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llvm / llvm-project / flang / ef06a153bc1f0d1545ff4a027f1ab6b7e9e4328d / . / lib / Parser / Fortran-parsers.cpp
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//===-- lib/Parser/Fortran-parsers.cpp ------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// Top-level grammar specification for Fortran. These parsers drive
// the tokenization parsers in cooked-tokens.h to consume characters,
// recognize the productions of Fortran, and to construct a parse tree.
// See ParserCombinators.md for documentation on the parser combinator
// library used here to implement an LL recursive descent recognizer.
// The productions that follow are derived from the draft Fortran 2018
// standard, with some necessary modifications to remove left recursion
// and some generalization in order to defer cases where parses depend
// on the definitions of symbols. The "Rxxx" numbers that appear in
// comments refer to these numbered requirements in the Fortran standard.
// The whole Fortran grammar originally constituted one header file,
// but that turned out to require more memory to compile with current
// C++ compilers than some people were willing to accept, so now the
// various per-type parsers are partitioned into several C++ source
// files. This file contains parsers for constants, types, declarations,
// and misfits (mostly clauses 7, 8, & 9 of Fortran 2018). The others:
// executable-parsers.cpp Executable statements
// expr-parsers.cpp Expressions
// io-parsers.cpp I/O statements and FORMAT
// openmp-parsers.cpp OpenMP directives
// program-parsers.cpp Program units
#include "basic-parsers.h"
#include "expr-parsers.h"
#include "misc-parsers.h"
#include "stmt-parser.h"
#include "token-parsers.h"
#include "type-parser-implementation.h"
#include "flang/Parser/parse-tree.h"
#include "flang/Parser/user-state.h"
namespace Fortran::parser {
// R601 alphanumeric-character -> letter | digit | underscore
// R603 name -> letter [alphanumeric-character]...
constexpr auto nonDigitIdChar{letter || otherIdChar};
constexpr auto rawName{nonDigitIdChar >> many(nonDigitIdChar || digit)};
TYPE_PARSER(space >> sourced(rawName >> construct<Name>()))
// R608 intrinsic-operator ->
// power-op | mult-op | add-op | concat-op | rel-op |
// not-op | and-op | or-op | equiv-op
// R610 extended-intrinsic-op -> intrinsic-operator
// These parsers must be ordered carefully to avoid misrecognition.
constexpr auto namedIntrinsicOperator{
".LT." >> pure(DefinedOperator::IntrinsicOperator::LT) ||
".LE." >> pure(DefinedOperator::IntrinsicOperator::LE) ||
".EQ." >> pure(DefinedOperator::IntrinsicOperator::EQ) ||
".NE." >> pure(DefinedOperator::IntrinsicOperator::NE) ||
".GE." >> pure(DefinedOperator::IntrinsicOperator::GE) ||
".GT." >> pure(DefinedOperator::IntrinsicOperator::GT) ||
".NOT." >> pure(DefinedOperator::IntrinsicOperator::NOT) ||
".AND." >> pure(DefinedOperator::IntrinsicOperator::AND) ||
".OR." >> pure(DefinedOperator::IntrinsicOperator::OR) ||
".EQV." >> pure(DefinedOperator::IntrinsicOperator::EQV) ||
".NEQV." >> pure(DefinedOperator::IntrinsicOperator::NEQV) ||
extension<LanguageFeature::XOROperator>(
".XOR." >> pure(DefinedOperator::IntrinsicOperator::NEQV)) ||
extension<LanguageFeature::LogicalAbbreviations>(
".N." >> pure(DefinedOperator::IntrinsicOperator::NOT) ||
".A." >> pure(DefinedOperator::IntrinsicOperator::AND) ||
".O." >> pure(DefinedOperator::IntrinsicOperator::OR) ||
extension<LanguageFeature::XOROperator>(
".X." >> pure(DefinedOperator::IntrinsicOperator::NEQV)))};
constexpr auto intrinsicOperator{
"**" >> pure(DefinedOperator::IntrinsicOperator::Power) ||
"*" >> pure(DefinedOperator::IntrinsicOperator::Multiply) ||
"//" >> pure(DefinedOperator::IntrinsicOperator::Concat) ||
"/=" >> pure(DefinedOperator::IntrinsicOperator::NE) ||
"/" >> pure(DefinedOperator::IntrinsicOperator::Divide) ||
"+" >> pure(DefinedOperator::IntrinsicOperator::Add) ||
"-" >> pure(DefinedOperator::IntrinsicOperator::Subtract) ||
"<=" >> pure(DefinedOperator::IntrinsicOperator::LE) ||
extension<LanguageFeature::AlternativeNE>(
"<>" >> pure(DefinedOperator::IntrinsicOperator::NE)) ||
"<" >> pure(DefinedOperator::IntrinsicOperator::LT) ||
"==" >> pure(DefinedOperator::IntrinsicOperator::EQ) ||
">=" >> pure(DefinedOperator::IntrinsicOperator::GE) ||
">" >> pure(DefinedOperator::IntrinsicOperator::GT) ||
namedIntrinsicOperator};
// R609 defined-operator ->
// defined-unary-op | defined-binary-op | extended-intrinsic-op
TYPE_PARSER(construct<DefinedOperator>(intrinsicOperator) ||
construct<DefinedOperator>(definedOpName))
// R505 implicit-part -> [implicit-part-stmt]... implicit-stmt
// N.B. PARAMETER, FORMAT, & ENTRY statements that appear before any
// other kind of declaration-construct will be parsed into the
// implicit-part.
TYPE_CONTEXT_PARSER("implicit part"_en_US,
construct<ImplicitPart>(many(Parser<ImplicitPartStmt>{})))
// R506 implicit-part-stmt ->
// implicit-stmt | parameter-stmt | format-stmt | entry-stmt
TYPE_PARSER(first(
construct<ImplicitPartStmt>(statement(indirect(Parser<ImplicitStmt>{}))),
construct<ImplicitPartStmt>(statement(indirect(parameterStmt))),
construct<ImplicitPartStmt>(statement(indirect(oldParameterStmt))),
construct<ImplicitPartStmt>(statement(indirect(formatStmt))),
construct<ImplicitPartStmt>(statement(indirect(entryStmt))),
construct<ImplicitPartStmt>(indirect(compilerDirective))))
// R512 internal-subprogram -> function-subprogram | subroutine-subprogram
// Internal subprograms are not program units, so their END statements
// can be followed by ';' and another statement on the same line.
TYPE_CONTEXT_PARSER("internal subprogram"_en_US,
(construct<InternalSubprogram>(indirect(functionSubprogram)) ||
construct<InternalSubprogram>(indirect(subroutineSubprogram))) /
forceEndOfStmt)
// R511 internal-subprogram-part -> contains-stmt [internal-subprogram]...
TYPE_CONTEXT_PARSER("internal subprogram part"_en_US,
construct<InternalSubprogramPart>(statement(containsStmt),
many(StartNewSubprogram{} >> Parser<InternalSubprogram>{})))
// R605 literal-constant ->
// int-literal-constant | real-literal-constant |
// complex-literal-constant | logical-literal-constant |
// char-literal-constant | boz-literal-constant
TYPE_PARSER(
first(construct<LiteralConstant>(Parser<HollerithLiteralConstant>{}),
construct<LiteralConstant>(realLiteralConstant),
construct<LiteralConstant>(intLiteralConstant),
construct<LiteralConstant>(Parser<ComplexLiteralConstant>{}),
construct<LiteralConstant>(Parser<BOZLiteralConstant>{}),
construct<LiteralConstant>(charLiteralConstant),
construct<LiteralConstant>(Parser<LogicalLiteralConstant>{})))
// R606 named-constant -> name
TYPE_PARSER(construct<NamedConstant>(name))
// R701 type-param-value -> scalar-int-expr | * | :
TYPE_PARSER(construct<TypeParamValue>(scalarIntExpr) ||
construct<TypeParamValue>(star) ||
construct<TypeParamValue>(construct<TypeParamValue::Deferred>(":"_tok)))
// R702 type-spec -> intrinsic-type-spec | derived-type-spec
// N.B. This type-spec production is one of two instances in the Fortran
// grammar where intrinsic types and bare derived type names can clash;
// the other is below in R703 declaration-type-spec. Look-ahead is required
// to disambiguate the cases where a derived type name begins with the name
// of an intrinsic type, e.g., REALITY.
