[Qemu-devel] [PATCH V2 3/3] qapi: Create an include directive for use in the JSON description files.

["Benoît Canet" <benoit.canet@irqsave.net>]

The new directive in the form { 'include': 'path/to/file.json' } will trigger the
parsing of path/to/file.json.
The directive will be replaced by the result of the parsing.

This will allow for easy modularisation of qapi JSON descriptions files.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 docs/qapi-code-gen.txt                 |   14 ++++++++++++++
 scripts/qapi.py                        |   17 ++++++++++++++++-
 tests/Makefile                         |    2 +-
 tests/qapi-schema/include.exit         |    1 +
 tests/qapi-schema/include.json         |    4 ++++
 tests/qapi-schema/include.out          |    8 ++++++++
 tests/qapi-schema/include/include.json |    7 +++++++
 tests/qapi-schema/include_loop.exit    |    1 +
 tests/qapi-schema/include_loop.json    |    1 +
 tests/qapi-schema/include_loop.out     |    1 +
 10 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 tests/qapi-schema/include.err
 create mode 100644 tests/qapi-schema/include.exit
 create mode 100644 tests/qapi-schema/include.json
 create mode 100644 tests/qapi-schema/include.out
 create mode 100644 tests/qapi-schema/include/include.json
 create mode 100644 tests/qapi-schema/include_loop.err
 create mode 100644 tests/qapi-schema/include_loop.exit
 create mode 100644 tests/qapi-schema/include_loop.json
 create mode 100644 tests/qapi-schema/include_loop.out

diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt
index d78921f..a16aa47 100644
--- a/docs/qapi-code-gen.txt
+++ b/docs/qapi-code-gen.txt
@@ -180,6 +180,20 @@ An example command is:
    'data': { 'arg1': 'str', '*arg2': 'str' },
    'returns': 'str' }
 
+=== Includes ===
+
+A schema file can include other sub schema files with the include
+directive.
+
+An example of include directive is:
+
+{ 'include': 'path/to/sub_schema.json' }
+
+The include path is relative to the current schema file.
+The include parsing method is recursive.
+The expressions resulting from the parsing of the sub schema are injected
+in place of the include directive like a C #include would do.
+
 
 == Code generation ==
 
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 597042a..0b0c8e4 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -269,6 +269,8 @@ def check_exprs(schema):
         if expr.has_key('union'):
             check_union(expr, expr_elem['info'])
 
+modules = []
+
 def build_schema(path):
     with open(path, "r") as fp:
         try:
@@ -281,13 +283,26 @@ def build_schema(path):
 def parse_schema(path):
     path = os.path.abspath(path)
 
+    if path in modules:
+        print "Module inclusion loop detected with module: %s" %\
+              get_filename(path)
+        sys.exit(1)
+
+    modules.append(path)
+
     schema = build_schema(path)
 
     exprs = []
 
     for expr_elem in schema.exprs:
         expr = expr_elem['expr']
-        if expr.has_key('enum'):
+        if expr.has_key('include'):
+            prefix = os.path.split(path)[0]
+            sub_path = os.path.join(prefix, expr['include'])
+            sub_exprs = parse_schema(sub_path)
+            exprs += sub_exprs
+            continue
+        elif expr.has_key('enum'):
             add_enum(expr['enum'], expr['data'])
         elif expr.has_key('union'):
             add_union(expr)
diff --git a/tests/Makefile b/tests/Makefile
index c4ed5c2..b5e4cf0 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -164,7 +164,7 @@ check-qapi-schema-y := $(addprefix tests/qapi-schema/, \
         duplicate-key.json union-invalid-base.json flat-union-no-base.json \
         flat-union-invalid-discriminator.json \
         flat-union-invalid-branch-key.json flat-union-reverse-define.json \
-        flat-union-string-discriminator.json)
+        flat-union-string-discriminator.json include.json include_loop.json)
 
 GENERATED_HEADERS += tests/test-qapi-types.h tests/test-qapi-visit.h tests/test-qmp-commands.h
 
diff --git a/tests/qapi-schema/include.err b/tests/qapi-schema/include.err
new file mode 100644
index 0000000..e69de29
diff --git a/tests/qapi-schema/include.exit b/tests/qapi-schema/include.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/tests/qapi-schema/include.exit
@@ -0,0 +1 @@
+0
diff --git a/tests/qapi-schema/include.json b/tests/qapi-schema/include.json
new file mode 100644
index 0000000..ffece21
--- /dev/null
+++ b/tests/qapi-schema/include.json
@@ -0,0 +1,4 @@
+{ 'enum': 'Status',
+  'data': [ 'good', 'bad', 'ugly' ] }
+{ 'include': './include/include.json' }
+{ 'foo': '42' }
diff --git a/tests/qapi-schema/include.out b/tests/qapi-schema/include.out
new file mode 100644
index 0000000..89e43e8
--- /dev/null
+++ b/tests/qapi-schema/include.out
@@ -0,0 +1,8 @@
+[OrderedDict([('enum', 'Status'), ('data', ['good', 'bad', 'ugly'])]),
+ OrderedDict([('bar', '33')]),
+ OrderedDict([('enum', 'Fruits'), ('data', ['orange', 'apple', 'gooseberry'])]),
+ OrderedDict([('baz', '54')]),
+ OrderedDict([('foo', '42')])]
+[{'enum_name': 'Status', 'enum_values': ['good', 'bad', 'ugly']},
+ {'enum_name': 'Fruits', 'enum_values': ['orange', 'apple', 'gooseberry']}]
+[]
diff --git a/tests/qapi-schema/include/include.json b/tests/qapi-schema/include/include.json
new file mode 100644
index 0000000..f445eee
--- /dev/null
+++ b/tests/qapi-schema/include/include.json
@@ -0,0 +1,7 @@
+
+{ 'bar': '33' }
+
+{ 'enum': 'Fruits',
+  'data': [ 'orange', 'apple', 'gooseberry' ] }
+
+{ 'baz': '54' }
diff --git a/tests/qapi-schema/include_loop.err b/tests/qapi-schema/include_loop.err
new file mode 100644
index 0000000..e69de29
diff --git a/tests/qapi-schema/include_loop.exit b/tests/qapi-schema/include_loop.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/tests/qapi-schema/include_loop.exit
@@ -0,0 +1 @@
+1
diff --git a/tests/qapi-schema/include_loop.json b/tests/qapi-schema/include_loop.json
new file mode 100644
index 0000000..cb8ff03
--- /dev/null
+++ b/tests/qapi-schema/include_loop.json
@@ -0,0 +1 @@
+{ 'include': 'include_loop.json' }
diff --git a/tests/qapi-schema/include_loop.out b/tests/qapi-schema/include_loop.out
new file mode 100644
index 0000000..35da4dd
--- /dev/null
+++ b/tests/qapi-schema/include_loop.out
@@ -0,0 +1 @@
+Module inclusion loop detected with module: include_loop.json
-- 
1.7.10.4