1 //===-- lib/Evaluate/variable.cpp -----------------------------------------===//
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 #include "flang/Evaluate/variable.h"
10 #include "flang/Common/idioms.h"
11 #include "flang/Evaluate/check-expression.h"
12 #include "flang/Evaluate/fold.h"
13 #include "flang/Evaluate/tools.h"
14 #include "flang/Parser/char-block.h"
15 #include "flang/Parser/characters.h"
16 #include "flang/Parser/message.h"
17 #include "flang/Semantics/scope.h"
18 #include "flang/Semantics/symbol.h"
19 #include <type_traits>
20 
21 using namespace Fortran::parser::literals;
22 
23 namespace Fortran::evaluate {
24 
25 // Constructors, accessors, mutators
26 
27 Triplet::Triplet() : stride_{Expr<SubscriptInteger>{1}} {}
28 
29 Triplet::Triplet(std::optional<Expr<SubscriptInteger>> &&l,
30     std::optional<Expr<SubscriptInteger>> &&u,
31     std::optional<Expr<SubscriptInteger>> &&s)
32     : stride_{s ? std::move(*s) : Expr<SubscriptInteger>{1}} {
33   if (l) {
34     lower_.emplace(std::move(*l));
35   }
36   if (u) {
37     upper_.emplace(std::move(*u));
38   }
39 }
40 
41 std::optional<Expr<SubscriptInteger>> Triplet::lower() const {
42   if (lower_) {
43     return {lower_.value().value()};
44   }
45   return std::nullopt;
46 }
47 
48 Triplet &Triplet::set_lower(Expr<SubscriptInteger> &&expr) {
49   lower_.emplace(std::move(expr));
50   return *this;
51 }
52 
53 std::optional<Expr<SubscriptInteger>> Triplet::upper() const {
54   if (upper_) {
55     return {upper_.value().value()};
56   }
57   return std::nullopt;
58 }
59 
60 Triplet &Triplet::set_upper(Expr<SubscriptInteger> &&expr) {
61   upper_.emplace(std::move(expr));
62   return *this;
63 }
64 
65 Expr<SubscriptInteger> Triplet::stride() const { return stride_.value(); }
66 
67 Triplet &Triplet::set_stride(Expr<SubscriptInteger> &&expr) {
68   stride_.value() = std::move(expr);
69   return *this;
70 }
71 
72 bool Triplet::IsStrideOne() const {
73   if (auto stride{ToInt64(stride_.value())}) {
74     return stride == 1;
75   } else {
76     return false;
77   }
78 }
79 
80 CoarrayRef::CoarrayRef(SymbolVector &&base, std::vector<Subscript> &&ss,
81     std::vector<Expr<SubscriptInteger>> &&css)
82     : base_{std::move(base)}, subscript_(std::move(ss)),
83       cosubscript_(std::move(css)) {
84   CHECK(!base_.empty());
85   CHECK(!cosubscript_.empty());
86 }
87 
88 std::optional<Expr<SomeInteger>> CoarrayRef::stat() const {
89   if (stat_) {
90     return stat_.value().value();
91   } else {
92     return std::nullopt;
93   }
94 }
95 
96 std::optional<Expr<SomeInteger>> CoarrayRef::team() const {
97   if (team_) {
98     return team_.value().value();
99   } else {
100     return std::nullopt;
101   }
102 }
103 
104 CoarrayRef &CoarrayRef::set_stat(Expr<SomeInteger> &&v) {
105   CHECK(IsVariable(v));
106   stat_.emplace(std::move(v));
107   return *this;
108 }
109 
110 CoarrayRef &CoarrayRef::set_team(Expr<SomeInteger> &&v, bool isTeamNumber) {
111   CHECK(IsVariable(v));
112   team_.emplace(std::move(v));
113   teamIsTeamNumber_ = isTeamNumber;
114   return *this;
115 }
116 
117 const Symbol &CoarrayRef::GetFirstSymbol() const { return base_.front(); }
118 
119 const Symbol &CoarrayRef::GetLastSymbol() const { return base_.back(); }
120 
121 void Substring::SetBounds(std::optional<Expr<SubscriptInteger>> &lower,
122     std::optional<Expr<SubscriptInteger>> &upper) {
123   if (lower) {
124     set_lower(std::move(lower.value()));
125   }
126   if (upper) {
127     set_upper(std::move(upper.value()));
128   }
129 }
130 
131 Expr<SubscriptInteger> Substring::lower() const {
132   if (lower_) {
133     return lower_.value().value();
134   } else {
135     return AsExpr(Constant<SubscriptInteger>{1});
136   }
137 }
138 
139 Substring &Substring::set_lower(Expr<SubscriptInteger> &&expr) {
140   lower_.emplace(std::move(expr));
141   return *this;
142 }
143 
144 std::optional<Expr<SubscriptInteger>> Substring::upper() const {
145   if (upper_) {
146     return upper_.value().value();
147   } else {
148     return std::visit(
149         common::visitors{
