2011-06-01 19:14:49 +02:00
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/*
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* QEMU Error Objects
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*
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* Copyright IBM, Corp. 2011
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2015-06-19 18:29:24 +02:00
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* Copyright (C) 2011-2015 Red Hat, Inc.
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2011-06-01 19:14:49 +02:00
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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2015-06-19 18:29:24 +02:00
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* Markus Armbruster <armbru@redhat.com>
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2011-06-01 19:14:49 +02:00
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*
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* This work is licensed under the terms of the GNU LGPL, version 2. See
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* the COPYING.LIB file in the top-level directory.
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*/
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2015-06-19 18:29:24 +02:00
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/*
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* Error reporting system loosely patterned after Glib's GError.
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*
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* Create an error:
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* error_setg(&err, "situation normal, all fouled up");
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*
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2015-12-18 16:35:08 +01:00
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* Create an error and add additional explanation:
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* error_setg(&err, "invalid quark");
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* error_append_hint(&err, "Valid quarks are up, down, strange, "
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* "charm, top, bottom.\n");
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*
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* Do *not* contract this to
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* error_setg(&err, "invalid quark\n"
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* "Valid quarks are up, down, strange, charm, top, bottom.");
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*
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2016-02-03 19:03:47 +01:00
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* Report an error to the current monitor if we have one, else stderr:
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2015-06-19 18:29:24 +02:00
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* error_report_err(err);
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* This frees the error object.
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*
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2016-02-03 19:03:47 +01:00
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* Likewise, but with additional text prepended:
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error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:
frobnicate(arg, &err);
error_setg(errp, "Can't frobnicate %s: %s",
arg, error_get_pretty(err));
error_free(err);
This is suboptimal, because it loses err's hint (if any). Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.
To avoid these issues, provide means to add to an error's message in
place:
frobnicate(arg, errp);
error_prepend(errp, "Can't frobnicate %s: ", arg);
Likewise, reporting an error like
frobnicate(arg, &err);
error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));
can lose err's hint. To avoid:
error_reportf_err(err, "Can't frobnicate %s: ", arg);
The next commits will put these functions to use.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2015-12-18 16:35:12 +01:00
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* error_reportf_err(err, "Could not frobnicate '%s': ", name);
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*
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2015-06-19 18:29:24 +02:00
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* Report an error somewhere else:
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* const char *msg = error_get_pretty(err);
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* do with msg what needs to be done...
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* error_free(err);
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2015-12-18 16:35:08 +01:00
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* Note that this loses hints added with error_append_hint().
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2015-06-19 18:29:24 +02:00
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*
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* Handle an error without reporting it (just for completeness):
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* error_free(err);
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*
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2015-11-06 07:35:31 +01:00
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* Assert that an expected error occurred, but clean it up without
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* reporting it (primarily useful in testsuites):
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* error_free_or_abort(&err);
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*
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2015-06-19 18:29:24 +02:00
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* Pass an existing error to the caller:
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* error_propagate(errp, err);
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* where Error **errp is a parameter, by convention the last one.
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*
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error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:
frobnicate(arg, &err);
error_setg(errp, "Can't frobnicate %s: %s",
arg, error_get_pretty(err));
error_free(err);
This is suboptimal, because it loses err's hint (if any). Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.
To avoid these issues, provide means to add to an error's message in
place:
frobnicate(arg, errp);
error_prepend(errp, "Can't frobnicate %s: ", arg);
Likewise, reporting an error like
frobnicate(arg, &err);
error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));
can lose err's hint. To avoid:
error_reportf_err(err, "Can't frobnicate %s: ", arg);
The next commits will put these functions to use.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2015-12-18 16:35:12 +01:00
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* Pass an existing error to the caller with the message modified:
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* error_propagate(errp, err);
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* error_prepend(errp, "Could not frobnicate '%s': ", name);
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*
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2015-06-19 18:29:24 +02:00
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* Create a new error and pass it to the caller:
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* error_setg(errp, "situation normal, all fouled up");
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*
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* Call a function and receive an error from it:
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* Error *err = NULL;
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* foo(arg, &err);
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* if (err) {
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* handle the error...
