//===----- CGHLSLRuntime.cpp - Interface to HLSL Runtimes -----------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This provides an abstract class for HLSL code generation.  Concrete
// subclasses of this implement code generation for specific HLSL
// runtime libraries.
//
//===----------------------------------------------------------------------===//

#include "CGHLSLRuntime.h"
#include "CodeGenModule.h"
#include "clang/Basic/TargetOptions.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"

using namespace clang;
using namespace CodeGen;
using namespace hlsl;
using namespace llvm;

namespace {
void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
  // The validation of ValVersionStr is done at HLSLToolChain::TranslateArgs.
  // Assume ValVersionStr is legal here.
  VersionTuple Version;
  if (Version.tryParse(ValVersionStr) || Version.getBuild() ||
      Version.getSubminor() || !Version.getMinor()) {
    return;
  }

  uint64_t Major = Version.getMajor();
  uint64_t Minor = *Version.getMinor();

  auto &Ctx = M.getContext();
  IRBuilder<> B(M.getContext());
  MDNode *Val = MDNode::get(Ctx, {ConstantAsMetadata::get(B.getInt32(Major)),
                                  ConstantAsMetadata::get(B.getInt32(Minor))});
  StringRef DxilValKey = "dx.valver";
  M.addModuleFlag(llvm::Module::ModFlagBehavior::AppendUnique, DxilValKey, Val);
}
} // namespace

void CGHLSLRuntime::finishCodeGen() {
  auto &TargetOpts = CGM.getTarget().getTargetOpts();

  llvm::Module &M = CGM.getModule();
  addDxilValVersion(TargetOpts.DxilValidatorVersion, M);
}

void CGHLSLRuntime::annotateHLSLResource(const VarDecl *D, GlobalVariable *GV) {
  const Type *Ty = D->getType()->getPointeeOrArrayElementType();
  if (!Ty)
    return;
  const auto *RD = Ty->getAsCXXRecordDecl();
  if (!RD)
    return;
  const auto *Attr = RD->getAttr<HLSLResourceAttr>();
  if (!Attr)
    return;

  HLSLResourceAttr::ResourceClass RC = Attr->getResourceType();
  uint32_t Counter = ResourceCounters[static_cast<uint32_t>(RC)]++;

  NamedMDNode *ResourceMD = nullptr;
  switch (RC) {
  case HLSLResourceAttr::ResourceClass::UAV:
    ResourceMD = CGM.getModule().getOrInsertNamedMetadata("hlsl.uavs");
    break;
  default:
    assert(false && "Unsupported buffer type!");
    return;
  }

  assert(ResourceMD != nullptr &&
         "ResourceMD must have been set by the switch above.");

  auto &Ctx = CGM.getModule().getContext();
  IRBuilder<> B(Ctx);
  QualType QT(Ty, 0);
  ResourceMD->addOperand(MDNode::get(
      Ctx, {ValueAsMetadata::get(GV), MDString::get(Ctx, QT.getAsString()),
            ConstantAsMetadata::get(B.getInt32(Counter))}));
}

void clang::CodeGen::CGHLSLRuntime::setHLSLFunctionAttributes(
    llvm::Function *F, const FunctionDecl *FD) {
  if (HLSLShaderAttr *ShaderAttr = FD->getAttr<HLSLShaderAttr>()) {
    const StringRef ShaderAttrKindStr = "dx.shader";
    F->addFnAttr(ShaderAttrKindStr,
                 ShaderAttr->ConvertShaderTypeToStr(ShaderAttr->getType()));
  }
}