When the Error API was created, we adopted the (unwritten) rule to
return void when the function returns no useful value on success,
unlike GError, which recommends to return true on success and false on
error then.
When a function returns a distinct error value, say false, a checked
call that passes the error up looks like
if (!frobnicate(..., errp)) {
handle the error...
}
When it returns void, we need
Error *err = NULL;
frobnicate(..., &err);
if (err) {
handle the error...
error_propagate(errp, err);
}
Not only is this more verbose, it also creates an Error object even
when @errp is null, &error_abort or &error_fatal.
People got tired of the additional boilerplate, and started to ignore
the unwritten rule. The result is confusion among developers about
the preferred usage.
This series adopts the GError rule (in writing), and updates a
substantial amount of code to honor the rule. Cuts the number of
error_propagate() calls nearly by half. The diffstat speaks for
itself.
Based on my "[PATCH v2 00/25] Error handling fixes & cleanups". Also
available from my public repository https://repo.or.cz/qemu/armbru.git
on branch error-smooth.
Based-on: <20200624083737.3086768-1-armbru@redhat.com>
Markus Armbruster (46):
error: Improve examples in error.h's big comment
error: Document Error API usage rules
qdev: Smooth error checking of qdev_realize() & friends
macio: Tidy up error handling in macio_newworld_realize()
virtio-crypto-pci: Tidy up virtio_crypto_pci_realize()
error: Avoid error_propagate() when error is not used here
error: Avoid more error_propagate() when error is not used here
error: Avoid unnecessary error_propagate() after error_setg()
error: Avoid error_propagate() after migrate_add_blocker()
qemu-option: Check return value instead of @err where convenient
qemu-option: Make uses of find_desc_by_name() more similar
qemu-option: Factor out helper find_default_by_name()
qemu-option: Simplify around find_default_by_name()
qemu-option: Factor out helper opt_create()
qemu-option: Tidy up opt_set() not to free arguments on failure
qemu-option: Make functions taking Error ** return bool, not void
qemu-option: Smooth error checking with Coccinelle
qemu-option: Smooth error checking manually
block: Avoid unnecessary error_propagate() after error_setg()
block: Avoid error accumulation in bdrv_img_create()
hmp: Eliminate a variable in hmp_migrate_set_parameter()
qapi: Make visitor functions taking Error ** return bool, not void
qapi: Smooth error checking with Coccinelle
qapi: Smooth error checking manually
qapi: Smooth visitor error checking in generated code
qapi: Smooth another visitor error checking pattern
qapi: Purge error_propagate() from QAPI core
block/parallels: Simplify parallels_open() after previous commit
acpi: Avoid unnecessary error_propagate() after error_setg()
s390x/pci: Fix harmless mistake in zpci's property fid's setter
