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Strict disable implicit fallthrough
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[RFC,v2,00/78] Strict disable implicit fallthrough
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[RFC,v2,01/78] include/qemu/compiler.h: replace QEMU_FALLTHROUGH with fallthrough
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[RFC,v2,02/78] block: add fallthrough pseudo-keyword
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[RFC,v2,03/78] fpu/softfloat: add fallthrough pseudo-keyword
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[RFC,v2,04/78] qapi/opts-visitor: add fallthrough pseudo-keyword
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[RFC,v2,05/78] qobject/json: add fallthrough pseudo-keyword
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[RFC,v2,06/78] tcg: add fallthrough pseudo-keyword
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[RFC,v2,07/78] hw/virtio/virtio-balloon.c: add fallthrough pseudo-keyword
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[RFC,v2,08/78] hw/block: add fallthrough pseudo-keyword
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[RFC,v2,09/78] hw/acpi/aml-build.c: add fallthrough pseudo-keyword
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[RFC,v2,10/78] hw/ide/atapi.c: add fallthrough pseudo-keyword
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[RFC,v2,11/78] hw/timer: add fallthrough pseudo-keyword
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[RFC,v2,12/78] hw/usb: add fallthrough pseudo-keyword
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[RFC,v2,13/78] hw/adc: add fallthrough pseudo-keyword
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[RFC,v2,14/78] util/error-report.c: add fallthrough pseudo-keyword
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[RFC,v2,15/78] accel/tcg: add fallthrough pseudo-keyword
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[RFC,v2,16/78] audio: add fallthrough pseudo-keyword
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[RFC,v2,17/78] ui/sdl2.c: add fallthrough pseudo-keyword
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[RFC,v2,18/78] ui/win32-kbd-hook.c: add fallthrough pseudo-keyword
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[RFC,v2,19/78] target/hppa: add fallthrough pseudo-keyword
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[RFC,v2,20/78] target/mips: add fallthrough pseudo-keyword
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[RFC,v2,21/78] target/sparc: add fallthrough pseudo-keyword
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[RFC,v2,22/78] target/ppc: add fallthrough pseudo-keyword
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[RFC,v2,23/78] target/arm: add fallthrough pseudo-keyword
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[RFC,v2,24/78] target/alpha: add fallthrough pseudo-keyword
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[RFC,v2,25/78] target/i386: add fallthrough pseudo-keyword
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[RFC,v2,26/78] target/s390x: add fallthrough pseudo-keyword
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[RFC,v2,27/78] target/riscv: add fallthrough pseudo-keyword
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[RFC,v2,28/78] target/avr: add fallthrough pseudo-keyword
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[RFC,v2,29/78] target/cris: add fallthrough pseudo-keyword
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[RFC,v2,30/78] target/nios2: add fallthrough pseudo-keyword
