Commit Graph

548 Commits

Author SHA1 Message Date
Markus Armbruster
577de12d22 qapi: Factor out QAPISchemaObjectTypeMember.check_clash()
While there, stick in a TODO change key of seen from QAPI name to C
name.  Can't do it right away, because it would fail the assertion for
tests/qapi-schema/args-has-clash.json.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-6-git-send-email-armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-10-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Markus Armbruster
23a4b2c6f1 qapi: Eliminate QAPISchemaObjectType.check() variable members
We can use seen.values() instead if we make it an OrderedDict.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-5-git-send-email-armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-9-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Markus Armbruster
08683353fc qapi: Fix up commit 7618b91's clash sanity checking change
This hunk

    @@ -964,6 +965,7 @@ class QAPISchemaObjectType(QAPISchemaType):
                 members = []
             seen = {}
             for m in members:
    +            assert c_name(m.name) not in seen
                 seen[m.name] = m
             for m in self.local_members:
                 m.check(schema, members, seen)

is plainly broken.

Asserting the members inherited from base don't clash is somewhat
redundant, because self.base.check() just checked that.  But it
doesn't hurt.

The idea to use c_name(m.name) instead of m.name for collision
checking is sound, because we need to catch clashes between the m.name
and between the c_name(m.name), and when two m.name clash, then their
c_name() also clash.

However, using c_name(m.name) instead of m.name in one of several
places doesn't work.  See the very next line.

Keep the assertion, but drop the c_name() for now.  A future commit
will bring it back.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-4-git-send-email-armbru@redhat.com>
[change TABs in commit message to space]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-8-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Markus Armbruster
cdc5fa37ed qapi: Clean up after previous commit
QAPISchemaObjectTypeVariants.check() parameter members and
QAPISchemaObjectTypeVariant.check() parameter seen are no longer used,
drop them.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-3-git-send-email-armbru@redhat.com>
[rebase to earlier changes that moved tag_member.check() of
alternate types]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-7-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Markus Armbruster
e564e2dd59 qapi: Simplify QAPISchemaObjectTypeMember.check()
QAPISchemaObjectTypeMember.check() currently does four things:

1. Compute self.type

2. Accumulate members in all_members

   Only one caller cares: QAPISchemaObjectType.check() uses it to
   compute self.members.  The other callers pass a throw-away
   accumulator.

3. Accumulate a map from names to members in seen

   Only one caller cares: QAPISchemaObjectType.check() uses it to
   compute its local variable seen, for self.variants.check(), which
   uses it to compute self.variants.tag_member from
   self.variants.tag_name.  The other callers pass a throw-away
   accumulator.

4. Check for collisions

   This piggybacks on 3: before adding a new entry, we assert it's new.

   Only one caller cares: QAPISchemaObjectType.check() uses it to
   assert non-variant members don't clash.

Simplify QAPISchemaObjectType.check(): move 2.-4. to
QAPISchemaObjectType.check(), and drop parameters all_members and
seen.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-2-git-send-email-armbru@redhat.com>
[rebase to earlier changes that moved tag_member.check() of
alternate types, commit message typo fix]
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-6-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Markus Armbruster
fff5f231d5 qapi: Drop obsolete tag value collision assertions
Union tag values can't clash with member names in generated C anymore
since commit e4ba22b, but QAPISchemaObjectTypeVariants.check() still
asserts they don't.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1446559499-26984-1-git-send-email-armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-5-git-send-email-eblake@redhat.com>
2015-12-17 08:21:26 +01:00
Eric Blake
7d9586f900 qapi-types: Simplify gen_struct_field[s]
Simplify gen_struct_fields() back to a single iteration over a
list of fields (like it was prior to commit f87ab7f9), by moving
the generated comments to gen_object().  Then, inline
gen_struct_field() into its only caller.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:26 +01:00
Eric Blake
570cd8d119 qapi-types: Consolidate gen_struct() and gen_union()
These two methods are now close enough that we can finally merge
them, relying on the fact that simple unions now provide a
reasonable local_members.  Change gen_struct() to gen_object()
that handles all forms of QAPISchemaObjectType, and rename and
shrink gen_union() to gen_variants() to handle the portion of
gen_object() needed when variants are present.

gen_struct_fields() now has a single caller, so it no longer
needs an optional parameter; however, I did not choose to inline
it into the caller.

No difference to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:26 +01:00
Eric Blake
da34a9bd99 qapi: Track simple union tag in object.local_members
We were previously creating all unions with an empty list for
local_members.  However, it will make it easier to unify struct
and union generation if we include the generated tag member in
local_members.  That way, we can have a common code pattern:
visit the base (if any), visit the local members (if any), visit
the variants (if any).  The local_members of a flat union
remains empty (because the discriminator is already visited as
part of the base).  Then, by visiting tag_member.check() during
AlternateType.check(), we no longer need to call it during
Variants.check().

The various front end entities now exist as follows:
struct: optional base, optional local_members, no variants
simple union: no base, one-element local_members, variants with tag_member
  from local_members
flat union: base, no local_members, variants with tag_member from base
alternate: no base, no local_members, variants

With the new local members, we require a bit of finesse to
avoid assertions in the clients.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1447836791-369-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:26 +01:00
Eric Blake
ce5fcb472d qapi: Provide nicer array names in introspection
For the sake of humans reading introspection output, it is nice
to have the name of implicit array types be recognizable as
arrays of the underlying type.  However, while this patch allows
humans to skip from a command with return type "[123]" straight
to the definition of type "123" without having to first inspect
type "[123]", document that this shortcut should not be taken by
client apps.