qom: Use error_reportf_err() instead of g_printerr() in examples
qom: Rename qdev_get_type() to object_get_type()
qom: Crash more nicely on object_property_get_link() failure
qom: Don't handle impossible object_property_get_link() failure
qom: Use return values to check for error where that's simpler
qom: Put name parameter before value / visitor parameter
qom: Make functions taking Error ** return bool, not void
qom: Smooth error checking with Coccinelle
qom: Smooth error checking manually
qom: Make functions taking Error ** return bool, not 0/-1
qdev: Make functions taking Error ** return bool, not void
qdev: Smooth error checking with Coccinelle
qdev: Smooth error checking manually
qemu-img: Ignore Error objects where the return value suffices
qdev: Ignore Error objects where the return value suffices
hmp: Ignore Error objects where the return value suffices
docs/devel/qapi-code-gen.txt | 103 ++++-----
include/hw/audio/pcspk.h | 2 +-
include/hw/qdev-properties.h | 4 +-
include/qapi/clone-visitor.h | 8 +-
include/qapi/error.h | 45 +++-
include/qapi/visitor-impl.h | 26 +--
include/qapi/visitor.h | 102 +++++----
include/qemu/option.h | 16 +-
include/qom/object.h | 105 +++++----
include/qom/object_interfaces.h | 12 +-
include/qom/qom-qobject.h | 9 +-
accel/kvm/kvm-all.c | 55 +++--
accel/tcg/tcg-all.c | 5 +-
audio/audio_legacy.c | 15 +-
backends/cryptodev-vhost-user.c | 3 +-
backends/cryptodev.c | 16 +-
backends/hostmem-file.c | 22 +-
backends/hostmem-memfd.c | 18 +-
backends/hostmem.c | 33 ++-
backends/rng.c | 2 +-
block.c | 21 +-
block/blkdebug.c | 9 +-
block/blklogwrites.c | 4 +-
block/blkverify.c | 4 +-
block/crypto.c | 5 +-
block/curl.c | 5 +-
block/file-posix.c | 16 +-
block/file-win32.c | 8 +-
block/gluster.c | 17 +-
block/iscsi.c | 4 +-
block/nbd.c | 10 +-
block/nfs.c | 7 +-
block/parallels.c | 29 +--
block/qcow.c | 16 +-
block/qcow2.c | 21 +-
block/qed.c | 10 +-
block/quorum.c | 19 +-
block/raw-format.c | 5 +-
block/rbd.c | 7 +-
block/replication.c | 19 +-
block/sheepdog.c | 16 +-
block/ssh.c | 11 +-
block/throttle-groups.c | 31 +--
block/throttle.c | 5 +-
block/vdi.c | 13 +-
block/vhdx.c | 15 +-
block/vmdk.c | 13 +-
block/vpc.c | 19 +-
block/vvfat.c | 10 +-
block/vxhs.c | 16 +-
blockdev.c | 40 ++--
bootdevice.c | 7 +-
chardev/char.c | 6 +-
contrib/ivshmem-server/main.c | 4 +-
crypto/secret.c | 2 +-
crypto/secret_keyring.c | 2 +-
crypto/tlscredsanon.c | 2 +-
crypto/tlscredspsk.c | 2 +-
crypto/tlscredsx509.c | 2 +-
dump/dump.c | 7 +-
hw/acpi/core.c | 19 +-
hw/acpi/cpu_hotplug.c | 4 +-
hw/acpi/ich9.c | 2 +-
hw/acpi/piix4.c | 2 +-
hw/arm/allwinner-a10.c | 27 +--
hw/arm/armsse.c | 208 ++++++------------
hw/arm/armv7m.c | 47 ++--
hw/arm/aspeed.c | 24 +--
hw/arm/aspeed_ast2600.c | 124 ++++-------
hw/arm/aspeed_soc.c | 85 +++-----
hw/arm/bcm2835_peripherals.c | 81 ++-----
hw/arm/bcm2836.c | 35 +--
