1 //===-- include/flang/Semantics/scope.h -------------------------*- C++ -*-===//
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 #ifndef FORTRAN_SEMANTICS_SCOPE_H_
10 #define FORTRAN_SEMANTICS_SCOPE_H_
11
12 #include "attr.h"
13 #include "symbol.h"
14 #include "flang/Common/Fortran.h"
15 #include "flang/Common/idioms.h"
16 #include "flang/Common/reference.h"
17 #include "flang/Parser/message.h"
18 #include "flang/Parser/provenance.h"
19 #include <list>
20 #include <map>
21 #include <optional>
22 #include <set>
23 #include <string>
24
25 namespace llvm {
26 class raw_ostream;
27 }
28
29 namespace Fortran::semantics {
30
31 using namespace parser::literals;
32
33 using common::ConstantSubscript;
34
35 class SemanticsContext;
36
37 // An equivalence object is represented by a symbol for the variable name,
38 // the indices for an array element, and the lower bound for a substring.
39 struct EquivalenceObject {
EquivalenceObjectEquivalenceObject40 EquivalenceObject(Symbol &symbol, std::vector<ConstantSubscript> subscripts,
41 std::optional<ConstantSubscript> substringStart, parser::CharBlock source)
42 : symbol{symbol}, subscripts{subscripts},
43 substringStart{substringStart}, source{source} {}
EquivalenceObjectEquivalenceObject44 explicit EquivalenceObject(Symbol &symbol)
45 : symbol{symbol}, source{symbol.name()} {}
46
47 bool operator==(const EquivalenceObject &) const;
48 bool operator<(const EquivalenceObject &) const;
49 std::string AsFortran() const;
50
51 Symbol &symbol;
52 std::vector<ConstantSubscript> subscripts; // for array elem
53 std::optional<ConstantSubscript> substringStart;
54 parser::CharBlock source;
55 };
56 using EquivalenceSet = std::vector<EquivalenceObject>;
57
58 class Scope {
59 using mapType = std::map<SourceName, MutableSymbolRef>;
60
61 public:
62 ENUM_CLASS(Kind, Global, IntrinsicModules, Module, MainProgram, Subprogram,
63 BlockData, DerivedType, BlockConstruct, Forall, OtherConstruct,
64 ImpliedDos)
65 using ImportKind = common::ImportKind;
66
67 // Create the Global scope -- the root of the scope tree
Scope(SemanticsContext & context)68 explicit Scope(SemanticsContext &context)
69 : Scope{*this, Kind::Global, nullptr, context} {}
Scope(Scope & parent,Kind kind,Symbol * symbol,SemanticsContext & context)70 Scope(Scope &parent, Kind kind, Symbol *symbol, SemanticsContext &context)
71 : parent_{parent}, kind_{kind}, symbol_{symbol}, context_{context} {
72 if (symbol) {
73 symbol->set_scope(this);
74 }
75 }
76 Scope(const Scope &) = delete;
77
78 bool operator==(const Scope &that) const { return this == &that; }
79 bool operator!=(const Scope &that) const { return this != &that; }
80
parent()81 Scope &parent() {
82 CHECK(&parent_ != this);
83 return parent_;
84 }
parent()85 const Scope &parent() const {
86 CHECK(&parent_ != this);
87 return parent_;
88 }
kind()89 Kind kind() const { return kind_; }
IsGlobal()90 bool IsGlobal() const { return kind_ == Kind::Global; }
IsIntrinsicModules()91 bool IsIntrinsicModules() const { return kind_ == Kind::IntrinsicModules; }
IsTopLevel()92 bool IsTopLevel() const {
93 return kind_ == Kind::Global || kind_ == Kind::IntrinsicModules;
94 }
IsModule()95 bool IsModule() const {
96 return kind_ == Kind::Module &&
97 !symbol_->get<ModuleDetails>().isSubmodule();
98 }
IsSubmodule()99 bool IsSubmodule() const {
100 return kind_ == Kind::Module && symbol_->get<ModuleDetails>().isSubmodule();
101 }
IsDerivedType()102 bool IsDerivedType() const { return kind_ == Kind::DerivedType; }
103 bool IsStmtFunction() const;
104 bool IsParameterizedDerivedType() const;
IsParameterizedDerivedTypeInstantiation()105 bool IsParameterizedDerivedTypeInstantiation() const {
106 return kind_ == Kind::DerivedType && !symbol_;
107 }
108 /// Does this derived type have at least one kind parameter ?
109 bool IsDerivedTypeWithKindParameter() const;
110 /// Does this derived type have at least one length parameter ?
