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

4 files changed, 74 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp b/clang-tools-extra/clang-tidy/android/AndroidTidyModule.cpp
index 237d5ff..e978309 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 "CloexecPipeCheck.h"
 #include "CloexecPipe2Check.h"
 #include "CloexecSocketCheck.h"
 #include "ComparisonInTempFailureRetryCheck.h"
@@ -50,6 +51,7 @@ public:
     CheckFactories.registerCheck<CloexecMemfdCreateCheck>(
         "android-cloexec-memfd-create");
     CheckFactories.registerCheck<CloexecOpenCheck>("android-cloexec-open");
+    CheckFactories.registerCheck<CloexecPipeCheck>("android-cloexec-pipe");
     CheckFactories.registerCheck<CloexecPipe2Check>("android-cloexec-pipe2");
     CheckFactories.registerCheck<CloexecSocketCheck>("android-cloexec-socket");
     CheckFactories.registerCheck<ComparisonInTempFailureRetryCheck>(
diff --git a/clang-tools-extra/clang-tidy/android/CMakeLists.txt b/clang-tools-extra/clang-tidy/android/CMakeLists.txt
index a89d7a4..9d04003 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
+  CloexecPipeCheck.cpp
   CloexecPipe2Check.cpp
   CloexecSocketCheck.cpp
   ComparisonInTempFailureRetryCheck.cpp
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
diff --git a/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.h b/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.h
new file mode 100644
index 0000000..c89fe79
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/android/CloexecPipeCheck.h
@@ -0,0 +1,34 @@
+//===--- CloexecPipeCheck.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_PIPE_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_PIPE_H
+
+#include "CloexecCheck.h"
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+/// Suggests to replace calls to pipe() with calls to pipe2().
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-pipe.html
+class CloexecPipeCheck : public CloexecCheck {
+public:
+  CloexecPipeCheck(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_PIPE_H