[clang-tools-extra] [clang-tidy]avoid bugprone-unused-return-value false negative for function with the same prefix as the default argument (PR #84333)

via cfe-commits cfe-commits at lists.llvm.org
Thu Mar 7 07:32:35 PST 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tools-extra

Author: Congcong Cai (HerrCai0907)

<details>
<summary>Changes</summary>

String without `$` end causes incorrectly match results, For example `std::unique` can match `std::unique_ptr::unique_ptr`.
It causes false negative.
Fixes: #<!-- -->84314.


---
Full diff: https://github.com/llvm/llvm-project/pull/84333.diff


3 Files Affected:

- (modified) clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp (+92-92) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+3-1) 
- (modified) clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value.cpp (+14) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
index b4bf85c912c3ca..1252b2f23805a1 100644
--- a/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/UnusedReturnValueCheck.cpp
@@ -34,102 +34,102 @@ UnusedReturnValueCheck::UnusedReturnValueCheck(llvm::StringRef Name,
                                                ClangTidyContext *Context)
     : ClangTidyCheck(Name, Context),
       CheckedFunctions(utils::options::parseStringList(
-          Options.get("CheckedFunctions", "::std::async;"
-                                          "::std::launder;"
-                                          "::std::remove;"
-                                          "::std::remove_if;"
-                                          "::std::unique;"
-                                          "::std::unique_ptr::release;"
-                                          "::std::basic_string::empty;"
-                                          "::std::vector::empty;"
-                                          "::std::back_inserter;"
-                                          "::std::distance;"
-                                          "::std::find;"
-                                          "::std::find_if;"
-                                          "::std::inserter;"
-                                          "::std::lower_bound;"
-                                          "::std::make_pair;"
-                                          "::std::map::count;"
-                                          "::std::map::find;"
-                                          "::std::map::lower_bound;"
-                                          "::std::multimap::equal_range;"
-                                          "::std::multimap::upper_bound;"
-                                          "::std::set::count;"
-                                          "::std::set::find;"
-                                          "::std::setfill;"
-                                          "::std::setprecision;"
-                                          "::std::setw;"
-                                          "::std::upper_bound;"
-                                          "::std::vector::at;"
+          Options.get("CheckedFunctions", "::std::async$;"
+                                          "::std::launder$;"
+                                          "::std::remove$;"
+                                          "::std::remove_if$;"
+                                          "::std::unique$;"
+                                          "::std::unique_ptr::release$;"
+                                          "::std::basic_string::empty$;"
+                                          "::std::vector::empty$;"
+                                          "::std::back_inserter$;"
+                                          "::std::distance$;"
+                                          "::std::find$;"
+                                          "::std::find_if$;"
+                                          "::std::inserter$;"
+                                          "::std::lower_bound$;"
+                                          "::std::make_pair$;"
+                                          "::std::map::count$;"
+                                          "::std::map::find$;"
+                                          "::std::map::lower_bound$;"
+                                          "::std::multimap::equal_range$;"
+                                          "::std::multimap::upper_bound$;"
+                                          "::std::set::count$;"
+                                          "::std::set::find$;"
+                                          "::std::setfill$;"
+                                          "::std::setprecision$;"
+                                          "::std::setw$;"
+                                          "::std::upper_bound$;"
+                                          "::std::vector::at$;"
                                           // C standard library
-                                          "::bsearch;"
-                                          "::ferror;"
-                                          "::feof;"
-                                          "::isalnum;"
-                                          "::isalpha;"
-                                          "::isblank;"
-                                          "::iscntrl;"
-                                          "::isdigit;"
-                                          "::isgraph;"
-                                          "::islower;"
-                                          "::isprint;"
-                                          "::ispunct;"
-                                          "::isspace;"
-                                          "::isupper;"
-                                          "::iswalnum;"
-                                          "::iswprint;"
-                                          "::iswspace;"
-                                          "::isxdigit;"
-                                          "::memchr;"
-                                          "::memcmp;"
-                                          "::strcmp;"
-                                          "::strcoll;"
-                                          "::strncmp;"
-                                          "::strpbrk;"
-                                          "::strrchr;"
-                                          "::strspn;"
-                                          "::strstr;"
-                                          "::wcscmp;"
+                                          "::bsearch$;"
+                                          "::ferror$;"
+                                          "::feof$;"
+                                          "::isalnum$;"
+                                          "::isalpha$;"
+                                          "::isblank$;"
+                                          "::iscntrl$;"
+                                          "::isdigit$;"
+                                          "::isgraph$;"
+                                          "::islower$;"
+                                          "::isprint$;"
+                                          "::ispunct$;"
+                                          "::isspace$;"
+                                          "::isupper$;"
+                                          "::iswalnum$;"
+                                          "::iswprint$;"
+                                          "::iswspace$;"
+                                          "::isxdigit$;"
+                                          "::memchr$;"
+                                          "::memcmp$;"
+                                          "::strcmp$;"
+                                          "::strcoll$;"
+                                          "::strncmp$;"
+                                          "::strpbrk$;"
+                                          "::strrchr$;"
+                                          "::strspn$;"
+                                          "::strstr$;"
+                                          "::wcscmp$;"
                                           // POSIX
-                                          "::access;"
-                                          "::bind;"
-                                          "::connect;"
-                                          "::difftime;"
-                                          "::dlsym;"
-                                          "::fnmatch;"
-                                          "::getaddrinfo;"
-                                          "::getopt;"
-                                          "::htonl;"
-                                          "::htons;"
-                                          "::iconv_open;"
-                                          "::inet_addr;"
-                                          "::isascii;"
-                                          "::isatty;"
-                                          "::mmap;"
-                                          "::newlocale;"
-                                          "::openat;"
-                                          "::pathconf;"
-                                          "::pthread_equal;"
-                                          "::pthread_getspecific;"
-                                          "::pthread_mutex_trylock;"
-                                          "::readdir;"
-                                          "::readlink;"
-                                          "::recvmsg;"
-                                          "::regexec;"
-                                          "::scandir;"
-                                          "::semget;"
-                                          "::setjmp;"
-                                          "::shm_open;"
-                                          "::shmget;"
-                                          "::sigismember;"
-                                          "::strcasecmp;"
-                                          "::strsignal;"
+                                          "::access$;"
+                                          "::bind$;"
+                                          "::connect$;"
+                                          "::difftime$;"
+                                          "::dlsym$;"
+                                          "::fnmatch$;"
+                                          "::getaddrinfo$;"
+                                          "::getopt$;"
+                                          "::htonl$;"
+                                          "::htons$;"
+                                          "::iconv_open$;"
+                                          "::inet_addr$;"
+                                          "::isascii$;"
+                                          "::isatty$;"
+                                          "::mmap$;"
+                                          "::newlocale$;"
+                                          "::openat$;"
+                                          "::pathconf$;"
+                                          "::pthread_equal$;"
+                                          "::pthread_getspecific$;"
+                                          "::pthread_mutex_trylock$;"
+                                          "::readdir$;"
+                                          "::readlink$;"
+                                          "::recvmsg$;"
+                                          "::regexec$;"
+                                          "::scandir$;"
+                                          "::semget$;"
+                                          "::setjmp$;"
+                                          "::shm_open$;"
+                                          "::shmget$;"
+                                          "::sigismember$;"
+                                          "::strcasecmp$;"
+                                          "::strsignal$;"
                                           "::ttyname"))),
       CheckedReturnTypes(utils::options::parseStringList(
-          Options.get("CheckedReturnTypes", "::std::error_code;"
-                                            "::std::error_condition;"
-                                            "::std::errc;"
-                                            "::std::expected;"
+          Options.get("CheckedReturnTypes", "::std::error_code$;"
+                                            "::std::error_condition$;"
+                                            "::std::errc$;"
+                                            "::std::expected$;"
                                             "::boost::system::error_code"))),
       AllowCastToVoid(Options.get("AllowCastToVoid", false)) {}
 
