Treat multiple successive slashes as a one slash.  Ignore trailing
slashes.  This is how POSIX pathnames work.

Also put error definitions in alphabetical order

While fully converted handlers are not supposed to print anything when
running in a QMP monitor, they are free to print in a human monitor.
For instance, device_add (not yet converted) prints help, and will
continue to do so after conversion.

Moreover, utility functions converted to QError should remain usable
from unconverted handlers.

Two problems:

* handler_audit() complains when a converted handler prints.  Limit
  that to QMP monitors.

* With QMP, handlers need to pass the error object by way of
  monitor_set_error().  However, we do that both for QMP and for the
  human monitor.  The human monitor prints the error object after the
  handler returns.  If the handler prints anything else, that output
  "overtakes" the error message.

  Limit use of monitor_set_error() to QMP monitors.  Update
  handler_audit() accordingly.

Users can't set them, so qdev_device_help() shouldn't list them.  Fix
that.  Also make qdev_prop_parse() hide them instead of printing a
meaningless "has no parser" error message.

Their value means nothing to users, so qdev_print_props() shouldn't
print it.  Fix by removing their print method.

Their only use is dirty hacks.  Document that.

Users can't create them, so qdev_device_help() shouldn't list them.
Fix that.

Also make qdev_device_add() pretend they don't exist.  Before, it
rejected them with a "can't be added via command line" message, which
wasn't quite right for monitor command device_add.

To make it obvious that -device and device_add can't die in
hw_error().

"device_add isa-serial,bus=pci.0" kills QEMU.  Not good.

New LOC_CMDLINE.  Use it for tracking option with argument in
lookup_opt().  We now report errors like this

    qemu: -device smbus-eeprom: Did not find I2C bus for smbus-eeprom

New LOC_FILE.  Use it for tracking file name and line number in
qemu_config_parse().  We now report errors like

    qemu:foo.conf:42: Did not find I2C bus for smbus-eeprom

In particular, gems like this message:

    -device: no driver specified

become almost nice now:

    qemu:foo.conf:44: -device: no driver specified

(A later commit will get rid of the bogus -device:)

New struct Location holds a location.  So far, the only location is
LOC_NONE, so this doesn't do anything useful yet.

Passing the current location all over the place would be too
cumbersome.  Hide it away in static cur_loc instead, and provide
accessors.  Print it in error_report().

Store it in QError, and print it in qerror_print().

Store it in QemuOpt, for use by qemu_opts_foreach().  This makes
error_report() do the right thing when it runs within
qemu_opts_foreach().

We may still have to store it in other data structures holding user
input for better error messages.  Left for another day.

error_report() terminates the message with a newline.  Strip it it
from its arguments.

This fixes a few error messages lacking a newline:
net_handle_fd_param()'s "No file descriptor named %s found", and
tap_open()'s "vnet_hdr=1 requested, but no kernel support for
IFF_VNET_HDR available" (all three versions).

There's one place that passes arguments without newlines
intentionally: load_vmstate().  Fix it up.

Commit 30d335d6 converted an informational message from
monitor_printf() to qemu_error(), probably because the latter doesn't
need a mon argument.  A later commit will make qemu_error() print
additional stuff that is only appropriate for proper errors, and then
this will break.  Clean it up.

qbus_find() adds an informational line to error messages, and prints
both lines with one qemu_error().  Use error_printf() for the
informational line instead.

While there, simplify: instead of printing buffers filled by
qbus_list_bus() and qbus_list_dev() in one go, make them print it.

qdev_device_help() prints device information with qemu_error().  A
later commit will make qemu_error() print additional stuff that is
only appropriate for proper errors, and then this will break.  Use
error_printf() instead.

While there, simplify: instead of printing a buffer filled by
qdev_print_devinfo() in one go, make qdev_print_devinfo() print it.

qemu_error_sink can either point to a monitor or a file.  In practice,
it always points to the current monitor if we have one, else to
stderr.  Simply route errors to the current monitor or else to stderr,
and remove qemu_error_sink along with the functions to control it.

Actually, the old code switches the sink slightly later, in
handle_user_command() and handle_qmp_command(), than it gets switched
now, implicitly, by setting the current monitor in monitor_read() and
monitor_control_read().  Likewise, it switches back slightly earlier
(same places).  Doesn't make a difference, because there are no calls
of qemu_error() in between.

They're about reporting errors, not about the monitor.

This separates the monitor part from the QError part.

The old test assumes that "hotplugged" implies "we have a current
monitor for reading the key".  This is in fact true, but it's not
obviously true.

Aside: if it were false, we could pass a null pointer to
monitor_read_bdrv_key_start(), which would then crash.

The previous commit permits us to check for "we have a current
monitor" directly, so do that.

Commits 376253ec..731b0364 introduced global variable cur_mon, which
points to the "default monitor" (if any), except during execution of
monitor_read() or monitor_control_read() it points to the monitor from
which we're reading instead (the "current monitor").  Monitor command
handlers run within monitor_read() or monitor_control_read().

Default monitor and current monitor are really separate things, and
squashing them together is confusing and error-prone.

For instance, usb_host_scan() can run both in "info usbhost" and
periodically via usb_host_auto_check().  It prints to cur_mon, which
is what we want in the former case: the monitor executing "info
usbhost".  But since that's the default monitor in the latter case, it
periodically spams the default monitor there.

A few places use cur_mon to log stuff to the default monitor.  If we
ever log something while cur_mon points to current monitor instead of
default monitor, the log temporarily "jumps" to another monitor.
Whether that can or cannot happen isn't always obvious.

Maybe logging to the default monitor (which may not even exist) is a
bad idea, and we should log to stderr or a logfile instead.  But
that's outside the scope of this commit.

Change cur_mon to point to the current monitor.  Create new
default_mon to point to the default monitor.  Update users of cur_mon
accordingly.

This fixes the periodical spamming of the default monitor by
usb_host_scan().  It also stops "log jumping", should that problem
exist.

Code duplicated in commit 0ecdffbb.  The two versions are similar, but
not identical:

* cmos_init() reports errors to stderr, pc_boot_set() via
  qemu_error().  The latter is fine for both, so pick that for the
  common code.

* cmos_init() obeys fd_bootchk, pc_boot_set() ignores it.  Make it a
  parameter of the common code.

Commit 0ecdffbb created pc_boot_set() for use from monitor command
"boot_set", via qemu_boot_set().  pc_boot_set() reports errors to
cur_mon, which works fine for monitor code.

Commit e0f084bf reused the function int reset handler
restore_boot_devices().  Use of cur_mon is problematic in that
context.  For instance, the "Too many boot devices for PC" error for
"-boot order=abcdefgh,once=c" goes to the monitor instead of stderr.
The monitor may not even exist.

Fix by switching to qemu_error().

A monitor may not even exist.

Change load_vmstate() to use qemu_error() instead of monitor_printf().
Parameter mon is now unused, remove it.

The monitor_printf() reports failure.  Printing is wrong, because the
caller tries various arguments, and expects the function to fail for
some or all.

Disabled since commit 26a9e82a.  Remove it.

Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>