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   class Type;
22 }
23 
24 namespace clang {
25   class ASTContext;
26   class TargetInfo;
27 
28 namespace CodeGen {
29   class ABIArgInfo;
30   class Address;
31   class CGCXXABI;
32   class CGFunctionInfo;
33   class CodeGenFunction;
34   class CodeGenTypes;
35   class SwiftABIInfo;
36 
37 namespace swiftcall {
38   class SwiftAggLowering;
39 }
40 
41   // FIXME: All of this stuff should be part of the target interface
42   // somehow. It is currently here because it is not clear how to factor
43   // the targets to support this, since the Targets currently live in a
44   // layer below types n'stuff.
45 
46 
47   /// ABIInfo - Target specific hooks for defining how a type should be
48   /// passed or returned from functions.
49   class ABIInfo {
50   public:
51     CodeGen::CodeGenTypes &CGT;
52   protected:
53     llvm::CallingConv::ID RuntimeCC;
54     llvm::CallingConv::ID BuiltinCC;
55   public:
ABIInfo(CodeGen::CodeGenTypes & cgt)56     ABIInfo(CodeGen::CodeGenTypes &cgt)
57       : CGT(cgt),
58         RuntimeCC(llvm::CallingConv::C),
59         BuiltinCC(llvm::CallingConv::C) {}
60 
61     virtual ~ABIInfo();
62 
supportsSwift()63     virtual bool supportsSwift() const { return false; }
64 
65     CodeGen::CGCXXABI &getCXXABI() const;
66     ASTContext &getContext() const;
67     llvm::LLVMContext &getVMContext() const;
68     const llvm::DataLayout &getDataLayout() const;
69     const TargetInfo &getTarget() const;
70 
71     /// Return the calling convention to use for system runtime
72     /// functions.
getRuntimeCC()73     llvm::CallingConv::ID getRuntimeCC() const {
74       return RuntimeCC;
75     }
76 
77     /// Return the calling convention to use for compiler builtins
getBuiltinCC()78     llvm::CallingConv::ID getBuiltinCC() const {
79       return BuiltinCC;
80     }
81 
82     virtual void computeInfo(CodeGen::CGFunctionInfo &FI) const = 0;
83 
84     /// EmitVAArg - Emit the target dependent code to load a value of
85     /// \arg Ty from the va_list pointed to by \arg VAListAddr.
86 
87     // FIXME: This is a gaping layering violation if we wanted to drop
88     // the ABI information any lower than CodeGen. Of course, for
89     // VAArg handling it has to be at this level; there is no way to
90     // abstract this out.
91     virtual CodeGen::Address EmitVAArg(CodeGen::CodeGenFunction &CGF,
92                                        CodeGen::Address VAListAddr,
93                                        QualType Ty) const = 0;
94 
95     bool isAndroid() const;
96 
97     /// Emit the target dependent code to load a value of
98     /// \arg Ty from the \c __builtin_ms_va_list pointed to by \arg VAListAddr.
99     virtual CodeGen::Address EmitMSVAArg(CodeGen::CodeGenFunction &CGF,
100                                          CodeGen::Address VAListAddr,
101                                          QualType Ty) const;
102 
103     virtual bool isHomogeneousAggregateBaseType(QualType Ty) const;
104 
105     virtual bool isHomogeneousAggregateSmallEnough(const Type *Base,
106                                                    uint64_t Members) const;
107 
108     virtual bool shouldSignExtUnsignedType(QualType Ty) const;
109 
110     bool isHomogeneousAggregate(QualType Ty, const Type *&Base,
111                                 uint64_t &Members) const;
112 
113     /// A convenience method to return an indirect ABIArgInfo with an
114     /// expected alignment equal to the ABI alignment of the given type.
115     CodeGen::ABIArgInfo
116     getNaturalAlignIndirect(QualType Ty, bool ByRef = true,
117                             bool Realign = false,
118                             llvm::Type *Padding = nullptr) const;
119 
120     CodeGen::ABIArgInfo
121     getNaturalAlignIndirectInReg(QualType Ty, bool Realign = false) const;
122 
123 
124   };
125 
126   /// A refining implementation of ABIInfo for targets that support swiftcall.
127   ///
128   /// If we find ourselves wanting multiple such refinements, they'll probably
129   /// be independent refinements, and we should probably find another way
130   /// to do it than simple inheritance.
131   class SwiftABIInfo : public ABIInfo {
132   public:
SwiftABIInfo(CodeGen::CodeGenTypes & cgt)133     SwiftABIInfo(CodeGen::CodeGenTypes &cgt) : ABIInfo(cgt) {}
134 
supportsSwift()135     bool supportsSwift() const final override { return true; }
136 
137     virtual bool shouldPassIndirectlyForSwift(CharUnits totalSize,
138                                               ArrayRef<llvm::Type*> types,
139                                               bool asReturnValue) const = 0;
140 
141     virtual bool isLegalVectorTypeForSwift(CharUnits totalSize,
142                                            llvm::Type *eltTy,
143                                            unsigned elts) const;
144 
classof(const ABIInfo * info)145     static bool classof(const ABIInfo *info) {
146       return info->supportsSwift();
147     }
148   };
149 
150 }  // end namespace CodeGen
151 }  // end namespace clang
152 
153 #endif
154