Files
clang-p2996/flang/lib/Semantics/check-stop.cpp
Peter Klausler 7e225423d3 [flang] Finer control over error recovery with GetExpr()
Prior to this patch, the semantics utility GetExpr() will crash
unconditionally if it encounters a typed expression in the parse
tree that has not been set by expression semantics.  This is the
right behavior when called from lowering, by which time it is known
that the program had no fatal user errors, since it signifies a
fatal internal error.  However, prior to lowering, in the statement
semantics checking code, a more nuanced test should be used before
crashing -- specifically, we should not crash in the face of a
missing typed expression when in error recovery mode.

Getting this right requires GetExpr() and its helper class to have
access to the semantics context, so that it can check AnyFatalErrors()
before crashing.  So this patch touches nearly all of its call sites.

Differential Revision: https://reviews.llvm.org/D123873
2022-04-15 14:25:41 -07:00

43 lines
1.6 KiB
C++

//===-- lib/Semantics/check-stop.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-stop.h"
#include "flang/Common/Fortran.h"
#include "flang/Evaluate/expression.h"
#include "flang/Parser/parse-tree.h"
#include "flang/Semantics/semantics.h"
#include "flang/Semantics/tools.h"
#include <optional>
namespace Fortran::semantics {
void StopChecker::Enter(const parser::StopStmt &stmt) {
const auto &stopCode{std::get<std::optional<parser::StopCode>>(stmt.t)};
if (const auto *expr{GetExpr(context_, stopCode)}) {
const parser::CharBlock &source{parser::FindSourceLocation(stopCode)};
if (ExprHasTypeCategory(*expr, common::TypeCategory::Integer)) {
// C1171 default kind
if (!ExprTypeKindIsDefault(*expr, context_)) {
context_.Say(
source, "INTEGER stop code must be of default kind"_err_en_US);
}
} else if (ExprHasTypeCategory(*expr, common::TypeCategory::Character)) {
// R1162 spells scalar-DEFAULT-char-expr
if (!ExprTypeKindIsDefault(*expr, context_)) {
context_.Say(
source, "CHARACTER stop code must be of default kind"_err_en_US);
}
} else {
context_.Say(
source, "Stop code must be of INTEGER or CHARACTER type"_err_en_US);
}
}
}
} // namespace Fortran::semantics