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[RFC,v2,31/78] target/xtensa: add fallthrough pseudo-keyword
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[RFC,v2,32/78] target/m68k: add fallthrough pseudo-keyword
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[RFC,v2,33/78] target/rx: add fallthrough pseudo-keyword
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[RFC,v2,34/78] target/tricore: add fallthrough pseudo-keyword
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[RFC,v2,35/78] target/sh4: add fallthrough pseudo-keyword
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[RFC,v2,36/78] target/openrisc: add fallthrough pseudo-keyword
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[RFC,v2,37/78] target/hexagon: add fallthrough pseudo-keyword
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[RFC,v2,38/78] system/rtc.c: add fallthrough pseudo-keyword
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[RFC,v2,39/78] hw/scsi: add fallthrough pseudo-keyword
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[RFC,v2,40/78] hw/sd/sdhci.c: add fallthrough pseudo-keyword
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[RFC,v2,41/78] linux-user: add fallthrough pseudo-keyword
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[RFC,v2,42/78] hw/i386: add fallthrough pseudo-keyword
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[RFC,v2,43/78] hw/misc: add fallthrough pseudo-keyword
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[RFC,v2,44/78] hw/m68k/mcf_intc.c: add fallthrough pseudo-keyword
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[RFC,v2,45/78] hw/dma: add fallthrough pseudo-keyword
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[RFC,v2,46/78] disas: add fallthrough pseudo-keyword
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[RFC,v2,47/78] contrib/rdmacm-mux: add fallthrough pseudo-keyword
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[RFC,v2,48/78] contrib/vhost-user-scsi: add fallthrough pseudo-keyword
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[RFC,v2,49/78] hw/arm: add fallthrough pseudo-keyword
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[RFC,v2,50/78] hw/audio: add fallthrough pseudo-keyword
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[RFC,v2,51/78] chardev: add fallthrough pseudo-keyword
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[RFC,v2,52/78] hw/char: add fallthrough pseudo-keyword
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[RFC,v2,53/78] nbd: add fallthrough pseudo-keyword
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[RFC,v2,54/78] hw/core: add fallthrough pseudo-keyword
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[RFC,v2,55/78] hw/display: add fallthrough pseudo-keyword
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[RFC,v2,56/78] hw/input: add fallthrough pseudo-keyword
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[RFC,v2,57/78] hw/net: add fallthrough pseudo-keyword
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[RFC,v2,58/78] hw/ppc: add fallthrough pseudo-keyword
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[RFC,v2,59/78] hw/intc: add fallthrough pseudo-keyword
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[RFC,v2,60/78] qga: add fallthrough pseudo-keyword
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[RFC,v2,61/78] semihosting: add fallthrough pseudo-keyword
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[RFC,v2,62/78] hw/gpio: add fallthrough pseudo-keyword
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[RFC,v2,63/78] hw/ipmi: add fallthrough pseudo-keyword
