1 //===-- lib/Parser/program-parsers.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 // Per-type parsers for program units
10
11 #include "basic-parsers.h"
12 #include "debug-parser.h"
13 #include "expr-parsers.h"
14 #include "misc-parsers.h"
15 #include "stmt-parser.h"
16 #include "token-parsers.h"
17 #include "type-parser-implementation.h"
18 #include "flang/Parser/characters.h"
19 #include "flang/Parser/parse-tree.h"
20
21 namespace Fortran::parser {
22
23 // R502 program-unit ->
24 // main-program | external-subprogram | module | submodule | block-data
25 // R503 external-subprogram -> function-subprogram | subroutine-subprogram
26 // N.B. "module" must precede "external-subprogram" in this sequence of
27 // alternatives to avoid ambiguity with the MODULE keyword prefix that
28 // they recognize. I.e., "modulesubroutinefoo" should start a module
29 // "subroutinefoo", not a subroutine "foo" with the MODULE prefix. The
30 // ambiguity is exacerbated by the extension that accepts a function
31 // statement without an otherwise empty list of dummy arguments. That
32 // MODULE prefix is disallowed by a constraint (C1547) in this context,
33 // so the standard language is not ambiguous, but disabling its misrecognition
34 // here would require context-sensitive keyword recognition or (or via)
35 // variant parsers for several productions; giving the "module" production
36 // priority here is a cleaner solution, though regrettably subtle. Enforcing
37 // C1547 is done in semantics.
38 static constexpr auto programUnit{
39 construct<ProgramUnit>(indirect(Parser<Module>{})) ||
40 construct<ProgramUnit>(indirect(functionSubprogram)) ||
41 construct<ProgramUnit>(indirect(subroutineSubprogram)) ||
42 construct<ProgramUnit>(indirect(Parser<Submodule>{})) ||
43 construct<ProgramUnit>(indirect(Parser<BlockData>{})) ||
44 construct<ProgramUnit>(indirect(Parser<MainProgram>{}))};
45 static constexpr auto normalProgramUnit{StartNewSubprogram{} >> programUnit /
46 skipMany(";"_tok) / space / recovery(endOfLine, SkipPast<'\n'>{})};
47 static constexpr auto globalCompilerDirective{
48 construct<ProgramUnit>(indirect(compilerDirective))};
49
50 // R501 program -> program-unit [program-unit]...
51 // This is the top-level production for the Fortran language.
52 // F'2018 6.3.1 defines a program unit as a sequence of one or more lines,
53 // implying that a line can't be part of two distinct program units.
54 // Consequently, a program unit END statement should be the last statement
55 // on its line. We parse those END statements via unterminatedStatement()
56 // and then skip over the end of the line here.
57 TYPE_PARSER(construct<Program>(
58 extension<LanguageFeature::EmptySourceFile>(skipStuffBeforeStatement >>
59 !nextCh >> pure<std::list<ProgramUnit>>()) ||
60 some(globalCompilerDirective || normalProgramUnit) /
61 skipStuffBeforeStatement))
62
63 // R504 specification-part ->
64 // [use-stmt]... [import-stmt]... [implicit-part]
65 // [declaration-construct]...
66 TYPE_CONTEXT_PARSER("specification part"_en_US,
67 construct<SpecificationPart>(many(openaccDeclarativeConstruct),
68 many(openmpDeclarativeConstruct), many(indirect(compilerDirective)),
69 many(statement(indirect(Parser<UseStmt>{}))),
70 many(unambiguousStatement(indirect(Parser<ImportStmt>{}))),
71 implicitPart, many(declarationConstruct)))
72
73 // R507 declaration-construct ->
74 // specification-construct | data-stmt | format-stmt |
75 // entry-stmt | stmt-function-stmt
76 // N.B. These parsers incorporate recognition of some other statements that
77 // may have been misplaced in the sequence of statements that are acceptable
78 // as a specification part in order to improve error recovery.
79 // Also note that many instances of specification-part in the standard grammar
80 // are in contexts that impose constraints on the kinds of statements that
81 // are allowed, and so we have a variant production for declaration-construct
82 // that implements those constraints.
