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 "clang/Basic/IdentifierTable.h"
  15 #include "clang/Basic/LangOptions.h"
  16 #include "clang/Basic/TargetInfo.h"
  17 #include "llvm/ADT/StringRef.h"
  18 using namespace clang;
  19
  20 static const Builtin::Info BuiltinInfo[] = {
  21   { "not a builtin function", nullptr, nullptr, nullptr, ALL_LANGUAGES,nullptr},
  22 #define BUILTIN(ID, TYPE, ATTRS)                                               \
  23   { #ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr },
  24 #define LANGBUILTIN(ID, TYPE, ATTRS, LANGS)                                    \
  25   { #ID, TYPE, ATTRS, nullptr, LANGS, nullptr },
  26 #define LIBBUILTIN(ID, TYPE, ATTRS, HEADER, LANGS)                             \
  27   { #ID, TYPE, ATTRS, HEADER, LANGS, nullptr },
  28 #include "clang/Basic/Builtins.def"
  29 };
  30
  31 const Builtin::Info &Builtin::Context::getRecord(unsigned ID) const {
  32   if (ID < Builtin::FirstTSBuiltin)
  33     return BuiltinInfo[ID];
  34   assert(((ID - Builtin::FirstTSBuiltin) <
  35           (TSRecords.size() + AuxTSRecords.size())) &&
  36          "Invalid builtin ID!");
  37   if (isAuxBuiltinID(ID))
  38     return AuxTSRecords[getAuxBuiltinID(ID) - Builtin::FirstTSBuiltin];
  39   return TSRecords[ID - Builtin::FirstTSBuiltin];
  40 }
  41
  42 void Builtin::Context::InitializeTarget(const TargetInfo &Target,
  43                                         const TargetInfo *AuxTarget) {
  44   assert(TSRecords.empty() && "Already initialized target?");
  45   TSRecords = Target.getTargetBuiltins();
  46   if (AuxTarget)
  47     AuxTSRecords = AuxTarget->getTargetBuiltins();
  48 }
  49
  50 bool Builtin::Context::isBuiltinFunc(llvm::StringRef FuncName) {
  51   for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin; ++i)
  52     if (FuncName.equals(BuiltinInfo[i].Name))
  53       return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
  54
  55   return false;
  56 }
  57
  58 bool Builtin::Context::builtinIsSupported(const Builtin::Info &BuiltinInfo,
  59                                           const LangOptions &LangOpts) {
  60   bool BuiltinsUnsupported =
  61       (LangOpts.NoBuiltin || LangOpts.isNoBuiltinFunc(BuiltinInfo.Name)) &&
  62       strchr(BuiltinInfo.Attributes, 'f');
  63   bool CorBuiltinsUnsupported =
  64       !LangOpts.Coroutines && (BuiltinInfo.Langs & COR_LANG);
  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 OclCUnsupported =
  73       !LangOpts.OpenCL && (BuiltinInfo.Langs & ALL_OCL_LANGUAGES);
  74   bool OclGASUnsupported =
  75       !LangOpts.OpenCLGenericAddressSpace && (BuiltinInfo.Langs & OCL_GAS);
  76   bool OclPipeUnsupported =
  77       !LangOpts.OpenCLPipes && (BuiltinInfo.Langs & OCL_PIPE);
  78   // Device side enqueue is not supported until OpenCL 2.0. In 2.0 and higher
  79   // support is indicated with language option for blocks.
  80   bool OclDSEUnsupported =
  81       (LangOpts.getOpenCLCompatibleVersion() < 200 || !LangOpts.Blocks) &&
  82       (BuiltinInfo.Langs & OCL_DSE);
  83   bool OpenMPUnsupported = !LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG;
  84   bool CUDAUnsupported = !LangOpts.CUDA && BuiltinInfo.Langs == CUDA_LANG;
  85   bool CPlusPlusUnsupported =
  86       !LangOpts.CPlusPlus && BuiltinInfo.Langs == CXX_LANG;
  87   return !BuiltinsUnsupported && !CorBuiltinsUnsupported &&
  88          !MathBuiltinsUnsupported && !OclCUnsupported && !OclGASUnsupported &&
  89          !OclPipeUnsupported && !OclDSEUnsupported && !OpenMPUnsupported &&
  90          !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported &&
  91          !CPlusPlusUnsupported && !CUDAUnsupported;
  92 }
  93
  94 /// initializeBuiltins - Mark the identifiers for all the builtins with their
  95 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
  96 /// such.
