android: add a close-on-exec check on pipe2()

On Android, pipe2() is better to set O_CLOEXEC flag to avoid file
descriptor leakage.

Patch by Jian Cai!

Differential Revision: https://reviews.llvm.org/D62049

llvm-svn: 362672

4 files changed, 70 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp
index 2baa3fbad81..237d5ff5e8a 100644
--- a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp
@@ -20,6 +20,7 @@
 #include "CloexecInotifyInitCheck.h"
 #include "CloexecMemfdCreateCheck.h"
 #include "CloexecOpenCheck.h"
+#include "CloexecPipe2Check.h"
 #include "CloexecSocketCheck.h"
 #include "ComparisonInTempFailureRetryCheck.h"
 
@@ -49,6 +50,7 @@ public:
     CheckFactories.registerCheck<CloexecMemfdCreateCheck>(
         "android-cloexec-memfd-create");
     CheckFactories.registerCheck<CloexecOpenCheck>("android-cloexec-open");
+    CheckFactories.registerCheck<CloexecPipe2Check>("android-cloexec-pipe2");
     CheckFactories.registerCheck<CloexecSocketCheck>("android-cloexec-socket");
     CheckFactories.registerCheck<ComparisonInTempFailureRetryCheck>(
         "android-comparison-in-temp-failure-retry");
diff --git a/clang-tools-extra/clang-tidy/android/CMakeLists.txt b/clang-tools-extra/clang-tidy/android/CMakeLists.txt
index 9733e229081..a89d7a42796 100644
--- a/clang-tools-extra/clang-tidy/android/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/android/CMakeLists.txt
@@ -14,6 +14,7 @@ add_clang_library(clangTidyAndroidModule
   CloexecInotifyInitCheck.cpp
   CloexecMemfdCreateCheck.cpp
   CloexecOpenCheck.cpp
+  CloexecPipe2Check.cpp
   CloexecSocketCheck.cpp
   ComparisonInTempFailureRetryCheck.cpp
 
diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp
new file mode 100644
index 00000000000..7e3107da3b7
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.cpp
@@ -0,0 +1,33 @@
+//===--- CloexecPipe2Check.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 "CloexecPipe2Check.h"
+#include "../utils/ASTUtils.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+void CloexecPipe2Check::registerMatchers(MatchFinder *Finder) {
+  registerMatchersImpl(Finder,
+                       functionDecl(returns(isInteger()), hasName("pipe2"),
+                                    hasParameter(0, hasType(pointsTo(isInteger()))),
+                                    hasParameter(1, hasType(isInteger()))));
+}
+
+void CloexecPipe2Check::check(const MatchFinder::MatchResult &Result) {
+  insertMacroFlag(Result, /*MacroFlag=*/"O_CLOEXEC", /*ArgPos=*/1);
+}
+
+} // namespace android
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h
new file mode 100644
index 00000000000..b58846675cb
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/android/CloexecPipe2Check.h
@@ -0,0 +1,34 @@
+//===--- CloexecPipe2Check.h - clang-tidy------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE2_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE2_H
+
+#include "CloexecCheck.h"
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+/// Finds code that uses pipe2() without using the O_CLOEXEC flag.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-pipe2.html
+class CloexecPipe2Check : public CloexecCheck {
+public:
+  CloexecPipe2Check(StringRef Name, ClangTidyContext *Context)
+      : CloexecCheck(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_PIPE2_H