83 constexpr auto execPartLookAhead{
84 first(actionStmt >> ok, openaccConstruct >> ok, openmpConstruct >> ok,
85 "ASSOCIATE ("_tok, "BLOCK"_tok, "SELECT"_tok, "CHANGE TEAM"_sptok,
86 "CRITICAL"_tok, "DO"_tok, "IF ("_tok, "WHERE ("_tok, "FORALL ("_tok)};
87 constexpr auto declErrorRecovery{
88 stmtErrorRecoveryStart >> !execPartLookAhead >> skipStmtErrorRecovery};
89 constexpr auto misplacedSpecificationStmt{Parser<UseStmt>{} >>
90 fail<DeclarationConstruct>("misplaced USE statement"_err_en_US) ||
91 Parser<ImportStmt>{} >>
92 fail<DeclarationConstruct>(
93 "IMPORT statements must follow any USE statements and precede all other declarations"_err_en_US) ||
94 Parser<ImplicitStmt>{} >>
95 fail<DeclarationConstruct>(
96 "IMPLICIT statements must follow USE and IMPORT and precede all other declarations"_err_en_US)};
97
98 TYPE_PARSER(recovery(
99 withMessage("expected declaration construct"_err_en_US,
100 CONTEXT_PARSER("declaration construct"_en_US,
101 first(construct<DeclarationConstruct>(specificationConstruct),
102 construct<DeclarationConstruct>(statement(indirect(dataStmt))),
103 construct<DeclarationConstruct>(
104 statement(indirect(formatStmt))),
105 construct<DeclarationConstruct>(statement(indirect(entryStmt))),
106 construct<DeclarationConstruct>(
107 statement(indirect(Parser<StmtFunctionStmt>{}))),
108 misplacedSpecificationStmt))),
109 construct<DeclarationConstruct>(declErrorRecovery)))
110
111 // R507 variant of declaration-construct for use in limitedSpecificationPart.
112 constexpr auto invalidDeclarationStmt{formatStmt >>
113 fail<DeclarationConstruct>(
114 "FORMAT statements are not permitted in this specification part"_err_en_US) ||
115 entryStmt >>
116 fail<DeclarationConstruct>(
117 "ENTRY statements are not permitted in this specification part"_err_en_US)};
118
119 constexpr auto limitedDeclarationConstruct{recovery(
120 withMessage("expected declaration construct"_err_en_US,
121 inContext("declaration construct"_en_US,
122 first(construct<DeclarationConstruct>(specificationConstruct),
123 construct<DeclarationConstruct>(statement(indirect(dataStmt))),
124 misplacedSpecificationStmt, invalidDeclarationStmt))),
125 construct<DeclarationConstruct>(
126 stmtErrorRecoveryStart >> skipStmtErrorRecovery))};
127
128 // R504 variant for many contexts (modules, submodules, BLOCK DATA subprograms,
129 // and interfaces) which have constraints on their specification parts that
130 // preclude FORMAT, ENTRY, and statement functions, and benefit from
131 // specialized error recovery in the event of a spurious executable
132 // statement.
133 constexpr auto limitedSpecificationPart{inContext("specification part"_en_US,
134 construct<SpecificationPart>(many(openaccDeclarativeConstruct),
135 many(openmpDeclarativeConstruct), many(indirect(compilerDirective)),
136 many(statement(indirect(Parser<UseStmt>{}))),
137 many(unambiguousStatement(indirect(Parser<ImportStmt>{}))),
138 implicitPart, many(limitedDeclarationConstruct)))};
139
140 // R508 specification-construct ->
141 // derived-type-def | enum-def | generic-stmt | interface-block |
142 // parameter-stmt | procedure-declaration-stmt |
143 // other-specification-stmt | type-declaration-stmt
144 TYPE_CONTEXT_PARSER("specification construct"_en_US,
145 first(construct<SpecificationConstruct>(indirect(Parser<DerivedTypeDef>{})),
146 construct<SpecificationConstruct>(indirect(Parser<EnumDef>{})),
147 construct<SpecificationConstruct>(
148 statement(indirect(Parser<GenericStmt>{}))),
149 construct<SpecificationConstruct>(indirect(interfaceBlock)),
150 construct<SpecificationConstruct>(statement(indirect(parameterStmt))),
151 construct<SpecificationConstruct>(
152 statement(indirect(oldParameterStmt))),
153 construct<SpecificationConstruct>(
154 statement(indirect(Parser<ProcedureDeclarationStmt>{}))),
155 construct<SpecificationConstruct>(
156 statement(Parser<OtherSpecificationStmt>{})),
157 construct<SpecificationConstruct>(
158 statement(indirect(typeDeclarationStmt))),
159 construct<SpecificationConstruct>(indirect(Parser<StructureDef>{})),
