* compile warning in i8259.c
@ 2021-03-15 15:14 Christian Borntraeger
2021-03-15 15:42 ` Thomas Huth
2021-03-15 15:44 ` Christian Borntraeger
0 siblings, 2 replies; 12+ messages in thread
From: Christian Borntraeger @ 2021-03-15 15:14 UTC (permalink / raw)
To: qemu-devel, qemu-s390x
For some time now I do see the following, when I compile x86-softmmu on s390:
FAILED: libcommon.fa.p/hw_intc_i8259.c.o
cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/capstone -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote . -iquote /home/cborntra/REPOS/qemu -iquote /home/cborntra/REPOS/qemu/include -iquote /home/cborntra/REPOS/qemu/disas/libvixl -iquote /home/cborntra/REPOS/qemu/tcg/s390 -iquote /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ libcommon.fa.p/hw_intc_i8259.c.o -MF libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o -c ../hw/intc/i8259.c
../hw/intc/i8259.c: In function ‘pic_read_irq’:
../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
203 | irq = irq2 + 8;
| ~~~~^~~~~~~~~~
cc1: all warnings being treated as errors
Due to other compile warnings I find this hard to bisect. Has anyone seen this as well?
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: compile warning in i8259.c 2021-03-15 15:14 compile warning in i8259.c Christian Borntraeger @ 2021-03-15 15:42 ` Thomas Huth 2021-03-15 15:46 ` Christian Borntraeger 2021-03-15 15:50 ` Philippe Mathieu-Daudé 2021-03-15 15:44 ` Christian Borntraeger 1 sibling, 2 replies; 12+ messages in thread From: Thomas Huth @ 2021-03-15 15:42 UTC (permalink / raw) To: Christian Borntraeger, qemu-devel, qemu-s390x On 15/03/2021 16.14, Christian Borntraeger wrote: > For some time now I do see the following, when I compile x86-softmmu on s390: > > FAILED: libcommon.fa.p/hw_intc_i8259.c.o > cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader > -I/usr/include/capstone -I/usr/include/glib-2.0 > -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid > -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 > -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz > -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi > -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 > -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 > -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 > -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/virgl > -I/usr/include/p11-kit-1 -I/usr/include/SDL2 -I/usr/include/cacard > -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/slirp > -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g > -isystem /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers > -iquote . -iquote /home/cborntra/REPOS/qemu -iquote > /home/cborntra/REPOS/qemu/include -iquote > /home/cborntra/REPOS/qemu/disas/libvixl -iquote > /home/cborntra/REPOS/qemu/tcg/s390 -iquote > /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE > -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 > -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef > -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common > -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits > -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body > -Wnested-externs -Wendif-labels -Wexpansion-to-defined > -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value > -Wno-psabi -fstack-protector-strong -fPIC -DSTRUCT_IOVEC_DEFINED > -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 > -DNCURSES_WIDECHAR -MD -MQ libcommon.fa.p/hw_intc_i8259.c.o -MF > libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o -c > ../hw/intc/i8259.c > ../hw/intc/i8259.c: In function ‘pic_read_irq’: > ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this > function [-Werror=maybe-uninitialized] > 203 | irq = irq2 + 8; > | ~~~~^~~~~~~~~~ > cc1: all warnings being treated as errors > > Due to other compile warnings I find this hard to bisect. Has anyone seen > this as well? I've never seen this warnings so far... which compiler version is this? Looking at the code, it seems to be a false positive to me. Thomas ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:42 ` Thomas Huth @ 2021-03-15 15:46 ` Christian Borntraeger 2021-03-15 15:50 ` Philippe Mathieu-Daudé 1 sibling, 0 replies; 12+ messages in thread From: Christian Borntraeger @ 2021-03-15 15:46 UTC (permalink / raw) To: Thomas Huth, qemu-devel, qemu-s390x, Paolo Bonzini, Michael S Tsirkin On 15.03.21 16:42, Thomas Huth wrote: > On 15/03/2021 16.14, Christian Borntraeger wrote: >> For some time now I do see the following, when I compile x86-softmmu on s390: >> >> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/capstone -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote . -iquote /home/cborntra/REPOS/qemu -iquote >> /home/cborntra/REPOS/qemu/include -iquote /home/cborntra/REPOS/qemu/disas/libvixl -iquote /home/cborntra/REPOS/qemu/tcg/s390 -iquote /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ libcommon.fa.p/hw_intc_i8259.c.o -MF libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o -c ../hw/intc/i8259.c >> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >> 203 | irq = irq2 + 8; >> | ~~~~^~~~~~~~~~ >> cc1: all warnings being treated as errors >> >> Due to other compile warnings I find this hard to bisect. Has anyone seen this as well? > > I've never seen this warnings so far... which compiler version is this? Looking at the code, it seems to be a false positive to me. Its the fedora33 gcc. ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:42 ` Thomas Huth 2021-03-15 15:46 ` Christian Borntraeger @ 2021-03-15 15:50 ` Philippe Mathieu-Daudé 2021-03-15 15:58 ` Thomas Huth 1 sibling, 1 reply; 12+ messages in thread From: Philippe Mathieu-Daudé @ 2021-03-15 15:50 UTC (permalink / raw) To: Thomas Huth, Christian Borntraeger, qemu-devel, qemu-s390x On 3/15/21 4:42 PM, Thomas Huth wrote: > On 15/03/2021 16.14, Christian Borntraeger wrote: >> For some time now I do see the following, when I compile x86-softmmu >> on s390: >> >> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader >> -I/usr/include/capstone -I/usr/include/glib-2.0 >> -I/usr/lib64/glib-2.0/include -I/usr/include/libmount >> -I/usr/include/blkid -I/usr/include/gio-unix-2.0 >> -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 >> -I/usr/include/pango-1.0 -I/usr/include/harfbuzz >> -I/usr/include/freetype2 -I/usr/include/libpng16 >> -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo >> -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 >> -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 >> -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 >> -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 >> -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 >> -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 >> -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall >> -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem >> /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote >> . -iquote /home/cborntra/REPOS/qemu -iquote >> /home/cborntra/REPOS/qemu/include -iquote >> /home/cborntra/REPOS/qemu/disas/libvixl -iquote >> /home/cborntra/REPOS/qemu/tcg/s390 -iquote >> /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE >> -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 >> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef >> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common >> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits >> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers >> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined >> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs >> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC >> -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE >> -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ >> libcommon.fa.p/hw_intc_i8259.c.o -MF >> libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o >> -c ../hw/intc/i8259.c >> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in >> this function [-Werror=maybe-uninitialized] >> 203 | irq = irq2 + 8; >> | ~~~~^~~~~~~~~~ >> cc1: all warnings being treated as errors >> >> Due to other compile warnings I find this hard to bisect. Has anyone >> seen this as well? > > I've never seen this warnings so far... which compiler version is this? > Looking at the code, it seems to be a false positive to me. https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html =) ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:50 ` Philippe Mathieu-Daudé @ 2021-03-15 15:58 ` Thomas Huth 2021-03-15 16:15 ` Christian Borntraeger 0 siblings, 1 reply; 12+ messages in thread From: Thomas Huth @ 2021-03-15 15:58 UTC (permalink / raw) To: Philippe Mathieu-Daudé, Christian Borntraeger, qemu-devel, qemu-s390x On 15/03/2021 16.50, Philippe Mathieu-Daudé wrote: > On 3/15/21 4:42 PM, Thomas Huth wrote: >> On 15/03/2021 16.14, Christian Borntraeger wrote: >>> For some time now I do see the following, when I compile x86-softmmu >>> on s390: >>> >>> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >>> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader >>> -I/usr/include/capstone -I/usr/include/glib-2.0 >>> -I/usr/lib64/glib-2.0/include -I/usr/include/libmount >>> -I/usr/include/blkid -I/usr/include/gio-unix-2.0 >>> -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 >>> -I/usr/include/pango-1.0 -I/usr/include/harfbuzz >>> -I/usr/include/freetype2 -I/usr/include/libpng16 >>> -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo >>> -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 >>> -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 >>> -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 >>> -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 >>> -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 >>> -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 >>> -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall >>> -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem >>> /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote >>> . -iquote /home/cborntra/REPOS/qemu -iquote >>> /home/cborntra/REPOS/qemu/include -iquote >>> /home/cborntra/REPOS/qemu/disas/libvixl -iquote >>> /home/cborntra/REPOS/qemu/tcg/s390 -iquote >>> /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE >>> -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 >>> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef >>> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common >>> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits >>> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers >>> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined >>> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs >>> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC >>> -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE >>> -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ >>> libcommon.fa.p/hw_intc_i8259.c.o -MF >>> libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o >>> -c ../hw/intc/i8259.c >>> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >>> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in >>> this function [-Werror=maybe-uninitialized] >>> 203 | irq = irq2 + 8; >>> | ~~~~^~~~~~~~~~ >>> cc1: all warnings being treated as errors >>> >>> Due to other compile warnings I find this hard to bisect. Has anyone >>> seen this as well? >> >> I've never seen this warnings so far... which compiler version is this? >> Looking at the code, it seems to be a false positive to me. > > https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html Oh, well, I completely forgot about that one ... but that was with -O3 ... interesting that it now occurs with -O2, too! But even after staring at the code for a while, I cannot see how irq2 may not be initialized here ... so this really rather sounds like a compiler bug to me... anyway, we could simply silence it by pre-initializing the variable to -1 or so? Thomas ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:58 ` Thomas Huth @ 2021-03-15 16:15 ` Christian Borntraeger 0 siblings, 0 replies; 12+ messages in thread From: Christian Borntraeger @ 2021-03-15 16:15 UTC (permalink / raw) To: Thomas Huth, Philippe Mathieu-Daudé, qemu-devel, qemu-s390x On 15.03.21 16:58, Thomas Huth wrote: > On 15/03/2021 16.50, Philippe Mathieu-Daudé wrote: >> On 3/15/21 4:42 PM, Thomas Huth wrote: >>> On 15/03/2021 16.14, Christian Borntraeger wrote: >>>> For some time now I do see the following, when I compile x86-softmmu >>>> on s390: >>>> >>>> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >>>> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader >>>> -I/usr/include/capstone -I/usr/include/glib-2.0 >>>> -I/usr/lib64/glib-2.0/include -I/usr/include/libmount >>>> -I/usr/include/blkid -I/usr/include/gio-unix-2.0 >>>> -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 >>>> -I/usr/include/pango-1.0 -I/usr/include/harfbuzz >>>> -I/usr/include/freetype2 -I/usr/include/libpng16 >>>> -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo >>>> -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 >>>> -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 >>>> -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 >>>> -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 >>>> -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 >>>> -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 >>>> -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall >>>> -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem >>>> /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote >>>> . -iquote /home/cborntra/REPOS/qemu -iquote >>>> /home/cborntra/REPOS/qemu/include -iquote >>>> /home/cborntra/REPOS/qemu/disas/libvixl -iquote >>>> /home/cborntra/REPOS/qemu/tcg/s390 -iquote >>>> /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE >>>> -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 >>>> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef >>>> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common >>>> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits >>>> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers >>>> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined >>>> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs >>>> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC >>>> -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE >>>> -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ >>>> libcommon.fa.p/hw_intc_i8259.c.o -MF >>>> libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o >>>> -c ../hw/intc/i8259.c >>>> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >>>> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in >>>> this function [-Werror=maybe-uninitialized] >>>> 203 | irq = irq2 + 8; >>>> | ~~~~^~~~~~~~~~ >>>> cc1: all warnings being treated as errors >>>> >>>> Due to other compile warnings I find this hard to bisect. Has anyone >>>> seen this as well? >>> >>> I've never seen this warnings so far... which compiler version is this? >>> Looking at the code, it seems to be a false positive to me. >> >> https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html > > Oh, well, I completely forgot about that one ... but that was with -O3 ... interesting that it now occurs with -O2, too! > > But even after staring at the code for a while, I cannot see how irq2 may not be initialized here ... so this really rather sounds like a compiler bug to me... Its not a bug, its part of the nature for "may be" warnings. The compiler cannot figure out. anyway, we could simply silence it by pre-initializing the variable to -1 or so? I can certainly spin up a patch with -1. ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:14 compile warning in i8259.c Christian Borntraeger 2021-03-15 15:42 ` Thomas Huth @ 2021-03-15 15:44 ` Christian Borntraeger 2021-03-15 15:55 ` Philippe Mathieu-Daudé 2021-03-15 16:20 ` Thomas Huth 1 sibling, 2 replies; 12+ messages in thread From: Christian Borntraeger @ 2021-03-15 15:44 UTC (permalink / raw) To: qemu-devel, qemu-s390x; +Cc: Paolo Bonzini, Michael S. Tsirkin On 15.03.21 16:14, Christian Borntraeger wrote: > For some time now I do see the following, when I compile x86-softmmu on s390: > > FAILED: libcommon.fa.p/hw_intc_i8259.c.o > cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/capstone -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote . -iquote /home/cborntra/REPOS/qemu -iquote > /home/cborntra/REPOS/qemu/include -iquote /home/cborntra/REPOS/qemu/disas/libvixl -iquote /home/cborntra/REPOS/qemu/tcg/s390 -iquote /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ libcommon.fa.p/hw_intc_i8259.c.o -MF libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o -c ../hw/intc/i8259.c > ../hw/intc/i8259.c: In function ‘pic_read_irq’: > ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > 203 | irq = irq2 + 8; > | ~~~~^~~~~~~~~~ > cc1: all warnings being treated as errors > > > Due to other compile warnings I find this hard to bisect. Has anyone seen this as well? cc Michael, Paolo, Something like diff --git a/hw/intc/i8259.c b/hw/intc/i8259.c index 344fd04db14d..7335b7a06a67 100644 --- a/hw/intc/i8259.c +++ b/hw/intc/i8259.c @@ -176,7 +176,7 @@ static void pic_intack(PICCommonState *s, int irq) int pic_read_irq(DeviceState *d) { PICCommonState *s = PIC_COMMON(d); - int irq, irq2, intno; + int irq, irq2 = 0, intno; irq = pic_get_irq(s); if (irq >= 0) { would do the trick. Let me know if I should do a proper patch or if you want to have things solved differently. ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:44 ` Christian Borntraeger @ 2021-03-15 15:55 ` Philippe Mathieu-Daudé 2021-03-15 16:43 ` Paolo Bonzini 2021-03-15 16:20 ` Thomas Huth 1 sibling, 1 reply; 12+ messages in thread From: Philippe Mathieu-Daudé @ 2021-03-15 15:55 UTC (permalink / raw) To: Christian Borntraeger, qemu-devel, qemu-s390x Cc: Paolo Bonzini, Michael S. Tsirkin On 3/15/21 4:44 PM, Christian Borntraeger wrote: > On 15.03.21 16:14, Christian Borntraeger wrote: >> For some time now I do see the following, when I compile x86-softmmu >> on s390: >> >> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader >> -I/usr/include/capstone -I/usr/include/glib-2.0 >> -I/usr/lib64/glib-2.0/include -I/usr/include/libmount >> -I/usr/include/blkid -I/usr/include/gio-unix-2.0 >> -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 >> -I/usr/include/pango-1.0 -I/usr/include/harfbuzz >> -I/usr/include/freetype2 -I/usr/include/libpng16 >> -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo >> -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 >> -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 >> -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 >> -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 >> -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 >> -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 >> -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall >> -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem >> /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote >> . -iquote /home/cborntra/REPOS/qemu -iquote >> /home/cborntra/REPOS/qemu/include -iquote >> /home/cborntra/REPOS/qemu/disas/libvixl -iquote >> /home/cborntra/REPOS/qemu/tcg/s390 -iquote >> /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE >> -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 >> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef >> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common >> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits >> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers >> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined >> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs >> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC >> -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE >> -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ >> libcommon.fa.p/hw_intc_i8259.c.o -MF >> libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o >> -c ../hw/intc/i8259.c >> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in >> this function [-Werror=maybe-uninitialized] >> 203 | irq = irq2 + 8; >> | ~~~~^~~~~~~~~~ >> cc1: all warnings being treated as errors >> >> >> Due to other compile warnings I find this hard to bisect. Has anyone >> seen this as well? > > cc Michael, Paolo, > > Something like > > diff --git a/hw/intc/i8259.c b/hw/intc/i8259.c > index 344fd04db14d..7335b7a06a67 100644 > --- a/hw/intc/i8259.c > +++ b/hw/intc/i8259.c > @@ -176,7 +176,7 @@ static void pic_intack(PICCommonState *s, int irq) > int pic_read_irq(DeviceState *d) > { > PICCommonState *s = PIC_COMMON(d); > - int irq, irq2, intno; > + int irq, irq2 = 0, intno; > > irq = pic_get_irq(s); > if (irq >= 0) { > > > would do the trick. Let me know if I should do a proper patch or if you > want to have things solved differently. Since you ask, I'd love to have things solved differently... One PIC has 8 IRQs, so we should model 2 cascaded PICs as 2 cascaded QOM PICs. But this code is so old and heavily used that my desire is unlikely to be realized. And your patch is simpler :> ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:55 ` Philippe Mathieu-Daudé @ 2021-03-15 16:43 ` Paolo Bonzini 0 siblings, 0 replies; 12+ messages in thread From: Paolo Bonzini @ 2021-03-15 16:43 UTC (permalink / raw) To: Philippe Mathieu-Daudé, Christian Borntraeger, qemu-devel, qemu-s390x Cc: Michael S. Tsirkin On 15/03/21 16:55, Philippe Mathieu-Daudé wrote: > Since you ask, I'd love to have things solved differently... > One PIC has 8 IRQs, so we should model 2 cascaded PICs as 2 cascaded > QOM PICs. But this code is so old and heavily used that my desire > is unlikely to be realized. And your patch is simpler :> They are modeled like that, see i8259_init. Perhaps you mean that pic_read_irq should call itself recursively on the slave PIC if irq == 2 && s->master? Paolo ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 15:44 ` Christian Borntraeger 2021-03-15 15:55 ` Philippe Mathieu-Daudé @ 2021-03-15 16:20 ` Thomas Huth 2021-03-15 16:27 ` Richard Henderson 2021-03-15 16:27 ` Christian Borntraeger 1 sibling, 2 replies; 12+ messages in thread From: Thomas Huth @ 2021-03-15 16:20 UTC (permalink / raw) To: Christian Borntraeger, qemu-devel, qemu-s390x Cc: Paolo Bonzini, Michael S. Tsirkin On 15/03/2021 16.44, Christian Borntraeger wrote: > On 15.03.21 16:14, Christian Borntraeger wrote: >> For some time now I do see the following, when I compile x86-softmmu on s390: >> >> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader >> -I/usr/include/capstone -I/usr/include/glib-2.0 >> -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid >> -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 >> -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz >> -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi >> -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 >> -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 >> -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 >> -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include >> -I/usr/include/at-spi-2.0 -I/usr/include/virgl -I/usr/include/p11-kit-1 >> -I/usr/include/SDL2 -I/usr/include/cacard -I/usr/include/nss3 >> -I/usr/include/nspr4 -I/usr/include/slirp -fdiagnostics-color=auto -pipe >> -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem >> /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote . >> -iquote /home/cborntra/REPOS/qemu -iquote >> /home/cborntra/REPOS/qemu/include -iquote >> /home/cborntra/REPOS/qemu/disas/libvixl -iquote >> /home/cborntra/REPOS/qemu/tcg/s390 -iquote >> /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE >> -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 >> -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef >> -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common >> -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits >> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers >> -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined >> -Wimplicit-fallthrough=2 -Wno-missing-include-dirs >> -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC >> -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE >> -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ >> libcommon.fa.p/hw_intc_i8259.c.o -MF libcommon.fa.p/hw_intc_i8259.c.o.d -o >> libcommon.fa.p/hw_intc_i8259.c.o -c ../hw/intc/i8259.c >> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this >> function [-Werror=maybe-uninitialized] >> 203 | irq = irq2 + 8; >> | ~~~~^~~~~~~~~~ >> cc1: all warnings being treated as errors >> >> >> Due to other compile warnings I find this hard to bisect. Has anyone seen >> this as well? > > cc Michael, Paolo, > > Something like > > diff --git a/hw/intc/i8259.c b/hw/intc/i8259.c > index 344fd04db14d..7335b7a06a67 100644 > --- a/hw/intc/i8259.c > +++ b/hw/intc/i8259.c > @@ -176,7 +176,7 @@ static void pic_intack(PICCommonState *s, int irq) > int pic_read_irq(DeviceState *d) > { > PICCommonState *s = PIC_COMMON(d); > - int irq, irq2, intno; > + int irq, irq2 = 0, intno; > > irq = pic_get_irq(s); > if (irq >= 0) { > > > would do the trick. Let me know if I should do a proper patch or if you want > to have things solved differently. Alternate idea, merge the two "irq == 2" blocks: diff a/hw/intc/i8259.c b/hw/intc/i8259.c --- a/hw/intc/i8259.c +++ b/hw/intc/i8259.c @@ -179,19 +179,19 @@ int pic_read_irq(DeviceState *d) int irq, irq2, intno; irq = pic_get_irq(s); - if (irq >= 0) { - if (irq == 2) { - irq2 = pic_get_irq(slave_pic); - if (irq2 >= 0) { - pic_intack(slave_pic, irq2); - } else { - /* spurious IRQ on slave controller */ - irq2 = 7; - } - intno = slave_pic->irq_base + irq2; + if (irq == 2) { + irq2 = pic_get_irq(slave_pic); + if (irq2 >= 0) { + pic_intack(slave_pic, irq2); } else { - intno = s->irq_base + irq; + /* spurious IRQ on slave controller */ + irq2 = 7; } + intno = slave_pic->irq_base + irq2; + pic_intack(s, irq); + irq = irq2 + 8; + } else if (irq >= 0) { + intno = s->irq_base + irq; pic_intack(s, irq); } else { /* spurious IRQ on host controller */ @@ -199,10 +199,6 @@ int pic_read_irq(DeviceState *d) intno = s->irq_base + irq; } - if (irq == 2) { - irq = irq2 + 8; - } - #ifdef DEBUG_IRQ_LATENCY printf("IRQ%d latency=%0.3fus\n", irq, It's a bigger patch, but the code is IMHO easier to read afterwards (less indentation). Thomas ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 16:20 ` Thomas Huth @ 2021-03-15 16:27 ` Richard Henderson 2021-03-15 16:27 ` Christian Borntraeger 1 sibling, 0 replies; 12+ messages in thread From: Richard Henderson @ 2021-03-15 16:27 UTC (permalink / raw) To: Thomas Huth, Christian Borntraeger, qemu-devel, qemu-s390x Cc: Paolo Bonzini, Michael S. Tsirkin On 3/15/21 10:20 AM, Thomas Huth wrote: > + if (irq == 2) { > + irq2 = pic_get_irq(slave_pic); This looks better. You should also be able to pull in the declaration to int irq2 = pic_get_irq(slave_pic); here. r~ ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: compile warning in i8259.c 2021-03-15 16:20 ` Thomas Huth 2021-03-15 16:27 ` Richard Henderson @ 2021-03-15 16:27 ` Christian Borntraeger 1 sibling, 0 replies; 12+ messages in thread From: Christian Borntraeger @ 2021-03-15 16:27 UTC (permalink / raw) To: Thomas Huth, qemu-devel, qemu-s390x; +Cc: Paolo Bonzini, Michael S. Tsirkin On 15.03.21 17:20, Thomas Huth wrote: > On 15/03/2021 16.44, Christian Borntraeger wrote: >> On 15.03.21 16:14, Christian Borntraeger wrote: >>> For some time now I do see the following, when I compile x86-softmmu on s390: >>> >>> FAILED: libcommon.fa.p/hw_intc_i8259.c.o >>> cc -Ilibcommon.fa.p -I. -I.. -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/capstone -I/usr/include/glib-2.0 -I/usr/lib64/glib-2.0/include -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/gio-unix-2.0 -I/usr/include/libusb-1.0 -I/usr/include/vte-2.91 -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/fribidi -I/usr/include/libxml2 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/gtk-3.