111 bool IsDerivedTypeWithLengthParameter() const;
symbol()112 Symbol *symbol() { return symbol_; }
symbol()113 const Symbol *symbol() const { return symbol_; }
context()114 SemanticsContext &context() const { return context_; }
115
116 inline const Symbol *GetSymbol() const;
117 const Scope *GetDerivedTypeParent() const;
118 const Scope &GetDerivedTypeBase() const;
119 inline std::optional<SourceName> GetName() const;
120 bool Contains(const Scope &) const;
121 /// Make a scope nested in this one
122 Scope &MakeScope(Kind kind, Symbol *symbol = nullptr);
GetMutableSemanticsContext()123 SemanticsContext &GetMutableSemanticsContext() const {
124 return const_cast<SemanticsContext &>(context());
125 }
126
127 using size_type = mapType::size_type;
128 using iterator = mapType::iterator;
129 using const_iterator = mapType::const_iterator;
130
begin()131 iterator begin() { return symbols_.begin(); }
end()132 iterator end() { return symbols_.end(); }
begin()133 const_iterator begin() const { return symbols_.begin(); }
end()134 const_iterator end() const { return symbols_.end(); }
cbegin()135 const_iterator cbegin() const { return symbols_.cbegin(); }
cend()136 const_iterator cend() const { return symbols_.cend(); }
137
138 // Return symbols in declaration order (the iterators above are in name order)
139 SymbolVector GetSymbols() const;
140 MutableSymbolVector GetSymbols();
141
142 iterator find(const SourceName &name);
find(const SourceName & name)143 const_iterator find(const SourceName &name) const {
144 return symbols_.find(name);
145 }
146 size_type erase(const SourceName &);
empty()147 bool empty() const { return symbols_.empty(); }
148
149 // Look for symbol by name in this scope and host (depending on imports).
150 Symbol *FindSymbol(const SourceName &) const;
151
152 // Look for component symbol by name in a derived type's scope and
153 // parents'.
154 Symbol *FindComponent(SourceName) const;
155
156 /// Make a Symbol with unknown details.
157 std::pair<iterator, bool> try_emplace(
158 const SourceName &name, Attrs attrs = Attrs()) {
159 return try_emplace(name, attrs, UnknownDetails());
160 }
161 /// Make a Symbol with provided details.
162 template <typename D>
try_emplace(const SourceName & name,D && details)163 common::IfNoLvalue<std::pair<iterator, bool>, D> try_emplace(
164 const SourceName &name, D &&details) {
165 return try_emplace(name, Attrs(), std::move(details));
166 }
167 /// Make a Symbol with attrs and details
168 template <typename D>
try_emplace(const SourceName & name,Attrs attrs,D && details)169 common::IfNoLvalue<std::pair<iterator, bool>, D> try_emplace(
170 const SourceName &name, Attrs attrs, D &&details) {
171 Symbol &symbol{MakeSymbol(name, attrs, std::move(details))};
172 return symbols_.emplace(name, symbol);
173 }
174 // Make a copy of a symbol in this scope; nullptr if one is already there
175 Symbol *CopySymbol(const Symbol &);
176
equivalenceSets()177 std::list<EquivalenceSet> &equivalenceSets() { return equivalenceSets_; }
equivalenceSets()178 const std::list<EquivalenceSet> &equivalenceSets() const {
179 return equivalenceSets_;
180 }
181 void add_equivalenceSet(EquivalenceSet &&);
182 // Cray pointers are saved as map of pointee name -> pointer symbol
crayPointers()183 const mapType &crayPointers() const { return crayPointers_; }
184 void add_crayPointer(const SourceName &, Symbol &);
commonBlocks()185 mapType &commonBlocks() { return commonBlocks_; }
commonBlocks()186 const mapType &commonBlocks() const { return commonBlocks_; }
187 Symbol &MakeCommonBlock(const SourceName &);
188 Symbol *FindCommonBlock(const SourceName &) const;
189
190 /// Make a Symbol but don't add it to the scope.
191 template <typename D>
MakeSymbol(const SourceName & name,Attrs attrs,D && details)192 common::IfNoLvalue<Symbol &, D> MakeSymbol(
193 const SourceName &name, Attrs attrs, D &&details) {
194 return allSymbols.Make(*this, name, attrs, std::move(details));
195 }
196
children()197 std::list<Scope> &children() { return children_; }
children()198 const std::list<Scope> &children() const { return children_; }
199
200 // For Module scope, maintain a mapping of all submodule scopes with this
201 // module as its ancestor module. AddSubmodule returns false if already there.
202 Scope *FindSubmodule(const SourceName &) const;
203 bool AddSubmodule(const SourceName &, Scope &);
204
205 const DeclTypeSpec *FindType(const DeclTypeSpec &) const;
206 const DeclTypeSpec &MakeNumericType(TypeCategory, KindExpr &&kind);
207 const DeclTypeSpec &MakeLogicalType(KindExpr &&kind);
208 const DeclTypeSpec &MakeCharacterType(
209 ParamValue &&length, KindExpr &&kind = KindExpr{0});
210 DeclTypeSpec &MakeDerivedType(DeclTypeSpec::Category, DerivedTypeSpec &&);
211 const DeclTypeSpec &MakeTypeStarType();
212 const DeclTypeSpec &MakeClassStarType();
213 const DeclTypeSpec *GetType(const SomeExpr &);
214
size()215 std::size_t size() const { return size_; }
set_size(std::size_t size)216 void set_size(std::size_t size) { size_ = size; }
alignment()217 std::optional<std::size_t> alignment() const { return alignment_; }
218
SetAlignment(std::size_t n)219 void SetAlignment(std::size_t n) {
220 alignment_ = std::max(alignment_.value_or(0), n);
221 }
222
223 ImportKind GetImportKind() const;
224 // Names appearing in IMPORT statements in this scope
importNames()225 std::set<SourceName> importNames() const { return importNames_; }
226
227 // Set the kind of imports from host into this scope.
