flang/lib/Parser/expr-parsers.cpp

   1 //===-- lib/Parser/expr-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 expressions.
  10
  11 #include "expr-parsers.h"
  12 #include "basic-parsers.h"
  13 #include "debug-parser.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 // R764 boz-literal-constant -> binary-constant | octal-constant | hex-constant
  24 // R765 binary-constant -> B ' digit [digit]... ' | B " digit [digit]... "
  25 // R766 octal-constant -> O ' digit [digit]... ' | O " digit [digit]... "
  26 // R767 hex-constant ->
  27 //        Z ' hex-digit [hex-digit]... ' | Z " hex-digit [hex-digit]... "
  28 // extension: X accepted for Z
  29 // extension: BOZX suffix accepted
  30 TYPE_PARSER(construct<BOZLiteralConstant>(BOZLiteral{}))
  31
  32 // R769 array-constructor -> (/ ac-spec /) | lbracket ac-spec rbracket
  33 TYPE_CONTEXT_PARSER("array constructor"_en_US,
  34     construct<ArrayConstructor>(
  35         "(/" >> Parser<AcSpec>{} / "/)" || bracketed(Parser<AcSpec>{})))
  36
  37 // R770 ac-spec -> type-spec :: | [type-spec ::] ac-value-list
  38 TYPE_PARSER(construct<AcSpec>(maybe(typeSpec / "::"),
  39                 nonemptyList("expected array constructor values"_err_en_US,
  40                     Parser<AcValue>{})) ||
  41     construct<AcSpec>(typeSpec / "::"))
  42
  43 // R773 ac-value -> expr | ac-implied-do
  44 TYPE_PARSER(
  45     // PGI/Intel extension: accept triplets in array constructors
  46     extension<LanguageFeature::TripletInArrayConstructor>(
  47         construct<AcValue>(construct<AcValue::Triplet>(scalarIntExpr,
  48             ":" >> scalarIntExpr, maybe(":" >> scalarIntExpr)))) ||
  49     construct<AcValue>(indirect(expr)) ||
  50     construct<AcValue>(indirect(Parser<AcImpliedDo>{})))
  51
  52 // R774 ac-implied-do -> ( ac-value-list , ac-implied-do-control )
  53 TYPE_PARSER(parenthesized(
  54     construct<AcImpliedDo>(nonemptyList(Parser<AcValue>{} / lookAhead(","_tok)),
  55         "," >> Parser<AcImpliedDoControl>{})))
  56
  57 // R775 ac-implied-do-control ->
  58 //        [integer-type-spec ::] ac-do-variable = scalar-int-expr ,
  59 //        scalar-int-expr [, scalar-int-expr]
  60 // R776 ac-do-variable -> do-variable
  61 TYPE_PARSER(construct<AcImpliedDoControl>(
  62     maybe(integerTypeSpec / "::"), loopBounds(scalarIntExpr)))
  63
  64 // R1001 primary ->
  65 //         literal-constant | designator | array-constructor |
  66 //         structure-constructor | function-reference | type-param-inquiry |
  67 //         type-param-name | ( expr )
  68 // N.B. type-param-inquiry is parsed as a structure component
  69 constexpr auto primary{instrumented("primary"_en_US,
  70     first(construct<Expr>(indirect(Parser<CharLiteralConstantSubstring>{})),
  71         construct<Expr>(literalConstant),
  72         construct<Expr>(construct<Expr::Parentheses>(parenthesized(expr))),
  73         construct<Expr>(indirect(functionReference) / !"("_tok),
  74         construct<Expr>(designator / !"("_tok),
  75         construct<Expr>(Parser<StructureConstructor>{}),
  76         construct<Expr>(Parser<ArrayConstructor>{}),
  77         // PGI/XLF extension: COMPLEX constructor (x,y)
  78         extension<LanguageFeature::ComplexConstructor>(
  79             construct<Expr>(parenthesized(
  80                 construct<Expr::ComplexConstructor>(expr, "," >> expr)))),
  81         extension<LanguageFeature::PercentLOC>(construct<Expr>("%LOC" >>
  82             parenthesized(construct<Expr::PercentLoc>(indirect(variable)))))))};
  83
  84 // R1002 level-1-expr -> [defined-unary-op] primary
  85 // TODO: Reasonable extension: permit multiple defined-unary-ops
  86 constexpr auto level1Expr{sourced(
  87     first(primary, // must come before define op to resolve .TRUE._8 ambiguity
  88         construct<Expr>(construct<Expr::DefinedUnary>(definedOpName, primary)),
  89         extension<LanguageFeature::SignedPrimary>(
  90             construct<Expr>(construct<Expr::UnaryPlus>("+" >> primary))),
  91         extension<LanguageFeature::SignedPrimary>(
  92             construct<Expr>(construct<Expr::Negate>("-" >> primary)))))};
  93
  94 // R1004 mult-operand -> level-1-expr [power-op mult-operand]
  95 // R1007 power-op -> **
  96 // Exponentiation (**) is Fortran's only right-associative binary operation.