TYPE_CONTEXT_PARSER("type spec"_en_US,
construct<TypeSpec>(intrinsicTypeSpec / lookAhead("::"_tok || ")"_tok)) ||
construct<TypeSpec>(derivedTypeSpec))
// R703 declaration-type-spec ->
// intrinsic-type-spec | TYPE ( intrinsic-type-spec ) |
// TYPE ( derived-type-spec ) | CLASS ( derived-type-spec ) |
// CLASS ( * ) | TYPE ( * )
// N.B. It is critical to distribute "parenthesized()" over the alternatives
// for TYPE (...), rather than putting the alternatives within it, which
// would fail on "TYPE(real_derived)" with a misrecognition of "real" as an
// intrinsic-type-spec.
TYPE_CONTEXT_PARSER("declaration type spec"_en_US,
construct<DeclarationTypeSpec>(intrinsicTypeSpec) ||
"TYPE" >>
(parenthesized(construct<DeclarationTypeSpec>(intrinsicTypeSpec)) ||
parenthesized(construct<DeclarationTypeSpec>(
construct<DeclarationTypeSpec::Type>(derivedTypeSpec))) ||
construct<DeclarationTypeSpec>(
"( * )" >> construct<DeclarationTypeSpec::TypeStar>())) ||
"CLASS" >> parenthesized(construct<DeclarationTypeSpec>(
construct<DeclarationTypeSpec::Class>(
derivedTypeSpec)) ||
construct<DeclarationTypeSpec>("*" >>
construct<DeclarationTypeSpec::ClassStar>())) ||
extension<LanguageFeature::DECStructures>(
construct<DeclarationTypeSpec>(
construct<DeclarationTypeSpec::Record>(
"RECORD /" >> name / "/"))))
// R704 intrinsic-type-spec ->
// integer-type-spec | REAL [kind-selector] | DOUBLE PRECISION |
// COMPLEX [kind-selector] | CHARACTER [char-selector] |
// LOGICAL [kind-selector]
// Extensions: DOUBLE COMPLEX, BYTE
TYPE_CONTEXT_PARSER("intrinsic type spec"_en_US,
first(construct<IntrinsicTypeSpec>(integerTypeSpec),
construct<IntrinsicTypeSpec>(
construct<IntrinsicTypeSpec::Real>("REAL" >> maybe(kindSelector))),
construct<IntrinsicTypeSpec>("DOUBLE PRECISION" >>
construct<IntrinsicTypeSpec::DoublePrecision>()),
construct<IntrinsicTypeSpec>(construct<IntrinsicTypeSpec::Complex>(
"COMPLEX" >> maybe(kindSelector))),
construct<IntrinsicTypeSpec>(construct<IntrinsicTypeSpec::Character>(
"CHARACTER" >> maybe(Parser<CharSelector>{}))),
construct<IntrinsicTypeSpec>(construct<IntrinsicTypeSpec::Logical>(
"LOGICAL" >> maybe(kindSelector))),
construct<IntrinsicTypeSpec>("DOUBLE COMPLEX" >>
extension<LanguageFeature::DoubleComplex>(
construct<IntrinsicTypeSpec::DoubleComplex>())),
extension<LanguageFeature::Byte>(
construct<IntrinsicTypeSpec>(construct<IntegerTypeSpec>(
"BYTE" >> construct<std::optional<KindSelector>>(pure(1)))))))
// R705 integer-type-spec -> INTEGER [kind-selector]
TYPE_PARSER(construct<IntegerTypeSpec>("INTEGER" >> maybe(kindSelector)))
// R706 kind-selector -> ( [KIND =] scalar-int-constant-expr )
// Legacy extension: kind-selector -> * digit-string
TYPE_PARSER(construct<KindSelector>(
parenthesized(maybe("KIND ="_tok) >> scalarIntConstantExpr)) ||
extension<LanguageFeature::StarKind>(construct<KindSelector>(
construct<KindSelector::StarSize>("*" >> digitString64 / spaceCheck))))
// R707 signed-int-literal-constant -> [sign] int-literal-constant
TYPE_PARSER(sourced(construct<SignedIntLiteralConstant>(
SignedIntLiteralConstantWithoutKind{}, maybe(underscore >> kindParam))))
// R708 int-literal-constant -> digit-string [_ kind-param]
// The negated look-ahead for a trailing underscore prevents misrecognition
// when the digit string is a numeric kind parameter of a character literal.
TYPE_PARSER(construct<IntLiteralConstant>(
space >> digitString, maybe(underscore >> kindParam) / !underscore))
// R709 kind-param -> digit-string | scalar-int-constant-name
TYPE_PARSER(construct<KindParam>(digitString64) ||
construct<KindParam>(scalar(integer(constant(name)))))
// R712 sign -> + | -
// N.B. A sign constitutes a whole token, so a space is allowed in free form
// after the sign and before a real-literal-constant or
// complex-literal-constant. A sign is not a unary operator in these contexts.
constexpr auto sign{
"+"_tok >> pure(Sign::Positive) || "-"_tok >> pure(Sign::Negative)};
// R713 signed-real-literal-constant -> [sign] real-literal-constant
constexpr auto signedRealLiteralConstant{
construct<SignedRealLiteralConstant>(maybe(sign), realLiteralConstant)};
// R714 real-literal-constant ->
// significand [exponent-letter exponent] [_ kind-param] |
// digit-string exponent-letter exponent [_ kind-param]
// R715 significand -> digit-string . [digit-string] | . digit-string
// R716 exponent-letter -> E | D
// Extension: Q
// R717 exponent -> signed-digit-string
constexpr auto exponentPart{
("ed"_ch || extension<LanguageFeature::QuadPrecision>("q"_ch)) >>
SignedDigitString{}};
TYPE_CONTEXT_PARSER("REAL literal constant"_en_US,
space >>
construct<RealLiteralConstant>(
sourced((digitString >> "."_ch >>
!(some(letter) >>
"."_ch /* don't misinterpret 1.AND. */) >>
maybe(digitString) >> maybe(exponentPart) >> ok ||
"."_ch >> digitString >> maybe(exponentPart) >> ok ||
digitString >> exponentPart >> ok) >>
construct<RealLiteralConstant::Real>()),
maybe(underscore >> kindParam)))
// R718 complex-literal-constant -> ( real-part , imag-part )
TYPE_CONTEXT_PARSER("COMPLEX literal constant"_en_US,
parenthesized(construct<ComplexLiteralConstant>(
Parser<ComplexPart>{} / ",", Parser<ComplexPart>{})))
// PGI/Intel extension: signed complex literal constant
TYPE_PARSER(construct<SignedComplexLiteralConstant>(
sign, Parser<ComplexLiteralConstant>{}))
// R719 real-part ->
// signed-int-literal-constant | signed-real-literal-constant |
// named-constant
// R720 imag-part ->
// signed-int-literal-constant | signed-real-literal-constant |
// named-constant
TYPE_PARSER(construct<ComplexPart>(signedRealLiteralConstant) ||
construct<ComplexPart>(signedIntLiteralConstant) ||
construct<ComplexPart>(namedConstant))
// R721 char-selector ->
// length-selector |
// ( LEN = type-param-value , KIND = scalar-int-constant-expr ) |
// ( type-param-value , [KIND =] scalar-int-constant-expr ) |
// ( KIND = scalar-int-constant-expr [, LEN = type-param-value] )
TYPE_PARSER(construct<CharSelector>(Parser<LengthSelector>{}) ||
parenthesized(construct<CharSelector>(
"LEN =" >> typeParamValue, ", KIND =" >> scalarIntConstantExpr)) ||
parenthesized(construct<CharSelector>(
typeParamValue / ",", maybe("KIND ="_tok) >> scalarIntConstantExpr)) ||
parenthesized(construct<CharSelector>(
"KIND =" >> scalarIntConstantExpr, maybe(", LEN =" >> typeParamValue))))
// R722 length-selector -> ( [LEN =] type-param-value ) | * char-length [,]
// N.B. The trailing [,] in the production is permitted by the Standard
// only in the context of a type-declaration-stmt, but even with that
// limitation, it would seem to be unnecessary and buggy to consume the comma
// here.
TYPE_PARSER(construct<LengthSelector>(
parenthesized(maybe("LEN ="_tok) >> typeParamValue)) ||
construct<LengthSelector>("*" >> charLength /* / maybe(","_tok) */))
// R723 char-length -> ( type-param-value ) | digit-string
TYPE_PARSER(construct<CharLength>(parenthesized(typeParamValue)) ||
construct<CharLength>(space >> digitString64 / spaceCheck))
// R724 char-literal-constant ->
// [kind-param _] ' [rep-char]... ' |
// [kind-param _] " [rep-char]... "
// "rep-char" is any non-control character. Doubled interior quotes are
// combined. Backslash escapes can be enabled.
