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>

1 files changed, 6 insertions, 8 deletions

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 223bb8f464..2a6a48744a 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -1499,10 +1499,10 @@ static void spapr_pci_plug(HotplugHandler *plug_handler,
          * we need to let them know it's not enabled
          */
         if (plugged_dev->hotplugged) {
-            error_setg(&local_err, QERR_BUS_NO_HOTPLUG,
+            error_setg(errp, QERR_BUS_NO_HOTPLUG,
                        object_get_typename(OBJECT(phb)));
         }
-        goto out;
+        return;
     }
 
     g_assert(drc);
@@ -1517,15 +1517,16 @@ static void spapr_pci_plug(HotplugHandler *plug_handler,
      */
     if (plugged_dev->hotplugged && bus->devices[PCI_DEVFN(slotnr, 0)] &&
         PCI_FUNC(pdev->devfn) != 0) {
-        error_setg(&local_err, "PCI: slot %d function 0 already ocuppied by %s,"
+        error_setg(errp, "PCI: slot %d function 0 already ocuppied by %s,"
                    " additional functions can no longer be exposed to guest.",
                    slotnr, bus->devices[PCI_DEVFN(slotnr, 0)]->name);
-        goto out;
+        return;
     }
 
     spapr_drc_attach(drc, DEVICE(pdev), &local_err);
     if (local_err) {
-        goto out;
+        error_propagate(errp, local_err);
+        return;
     }
 
     /* If this is function 0, signal hotplug for all the device functions.
@@ -1551,9 +1552,6 @@ static void spapr_pci_plug(HotplugHandler *plug_handler,
             }
         }
     }
-
-out:
-    error_propagate(errp, local_err);
 }
 
 static void spapr_pci_bridge_unplug(SpaprPhbState *phb,