hw/arm/cubieboard.c | 14 +-
hw/arm/digic.c | 18 +-
hw/arm/digic_boards.c | 3 +-
hw/arm/exynos4210.c | 13 +-
hw/arm/fsl-imx25.c | 58 ++---
hw/arm/fsl-imx31.c | 34 +--
hw/arm/fsl-imx6.c | 85 +++-----
hw/arm/fsl-imx6ul.c | 24 +--
hw/arm/fsl-imx7.c | 31 ++-
hw/arm/highbank.c | 12 +-
hw/arm/integratorcp.c | 2 +-
hw/arm/microbit.c | 4 +-
hw/arm/mps2-tz.c | 31 ++-
hw/arm/mps2.c | 10 +-
hw/arm/msf2-soc.c | 29 +--
hw/arm/musca.c | 18 +-
hw/arm/musicpal.c | 4 +-
hw/arm/nrf51_soc.c | 36 +---
hw/arm/orangepi.c | 13 +-
hw/arm/raspi.c | 2 +-
hw/arm/realview.c | 6 +-
hw/arm/sbsa-ref.c | 16 +-
hw/arm/stellaris.c | 4 +-
hw/arm/stm32f205_soc.c | 37 +---
hw/arm/stm32f405_soc.c | 48 ++---
hw/arm/versatilepb.c | 4 +-
hw/arm/vexpress.c | 8 +-
hw/arm/virt.c | 35 +--
hw/arm/xilinx_zynq.c | 6 +-
hw/arm/xlnx-versal-virt.c | 8 +-
hw/arm/xlnx-versal.c | 30 ++-
hw/arm/xlnx-zcu102.c | 8 +-
hw/arm/xlnx-zynqmp.c | 117 ++++------
hw/block/fdc.c | 12 +-
hw/block/xen-block.c | 30 +--
hw/char/serial-pci-multi.c | 5 +-
hw/char/serial-pci.c | 5 +-
hw/char/serial.c | 10 +-
hw/core/bus.c | 12 +-
hw/core/cpu.c | 3 +-
hw/core/machine.c | 5 +-
hw/core/numa.c | 55 ++---
hw/core/platform-bus.c | 5 +-
hw/core/qdev-properties-system.c | 32 +--
hw/core/qdev-properties.c | 93 +++-----
hw/core/qdev.c | 14 +-
hw/cpu/a15mpcore.c | 5 +-
hw/cpu/a9mpcore.c | 21 +-
hw/cpu/arm11mpcore.c | 17 +-
hw/cpu/core.c | 10 +-
hw/cpu/realview_mpcore.c | 9 +-
hw/display/bcm2835_fb.c | 8 +-
hw/display/virtio-gpu-base.c | 5 +-
hw/display/virtio-gpu-pci.c | 11 +-
hw/display/virtio-vga.c | 10 +-
hw/dma/bcm2835_dma.c | 9 +-
hw/dma/sparc32_dma.c | 6 +-
hw/dma/xilinx_axidma.c | 4 +-
hw/gpio/aspeed_gpio.c | 5 +-
hw/gpio/bcm2835_gpio.c | 15 +-
hw/hyperv/vmbus.c | 5 +-
hw/i386/pc.c | 48 ++---
hw/i386/pc_piix.c | 4 +-
hw/i386/pc_q35.c | 28 +--
hw/i386/x86.c | 2 +-
hw/ide/qdev.c | 7 +-
hw/intc/apic_common.c | 5 +-
hw/intc/arm_gic_kvm.c | 4 +-
hw/intc/arm_gicv3_its_kvm.c | 4 +-
hw/intc/arm_gicv3_kvm.c | 4 +-
hw/intc/armv7m_nvic.c | 9 +-
hw/intc/nios2_iic.c | 8 +-
hw/intc/pnv_xive.c | 17 +-
hw/intc/realview_gic.c | 5 +-
hw/intc/spapr_xive.c | 17 +-
hw/intc/xics.c | 9 +-
hw/intc/xics_kvm.c | 3 +-
hw/intc/xive.c | 7 +-
hw/isa/piix4.c | 5 +-
hw/m68k/q800.c | 4 +-
hw/mem/nvdimm.c | 30 +--
hw/mem/pc-dimm.c | 18 +-
hw/microblaze/petalogix_ml605_mmu.c | 24 +--
hw/microblaze/petalogix_s3adsp1800_mmu.c | 2 +-
hw/microblaze/xlnx-zynqmp-pmu.c | 39 ++--
hw/mips/boston.c | 4 +-
hw/mips/cps.c | 41 ++--
hw/mips/jazz.c | 4 +-
hw/mips/malta.c | 4 +-
hw/misc/aspeed_sdmc.c | 8 +-
hw/misc/bcm2835_mbox.c | 9 +-
hw/misc/bcm2835_property.c | 17 +-
hw/misc/iotkit-sysctl.c | 2 +-
hw/misc/ivshmem.c | 4 +-
hw/misc/macio/cuda.c | 5 +-
hw/misc/macio/macio.c | 35 ++-
hw/misc/macio/pmu.c | 5 +-
hw/misc/pca9552.c | 5 +-
hw/misc/tmp105.c | 5 +-
hw/misc/tmp421.c | 5 +-
hw/net/ne2000-isa.c | 7 +-
hw/net/virtio-net.c | 7 +-
hw/net/xilinx_axienet.c | 4 +-