// N.B. the parsing of "kind-param" takes care to not consume the '_'.
TYPE_CONTEXT_PARSER("CHARACTER literal constant"_en_US,
construct<CharLiteralConstant>(
kindParam / underscore, charLiteralConstantWithoutKind) ||
construct<CharLiteralConstant>(construct<std::optional<KindParam>>(),
space >> charLiteralConstantWithoutKind))
TYPE_CONTEXT_PARSER(
"Hollerith"_en_US, construct<HollerithLiteralConstant>(rawHollerithLiteral))
// R725 logical-literal-constant ->
// .TRUE. [_ kind-param] | .FALSE. [_ kind-param]
// Also accept .T. and .F. as extensions.
TYPE_PARSER(construct<LogicalLiteralConstant>(
logicalTRUE, maybe(underscore >> kindParam)) ||
construct<LogicalLiteralConstant>(
logicalFALSE, maybe(underscore >> kindParam)))
// R726 derived-type-def ->
// derived-type-stmt [type-param-def-stmt]...
// [private-or-sequence]... [component-part]
// [type-bound-procedure-part] end-type-stmt
// R735 component-part -> [component-def-stmt]...
TYPE_CONTEXT_PARSER("derived type definition"_en_US,
construct<DerivedTypeDef>(statement(Parser<DerivedTypeStmt>{}),
many(unambiguousStatement(Parser<TypeParamDefStmt>{})),
many(statement(Parser<PrivateOrSequence>{})),
many(inContext("component"_en_US,
unambiguousStatement(Parser<ComponentDefStmt>{}))),
maybe(Parser<TypeBoundProcedurePart>{}),
statement(Parser<EndTypeStmt>{})))
// R727 derived-type-stmt ->
// TYPE [[, type-attr-spec-list] ::] type-name [(
// type-param-name-list )]
TYPE_CONTEXT_PARSER("TYPE statement"_en_US,
construct<DerivedTypeStmt>(
"TYPE" >> optionalListBeforeColons(Parser<TypeAttrSpec>{}), name,
defaulted(parenthesized(nonemptyList(name)))))
// R728 type-attr-spec ->
// ABSTRACT | access-spec | BIND(C) | EXTENDS ( parent-type-name )
TYPE_PARSER(construct<TypeAttrSpec>(construct<Abstract>("ABSTRACT"_tok)) ||
construct<TypeAttrSpec>(construct<TypeAttrSpec::BindC>("BIND ( C )"_tok)) ||
construct<TypeAttrSpec>(
construct<TypeAttrSpec::Extends>("EXTENDS" >> parenthesized(name))) ||
construct<TypeAttrSpec>(accessSpec))
// R729 private-or-sequence -> private-components-stmt | sequence-stmt
TYPE_PARSER(construct<PrivateOrSequence>(Parser<PrivateStmt>{}) ||
construct<PrivateOrSequence>(Parser<SequenceStmt>{}))
// R730 end-type-stmt -> END TYPE [type-name]
TYPE_PARSER(construct<EndTypeStmt>(
recovery("END TYPE" >> maybe(name), endStmtErrorRecovery)))
// R731 sequence-stmt -> SEQUENCE
TYPE_PARSER(construct<SequenceStmt>("SEQUENCE"_tok))
// R732 type-param-def-stmt ->
// integer-type-spec , type-param-attr-spec :: type-param-decl-list
// R734 type-param-attr-spec -> KIND | LEN
constexpr auto kindOrLen{"KIND" >> pure(common::TypeParamAttr::Kind) ||
"LEN" >> pure(common::TypeParamAttr::Len)};
TYPE_PARSER(construct<TypeParamDefStmt>(integerTypeSpec / ",", kindOrLen,
"::" >> nonemptyList("expected type parameter declarations"_err_en_US,
Parser<TypeParamDecl>{})))
// R733 type-param-decl -> type-param-name [= scalar-int-constant-expr]
TYPE_PARSER(construct<TypeParamDecl>(name, maybe("=" >> scalarIntConstantExpr)))
// R736 component-def-stmt -> data-component-def-stmt |
// proc-component-def-stmt
// Accidental extension not enabled here: PGI accepts type-param-def-stmt in
// component-part of derived-type-def.
TYPE_PARSER(recovery(
withMessage("expected component definition"_err_en_US,
first(construct<ComponentDefStmt>(Parser<DataComponentDefStmt>{}),
construct<ComponentDefStmt>(Parser<ProcComponentDefStmt>{}))),
construct<ComponentDefStmt>(inStmtErrorRecovery)))
// R737 data-component-def-stmt ->
// declaration-type-spec [[, component-attr-spec-list] ::]
// component-decl-list
// N.B. The standard requires double colons if there's an initializer.
TYPE_PARSER(construct<DataComponentDefStmt>(declarationTypeSpec,
optionalListBeforeColons(Parser<ComponentAttrSpec>{}),
nonemptyList(
"expected component declarations"_err_en_US, Parser<ComponentDecl>{})))
// R738 component-attr-spec ->
// access-spec | ALLOCATABLE |
// CODIMENSION lbracket coarray-spec rbracket |
// CONTIGUOUS | DIMENSION ( component-array-spec ) | POINTER
TYPE_PARSER(construct<ComponentAttrSpec>(accessSpec) ||
construct<ComponentAttrSpec>(allocatable) ||
construct<ComponentAttrSpec>("CODIMENSION" >> coarraySpec) ||
construct<ComponentAttrSpec>(contiguous) ||
construct<ComponentAttrSpec>("DIMENSION" >> Parser<ComponentArraySpec>{}) ||
construct<ComponentAttrSpec>(pointer) ||
construct<ComponentAttrSpec>(recovery(
fail<ErrorRecovery>(
"type parameter definitions must appear before component declarations"_err_en_US),
kindOrLen >> construct<ErrorRecovery>())))
// R739 component-decl ->
// component-name [( component-array-spec )]
// [lbracket coarray-spec rbracket] [* char-length]
// [component-initialization]
TYPE_CONTEXT_PARSER("component declaration"_en_US,
construct<ComponentDecl>(name, maybe(Parser<ComponentArraySpec>{}),
maybe(coarraySpec), maybe("*" >> charLength), maybe(initialization)))
// R740 component-array-spec ->
// explicit-shape-spec-list | deferred-shape-spec-list
// N.B. Parenthesized here rather than around references to this production.
TYPE_PARSER(construct<ComponentArraySpec>(parenthesized(
nonemptyList("expected explicit shape specifications"_err_en_US,
explicitShapeSpec))) ||
construct<ComponentArraySpec>(parenthesized(deferredShapeSpecList)))
// R741 proc-component-def-stmt ->
// PROCEDURE ( [proc-interface] ) , proc-component-attr-spec-list
// :: proc-decl-list
TYPE_CONTEXT_PARSER("PROCEDURE component definition statement"_en_US,
construct<ProcComponentDefStmt>(
"PROCEDURE" >> parenthesized(maybe(procInterface)),
localRecovery("expected PROCEDURE component attributes"_err_en_US,
"," >> nonemptyList(Parser<ProcComponentAttrSpec>{}), ok),
localRecovery("expected PROCEDURE declarations"_err_en_US,
"::" >> nonemptyList(procDecl), SkipTo<'\n'>{})))
// R742 proc-component-attr-spec ->
// access-spec | NOPASS | PASS [(arg-name)] | POINTER
constexpr auto noPass{construct<NoPass>("NOPASS"_tok)};
constexpr auto pass{construct<Pass>("PASS" >> maybe(parenthesized(name)))};
TYPE_PARSER(construct<ProcComponentAttrSpec>(accessSpec) ||
construct<ProcComponentAttrSpec>(noPass) ||
construct<ProcComponentAttrSpec>(pass) ||
construct<ProcComponentAttrSpec>(pointer))
// R744 initial-data-target -> designator
constexpr auto initialDataTarget{indirect(designator)};
// R743 component-initialization ->
// = constant-expr | => null-init | => initial-data-target
// R805 initialization ->
// = constant-expr | => null-init | => initial-data-target
// Universal extension: initialization -> / data-stmt-value-list /
TYPE_PARSER(construct<Initialization>("=>" >> nullInit) ||
construct<Initialization>("=>" >> initialDataTarget) ||
construct<Initialization>("=" >> constantExpr) ||
extension<LanguageFeature::SlashInitialization>(construct<Initialization>(
"/" >> nonemptyList("expected values"_err_en_US,
indirect(Parser<DataStmtValue>{})) /
"/")))
// R745 private-components-stmt -> PRIVATE
// R747 binding-private-stmt -> PRIVATE
TYPE_PARSER(construct<PrivateStmt>("PRIVATE"_tok))
// R746 type-bound-procedure-part ->
// contains-stmt [binding-private-stmt] [type-bound-proc-binding]...
