xref: /freebsd/contrib/llvm-project/clang/lib/AST/TemplateBase.cpp (revision a521f2116473fbd8c09db395518f060a27d02334) 
1 //===- TemplateBase.cpp - Common template AST class 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 common classes used throughout C++ template
10 // representations.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/AST/TemplateBase.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclBase.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/DependenceFlags.h"
20 #include "clang/AST/Expr.h"
21 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/PrettyPrinter.h"
23 #include "clang/AST/TemplateName.h"
24 #include "clang/AST/Type.h"
25 #include "clang/AST/TypeLoc.h"
26 #include "clang/Basic/Diagnostic.h"
27 #include "clang/Basic/LLVM.h"
28 #include "clang/Basic/LangOptions.h"
29 #include "clang/Basic/SourceLocation.h"
30 #include "llvm/ADT/APSInt.h"
31 #include "llvm/ADT/FoldingSet.h"
32 #include "llvm/ADT/None.h"
33 #include "llvm/ADT/SmallString.h"
34 #include "llvm/ADT/StringRef.h"
35 #include "llvm/Support/Casting.h"
36 #include "llvm/Support/Compiler.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/raw_ostream.h"
39 #include <cassert>
40 #include <cstddef>
41 #include <cstdint>
42 #include <cstring>
43 
44 using namespace clang;
45 
46 /// Print a template integral argument value.
47 ///
48 /// \param TemplArg the TemplateArgument instance to print.
49 ///
50 /// \param Out the raw_ostream instance to use for printing.
51 ///
52 /// \param Policy the printing policy for EnumConstantDecl printing.
53 static void printIntegral(const TemplateArgument &TemplArg,
54                           raw_ostream &Out, const PrintingPolicy& Policy) {
55   const Type *T = TemplArg.getIntegralType().getTypePtr();
56   const llvm::APSInt &Val = TemplArg.getAsIntegral();
57 
58   if (const EnumType *ET = T->getAs<EnumType>()) {
59     for (const EnumConstantDecl* ECD : ET->getDecl()->enumerators()) {
60       // In Sema::CheckTemplateArugment, enum template arguments value are
61       // extended to the size of the integer underlying the enum type.  This
62       // may create a size difference between the enum value and template
63       // argument value, requiring isSameValue here instead of operator==.
64       if (llvm::APSInt::isSameValue(ECD->getInitVal(), Val)) {
65         ECD->printQualifiedName(Out, Policy);
66         return;
67       }
68     }
69   }
70 
71   if (T->isBooleanType() && !Policy.MSVCFormatting) {
72     Out << (Val.getBoolValue() ? "true" : "false");
73   } else if (T->isCharType()) {
74     const char Ch = Val.getZExtValue();
75     Out << ((Ch == '\'') ? "'\\" : "'");
76     Out.write_escaped(StringRef(&Ch, 1), /*UseHexEscapes=*/ true);
77     Out << "'";
78   } else {
79     Out << Val;
80   }
81 }
82 
83 //===----------------------------------------------------------------------===//
84 // TemplateArgument Implementation
85 //===----------------------------------------------------------------------===//
86 
87 TemplateArgument::TemplateArgument(ASTContext &Ctx, const llvm::APSInt &Value,
88                                    QualType Type) {
89   Integer.Kind = Integral;
90   // Copy the APSInt value into our decomposed form.
