[libc++] Enable _LIBCPP_NODEBUG again

[philnik777]

_LIBCPP_NODEBUG has been disabled temporarily, since there were a few problems when adding a bunch of annotations throughout the code base. They have been resolved now, so we can enable all the annotations again.

Reverts #122393

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Nikolas Klauser (philnik777)

Changes

_LIBCPP_NODEBUG has been disabled temporarily, since there were a few problems when adding a bunch of annotations throughout the code base. They have been resolved now, so we can enable all the annotations again.

Reverts llvm/llvm-project#122393

---

Full diff: https://github.com/llvm/llvm-project/pull/123318.diff

2 Files Affected:

• (modified) libcxx/include/__config (+1-3)
• (modified) libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp (+1-1)

diff --git a/libcxx/include/__config b/libcxx/include/__config
index 658a7e16fae916..5d5c90d7b87a7b 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1166,9 +1166,7 @@ typedef __char32_t char32_t;
 #    define _LIBCPP_NOESCAPE
 #  endif
 
-// FIXME: Expand this to [[__gnu__::__nodebug__]] again once the testcase reported in
-// https://github.com/llvm/llvm-project/pull/118710 has been analyzed
-#  define _LIBCPP_NODEBUG
+#  define _LIBCPP_NODEBUG [[__gnu__::__nodebug__]]
 
 #  if __has_attribute(__standalone_debug__)
 #    define _LIBCPP_STANDALONE_DEBUG __attribute__((__standalone_debug__))
diff --git a/libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp b/libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp
index f49f3e3c615ca9..bc7c8ce7ec443a 100644
--- a/libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp
+++ b/libcxx/test/tools/clang_tidy_checks/libcpp_module.cpp
@@ -27,7 +27,7 @@ class LibcxxTestModule : public clang::tidy::ClangTidyModule {
     check_factories.registerCheck<libcpp::header_exportable_declarations>("libcpp-header-exportable-declarations");
     check_factories.registerCheck<libcpp::hide_from_abi>("libcpp-hide-from-abi");
     check_factories.registerCheck<libcpp::internal_ftm_use>("libcpp-internal-ftms");
-    // check_factories.registerCheck<libcpp::nodebug_on_aliases>("libcpp-nodebug-on-aliases");
+    check_factories.registerCheck<libcpp::nodebug_on_aliases>("libcpp-nodebug-on-aliases");
     check_factories.registerCheck<libcpp::proper_version_checks>("libcpp-cpp-version-check");
     check_factories.registerCheck<libcpp::robust_against_adl_check>("libcpp-robust-against-adl");
     check_factories.registerCheck<libcpp::uglify_attributes>("libcpp-uglify-attributes");

[nico]

This depends on a clang that has 504dd57 and #123253 to work. Those are very recent clang changes. Doesn't libc++ usually support building with clangs that are older than tip-of-tree?

[philnik777]

This depends on a clang that has 504dd57 and #123253 to work. Those are very recent clang changes. Doesn't libc++ usually support building with clangs that are older than tip-of-tree?

Yes, to some extent. We support older releases in general, but not clang built from arbitrary commits. I was under the impression that these bugs were recent and the cases where you run into them are relatively obscure. Not sure there is any basis in reality for that impression though. Did you run into issues with older compilers due to this?

[ldionne]

The other alternative would be to use #if __clang_ >= version to conditionally enable _LIBCPP_NODEBUG, but that would have an adverse effect on older clangs as well, so that may not be the best option.