TYPE_CONTEXT_PARSER("type bound procedure part"_en_US,
construct<TypeBoundProcedurePart>(statement(containsStmt),
maybe(statement(Parser<PrivateStmt>{})),
many(statement(Parser<TypeBoundProcBinding>{}))))
// R748 type-bound-proc-binding ->
// type-bound-procedure-stmt | type-bound-generic-stmt |
// final-procedure-stmt
TYPE_CONTEXT_PARSER("type bound procedure binding"_en_US,
recovery(
first(construct<TypeBoundProcBinding>(Parser<TypeBoundProcedureStmt>{}),
construct<TypeBoundProcBinding>(Parser<TypeBoundGenericStmt>{}),
construct<TypeBoundProcBinding>(Parser<FinalProcedureStmt>{})),
construct<TypeBoundProcBinding>(
!"END"_tok >> SkipTo<'\n'>{} >> construct<ErrorRecovery>())))
// R749 type-bound-procedure-stmt ->
// PROCEDURE [[, bind-attr-list] ::] type-bound-proc-decl-list |
// PROCEDURE ( interface-name ) , bind-attr-list :: binding-name-list
TYPE_CONTEXT_PARSER("type bound PROCEDURE statement"_en_US,
"PROCEDURE" >>
(construct<TypeBoundProcedureStmt>(
construct<TypeBoundProcedureStmt::WithInterface>(
parenthesized(name),
localRecovery("expected list of binding attributes"_err_en_US,
"," >> nonemptyList(Parser<BindAttr>{}), ok),
localRecovery("expected list of binding names"_err_en_US,
"::" >> listOfNames, SkipTo<'\n'>{}))) ||
construct<TypeBoundProcedureStmt>(
construct<TypeBoundProcedureStmt::WithoutInterface>(
optionalListBeforeColons(Parser<BindAttr>{}),
nonemptyList(
"expected type bound procedure declarations"_err_en_US,
Parser<TypeBoundProcDecl>{})))))
// R750 type-bound-proc-decl -> binding-name [=> procedure-name]
TYPE_PARSER(construct<TypeBoundProcDecl>(name, maybe("=>" >> name)))
// R751 type-bound-generic-stmt ->
// GENERIC [, access-spec] :: generic-spec => binding-name-list
TYPE_CONTEXT_PARSER("type bound GENERIC statement"_en_US,
construct<TypeBoundGenericStmt>("GENERIC" >> maybe("," >> accessSpec),
"::" >> indirect(genericSpec), "=>" >> listOfNames))
// R752 bind-attr ->
// access-spec | DEFERRED | NON_OVERRIDABLE | NOPASS | PASS [(arg-name)]
TYPE_PARSER(construct<BindAttr>(accessSpec) ||
construct<BindAttr>(construct<BindAttr::Deferred>("DEFERRED"_tok)) ||
construct<BindAttr>(
construct<BindAttr::Non_Overridable>("NON_OVERRIDABLE"_tok)) ||
construct<BindAttr>(noPass) || construct<BindAttr>(pass))
// R753 final-procedure-stmt -> FINAL [::] final-subroutine-name-list
TYPE_CONTEXT_PARSER("FINAL statement"_en_US,
construct<FinalProcedureStmt>("FINAL" >> maybe("::"_tok) >> listOfNames))
// R754 derived-type-spec -> type-name [(type-param-spec-list)]
TYPE_PARSER(construct<DerivedTypeSpec>(name,
defaulted(parenthesized(nonemptyList(
"expected type parameters"_err_en_US, Parser<TypeParamSpec>{})))))
// R755 type-param-spec -> [keyword =] type-param-value
TYPE_PARSER(construct<TypeParamSpec>(maybe(keyword / "="), typeParamValue))
// R756 structure-constructor -> derived-type-spec ( [component-spec-list] )
TYPE_PARSER((construct<StructureConstructor>(derivedTypeSpec,
parenthesized(optionalList(Parser<ComponentSpec>{}))) ||
// This alternative corrects misrecognition of the
// component-spec-list as the type-param-spec-list in
// derived-type-spec.
construct<StructureConstructor>(
construct<DerivedTypeSpec>(
name, construct<std::list<TypeParamSpec>>()),
parenthesized(optionalList(Parser<ComponentSpec>{})))) /
!"("_tok)
// R757 component-spec -> [keyword =] component-data-source
TYPE_PARSER(construct<ComponentSpec>(
maybe(keyword / "="), Parser<ComponentDataSource>{}))
// R758 component-data-source -> expr | data-target | proc-target
TYPE_PARSER(construct<ComponentDataSource>(indirect(expr)))
// R759 enum-def ->
// enum-def-stmt enumerator-def-stmt [enumerator-def-stmt]...
// end-enum-stmt
TYPE_CONTEXT_PARSER("enum definition"_en_US,
construct<EnumDef>(statement(Parser<EnumDefStmt>{}),
some(unambiguousStatement(Parser<EnumeratorDefStmt>{})),
statement(Parser<EndEnumStmt>{})))
// R760 enum-def-stmt -> ENUM, BIND(C)
TYPE_PARSER(construct<EnumDefStmt>("ENUM , BIND ( C )"_tok))
// R761 enumerator-def-stmt -> ENUMERATOR [::] enumerator-list
TYPE_CONTEXT_PARSER("ENUMERATOR statement"_en_US,
construct<EnumeratorDefStmt>("ENUMERATOR" >> maybe("::"_tok) >>
nonemptyList("expected enumerators"_err_en_US, Parser<Enumerator>{})))
// R762 enumerator -> named-constant [= scalar-int-constant-expr]
TYPE_PARSER(
construct<Enumerator>(namedConstant, maybe("=" >> scalarIntConstantExpr)))
// R763 end-enum-stmt -> END ENUM
TYPE_PARSER(recovery("END ENUM"_tok, "END" >> SkipPast<'\n'>{}) >>
construct<EndEnumStmt>())
// R801 type-declaration-stmt ->
// declaration-type-spec [[, attr-spec]... ::] entity-decl-list
constexpr auto entityDeclWithoutEqInit{construct<EntityDecl>(name,
maybe(arraySpec), maybe(coarraySpec), maybe("*" >> charLength),
!"="_tok >> maybe(initialization))}; // old-style REAL A/0/ still works
TYPE_PARSER(
construct<TypeDeclarationStmt>(declarationTypeSpec,
defaulted("," >> nonemptyList(Parser<AttrSpec>{})) / "::",
nonemptyList("expected entity declarations"_err_en_US, entityDecl)) ||
// C806: no initializers allowed without colons ("REALA=1" is ambiguous)
construct<TypeDeclarationStmt>(declarationTypeSpec,
construct<std::list<AttrSpec>>(),
nonemptyList("expected entity declarations"_err_en_US,
entityDeclWithoutEqInit)) ||
// PGI-only extension: comma in place of doubled colons
extension<LanguageFeature::MissingColons>(construct<TypeDeclarationStmt>(
declarationTypeSpec, defaulted("," >> nonemptyList(Parser<AttrSpec>{})),
withMessage("expected entity declarations"_err_en_US,
"," >> nonemptyList(entityDecl)))))
// R802 attr-spec ->
// access-spec | ALLOCATABLE | ASYNCHRONOUS |
// CODIMENSION lbracket coarray-spec rbracket | CONTIGUOUS |
// DIMENSION ( array-spec ) | EXTERNAL | INTENT ( intent-spec ) |
// INTRINSIC | language-binding-spec | OPTIONAL | PARAMETER | POINTER |
// PROTECTED | SAVE | TARGET | VALUE | VOLATILE
TYPE_PARSER(construct<AttrSpec>(accessSpec) ||
construct<AttrSpec>(allocatable) ||
construct<AttrSpec>(construct<Asynchronous>("ASYNCHRONOUS"_tok)) ||
construct<AttrSpec>("CODIMENSION" >> coarraySpec) ||
construct<AttrSpec>(contiguous) ||
construct<AttrSpec>("DIMENSION" >> arraySpec) ||
construct<AttrSpec>(construct<External>("EXTERNAL"_tok)) ||
construct<AttrSpec>("INTENT" >> parenthesized(intentSpec)) ||
construct<AttrSpec>(construct<Intrinsic>("INTRINSIC"_tok)) ||
construct<AttrSpec>(languageBindingSpec) || construct<AttrSpec>(optional) ||
construct<AttrSpec>(construct<Parameter>("PARAMETER"_tok)) ||
construct<AttrSpec>(pointer) || construct<AttrSpec>(protectedAttr) ||
construct<AttrSpec>(save) ||
construct<AttrSpec>(construct<Target>("TARGET"_tok)) ||
construct<AttrSpec>(construct<Value>("VALUE"_tok)) ||
construct<AttrSpec>(construct<Volatile>("VOLATILE"_tok)))
// R804 object-name -> name
constexpr auto objectName{name};
// R803 entity-decl ->
// object-name [( array-spec )] [lbracket coarray-spec rbracket]
// [* char-length] [initialization] |
// function-name [* char-length]
TYPE_PARSER(construct<EntityDecl>(objectName, maybe(arraySpec),
maybe(coarraySpec), maybe("*" >> charLength), maybe(initialization)))
// R806 null-init -> function-reference ... which must resolve to NULL()
TYPE_PARSER(lookAhead(name / "( )") >> construct<NullInit>(expr))
// R807 access-spec -> PUBLIC | PRIVATE
TYPE_PARSER(construct<AccessSpec>("PUBLIC" >> pure(AccessSpec::Kind::Public)) ||
construct<AccessSpec>("PRIVATE" >> pure(AccessSpec::Kind::Private)))
// R808 language-binding-spec ->
// BIND ( C [, NAME = scalar-default-char-constant-expr] )
// R1528 proc-language-binding-spec -> language-binding-spec
TYPE_PARSER(construct<LanguageBindingSpec>(
"BIND ( C" >> maybe(", NAME =" >> scalarDefaultCharConstantExpr) / ")"))
// R809 coarray-spec -> deferred-coshape-spec-list | explicit-coshape-spec
// N.B. Bracketed here rather than around references, for consistency with
// array-spec.
