//===--- XRayArgs.cpp - Arguments for XRay --------------------------------===//

//

// 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 "clang/Driver/XRayArgs.h"

#include "ToolChains/CommonArgs.h"

#include "clang/Driver/Driver.h"

#include "clang/Driver/DriverDiagnostic.h"

#include "clang/Driver/Options.h"

#include "clang/Driver/ToolChain.h"

#include "llvm/ADT/StringExtras.h"

#include "llvm/ADT/StringSwitch.h"

#include "llvm/Support/Path.h"

#include "llvm/Support/ScopedPrinter.h"

#include "llvm/Support/SpecialCaseList.h"

#include "llvm/Support/VirtualFileSystem.h"

using namespace clang;

using namespace clang::driver;

using namespace llvm::opt;

constexpr const char *XRaySupportedModes[] = {"xray-fdr", "xray-basic"};

XRayArgs::XRayArgs(const ToolChain &TC, const ArgList &Args) {

  const Driver &D = TC.getDriver();

  const llvm::Triple &Triple = TC.getTriple();

  if (!Args.hasFlag(options::OPT_fxray_instrument,

                    options::OPT_fno_xray_instrument, false))

    return;

  XRayInstrument = Args.getLastArg(options::OPT_fxray_instrument);

  if (Triple.isMacOSX()) {

    switch (Triple.getArch()) {

    case llvm::Triple::aarch64:

    case llvm::Triple::x86_64:

      break;

    default:

      D.Diag(diag::err_drv_unsupported_opt_for_target)

          << XRayInstrument->getSpelling() << Triple.str();

      break;

    }

  } else if (Triple.isOSBinFormatELF()) {

    switch (Triple.getArch()) {

    case llvm::Triple::x86_64:

    case llvm::Triple::arm:

    case llvm::Triple::aarch64:

    case llvm::Triple::hexagon:

    case llvm::Triple::ppc64le:

    case llvm::Triple::loongarch64:

    case llvm::Triple::mips:

    case llvm::Triple::mipsel:

    case llvm::Triple::mips64:

    case llvm::Triple::mips64el:

      break;

    default:

      D.Diag(diag::err_drv_unsupported_opt_for_target)

          << XRayInstrument->getSpelling() << Triple.str();

    }

  } else {

    D.Diag(diag::err_drv_unsupported_opt_for_target)

        << XRayInstrument->getSpelling() << Triple.str();

  }

  // Both XRay and -fpatchable-function-entry use

  // TargetOpcode::PATCHABLE_FUNCTION_ENTER.

  if (Arg *A = Args.getLastArg(options::OPT_fpatchable_function_entry_EQ))

    D.Diag(diag::err_drv_argument_not_allowed_with)

        << XRayInstrument->getSpelling() << A->getSpelling();

  if (!Args.hasFlag(options::OPT_fxray_link_deps,

                    options::OPT_fno_xray_link_deps, true))

    XRayRT = false;

  auto Bundles =

      Args.getAllArgValues(options::OPT_fxray_instrumentation_bundle);

  if (Bundles.empty())

    InstrumentationBundle.Mask = XRayInstrKind::All;

  else

    for (const auto &B : Bundles) {

      llvm::SmallVector<StringRef, 2> BundleParts;

      llvm::SplitString(B, BundleParts, ",");

      for (const auto &P : BundleParts) {

        // TODO: Automate the generation of the string case table.

        auto Valid = llvm::StringSwitch<bool>(P)

                         .Cases("none", "all", "function", "function-entry",

                                "function-exit", "custom", true)

                         .Default(false);

        if (!Valid) {

          D.Diag(clang::diag::err_drv_invalid_value)

              << "-fxray-instrumentation-bundle=" << P;

          continue;

        }

        auto Mask = parseXRayInstrValue(P);

        if (Mask == XRayInstrKind::None) {

          InstrumentationBundle.clear();

          break;

        }

        InstrumentationBundle.Mask |= Mask;

      }

    }

  // Validate the always/never attribute files. We also make sure that they

  // are treated as actual dependencies.

  for (const auto &Filename :

       Args.getAllArgValues(options::OPT_fxray_always_instrument)) {

    if (D.getVFS().exists(Filename)) {

      AlwaysInstrumentFiles.push_back(Filename);

      ExtraDeps.push_back(Filename);

    } else

      D.Diag(clang::diag::err_drv_no_such_file) << Filename;

  }

  for (const auto &Filename :

       Args.getAllArgValues(options::OPT_fxray_never_instrument)) {

    if (D.getVFS().exists(Filename)) {

      NeverInstrumentFiles.push_back(Filename);

      ExtraDeps.push_back(Filename);

    } else

      D.Diag(clang::diag::err_drv_no_such_file) << Filename;

  }

  for (const auto &Filename :

       Args.getAllArgValues(options::OPT_fxray_attr_list)) {

    if (D.getVFS().exists(Filename)) {

      AttrListFiles.push_back(Filename);

      ExtraDeps.push_back(Filename);

    } else

      D.Diag(clang::diag::err_drv_no_such_file) << Filename;

