[all-commits] [llvm/llvm-project] 946849: [libc++] Workaround the absence of the __GLIBC_USE...

[Tom Honermann via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 946849f6d076dcaebc8b94e2b2eff65224ee27f3
      https://github.com/llvm/llvm-project/commit/946849f6d076dcaebc8b94e2b2eff65224ee27f3
  Author: Tom Honermann <tom at honermann.net>
  Date:   2022-09-11 (Sun, 11 Sep 2022)

  Changed paths:
    M libcxx/include/__config

  Log Message:
  -----------
  [libc++] Workaround the absence of the __GLIBC_USE macro in glibc versions prior to 2.25.

This change correct a configuration check that relies on the glibc __GLIBC_USE
macro being defined. Previously, the function-like macro was expanded without
ensuring it was actually defined. This resulted in compilation failures for
glibc versions prior to 2.25 (the glibc version in which the macro was added).

Differential Revision: https://reviews.llvm.org/D130946