add new check to find OSSpinlock usage

Summary:
This check finds the use of methods related to OSSpinlock in Objective-C code, which should be deprecated due to livelock issues.
The following method call will be detected:

- OSSpinlockLock()
- OSSpinlockTry()
- OSSpinlockUnlcok()

Reviewers: hokein, benhamilton

Reviewed By: benhamilton

Subscribers: klimek, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D40325

llvm-svn: 319098

4 files changed, 77 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.cpp b/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.cpp
new file mode 100644
index 00000000000..21ec3642184
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.cpp
@@ -0,0 +1,37 @@
+//===--- AvoidSpinlockCheck.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 "AvoidSpinlockCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace objc {
+
+void AvoidSpinlockCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      callExpr(callee((functionDecl(hasAnyName(
+                   "OSSpinlockLock", "OSSpinlockUnlock", "OSSpinlockTry")))))
+          .bind("spinlock"),
+      this);
+}
+
+void AvoidSpinlockCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *MatchedExpr = Result.Nodes.getNodeAs<CallExpr>("spinlock");
+  diag(MatchedExpr->getLocStart(),
+       "use os_unfair_lock_lock() or dispatch queue APIs instead of the "
+       "deprecated OSSpinLock");
+}
+
+}  // namespace objc
+}  // namespace tidy
+}  // namespace clang
diff --git a/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.h b/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.h
new file mode 100644
index 00000000000..d9dbf8cb74b
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/objc/AvoidSpinlockCheck.h
@@ -0,0 +1,36 @@
+//===--- AvoidSpinlockCheck.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_OBJC_AVOID_SPINLOCK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OBJC_AVOID_SPINLOCK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace objc {
+
+/// Finds usages of OSSpinlock, which is deprecated due to potential livelock
+/// problems.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/objc-avoid-spinlock.html
+class AvoidSpinlockCheck : public ClangTidyCheck {
+ public:
+  AvoidSpinlockCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+}  // namespace objc
+}  // namespace tidy
+}  // namespace clang
+
+#endif  // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_OBJC_AVOID_SPINLOCK_H
diff --git a/clang-tools-extra/clang-tidy/objc/CMakeLists.txt b/clang-tools-extra/clang-tidy/objc/CMakeLists.txt
index daec7a1d648..dae8087df82 100644
--- a/clang-tools-extra/clang-tidy/objc/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/objc/CMakeLists.txt
@@ -1,6 +1,7 @@
 set(LLVM_LINK_COMPONENTS support)
 
 add_clang_library(clangTidyObjCModule
+  AvoidSpinlockCheck.cpp
   ForbiddenSubclassingCheck.cpp
   ObjCTidyModule.cpp
   PropertyDeclarationCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/objc/ObjCTidyModule.cpp b/clang-tools-extra/clang-tidy/objc/ObjCTidyModule.cpp
index 6fe12c3a53f..674da340c6d 100644
--- a/clang-tools-extra/clang-tidy/objc/ObjCTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/objc/ObjCTidyModule.cpp
@@ -10,6 +10,7 @@
 #include "../ClangTidy.h"
 #include "../ClangTidyModule.h"
 #include "../ClangTidyModuleRegistry.h"
+#include "AvoidSpinlockCheck.h"
 #include "ForbiddenSubclassingCheck.h"
 #include "PropertyDeclarationCheck.h"
 
@@ -22,6 +23,8 @@ namespace objc {
 class ObjCModule : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+    CheckFactories.registerCheck<AvoidSpinlockCheck>(
+        "objc-avoid-spinlock");
     CheckFactories.registerCheck<ForbiddenSubclassingCheck>(
         "objc-forbidden-subclassing");
     CheckFactories.registerCheck<PropertyDeclarationCheck>(