--- muppet wrote:
> writing your own printf-style macros is actually a very common idiom
> for getting around this sort of technical problem. they, of course,
> raise the further problem that GCC's vararg macros are not portable,
> and C99's vararg macros are not yet universally supported.
Agreed. I missed that __VA_ARGS__ earlier; that won't work on many
current C compilers.
In an attempt to do varargs ok() without the magical __VA_ARGS__,
I've come up with two little example solutions shown below.
Improvements welcome.
/* Sound version but with ugly XX symbol ----------------- */
#include <stdio.h>
#include <stdarg.h>
#define XX __FILE__,__LINE__
void ok(int cond, const char* file, unsigned long line, const char* fmt, ...) {
va_list t;
printf("cond:%d file:%s line:%lu, ", cond, file, line);
va_start(t, fmt);
vprintf(fmt, t);
va_end(t);
}
int main() {
ok(1==1, XX, "test %s %d\n", "one eq one", 42);
ok(0==1, XX, "test %s %d\n", "zero eq one", 43);
return 0;
}
/* Horrible hacky thread-unsafe version but no XX -------- */
#include <stdio.h>
#include <stdarg.h>
#define ok ok_save(__FILE__, __LINE__)
typedef void (*ok_t)(int, const char*, ...);
static const char* g_file;
static unsigned long g_line;
void gr(int cond, const char* fmt, ...) {
va_list t;
printf("cond:%d file:%s line:%lu, ", cond, g_file, g_line);
va_start(t, fmt);
vprintf(fmt, t);
va_end(t);
}
ok_t ok_save(const char* file, unsigned long line) {
g_file = file;
g_line = line;
return gr;
}
int main() {
ok(1==1, "test %s %d\n", "one eq one", 42);
ok(0==1, "test %s %d\n", "zero eq one", 43);
return 0;
}
/* ------------------------------------------------------- */
/-\
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