[clang-tools-extra] Enforce SL.con.3: Add check to replace operator[] with at() [Cont.] (PR #95220)

[Julian Schmidt via cfe-commits]

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In-Reply-To: <llvm.org/llvm/llvm-project/pull/95220 at github.com>


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@@ -0,0 +1,124 @@
+//===--- ProBoundsAvoidUncheckedContainerAccesses.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 "ProBoundsAvoidUncheckedContainerAccesses.h"
+#include "../utils/Matchers.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "llvm/ADT/StringRef.h"
+#include <numeric>
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::cppcoreguidelines {
+
+static constexpr std::array<llvm::StringRef, 3> SubscriptDefaultExclusions = {
+    llvm::StringRef("::std::map"), llvm::StringRef("::std::unordered_map"),
+    llvm::StringRef("::std::flat_map")};
+
+ProBoundsAvoidUncheckedContainerAccesses::
+    ProBoundsAvoidUncheckedContainerAccesses(StringRef Name,
+                                             ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+
+  SubscriptExcludedClasses = clang::tidy::utils::options::parseStringList(
+      Options.get("ExcludeClasses", ""));
+  SubscriptExcludedClasses.insert(SubscriptExcludedClasses.end(),
+                                  SubscriptDefaultExclusions.begin(),
+                                  SubscriptDefaultExclusions.end());
+}
+
+void ProBoundsAvoidUncheckedContainerAccesses::storeOptions(
+    ClangTidyOptions::OptionMap &Opts) {
+
+  if (SubscriptExcludedClasses.size() == SubscriptDefaultExclusions.size()) {
+    Options.store(Opts, "ExcludeClasses", "");
+    return;
+  }
+
+  // Sum up the sizes of the defaults ( + semicolons), so we can remove them
+  // from the saved options
+  size_t DefaultsStringLength = std::transform_reduce(
+      SubscriptDefaultExclusions.begin(), SubscriptDefaultExclusions.end(),
+      SubscriptDefaultExclusions.size(), std::plus<>(),
+      [](llvm::StringRef Name) { return Name.size(); });
+
+  std::string Serialized = clang::tidy::utils::options::serializeStringList(
+      SubscriptExcludedClasses);
+
+  Options.store(Opts, "ExcludeClasses",
+                Serialized.substr(0, Serialized.size() - DefaultsStringLength));
+}
+
+const CXXMethodDecl *findAlternative(const CXXRecordDecl *MatchedParent,
+                                     const CXXMethodDecl *MatchedOperator) {
+  for (const CXXMethodDecl *Method : MatchedParent->methods()) {
+    const bool CorrectName = Method->getNameInfo().getAsString() == "at";
----------------
5chmidti wrote:

It would be good to check that the `at` function that is found as an alternative can actually be accessed (`private` vs `public` etc), and that constness and references are the same, as @PiotrZSL requested here: https://github.com/llvm/llvm-project/pull/90043#discussion_r1579837894.

```c++
  const QualType SubscriptThisObjType =
      MatchedOperator->getFunctionObjectParameterReferenceType();

  for (const CXXMethodDecl *Method : MatchedParent->methods()) {
    // Require 'Method' to be as accessible as 'MatchedOperator' or more
    if (MatchedOperator->getAccess() < Method->getAccess())
      continue;

    if (MatchedOperator->isConst() != Method->isConst())
      continue;

    const QualType AtThisObjType =
        Method->getFunctionObjectParameterReferenceType();
    if (SubscriptThisObjType != AtThisObjType)
      continue;

    [...]
```

https://github.com/llvm/llvm-project/pull/95220