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Builtins.h
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1 //===--- Builtins.h - Builtin function header -------------------*- 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 /// \file
10 /// Defines enum values for all the target-independent builtin
11 /// functions.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_BASIC_BUILTINS_H
16 #define LLVM_CLANG_BASIC_BUILTINS_H
17 
18 #include "llvm/ADT/ArrayRef.h"
19 #include <cstring>
20 
21 // VC++ defines 'alloca' as an object-like macro, which interferes with our
22 // builtins.
23 #undef alloca
24 
25 namespace clang {
26 class TargetInfo;
27 class IdentifierTable;
28 class ASTContext;
29 class QualType;
30 class LangOptions;
31 
32 enum LanguageID {
33  GNU_LANG = 0x1, // builtin requires GNU mode.
34  C_LANG = 0x2, // builtin for c only.
35  CXX_LANG = 0x4, // builtin for cplusplus only.
36  OBJC_LANG = 0x8, // builtin for objective-c and objective-c++
37  MS_LANG = 0x10, // builtin requires MS mode.
38  OCLC20_LANG = 0x20, // builtin for OpenCL C 2.0 only.
39  OCLC1X_LANG = 0x40, // builtin for OpenCL C 1.x only.
40  OMP_LANG = 0x80, // builtin requires OpenMP.
41  ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
42  ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG, // builtin requires GNU mode.
43  ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG, // builtin requires MS mode.
44  ALL_OCLC_LANGUAGES = OCLC1X_LANG | OCLC20_LANG // builtin for OCLC languages.
45 };
46 
47 namespace Builtin {
48 enum ID {
49  NotBuiltin = 0, // This is not a builtin function.
50 #define BUILTIN(ID, TYPE, ATTRS) BI##ID,
51 #include "clang/Basic/Builtins.def"
53 };
54 
55 struct Info {
56  const char *Name, *Type, *Attributes, *HeaderName;
58  const char *Features;
59 };
60 
61 /// Holds information about both target-independent and
62 /// target-specific builtins, allowing easy queries by clients.
63 ///
64 /// Builtins from an optional auxiliary target are stored in
65 /// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to
66 /// be translated back with getAuxBuiltinID() before use.
67 class Context {
68  llvm::ArrayRef<Info> TSRecords;
69  llvm::ArrayRef<Info> AuxTSRecords;
70 
71 public:
72  Context() {}
73 
74  /// Perform target-specific initialization
75  /// \param AuxTarget Target info to incorporate builtins from. May be nullptr.
76  void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget);
77 
78  /// Mark the identifiers for all the builtins with their
79  /// appropriate builtin ID # and mark any non-portable builtin identifiers as
80  /// such.
81  void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
82 
83  /// Return the identifier name for the specified builtin,
84  /// e.g. "__builtin_abs".
85  const char *getName(unsigned ID) const {
86  return getRecord(ID).Name;
87  }
88 
89  /// Get the type descriptor string for the specified builtin.
90  const char *getTypeString(unsigned ID) const {
91  return getRecord(ID).Type;
92  }
93 
94  /// Return true if this function is a target-specific builtin.
95  bool isTSBuiltin(unsigned ID) const {
96  return ID >= Builtin::FirstTSBuiltin;
97  }
98 
99  /// Return true if this function has no side effects.
100  bool isPure(unsigned ID) const {
101  return strchr(getRecord(ID).Attributes, 'U') != nullptr;
102  }
103 
104  /// Return true if this function has no side effects and doesn't
105  /// read memory.
106  bool isConst(unsigned ID) const {
107  return strchr(getRecord(ID).Attributes, 'c') != nullptr;
108  }
109 
110  /// Return true if we know this builtin never throws an exception.
111  bool isNoThrow(unsigned ID) const {
112  return strchr(getRecord(ID).Attributes, 'n') != nullptr;
113  }
114 
115  /// Return true if we know this builtin never returns.
116  bool isNoReturn(unsigned ID) const {
117  return strchr(getRecord(ID).Attributes, 'r') != nullptr;
118  }
119 
120  /// Return true if we know this builtin can return twice.
121  bool isReturnsTwice(unsigned ID) const {
122  return strchr(getRecord(ID).Attributes, 'j') != nullptr;
123  }
124 
125  /// Returns true if this builtin does not perform the side-effects
126  /// of its arguments.