150             [](const DataRef &dataRef) { return dataRef.LEN(); },
151             [](const StaticDataObject::Pointer &object)
152                 -> std::optional<Expr<SubscriptInteger>> {
153               return AsExpr(Constant<SubscriptInteger>{object->data().size()});
154             },
155         },
156         parent_);
157   }
158 }
159 
160 Substring &Substring::set_upper(Expr<SubscriptInteger> &&expr) {
161   upper_.emplace(std::move(expr));
162   return *this;
163 }
164 
165 std::optional<Expr<SomeCharacter>> Substring::Fold(FoldingContext &context) {
166   if (!lower_) {
167     lower_ = AsExpr(Constant<SubscriptInteger>{1});
168   }
169   lower_.value() = evaluate::Fold(context, std::move(lower_.value().value()));
170   std::optional<ConstantSubscript> lbi{ToInt64(lower_.value().value())};
171   if (lbi && *lbi < 1) {
172     context.messages().Say(
173         "Lower bound (%jd) on substring is less than one"_en_US, *lbi);
174     *lbi = 1;
175     lower_ = AsExpr(Constant<SubscriptInteger>{1});
176   }
177   if (!upper_) {
178     upper_ = upper();
179     if (!upper_) {
180       return std::nullopt;
181     }
182   }
183   upper_.value() = evaluate::Fold(context, std::move(upper_.value().value()));
184   if (std::optional<ConstantSubscript> ubi{ToInt64(upper_.value().value())}) {
185     auto *literal{std::get_if<StaticDataObject::Pointer>(&parent_)};
186     std::optional<ConstantSubscript> length;
187     if (literal) {
188       length = (*literal)->data().size();
189     } else if (const Symbol * symbol{GetLastSymbol()}) {
190       if (const semantics::DeclTypeSpec * type{symbol->GetType()}) {
191         if (type->category() == semantics::DeclTypeSpec::Character) {
192           length = ToInt64(type->characterTypeSpec().length().GetExplicit());
193         }
194       }
195     }
196     if (*ubi < 1 || (lbi && *ubi < *lbi)) {
197       // Zero-length string: canonicalize
198       *lbi = 1, *ubi = 0;
199       lower_ = AsExpr(Constant<SubscriptInteger>{*lbi});
200       upper_ = AsExpr(Constant<SubscriptInteger>{*ubi});
201     } else if (length && *ubi > *length) {
202       context.messages().Say("Upper bound (%jd) on substring is greater "
203                              "than character length (%jd)"_en_US,
204           *ubi, *length);
205       *ubi = *length;
206     }
207     if (lbi && literal) {
208       auto newStaticData{StaticDataObject::Create()};
209       auto items{0}; // If the lower bound is greater, the length is 0
210       if (*ubi >= *lbi) {
211         items = *ubi - *lbi + 1;
212       }
213       auto width{(*literal)->itemBytes()};
214       auto bytes{items * width};
215       auto startByte{(*lbi - 1) * width};
216       const auto *from{&(*literal)->data()[0] + startByte};
217       for (auto j{0}; j < bytes; ++j) {
218         newStaticData->data().push_back(from[j]);
219       }
220       parent_ = newStaticData;
221       lower_ = AsExpr(Constant<SubscriptInteger>{1});
222       ConstantSubscript length = newStaticData->data().size();
223       upper_ = AsExpr(Constant<SubscriptInteger>{length});
224       switch (width) {
225       case 1:
226         return {
227             AsCategoryExpr(AsExpr(Constant<Type<TypeCategory::Character, 1>>{
228                 *newStaticData->AsString()}))};
229       case 2:
230         return {AsCategoryExpr(Constant<Type<TypeCategory::Character, 2>>{
231             *newStaticData->AsU16String()})};
232       case 4:
233         return {AsCategoryExpr(Constant<Type<TypeCategory::Character, 4>>{
234             *newStaticData->AsU32String()})};
235       default:
236         CRASH_NO_CASE;
237       }
238     }
239   }
240   return std::nullopt;
241 }
242 
243 DescriptorInquiry::DescriptorInquiry(
244     const NamedEntity &base, Field field, int dim)
245     : base_{base}, field_{field}, dimension_{dim} {
246   const Symbol &last{base_.GetLastSymbol()};
247   CHECK(IsDescriptor(last));
248   CHECK((field == Field::Len && dim == 0) ||
249       (field != Field::Len && dim >= 0 && dim < last.Rank()));
250 }
251 
252 DescriptorInquiry::DescriptorInquiry(NamedEntity &&base, Field field, int dim)
