clang 19.0.0git
CodeGenTBAA.h
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1//===--- CodeGenTBAA.h - TBAA information 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 manages TBAA information and defines the TBAA policy
10// for the optimizer to use.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTBAA_H
15#define LLVM_CLANG_LIB_CODEGEN_CODEGENTBAA_H
16
17#include "clang/AST/Type.h"
18#include "clang/Basic/LLVM.h"
19#include "llvm/ADT/DenseMap.h"
20#include "llvm/IR/MDBuilder.h"
21#include "llvm/IR/Metadata.h"
22
23namespace clang {
24 class ASTContext;
25 class CodeGenOptions;
26 class LangOptions;
27 class MangleContext;
28 class QualType;
29 class Type;
30
31namespace CodeGen {
32class CodeGenTypes;
33
34// TBAAAccessKind - A kind of TBAA memory access descriptor.
35enum class TBAAAccessKind : unsigned {
39};
40
41// TBAAAccessInfo - Describes a memory access in terms of TBAA.
44 llvm::MDNode *AccessType, uint64_t Offset, uint64_t Size)
47 {}
48
49 TBAAAccessInfo(llvm::MDNode *BaseType, llvm::MDNode *AccessType,
50 uint64_t Offset, uint64_t Size)
52 Offset, Size)
53 {}
54
55 explicit TBAAAccessInfo(llvm::MDNode *AccessType, uint64_t Size)
56 : TBAAAccessInfo(/* BaseType= */ nullptr, AccessType, /* Offset= */ 0, Size)
57 {}
58
60 : TBAAAccessInfo(/* AccessType= */ nullptr, /* Size= */ 0)
61 {}
62
65 /* BaseType= */ nullptr, /* AccessType= */ nullptr,
66 /* Offset= */ 0, /* Size= */ 0);
67 }
68
69 bool isMayAlias() const { return Kind == TBAAAccessKind::MayAlias; }
70
73 /* BaseType= */ nullptr, /* AccessType= */ nullptr,
74 /* Offset= */ 0, /* Size= */ 0);
75 }
76
77 bool isIncomplete() const { return Kind == TBAAAccessKind::Incomplete; }
78
79 bool operator==(const TBAAAccessInfo &Other) const {
80 return Kind == Other.Kind &&
81 BaseType == Other.BaseType &&
82 AccessType == Other.AccessType &&
83 Offset == Other.Offset &&
84 Size == Other.Size;
85 }
86
87 bool operator!=(const TBAAAccessInfo &Other) const {
88 return !(*this == Other);
89 }
90
91 explicit operator bool() const {
92 return *this != TBAAAccessInfo();
93 }
94
95 /// Kind - The kind of the access descriptor.
97
98 /// BaseType - The base/leading access type. May be null if this access
99 /// descriptor represents an access that is not considered to be an access
100 /// to an aggregate or union member.
101 llvm::MDNode *BaseType;
102
103 /// AccessType - The final access type. May be null if there is no TBAA
104 /// information available about this access.
105 llvm::MDNode *AccessType;
106
107 /// Offset - The byte offset of the final access within the base one. Must be
108 /// zero if the base access type is not specified.
109 uint64_t Offset;
110
111 /// Size - The size of access, in bytes.
112 uint64_t Size;
113};
114
115/// CodeGenTBAA - This class organizes the cross-module state that is used
116/// while lowering AST types to LLVM types.
118 ASTContext &Context;
119 CodeGenTypes &CGTypes;
120 llvm::Module &Module;
121 const CodeGenOptions &CodeGenOpts;
122 const LangOptions &Features;
123 MangleContext &MContext;
124
125 // MDHelper - Helper for creating metadata.
126 llvm::MDBuilder MDHelper;
127
128 /// MetadataCache - This maps clang::Types to scalar llvm::MDNodes describing
129 /// them.
130 llvm::DenseMap<const Type *, llvm::MDNode *> MetadataCache;
131 /// This maps clang::Types to a base access type in the type DAG.
132 llvm::DenseMap<const Type *, llvm::MDNode *> BaseTypeMetadataCache;
133 /// This maps TBAA access descriptors to tag nodes.
134 llvm::DenseMap<TBAAAccessInfo, llvm::MDNode *> AccessTagMetadataCache;
135
136 /// StructMetadataCache - This maps clang::Types to llvm::MDNodes describing
137 /// them for struct assignments.
138 llvm::DenseMap<const Type *, llvm::MDNode *> StructMetadataCache;
139
140 llvm::MDNode *Root;
141 llvm::MDNode *Char;
142
143 /// getRoot - This is the mdnode for the root of the metadata type graph
144 /// for this translation unit.
145 llvm::MDNode *getRoot();
146
147 /// getChar - This is the mdnode for "char", which is special, and any types
148 /// considered to be equivalent to it.