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index d98c4ff9a75044..aecf7cac66097c 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -152,7 +152,9 @@ Changes in existing checks
 
 - Improved :doc:`bugprone-unused-return-value
   <clang-tidy/checks/bugprone/unused-return-value>` check by updating the
-  parameter `CheckedFunctions` to support regexp.
+  parameter `CheckedFunctions` to support regexp and avoiding false negative for
+  function with the same prefix as the default argument, e.g. ``std::unique_ptr``
+  and ``std::unique``.
 
 - Improved :doc:`bugprone-use-after-move
   <clang-tidy/checks/bugprone/use-after-move>` check to also handle
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value.cpp
index 5c6ce1e4bf1fd2..e784c9b85172cf 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unused-return-value.cpp
@@ -30,6 +30,11 @@ struct default_delete;
 
 template <typename T, typename Deleter = std::default_delete<T>>
 struct unique_ptr {
+  unique_ptr();
+  unique_ptr(unique_ptr const&);
+  unique_ptr(unique_ptr &&);
+  unique_ptr& operator=(unique_ptr const&);
+  unique_ptr& operator=(unique_ptr &&);
   T *release() noexcept;
 };
 
@@ -254,3 +259,12 @@ void noWarning() {
   ({ std::async(increment, 42); });
   auto StmtExprRetval = ({ std::async(increment, 42); });
 }
+
+namespace gh84314 {
+
+extern std::unique_ptr<int> alloc();
+void f1(std::unique_ptr<int> &foo) {
+    foo = alloc();
+}
+
+} // namespace gh84314
\ No newline at end of file

``````````

</details>


https://github.com/llvm/llvm-project/pull/84333


More information about the cfe-commits mailing list