253     : base_{std::move(base)}, field_{field}, dimension_{dim} {
254   const Symbol &last{base_.GetLastSymbol()};
255   CHECK(IsDescriptor(last));
256   CHECK((field == Field::Len && dim == 0) ||
257       (field != Field::Len && dim >= 0 && dim < last.Rank()));
258 }
259 
260 // LEN()
261 static std::optional<Expr<SubscriptInteger>> SymbolLEN(const Symbol &symbol) {
262   const Symbol &ultimate{symbol.GetUltimate()};
263   if (const auto *assoc{ultimate.detailsIf<semantics::AssocEntityDetails>()}) {
264     if (const auto *chExpr{UnwrapExpr<Expr<SomeCharacter>>(assoc->expr())}) {
265       return chExpr->LEN();
266     }
267   } else if (auto dyType{DynamicType::From(ultimate)}) {
268     if (const semantics::ParamValue * len{dyType->charLength()}) {
269       if (len->isExplicit()) {
270         if (auto intExpr{len->GetExplicit()}) {
271           if (IsConstantExpr(*intExpr)) {
272             return ConvertToType<SubscriptInteger>(*std::move(intExpr));
273           }
274         }
275       }
276       if (IsDescriptor(ultimate) && !ultimate.owner().IsDerivedType()) {
277         return Expr<SubscriptInteger>{DescriptorInquiry{
278             NamedEntity{ultimate}, DescriptorInquiry::Field::Len}};
279       }
280     }
281   }
282   return std::nullopt;
283 }
284 
285 std::optional<Expr<SubscriptInteger>> BaseObject::LEN() const {
286   return std::visit(
287       common::visitors{
288           [](const Symbol &symbol) { return SymbolLEN(symbol); },
289           [](const StaticDataObject::Pointer &object)
290               -> std::optional<Expr<SubscriptInteger>> {
291             return AsExpr(Constant<SubscriptInteger>{object->data().size()});
292           },
293       },
294       u);
295 }
296 
297 std::optional<Expr<SubscriptInteger>> Component::LEN() const {
298   return SymbolLEN(GetLastSymbol());
299 }
300 
301 std::optional<Expr<SubscriptInteger>> NamedEntity::LEN() const {
302   return SymbolLEN(GetLastSymbol());
303 }
304 
305 std::optional<Expr<SubscriptInteger>> ArrayRef::LEN() const {
306   return base_.LEN();
307 }
308 
309 std::optional<Expr<SubscriptInteger>> CoarrayRef::LEN() const {
310   return SymbolLEN(GetLastSymbol());
311 }
312 
313 std::optional<Expr<SubscriptInteger>> DataRef::LEN() const {
314   return std::visit(common::visitors{
315                         [](SymbolRef symbol) { return SymbolLEN(symbol); },
316                         [](const auto &x) { return x.LEN(); },
317                     },
318       u);
319 }
320 
321 std::optional<Expr<SubscriptInteger>> Substring::LEN() const {
322   if (auto top{upper()}) {
323     return AsExpr(Extremum<SubscriptInteger>{Ordering::Greater,
324         AsExpr(Constant<SubscriptInteger>{0}),
325         *std::move(top) - lower() + AsExpr(Constant<SubscriptInteger>{1})});
326   } else {
327     return std::nullopt;
328   }
329 }
330 
331 template <typename T>
332 std::optional<Expr<SubscriptInteger>> Designator<T>::LEN() const {
333   if constexpr (T::category == TypeCategory::Character) {
334     return std::visit(common::visitors{
335                           [](SymbolRef symbol) { return SymbolLEN(symbol); },
336                           [](const auto &x) { return x.LEN(); },
337                       },
338         u);
339   } else {
340     common::die("Designator<non-char>::LEN() called");
341     return std::nullopt;
342   }
343 }
344 
345 std::optional<Expr<SubscriptInteger>> ProcedureDesignator::LEN() const {
346   using T = std::optional<Expr<SubscriptInteger>>;
347   return std::visit(
348       common::visitors{
349           [](SymbolRef symbol) -> T { return SymbolLEN(symbol); },
350           [](const common::CopyableIndirection<Component> &c) -> T {
351             return c.value().LEN();
352           },
353           [](const SpecificIntrinsic &i) -> T {
354             if (i.name == "char") {
355               return Expr<SubscriptInteger>{1};
356             }
357             // Some other cases whose results' lengths can be determined
358             // from the lengths of their arguments are handled in
359             // ProcedureRef::LEN().