  97 struct MultOperand {
  98   using resultType = Expr;
  99   constexpr MultOperand() {}
 100   static inline std::optional<Expr> Parse(ParseState &);
 101 };
 102
 103 static constexpr auto multOperand{sourced(MultOperand{})};
 104
 105 inline std::optional<Expr> MultOperand::Parse(ParseState &state) {
 106   std::optional<Expr> result{level1Expr.Parse(state)};
 107   if (result) {
 108     static constexpr auto op{attempt("**"_tok)};
 109     if (op.Parse(state)) {
 110       std::function<Expr(Expr &&)> power{[&result](Expr &&right) {
 111         return Expr{Expr::Power(std::move(result).value(), std::move(right))};
 112       }};
 113       return applyLambda(power, multOperand).Parse(state); // right-recursive
 114     }
 115   }
 116   return result;
 117 }
 118
 119 // R1005 add-operand -> [add-operand mult-op] mult-operand
 120 // R1008 mult-op -> * | /
 121 // The left recursion in the grammar is implemented iteratively.
 122 struct AddOperand {
 123   using resultType = Expr;
 124   constexpr AddOperand() {}
 125   static inline std::optional<Expr> Parse(ParseState &state) {
 126     std::optional<Expr> result{multOperand.Parse(state)};
 127     if (result) {
 128       auto source{result->source};
 129       std::function<Expr(Expr &&)> multiply{[&result](Expr &&right) {
 130         return Expr{
 131             Expr::Multiply(std::move(result).value(), std::move(right))};
 132       }};
 133       std::function<Expr(Expr &&)> divide{[&result](Expr &&right) {
 134         return Expr{Expr::Divide(std::move(result).value(), std::move(right))};
 135       }};
 136       auto more{attempt(sourced("*" >> applyLambda(multiply, multOperand) ||
 137           "/" >> applyLambda(divide, multOperand)))};
 138       while (std::optional<Expr> next{more.Parse(state)}) {
 139         result = std::move(next);
 140         result->source.ExtendToCover(source);
 141       }
 142     }
 143     return result;
 144   }
 145 };
 146 constexpr AddOperand addOperand;
 147
 148 // R1006 level-2-expr -> [[level-2-expr] add-op] add-operand
 149 // R1009 add-op -> + | -
 150 // These are left-recursive productions, implemented iteratively.
 151 // Note that standard Fortran admits a unary + or - to appear only here,
 152 // by means of a missing first operand; e.g., 2*-3 is valid in C but not
 153 // standard Fortran.  We accept unary + and - to appear before any primary
 154 // as an extension.
