//===--- SPIRV.cpp - SPIR-V Tool 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 "SPIRV.h"
#include "clang/Driver/CommonArgs.h"
#include "clang/Driver/Compilation.h"
#include "clang/Driver/Driver.h"
#include "clang/Driver/InputInfo.h"
#include "clang/Options/Options.h"

using namespace clang::driver;
using namespace clang::driver::toolchains;
using namespace clang::driver::tools;
using namespace llvm::opt;

void SPIRV::constructTranslateCommand(Compilation &C, const Tool &T,
                                      const JobAction &JA,
                                      const InputInfo &Output,
                                      const InputInfo &Input,
                                      const llvm::opt::ArgStringList &Args) {
  llvm::opt::ArgStringList CmdArgs(Args);
  CmdArgs.push_back(Input.getFilename());

  assert(Input.getType() != types::TY_PP_Asm && "Unexpected input type");

  if (Output.getType() == types::TY_PP_Asm)
    CmdArgs.push_back("--spirv-tools-dis");

  CmdArgs.append({"-o", Output.getFilename()});

  // Try to find "llvm-spirv-<LLVM_VERSION_MAJOR>". Otherwise, fall back to
  // plain "llvm-spirv".
  // AMD FORK ONLY: instead of llvm-spirv we look for the amd-llvm-spirv, which
  // is our ephemeral, temporary build of the translator that nests changes that
  // are not in upstream. This will be removed in the future.
  using namespace std::string_literals;
  auto VersionedTool = "llvm-spirv-"s + std::to_string(LLVM_VERSION_MAJOR);
  if (T.getToolChain().getTriple().getVendor() == llvm::Triple::VendorType::AMD)
    VersionedTool.insert(0, "amd-");
  std::string ExeCand = T.getToolChain().GetProgramPath(VersionedTool.c_str());
  if (!llvm::sys::fs::can_execute(ExeCand))
    ExeCand = T.getToolChain().GetProgramPath(
        VersionedTool.substr(0, VersionedTool.find_last_of('-')).c_str());

  const char *Exec = C.getArgs().MakeArgString(ExeCand);
  C.addCommand(std::make_unique<Command>(JA, T, ResponseFileSupport::None(),
                                         Exec, CmdArgs, Input, Output));
}

void SPIRV::constructAssembleCommand(Compilation &C, const Tool &T,
                                     const JobAction &JA,
                                     const InputInfo &Output,
                                     const InputInfo &Input,
                                     const llvm::opt::ArgStringList &Args) {
  llvm::opt::ArgStringList CmdArgs(Args);
  CmdArgs.push_back(Input.getFilename());

  assert(Input.getType() == types::TY_PP_Asm && "Unexpected input type");

  CmdArgs.append({"-o", Output.getFilename()});

  // Try to find "spirv-as-<LLVM_VERSION_MAJOR>". Otherwise, fall back to
  // plain "spirv-as".
  using namespace std::string_literals;
  auto VersionedTool = "spirv-as-"s + std::to_string(LLVM_VERSION_MAJOR);
  std::string ExeCand = T.getToolChain().GetProgramPath(VersionedTool.c_str());
  if (!llvm::sys::fs::can_execute(ExeCand))
    ExeCand = T.getToolChain().GetProgramPath("spirv-as");

  if (!llvm::sys::fs::can_execute(ExeCand) &&
      !C.getArgs().hasArg(clang::options::OPT__HASH_HASH_HASH)) {
    C.getDriver().Diag(clang::diag::err_drv_no_spv_tools) << "spirv-as";
    return;
  }
  const char *Exec = C.getArgs().MakeArgString(ExeCand);
  C.addCommand(std::make_unique<Command>(JA, T, ResponseFileSupport::None(),
                                         Exec, CmdArgs, Input, Output));
}

void SPIRV::constructLLVMLinkCommand(Compilation &C, const Tool &T,
                                     const JobAction &JA,
                                     const InputInfo &Output,
                                     const InputInfoList &Inputs,
                                     const llvm::opt::ArgList &Args) {