360             return std::nullopt;
361           },
362       },
363       u);
364 }
365 
366 // Rank()
367 int BaseObject::Rank() const {
368   return std::visit(common::visitors{
369                         [](SymbolRef symbol) { return symbol->Rank(); },
370                         [](const StaticDataObject::Pointer &) { return 0; },
371                     },
372       u);
373 }
374 
375 int Component::Rank() const {
376   if (int rank{symbol_->Rank()}; rank > 0) {
377     return rank;
378   }
379   return base().Rank();
380 }
381 
382 int NamedEntity::Rank() const {
383   return std::visit(common::visitors{
384                         [](const SymbolRef s) { return s->Rank(); },
385                         [](const Component &c) { return c.Rank(); },
386                     },
387       u_);
388 }
389 
390 int Subscript::Rank() const {
391   return std::visit(common::visitors{
392                         [](const IndirectSubscriptIntegerExpr &x) {
393                           return x.value().Rank();
394                         },
395                         [](const Triplet &) { return 1; },
396                     },
397       u);
398 }
399 
400 int ArrayRef::Rank() const {
401   int rank{0};
402   for (const auto &expr : subscript_) {
403     rank += expr.Rank();
404   }
405   if (rank > 0) {
406     return rank;
407   } else if (const Component * component{base_.UnwrapComponent()}) {
408     return component->base().Rank();
409   } else {
410     return 0;
411   }
412 }
413 
414 int CoarrayRef::Rank() const {
415   if (!subscript_.empty()) {
416     int rank{0};
417     for (const auto &expr : subscript_) {
418       rank += expr.Rank();
419     }
420     return rank;
421   } else {
422     return base_.back()->Rank();
423   }
424 }
425 
426 int DataRef::Rank() const {
427   return std::visit(common::visitors{
428                         [](SymbolRef symbol) { return symbol->Rank(); },
429                         [](const auto &x) { return x.Rank(); },
430                     },
431       u);
432 }
433 
434 int Substring::Rank() const {
435   return std::visit(common::visitors{
436                         [](const DataRef &dataRef) { return dataRef.Rank(); },
437                         [](const StaticDataObject::Pointer &) { return 0; },
438                     },
439       parent_);
440 }
441 
442 int ComplexPart::Rank() const { return complex_.Rank(); }
443 
444 template <typename T> int Designator<T>::Rank() const {
445   return std::visit(common::visitors{
446                         [](SymbolRef symbol) { return symbol->Rank(); },
447                         [](const auto &x) { return x.Rank(); },
448                     },
449       u);
450 }
451 
452 // GetBaseObject(), GetFirstSymbol(), GetLastSymbol(), &c.
