(HTC, Args, CmdArgs, C);
  bool NeedsXRayDeps = addXRayRuntime(HTC, Args, CmdArgs);
 
  //----------------------------------------------------------------------------
  // Silence warnings for various options
  //----------------------------------------------------------------------------
  Args.ClaimAllArgs(options::OPT_g_Group);
  Args.ClaimAllArgs(options::OPT_emit_llvm);
  Args.ClaimAllArgs(options::OPT_w); // Other warning options are already
                                     // handled somewhere else.
  Args.ClaimAllArgs(options::OPT_static_libgcc);
 
  CmdArgs.push_back("--eh-frame-hdr");
  //----------------------------------------------------------------------------
  //
  //----------------------------------------------------------------------------
  if (Args.hasArg(options::OPT_s))
    CmdArgs.push_back("-s");
 
  if (Args.hasArg(options::OPT_r))
    CmdArgs.push_back("-r");
 
  for (const auto &Opt : HTC.ExtraOpts)
    CmdArgs.push_back(Opt.c_str());
 
  if (!UseLLD) {
    CmdArgs.push_back("-march=hexagon");
    CmdArgs.push_back(Args.MakeArgString("-mcpu=hexagon" + CpuVer));
  }
 
  if (IsShared) {
    CmdArgs.push_back("-shared");
    // The following should be the default, but doing as hexagon-gcc does.
    CmdArgs.push_back("-call_shared");
  }
 
  if (IsStatic)
    CmdArgs.push_back("-static");
 
  if (IsPIE && !IsShared && !Args.hasArg(options::OPT_r))
    CmdArgs.push_back("-pie");
 
  if (auto G = toolchains::HexagonToolChain::getSmallDataThreshold(Args))
    CmdArgs.push_back(Args.MakeArgString("-G" + Twine(*G)));
 
  CmdArgs.push_back("-o");
  CmdArgs.push_back(Output.getFilename());
 
  if (HTC.getTriple().isMusl()) {
    if (!Args.hasArg(options::OPT_shared, options::OPT_static, options::OPT_r))
      CmdArgs.push_back("-dynamic-linker=/lib/ld-musl-hexagon.so.1");
 
    StringRef MLSuffix;
    if (!HTC.getSelectedMultilibs().empty() &&
        !HTC.getSelectedMultilibs().back().isDefault())
      MLSuffix = HTC.getSelectedMultilibs().back().gccSuffix();
    auto StartFile = [&](StringRef Name) -> std::string {
      return D.SysRoot + "/usr/lib" + MLSuffix.str() + "/" + Name.str();
    };
 
    if (!Args.hasArg(options::OPT_shared, options::OPT_nostartfiles,
                     options::OPT_nostdlib, options::OPT_r)) {
      if (IsStatic && IsPIE)
        CmdArgs.push_back(Args.MakeArgString(StartFile("rcrt1.o")));
      else
        CmdArgs.push_back(Args.MakeArgString(StartFile("crt1.o")));
    } else if (Args.hasArg(options::OPT_shared) &&
               !Args.hasArg(options::OPT_nostartfiles, options::OPT_nostdlib,
                            options::OPT_r))
      CmdArgs.push_back(Args.MakeArgString(StartFile("crti.o")));
 
    if (!MLSuffix.empty()) {
      CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + D.SysRoot +
                                           "/usr/lib" + MLSuffix));
    }
    CmdArgs.push_back(
        Args.MakeArgString(StringRef("-L") + D.SysRoot + "/usr/lib"));
    Args.addAllArgs(CmdArgs, {options::OPT_T_Group, options::OPT_s,
                              options::OPT_t, options::OPT_u_Group});
    AddLinkerInputs(HTC, Inputs, Args, CmdArgs, JA);
 
    if (auto LTO = HTC.getLTOMode(Args); LTO != LTOK_None)
      addLTOOptions(HTC, Args, CmdArgs, Output, Inputs, LTO == LTOK_Thin);
 
