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 (const auto &P : pack_elements())
118       if (P.isDependent())
119         return true;
120     return false;
121   }
122 
123   llvm_unreachable("Invalid TemplateArgument Kind!");
124 }
125 
126 bool TemplateArgument::isInstantiationDependent() const {
127   switch (getKind()) {
128   case Null:
129     llvm_unreachable("Should not have a NULL template argument");
130 
131   case Type:
132     return getAsType()->isInstantiationDependentType();
133 
134   case Template:
135     return getAsTemplate().isInstantiationDependent();
136 
137   case TemplateExpansion:
138     return true;
139 
140   case Declaration:
141     if (DeclContext *DC = dyn_cast<DeclContext>(getAsDecl()))
142       return DC->isDependentContext();
143     return getAsDecl()->getDeclContext()->isDependentContext();
144 
145   case NullPtr:
146     return false;
147 
148   case Integral:
149     // Never dependent
150     return false;
151 
152   case Expression:
153     return getAsExpr()->isInstantiationDependent();
154 
155   case Pack:
156     for (const auto &P : pack_elements())
157       if (P.isInstantiationDependent())
158         return true;
159     return false;
160   }
161 
162   llvm_unreachable("Invalid TemplateArgument Kind!");
163 }
164 
165 bool TemplateArgument::isPackExpansion() const {
166   switch (getKind()) {
167   case Null:
168   case Declaration:
169   case Integral:
170   case Pack:
171   case Template:
172   case NullPtr:
173     return false;
174 
175   case TemplateExpansion:
176     return true;
177 
178   case Type:
179     return isa<PackExpansionType>(getAsType());
180 
181   case Expression:
182     return isa<PackExpansionExpr>(getAsExpr());
183   }
184 
185   llvm_unreachable("Invalid TemplateArgument Kind!");
186 }
187 
188 bool TemplateArgument::containsUnexpandedParameterPack() const {
189   switch (getKind()) {
190   case Null:
191   case Declaration:
192   case Integral:
193   case TemplateExpansion:
194   case NullPtr:
195     break;
196 
197   case Type:
198     if (getAsType()->containsUnexpandedParameterPack())
199       return true;
200     break;
201 
202   case Template:
203     if (getAsTemplate().containsUnexpandedParameterPack())
204       return true;
205     break;
206 
207   case Expression:
208     if (getAsExpr()->containsUnexpandedParameterPack())
209       return true;
210     break;
211 
212   case Pack:
213     for (const auto &P : pack_elements())
214       if (P.containsUnexpandedParameterPack())
215         return true;
216 
217     break;
218   }
219 
220   return false;
221 }
222 
223 Optional<unsigned> TemplateArgument::getNumTemplateExpansions() const {
224   assert(getKind() == TemplateExpansion);
225   if (TemplateArg.NumExpansions)
226     return TemplateArg.NumExpansions - 1;
227 
228   return None;
229 }
230 
231 void TemplateArgument::Profile(llvm::FoldingSetNodeID &ID,
232                                const ASTContext &Context) const {
233   ID.AddInteger(getKind());
234   switch (getKind()) {
235   case Null:
236     break;
237 
238   case Type:
239     getAsType().Profile(ID);
240     break;
241 
242   case NullPtr:
243     getNullPtrType().Profile(ID);
244     break;
245 
246   case Declaration:
247     ID.AddPointer(getAsDecl()? getAsDecl()->getCanonicalDecl() : nullptr);
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.V == Other.TypeOrValue.V;
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, nullptr, Policy);
386     break;
387 
388   case Pack:
