clang 10.0.0git

CodeGenTypes.h
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1 //===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- 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 // This is the code that handles AST -> LLVM type lowering.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
14 #define LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H
15
16 #include "CGCall.h"
17 #include "clang/Basic/ABI.h"
18 #include "clang/CodeGen/CGFunctionInfo.h"
19 #include "llvm/ADT/DenseMap.h"
20 #include "llvm/IR/Module.h"
21
22 namespace llvm {
23 class FunctionType;
24 class DataLayout;
25 class Type;
26 class LLVMContext;
27 class StructType;
28 }
29
30 namespace clang {
31 class ASTContext;
32 template <typename> class CanQual;
33 class CXXConstructorDecl;
34 class CXXDestructorDecl;
35 class CXXMethodDecl;
36 class CodeGenOptions;
37 class FieldDecl;
38 class FunctionProtoType;
39 class ObjCInterfaceDecl;
40 class ObjCIvarDecl;
41 class PointerType;
42 class QualType;
43 class RecordDecl;
44 class TagDecl;
45 class TargetInfo;
46 class Type;
47 typedef CanQual<Type> CanQualType;
48 class GlobalDecl;
49
50 namespace CodeGen {
51 class ABIInfo;
52 class CGCXXABI;
53 class CGRecordLayout;
54 class CodeGenModule;
55 class RequiredArgs;
56
57 /// This class organizes the cross-module state that is used while lowering
58 /// AST types to LLVM types.
59 class CodeGenTypes {
60 CodeGenModule &CGM;
61 // Some of this stuff should probably be left on the CGM.
62 ASTContext &Context;
63 llvm::Module &TheModule;
64 const TargetInfo &Target;
65 CGCXXABI &TheCXXABI;
66
67 // This should not be moved earlier, since its initialization depends on some
68 // of the previous reference members being already initialized
69 const ABIInfo &TheABIInfo;
70
71 /// The opaque type map for Objective-C interfaces. All direct
72 /// manipulation is done by the runtime interfaces, which are
73 /// responsible for coercing to the appropriate type; these opaque
74 /// types are never refined.
75 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes;
76
77 /// Maps clang struct type with corresponding record layout info.
78 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts;
79
80 /// Contains the LLVM IR type for any converted RecordDecl.
81 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes;
82
83 /// Hold memoized CGFunctionInfo results.
84 llvm::FoldingSet<CGFunctionInfo> FunctionInfos;
85
86 /// This set keeps track of records that we're currently converting
87 /// to an IR type. For example, when converting:
88 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B'
89 /// types will be in this set.
90 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut;
91
92 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed;
93
94 /// True if we didn't layout a function due to a being inside
95 /// a recursive struct conversion, set this to true.
96 bool SkippedLayout;
97
98 SmallVector<const RecordDecl *, 8> DeferredRecords;
99
100 /// This map keeps cache of llvm::Types and maps clang::Type to
101 /// corresponding llvm::Type.
102 llvm::DenseMap<const Type *, llvm::Type *> TypeCache;
103
104 llvm::SmallSet<const Type *, 8> RecordsWithOpaqueMemberPointers;
105
106 /// Helper for ConvertType.
107 llvm::Type *ConvertFunctionTypeInternal(QualType FT);
108
109 public:
110 CodeGenTypes(CodeGenModule &cgm);
111 ~CodeGenTypes();
112
113 const llvm::DataLayout &getDataLayout() const {
114 return TheModule.getDataLayout();
115 }
116 ASTContext &getContext() const { return Context; }
117 const ABIInfo &getABIInfo() const { return TheABIInfo; }
118 const TargetInfo &getTarget() const { return Target; }
119 CGCXXABI &getCXXABI() const { return TheCXXABI; }
120 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); }
121 const CodeGenOptions &getCodeGenOpts() const;
122
123 /// Convert clang calling convention to LLVM callilng convention.
124 unsigned ClangCallConvToLLVMCallConv(CallingConv CC);
125
126 /// Derives the 'this' type for codegen purposes, i.e. ignoring method CVR
127 /// qualification.
128 CanQualType DeriveThisType(const CXXRecordDecl *RD, const CXXMethodDecl *MD);
129
130 /// ConvertType - Convert type T into a llvm::Type.