TYPE_PARSER(
construct<CoarraySpec>(bracketed(Parser<DeferredCoshapeSpecList>{})) ||
construct<CoarraySpec>(bracketed(Parser<ExplicitCoshapeSpec>{})))
// R810 deferred-coshape-spec -> :
// deferred-coshape-spec-list - just a list of colons
inline int listLength(std::list<Success> &&xs) { return xs.size(); }
TYPE_PARSER(construct<DeferredCoshapeSpecList>(
applyFunction(listLength, nonemptyList(":"_tok))))
// R811 explicit-coshape-spec ->
// [[lower-cobound :] upper-cobound ,]... [lower-cobound :] *
// R812 lower-cobound -> specification-expr
// R813 upper-cobound -> specification-expr
TYPE_PARSER(construct<ExplicitCoshapeSpec>(
many(explicitShapeSpec / ","), maybe(specificationExpr / ":") / "*"))
// R815 array-spec ->
// explicit-shape-spec-list | assumed-shape-spec-list |
// deferred-shape-spec-list | assumed-size-spec | implied-shape-spec |
// implied-shape-or-assumed-size-spec | assumed-rank-spec
// N.B. Parenthesized here rather than around references to avoid
// a need for forced look-ahead.
// Shape specs that could be deferred-shape-spec or assumed-shape-spec
// (e.g. '(:,:)') are parsed as the former.
TYPE_PARSER(
construct<ArraySpec>(parenthesized(nonemptyList(explicitShapeSpec))) ||
construct<ArraySpec>(parenthesized(deferredShapeSpecList)) ||
construct<ArraySpec>(
parenthesized(nonemptyList(Parser<AssumedShapeSpec>{}))) ||
construct<ArraySpec>(parenthesized(Parser<AssumedSizeSpec>{})) ||
construct<ArraySpec>(parenthesized(Parser<ImpliedShapeSpec>{})) ||
construct<ArraySpec>(parenthesized(Parser<AssumedRankSpec>{})))
// R816 explicit-shape-spec -> [lower-bound :] upper-bound
// R817 lower-bound -> specification-expr
// R818 upper-bound -> specification-expr
TYPE_PARSER(construct<ExplicitShapeSpec>(
maybe(specificationExpr / ":"), specificationExpr))
// R819 assumed-shape-spec -> [lower-bound] :
TYPE_PARSER(construct<AssumedShapeSpec>(maybe(specificationExpr) / ":"))
// R820 deferred-shape-spec -> :
// deferred-shape-spec-list - just a list of colons
TYPE_PARSER(construct<DeferredShapeSpecList>(
applyFunction(listLength, nonemptyList(":"_tok))))
// R821 assumed-implied-spec -> [lower-bound :] *
TYPE_PARSER(construct<AssumedImpliedSpec>(maybe(specificationExpr / ":") / "*"))
// R822 assumed-size-spec -> explicit-shape-spec-list , assumed-implied-spec
TYPE_PARSER(construct<AssumedSizeSpec>(
nonemptyList(explicitShapeSpec) / ",", assumedImpliedSpec))
// R823 implied-shape-or-assumed-size-spec -> assumed-implied-spec
// R824 implied-shape-spec -> assumed-implied-spec , assumed-implied-spec-list
// I.e., when the assumed-implied-spec-list has a single item, it constitutes an
// implied-shape-or-assumed-size-spec; otherwise, an implied-shape-spec.
TYPE_PARSER(construct<ImpliedShapeSpec>(nonemptyList(assumedImpliedSpec)))
// R825 assumed-rank-spec -> ..
TYPE_PARSER(construct<AssumedRankSpec>(".."_tok))
// R826 intent-spec -> IN | OUT | INOUT
TYPE_PARSER(construct<IntentSpec>("IN OUT" >> pure(IntentSpec::Intent::InOut) ||
"IN" >> pure(IntentSpec::Intent::In) ||
"OUT" >> pure(IntentSpec::Intent::Out)))
// R827 access-stmt -> access-spec [[::] access-id-list]
TYPE_PARSER(construct<AccessStmt>(accessSpec,
defaulted(maybe("::"_tok) >>
nonemptyList("expected names and generic specifications"_err_en_US,
Parser<AccessId>{}))))
// R828 access-id -> access-name | generic-spec
TYPE_PARSER(construct<AccessId>(indirect(genericSpec)) ||
construct<AccessId>(name)) // initially ambiguous with genericSpec
// R829 allocatable-stmt -> ALLOCATABLE [::] allocatable-decl-list
TYPE_PARSER(construct<AllocatableStmt>("ALLOCATABLE" >> maybe("::"_tok) >>
nonemptyList(
"expected object declarations"_err_en_US, Parser<ObjectDecl>{})))
// R830 allocatable-decl ->
// object-name [( array-spec )] [lbracket coarray-spec rbracket]
// R860 target-decl ->
// object-name [( array-spec )] [lbracket coarray-spec rbracket]
TYPE_PARSER(
construct<ObjectDecl>(objectName, maybe(arraySpec), maybe(coarraySpec)))
// R831 asynchronous-stmt -> ASYNCHRONOUS [::] object-name-list
TYPE_PARSER(construct<AsynchronousStmt>("ASYNCHRONOUS" >> maybe("::"_tok) >>
nonemptyList("expected object names"_err_en_US, objectName)))
// R832 bind-stmt -> language-binding-spec [::] bind-entity-list
TYPE_PARSER(construct<BindStmt>(languageBindingSpec / maybe("::"_tok),
nonemptyList("expected bind entities"_err_en_US, Parser<BindEntity>{})))
// R833 bind-entity -> entity-name | / common-block-name /
TYPE_PARSER(construct<BindEntity>(pure(BindEntity::Kind::Object), name) ||
construct<BindEntity>("/" >> pure(BindEntity::Kind::Common), name / "/"))
// R834 codimension-stmt -> CODIMENSION [::] codimension-decl-list
TYPE_PARSER(construct<CodimensionStmt>("CODIMENSION" >> maybe("::"_tok) >>
nonemptyList("expected codimension declarations"_err_en_US,
Parser<CodimensionDecl>{})))
// R835 codimension-decl -> coarray-name lbracket coarray-spec rbracket
TYPE_PARSER(construct<CodimensionDecl>(name, coarraySpec))
// R836 contiguous-stmt -> CONTIGUOUS [::] object-name-list
TYPE_PARSER(construct<ContiguousStmt>("CONTIGUOUS" >> maybe("::"_tok) >>
nonemptyList("expected object names"_err_en_US, objectName)))
// R837 data-stmt -> DATA data-stmt-set [[,] data-stmt-set]...
