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      1 //===--- TemplateBase.cpp - Common template AST class 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 common classes used throughout C++ template
     11 // representations.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "clang/AST/TemplateBase.h"
     16 #include "clang/AST/ASTContext.h"
     17 #include "clang/AST/DeclBase.h"
     18 #include "clang/AST/DeclTemplate.h"
     19 #include "clang/AST/Expr.h"
     20 #include "clang/AST/ExprCXX.h"
     21 #include "clang/AST/Type.h"
     22 #include "clang/AST/TypeLoc.h"
     23 #include "clang/Basic/Diagnostic.h"
     24 #include "llvm/ADT/FoldingSet.h"
     25 #include "llvm/ADT/SmallString.h"
     26 #include "llvm/Support/raw_ostream.h"
     27 #include <algorithm>
     28 
     29 using namespace clang;
     30 
     31 /// \brief Print a template integral argument value.
     32 ///
     33 /// \param TemplArg the TemplateArgument instance to print.
     34 ///
     35 /// \param Out the raw_ostream instance to use for printing.
     36 static void printIntegral(const TemplateArgument &TemplArg,
     37                           raw_ostream &Out) {
     38   const ::clang::Type *T = TemplArg.getIntegralType().getTypePtr();
     39   const llvm::APSInt &Val = TemplArg.getAsIntegral();
     40 
     41   if (T->isBooleanType()) {
     42     Out << (Val.getBoolValue() ? "true" : "false");
     43   } else if (T->isCharType()) {
     44     const char Ch = Val.getZExtValue();
     45     Out << ((Ch == '\'') ? "'\\" : "'");
     46     Out.write_escaped(StringRef(&Ch, 1), /*UseHexEscapes=*/ true);
     47     Out << "'";
     48   } else {
     49     Out << Val;
     50   }
     51 }
     52 
     53 //===----------------------------------------------------------------------===//
     54 // TemplateArgument Implementation
     55 //===----------------------------------------------------------------------===//
     56 
     57 TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
     58                                    QualType Type) {
     59   Integer.Kind = Integral;
     60   // Copy the APSInt value into our decomposed form.
     61   Integer.BitWidth = Value.getBitWidth();
     62   Integer.IsUnsigned = Value.isUnsigned();
     63   // If the value is large, we have to get additional memory from the ASTContext
     64   unsigned NumWords = Value.getNumWords();
     65   if (NumWords > 1) {
     66     void *Mem = Ctx.Allocate(NumWords * sizeof(uint64_t));
     67     std::memcpy(Mem, Value.getRawData(), NumWords * sizeof(uint64_t));
     68     Integer.pVal = static_cast<uint64_t *>(Mem);
     69   } else {
     70     Integer.VAL = Value.getZExtValue();
     71   }
     72 
     73   Integer.Type = Type.getAsOpaquePtr();
     74 }
     75 
     76 TemplateArgument TemplateArgument::CreatePackCopy(ASTContext &Context,
     77                                                   const TemplateArgument *Args,
     78                                                   unsigned NumArgs) {
     79   if (NumArgs == 0)
     80     return getEmptyPack();
     81 
     82   TemplateArgument *Storage = new (Context) TemplateArgument [NumArgs];
     83   std::copy(Args, Args + NumArgs, Storage);
     84   return TemplateArgument(Storage, NumArgs);
     85 }
     86 
     87 bool TemplateArgument::isDependent() const {
     88   switch (getKind()) {
     89   case Null:
     90     llvm_unreachable("Should not have a NULL template argument");
     91 
     92   case Type:
     93     return getAsType()->isDependentType();
     94 
     95   case Template:
     96     return getAsTemplate().isDependent();
     97 
     98   case TemplateExpansion:
     99     return true;
    100 
    101   case Declaration:
    102     if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
    103       return DC->isDependentContext();
    104     return getAsDecl()->getDeclContext()->isDependentContext();
    105 
    106   case NullPtr:
