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 
32 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 
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 
51 bool Builtin::Context::isBuiltinFunc(const char *Name) {
52   StringRef FuncName(Name);
53   for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin; ++i)
54     if (FuncName.equals(BuiltinInfo[i].Name))
55       return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
56 
57   return false;
58 }
59 
60 bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo,
61                                           const LangOptions &LangOpts) {
62   bool BuiltinsUnsupported =
63       (LangOpts.NoBuiltin || LangOpts.isNoBuiltinFunc(BuiltinInfo.Name)) &&
64       strchr(BuiltinInfo.Attributes, 'f');
65   bool MathBuiltinsUnsupported =
66     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
67     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
68   bool GnuModeUnsupported = !LangOpts.GNUMode && (BuiltinInfo.Langs & GNU_LANG);
69   bool MSModeUnsupported =
70       !LangOpts.MicrosoftExt && (BuiltinInfo.Langs & MS_LANG);
71   bool ObjCUnsupported = !LangOpts.ObjC && BuiltinInfo.Langs == OBJC_LANG;
72   bool OclC1Unsupported = (LangOpts.OpenCLVersion / 100) != 1 &&
73                           (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES ) ==  OCLC1X_LANG;
74   bool OclC2Unsupported = LangOpts.OpenCLVersion != 200 &&
75                           (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES) == OCLC20_LANG;
76   bool OclCUnsupported = !LangOpts.OpenCL &&
77                          (BuiltinInfo.Langs & ALL_OCLC_LANGUAGES);
78   bool OpenMPUnsupported = !LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG;
79   return !BuiltinsUnsupported && !MathBuiltinsUnsupported && !OclCUnsupported &&
80          !OclC1Unsupported && !OclC2Unsupported && !OpenMPUnsupported &&
81          !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported;
82 }
83 
84 /// initializeBuiltins - Mark the identifiers for all the builtins with their
85 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
86 /// such.
87 void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
88                                           const LangOptions& LangOpts) {
89   // Step #1: mark all target-independent builtins with their ID's.
90   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
91     if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
92       Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
93     }
94 
95   // Step #2: Register target-specific builtins.
96   for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
97     if (builtinIsSupported(TSRecords[i], LangOpts))
98       Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
99 
100   // Step #3: Register target-specific builtins for AuxTarget.
101   for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
102     Table.get(AuxTSRecords[i].Name)
103         .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
104 }
105 
106 void Builtin::Context::forgetBuiltin(unsigned ID, IdentifierTable &Table) {
107   Table.get(getRecord(ID).Name).setBuiltinID(0);
108 }
109 
110 unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
111   const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
112   if (!WidthPos)
113     return 0;
114 
115   ++WidthPos;
116   assert(*WidthPos == ':' &&
117          "Vector width specifier must be followed by a ':'");
118   ++WidthPos;
119 
120   char *EndPos;
121   unsigned Width = ::strtol(WidthPos, &EndPos, 10);
122   assert(*EndPos == ':' && "Vector width specific must end with a ':'");
123   return Width;
124 }
125 
126 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
127                               bool &HasVAListArg, const char *Fmt) const {
128   assert(Fmt && "Not passed a format string");
129   assert(::strlen(Fmt) == 2 &&
130          "Format string needs to be two characters long");
131   assert(::toupper(Fmt[0]) == Fmt[1] &&
132          "Format string is not in the form \"xX\"");
133 
134   const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
135   if (!Like)
136     return false;
137 
138   HasVAListArg = (*Like == Fmt[1]);
139 
140   ++Like;
141   assert(*Like == ':' && "Format specifier must be followed by a ':'");
142   ++Like;
143 
144   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
145   FormatIdx = ::strtol(Like, nullptr, 10);
146   return true;
147 }
148 
149 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
150                                     bool &HasVAListArg) {
151   return isLike(ID, FormatIdx, HasVAListArg, "pP");
152 }
153 
154 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
155                                    bool &HasVAListArg) {
156   return isLike(ID, FormatIdx, HasVAListArg, "sS");
157 }
158 
159 bool Builtin::Context::canBeRedeclared(unsigned ID) const {
160   return ID == Builtin::NotBuiltin ||
161          ID == Builtin::BI__va_start ||
162          (!hasReferenceArgsOrResult(ID) &&
163           !hasCustomTypechecking(ID));
164 }
165