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* }
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*
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* Call a function ignoring errors:
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* foo(arg, NULL);
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*
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* Call a function aborting on errors:
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* foo(arg, &error_abort);
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*
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2015-09-11 16:51:42 +02:00
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* Call a function treating errors as fatal:
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* foo(arg, &error_fatal);
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*
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2015-06-19 18:29:24 +02:00
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* Receive an error and pass it on to the caller:
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* Error *err = NULL;
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* foo(arg, &err);
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* if (err) {
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* handle the error...
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* error_propagate(errp, err);
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* }
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* where Error **errp is a parameter, by convention the last one.
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*
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* Do *not* "optimize" this to
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* foo(arg, errp);
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* if (*errp) { // WRONG!
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* handle the error...
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* }
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* because errp may be NULL!
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*
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* But when all you do with the error is pass it on, please use
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* foo(arg, errp);
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* for readability.
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2015-11-17 17:05:49 +01:00
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*
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* Receive and accumulate multiple errors (first one wins):
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* Error *err = NULL, *local_err = NULL;
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* foo(arg, &err);
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* bar(arg, &local_err);
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* error_propagate(&err, local_err);
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* if (err) {
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* handle the error...
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* }
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*
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* Do *not* "optimize" this to
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* foo(arg, &err);
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* bar(arg, &err); // WRONG!
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* if (err) {
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* handle the error...
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* }
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* because this may pass a non-null err to bar().
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2015-06-19 18:29:24 +02:00
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*/
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2011-06-01 19:14:49 +02:00
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#ifndef ERROR_H
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#define ERROR_H
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2012-07-27 19:09:29 +02:00
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#include "qapi-types.h"
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2011-06-01 19:14:49 +02:00
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qapi: Add alias for ErrorClass
The qapi enum ErrorClass is unusual that it uses 'CamelCase' names,
contrary to our documented convention of preferring 'lower-case'.
However, this enum is entrenched in the API; we cannot change
what strings QMP outputs. Meanwhile, we want to simplify how
c_enum_const() is used to generate enum constants, by moving away
from the heuristics of camel_to_upper() to a more straightforward
c_name(N).upper() - but doing so will rename all of the ErrorClass
constants and cause churn to all client files, where the new names
are aesthetically less pleasing (ERROR_CLASS_DEVICENOTFOUND looks
like we can't make up our minds on whether to break between words).
So as always in computer science, solve the problem by some more
indirection: rename the qapi type to QapiErrorClass, and add a
new enum ErrorClass in error.h whose members are aliases of the
qapi type, but with the spelling expected elsewhere in the tree.
Then, when c_enum_const() changes the munging, we only have to
adjust the one alias spot.
Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-26-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-18 09:53:00 +01:00
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/*
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* Overall category of an error.
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* Based on the qapi type QapiErrorClass, but reproduced here for nicer
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* enum names.
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*/
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typedef enum ErrorClass {
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qapi: Change munging of CamelCase enum values
When munging enum values, the fact that we were passing the entire
prefix + value through camel_to_upper() meant that enum values
spelled with CamelCase could be turned into CAMEL_CASE. However,
this provides a potential collision (both OneTwo and One-Two would
munge into ONE_TWO) for enum types, when the same two names are
valid side-by-side as QAPI member names. By changing the generation
of enum constants to always be prefix + '_' + c_name(value,
False).upper(), and ensuring that there are no case collisions (in
the next patches), we no longer have to worry about names that
would be distinct as QAPI members but collide as variant tag names,
without having to think about what munging the heuristics in
camel_to_upper() will actually perform on an enum value.
Making the change will affect enums that did not follow coding
conventions, using 'CamelCase' rather than desired 'lower-case'.
Thankfully, there are only two culprits: InputButton and ErrorClass.