    107     return false;
    108 
    109   case Integral:
    110     // Never dependent
    111     return false;
    112 
    113   case Expression:
    114     return (getAsExpr()->isTypeDependent() || getAsExpr()->isValueDependent());
    115 
    116   case Pack:
    117     for (pack_iterator P = pack_begin(), PEnd = pack_end(); P != PEnd; ++P) {
    118       if (P->isDependent())
    119         return true;
    120     }
    121 
    122     return false;
    123   }
    124 
    125   llvm_unreachable("Invalid TemplateArgument Kind!");
    126 }
    127 
    128 bool TemplateArgument::isInstantiationDependent() const {
    129   switch (getKind()) {
    130   case Null:
    131     llvm_unreachable("Should not have a NULL template argument");
    132 
    133   case Type:
    134     return getAsType()->isInstantiationDependentType();
    135 
    136   case Template:
    137     return getAsTemplate().isInstantiationDependent();
    138 
    139   case TemplateExpansion:
    140     return true;
    141 
    142   case Declaration:
    143     if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
    144       return DC->isDependentContext();
    145     return getAsDecl()->getDeclContext()->isDependentContext();
    146 
    147   case NullPtr:
    148     return false;
    149 
    150   case Integral:
    151     // Never dependent
    152     return false;
    153 
    154   case Expression:
    155     return getAsExpr()->isInstantiationDependent();
    156 
    157   case Pack:
    158     for (pack_iterator P = pack_begin(), PEnd = pack_end(); P != PEnd; ++P) {
    159       if (P->isInstantiationDependent())
    160         return true;
    161     }
    162 
    163     return false;
    164   }
    165 
    166   llvm_unreachable("Invalid TemplateArgument Kind!");
    167 }
    168 
    169 bool TemplateArgument::isPackExpansion() const {
    170   switch (getKind()) {
    171   case Null:
    172   case Declaration:
    173   case Integral:
    174   case Pack:
    175   case Template:
    176   case NullPtr:
    177     return false;
    178 
    179   case TemplateExpansion:
    180     return true;
    181 
    182   case Type:
    183     return isa<PackExpansionType>(getAsType());
    184 
    185   case Expression:
    186     return isa<PackExpansionExpr>(getAsExpr());
    187   }
    188 
    189   llvm_unreachable("Invalid TemplateArgument Kind!");
    190 }
    191 
    192 bool TemplateArgument::containsUnexpandedParameterPack() const {
    193   switch (getKind()) {
    194   case Null:
    195   case Declaration:
    196   case Integral:
    197   case TemplateExpansion:
    198   case NullPtr:
    199     break;
    200 
    201   case Type:
    202     if (getAsType()->containsUnexpandedParameterPack())
    203       return true;
    204     break;
    205 
    206   case Template:
    207     if (getAsTemplate().containsUnexpandedParameterPack())
    208       return true;
    209     break;
    210 
    211   case Expression:
    212     if (getAsExpr()->containsUnexpandedParameterPack())
    213       return true;
    214     break;
    215 
    216   case Pack:
    217     for (pack_iterator P = pack_begin(), PEnd = pack_end(); P != PEnd; ++P)
    218       if (P->containsUnexpandedParameterPack())
    219         return true;
    220 
    221     break;
    222   }
    223 
    224   return false;
    225 }
    226 
    227 Optional<unsigned> TemplateArgument::getNumTemplateExpansions() const {
    228   assert(getKind() == TemplateExpansion);
    229   if (TemplateArg.NumExpansions)
    230     return TemplateArg.NumExpansions - 1;
    231 
    232   return None;
    233 }
    234 
    235 void TemplateArgument::Profile(llvm::FoldingSetNodeID &ID,
    236                                const ASTContext &Context) const {
    237   ID.AddInteger(getKind());
    238   switch (getKind()) {
    239   case Null:
    240     break;
    241 
    242   case Type:
    243     getAsType().Profile(ID);
    244     break;