127  bool isUnevaluated(unsigned ID) const {
128  return strchr(getRecord(ID).Attributes, 'u') != nullptr;
129  }
130 
131  /// Return true if this is a builtin for a libc/libm function,
132  /// with a "__builtin_" prefix (e.g. __builtin_abs).
133  bool isLibFunction(unsigned ID) const {
134  return strchr(getRecord(ID).Attributes, 'F') != nullptr;
135  }
136 
137  /// Determines whether this builtin is a predefined libc/libm
138  /// function, such as "malloc", where we know the signature a
139  /// priori.
140  bool isPredefinedLibFunction(unsigned ID) const {
141  return strchr(getRecord(ID).Attributes, 'f') != nullptr;
142  }
143 
144  /// Returns true if this builtin requires appropriate header in other
145  /// compilers. In Clang it will work even without including it, but we can emit
146  /// a warning about missing header.
147  bool isHeaderDependentFunction(unsigned ID) const {
148  return strchr(getRecord(ID).Attributes, 'h') != nullptr;
149  }
150 
151  /// Determines whether this builtin is a predefined compiler-rt/libgcc
152  /// function, such as "__clear_cache", where we know the signature a
153  /// priori.
154  bool isPredefinedRuntimeFunction(unsigned ID) const {
155  return strchr(getRecord(ID).Attributes, 'i') != nullptr;
156  }
157 
158  /// Determines whether this builtin has custom typechecking.
159  bool hasCustomTypechecking(unsigned ID) const {
160  return strchr(getRecord(ID).Attributes, 't') != nullptr;
161  }
162 
163  /// Determines whether this builtin has a result or any arguments which
164  /// are pointer types.
165  bool hasPtrArgsOrResult(unsigned ID) const {
166  return strchr(getRecord(ID).Type, '*') != nullptr;
167  }
168 
169  /// Return true if this builtin has a result or any arguments which are
170  /// reference types.
171  bool hasReferenceArgsOrResult(unsigned ID) const {
172  return strchr(getRecord(ID).Type, '&') != nullptr ||
173  strchr(getRecord(ID).Type, 'A') != nullptr;
174  }
175 
176  /// Completely forget that the given ID was ever considered a builtin,
177  /// e.g., because the user provided a conflicting signature.
178  void forgetBuiltin(unsigned ID, IdentifierTable &Table);
179 
180  /// If this is a library function that comes from a specific
181  /// header, retrieve that header name.
182  const char *getHeaderName(unsigned ID) const {
183  return getRecord(ID).HeaderName;
184  }
185 
186  /// Determine whether this builtin is like printf in its
187  /// formatting rules and, if so, set the index to the format string
188  /// argument and whether this function as a va_list argument.
189  bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
190 
191  /// Determine whether this builtin is like scanf in its
192  /// formatting rules and, if so, set the index to the format string
193  /// argument and whether this function as a va_list argument.
194  bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
195 
196  /// Determine whether this builtin has callback behavior (see
197  /// llvm::AbstractCallSites for details). If so, add the index to the
198  /// callback callee argument and the callback payload arguments.
199  bool performsCallback(unsigned ID,
201 
202  /// Return true if this function has no side effects and doesn't
203  /// read memory, except for possibly errno.
204  ///
205  /// Such functions can be const when the MathErrno lang option is disabled.
206  bool isConstWithoutErrno(unsigned ID) const {
207  return strchr(getRecord(ID).Attributes, 'e') != nullptr;
208  }
209 
210  const char *getRequiredFeatures(unsigned ID) const {
211  return getRecord(ID).Features;
212  }
213 
214  unsigned getRequiredVectorWidth(unsigned ID) const;
215 
216  /// Return true if builtin ID belongs to AuxTarget.
217  bool isAuxBuiltinID(unsigned ID) const {
218  return ID >= (Builtin::FirstTSBuiltin + TSRecords.size());
219  }
220 
221  /// Return real builtin ID (i.e. ID it would have during compilation
222  /// for AuxTarget).
223  unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); }
224 
225  /// Returns true if this is a libc/libm function without the '__builtin_'
226  /// prefix.
227  static bool isBuiltinFunc(const char *Name);
228 
229  /// Returns true if this is a builtin that can be redeclared. Returns true
230  /// for non-builtins.
231  bool canBeRedeclared(unsigned ID) const;
232 
233 private:
234  const Info &getRecord(unsigned ID) const;
235 
236  /// Is this builtin supported according to the given language options?
237  bool builtinIsSupported(const Builtin::Info &BuiltinInfo,
238  const LangOptions &LangOpts);
239 
240  /// Helper function for isPrintfLike and isScanfLike.