 155 struct Level2Expr {
 156   using resultType = Expr;
 157   constexpr Level2Expr() {}
 158   static inline std::optional<Expr> Parse(ParseState &state) {
 159     static constexpr auto unary{
 160         sourced(
 161             construct<Expr>(construct<Expr::UnaryPlus>("+" >> addOperand)) ||
 162             construct<Expr>(construct<Expr::Negate>("-" >> addOperand))) ||
 163         addOperand};
 164     std::optional<Expr> result{unary.Parse(state)};
 165     if (result) {
 166       auto source{result->source};
 167       std::function<Expr(Expr &&)> add{[&result](Expr &&right) {
 168         return Expr{Expr::Add(std::move(result).value(), std::move(right))};
 169       }};
 170       std::function<Expr(Expr &&)> subtract{[&result](Expr &&right) {
 171         return Expr{
 172             Expr::Subtract(std::move(result).value(), std::move(right))};
 173       }};
 174       auto more{attempt(sourced("+" >> applyLambda(add, addOperand) ||
 175           "-" >> applyLambda(subtract, addOperand)))};
 176       while (std::optional<Expr> next{more.Parse(state)}) {
 177         result = std::move(next);
 178         result->source.ExtendToCover(source);
 179       }
 180     }
 181     return result;
 182   }
 183 };
 184 constexpr Level2Expr level2Expr;
 185
 186 // R1010 level-3-expr -> [level-3-expr concat-op] level-2-expr
 187 // R1011 concat-op -> //
 188 // Concatenation (//) is left-associative for parsing performance, although
 189 // one would never notice if it were right-associated.
 190 struct Level3Expr {
 191   using resultType = Expr;
 192   constexpr Level3Expr() {}
 193   static inline std::optional<Expr> Parse(ParseState &state) {
 194     std::optional<Expr> result{level2Expr.Parse(state)};
 195     if (result) {
 196       auto source{result->source};
 197       std::function<Expr(Expr &&)> concat{[&result](Expr &&right) {
 198         return Expr{Expr::Concat(std::move(result).value(), std::move(right))};
 199       }};
 200       auto more{attempt(sourced("//" >> applyLambda(concat, level2Expr)))};
 201       while (std::optional<Expr> next{more.Parse(state)}) {
 202         result = std::move(next);
 203         result->source.ExtendToCover(source);
 204       }
 205     }
 206     return result;
 207   }
 208 };
 209 constexpr Level3Expr level3Expr;
 210
 211 // R1012 level-4-expr -> [level-3-expr rel-op] level-3-expr
 212 // R1013 rel-op ->
 213 //         .EQ. | .NE. | .LT. | .LE. | .GT. | .GE. |
 214 //          == | /= | < | <= | > | >=  @ | <>
 215 // N.B. relations are not recursive (i.e., LOGICAL is not ordered)
 216 struct Level4Expr {
 217   using resultType = Expr;
 218   constexpr Level4Expr() {}
 219   static inline std::optional<Expr> Parse(ParseState &state) {
 220     std::optional<Expr> result{level3Expr.Parse(state)};
 221     if (result) {
 222       auto source{result->source};
 223       std::function<Expr(Expr &&)> lt{[&result](Expr &&right) {
 224         return Expr{Expr::LT(std::move(result).value(), std::move(right))};
 225       }};
 226       std::function<Expr(Expr &&)> le{[&result](Expr &&right) {
 227         return Expr{Expr::LE(std::move(result).value(), std::move(right))};
 228       }};
 229       std::function<Expr(Expr &&)> eq{[&result](Expr &&right) {
 230         return Expr{Expr::EQ(std::move(result).value(), std::move(right))};
 231       }};
 232       std::function<Expr(Expr &&)> ne{[&result](Expr &&right) {
 233         return Expr{Expr::NE(std::move(result).value(), std::move(right))};
