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