qapi: Speed up frontend tests

"make check-qapi-schema" takes around 10s user + system time for me.
With -j, it takes a bit over 3s real time. We have worse tests. It's
still annoying when you work

qapi: Speed up frontend tests

"make check-qapi-schema" takes around 10s user + system time for me.
With -j, it takes a bit over 3s real time. We have worse tests. It's
still annoying when you work on the QAPI generator.

Some 1.4s user + system time is consumed by make figuring out what to
do, measured by making a target that does nothing. There's nothing I
can do about that right now. But let's see what we can do about the
other 8s.

Almost 7s are spent running test-qapi.py for every test case, the rest
normalizing and diffing test-qapi.py output. We have 190 test cases.

If I downgrade to python2, it's 4.5s, but python2 is a goner.

Hacking up test-qapi.py to exit(0) without doing anything makes it
only marginally faster. The problem is Python startup overhead.

Our configure puts -B into $(PYTHON). Running without -B is faster:
4.4s.

We could improve the Makefile to run test cases only when the test
case or the generator changed. But I'm after improvement in the case
where the generator changed.

test-qapi.py is designed to be the simplest possible building block
for a shell script to do the complete job (it's actually a Makefile,
not a shell script; no real difference). Python is just not meant for
that. It's for bigger blocks.

Move the post-processing and diffing into test-qapi.py, and make it
capable of testing multiple schema files. Set executable bits while
there.

Running it once per test case now takes slightly longer than 8s. But
running it once for all of them takes under 0.2s.

Messing with the Makefile to run it only on the tests that need
retesting is clearly not worth the bother.

Expected error output changes because the new normalization strips off
$(SRCDIR)/tests/qapi-schema/ instead of just $(SRCDIR)/.

The .exit files go away, because there is no exit status to test
anymore.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20191018074345.24034-5-armbru@redhat.com>

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qapi: Change frontend error messages to start with lower case

Starting error messages with a capital letter complicates things when
text can get interpolated both at the beginning and in the middle

qapi: Change frontend error messages to start with lower case

Starting error messages with a capital letter complicates things when
text can get interpolated both at the beginning and in the middle of
an error message. The next patch will do that. Switch to lower case
to keep it simpler.

For what it's worth, the GNU Coding Standards advise the message
"should not begin with a capital letter when it follows a program name
and/or file name, because that isn’t the beginning of a sentence. (The
sentence conceptually starts at the beginning of the line.)"

While there, avoid breaking lines containing multiple arguments in the
middle of an argument.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190927134639.4284-7-armbru@redhat.com>

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qapi: Use quotes more consistently in frontend error messages

Consistently enclose error messages in double quotes. Use single
quotes within, except for one case of "'".

Signed-off-by: Markus Armb

qapi: Use quotes more consistently in frontend error messages

Consistently enclose error messages in double quotes. Use single
quotes within, except for one case of "'".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190914153506.2151-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

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qapi: Support (subset of) \u escapes in strings

The handling of \ inside QAPI strings was less than ideal, and
really only worked JSON's \/, \\, \", and our extension of \'
(an obvious extension, wh

qapi: Support (subset of) \u escapes in strings

The handling of \ inside QAPI strings was less than ideal, and
really only worked JSON's \/, \\, \", and our extension of \'
(an obvious extension, when you realize we use '' instead of ""
for strings). For other things, like '\n', it resulted in a
literal 'n' instead of a newline.

Of course, at the moment, we really have no use for escaped
characters, as QAPI has to map to C identifiers, and we currently
support ASCII only for that. But down the road, we may add
support for default values for string parameters to a command
or struct; if that happens, it would be nice to correctly support
all JSON escape sequences, such as \n or \uXXXX. This gets us
closer, by supporting Unicode escapes in the ASCII range.

Since JSON does not require \OCTAL or \xXX escapes, and our QMP
implementation does not understand them either, I intentionally
reject it here, but it would be an easy addition if we desired it.
Likewise, intentionally refusing the NUL byte means we don't have
to worry about C strings being shorter than the qapi input.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

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