241  bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg,
242  const char *Fmt) const;
243 };
244 
245 }
246 
247 /// Kinds of BuiltinTemplateDecl.
249  /// This names the __make_integer_seq BuiltinTemplateDecl.
251 
252  /// This names the __type_pack_element BuiltinTemplateDecl.
254 };
255 
256 } // end namespace clang
257 #endif
const char * getHeaderName(unsigned ID) const
If this is a library function that comes from a specific header, retrieve that header name...
Definition: Builtins.h:182
bool isPure(unsigned ID) const
Return true if this function has no side effects.
Definition: Builtins.h:100
bool hasReferenceArgsOrResult(unsigned ID) const
Return true if this builtin has a result or any arguments which are reference types.
Definition: Builtins.h:171
bool isPredefinedLibFunction(unsigned ID) const
Determines whether this builtin is a predefined libc/libm function, such as "malloc", where we know the signature a priori.
Definition: Builtins.h:140
Holds information about both target-independent and target-specific builtins, allowing easy queries b...
Definition: Builtins.h:67
const char * Attributes
Definition: Builtins.h:56
static const Builtin::Info BuiltinInfo[]
Definition: Builtins.cpp:20
The base class of the type hierarchy.
Definition: Type.h:1436
const char * Name
Definition: Builtins.h:56
const char * getTypeString(unsigned ID) const
Get the type descriptor string for the specified builtin.
Definition: Builtins.h:90
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:49
bool isLibFunction(unsigned ID) const
Return true if this is a builtin for a libc/libm function, with a "__builtin_" prefix (e...
Definition: Builtins.h:133
bool isConstWithoutErrno(unsigned ID) const
Return true if this function has no side effects and doesn&#39;t read memory, except for possibly errno...
Definition: Builtins.h:206
unsigned getAuxBuiltinID(unsigned ID) const
Return real builtin ID (i.e.
Definition: Builtins.h:223
LanguageID Langs
Definition: Builtins.h:57
bool isUnevaluated(unsigned ID) const
Returns true if this builtin does not perform the side-effects of its arguments.
Definition: Builtins.h:127
const char * Type
Definition: Builtins.h:56
const char * getName(unsigned ID) const
Return the identifier name for the specified builtin, e.g.
Definition: Builtins.h:85
Exposes information about the current target.
Definition: TargetInfo.h:161
bool isNoReturn(unsigned ID) const
Return true if we know this builtin never returns.
Definition: Builtins.h:116
Implements an efficient mapping from strings to IdentifierInfo nodes.
bool isPredefinedRuntimeFunction(unsigned ID) const
Determines whether this builtin is a predefined compiler-rt/libgcc function, such as "__clear_cache"...
Definition: Builtins.h:154
const char * getRequiredFeatures(unsigned ID) const
Definition: Builtins.h:210
const char * HeaderName
Definition: Builtins.h:56
bool hasPtrArgsOrResult(unsigned ID) const
Determines whether this builtin has a result or any arguments which are pointer types.
Definition: Builtins.h:165
bool isAuxBuiltinID(unsigned ID) const
Return true if builtin ID belongs to AuxTarget.
Definition: Builtins.h:217
This names the __make_integer_seq BuiltinTemplateDecl.
Definition: Builtins.h:250
bool isConst(unsigned ID) const
Return true if this function has no side effects and doesn&#39;t read memory.
Definition: Builtins.h:106
BuiltinTemplateKind
Kinds of BuiltinTemplateDecl.
Definition: Builtins.h:248
bool isHeaderDependentFunction(unsigned ID) const
Returns true if this builtin requires appropriate header in other compilers.
Definition: Builtins.h:147
Dataflow Directional Tag Classes.
This names the __type_pack_element BuiltinTemplateDecl.
Definition: Builtins.h:253
const char * Features
Definition: Builtins.h:58
bool isNoThrow(unsigned ID) const
Return true if we know this builtin never throws an exception.
Definition: Builtins.h:111
bool isTSBuiltin(unsigned ID) const
Return true if this function is a target-specific builtin.
Definition: Builtins.h:95
bool hasCustomTypechecking(unsigned ID) const
Determines whether this builtin has custom typechecking.
Definition: Builtins.h:159
bool isReturnsTwice(unsigned ID) const
Return true if we know this builtin can return twice.
Definition: Builtins.h:121
LanguageID
Definition: Builtins.h:32