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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   : 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(Kind == 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(Kind);
    238   switch (Kind) {
    239   case Null:
    240     break;
    241 
    242   case Type:
    243     getAsType().Profile(ID);
    244     break;
    245 
    246   case Declaration:
    247     ID.AddPointer(getAsDecl()? getAsDecl()->getCanonicalDecl() : 0);
    248     break;
    249 
    250   case Template:
    251   case TemplateExpansion: {
    252     TemplateName Template = getAsTemplateOrTemplatePattern();
    253     if (TemplateTemplateParmDecl *TTP
    254           = dyn_cast_or_null<TemplateTemplateParmDecl>(
    255                                                 Template.getAsTemplateDecl())) {
    256       ID.AddBoolean(true);
    257       ID.AddInteger(TTP->getDepth());
    258       ID.AddInteger(TTP->getPosition());
    259       ID.AddBoolean(TTP->isParameterPack());
    260     } else {
    261       ID.AddBoolean(false);
    262       ID.AddPointer(Context.getCanonicalTemplateName(Template)
    263                                                           .getAsVoidPointer());
    264     }
    265     break;
    266   }
    267 
    268   case Integral:
    269     getAsIntegral().Profile(ID);
    270     getIntegralType().Profile(ID);
    271     break;
    272 
    273   case Expression:
    274     getAsExpr()->Profile(ID, Context, true);
    275     break;
    276 
    277   case Pack:
    278     ID.AddInteger(Args.NumArgs);
    279     for (unsigned I = 0; I != Args.NumArgs; ++I)
    280       Args.Args[I].Profile(ID, Context);
    281   }
    282 }
    283 
    284 bool TemplateArgument::structurallyEquals(const TemplateArgument &Other) const {
    285   if (getKind() != Other.getKind()) return false;
    286 
    287   switch (getKind()) {
    288   case Null:
    289   case Type:
    290   case Expression:
    291   case Template:
    292   case TemplateExpansion:
    293   case NullPtr:
    294     return TypeOrValue == Other.TypeOrValue;
    295 
    296   case Declaration:
    297     return getAsDecl() == Other.getAsDecl() &&
    298            isDeclForReferenceParam() && Other.isDeclForReferenceParam();
    299 
    300   case Integral:
    301     return getIntegralType() == Other.getIntegralType() &&
    302            getAsIntegral() == Other.getAsIntegral();
    303 
    304   case Pack:
    305     if (Args.NumArgs != Other.Args.NumArgs) return false;
    306     for (unsigned I = 0, E = Args.NumArgs; I != E; ++I)
    307       if (!Args.Args[I].structurallyEquals(Other.Args.Args[I]))
    308         return false;
    309     return true;
    310   }
    311 
    312   llvm_unreachable("Invalid TemplateArgument Kind!");
    313 }
    314 
    315 TemplateArgument TemplateArgument::getPackExpansionPattern() const {
    316   assert(isPackExpansion());
    317 
    318   switch (getKind()) {
    319   case Type:
    320     return getAsType()->getAs<PackExpansionType>()->getPattern();
    321 
    322   case Expression:
    323     return cast<PackExpansionExpr>(getAsExpr())->getPattern();
    324 
    325   case TemplateExpansion:
    326     return TemplateArgument(getAsTemplateOrTemplatePattern());
    327 
    328   case Declaration:
    329   case Integral:
    330   case Pack:
    331   case Null:
    332   case Template:
    333   case NullPtr:
    334     return TemplateArgument();
    335   }
    336 
    337   llvm_unreachable("Invalid TemplateArgument Kind!");
    338 }
    339 
    340 void TemplateArgument::print(const PrintingPolicy &Policy,
    341                              raw_ostream &Out) const {
    342   switch (getKind()) {
    343   case Null:
    344     Out << "<no value>";
    345     break;
    346 
    347   case Type: {
    348     PrintingPolicy SubPolicy(Policy);
    349     SubPolicy.SuppressStrongLifetime = true;
    350     getAsType().print(Out, SubPolicy);
    351     break;
    352   }
    353 
    354   case Declaration: {
    355     NamedDecl *ND = cast<NamedDecl>(getAsDecl());
    356     Out << '&';
    357     if (ND->getDeclName()) {
    358       // FIXME: distinguish between pointer and reference args?