91   Integer.BitWidth = Value.getBitWidth();
92   Integer.IsUnsigned = Value.isUnsigned();
93   // If the value is large, we have to get additional memory from the ASTContext
94   unsigned NumWords = Value.getNumWords();
95   if (NumWords > 1) {
96     void *Mem = Ctx.Allocate(NumWords * sizeof(uint64_t));
97     std::memcpy(Mem, Value.getRawData(), NumWords * sizeof(uint64_t));
98     Integer.pVal = static_cast<uint64_t *>(Mem);
99   } else {
100     Integer.VAL = Value.getZExtValue();
101   }
102 
103   Integer.Type = Type.getAsOpaquePtr();
104 }
105 
106 TemplateArgument
107 TemplateArgument::CreatePackCopy(ASTContext &Context,
108                                  ArrayRef<TemplateArgument> Args) {
109   if (Args.empty())
110     return getEmptyPack();
111 
112   return TemplateArgument(Args.copy(Context));
113 }
114 
115 TemplateArgumentDependence TemplateArgument::getDependence() const {
116   auto Deps = TemplateArgumentDependence::None;
117   switch (getKind()) {
118   case Null:
119     llvm_unreachable("Should not have a NULL template argument");
120 
121   case Type:
122     Deps = toTemplateArgumentDependence(getAsType()->getDependence());
123     if (isa<PackExpansionType>(getAsType()))
124       Deps |= TemplateArgumentDependence::Dependent;
125     return Deps;
126 
127   case Template:
128     return toTemplateArgumentDependence(getAsTemplate().getDependence());
129 
130   case TemplateExpansion:
131     return TemplateArgumentDependence::Dependent |
132            TemplateArgumentDependence::Instantiation;
133 
134   case Declaration: {
135     auto *DC = dyn_cast<DeclContext>(getAsDecl());
136     if (!DC)
137       DC = getAsDecl()->getDeclContext();
138     if (DC->isDependentContext())
139       Deps = TemplateArgumentDependence::Dependent |
140              TemplateArgumentDependence::Instantiation;
141     return Deps;
142   }
143 
144   case NullPtr:
145   case Integral:
146     return TemplateArgumentDependence::None;
147 
148   case Expression:
149     Deps = toTemplateArgumentDependence(getAsExpr()->getDependence());
150     if (isa<PackExpansionExpr>(getAsExpr()))
151       Deps |= TemplateArgumentDependence::Dependent |
152               TemplateArgumentDependence::Instantiation;
153     return Deps;
154 
155   case Pack:
156     for (const auto &P : pack_elements())
157       Deps |= P.getDependence();
158     return Deps;
159   }
160   llvm_unreachable("unhandled ArgKind");
161 }
162 
163 bool TemplateArgument::isDependent() const {
164   return getDependence() & TemplateArgumentDependence::Dependent;
165 }
166 
167 bool TemplateArgument::isInstantiationDependent() const {
168   return getDependence() & TemplateArgumentDependence::Instantiation;
169 }
170 
171 bool TemplateArgument::isPackExpansion() const {
172   switch (getKind()) {
173   case Null:
174   case Declaration:
175   case Integral:
176   case Pack:
177   case Template:
178   case NullPtr:
179     return false;
180 
181   case TemplateExpansion:
182     return true;
183 
184   case Type:
185     return isa<PackExpansionType>(getAsType());
186 
187   case Expression:
188     return isa<PackExpansionExpr>(getAsExpr());
189   }
190 
191   llvm_unreachable("Invalid TemplateArgument Kind!");
192 }
193 
194 bool TemplateArgument::containsUnexpandedParameterPack() const {
195   return getDependence() & TemplateArgumentDependence::UnexpandedPack;
196 }
197 
198 Optional<unsigned> TemplateArgument::getNumTemplateExpansions() const {
199   assert(getKind() == TemplateExpansion);
200   if (TemplateArg.NumExpansions)
201     return TemplateArg.NumExpansions - 1;
202 
203   return None;
204 }
205 
206 QualType TemplateArgument::getNonTypeTemplateArgumentType() const {
207   switch (getKind()) {
208   case TemplateArgument::Null:
209   case TemplateArgument::Type:
210   case TemplateArgument::Template:
211   case TemplateArgument::TemplateExpansion:
212   case TemplateArgument::Pack:
213     return QualType();
214 
215   case TemplateArgument::Integral:
216     return getIntegralType();
217 
218   case TemplateArgument::Expression:
219     return getAsExpr()->getType();
220 
221   case TemplateArgument::Declaration:
222     return getParamTypeForDecl();
223 
224   case TemplateArgument::NullPtr:
225     return getNullPtrType();
226   }
227 
228   llvm_unreachable("Invalid TemplateArgument Kind!");
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 
299   case Integral:
300     return getIntegralType() == Other.getIntegralType() &&
301            getAsIntegral() == Other.getAsIntegral();
302 
303   case Pack:
304     if (Args.NumArgs != Other.Args.NumArgs) return false;
305     for (unsigned I = 0, E = Args.NumArgs; I != E; ++I)
306       if (!Args.Args[I].structurallyEquals(Other.Args.Args[I]))
307         return false;
308     return true;
309   }
310 
311   llvm_unreachable("Invalid TemplateArgument Kind!");
312 }
313 
314 TemplateArgument TemplateArgument::getPackExpansionPattern() const {
