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 "clang/Basic/LLVM.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 {
27  class TargetInfo;
28  class IdentifierTable;
29  class ASTContext;
30  class QualType;
31  class LangOptions;
32
33  enum 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    ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
40    ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG,  // builtin requires GNU mode.
41    ALL_MS_LANGUAGES = ALL_LANGUAGES | MS_LANG     // builtin requires MS mode.
42  };
43
44namespace Builtin {
45enum ID {
46  NotBuiltin  = 0,      // This is not a builtin function.
47#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
48#include "clang/Basic/Builtins.def"
49  FirstTSBuiltin
50};
51
52struct Info {
53  const char *Name, *Type, *Attributes, *HeaderName;
54  LanguageID builtin_lang;
55
56  bool operator==(const Info &RHS) const {
57    return !strcmp(Name, RHS.Name) &&
58           !strcmp(Type, RHS.Type) &&
59           !strcmp(Attributes, RHS.Attributes);
60  }
61  bool operator!=(const Info &RHS) const { return !(*this == RHS); }
62};
63
64/// \brief Holds information about both target-independent and
65/// target-specific builtins, allowing easy queries by clients.
66class Context {
67  const Info *TSRecords;
68  unsigned NumTSRecords;
69public:
70  Context();
71
72  /// \brief Perform target-specific initialization
73  void InitializeTarget(const TargetInfo &Target);
74
75  /// \brief Mark the identifiers for all the builtins with their
76  /// appropriate builtin ID # and mark any non-portable builtin identifiers as
77  /// such.
78  void InitializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
79
80  /// \brief Populate the vector with the names of all of the builtins.
81  void GetBuiltinNames(SmallVectorImpl<const char *> &Names);
82
83  /// \brief 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  /// \brief Get the type descriptor string for the specified builtin.
90  const char *GetTypeString(unsigned ID) const {
91    return GetRecord(ID).Type;
92  }
93
94  /// \brief Return true if this function has no side effects and doesn't
95  /// read memory.
96  bool isConst(unsigned ID) const {
97    return strchr(GetRecord(ID).Attributes, 'c') != nullptr;
98  }
99
100  /// \brief Return true if we know this builtin never throws an exception.
101  bool isNoThrow(unsigned ID) const {
102    return strchr(GetRecord(ID).Attributes, 'n') != nullptr;
103  }
104
105  /// \brief Return true if we know this builtin never returns.
106  bool isNoReturn(unsigned ID) const {
107    return strchr(GetRecord(ID).Attributes, 'r') != nullptr;
108  }
109
110  /// \brief Return true if we know this builtin can return twice.
111  bool isReturnsTwice(unsigned ID) const {
112    return strchr(GetRecord(ID).Attributes, 'j') != nullptr;
113  }
114
115  /// \brief Returns true if this builtin does not perform the side-effects
116  /// of its arguments.
117  bool isUnevaluated(unsigned ID) const {
118    return strchr(GetRecord(ID).Attributes, 'u') != nullptr;
119  }
120
121  /// \brief Return true if this is a builtin for a libc/libm function,
122  /// with a "__builtin_" prefix (e.g. __builtin_abs).
123  bool isLibFunction(unsigned ID) const {
124    return strchr(GetRecord(ID).Attributes, 'F') != nullptr;
125  }
126
127  /// \brief Determines whether this builtin is a predefined libc/libm
128  /// function, such as "malloc", where we know the signature a
129  /// priori.
130  bool isPredefinedLibFunction(unsigned ID) const {
131    return strchr(GetRecord(ID).Attributes, 'f') != nullptr;
132  }
133
134  /// \brief Determines whether this builtin is a predefined compiler-rt/libgcc
135  /// function, such as "__clear_cache", where we know the signature a
136  /// priori.
137  bool isPredefinedRuntimeFunction(unsigned ID) const {
138    return strchr(GetRecord(ID).Attributes, 'i') != nullptr;
139  }
140
141  /// \brief Determines whether this builtin has custom typechecking.
142  bool hasCustomTypechecking(unsigned ID) const {
143    return strchr(GetRecord(ID).Attributes, 't') != nullptr;
144  }
145
146  /// \brief Completely forget that the given ID was ever considered a builtin,
147  /// e.g., because the user provided a conflicting signature.
148  void ForgetBuiltin(unsigned ID, IdentifierTable &Table);
149
150  /// \brief If this is a library function that comes from a specific
151  /// header, retrieve that header name.
152  const char *getHeaderName(unsigned ID) const {
153    return GetRecord(ID).HeaderName;
154  }
155
156  /// \brief Determine whether this builtin is like printf in its
157  /// formatting rules and, if so, set the index to the format string
158  /// argument and whether this function as a va_list argument.
159  bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
160
161  /// \brief Determine whether this builtin is like scanf in its
162  /// formatting rules and, if so, set the index to the format string
163  /// argument and whether this function as a va_list argument.
164  bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
165
166  /// \brief Return true if this function has no side effects and doesn't
167  /// read memory, except for possibly errno.
168  ///
169  /// Such functions can be const when the MathErrno lang option is disabled.
170  bool isConstWithoutErrno(unsigned ID) const {
171    return strchr(GetRecord(ID).Attributes, 'e') != nullptr;
172  }
173
174private:
175  const Info &GetRecord(unsigned ID) const;
176
177  /// \brief Is this builtin supported according to the given language options?
178  bool BuiltinIsSupported(const Builtin::Info &BuiltinInfo,
179                          const LangOptions &LangOpts);
180
181  /// \brief Helper function for isPrintfLike and isScanfLike.
182  bool isLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg,
183              const char *Fmt) const;
184};
185
186}
187} // end namespace clang
188#endif
189