453 const Symbol &Component::GetFirstSymbol() const {
454   return base_.value().GetFirstSymbol();
455 }
456 
457 const Symbol &NamedEntity::GetFirstSymbol() const {
458   return std::visit(common::visitors{
459                         [](SymbolRef s) -> const Symbol & { return s; },
460                         [](const Component &c) -> const Symbol & {
461                           return c.GetFirstSymbol();
462                         },
463                     },
464       u_);
465 }
466 
467 const Symbol &NamedEntity::GetLastSymbol() const {
468   return std::visit(common::visitors{
469                         [](SymbolRef s) -> const Symbol & { return s; },
470                         [](const Component &c) -> const Symbol & {
471                           return c.GetLastSymbol();
472                         },
473                     },
474       u_);
475 }
476 
477 const Component *NamedEntity::UnwrapComponent() const {
478   return std::visit(common::visitors{
479                         [](SymbolRef) -> const Component * { return nullptr; },
480                         [](const Component &c) { return &c; },
481                     },
482       u_);
483 }
484 
485 Component *NamedEntity::UnwrapComponent() {
486   return std::visit(common::visitors{
487                         [](SymbolRef &) -> Component * { return nullptr; },
488                         [](Component &c) { return &c; },
489                     },
490       u_);
491 }
492 
493 const Symbol &ArrayRef::GetFirstSymbol() const {
494   return base_.GetFirstSymbol();
495 }
496 
497 const Symbol &ArrayRef::GetLastSymbol() const { return base_.GetLastSymbol(); }
498 
499 const Symbol &DataRef::GetFirstSymbol() const {
500   return *std::visit(common::visitors{
501                          [](SymbolRef symbol) { return &*symbol; },
502                          [](const auto &x) { return &x.GetFirstSymbol(); },
503                      },
504       u);
505 }
506 
507 const Symbol &DataRef::GetLastSymbol() const {
508   return *std::visit(common::visitors{
509                          [](SymbolRef symbol) { return &*symbol; },
510                          [](const auto &x) { return &x.GetLastSymbol(); },
511                      },
512       u);
513 }
514 
515 BaseObject Substring::GetBaseObject() const {
516   return std::visit(common::visitors{
517                         [](const DataRef &dataRef) {
518                           return BaseObject{dataRef.GetFirstSymbol()};
519                         },
520                         [](StaticDataObject::Pointer pointer) {
521                           return BaseObject{std::move(pointer)};
522                         },
523                     },
524       parent_);
525 }
526 
527 const Symbol *Substring::GetLastSymbol() const {
528   return std::visit(
529       common::visitors{
530           [](const DataRef &dataRef) { return &dataRef.GetLastSymbol(); },
531           [](const auto &) -> const Symbol * { return nullptr; },
532       },
533       parent_);
534 }
535 
536 template <typename T> BaseObject Designator<T>::GetBaseObject() const {
537   return std::visit(
538       common::visitors{
539           [](SymbolRef symbol) { return BaseObject{symbol}; },
540           [](const Substring &sstring) { return sstring.GetBaseObject(); },
541           [](const auto &x) {
542 #if !__clang__ && __GNUC__ == 7 && __GNUC_MINOR__ == 2
543             if constexpr (std::is_same_v<std::decay_t<decltype(x)>,
544                               Substring>) {
545               return x.GetBaseObject();
546             } else
547 #endif
548               return BaseObject{x.GetFirstSymbol()};
549           },
550       },
551       u);
552 }
553 
554 template <typename T> const Symbol *Designator<T>::GetLastSymbol() const {
555   return std::visit(
556       common::visitors{
557           [](SymbolRef symbol) { return &*symbol; },
558           [](const Substring &sstring) { return sstring.GetLastSymbol(); },
559           [](const auto &x) {
560 #if !__clang__ && __GNUC__ == 7 && __GNUC_MINOR__ == 2
561             if constexpr (std::is_same_v<std::decay_t<decltype(x)>,
562                               Substring>) {
563               return x.GetLastSymbol();
564             } else
565 #endif
566               return &x.GetLastSymbol();
567           },
568       },
569       u);
570 }
571 
572 template <typename T>
573 std::optional<DynamicType> Designator<T>::GetType() const {
574   if constexpr (IsLengthlessIntrinsicType<Result>) {
575     return Result::GetType();
576   } else if (const Symbol * symbol{GetLastSymbol()}) {
577     return DynamicType::From(*symbol);
578   } else if constexpr (Result::category == TypeCategory::Character) {
579     if (const Substring * substring{std::get_if<Substring>(&u)}) {
580       const auto *parent{substring->GetParentIf<StaticDataObject::Pointer>()};
581       CHECK(parent);
582       return DynamicType{TypeCategory::Character, (*parent)->itemBytes()};
583     }
584   }
585   return std::nullopt;
586 }
587 
588 static NamedEntity AsNamedEntity(const SymbolVector &x) {
589   CHECK(!x.empty());
590   NamedEntity result{x.front()};
591   int j{0};
592   for (const Symbol &symbol : x) {
593     if (j++ != 0) {
594       DataRef base{result.IsSymbol() ? DataRef{result.GetLastSymbol()}
595                                      : DataRef{result.GetComponent()}};
596       result = NamedEntity{Component{std::move(base), symbol}};
597     }
598   }
599   return result;
600 }
601 
602 NamedEntity CoarrayRef::GetBase() const { return AsNamedEntity(base_); }
603 
604 // Equality testing
605 
606 // For the purposes of comparing type parameter expressions while
607 // testing the compatibility of procedure characteristics, two
608 // object dummy arguments with the same name are considered equal.
