clang/lib/CodeGen/ABIInfo.h

   1 //===----- ABIInfo.h - ABI information access & encapsulation ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_CLANG_LIB_CODEGEN_ABIINFO_H
  10 #define LLVM_CLANG_LIB_CODEGEN_ABIINFO_H
  11
  12 #include "clang/AST/Attr.h"
  13 #include "clang/AST/CharUnits.h"
  14 #include "clang/AST/Type.h"
  15 #include "llvm/IR/CallingConv.h"
  16 #include "llvm/IR/Type.h"
  17
  18 namespace llvm {
  19 class Value;
  20 class LLVMContext;
  21 class DataLayout;
  22 class Type;
  23 } // namespace llvm
  24
  25 namespace clang {
  26 class ASTContext;
  27 class CodeGenOptions;
  28 class TargetInfo;
  29
  30 namespace CodeGen {
  31 class ABIArgInfo;
  32 class Address;
  33 class CGCXXABI;
  34 class CGFunctionInfo;
  35 class CodeGenFunction;
  36 class CodeGenTypes;
  37 class RValue;
  38 class AggValueSlot;
  39
  40 // FIXME: All of this stuff should be part of the target interface
  41 // somehow. It is currently here because it is not clear how to factor
  42 // the targets to support this, since the Targets currently live in a
  43 // layer below types n'stuff.
  44
  45 /// ABIInfo - Target specific hooks for defining how a type should be
  46 /// passed or returned from functions.
  47 class ABIInfo {
  48 protected:
  49   CodeGen::CodeGenTypes &CGT;
  50   llvm::CallingConv::ID RuntimeCC;
  51
  52 public:
  53   ABIInfo(CodeGen::CodeGenTypes &cgt)
  54       : CGT(cgt), RuntimeCC(llvm::CallingConv::C) {}
  55
  56   virtual ~ABIInfo();
  57
  58   virtual bool allowBFloatArgsAndRet() const { return false; }
  59
  60   CodeGen::CGCXXABI &getCXXABI() const;
  61   ASTContext &getContext() const;
  62   llvm::LLVMContext &getVMContext() const;
  63   const llvm::DataLayout &getDataLayout() const;
  64   const TargetInfo &getTarget() const;
  65   const CodeGenOptions &getCodeGenOpts() const;
  66
  67   /// Return the calling convention to use for system runtime
  68   /// functions.
  69   llvm::CallingConv::ID getRuntimeCC() const { return RuntimeCC; }
  70
  71   virtual void computeInfo(CodeGen::CGFunctionInfo &FI) const = 0;
  72
  73   /// EmitVAArg - Emit the target dependent code to load a value of
  74   /// \arg Ty from the va_list pointed to by \arg VAListAddr.
  75
  76   // FIXME: This is a gaping layering violation if we wanted to drop
  77   // the ABI information any lower than CodeGen. Of course, for
  78   // VAArg handling it has to be at this level; there is no way to
  79   // abstract this out.
  80   virtual RValue EmitVAArg(CodeGen::CodeGenFunction &CGF,
  81                            CodeGen::Address VAListAddr, QualType Ty,
  82                            AggValueSlot Slot) const = 0;
  83
  84   bool isAndroid() const;
  85   bool isOHOSFamily() const;
  86
  87   /// Emit the target dependent code to load a value of
  88   /// \arg Ty from the \c __builtin_ms_va_list pointed to by \arg VAListAddr.
  89   virtual RValue EmitMSVAArg(CodeGen::CodeGenFunction &CGF,
  90                              CodeGen::Address VAListAddr, QualType Ty,
  91                              AggValueSlot Slot) const;
  92
  93   virtual bool isHomogeneousAggregateBaseType(QualType Ty) const;
  94
  95   virtual bool isHomogeneousAggregateSmallEnough(const Type *Base,
  96                                                  uint64_t Members) const;
  97   virtual bool isZeroLengthBitfieldPermittedInHomogeneousAggregate() const;
  98
  99   /// isHomogeneousAggregate - Return true if a type is an ELFv2 homogeneous
 100   /// aggregate.  Base is set to the base element type, and Members is set
 101   /// to the number of base elements.
 102   bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
 103                               uint64_t &Members) const;
 104
 105   // Implement the Type::IsPromotableIntegerType for ABI specific needs. The
 106   // only difference is that this considers bit-precise integer types as well.
 107   bool isPromotableIntegerTypeForABI(QualType Ty) const;
 108
 109   /// A convenience method to return an indirect ABIArgInfo with an
 110   /// expected alignment equal to the ABI alignment of the given type.
 111   CodeGen::ABIArgInfo
 112   getNaturalAlignIndirect(QualType Ty, bool ByVal = true, bool Realign = false,
 113                           llvm::Type *Padding = nullptr) const;
 114
 115   CodeGen::ABIArgInfo getNaturalAlignIndirectInReg(QualType Ty,
 116                                                    bool Realign = false) const;
 117
 118   virtual void appendAttributeMangling(TargetAttr *Attr,
 119                                        raw_ostream &Out) const;
 120   virtual void appendAttributeMangling(TargetVersionAttr *Attr,
 121                                        raw_ostream &Out) const;
 122   virtual void appendAttributeMangling(TargetClonesAttr *Attr, unsigned Index,
 123                                        raw_ostream &Out) const;
 124   virtual void appendAttributeMangling(StringRef AttrStr,
 125                                        raw_ostream &Out) const;
 126 };
 127
 128 /// Target specific hooks for defining how a type should be passed or returned
 129 /// from functions with one of the Swift calling conventions.
 130 class SwiftABIInfo {
 131 protected:
 132   CodeGenTypes &CGT;
 133   bool SwiftErrorInRegister;
 134
 135   bool occupiesMoreThan(ArrayRef<llvm::Type *> scalarTypes,
 136                         unsigned maxAllRegisters) const;
 137
 138 public:
 139   SwiftABIInfo(CodeGen::CodeGenTypes &CGT, bool SwiftErrorInRegister)
 140       : CGT(CGT), SwiftErrorInRegister(SwiftErrorInRegister) {}
 141
 142   virtual ~SwiftABIInfo();
 143
 144   /// Returns true if an aggregate which expands to the given type sequence
 145   /// should be passed / returned indirectly.
 146   virtual bool shouldPassIndirectly(ArrayRef<llvm::Type *> ComponentTys,
 147                                     bool AsReturnValue) const;
 148
 149   /// Returns true if the given vector type is legal from Swift's calling
 150   /// convention perspective.
 151   virtual bool isLegalVectorType(CharUnits VectorSize, llvm::Type *EltTy,
 152                                  unsigned NumElts) const;
 153
 154   /// Returns true if swifterror is lowered to a register by the target ABI.
 155   bool isSwiftErrorInRegister() const { return SwiftErrorInRegister; };
 156 };
 157 } // end namespace CodeGen
 158 } // end namespace clang
 159
 160 #endif