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -I/usr/include/at-spi-2.0 -I/usr/include/virgl -I/usr/include/p11-kit-1 -I/usr/include/SDL2 -I/usr/include/cacard -I/usr/include/nss3 -I/usr/include/nspr4 -I/usr/include/slirp -fdiagnostics-color=auto -pipe -Wall -Winvalid-pch -Werror -std=gnu99 -O2 -g -isystem /home/cborntra/REPOS/qemu/linux-headers -isystem linux-headers -iquote . -iquote /home/cborntra/REPOS/qemu >>> -iquote /home/cborntra/REPOS/qemu/include -iquote /home/cborntra/REPOS/qemu/disas/libvixl -iquote /home/cborntra/REPOS/qemu/tcg/s390 -iquote /home/cborntra/REPOS/qemu/accel/tcg -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -m64 -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes -Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes -fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration -Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels -Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs -Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIC -DSTRUCT_IOVEC_DEFINED -D_REENTRANT -Wno-undef -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -DNCURSES_WIDECHAR -MD -MQ libcommon.fa.p/hw_intc_i8259.c.o -MF libcommon.fa.p/hw_intc_i8259.c.o.d -o libcommon.fa.p/hw_intc_i8259.c.o -c ../hw/intc/i8259.c >>> ../hw/intc/i8259.c: In function ‘pic_read_irq’: >>> ../hw/intc/i8259.c:203:13: error: ‘irq2’ may be used uninitialized in this function [-Werror=maybe-uninitialized] >>> 203 | irq = irq2 + 8; >>> | ~~~~^~~~~~~~~~ >>> cc1: all warnings being treated as errors >>> >>> >>> Due to other compile warnings I find this hard to bisect. Has anyone seen this as well? >> >> cc Michael, Paolo, >> >> Something like >> >> diff --git a/hw/intc/i8259.c b/hw/intc/i8259.c >> index 344fd04db14d..7335b7a06a67 100644 >> --- a/hw/intc/i8259.c >> +++ b/hw/intc/i8259.c >> @@ -176,7 +176,7 @@ static void pic_intack(PICCommonState *s, int irq) >> int pic_read_irq(DeviceState *d) >> { >> PICCommonState *s = PIC_COMMON(d); >> - int irq, irq2, intno; >> + int irq, irq2 = 0, intno; >> >> irq = pic_get_irq(s); >> if (irq >= 0) { >> >> >> would do the trick. Let me know if I should do a proper patch or if you want to have things solved differently. > > Alternate idea, merge the two "irq == 2" blocks: > > diff a/hw/intc/i8259.c b/hw/intc/i8259.c > --- a/hw/intc/i8259.c > +++ b/hw/intc/i8259.c > @@ -179,19 +179,19 @@ int pic_read_irq(DeviceState *d) > int irq, irq2, intno; > > irq = pic_get_irq(s); > - if (irq >= 0) { > - if (irq == 2) { > - irq2 = pic_get_irq(slave_pic); > - if (irq2 >= 0) { > - pic_intack(slave_pic, irq2); > - } else { > - /* spurious IRQ on slave controller */ > - irq2 = 7; > - } > - intno = slave_pic->irq_base + irq2; > + if (irq == 2) { > + irq2 = pic_get_irq(slave_pic); > + if (irq2 >= 0) { > + pic_intack(slave_pic, irq2); > } else { > - intno = s->irq_base + irq; > + /* spurious IRQ on slave controller */ > + irq2 = 7; > } > + intno = slave_pic->irq_base + irq2; > + pic_intack(s, irq); > + irq = irq2 + 8; > + } else if (irq >= 0) { > + intno = s->irq_base + irq; > pic_intack(s, irq); > } else { > /* spurious IRQ on host controller */ > @@ -199,10 +199,6 @@ int pic_read_irq(DeviceState *d) > intno = s->irq_base + irq; > } > > - if (irq == 2) { > - irq = irq2 + 8; > - } > - > #ifdef DEBUG_IRQ_LATENCY > printf("IRQ%d latency=%0.3fus\n", > irq, > > It's a bigger patch, but the code is IMHO easier to read afterwards (less indentation). I would defer such a change to someone more familiar with x86. ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2021-03-15 16:48 UTC | newest] Thread overview: 12+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2021-03-15 15:14 compile warning in i8259.c Christian Borntraeger 2021-03-15 15:42 ` Thomas Huth 2021-03-15 15:46 ` Christian Borntraeger 2021-03-15 15:50 ` Philippe Mathieu-Daudé 2021-03-15 15:58 ` Thomas Huth 2021-03-15 16:15 ` Christian Borntraeger 2021-03-15 15:44 ` Christian Borntraeger 2021-03-15 15:55 ` Philippe Mathieu-Daudé 2021-03-15 16:43 ` Paolo Bonzini 2021-03-15 16:20 ` Thomas Huth 2021-03-15 16:27 ` Richard Henderson 2021-03-15 16:27 ` Christian Borntraeger
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