315   assert(isPackExpansion());
316 
317   switch (getKind()) {
318   case Type:
319     return getAsType()->castAs<PackExpansionType>()->getPattern();
320 
321   case Expression:
322     return cast<PackExpansionExpr>(getAsExpr())->getPattern();
323 
324   case TemplateExpansion:
325     return TemplateArgument(getAsTemplateOrTemplatePattern());
326 
327   case Declaration:
328   case Integral:
329   case Pack:
330   case Null:
331   case Template:
332   case NullPtr:
333     return TemplateArgument();
334   }
335 
336   llvm_unreachable("Invalid TemplateArgument Kind!");
337 }
338 
339 void TemplateArgument::print(const PrintingPolicy &Policy,
340                              raw_ostream &Out) const {
341   switch (getKind()) {
342   case Null:
343     Out << "(no value)";
344     break;
345 
346   case Type: {
347     PrintingPolicy SubPolicy(Policy);
348     SubPolicy.SuppressStrongLifetime = true;
349     getAsType().print(Out, SubPolicy);
350     break;
351   }
352 
353   case Declaration: {
354     NamedDecl *ND = getAsDecl();
355     if (!getParamTypeForDecl()->isReferenceType())
356       Out << '&';
357     ND->printQualifiedName(Out);
358     break;
359   }
360 
361   case NullPtr:
362     Out << "nullptr";
363     break;
364 
365   case Template:
366     getAsTemplate().print(Out, Policy);
367     break;
368 
369   case TemplateExpansion:
370     getAsTemplateOrTemplatePattern().print(Out, Policy);
371     Out << "...";
372     break;
373 
374   case Integral:
375     printIntegral(*this, Out, Policy);
376     break;
377 
378   case Expression:
379     getAsExpr()->printPretty(Out, nullptr, Policy);
380     break;
381 
382   case Pack:
383     Out << "<";
384     bool First = true;
385     for (const auto &P : pack_elements()) {
386       if (First)
387         First = false;
388       else
389         Out << ", ";
390 
391       P.print(Policy, Out);
392     }
393     Out << ">";
394     break;
395   }
396 }
397 
398 void TemplateArgument::dump(raw_ostream &Out) const {
399   LangOptions LO; // FIXME! see also TemplateName::dump().
400   LO.CPlusPlus = true;
401   LO.Bool = true;
402   print(PrintingPolicy(LO), Out);
403 }
404 
405 LLVM_DUMP_METHOD void TemplateArgument::dump() const { dump(llvm::errs()); }
406 
407 //===----------------------------------------------------------------------===//
408 // TemplateArgumentLoc Implementation
409 //===----------------------------------------------------------------------===//
410 
411 SourceRange TemplateArgumentLoc::getSourceRange() const {
412   switch (Argument.getKind()) {
413   case TemplateArgument::Expression:
414     return getSourceExpression()->getSourceRange();
415 
416   case TemplateArgument::Declaration:
417     return getSourceDeclExpression()->getSourceRange();
418 
419   case TemplateArgument::NullPtr:
420     return getSourceNullPtrExpression()->getSourceRange();
421 
422   case TemplateArgument::Type:
423     if (TypeSourceInfo *TSI = getTypeSourceInfo())
424       return TSI->getTypeLoc().getSourceRange();
425     else
426       return SourceRange();
427 
428   case TemplateArgument::Template:
429     if (getTemplateQualifierLoc())
430       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
431                          getTemplateNameLoc());
432     return SourceRange(getTemplateNameLoc());
433 
434   case TemplateArgument::TemplateExpansion:
435     if (getTemplateQualifierLoc())
436       return SourceRange(getTemplateQualifierLoc().getBeginLoc(),
437                          getTemplateEllipsisLoc());
438     return SourceRange(getTemplateNameLoc(), getTemplateEllipsisLoc());
439 
440   case TemplateArgument::Integral:
441     return getSourceIntegralExpression()->getSourceRange();
442 
443   case TemplateArgument::Pack:
444   case TemplateArgument::Null:
445     return SourceRange();
446   }
447 
448   llvm_unreachable("Invalid TemplateArgument Kind!");
449 }
450 
451 const DiagnosticBuilder &clang::operator<<(const DiagnosticBuilder &DB,
452                                            const TemplateArgument &Arg) {
453   switch (Arg.getKind()) {
454   case TemplateArgument::Null:
455     // This is bad, but not as bad as crashing because of argument
456     // count mismatches.
457     return DB << "(null template argument)";
458 
459   case TemplateArgument::Type:
460     return DB << Arg.getAsType();
461 
462   case TemplateArgument::Declaration:
463     return DB << Arg.getAsDecl();
464 
465   case TemplateArgument::NullPtr:
466     return DB << "nullptr";
467 
468   case TemplateArgument::Integral:
469     return DB << Arg.getAsIntegral().toString(10);
470 
471   case TemplateArgument::Template:
472     return DB << Arg.getAsTemplate();
473 
474   case TemplateArgument::TemplateExpansion:
475     return DB << Arg.getAsTemplateOrTemplatePattern() << "...";
476 
477   case TemplateArgument::Expression: {
478     // This shouldn't actually ever happen, so it's okay that we're
479     // regurgitating an expression here.
