flang/lib/Parser/parse-tree.cpp

   1 //===-- lib/Parser/parse-tree.cpp -----------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "flang/Parser/parse-tree.h"
  10 #include "flang/Common/idioms.h"
  11 #include "flang/Common/indirection.h"
  12 #include "flang/Parser/tools.h"
  13 #include "flang/Parser/user-state.h"
  14 #include "llvm/Support/raw_ostream.h"
  15 #include <algorithm>
  16
  17 namespace Fortran::parser {
  18
  19 // R867
  20 ImportStmt::ImportStmt(common::ImportKind &&k, std::list<Name> &&n)
  21     : kind{k}, names(std::move(n)) {
  22   CHECK(kind == common::ImportKind::Default ||
  23       kind == common::ImportKind::Only || names.empty());
  24 }
  25
  26 // R873
  27 CommonStmt::CommonStmt(std::optional<Name> &&name,
  28     std::list<CommonBlockObject> &&objects, std::list<Block> &&others) {
  29   blocks.emplace_front(std::move(name), std::move(objects));
  30   blocks.splice(blocks.end(), std::move(others));
  31 }
  32
  33 // R901 designator
  34 bool Designator::EndsInBareName() const {
  35   return std::visit(
  36       common::visitors{
  37           [](const DataRef &dr) {
  38             return std::holds_alternative<Name>(dr.u) ||
  39                 std::holds_alternative<common::Indirection<StructureComponent>>(
  40                     dr.u);
  41           },
  42           [](const Substring &) { return false; },
  43       },
  44       u);
  45 }
  46
  47 // R911 data-ref -> part-ref [% part-ref]...
  48 DataRef::DataRef(std::list<PartRef> &&prl) : u{std::move(prl.front().name)} {
  49   for (bool first{true}; !prl.empty(); first = false, prl.pop_front()) {
  50     PartRef &pr{prl.front()};
  51     if (!first) {
  52       u = common::Indirection<StructureComponent>::Make(
  53           std::move(*this), std::move(pr.name));
  54     }
  55     if (!pr.subscripts.empty()) {
  56       u = common::Indirection<ArrayElement>::Make(
  57           std::move(*this), std::move(pr.subscripts));
  58     }
  59     if (pr.imageSelector) {
  60       u = common::Indirection<CoindexedNamedObject>::Make(
  61           std::move(*this), std::move(*pr.imageSelector));
  62     }
  63   }
  64 }
  65
  66 // R1001 - R1022 expression
  67 Expr::Expr(Designator &&x)
  68     : u{common::Indirection<Designator>::Make(std::move(x))} {}
  69 Expr::Expr(FunctionReference &&x)
  70     : u{common::Indirection<FunctionReference>::Make(std::move(x))} {}
  71
  72 const std::optional<LoopControl> &DoConstruct::GetLoopControl() const {
  73   const NonLabelDoStmt &doStmt{
  74       std::get<Statement<NonLabelDoStmt>>(t).statement};
  75   const std::optional<LoopControl> &control{
  76       std::get<std::optional<LoopControl>>(doStmt.t)};
  77   return control;
  78 }
  79
  80 bool DoConstruct::IsDoNormal() const {
  81   const std::optional<LoopControl> &control{GetLoopControl()};
  82   return control && std::holds_alternative<LoopControl::Bounds>(control->u);
  83 }
  84
  85 bool DoConstruct::IsDoWhile() const {
  86   const std::optional<LoopControl> &control{GetLoopControl()};
  87   return control && std::holds_alternative<ScalarLogicalExpr>(control->u);
  88 }
  89
  90 bool DoConstruct::IsDoConcurrent() const {
  91   const std::optional<LoopControl> &control{GetLoopControl()};
  92   return control && std::holds_alternative<LoopControl::Concurrent>(control->u);
  93 }
  94
  95 static Designator MakeArrayElementRef(
  96     const Name &name, std::list<Expr> &&subscripts) {
  97   ArrayElement arrayElement{DataRef{Name{name}}, std::list<SectionSubscript>{}};
  98   for (Expr &expr : subscripts) {
  99     arrayElement.subscripts.push_back(
 100         SectionSubscript{Integer{common::Indirection{std::move(expr)}}});
 101   }
 102   return Designator{DataRef{common::Indirection{std::move(arrayElement)}}};
 103 }
 104
 105 static Designator MakeArrayElementRef(
 106     StructureComponent &&sc, std::list<Expr> &&subscripts) {
 107   ArrayElement arrayElement{DataRef{common::Indirection{std::move(sc)}},
 108       std::list<SectionSubscript>{}};
 109   for (Expr &expr : subscripts) {
 110     arrayElement.subscripts.push_back(
 111         SectionSubscript{Integer{common::Indirection{std::move(expr)}}});
 112   }
 113   return Designator{DataRef{common::Indirection{std::move(arrayElement)}}};
 114 }
 115
 116 // Set source in any type of node that has it.