    ToolChain::UnwindLibType UNW = HTC.GetUnwindLibType(Args);
 
    if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
      if (NeedsSanitizerDeps) {
        linkSanitizerRuntimeDeps(HTC, Args, CmdArgs);
 
        if (UNW != ToolChain::UNW_None)
          CmdArgs.push_back("-lunwind");
      }
      if (NeedsXRayDeps)
        linkXRayRuntimeDeps(HTC, Args, CmdArgs);
 
      if (!Args.hasArg(options::OPT_nolibc))
        CmdArgs.push_back("-lc");
      CmdArgs.push_back("-lclang_rt.builtins-hexagon");
    }
    if (D.CCCIsCXX()) {
      if (HTC.ShouldLinkCXXStdlib(Args))
        HTC.AddCXXStdlibLibArgs(Args, CmdArgs);
    }
    const ToolChain::path_list &LibPaths = HTC.getFilePaths();
    for (const auto &LibPath : LibPaths)
      CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
    Args.ClaimAllArgs(options::OPT_L);
    return;
  }
 
  //----------------------------------------------------------------------------
  // moslib
  //----------------------------------------------------------------------------
  std::vector<std::string> OsLibs;
  bool HasStandalone = false;
  for (const Arg *A : Args.filtered(options::OPT_moslib_EQ)) {
    A->claim();
    OsLibs.emplace_back(A->getValue());
    HasStandalone = HasStandalone || (OsLibs.back() == "standalone");
  }
  if (OsLibs.empty()) {
    OsLibs.push_back("standalone");
    HasStandalone = true;
  }
 
  //----------------------------------------------------------------------------
  // Start Files
  //----------------------------------------------------------------------------
  SmallString<128> LibraryDir;
  HTC.getLibraryDir(Args, LibraryDir);
 
  if (IncStdLib && IncStartFiles) {
    if (HTC.GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
      SmallString<128> Crt0 = LibraryDir;
      if (HTC.getTriple().isOSH2()) {
        llvm::sys::path::append(Crt0, "crt0-noflash-hosted.o");
        CmdArgs.push_back(Args.MakeArgString(Crt0));
      } else if (HTC.getTriple().isOSUnknown()) {
        llvm::sys::path::append(Crt0, "crt0-semihost.o");
        CmdArgs.push_back(Args.MakeArgString(Crt0));
      } else if (HTC.getTriple().isOSQurt()) {
        // QURT provides its own crt0.
      }
      // Known OS other than H2/QURT: no semihost crt0; OS provides its own.
    } else {
      if (!IsShared) {
        if (HasStandalone) {
          SmallString<128> Crt0SA = LibraryDir;
          llvm::sys::path::append(Crt0SA, "crt0_standalone.o");
          CmdArgs.push_back(Args.MakeArgString(Crt0SA));
        }
        SmallString<128> Crt0 = LibraryDir;
        llvm::sys::path::append(Crt0, "crt0.o");
        CmdArgs.push_back(Args.MakeArgString(Crt0));
      }
    }
    if (HTC.GetCStdlibType(Args) != ToolChain::CST_Picolibc) {
      SmallString<128> Init = LibraryDir;
      llvm::sys::path::append(Init, UseShared ? "initS.o" : "init.o");
      CmdArgs.push_back(Args.MakeArgString(Init));
    }
  }
 
  //----------------------------------------------------------------------------
  // Library Search Paths
  //----------------------------------------------------------------------------
  const ToolChain::path_list &LibPaths = HTC.getFilePaths();
  for (const auto &LibPath : LibPaths)
    CmdArgs.push_back(Args.MakeArgString(StringRef("-L") + LibPath));
  Args.ClaimAllArgs(options::OPT_L);
 
  //----------------------------------------------------------------------------
  //
  //----------------------------------------------------------------------------
  Args.addAllArgs(CmdArgs, {options::OPT_T_Group, options::OPT_s,
                            options::OPT_t, options::OPT_u_Group});
 
  AddLinkerInputs(HTC, Inputs, Args, CmdArgs, JA);
 
  if (auto LTO = HTC.getLTOMode(Args); LTO != LTOK_None)
    addLTOOptions(HTC, Args, CmdArgs, Output, Inputs, LTO == LTOK_Thin);
 
