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[Qemu-devel] [PATCH v6 29/36] qapi: Document 'struct' metatype
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH v6 29/36] qapi: Document 'struct' metatype |
Date: |
Sat, 4 Apr 2015 22:08:00 -0600 |
Referring to "type" as both a meta-type (built-in, enum, union,
alternte, or struct) and a specific type (the name that the
schema uses for declaring structs) is confusing. Now that the
generator accepts 'struct' as a synonym for 'type', update all
documentation to use saner wording.
Signed-off-by: Eric Blake <address@hidden>
---
v6: new patch
---
docs/qapi-code-gen.txt | 56 +++++++++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index 8a76cc1..6206032 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -71,7 +71,7 @@ x.y.z)' comment. For example:
#
# Since: 0.14.0
##
- { 'type': 'BlockStats',
+ { 'struct': 'BlockStats',
'data': {'*device': 'str', 'stats': 'BlockDeviceStats',
'*parent': 'BlockStats',
'*backing': 'BlockStats'} }
@@ -85,7 +85,7 @@ types, and allows for indefinite nesting of QMP that
satisfies the
schema. A type name should not be defined more than once.
There are seven top-level expressions recognized by the parser:
-'include', 'command', 'type', 'enum', 'union', 'alternate', and
+'include', 'command', 'struct', 'enum', 'union', 'alternate', and
'event'. There are several groups of types: simple types (a number of
built-in types, such as 'int' and 'str'; as well as enumerations),
complex types (structs and two flavors of unions), and alternate types
@@ -127,9 +127,9 @@ In the rest of this document, usage lines are given for each
expression type, with literal strings written in lower case and
placeholders written in capitals. If a literal string includes a
prefix of '*', that key/value pair can be omitted from the expression.
-For example, a usage statement that includes '*base':COMPLEX-TYPE-NAME
+For example, a usage statement that includes '*base':STRUCT-NAME
means that an expression has an optional key 'base', which if present
-must have a value that forms a complex type name.
+must have a value that forms a struct name.
=== Built-in Types ===
@@ -167,17 +167,17 @@ an outer file. The parser may be made stricter in the
future to
prevent incomplete include files.
-=== Complex types ===
+=== Struct types ===
-Usage: { 'type': STRING, 'data': DICT, '*base': COMPLEX-TYPE-NAME }
+Usage: { 'struct': STRING, 'data': DICT, '*base': STRUCT-NAME }
-A complex type is a dictionary containing a single 'data' key whose
+A struct is a dictionary containing a single 'data' key whose
value is a dictionary. This corresponds to a struct in C or an Object
in JSON. Each value of the 'data' dictionary must be the name of a
type, or a one-element array containing a type name. An example of a
-complex type is:
+struct is:
- { 'type': 'MyType',
+ { 'struct': 'MyType',
'data': { 'member1': 'str', 'member2': 'int', '*member3': 'str' } }
The use of '*' as a prefix to the name means the member is optional in
@@ -210,13 +210,13 @@ A structure that is used in both input and output of
various commands
must consider the backwards compatibility constraints of both directions
of use.
-A complex type definition can specify another complex type as its base.
+A struct definition can specify another struct as its base.
In this case, the fields of the base type are included as top-level fields
-of the new complex type's dictionary in the QMP wire format. An example
+of the new struct's dictionary in the QMP wire format. An example
definition is:
- { 'type': 'BlockdevOptionsGenericFormat', 'data': { 'file': 'str' } }
- { 'type': 'BlockdevOptionsGenericCOWFormat',
+ { 'struct': 'BlockdevOptionsGenericFormat', 'data': { 'file': 'str' } }
+ { 'struct': 'BlockdevOptionsGenericCOWFormat',
'base': 'BlockdevOptionsGenericFormat',
'data': { '*backing': 'str' } }
@@ -251,7 +251,7 @@ converting between strings and enum values. Since the wire
format
always passes by name, it is acceptable to reorder or add new
enumeration members in any location without breaking QMP clients;
however, removing enum values would break compatibility. For any
-complex type that has a field that will only contain a finite set of
+struct that has a field that will only contain a finite set of
string values, using an enum type for that field is better than
open-coding the field to be type 'str'.
@@ -259,7 +259,7 @@ open-coding the field to be type 'str'.
=== Union types ===
Usage: { 'union': STRING, 'data': DICT }
-or: { 'union': STRING, 'data': DICT, 'base': COMPLEX-TYPE-NAME,
+or: { 'union': STRING, 'data': DICT, 'base': STRUCT-NAME,
'discriminator': ENUM-MEMBER-OF-BASE }
Union types are used to let the user choose between several different
@@ -271,8 +271,8 @@ paragraphs.
A simple union type defines a mapping from automatic discriminator
values to data types like in this example:
- { 'type': 'FileOptions', 'data': { 'filename': 'str' } }
- { 'type': 'Qcow2Options',
+ { 'struct': 'FileOptions', 'data': { 'filename': 'str' } }
+ { 'struct': 'Qcow2Options',
'data': { 'backing-file': 'str', 'lazy-refcounts': 'bool' } }
{ 'union': 'BlockdevOptions',
@@ -295,13 +295,13 @@ the union can be named 'max', as this would collide with
the implicit
enum. The value for each branch can be of any type.