131 llvm::Type *ConvertType(QualType T);
132
133 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from
134 /// ConvertType in that it is used to convert to the memory representation for
135 /// a type. For example, the scalar representation for _Bool is i1, but the
136 /// memory representation is usually i8 or i32, depending on the target.
137 llvm::Type *ConvertTypeForMem(QualType T);
138
139 /// GetFunctionType - Get the LLVM function type for \arg Info.
140 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info);
141
142 llvm::FunctionType *GetFunctionType(GlobalDecl GD);
143
144 /// isFuncTypeConvertible - Utility to check whether a function type can
145 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag
146 /// type).
147 bool isFuncTypeConvertible(const FunctionType *FT);
148 bool isFuncParamTypeConvertible(QualType Ty);
149
150 /// Determine if a C++ inheriting constructor should have parameters matching
151 /// those of its inherited constructor.
152 bool inheritingCtorHasParams(const InheritedConstructor &Inherited,
153 CXXCtorType Type);
154
155 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable,
156 /// given a CXXMethodDecl. If the method to has an incomplete return type,
157 /// and/or incomplete argument types, this will return the opaque type.
158 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD);
159
160 const CGRecordLayout &getCGRecordLayout(const RecordDecl*);
161
162 /// UpdateCompletedType - When we find the full definition for a TagDecl,
163 /// replace the 'opaque' type we previously made for it if applicable.
164 void UpdateCompletedType(const TagDecl *TD);
165
166 /// Remove stale types from the type cache when an inheritance model
167 /// gets assigned to a class.
168 void RefreshTypeCacheForClass(const CXXRecordDecl *RD);
169
170 // The arrangement methods are split into three families:
171 // - those meant to drive the signature and prologue/epilogue
172 // of a function declaration or definition,
173 // - those meant for the computation of the LLVM type for an abstract
174 // appearance of a function, and
175 // - those meant for performing the IR-generation of a call.
176 // They differ mainly in how they deal with optional (i.e. variadic)
177 // arguments, as well as unprototyped functions.
178 //
179 // Key points:
180 // - The CGFunctionInfo for emitting a specific call site must include
181 // entries for the optional arguments.
182 // - The function type used at the call site must reflect the formal
183 // signature of the declaration being called, or else the call will
184 // go awry.
185 // - For the most part, unprototyped functions are called by casting to
186 // a formal signature inferred from the specific argument types used
187 // at the call-site. However, some targets (e.g. x86-64) screw with
188 // this for compatibility reasons.
189
190 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD);
191
192 /// Given a function info for a declaration, return the function info
193 /// for a call with the given arguments.
194 ///
195 /// Often this will be able to simply return the declaration info.
196 const CGFunctionInfo &arrangeCall(const CGFunctionInfo &declFI,
197 const CallArgList &args);
198
199 /// Free functions are functions that are compatible with an ordinary
200 /// C function pointer type.
201 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD);
202 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args,
203 const FunctionType *Ty,
204 bool ChainCall);
205 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty);
206 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty);
207
208 /// A nullary function is a freestanding function of type 'void ()'.
209 /// This method works for both calls and declarations.
210 const CGFunctionInfo &arrangeNullaryFunction();
211
212 /// A builtin function is a freestanding function using the default
213 /// C conventions.
214 const CGFunctionInfo &
215 arrangeBuiltinFunctionDeclaration(QualType resultType,
216 const FunctionArgList &args);
217 const CGFunctionInfo &
218 arrangeBuiltinFunctionDeclaration(CanQualType resultType,
219 ArrayRef<CanQualType> argTypes);
220 const CGFunctionInfo &arrangeBuiltinFunctionCall(QualType resultType,
221 const CallArgList &args);
222
223 /// Objective-C methods are C functions with some implicit parameters.
224 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD);
225 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD,
226 QualType receiverType);
227 const CGFunctionInfo &arrangeUnprototypedObjCMessageSend(
228 QualType returnType,
229 const CallArgList &args);
230
231 /// Block invocation functions are C functions with an implicit parameter.
232 const CGFunctionInfo &arrangeBlockFunctionDeclaration(
233 const FunctionProtoType *type,
234 const FunctionArgList &args);
235 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args,
236 const FunctionType *type);
237
238 /// C++ methods have some special rules and also have implicit parameters.
