Re: [PATCH v3 2/3] win32: allow building with pedantic mode enabled
From: Junio C Hamano <hidden>
Date: 2021-09-03 20:32:40
Carlo Marcelo Arenas Belón [off-list ref] writes:
quoted
A slightly shorter fix would be to replace "tck" with "mem". Not as obvious without further context, though.so something like this on top?
quoted hunk
Carlo ---- > 8 ----diff --git a/compat/nedmalloc/nedmalloc.c b/compat/nedmalloc/nedmalloc.c index edb438a777..14e8c4df4f 100644 --- a/compat/nedmalloc/nedmalloc.c +++ b/compat/nedmalloc/nedmalloc.c@@ -510,7 +510,15 @@ static void threadcache_free(nedpool *p, threadcache *tc, int mymspace, void *me assert(idx<=THREADCACHEMAXBINS); if(tck==*binsptr) { - fprintf(stderr, "Attempt to free already freed memory block %p - aborting!\n", (void *)tck); + /* + * Original code used tck instead of mem, but that was changed + * to workaround a pedantic warning from mingw64 gcc 10.3 that + * requires %p to have a explicit (void *) as a parameter. + * + * This might seem to be a compiler bug or limitation that + * should be changed back if fixed for maintanability. + */ + fprintf(stderr, "Attempt to free already freed memory block %p - aborting!\n", mem); abort(); }
The new comment explains why the original (i.e. unadorned 'tck'), which should work fine, needs to be changed. The reason is because a version of compiler wants an explict (void *) cast to go with the placeholder "%p". Given that, it would be much better to pass (void *)tck instead of mem, no? Especially since the comment does not say tck and mem have the same pointer value. Having said lal that, I have to wonder if how much help the developer who is hunting for allocation bug is getting out of a raw pointer value in this message, though.