TYPE_CONTEXT_PARSER("DATA statement"_en_US,
construct<DataStmt>(
"DATA" >> nonemptySeparated(Parser<DataStmtSet>{}, maybe(","_tok))))
// R838 data-stmt-set -> data-stmt-object-list / data-stmt-value-list /
TYPE_PARSER(construct<DataStmtSet>(
nonemptyList(
"expected DATA statement objects"_err_en_US, Parser<DataStmtObject>{}),
withMessage("expected DATA statement value list"_err_en_US,
"/"_tok >> nonemptyList("expected DATA statement values"_err_en_US,
Parser<DataStmtValue>{})) /
"/"))
// R839 data-stmt-object -> variable | data-implied-do
TYPE_PARSER(construct<DataStmtObject>(indirect(variable)) ||
construct<DataStmtObject>(dataImpliedDo))
// R840 data-implied-do ->
// ( data-i-do-object-list , [integer-type-spec ::] data-i-do-variable
// = scalar-int-constant-expr , scalar-int-constant-expr
// [, scalar-int-constant-expr] )
// R842 data-i-do-variable -> do-variable
TYPE_PARSER(parenthesized(construct<DataImpliedDo>(
nonemptyList(Parser<DataIDoObject>{} / lookAhead(","_tok)) / ",",
maybe(integerTypeSpec / "::"), loopBounds(scalarIntConstantExpr))))
// R841 data-i-do-object ->
// array-element | scalar-structure-component | data-implied-do
TYPE_PARSER(construct<DataIDoObject>(scalar(indirect(designator))) ||
construct<DataIDoObject>(indirect(dataImpliedDo)))
// R843 data-stmt-value -> [data-stmt-repeat *] data-stmt-constant
TYPE_PARSER(construct<DataStmtValue>(
maybe(Parser<DataStmtRepeat>{} / "*"), Parser<DataStmtConstant>{}))
// R847 constant-subobject -> designator
// R846 int-constant-subobject -> constant-subobject
constexpr auto constantSubobject{constant(indirect(designator))};
// R844 data-stmt-repeat -> scalar-int-constant | scalar-int-constant-subobject
// R607 int-constant -> constant
// Factored into: constant -> literal-constant -> int-literal-constant
// The named-constant alternative of constant is subsumed by constant-subobject
TYPE_PARSER(construct<DataStmtRepeat>(intLiteralConstant) ||
construct<DataStmtRepeat>(scalar(integer(constantSubobject))))
// R845 data-stmt-constant ->
// scalar-constant | scalar-constant-subobject |
// signed-int-literal-constant | signed-real-literal-constant |
// null-init | initial-data-target |
// constant-structure-constructor
// N.B. scalar-constant and scalar-constant-subobject are ambiguous with
// initial-data-target; null-init and structure-constructor are ambiguous
// in the absence of parameters and components; structure-constructor with
// components can be ambiguous with a scalar-constant-subobject.
// So we parse literal constants, designator, null-init, and
// structure-constructor, so that semantics can figure things out later
// with the symbol table.
TYPE_PARSER(sourced(first(construct<DataStmtConstant>(literalConstant),
construct<DataStmtConstant>(signedRealLiteralConstant),
construct<DataStmtConstant>(signedIntLiteralConstant),
extension<LanguageFeature::SignedComplexLiteral>(
construct<DataStmtConstant>(Parser<SignedComplexLiteralConstant>{})),
construct<DataStmtConstant>(nullInit),
construct<DataStmtConstant>(indirect(designator) / !"("_tok),
construct<DataStmtConstant>(Parser<StructureConstructor>{}))))
// R848 dimension-stmt ->
// DIMENSION [::] array-name ( array-spec )
// [, array-name ( array-spec )]...
TYPE_CONTEXT_PARSER("DIMENSION statement"_en_US,
construct<DimensionStmt>("DIMENSION" >> maybe("::"_tok) >>
nonemptyList("expected array specifications"_err_en_US,
construct<DimensionStmt::Declaration>(name, arraySpec))))
// R849 intent-stmt -> INTENT ( intent-spec ) [::] dummy-arg-name-list
TYPE_CONTEXT_PARSER("INTENT statement"_en_US,
construct<IntentStmt>(
"INTENT" >> parenthesized(intentSpec) / maybe("::"_tok), listOfNames))
// R850 optional-stmt -> OPTIONAL [::] dummy-arg-name-list
TYPE_PARSER(
construct<OptionalStmt>("OPTIONAL" >> maybe("::"_tok) >> listOfNames))
// R851 parameter-stmt -> PARAMETER ( named-constant-def-list )
// Legacy extension: omitted parentheses, no implicit typing from names
TYPE_CONTEXT_PARSER("PARAMETER statement"_en_US,
construct<ParameterStmt>(
"PARAMETER" >> parenthesized(nonemptyList(Parser<NamedConstantDef>{}))))
TYPE_CONTEXT_PARSER("old style PARAMETER statement"_en_US,
extension<LanguageFeature::OldStyleParameter>(construct<OldParameterStmt>(
"PARAMETER" >> nonemptyList(Parser<NamedConstantDef>{}))))
// R852 named-constant-def -> named-constant = constant-expr
TYPE_PARSER(construct<NamedConstantDef>(namedConstant, "=" >> constantExpr))
// R853 pointer-stmt -> POINTER [::] pointer-decl-list
TYPE_PARSER(construct<PointerStmt>("POINTER" >> maybe("::"_tok) >>
nonemptyList(
"expected pointer declarations"_err_en_US, Parser<PointerDecl>{})))
// R854 pointer-decl ->
// object-name [( deferred-shape-spec-list )] | proc-entity-name
TYPE_PARSER(
construct<PointerDecl>(name, maybe(parenthesized(deferredShapeSpecList))))
// R855 protected-stmt -> PROTECTED [::] entity-name-list
TYPE_PARSER(
construct<ProtectedStmt>("PROTECTED" >> maybe("::"_tok) >> listOfNames))
// R856 save-stmt -> SAVE [[::] saved-entity-list]
TYPE_PARSER(construct<SaveStmt>(
"SAVE" >> defaulted(maybe("::"_tok) >>
nonemptyList("expected SAVE entities"_err_en_US,
Parser<SavedEntity>{}))))
// R857 saved-entity -> object-name | proc-pointer-name | / common-block-name /
// R858 proc-pointer-name -> name
TYPE_PARSER(construct<SavedEntity>(pure(SavedEntity::Kind::Entity), name) ||
construct<SavedEntity>("/" >> pure(SavedEntity::Kind::Common), name / "/"))
// R859 target-stmt -> TARGET [::] target-decl-list
TYPE_PARSER(construct<TargetStmt>("TARGET" >> maybe("::"_tok) >>
nonemptyList("expected objects"_err_en_US, Parser<ObjectDecl>{})))
// R861 value-stmt -> VALUE [::] dummy-arg-name-list
TYPE_PARSER(construct<ValueStmt>("VALUE" >> maybe("::"_tok) >> listOfNames))
// R862 volatile-stmt -> VOLATILE [::] object-name-list
TYPE_PARSER(construct<VolatileStmt>("VOLATILE" >> maybe("::"_tok) >>
nonemptyList("expected object names"_err_en_US, objectName)))
// R866 implicit-name-spec -> EXTERNAL | TYPE
constexpr auto implicitNameSpec{
"EXTERNAL" >> pure(ImplicitStmt::ImplicitNoneNameSpec::External) ||
"TYPE" >> pure(ImplicitStmt::ImplicitNoneNameSpec::Type)};
// R863 implicit-stmt ->
// IMPLICIT implicit-spec-list |
// IMPLICIT NONE [( [implicit-name-spec-list] )]
TYPE_CONTEXT_PARSER("IMPLICIT statement"_en_US,
construct<ImplicitStmt>(
"IMPLICIT" >> nonemptyList("expected IMPLICIT specifications"_err_en_US,
Parser<ImplicitSpec>{})) ||
construct<ImplicitStmt>("IMPLICIT NONE"_sptok >>
defaulted(parenthesized(optionalList(implicitNameSpec)))))
// R864 implicit-spec -> declaration-type-spec ( letter-spec-list )
// The variant form of declarationTypeSpec is meant to avoid misrecognition
// of a letter-spec as a simple parenthesized expression for kind or character
// length, e.g., PARAMETER(I=5,N=1); IMPLICIT REAL(I-N)(O-Z) vs.
