https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88993
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-01-24
Known to work| |8.2.0
Blocks| |85741
Summary|GCC 9 -Wformat-overflow=2 |[9 Regression] GCC 9
|should reflect real libc |-Wformat-overflow=2 should
|limits |reflect real libc limits
Ever confirmed|0 |1
Known to fail| |9.0
--- Comment #7 from Martin Sebor <msebor at gcc dot gnu.org> ---
Thanks. I've built qemu 3.1.0 with -Wformat-overflow=2 myself and reproduced
the warnings below. Of those, 16 are for fprintf, 106 for printf, and 20 for
sprintf. At least some of these look like they would be hard to deal with and
for little gain. For example:
qemu-3.1.0/linux-user/main.c:484:27: warning: ‘%-*s’ directive output
between 0 and 2147483648 bytes may exceed minimum required size of 4095
[-Wform
at-overflow=]
484 | printf("-%-*s %-*s %s\n", maxarglen, arginfo->argv,
| ^~~~
Let me confirm this as a regression and look into doing something about it for
GCC 9.
Diagnostic Count Unique Files
-Wstringop-truncation 247 1 1
-Waddress-of-packed-member 189 134 15
-Wformat-overflow= 143 24 6
-Wformat-overflow Instances:
/build/tmp/qemu-3.1.0/hw/intc/exynos4210_gic.c:316
/build/tmp/qemu-3.1.0/hw/intc/exynos4210_gic.c:326
/build/tmp/qemu-3.1.0/hw/vfio/pci.c:2220
/build/tmp/qemu-3.1.0/linux-user/main.c:475
/build/tmp/qemu-3.1.0/linux-user/main.c:480
/build/tmp/qemu-3.1.0/linux-user/main.c:484
migration/savevm.c:418
migration/savevm.c:420
migration/savevm.c:421
migration/savevm.c:423
migration/savevm.c:425
migration/savevm.c:430
migration/savevm.c:447
migration/savevm.c:449
migration/savevm.c:452
migration/savevm.c:453
migration/savevm.c:455
migration/savevm.c:461
migration/savevm.c:476
migration/savevm.c:482
migration/savevm.c:492
migration/savevm.c:494
qemu-img.c:200
qemu-io.c:422
-Wstringop-truncation Instances:
/usr/include/bits/string_fortified.h:106
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85741
[Bug 85741] [meta-bug] bogus/missing -Wformat-overflow
