[libc-commits] [libc] [llvm] [libc] Clean up libc_errno implementation, dependencies, and add __errno_location alias (PR #235421)

[Pavel Labath via libc-commits]

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@@ -46,13 +47,20 @@
 
 #if !defined(LIBC_ERRNO_MODE) || LIBC_ERRNO_MODE == LIBC_ERRNO_MODE_DEFAULT
 #undef LIBC_ERRNO_MODE
-#if defined(LIBC_FULL_BUILD) || !defined(LIBC_COPT_PUBLIC_PACKAGING)
+#if defined(LIBC_FULL_BUILD) || (!defined(LIBC_COPT_PUBLIC_PACKAGING) &&       \
+                                 !defined(LLVM_LIBC_SHARED_LIBC_COMMON_H))
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labath wrote:

Having a different behavior depending on whether some other header was included (first) seems dangerous, as one generally assumes that e.g. clang-formatting the include list is a no-op. What is this trying to do, and is there a way to avoid that?

https://github.com/llvm/llvm-project/pull/235421