// IMPLICIT REAL(I-N). The variant form needs to attempt to reparse only
// types with optional parenthesized kind/length expressions, so derived
// type specs, DOUBLE PRECISION, and DOUBLE COMPLEX need not be considered.
constexpr auto noKindSelector{construct<std::optional<KindSelector>>()};
constexpr auto implicitSpecDeclarationTypeSpecRetry{
construct<DeclarationTypeSpec>(first(
construct<IntrinsicTypeSpec>(
construct<IntegerTypeSpec>("INTEGER" >> noKindSelector)),
construct<IntrinsicTypeSpec>(
construct<IntrinsicTypeSpec::Real>("REAL" >> noKindSelector)),
construct<IntrinsicTypeSpec>(
construct<IntrinsicTypeSpec::Complex>("COMPLEX" >> noKindSelector)),
construct<IntrinsicTypeSpec>(construct<IntrinsicTypeSpec::Character>(
"CHARACTER" >> construct<std::optional<CharSelector>>())),
construct<IntrinsicTypeSpec>(construct<IntrinsicTypeSpec::Logical>(
"LOGICAL" >> noKindSelector))))};
TYPE_PARSER(construct<ImplicitSpec>(declarationTypeSpec,
parenthesized(nonemptyList(Parser<LetterSpec>{}))) ||
construct<ImplicitSpec>(implicitSpecDeclarationTypeSpecRetry,
parenthesized(nonemptyList(Parser<LetterSpec>{}))))
// R865 letter-spec -> letter [- letter]
TYPE_PARSER(space >> (construct<LetterSpec>(letter, maybe("-" >> letter)) ||
construct<LetterSpec>(otherIdChar,
construct<std::optional<const char *>>())))
// R867 import-stmt ->
// IMPORT [[::] import-name-list] |
// IMPORT , ONLY : import-name-list | IMPORT , NONE | IMPORT , ALL
TYPE_CONTEXT_PARSER("IMPORT statement"_en_US,
construct<ImportStmt>(
"IMPORT , ONLY :" >> pure(common::ImportKind::Only), listOfNames) ||
construct<ImportStmt>(
"IMPORT , NONE" >> pure(common::ImportKind::None)) ||
construct<ImportStmt>(
"IMPORT , ALL" >> pure(common::ImportKind::All)) ||
construct<ImportStmt>(
"IMPORT" >> maybe("::"_tok) >> optionalList(name)))
// R868 namelist-stmt ->
// NAMELIST / namelist-group-name / namelist-group-object-list
// [[,] / namelist-group-name / namelist-group-object-list]...
// R869 namelist-group-object -> variable-name
TYPE_PARSER(construct<NamelistStmt>("NAMELIST" >>
nonemptySeparated(
construct<NamelistStmt::Group>("/" >> name / "/", listOfNames),
maybe(","_tok))))
// R870 equivalence-stmt -> EQUIVALENCE equivalence-set-list
// R871 equivalence-set -> ( equivalence-object , equivalence-object-list )
TYPE_PARSER(construct<EquivalenceStmt>("EQUIVALENCE" >>
nonemptyList(
parenthesized(nonemptyList("expected EQUIVALENCE objects"_err_en_US,
Parser<EquivalenceObject>{})))))
// R872 equivalence-object -> variable-name | array-element | substring
TYPE_PARSER(construct<EquivalenceObject>(indirect(designator)))
// R873 common-stmt ->
// COMMON [/ [common-block-name] /] common-block-object-list
// [[,] / [common-block-name] / common-block-object-list]...
TYPE_PARSER(
construct<CommonStmt>("COMMON" >> defaulted("/" >> maybe(name) / "/"),
nonemptyList("expected COMMON block objects"_err_en_US,
Parser<CommonBlockObject>{}),
many(maybe(","_tok) >>
construct<CommonStmt::Block>("/" >> maybe(name) / "/",
nonemptyList("expected COMMON block objects"_err_en_US,
Parser<CommonBlockObject>{})))))
// R874 common-block-object -> variable-name [( array-spec )]
TYPE_PARSER(construct<CommonBlockObject>(name, maybe(arraySpec)))
// R901 designator -> object-name | array-element | array-section |
// coindexed-named-object | complex-part-designator |
// structure-component | substring
// The Standard's productions for designator and its alternatives are
// ambiguous without recourse to a symbol table. Many of the alternatives
// for designator (viz., array-element, coindexed-named-object,
// and structure-component) are all syntactically just data-ref.
// What designator boils down to is this:
// It starts with either a name or a character literal.
// If it starts with a character literal, it must be a substring.
// If it starts with a name, it's a sequence of %-separated parts;
// each part is a name, maybe a (section-subscript-list), and
// maybe an [image-selector].
// If it's a substring, it ends with (substring-range).
TYPE_CONTEXT_PARSER("designator"_en_US,
sourced(construct<Designator>(substring) || construct<Designator>(dataRef)))
constexpr auto percentOrDot{"%"_tok ||
// legacy VAX extension for RECORD field access
extension<LanguageFeature::DECStructures>(
"."_tok / lookAhead(OldStructureComponentName{}))};
// R902 variable -> designator | function-reference
// This production appears to be left-recursive in the grammar via
// function-reference -> procedure-designator -> proc-component-ref ->
// scalar-variable
// and would be so if we were to allow functions to be called via procedure
// pointer components within derived type results of other function references
// (a reasonable extension, esp. in the case of procedure pointer components
// that are NOPASS). However, Fortran constrains the use of a variable in a
// proc-component-ref to be a data-ref without coindices (C1027).
// Some array element references will be misrecognized as function references.
constexpr auto noMoreAddressing{!"("_tok >> !"["_tok >> !percentOrDot};
TYPE_CONTEXT_PARSER("variable"_en_US,
construct<Variable>(indirect(functionReference / noMoreAddressing)) ||
construct<Variable>(indirect(designator)))
// R908 substring -> parent-string ( substring-range )
// R909 parent-string ->
// scalar-variable-name | array-element | coindexed-named-object |
// scalar-structure-component | scalar-char-literal-constant |
// scalar-named-constant
TYPE_PARSER(
construct<Substring>(dataRef, parenthesized(Parser<SubstringRange>{})))
TYPE_PARSER(construct<CharLiteralConstantSubstring>(
charLiteralConstant, parenthesized(Parser<SubstringRange>{})))
// R910 substring-range -> [scalar-int-expr] : [scalar-int-expr]
TYPE_PARSER(construct<SubstringRange>(
maybe(scalarIntExpr), ":" >> maybe(scalarIntExpr)))
// R911 data-ref -> part-ref [% part-ref]...
// R914 coindexed-named-object -> data-ref
// R917 array-element -> data-ref
TYPE_PARSER(
construct<DataRef>(nonemptySeparated(Parser<PartRef>{}, percentOrDot)))
// R912 part-ref -> part-name [( section-subscript-list )] [image-selector]
TYPE_PARSER(construct<PartRef>(name,
defaulted(
parenthesized(nonemptyList(Parser<SectionSubscript>{})) / !"=>"_tok),
maybe(Parser<ImageSelector>{})))
// R913 structure-component -> data-ref
// The final part-ref in the data-ref is not allowed to have subscripts.
TYPE_PARSER(construct<StructureComponent>(
construct<DataRef>(some(Parser<PartRef>{} / percentOrDot)), name))
// R919 subscript -> scalar-int-expr
constexpr auto subscript{scalarIntExpr};
// R920 section-subscript -> subscript | subscript-triplet | vector-subscript
// R923 vector-subscript -> int-expr
// N.B. The distinction that needs to be made between "subscript" and
// "vector-subscript" is deferred to semantic analysis.