    359       ND->printQualifiedName(Out);
    360     } else {
    361       Out << "<anonymous>";
    362     }
    363     break;
    364   }
    365 
    366   case NullPtr:
    367     Out << "nullptr";
    368     break;
    369 
    370   case Template:
    371     getAsTemplate().print(Out, Policy);
    372     break;
    373 
    374   case TemplateExpansion:
    375     getAsTemplateOrTemplatePattern().print(Out, Policy);
    376     Out << "...";
    377     break;
    378 
    379   case Integral: {
    380     printIntegral(*this, Out);
    381     break;
    382   }
    383 
    384   case Expression:
    385     getAsExpr()->printPretty(Out, 0, Policy);
    386     break;
    387 
    388   case Pack:
    389     Out << "<";
    390     bool First = true;
    391     for (TemplateArgument::pack_iterator P = pack_begin(), PEnd = pack_end();
    392          P != PEnd; ++P) {
    393       if (First)
    394         First = false;
    395       else
    396         Out << ", ";
    397 
    398       P->print(Policy, Out);
    399     }
    400     Out << ">";
    401     break;
    402   }
    403 }
    404 
    405 //===----------------------------------------------------------------------===//
    406 // TemplateArgumentLoc Implementation
    407 //===----------------------------------------------------------------------===//
    408 
    409 TemplateArgumentLocInfo::TemplateArgumentLocInfo() {
    410   memset((void*)this, 0, sizeof(TemplateArgumentLocInfo));
    411 }
    412 
    413 SourceRange TemplateArgumentLoc::getSourceRange() const {
    414   switch (Argument.getKind()) {
    415   case TemplateArgument::Expression:
    416     return getSourceExpression()->getSourceRange();
    417 
    418   case TemplateArgument::Declaration:
    419     return getSourceDeclExpression()->getSourceRange();
    420 
    421   case TemplateArgument::NullPtr:
    422     return getSourceNullPtrExpression()->getSourceRange();
    423 
    424   case TemplateArgument::Type:
    425     if (TypeSourceInfo *TSI = getTypeSourceInfo())
    426       return TSI->getTypeLoc().getSourceRange();
    427     else
    428       return SourceRange();
    429 
    430   case TemplateArgument::Template:
    431     if (getTemplateQualifierLoc())
    432       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
    433                          getTemplateNameLoc());
    434     return SourceRange(getTemplateNameLoc());
    435 
    436   case TemplateArgument::TemplateExpansion:
    437     if (getTemplateQualifierLoc())
    438       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
    439                          getTemplateEllipsisLoc());
    440     return SourceRange(getTemplateNameLoc(), getTemplateEllipsisLoc());
    441 
    442   case TemplateArgument::Integral:
    443     return getSourceIntegralExpression()->getSourceRange();
    444 
    445   case TemplateArgument::Pack:
    446   case TemplateArgument::Null:
    447     return SourceRange();
    448   }
    449 
    450   llvm_unreachable("Invalid TemplateArgument Kind!");
    451 }
    452 
    453 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
    454                                            const TemplateArgument &Arg) {
    455   switch (Arg.getKind()) {
    456   case TemplateArgument::Null:
    457     // This is bad, but not as bad as crashing because of argument
    458     // count mismatches.
    459     return DB << "(null template argument)";
    460 
    461   case TemplateArgument::Type:
    462     return DB << Arg.getAsType();
    463 
    464   case TemplateArgument::Declaration:
    465     return DB << Arg.getAsDecl();
    466 
    467   case TemplateArgument::NullPtr:
    468     return DB << "nullptr";
    469 
    470   case TemplateArgument::Integral:
    471     return DB << Arg.getAsIntegral().toString(10);
    472 
    473   case TemplateArgument::Template:
    474     return DB << Arg.getAsTemplate();
    475 
    476   case TemplateArgument::TemplateExpansion:
    477     return DB << Arg.getAsTemplateOrTemplatePattern() << "...";
    478 
    479   case TemplateArgument::Expression: {
    480     // This shouldn't actually ever happen, so it's okay that we're
    481     // regurgitating an expression here.
    482     // FIXME: We're guessing at LangOptions!
    483     SmallString<32> Str;
    484     llvm::raw_svector_ostream OS(Str);
    485     LangOptions LangOpts;
    486     LangOpts.CPlusPlus = true;
    487     PrintingPolicy Policy(LangOpts);
    488     Arg.getAsExpr()->printPretty(OS, 0, Policy);
    489     return DB << OS.str();
    490   }
    491 
    492   case TemplateArgument::Pack: {
    493     // FIXME: We're guessing at LangOptions!
