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

[Piotr Zegar 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 +1,137 @@
+//===--- 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));
+}
+
+static const CXXMethodDecl *
+findAlternative(const CXXMethodDecl *MatchedOperator) {
+  const CXXRecordDecl *Parent = MatchedOperator->getParent();
+  const QualType SubscriptThisObjType =
+      MatchedOperator->getFunctionObjectParameterReferenceType();
+
+  for (const CXXMethodDecl *Method : Parent->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;
+
+    const bool CorrectName = Method->getNameInfo().getAsString() == "at";
+    if (!CorrectName)
+      continue;
+
+    const bool SameReturnType =
+        Method->getReturnType() == MatchedOperator->getReturnType();
+    if (!SameReturnType)
+      continue;
+
+    const bool SameNumberOfArguments =
+        Method->getNumParams() == MatchedOperator->getNumParams();
+    if (!SameNumberOfArguments)
+      continue;
+
+    for (unsigned ArgInd = 0; ArgInd < Method->getNumParams(); ArgInd++) {
+      const bool SameArgType =
+          Method->parameters()[ArgInd]->getOriginalType() ==
+          MatchedOperator->parameters()[ArgInd]->getOriginalType();
+      if (!SameArgType)
+        continue;
+    }
+
+    return Method;
+  }
+  return nullptr;
+}
+
+void ProBoundsAvoidUncheckedContainerAccesses::registerMatchers(
+    MatchFinder *Finder) {
+  Finder->addMatcher(
+      mapAnyOf(cxxOperatorCallExpr, cxxMemberCallExpr)
+          .with(callee(cxxMethodDecl(hasOverloadedOperatorName("[]"),
----------------
PiotrZSL wrote:

you could verify here that called operator got single argument, and called argument is an integer type
this could help excluding quickly many calls on maps with non integer key.

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