release/21.x: [libc++] Add checks for misused hardening macros (#150669) #151582
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@philnik777 What do you think about merging this PR to the release branch? |
llvmbot
added
the
libc++
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@llvm/pr-subscribers-libcxx Author: None (llvmbot) ChangesBackport 955ece4 Requested by: @ldionne Full diff: https://github.com/llvm/llvm-project/pull/151582.diff 1 Files Affected:
diff --git a/libcxx/include/__config b/libcxx/include/__config
index 7bb5d9ac77ea4..b1660c3f89b01 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -40,9 +40,21 @@
// HARDENING {
-// TODO: Remove in LLVM 21. We're making this an error to catch folks who might not have migrated.
-# ifdef _LIBCPP_ENABLE_ASSERTIONS
-# error "_LIBCPP_ENABLE_ASSERTIONS has been removed, please use _LIBCPP_HARDENING_MODE instead"
+// TODO(LLVM 23): Remove this. We're making these an error to catch folks who might not have migrated.
+// Since hardening went through several changes (many of which impacted user-facing macros),
+// we're keeping these checks around for a bit longer than usual. Failure to properly configure
+// hardening results in checks being dropped silently, which is a pretty big deal.
+# if defined(_LIBCPP_ENABLE_ASSERTIONS)
+# error "_LIBCPP_ENABLE_ASSERTIONS has been removed, please use _LIBCPP_HARDENING_MODE=<mode> instead (see docs)"
+# endif
+# if defined(_LIBCPP_ENABLE_HARDENED_MODE)
+# error "_LIBCPP_ENABLE_HARDENED_MODE has been removed, please use _LIBCPP_HARDENING_MODE=<mode> instead (see docs)"
+# endif
+# if defined(_LIBCPP_ENABLE_SAFE_MODE)
+# error "_LIBCPP_ENABLE_SAFE_MODE has been removed, please use _LIBCPP_HARDENING_MODE=<mode> instead (see docs)"
+# endif
+# if defined(_LIBCPP_ENABLE_DEBUG_MODE)
+# error "_LIBCPP_ENABLE_DEBUG_MODE has been removed, please use _LIBCPP_HARDENING_MODE=<mode> instead (see docs)"
# endif
// The library provides the macro `_LIBCPP_HARDENING_MODE` which can be set to one of the following values:
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Who can review? btw what's up with the buildkite ci never ending? |
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ping |
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philnik777
approved these changes
Aug 11, 2025
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I don't know; I've pinged the owner. I don't think it should be blocking though. |
github-project-automation
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Libc++ hardening went through several iterations, sometimes within a single release. However, some folks in the wild have picked up these macros that were either public at some point or that were used temporarily on `main`, and unfortunately those are now ignored. This can lead to some users thinking they enable hardening when in reality they don't, which is a pretty big deal. This patch simply checks various old hardening-related macros and ensures that they are not set, which will catch such misuse. (cherry picked from commit 955ece4)
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Backport 955ece4
Requested by: @ldionne