    494     SmallString<32> Str;
    495     llvm::raw_svector_ostream OS(Str);
    496     LangOptions LangOpts;
    497     LangOpts.CPlusPlus = true;
    498     PrintingPolicy Policy(LangOpts);
    499     Arg.print(Policy, OS);
    500     return DB << OS.str();
    501   }
    502   }
    503 
    504   llvm_unreachable("Invalid TemplateArgument Kind!");
    505 }
    506 
    507 const ASTTemplateArgumentListInfo *
    508 ASTTemplateArgumentListInfo::Create(ASTContext &C,
    509                                     const TemplateArgumentListInfo &List) {
    510   std::size_t size = ASTTemplateArgumentListInfo::sizeFor(List.size());
    511   void *Mem = C.Allocate(size, llvm::alignOf<ASTTemplateArgumentListInfo>());
    512   ASTTemplateArgumentListInfo *TAI = new (Mem) ASTTemplateArgumentListInfo();
    513   TAI->initializeFrom(List);
    514   return TAI;
    515 }
    516 
    517 void ASTTemplateArgumentListInfo::initializeFrom(
    518                                       const TemplateArgumentListInfo &Info) {
    519   LAngleLoc = Info.getLAngleLoc();
    520   RAngleLoc = Info.getRAngleLoc();
    521   NumTemplateArgs = Info.size();
    522 
    523   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
    524   for (unsigned i = 0; i != NumTemplateArgs; ++i)
    525     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
    526 }
    527 
    528 void ASTTemplateArgumentListInfo::initializeFrom(
    529                                           const TemplateArgumentListInfo &Info,
    530                                                   bool &Dependent,
    531                                                   bool &InstantiationDependent,
    532                                        bool &ContainsUnexpandedParameterPack) {
    533   LAngleLoc = Info.getLAngleLoc();
    534   RAngleLoc = Info.getRAngleLoc();
    535   NumTemplateArgs = Info.size();
    536 
    537   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
    538   for (unsigned i = 0; i != NumTemplateArgs; ++i) {
    539     Dependent = Dependent || Info[i].getArgument().isDependent();
    540     InstantiationDependent = InstantiationDependent ||
    541                              Info[i].getArgument().isInstantiationDependent();
    542     ContainsUnexpandedParameterPack
    543       = ContainsUnexpandedParameterPack ||
    544         Info[i].getArgument().containsUnexpandedParameterPack();
    545 
    546     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
    547   }
    548 }
    549 
    550 void ASTTemplateArgumentListInfo::copyInto(
    551                                       TemplateArgumentListInfo &Info) const {
    552   Info.setLAngleLoc(LAngleLoc);
    553   Info.setRAngleLoc(RAngleLoc);
    554   for (unsigned I = 0; I != NumTemplateArgs; ++I)
    555     Info.addArgument(getTemplateArgs()[I]);
    556 }
    557 
    558 std::size_t ASTTemplateArgumentListInfo::sizeFor(unsigned NumTemplateArgs) {
    559   return sizeof(ASTTemplateArgumentListInfo) +
    560          sizeof(TemplateArgumentLoc) * NumTemplateArgs;
    561 }
    562 
    563 void
    564 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc,
    565                                          const TemplateArgumentListInfo &Info) {
    566   Base::initializeFrom(Info);
    567   setTemplateKeywordLoc(TemplateKWLoc);
    568 }
    569 
    570 void
    571 ASTTemplateKWAndArgsInfo
    572 ::initializeFrom(SourceLocation TemplateKWLoc,
    573                  const TemplateArgumentListInfo &Info,
    574                  bool &Dependent,
    575                  bool &InstantiationDependent,
    576                  bool &ContainsUnexpandedParameterPack) {
    577   Base::initializeFrom(Info, Dependent, InstantiationDependent,
    578                        ContainsUnexpandedParameterPack);
    579   setTemplateKeywordLoc(TemplateKWLoc);
    580 }
    581 
    582 void
    583 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc) {
    584   // No explicit template arguments, but template keyword loc is valid.
    585   assert(TemplateKWLoc.isValid());
    586   LAngleLoc = SourceLocation();
    587   RAngleLoc = SourceLocation();
    588   NumTemplateArgs = 0;
    589   setTemplateKeywordLoc(TemplateKWLoc);
    590 }
    591 
    592 std::size_t
    593 ASTTemplateKWAndArgsInfo::sizeFor(unsigned NumTemplateArgs) {
    594   // Add space for the template keyword location.
    595   // FIXME: There's room for this in the padding before the template args in
    596   //        64-bit builds.
    597   return Base::sizeFor(NumTemplateArgs) + sizeof(SourceLocation);
    598 }
    599