 234       }};
 235       std::function<Expr(Expr &&)> ge{[&result](Expr &&right) {
 236         return Expr{Expr::GE(std::move(result).value(), std::move(right))};
 237       }};
 238       std::function<Expr(Expr &&)> gt{[&result](Expr &&right) {
 239         return Expr{Expr::GT(std::move(result).value(), std::move(right))};
 240       }};
 241       auto more{attempt(
 242           sourced((".LT."_tok || "<"_tok) >> applyLambda(lt, level3Expr) ||
 243               (".LE."_tok || "<="_tok) >> applyLambda(le, level3Expr) ||
 244               (".EQ."_tok || "=="_tok) >> applyLambda(eq, level3Expr) ||
 245               (".NE."_tok || "/="_tok ||
 246                   extension<LanguageFeature::AlternativeNE>(
 247                       "<>"_tok /* PGI/Cray extension; Cray also has .LG. */)) >>
 248                   applyLambda(ne, level3Expr) ||
 249               (".GE."_tok || ">="_tok) >> applyLambda(ge, level3Expr) ||
 250               (".GT."_tok || ">"_tok) >> applyLambda(gt, level3Expr)))};
 251       if (std::optional<Expr> next{more.Parse(state)}) {
 252         next->source.ExtendToCover(source);
 253         return next;
 254       }
 255     }
 256     return result;
 257   }
 258 };
 259 constexpr Level4Expr level4Expr;
 260
 261 // R1014 and-operand -> [not-op] level-4-expr
 262 // R1018 not-op -> .NOT.
 263 // N.B. Fortran's .NOT. binds less tightly than its comparison operators do.
 264 // PGI/Intel extension: accept multiple .NOT. operators
 265 struct AndOperand {
 266   using resultType = Expr;
 267   constexpr AndOperand() {}
 268   static inline std::optional<Expr> Parse(ParseState &);
 269 };
 270 constexpr AndOperand andOperand;
 271
 272 // Match a logical operator or, optionally, its abbreviation.
 273 inline constexpr auto logicalOp(const char *op, const char *abbrev) {
 274   return TokenStringMatch{op} ||
 275       extension<LanguageFeature::LogicalAbbreviations>(
 276           TokenStringMatch{abbrev});
 277 }
 278
 279 inline std::optional<Expr> AndOperand::Parse(ParseState &state) {
 280   static constexpr auto notOp{attempt(logicalOp(".NOT.", ".N.") >> andOperand)};
 281   if (std::optional<Expr> negation{notOp.Parse(state)}) {
 282     return Expr{Expr::NOT{std::move(*negation)}};
 283   } else {
 284     return level4Expr.Parse(state);
 285   }
 286 }
 287
 288 // R1015 or-operand -> [or-operand and-op] and-operand
 289 // R1019 and-op -> .AND.
 290 // .AND. is left-associative
 291 struct OrOperand {
 292   using resultType = Expr;
 293   constexpr OrOperand() {}
 294   static inline std::optional<Expr> Parse(ParseState &state) {
 295     static constexpr auto operand{sourced(andOperand)};
 296     std::optional<Expr> result{operand.Parse(state)};
 297     if (result) {
 298       auto source{result->source};
 299       std::function<Expr(Expr &&)> logicalAnd{[&result](Expr &&right) {
 300         return Expr{Expr::AND(std::move(result).value(), std::move(right))};
 301       }};
 302       auto more{attempt(sourced(
 303           logicalOp(".AND.", ".A.") >> applyLambda(logicalAnd, andOperand)))};
 304       while (std::optional<Expr> next{more.Parse(state)}) {
 305         result = std::move(next);
 306         result->source.ExtendToCover(source);
 307       }
 308     }
 309     return result;
 310   }
 311 };
 312 constexpr OrOperand orOperand;
 313
 314 // R1016 equiv-operand -> [equiv-operand or-op] or-operand
 315 // R1020 or-op -> .OR.
