atf-c/macros/use: fails with clang -Wunused on FreeBSD head

[ngie-eign]

Both the base and port testcases for atf appear to be failing on FreeBSD CURRENT because of clang -Wunused ( http://kyua3.nyi.freebsd.org/head/data/0-LATEST/results/local_atf_atf-c_macros_test_use.html ):

/usr/tests/local/atf/atf-c/macros_h_test.c:86:1: error: unused variable 'atfu_TEST_MACRO_1_tc_pack' [-Werror,-Wunused-const-variable]
ATF_TC(TEST_MACRO_1);
^
/usr/local/include/atf-c/macros.h:61:26: note: expanded from macro 'ATF_TC'
    static atf_tc_pack_t atfu_ ## tc ## _tc_pack = { \
                         ^
:41:1: note: expanded from here
atfu_TEST_MACRO_1_tc_pack
^
/usr/tests/local/atf/atf-c/macros_h_test.c:92:1: error: unused variable 'atfu_TEST_MACRO_2_tc_pack' [-Werror,-Wunused-const-variable]
ATF_TC_WITH_CLEANUP(TEST_MACRO_2);
^
/usr/local/include/atf-c/macros.h:73:26: note: expanded from macro 'ATF_TC_WITH_CLEANUP'
    static atf_tc_pack_t atfu_ ## tc ## _tc_pack = { \
                         ^
:66:1: note: expanded from here
atfu_TEST_MACRO_2_tc_pack
^
/usr/tests/local/atf/atf-c/macros_h_test.c:100:1: error: unused variable 'atfu_TEST_MACRO_3_tc_pack' [-Werror,-Wunused-const-variable]
ATF_TC_WITHOUT_HEAD(TEST_MACRO_3);
^
/usr/local/include/atf-c/macros.h:50:26: note: expanded from macro 'ATF_TC_WITHOUT_HEAD'
    static atf_tc_pack_t atfu_ ## tc ## _tc_pack = { \
                         ^
:93:1: note: expanded from here
atfu_TEST_MACRO_3_tc_pack
^
3 errors generated.
cc failed with exit code 1

The code will probably need to be modified to use the variable, or to just add __attribute__((__unused__)) around the declaration.

[ngie-eign]

Confirmed that it's still occurring with handrolled copy of atf via bd96595.

[jmmv]

Oh wow, I wonder how this went unnoticed for so long. Seems a legitimate problem with the tests but I haven't tried to reproduce yet. Bleh, different warning diagnostics across different compilers.

Adding __attribute__((__unused__)) is going to be tricky because the code triggering the problem comes from within macros.

The easiest way out, I think, would be to actually put the unused variables to use by referencing them. Doing something like:

atf_tc_pack_t *test_pack_1 = ATF_TC_PACK_NAME(TEST_MACRO_1)

should do the trick. The trick is to not make pack1 static so that the compiler can't tell it's not being used (just as we do with test_name_1).