This makes the resulting introspection string slightly larger by
default (just over 200 bytes), but it's in the noise (less than
0.3% of the overall 70k size of 'query-qmp-capabilities').

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1446791754-23823-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-10 08:09:15 +01:00
Eric Blake
dd5ee2c2d3 qapi: Test failure in middle of array parse
Our generated list visitors have the same problem as has been
mentioned elsewhere (see commit 2f52e20): they allocate data
even on failure. An upcoming patch will correct things to
provide saner guarantees, but first we need to expose the
behavior in the testsuite to ensure we aren't introducing any
memory usage bugs.

There are more test cases throughout the test-qmp-input-* tests
that already deal with partial allocation; a later commit will
clean up all visit_type_FOO(), without marking all of the tests
with FIXME at this time.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1446791754-23823-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-10 08:09:14 +01:00
Peter Maydell
496c1b19fa * Guest ABI fixes for PC machines (hw_version)
* Fixes for recent Perl
 * John Snow's configure fixes
 * file-backed RAM improvements (Igor, Pavel)
 * -Werror=clobbered fixes (Stefan)
 * Kill -d ioport
 * Fix qemu-system-s390x
 * Performance improvement for kvmclock migration
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJWO1zDAAoJEL/70l94x66DXRgH/ArIMi9MGU2Vxi6wNFG9hKUl
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Guest ABI fixes for PC machines (hw_version)
* Fixes for recent Perl
* John Snow's configure fixes
* file-backed RAM improvements (Igor, Pavel)
* -Werror=clobbered fixes (Stefan)
* Kill -d ioport
* Fix qemu-system-s390x
* Performance improvement for kvmclock migration

# gpg: Signature made Thu 05 Nov 2015 13:42:27 GMT using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream:
  iscsi: Translate scsi sense into error code
  Revert "Introduce cpu_clean_all_dirty"
  kvmclock: add a new function to update env->tsc.
  configure: disable FORTIFY_SOURCE under clang
  backends/hostmem-file: Allow to specify full pathname for backing file
  configure: disallow ccache during compile tests
  cpu-exec: Fix compiler warning (-Werror=clobbered)
  memory: call begin, log_start and commit when registering a new listener
  megasas: Use qemu_hw_version() instead of QEMU_VERSION
  osdep: Rename qemu_{get, set}_version() to qemu_{, set_}hw_version()
  pc: Set hw_version on all machine classes
  qemu-log: remove -d ioport
  ioport: do not use CPU_LOG_IOPORT
  target-i386: fix pcmpxstrx equal-ordered (strstr) mode
  scripts/text2pod.pl: Escape left brace
  file_ram_alloc: propagate error to caller instead of terminating QEMU

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-11-05 14:31:24 +00:00
Mark Cave-Ayland
96e5c9bc77 migration: fix analyze-migration.py script
Commit 61964 "Add configuration section" broke the analyze-migration.py script
which terminates due to the unrecognised section. Fix the script by parsing
the contents of the configuration section directly into a new
ConfigurationSection object (although nothing is done with it yet).

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Juan Quintela <quintela@redhat.com>al3
Signed-off-by: Juan Quintela <quintela@redhat.com>al3
2015-11-04 13:40:13 +01:00
Fam Zheng
aa5ccadcca scripts/text2pod.pl: Escape left brace
Latest perl now deprecates "{" literal in regex and print warnings like
"unescaped left brace in regex is deprecated".  Add escapes to keep it
happy.

Signed-off-by: Fam Zheng <famz@redhat.com>

Message-Id: <1445326726-16031-1-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-02 14:50:27 +01:00
Eric Blake
32bc6879be qapi: Simplify gen_struct_field()
Rather than having all callers pass a name, type, and optional
flag, have them instead pass a QAPISchemaObjectTypeMember which
already has all that information.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-25-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:28 +01:00
Eric Blake
5e59baf90a qapi: Reserve 'u' member name
Now that we have separated union tag values from colliding with
non-variant C names, by naming the union 'u', we should reserve
this name for our use.  Note that we want to forbid 'u' even in
a struct with no variants, because it is possible for a future
qemu release to extend QMP in a backwards-compatible manner while
converting from a struct to a flat union.  Fortunately, no
existing clients were using this member name.  If we ever find
the need for QMP to have a member 'u', we could at that time
relax things, perhaps by having c_name() munge the QMP member to
'q_u'.

Note that we cannot forbid 'u' everywhere (by adding the
rejection code to check_name()), because the existing QKeyCode
enum already uses it; therefore we only reserve it as a struct
type member name.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-24-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:28 +01:00
Eric Blake
e4ba22b319 qapi: Finish converting to new qapi union layout
We have two issues with our qapi union layout:
1) Even though the QMP wire format spells the tag 'type', the
C code spells it 'kind', requiring some hacks in the generator.
2) The C struct uses an anonymous union, which places all tag
values in the same namespace as all non-variant members. This
leads to spurious collisions if a tag value matches a non-variant
member's name.

This patch is the back end for a series that converts to a
saner qapi union layout.  Now that all clients have been
converted to use 'type' and 'obj->u.value', we can drop the
temporary parallel support for 'kind' and 'obj->value'.

Given a simple union qapi type:

{ 'union':'Foo', 'data': { 'a':'int', 'b':'bool' } }

this is the overall effect, when compared to the state before
this series of patches:

| struct Foo {
|-    FooKind kind;
|-    union { /* union tag is @kind */
|+    FooKind type;
|+    union { /* union tag is @type */
|         void *data;
|         int64_t a;
|         bool b;
|-    };
|+    } u;
| };

The testsuite still contains some examples of artificial restrictions
(see flat-union-clash-type.json, for example) that are no longer
technically necessary, now that there is no longer a collision between
enum tag values and non-variant member names; but fixing this will be
done in later patches, in part because some further changes are required
to keep QAPISchema*.check() from asserting.  Also, a later patch will
add a reservation for the member name 'u' to avoid a collision between a
user's non-variant names and our internal choice of C union name.

