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/SmallVector.h"
19 #include "llvm/ADT/StringRef.h"
20 using namespace clang;
21 
22 static const Builtin::Info BuiltinInfo[] = {
23   { "not a builtin function", nullptr, nullptr, nullptr, ALL_LANGUAGES},
24 #define BUILTIN(ID, TYPE, ATTRS) { #ID, TYPE, ATTRS, 0, ALL_LANGUAGES },
25 #define LANGBUILTIN(ID, TYPE, ATTRS, BUILTIN_LANG) { #ID, TYPE, ATTRS, 0, BUILTIN_LANG },
26 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, BUILTIN_LANG) { #ID, TYPE, ATTRS, HEADER,\
27                                                             BUILTIN_LANG },
28 #include "clang/Basic/Builtins.def"
29 };
30 
GetRecord(unsigned ID) const31 const Builtin::Info &Builtin::Context::GetRecord(unsigned ID) const {
32   if (ID < Builtin::FirstTSBuiltin)
33     return BuiltinInfo[ID];
34   assert(ID - Builtin::FirstTSBuiltin < NumTSRecords && "Invalid builtin ID!");
35   return TSRecords[ID - Builtin::FirstTSBuiltin];
36 }
37 
Context()38 Builtin::Context::Context() {
39   // Get the target specific builtins from the target.
40   TSRecords = nullptr;
41   NumTSRecords = 0;
42 }
43 
InitializeTarget(const TargetInfo & Target)44 void Builtin::Context::InitializeTarget(const TargetInfo &Target) {
45   assert(NumTSRecords == 0 && "Already initialized target?");
46   Target.getTargetBuiltins(TSRecords, NumTSRecords);
47 }
48 
BuiltinIsSupported(const Builtin::Info & BuiltinInfo,const LangOptions & LangOpts)49 bool Builtin::Context::BuiltinIsSupported(const Builtin::Info &BuiltinInfo,
50                                           const LangOptions &LangOpts) {
51   bool BuiltinsUnsupported = LangOpts.NoBuiltin &&
52                              strchr(BuiltinInfo.Attributes, 'f');
53   bool MathBuiltinsUnsupported =
54     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
55     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
56   bool GnuModeUnsupported = !LangOpts.GNUMode &&
57                             (BuiltinInfo.builtin_lang & GNU_LANG);
58   bool MSModeUnsupported = !LangOpts.MicrosoftExt &&
59                            (BuiltinInfo.builtin_lang & MS_LANG);
60   bool ObjCUnsupported = !LangOpts.ObjC1 &&
61                          BuiltinInfo.builtin_lang == 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 = NumTSRecords; i != e; ++i)
79     if (BuiltinIsSupported(TSRecords[i], LangOpts))
80       Table.get(TSRecords[i].Name).setBuiltinID(i+Builtin::FirstTSBuiltin);
81 }
82 
83 void
GetBuiltinNames(SmallVectorImpl<const char * > & Names)84 Builtin::Context::GetBuiltinNames(SmallVectorImpl<const char *> &Names) {
85   // Final all target-independent names
86   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
87     if (!strchr(BuiltinInfo[i].Attributes, 'f'))
88       Names.push_back(BuiltinInfo[i].Name);
89 
90   // Find target-specific names.
91   for (unsigned i = 0, e = NumTSRecords; i != e; ++i)
92     if (!strchr(TSRecords[i].Attributes, 'f'))
93       Names.push_back(TSRecords[i].Name);
94 }
95 
ForgetBuiltin(unsigned ID,IdentifierTable & Table)96 void Builtin::Context::ForgetBuiltin(unsigned ID, IdentifierTable &Table) {
97   Table.get(GetRecord(ID).Name).setBuiltinID(0);
98 }
99 
isLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg,const char * Fmt) const100 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
101                               bool &HasVAListArg, const char *Fmt) const {
102   assert(Fmt && "Not passed a format string");
103   assert(::strlen(Fmt) == 2 &&
104          "Format string needs to be two characters long");
105   assert(::toupper(Fmt[0]) == Fmt[1] &&
106          "Format string is not in the form \"xX\"");
107 
108   const char *Like = ::strpbrk(GetRecord(ID).Attributes, Fmt);
109   if (!Like)
110     return false;
111 
112   HasVAListArg = (*Like == Fmt[1]);
113 
114   ++Like;
115   assert(*Like == ':' && "Format specifier must be followed by a ':'");
116   ++Like;
117 
118   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
119   FormatIdx = ::strtol(Like, nullptr, 10);
120   return true;
121 }
122 
isPrintfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)123 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
124                                     bool &HasVAListArg) {
125   return isLike(ID, FormatIdx, HasVAListArg, "pP");
126 }
127 
isScanfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)128 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
129                                    bool &HasVAListArg) {
130   return isLike(ID, FormatIdx, HasVAListArg, "sS");
131 }
132