389     Out << "<";
390     bool First = true;
391     for (const auto &P : pack_elements()) {
392       if (First)
393         First = false;
394       else
395         Out << ", ";
396 
397       P.print(Policy, Out);
398     }
399     Out << ">";
400     break;
401   }
402 }
403 
404 //===----------------------------------------------------------------------===//
405 // TemplateArgumentLoc Implementation
406 //===----------------------------------------------------------------------===//
407 
408 TemplateArgumentLocInfo::TemplateArgumentLocInfo() {
409   memset((void*)this, 0, sizeof(TemplateArgumentLocInfo));
410 }
411 
412 SourceRange TemplateArgumentLoc::getSourceRange() const {
413   switch (Argument.getKind()) {
414   case TemplateArgument::Expression:
415     return getSourceExpression()->getSourceRange();
416 
417   case TemplateArgument::Declaration:
418     return getSourceDeclExpression()->getSourceRange();
419 
420   case TemplateArgument::NullPtr:
421     return getSourceNullPtrExpression()->getSourceRange();
422 
423   case TemplateArgument::Type:
424     if (TypeSourceInfo *TSI = getTypeSourceInfo())
425       return TSI->getTypeLoc().getSourceRange();
426     else
427       return SourceRange();
428 
429   case TemplateArgument::Template:
430     if (getTemplateQualifierLoc())
431       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
432                          getTemplateNameLoc());
433     return SourceRange(getTemplateNameLoc());
434 
435   case TemplateArgument::TemplateExpansion:
436     if (getTemplateQualifierLoc())
437       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
438                          getTemplateEllipsisLoc());
439     return SourceRange(getTemplateNameLoc(), getTemplateEllipsisLoc());
440 
441   case TemplateArgument::Integral:
442     return getSourceIntegralExpression()->getSourceRange();
443 
444   case TemplateArgument::Pack:
445   case TemplateArgument::Null:
446     return SourceRange();
447   }
448 
449   llvm_unreachable("Invalid TemplateArgument Kind!");
450 }
451 
452 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
453                                            const TemplateArgument &Arg) {
454   switch (Arg.getKind()) {
455   case TemplateArgument::Null:
456     // This is bad, but not as bad as crashing because of argument
457     // count mismatches.
458     return DB << "(null template argument)";
459 
460   case TemplateArgument::Type:
461     return DB << Arg.getAsType();
462 
463   case TemplateArgument::Declaration:
464     return DB << Arg.getAsDecl();
465 
466   case TemplateArgument::NullPtr:
467     return DB << "nullptr";
468 
469   case TemplateArgument::Integral:
470     return DB << Arg.getAsIntegral().toString(10);
471 
472   case TemplateArgument::Template:
473     return DB << Arg.getAsTemplate();
474 
475   case TemplateArgument::TemplateExpansion:
476     return DB << Arg.getAsTemplateOrTemplatePattern() << "...";
477 
478   case TemplateArgument::Expression: {
479     // This shouldn't actually ever happen, so it's okay that we're
480     // regurgitating an expression here.
481     // FIXME: We're guessing at LangOptions!
482     SmallString<32> Str;
483     llvm::raw_svector_ostream OS(Str);
484     LangOptions LangOpts;
485     LangOpts.CPlusPlus = true;
486     PrintingPolicy Policy(LangOpts);
487     Arg.getAsExpr()->printPretty(OS, nullptr, Policy);
488     return DB << OS.str();
489   }
490 
491   case TemplateArgument::Pack: {
492     // FIXME: We're guessing at LangOptions!
