[clang-tidy] Add a close-on-exec check on inotify_init() in Android module.

[yawanng]

Summary

inotify_init() is better to be replaced by inotify_init1() with IN_CLOEXEC flag to avoid file descriptor leakage.

[Eugene.Zelenko]

docs/ReleaseNotes.rst

60

Please sort checks in alphabetical order.

[alexfh]

See the comment on D35372.

[hokein]

clang-tidy/android/CloexecInotifyInitCheck.cpp

28

The parameter 2 and 3 are not clear at the first glance. Maybe add /*WarningMsg=*/, and /*FixMsg=*/.

test/clang-tidy/android-cloexec-inotify-init.cpp

9

nit: trailing ;.

[hokein]

LGTM

clang-tidy/android/AndroidTidyModule.cpp

 #include "../ClangTidyModuleRegistry.h"
 #include "CloexecCreatCheck.h"
 #include "CloexecFopenCheck.h"
+#include "CloexecInotifyInitCheck.h"
 #include "CloexecOpenCheck.h"
 #include "CloexecSocketCheck.h"
 

   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<CloexecCreatCheck>("android-cloexec-creat");
     CheckFactories.registerCheck<CloexecFopenCheck>("android-cloexec-fopen");
+    CheckFactories.registerCheck<CloexecInotifyInitCheck>(
+        "android-cloexec-inotify-init");
     CheckFactories.registerCheck<CloexecOpenCheck>("android-cloexec-open");
     CheckFactories.registerCheck<CloexecSocketCheck>("android-cloexec-socket");
   }

clang-tidy/android/CMakeLists.txt

   AndroidTidyModule.cpp
   CloexecCreatCheck.cpp
   CloexecFopenCheck.cpp
+  CloexecInotifyInitCheck.cpp
   CloexecOpenCheck.cpp
   CloexecSocketCheck.cpp
 

clang-tidy/android/CloexecInotifyInitCheck.h

+//===--- CloexecInotifyInitCheck.h - clang-tidy------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_INOTIFY_INIT_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_INOTIFY_INIT_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+/// inotify_init() is better to be replaced by inotify_init1().
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-inotify-init.html
+class CloexecInotifyInitCheck : public ClangTidyCheck {
+public:
+  CloexecInotifyInitCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace android
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_INOTIFY_INIT_H

clang-tidy/android/CloexecInotifyInitCheck.cpp

+//===--- CloexecInotifyInitCheck.cpp - clang-tidy--------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CloexecInotifyInitCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+void CloexecInotifyInitCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      callExpr(callee(functionDecl(isExternC(), returns(isInteger()),
+                                   hasName("inotify_init"))
+                          .bind("funcDecl")))
+          .bind("inotifyInitFn"),
+      this);
+}
+
+void CloexecInotifyInitCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>("inotifyInitFn");
+
+  diag(MatchedCall->getLocStart(), "prefer inotify_init() to inotify_init1() "
+                                   "because inotify_init1() allows IN_CLOEXEC")
+      << FixItHint::CreateReplacement(MatchedCall->getSourceRange(),
+                                      "inotify_init1(IN_CLOEXEC)");
+}
+
+} // namespace android
+} // namespace tidy
+} // namespace clang

docs/ReleaseNotes.rst

 
   Checks if the required mode ``e`` exists in the mode argument of ``fopen()``.
 
+- New `android-cloexec-inotify-init
+  <http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-inotify-init.html>`_ check
+
+  Detects usage of ``inotify_init()``.
+
 - New `android-cloexec-socket
   <http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-socket.html>`_ check
 

docs/clang-tidy/checks/android-cloexec-inotify-init.rst

+.. title:: clang-tidy - android-cloexec-inotify-init
+
+android-cloexec-inotify-init
+============================
+
+The usage of ``inotify_init()`` is not recommended, it's better to use
+``inotify_init1()``.
+
+Examples:
+
+.. code-block:: c++
+
+  inotify_init();
+
+  // becomes
+
+  inotify_init1(IN_CLOEXEC);

docs/clang-tidy/checks/list.rst

 .. toctree::
    android-cloexec-creat
    android-cloexec-fopen
+   android-cloexec-inotify-init
    android-cloexec-open
    android-cloexec-socket
    boost-use-to-string

test/clang-tidy/android-cloexec-inotify-init.cpp

+// RUN: %check_clang_tidy %s android-cloexec-inotify-init %t
+
+extern "C" int inotify_init();
+
+void f() {
+  inotify_init();
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: prefer inotify_init() to inotify_init1() because inotify_init1() allows IN_CLOEXEC [android-cloexec-inotify-init]
+  // CHECK-FIXES: inotify_init1(IN_CLOEXEC)
+}
+
+namespace i {
+int inotify_init();
+void g() {
+  inotify_init();
+}
+} // namespace i
+
+class C {
+public:
+  int inotify_init();
+  void h() {
+    inotify_init();
+  }
+};