Note, however, that we do not rename the generated enum, which
is still 'FooKind'.  A further patch could generate implicit
enums as 'FooType', but while the generator already reserved
the '*Kind' namespace (commit 4dc2e69), there are already QMP
constructs with '*Type' naming, which means changing our
reservation namespace would have lots of churn to C code to
deal with a forced name change.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-23-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:28 +01:00
Eric Blake
150d0564a4 qapi-visit: Convert to new qapi union layout
We have two issues with our qapi union layout:
1) Even though the QMP wire format spells the tag 'type', the
C code spells it 'kind', requiring some hacks in the generator.
2) The C struct uses an anonymous union, which places all tag
values in the same namespace as all non-variant members. This
leads to spurious collisions if a tag value matches a non-variant
member's name.

Make the conversion to the new layout for qapi-visit.py.

Generated code changes look like:

|@@ -4912,16 +4912,16 @@ void visit_type_MemoryDeviceInfo(Visitor
|     if (!*obj) {
|         goto out_obj;
|     }
|-    visit_type_MemoryDeviceInfoKind(v, &(*obj)->kind, "type", &err);
|+    visit_type_MemoryDeviceInfoKind(v, &(*obj)->type, "type", &err);
|     if (err) {
|         goto out_obj;
|     }
|-    if (!visit_start_union(v, !!(*obj)->data, &err) || err) {
|+    if (!visit_start_union(v, !!(*obj)->u.data, &err) || err) {
|         goto out_obj;
|     }
|-    switch ((*obj)->kind) {
|+    switch ((*obj)->type) {
|     case MEMORY_DEVICE_INFO_KIND_DIMM:
|-        visit_type_PCDIMMDeviceInfo(v, &(*obj)->dimm, "data", &err);
|+        visit_type_PCDIMMDeviceInfo(v, &(*obj)->u.dimm, "data", &err);
|         break;
|     default:
|         abort();
|@@ -4930,7 +4930,7 @@ out_obj:
|     error_propagate(errp, err);
|     err = NULL;
|     if (*obj) {
|-        visit_end_union(v, !!(*obj)->data, &err);
|+        visit_end_union(v, !!(*obj)->u.data, &err);
|     }
|     error_propagate(errp, err);
|     err = NULL;

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-14-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:27 +01:00
Eric Blake
f51d8fab44 qapi: Start converting to new qapi union layout
We have two issues with our qapi union layout:
1) Even though the QMP wire format spells the tag 'type', the
C code spells it 'kind', requiring some hacks in the generator.
2) The C struct uses an anonymous union, which places all tag
values in the same namespace as all non-variant members. This
leads to spurious collisions if a tag value matches a non-variant
member's name.

This patch is the front end for a series that converts to a
saner qapi union layout.  By the end of the series, we will no
longer have the type/kind mismatch, and all tag values will be
under a named union, which requires clients to access
'obj->u.value' instead of 'obj->value'.  But since the
conversion touches a number of files, it is easiest if we
temporarily support BOTH layouts simultaneously.

Given a simple union qapi type:

{ 'union':'Foo', 'data': { 'a':'int', 'b':'bool' } }

make the following changes in generated qapi-types.h:

| struct Foo {
|-    FooKind kind;
|-    union { /* union tag is @kind */
|+    union {
|+        FooKind kind;
|+        FooKind type;
|+    };
|+    union { /* union tag is @type */
|         void *data;
|         int64_t a;
|         bool b;
|+        union { /* union tag is @type */
|+            void *data;
|+            int64_t a;
|+            bool b;
|+        } u;
|     };
| };

Flat unions do not need the anonymous union for the tag member,
as we already fixed that to use the member name instead of 'kind'
back in commit 0f61af3e.

One additional change is needed in qapi.py: check_union() now
needs to check for collisions with 'type' in addition to those
with 'kind'.

Later, when the conversions are complete, we will remove the
duplication hacks, and also drop the check_union() restrictions.

Note, however, that we do not rename the generated enum, which
is still 'FooKind'.  A further patch could generate implicit
enums as 'FooType', but while the generator already reserved
the '*Kind' namespace (commit 4dc2e69), there are already QMP
constructs with '*Type' naming, which means changing our
reservation namespace would have lots of churn to C code to
deal with a forced name change.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-13-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:27 +01:00
Eric Blake
5c5e51a05b qapi-visit: Remove redundant functions for flat union base
The code for visiting the base class of a child struct created
visit_type_Base_fields() which covers all fields of Base; while
the code for visiting the base class of a flat union created
visit_type_Union_fields() covering all fields of the base
except the discriminator.  But since the base class includes
the discriminator of a flat union, we can just visit the entire
base, without needing a separate visit of the discriminator.
Not only is consistently visiting all fields easier to
understand, it lets us share code.

