1//===-- lib/Semantics/check-nullify.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 "check-nullify.h"
10#include "definable.h"
11#include "flang/Evaluate/expression.h"
12#include "flang/Parser/message.h"
13#include "flang/Parser/parse-tree.h"
14#include "flang/Semantics/expression.h"
15#include "flang/Semantics/tools.h"
16
17namespace Fortran::semantics {
18
19void NullifyChecker::Leave(const parser::NullifyStmt &nullifyStmt) {
20 CHECK(context_.location());
21 const Scope &scope{context_.FindScope(*context_.location())};
22 for (const parser::PointerObject &pointerObject : nullifyStmt.v) {
23 common::visit(
24 common::visitors{
25 [&](const parser::Name &name) {
26 if (name.symbol) {
27 if (auto whyNot{WhyNotDefinable(name.source, scope,
28 DefinabilityFlags{DefinabilityFlag::PointerDefinition},
29 *name.symbol)}) {
30 context_.messages()
31 .Say(name.source,
32 "'%s' may not appear in NULLIFY"_err_en_US,
33 name.source)
34 .Attach(std::move(
35 whyNot->set_severity(parser::Severity::Because)));
36 }
37 }
38 },
39 [&](const parser::StructureComponent &structureComponent) {
40 const auto &component{structureComponent.component};
41 SourceName at{component.source};
42 if (const auto *checkedExpr{GetExpr(context_, pointerObject)}) {
43 if (auto whyNot{WhyNotDefinable(at, scope,
44 DefinabilityFlags{DefinabilityFlag::PointerDefinition},
45 *checkedExpr)}) {
46 context_.messages()
47 .Say(at, "'%s' may not appear in NULLIFY"_err_en_US, at)
48 .Attach(std::move(
49 whyNot->set_severity(parser::Severity::Because)));
50 }
51 }
52 },
53 },
54 pointerObject.u);
55 }
56 // From 9.7.3.1(1)
57 // A pointer-object shall not depend on the value,
58 // bounds, or association status of another pointer-
59 // object in the same NULLIFY statement.
60 // This restriction is the programmer's responsibility.
61 // Some dependencies can be found compile time or at
62 // runtime, but for now we choose to skip such checks.
63}
64} // namespace Fortran::semantics
65

source code of flang/lib/Semantics/check-nullify.cpp