 316 // .OR. is left-associative
 317 struct EquivOperand {
 318   using resultType = Expr;
 319   constexpr EquivOperand() {}
 320   static inline std::optional<Expr> Parse(ParseState &state) {
 321     std::optional<Expr> result{orOperand.Parse(state)};
 322     if (result) {
 323       auto source{result->source};
 324       std::function<Expr(Expr &&)> logicalOr{[&result](Expr &&right) {
 325         return Expr{Expr::OR(std::move(result).value(), std::move(right))};
 326       }};
 327       auto more{attempt(sourced(
 328           logicalOp(".OR.", ".O.") >> applyLambda(logicalOr, orOperand)))};
 329       while (std::optional<Expr> next{more.Parse(state)}) {
 330         result = std::move(next);
 331         result->source.ExtendToCover(source);
 332       }
 333     }
 334     return result;
 335   }
 336 };
 337 constexpr EquivOperand equivOperand;
 338
 339 // R1017 level-5-expr -> [level-5-expr equiv-op] equiv-operand
 340 // R1021 equiv-op -> .EQV. | .NEQV.
 341 // Logical equivalence is left-associative.
 342 // Extension: .XOR. as synonym for .NEQV.
 343 struct Level5Expr {
 344   using resultType = Expr;
 345   constexpr Level5Expr() {}
 346   static inline std::optional<Expr> Parse(ParseState &state) {
 347     std::optional<Expr> result{equivOperand.Parse(state)};
 348     if (result) {
 349       auto source{result->source};
 350       std::function<Expr(Expr &&)> eqv{[&result](Expr &&right) {
 351         return Expr{Expr::EQV(std::move(result).value(), std::move(right))};
 352       }};
 353       std::function<Expr(Expr &&)> neqv{[&result](Expr &&right) {
 354         return Expr{Expr::NEQV(std::move(result).value(), std::move(right))};
 355       }};
 356       auto more{attempt(sourced(".EQV." >> applyLambda(eqv, equivOperand) ||
 357           (".NEQV."_tok ||
 358               extension<LanguageFeature::XOROperator>(
 359                   logicalOp(".XOR.", ".X."))) >>
 360               applyLambda(neqv, equivOperand)))};
 361       while (std::optional<Expr> next{more.Parse(state)}) {
 362         result = std::move(next);
 363         result->source.ExtendToCover(source);
 364       }
 365     }
 366     return result;
 367   }
 368 };
 369 constexpr Level5Expr level5Expr;
 370
 371 // R1022 expr -> [expr defined-binary-op] level-5-expr
 372 // Defined binary operators associate leftwards.
 373 template <> std::optional<Expr> Parser<Expr>::Parse(ParseState &state) {
 374   std::optional<Expr> result{level5Expr.Parse(state)};
 375   if (result) {
 376     auto source{result->source};
 377     std::function<Expr(DefinedOpName &&, Expr &&)> defBinOp{
 378         [&result](DefinedOpName &&op, Expr &&right) {
 379           return Expr{Expr::DefinedBinary(
 380               std::move(op), std::move(result).value(), std::move(right))};
 381         }};
 382     auto more{attempt(
 383         sourced(applyLambda<Expr>(defBinOp, definedOpName, level5Expr)))};
 384     while (std::optional<Expr> next{more.Parse(state)}) {
 385       result = std::move(next);
 386       result->source.ExtendToCover(source);
 387     }
 388   }
 389   return result;
 390 }
 391
 392 // R1003 defined-unary-op -> . letter [letter]... .
 393 // R1023 defined-binary-op -> . letter [letter]... .
 394 // R1414 local-defined-operator -> defined-unary-op | defined-binary-op
 395 // R1415 use-defined-operator -> defined-unary-op | defined-binary-op
 396 // C1003 A defined operator must be distinct from logical literal constants
 397 // and intrinsic operator names; this is handled by attempting their parses
 398 // first, and by name resolution on their definitions, for best errors.
 399 // N.B. The name of the operator is captured with the dots around it.