    245 
    246   case NullPtr:
    247     getNullPtrType().Profile(ID);
    248     break;
    249 
    250   case Declaration:
    251     ID.AddPointer(getAsDecl()? getAsDecl()->getCanonicalDecl() : nullptr);
    252     break;
    253 
    254   case Template:
    255   case TemplateExpansion: {
    256     TemplateName Template = getAsTemplateOrTemplatePattern();
    257     if (TemplateTemplateParmDecl *TTP
    258           = dyn_cast_or_null<TemplateTemplateParmDecl>(
    259                                                 Template.getAsTemplateDecl())) {
    260       ID.AddBoolean(true);
    261       ID.AddInteger(TTP->getDepth());
    262       ID.AddInteger(TTP->getPosition());
    263       ID.AddBoolean(TTP->isParameterPack());
    264     } else {
    265       ID.AddBoolean(false);
    266       ID.AddPointer(Context.getCanonicalTemplateName(Template)
    267                                                           .getAsVoidPointer());
    268     }
    269     break;
    270   }
    271 
    272   case Integral:
    273     getAsIntegral().Profile(ID);
    274     getIntegralType().Profile(ID);
    275     break;
    276 
    277   case Expression:
    278     getAsExpr()->Profile(ID, Context, true);
    279     break;
    280 
    281   case Pack:
    282     ID.AddInteger(Args.NumArgs);
    283     for (unsigned I = 0; I != Args.NumArgs; ++I)
    284       Args.Args[I].Profile(ID, Context);
    285   }
    286 }
    287 
    288 bool TemplateArgument::structurallyEquals(const TemplateArgument &Other) const {
    289   if (getKind() != Other.getKind()) return false;
    290 
    291   switch (getKind()) {
    292   case Null:
    293   case Type:
    294   case Expression:
    295   case Template:
    296   case TemplateExpansion:
    297   case NullPtr:
    298     return TypeOrValue.V == Other.TypeOrValue.V;
    299 
    300   case Declaration:
    301     return getAsDecl() == Other.getAsDecl() &&
    302            isDeclForReferenceParam() && Other.isDeclForReferenceParam();
    303 
    304   case Integral:
    305     return getIntegralType() == Other.getIntegralType() &&
    306            getAsIntegral() == Other.getAsIntegral();
    307 
    308   case Pack:
    309     if (Args.NumArgs != Other.Args.NumArgs) return false;
    310     for (unsigned I = 0, E = Args.NumArgs; I != E; ++I)
    311       if (!Args.Args[I].structurallyEquals(Other.Args.Args[I]))
    312         return false;
    313     return true;
    314   }
    315 
    316   llvm_unreachable("Invalid TemplateArgument Kind!");
    317 }
    318 
    319 TemplateArgument TemplateArgument::getPackExpansionPattern() const {
    320   assert(isPackExpansion());
    321 
    322   switch (getKind()) {
    323   case Type:
    324     return getAsType()->getAs<PackExpansionType>()->getPattern();
    325 
    326   case Expression:
    327     return cast<PackExpansionExpr>(getAsExpr())->getPattern();
    328 
    329   case TemplateExpansion:
    330     return TemplateArgument(getAsTemplateOrTemplatePattern());
    331 
    332   case Declaration:
    333   case Integral:
    334   case Pack:
    335   case Null:
    336   case Template:
    337   case NullPtr:
    338     return TemplateArgument();
    339   }
    340 
    341   llvm_unreachable("Invalid TemplateArgument Kind!");
    342 }
    343 
    344 void TemplateArgument::print(const PrintingPolicy &Policy,
    345                              raw_ostream &Out) const {
    346   switch (getKind()) {
    347   case Null:
    348     Out << "(no value)";
    349     break;
    350 
    351   case Type: {
    352     PrintingPolicy SubPolicy(Policy);
    353     SubPolicy.SuppressStrongLifetime = true;
    354     getAsType().print(Out, SubPolicy);
    355     break;
    356   }
    357 
    358   case Declaration: {
    359     NamedDecl *ND = cast<NamedDecl>(getAsDecl());
    360     Out << '&';
    361     if (ND->getDeclName()) {
    362       // FIXME: distinguish between pointer and reference args?