  //----------------------------------------------------------------------------
  // Libraries
  //----------------------------------------------------------------------------
  if (IncStdLib && IncDefLibs) {
    if (D.CCCIsCXX()) {
      if (HTC.ShouldLinkCXXStdlib(Args))
        HTC.AddCXXStdlibLibArgs(Args, CmdArgs);
      CmdArgs.push_back("-lm");
    }
 
    CmdArgs.push_back("--start-group");
 
    if (!IsShared) {
      if (HTC.GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
        if (HTC.getTriple().isOSH2()) {
          CmdArgs.push_back("-lh2");
          CmdArgs.push_back("-lsyscall_wrapper");
        } else if (HTC.getTriple().isOSUnknown()) {
          CmdArgs.push_back("-lsemihost");
        }
        // Known OS other than H2: no semihost lib; OS provides its own.
      } else {
        for (StringRef Lib : OsLibs)
          CmdArgs.push_back(Args.MakeArgString("-l" + Lib));
      }
      if (!Args.hasArg(options::OPT_nolibc))
        CmdArgs.push_back("-lc");
    }
    if (HTC.GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
      if (HTC.GetRuntimeLibType(Args) == ToolChain::RLT_CompilerRT)
        CmdArgs.push_back("-lclang_rt.builtins");
      else
        CmdArgs.push_back("-lgcc");
    } else {
      CmdArgs.push_back("-lgcc");
    }
 
    CmdArgs.push_back("--end-group");
  }
 
  //----------------------------------------------------------------------------
  // End files
  //----------------------------------------------------------------------------
  if (IncStdLib && IncStartFiles) {
    if (HTC.GetCStdlibType(Args) != ToolChain::CST_Picolibc) {
      SmallString<128> Fini = LibraryDir;
      llvm::sys::path::append(Fini, UseShared ? "finiS.o" : "fini.o");
      CmdArgs.push_back(Args.MakeArgString(Fini));
    }
  }
}
 
void hexagon::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                   const InputInfo &Output,
                                   const InputInfoList &Inputs,
                                   const ArgList &Args,
                                   const char *LinkingOutput) const {
  auto &HTC = static_cast<const toolchains::HexagonToolChain&>(getToolChain());
 
  ArgStringList CmdArgs;
  constructHexagonLinkArgs(C, JA, HTC, Output, Inputs, Args, CmdArgs,
                           LinkingOutput);
 
  const char *Exec = Args.MakeArgString(HTC.GetLinkerPath());
  C.addCommand(std::make_unique<Command>(JA, *this,
                                         ResponseFileSupport::AtFileCurCP(),
                                         Exec, CmdArgs, Inputs, Output));
}
// Hexagon tools end.
 
/// Hexagon Toolchain
 
std::string HexagonToolChain::getHexagonTargetDir(
      const std::string &InstalledDir,
      const SmallVectorImpl<std::string> &PrefixDirs) const {
  const Driver &D = getDriver();
 
  // Locate the rest of the toolchain ...
  for (auto &I : PrefixDirs)
    if (D.getVFS().exists(I))
      return I;
 
  SmallString<128> Dir(InstalledDir);
  llvm::sys::path::append(Dir, "..", "target");
  return std::string(Dir);
}
 
SmallString<128>
HexagonToolChain::getEffectiveSysRoot(const ArgList &Args) const {
  const Driver &D = getDriver();
  // The user-specified `--sysroot` always takes precedence.
  if (!D.SysRoot.empty())
    return SmallString<128>(D.SysRoot);
  SmallString<128> Dir(getHexagonTargetDir(D.Dir, D.PrefixDirs));
  // For Picolibc, use picolibc/<triple> with no fallback.
  if (GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
    llvm::sys::path::append(Dir, "picolibc", getTripleString());
    return Dir;
  }
  // Otherwise, try a triple subdirectory first, then fall back to "hexagon".
  llvm::sys::path::append(Dir, getTripleString());
  if (getVFS().exists(Dir))
    return Dir;
  Dir = getHexagonTargetDir(D.Dir, D.PrefixDirs);
  llvm::sys::path::append(Dir, "hexagon");
  return Dir;
}
 