 400 constexpr auto definedOpNameChar{
 401     letter || extension<LanguageFeature::PunctuationInNames>("$@"_ch)};
 402 TYPE_PARSER(
 403     space >> construct<DefinedOpName>(sourced("."_ch >>
 404                  some(definedOpNameChar) >> construct<Name>() / "."_ch)))
 405
 406 // R1028 specification-expr -> scalar-int-expr
 407 TYPE_PARSER(construct<SpecificationExpr>(scalarIntExpr))
 408
 409 // R1032 assignment-stmt -> variable = expr
 410 TYPE_CONTEXT_PARSER("assignment statement"_en_US,
 411     construct<AssignmentStmt>(variable / "=", expr))
 412
 413 // R1033 pointer-assignment-stmt ->
 414 //         data-pointer-object [( bounds-spec-list )] => data-target |
 415 //         data-pointer-object ( bounds-remapping-list ) => data-target |
 416 //         proc-pointer-object => proc-target
 417 // R1034 data-pointer-object ->
 418 //         variable-name | scalar-variable % data-pointer-component-name
 419 //   C1022 a scalar-variable shall be a data-ref
 420 //   C1024 a data-pointer-object shall not be a coindexed object
 421 // R1038 proc-pointer-object -> proc-pointer-name | proc-component-ref
 422 //
 423 // A distinction can't be made at the time of the initial parse between
 424 // data-pointer-object and proc-pointer-object, or between data-target
 425 // and proc-target.
 426 TYPE_CONTEXT_PARSER("pointer assignment statement"_en_US,
 427     construct<PointerAssignmentStmt>(dataRef,
 428         parenthesized(nonemptyList(Parser<BoundsRemapping>{})), "=>" >> expr) ||
 429         construct<PointerAssignmentStmt>(dataRef,
 430             defaulted(parenthesized(nonemptyList(Parser<BoundsSpec>{}))),
 431             "=>" >> expr))
 432
 433 // R1035 bounds-spec -> lower-bound-expr :
 434 TYPE_PARSER(construct<BoundsSpec>(boundExpr / ":"))
 435
 436 // R1036 bounds-remapping -> lower-bound-expr : upper-bound-expr
 437 TYPE_PARSER(construct<BoundsRemapping>(boundExpr / ":", boundExpr))
 438
 439 // R1039 proc-component-ref -> scalar-variable % procedure-component-name
 440 //   C1027 the scalar-variable must be a data-ref without coindices.
 441 TYPE_PARSER(construct<ProcComponentRef>(structureComponent))
 442
 443 // R1041 where-stmt -> WHERE ( mask-expr ) where-assignment-stmt
 444 // R1045 where-assignment-stmt -> assignment-stmt
 445 // R1046 mask-expr -> logical-expr
 446 TYPE_CONTEXT_PARSER("WHERE statement"_en_US,
 447     construct<WhereStmt>("WHERE" >> parenthesized(logicalExpr), assignmentStmt))
 448
 449 // R1042 where-construct ->
 450 //         where-construct-stmt [where-body-construct]...
 451 //         [masked-elsewhere-stmt [where-body-construct]...]...