We already tweaked ErrorClass to make it an alias of QapiErrorClass,
where only the alias needs changing rather than the whole tree. So
the bulk of this change is modifying INPUT_BUTTON_WHEEL_UP to the
new INPUT_BUTTON_WHEELUP (and likewise for WHEELDOWN). That part
of this commit may later need reverting if we rename the enum
constants from 'WheelUp' to 'wheel-up' as part of moving
x-input-send-event to a stable interface; but at least we have
documentation bread crumbs in place to remind us (commit 513e7cd),
and it matches the fact that SDL constants are also spelled
SDL_BUTTON_WHEELUP.
Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-27-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-18 09:53:01 +01:00
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ERROR_CLASS_GENERIC_ERROR = QAPI_ERROR_CLASS_GENERICERROR,
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ERROR_CLASS_COMMAND_NOT_FOUND = QAPI_ERROR_CLASS_COMMANDNOTFOUND,
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ERROR_CLASS_DEVICE_NOT_ACTIVE = QAPI_ERROR_CLASS_DEVICENOTACTIVE,
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ERROR_CLASS_DEVICE_NOT_FOUND = QAPI_ERROR_CLASS_DEVICENOTFOUND,
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ERROR_CLASS_KVM_MISSING_CAP = QAPI_ERROR_CLASS_KVMMISSINGCAP,
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qapi: Add alias for ErrorClass
The qapi enum ErrorClass is unusual that it uses 'CamelCase' names,
contrary to our documented convention of preferring 'lower-case'.
However, this enum is entrenched in the API; we cannot change
what strings QMP outputs. Meanwhile, we want to simplify how
c_enum_const() is used to generate enum constants, by moving away
from the heuristics of camel_to_upper() to a more straightforward
c_name(N).upper() - but doing so will rename all of the ErrorClass
constants and cause churn to all client files, where the new names
are aesthetically less pleasing (ERROR_CLASS_DEVICENOTFOUND looks
like we can't make up our minds on whether to break between words).
So as always in computer science, solve the problem by some more
indirection: rename the qapi type to QapiErrorClass, and add a
new enum ErrorClass in error.h whose members are aliases of the
qapi type, but with the spelling expected elsewhere in the tree.
Then, when c_enum_const() changes the munging, we only have to
adjust the one alias spot.
Suggested by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-26-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-18 09:53:00 +01:00
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} ErrorClass;
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2015-06-19 18:29:24 +02:00
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/*
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* Get @err's human-readable error message.
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2011-06-01 19:14:49 +02:00
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*/
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migration: add reporting of errors for outgoing migration
Currently if an application initiates an outgoing migration,
it may or may not, get an error reported back on failure. If
the error occurs synchronously to the 'migrate' command
execution, the client app will see the error message. This
is the case for DNS lookup failures. If the error occurs
asynchronously to the monitor command though, the error
will be thrown away and the client left guessing about
what went wrong. This is the case for failure to connect
to the TCP server (eg due to wrong port, or firewall
rules, or other similar errors).
In the future we'll be adding more scope for errors to
happen asynchronously with the TLS protocol handshake.
TLS errors are hard to diagnose even when they are well
reported, so discarding errors entirely will make it
impossible to debug TLS connection problems.
Management apps which do migration are already using
'query-migrate' / 'info migrate' to check up on progress
of background migration operations and to see their end
status. This is a fine place to also include the error
message when things go wrong.
This patch thus adds an 'error-desc' field to the
MigrationInfo struct, which will be populated when
the 'status' is set to 'failed':
(qemu) migrate -d tcp:localhost:9001
(qemu) info migrate
capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off x-postcopy-ram: off
Migration status: failed (Error connecting to socket: Connection refused)
total time: 0 milliseconds
In the HMP, when doing non-detached migration, it is
also possible to display this error message directly
to the app.
(qemu) migrate tcp:localhost:9001
Error connecting to socket: Connection refused
Or with QMP
{
"execute": "query-migrate",
"arguments": {}
}
{
"return": {
"status": "failed",
"error-desc": "address resolution failed for myhost:9000: No address associated with hostname"
}
}
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <1461751518-12128-11-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2016-04-27 12:05:00 +02:00
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const char *error_get_pretty(const Error *err);
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2011-06-01 19:14:49 +02:00
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2015-06-19 18:29:24 +02:00
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/*
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* Get @err's error class.
