llvm-project/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsPointerArithmeticCheck.cpp
Matheus Izvekov c9e46219f3
[clang] retain type sugar in auto / template argument deduction
This implements the following changes:
* AutoType retains sugared deduced-as-type.
* Template argument deduction machinery analyses the sugared type all the way
down. It would previously lose the sugar on first recursion.
* Undeduced AutoType will be properly canonicalized, including the constraint
template arguments.
* Remove the decltype node created from the decltype(auto) deduction.

As a result, we start seeing sugared types in a lot more test cases,
including some which showed very unfriendly `type-parameter-*-*` types.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rsmith, #libc, ldionne

Differential Revision: https://reviews.llvm.org/D110216
2021-11-15 23:07:45 +01:00

62 lines
2.0 KiB
C++

//===--- ProBoundsPointerArithmeticCheck.cpp - clang-tidy------------------===//
//
// 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 "ProBoundsPointerArithmeticCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace cppcoreguidelines {
void ProBoundsPointerArithmeticCheck::registerMatchers(MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus)
return;
const auto AllPointerTypes =
anyOf(hasType(pointerType()),
hasType(autoType(
hasDeducedType(hasUnqualifiedDesugaredType(pointerType())))),
hasType(decltypeType(hasUnderlyingType(pointerType()))));
// Flag all operators +, -, +=, -=, ++, -- that result in a pointer
Finder->addMatcher(
binaryOperator(
hasAnyOperatorName("+", "-", "+=", "-="), AllPointerTypes,
unless(hasLHS(ignoringImpCasts(declRefExpr(to(isImplicit()))))))
.bind("expr"),
this);
Finder->addMatcher(
unaryOperator(hasAnyOperatorName("++", "--"), hasType(pointerType()))
.bind("expr"),
this);
// Array subscript on a pointer (not an array) is also pointer arithmetic
Finder->addMatcher(
arraySubscriptExpr(
hasBase(ignoringImpCasts(
anyOf(AllPointerTypes,
hasType(decayedType(hasDecayedType(pointerType())))))))
.bind("expr"),
this);
}
void ProBoundsPointerArithmeticCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *MatchedExpr = Result.Nodes.getNodeAs<Expr>("expr");
diag(MatchedExpr->getExprLoc(), "do not use pointer arithmetic");
}
} // namespace cppcoreguidelines
} // namespace tidy
} // namespace clang