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| author | Lonnie Abelbeck <lonnie@abelbeck.com> | 2022-05-08 14:05:56 -0500 |
|---|---|---|
| committer | Tormod Volden <debian.tormod@gmail.com> | 2022-06-26 17:09:14 +0200 |
| commit | 95e601ce116dd46ea7915c171976b85ea0905d58 (patch) | |
| tree | 76fb50434456b0b2d15ac01495882e7d4e57866d | |
| parent | 0c09ba6dafd4da2f803743c5b344b195b1338077 (diff) | |
| download | libusb-95e601ce116dd46ea7915c171976b85ea0905d58.tar.gz | |
configure.ac: Link with -latomic only if no atomic builtins
Follow-up to 561dbda, a check of GCC atomic builtins needs to be done
first.
I'm no autoconf guru, but using this:
https://github.com/mesa3d/mesa/blob/0df485c285b73c34ba9062f0c27e55c3c702930d/configure.ac#L469
as inspiration, I created a pre-check before calling AC_SEARCH_LIBS(...)
Fixes #1135
Closes #1139
| -rw-r--r-- | configure.ac | 16 | ||||
| -rw-r--r-- | libusb/version_nano.h | 2 |
2 files changed, 16 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac index 968cdb7..bf423d1 100644 --- a/configure.ac +++ b/configure.ac @@ -153,7 +153,21 @@ if test "x$platform" = xposix; then AC_SEARCH_LIBS([pthread_create], [pthread], [test "x$ac_cv_search_pthread_create" != "xnone required" && AC_SUBST(THREAD_LIBS, [-lpthread])], [], []) - AC_SEARCH_LIBS([__atomic_fetch_add_4], [atomic]) + dnl Check for new-style atomic builtins. We first check without linking to -latomic. + AC_MSG_CHECKING(whether __atomic_load_n is supported) + AC_LINK_IFELSE([AC_LANG_SOURCE([[ + #include <stdint.h> + int main() { + struct { + uint64_t *v; + } x; + return (int)__atomic_load_n(x.v, __ATOMIC_ACQUIRE) & + (int)__atomic_add_fetch(x.v, (uint64_t)1, __ATOMIC_ACQ_REL); + }]])], GCC_ATOMIC_BUILTINS_SUPPORTED=yes, GCC_ATOMIC_BUILTINS_SUPPORTED=no) + AC_MSG_RESULT($GCC_ATOMIC_BUILTINS_SUPPORTED) + if test "x$GCC_ATOMIC_BUILTINS_SUPPORTED" != xyes; then + AC_SEARCH_LIBS([__atomic_fetch_add_4], [atomic]) + fi elif test "x$platform" = xwindows; then AC_DEFINE([PLATFORM_WINDOWS], [1], [Define to 1 if compiling for a Windows platform.]) else diff --git a/libusb/version_nano.h b/libusb/version_nano.h index 80f51e2..f5bc7d1 100644 --- a/libusb/version_nano.h +++ b/libusb/version_nano.h @@ -1 +1 @@ -#define LIBUSB_NANO 11733 +#define LIBUSB_NANO 11734 |