  }

  // Get the list of modes we want to support.

  auto SpecifiedModes = Args.getAllArgValues(options::OPT_fxray_modes);

  if (SpecifiedModes.empty())

    llvm::copy(XRaySupportedModes, std::back_inserter(Modes));

  else

    for (const auto &Arg : SpecifiedModes) {

      // Parse CSV values for -fxray-modes=...

      llvm::SmallVector<StringRef, 2> ModeParts;

      llvm::SplitString(Arg, ModeParts, ",");

      for (const auto &M : ModeParts)

        if (M == "none")

          Modes.clear();

        else if (M == "all")

          llvm::copy(XRaySupportedModes, std::back_inserter(Modes));

        else

          Modes.push_back(std::string(M));

    }

  // Then we want to sort and unique the modes we've collected.

  llvm::sort(Modes);

  Modes.erase(std::unique(Modes.begin(), Modes.end()), Modes.end());

}

void XRayArgs::addArgs(const ToolChain &TC, const ArgList &Args,

                       ArgStringList &CmdArgs, types::ID InputType) const {

  if (!XRayInstrument)

    return;

  const Driver &D = TC.getDriver();

  XRayInstrument->render(Args, CmdArgs);

  // By default, the back-end will not emit the lowering for XRay customevent

  // calls if the function is not instrumented. In the future we will change

  // this default to be the reverse, but in the meantime we're going to

  // introduce the new functionality behind a flag.

  Args.addOptInFlag(CmdArgs, options::OPT_fxray_always_emit_customevents,

                    options::OPT_fno_xray_always_emit_customevents);

  Args.addOptInFlag(CmdArgs, options::OPT_fxray_always_emit_typedevents,

                    options::OPT_fno_xray_always_emit_typedevents);

  Args.addOptInFlag(CmdArgs, options::OPT_fxray_ignore_loops,

                    options::OPT_fno_xray_ignore_loops);

  Args.addOptOutFlag(CmdArgs, options::OPT_fxray_function_index,

                     options::OPT_fno_xray_function_index);

  if (const Arg *A =

          Args.getLastArg(options::OPT_fxray_instruction_threshold_EQ)) {

    int Value;

    StringRef S = A->getValue();

    if (S.getAsInteger(0, Value) || Value < 0)

      D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;

    else

      A->render(Args, CmdArgs);

  }

  int XRayFunctionGroups = 1;

  int XRaySelectedFunctionGroup = 0;

  if (const Arg *A = Args.getLastArg(options::OPT_fxray_function_groups)) {

    StringRef S = A->getValue();

    if (S.getAsInteger(0, XRayFunctionGroups) || XRayFunctionGroups < 1)

      D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;

    if (XRayFunctionGroups > 1)

      A->render(Args, CmdArgs);

  }

  if (const Arg *A =

          Args.getLastArg(options::OPT_fxray_selected_function_group)) {

    StringRef S = A->getValue();

    if (S.getAsInteger(0, XRaySelectedFunctionGroup) ||

        XRaySelectedFunctionGroup < 0 ||

        XRaySelectedFunctionGroup >= XRayFunctionGroups)

      D.Diag(clang::diag::err_drv_invalid_value) << A->getAsString(Args) << S;

    if (XRaySelectedFunctionGroup != 0)

      A->render(Args, CmdArgs);

  }

  for (const auto &Always : AlwaysInstrumentFiles) {

    SmallString<64> AlwaysInstrumentOpt("-fxray-always-instrument=");

    AlwaysInstrumentOpt += Always;

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

  }

  for (const auto &Never : NeverInstrumentFiles) {

    SmallString<64> NeverInstrumentOpt("-fxray-never-instrument=");

    NeverInstrumentOpt += Never;

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

  }

  for (const auto &AttrFile : AttrListFiles) {

    SmallString<64> AttrListFileOpt("-fxray-attr-list=");

    AttrListFileOpt += AttrFile;

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

  }

  for (const auto &Dep : ExtraDeps) {

    SmallString<64> ExtraDepOpt("-fdepfile-entry=");

    ExtraDepOpt += Dep;

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

  }

  for (const auto &Mode : Modes) {

    SmallString<64> ModeOpt("-fxray-modes=");

    ModeOpt += Mode;

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

  }

  SmallString<64> Bundle("-fxray-instrumentation-bundle=");

  if (InstrumentationBundle.full()) {

    Bundle += "all";

  } else if (InstrumentationBundle.empty()) {

    Bundle += "none";

  } else {

    if (InstrumentationBundle.has(XRayInstrKind::FunctionEntry) &&

        InstrumentationBundle.has(XRayInstrKind::FunctionExit))

      Bundle += "function";

    else if (InstrumentationBundle.has(XRayInstrKind::FunctionEntry))

      Bundle += "function-entry";

    else if (InstrumentationBundle.has(XRayInstrKind::FunctionExit))

      Bundle += "function-exit";

    if (InstrumentationBundle.has(XRayInstrKind::Custom))

      Bundle += "custom";

    if (InstrumentationBundle.has(XRayInstrKind::Typed))

      Bundle += "typed";

  }

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

}