 452 //         [elsewhere-stmt [where-body-construct]...] end-where-stmt
 453 TYPE_CONTEXT_PARSER("WHERE construct"_en_US,
 454     construct<WhereConstruct>(statement(Parser<WhereConstructStmt>{}),
 455         many(whereBodyConstruct),
 456         many(construct<WhereConstruct::MaskedElsewhere>(
 457             statement(Parser<MaskedElsewhereStmt>{}),
 458             many(whereBodyConstruct))),
 459         maybe(construct<WhereConstruct::Elsewhere>(
 460             statement(Parser<ElsewhereStmt>{}), many(whereBodyConstruct))),
 461         statement(Parser<EndWhereStmt>{})))
 462
 463 // R1043 where-construct-stmt -> [where-construct-name :] WHERE ( mask-expr )
 464 TYPE_CONTEXT_PARSER("WHERE construct statement"_en_US,
 465     construct<WhereConstructStmt>(
 466         maybe(name / ":"), "WHERE" >> parenthesized(logicalExpr)))
 467
 468 // R1044 where-body-construct ->
 469 //         where-assignment-stmt | where-stmt | where-construct
 470 TYPE_PARSER(construct<WhereBodyConstruct>(statement(assignmentStmt)) ||
 471     construct<WhereBodyConstruct>(statement(whereStmt)) ||
 472     construct<WhereBodyConstruct>(indirect(whereConstruct)))
 473
 474 // R1047 masked-elsewhere-stmt ->
 475 //         ELSEWHERE ( mask-expr ) [where-construct-name]
 476 TYPE_CONTEXT_PARSER("masked ELSEWHERE statement"_en_US,
 477     construct<MaskedElsewhereStmt>(
 478         "ELSE WHERE" >> parenthesized(logicalExpr), maybe(name)))
 479
 480 // R1048 elsewhere-stmt -> ELSEWHERE [where-construct-name]
 481 TYPE_CONTEXT_PARSER("ELSEWHERE statement"_en_US,
 482     construct<ElsewhereStmt>("ELSE WHERE" >> maybe(name)))
 483
 484 // R1049 end-where-stmt -> ENDWHERE [where-construct-name]
 485 TYPE_CONTEXT_PARSER("END WHERE statement"_en_US,
 486     construct<EndWhereStmt>(
 487         recovery("END WHERE" >> maybe(name), endStmtErrorRecovery)))
 488
 489 // R1050 forall-construct ->
 490 //         forall-construct-stmt [forall-body-construct]... end-forall-stmt
 491 TYPE_CONTEXT_PARSER("FORALL construct"_en_US,
 492     construct<ForallConstruct>(statement(Parser<ForallConstructStmt>{}),
 493         many(Parser<ForallBodyConstruct>{}),
 494         statement(Parser<EndForallStmt>{})))
 495
 496 // R1051 forall-construct-stmt ->
 497 //         [forall-construct-name :] FORALL concurrent-header
 498 TYPE_CONTEXT_PARSER("FORALL construct statement"_en_US,
 499     construct<ForallConstructStmt>(
 500         maybe(name / ":"), "FORALL" >> indirect(concurrentHeader)))
 501
 502 // R1052 forall-body-construct ->
 503 //         forall-assignment-stmt | where-stmt | where-construct |
 504 //         forall-construct | forall-stmt
 505 TYPE_PARSER(construct<ForallBodyConstruct>(statement(forallAssignmentStmt)) ||
 506     construct<ForallBodyConstruct>(statement(whereStmt)) ||
 507     construct<ForallBodyConstruct>(whereConstruct) ||
 508     construct<ForallBodyConstruct>(indirect(forallConstruct)) ||
 509     construct<ForallBodyConstruct>(statement(forallStmt)))
 510
 511 // R1053 forall-assignment-stmt -> assignment-stmt | pointer-assignment-stmt
 512 TYPE_PARSER(construct<ForallAssignmentStmt>(assignmentStmt) ||
 513     construct<ForallAssignmentStmt>(pointerAssignmentStmt))
 514
 515 // R1054 end-forall-stmt -> END FORALL [forall-construct-name]
 516 TYPE_CONTEXT_PARSER("END FORALL statement"_en_US,
 517     construct<EndForallStmt>(
 518         recovery("END FORALL" >> maybe(name), endStmtErrorRecovery)))
 519
 520 // R1055 forall-stmt -> FORALL concurrent-header forall-assignment-stmt
 521 TYPE_CONTEXT_PARSER("FORALL statement"_en_US,
 522     construct<ForallStmt>("FORALL" >> indirect(concurrentHeader),
 523         unlabeledStatement(forallAssignmentStmt)))
 524 } // namespace Fortran::parser