149 llvm::MDNode *getChar();
150
151 /// CollectFields - Collect information about the fields of a type for
152 /// !tbaa.struct metadata formation. Return false for an unsupported type.
153 bool CollectFields(uint64_t BaseOffset,
154 QualType Ty,
156 bool MayAlias);
157
158 /// createScalarTypeNode - A wrapper function to create a metadata node
159 /// describing a scalar type.
160 llvm::MDNode *createScalarTypeNode(StringRef Name, llvm::MDNode *Parent,
161 uint64_t Size);
162
163 /// getTypeInfoHelper - An internal helper function to generate metadata used
164 /// to describe accesses to objects of the given type.
165 llvm::MDNode *getTypeInfoHelper(const Type *Ty);
166
167 /// getBaseTypeInfoHelper - An internal helper function to generate metadata
168 /// used to describe accesses to objects of the given base type.
169 llvm::MDNode *getBaseTypeInfoHelper(const Type *Ty);
170
171 /// getValidBaseTypeInfo - Return metadata that describes the given base
172 /// access type. The type must be suitable.
173 llvm::MDNode *getValidBaseTypeInfo(QualType QTy);
174
175public:
176 CodeGenTBAA(ASTContext &Ctx, CodeGenTypes &CGTypes, llvm::Module &M,
177 const CodeGenOptions &CGO, const LangOptions &Features,
178 MangleContext &MContext);
179 ~CodeGenTBAA();
180
181 /// getTypeInfo - Get metadata used to describe accesses to objects of the
182 /// given type.
183 llvm::MDNode *getTypeInfo(QualType QTy);
184
185 /// getAccessInfo - Get TBAA information that describes an access to
186 /// an object of the given type.
188
189 /// getVTablePtrAccessInfo - Get the TBAA information that describes an
190 /// access to a virtual table pointer.
191 TBAAAccessInfo getVTablePtrAccessInfo(llvm::Type *VTablePtrType);
192
193 /// getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of
194 /// the given type.
195 llvm::MDNode *getTBAAStructInfo(QualType QTy);
196
197 /// getBaseTypeInfo - Get metadata that describes the given base access
198 /// type. Return null if the type is not suitable for use in TBAA access
199 /// tags.
200 llvm::MDNode *getBaseTypeInfo(QualType QTy);
201
202 /// getAccessTagInfo - Get TBAA tag for a given memory access.
203 llvm::MDNode *getAccessTagInfo(TBAAAccessInfo Info);
204
205 /// mergeTBAAInfoForCast - Get merged TBAA information for the purpose of
206 /// type casts.
209
210 /// mergeTBAAInfoForConditionalOperator - Get merged TBAA information for the
211 /// purpose of conditional operator.
213 TBAAAccessInfo InfoB);
214
215 /// mergeTBAAInfoForMemoryTransfer - Get merged TBAA information for the
216 /// purpose of memory transfer calls.
218 TBAAAccessInfo SrcInfo);
219};
220
221} // end namespace CodeGen
222} // end namespace clang
223
224namespace llvm {
225
226template<> struct DenseMapInfo<clang::CodeGen::TBAAAccessInfo> {
228 unsigned UnsignedKey = DenseMapInfo<unsigned>::getEmptyKey();
230 static_cast<clang::CodeGen::TBAAAccessKind>(UnsignedKey),
231 DenseMapInfo<MDNode *>::getEmptyKey(),
232 DenseMapInfo<MDNode *>::getEmptyKey(),
233 DenseMapInfo<uint64_t>::getEmptyKey(),
234 DenseMapInfo<uint64_t>::getEmptyKey());
235 }
236
238 unsigned UnsignedKey = DenseMapInfo<unsigned>::getTombstoneKey();
240 static_cast<clang::CodeGen::TBAAAccessKind>(UnsignedKey),
241 DenseMapInfo<MDNode *>::getTombstoneKey(),
242 DenseMapInfo<MDNode *>::getTombstoneKey(),
243 DenseMapInfo<uint64_t>::getTombstoneKey(),
244 DenseMapInfo<uint64_t>::getTombstoneKey());
245 }
246
247 static unsigned getHashValue(const clang::CodeGen::TBAAAccessInfo &Val) {
248 auto KindValue = static_cast<unsigned>(Val.Kind);
249 return DenseMapInfo<unsigned>::getHashValue(KindValue) ^
250 DenseMapInfo<MDNode *>::getHashValue(Val.BaseType) ^
251 DenseMapInfo<MDNode *>::getHashValue(Val.AccessType) ^
252 DenseMapInfo<uint64_t>::getHashValue(Val.Offset) ^
253 DenseMapInfo<uint64_t>::getHashValue(Val.Size);
254 }
255
258 return LHS == RHS;
259 }
260};
261
262} // end namespace llvm
263
264#endif
NodeId Parent
Definition: ASTDiff.cpp:191
MatchType Type
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified.
