[clang-tools-extra] [clang-tidy] Create bugprone-incorrect-enable-shared-from-this check (PR #102299)

[Piotr Zegar via cfe-commits]

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@@ -0,0 +1,120 @@
+//===--- IncorrectEnableSharedFromThisCheck.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 "IncorrectEnableSharedFromThisCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Basic/Specifiers.h"
+#include "llvm/ADT/SmallPtrSet.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+void IncorrectEnableSharedFromThisCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(translationUnitDecl(), this);
+}
+
+void IncorrectEnableSharedFromThisCheck::check(
+    const MatchFinder::MatchResult &Result) {
+
+  class Visitor : public RecursiveASTVisitor<Visitor> {
+    IncorrectEnableSharedFromThisCheck &Check;
+    llvm::SmallPtrSet<const CXXRecordDecl *, 16> EnableSharedClassSet;
+
+  public:
+    explicit Visitor(IncorrectEnableSharedFromThisCheck &Check)
+        : Check(Check) {}
+
+    bool VisitCXXRecordDecl(CXXRecordDecl *RDecl) {
+      for (const auto &Base : RDecl->bases()) {
+        VisitCXXBaseSpecifier(Base, RDecl);
+      }
+      for (const auto &Base : RDecl->bases()) {
+        const CXXRecordDecl *BaseType = Base.getType()->getAsCXXRecordDecl();
+        if (BaseType && BaseType->getQualifiedNameAsString() ==
+                            "std::enable_shared_from_this") {
+          EnableSharedClassSet.insert(RDecl->getCanonicalDecl());
+          return true;
+        }
+      }
+      return true;
+    }
+
+    bool VisitCXXBaseSpecifier(const CXXBaseSpecifier &Base,
+                               CXXRecordDecl *RDecl) {
+      const CXXRecordDecl *BaseType = Base.getType()->getAsCXXRecordDecl();
+      const clang::AccessSpecifier AccessSpec = Base.getAccessSpecifier();
+
+      if (BaseType &&
+          BaseType->getQualifiedNameAsString() == "enable_shared_from_this") {
+        if (AccessSpec == clang::AS_public) {
+          const SourceLocation InsertLocation = Base.getBaseTypeLoc();
+          const FixItHint Hint = FixItHint::CreateInsertion(InsertLocation, "std::");
+          Check.diag(RDecl->getLocation(),
+                     "Should be std::enable_shared_from_this",
+                     DiagnosticIDs::Warning)
+              << Hint;
+
+        } else {
+          const SourceRange ReplacementRange = Base.getSourceRange();
+          const std::string ReplacementString =
+              "public std::" + Base.getType().getAsString();
+          const FixItHint Hint =
+              FixItHint::CreateReplacement(ReplacementRange, ReplacementString);
+          Check.diag(
+              RDecl->getLocation(),
+              "Should be std::enable_shared_from_this and "
+              "inheritance from std::enable_shared_from_this should be public "
+              "inheritance, otherwise the internal weak_ptr won't be "
----------------
PiotrZSL wrote:

noneone care/know about "internal weak_ptr, write how it would behave from user perspective, start with lower caps.
For me this is too long. it should say: whats wrong (+why it's wrong), how to fix (+why fix)


https://github.com/llvm/llvm-project/pull/102299