160 construct<SpecificationConstruct>(
161 indirect(openaccDeclarativeConstruct)),
162 construct<SpecificationConstruct>(indirect(openmpDeclarativeConstruct)),
163 construct<SpecificationConstruct>(indirect(compilerDirective))))
164
165 // R513 other-specification-stmt ->
166 // access-stmt | allocatable-stmt | asynchronous-stmt | bind-stmt |
167 // codimension-stmt | contiguous-stmt | dimension-stmt | external-stmt |
168 // intent-stmt | intrinsic-stmt | namelist-stmt | optional-stmt |
169 // pointer-stmt | protected-stmt | save-stmt | target-stmt |
170 // volatile-stmt | value-stmt | common-stmt | equivalence-stmt
TYPE_PARSER(first (construct<OtherSpecificationStmt> (indirect (Parser<AccessStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<AllocatableStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<AsynchronousStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<BindStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<CodimensionStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<ContiguousStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<DimensionStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<ExternalStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<IntentStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<IntrinsicStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<NamelistStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<OptionalStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<PointerStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<ProtectedStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<SaveStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<TargetStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<ValueStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<VolatileStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<CommonStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<EquivalenceStmt>{})),construct<OtherSpecificationStmt> (indirect (Parser<BasedPointerStmt>{}))))171 TYPE_PARSER(first(
172 construct<OtherSpecificationStmt>(indirect(Parser<AccessStmt>{})),
173 construct<OtherSpecificationStmt>(indirect(Parser<AllocatableStmt>{})),
174 construct<OtherSpecificationStmt>(indirect(Parser<AsynchronousStmt>{})),
175 construct<OtherSpecificationStmt>(indirect(Parser<BindStmt>{})),
176 construct<OtherSpecificationStmt>(indirect(Parser<CodimensionStmt>{})),
177 construct<OtherSpecificationStmt>(indirect(Parser<ContiguousStmt>{})),
178 construct<OtherSpecificationStmt>(indirect(Parser<DimensionStmt>{})),
179 construct<OtherSpecificationStmt>(indirect(Parser<ExternalStmt>{})),
180 construct<OtherSpecificationStmt>(indirect(Parser<IntentStmt>{})),
181 construct<OtherSpecificationStmt>(indirect(Parser<IntrinsicStmt>{})),
182 construct<OtherSpecificationStmt>(indirect(Parser<NamelistStmt>{})),
183 construct<OtherSpecificationStmt>(indirect(Parser<OptionalStmt>{})),
184 construct<OtherSpecificationStmt>(indirect(Parser<PointerStmt>{})),
185 construct<OtherSpecificationStmt>(indirect(Parser<ProtectedStmt>{})),
186 construct<OtherSpecificationStmt>(indirect(Parser<SaveStmt>{})),
187 construct<OtherSpecificationStmt>(indirect(Parser<TargetStmt>{})),
188 construct<OtherSpecificationStmt>(indirect(Parser<ValueStmt>{})),
189 construct<OtherSpecificationStmt>(indirect(Parser<VolatileStmt>{})),
190 construct<OtherSpecificationStmt>(indirect(Parser<CommonStmt>{})),
191 construct<OtherSpecificationStmt>(indirect(Parser<EquivalenceStmt>{})),
192 construct<OtherSpecificationStmt>(indirect(Parser<BasedPointerStmt>{}))))
193
194 // R1401 main-program ->
195 // [program-stmt] [specification-part] [execution-part]
196 // [internal-subprogram-part] end-program-stmt
197 TYPE_CONTEXT_PARSER("main program"_en_US,
198 construct<MainProgram>(maybe(statement(Parser<ProgramStmt>{})),
199 specificationPart, executionPart, maybe(internalSubprogramPart),
200 unterminatedStatement(Parser<EndProgramStmt>{})))
201
202 // R1402 program-stmt -> PROGRAM program-name
203 // PGI allows empty parentheses after the name.
