diff options
Diffstat (limited to 'autoconf/configure.ac')
| -rw-r--r-- | autoconf/configure.ac | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/autoconf/configure.ac b/autoconf/configure.ac index cb217a5..56853e9 100644 --- a/autoconf/configure.ac +++ b/autoconf/configure.ac @@ -372,7 +372,6 @@ case "$enableval" in default) AC_SUBST(ENABLE_THREADS,[1]) ;; *) AC_MSG_ERROR([Invalid setting for --enable-threads. Use "yes" or "no"]) ;; esac -AC_DEFINE_UNQUOTED([ENABLE_THREADS],$ENABLE_THREADS,[Define if threads enabled]) dnl Allow building without position independent code AC_ARG_ENABLE(pic, @@ -897,6 +896,26 @@ if test "$llvm_cv_platform_type" = "Unix" ; then fi fi +dnl atomic builtins are required for threading support. +if test "$ENABLE_THREADS" -eq 1 ; then + AC_MSG_CHECKING(for GCC atomic builtins) + AC_LINK_IFELSE( + AC_LANG_SOURCE( + [[int main() { + volatile unsigned long val = 1; + __sync_synchronize(); + __sync_val_compare_and_swap(&val, 1, 0); + return 0; + } + ]]), + AC_MSG_RESULT(yes), + AC_MSG_RESULT(no) + AC_SUBST(ENABLE_THREADS, [0]) + AC_MSG_WARN([Threading support disabled because atomic builtins are missing])) +fi + +AC_DEFINE_UNQUOTED([ENABLE_THREADS],$ENABLE_THREADS,[Define if threads enabled]) + dnl===-----------------------------------------------------------------------=== dnl=== dnl=== SECTION 9: Additional checks, variables, etc. |