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* Note: use of error classes other than ERROR_CLASS_GENERIC_ERROR is
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* strongly discouraged.
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*/
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ErrorClass error_get_class(const Error *err);
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/*
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* Create a new error object and assign it to *@errp.
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* If @errp is NULL, the error is ignored. Don't bother creating one
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* then.
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* If @errp is &error_abort, print a suitable message and abort().
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2015-09-11 16:51:42 +02:00
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* If @errp is &error_fatal, print a suitable message and exit(1).
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2015-06-19 18:29:24 +02:00
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* If @errp is anything else, *@errp must be NULL.
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* The new error's class is ERROR_CLASS_GENERIC_ERROR, and its
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* human-readable error message is made from printf-style @fmt, ...
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2015-12-18 16:35:08 +01:00
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* The resulting message should be a single phrase, with no newline or
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* trailing punctuation.
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2016-02-03 19:03:47 +01:00
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* Please don't error_setg(&error_fatal, ...), use error_report() and
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* exit(), because that's more obvious.
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* Likewise, don't error_setg(&error_abort, ...), use assert().
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2015-06-19 18:29:24 +02:00
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*/
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error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created. Looks like this:
Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
Aborted (core dumped)
Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().
To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments. Not exactly
pretty, but it works.
The macro trickery breaks down when you take the address of an
error_setFOO(). Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL". Use error_setg_win32_internal() there. The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.
Code size increases by some 35KiB for me (0.7%). Tolerable. Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-06-19 19:21:59 +02:00
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#define error_setg(errp, fmt, ...) \
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error_setg_internal((errp), __FILE__, __LINE__, __func__, \
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(fmt), ## __VA_ARGS__)
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void error_setg_internal(Error **errp,
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const char *src, int line, const char *func,
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const char *fmt, ...)
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GCC_FMT_ATTR(5, 6);
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2015-06-19 18:29:24 +02:00
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/*
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* Just like error_setg(), with @os_error info added to the message.
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* If @os_error is non-zero, ": " + strerror(os_error) is appended to
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* the human-readable error message.
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2016-07-27 11:24:26 +02:00
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*
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* The value of errno (which usually can get clobbered by almost any
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* function call) will be preserved.
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2012-10-02 09:00:45 +02:00
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*/
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error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created. Looks like this:
Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
Aborted (core dumped)
Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().
To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments. Not exactly
pretty, but it works.
The macro trickery breaks down when you take the address of an
error_setFOO(). Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL". Use error_setg_win32_internal() there. The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.
Code size increases by some 35KiB for me (0.7%). Tolerable. Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-06-19 19:21:59 +02:00
|
|
|
#define error_setg_errno(errp, os_error, fmt, ...) \
|
|
|
|
error_setg_errno_internal((errp), __FILE__, __LINE__, __func__, \
|
|
|
|
(os_error), (fmt), ## __VA_ARGS__)
|
|
|
|
void error_setg_errno_internal(Error **errp,
|
|
|
|
const char *fname, int line, const char *func,
|
|
|
|
int os_error, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(6, 7);
|
2012-10-02 09:00:45 +02:00
|
|
|
|
2013-08-07 17:40:11 +02:00
|
|
|
#ifdef _WIN32
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Just like error_setg(), with @win32_error info added to the message.
|
|
|
|
* If @win32_error is non-zero, ": " + g_win32_error_message(win32_err)
|
|
|
|
* is appended to the human-readable error message.
|
2013-08-07 17:40:11 +02:00
|
|
|
*/
|
error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created. Looks like this:
Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
Aborted (core dumped)
Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().
To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments. Not exactly
pretty, but it works.
The macro trickery breaks down when you take the address of an
error_setFOO(). Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL". Use error_setg_win32_internal() there. The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.
