xemu/hw/sd
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
..
allwinner-sdhost.c hw/arm/allwinner: add SD/MMC host controller 2020-03-12 16:27:33 +00:00
aspeed_sdhci.c error: Eliminate error_propagate() with Coccinelle, part 1 2020-07-10 15:18:08 +02:00
bcm2835_sdhost.c Include migration/vmstate.h less 2019-08-16 13:31:52 +02:00
core.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
Kconfig hw/sd/sdhci: Move PCI-related code into a separate file 2019-03-12 07:49:04 +01:00
Makefile.objs hw/arm/allwinner: add SD/MMC host controller 2020-03-12 16:27:33 +00:00
milkymist-memcard.c sd/milkymist-memcard: Plug minor memory leak in realize 2020-07-02 06:25:29 +02:00
omap_mmc.c add device_legacy_reset function to prepare for reset api change 2020-01-30 16:02:03 +00:00
pl181.c add device_legacy_reset function to prepare for reset api change 2020-01-30 16:02:03 +00:00
pxa2xx_mmci.c sd/pxa2xx_mmci: Don't crash on pxa2xx_mmci_init() error 2020-06-23 16:07:07 +02:00
sd.c qdev: Use returned bool to check for failure, Coccinelle part 2020-07-10 15:18:08 +02:00
sdhci-internal.h sd: sdhci: Implement basic vendor specific register support 2020-06-16 10:32:29 +01:00
sdhci-pci.c qdev: Unrealize must not fail 2020-05-15 07:08:14 +02:00
sdhci.c sd: sdhci: Implement basic vendor specific register support 2020-06-16 10:32:29 +01:00
sdmmc-internal.c sdcard: Display command name when tracing CMD/ACMD 2018-03-09 17:09:44 +00:00
sdmmc-internal.h Clean up header guards that don't match their file name 2019-05-13 08:58:55 +02:00
ssi-sd.c qdev: Use returned bool to check for failure, Coccinelle part 2020-07-10 15:18:08 +02:00
trace-events hw/arm/allwinner: add SD/MMC host controller 2020-03-12 16:27:33 +00:00