error: Avoid unnecessary error_propagate() after error_setg()

Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

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

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>

2 files changed, 15 insertions, 16 deletions

diff --git a/hw/mem/nvdimm.c b/hw/mem/nvdimm.c
index 1fa976c56c..838ebcd227 100644
--- a/hw/mem/nvdimm.c
+++ b/hw/mem/nvdimm.c
@@ -49,23 +49,22 @@ static void nvdimm_set_label_size(Object *obj, Visitor *v, const char *name,
     uint64_t value;
 
     if (nvdimm->nvdimm_mr) {
-        error_setg(&local_err, "cannot change property value");
-        goto out;
+        error_setg(errp, "cannot change property value");
+        return;
     }
 
     if (!visit_type_size(v, name, &value, &local_err)) {
-        goto out;
+        error_propagate(errp, local_err);
+        return;
     }
     if (value < MIN_NAMESPACE_LABEL_SIZE) {
-        error_setg(&local_err, "Property '%s.%s' (0x%" PRIx64 ") is required"
-                   " at least 0x%lx", object_get_typename(obj),
-                   name, value, MIN_NAMESPACE_LABEL_SIZE);
-        goto out;
+        error_setg(errp, "Property '%s.%s' (0x%" PRIx64 ") is required"
+                   " at least 0x%lx", object_get_typename(obj), name, value,
+                   MIN_NAMESPACE_LABEL_SIZE);
+        return;
     }
 
     nvdimm->label_size = value;
-out:
-    error_propagate(errp, local_err);
 }
 
 static void nvdimm_get_uuid(Object *obj, Visitor *v, const char *name,
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 8a075fbf72..9d3f0b9691 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -44,24 +44,24 @@ void pc_dimm_pre_plug(PCDIMMDevice *dimm, MachineState *machine,
                                    &error_abort);
     if ((slot < 0 || slot >= machine->ram_slots) &&
          slot != PC_DIMM_UNASSIGNED_SLOT) {
-        error_setg(&local_err, "invalid slot number %d, valid range is [0-%"
-                   PRIu64 "]", slot, machine->ram_slots - 1);
-        goto out;
+        error_setg(errp,
+                   "invalid slot number %d, valid range is [0-%" PRIu64 "]",
+                   slot, machine->ram_slots - 1);
+        return;
     }
 
     slot = pc_dimm_get_free_slot(slot == PC_DIMM_UNASSIGNED_SLOT ? NULL : &slot,
                                  machine->ram_slots, &local_err);
     if (local_err) {
-        goto out;
+        error_propagate(errp, local_err);
+        return;
     }
     object_property_set_int(OBJECT(dimm), PC_DIMM_SLOT_PROP, slot,
                             &error_abort);
     trace_mhp_pc_dimm_assigned_slot(slot);
 
     memory_device_pre_plug(MEMORY_DEVICE(dimm), machine, legacy_align,
-                           &local_err);
-out:
-    error_propagate(errp, local_err);
+                           errp);
 }
 
 void pc_dimm_plug(PCDIMMDevice *dimm, MachineState *machine, Error **errp)