Code size increases by some 35KiB for me (0.7%). Tolerable. Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-06-19 19:21:59 +02:00
|
|
|
#define error_setg_win32(errp, win32_err, fmt, ...) \
|
|
|
|
error_setg_win32_internal((errp), __FILE__, __LINE__, __func__, \
|
|
|
|
(win32_err), (fmt), ## __VA_ARGS__)
|
|
|
|
void error_setg_win32_internal(Error **errp,
|
|
|
|
const char *src, int line, const char *func,
|
|
|
|
int win32_err, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(6, 7);
|
2013-08-07 17:40:11 +02:00
|
|
|
#endif
|
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Propagate error object (if any) from @local_err to @dst_errp.
|
|
|
|
* If @local_err is NULL, do nothing (because there's nothing to
|
|
|
|
* propagate).
|
|
|
|
* Else, if @dst_errp is NULL, errors are being ignored. Free the
|
|
|
|
* error object.
|
|
|
|
* Else, if @dst_errp is &error_abort, print a suitable message and
|
|
|
|
* abort().
|
2015-09-11 16:51:42 +02:00
|
|
|
* Else, if @dst_errp is &error_fatal, print a suitable message and
|
|
|
|
* exit(1).
|
2015-06-19 18:29:24 +02:00
|
|
|
* Else, if @dst_errp already contains an error, ignore this one: free
|
|
|
|
* the error object.
|
|
|
|
* Else, move the error object from @local_err to *@dst_errp.
|
|
|
|
* On return, @local_err is invalid.
|
2016-02-03 19:03:47 +01:00
|
|
|
* Please don't error_propagate(&error_fatal, ...), use
|
|
|
|
* error_report_err() and exit(), because that's more obvious.
|
2012-08-29 16:20:57 +02:00
|
|
|
*/
|
2015-06-19 18:29:24 +02:00
|
|
|
void error_propagate(Error **dst_errp, Error *local_err);
|
2012-08-29 16:20:57 +02:00
|
|
|
|
error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:
frobnicate(arg, &err);
error_setg(errp, "Can't frobnicate %s: %s",
arg, error_get_pretty(err));
error_free(err);
This is suboptimal, because it loses err's hint (if any). Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.
To avoid these issues, provide means to add to an error's message in
place:
frobnicate(arg, errp);
error_prepend(errp, "Can't frobnicate %s: ", arg);
Likewise, reporting an error like
frobnicate(arg, &err);
error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));
can lose err's hint. To avoid:
error_reportf_err(err, "Can't frobnicate %s: ", arg);
The next commits will put these functions to use.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2015-12-18 16:35:12 +01:00
|
|
|
/*
|
|
|
|
* Prepend some text to @errp's human-readable error message.
|
|
|
|
* The text is made by formatting @fmt, @ap like vprintf().
|
|
|
|
*/
|
|
|
|
void error_vprepend(Error **errp, const char *fmt, va_list ap);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Prepend some text to @errp's human-readable error message.
|
|
|
|
* The text is made by formatting @fmt, ... like printf().
|
|
|
|
*/
|
|
|
|
void error_prepend(Error **errp, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(2, 3);
|
|
|
|
|
|
|
|
/*
|
hmp: Allow for error message hints on HMP
Commits 7216ae3d and d2828429 disabled some error message hints,
all because a change to use modern error reporting meant that the
hint would be output prior to the actual error. Fix this by making
hints a first-class member of Error.
For example, we are now back to the pleasant:
$ qemu-system-x86_64 --nodefaults -S --vnc :0 --chardev null,id=,
qemu-system-x86_64: --chardev null,id=,: Parameter 'id' expects an identifier
Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1441901956-21991-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-10 18:19:16 +02:00
|
|
|
* Append a printf-style human-readable explanation to an existing error.
|
2017-08-10 12:06:28 +02:00
|
|
|
* If the error is later reported to a human user with
|
|
|
|
* error_report_err() or warn_report_err(), the hints will be shown,
|
|
|
|
* too. If it's reported via QMP, the hints will be ignored.
|
|
|
|
* Intended use is adding helpful hints on the human user interface,
|
|
|
|
* e.g. a list of valid values. It's not for clarifying a confusing
|
|
|
|
* error message.