239 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD);
240 const CGFunctionInfo &arrangeCXXStructorDeclaration(GlobalDecl GD);
241 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args,
242 const CXXConstructorDecl *D,
243 CXXCtorType CtorKind,
244 unsigned ExtraPrefixArgs,
245 unsigned ExtraSuffixArgs,
246 bool PassProtoArgs = true);
247
248 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args,
249 const FunctionProtoType *type,
250 RequiredArgs required,
251 unsigned numPrefixArgs);
252 const CGFunctionInfo &
253 arrangeUnprototypedMustTailThunk(const CXXMethodDecl *MD);
254 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD,
255 CXXCtorType CT);
256 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD,
257 const FunctionProtoType *FTP,
258 const CXXMethodDecl *MD);
259
260 /// "Arrange" the LLVM information for a call or type with the given
261 /// signature. This is largely an internal method; other clients
262 /// should use one of the above routines, which ultimately defer to
263 /// this.
264 ///
265 /// \param argTypes - must all actually be canonical as params
266 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType,
267 bool instanceMethod,
268 bool chainCall,
269 ArrayRef<CanQualType> argTypes,
270 FunctionType::ExtInfo info,
271 ArrayRef<FunctionProtoType::ExtParameterInfo> paramInfos,
272 RequiredArgs args);
273
274 /// Compute a new LLVM record layout object for the given record.
275 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D,
276 llvm::StructType *Ty);
277
278 /// addRecordTypeName - Compute a name from the given record decl with an
279 /// optional suffix and name the given LLVM type using it.
280 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty,
281 StringRef suffix);
282
283
284 public: // These are internal details of CGT that shouldn't be used externally.
285 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
286 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD);
287
288 /// getExpandedTypes - Expand the type \arg Ty into the LLVM
289 /// argument types it would be passed as. See ABIArgInfo::Expand.
290 void getExpandedTypes(QualType Ty,
291 SmallVectorImpl<llvm::Type *>::iterator &TI);
292
293 /// IsZeroInitializable - Return whether a type can be
294 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
295 bool isZeroInitializable(QualType T);
296
297 /// Check if the pointer type can be zero-initialized (in the C++ sense)
298 /// with an LLVM zeroinitializer.
299 bool isPointerZeroInitializable(QualType T);
300
301 /// IsZeroInitializable - Return whether a record type can be
302 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer.
303 bool isZeroInitializable(const RecordDecl *RD);
304
305 bool isRecordLayoutComplete(const Type *Ty) const;
306 bool noRecordsBeingLaidOut() const {
307 return RecordsBeingLaidOut.empty();
308 }
309 bool isRecordBeingLaidOut(const Type *Ty) const {
310 return RecordsBeingLaidOut.count(Ty);
311 }
312
313 };
314
315 } // end namespace CodeGen
316 } // end namespace clang
317
318 #endif
clang::CodeGen::CodeGenTypes::noRecordsBeingLaidOut
bool noRecordsBeingLaidOut() const
Definition: CodeGenTypes.h:306
clang::CodeGen::CodeGenTypes::getCXXABI
CGCXXABI & getCXXABI() const
Definition: CodeGenTypes.h:119
clang::FunctionDecl
Represents a function declaration or definition.
Definition: Decl.h:1783
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:654
CGCall.h
clang::CodeGen::CGRecordLayout
CGRecordLayout - This class handles struct and union layout info while lowering AST types to LLVM typ...
Definition: CGRecordLayout.h:108
llvm
Specialize PointerLikeTypeTraits to allow LazyGenerationalUpdatePtr to be placed into a PointerUnion...
Definition: Dominators.h:30
clang::CodeGen::CodeGenTypes::getABIInfo
const ABIInfo & getABIInfo() const
Definition: CodeGenTypes.h:117
clang::FunctionType
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3422
clang::CodeGen::CodeGenTypes::isRecordBeingLaidOut
bool isRecordBeingLaidOut(const Type *Ty) const
Definition: CodeGenTypes.h:309
clang::CodeGen::CodeGenTypes::getDataLayout
const llvm::DataLayout & getDataLayout() const
Definition: CodeGenTypes.h:113
clang::Type
The base class of the type hierarchy.
Definition: Type.h:1450
clang::CodeGen::arrangeFreeFunctionType
const CGFunctionInfo & arrangeFreeFunctionType(CodeGenModule &CGM, CanQual< FunctionProtoType > Ty)
Definition: CodeGenABITypes.cpp:36
clang::CXXConstructorDecl
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2383
clang::ObjCMethodDecl
ObjCMethodDecl - Represents an instance or class method declaration.
