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From: "vries at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/65901] New: no warning or error for va_arg (ap, void) Date: Mon, 27 Apr 2015 12:48:00 -0000 [thread overview] Message-ID: <bug-65901-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65901 Bug ID: 65901 Summary: no warning or error for va_arg (ap, void) Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: minor Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: vries at gcc dot gnu.org Target Milestone: --- We have va_arg (ap, void) somewhere in the testsuite (gcc.c-torture/compile/pr48767.c). AFAIU, using void in va_arg is undefined behaviour in c. Currently, we just compile it without warning or error: ... $ cat ~/va-arg-void.c #include <stdarg.h> int f (int d, ...) { int res; va_list ap; va_start (ap, d); va_arg (ap, void); res = va_arg (ap, int); va_end (ap); return res; } int main (void) { return f (1, 2, 3); } $ gcc -O2 ~/va-arg-void.c $ ./a.out ; echo $? 3 ... Btw, note that va_arg (ap, void) has an effect on ap.
next reply other threads:[~2015-04-27 12:48 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-04-27 12:48 vries at gcc dot gnu.org [this message] 2015-04-27 16:04 ` [Bug c/65901] " mpolacek at gcc dot gnu.org 2015-04-28 8:37 ` mpolacek at gcc dot gnu.org 2015-04-28 8:37 ` mpolacek at gcc dot gnu.org
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