493     SmallString<32> Str;
494     llvm::raw_svector_ostream OS(Str);
495     LangOptions LangOpts;
496     LangOpts.CPlusPlus = true;
497     PrintingPolicy Policy(LangOpts);
498     Arg.print(Policy, OS);
499     return DB << OS.str();
500   }
501   }
502 
503   llvm_unreachable("Invalid TemplateArgument Kind!");
504 }
505 
506 const ASTTemplateArgumentListInfo *
507 ASTTemplateArgumentListInfo::Create(ASTContext &C,
508                                     const TemplateArgumentListInfo &List) {
509   assert(llvm::alignOf<ASTTemplateArgumentListInfo>() >=
510          llvm::alignOf<TemplateArgumentLoc>());
511   std::size_t size = ASTTemplateArgumentListInfo::sizeFor(List.size());
512   void *Mem = C.Allocate(size, llvm::alignOf<ASTTemplateArgumentListInfo>());
513   ASTTemplateArgumentListInfo *TAI = new (Mem) ASTTemplateArgumentListInfo();
514   TAI->initializeFrom(List);
515   return TAI;
516 }
517 
518 void ASTTemplateArgumentListInfo::initializeFrom(
519                                       const TemplateArgumentListInfo &Info) {
520   LAngleLoc = Info.getLAngleLoc();
521   RAngleLoc = Info.getRAngleLoc();
522   NumTemplateArgs = Info.size();
523 
524   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
525   for (unsigned i = 0; i != NumTemplateArgs; ++i)
526     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
527 }
528 
529 void ASTTemplateArgumentListInfo::initializeFrom(
530                                           const TemplateArgumentListInfo &Info,
531                                                   bool &Dependent,
532                                                   bool &InstantiationDependent,
533                                        bool &ContainsUnexpandedParameterPack) {
534   LAngleLoc = Info.getLAngleLoc();
535   RAngleLoc = Info.getRAngleLoc();
536   NumTemplateArgs = Info.size();
537 
538   TemplateArgumentLoc *ArgBuffer = getTemplateArgs();
539   for (unsigned i = 0; i != NumTemplateArgs; ++i) {
540     Dependent = Dependent || Info[i].getArgument().isDependent();
541     InstantiationDependent = InstantiationDependent ||
542                              Info[i].getArgument().isInstantiationDependent();
543     ContainsUnexpandedParameterPack
544       = ContainsUnexpandedParameterPack ||
545         Info[i].getArgument().containsUnexpandedParameterPack();
546 
547     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
548   }
549 }
550 
551 void ASTTemplateArgumentListInfo::copyInto(
552                                       TemplateArgumentListInfo &Info) const {
553   Info.setLAngleLoc(LAngleLoc);
554   Info.setRAngleLoc(RAngleLoc);
555   for (unsigned I = 0; I != NumTemplateArgs; ++I)
556     Info.addArgument(getTemplateArgs()[I]);
557 }
558 
559 std::size_t ASTTemplateArgumentListInfo::sizeFor(unsigned NumTemplateArgs) {
560   return sizeof(ASTTemplateArgumentListInfo) +
561          sizeof(TemplateArgumentLoc) * NumTemplateArgs;
562 }
563 
564 void
565 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc,
566                                          const TemplateArgumentListInfo &Info) {
567   Base::initializeFrom(Info);
568   setTemplateKeywordLoc(TemplateKWLoc);
569 }
570 
571 void
572 ASTTemplateKWAndArgsInfo
573 ::initializeFrom(SourceLocation TemplateKWLoc,
574                  const TemplateArgumentListInfo &Info,
575                  bool &Dependent,
576                  bool &InstantiationDependent,
577                  bool &ContainsUnexpandedParameterPack) {
578   Base::initializeFrom(Info, Dependent, InstantiationDependent,
579                        ContainsUnexpandedParameterPack);
580   setTemplateKeywordLoc(TemplateKWLoc);
581 }
582 
583 void
584 ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc) {
585   // No explicit template arguments, but template keyword loc is valid.
586   assert(TemplateKWLoc.isValid());
587   LAngleLoc = SourceLocation();
588   RAngleLoc = SourceLocation();
589   NumTemplateArgs = 0;
590   setTemplateKeywordLoc(TemplateKWLoc);
591 }
592 
593 std::size_t
594 ASTTemplateKWAndArgsInfo::sizeFor(unsigned NumTemplateArgs) {
595   // Add space for the template keyword location.
596   // FIXME: There's room for this in the padding before the template args in
597   //        64-bit builds.
598   return Base::sizeFor(NumTemplateArgs) + sizeof(SourceLocation);
599 }
600