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[RFC,v2,64/78] hw/mips: add fallthrough pseudo-keyword
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[RFC,v2,65/78] hw/nvme: add fallthrough pseudo-keyword
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[RFC,v2,66/78] hw/nvram/eeprom_at24c.c: add fallthrough pseudo-keyword
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[RFC,v2,67/78] hw/pci-host/pnv_phb3.c: add fallthrough pseudo-keyword
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[RFC,v2,68/78] hw/pci: add fallthrough pseudo-keyword
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[RFC,v2,69/78] hw/rdma/rdma_backend.c: add fallthrough pseudo-keyword
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[RFC,v2,70/78] hw/rtc: add fallthrough pseudo-keyword
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[RFC,v2,71/78] hw/s390x: add fallthrough pseudo-keyword
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[RFC,v2,72/78] hw/ssi: add fallthrough pseudo-keyword
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[RFC,v2,73/78] hw/watchdog/wdt_diag288.c: add fallthrough pseudo-keyword
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[RFC,v2,74/78] hw/cxl/cxl-device-utils.c: add fallthrough pseudo-keyword
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[RFC,v2,75/78] migration: add fallthrough pseudo-keyword
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[RFC,v2,76/78] qemu-img.c: add fallthrough pseudo-keyword
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[RFC,v2,77/78] tests/unit/test-char.c: add fallthrough pseudo-keyword
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[RFC,v2,78/78] meson.build: increase -Wimplicit-fallthrough to 5
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/* resubmitted because git-send-email crashed with previous attempt */ Hello, This RFC is inspired by the kernel's move to -Wimplicit-fallthrough=3 back in 2019.[0] We take one step (or two) further by increasing it to 5 which rejects fall through comments and requires an attribute statement. [0]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a035d552a93b The line differences are not many, but they spread all over different subsystems, architectures and devices. An attempt has been made to split them in cohesive patches to aid post-RFC review. Part of the RFC is to determine whether these patch divisions needs improvement. Main questions this RFC poses ============================= - Is this change desirable and net-positive. - Should the `fallthrough;` pseudo-keyword be defined like in the Linux kernel, or use glib's G_GNUC_FALLTHROUGH, or keep the already existing QEMU_FALLTHROUGH macro. - Should fallthrough comments be removed if they do not include extra information. Some external resources ======================= See the RFC discussion in the kernel: https://lore.kernel.org/lkml/1d2830aadbe9d8151728a7df5b88528fc72a0095.1564549413.git.joe@perches.com/ The `fallthrough;` pseudo-keyword in the kernel source code: https://elixir.bootlin.com/linux/latest/C/ident/fallthrough In summary, I quote the doc comment and definition: /* * Add the pseudo keyword 'fallthrough' so case statement blocks * must end with any of these keywords: * break; * fallthrough; * continue; * goto <label>; * return [expression]; * * gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attributes */ #if __has_attribute(__fallthrough__) # define fallthrough __attribute__((__fallthrough__)) #else # define fallthrough do {} while (0) /* fallthrough */ #endif