void HexagonToolChain::getLibraryDir(const ArgList &Args,
                                     llvm::SmallString<128> &Dir) const {
  bool IsLinuxMusl = getTriple().isMusl() && getTriple().isOSLinux();
  const llvm::SmallString<128> SysRoot = getEffectiveSysRoot(Args);
  // Linux toolchain uses "usr/lib" but it also should accept "lib" in case an
  // external sysroot is used. Similar logic is for include paths.
  if (IsLinuxMusl) {
    Dir = SysRoot;
    llvm::sys::path::append(Dir, "usr", "lib");
  }
  if (!IsLinuxMusl || !getVFS().exists(Dir)) {
    Dir = SysRoot;
    llvm::sys::path::append(Dir, "lib");
  }
  std::string CpuVer = GetTargetCPUVersion(Args).str();
  bool IsPicolibc = GetCStdlibType(Args) == ToolChain::CST_Picolibc;
  bool IsG0 =
      toolchains::HexagonToolChain::getSmallDataThreshold(Args).value_or(1) ==
      0;
  bool IsStatic = Args.hasArg(options::OPT_static);
  bool IsShared = Args.hasArg(options::OPT_shared);
  bool IsPic = Args.hasArg(options::OPT_fpic, options::OPT_fPIC);
  if (IsPicolibc) {
    // Flat layout: lib/v68-G0-pic, lib/v68-G0, lib/v68
    std::string Variant = CpuVer;
    if (IsG0)
      Variant += "-G0";
    if (IsPic || IsShared)
      Variant += "-pic";
    llvm::sys::path::append(Dir, Variant);
  } else {
    // Nested layout (non-Picolibc): lib/v68/G0/pic
    llvm::sys::path::append(Dir, CpuVer);
    if (IsG0)
      llvm::sys::path::append(Dir, "G0");
    if (IsShared && !IsStatic)
      llvm::sys::path::append(Dir, "pic");
  }
}
 
void HexagonToolChain::getBaseIncludeDir(const ArgList &Args,
                                         llvm::SmallString<128> &Dir) const {
  bool IsLinuxMusl = getTriple().isMusl() && getTriple().isOSLinux();
  const llvm::SmallString<128> SysRoot = getEffectiveSysRoot(Args);
  if (IsLinuxMusl) {
    Dir = SysRoot;
    llvm::sys::path::append(Dir, "usr", "include");
  }
  if (!IsLinuxMusl || !getVFS().exists(Dir)) {
    Dir = SysRoot;
    llvm::sys::path::append(Dir, "include");
  }
}
 
std::optional<unsigned>
HexagonToolChain::getSmallDataThreshold(const ArgList &Args) {
  StringRef Gn = "";
  if (Arg *A = Args.getLastArg(options::OPT_G)) {
    Gn = A->getValue();
  } else if (Args.getLastArg(options::OPT_shared, options::OPT_fpic,
                             options::OPT_fPIC)) {
    Gn = "0";
  }
 
  unsigned G;
  if (!Gn.getAsInteger(10, G))
    return G;
 
  return std::nullopt;
}
 
std::string HexagonToolChain::getCompilerRTPath() const {
  SmallString<128> Dir(getDriver().SysRoot);
  llvm::sys::path::append(Dir, "usr", "lib");
  if (!SelectedMultilibs.empty()) {
    Dir += SelectedMultilibs.back().gccSuffix();
  }
  return std::string(Dir);
}
 
void HexagonToolChain::getHexagonLibraryPaths(const ArgList &Args,
      ToolChain::path_list &LibPaths) const {
  const Driver &D = getDriver();
 
  //----------------------------------------------------------------------------
  // -L Args
  //----------------------------------------------------------------------------
  for (Arg *A : Args.filtered(options::OPT_L))
    llvm::append_range(LibPaths, A->getValues());
 
