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, 10 insertions, 13 deletions

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 7c893e5..d46b1f0 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -117,7 +117,6 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
     uint64_t pentry;
     char *magic;
     int kernel_size;
-    Error *err = NULL;
 
     int bios_size;
     char *bios_filename;
@@ -135,8 +134,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
 
         bios_filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
         if (bios_filename == NULL) {
-            error_setg(&err, "could not find stage1 bootloader");
-            goto error;
+            error_setg(errp, "could not find stage1 bootloader");
+            return;
         }
 
         bios_size = load_elf(bios_filename, NULL,
@@ -155,8 +154,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
         g_free(bios_filename);
 
         if (bios_size == -1) {
-            error_setg(&err, "could not load bootloader '%s'", bios_name);
-            goto error;
+            error_setg(errp, "could not load bootloader '%s'", bios_name);
+            return;
         }
 
         /* default boot target is the bios */
@@ -170,8 +169,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
         if (kernel_size < 0) {
             kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
             if (kernel_size < 0) {
-                error_setg(&err, "could not load kernel '%s'", ipl->kernel);
-                goto error;
+                error_setg(errp, "could not load kernel '%s'", ipl->kernel);
+                return;
             }
             /* if this is Linux use KERN_IMAGE_START */
             magic = rom_ptr(LINUX_MAGIC_ADDR, 6);
@@ -183,8 +182,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
                 if (ipl_psw) {
                     pentry = be32_to_cpu(*ipl_psw) & PSW_MASK_SHORT_ADDR;
                 } else {
-                    error_setg(&err, "Could not get IPL PSW");
-                    goto error;
+                    error_setg(errp, "Could not get IPL PSW");
+                    return;
                 }
             }
         }
@@ -217,8 +216,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
             initrd_size = load_image_targphys(ipl->initrd, initrd_offset,
                                               ram_size - initrd_offset);
             if (initrd_size == -1) {
-                error_setg(&err, "could not load initrd '%s'", ipl->initrd);
-                goto error;
+                error_setg(errp, "could not load initrd '%s'", ipl->initrd);
+                return;
             }
 
             /*
@@ -248,8 +247,6 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
      * TODO: there should be a better way to do this.
      */
     qemu_register_reset(resettable_cold_reset_fn, dev);
-error:
-    error_propagate(errp, err);
 }
 
 static Property s390_ipl_properties[] = {