204 TYPE_CONTEXT_PARSER("PROGRAM statement"_en_US,
205 construct<ProgramStmt>("PROGRAM" >> name /
206 maybe(extension<LanguageFeature::ProgramParentheses>(
207 parenthesized(ok)))))
208
209 // R1403 end-program-stmt -> END [PROGRAM [program-name]]
210 TYPE_CONTEXT_PARSER("END PROGRAM statement"_en_US,
211 construct<EndProgramStmt>(recovery(
212 "END PROGRAM" >> maybe(name) || bareEnd, progUnitEndStmtErrorRecovery)))
213
214 // R1404 module ->
215 // module-stmt [specification-part] [module-subprogram-part]
216 // end-module-stmt
217 TYPE_CONTEXT_PARSER("module"_en_US,
218 construct<Module>(statement(Parser<ModuleStmt>{}), limitedSpecificationPart,
219 maybe(Parser<ModuleSubprogramPart>{}),
220 unterminatedStatement(Parser<EndModuleStmt>{})))
221
222 // R1405 module-stmt -> MODULE module-name
223 TYPE_CONTEXT_PARSER(
224 "MODULE statement"_en_US, construct<ModuleStmt>("MODULE" >> name))
225
226 // R1406 end-module-stmt -> END [MODULE [module-name]]
227 TYPE_CONTEXT_PARSER("END MODULE statement"_en_US,
228 construct<EndModuleStmt>(recovery(
229 "END MODULE" >> maybe(name) || bareEnd, progUnitEndStmtErrorRecovery)))
230
231 // R1407 module-subprogram-part -> contains-stmt [module-subprogram]...
232 TYPE_CONTEXT_PARSER("module subprogram part"_en_US,
233 construct<ModuleSubprogramPart>(statement(containsStmt),
234 many(StartNewSubprogram{} >> Parser<ModuleSubprogram>{})))
235
236 // R1408 module-subprogram ->
237 // function-subprogram | subroutine-subprogram |
238 // separate-module-subprogram
239 TYPE_PARSER(construct<ModuleSubprogram>(indirect(functionSubprogram)) ||
240 construct<ModuleSubprogram>(indirect(subroutineSubprogram)) ||
241 construct<ModuleSubprogram>(indirect(Parser<SeparateModuleSubprogram>{})))
242
243 // R1410 module-nature -> INTRINSIC | NON_INTRINSIC
244 constexpr auto moduleNature{
245 "INTRINSIC" >> pure(UseStmt::ModuleNature::Intrinsic) ||
246 "NON_INTRINSIC" >> pure(UseStmt::ModuleNature::Non_Intrinsic)};
247
248 // R1409 use-stmt ->
249 // USE [[, module-nature] ::] module-name [, rename-list] |
250 // USE [[, module-nature] ::] module-name , ONLY : [only-list]
251 // N.B. Lookahead to the end of the statement is necessary to resolve
252 // ambiguity with assignments and statement function definitions that
253 // begin with the letters "USE".
254 TYPE_PARSER(construct<UseStmt>("USE" >> optionalBeforeColons(moduleNature),
255 name, ", ONLY :" >> optionalList(Parser<Only>{})) ||
256 construct<UseStmt>("USE" >> optionalBeforeColons(moduleNature), name,
257 defaulted("," >>
258 nonemptyList("expected renamings"_err_en_US, Parser<Rename>{})) /
259 lookAhead(endOfStmt)))
260
261 // R1411 rename ->
262 // local-name => use-name |
263 // OPERATOR ( local-defined-operator ) =>
264 // OPERATOR ( use-defined-operator )
265 TYPE_PARSER(construct<Rename>("OPERATOR (" >>
266 construct<Rename::Operators>(
267 definedOpName / ") => OPERATOR (", definedOpName / ")")) ||
268 construct<Rename>(construct<Rename::Names>(name, "=>" >> name)))
269
270 // R1412 only -> generic-spec | only-use-name | rename
271 // R1413 only-use-name -> use-name
272 TYPE_PARSER(construct<Only>(Parser<Rename>{}) ||
273 construct<Only>(indirect(genericSpec)) ||
274 construct<Only>(name)) // TODO: ambiguous, accepted by genericSpec
275
276 // R1416 submodule ->
277 // submodule-stmt [specification-part] [module-subprogram-part]
278 // end-submodule-stmt
279 TYPE_CONTEXT_PARSER("submodule"_en_US,
280 construct<Submodule>(statement(Parser<SubmoduleStmt>{}),
281 limitedSpecificationPart, maybe(Parser<ModuleSubprogramPart>{}),
282 unterminatedStatement(Parser<EndSubmoduleStmt>{})))
283
284 // R1417 submodule-stmt -> SUBMODULE ( parent-identifier ) submodule-name
285 TYPE_CONTEXT_PARSER("SUBMODULE statement"_en_US,
286 construct<SubmoduleStmt>(
287 "SUBMODULE" >> parenthesized(Parser<ParentIdentifier>{}), name))
288
