| //===-- lib/Semantics/definable.h -------------------------------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef FORTRAN_SEMANTICS_DEFINABLE_H_ |
| #define FORTRAN_SEMANTICS_DEFINABLE_H_ |
| |
| // Utilities for checking the definability of variables and pointers in context, |
| // including checks for attempted definitions in PURE subprograms. |
| // Fortran 2018 C1101, C1158, C1594, &c. |
| |
| #include "flang/Common/enum-set.h" |
| #include "flang/Common/idioms.h" |
| #include "flang/Evaluate/expression.h" |
| #include "flang/Parser/char-block.h" |
| #include "flang/Parser/message.h" |
| #include <optional> |
| |
| namespace Fortran::semantics { |
| |
| class Symbol; |
| class Scope; |
| |
| ENUM_CLASS(DefinabilityFlag, |
| VectorSubscriptIsOk, // a vector subscript may appear (i.e., assignment) |
| DuplicatesAreOk, // vector subscript may have duplicates |
| PointerDefinition, // a pointer is being defined, not its target |
| AcceptAllocatable, // treat allocatable as if it were a pointer |
| PolymorphicOkInPure) // don't check for polymorphic type in pure subprogram |
| |
| using DefinabilityFlags = |
| common::EnumSet<DefinabilityFlag, DefinabilityFlag_enumSize>; |
| |
| // Tests a symbol or LHS variable or pointer for definability in a given scope. |
| // When the entity is not definable, returns a "because:" Message suitable for |
| // attachment to an error message to explain why the entity cannot be defined. |
| // When the entity can be defined in that context, returns std::nullopt. |
| std::optional<parser::Message> WhyNotDefinable( |
| parser::CharBlock, const Scope &, DefinabilityFlags, const Symbol &); |
| std::optional<parser::Message> WhyNotDefinable(parser::CharBlock, const Scope &, |
| DefinabilityFlags, const evaluate::Expr<evaluate::SomeType> &); |
| |
| // If a symbol would not be definable in a pure scope, or not be usable as the |
| // target of a pointer assignment in a pure scope, return a constant string |
| // describing why. |
| const char *WhyBaseObjectIsSuspicious(const Symbol &, const Scope &); |
| |
| } // namespace Fortran::semantics |
| #endif // FORTRAN_SEMANTICS_DEFINABLE_H_ |