  //----------------------------------------------------------------------------
  // Other standard paths
  //----------------------------------------------------------------------------
  std::vector<std::string> RootDirs;
  std::copy(D.PrefixDirs.begin(), D.PrefixDirs.end(),
            std::back_inserter(RootDirs));
 
  std::string SysRoot(getEffectiveSysRoot(Args));
  if (!llvm::is_contained(RootDirs, SysRoot))
    RootDirs.push_back(SysRoot);
 
  bool HasPIC = Args.hasArg(options::OPT_fpic, options::OPT_fPIC);
  // Assume G0 with -shared.
  bool HasG0 = Args.hasArg(options::OPT_shared);
  if (auto G = getSmallDataThreshold(Args))
    HasG0 = *G == 0;
 
  bool IsPicolibc = GetCStdlibType(Args) == ToolChain::CST_Picolibc;
  const std::string CpuVer = GetTargetCPUVersion(Args).str();
  for (auto &Dir : RootDirs) {
    std::string LibDir = Dir + "/lib";
    std::string LibDirCpu = LibDir + '/' + CpuVer;
    if (IsPicolibc) {
      // Flat layout: push only the single most-specific variant dir, then lib.
      // Base case (no G0/pic): lib/v68, lib.
      // -shared also implies -pic for Picolibc library search paths.
      bool HasPICOrShared = HasPIC || Args.hasArg(options::OPT_shared);
      if (HasG0) {
        std::string Variant = CpuVer + "-G0";
        if (HasPICOrShared)
          Variant += "-pic";
        LibPaths.push_back(LibDir + "/" + Variant);
      } else {
        LibPaths.push_back(LibDirCpu);
      }
    } else {
      // Nested layout (non-Picolibc): lib/v68/G0/pic, lib/v68/G0
      if (HasG0) {
        if (HasPIC)
          LibPaths.push_back(LibDirCpu + "/G0/pic");
        LibPaths.push_back(LibDirCpu + "/G0");
      }
      LibPaths.push_back(LibDirCpu);
    }
    LibPaths.push_back(LibDir);
  }
}
 
HexagonToolChain::HexagonToolChain(const Driver &D, const llvm::Triple &Triple,
                                   const llvm::opt::ArgList &Args)
    : Linux(D, Triple, Args) {
  ToolChain::path_list &LibPaths = getFilePaths();
 
  // Remove paths added by Linux toolchain. Currently Hexagon_TC really targets
  // 'elf' OS type, so the Linux paths are not appropriate. When we actually
  // support 'linux' we'll need to fix this up
  LibPaths.clear();
  getHexagonLibraryPaths(Args, LibPaths);
 
  if (getTriple().isMusl()) {
    Multilibs.push_back(Multilib());
    Multilibs.push_back(MultilibBuilder("msan", {}, {})
                            .flag("-fsanitize=memory")
                            .makeMultilib());
    Multilibs.push_back(MultilibBuilder("asan", {}, {})
                            .flag("-fsanitize=address")
                            .makeMultilib());
    Multilibs.push_back(MultilibBuilder("scs", {}, {})
                            .flag("-fsanitize=shadow-call-stack")
                            .makeMultilib());
 
    Multilib::flags_list Flags;
    addMultilibFlag(getSanitizerArgs(Args).needsMsanRt(), "-fsanitize=memory",
                    Flags);
    addMultilibFlag(getSanitizerArgs(Args).needsAsanRt(), "-fsanitize=address",
                    Flags);
    addMultilibFlag(getSanitizerArgs(Args).hasShadowCallStack(),
                    "-fsanitize=shadow-call-stack", Flags);
 
    if (Multilibs.select(D, Flags, SelectedMultilibs)) {
      Multilib LastSelected = SelectedMultilibs.back();
      SelectedMultilibs = {LastSelected};
 
      if (!SelectedMultilibs.back().isDefault()) {
        SmallString<128> SanLibPath(D.SysRoot);
        llvm::sys::path::append(SanLibPath, "usr", "lib");
        SanLibPath += SelectedMultilibs.back().gccSuffix();
        LibPaths.insert(LibPaths.begin(), std::string(SanLibPath));
      }
    }
  }
}
 
