doc: note why we can't use thread_local with glibc back compat

5 years ago · 20a30922fb
parent d65631171c
commit 20a30922fb
1 changed files with 3 additions and 0 deletions
--- a/configure.ac
+++ b/configure.ac
@ -861,6 +861,9 @@ AC_LINK_IFELSE([AC_LANG_SOURCE([
  ]
 )

+dnl thread_local is currently disabled when building with glibc back compat.
+dnl Our minimum supported glibc is 2.17, however support for thread_local
+dnl did not arrive in glibc until 2.18.
 if test "x$use_thread_local" = xyes || { test "x$use_thread_local" = xauto && test "x$use_glibc_compat" = xno; }; then
  TEMP_LDFLAGS="$LDFLAGS"
  LDFLAGS="$TEMP_LDFLAGS $PTHREAD_CFLAGS"