motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-04 00:03:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

error: On abort, report where the error was created

Browse source 
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>
This commit is contained in:
Markus Armbruster 2015-06-19 19:21:59 +02:00
parent edf6f3b335
commit 1e9b65bb1b
5 changed files with 81 additions and 30 deletions
Download patch file Download diff file Expand all files Collapse all files

5
qga/vss-win32/requester.cpp
View file

@ -23,8 +23,9 @@
/* Call QueryStatus every 10 ms while waiting for frozen event */
#define VSS_TIMEOUT_EVENT_MSEC 10
#define err_set(e, err, fmt, ...) \
((e)->error_setg_win32((e)->errp, err, fmt, ## __VA_ARGS__))
#define err_set(e, err, fmt, ...) \
((e)->error_setg_win32((e)->errp, __FILE__, __LINE__, __func__, \
err, fmt, ## __VA_ARGS__))
/* Bad idea, works only when (e)->errp != NULL: */
#define err_is_set(e) ((e)->errp && *(e)->errp)
/* To lift this restriction, error_propagate(), like we do in QEMU code */