llvm-project/flang/lib/Semantics/check-nullify.cpp

68 lines
2.9 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 "assignment.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())};
const Scope *pure{FindPureProcedureContaining(scope)};
parser::ContextualMessages messages{
*context_.location(), &context_.messages()};
for (const parser::PointerObject &pointerObject : nullifyStmt.v) {
std::visit(
common::visitors{
[&](const parser::Name &name) {
const Symbol &symbol{DEREF(name.symbol)};
if (context_.HasError(&symbol)) {
// already reported an error
} else if (!IsVariableName(symbol) && !IsProcName(symbol)) {
messages.Say(name.source,
"name in NULLIFY statement must be a variable or procedure pointer name"_err_en_US);
} else if (!IsPointer(symbol)) { // C951
messages.Say(name.source,
"name in NULLIFY statement must have the POINTER attribute"_err_en_US);
} else if (pure) {
CheckDefinabilityInPureScope(messages, symbol, scope, *pure);
}
},
[&](const parser::StructureComponent &structureComponent) {
evaluate::ExpressionAnalyzer analyzer{context_};
if (MaybeExpr checked{analyzer.Analyze(structureComponent)}) {
if (!IsPointer(*structureComponent.component.symbol)) { // C951
messages.Say(structureComponent.component.source,
"component in NULLIFY statement must have the POINTER attribute"_err_en_US);
} else if (pure) {
if (const Symbol * symbol{GetFirstSymbol(checked)}) {
CheckDefinabilityInPureScope(
messages, *symbol, scope, *pure);
}
}
}
},
},
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 responsibilty.
// Some dependencies can be found compile time or at
// runtime, but for now we choose to skip such checks.
}
} // namespace Fortran::semantics