The point of writing a macro embedded in a 'do { ... } while (0)'
loop (particularly if the macro has multiple statements or would
otherwise end with an 'if' statement) is so that the macro can be
used as a drop-in statement with the caller supplying the
trailing ';'. Although our coding style frowns on brace-less 'if':
if (cond)
statement;
else
something else;
that is the classic case where failure to use do/while(0) wrapping
would cause the 'else' to pair with any embedded 'if' in the macro
rather than the intended outer 'if'. But conversely, if the macro
includes an embedded ';', then the same brace-less coding style
would now have two statements, making the 'else' a syntax error
rather than pairing with the outer 'if'. Thus, even though our
coding style with required braces is not impacted, ending a macro
with ';' makes our code harder to port to projects that use
brace-less styles.
The change should have no semantic impact. I was not able to
fully compile-test all of the changes (as some of them are
examples of the ugly bit-rotting debug print statements that are
completely elided by default, and I didn't want to recompile
with the necessary -D witnesses - cleaning those up is left as a
bite-sized task for another day); I did, however, audit that for
all files touched, all callers of the changed macros DID supply
a trailing ';' at the callsite, and did not appear to be used
as part of a brace-less conditional.
Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20171201232433.25193-7-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The mmio-interface device is not something we want to allow
users to create on the command line:
* it is intended as an implementation detail of the memory
subsystem, which gets created and deleted by that
subsystem on demand; it makes no sense to create it
by hand on the command line
* it uses a pointer property 'host_ptr' which can't be
set on the command line
Mark the device as not user_creatable to avoid confusion.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1502807418-9994-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Thomas Huth <thuth@redhat.com>
QEMU currently abort()s if the user tries to specify the mmio_interface
device without parameters:
x86_64-softmmu/qemu-system-x86_64 -nographic -device mmio_interface
qemu-system-x86_64: /home/thuth/devel/qemu/util/error.c:57: error_setv:
Assertion `*errp == ((void *)0)' failed.
Aborted (core dumped)
This happens because the realize function is trying to set the errp
twice in this case. After setting an error, the realize function
should immediately return instead.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
This introduces mmio_interface object which contains a MemoryRegion
and can be hotplugged/hotunplugged.
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Eric Blake