289 // R1418 parent-identifier -> ancestor-module-name [: parent-submodule-name]
290 TYPE_PARSER(construct<ParentIdentifier>(name, maybe(":" >> name)))
291
292 // R1419 end-submodule-stmt -> END [SUBMODULE [submodule-name]]
293 TYPE_CONTEXT_PARSER("END SUBMODULE statement"_en_US,
294 construct<EndSubmoduleStmt>(
295 recovery("END SUBMODULE" >> maybe(name) || bareEnd,
296 progUnitEndStmtErrorRecovery)))
297
298 // R1420 block-data -> block-data-stmt [specification-part] end-block-data-stmt
299 TYPE_CONTEXT_PARSER("BLOCK DATA subprogram"_en_US,
300 construct<BlockData>(statement(Parser<BlockDataStmt>{}),
301 limitedSpecificationPart,
302 unterminatedStatement(Parser<EndBlockDataStmt>{})))
303
304 // R1421 block-data-stmt -> BLOCK DATA [block-data-name]
305 TYPE_CONTEXT_PARSER("BLOCK DATA statement"_en_US,
306 construct<BlockDataStmt>("BLOCK DATA" >> maybe(name)))
307
308 // R1422 end-block-data-stmt -> END [BLOCK DATA [block-data-name]]
309 TYPE_CONTEXT_PARSER("END BLOCK DATA statement"_en_US,
310 construct<EndBlockDataStmt>(
311 recovery("END BLOCK DATA" >> maybe(name) || bareEnd,
312 progUnitEndStmtErrorRecovery)))
313
314 // R1501 interface-block ->
315 // interface-stmt [interface-specification]... end-interface-stmt
TYPE_PARSER(construct<InterfaceBlock> (statement (Parser<InterfaceStmt>{}),many (Parser<InterfaceSpecification>{}),statement (Parser<EndInterfaceStmt>{})))316 TYPE_PARSER(construct<InterfaceBlock>(statement(Parser<InterfaceStmt>{}),
317 many(Parser<InterfaceSpecification>{}),
318 statement(Parser<EndInterfaceStmt>{})))
319
320 // R1502 interface-specification -> interface-body | procedure-stmt
321 TYPE_PARSER(construct<InterfaceSpecification>(Parser<InterfaceBody>{}) ||
322 construct<InterfaceSpecification>(statement(Parser<ProcedureStmt>{})))
323
324 // R1503 interface-stmt -> INTERFACE [generic-spec] | ABSTRACT INTERFACE
325 TYPE_PARSER(construct<InterfaceStmt>("INTERFACE" >> maybe(genericSpec)) ||
326 construct<InterfaceStmt>(construct<Abstract>("ABSTRACT INTERFACE"_sptok)))
327
328 // R1504 end-interface-stmt -> END INTERFACE [generic-spec]
329 TYPE_PARSER(construct<EndInterfaceStmt>("END INTERFACE" >> maybe(genericSpec)))
330
331 // R1505 interface-body ->
332 // function-stmt [specification-part] end-function-stmt |
333 // subroutine-stmt [specification-part] end-subroutine-stmt
334 TYPE_CONTEXT_PARSER("interface body"_en_US,
335 construct<InterfaceBody>(
336 construct<InterfaceBody::Function>(statement(functionStmt),
337 indirect(limitedSpecificationPart), statement(endFunctionStmt))) ||
338 construct<InterfaceBody>(construct<InterfaceBody::Subroutine>(
339 statement(subroutineStmt), indirect(limitedSpecificationPart),
340 statement(endSubroutineStmt))))
341
342 // R1507 specific-procedure -> procedure-name
343 constexpr auto specificProcedures{
344 nonemptyList("expected specific procedure names"_err_en_US, name)};
345
346 // R1506 procedure-stmt -> [MODULE] PROCEDURE [::] specific-procedure-list
347 TYPE_PARSER(construct<ProcedureStmt>("MODULE PROCEDURE"_sptok >>
348 pure(ProcedureStmt::Kind::ModuleProcedure),
349 maybe("::"_tok) >> specificProcedures) ||
350 construct<ProcedureStmt>(
351 "PROCEDURE" >> pure(ProcedureStmt::Kind::Procedure),
352 maybe("::"_tok) >> specificProcedures))
353
354 // R1508 generic-spec ->
355 // generic-name | OPERATOR ( defined-operator ) |
356 // ASSIGNMENT ( = ) | defined-io-generic-spec
357 // R1509 defined-io-generic-spec ->
358 // READ ( FORMATTED ) | READ ( UNFORMATTED ) |
359 // WRITE ( FORMATTED ) | WRITE ( UNFORMATTED )
360 TYPE_PARSER(sourced(first(construct<GenericSpec>("OPERATOR" >>
361 parenthesized(Parser<DefinedOperator>{})),
362 construct<GenericSpec>(
363 construct<GenericSpec::Assignment>("ASSIGNMENT ( = )"_tok)),
364 construct<GenericSpec>(
365 construct<GenericSpec::ReadFormatted>("READ ( FORMATTED )"_tok)),
366 construct<GenericSpec>(