Background - Motivation ======================= The C switch statement allows you to conditionally goto different labels depending on a value. A break; statement conveniently goto's the end of the switch. If a "case" does not end in a break, we say that the control flow falls through the next case label, if any, implicitly. This can lead to bugs and QEMU uses the GCC warning -Wimplicit-fallthrough to prevent this. Currently, QEMU is built with -Wimplicit-fallthrough=2. This makes GCC's static analyzer check for a case-insensitive matches of the .*falls?[ \t-]*thr(ough|u).* regular expression. This means the following list of comments taken from QEMU all disable the implicit fallthrough warning: - /* FALLTHRU */ - /* fall through */ - /* Fall through. */ - /* Fall through... */ - /* fall through if hEventTimeout is signaled */ - /* FALL THROUGH */ To keep a constistent code style, this commit adds a macro `fallthrough` that looks like a C keyword but expands to an attribute statement in supported compilers (GCC at the moment). Note: there was already such a macro, QEMU_FALLTHROUGH, and it was used only around 7 times in the code base. The first commit replaces it. Emmanouil Pitsidianakis (78): include/qemu/compiler.h: replace QEMU_FALLTHROUGH with fallthrough block: add fallthrough pseudo-keyword fpu/softfloat: add fallthrough pseudo-keyword qapi/opts-visitor: add fallthrough pseudo-keyword qobject/json: add fallthrough pseudo-keyword tcg: add fallthrough pseudo-keyword hw/virtio/virtio-balloon.c: add fallthrough pseudo-keyword hw/block: add fallthrough pseudo-keyword hw/acpi/aml-build.c: add fallthrough pseudo-keyword hw/ide/atapi.c: add fallthrough pseudo-keyword hw/timer: add fallthrough pseudo-keyword hw/usb: add fallthrough pseudo-keyword hw/adc: add fallthrough pseudo-keyword util/error-report.c: add fallthrough pseudo-keyword accel/tcg: add fallthrough pseudo-keyword audio: add fallthrough pseudo-keyword ui/sdl2.c: add fallthrough pseudo-keyword ui/win32-kbd-hook.c: add fallthrough pseudo-keyword target/hppa: add fallthrough pseudo-keyword target/mips: add fallthrough pseudo-keyword target/sparc: add fallthrough pseudo-keyword target/ppc: add fallthrough pseudo-keyword target/arm: add fallthrough pseudo-keyword target/alpha: add fallthrough pseudo-keyword target/i386: add fallthrough pseudo-keyword target/s390x: add fallthrough pseudo-keyword target/riscv: add fallthrough pseudo-keyword target/avr: add fallthrough pseudo-keyword target/cris: add fallthrough pseudo-keyword target/nios2: add fallthrough pseudo-keyword target/xtensa: add fallthrough pseudo-keyword target/m68k: add fallthrough pseudo-keyword target/rx: add fallthrough pseudo-keyword target/tricore: add fallthrough pseudo-keyword target/sh4: add fallthrough pseudo-keyword target/openrisc: add fallthrough pseudo-keyword target/hexagon: add fallthrough pseudo-keyword system/rtc.c: add fallthrough pseudo-keyword hw/scsi: add fallthrough pseudo-keyword hw/sd/sdhci.c: add fallthrough pseudo-keyword linux-user: add fallthrough pseudo-keyword hw/i386: add fallthrough pseudo-keyword hw/misc: add fallthrough pseudo-keyword hw/m68k/mcf_intc.c: add fallthrough pseudo-keyword hw/dma: add fallthrough pseudo-keyword disas: add fallthrough pseudo-keyword contrib/rdmacm-mux: add fallthrough pseudo-keyword contrib/vhost-user-scsi: add fallthrough pseudo-keyword hw/arm: add fallthrough pseudo-keyword hw/audio: add fallthrough pseudo-keyword chardev: add fallthrough pseudo-keyword hw/char: add fallthrough pseudo-keyword nbd: add fallthrough pseudo-keyword hw/core: add fallthrough