[clang-tools-extra] 42c83e3 - [clang-tidy] Ignore implicit code in bugprone-branch-clone

[Piotr Zegar via cfe-commits]

Author: Piotr Zegar
Date: 2023-05-23T19:32:36Z
New Revision: 42c83e32706e2284acb880468295701743d437c6

URL: https://github.com/llvm/llvm-project/commit/42c83e32706e2284acb880468295701743d437c6
DIFF: https://github.com/llvm/llvm-project/commit/42c83e32706e2284acb880468295701743d437c6.diff

LOG: [clang-tidy] Ignore implicit code in bugprone-branch-clone

Implicit code like, template instances, compiler generated
code are not excluded in this check by using
TK_IgnoreUnlessSpelledInSource.

Fixes #62693

Reviewed By: donat.nagy

Differential Revision: https://reviews.llvm.org/D151133

Added: 
    

Modified: 
    clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.h
    clang-tools-extra/docs/ReleaseNotes.rst
    clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.h b/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.h
index 03486cc40d876..599da14c136fd 100644
--- a/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.h
+++ b/clang-tools-extra/clang-tidy/bugprone/BranchCloneCheck.h
@@ -27,6 +27,9 @@ class BranchCloneCheck : public ClangTidyCheck {
       : ClangTidyCheck(Name, Context) {}
   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  std::optional<TraversalKind> getCheckTraversalKind() const override {
+    return TK_IgnoreUnlessSpelledInSource;
+  }
 };
 
 } // namespace clang::tidy::bugprone

diff  --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index a024bd604d16e..7fe2b97de8643 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -202,9 +202,10 @@ New check aliases
 Changes in existing checks
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-- Fixed false-positive in :doc:`bugprone-branch-clone
-  <clang-tidy/checks/bugprone/branch-clone>` check by ignoring duplicated
-  switch cases marked with the ``[[fallthrough]]`` attribute.
+- Fixed false-positives in :doc:`bugprone-branch-clone
+  <clang-tidy/checks/bugprone/branch-clone>` check by ignoring auto-generated
+  code, template instances, implicit code patterns and duplicated switch cases
+  marked with the ``[[fallthrough]]`` attribute.
 
 - Improved :doc:`readability-redundant-string-cstr
   <clang-tidy/checks/readability/redundant-string-cstr>` check to recognise

diff  --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp
index 1525ba2802d16..42231746149f2 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone.cpp
@@ -1024,3 +1024,48 @@ void dontCrash() {
   SEMICOLON_CASE_COLON(3);
   }
 }
+
+namespace PR62693 {
+  class Object {
+    public:
+      template <typename T>
+        bool ConvertableTo() const;
+
+      template <typename T>
+        void Handle();
+  };
+
+  template <typename T>
+  void update(Object &a) {
+    if (a.ConvertableTo<char *>()) {
+      a.Handle<char *>();
+    } else {
+      a.Handle<T>();
+    }
+  }
+
+  template <typename T>
+  void update2(Object &a) {
+    if (a.ConvertableTo<char *>()) {
+      a.Handle<char *>();
+    } else {
+      a.Handle<T>();
+    }
+  }
+
+  void foo(Object &a) {
+    update<int>(a);
+    update2<char *>(a);
+  }
+
+  template <typename T>
+  int branch_clone_in_template(T t) {
+    // CHECK-MESSAGES: :[[@LINE+2]]:5: warning: if with identical then and else branches [bugprone-branch-clone]
+    // CHECK-MESSAGES: :[[@LINE+3]]:7: note: else branch starts here
+    if (t) {
+      return 42;
+    } else {
+      return 42;
+    }
+  }
+}