HexagonToolChain::~HexagonToolChain() {}
 
void HexagonToolChain::AddCXXStdlibLibArgs(const ArgList &Args,
                                           ArgStringList &CmdArgs) const {
  CXXStdlibType Type = GetCXXStdlibType(Args);
  ToolChain::UnwindLibType UNW = GetUnwindLibType(Args);
  if (UNW != ToolChain::UNW_None && UNW != ToolChain::UNW_CompilerRT) {
    const Arg *A = Args.getLastArg(options::OPT_unwindlib_EQ);
    if (A) {
      getDriver().Diag(diag::err_drv_unsupported_unwind_for_platform)
          << A->getValue() << getTripleString();
      return;
    }
  }
 
  switch (Type) {
  case ToolChain::CST_Libcxx:
    CmdArgs.push_back("-lc++");
    if (Args.hasArg(options::OPT_fexperimental_library))
      CmdArgs.push_back("-lc++experimental");
    CmdArgs.push_back("-lc++abi");
    if (UNW != ToolChain::UNW_None)
      CmdArgs.push_back("-lunwind");
    break;
 
  case ToolChain::CST_Libstdcxx:
    CmdArgs.push_back("-lstdc++");
    break;
  }
}
 
Tool *HexagonToolChain::buildAssembler() const {
  return new tools::hexagon::Assembler(*this);
}
 
Tool *HexagonToolChain::buildLinker() const {
  return new tools::hexagon::Linker(*this);
}
 
unsigned HexagonToolChain::getOptimizationLevel(
    const llvm::opt::ArgList &DriverArgs) const {
  // Copied in large part from lib/Frontend/CompilerInvocation.cpp.
  Arg *A = DriverArgs.getLastArg(options::OPT_O_Group);
  if (!A)
    return 0;
 
  if (A->getOption().matches(options::OPT_O0))
    return 0;
  if (A->getOption().matches(options::OPT_Ofast) ||
      A->getOption().matches(options::OPT_O4))
    return 3;
  assert(A->getNumValues() != 0);
  StringRef S(A->getValue());
  if (S == "s" || S == "z" || S.empty())
    return 2;
  if (S == "g")
    return 1;
 
  unsigned OptLevel;
  if (S.getAsInteger(10, OptLevel))
    return 0;
  return OptLevel;
}
 
void HexagonToolChain::addClangTargetOptions(const ArgList &DriverArgs,
                                             ArgStringList &CC1Args,
                                             BoundArch BA,
                                             Action::OffloadKind) const {
 
  bool UseInitArrayDefault =
      getTriple().isMusl() ||
      GetCStdlibType(DriverArgs) == ToolChain::CST_Picolibc;
 
  if (!DriverArgs.hasFlag(options::OPT_fuse_init_array,
                          options::OPT_fno_use_init_array,
                          UseInitArrayDefault))
    CC1Args.push_back("-fno-use-init-array");
 
  // The bool marks caller-saved (scratch) registers in the Hexagon ABI.
  // Reserving those only behaves correctly if every other translation unit and
  // library reserves them too, so we warn when the user does so.
  static const std::tuple<options::ID, const char *, bool> FixedRegs[] = {
      {options::OPT_ffixed_r6, "+reserved-r6", true},
      {options::OPT_ffixed_r7, "+reserved-r7", true},
      {options::OPT_ffixed_r8, "+reserved-r8", true},
      {options::OPT_ffixed_r9, "+reserved-r9", true},
      {options::OPT_ffixed_r10, "+reserved-r10", true},
      {options::OPT_ffixed_r11, "+reserved-r11", true},
      {options::OPT_ffixed_r12, "+reserved-r12", true},
      {options::OPT_ffixed_r13, "+reserved-r13", true},
      {options::OPT_ffixed_r14, "+reserved-r14", true},
      {options::OPT_ffixed_r15, "+reserved-r15", true},
      {options::OPT_ffixed_r16, "+reserved-r16", false},
      {options::OPT_ffixed_r17, "+reserved-r17", false},
      {options::OPT_ffixed_r18, "+reserved-r18", false},
      {options::OPT_ffixed_r19, "+reserved-r19", false},
      {options::OPT_ffixed_r20, "+reserved-r20", false},
      {options::OPT_ffixed_r21, "+reserved-r21", false},
      {options::OPT_ffixed_r22, "+reserved-r22", false},
      {options::OPT_ffixed_r23, "+reserved-r23", false},
      {options::OPT_ffixed_r24, "+reserved-r24", false},
      {options::OPT_ffixed_r25, "+reserved-r25", false},
      {options::OPT_ffixed_r26, "+reserved-r26", false},
      {options::OPT_ffixed_r27, "+reserved-r27", false},
      {options::OPT_ffixed_r28, "+reserved-r28", false},
  };
  for (const auto &[Opt, Feature, IsCallerSaved] : FixedRegs) {
    if (Arg *A = DriverArgs.getLastArg(Opt)) {
      if (IsCallerSaved)
        getDriver().Diag(diag::warn_drv_hexagon_reserved_caller_saved_reg)
            << A->getOption().getName();
      CC1Args.push_back("-target-feature");
      CC1Args.push_back(Feature);
    }
  }
 
