1//===--- Builtins.h - Builtin function header -------------------*- 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/// \file
11/// \brief Defines enum values for all the target-independent builtin
12/// functions.
13///
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CLANG_BASIC_BUILTINS_H
17#define LLVM_CLANG_BASIC_BUILTINS_H
18
19#include "llvm/ADT/ArrayRef.h"
20#include <cstring>
21
22// VC++ defines 'alloca' as an object-like macro, which interferes with our
23// builtins.
24#undef alloca
25
26namespace clang {
27class TargetInfo;
28class IdentifierTable;
29class ASTContext;
30class QualType;
31class LangOptions;
32
33enum LanguageID {
34  GNU_LANG = 0x1,     // builtin requires GNU mode.
35  C_LANG = 0x2,       // builtin for c only.
36  CXX_LANG = 0x4,     // builtin for cplusplus only.
37  OBJC_LANG = 0x8,    // builtin for objective-c and objective-c++
38  MS_LANG = 0x10,     // builtin requires MS mode.
39  OCLC20_LANG = 0x20, // builtin for OpenCL C 2.0 only.
40  OCLC1X_LANG = 0x40, // builtin for OpenCL C 1.x only.
41  OMP_LANG = 0x80,    // builtin requires OpenMP.
42  ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
43  ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG,  // builtin requires GNU mode.
44  ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG,    // builtin requires MS mode.
45  ALL_OCLC_LANGUAGES = OCLC1X_LANG | OCLC20_LANG // builtin for OCLC languages.
46};
47
48namespace Builtin {
49enum ID {
50  NotBuiltin  = 0,      // This is not a builtin function.
51#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
52#include "clang/Basic/Builtins.def"
53  FirstTSBuiltin
54};
55
56struct Info {
57  const char *Name, *Type, *Attributes, *HeaderName;
58  LanguageID Langs;
59  const char *Features;
60};
61
62/// \brief Holds information about both target-independent and
63/// target-specific builtins, allowing easy queries by clients.
64///
65/// Builtins from an optional auxiliary target are stored in
66/// AuxTSRecords. Their IDs are shifted up by TSRecords.size() and need to
67/// be translated back with getAuxBuiltinID() before use.
68class Context {
69  llvm::ArrayRef<Info> TSRecords;
70  llvm::ArrayRef<Info> AuxTSRecords;
71
72public:
73  Context() {}
74
75  /// \brief Perform target-specific initialization
76  /// \param AuxTarget Target info to incorporate builtins from. May be nullptr.
77  void InitializeTarget(const TargetInfo &Target, const TargetInfo *AuxTarget);
78
79  /// \brief Mark the identifiers for all the builtins with their
80  /// appropriate builtin ID # and mark any non-portable builtin identifiers as
81  /// such.
82  void initializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
83
84  /// \brief Return the identifier name for the specified builtin,
85  /// e.g. "__builtin_abs".
86  const char *getName(unsigned ID) const {
87    return getRecord(ID).Name;
88  }
89
90  /// \brief Get the type descriptor string for the specified builtin.
91  const char *getTypeString(unsigned ID) const {
92    return getRecord(ID).Type;
93  }
94
95  /// \brief Return true if this function is a target-specific builtin.
96  bool isTSBuiltin(unsigned ID) const {
97    return ID >= Builtin::FirstTSBuiltin;
98  }
99
100  /// \brief Return true if this function has no side effects.
101  bool isPure(unsigned ID) const {
102    return strchr(getRecord(ID).Attributes, 'U') != nullptr;
103  }
104
105  /// \brief Return true if this function has no side effects and doesn't
106  /// read memory.
107  bool isConst(unsigned ID) const {
108    return strchr(getRecord(ID).Attributes, 'c') != nullptr;
109  }
110
111  /// \brief Return true if we know this builtin never throws an exception.
112  bool isNoThrow(unsigned ID) const {
113    return strchr(getRecord(ID).Attributes, 'n') != nullptr;
114  }
115
116  /// \brief Return true if we know this builtin never returns.
117  bool isNoReturn(unsigned ID) const {
118    return strchr(getRecord(ID).Attributes, 'r') != nullptr;
119  }
120
121  /// \brief Return true if we know this builtin can return twice.
122  bool isReturnsTwice(unsigned ID) const {
123    return strchr(getRecord(ID).Attributes, 'j') != nullptr;
124  }
125
126  /// \brief Returns true if this builtin does not perform the side-effects
127  /// of its arguments.
