58 lines · c
1//===-- lib/Semantics/definable.h -------------------------------*- C++ -*-===//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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef FORTRAN_SEMANTICS_DEFINABLE_H_10#define FORTRAN_SEMANTICS_DEFINABLE_H_11 12// Utilities for checking the definability of variables and pointers in context,13// including checks for attempted definitions in PURE subprograms.14// Fortran 2018 C1101, C1158, C1594, &c.15 16#include "flang/Common/enum-set.h"17#include "flang/Common/idioms.h"18#include "flang/Evaluate/expression.h"19#include "flang/Parser/char-block.h"20#include "flang/Parser/message.h"21#include <optional>22 23namespace Fortran::semantics {24 25class Symbol;26class Scope;27 28ENUM_CLASS(DefinabilityFlag,29 VectorSubscriptIsOk, // a vector subscript may appear (i.e., assignment)30 DuplicatesAreOk, // vector subscript may have duplicates31 PointerDefinition, // a pointer is being defined, not its target32 AcceptAllocatable, // treat allocatable as if it were a pointer33 SourcedAllocation, // ALLOCATE(a,SOURCE=)34 PolymorphicOkInPure, // don't check for polymorphic type in pure subprogram35 DoNotNoteDefinition, // context does not imply definition36 AllowEventLockOrNotifyType, PotentialDeallocation)37 38using DefinabilityFlags =39 common::EnumSet<DefinabilityFlag, DefinabilityFlag_enumSize>;40 41// Tests a symbol or LHS variable or pointer for definability in a given scope.42// When the entity is not definable, returns a Message suitable for attachment43// to an error or warning message (as a "because: addendum) to explain why the44// entity cannot be defined.45// When the entity can be defined in that context, returns std::nullopt.46std::optional<parser::Message> WhyNotDefinable(47 parser::CharBlock, const Scope &, DefinabilityFlags, const Symbol &);48std::optional<parser::Message> WhyNotDefinable(parser::CharBlock, const Scope &,49 DefinabilityFlags, const evaluate::Expr<evaluate::SomeType> &);50 51// If a symbol would not be definable in a pure scope, or not be usable as the52// target of a pointer assignment in a pure scope, return a constant string53// describing why.54const char *WhyBaseObjectIsSuspicious(const Symbol &, const Scope &);55 56} // namespace Fortran::semantics57#endif // FORTRAN_SEMANTICS_DEFINABLE_H_58