OpenBSD.cpp

//===--- OpenBSD.cpp - OpenBSD 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 "OpenBSD.h"
#include "Arch/ARM.h"
#include "Arch/Mips.h"
#include "Arch/Sparc.h"
#include "CommonArgs.h"
#include "clang/Config/config.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Options.h"
#include "clang/Driver/SanitizerArgs.h"
#include "llvm/Option/ArgList.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;

void openbsd::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                      const InputInfo &Output,
                                      const InputInfoList &Inputs,
                                      const ArgList &Args,
                                      const char *LinkingOutput) const {
  const auto &ToolChain = static_cast<const OpenBSD &>(getToolChain());
  const Driver &D = ToolChain.getDriver();
  const llvm::Triple &Triple = ToolChain.getTriple();
  ArgStringList CmdArgs;

  claimNoWarnArgs(Args);

  switch (ToolChain.getArch()) {
  case llvm::Triple::x86:
    // When building 32-bit code on OpenBSD/amd64, we have to explicitly
    // instruct as in the base system to assemble 32-bit code.
    CmdArgs.push_back("--32");
    break;

  case llvm::Triple::arm: {
    StringRef MArch, MCPU;
    arm::getARMArchCPUFromArgs(Args, MArch, MCPU, /*FromAs*/ true);
    std::string Arch = arm::getARMTargetCPU(MCPU, MArch, Triple);
    CmdArgs.push_back(Args.MakeArgString("-mcpu=" + Arch));
    break;
  }

  case llvm::Triple::ppc:
    CmdArgs.push_back("-mppc");
    CmdArgs.push_back("-many");
    break;

  case llvm::Triple::sparcv9: {
    CmdArgs.push_back("-64");
    std::string CPU = getCPUName(D, Args, Triple);
    CmdArgs.push_back(sparc::getSparcAsmModeForCPU(CPU, Triple));
    AddAssemblerKPIC(ToolChain, Args, CmdArgs);
    break;
  }

  case llvm::Triple::mips64:
  case llvm::Triple::mips64el: {
    StringRef CPUName;
    StringRef ABIName;
    mips::getMipsCPUAndABI(Args, Triple, CPUName, ABIName);

    CmdArgs.push_back("-march");
    CmdArgs.push_back(CPUName.data());

    CmdArgs.push_back("-mabi");
    CmdArgs.push_back(mips::getGnuCompatibleMipsABIName(ABIName).data());

    if (Triple.isLittleEndian())
      CmdArgs.push_back("-EL");
    else
      CmdArgs.push_back("-EB");

    AddAssemblerKPIC(ToolChain, Args, CmdArgs);
    break;
  }

  default:
    break;
  }

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

  CmdArgs.push_back("-o");
  CmdArgs.push_back(Output.getFilename());

  for (const auto &II : Inputs)
    CmdArgs.push_back(II.getFilename());

  const char *Exec = Args.MakeArgString(ToolChain.GetProgramPath("as"));
  C.addCommand(std::make_unique<Command>(JA, *this,
                                         ResponseFileSupport::AtFileCurCP(),
                                         Exec, CmdArgs, Inputs, Output));
}

void openbsd::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                   const InputInfo &Output,
                                   const InputInfoList &Inputs,
                                   const ArgList &Args,
                                   const char *LinkingOutput) const {
  const auto &ToolChain = static_cast<const OpenBSD &>(getToolChain());
  const Driver &D = ToolChain.getDriver();
  const llvm::Triple &Triple = ToolChain.getTriple();
  const llvm::Triple::ArchType Arch = ToolChain.getArch();
  const bool Static = Args.hasArg(options::OPT_static);
  const bool Shared = Args.hasArg(options::OPT_shared);
  const bool Profiling = Args.hasArg(options::OPT_pg);
  const bool Pie = Args.hasArg(options::OPT_pie);
  const bool Nopie = Args.hasArg(options::OPT_no_pie, options::OPT_nopie);
  const bool Relocatable = Args.hasArg(options::OPT_r);
  ArgStringList CmdArgs;

  // Silence warning for "clang -g foo.o -o foo"
  Args.ClaimAllArgs(options::OPT_g_Group);
  // and "clang -emit-llvm foo.o -o foo"
  Args.ClaimAllArgs(options::OPT_emit_llvm);
  // and for "clang -w foo.o -o foo". Other warning options are already
  // handled somewhere else.
  Args.ClaimAllArgs(options::OPT_w);

  if (!D.SysRoot.empty())
    CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));

  if (Arch == llvm::Triple::mips64)
    CmdArgs.push_back("-EB");
  else if (Arch == llvm::Triple::mips64el)
    CmdArgs.push_back("-EL");

  if (!Args.hasArg(options::OPT_nostdlib) && !Shared && !Relocatable) {
    CmdArgs.push_back("-e");
    CmdArgs.push_back("__start");
  }

