[libc] Fix vdso VER_FLG_BASE redefinition in overlay mod.

[lntue]

No description provided.

[llvmbot]

@llvm/pr-subscribers-libc

Author: None (lntue)

Changes

---

Full diff: /~https://github.com/llvm/llvm-project/pull/108628.diff

1 Files Affected:

• (modified) libc/src/__support/OSUtil/linux/vdso.cpp (+2)

diff --git a/libc/src/__support/OSUtil/linux/vdso.cpp b/libc/src/__support/OSUtil/linux/vdso.cpp
index cb43764badad1f..8c9bd3e1bcc72b 100644
--- a/libc/src/__support/OSUtil/linux/vdso.cpp
+++ b/libc/src/__support/OSUtil/linux/vdso.cpp
@@ -57,7 +57,9 @@ struct Verdef {
 // https://refspecs.linuxfoundation.org/LSB_1.3.0/gLSB/gLSB/symversion.html#SYMVERTBL
 cpp::string_view find_version(Verdef *verdef, ElfW(Half) * versym,
                               const char *strtab, size_t idx) {
+#ifndef VER_FLG_BASE
   constexpr ElfW(Half) VER_FLG_BASE = 0x1;
+#endif
   if (!versym)
     return "";
   ElfW(Half) identifier = versym[idx] & 0x7FFF;