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      1 //===----- ABIInfo.h - ABI information access & encapsulation ---*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #ifndef LLVM_CLANG_LIB_CODEGEN_ABIINFO_H
     11 #define LLVM_CLANG_LIB_CODEGEN_ABIINFO_H
     12 
     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 }
     22 
     23 namespace clang {
     24   class ASTContext;
     25   class TargetInfo;
     26 
     27   namespace CodeGen {
     28     class ABIArgInfo;
     29     class Address;
     30     class CGCXXABI;
     31     class CGFunctionInfo;
     32     class CodeGenFunction;
     33     class CodeGenTypes;
     34   }
     35 
     36   // FIXME: All of this stuff should be part of the target interface
     37   // somehow. It is currently here because it is not clear how to factor
     38   // the targets to support this, since the Targets currently live in a
     39   // layer below types n'stuff.
     40 
     41 
     42   /// ABIInfo - Target specific hooks for defining how a type should be
     43   /// passed or returned from functions.
     44   class ABIInfo {
     45   public:
     46     CodeGen::CodeGenTypes &CGT;
     47   protected:
     48     llvm::CallingConv::ID RuntimeCC;
     49     llvm::CallingConv::ID BuiltinCC;
     50   public:
     51     ABIInfo(CodeGen::CodeGenTypes &cgt)
     52       : CGT(cgt),
     53         RuntimeCC(llvm::CallingConv::C),
     54         BuiltinCC(llvm::CallingConv::C) {}
     55 
     56     virtual ~ABIInfo();
     57 
     58     CodeGen::CGCXXABI &getCXXABI() const;
     59     ASTContext &getContext() const;
     60     llvm::LLVMContext &getVMContext() const;
     61     const llvm::DataLayout &getDataLayout() const;
     62     const TargetInfo &getTarget() const;
     63 
     64     /// Return the calling convention to use for system runtime
     65     /// functions.
     66     llvm::CallingConv::ID getRuntimeCC() const {
     67       return RuntimeCC;
     68     }
     69 
     70     /// Return the calling convention to use for compiler builtins
     71     llvm::CallingConv::ID getBuiltinCC() const {
     72       return BuiltinCC;
     73     }
     74 
     75     virtual void computeInfo(CodeGen::CGFunctionInfo &FI) const = 0;
     76 
     77     /// EmitVAArg - Emit the target dependent code to load a value of
     78     /// \arg Ty from the va_list pointed to by \arg VAListAddr.
     79 
     80     // FIXME: This is a gaping layering violation if we wanted to drop
     81     // the ABI information any lower than CodeGen. Of course, for
     82     // VAArg handling it has to be at this level; there is no way to
     83     // abstract this out.
     84     virtual CodeGen::Address EmitVAArg(CodeGen::CodeGenFunction &CGF,
     85                                        CodeGen::Address VAListAddr,
     86                                        QualType Ty) const = 0;
     87 
     88     /// Emit the target dependent code to load a value of
     89     /// \arg Ty from the \c __builtin_ms_va_list pointed to by \arg VAListAddr.
     90     virtual CodeGen::Address EmitMSVAArg(CodeGen::CodeGenFunction &CGF,
     91                                          CodeGen::Address VAListAddr,
     92                                          QualType Ty) const;
     93 
     94     virtual bool isHomogeneousAggregateBaseType(QualType Ty) const;
     95 
     96     virtual bool isHomogeneousAggregateSmallEnough(const Type *Base,
     97                                                    uint64_t Members) const;
     98 
     99     virtual bool shouldSignExtUnsignedType(QualType Ty) const;
    100 
    101     bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
    102                                 uint64_t &Members) const;
    103 
    104     /// A convenience method to return an indirect ABIArgInfo with an
    105     /// expected alignment equal to the ABI alignment of the given type.
    106     CodeGen::ABIArgInfo
    107     getNaturalAlignIndirect(QualType Ty, bool ByRef = true,
    108                             bool Realign = false,
    109                             llvm::Type *Padding = nullptr) const;
    110 
    111     CodeGen::ABIArgInfo
    112     getNaturalAlignIndirectInReg(QualType Ty, bool Realign = false) const;
    113   };
    114 }  // end namespace clang
    115 
    116 #endif
    117