qemu/hw/char/serial-pci.c
Markus Armbruster 668f62ec62 error: Eliminate error_propagate() with Coccinelle, part 1
When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10 15:18:08 +02:00

129 lines
4.0 KiB
C

/*
* QEMU 16550A UART emulation
*
* Copyright (c) 2003-2004 Fabrice Bellard
* Copyright (c) 2008 Citrix Systems, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* see docs/specs/pci-serial.txt */
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/module.h"
#include "hw/char/serial.h"
#include "hw/irq.h"
#include "hw/pci/pci.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
typedef struct PCISerialState {
PCIDevice dev;
SerialState state;
uint8_t prog_if;
} PCISerialState;
#define TYPE_PCI_SERIAL "pci-serial"
#define PCI_SERIAL(s) OBJECT_CHECK(PCISerialState, (s), TYPE_PCI_SERIAL)
static void serial_pci_realize(PCIDevice *dev, Error **errp)
{
PCISerialState *pci = DO_UPCAST(PCISerialState, dev, dev);
SerialState *s = &pci->state;
if (!qdev_realize(DEVICE(s), NULL, errp)) {
return;
}
pci->dev.config[PCI_CLASS_PROG] = pci->prog_if;
pci->dev.config[PCI_INTERRUPT_PIN] = 0x01;
s->irq = pci_allocate_irq(&pci->dev);
memory_region_init_io(&s->io, OBJECT(pci), &serial_io_ops, s, "serial", 8);
pci_register_bar(&pci->dev, 0, PCI_BASE_ADDRESS_SPACE_IO, &s->io);
}
static void serial_pci_exit(PCIDevice *dev)
{
PCISerialState *pci = DO_UPCAST(PCISerialState, dev, dev);
SerialState *s = &pci->state;
qdev_unrealize(DEVICE(s));
qemu_free_irq(s->irq);
}
static const VMStateDescription vmstate_pci_serial = {
.name = "pci-serial",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_PCI_DEVICE(dev, PCISerialState),
VMSTATE_STRUCT(state, PCISerialState, 0, vmstate_serial, SerialState),
VMSTATE_END_OF_LIST()
}
};
static Property serial_pci_properties[] = {
DEFINE_PROP_CHR("chardev", PCISerialState, state.chr),
DEFINE_PROP_UINT8("prog_if", PCISerialState, prog_if, 0x02),
DEFINE_PROP_END_OF_LIST(),
};
static void serial_pci_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
PCIDeviceClass *pc = PCI_DEVICE_CLASS(klass);
pc->realize = serial_pci_realize;
pc->exit = serial_pci_exit;
pc->vendor_id = PCI_VENDOR_ID_REDHAT;
pc->device_id = PCI_DEVICE_ID_REDHAT_SERIAL;
pc->revision = 1;
pc->class_id = PCI_CLASS_COMMUNICATION_SERIAL;
dc->vmsd = &vmstate_pci_serial;
device_class_set_props(dc, serial_pci_properties);
set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
}
static void serial_pci_init(Object *o)
{
PCISerialState *ps = PCI_SERIAL(o);
object_initialize_child(o, "serial", &ps->state, TYPE_SERIAL);
}
static const TypeInfo serial_pci_info = {
.name = TYPE_PCI_SERIAL,
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(PCISerialState),
.instance_init = serial_pci_init,
.class_init = serial_pci_class_initfn,
.interfaces = (InterfaceInfo[]) {
{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
{ },
},
};
static void serial_pci_register_types(void)
{
type_register_static(&serial_pci_info);
}
type_init(serial_pci_register_types)