https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105316
Bug ID: 105316
Summary: Seemingly bogus -Wdangling-pointer from ppc/ppc64
kernel printk with gcc12
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: raj.khem at gmail dot com
Target Milestone: ---
I have reduced this case from ppc kernel 5.15, this breaks the kernel build as
the warning is treated as error.
ftrace.i
======================
int _printk(const char *fmt, ...);
static void ftrace_modify_code() {
_printk("replaced (%s)", ({ char __str[sizeof("00000000 00000000")]; __str;
}));
}
=====================
powerpc64le-yoe-linux-musl-gcc -c ftrace.i -Werror=dangling-pointer
ftrace.i: In function 'ftrace_modify_code':
ftrace.i:4:2: error: using a dangling pointer to '__str'
[-Werror=dangling-pointer=]
4 | _printk("replaced (%s)", ({ char __str[sizeof("00000000 00000000")];
__str; }));
|
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ftrace.i:4:35: note: '__str' declared here
4 | _printk("replaced (%s)", ({ char __str[sizeof("00000000 00000000")];
__str; }));
| ^~~~~
cc1: some warnings being treated as errors
