https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86850
Bug ID: 86850
Summary: ubsan: runtime error: member call on null pointer
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
This C code:
struct {
long a[0]
} b;
c, d, k;
long l() {
long e, g, h, j;
int f, i;
for (; i < 4; i++)
j = h < 0;
e += i >> i + j ^ j;
g -= h + j ^ j;
for (i--; i; i++) {
j = -(h < 0);
e += i >> i + j ^ g >> 1;
g -= h >> 1 + j ^ j;
h -= c + j ^ j;
}
return f << 7 + e;
}
m() {
if (d)
if (k)
b.a[1] = b.a[0] = l() - 4;
}
when compiled by a recent ubsan version of trunk, does this:
$ ~/gcc/results.263285.ubsan/bin/gcc -c -O3 -std=c89 -w bug453.c
../../trunk/gcc/vec.h:1688:5: runtime error: member call on null pointer of
type 'struct vec'
It is fine at lower optimise levels:
$ ~/gcc/results.263285.ubsan/bin/gcc -c -O2 -std=c89 -w bug453.c
$
