Older versions of Solaris didn't declare __builtin_alloca; the prototype provided for it with gdb doesn't agree with the one supplied with current Solaris versions.
--- ./libiberty/alloca-norm.h.org Thu Jun 29 04:15:41 1995 +++ ./libiberty/alloca-norm.h Sat Sep 6 14:50:35 1997 @@ -5,7 +5,7 @@ #else /* not __GNUC__ */ #ifdef sparc #include <alloca.h> -extern char *__builtin_alloca(); /* Stupid include file doesn't declare it */ +extern void *__builtin_alloca(); /* Stupid include file doesn't declare it */ #else #ifdef __STDC__ PTR alloca (size_t);