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    ALL_LANGUAGES = C_LANG | CXX_LANG | OBJC_LANG, // builtin for all languages.
39    ALL_GNU_LANGUAGES = ALL_LANGUAGES | GNU_LANG   // builtin requires GNU mode.
40  };
41
42namespace Builtin {
43enum ID {
44  NotBuiltin  = 0,      // This is not a builtin function.
45#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
46#include "clang/Basic/Builtins.def"
47  FirstTSBuiltin
48};
49
50struct Info {
51  const char *Name, *Type, *Attributes, *HeaderName;
52  LanguageID builtin_lang;
53
54  bool operator==(const Info &RHS) const {
55    return !strcmp(Name, RHS.Name) &&
56           !strcmp(Type, RHS.Type) &&
57           !strcmp(Attributes, RHS.Attributes);
58  }
59  bool operator!=(const Info &RHS) const { return !(*this == RHS); }
60};
61
62/// \brief Holds information about both target-independent and
63/// target-specific builtins, allowing easy queries by clients.
64class Context {
65  const Info *TSRecords;
66  unsigned NumTSRecords;
67public:
68  Context();
69
70  /// \brief Perform target-specific initialization
71  void InitializeTarget(const TargetInfo &Target);
72
73  /// \brief Mark the identifiers for all the builtins with their
74  /// appropriate builtin ID # and mark any non-portable builtin identifiers as
75  /// such.
76  void InitializeBuiltins(IdentifierTable &Table, const LangOptions& LangOpts);
77
78  /// \brief Populate the vector with the names of all of the builtins.
79  void GetBuiltinNames(SmallVectorImpl<const char *> &Names);
80
81  /// \brief Return the identifier name for the specified builtin,
82  /// e.g. "__builtin_abs".
83  const char *GetName(unsigned ID) const {
84    return GetRecord(ID).Name;
85  }
86
87  /// \brief Get the type descriptor string for the specified builtin.
88  const char *GetTypeString(unsigned ID) const {
89    return GetRecord(ID).Type;
90  }
91
92  /// \brief Return true if this function has no side effects and doesn't
93  /// read memory.
94  bool isConst(unsigned ID) const {
95    return strchr(GetRecord(ID).Attributes, 'c') != 0;
96  }
97
98  /// \brief Return true if we know this builtin never throws an exception.
99  bool isNoThrow(unsigned ID) const {
100    return strchr(GetRecord(ID).Attributes, 'n') != 0;
101  }
102
103  /// \brief Return true if we know this builtin never returns.
104  bool isNoReturn(unsigned ID) const {
105    return strchr(GetRecord(ID).Attributes, 'r') != 0;
106  }
107
108  /// \brief Return true if we know this builtin can return twice.
109  bool isReturnsTwice(unsigned ID) const {
110    return strchr(GetRecord(ID).Attributes, 'j') != 0;
111  }
112
113  /// \brief Returns true if this builtin does not perform the side-effects
114  /// of its arguments.
115  bool isUnevaluated(unsigned ID) const {
116    return strchr(GetRecord(ID).Attributes, 'u') != 0;
117  }
118
119  /// \brief Return true if this is a builtin for a libc/libm function,
120  /// with a "__builtin_" prefix (e.g. __builtin_abs).
121  bool isLibFunction(unsigned ID) const {
122    return strchr(GetRecord(ID).Attributes, 'F') != 0;
123  }
124
125  /// \brief Determines whether this builtin is a predefined libc/libm
126  /// function, such as "malloc", where we know the signature a
127  /// priori.
128  bool isPredefinedLibFunction(unsigned ID) const {
129    return strchr(GetRecord(ID).Attributes, 'f') != 0;
130  }
131
132  /// \brief Determines whether this builtin is a predefined compiler-rt/libgcc
133  /// function, such as "__clear_cache", where we know the signature a
134  /// priori.
135  bool isPredefinedRuntimeFunction(unsigned ID) const {
136    return strchr(GetRecord(ID).Attributes, 'i') != 0;
137  }
138
139  /// \brief Determines whether this builtin has custom typechecking.
140  bool hasCustomTypechecking(unsigned ID) const {
141    return strchr(GetRecord(ID).Attributes, 't') != 0;
142  }
143
144  /// \brief Completely forget that the given ID was ever considered a builtin,
145  /// e.g., because the user provided a conflicting signature.
146  void ForgetBuiltin(unsigned ID, IdentifierTable &Table);
147
148  /// \brief If this is a library function that comes from a specific
149  /// header, retrieve that header name.
150  const char *getHeaderName(unsigned ID) const {
151    return GetRecord(ID).HeaderName;
152  }
153
154  /// \brief Determine whether this builtin is like printf in its
155  /// formatting rules and, if so, set the index to the format string
156  /// argument and whether this function as a va_list argument.
157  bool isPrintfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
158
159  /// \brief Determine whether this builtin is like scanf in its
160  /// formatting rules and, if so, set the index to the format string
161  /// argument and whether this function as a va_list argument.
162  bool isScanfLike(unsigned ID, unsigned &FormatIdx, bool &HasVAListArg);
163
164  /// \brief Return true if this function has no side effects and doesn't
165  /// read memory, except for possibly errno.
166  ///
167  /// Such functions can be const when the MathErrno lang option is disabled.
168  bool isConstWithoutErrno(unsigned ID) const {
169    return strchr(GetRecord(ID).Attributes, 'e') != 0;
170  }
171
172private:
173  const Info &GetRecord(unsigned ID) const;
174
175  /// \brief Is this builtin supported according to the given language options?
176  bool BuiltinIsSupported(const Builtin::Info &BuiltinInfo,
177                          const LangOptions &LangOpts);
178};
179
180}
181} // end namespace clang
182#endif
183