367 construct<GenericSpec::ReadUnformatted>("READ ( UNFORMATTED )"_tok)),
368 construct<GenericSpec>(
369 construct<GenericSpec::WriteFormatted>("WRITE ( FORMATTED )"_tok)),
370 construct<GenericSpec>(
371 construct<GenericSpec::WriteUnformatted>("WRITE ( UNFORMATTED )"_tok)),
372 construct<GenericSpec>(name))))
373
374 // R1510 generic-stmt ->
375 // GENERIC [, access-spec] :: generic-spec => specific-procedure-list
376 TYPE_PARSER(construct<GenericStmt>("GENERIC" >> maybe("," >> accessSpec),
377 "::" >> genericSpec, "=>" >> specificProcedures))
378
379 // R1511 external-stmt -> EXTERNAL [::] external-name-list
380 TYPE_PARSER(
381 "EXTERNAL" >> maybe("::"_tok) >> construct<ExternalStmt>(listOfNames))
382
383 // R1512 procedure-declaration-stmt ->
384 // PROCEDURE ( [proc-interface] ) [[, proc-attr-spec]... ::]
385 // proc-decl-list
386 TYPE_PARSER("PROCEDURE" >>
387 construct<ProcedureDeclarationStmt>(parenthesized(maybe(procInterface)),
388 optionalListBeforeColons(Parser<ProcAttrSpec>{}),
389 nonemptyList("expected procedure declarations"_err_en_US, procDecl)))
390
391 // R1513 proc-interface -> interface-name | declaration-type-spec
392 // R1516 interface-name -> name
393 // N.B. Simple names of intrinsic types (e.g., "REAL") are not
394 // ambiguous here - they take precedence over derived type names
395 // thanks to C1516.
396 TYPE_PARSER(
397 construct<ProcInterface>(declarationTypeSpec / lookAhead(")"_tok)) ||
398 construct<ProcInterface>(name))
399
400 // R1514 proc-attr-spec ->
401 // access-spec | proc-language-binding-spec | INTENT ( intent-spec ) |
402 // OPTIONAL | POINTER | PROTECTED | SAVE
403 TYPE_PARSER(construct<ProcAttrSpec>(accessSpec) ||
404 construct<ProcAttrSpec>(languageBindingSpec) ||
405 construct<ProcAttrSpec>("INTENT" >> parenthesized(intentSpec)) ||
406 construct<ProcAttrSpec>(optional) || construct<ProcAttrSpec>(pointer) ||
407 construct<ProcAttrSpec>(protectedAttr) || construct<ProcAttrSpec>(save))
408
409 // R1515 proc-decl -> procedure-entity-name [=> proc-pointer-init]
410 TYPE_PARSER(construct<ProcDecl>(name, maybe("=>" >> Parser<ProcPointerInit>{})))
411
412 // R1517 proc-pointer-init -> null-init | initial-proc-target
413 // R1518 initial-proc-target -> procedure-name
414 TYPE_PARSER(
415 construct<ProcPointerInit>(nullInit) || construct<ProcPointerInit>(name))
416
417 // R1519 intrinsic-stmt -> INTRINSIC [::] intrinsic-procedure-name-list
418 TYPE_PARSER(
419 "INTRINSIC" >> maybe("::"_tok) >> construct<IntrinsicStmt>(listOfNames))
420
421 // R1520 function-reference -> procedure-designator ( [actual-arg-spec-list] )
422 TYPE_CONTEXT_PARSER("function reference"_en_US,
423 construct<FunctionReference>(
424 sourced(construct<Call>(Parser<ProcedureDesignator>{},
425 parenthesized(optionalList(actualArgSpec))))) /
426 !"["_tok)
427
428 // R1521 call-stmt -> CALL procedure-designator [( [actual-arg-spec-list] )]
429 TYPE_PARSER(construct<CallStmt>(
430 sourced(construct<Call>("CALL" >> Parser<ProcedureDesignator>{},
431 defaulted(parenthesized(optionalList(actualArgSpec)))))))
432
433 // R1522 procedure-designator ->
434 // procedure-name | proc-component-ref | data-ref % binding-name
435 TYPE_PARSER(construct<ProcedureDesignator>(Parser<ProcComponentRef>{}) ||
436 construct<ProcedureDesignator>(name))
437
438 // R1523 actual-arg-spec -> [keyword =] actual-arg
439 TYPE_PARSER(construct<ActualArgSpec>(
440 maybe(keyword / "=" / !"="_ch), Parser<ActualArg>{}))
441
442 // R1524 actual-arg ->
443 // expr | variable | procedure-name | proc-component-ref |
444 // alt-return-spec
445 // N.B. the "procedure-name" and "proc-component-ref" alternatives can't
446 // yet be distinguished from "variable", many instances of which can't be
447 // distinguished from "expr" anyway (to do so would misparse structure
448 // constructors and function calls as array elements).