TYPE_PARSER(construct<SectionSubscript>(Parser<SubscriptTriplet>{}) ||
construct<SectionSubscript>(intExpr))
// R921 subscript-triplet -> [subscript] : [subscript] [: stride]
TYPE_PARSER(construct<SubscriptTriplet>(
maybe(subscript), ":" >> maybe(subscript), maybe(":" >> subscript)))
// R925 cosubscript -> scalar-int-expr
constexpr auto cosubscript{scalarIntExpr};
// R924 image-selector ->
// lbracket cosubscript-list [, image-selector-spec-list] rbracket
TYPE_CONTEXT_PARSER("image selector"_en_US,
construct<ImageSelector>(
"[" >> nonemptyList(cosubscript / lookAhead(space / ",]"_ch)),
defaulted("," >> nonemptyList(Parser<ImageSelectorSpec>{})) / "]"))
// R926 image-selector-spec ->
// STAT = stat-variable | TEAM = team-value |
// TEAM_NUMBER = scalar-int-expr
TYPE_PARSER(construct<ImageSelectorSpec>(construct<ImageSelectorSpec::Stat>(
"STAT =" >> scalar(integer(indirect(variable))))) ||
construct<ImageSelectorSpec>(construct<TeamValue>("TEAM =" >> teamValue)) ||
construct<ImageSelectorSpec>(construct<ImageSelectorSpec::Team_Number>(
"TEAM_NUMBER =" >> scalarIntExpr)))
// R927 allocate-stmt ->
// ALLOCATE ( [type-spec ::] allocation-list [, alloc-opt-list] )
TYPE_CONTEXT_PARSER("ALLOCATE statement"_en_US,
construct<AllocateStmt>("ALLOCATE (" >> maybe(typeSpec / "::"),
nonemptyList(Parser<Allocation>{}),
defaulted("," >> nonemptyList(Parser<AllocOpt>{})) / ")"))
// R928 alloc-opt ->
// ERRMSG = errmsg-variable | MOLD = source-expr |
// SOURCE = source-expr | STAT = stat-variable
// R931 source-expr -> expr
TYPE_PARSER(construct<AllocOpt>(
construct<AllocOpt::Mold>("MOLD =" >> indirect(expr))) ||
construct<AllocOpt>(
construct<AllocOpt::Source>("SOURCE =" >> indirect(expr))) ||
construct<AllocOpt>(statOrErrmsg))
// R929 stat-variable -> scalar-int-variable
TYPE_PARSER(construct<StatVariable>(scalar(integer(variable))))
// R932 allocation ->
// allocate-object [( allocate-shape-spec-list )]
// [lbracket allocate-coarray-spec rbracket]
TYPE_PARSER(construct<Allocation>(Parser<AllocateObject>{},
defaulted(parenthesized(nonemptyList(Parser<AllocateShapeSpec>{}))),
maybe(bracketed(Parser<AllocateCoarraySpec>{}))))
// R933 allocate-object -> variable-name | structure-component
TYPE_PARSER(construct<AllocateObject>(structureComponent) ||
construct<AllocateObject>(name / !"="_tok))
// R934 allocate-shape-spec -> [lower-bound-expr :] upper-bound-expr
// R938 allocate-coshape-spec -> [lower-bound-expr :] upper-bound-expr
TYPE_PARSER(construct<AllocateShapeSpec>(maybe(boundExpr / ":"), boundExpr))
// R937 allocate-coarray-spec ->
// [allocate-coshape-spec-list ,] [lower-bound-expr :] *
TYPE_PARSER(construct<AllocateCoarraySpec>(
defaulted(nonemptyList(Parser<AllocateShapeSpec>{}) / ","),
maybe(boundExpr / ":") / "*"))
// R939 nullify-stmt -> NULLIFY ( pointer-object-list )
TYPE_CONTEXT_PARSER("NULLIFY statement"_en_US,
"NULLIFY" >> parenthesized(construct<NullifyStmt>(
nonemptyList(Parser<PointerObject>{}))))
// R940 pointer-object ->
// variable-name | structure-component | proc-pointer-name
TYPE_PARSER(construct<PointerObject>(structureComponent) ||
construct<PointerObject>(name))
// R941 deallocate-stmt ->
// DEALLOCATE ( allocate-object-list [, dealloc-opt-list] )
TYPE_CONTEXT_PARSER("DEALLOCATE statement"_en_US,
construct<DeallocateStmt>(
"DEALLOCATE (" >> nonemptyList(Parser<AllocateObject>{}),
defaulted("," >> nonemptyList(statOrErrmsg)) / ")"))
// R942 dealloc-opt -> STAT = stat-variable | ERRMSG = errmsg-variable
// R1165 sync-stat -> STAT = stat-variable | ERRMSG = errmsg-variable
TYPE_PARSER(construct<StatOrErrmsg>("STAT =" >> statVariable) ||
construct<StatOrErrmsg>("ERRMSG =" >> msgVariable))
// Directives, extensions, and deprecated statements
// !DIR$ IGNORE_TKR [ [(tkr...)] name ]...
// !DIR$ name...
constexpr auto beginDirective{skipStuffBeforeStatement >> "!"_ch};
constexpr auto endDirective{space >> endOfLine};
constexpr auto ignore_tkr{
"DIR$ IGNORE_TKR" >> optionalList(construct<CompilerDirective::IgnoreTKR>(
defaulted(parenthesized(some("tkr"_ch))), name))};
TYPE_PARSER(beginDirective >>
sourced(construct<CompilerDirective>(ignore_tkr) ||
construct<CompilerDirective>(
"DIR$" >> many(construct<CompilerDirective::NameValue>(name,
maybe(("="_tok || ":"_tok) >> digitString64))))) /
endDirective)
TYPE_PARSER(extension<LanguageFeature::CrayPointer>(construct<BasedPointerStmt>(
"POINTER" >> nonemptyList("expected POINTER associations"_err_en_US,
construct<BasedPointer>("(" >> objectName / ",",
objectName, maybe(Parser<ArraySpec>{}) / ")")))))
TYPE_PARSER(construct<StructureStmt>("STRUCTURE /" >> name / "/", pure(true),
optionalList(entityDecl)) ||
construct<StructureStmt>(
"STRUCTURE" >> name, pure(false), pure<std::list<EntityDecl>>()))
TYPE_PARSER(construct<StructureField>(statement(StructureComponents{})) ||
construct<StructureField>(indirect(Parser<Union>{})) ||
construct<StructureField>(indirect(Parser<StructureDef>{})))
TYPE_CONTEXT_PARSER("STRUCTURE definition"_en_US,
extension<LanguageFeature::DECStructures>(construct<StructureDef>(
statement(Parser<StructureStmt>{}), many(Parser<StructureField>{}),
statement(
construct<StructureDef::EndStructureStmt>("END STRUCTURE"_tok)))))
TYPE_CONTEXT_PARSER("UNION definition"_en_US,
construct<Union>(statement(construct<Union::UnionStmt>("UNION"_tok)),
many(Parser<Map>{}),
statement(construct<Union::EndUnionStmt>("END UNION"_tok))))
TYPE_CONTEXT_PARSER("MAP definition"_en_US,
construct<Map>(statement(construct<Map::MapStmt>("MAP"_tok)),
many(Parser<StructureField>{}),
statement(construct<Map::EndMapStmt>("END MAP"_tok))))
TYPE_CONTEXT_PARSER("arithmetic IF statement"_en_US,
deprecated<LanguageFeature::ArithmeticIF>(construct<ArithmeticIfStmt>(
"IF" >> parenthesized(expr), label / ",", label / ",", label)))
TYPE_CONTEXT_PARSER("ASSIGN statement"_en_US,
deprecated<LanguageFeature::Assign>(
construct<AssignStmt>("ASSIGN" >> label, "TO" >> name)))
TYPE_CONTEXT_PARSER("assigned GOTO statement"_en_US,
deprecated<LanguageFeature::AssignedGOTO>(construct<AssignedGotoStmt>(
"GO TO" >> name,
defaulted(maybe(","_tok) >>
parenthesized(nonemptyList("expected labels"_err_en_US, label))))))
TYPE_CONTEXT_PARSER("PAUSE statement"_en_US,
deprecated<LanguageFeature::Pause>(
construct<PauseStmt>("PAUSE" >> maybe(Parser<StopCode>{}))))
// These requirement productions are defined by the Fortran standard but never
// used directly by the grammar:
// R620 delimiter -> ( | ) | / | [ | ] | (/ | /)
// R1027 numeric-expr -> expr
// R1031 int-constant-expr -> int-expr
// R1221 dtv-type-spec -> TYPE ( derived-type-spec ) |
// CLASS ( derived-type-spec )
//
// These requirement productions are defined and used, but need not be
// defined independently here in this file:
// R771 lbracket -> [
// R772 rbracket -> ]
//
// Further note that:
// R607 int-constant -> constant
// is used only once via R844 scalar-int-constant
// R904 logical-variable -> variable
// is used only via scalar-logical-variable
// R906 default-char-variable -> variable
// is used only via scalar-default-char-variable
// R907 int-variable -> variable
// is used only via scalar-int-variable
// R915 complex-part-designator -> designator % RE | designator % IM
// %RE and %IM are initially recognized as structure components
// R916 type-param-inquiry -> designator % type-param-name
// is occulted by structure component designators
// R918 array-section ->
// data-ref [( substring-range )] | complex-part-designator
// is not used because parsing is not sensitive to rank
// R1030 default-char-constant-expr -> default-char-expr
// is only used via scalar-default-char-constant-expr
} // namespace Fortran::parser