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
25namespace clang {
26class TargetInfo;
27class IdentifierTable;
28class LangOptions;
29
30enum LanguageID {
31 GNU_LANG = 0x1, // builtin requires GNU mode.
32 C_LANG = 0x2, // builtin for c only.
33 CXX_LANG = 0x4, // builtin for cplusplus only.
34 OBJC_LANG = 0x8, // builtin for objective-c and objective-c++
35 MS_LANG = 0x10, // builtin requires MS mode.
36 OCLC20_LANG = 0x20, // builtin for OpenCL C 2.0 only.
37 OCLC1X_LANG = 0x40, // builtin for OpenCL C 1.x only.
38 OMP_LANG = 0x80, // builtin requires OpenMP.
39 CUDA_LANG = 0x100, // builtin requires CUDA.
40 ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
41 ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG, // builtin requires GNU mode.
42 ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG, // builtin requires MS mode.
43 ALL_OCLC_LANGUAGES = OCLC1X_LANG | OCLC20_LANG // builtin for OCLC languages.
44};
45
46namespace Builtin {
47enum ID {
48 NotBuiltin = 0, // This is not a builtin function.
49#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
50#include "clang/Basic/Builtins.def"
51 FirstTSBuiltin
52};
53
54struct Info {
55 const char *Name, *Type, *Attributes, *HeaderName;
56 LanguageID Langs;
57 const char *Features;
58};
59
60/// Holds information about both target-independent and
61/// target-specific builtins, allowing easy queries by clients.
62///
63/// Builtins from an optional auxiliary target are stored in
64/// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to
65/// be translated back with getAuxBuiltinID() before use.
66class Context {
67 llvm::ArrayRef<Info> TSRecords;
68 llvm::ArrayRef<Info> AuxTSRecords;
69
70public:
71 Context() {}
72
73 /// Perform target-specific initialization
74 /// \param AuxTarget Target info to incorporate builtins from. May be nullptr.
75 void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget);
76
77 /// Mark the identifiers for all the builtins with their
78 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
79 /// such.
80 void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
81
82 /// Return the identifier name for the specified builtin,
83 /// e.g. "__builtin_abs".
84 const char *getName(unsigned ID) const {
85 return getRecord(ID).Name;
86 }
87
88 /// Get the type descriptor string for the specified builtin.
89 const char *getTypeString(unsigned ID) const {
90 return getRecord(ID).Type;
91 }
92
93 /// Return true if this function is a target-specific builtin.
94 bool isTSBuiltin(unsigned ID) const {
95 return ID >= Builtin::FirstTSBuiltin;
96 }
97
98 /// Return true if this function has no side effects.
99 bool isPure(unsigned ID) const {
100 return strchr(getRecord(ID).Attributes, 'U') != nullptr;
101 }
102
103 /// Return true if this function has no side effects and doesn't
104 /// read memory.
105 bool isConst(unsigned ID) const {
106 return strchr(getRecord(ID).Attributes, 'c') != nullptr;
107 }
108
109 /// Return true if we know this builtin never throws an exception.
110 bool isNoThrow(unsigned ID) const {
111 return strchr(getRecord(ID).Attributes, 'n') != nullptr;
112 }
113
114 /// Return true if we know this builtin never returns.
115 bool isNoReturn(unsigned ID) const {
116 return strchr(getRecord(ID).Attributes, 'r') != nullptr;
117 }
118
119 /// Return true if we know this builtin can return twice.
120 bool isReturnsTwice(unsigned ID) const {
121 return strchr(getRecord(ID).Attributes, 'j') != nullptr;
122 }
123
124 /// Returns true if this builtin does not perform the side-effects
125 /// of its arguments.
126 bool isUnevaluated(unsigned ID) const {
127 return strchr(getRecord(ID).Attributes, 'u') != nullptr;
128 }
129
130 /// Return true if this is a builtin for a libc/libm function,
131 /// with a "__builtin_" prefix (e.g. __builtin_abs).
132 bool isLibFunction(unsigned ID) const {
133 return strchr(getRecord(ID).Attributes, 'F') != nullptr;
134 }
135
136 /// Determines whether this builtin is a predefined libc/libm
137 /// function, such as "malloc", where we know the signature a
138 /// priori.
139 bool isPredefinedLibFunction(unsigned ID) const {
140 return strchr(getRecord(ID).Attributes, 'f') != nullptr;
141 }
142
143 /// Returns true if this builtin requires appropriate header in other
144 /// compilers. In Clang it will work even without including it, but we can emit
145 /// a warning about missing header.
