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 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(llvm::StringRef FuncName) {
  52   bool InStdNamespace = FuncName.consume_front("std-");
  53   for (unsigned i = Builtin::NotBuiltin + 1; i != Builtin::FirstTSBuiltin;
  54        ++i) {
  55     if (FuncName.equals(BuiltinInfo[i].Name) &&
  56         (bool)strchr(BuiltinInfo[i].Attributes, 'z') == InStdNamespace)
  57       return strchr(BuiltinInfo[i].Attributes, 'f') != nullptr;
  58   }
  59
  60   return false;
  61 }
  62
  63 /// Is this builtin supported according to the given language options?
  64 static bool builtinIsSupported(const Builtin::Info &BuiltinInfo,
  65                                const LangOptions &LangOpts) {
  66   bool BuiltinsUnsupported =
  67       LangOpts.NoBuiltin && strchr(BuiltinInfo.Attributes, 'f') != nullptr;
  68   bool CorBuiltinsUnsupported =
  69       !LangOpts.Coroutines && (BuiltinInfo.Langs & COR_LANG);
  70   bool MathBuiltinsUnsupported =
  71     LangOpts.NoMathBuiltin && BuiltinInfo.HeaderName &&
  72     llvm::StringRef(BuiltinInfo.HeaderName).equals("math.h");
  73   bool GnuModeUnsupported = !LangOpts.GNUMode && (BuiltinInfo.Langs & GNU_LANG);
  74   bool MSModeUnsupported =
  75       !LangOpts.MicrosoftExt && (BuiltinInfo.Langs & MS_LANG);
  76   bool ObjCUnsupported = !LangOpts.ObjC && BuiltinInfo.Langs == OBJC_LANG;
  77   bool OclCUnsupported =
  78       !LangOpts.OpenCL && (BuiltinInfo.Langs & ALL_OCL_LANGUAGES);
  79   bool OclGASUnsupported =
  80       !LangOpts.OpenCLGenericAddressSpace && (BuiltinInfo.Langs & OCL_GAS);
  81   bool OclPipeUnsupported =
  82       !LangOpts.OpenCLPipes && (BuiltinInfo.Langs & OCL_PIPE);
  83   // Device side enqueue is not supported until OpenCL 2.0. In 2.0 and higher
  84   // support is indicated with language option for blocks.
  85   bool OclDSEUnsupported =
  86       (LangOpts.getOpenCLCompatibleVersion() < 200 || !LangOpts.Blocks) &&
  87       (BuiltinInfo.Langs & OCL_DSE);
  88   bool OpenMPUnsupported = !LangOpts.OpenMP && BuiltinInfo.Langs == OMP_LANG;
  89   bool CUDAUnsupported = !LangOpts.CUDA && BuiltinInfo.Langs == CUDA_LANG;
  90   bool CPlusPlusUnsupported =
  91       !LangOpts.CPlusPlus && BuiltinInfo.Langs == CXX_LANG;
  92   return !BuiltinsUnsupported && !CorBuiltinsUnsupported &&
  93          !MathBuiltinsUnsupported && !OclCUnsupported && !OclGASUnsupported &&
  94          !OclPipeUnsupported && !OclDSEUnsupported && !OpenMPUnsupported &&
  95          !GnuModeUnsupported && !MSModeUnsupported && !ObjCUnsupported &&
  96          !CPlusPlusUnsupported && !CUDAUnsupported;
  97 }
  98
  99 /// initializeBuiltins - Mark the identifiers for all the builtins with their
 100 /// appropriate builtin ID # and mark any non-portable builtin identifiers as
 101 /// such.
 102 void Builtin::Context::initializeBuiltins(IdentifierTable &Table,
 103                                           const LangOptions& LangOpts) {
 104   // Step #1: mark all target-independent builtins with their ID's.
 105   for (unsigned i = Builtin::NotBuiltin+1; i != Builtin::FirstTSBuiltin; ++i)
 106     if (builtinIsSupported(BuiltinInfo[i], LangOpts)) {
 107       Table.get(BuiltinInfo[i].Name).setBuiltinID(i);
 108     }
 109
 110   // Step #2: Register target-specific builtins.
 111   for (unsigned i = 0, e = TSRecords.size(); i != e; ++i)
 112     if (builtinIsSupported(TSRecords[i], LangOpts))
 113       Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
 114
 115   // Step #3: Register target-specific builtins for AuxTarget.
 116   for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
 117     Table.get(AuxTSRecords[i].Name)
 118         .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
 119
 120   // Step #4: Unregister any builtins specified by -fno-builtin-foo.