609 static bool AreSameSymbol(const Symbol &x, const Symbol &y) {
610   if (&x == &y) {
611     return true;
612   }
613   if (x.name() == y.name()) {
614     if (const auto *xObject{x.detailsIf<semantics::ObjectEntityDetails>()}) {
615       if (const auto *yObject{y.detailsIf<semantics::ObjectEntityDetails>()}) {
616         return xObject->isDummy() && yObject->isDummy();
617       }
618     }
619   }
620   return false;
621 }
622 
623 // Implements operator==() for a union type, using special case handling
624 // for Symbol references.
625 template <typename A> static bool TestVariableEquality(const A &x, const A &y) {
626   const SymbolRef *xSymbol{std::get_if<SymbolRef>(&x.u)};
627   if (const SymbolRef * ySymbol{std::get_if<SymbolRef>(&y.u)}) {
628     return xSymbol && AreSameSymbol(*xSymbol, *ySymbol);
629   } else {
630     return x.u == y.u;
631   }
632 }
633 
634 bool BaseObject::operator==(const BaseObject &that) const {
635   return TestVariableEquality(*this, that);
636 }
637 bool Component::operator==(const Component &that) const {
638   return base_ == that.base_ && &*symbol_ == &*that.symbol_;
639 }
640 bool NamedEntity::operator==(const NamedEntity &that) const {
641   if (IsSymbol()) {
642     return that.IsSymbol() &&
643         AreSameSymbol(GetFirstSymbol(), that.GetFirstSymbol());
644   } else {
645     return !that.IsSymbol() && GetComponent() == that.GetComponent();
646   }
647 }
648 bool TypeParamInquiry::operator==(const TypeParamInquiry &that) const {
649   return &*parameter_ == &*that.parameter_ && base_ == that.base_;
650 }
651 bool Triplet::operator==(const Triplet &that) const {
652   return lower_ == that.lower_ && upper_ == that.upper_ &&
653       stride_ == that.stride_;
654 }
655 bool Subscript::operator==(const Subscript &that) const { return u == that.u; }
656 bool ArrayRef::operator==(const ArrayRef &that) const {
657   return base_ == that.base_ && subscript_ == that.subscript_;
658 }
659 bool CoarrayRef::operator==(const CoarrayRef &that) const {
660   return base_ == that.base_ && subscript_ == that.subscript_ &&
661       cosubscript_ == that.cosubscript_ && stat_ == that.stat_ &&
662       team_ == that.team_ && teamIsTeamNumber_ == that.teamIsTeamNumber_;
663 }
664 bool DataRef::operator==(const DataRef &that) const {
665   return TestVariableEquality(*this, that);
666 }
667 bool Substring::operator==(const Substring &that) const {
668   return parent_ == that.parent_ && lower_ == that.lower_ &&
669       upper_ == that.upper_;
670 }
671 bool ComplexPart::operator==(const ComplexPart &that) const {
672   return part_ == that.part_ && complex_ == that.complex_;
673 }
674 bool ProcedureRef::operator==(const ProcedureRef &that) const {
675   return proc_ == that.proc_ && arguments_ == that.arguments_;
676 }
677 template <typename T>
678 bool Designator<T>::operator==(const Designator<T> &that) const {
679   return TestVariableEquality(*this, that);
680 }
681 bool DescriptorInquiry::operator==(const DescriptorInquiry &that) const {
682   return field_ == that.field_ && base_ == that.base_ &&
683       dimension_ == that.dimension_;
684 }
685 
686 INSTANTIATE_VARIABLE_TEMPLATES
687 } // namespace Fortran::evaluate
688 
689 template class Fortran::common::Indirection<Fortran::evaluate::Component, true>;
690