  // Select the shadow call stack pointer register.  It has to hold a value
  // across arbitrary calls, so only the callee-saved registers r16-r27 are
  // allowed (Hexagon ABI, "Register usage across calls").
  if (Arg *A = DriverArgs.getLastArg(options::OPT_mhexagon_scs_reg)) {
    StringRef Val(A->getValue());
    unsigned RegNo = 0;
    if (!Val.consume_front("r") || Val.getAsInteger(10, RegNo) || RegNo < 16 ||
        RegNo > 27) {
      getDriver().Diag(diag::err_drv_invalid_value)
          << A->getSpelling() << A->getValue();
    } else {
      CC1Args.push_back("-target-feature");
      CC1Args.push_back(DriverArgs.MakeArgString("+scs-reg-r" + Twine(RegNo)));
    }
  }
 
  if (isAutoHVXEnabled(DriverArgs)) {
    CC1Args.push_back("-mllvm");
    CC1Args.push_back("-hexagon-autohvx");
  }
}
 
void HexagonToolChain::AddClangSystemIncludeArgs(const ArgList &DriverArgs,
                                                 ArgStringList &CC1Args) const {
  if (DriverArgs.hasArg(options::OPT_nostdinc))
    return;
 
  const Driver &D = getDriver();
  const bool UseBuiltins = !DriverArgs.hasArg(options::OPT_nobuiltininc);
  if (UseBuiltins) {
    SmallString<128> ResourceDirInclude(D.ResourceDir);
    llvm::sys::path::append(ResourceDirInclude, "include");
    addSystemInclude(DriverArgs, CC1Args, ResourceDirInclude);
  }
  if (!DriverArgs.hasArg(options::OPT_nostdlibinc)) {
    SmallString<128> CIncludeDir;
    getBaseIncludeDir(DriverArgs, CIncludeDir);
    addExternCSystemInclude(DriverArgs, CC1Args, std::string(CIncludeDir));
    bool IsLinuxMusl = getTriple().isMusl() && getTriple().isOSLinux();
    if (IsLinuxMusl) {
      SmallString<128> LocalIncludeDir = getEffectiveSysRoot(DriverArgs);
      llvm::sys::path::append(LocalIncludeDir, "usr", "local", "include");
      addSystemInclude(DriverArgs, CC1Args, LocalIncludeDir);
    }
    // TOOL_INCLUDE_DIR
    AddMultilibIncludeArgs(DriverArgs, CC1Args);
  }
}
 
void HexagonToolChain::addLibCxxIncludePaths(
    const llvm::opt::ArgList &DriverArgs,
    llvm::opt::ArgStringList &CC1Args) const {
  SmallString<128> Dir;
  getBaseIncludeDir(DriverArgs, Dir);
  llvm::sys::path::append(Dir, "c++", "v1");
  addLibStdCXXIncludePaths(Dir, "", "", DriverArgs, CC1Args);
}
 
void HexagonToolChain::addLibStdCxxIncludePaths(
    const llvm::opt::ArgList &DriverArgs,
    llvm::opt::ArgStringList &CC1Args) const {
  SmallString<128> Dir;
  getBaseIncludeDir(DriverArgs, Dir);
  llvm::sys::path::append(Dir, "c++");
  addLibStdCXXIncludePaths(Dir, "", "", DriverArgs, CC1Args);
}
 