  97 void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
  98                                           const LangOptions& LangOpts) {
  99   // Step #1: mark all target-independent builtins with their ID's.
 100   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
 101     if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
 102       Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
 103     }
 104
 105   // Step #2: Register target-specific builtins.
 106   for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
 107     if (builtinIsSupported(TSRecords[i], LangOpts))
 108       Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
 109
 110   // Step #3: Register target-specific builtins for AuxTarget.
 111   for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
 112     Table.get(AuxTSRecords[i].Name)
 113         .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
 114 }
 115
 116 unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
 117   const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
 118   if (!WidthPos)
 119     return 0;
 120
 121   ++WidthPos;
 122   assert(*WidthPos == ':' &&
 123          "Vector width specifier must be followed by a ':'");
 124   ++WidthPos;
 125
 126   char *EndPos;
 127   unsigned Width = ::strtol(WidthPos, &EndPos, 10);
 128   assert(*EndPos == ':' && "Vector width specific must end with a ':'");
 129   return Width;
 130 }
 131
 132 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
 133                               bool &HasVAListArg, const char *Fmt) const {
 134   assert(Fmt && "Not passed a format string");
 135   assert(::strlen(Fmt) == 2 &&
 136          "Format string needs to be two characters long");
 137   assert(::toupper(Fmt[0]) == Fmt[1] &&
 138          "Format string is not in the form \"xX\"");
 139
 140   const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
 141   if (!Like)
 142     return false;
 143
 144   HasVAListArg = (*Like == Fmt[1]);
 145
 146   ++Like;
 147   assert(*Like == ':' && "Format specifier must be followed by a ':'");
 148   ++Like;
 149
 150   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
 151   FormatIdx = ::strtol(Like, nullptr, 10);
 152   return true;
 153 }
 154
 155 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
 156                                     bool &HasVAListArg) {
 157   return isLike(ID, FormatIdx, HasVAListArg, "pP");
 158 }
 159
 160 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
 161                                    bool &HasVAListArg) {
 162   return isLike(ID, FormatIdx, HasVAListArg, "sS");
 163 }
 164
 165 bool Builtin::Context::performsCallback(unsigned ID,
 166                                         SmallVectorImpl<int> &Encoding) const {
 167   const char *CalleePos = ::strchr(getRecord(ID).Attributes, 'C');
 168   if (!CalleePos)
 169     return false;
 170
 171   ++CalleePos;
 172   assert(*CalleePos == '<' &&
 173          "Callback callee specifier must be followed by a '<'");
 174   ++CalleePos;
 175
 176   char *EndPos;
 177   int CalleeIdx = ::strtol(CalleePos, &EndPos, 10);
 178   assert(CalleeIdx >= 0 && "Callee index is supposed to be positive!");
 179   Encoding.push_back(CalleeIdx);
 180
 181   while (*EndPos == ',') {
 182     const char *PayloadPos = EndPos + 1;
 183
 184     int PayloadIdx = ::strtol(PayloadPos, &EndPos, 10);
 185     Encoding.push_back(PayloadIdx);
 186   }
 187
 188   assert(*EndPos == '>' && "Callback callee specifier must end with a '>'");
 189   return true;
 190 }
 191
 192 bool Builtin::Context::canBeRedeclared(unsigned ID) const {
 193   return ID == Builtin::NotBuiltin ||
 194          ID == Builtin::BI__va_start ||
 195          (!hasReferenceArgsOrResult(ID) &&
 196           !hasCustomTypechecking(ID));
 197 }