The generated code in qapi-visit.c loses several now-unused
visit_type_UNION_fields(), along with changes like:

|@@ -1654,11 +1557,7 @@ void visit_type_BlockdevOptions(Visitor
|     if (!*obj) {
|         goto out_obj;
|     }
|-    visit_type_BlockdevOptions_fields(v, obj, &err);
|-    if (err) {
|-        goto out_obj;
|-    }
|-    visit_type_BlockdevDriver(v, &(*obj)->driver, "driver", &err);
|+    visit_type_BlockdevOptionsBase_fields(v, (BlockdevOptionsBase **)obj, &err);
|     if (err) {
|         goto out_obj;
|     }

and forward declarations where needed.  Note that the cast of obj
to BASE ** is necessary to call visit_type_BASE_fields() (and we
can't use our upcast wrappers, because those work on pointers while
we have a pointer-to-pointer).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:27 +01:00
Eric Blake
ddf2190896 qapi: Unbox base members
Rather than storing a base class as a pointer to a box, just
store the fields of that base class in the same order, so that
a child struct can be directly cast to its parent.  This gives
less malloc overhead, less pointer dereferencing, and even less
generated code.  Compare to the earlier commit 1e6c1616a "qapi:
Generate a nicer struct for flat unions" (although that patch
had fewer places to change, as less of qemu was directly using
qapi structs for flat unions).  It also allows us to turn on
automatic type-safe wrappers for upcasting to the base class
of a struct.

Changes to the generated code look like this in qapi-types.h:

| struct SpiceChannel {
|-    SpiceBasicInfo *base;
|+    /* Members inherited from SpiceBasicInfo: */
|+    char *host;
|+    char *port;
|+    NetworkAddressFamily family;
|+    /* Own members: */
|     int64_t connection_id;

as well as additional upcast functions like qapi_SpiceChannel_base().
Meanwhile, changes to qapi-visit.c look like:

| static void visit_type_SpiceChannel_fields(Visitor *v, SpiceChannel **obj, Error **errp)
| {
|     Error *err = NULL;
|
|-    visit_type_implicit_SpiceBasicInfo(v, &(*obj)->base, &err);
|+    visit_type_SpiceBasicInfo_fields(v, (SpiceBasicInfo **)obj, &err);
|     if (err) {

(the cast is necessary, since our upcast wrappers only deal with a
single pointer, not pointer-to-pointer); plus the wholesale
elimination of some now-unused visit_type_implicit_FOO() functions.

Without boxing, the corner case of one empty struct having
another empty struct as its base type now requires inserting a
dummy member (previously, the 'Base *base' member sufficed).

And now that we no longer consume a 'base' member in the generated
C struct, we can delete the former negative struct-base-clash-base
test.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-11-git-send-email-eblake@redhat.com>
[Commit message tweaked slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
30594fe1cd qapi: Prefer typesafe upcasts to qapi base classes
A previous patch (commit 1e6c1616) made it possible to
directly cast from a qapi flat union type to its base type.
However, it requires the use of a C cast, which turns off
compiler type-safety checks.  Fortunately, no such casts
exist, just yet.

Regardless, add inline type-safe wrappers named
qapi_FOO_base() for any union type FOO that has a base,
which can be used for a safer upcast, and enhance the
testsuite to cover the new functionality.

A future patch will extend the upcast support to structs,
where such conversions do exist already.

Note that C makes const-correct upcasts annoying because
it lacks overloads; these functions cast away const so that
they can accept user pointers whether const or not, and the
result in turn can be assigned to normal or const pointers.
Alternatively, this could have been done with macros, but
type-safe macros are hairy, and not worthwhile here.

This patch just adds upcasts.  None of our code needed to
downcast from a base qapi class to a child.  Also, in the
case of grandchildren (such as BlockdevOptionsQcow2), the
caller will need to call two functions to get to the inner
base (although it wouldn't be too hard to generate a
qapi_FOO_base_base() if desired).  If a user changes qapi
to alter the base class hierarchy, such as going from
'A -> C' to 'A -> B -> C', it will change the type of
'qapi_C_base()', and the compiler will point out the places
that are affected by the new base.

One alternative was proposed, but was deemed too ugly to use
in practice: the generators could output redundant
information using anonymous types:
| struct Child {
|     union {
|         struct {
|             Type1 parent_member1;
|             Type2 parent_member2;
|         };
|         Parent base;
|     };
| };
With that ugly proposal, for a given qapi type, obj->member
and obj->base.member would refer to the same storage; allowing
convenience in working with members without needing 'base.'
allowing typesafe upcast without needing a C cast by accessing
'&obj->base', and allowing downcasts from the parent back to
the child possible through container_of(obj, Child, base).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-10-git-send-email-eblake@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
f87ab7f9bd qapi-types: Refactor base fields output
Move code from gen_union() into gen_struct_fields() in order for
a later patch to share code when enumerating inherited fields
for struct types.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-9-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
d02cf37766 qapi-visit: Split off visit_type_FOO_fields forward decl
We generate a static visit_type_FOO_fields() for every type
FOO.  However, sometimes we need a forward declaration. Split
the code to generate the forward declaration out of
gen_visit_implicit_struct() into a new gen_visit_fields_decl(),
and also prepare for a forward declaration to be emitted
during gen_visit_struct(), so that a future patch can switch
from using visit_type_FOO_implicit() to the simpler
visit_type_FOO_fields() as part of unboxing the base class
of a struct.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
9fb081e0b9 qapi: Reserve 'q_*' and 'has_*' member names
c_name() produces names starting with 'q_' when protecting a
dictionary member name that would fail to directly compile, but
in doing so can cause clashes with any member name already
beginning with 'q-' or 'q_'.  Likewise, we create a C name 'has_'
for any optional member that can clash with any member name
beginning with 'has-' or 'has_'.

Technically, rather than blindly reserving the namespace,
we could try to complain about user names only when an actual
collision occurs, or even teach c_name() how to munge names
to avoid collisions.  But it is not trivial, especially when
collisions can occur across multiple types (such as via
inheritance or flat unions).  Besides, no existing .json
files are trying to use these names.  So it's easier to just
outright forbid the potential for collision.  We can always
relax things in the future if a real need arises for QMP to
express member names that have been forbidden here.

