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