hw/pci-host/pnv_phb3.c | 33 ++-
hw/pci-host/pnv_phb4.c | 9 +-
hw/pci-host/pnv_phb4_pec.c | 9 +-
hw/pci-host/prep.c | 4 +-
hw/ppc/e500.c | 5 +-
hw/ppc/mac_newworld.c | 10 +-
hw/ppc/mac_oldworld.c | 4 +-
hw/ppc/pnv.c | 171 +++++++--------
hw/ppc/pnv_core.c | 4 +-
hw/ppc/pnv_psi.c | 22 +-
hw/ppc/rs6000_mc.c | 9 +-
hw/ppc/spapr.c | 77 +++----
hw/ppc/spapr_caps.c | 15 +-
hw/ppc/spapr_cpu_core.c | 3 +-
hw/ppc/spapr_drc.c | 16 +-
hw/ppc/spapr_hcall.c | 3 +-
hw/ppc/spapr_irq.c | 11 +-
hw/ppc/spapr_pci.c | 16 +-
hw/ppc/spapr_pci_nvlink2.c | 8 +-
hw/riscv/opentitan.c | 13 +-
hw/riscv/sifive_e.c | 10 +-
hw/riscv/sifive_u.c | 11 +-
hw/riscv/spike.c | 4 +-
hw/riscv/virt.c | 4 +-
hw/rx/rx-gdbsim.c | 12 +-
hw/s390x/css.c | 5 +-
hw/s390x/event-facility.c | 13 +-
hw/s390x/ipl.c | 27 ++-
hw/s390x/s390-pci-bus.c | 14 +-
hw/s390x/s390-skeys.c | 2 +-
hw/s390x/s390-stattrib.c | 2 +-
hw/s390x/s390-virtio-ccw.c | 20 +-
hw/s390x/sclp.c | 13 +-
hw/s390x/virtio-ccw-crypto.c | 10 +-
hw/s390x/virtio-ccw-rng.c | 8 +-
hw/scsi/scsi-bus.c | 15 +-
hw/scsi/vhost-scsi.c | 4 +-
hw/sd/aspeed_sdhci.c | 15 +-
hw/sd/sd.c | 3 +-
hw/sd/ssi-sd.c | 11 +-
hw/smbios/smbios.c | 33 +--
hw/sparc/sun4m.c | 2 +-
hw/sparc64/sun4u.c | 2 +-
hw/tpm/tpm_util.c | 5 +-
hw/usb/bus.c | 7 +-
hw/usb/dev-storage.c | 9 +-
hw/usb/hcd-dwc2.c | 9 +-
hw/vfio/pci-quirks.c | 5 +-
hw/vfio/pci.c | 10 +-
hw/virtio/virtio-balloon.c | 17 +-
hw/virtio/virtio-crypto-pci.c | 9 +-
hw/virtio/virtio-iommu-pci.c | 4 +-
hw/virtio/virtio-pmem-pci.c | 2 +-
hw/virtio/virtio-rng-pci.c | 8 +-
hw/virtio/virtio-rng.c | 10 +-
hw/xen/xen_pt_config_init.c | 3 +-
iothread.c | 18 +-
linux-user/syscall.c | 2 +-
monitor/hmp-cmds.c | 11 +-
monitor/monitor.c | 21 +-
net/colo-compare.c | 26 +--
net/dump.c | 13 +-
net/filter-buffer.c | 13 +-
net/filter.c | 2 +-
net/net.c | 10 +-
qapi/opts-visitor.c | 58 ++---
qapi/qapi-clone-visitor.c | 33 +--
qapi/qapi-dealloc-visitor.c | 27 ++-
qapi/qapi-visit-core.c | 197 +++++++++--------
qapi/qobject-input-visitor.c | 109 ++++++----
qapi/qobject-output-visitor.c | 27 ++-
qapi/string-input-visitor.c | 67 +++---
qapi/string-output-visitor.c | 32 +--
qdev-monitor.c | 38 ++--
qemu-img.c | 23 +-
qga/commands-win32.c | 19 +-
qom/object.c | 221 +++++++++----------
qom/object_interfaces.c | 30 +--
qom/qom-hmp-cmds.c | 2 +-
qom/qom-qmp-cmds.c | 2 +-
qom/qom-qobject.c | 14 +-
softmmu/vl.c | 17 +-
target/arm/cpu64.c | 15 +-
target/arm/monitor.c | 7 +-
target/i386/cpu.c | 98 +++------
target/ppc/compat.c | 5 +-
target/ppc/translate_init.inc.c | 2 +-
target/s390x/cpu_models.c | 17 +-
target/sparc/cpu.c | 5 +-
tpm.c | 5 +-
ui/console.c | 4 +-
ui/vnc.c | 2 +-
util/main-loop.c | 4 +-
util/qemu-config.c | 25 +--
util/qemu-option.c | 261 ++++++++++++-----------
scripts/qapi/commands.py | 22 +-
scripts/qapi/visit.py | 107 ++++------
272 files changed, 2312 insertions(+), 3460 deletions(-)
--
2.26.2