128  bool isUnevaluated(unsigned ID) const {
129    return strchr(getRecord(ID).Attributes, 'u') != nullptr;
130  }
131
132  /// \brief Return true if this is a builtin for a libc/libm function,
133  /// with a "__builtin_" prefix (e.g. __builtin_abs).
134  bool isLibFunction(unsigned ID) const {
135    return strchr(getRecord(ID).Attributes, 'F') != nullptr;
136  }
137
138  /// \brief Determines whether this builtin is a predefined libc/libm
139  /// function, such as "malloc", where we know the signature a
140  /// priori.
141  bool isPredefinedLibFunction(unsigned ID) const {
142    return strchr(getRecord(ID).Attributes, 'f') != nullptr;
143  }
144
145  /// \brief Returns true if this builtin requires appropriate header in other
146  /// compilers. In Clang it will work even without including it, but we can emit
147  /// a warning about missing header.
148  bool isHeaderDependentFunction(unsigned ID) const {
149    return strchr(getRecord(ID).Attributes, 'h') != nullptr;
150  }
151
152  /// \brief Determines whether this builtin is a predefined compiler-rt/libgcc
153  /// function, such as "__clear_cache", where we know the signature a
154  /// priori.
155  bool isPredefinedRuntimeFunction(unsigned ID) const {
156    return strchr(getRecord(ID).Attributes, 'i') != nullptr;
157  }
158
159  /// \brief Determines whether this builtin has custom typechecking.
160  bool hasCustomTypechecking(unsigned ID) const {
161    return strchr(getRecord(ID).Attributes, 't') != nullptr;
162  }
163
164  /// \brief Determines whether this builtin has a result or any arguments which
165  /// are pointer types.
166  bool hasPtrArgsOrResult(unsigned ID) const {
167    return strchr(getRecord(ID).Type, '*') != nullptr;
168  }
169
170  /// \brief Completely forget that the given ID was ever considered a builtin,
171  /// e.g., because the user provided a conflicting signature.
172  void forgetBuiltin(unsigned ID, IdentifierTable &Table);
173
174  /// \brief If this is a library function that comes from a specific
175  /// header, retrieve that header name.
176  const char *getHeaderName(unsigned ID) const {
177    return getRecord(ID).HeaderName;
178  }
179
180  /// \brief Determine whether this builtin is like printf in its
181  /// formatting rules and, if so, set the index to the format string
182  /// argument and whether this function as a va_list argument.
183  bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
184
185  /// \brief Determine whether this builtin is like scanf in its
186  /// formatting rules and, if so, set the index to the format string
187  /// argument and whether this function as a va_list argument.
188  bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
189
190  /// \brief Return true if this function has no side effects and doesn't
191  /// read memory, except for possibly errno.
192  ///
193  /// Such functions can be const when the MathErrno lang option is disabled.
194  bool isConstWithoutErrno(unsigned ID) const {
195    return strchr(getRecord(ID).Attributes, 'e') != nullptr;
196  }
197
198  const char *getRequiredFeatures(unsigned ID) const {
199    return getRecord(ID).Features;
200  }
201
202  /// \brief Return true if builtin ID belongs to AuxTarget.
203  bool isAuxBuiltinID(unsigned ID) const {
204    return ID >= (Builtin::FirstTSBuiltin + TSRecords.size());
205  }
206
207  /// Return real buitin ID (i.e. ID it would have furing compilation
208  /// for AuxTarget).
209  unsigned getAuxBuiltinID(unsigned ID) const { return ID - TSRecords.size(); }
210
211  /// Returns true if this is a libc/libm function without the '__builtin_'
212  /// prefix.
213  static bool isBuiltinFunc(const char *Name);
214
215private:
216  const Info &getRecord(unsigned ID) const;
217
218  /// \brief Is this builtin supported according to the given language options?
219  bool builtinIsSupported(const Builtin::Info &BuiltinInfo,
220                          const LangOptions &LangOpts);
221
222  /// \brief Helper function for isPrintfLike and isScanfLike.
223  bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg,
224              const char *Fmt) const;
225};
226
227}
228
229/// \brief Kinds of BuiltinTemplateDecl.
230enum BuiltinTemplateKind : int {
231  /// \brief This names the __make_integer_seq BuiltinTemplateDecl.
232  BTK__make_integer_seq,
233
234  /// \brief This names the __type_pack_element BuiltinTemplateDecl.
235  BTK__type_pack_element
236};
237
238} // end namespace clang
239#endif
240