'has_' only has to be reserved for struct/union member names,
while 'q_' is reserved everywhere (matching the fact that
only members can be optional, while we use c_name() for munging
both members and entities).  Note that we could relax 'q_'
restrictions on entities independently from member names; for
example, c_name('qmp_' + 'unix') would result in a different
function name than our current 'qmp_' + c_name('unix').

Update and add tests to cover the new error messages.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-6-git-send-email-eblake@redhat.com>
[Consistently pass protect=False to c_name(); commit message tweaked
slightly]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
255960dd37 qapi: Reserve '*List' type names for list types
Type names ending in 'List' can clash with qapi list types in
generated C.  We don't currently use such names. It is easier to
outlaw them now than to worry about how to resolve such a clash
in the future. For precedence, see commit 4dc2e69, which did the
same for names ending in 'Kind' versus implicit enum types for
qapi unions.

Update the testsuite to match.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
f9e6102b48 qapi: More robust conditions for when labels are needed
We were using regular expressions to see if ret included
any earlier text that emitted a 'goto out;' line, to decide
whether we needed to output an 'out:' label.  But this is
fragile, if the ret text can possibly combine more than one
generated function body, where the first function used a
goto but the second does not.  Change the code to just check
for the known conditions which cause an error check to be
needed.  Besides, it's slightly more efficient to use plain
checks than regular expression searching.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-4-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Eric Blake
8712fa5333 qapi: More idiomatic string operations
Rather than slicing the end of a string, we can use python's
endswith().  And rather than creating a set of characters,
we can search for a character within a string.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1445898903-12082-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-11-02 08:30:26 +01:00
Dr. David Alan Gilbert
c900ef86c5 gdb command: qemu handlers
A new gdb commands are added:

  qemu handlers

     That dumps an AioContext list (by default qemu_aio_context)
     possibly including a backtrace for cases it knows about
     (with the verbose option).  Intended to help find why something
     is hanging waiting for IO.

  Use 'qemu handlers --verbose iohandler_ctx'  to find out why
your incoming migration is stuck.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 1445951385-11924-1-git-send-email-dgilbert@redhat.com

V2:
  Merge into one command with optional handlers arg, and only do
    backtrace in verbose mode

 (gdb) qemu handlers
 ----
 {pfd = {fd = 6, events = 25, revents = 0}, io_read = 0x55869656ffd0
 <event_notifier_dummy_cb>, io_write = 0x0, deleted = 0, opaque =
 0x558698c4ce08, node = {le_next = 0x0, le_prev = 0x558698c4cdc0}}

 (gdb) qemu handlers iohandler_ctx
 ----
 {pfd = {fd = 9, events = 25, revents = 0}, io_read = 0x558696581380
 <fd_coroutine_enter>, io_write = 0x0, deleted = 0, opaque =
 0x558698dc99d0, node = {le_next = 0x558698c4cca0, le_prev =
 0x558698c4c1d0}}
 ----
 {pfd = {fd = 4, events = 25, revents = 0}, io_read = 0x55869657b330
 <sigfd_handler>, io_write = 0x0, deleted = 0, opaque = 0x4, node =
 {le_next = 0x558698c4c260, le_prev = 0x558699f72508}}
 ----
 {pfd = {fd = 5, events = 25, revents = 0}, io_read = 0x55869656ffd0
 <event_notifier_dummy_cb>, io_write = 0x0, deleted = 0, opaque =
 0x558698c4c218, node = {le_next = 0x0, le_prev = 0x558698c4ccc8}}
 ----
 (gdb) qemu handlers --verbose iohandler_ctx
 ----
 {pfd = {fd = 9, events = 25, revents = 0}, io_read = 0x558696581380
 <fd_coroutine_enter>, io_write = 0x0, deleted = 0, opaque =
 0x558698dc99d0, node = {le_next = 0x558698c4cca0, le_prev =
 0x558698c4c1d0}}
 #0  0x0000558696581820 in qemu_coroutine_switch
 (from_=from_@entry=0x558698cb3cf0, to_=to_@entry=0x7f421c37eac8,
 action=action@entry=COROUTINE_YIELD) at
 /home/dgilbert/git/qemu/coroutine-ucontext.c:177
 #1  0x0000558696580c00 in qemu_coroutine_yield () at
 /home/dgilbert/git/qemu/qemu-coroutine.c:145
 #2  0x00005586965814f5 in yield_until_fd_readable (fd=9) at
 /home/dgilbert/git/qemu/qemu-coroutine-io.c:90
 #3  0x0000558696523937 in socket_get_buffer (opaque=0x55869a3dc620,
 buf=0x558698c505a0 "", pos=<optimized out>, size=32768) at
 /home/dgilbert/git/qemu/migration/qemu-file-unix.c:101
 #4  0x0000558696521fac in qemu_fill_buffer (f=0x558698c50570) at
 /home/dgilbert/git/qemu/migration/qemu-file.c:227
 #5  0x0000558696522989 in qemu_peek_byte (f=0x558698c50570, offset=0)
     at /home/dgilbert/git/qemu/migration/qemu-file.c:507
 #6  0x0000558696522bf4 in qemu_get_be32 (f=0x558698c50570) at
 /home/dgilbert/git/qemu/migration/qemu-file.c:520
 #7  0x0000558696522bf4 in qemu_get_be32 (f=f@entry=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/qemu-file.c:604
 #8  0x0000558696347e5c in qemu_loadvm_state (f=f@entry=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/savevm.c:1821
 #9  0x000055869651de8c in process_incoming_migration_co
 (opaque=0x558698c50570)
     at /home/dgilbert/git/qemu/migration/migration.c:336
 #10 0x000055869658188a in coroutine_trampoline (i0=<optimized out>,
 i1=<optimized out>)
     at /home/dgilbert/git/qemu/coroutine-ucontext.c:80
 #11 0x00007f420f05df10 in __start_context () at /lib64/libc.so.6
 #12 0x00007ffc40815f50 in  ()
 #13 0x0000000000000000 in  ()