146 bool isHeaderDependentFunction(unsigned ID) const {
147 return strchr(getRecord(ID).Attributes, 'h') != nullptr;
148 }
149
150 /// Determines whether this builtin is a predefined compiler-rt/libgcc
151 /// function, such as "__clear_cache", where we know the signature a
152 /// priori.
153 bool isPredefinedRuntimeFunction(unsigned ID) const {
154 return strchr(getRecord(ID).Attributes, 'i') != nullptr;
155 }
156
157 /// Determines whether this builtin has custom typechecking.
158 bool hasCustomTypechecking(unsigned ID) const {
159 return strchr(getRecord(ID).Attributes, 't') != nullptr;
160 }
161
162 /// Determines whether a declaration of this builtin should be recognized
163 /// even if the type doesn't match the specified signature.
164 bool allowTypeMismatch(unsigned ID) const {
165 return strchr(getRecord(ID).Attributes, 'T') != nullptr ||
166 hasCustomTypechecking(ID);
167 }
168
169 /// Determines whether this builtin has a result or any arguments which
170 /// are pointer types.
171 bool hasPtrArgsOrResult(unsigned ID) const {
172 return strchr(getRecord(ID).Type, '*') != nullptr;
173 }
174
175 /// Return true if this builtin has a result or any arguments which are
176 /// reference types.
177 bool hasReferenceArgsOrResult(unsigned ID) const {
178 return strchr(getRecord(ID).Type, '&') != nullptr ||
179 strchr(getRecord(ID).Type, 'A') != nullptr;
180 }
181
182 /// If this is a library function that comes from a specific
183 /// header, retrieve that header name.
184 const char *getHeaderName(unsigned ID) const {
185 return getRecord(ID).HeaderName;
186 }
187
188 /// Determine whether this builtin is like printf in its
189 /// formatting rules and, if so, set the index to the format string
190 /// argument and whether this function as a va_list argument.
191 bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
192
193 /// Determine whether this builtin is like scanf in its
194 /// formatting rules and, if so, set the index to the format string
195 /// argument and whether this function as a va_list argument.
196 bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
197
198 /// Determine whether this builtin has callback behavior (see
199 /// llvm::AbstractCallSites for details). If so, add the index to the
200 /// callback callee argument and the callback payload arguments.
201 bool performsCallback(unsigned ID,
202 llvm::SmallVectorImpl<int> &Encoding) const;
203
204 /// Return true if this function has no side effects and doesn't
205 /// read memory, except for possibly errno.
206 ///
207 /// Such functions can be const when the MathErrno lang option is disabled.
208 bool isConstWithoutErrno(unsigned ID) const {
209 return strchr(getRecord(ID).Attributes, 'e') != nullptr;
210 }
211
212 const char *getRequiredFeatures(unsigned ID) const {
213 return getRecord(ID).Features;
214 }
215
216 unsigned getRequiredVectorWidth(unsigned ID) const;
217
218 /// Return true if builtin ID belongs to AuxTarget.
219 bool isAuxBuiltinID(unsigned ID) const {
220 return ID >= (Builtin::FirstTSBuiltin + TSRecords.size());
221 }
222
223 /// Return real builtin ID (i.e. ID it would have during compilation
224 /// for AuxTarget).
225 unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); }
226
227 /// Returns true if this is a libc/libm function without the '__builtin_'
228 /// prefix.
229 static bool isBuiltinFunc(llvm::StringRef Name);
230
231 /// Returns true if this is a builtin that can be redeclared. Returns true
232 /// for non-builtins.
233 bool canBeRedeclared(unsigned ID) const;
234
235private:
236 const Info &getRecord(unsigned ID) const;
237
238 /// Is this builtin supported according to the given language options?
239 bool builtinIsSupported(const Builtin::Info &BuiltinInfo,
240 const LangOptions &LangOpts);
241
242 /// Helper function for isPrintfLike and isScanfLike.
243 bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg,
244 const char *Fmt) const;
245};
246
247}
248
249/// Kinds of BuiltinTemplateDecl.
250enum BuiltinTemplateKind : int {
251 /// This names the __make_integer_seq BuiltinTemplateDecl.
252 BTK__make_integer_seq,
253
254 /// This names the __type_pack_element BuiltinTemplateDecl.
255 BTK__type_pack_element
256};
257
258} // end namespace clang
259#endif
260