 121   for (llvm::StringRef Name : LangOpts.NoBuiltinFuncs) {
 122     bool InStdNamespace = Name.consume_front("std-");
 123     auto NameIt = Table.find(Name);
 124     if (NameIt != Table.end()) {
 125       unsigned ID = NameIt->second->getBuiltinID();
 126       if (ID != Builtin::NotBuiltin && isPredefinedLibFunction(ID) &&
 127           isInStdNamespace(ID) == InStdNamespace) {
 128         Table.get(Name).setBuiltinID(Builtin::NotBuiltin);
 129       }
 130     }
 131   }
 132 }
 133
 134 unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
 135   const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
 136   if (!WidthPos)
 137     return 0;
 138
 139   ++WidthPos;
 140   assert(*WidthPos == ':' &&
 141          "Vector width specifier must be followed by a ':'");
 142   ++WidthPos;
 143
 144   char *EndPos;
 145   unsigned Width = ::strtol(WidthPos, &EndPos, 10);
 146   assert(*EndPos == ':' && "Vector width specific must end with a ':'");
 147   return Width;
 148 }
 149
 150 bool Builtin::Context::isLike(unsigned ID, unsigned &FormatIdx,
 151                               bool &HasVAListArg, const char *Fmt) const {
 152   assert(Fmt && "Not passed a format string");
 153   assert(::strlen(Fmt) == 2 &&
 154          "Format string needs to be two characters long");
 155   assert(::toupper(Fmt[0]) == Fmt[1] &&
 156          "Format string is not in the form \"xX\"");
 157
 158   const char *Like = ::strpbrk(getRecord(ID).Attributes, Fmt);
 159   if (!Like)
 160     return false;
 161
 162   HasVAListArg = (*Like == Fmt[1]);
 163
 164   ++Like;
 165   assert(*Like == ':' && "Format specifier must be followed by a ':'");
 166   ++Like;
 167
 168   assert(::strchr(Like, ':') && "Format specifier must end with a ':'");
 169   FormatIdx = ::strtol(Like, nullptr, 10);
 170   return true;
 171 }
 172
 173 bool Builtin::Context::isPrintfLike(unsigned ID, unsigned &FormatIdx,
 174                                     bool &HasVAListArg) {
 175   return isLike(ID, FormatIdx, HasVAListArg, "pP");
 176 }
 177
 178 bool Builtin::Context::isScanfLike(unsigned ID, unsigned &FormatIdx,
 179                                    bool &HasVAListArg) {
 180   return isLike(ID, FormatIdx, HasVAListArg, "sS");
 181 }
 182
 183 bool Builtin::Context::performsCallback(unsigned ID,
 184                                         SmallVectorImpl<int> &Encoding) const {
 185   const char *CalleePos = ::strchr(getRecord(ID).Attributes, 'C');
 186   if (!CalleePos)
 187     return false;
 188
 189   ++CalleePos;
 190   assert(*CalleePos == '<' &&
 191          "Callback callee specifier must be followed by a '<'");
 192   ++CalleePos;
 193
 194   char *EndPos;
 195   int CalleeIdx = ::strtol(CalleePos, &EndPos, 10);
 196   assert(CalleeIdx >= 0 && "Callee index is supposed to be positive!");
 197   Encoding.push_back(CalleeIdx);
 198
 199   while (*EndPos == ',') {
 200     const char *PayloadPos = EndPos + 1;
 201
 202     int PayloadIdx = ::strtol(PayloadPos, &EndPos, 10);
 203     Encoding.push_back(PayloadIdx);
 204   }
 205
 206   assert(*EndPos == '>' && "Callback callee specifier must end with a '>'");
 207   return true;
 208 }
 209
 210 bool Builtin::Context::canBeRedeclared(unsigned ID) const {
 211   return ID == Builtin::NotBuiltin || ID == Builtin::BI__va_start ||
 212          (!hasReferenceArgsOrResult(ID) && !hasCustomTypechecking(ID)) ||
 213          isInStdNamespace(ID);
 214 }
 215
 216 bool Builtin::evaluateRequiredTargetFeatures(
 217     StringRef RequiredFeatures, const llvm::StringMap<bool> &TargetFetureMap) {
 218   // Return true if the builtin doesn't have any required features.
 219   if (RequiredFeatures.empty())
 220     return true;
 221   assert(!RequiredFeatures.contains(' ') && "Space in feature list");
 222
 223   TargetFeatures TF(TargetFetureMap);
 224   return TF.hasRequiredFeatures(RequiredFeatures);
 225 }