  ----
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:27 +00:00
Paolo Bonzini
a201b0ff28 qemu-gdb: add $qemu_coroutine_sp and $qemu_coroutine_pc
These can be useful to manually get a stack trace of a coroutine inside
a core dump.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Paolo Bonzini
80ab31b257 qemu-gdb: extract parts of "qemu coroutine" implementation
Provide useful Python functions to reach and decipher a jmpbuf.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Paolo Bonzini
1138f24645 qemu-gdb: allow using glibc_pointer_guard() on core dumps
get_fs_base() cannot be run on a core dump, because it uses the arch_prctl
system call.  The fs base is the value that is returned by pthread_self(),
and it would be nice to just glean it from the "info threads" output:

* 1    Thread 0x7f16a3fff700 (LWP 33642) pthread_cond_wait@@GLIBC_2.3.2 ()
              ^^^^^^^^^^^^^^

but unfortunately the gdb API does not provide that.  Instead, we can
look for the "arg" argument of the start_thread function if glibc debug
information are available.  If not, fall back to the old mechanism.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1444636974-19950-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:26 +00:00
Peter Maydell
ca3e40e233 vhost, pc, virtio features, fixes, cleanups
New features:
     VT-d support for devices behind a bridge
     vhost-user migration support
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

vhost, pc, virtio features, fixes, cleanups

New features:
    VT-d support for devices behind a bridge
    vhost-user migration support

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 22 Oct 2015 12:39:19 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream: (37 commits)
  hw/isa/lpc_ich9: inject the SMI on the VCPU that is writing to APM_CNT
  i386: keep cpu_model field in MachineState uptodate
  vhost: set the correct queue index in case of migration with multiqueue
  piix: fix resource leak reported by Coverity
  seccomp: add memfd_create to whitelist
  vhost-user-test: check ownership during migration
  vhost-user-test: add live-migration test
  vhost-user-test: learn to tweak various qemu arguments
  vhost-user-test: wrap server in TestServer struct
  vhost-user-test: remove useless static check
  vhost-user-test: move wait_for_fds() out
  vhost: add migration block if memfd failed
  vhost-user: use an enum helper for features mask
  vhost user: add rarp sending after live migration for legacy guest
  vhost user: add support of live migration
  net: add trace_vhost_user_event
  vhost-user: document migration log
  vhost: use a function for each call
  vhost-user: add a migration blocker
  vhost-user: send log shm fd along with log_base
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-10-22 12:41:44 +01:00
Marc-André Lureau
1842bdfdba linux-headers: add unistd.h
New syscalls are not yet widely distributed. Add them to qemu
linux-headers include directory. Update based on v4.3-rc3 kernel headers.

Exclude mips for now, which is more problematic due to extra header
inclusion and probably unnecessary here.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
2015-10-22 14:34:48 +03:00
Peter Maydell
526d5809a0 * KVM page size fix for PPC
* Support for Linux 4.4's new Hyper-V features
 * Eliminate g_slice from areas I maintain
 * checkpatch fix
 * Peter's cpu_reload_memory_map() cleanups
 * More changes to MAINTAINERS
 * Require Python 2.6
 * chardev creation fixes
 * PCI requester id for ARM KVM
 * cleanups and doc fixes
 * Allow customization of the Hyper-V vendor id
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* KVM page size fix for PPC
* Support for Linux 4.4's new Hyper-V features
* Eliminate g_slice from areas I maintain
* checkpatch fix
* Peter's cpu_reload_memory_map() cleanups
* More changes to MAINTAINERS
* Require Python 2.6
* chardev creation fixes
* PCI requester id for ARM KVM
* cleanups and doc fixes
* Allow customization of the Hyper-V vendor id

# gpg: Signature made Mon 19 Oct 2015 09:13:10 BST using RSA key ID 78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"

* remotes/bonzini/tags/for-upstream: (49 commits)
  kvm: Allow the Hyper-V vendor ID to be specified
  kvm: Move x86-specific functions into target-i386/kvm.c
  kvm: Pass PCI device pointer to MSI routing functions
  hw/pci: Introduce pci_requester_id()
  kvm: Make KVM_CAP_SIGNAL_MSI globally available
  doc/rcu: fix g_free_rcu() usage example
  qemu-char: cleanup after completed conversion to cd->create
  qemu-char: convert ringbuf backend to data-driven creation
  qemu-char: convert vc backend to data-driven creation
  qemu-char: convert spice backend to data-driven creation
  qemu-char: convert console backend to data-driven creation
  qemu-char: convert stdio backend to data-driven creation
  qemu-char: convert testdev backend to data-driven creation
  qemu-char: convert braille backend to data-driven creation
  qemu-char: convert msmouse backend to data-driven creation
  qemu-char: convert mux backend to data-driven creation
  qemu-char: convert null backend to data-driven creation
  qemu-char: convert pty backend to data-driven creation
  qemu-char: convert UDP backend to data-driven creation
  qemu-char: convert socket backend to data-driven creation
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-10-19 10:52:39 +01:00
Eric Blake
99df5289d8 qapi: Track location that created an implicit type
A future patch will move some error checking from the parser
to the various QAPISchema*.check() methods, which run only
after parsing completes.  It will thus be possible to create
a python instance representing an implicit QAPI type that
parses fine but will fail validation during check().  Since
all errors have to have an associated 'info' location, we
need a location to be associated with those implicit types.
The intuitive info to use is the location of the enclosing
entity that caused the creation of the implicit type.