  CmdArgs.push_back("--eh-frame-hdr");
  if (Static) {
    CmdArgs.push_back("-Bstatic");
  } else {
    if (Args.hasArg(options::OPT_rdynamic))
      CmdArgs.push_back("-export-dynamic");
    if (Shared) {
      CmdArgs.push_back("-shared");
    } else if (!Relocatable) {
      CmdArgs.push_back("-dynamic-linker");
      CmdArgs.push_back("/usr/libexec/ld.so");
    }
  }

  if (Pie)
    CmdArgs.push_back("-pie");
  if (Nopie || Profiling)
    CmdArgs.push_back("-nopie");

  if (Triple.isRISCV64()) {
    CmdArgs.push_back("-X");
    if (Args.hasArg(options::OPT_mno_relax))
      CmdArgs.push_back("--no-relax");
  }

  assert((Output.isFilename() || Output.isNothing()) && "Invalid output.");
  if (Output.isFilename()) {
    CmdArgs.push_back("-o");
    CmdArgs.push_back(Output.getFilename());
  }

  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
                   options::OPT_r)) {
    const char *crt0 = nullptr;
    const char *crtbegin = nullptr;
    if (!Shared) {
      if (Profiling)
        crt0 = "gcrt0.o";
      else if (Static && !Nopie)
        crt0 = "rcrt0.o";
      else
        crt0 = "crt0.o";
      crtbegin = "crtbegin.o";
    } else {
      crtbegin = "crtbeginS.o";
    }

    if (crt0)
      CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crt0)));
    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtbegin)));
  }

  Args.AddAllArgs(CmdArgs, options::OPT_L);
  ToolChain.AddFilePathLibArgs(Args, CmdArgs);
  Args.addAllArgs(CmdArgs,
                  {options::OPT_T_Group, options::OPT_s, options::OPT_t});

  if (D.isUsingLTO()) {
    assert(!Inputs.empty() && "Must have at least one input.");
    // Find the first filename InputInfo object.
    auto Input = llvm::find_if(
        Inputs, [](const InputInfo &II) -> bool { return II.isFilename(); });
    if (Input == Inputs.end())
      // For a very rare case, all of the inputs to the linker are
      // InputArg. If that happens, just use the first InputInfo.
      Input = Inputs.begin();

    addLTOOptions(ToolChain, Args, CmdArgs, Output, *Input,
                  D.getLTOMode() == LTOK_Thin);
  }

  bool NeedsSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
  bool NeedsXRayDeps = addXRayRuntime(ToolChain, Args, CmdArgs);
  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);

  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
                   options::OPT_r)) {
    // Use the static OpenMP runtime with -static-openmp
    bool StaticOpenMP = Args.hasArg(options::OPT_static_openmp) && !Static;
    addOpenMPRuntime(C, CmdArgs, ToolChain, Args, StaticOpenMP);

    if (D.CCCIsCXX()) {
      if (ToolChain.ShouldLinkCXXStdlib(Args))
        ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
      if (Profiling)
        CmdArgs.push_back("-lm_p");
      else
        CmdArgs.push_back("-lm");
    }

    // Silence warnings when linking C code with a C++ '-stdlib' argument.
    Args.ClaimAllArgs(options::OPT_stdlib_EQ);

    // Additional linker set-up and flags for Fortran. This is required in order
    // to generate executables. As Fortran runtime depends on the C runtime,
    // these dependencies need to be listed before the C runtime below (i.e.
    // AddRunTimeLibs).
    if (D.IsFlangMode()) {
      addFortranRuntimeLibraryPath(ToolChain, Args, CmdArgs);
      addFortranRuntimeLibs(ToolChain, Args, CmdArgs);
      if (Profiling)
        CmdArgs.push_back("-lm_p");
      else
        CmdArgs.push_back("-lm");
    }

    if (NeedsSanitizerDeps) {
      CmdArgs.push_back(ToolChain.getCompilerRTArgString(Args, "builtins"));
      linkSanitizerRuntimeDeps(ToolChain, Args, CmdArgs);
    }
    if (NeedsXRayDeps) {
      CmdArgs.push_back(ToolChain.getCompilerRTArgString(Args, "builtins"));
      linkXRayRuntimeDeps(ToolChain, Args, CmdArgs);
    }
    // FIXME: For some reason GCC passes -lgcc before adding
    // the default system libraries. Just mimic this for now.
    CmdArgs.push_back("-lcompiler_rt");

    if (Args.hasArg(options::OPT_pthread)) {
      if (!Shared && Profiling)
        CmdArgs.push_back("-lpthread_p");
      else
        CmdArgs.push_back("-lpthread");
    }

    if (!Shared) {
      if (Profiling)
        CmdArgs.push_back("-lc_p");
      else
        CmdArgs.push_back("-lc");
    }

    CmdArgs.push_back("-lcompiler_rt");
  }

  if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
                   options::OPT_r)) {
    const char *crtend = nullptr;
    if (!Shared)
      crtend = "crtend.o";
    else
      crtend = "crtendS.o";

    CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtend)));
  }

  ToolChain.addProfileRTLibs(Args, CmdArgs);

  const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
  C.addCommand(std::make_unique<Command>(JA, *this,
                                         ResponseFileSupport::AtFileCurCP(),
                                         Exec, CmdArgs, Inputs, Output));
}

SanitizerMask OpenBSD::getSupportedSanitizers() const {
  const bool IsX86 = getTriple().getArch() == llvm::Triple::x86;
  const bool IsX86_64 = getTriple().getArch() == llvm::Triple::x86_64;
  SanitizerMask Res = ToolChain::getSupportedSanitizers();
  if (IsX86 || IsX86_64) {
    Res |= SanitizerKind::Vptr;
    Res |= SanitizerKind::Fuzzer;
    Res |= SanitizerKind::FuzzerNoLink;
  }
  if (IsX86_64) {
    Res |= SanitizerKind::KernelAddress;
  }
  return Res;
}

/// OpenBSD - OpenBSD tool chain which can call as(1) and ld(1) directly.

OpenBSD::OpenBSD(const Driver &D, const llvm::Triple &Triple,
                 const ArgList &Args)
    : Generic_ELF(D, Triple, Args) {
  getFilePaths().push_back(concat(getDriver().SysRoot, "/usr/lib"));
}

void OpenBSD::AddClangSystemIncludeArgs(
    const llvm::opt::ArgList &DriverArgs,
    llvm::opt::ArgStringList &CC1Args) const {
  const Driver &D = getDriver();

  if (DriverArgs.hasArg(clang::driver::options::OPT_nostdinc))
    return;

  if (!DriverArgs.hasArg(options::OPT_nobuiltininc)) {
    SmallString<128> Dir(D.ResourceDir);
    llvm::sys::path::append(Dir, "include");
    addSystemInclude(DriverArgs, CC1Args, Dir.str());
  }

  if (DriverArgs.hasArg(options::OPT_nostdlibinc))
    return;

  // Check for configure-time C include directories.
  StringRef CIncludeDirs(C_INCLUDE_DIRS);
  if (CIncludeDirs != "") {
    SmallVector<StringRef, 5> dirs;
    CIncludeDirs.split(dirs, ":");
    for (StringRef dir : dirs) {
      StringRef Prefix =
          llvm::sys::path::is_absolute(dir) ? StringRef(D.SysRoot) : "";
      addExternCSystemInclude(DriverArgs, CC1Args, Prefix + dir);
    }
    return;
  }

  addExternCSystemInclude(DriverArgs, CC1Args,
                          concat(D.SysRoot, "/usr/include"));
}

void OpenBSD::addLibCxxIncludePaths(const llvm::opt::ArgList &DriverArgs,
                                    llvm::opt::ArgStringList &CC1Args) const {
  addSystemInclude(DriverArgs, CC1Args,
                   concat(getDriver().SysRoot, "/usr/include/c++/v1"));
}

void OpenBSD::AddCXXStdlibLibArgs(const ArgList &Args,
                                  ArgStringList &CmdArgs) const {
  bool Profiling = Args.hasArg(options::OPT_pg);

  CmdArgs.push_back(Profiling ? "-lc++_p" : "-lc++");
  if (Args.hasArg(options::OPT_fexperimental_library))
    CmdArgs.push_back("-lc++experimental");
  CmdArgs.push_back(Profiling ? "-lc++abi_p" : "-lc++abi");
  CmdArgs.push_back(Profiling ? "-lpthread_p" : "-lpthread");
}

std::string OpenBSD::getCompilerRT(const ArgList &Args, StringRef Component,
                                   FileType Type) const {
  if (Component == "builtins") {
    SmallString<128> Path(getDriver().SysRoot);
    llvm::sys::path::append(Path, "/usr/lib/libcompiler_rt.a");
    if (getVFS().exists(Path))
      return std::string(Path);
  }
  SmallString<128> P(getDriver().ResourceDir);
  std::string CRTBasename =
      buildCompilerRTBasename(Args, Component, Type, /*AddArch=*/false);
  llvm::sys::path::append(P, "lib", CRTBasename);
  // Checks if this is the base system case which uses a different location.
  if (getVFS().exists(P))
    return std::string(P);
  return ToolChain::getCompilerRT(Args, Component, Type);
}

Tool *OpenBSD::buildAssembler() const {
  return new tools::openbsd::Assembler(*this);
}

Tool *OpenBSD::buildLinker() const { return new tools::openbsd::Linker(*this); }

bool OpenBSD::HasNativeLLVMSupport() const { return true; }

ToolChain::UnwindTableLevel
OpenBSD::getDefaultUnwindTableLevel(const ArgList &Args) const {
  switch (getArch()) {
  case llvm::Triple::arm:
    return UnwindTableLevel::None;
  default:
    return UnwindTableLevel::Asynchronous;
  }
}