 117 template <typename T> T WithSource(CharBlock source, T &&x) {
 118   x.source = source;
 119   return std::move(x);
 120 }
 121
 122 static Expr ActualArgToExpr(ActualArgSpec &arg) {
 123   return std::visit(
 124       common::visitors{
 125           [&](common::Indirection<Expr> &y) { return std::move(y.value()); },
 126           [&](common::Indirection<Variable> &y) {
 127             return std::visit(
 128                 common::visitors{
 129                     [&](common::Indirection<Designator> &z) {
 130                       return WithSource(
 131                           z.value().source, Expr{std::move(z.value())});
 132                     },
 133                     [&](common::Indirection<FunctionReference> &z) {
 134                       return WithSource(
 135                           z.value().v.source, Expr{std::move(z.value())});
 136                     },
 137                 },
 138                 y.value().u);
 139           },
 140           [&](auto &) -> Expr { common::die("unexpected type"); },
 141       },
 142       std::get<ActualArg>(arg.t).u);
 143 }
 144
 145 Designator FunctionReference::ConvertToArrayElementRef() {
 146   std::list<Expr> args;
 147   for (auto &arg : std::get<std::list<ActualArgSpec>>(v.t)) {
 148     args.emplace_back(ActualArgToExpr(arg));
 149   }
 150   return std::visit(
 151       common::visitors{
 152           [&](const Name &name) {
 153             return WithSource(
 154                 v.source, MakeArrayElementRef(name, std::move(args)));
 155           },
 156           [&](ProcComponentRef &pcr) {
 157             return WithSource(v.source,
 158                 MakeArrayElementRef(std::move(pcr.v.thing), std::move(args)));
 159           },
 160       },
 161       std::get<ProcedureDesignator>(v.t).u);
 162 }
 163
 164 StructureConstructor FunctionReference::ConvertToStructureConstructor(
 165     const semantics::DerivedTypeSpec &derived) {
 166   Name name{std::get<parser::Name>(std::get<ProcedureDesignator>(v.t).u)};
 167   std::list<ComponentSpec> components;
 168   for (auto &arg : std::get<std::list<ActualArgSpec>>(v.t)) {
 169     std::optional<Keyword> keyword;
 170     if (auto &kw{std::get<std::optional<Keyword>>(arg.t)}) {
 171       keyword.emplace(Keyword{Name{kw->v}});
 172     }
 173     components.emplace_back(
 174         std::move(keyword), ComponentDataSource{ActualArgToExpr(arg)});
 175   }
 176   DerivedTypeSpec spec{std::move(name), std::list<TypeParamSpec>{}};
 177   spec.derivedTypeSpec = &derived;
 178   return StructureConstructor{std::move(spec), std::move(components)};
 179 }
 180
 181 StructureConstructor ArrayElement::ConvertToStructureConstructor(
 182     const semantics::DerivedTypeSpec &derived) {
 183   Name name{std::get<parser::Name>(base.u)};
 184   std::list<ComponentSpec> components;
 185   for (auto &subscript : subscripts) {
 186     components.emplace_back(std::optional<Keyword>{},
 187         ComponentDataSource{std::move(*Unwrap<Expr>(subscript))});
 188   }
 189   DerivedTypeSpec spec{std::move(name), std::list<TypeParamSpec>{}};
 190   spec.derivedTypeSpec = &derived;
 191   return StructureConstructor{std::move(spec), std::move(components)};
 192 }
 193
 194 Substring ArrayElement::ConvertToSubstring() {
 195   auto iter{subscripts.begin()};
 196   CHECK(iter != subscripts.end());
 197   auto &triplet{std::get<SubscriptTriplet>(iter->u)};
 198   CHECK(!std::get<2>(triplet.t));
 199   CHECK(++iter == subscripts.end());
 200   return Substring{std::move(base),
 201       SubstringRange{std::get<0>(std::move(triplet.t)),
 202           std::get<1>(std::move(triplet.t))}};
 203 }
 204
 205 // R1544 stmt-function-stmt
 206 // Convert this stmt-function-stmt to an array element assignment statement.
 207 Statement<ActionStmt> StmtFunctionStmt::ConvertToAssignment() {
 208   auto &funcName{std::get<Name>(t)};
 209   auto &funcArgs{std::get<std::list<Name>>(t)};
 210   auto &funcExpr{std::get<Scalar<Expr>>(t).thing};
 211   CharBlock source{funcName.source};
 212   std::list<Expr> subscripts;
 213   for (Name &arg : funcArgs) {
 214     subscripts.push_back(WithSource(arg.source,
 215         Expr{common::Indirection{
 216             WithSource(arg.source, Designator{DataRef{Name{arg}}})}}));
 217     source.ExtendToCover(arg.source);
 218   }
 219   // extend source to include closing paren
 220   if (funcArgs.empty()) {
 221     CHECK(*source.end() == '(');
 222     source = CharBlock{source.begin(), source.end() + 1};
 223   }
 224   CHECK(*source.end() == ')');
 225   source = CharBlock{source.begin(), source.end() + 1};
 226   auto variable{Variable{common::Indirection{WithSource(
 227       source, MakeArrayElementRef(funcName, std::move(subscripts)))}}};
 228   return Statement{std::nullopt,
 229       ActionStmt{common::Indirection{
 230           AssignmentStmt{std::move(variable), std::move(funcExpr)}}}};
 231 }
 232
 233 CharBlock Variable::GetSource() const {
 234   return std::visit(
 235       common::visitors{
 236           [&](const common::Indirection<Designator> &des) {
 237             return des.value().source;
 238           },
 239           [&](const common::Indirection<parser::FunctionReference> &call) {
 240             return call.value().v.source;
 241           },
 242       },
 243       u);
 244 }
 245
 246 llvm::raw_ostream &operator<<(llvm::raw_ostream &os, const Name &x) {
 247   return os << x.ToString();
 248 }
 249 } // namespace Fortran::parser