    363       ND->printQualifiedName(Out);
    364     } else {
    365       Out << "(anonymous)";
    366     }
    367     break;
    368   }
    369 
    370   case NullPtr:
    371     Out << "nullptr";
    372     break;
    373 
    374   case Template:
    375     getAsTemplate().print(Out, Policy);
    376     break;
    377 
    378   case TemplateExpansion:
    379     getAsTemplateOrTemplatePattern().print(Out, Policy);
    380     Out << "...";
    381     break;
    382 
    383   case Integral: {
    384     printIntegral(*this, Out);
    385     break;
    386   }
    387 
    388   case Expression:
    389     getAsExpr()->printPretty(Out, nullptr, Policy);
    390     break;
    391 
    392   case Pack:
    393     Out << "<";
    394     bool First = true;
    395     for (TemplateArgument::pack_iterator P = pack_begin(), PEnd = pack_end();
    396          P != PEnd; ++P) {
    397       if (First)
    398         First = false;
    399       else
    400         Out << ", ";
    401 
    402       P->print(Policy, Out);
    403     }
    404     Out << ">";
    405     break;
    406   }
    407 }
    408 
    409 //===----------------------------------------------------------------------===//
    410 // TemplateArgumentLoc Implementation
    411 //===----------------------------------------------------------------------===//
    412 
    413 TemplateArgumentLocInfo::TemplateArgumentLocInfo() {
    414   memset((void*)this, 0, sizeof(TemplateArgumentLocInfo));
    415 }
    416 
    417 SourceRange TemplateArgumentLoc::getSourceRange() const {
    418   switch (Argument.getKind()) {
    419   case TemplateArgument::Expression:
    420     return getSourceExpression()->getSourceRange();
    421 
    422   case TemplateArgument::Declaration:
    423     return getSourceDeclExpression()->getSourceRange();
    424 
    425   case TemplateArgument::NullPtr:
    426     return getSourceNullPtrExpression()->getSourceRange();
    427 
    428   case TemplateArgument::Type:
    429     if (TypeSourceInfo *TSI = getTypeSourceInfo())
    430       return TSI->getTypeLoc().getSourceRange();
    431     else
    432       return SourceRange();
    433 
    434   case TemplateArgument::Template:
    435     if (getTemplateQualifierLoc())
    436       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
    437                          getTemplateNameLoc());
    438     return SourceRange(getTemplateNameLoc());
    439 
    440   case TemplateArgument::TemplateExpansion:
    441     if (getTemplateQualifierLoc())
    442       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
    443                          getTemplateEllipsisLoc());
    444     return SourceRange(getTemplateNameLoc(), getTemplateEllipsisLoc());
    445 
    446   case TemplateArgument::Integral:
    447     return getSourceIntegralExpression()->getSourceRange();
    448 
    449   case TemplateArgument::Pack:
    450   case TemplateArgument::Null:
    451     return SourceRange();
    452   }
    453 
    454   llvm_unreachable("Invalid TemplateArgument Kind!");
    455 }
    456 
    457 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
    458                                            const TemplateArgument &Arg) {
    459   switch (Arg.getKind()) {
    460   case TemplateArgument::Null:
    461     // This is bad, but not as bad as crashing because of argument
    462     // count mismatches.
    463     return DB << "(null template argument)";
    464 
    465   case TemplateArgument::Type:
    466     return DB << Arg.getAsType();
    467 
    468   case TemplateArgument::Declaration:
    469     return DB << Arg.getAsDecl();
    470 
    471   case TemplateArgument::NullPtr:
    472     return DB << "nullptr";
    473 
    474   case TemplateArgument::Integral:
    475     return DB << Arg.getAsIntegral().toString(10);
    476 
    477   case TemplateArgument::Template:
    478     return DB << Arg.getAsTemplate();
    479 
    480   case TemplateArgument::TemplateExpansion:
    481     return DB << Arg.getAsTemplateOrTemplatePattern() << "...";
    482 
    483   case TemplateArgument::Expression: {
    484     // This shouldn't actually ever happen, so it's okay that we're
    485     // regurgitating an expression here.
    486     // FIXME: We're guessing at LangOptions!
    487     SmallString<32> Str;
    488     llvm::raw_svector_ostream OS(Str);
    489     LangOptions LangOpts;
    490     LangOpts.CPlusPlus = true;
    491     PrintingPolicy Policy(LangOpts);
    492     Arg.getAsExpr()->printPretty(OS, nullptr, Policy);
    493     return DB << OS.str();
    494   }
    495 
    496   case TemplateArgument::Pack: {
    497     // FIXME: We're guessing at LangOptions!