228 // Return an error message for incompatible kinds.
229 std::optional<parser::MessageFixedText> SetImportKind(ImportKind);
230
231 void add_importName(const SourceName &);
232
233 // These members pertain to instantiations of parameterized derived types.
derivedTypeSpec()234 const DerivedTypeSpec *derivedTypeSpec() const { return derivedTypeSpec_; }
derivedTypeSpec()235 DerivedTypeSpec *derivedTypeSpec() { return derivedTypeSpec_; }
set_derivedTypeSpec(DerivedTypeSpec & spec)236 void set_derivedTypeSpec(DerivedTypeSpec &spec) { derivedTypeSpec_ = &spec; }
instantiationContext()237 parser::Message::Reference instantiationContext() const {
238 return instantiationContext_;
239 };
set_instantiationContext(parser::Message::Reference && mref)240 void set_instantiationContext(parser::Message::Reference &&mref) {
241 instantiationContext_ = std::move(mref);
242 }
243
hasSAVE()244 bool hasSAVE() const { return hasSAVE_; }
245 void set_hasSAVE(bool yes = true) { hasSAVE_ = yes; }
246
247 // The range of the source of this and nested scopes.
sourceRange()248 const parser::CharBlock &sourceRange() const { return sourceRange_; }
249 void AddSourceRange(const parser::CharBlock &);
250 // Find the smallest scope under this one that contains source
251 const Scope *FindScope(parser::CharBlock) const;
252 Scope *FindScope(parser::CharBlock);
253
254 // Attempts to find a match for a derived type instance
255 const DeclTypeSpec *FindInstantiatedDerivedType(const DerivedTypeSpec &,
256 DeclTypeSpec::Category = DeclTypeSpec::TypeDerived) const;
257
IsModuleFile()258 bool IsModuleFile() const {
259 return kind_ == Kind::Module && symbol_ &&
260 symbol_->test(Symbol::Flag::ModFile);
261 }
262
263 void InstantiateDerivedTypes();
264
runtimeDerivedTypeDescription()265 const Symbol *runtimeDerivedTypeDescription() const {
266 return runtimeDerivedTypeDescription_;
267 }
set_runtimeDerivedTypeDescription(const Symbol & symbol)268 void set_runtimeDerivedTypeDescription(const Symbol &symbol) {
269 runtimeDerivedTypeDescription_ = &symbol;
270 }
271
272 private:
273 Scope &parent_; // this is enclosing scope, not extended derived type base
274 const Kind kind_;
275 std::size_t size_{0}; // size in bytes
276 std::optional<std::size_t> alignment_; // required alignment in bytes
277 parser::CharBlock sourceRange_;
278 Symbol *const symbol_; // if not null, symbol_->scope() == this
279 std::list<Scope> children_;
280 mapType symbols_;
281 mapType commonBlocks_;
282 std::list<EquivalenceSet> equivalenceSets_;
283 mapType crayPointers_;
284 std::map<SourceName, common::Reference<Scope>> submodules_;
285 std::list<DeclTypeSpec> declTypeSpecs_;
286 std::optional<ImportKind> importKind_;
287 std::set<SourceName> importNames_;
288 DerivedTypeSpec *derivedTypeSpec_{nullptr}; // dTS->scope() == this
289 parser::Message::Reference instantiationContext_;
290 bool hasSAVE_{false}; // scope has a bare SAVE statement
291 const Symbol *runtimeDerivedTypeDescription_{nullptr};
292 SemanticsContext &context_;
293 // When additional data members are added to Scope, remember to
294 // copy them, if appropriate, in FindOrInstantiateDerivedType().
295
296 // Storage for all Symbols. Every Symbol is in allSymbols and every Symbol*
297 // or Symbol& points to one in there.
298 static Symbols<1024> allSymbols;
299
300 bool CanImport(const SourceName &) const;
301 const DeclTypeSpec &MakeLengthlessType(DeclTypeSpec &&);
302
303 friend llvm::raw_ostream &operator<<(llvm::raw_ostream &, const Scope &);
304 };
305
306 // Inline so that it can be called from Evaluate without a link-time dependency.
307
GetSymbol()308 inline const Symbol *Scope::GetSymbol() const {
309 return symbol_ ? symbol_
310 : derivedTypeSpec_ ? &derivedTypeSpec_->typeSymbol()
311 : nullptr;
312 }
313
GetName()314 inline std::optional<SourceName> Scope::GetName() const {
315 if (const auto *sym{GetSymbol()}) {
316 return sym->name();
317 } else {
318 return std::nullopt;
319 }
320 }
321
322 } // namespace Fortran::semantics
323 #endif // FORTRAN_SEMANTICS_SCOPE_H_
324