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error: Eliminate error_propagate() with Coccinelle, part 1

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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>
This commit is contained in:
Markus Armbruster 2020-07-07 18:06:02 +02:00
parent dcfe480544
commit 668f62ec62
114 changed files with 383 additions and 896 deletions
Download patch file Download diff file Expand all files Collapse all files

44
hw/core/qdev-properties.c
View file

@ -117,7 +117,6 @@ static void prop_set_bit(Object *obj, Visitor *v, const char *name,
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
Error *local_err = NULL;
bool value;
if (dev->realized) {
@ -125,8 +124,7 @@ static void prop_set_bit(Object *obj, Visitor *v, const char *name,
return;
}
if (!visit_type_bool(v, name, &value, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_bool(v, name, &value, errp)) {
return;
}
bit_prop_set(dev, prop, value);
@ -180,7 +178,6 @@ static void prop_set_bit64(Object *obj, Visitor *v, const char *name,
{
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
Error *local_err = NULL;
bool value;
if (dev->realized) {
@ -188,8 +185,7 @@ static void prop_set_bit64(Object *obj, Visitor *v, const char *name,
return;
}
if (!visit_type_bool(v, name, &value, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_bool(v, name, &value, errp)) {
return;
}
bit64_prop_set(dev, prop, value);
@ -476,7 +472,6 @@ static void set_string(Object *obj, Visitor *v, const char *name,
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
char **ptr = qdev_get_prop_ptr(dev, prop);
Error *local_err = NULL;
char *str;
if (dev->realized) {
@ -484,8 +479,7 @@ static void set_string(Object *obj, Visitor *v, const char *name,
return;
}
if (!visit_type_str(v, name, &str, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_str(v, name, &str, errp)) {
return;
}
g_free(*ptr);
@ -528,7 +522,6 @@ static void set_mac(Object *obj, Visitor *v, const char *name, void *opaque,
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
MACAddr *mac = qdev_get_prop_ptr(dev, prop);
Error *local_err = NULL;
int i, pos;
char *str, *p;
@ -537,8 +530,7 @@ static void set_mac(Object *obj, Visitor *v, const char *name, void *opaque,
return;
}
if (!visit_type_str(v, name, &str, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_str(v, name, &str, errp)) {
return;
}
@ -832,15 +824,13 @@ static void set_size32(Object *obj, Visitor *v, const char *name, void *opaque,
Property *prop = opaque;
uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
uint64_t value;
Error *local_err = NULL;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_size(v, name, &value, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_size(v, name, &value, errp)) {
return;
}
@ -881,15 +871,13 @@ static void set_blocksize(Object *obj, Visitor *v, const char *name,
Property *prop = opaque;
uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
uint64_t value;
Error *local_err = NULL;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
return;
}
if (!visit_type_size(v, name, &value, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_size(v, name, &value, errp)) {
return;
}
/* value of 0 means "unset" */
@ -957,7 +945,6 @@ static void set_pci_host_devaddr(Object *obj, Visitor *v, const char *name,
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
PCIHostDeviceAddress *addr = qdev_get_prop_ptr(dev, prop);
Error *local_err = NULL;
char *str, *p;
char *e;
unsigned long val;
@ -969,8 +956,7 @@ static void set_pci_host_devaddr(Object *obj, Visitor *v, const char *name,
return;
}
if (!visit_type_str(v, name, &str, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_str(v, name, &str, errp)) {
return;
}
@ -1060,7 +1046,6 @@ static void set_uuid(Object *obj, Visitor *v, const char *name, void *opaque,
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
QemuUUID *uuid = qdev_get_prop_ptr(dev, prop);
Error *local_err = NULL;
char *str;
if (dev->realized) {
@ -1068,8 +1053,7 @@ static void set_uuid(Object *obj, Visitor *v, const char *name, void *opaque,
return;
}
if (!visit_type_str(v, name, &str, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_str(v, name, &str, errp)) {
return;
}
@ -1135,7 +1119,6 @@ static void set_prop_arraylen(Object *obj, Visitor *v, const char *name,
Property *prop = opaque;
uint32_t *alenptr = qdev_get_prop_ptr(dev, prop);
void **arrayptr = (void *)dev + prop->arrayoffset;
Error *local_err = NULL;
void *eltptr;
const char *arrayname;
int i;
@ -1149,8 +1132,7 @@ static void set_prop_arraylen(Object *obj, Visitor *v, const char *name,
name);
return;
}
if (!visit_type_uint32(v, name, alenptr, &local_err)) {
error_propagate(errp, local_err);
if (!visit_type_uint32(v, name, alenptr, errp)) {
return;
}
if (!*alenptr) {
@ -1473,7 +1455,6 @@ static void set_prop_pcielinkspeed(Object *obj, Visitor *v, const char *name,
Property *prop = opaque;
PCIExpLinkSpeed *p = qdev_get_prop_ptr(dev, prop);
int speed;
Error *local_err = NULL;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
@ -1481,8 +1462,7 @@ static void set_prop_pcielinkspeed(Object *obj, Visitor *v, const char *name,
}
if (!visit_type_enum(v, prop->name, &speed, prop->info->enum_table,
&local_err)) {
error_propagate(errp, local_err);
errp)) {
return;
}
@ -1561,7 +1541,6 @@ static void set_prop_pcielinkwidth(Object *obj, Visitor *v, const char *name,
Property *prop = opaque;
PCIExpLinkWidth *p = qdev_get_prop_ptr(dev, prop);
int width;
Error *local_err = NULL;
if (dev->realized) {
qdev_prop_set_after_realize(dev, name, errp);
@ -1569,8 +1548,7 @@ static void set_prop_pcielinkwidth(Object *obj, Visitor *v, const char *name,
}
if (!visit_type_enum(v, prop->name, &width, prop->info->enum_table,
&local_err)) {
error_propagate(errp, local_err);
errp)) {
return;
}