Definition: DeclObjC.h:138
arrangeLLVMFunctionInfo
static const CGFunctionInfo & arrangeLLVMFunctionInfo(CodeGenTypes &CGT, bool instanceMethod, SmallVectorImpl< CanQualType > &prefix, CanQual< FunctionProtoType > FTP)
Arrange the LLVM function layout for a value of the given function type, on top of any implicit param...
Definition: CGCall.cpp:176
clang::CodeGen::arrangeCXXMethodType
const CGFunctionInfo & arrangeCXXMethodType(CodeGenModule &CGM, const CXXRecordDecl *RD, const FunctionProtoType *FTP, const CXXMethodDecl *MD)
Definition: CodeGenABITypes.cpp:48
clang::MultiVersionKind::Target
clang::RecordDecl
Represents a struct/union/class.
Definition: Decl.h:3748
clang::InheritedConstructor
Description of a constructor that was inherited from a base class.
Definition: DeclCXX.h:2357
clang::ASTContext
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:168
llvm::SmallVectorImpl
Definition: LLVM.h:36
ABI.h
Enums/classes describing ABI related information about constructors, destructors and thunks...
CGFunctionInfo.h
llvm::ArrayRef
Definition: LLVM.h:31
clang::CodeGen::arrangeObjCMessageSendSignature
const CGFunctionInfo & arrangeObjCMessageSendSignature(CodeGenModule &CGM, const ObjCMethodDecl *MD, QualType receiverType)
Definition: CodeGenABITypes.cpp:29
clang::FunctionProtoType
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3754
clang::TargetInfo
Exposes information about the current target.
Definition: TargetInfo.h:164
clang::CodeGen::RequiredArgs
A class for recording the number of arguments that a function signature requires. ...
Definition: CGFunctionInfo.h:410
clang::CallingConv
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:265
clang::GlobalDecl
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:40
clang::TagDecl
Represents the declaration of a struct/union/class/enum.
Definition: Decl.h:3219
clang::CXXMethodDecl
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1931
clang::CodeGen::arrangeFreeFunctionCall
const CGFunctionInfo & arrangeFreeFunctionCall(CodeGenModule &CGM, CanQualType returnType, ArrayRef< CanQualType > argTypes, FunctionType::ExtInfo info, RequiredArgs args)
Definition: CodeGenABITypes.cpp:56
clang::CanQual< FunctionProtoType >
clang::CanQualType
CanQual< Type > CanQualType
Represents a canonical, potentially-qualified type.
Definition: CanonicalType.h:212
llvm::SmallVector
Definition: LLVM.h:35
clang::CodeGen::CodeGenTypes::getLLVMContext
llvm::LLVMContext & getLLVMContext()
Definition: CodeGenTypes.h:120
clang::CXXCtorType
CXXCtorType
C++ constructor types.
Definition: ABI.h:24
clang::CodeGen::FunctionArgList
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:355
clang::CodeGen::CodeGenTypes::getTarget
const TargetInfo & getTarget() const
Definition: CodeGenTypes.h:118
clang::CodeGen::CGFunctionInfo
CGFunctionInfo - Class to encapsulate the information about a function definition.
Definition: CGFunctionInfo.h:476
clang::CodeGen::CodeGenModule
This class organizes the cross-function state that is used while generating LLVM code.
Definition: CodeGenModule.h:280
Type
Optional< types::ID > Type
Definition: InterpolatingCompilationDatabase.cpp:127
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:21
type
clang::CodeGen::CGCXXABI
Implements C++ ABI-specific code generation functions.
Definition: CGCXXABI.h:43
clang::CodeGen::CodeGenTypes
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:59
clang::CodeGenOptions
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
Definition: CodeGenOptions.h:46
clang::CodeGen::CodeGenTypes::getContext
ASTContext & getContext() const
Definition: CodeGenTypes.h:116
clang::CXXRecordDecl
Represents a C++ struct/union/class.
Definition: DeclCXX.h:253
clang::CodeGen::ABIInfo
ABIInfo - Target specific hooks for defining how a type should be passed or returned from functions...
Definition: ABIInfo.h:50
clang::CodeGen::CallArgList
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:261
clang::FunctionType::ExtInfo
A class which abstracts out some details necessary for making a call.
Definition: Type.h:3533