Note that we do not anticipate builtin types being used in
an error message (as they are not part of the user's QAPI
input, the user can't cause a semantic error in their
behavior), so we exempt those types from requiring info, by
setting a flag to track the completion of _def_predefineds(),
and tracking that flag in _def_entity().

No change to the generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-13-git-send-email-eblake@redhat.com>
[Missing QAPISchemaArrayType.is_implicit() supplied]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:08 +02:00
Eric Blake
46292ba75c qapi: Create simple union type member earlier
For simple unions, we were creating the implicit 'type' tag
member during the QAPISchemaObjectTypeVariants constructor.
This is different from every other implicit QAPISchemaEntity
object, which get created by QAPISchema methods.  Hoist the
creation to the caller (renaming _make_tag_enum() to
_make_implicit_tag()), and pass the entity rather than the
string name, so that we have the nice property that no
entities are created as a side effect within a different
entity.  A later patch will then have an easier time of
associating location info with each entity creation.

No change to generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-10-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:08 +02:00
Eric Blake
9f08c8ec73 qapi: Lazy creation of array types
Commit ac88219a had several TODO markers about whether we needed
to automatically create the corresponding array type alongside
any other type.  It turns out that most of the time, we don't!

There are a few exceptions: 1) We have a few situations where we
use an array type in internal code but do not expose that type
through QMP; fix it by declaring a dummy type that forces the
generator to see that we want to use the array type.

2) The builtin arrays (such as intList for QAPI ['int']) must
always be generated, because of the way our QAPI_TYPES_BUILTIN
compile guard works: we have situations (at the very least
tests/test-qmp-output-visitor.c) that include both top-level
"qapi-types.h" (via "error.h") and a secondary
"test-qapi-types.h". If we were to only emit the builtin types
when used locally, then the first .h file would not include all
types, but the second .h does not declare anything at all because
the first .h set QAPI_TYPES_BUILTIN, and we would end up with
compilation error due to things like unknown type 'int8List'.

Actually, we may need to revisit how we do type guards, and
change from a single QAPI_TYPES_BUILTIN over to a different
usage pattern that does one #ifdef per qapi type - right now,
the only types that are declared multiple times between two qapi
.json files for inclusion by a single .c file happen to be the
builtin arrays.  But now that we have QAPI 'include' statements,
it is logical to assume that we will soon reach a point where
we want to reuse non-builtin types (yes, I'm thinking about what
it will take to add introspection to QGA, where we will want to
reuse the SchemaInfo type and friends).  One #ifdef per type
will help ensure that generating the same qapi type into more
than one qapi-types.h won't cause collisions when both are
included in the same .c file; but we also have to solve how to
avoid creating duplicate qapi-types.c entry points.  So that
is a problem left for another day.

Generated code for qapi-types and qapi-visit is drastically
reduced; less than a third of the arrays that were blindly
created were actually needed (a quick grep shows we dropped
from 219 to 69 *List types), and the .o files lost more than
30% of their bulk.  [For best results, diff the generated
files with 'git diff --patience --no-index pre post'.]

Interestingly, the introspection output is unchanged - this is
because we already cull all types that are not indirectly
reachable from a command or event, so introspection was already
using only a subset of array types.  The subset of types
introspected is now a much larger percentage of the overall set
of array types emitted in qapi-types.h (since the larger set
shrunk), but still not 100% (evidence that the array types
emitted for our new Dummy structs, and the new struct itself,
don't affect QMP).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-9-git-send-email-eblake@redhat.com>
[Moved array info tracking to a later patch]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:08 +02:00
Eric Blake
49823c4b43 qapi: Don't use info as witness of implicit object type
A future patch will enable error reporting from the various
QAPISchema*.check() methods.  But to report an error related
to an implicit type, we'll need to associate a location with
the type (the same location as the top-level entity that is
causing the creation of the implicit type), and once we do
that, keying off of whether foo.info exists is no longer a
viable way to determine if foo is an implicit type.

Instead, add an is_implicit() method to QAPISchemaEntity, and use it.
It can be overridden later for ObjectType and EnumType, when implicit
instances of those classes gain info.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-8-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:08 +02:00
Eric Blake
cae95eae62 qapi: Drop redundant returns-int test
qapi-schema-test was already testing that we could have a
command returning int, but burned a command name in the whitelist.
Merge the redundant positive test returns-int, and pick a name
that reduces the whitelist size.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-6-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:07 +02:00
Eric Blake
7618b91ff8 qapi: Prepare for errors during check()
The next few patches will start migrating error checking from
ad hoc parse methods into the QAPISchema*.check() methods.  But
for an error message to display, we first have to fix the
overall 'try' to catch those errors.  We also want to enable a
few more assertions, such as making sure every attempt to
raise a semantic error is passed a valid location info, or that
various preconditions hold.

The general approach for moving error checking will then be to
relax an assertion into an if that raises an exception if the
condition does not hold, and removing the counterpart ad hoc
check done during the parse phase.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:07 +02:00
Eric Blake
25a0d9c977 qapi: Use predicate callback to determine visit filtering
Previously, qapi-types and qapi-visit filtered out implicit
objects during visit_object_type() by using 'info' (works since
implicit objects do not [yet] have associated info); meanwhile
qapi-introspect filtered out all schema types on the first pass
by returning a python type from visit_begin(), which was then
used at a distance in QAPISchema.visit() to do the filtering.

