__config: also ignore shift-out-of-bounds error with ubsan checks

[jcelerier]

Otherwise functions such as __hash_len_16 in hash.h still trigger harmless but frustrating ubsan warnings despite being marked as _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK.

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[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Jean-Michaël Celerier (jcelerier)

Changes

Otherwise functions such as __hash_len_16 in hash.h still trigger harmless but frustrating ubsan warnings despite being marked as _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK.

---

Full diff: https://github.com/llvm/llvm-project/pull/146688.diff

1 Files Affected:

• (modified) libcxx/include/__config (+1-1)

diff --git a/libcxx/include/__config b/libcxx/include/__config
index af8a297fdf3fd..b8331a2b4f63a 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1155,7 +1155,7 @@ typedef __char32_t char32_t;
 
 // Allow for build-time disabling of unsigned integer sanitization
 #  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
-#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
+#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow", "shift-out-of-bounds")))
 #  else
 #    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
 #  endif

[github-actions]

⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

You can test this locally with the following command:

git-clang-format --diff HEAD~1 HEAD --extensions  -- libcxx/include/__config

View the diff from clang-format here.

diff --git a/libcxx/include/__config b/libcxx/include/__config
index b8331a2b4..e8177cde8 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1155,7 +1155,8 @@ typedef __char32_t char32_t;
 
 // Allow for build-time disabling of unsigned integer sanitization
 #  if __has_attribute(no_sanitize) && !defined(_LIBCPP_COMPILER_GCC)
-#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow", "shift-out-of-bounds")))
+#    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK                                                               \
+      __attribute__((__no_sanitize__("unsigned-integer-overflow", "shift-out-of-bounds")))
 #  else
 #    define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
 #  endif

[jcelerier]

@cor3ntin

[jcelerier]

well that was worth a try!

[cor3ntin]

@jcelerier, I suspect there is a reason this was closed just after being open?

[jcelerier]

yes, my patch was wrong (for some reason it did not fail on my local build but Werror here made it very apparent)

Correct patch is #146715