-A flat union definition specifies a complex type as its base, and
+A flat union definition specifies a struct as its base, and
avoids nesting on the wire. All branches of the union must be
complex types, and the top-level fields of the union dictionary on
the wire will be combination of fields from both the base type and the
appropriate branch type (when merging two dictionaries, there must be
no keys in common). The 'discriminator' field must be the name of an
-enum-typed member of the base type.
+enum-typed member of the base struct.
The following example enhances the above simple union example by
adding a common field 'readonly', renaming the discriminator to
@@ -309,7 +309,7 @@ something more applicable, and reducing the number of {}
required on
the wire:
{ 'enum': 'BlockdevDriver', 'data': [ 'raw', 'qcow2' ] }
- { 'type': 'BlockdevCommonOptions',
+ { 'struct': 'BlockdevCommonOptions',
'data': { 'driver': 'BlockdevDriver', 'readonly': 'bool' } }
{ 'union': 'BlockdevOptions',
'base': 'BlockdevCommonOptions',
@@ -341,9 +341,9 @@ union has a complex type with a single member named 'data'.
That is,
is identical on the wire to:
{ 'enum': 'Enum', 'data': ['one', 'two'] }
- { 'type': 'Base', 'data': { 'type': 'Enum' } }
- { 'type': 'Branch1', 'data': { 'data': 'str' } }
- { 'type': 'Branch2', 'data': { 'data': 'int' } }
+ { 'struct': 'Base', 'data': { 'type': 'Enum' } }
+ { 'struct': 'Branch1', 'data': { 'data': 'str' } }
+ { 'struct': 'Branch2', 'data': { 'data': 'int' } }
{ 'union': 'Flat': 'base': 'Base', 'discriminator': 'type',
'data': { 'one': 'Branch1', 'two': 'Branch2' } }
@@ -401,7 +401,7 @@ part of a QMP command. The 'data' member is optional and
defaults to
{} (an empty dictionary). If present, it must be the string name of a
complex type, a one-element array containing the name of a complex
type, or a dictionary that declares an anonymous type with the same
-semantics as a 'type' expression, with one exception noted below when
+semantics as a 'struct' expression, with one exception noted below when
'gen' is used.
The 'returns' member describes what will appear in the "return" field
@@ -410,7 +410,7 @@ optional from the command declaration; if absent, the
"return" field
will be an empty dictionary. If 'returns' is present, it must be the
string name of a complex or built-in type, a one-element array
containing the name of a complex or built-in type, or a dictionary
-that declares an anonymous type with the same semantics as a 'type'
+that declares an anonymous type with the same semantics as a 'struct'
expression, with one exception noted below when 'gen' is used.
Although it is permitted to have the 'returns' member name a built-in
type or an array of built-in types, any command that does this cannot
@@ -429,7 +429,7 @@ Some example commands:
{ 'command': 'my-first-command',
'data': { 'arg1': 'str', '*arg2': 'str' } }
- { 'type': 'MyType', 'data': { '*value': 'str' } }
+ { 'struct': 'MyType', 'data': { '*value': 'str' } }
{ 'command': 'my-second-command',
'returns': [ 'MyType' ] }
@@ -473,7 +473,7 @@ Events are defined with the keyword 'event'. It is not
allowed to
name an event 'MAX', since the generator also produces a C enumeration
of all event names with a generated _MAX value at the end. When
'data' is also specified, additional info will be included in the
-event, with similar semantics to a 'type' expression. Finally there
+event, with similar semantics to a 'struct' expression. Finally there
will be C API generated in qapi-event.h; when called by QEMU code, a
message with timestamp will be emitted on the wire.
@@ -504,7 +504,7 @@ case we want to accept/return a list of this type with a
command), and a
command which takes that type as a parameter and returns the same type:
$ cat example-schema.json
- { 'type': 'UserDefOne',
+ { 'struct': 'UserDefOne',
'data': { 'integer': 'int', 'string': 'str' } }
{ 'command': 'my-command',
--
2.1.0
- [Qemu-devel] [PATCH v6 26/36] qapi: Whitelist commands that don't return dictionary, (continued)
- [Qemu-devel] [PATCH v6 26/36] qapi: Whitelist commands that don't return dictionary, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 27/36] qapi: More rigorous checking for type safety bypass, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 25/36] qapi: Require valid names, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 24/36] qapi: More rigourous checking of types, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 23/36] qapi: Add some type check tests, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 28/36] qapi: Prefer 'struct' over 'type' in generator, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 29/36] qapi: Document 'struct' metatype,
Eric Blake <=
- [Qemu-devel] [PATCH v6 31/36] qapi: Merge UserDefTwo and UserDefNested in tests, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 34/36] qapi: Drop inline nested structs in query-pci, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 33/36] qapi: Drop inline nested struct in query-version, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 35/36] qapi: Drop support for inline nested types, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 36/36] qapi: Tweak doc references to QMP when QGA is also meant, Eric Blake, 2015/04/05
- [Qemu-devel] [PATCH v6 32/36] qapi: Drop tests for inline nested structs, Eric Blake, 2015/04/05