ToolChain::RuntimeLibType
HexagonToolChain::GetRuntimeLibType(const ArgList &Args) const {
  if (GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
    if (Args.getLastArg(options::OPT_rtlib_EQ))
      return ToolChain::GetRuntimeLibType(Args);
    return ToolChain::RLT_CompilerRT;
  }
  return ToolChain::GetRuntimeLibType(Args);
}
 
ToolChain::UnwindLibType
HexagonToolChain::GetUnwindLibType(const ArgList &Args) const {
  if (GetCStdlibType(Args) == ToolChain::CST_Picolibc) {
    if (Args.getLastArg(options::OPT_unwindlib_EQ))
      return ToolChain::GetUnwindLibType(Args);
    return ToolChain::UNW_CompilerRT;
  }
  return ToolChain::GetUnwindLibType(Args);
}
 
ToolChain::CXXStdlibType
HexagonToolChain::GetCXXStdlibType(const ArgList &Args) const {
  Arg *A = Args.getLastArg(options::OPT_stdlib_EQ);
  if (!A) {
    if (getTriple().isMusl() || GetCStdlibType(Args) == ToolChain::CST_Picolibc)
      return ToolChain::CST_Libcxx;
    else
      return ToolChain::CST_Libstdcxx;
  }
  StringRef Value = A->getValue();
  if (Value != "libstdc++" && Value != "libc++")
    getDriver().Diag(diag::err_drv_invalid_stdlib_name) << A->getAsString(Args);
 
  if (Value == "libstdc++")
    return ToolChain::CST_Libstdcxx;
  else if (Value == "libc++")
    return ToolChain::CST_Libcxx;
  else
    return ToolChain::CST_Libstdcxx;
}
 
bool HexagonToolChain::isAutoHVXEnabled(const llvm::opt::ArgList &Args) {
  if (Arg *A = Args.getLastArg(options::OPT_fvectorize,
                               options::OPT_fno_vectorize))
    return A->getOption().matches(options::OPT_fvectorize);
  return false;
}
 
//
// Returns the default CPU for Hexagon. This is the default compilation target
// if no Hexagon processor is selected at the command-line.
//
StringRef HexagonToolChain::GetDefaultCPU() { return "hexagonv68"; }
 
StringRef HexagonToolChain::GetTargetCPUVersion(const ArgList &Args) {
  Arg *CpuArg = nullptr;
  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ))
    CpuArg = A;
 
  StringRef CPU = CpuArg ? CpuArg->getValue() : GetDefaultCPU();
  CPU.consume_front("hexagon");
  return CPU;
}
 
std::optional<std::string>
HexagonToolChain::GetHVXVersion(const ArgList &Args) {
  // Handle -mh[v]x= and -mno-hvx. If versioned and versionless flags
  // are both present, the last one wins.
  Arg *HvxEnablingArg =
      Args.getLastArg(options::OPT_mhexagon_hvx, options::OPT_mhexagon_hvx_EQ,
                      options::OPT_mno_hexagon_hvx);
  if (!HvxEnablingArg ||
      HvxEnablingArg->getOption().matches(options::OPT_mno_hexagon_hvx))
    return std::nullopt;
 
  StringRef Cpu(toolchains::HexagonToolChain::GetTargetCPUVersion(Args));
  std::string HvxVer;
  if (!Cpu.empty() && (Cpu.back() == 'T' || Cpu.back() == 't'))
    HvxVer = Cpu.drop_back(1).str();
  else
    HvxVer = Cpu.str();
 
  if (HvxEnablingArg->getOption().matches(options::OPT_mhexagon_hvx_EQ))
    HvxVer = StringRef(HvxEnablingArg->getValue()).lower();
 
  return HvxVer;
}
 
// End Hexagon