[clang-tools-extra] [clang-tidy] Add check to diagnose coroutine-hostile RAII objects (PR #68738)

[Piotr Zegar via cfe-commits]

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@@ -0,0 +1,82 @@
+//===--- CoroutineSuspensionHostileCheck.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 "CoroutineHostileRAIICheck.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/AST/Attrs.inc"
+#include "clang/AST/Decl.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Type.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::misc {
+CoroutineHostileRAIICheck::CoroutineHostileRAIICheck(StringRef Name,
+                                                     ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+  for (StringRef Denied :
+       utils::options::parseStringList(Options.get("RAIIDenyList", ""))) {
+    Denied.consume_front("::");
+    RAIIDenyList.push_back(Denied);
+  }
+}
+
+void CoroutineHostileRAIICheck::registerMatchers(MatchFinder *Finder) {
+  // A suspension happens with co_await or co_yield.
+  Finder->addMatcher(coawaitExpr().bind("suspension"), this);
+  Finder->addMatcher(coyieldExpr().bind("suspension"), this);
+}
+
+void CoroutineHostileRAIICheck::checkVarDecl(VarDecl *VD) {
+  RecordDecl *RD = VD->getType().getCanonicalType()->getAsRecordDecl();
+  if (RD->hasAttr<clang::ScopedLockableAttr>()) {
+    diag(VD->getLocation(),
+         "%0 holds a lock across a suspension point of coroutine and could be "
+         "unlocked by a different thread")
+        << VD;
+  }
+  if (std::find(RAIIDenyList.begin(), RAIIDenyList.end(),
+                RD->getQualifiedNameAsString()) != RAIIDenyList.end()) {
+    diag(VD->getLocation(),
+         "%0 persists across a suspension point of coroutine")
+        << VD;
+  }
+}
+
+void CoroutineHostileRAIICheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *Suspension = Result.Nodes.getNodeAs<Stmt>("suspension");
+  DynTypedNode P;
+  for (const Stmt *Child = Suspension; Child; Child = P.get<Stmt>()) {
----------------
PiotrZSL wrote:

Please rewrite this in Matcher by writing custom one (best option).
Or at least split into functions:
- one for iterating over child's declared before this.
- one for handling single child


https://github.com/llvm/llvm-project/pull/68738