fixed-width macro lines

gistfile1.c

/* macro.h */
#define GREATEST_ASSERT_EQm(MSG, EXP, GOT)                              \
    do {                                                                \
        greatest_info.msg = MSG;                                        \
        greatest_info.fail_file = __FILE__;                             \
        greatest_info.fail_line = __LINE__;                             \
        if ((EXP) != (GOT)) {                                           \
            GREATEST_CALL_TEARDOWN();                                   \
            return -1;                                                  \
        }                                                               \
        greatest_info.msg = NULL;                                       \
    } while (0)

/* use.c */
#include "macro.h"
TEST test_example() {
    GREATEST_ASSERT_EQm("example message", x + 1, 10);

    GREATEST_ASSERT_EQm("example message", x*x, y*y);
}

/* To expand the macro and wrap lines at 70 characters:
       $ cpp use.c | fmt -w 70
*/