C Language Family Type Representation.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:185
CodeGenOptions - Track various options which control how the code is optimized and passed to the back...
CodeGenTBAA - This class organizes the cross-module state that is used while lowering AST types to LL...
Definition: CodeGenTBAA.h:117
llvm::MDNode * getBaseTypeInfo(QualType QTy)
getBaseTypeInfo - Get metadata that describes the given base access type.
llvm::MDNode * getTypeInfo(QualType QTy)
getTypeInfo - Get metadata used to describe accesses to objects of the given type.
TBAAAccessInfo getVTablePtrAccessInfo(llvm::Type *VTablePtrType)
getVTablePtrAccessInfo - Get the TBAA information that describes an access to a virtual table pointer...
TBAAAccessInfo mergeTBAAInfoForMemoryTransfer(TBAAAccessInfo DestInfo, TBAAAccessInfo SrcInfo)
mergeTBAAInfoForMemoryTransfer - Get merged TBAA information for the purpose of memory transfer calls...
TBAAAccessInfo mergeTBAAInfoForCast(TBAAAccessInfo SourceInfo, TBAAAccessInfo TargetInfo)
mergeTBAAInfoForCast - Get merged TBAA information for the purpose of type casts.
TBAAAccessInfo mergeTBAAInfoForConditionalOperator(TBAAAccessInfo InfoA, TBAAAccessInfo InfoB)
mergeTBAAInfoForConditionalOperator - Get merged TBAA information for the purpose of conditional oper...
llvm::MDNode * getAccessTagInfo(TBAAAccessInfo Info)
getAccessTagInfo - Get TBAA tag for a given memory access.
llvm::MDNode * getTBAAStructInfo(QualType QTy)
getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of the given type.
TBAAAccessInfo getAccessInfo(QualType AccessType)
getAccessInfo - Get TBAA information that describes an access to an object of the given type.
This class organizes the cross-module state that is used while lowering AST types to LLVM types.
Definition: CodeGenTypes.h:54
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:461
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:45
Describes a module or submodule.
Definition: Module.h:105
A (possibly-)qualified type.
Definition: Type.h:940
Exposes information about the current target.
Definition: TargetInfo.h:218
The base class of the type hierarchy.
Definition: Type.h:1827
The JSON file list parser is used to communicate input to InstallAPI.
@ Other
Other implicit parameter.
Diagnostic wrappers for TextAPI types for error reporting.
Definition: Dominators.h:30
#define bool
Definition: stdbool.h:24
TBAAAccessKind Kind
Kind - The kind of the access descriptor.
Definition: CodeGenTBAA.h:96
llvm::MDNode * AccessType
AccessType - The final access type.
Definition: CodeGenTBAA.h:105
uint64_t Offset
Offset - The byte offset of the final access within the base one.
Definition: CodeGenTBAA.h:109
TBAAAccessInfo(TBAAAccessKind Kind, llvm::MDNode *BaseType, llvm::MDNode *AccessType, uint64_t Offset, uint64_t Size)
Definition: CodeGenTBAA.h:43
static TBAAAccessInfo getMayAliasInfo()
Definition: CodeGenTBAA.h:63
TBAAAccessInfo(llvm::MDNode *AccessType, uint64_t Size)
Definition: CodeGenTBAA.h:55
uint64_t Size
Size - The size of access, in bytes.
Definition: CodeGenTBAA.h:112
bool operator==(const TBAAAccessInfo &Other) const
Definition: CodeGenTBAA.h:79
static TBAAAccessInfo getIncompleteInfo()
Definition: CodeGenTBAA.h:71
bool operator!=(const TBAAAccessInfo &Other) const
Definition: CodeGenTBAA.h:87
llvm::MDNode * BaseType
BaseType - The base/leading access type.
Definition: CodeGenTBAA.h:101
TBAAAccessInfo(llvm::MDNode *BaseType, llvm::MDNode *AccessType, uint64_t Offset, uint64_t Size)
Definition: CodeGenTBAA.h:49
static clang::CodeGen::TBAAAccessInfo getTombstoneKey()
Definition: CodeGenTBAA.h:237
static clang::CodeGen::TBAAAccessInfo getEmptyKey()
Definition: CodeGenTBAA.h:227
static unsigned getHashValue(const clang::CodeGen::TBAAAccessInfo &Val)
Definition: CodeGenTBAA.h:247
static bool isEqual(const clang::CodeGen::TBAAAccessInfo &LHS, const clang::CodeGen::TBAAAccessInfo &RHS)
Definition: CodeGenTBAA.h:256