Rather than keeping these ad hoc approaches, add a new visitor
callback visit_needed() which returns False to skip a given
entity, and which defaults to True unless overridden.  Use the
new mechanism to simplify all three filtering visitors.

No change to the generated code.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444710158-8723-2-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:39:07 +02:00
Eric Blake
d08ac81a45 qapi: Fix regression with '-netdev help'
Commit e36c714e causes 'qemu -netdev help' to dump core, because the
call to visit_end_union() is no longer conditional on whether *obj was
allocated.

Reported by Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1444861825-19256-1-git-send-email-eblake@redhat.com>
[Commit message tweaked to say 'help' instead of '?']
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-15 08:37:11 +02:00
Eric Blake
18bdbc3ac8 qapi: Simplify gen_visit_fields() error handling
Since we have consolidated all generated code to use 'err' as
the name of the local variable for error detection, we can
simplify the decision on whether to skip error detection (useful
for deallocation paths) to be a boolean.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-18-git-send-email-eblake@redhat.com>
[Change to gen_visit_fields() simplified]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:50 +02:00
Eric Blake
82ca8e4696 qapi: Share gen_visit_fields()
Consolidate the code between visit, command marshalling, and
event generation that iterates over the members of a struct.
It reduces code duplication in the generator, so that a future
patch can reduce the size of generated code while touching only
one instead of three locations.

There are no changes to the generated marshal code.

The visitor code becomes slightly more verbose, but remains
semantically equivalent, and is actually easier to read as
it follows a more common idiom:

|     visit_optional(v, &(*obj)->has_device, "device", &err);
|-    if (!err && (*obj)->has_device) {
|-        visit_type_str(v, &(*obj)->device, "device", &err);
|-    }
|     if (err) {
|         goto out;
|     }
|+    if ((*obj)->has_device) {
|+        visit_type_str(v, &(*obj)->device, "device", &err);
|+        if (err) {
|+            goto out;
|+        }
|+    }

The event code becomes slightly more verbose, but this is
arguably a bug fix: although the visitors are not well
documented, use of an optional member should not be attempted
unless guarded by a prior call to visit_optional().  Works only
because the output qmp visitor has a no-op visit_optional():

|+    visit_optional(v, &has_offset, "offset", &err);
|+    if (err) {
|+        goto out;
|+    }
|     if (has_offset) {
|         visit_type_int(v, &offset, "offset", &err);

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-17-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:50 +02:00
Eric Blake
1f35334489 qapi: Share gen_err_check()
qapi-commands has a nice helper gen_err_check(), but did not
use it everywhere. In fact, using it in more places makes it
easier to reduce the lines of code used for generating error
checks.  This in turn will make it easier for later patches
to consolidate another common pattern among the generators.

The generated code has fewer blank lines in qapi-event.c functions,
but has no semantic difference.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-16-git-send-email-eblake@redhat.com>
[Drop another blank line for symmetry]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:50 +02:00
Eric Blake
05372f708a qapi: Consistent generated code: minimize push_indent() usage
We had some pointless differences in the generated code for visit,
command marshalling, and events; unifying them makes it easier for
future patches to consolidate to common helper functions.
This is one patch of a series to clean up these differences.

This patch reduces the number of push_indent()/pop_indent() pairs
so that generated code is typically already at its natural output
indentation in the python files.  It is easier to reason about
generated code if the reader does not have to track how much
spacing will be inserted alongside the code, and moreso when all
of the generators use the same patterns (qapi-type and qapi-event
were already using in-place indentation).

Arguably, the resulting python may be a bit harder to read with C
code at the same indentation as python; on the other hand, not
having to think about push_indent() is a win, and most decent
editors provide syntax highlighting that makes it easier to
visually distinguish python code from string literals that will
become C code.

There is no change to the generated output.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-15-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:49 +02:00
Eric Blake
e36c714e6a qapi: Consistent generated code: prefer common indentation
We had some pointless differences in the generated code for visit,
command marshalling, and events; unifying them makes it easier for
future patches to consolidate to common helper functions.
This is one patch of a series to clean up these differences.

This patch adjusts gen_visit_union() to use the same indentation
as other functions, namely, by jumping early to the error label
if the object was not set rather than placing the rest of the
body inside an if for when it is set.

No change in semantics to the generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-14-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:49 +02:00
Eric Blake
f782399cb4 qapi: Consistent generated code: prefer common labels
We had some pointless differences in the generated code for visit,
command marshalling, and events; unifying them makes it easier for
future patches to consolidate to common helper functions.
This is one patch of a series to clean up these differences.

This patch names the goto labels 'out' (not 'clean') and 'out_obj'
(not 'out_end').  Additionally, the generator was inconsistent on
whether labels had a leading space [our HACKING is silent; while
emacs 'gnu' style adds the space to avoid littering column 1].
For minimal churn, prefer no leading space; this also matches
the style that is more prevalent in current qemu.git.

No change in semantics to the generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-13-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:49 +02:00
Eric Blake
f8b7f1a8ea qapi: Consistent generated code: prefer visitor 'v'
We had some pointless differences in the generated code for visit,
command marshalling, and events; unifying them makes it easier for
future patches to consolidate to common helper functions.
This is one patch of a series to clean up these differences.

This patch names the local visitor variable 'v' rather than 'm'.
Related objects, such as 'QapiDeallocVisitor', are also named by
their initials instead of an unrelated leading m.

No change in semantics to the generated code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1443565276-4535-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-10-12 18:46:49 +02:00