Meson and Muon seem to add -Wpedantic automatically.
With GCC 12, even with -std=gnu99, -Wpedantic complains about %m in format strings, __PRETTY_FUNCTION__, braces inside expressions, etc.; and it makes some of these into errors.
Workaround:
--- a/meson.build
+++ b/meson.build
@@ -61,6 +61,9 @@ possible_cc_flags = [
# work-around for gcc 7.1 turning this on on its own.
'-Wno-error=nonnull',
+ # work-around -Wpedantic added by meson/muon
+ '-Wno-pedantic',
+
# Disable -Wmaybe-uninitialized, since it's noisy on gcc 8 with
# optimizations enabled, producing essentially false positives.
'-Wno-maybe-uninitialized',
Error log:
samu: job failed: cc -std=gnu99 -g -Og -Wpedantic -Wextra -Wall -Wextra -Werror=undef -Wlogical-op -Wmissing-include-dirs -Wold-style-definition -Wpointer-arith -Winit-self -Wfloat-equal -Wsuggest-attribute=noretu rn -Werror=missing-prototypes -Werror=implicit-function-declaration -Werror=missing-declarations -Werror=return-type -Werror=incompatible-pointer-types -Werror=format=2 -Wstrict-prototypes -Wredundant-decls -Wmiss ing-noreturn -Wimplicit-fallthrough=5 -Wshadow -Wendif-labels -Wstrict-aliasing=2 -Wwrite-strings -Werror=overflow -Werror=shift-count-overflow -Werror=shift-overflow=2 -Wdate-time -Wnested-externs -Wno-unused-par ameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Wno-format-nonliteral -Wno-error=nonnull -Wno-maybe-uninitialized -ffast-math -fno-common -fdiagnostics-show-option -fno-strict-ali asing -fvisibility=hidden -fstack-protector -fstack-protector-strong --param=ssp-buffer-size=4 -fPIE -ffunction-sections -fdata-sections -Werror=shadow -include /home/ismael/projects/libs/basu/build/config.h -I sr c/test -I ../src/test -I src/basic -I ../src/basic -I src/systemd -I ../src/systemd -I ../src/libsystemd/sd-bus -I ../src/libsystemd/sd-daemon -I ../src/libsystemd/sd-id128 -pthread -fpic -MD -MQ src/test/liblibte st.a.p/tests.c.o -MF src/test/liblibtest.a.p/tests.c.o.d -o src/test/liblibtest.a.p/tests.c.o -c ../src/test/tests.c In file included from ../src/basic/macro.h:381, from ../src/basic/util.h:19, from ../src/test/tests.c:4: ../src/basic/util.h: In function 'qsort_safe': ../src/basic/macro.h:208:72: warning: ISO C does not support '__PRETTY_FUNCTION__' predefined identifier [-Wpedantic] 208 | log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ | ^~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:58:52: note: in definition of macro 'log_assert_failed' 58 | log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__) | ^~~~~~~~~~~ ../src/basic/macro.h:224:22: note: in expansion of macro 'assert_message_se' 224 | #define assert(expr) assert_message_se(expr, #expr) | ^~~~~~~~~~~~~~~~~ ../src/basic/util.h:50:9: note: in expansion of macro 'assert' 50 | assert(base); | ^~~~~~ ../src/basic/util.h: In function 'memcpy_safe': ../src/basic/macro.h:208:72: warning: ISO C does not support '__PRETTY_FUNCTION__' predefined identifier [-Wpedantic] 208 | log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ | ^~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:58:52: note: in definition of macro 'log_assert_failed' 58 | log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__) | ^~~~~~~~~~~ ../src/basic/macro.h:224:22: note: in expansion of macro 'assert_message_se' 224 | #define assert(expr) assert_message_se(expr, #expr) | ^~~~~~~~~~~~~~~~~ ../src/basic/util.h:66:9: note: in expansion of macro 'assert' 66 | assert(src); | ^~~~~~ ../src/basic/util.h: In function 'log2u': ../src/basic/macro.h:208:72: warning: ISO C does not support '__PRETTY_FUNCTION__' predefined identifier [-Wpedantic] 208 | log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ | ^~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:58:52: note: in definition of macro 'log_assert_failed' 58 | log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__) | ^~~~~~~~~~~ ../src/basic/macro.h:224:22: note: in expansion of macro 'assert_message_se' 224 | #define assert(expr) assert_message_se(expr, #expr) | ^~~~~~~~~~~~~~~~~ ../src/basic/util.h:92:9: note: in expansion of macro 'assert' 92 | assert(x > 0); | ^~~~~~ ../src/basic/util.h: In function 'log2u_round_up': ../src/basic/macro.h:208:72: warning: ISO C does not support '__PRETTY_FUNCTION__' predefined identifier [-Wpedantic] 208 | log_assert_failed(message, __FILE__, __LINE__, __PRETTY_FUNCTION__); \ | ^~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:58:52: note: in definition of macro 'log_assert_failed' 58 | log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__) | ^~~~~~~~~~~ ../src/basic/macro.h:224:22: note: in expansion of macro 'assert_message_se' 224 | #define assert(expr) assert_message_se(expr, #expr) | ^~~~~~~~~~~~~~~~~ ../src/basic/util.h:98:9: note: in expansion of macro 'assert' 98 | assert(x > 0); | ^~~~~~ ../src/test/tests.c: In function 'log_tests_skipped': ../src/basic/log.h:80:9: warning: ISO C forbids braced-groups within expressions [-Wpedantic] 80 | ({ \ | ^ ../src/basic/log.h:89:9: note: in expansion of macro 'log_full_errno_realm' 89 | log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:91:30: note: in expansion of macro 'log_full_errno' 91 | #define log_full(level, ...) log_full_errno((level), 0, __VA_ARGS__) | ^~~~~~~~~~~~~~ ../src/basic/log.h:96:28: note: in expansion of macro 'log_full' 96 | #define log_notice(...) log_full(LOG_NOTICE, __VA_ARGS__) | ^~~~~~~~ ../src/test/tests.c:19:9: note: in expansion of macro 'log_notice' 19 | log_notice("%s: %s, skipping tests.", | ^~~~~~~~~~ ../src/test/tests.c: In function 'log_tests_skipped_errno': ../src/test/tests.c:25:29: error: ISO C does not support the '%m' gnu_printf format [-Werror=format=] 25 | log_notice_errno(r, "%s: %s, skipping tests: %m", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:84:76: note: in definition of macro 'log_full_errno_realm' 84 | __FILE__, __LINE__, __func__, __VA_ARGS__) \ | ^~~~~~~~~~~ ../src/basic/log.h:102:41: note: in expansion of macro 'log_full_errno' 102 | #define log_notice_errno(error, ...) log_full_errno(LOG_NOTICE, error, __VA_ARGS__) | ^~~~~~~~~~~~~~ ../src/test/tests.c:25:9: note: in expansion of macro 'log_notice_errno' 25 | log_notice_errno(r, "%s: %s, skipping tests: %m", | ^~~~~~~~~~~~~~~~ ../src/test/tests.c:25:55: note: format string is defined here 25 | log_notice_errno(r, "%s: %s, skipping tests: %m", | ^ ../src/basic/log.h:80:9: warning: ISO C forbids braced-groups within expressions [-Wpedantic] 80 | ({ \ | ^ ../src/basic/log.h:89:9: note: in expansion of macro 'log_full_errno_realm' 89 | log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__) | ^~~~~~~~~~~~~~~~~~~~ ../src/basic/log.h:102:41: note: in expansion of macro 'log_full_errno' 102 | #define log_notice_errno(error, ...) log_full_errno(LOG_NOTICE, error, __VA_ARGS__) | ^~~~~~~~~~~~~~ ../src/test/tests.c:25:9: note: in expansion of macro 'log_notice_errno' 25 | log_notice_errno(r, "%s: %s, skipping tests: %m", | ^~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors
Ismael Luceno referenced this ticket in commit f207324.