1 //===--- Builtins.cpp - Builtin function implementation -------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements various things for builtin functions.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "clang/Basic/Builtins.h"
14 #include "BuiltinTargetFeatures.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
getName() const21 const char *HeaderDesc::getName() const {
22 switch (ID) {
23 #define HEADER(ID, NAME) \
24 case ID: \
25 return NAME;
26 #include "clang/Basic/BuiltinHeaders.def"
27 #undef HEADER
28 };
29 llvm_unreachable("Unknown HeaderDesc::HeaderID enum");
30 }
31
32 static constexpr Builtin::Info BuiltinInfo[] = {
33 {"not a builtin function", nullptr, nullptr, nullptr, HeaderDesc::NO_HEADER,
34 ALL_LANGUAGES},
35 #define BUILTIN(ID, TYPE, ATTRS) \
36 {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, ALL_LANGUAGES},
37 #define LANGBUILTIN(ID, TYPE, ATTRS, LANGS) \
38 {#ID, TYPE, ATTRS, nullptr, HeaderDesc::NO_HEADER, LANGS},
39 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, LANGS) \
40 {#ID, TYPE, ATTRS, nullptr, HeaderDesc::HEADER, LANGS},
41 #include "clang/Basic/Builtins.def"
42 };
43
getRecord(unsigned ID) const44 const Builtin::Info &Builtin::Context::getRecord(unsigned ID) const {
45 if (ID < Builtin::FirstTSBuiltin)
46 return BuiltinInfo[ID];
47 assert(((ID - Builtin::FirstTSBuiltin) <
48 (TSRecords.size() + AuxTSRecords.size())) &&
49 "Invalid builtin ID!");
50 if (isAuxBuiltinID(ID))
51 return AuxTSRecords[getAuxBuiltinID(ID) - Builtin::FirstTSBuiltin];
52 return TSRecords[ID - Builtin::FirstTSBuiltin];
53 }
54
InitializeTarget(const TargetInfo & Target,const TargetInfo * AuxTarget)55 void Builtin::Context::InitializeTarget(const TargetInfo &Target,
56 const TargetInfo *AuxTarget) {
57 assert(TSRecords.empty() && "Already initialized target?");
58 TSRecords = Target.getTargetBuiltins();
59 if (AuxTarget)
60 AuxTSRecords = AuxTarget->getTargetBuiltins();
61 }
62
isBuiltinFunc(llvm::StringRef FuncName)63 bool Builtin::Context::isBuiltinFunc(llvm::StringRef FuncName) {
64 bool InStdNamespace = FuncName.consume_front("std-");
65 for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin;
66 ++i) {
67 if (FuncName.equals(BuiltinInfo[i].Name) &&
68 (bool)strchr(BuiltinInfo[i].Attributes, 'z') == InStdNamespace)
69 return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
70 }
71
72 return false;
73 }
74
75 /// Is this builtin supported according to the given language options?
builtinIsSupported(const Builtin::Info & BuiltinInfo,const LangOptions & LangOpts)76 static bool builtinIsSupported(const Builtin::Info &BuiltinInfo,
77 const LangOptions &LangOpts) {
78 /* Builtins Unsupported */
79 if (LangOpts.NoBuiltin && strchr(BuiltinInfo.Attributes, 'f') != nullptr)
80 return false;
81 /* CorBuiltins Unsupported */
82 if (!LangOpts.Coroutines && (BuiltinInfo.Langs & COR_LANG))
83 return false;
84 /* MathBuiltins Unsupported */
85 if (LangOpts.NoMathBuiltin && BuiltinInfo.Header.ID == HeaderDesc::MATH_H)
86 return false;
87 /* GnuMode Unsupported */
88 if (!LangOpts.GNUMode && (BuiltinInfo.Langs & GNU_LANG))
89 return false;
90 /* MSMode Unsupported */
91 if (!LangOpts.MicrosoftExt && (BuiltinInfo.Langs & MS_LANG))
92 return false;
93 /* ObjC Unsupported */
94 if (!LangOpts.ObjC && BuiltinInfo.Langs == OBJC_LANG)
95 return false;
96 /* OpenCLC Unsupported */
97 if (!LangOpts.OpenCL && (BuiltinInfo.Langs & ALL_OCL_LANGUAGES))
98 return false;
99 /* OopenCL GAS Unsupported */
100 if (!LangOpts.OpenCLGenericAddressSpace && (BuiltinInfo.Langs & OCL_GAS))
101 return false;
102 /* OpenCL Pipe Unsupported */
103 if (!LangOpts.OpenCLPipes && (BuiltinInfo.Langs & OCL_PIPE))
104 return false;
105
106 // Device side enqueue is not supported until OpenCL 2.0. In 2.0 and higher
107 // support is indicated with language option for blocks.
