clang/lib/Basic/Builtins.cpp

   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
  21 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
  44 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
  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
  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?
  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.
 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         Table.get(Name).setBuiltinID(Builtin::NotBuiltin);
 155       }
 156     }
 157   }
 158 }
 159
 160 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
 176 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
 199 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
 200                                     bool &HasVAListArg) {
 201   return isLike(ID, FormatIdx, HasVAListArg, "pP");
 202 }
 203
 204 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
 205                                    bool &HasVAListArg) {
 206   return isLike(ID, FormatIdx, HasVAListArg, "sS");
 207 }
 208
 209 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
 236 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
 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 }