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

On Android, pipe() is better to be replaced by pipe2() with O_CLOEXEC
flag to avoid file descriptor leakage.

Patch by Jian Cai!

Differential Revision: https://reviews.llvm.org/D61967

llvm-svn: 362673

1 files changed, 37 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.cpp b/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.cpp
new file mode 100644
index 0000000..94b9450
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.cpp
@@ -0,0 +1,37 @@
+//===--- CloexecPipeCheck.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 "CloexecPipeCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+void CloexecPipeCheck::registerMatchers(MatchFinder *Finder) {
+  registerMatchersImpl(Finder,
+                       functionDecl(returns(isInteger()), hasName("pipe"),
+                                    hasParameter(0, hasType(pointsTo(isInteger())))));
+}
+
+void CloexecPipeCheck::check(const MatchFinder::MatchResult &Result) {
+  std::string ReplacementText =
+      (Twine("pipe2(") + getSpellingArg(Result, 0) + ", O_CLOEXEC)").str();
+
+  replaceFunc(
+      Result,
+      "prefer pipe2() with O_CLOEXEC to avoid leaking file descriptors to child processes",
+      ReplacementText);
+}
+
+} // namespace android
+} // namespace tidy
+} // namespace clang