480     // FIXME: We're guessing at LangOptions!
481     SmallString<32> Str;
482     llvm::raw_svector_ostream OS(Str);
483     LangOptions LangOpts;
484     LangOpts.CPlusPlus = true;
485     PrintingPolicy Policy(LangOpts);
486     Arg.getAsExpr()->printPretty(OS, nullptr, Policy);
487     return DB << OS.str();
488   }
489 
490   case TemplateArgument::Pack: {
491     // FIXME: We're guessing at LangOptions!
492     SmallString<32> Str;
493     llvm::raw_svector_ostream OS(Str);
494     LangOptions LangOpts;
495     LangOpts.CPlusPlus = true;
496     PrintingPolicy Policy(LangOpts);
497     Arg.print(Policy, OS);
498     return DB << OS.str();
499   }
500   }
501 
502   llvm_unreachable("Invalid TemplateArgument Kind!");
503 }
504 
505 const ASTTemplateArgumentListInfo *
506 ASTTemplateArgumentListInfo::Create(const ASTContext &C,
507                                     const TemplateArgumentListInfo &List) {
508   std::size_t size = totalSizeToAlloc<TemplateArgumentLoc>(List.size());
509   void *Mem = C.Allocate(size, alignof(ASTTemplateArgumentListInfo));
510   return new (Mem) ASTTemplateArgumentListInfo(List);
511 }
512 
513 ASTTemplateArgumentListInfo::ASTTemplateArgumentListInfo(
514     const TemplateArgumentListInfo &Info) {
515   LAngleLoc = Info.getLAngleLoc();
516   RAngleLoc = Info.getRAngleLoc();
517   NumTemplateArgs = Info.size();
518 
519   TemplateArgumentLoc *ArgBuffer = getTrailingObjects<TemplateArgumentLoc>();
520   for (unsigned i = 0; i != NumTemplateArgs; ++i)
521     new (&ArgBuffer[i]) TemplateArgumentLoc(Info[i]);
522 }
523 
524 void ASTTemplateKWAndArgsInfo::initializeFrom(
525     SourceLocation TemplateKWLoc, const TemplateArgumentListInfo &Info,
526     TemplateArgumentLoc *OutArgArray) {
527   this->TemplateKWLoc = TemplateKWLoc;
528   LAngleLoc = Info.getLAngleLoc();
529   RAngleLoc = Info.getRAngleLoc();
530   NumTemplateArgs = Info.size();
531 
532   for (unsigned i = 0; i != NumTemplateArgs; ++i)
533     new (&OutArgArray[i]) TemplateArgumentLoc(Info[i]);
534 }
535 
536 void ASTTemplateKWAndArgsInfo::initializeFrom(SourceLocation TemplateKWLoc) {
537   assert(TemplateKWLoc.isValid());
538   LAngleLoc = SourceLocation();
539   RAngleLoc = SourceLocation();
540   this->TemplateKWLoc = TemplateKWLoc;
541   NumTemplateArgs = 0;
542 }
543 
544 void ASTTemplateKWAndArgsInfo::initializeFrom(
545     SourceLocation TemplateKWLoc, const TemplateArgumentListInfo &Info,
546     TemplateArgumentLoc *OutArgArray, TemplateArgumentDependence &Deps) {
547   this->TemplateKWLoc = TemplateKWLoc;
548   LAngleLoc = Info.getLAngleLoc();
549   RAngleLoc = Info.getRAngleLoc();
550   NumTemplateArgs = Info.size();
551 
552   for (unsigned i = 0; i != NumTemplateArgs; ++i) {
553     Deps |= Info[i].getArgument().getDependence();
554 
555     new (&OutArgArray[i]) TemplateArgumentLoc(Info[i]);
556   }
557 }
558 
559 void ASTTemplateKWAndArgsInfo::copyInto(const TemplateArgumentLoc *ArgArray,
560                                         TemplateArgumentListInfo &Info) const {
561   Info.setLAngleLoc(LAngleLoc);
562   Info.setRAngleLoc(RAngleLoc);
563   for (unsigned I = 0; I != NumTemplateArgs; ++I)
564     Info.addArgument(ArgArray[I]);
565 }
566