|
2015-12-18 16:35:08 +01:00
|
|
|
* @errp may be NULL, but not &error_fatal or &error_abort.
|
|
|
|
* Trivially the case if you call it only after error_setg() or
|
|
|
|
* error_propagate().
|
|
|
|
* May be called multiple times. The resulting hint should end with a
|
|
|
|
* newline.
|
hmp: Allow for error message hints on HMP
Commits 7216ae3d and d2828429 disabled some error message hints,
all because a change to use modern error reporting meant that the
hint would be output prior to the actual error. Fix this by making
hints a first-class member of Error.
For example, we are now back to the pleasant:
$ qemu-system-x86_64 --nodefaults -S --vnc :0 --chardev null,id=,
qemu-system-x86_64: --chardev null,id=,: Parameter 'id' expects an identifier
Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1441901956-21991-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-09-10 18:19:16 +02:00
|
|
|
*/
|
|
|
|
void error_append_hint(Error **errp, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(2, 3);
|
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Convenience function to report open() failure.
|
2013-06-07 20:24:49 +02:00
|
|
|
*/
|
error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created. Looks like this:
Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
Aborted (core dumped)
Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().
To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments. Not exactly
pretty, but it works.
The macro trickery breaks down when you take the address of an
error_setFOO(). Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL". Use error_setg_win32_internal() there. The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.
Code size increases by some 35KiB for me (0.7%). Tolerable. Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-06-19 19:21:59 +02:00
|
|
|
#define error_setg_file_open(errp, os_errno, filename) \
|
|
|
|
error_setg_file_open_internal((errp), __FILE__, __LINE__, __func__, \
|
|
|
|
(os_errno), (filename))
|
|
|
|
void error_setg_file_open_internal(Error **errp,
|
|
|
|
const char *src, int line, const char *func,
|
|
|
|
int os_errno, const char *filename);
|
2013-06-07 20:24:49 +02:00
|
|
|
|
2012-08-01 21:29:38 +02:00
|
|
|
/*
|
2015-06-19 18:29:24 +02:00
|
|
|
* Return an exact copy of @err.
|
2011-12-05 19:04:05 +01:00
|
|
|
*/
|
|
|
|
Error *error_copy(const Error *err);
|
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Free @err.
|
|
|
|
* @err may be NULL.
|
2011-06-01 19:14:49 +02:00
|
|
|
*/
|
2015-06-19 18:29:24 +02:00
|
|
|
void error_free(Error *err);
|
2011-06-01 19:14:49 +02:00
|
|
|
|
2015-11-06 07:35:31 +01:00
|
|
|
/*
|
|
|
|
* Convenience function to assert that *@errp is set, then silently free it.
|
|
|
|
*/
|
|
|
|
void error_free_or_abort(Error **errp);
|
|
|
|
|
2017-07-12 15:57:52 +02:00
|
|
|
/*
|
|
|
|
* Convenience function to warn_report() and free @err.
|
2017-08-10 12:06:28 +02:00
|
|
|
* The report includes hints added with error_append_hint().
|
2017-07-12 15:57:52 +02:00
|
|
|
*/
|
|
|
|
void warn_report_err(Error *err);
|
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Convenience function to error_report() and free @err.
|
2017-08-10 12:06:28 +02:00
|
|
|
* The report includes hints added with error_append_hint().
|
2015-02-06 15:27:19 +01:00
|
|
|
*/
|
2015-12-18 16:35:08 +01:00
|
|
|
void error_report_err(Error *err);
|
2015-02-06 15:27:19 +01:00
|
|
|
|
2017-07-12 15:57:52 +02:00
|
|
|
/*
|
|
|
|
* Convenience function to error_prepend(), warn_report() and free @err.
|
|
|
|
*/
|
|
|
|
void warn_reportf_err(Error *err, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(2, 3);
|
|
|
|
|
error: New error_prepend(), error_reportf_err()
Instead of simply propagating an error verbatim, we sometimes want to
add to its message, like this:
frobnicate(arg, &err);
error_setg(errp, "Can't frobnicate %s: %s",
arg, error_get_pretty(err));
error_free(err);
This is suboptimal, because it loses err's hint (if any). Moreover,
when errp is &error_abort or is subsequently propagated to
&error_abort, the abort message points to the place where we last
added to the error, not to the place where it originated.
