llvm-project/flang/lib/Semantics/check-nullify.cpp
Peter Klausler d5285fef00
[flang] Downgrade error message to a portability warning (#98368)
f18 current emits an error when an assignment is made to an array
section with a vector subscript, and the array is finalized with a
non-elemental final subroutine. Some other compilers emit this error
because (I think) they want variables to only be finalized in place, not
by a subroutine call involving copy-in & copy-out of the finalized
elements.

Since many other Fortran compilers can handle this case, and there's
nothing in the standards to preclude it, let's downgrade this error
message to a portability warning.

This patch got complicated because the API for the WhyNotDefinable()
utility routine was such that it would return a message only in error
cases, and there was no provision for returning non-fatal messages. It
now returns either nothing, a fatal message, or a non-fatal warning
message, and all of its call sites have been modified to cope.
2024-07-11 13:12:00 -07:00

65 lines
2.6 KiB
C++

//===-- lib/Semantics/check-nullify.cpp -----------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "check-nullify.h"
#include "definable.h"
#include "flang/Evaluate/expression.h"
#include "flang/Parser/message.h"
#include "flang/Parser/parse-tree.h"
#include "flang/Semantics/expression.h"
#include "flang/Semantics/tools.h"
namespace Fortran::semantics {
void NullifyChecker::Leave(const parser::NullifyStmt &nullifyStmt) {
CHECK(context_.location());
const Scope &scope{context_.FindScope(*context_.location())};
for (const parser::PointerObject &pointerObject : nullifyStmt.v) {
common::visit(
common::visitors{
[&](const parser::Name &name) {
if (name.symbol) {
if (auto whyNot{WhyNotDefinable(name.source, scope,
DefinabilityFlags{DefinabilityFlag::PointerDefinition},
*name.symbol)}) {
context_.messages()
.Say(name.source,
"'%s' may not appear in NULLIFY"_err_en_US,
name.source)
.Attach(std::move(
whyNot->set_severity(parser::Severity::Because)));
}
}
},
[&](const parser::StructureComponent &structureComponent) {
const auto &component{structureComponent.component};
SourceName at{component.source};
if (const auto *checkedExpr{GetExpr(context_, pointerObject)}) {
if (auto whyNot{WhyNotDefinable(at, scope,
DefinabilityFlags{DefinabilityFlag::PointerDefinition},
*checkedExpr)}) {
context_.messages()
.Say(at, "'%s' may not appear in NULLIFY"_err_en_US, at)
.Attach(std::move(
whyNot->set_severity(parser::Severity::Because)));
}
}
},
},
pointerObject.u);
}
// From 9.7.3.1(1)
// A pointer-object shall not depend on the value,
// bounds, or association status of another pointer-
// object in the same NULLIFY statement.
// This restriction is the programmer's responsibility.
// Some dependencies can be found compile time or at
// runtime, but for now we choose to skip such checks.
}
} // namespace Fortran::semantics