449 // Semantics sorts it all out later.
450 TYPE_PARSER(construct<ActualArg>(expr) ||
451 construct<ActualArg>(Parser<AltReturnSpec>{}) ||
452 extension<LanguageFeature::PercentRefAndVal>(construct<ActualArg>(
453 construct<ActualArg::PercentRef>("%REF" >> parenthesized(variable)))) ||
454 extension<LanguageFeature::PercentRefAndVal>(construct<ActualArg>(
455 construct<ActualArg::PercentVal>("%VAL" >> parenthesized(expr)))))
456
457 // R1525 alt-return-spec -> * label
458 TYPE_PARSER(construct<AltReturnSpec>(star >> label))
459
460 // R1527 prefix-spec ->
461 // declaration-type-spec | ELEMENTAL | IMPURE | MODULE |
462 // NON_RECURSIVE | PURE | RECURSIVE
463 TYPE_PARSER(first(construct<PrefixSpec>(declarationTypeSpec),
464 construct<PrefixSpec>(construct<PrefixSpec::Elemental>("ELEMENTAL"_tok)),
465 construct<PrefixSpec>(construct<PrefixSpec::Impure>("IMPURE"_tok)),
466 construct<PrefixSpec>(construct<PrefixSpec::Module>("MODULE"_tok)),
467 construct<PrefixSpec>(
468 construct<PrefixSpec::Non_Recursive>("NON_RECURSIVE"_tok)),
469 construct<PrefixSpec>(construct<PrefixSpec::Pure>("PURE"_tok)),
470 construct<PrefixSpec>(construct<PrefixSpec::Recursive>("RECURSIVE"_tok))))
471
472 // R1529 function-subprogram ->
473 // function-stmt [specification-part] [execution-part]
474 // [internal-subprogram-part] end-function-stmt
475 TYPE_CONTEXT_PARSER("FUNCTION subprogram"_en_US,
476 construct<FunctionSubprogram>(statement(functionStmt), specificationPart,
477 executionPart, maybe(internalSubprogramPart),
478 unterminatedStatement(endFunctionStmt)))
479
480 // R1530 function-stmt ->
481 // [prefix] FUNCTION function-name ( [dummy-arg-name-list] ) [suffix]
482 // R1526 prefix -> prefix-spec [prefix-spec]...