To avoid these issues, provide means to add to an error's message in
place:
frobnicate(arg, errp);
error_prepend(errp, "Can't frobnicate %s: ", arg);
Likewise, reporting an error like
frobnicate(arg, &err);
error_report("Can't frobnicate %s: %s", arg, error_get_pretty(err));
can lose err's hint. To avoid:
error_reportf_err(err, "Can't frobnicate %s: ", arg);
The next commits will put these functions to use.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1450452927-8346-10-git-send-email-armbru@redhat.com>
2015-12-18 16:35:12 +01:00
|
|
|
/*
|
|
|
|
* Convenience function to error_prepend(), error_report() and free @err.
|
|
|
|
*/
|
|
|
|
void error_reportf_err(Error *err, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(2, 3);
|
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
|
|
|
* Just like error_setg(), except you get to specify the error class.
|
|
|
|
* Note: use of error classes other than ERROR_CLASS_GENERIC_ERROR is
|
|
|
|
* strongly discouraged.
|
2011-06-01 19:14:49 +02:00
|
|
|
*/
|
error: On abort, report where the error was created
This is particularly useful when we abort in error_propagate(),
because there the stack backtrace doesn't lead to where the error was
created. Looks like this:
Unexpected error in parse_block_error_action() at .../qemu/blockdev.c:322:
qemu-system-x86_64: -drive if=none,werror=foo: 'foo' invalid write error action
Aborted (core dumped)
Note: to get this example output, I monkey-patched drive_new() to pass
&error_abort to blockdev_init().
To keep the error handling boiler plate from growing even more, all
error_setFOO() become macros expanding into error_setFOO_internal()
with additional __FILE__, __LINE__, __func__ arguments. Not exactly
pretty, but it works.
The macro trickery breaks down when you take the address of an
error_setFOO(). Fortunately, we do that in just one place: qemu-ga's
Windows VSS provider and requester DLL wants to call
error_setg_win32() through a function pointer "to avoid linking glib
to the DLL". Use error_setg_win32_internal() there. The use of the
function pointer is already wrapped in a macro, so the churn isn't
bad.
Code size increases by some 35KiB for me (0.7%). Tolerable. Could be
less if we passed relative rather than absolute source file names to
the compiler, or forwent reporting __func__.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
2015-06-19 19:21:59 +02:00
|
|
|
#define error_set(errp, err_class, fmt, ...) \
|
|
|
|
error_set_internal((errp), __FILE__, __LINE__, __func__, \
|
|
|
|
(err_class), (fmt), ## __VA_ARGS__)
|
|
|
|
void error_set_internal(Error **errp,
|
|
|
|
const char *src, int line, const char *func,
|
|
|
|
ErrorClass err_class, const char *fmt, ...)
|
|
|
|
GCC_FMT_ATTR(6, 7);
|
2011-06-01 19:14:49 +02:00
|
|
|
|
2015-06-19 18:29:24 +02:00
|
|
|
/*
|
2016-02-03 19:03:47 +01:00
|
|
|
* Special error destination to abort on error.
|
|
|
|
* See error_setg() and error_propagate() for details.
|
2014-01-02 03:46:59 +01:00
|
|
|
*/
|
|
|
|
extern Error *error_abort;
|
|
|
|
|
2015-09-11 16:51:42 +02:00
|
|
|
/*
|
2016-02-03 19:03:47 +01:00
|
|
|
* Special error destination to exit(1) on error.
|
|
|
|
* See error_setg() and error_propagate() for details.
|
2015-09-11 16:51:42 +02:00
|
|
|
*/
|
|
|
|
extern Error *error_fatal;
|
|
|
|
|
2011-06-01 19:14:49 +02:00
|
|
|
#endif
|