108
109 /* OpenCL DSE Unsupported */
110 if ((LangOpts.getOpenCLCompatibleVersion() < 200 || !LangOpts.Blocks) &&
111 (BuiltinInfo.Langs & OCL_DSE))
112 return false;
113 /* OpenMP Unsupported */
114 if (!LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG)
115 return false;
116 /* CUDA Unsupported */
117 if (!LangOpts.CUDA && BuiltinInfo.Langs == CUDA_LANG)
118 return false;
119 /* CPlusPlus Unsupported */
120 if (!LangOpts.CPlusPlus && BuiltinInfo.Langs == CXX_LANG)
121 return false;
122 return true;
123 }
124
125 /// initializeBuiltins - Mark the identifiers for all the builtins with their
126 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
127 /// such.
initializeBuiltins(IdentifierTable & Table,const LangOptions & LangOpts)128 void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
129 const LangOptions& LangOpts) {
130 // Step #1: mark all target-independent builtins with their ID's.
131 for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
132 if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
133 Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
134 }
135
136 // Step #2: Register target-specific builtins.
137 for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
138 if (builtinIsSupported(TSRecords[i], LangOpts))
139 Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
140
141 // Step #3: Register target-specific builtins for AuxTarget.
142 for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
143 Table.get(AuxTSRecords[i].Name)
144 .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
145
146 // Step #4: Unregister any builtins specified by -fno-builtin-foo.
147 for (llvm::StringRef Name : LangOpts.NoBuiltinFuncs) {
148 bool InStdNamespace = Name.consume_front("std-");
149 auto NameIt = Table.find(Name);
150 if (NameIt != Table.end()) {
151 unsigned ID = NameIt->second->getBuiltinID();
152 if (ID != Builtin::NotBuiltin && isPredefinedLibFunction(ID) &&
153 isInStdNamespace(ID) == InStdNamespace) {
154 NameIt->second->clearBuiltinID();
155 }
156 }
157 }
158 }
159
getRequiredVectorWidth(unsigned ID) const160 unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
161 const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
162 if (!WidthPos)
163 return 0;
164
165 ++WidthPos;
166 assert(*WidthPos == ':' &&
167 "Vector width specifier must be followed by a ':'");
168 ++WidthPos;
169
170 char *EndPos;
171 unsigned Width = ::strtol(WidthPos, &EndPos, 10);
172 assert(*EndPos == ':' && "Vector width specific must end with a ':'");
173 return Width;
174 }
175
isLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg,const char * Fmt) const176 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
177 bool &HasVAListArg, const char *Fmt) const {
178 assert(Fmt && "Not passed a format string");
179 assert(::strlen(Fmt) == 2 &&
180 "Format string needs to be two characters long");
181 assert(::toupper(Fmt[0]) == Fmt[1] &&
182 "Format string is not in the form \"xX\"");
183
184 const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
185 if (!Like)
186 return false;
187
188 HasVAListArg = (*Like == Fmt[1]);
189
190 ++Like;
191 assert(*Like == ':' && "Format specifier must be followed by a ':'");
192 ++Like;
193
194 assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
195 FormatIdx = ::strtol(Like, nullptr, 10);
196 return true;
197 }
198
isPrintfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)199 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
200 bool &HasVAListArg) {
201 return isLike(ID, FormatIdx, HasVAListArg, "pP");
202 }
203
isScanfLike(unsigned ID,unsigned & FormatIdx,bool & HasVAListArg)204 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
205 bool &HasVAListArg) {
206 return isLike(ID, FormatIdx, HasVAListArg, "sS");
207 }
208
performsCallback(unsigned ID,SmallVectorImpl<int> & Encoding) const209 bool Builtin::Context::performsCallback(unsigned ID,
210 SmallVectorImpl<int> &Encoding) const {
211 const char *CalleePos = ::strchr(getRecord(ID).Attributes, 'C');
212 if (!CalleePos)
213 return false;
214
215 ++CalleePos;
216 assert(*CalleePos == '<' &&
217 "Callback callee specifier must be followed by a '<'");
218 ++CalleePos;
219
220 char *EndPos;
221 int CalleeIdx = ::strtol(CalleePos, &EndPos, 10);
222 assert(CalleeIdx >= 0 && "Callee index is supposed to be positive!");
223 Encoding.push_back(CalleeIdx);
224
225 while (*EndPos == ',') {
226 const char *PayloadPos = EndPos + 1;
227
228 int PayloadIdx = ::strtol(PayloadPos, &EndPos, 10);
229 Encoding.push_back(PayloadIdx);
230 }
231
232 assert(*EndPos == '>' && "Callback callee specifier must end with a '>'");
233 return true;
234 }
235
canBeRedeclared(unsigned ID) const236 bool Builtin::Context::canBeRedeclared(unsigned ID) const {
237 return ID == Builtin::NotBuiltin || ID == Builtin::BI__va_start ||
238 ID == Builtin::BI__builtin_assume_aligned ||
239 (!hasReferenceArgsOrResult(ID) && !hasCustomTypechecking(ID)) ||
240 isInStdNamespace(ID);
241 }
242
evaluateRequiredTargetFeatures(StringRef RequiredFeatures,const llvm::StringMap<bool> & TargetFetureMap)243 bool Builtin::evaluateRequiredTargetFeatures(
244 StringRef RequiredFeatures, const llvm::StringMap<bool> &TargetFetureMap) {
245 // Return true if the builtin doesn't have any required features.
246 if (RequiredFeatures.empty())
247 return true;
248 assert(!RequiredFeatures.contains(' ') && "Space in feature list");
249
250 TargetFeatures TF(TargetFetureMap);
251 return TF.hasRequiredFeatures(RequiredFeatures);
252 }
253