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| author | Nick Mathewson <nickm@torproject.org> | 2018-08-08 15:41:40 -0400 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2018-08-08 15:49:39 -0400 |
| commit | b66386865e68d8df0f228187781fcd5bc2dbf184 (patch) | |
| tree | ff8a46127ecef42de61e631cbfa090a66547d0e6 /configure.ac | |
| parent | 00536254b765900127af04f278ed591d562434d9 (diff) | |
| download | tor-b66386865e68d8df0f228187781fcd5bc2dbf184.tar.gz tor-b66386865e68d8df0f228187781fcd5bc2dbf184.zip | |
Detect broken stdatomic.h, and pretend that it isn't there at all
I hope that the debian clang maintainers will look at debian bug
903709 soon. But until they do, this should keep our users and our
CI happy on sid with clang.
Closes ticket 26779.
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index cd591c785f..8e6683bb71 100644 --- a/configure.ac +++ b/configure.ac @@ -1557,6 +1557,26 @@ AC_CHECK_SIZEOF(socklen_t, , [AC_INCLUDES_DEFAULT() AC_CHECK_SIZEOF(cell_t) +# Let's see if stdatomic works. (There are some debian clangs that screw it +# up; see Tor bug #26779 and debian bug 903709.) +AC_CACHE_CHECK([whether C11 stdatomic.h actually works], + tor_cv_stdatomic_works, +[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ +#include <stdatomic.h> +struct x { atomic_size_t y; }; +void try_atomic_init(struct x *xx) +{ + atomic_init(&xx->y, 99); + atomic_fetch_add(&xx->y, 1); +} +]])], [tor_cv_stdatomic_works=yes], [tor_cv_stdatomic_works=no])]) + +if test "$tor_cv_stdatomic_works" = "yes"; then + AC_DEFINE(STDATOMIC_WORKS, 1, [Set to 1 if we can compile a simple stdatomic example.]) +elif test "$ac_cv_header_stdatomic_h" = "yes"; then + AC_MSG_WARN([Your compiler provides the stdatomic.h header, but it doesn't seem to work. I'll pretend it isn't there. If you are using Clang on Debian, maybe this is because of https://bugs.debian.org/903709 ]) +fi + # Now make sure that NULL can be represented as zero bytes. AC_CACHE_CHECK([whether memset(0) sets pointers to NULL], tor_cv_null_is_zero, [AC_RUN_IFELSE([AC_LANG_SOURCE( |