  ArgStringList LlvmLinkArgs;

  for (auto Input : Inputs) {
    if (Input.isFilename()) {
      LlvmLinkArgs.push_back(Input.getFilename());
    } else {
      // Warn that any linker arguments will be dropped.
      assert(Input.isInputArg() && "Unexpected linker input");
      const llvm::opt::Arg &LinkerOpt = Input.getInputArg();
      std::string LinkerOptStr = LinkerOpt.getAsString(Args);
      const llvm::opt::Arg *EmitLLVM = Args.getLastArg(options::OPT_emit_llvm);
      assert(EmitLLVM && "Unexpected linker input");
      std::string EmitLLVMStr = EmitLLVM ? EmitLLVM->getAsString(Args) : "";
      llvm::Triple Triple(T.getToolChain().getTriple());
      C.getDriver().Diag(clang::diag::warn_drv_input_file_unused)
          << Triple.getTriple() << LinkerOptStr << false << EmitLLVMStr;
    }
  }

  tools::constructLLVMLinkCommand(C, T, JA, Inputs, LlvmLinkArgs, Output, Args);
}

void SPIRV::Translator::ConstructJob(Compilation &C, const JobAction &JA,
                                     const InputInfo &Output,
                                     const InputInfoList &Inputs,
                                     const ArgList &Args,
                                     const char *LinkingOutput) const {
  claimNoWarnArgs(Args);
  if (Inputs.size() != 1)
    llvm_unreachable("Invalid number of input files.");
  constructTranslateCommand(C, *this, JA, Output, Inputs[0], {});
}

void SPIRV::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
                                    const InputInfo &Output,
                                    const InputInfoList &Inputs,
                                    const ArgList &Args,
                                    const char *AssembleOutput) const {
  claimNoWarnArgs(Args);
  if (Inputs.size() != 1)
    llvm_unreachable("Invalid number of input files.");
  constructAssembleCommand(C, *this, JA, Output, Inputs[0], {});
}

clang::driver::Tool *SPIRVToolChain::getAssembler() const {
  if (!Assembler)
    Assembler = std::make_unique<SPIRV::Assembler>(*this);
  return Assembler.get();
}

clang::driver::Tool *SPIRVToolChain::SelectTool(const JobAction &JA) const {
  Action::ActionClass AC = JA.getKind();
  return SPIRVToolChain::getTool(AC);
}

clang::driver::Tool *SPIRVToolChain::getTool(Action::ActionClass AC) const {
  switch (AC) {
  default:
    break;
  case Action::AssembleJobClass:
    return SPIRVToolChain::getAssembler();
  }
  return ToolChain::getTool(AC);
}
clang::driver::Tool *SPIRVToolChain::buildLinker() const {
  return new tools::SPIRV::Linker(*this);
}

void SPIRV::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                 const InputInfo &Output,
                                 const InputInfoList &Inputs,
                                 const ArgList &Args,
                                 const char *LinkingOutput) const {
  if (JA.getType() == types::TY_LLVM_BC) {
    constructLLVMLinkCommand(C, *this, JA, Output, Inputs, Args);
    return;
  }
  const ToolChain &ToolChain = getToolChain();
  std::string Linker = ToolChain.GetProgramPath(getShortName());
  ArgStringList CmdArgs;
  AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);

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

  // TODO: Consider moving SPIR-V linking to a separate tool.
  if (ToolChain.isUsingLTO(Args)) {
    // Implement limited LTO support through llvm-lto.
    if (Args.hasArg(options::OPT_sycl_link)) {
      // For unsupported cases, throw the same error as when LTO isn't supported
      // at all.
      C.getDriver().Diag(clang::diag::err_drv_no_linker_llvm_support)
          << ToolChain.getTriple().getTriple();
      return;
    }
    Linker = ToolChain.GetProgramPath("llvm-lto");
    // Disable internalization, otherwise GlobalDCE will optimize everything
    // out.
    CmdArgs.push_back("-enable-lto-internalization=false");
  } else if (Args.hasArg(options::OPT_sycl_link)) {
    // Use of --sycl-link will call the clang-sycl-linker instead of
    // the default linker (spirv-link).
    Linker = ToolChain.GetProgramPath("clang-sycl-linker");
    if (Args.hasArg(options::OPT_v))
      CmdArgs.push_back("-v");
  } else if (!llvm::sys::fs::can_execute(Linker) &&
             !C.getArgs().hasArg(clang::options::OPT__HASH_HASH_HASH)) {
    C.getDriver().Diag(clang::diag::err_drv_no_spv_tools) << getShortName();
    return;
  }
  C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                         Args.MakeArgString(Linker), CmdArgs,
                                         Inputs, Output));
}

SPIRVToolChain::SPIRVToolChain(const Driver &D, const llvm::Triple &Triple,
                               const ArgList &Args)
    : ToolChain(D, Triple, Args) {
  // TODO: Revisit need/use of --sycl-link option once SYCL toolchain is
  // available and SYCL linking support is moved there.
  NativeLLVMSupport = Args.hasArg(options::OPT_sycl_link) || isUsingLTO(Args);

  // Lookup binaries into the driver directory.
  getProgramPaths().push_back(getDriver().Dir);
}

bool SPIRVToolChain::HasNativeLLVMSupport() const { return NativeLLVMSupport; }