//===----- ABIInfo.h - ABI information access & encapsulation ---*- 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

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_LIB_CODEGEN_ABIINFO_H

#define LLVM_CLANG_LIB_CODEGEN_ABIINFO_H

#include "clang/AST/CharUnits.h"

#include "clang/AST/Type.h"

#include "llvm/IR/CallingConv.h"

#include "llvm/IR/Type.h"

namespace llvm {

class Value;

class LLVMContext;

class DataLayout;

class Type;

} // namespace llvm

namespace clang {

class ASTContext;

class CodeGenOptions;

class TargetInfo;

namespace CodeGen {

class ABIArgInfo;

class Address;

class CGCXXABI;

class CGFunctionInfo;

class CodeGenFunction;

class CodeGenTypes;

// FIXME: All of this stuff should be part of the target interface

// somehow. It is currently here because it is not clear how to factor

// the targets to support this, since the Targets currently live in a

// layer below types n'stuff.

/// ABIInfo - Target specific hooks for defining how a type should be

/// passed or returned from functions.

class ABIInfo {

protected:

  CodeGen::CodeGenTypes &CGT;

  llvm::CallingConv::ID RuntimeCC;

public:

  ABIInfo(CodeGen::CodeGenTypes &cgt)

      : CGT(cgt), RuntimeCC(llvm::CallingConv::C) {}

  virtual ~ABIInfo();

  virtual bool allowBFloatArgsAndRet() const { return false; }

  CodeGen::CGCXXABI &getCXXABI() const;

  ASTContext &getContext() const;

  llvm::LLVMContext &getVMContext() const;

  const llvm::DataLayout &getDataLayout() const;

  const TargetInfo &getTarget() const;

  const CodeGenOptions &getCodeGenOpts() const;

  /// Return the calling convention to use for system runtime

  /// functions.

  llvm::CallingConv::ID getRuntimeCC() const { return RuntimeCC; }

  virtual void computeInfo(CodeGen::CGFunctionInfo &FI) const = 0;

  /// EmitVAArg - Emit the target dependent code to load a value of

  /// \arg Ty from the va_list pointed to by \arg VAListAddr.

  // FIXME: This is a gaping layering violation if we wanted to drop

  // the ABI information any lower than CodeGen. Of course, for

  // VAArg handling it has to be at this level; there is no way to

  // abstract this out.

  virtual CodeGen::Address EmitVAArg(CodeGen::CodeGenFunction &CGF,

                                     CodeGen::Address VAListAddr,

                                     QualType Ty) const = 0;

  bool isAndroid() const;

  bool isOHOSFamily() const;

  /// Emit the target dependent code to load a value of

  /// \arg Ty from the \c __builtin_ms_va_list pointed to by \arg VAListAddr.

  virtual CodeGen::Address EmitMSVAArg(CodeGen::CodeGenFunction &CGF,

                                       CodeGen::Address VAListAddr,

                                       QualType Ty) const;

  virtual bool isHomogeneousAggregateBaseType(QualType Ty) const;

  virtual bool isHomogeneousAggregateSmallEnough(const Type *Base,

                                                 uint64_t Members) const;

  virtual bool isZeroLengthBitfieldPermittedInHomogeneousAggregate() const;

  /// isHomogeneousAggregate - Return true if a type is an ELFv2 homogeneous

  /// aggregate.  Base is set to the base element type, and Members is set

  /// to the number of base elements.

  bool isHomogeneousAggregate(QualType Ty, const Type *&Base,

                              uint64_t &Members) const;

  // Implement the Type::IsPromotableIntegerType for ABI specific needs. The

  // only difference is that this considers bit-precise integer types as well.

  bool isPromotableIntegerTypeForABI(QualType Ty) const;

  /// A convenience method to return an indirect ABIArgInfo with an

  /// expected alignment equal to the ABI alignment of the given type.

  CodeGen::ABIArgInfo

  getNaturalAlignIndirect(QualType Ty, bool ByVal = true, bool Realign = false,

                          llvm::Type *Padding = nullptr) const;

  CodeGen::ABIArgInfo getNaturalAlignIndirectInReg(QualType Ty,

                                                   bool Realign = false) const;

};

/// Target specific hooks for defining how a type should be passed or returned

/// from functions with one of the Swift calling conventions.

class SwiftABIInfo {

protected:

  CodeGenTypes &CGT;

  bool SwiftErrorInRegister;

  bool occupiesMoreThan(ArrayRef<llvm::Type *> scalarTypes,

                        unsigned maxAllRegisters) const;

public:

  SwiftABIInfo(CodeGen::CodeGenTypes &CGT, bool SwiftErrorInRegister)

      : CGT(CGT), SwiftErrorInRegister(SwiftErrorInRegister) {}

  virtual ~SwiftABIInfo();

  /// Returns true if an aggregate which expands to the given type sequence

  /// should be passed / returned indirectly.

  virtual bool shouldPassIndirectly(ArrayRef<llvm::Type *> ComponentTys,

                                    bool AsReturnValue) const;

  /// Returns true if the given vector type is legal from Swift's calling

  /// convention perspective.

  virtual bool isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,

                                 unsigned NumElts) const;

  /// Returns true if swifterror is lowered to a register by the target ABI.

  bool isSwiftErrorInRegister() const { return SwiftErrorInRegister; };

};

} // end namespace CodeGen

} // end namespace clang

#endif