    498     SmallString<32> Str;
    499     llvm::raw_svector_ostream OS(Str);
    500     LangOptions LangOpts;
    501     LangOpts.CPlusPlus = true;
    502     PrintingPolicy Policy(LangOpts);
    503     Arg.print(Policy, OS);
    504     return DB << OS.str();
    505   }
    506   }
    507 
    508   llvm_unreachable("Invalid TemplateArgument Kind!");
    509 }
    510 
    511 const ASTTemplateArgumentListInfo *
    512 ASTTemplateArgumentListInfo::Create(ASTContext &C,
    513                                     const TemplateArgumentListInfo &List) {
    514   assert(llvm::alignOf<ASTTemplateArgumentListInfo>() >=
    515          llvm::alignOf<TemplateArgumentLoc>());
    516   std::size_t size = ASTTemplateArgumentListInfo::sizeFor(List.size());
    517   void *Mem = C.Allocate(size, llvm::alignOf<ASTTemplateArgumentListInfo>());
    518   ASTTemplateArgumentListInfo *TAI = new (Mem) ASTTemplateArgumentListInfo();
    519   TAI->initializeFrom(List);
    520   return TAI;
    521 }
    522 
    523 void ASTTemplateArgumentListInfo::initializeFrom(
    524                                       const TemplateArgumentListInfo &Info) {
    525   LAngleLoc = Info.getLAngleLoc();
    526   RAngleLoc = Info.getRAngleLoc();
    527   NumTemplateArgs = Info.size();
    528 
    529   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
    530   for (unsigned i = 0; i != NumTemplateArgs; ++i)
    531     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
    532 }
    533 
    534 void ASTTemplateArgumentListInfo::initializeFrom(
    535                                           const TemplateArgumentListInfo &Info,
    536                                                   bool &Dependent,
    537                                                   bool &InstantiationDependent,
    538                                        bool &ContainsUnexpandedParameterPack) {
    539   LAngleLoc = Info.getLAngleLoc();
    540   RAngleLoc = Info.getRAngleLoc();
    541   NumTemplateArgs = Info.size();
    542 
    543   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
    544   for (unsigned i = 0; i != NumTemplateArgs; ++i) {
    545     Dependent = Dependent || Info[i].getArgument().isDependent();
    546     InstantiationDependent = InstantiationDependent ||
    547                              Info[i].getArgument().isInstantiationDependent();
    548     ContainsUnexpandedParameterPack
    549       = ContainsUnexpandedParameterPack ||
    550         Info[i].getArgument().containsUnexpandedParameterPack();
    551 
    552     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
    553   }
    554 }
    555 
    556 void ASTTemplateArgumentListInfo::copyInto(
    557                                       TemplateArgumentListInfo &Info) const {
    558   Info.setLAngleLoc(LAngleLoc);
    559   Info.setRAngleLoc(RAngleLoc);
    560   for (unsigned I = 0; I != NumTemplateArgs; ++I)
    561     Info.addArgument(getTemplateArgs()[I]);
    562 }
    563 
    564 std::size_t ASTTemplateArgumentListInfo::sizeFor(unsigned NumTemplateArgs) {
    565   return sizeof(ASTTemplateArgumentListInfo) +
    566          sizeof(TemplateArgumentLoc) * NumTemplateArgs;
    567 }
    568 
    569 void
    570 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc,
    571                                          const TemplateArgumentListInfo &Info) {
    572   Base::initializeFrom(Info);
    573   setTemplateKeywordLoc(TemplateKWLoc);
    574 }
    575 
    576 void
    577 ASTTemplateKWAndArgsInfo
    578 ::initializeFrom(SourceLocation TemplateKWLoc,
    579                  const TemplateArgumentListInfo &Info,
    580                  bool &Dependent,
    581                  bool &InstantiationDependent,
    582                  bool &ContainsUnexpandedParameterPack) {
    583   Base::initializeFrom(Info, Dependent, InstantiationDependent,
    584                        ContainsUnexpandedParameterPack);
    585   setTemplateKeywordLoc(TemplateKWLoc);
    586 }
    587 
    588 void
    589 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc) {
    590   // No explicit template arguments, but template keyword loc is valid.
    591   assert(TemplateKWLoc.isValid());
    592   LAngleLoc = SourceLocation();
    593   RAngleLoc = SourceLocation();
    594   NumTemplateArgs = 0;
    595   setTemplateKeywordLoc(TemplateKWLoc);
    596 }
    597 
    598 std::size_t
    599 ASTTemplateKWAndArgsInfo::sizeFor(unsigned NumTemplateArgs) {
    600   // Add space for the template keyword location.
    601   // FIXME: There's room for this in the padding before the template args in
    602   //        64-bit builds.
    603   return Base::sizeFor(NumTemplateArgs) + sizeof(SourceLocation);
    604 }
    605