[clang-tidy][Part2] Add a new module Android and three new checks

[yawanng]

Summary

• creat() should be replaced by open(). [android-creat-usage]

[hokein]

clang-tidy/utils/ExprToStr.cpp

17 ↗

(On Diff #101254)

Maybe you can use clang::Lexer::getSourceText( CharSourceRange::getTokenRange(EX->getSourceRange()), ...) here? so that we don't need this utility fucntion.

[chh]

clang-tidy/android/CreatUsageCheck.cpp

42 ↗

(On Diff #101829)

Most coding styles would prefer replacement text as "open(", instead of "open (".

[yawanng]

Format fix.

[hokein]

clang-tidy/android/CreatUsageCheck.cpp

29 ↗

(On Diff #103792)

Nit: put the returns(isInteger()) in front of hasName() (make it align with cpp function declaration).

39 ↗

(On Diff #103792)

Use MatchedCall->getSourceRange().

Again, no need to create a separate variable as this variable is used only once.

docs/clang-tidy/checks/android-creat-usage.rst

6 ↗

(On Diff #103792)

Would be nice to give some examples in the doc.

test/clang-tidy/android-creat-usage.cpp

9 ↗

(On Diff #103792)

Could you add test cases where the second parameter is not a magic number? E.g. creat("filename", mode);.

[hokein]

Looks good.

[yawanng]

rename this check.

[yawanng]

Format change.

[chh]

Summary should be updated. s/android-creat-usage/android-cloexec-creat/

clang-tidy/android/AndroidTidyModule.cpp

 #include "../ClangTidy.h"
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
+#include "CloexecCreatCheck.h"
 #include "FileOpenFlagCheck.h"
 
 using namespace clang::ast_matchers;

 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
     CheckFactories.registerCheck<FileOpenFlagCheck>("android-file-open-flag");
+    CheckFactories.registerCheck<CloexecCreatCheck>("android-cloexec-creat");
   }
 };
 

clang-tidy/android/CMakeLists.txt

 
 add_clang_library(clangTidyAndroidModule
   AndroidTidyModule.cpp
+  CloexecCreatCheck.cpp
   FileOpenFlagCheck.cpp
 
   LINK_LIBS

clang-tidy/android/CloexecCreatCheck.h

+//===--- CloexecCreatCheck.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_CREAT_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_CREAT_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+/// creat() is better to be replaced by open().
+/// Find the usage of creat() and redirect user to use open().
+
+/// http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-creat.html
+class CloexecCreatCheck : public ClangTidyCheck {
+public:
+  CloexecCreatCheck(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_CREAT_H

clang-tidy/android/CloexecCreatCheck.cpp

+//===--- CloexecCreatCheck.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 "CloexecCreatCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Lex/Lexer.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace android {
+
+void CloexecCreatCheck::registerMatchers(MatchFinder *Finder) {
+  auto CharPointerType = hasType(pointerType(pointee(isAnyCharacter())));
+  auto MODETType = hasType(namedDecl(hasName("mode_t")));
+
+  Finder->addMatcher(
+      callExpr(callee(functionDecl(isExternC(), returns(isInteger()),
+                                   hasName("creat"),
+                                   hasParameter(0, CharPointerType),
+                                   hasParameter(1, MODETType))
+                          .bind("funcDecl")))
+          .bind("creatFn"),
+      this);
+}
+
+void CloexecCreatCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>("creatFn");
+  const SourceManager &SM = *Result.SourceManager;
+
+  const std::string &ReplacementText =
+      (Twine("open (") +
+       Lexer::getSourceText(CharSourceRange::getTokenRange(
+                                MatchedCall->getArg(0)->getSourceRange()),
+                            SM, Result.Context->getLangOpts()) +
+       ", O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, " +
+       Lexer::getSourceText(CharSourceRange::getTokenRange(
+                                MatchedCall->getArg(1)->getSourceRange()),
+                            SM, Result.Context->getLangOpts()) +
+       ")")
+          .str();
+
+  diag(MatchedCall->getLocStart(),
+       "prefer open() to creat() because open() allows O_CLOEXEC")
+      << FixItHint::CreateReplacement(MatchedCall->getSourceRange(),
+                                      ReplacementText);
+}
+
+} // namespace android
+} // namespace tidy
+} // namespace clang

docs/ReleaseNotes.rst

 Improvements to clang-tidy
 --------------------------
 
+- New `android-cloexec-creat
+  <http://clang.llvm.org/extra/clang-tidy/checks/android-cloexec-creat.html>`_ check
+
+  Detect usage of ``creat()``.
+
 - New `android-file-open-flag
   <http://clang.llvm.org/extra/clang-tidy/checks/android-file-open-flag.html>`_ check
 

docs/clang-tidy/checks/android-cloexec-creat.rst

+.. title:: clang-tidy - android-cloexec-creat
+
+android-cloexec-creat
+===================
+
+The usage of ``creat()`` is not recommended, it's better to use ``open()``.
+
+Examples:
+
+.. code-block:: c++
+
+  int fd = creat(path, mode);
+
+  // becomes
+
+  int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);

test/clang-tidy/android-cloexec-creat.cpp

+// RUN: %check_clang_tidy %s android-cloexec-creat %t
+
+typedef int mode_t;
+
+extern "C" int creat(const char *path, mode_t, ...);
+extern "C" int create(const char *path, mode_t, ...);
+
+void f() {
+  creat("filename", 0);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: prefer open() to creat() because open() allows O_CLOEXEC [android-cloexec-creat]
+  // CHECK-FIXES: open ("filename", O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0);
+  create("filename", 0);
+  // CHECK-MESSAGES-NOT: warning:
+  mode_t mode = 0755;
+  creat("filename", mode);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning:
+  // CHECK-FIXES: open ("filename", O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
+}
+
+namespace i {
+int creat(const char *path, mode_t, ...);
+void g() {
+  creat("filename", 0);
+  // CHECK-MESSAGES-NOT: warning:
+}
+} // namespace i
+
+class C {
+public:
+  int creat(const char *path, mode_t, ...);
+  void h() {
+    creat("filename", 0);
+    // CHECK-MESSAGES-NOT: warning:
+  }
+};