1 //===--- Builtins.cpp - Builtin function implementation -------------------===//
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 //  This file implements various things for builtin functions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Basic/Builtins.h"
15 #include "clang/Basic/IdentifierTable.h"
16 #include "clang/Basic/LangOptions.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "llvm/ADT/StringRef.h"
19 using namespace clang;
20 
21 static const Builtin::Info BuiltinInfo[] = {
22   { "not a builtin function", nullptr, nullptr, nullptr, ALL_LANGUAGES,nullptr},
23 #define BUILTIN(ID, TYPE, ATTRS)                                               \
24   { #ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr },
25 #define LANGBUILTIN(ID, TYPE, ATTRS, LANGS)                                    \
26   { #ID, TYPE, ATTRS, nullptr, LANGS, nullptr },
27 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, LANGS)                             \
28   { #ID, TYPE, ATTRS, HEADER, LANGS, nullptr },
29 #include "clang/Basic/Builtins.def"
30 };
31 
getRecord(unsigned ID) const32 const Builtin::Info &Builtin::Context::getRecord(unsigned ID) const {
33   if (ID < Builtin::FirstTSBuiltin)
34     return BuiltinInfo[ID];
35   assert(((ID - Builtin::FirstTSBuiltin) <
36           (TSRecords.size() + AuxTSRecords.size())) &&
37          "Invalid builtin ID!");
38   if (isAuxBuiltinID(ID))
39     return AuxTSRecords[getAuxBuiltinID(ID) - Builtin::FirstTSBuiltin];
40   return TSRecords[ID - Builtin::FirstTSBuiltin];
41 }
42 
InitializeTarget(const TargetInfo & Target,const TargetInfo * AuxTarget)43 void Builtin::Context::InitializeTarget(const TargetInfo &Target,
44                                         const TargetInfo *AuxTarget) {
45   assert(TSRecords.empty() && "Already initialized target?");
46   TSRecords = Target.getTargetBuiltins();
47   if (AuxTarget)
48     AuxTSRecords = AuxTarget->getTargetBuiltins();
49 }
50 
builtinIsSupported(const Builtin::Info & BuiltinInfo,const LangOptions & LangOpts)51 bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo,
52                                           const LangOptions &LangOpts) {
53   bool BuiltinsUnsupported = LangOpts.NoBuiltin &&
54                              strchr(BuiltinInfo.Attributes, 'f');
55   bool MathBuiltinsUnsupported =
56     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
57     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
58   bool GnuModeUnsupported = !LangOpts.GNUMode && (BuiltinInfo.Langs & GNU_LANG);
59   bool MSModeUnsupported =
60       !LangOpts.MicrosoftExt && (BuiltinInfo.Langs & MS_LANG);
61   bool ObjCUnsupported = !LangOpts.ObjC1 && BuiltinInfo.Langs == OBJC_LANG;
62   return !BuiltinsUnsupported && !MathBuiltinsUnsupported &&
63          !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported;
64 }
65 
66 /// initializeBuiltins - Mark the identifiers for all the builtins with their
67 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
68 /// such.
initializeBuiltins(IdentifierTable & Table,const LangOptions & LangOpts)69 void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
70                                           const LangOptions& LangOpts) {
71   // Step #1: mark all target-independent builtins with their ID's.
72   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
73     if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
74       Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
75     }
76 
77   // Step #2: Register target-specific builtins.
78   for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
79     if (builtinIsSupported(TSRecords[i], LangOpts))
80       Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
81 
82   // Step #3: Register target-specific builtins for AuxTarget.
83   for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
84     Table.get(AuxTSRecords[i].Name)
85         .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
86 }
87 
forgetBuiltin(unsigned ID,IdentifierTable & Table)88 void Builtin::Context::forgetBuiltin(unsigned ID, IdentifierTable &Table) {
89   Table.get(getRecord(ID).Name).setBuiltinID(0);
90 }
91 
isLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg,const char * Fmt) const92 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
93                               bool &HasVAListArg, const char *Fmt) const {
94   assert(Fmt && "Not passed a format string");
95   assert(::strlen(Fmt) == 2 &&
96          "Format string needs to be two characters long");
97   assert(::toupper(Fmt[0]) == Fmt[1] &&
98          "Format string is not in the form \"xX\"");
99 
100   const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
101   if (!Like)
102     return false;
103 
104   HasVAListArg = (*Like == Fmt[1]);
105 
106   ++Like;
107   assert(*Like == ':' && "Format specifier must be followed by a ':'");
108   ++Like;
109 
110   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
111   FormatIdx = ::strtol(Like, nullptr, 10);
112   return true;
113 }
114 
isPrintfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)115 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
116                                     bool &HasVAListArg) {
117   return isLike(ID, FormatIdx, HasVAListArg, "pP");
118 }
119 
isScanfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)120 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
121                                    bool &HasVAListArg) {
122   return isLike(ID, FormatIdx, HasVAListArg, "sS");
123 }
124