483 // R1531 dummy-arg-name -> name
484 TYPE_CONTEXT_PARSER("FUNCTION statement"_en_US,
485 construct<FunctionStmt>(many(prefixSpec), "FUNCTION" >> name,
486 parenthesized(optionalList(name)), maybe(suffix)) ||
487 extension<LanguageFeature::OmitFunctionDummies>(
488 construct<FunctionStmt>( // PGI & Intel accept "FUNCTION F"
489 many(prefixSpec), "FUNCTION" >> name,
490 construct<std::list<Name>>(),
491 construct<std::optional<Suffix>>())))
492
493 // R1532 suffix ->
494 // proc-language-binding-spec [RESULT ( result-name )] |
495 // RESULT ( result-name ) [proc-language-binding-spec]
496 TYPE_PARSER(construct<Suffix>(
497 languageBindingSpec, maybe("RESULT" >> parenthesized(name))) ||
498 construct<Suffix>(
499 "RESULT" >> parenthesized(name), maybe(languageBindingSpec)))
500
501 // R1533 end-function-stmt -> END [FUNCTION [function-name]]
502 TYPE_PARSER(construct<EndFunctionStmt>(recovery(
503 "END FUNCTION" >> maybe(name) || bareEnd, progUnitEndStmtErrorRecovery)))
504
505 // R1534 subroutine-subprogram ->
506 // subroutine-stmt [specification-part] [execution-part]
507 // [internal-subprogram-part] end-subroutine-stmt
508 TYPE_CONTEXT_PARSER("SUBROUTINE subprogram"_en_US,
509 construct<SubroutineSubprogram>(statement(subroutineStmt),
510 specificationPart, executionPart, maybe(internalSubprogramPart),
511 unterminatedStatement(endSubroutineStmt)))
512
513 // R1535 subroutine-stmt ->
514 // [prefix] SUBROUTINE subroutine-name [( [dummy-arg-list] )
515 // [proc-language-binding-spec]]
516 TYPE_PARSER(
517 construct<SubroutineStmt>(many(prefixSpec), "SUBROUTINE" >> name,
518 parenthesized(optionalList(dummyArg)), maybe(languageBindingSpec)) ||
519 construct<SubroutineStmt>(many(prefixSpec), "SUBROUTINE" >> name,
520 pure<std::list<DummyArg>>(),
521 pure<std::optional<LanguageBindingSpec>>()))
522
523 // R1536 dummy-arg -> dummy-arg-name | *
524 TYPE_PARSER(construct<DummyArg>(name) || construct<DummyArg>(star))
525
526 // R1537 end-subroutine-stmt -> END [SUBROUTINE [subroutine-name]]
527 TYPE_PARSER(construct<EndSubroutineStmt>(recovery(
528 "END SUBROUTINE" >> maybe(name) || bareEnd, progUnitEndStmtErrorRecovery)))
529
530 // R1538 separate-module-subprogram ->
531 // mp-subprogram-stmt [specification-part] [execution-part]
532 // [internal-subprogram-part] end-mp-subprogram-stmt
533 TYPE_CONTEXT_PARSER("separate module subprogram"_en_US,
534 construct<SeparateModuleSubprogram>(statement(Parser<MpSubprogramStmt>{}),
535 specificationPart, executionPart, maybe(internalSubprogramPart),
536 statement(Parser<EndMpSubprogramStmt>{})))
537
538 // R1539 mp-subprogram-stmt -> MODULE PROCEDURE procedure-name
539 TYPE_CONTEXT_PARSER("MODULE PROCEDURE statement"_en_US,
540 construct<MpSubprogramStmt>("MODULE PROCEDURE"_sptok >> name))
541
542 // R1540 end-mp-subprogram-stmt -> END [PROCEDURE [procedure-name]]
543 TYPE_CONTEXT_PARSER("END PROCEDURE statement"_en_US,
544 construct<EndMpSubprogramStmt>(
545 recovery("END PROCEDURE" >> maybe(name) || bareEnd,
546 progUnitEndStmtErrorRecovery)))
547
548 // R1541 entry-stmt -> ENTRY entry-name [( [dummy-arg-list] ) [suffix]]
549 TYPE_PARSER(
550 "ENTRY" >> (construct<EntryStmt>(name,
551 parenthesized(optionalList(dummyArg)), maybe(suffix)) ||
552 construct<EntryStmt>(name, construct<std::list<DummyArg>>(),
553 construct<std::optional<Suffix>>())))
554
555 // R1542 return-stmt -> RETURN [scalar-int-expr]
556 TYPE_CONTEXT_PARSER("RETURN statement"_en_US,
557 construct<ReturnStmt>("RETURN" >> maybe(scalarIntExpr)))
558
559 // R1543 contains-stmt -> CONTAINS
560 TYPE_PARSER(construct<ContainsStmt>("CONTAINS"_tok))
561
562 // R1544 stmt-function-stmt ->
563 // function-name ( [dummy-arg-name-list] ) = scalar-expr
564 TYPE_CONTEXT_PARSER("statement function definition"_en_US,
565 construct<StmtFunctionStmt>(
566 name, parenthesized(optionalList(name)), "=" >> scalar(expr)))
567 } // namespace Fortran::parser
568