https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99676
Bug ID: 99676
Summary: missing detail in warning for passing smaller array to
bigger argument
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The warning(s) below are confusing:
1) each mentions the argument type is 'int *' when it actually uses 'int[4]' to
trigger, and
2) it doesn't point to the declaration of the object or subobject whose size it
uses.
In cases like pr99673 the missing details make the warning harder than
necessary to understand and decide if it's a false positive.
$ cat x.c && gcc -O -S -Wall x.c
struct A { int a[2], b[2]; };
void f (int[4], int[4]);
void g (int *p, int *q)
{
f (p, q);
}
void h (struct A *p)
{
g (p->a, p->b);
}
In function ‘g’,
inlined from ‘h’ at x.c:12:3:
x.c:7:3: warning: ‘f’ accessing 16 bytes in a region of size 8
[-Wstringop-overflow=]
7 | f (p, q);
| ^~~~~~~~
x.c: In function ‘h’:
x.c:7:3: note: referencing argument 1 of type ‘int *’
In function ‘g’,
inlined from ‘h’ at x.c:12:3:
x.c:7:3: warning: ‘f’ accessing 16 bytes in a region of size 8
[-Wstringop-overflow=]
x.c: In function ‘h’:
x.c:7:3: note: referencing argument 2 of type ‘int *’
x.c:3:6: note: in a call to function ‘f’
3 | void f (int[4], int[4]);
| ^
