https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92016
Bug ID: 92016
Summary: excess errors in Wstringop-overflow-17.c
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
The recently added gcc.dg/Wstringop-overflow-17.c test shows excess errors:
FAIL: gcc.dg/Wstringop-overflow-17.c (test for excess errors)
E.g.: https://gcc.gnu.org/ml/gcc-testresults/2019-10/msg00450.html
The output shows that the exact same warning is repeated for each past-the-end
write by the test (made in a loop). This is most likely the result of the
even more recent optimization improvement in r276645 (pr91975). The warning is
correct but the output too noisy. It would be much better to emit just a
single instance for all the invalid accesses.
In function ‘copy_n’,
inlined from ‘call_copy_n’ at gcc.dg/Wstringop-overflow-17.c:18:3:
gcc.dg/Wstringop-overflow-17.c:9:10: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]
9 | *d++ = *s++;
| ~~~~~^~~~~~
gcc.dg/Wstringop-overflow-17.c: In function ‘call_copy_n’:
gcc.dg/Wstringop-overflow-17.c:17:8: note: destination object declared here
17 | char a[3]; // { dg-message "destination object declared here"
}
| ^
In function ‘copy_n’,
inlined from ‘call_copy_n’ at gcc.dg/Wstringop-overflow-17.c:18:3:
gcc.dg/Wstringop-overflow-17.c:9:10: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]
9 | *d++ = *s++;
| ~~~~~^~~~~~
gcc.dg/Wstringop-overflow-17.c: In function ‘call_copy_n’:
gcc.dg/Wstringop-overflow-17.c:17:8: note: destination object declared here
17 | char a[3]; // { dg-message "destination object declared here"
}
| ^
In function ‘copy_n’,
inlined from ‘call_copy_n’ at gcc.dg/Wstringop-overflow-17.c:18:3:
gcc.dg/Wstringop-overflow-17.c:9:10: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]
9 | *d++ = *s++;
| ~~~~~^~~~~~
gcc.dg/Wstringop-overflow-17.c: In function ‘call_copy_n’:
gcc.dg/Wstringop-overflow-17.c:17:8: note: destination object declared here
17 | char a[3]; // { dg-message "destination object declared here"
}
| ^
In function ‘copy_n’,
inlined from ‘call_copy_n’ at gcc.dg/Wstringop-overflow-17.c:18:3:
gcc.dg/Wstringop-overflow-17.c:9:10: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]
9 | *d++ = *s++;
| ~~~~~^~~~~~
gcc.dg/Wstringop-overflow-17.c: In function ‘call_copy_n’:
gcc.dg/Wstringop-overflow-17.c:17:8: note: destination object declared here
17 | char a[3]; // { dg-message "destination object declared here"
}
| ^
In function ‘copy_n’,
inlined from ‘call_copy_n’ at gcc.dg/Wstringop-overflow-17.c:18:3:
gcc.dg/Wstringop-overflow-17.c:10:6: warning: writing 1 byte into a region of
size 0 [-Wstringop-overflow=]
10 | *d = 0; // { dg-warning "writing 1 byte into a region of
size 0" }
| ~~~^~~
gcc.dg/Wstringop-overflow-17.c: In function ‘call_copy_n’:
gcc.dg/Wstringop-overflow-17.c:17:8: note: destination object declared here
17 | char a[3]; // { dg-message "destination object declared here"
}
| ^