pseudo-keyword hw/display: add fallthrough pseudo-keyword hw/input: add fallthrough pseudo-keyword hw/net: add fallthrough pseudo-keyword hw/ppc: add fallthrough pseudo-keyword hw/intc: add fallthrough pseudo-keyword qga: add fallthrough pseudo-keyword semihosting: add fallthrough pseudo-keyword hw/gpio: add fallthrough pseudo-keyword hw/ipmi: add fallthrough pseudo-keyword hw/mips: add fallthrough pseudo-keyword hw/nvme: add fallthrough pseudo-keyword hw/nvram/eeprom_at24c.c: add fallthrough pseudo-keyword hw/pci-host/pnv_phb3.c: add fallthrough pseudo-keyword hw/pci: add fallthrough pseudo-keyword hw/rdma/rdma_backend.c: add fallthrough pseudo-keyword hw/rtc: add fallthrough pseudo-keyword hw/s390x: add fallthrough pseudo-keyword hw/ssi: add fallthrough pseudo-keyword hw/watchdog/wdt_diag288.c: add fallthrough pseudo-keyword hw/cxl/cxl-device-utils.c: add fallthrough pseudo-keyword migration: add fallthrough pseudo-keyword qemu-img.c: add fallthrough pseudo-keyword tests/unit/test-char.c: add fallthrough pseudo-keyword meson.build: increase -Wimplicit-fallthrough to 5 accel/tcg/cputlb.c | 4 +- accel/tcg/ldst_atomicity.c.inc | 2 +- accel/tcg/plugin-gen.c | 2 +- audio/audio.c | 16 ++-- audio/jackaudio.c | 4 +- audio/pwaudio.c | 12 +-- block/block-copy.c | 1 + block/file-posix.c | 1 + block/io.c | 1 + block/iscsi.c | 1 + block/qcow2-cluster.c | 5 +- block/vhdx.c | 17 +++- chardev/char-socket.c | 2 +- contrib/rdmacm-mux/main.c | 10 +-- contrib/vhost-user-scsi/vhost-user-scsi.c | 3 +- disas/hppa.c | 4 +- disas/m68k.c | 2 +- disas/sh4.c | 6 +- disas/sparc.c | 2 +- docs/devel/style.rst | 23 +++++ fpu/softfloat-parts.c.inc | 8 +- fpu/softfloat.c | 7 +- hw/acpi/aml-build.c | 6 +- hw/adc/aspeed_adc.c | 12 +-- hw/adc/zynq-xadc.c | 2 +- hw/arm/omap1.c | 8 +- hw/arm/pxa2xx.c | 6 +- hw/arm/smmuv3.c | 2 +- hw/arm/stellaris.c | 1 + hw/audio/asc.c | 2 +- hw/audio/cs4231a.c | 2 +- hw/audio/gusemu_hal.c | 2 +- hw/block/dataplane/xen-block.c | 4 +- hw/block/m25p80.c | 2 +- hw/block/onenand.c | 2 +- hw/block/pflash_cfi01.c | 1 + hw/block/pflash_cfi02.c | 6 +- hw/char/nrf51_uart.c | 4 +- hw/core/loader.c | 2 +- hw/cxl/cxl-device-utils.c | 4 +- hw/display/cg3.c | 2 +- hw/display/cirrus_vga.c | 2 +- hw/display/tcx.c | 4 +- hw/dma/omap_dma.c | 32 +++---- hw/dma/pxa2xx_dma.c | 4 +- hw/dma/sparc32_dma.c | 2 +- hw/gpio/omap_gpio.c | 2 +- hw/i2c/bitbang_i2c.c | 2 +- hw/i386/intel_iommu.c | 4 +- hw/i386/kvm/xen_evtchn.c | 2 +- hw/i386/x86.c | 2 +- hw/ide/atapi.c | 1 + hw/input/hid.c | 3 +- hw/input/tsc2005.c | 4 +- hw/input/tsc210x.c | 2 +- hw/intc/apic.c | 2 +- hw/intc/arm_gicv3_kvm.c | 16 ++-- hw/intc/armv7m_nvic.c | 12 +-- hw/intc/xilinx_intc.c | 2 +- hw/ipmi/ipmi_bmc_extern.c | 2 +- hw/ipmi/smbus_ipmi.c | 4 +- hw/m68k/mcf_intc.c | 2 +- hw/mips/boston.c | 12 +-- hw/misc/a9scu.c | 2 + hw/misc/aspeed_scu.c | 2 +- hw/misc/bcm2835_property.c | 12 +-- hw/misc/mos6522.c | 4 +- hw/net/cadence_gem.c | 4 +- hw/net/can/can_sja1000.c | 4 +- hw/net/igb_core.c | 2 +- hw/net/igbvf.c | 2 +- hw/net/imx_fec.c | 2 +- hw/net/net_rx_pkt.c | 2 +- hw/net/pcnet.c | 2 +- hw/net/rtl8139.c | 6 +- hw/net/xilinx_ethlite.c | 2 +- hw/nvme/ctrl.c | 24 +++--- hw/nvme/dif.c | 4 +- hw/nvram/eeprom_at24c.c | 2 +- hw/pci-host/pnv_phb3.c | 2 +- hw/pci/pcie_aer.c | 3 +- hw/pci/pcie_doe.c | 2 +- hw/ppc/pnv_bmc.c | 2 +- hw/ppc/spapr_events.c | 1 + hw/rdma/rdma_backend.c | 2 +- hw/rtc/aspeed_rtc.c | 4 +- hw/rtc/mc146818rtc.c | 4 +- hw/s390x/ipl.c | 1 + hw/s390x/s390-pci-inst.c | 4 +- hw/s390x/sclp.c | 4 +- hw/scsi/esp.c | 2 +- hw/scsi/megasas.c | 2 +- hw/scsi/scsi-bus.c | 4 +- hw/scsi/scsi-disk.c | 2 +- hw/sd/sdhci.c | 8 +- hw/ssi/npcm7xx_fiu.c | 14 +-- hw/ssi/omap_spi.c | 48 +++++------ hw/timer/a9gtimer.c | 8 +- hw/timer/aspeed_timer.c | 1 + hw/timer/pxa2xx_timer.c | 94 ++++++++++----------- hw/timer/renesas_tmr.c | 2 +- hw/timer/sh_timer.c | 8 +- hw/usb/dev-mtp.c | 2 +- hw/usb/dev-wacom.c | 2 +- hw/usb/hcd-ehci.c | 4 +- hw/usb/hcd-xhci.c | 4 +- hw/usb/redirect.c | 4 +- hw/usb/tusb6010.c | 2 +- hw/virtio/virtio-balloon.c | 1 + hw/watchdog/wdt_diag288.c | 2 +- include/qemu/compiler.h | 30 +++++-- include/qemu/osdep.h | 4 +- linux-user/mips/cpu_loop.c | 8 +- linux-user/mmap.c | 2 +- linux-user/syscall.c | 2 +- meson.build | 2 +- migration/migration.c | 2 +- nbd/client.c | 4 +- nbd/common.c | 2 +- qapi/opts-visitor.c | 1 + qapi/string-input-visitor.c | 4 +- qemu-img.c | 2 +- qemu-nbd.c | 4 +- qga/main.c | 2 +- qga/vss-win32/requester.cpp | 1 + qobject/json-lexer.c | 4 +- qobject/json-parser.c | 5 +- semihosting/arm-compat-semi.c | 2 +- system/rtc.c | 2 +- target/alpha/helper.c | 6 +- target/alpha/translate.c | 4 +- target/arm/helper.c | 34 ++++---- target/arm/ptw.c | 10 +-- target/arm/tcg/psci.c | 2 +- target/arm/tcg/translate-a64.c | 76 ++++++++--------- target/arm/tcg/translate-m-nocp.c | 2 +- target/arm/tcg/translate-vfp.c | 2 +- target/arm/tcg/translate.c | 8 +- target/avr/translate.c | 4 +- target/cris/translate.c | 4 +- target/hexagon/idef-parser/parser-helpers.c | 5 +- target/hppa/translate.c | 10 +-- target/i386/cpu.c | 2 +- target/i386/hvf/x86_decode.c | 1 + target/i386/kvm/kvm.c | 4 +- target/i386/tcg/decode-new.c.inc | 6 +- target/i386/tcg/emit.c.inc | 2 +- target/i386/tcg/translate.c | 11 +-- target/loongarch/cpu.c | 4 +- target/loongarch/translate.c | 2 +- target/m68k/op_helper.c | 3 +- target/m68k/translate.c | 10 +-- target/mips/sysemu/physaddr.c | 2 +- target/mips/tcg/micromips_translate.c.inc | 4 +- target/mips/tcg/mips16e_translate.c.inc | 30 +++---- target/mips/tcg/mxu_translate.c | 8 +- target/mips/tcg/nanomips_translate.c.inc | 4 +- target/mips/tcg/op_helper.c | 2 +- target/mips/tcg/translate.c | 79 ++++++++--------- target/nios2/helper.c | 6 +- target/nios2/translate.c | 2 +- target/openrisc/mmu.c | 2 +- target/openrisc/translate.c | 2 +- target/ppc/cpu_init.c | 8 +- target/ppc/excp_helper.c | 6 +- target/ppc/mmu-radix64.c | 6 +- target/ppc/mmu_common.c | 12 +-- target/ppc/translate.c | 6 +- target/riscv/insn_trans/trans_rvi.c.inc | 2 +- target/riscv/insn_trans/trans_rvzce.c.inc | 22 ++--- target/riscv/translate.c | 4 +- target/rx/translate.c | 2 +- target/s390x/cpu.c | 4 +- target/s390x/kvm/kvm.c | 2 +- target/s390x/mmu_helper.c | 6 +- target/s390x/tcg/translate.c | 18 ++-- target/s390x/tcg/translate_vx.c.inc | 2 +- target/sh4/helper.c | 2 +- target/sparc/ldst_helper.c | 4 +- target/sparc/mmu_helper.c | 6 +- target/sparc/translate.c | 3 +- target/sparc/win_helper.c | 1 + target/tricore/translate.c | 4 +- target/xtensa/op_helper.c | 8 +- target/xtensa/translate.c | 2 +- tcg/aarch64/tcg-target.c.inc | 15 +++- tcg/arm/tcg-target.c.inc | 5 +- tcg/i386/tcg-target.c.inc | 20 +++-- tcg/loongarch64/tcg-target.c.inc | 4 +- tcg/mips/tcg-target.c.inc | 8 +- tcg/optimize.c | 8 +- tcg/ppc/tcg-target.c.inc | 19 +++-- tcg/riscv/tcg-target.c.inc | 5 +- tcg/s390x/tcg-target.c.inc | 8 +- tcg/tcg-op-gvec.c | 24 +++--- tcg/tcg-op-ldst.c | 2 +- tcg/tcg.c | 24 +++--- tcg/tci.c | 2 +- tcg/tci/tcg-target.c.inc | 2 +- tests/unit/test-char.c | 2 +- ui/sdl2.c | 2 +- ui/win32-kbd-hook.c | 7 -- util/error-report.c | 2 +- 203 files changed, 747 insertions(+), 618 deletions(-) base-commit: cea3ea670fe265421131aad90c36fbb87bc4d206