qapi: Prefer 'struct' over 'type' in generator

Referring to "type" as both a meta-type (built-in, enum, union,
alternate, or struct) and a specific type (the name that the
schema uses for declaring structs) is confusing.  The confusion
is only made worse by the fact that the generator mostly already
refers to struct even when dealing with expr['type'].  This
commit changes the generator to consistently refer to it as
struct everywhere, plus a single back-compat tweak that allows
accepting the existing .json files as-is, so that the meat of
this change is separate from the mindless churn of that change.

Fix the testsuite fallout for error messages that change, and
in some cases, become more legible.  Improve comments to better
match our intentions where a struct (rather than any complex
type) is required.  Note that in some cases, an error message
now refers to 'struct' while the schema still refers to 'type';
that will be cleaned up in the later commit to the schema.

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

1 files changed, 29 insertions, 17 deletions

diff --git a/scripts/qapi.py b/scripts/qapi.py
index e391b5a649..e50fec826b 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -419,7 +419,7 @@ def check_union(expr, expr_info):
     members = expr['data']
     values = { 'MAX': '(automatic)' }
 
-    # If the object has a member 'base', its value must name a complex type,
+    # If the object has a member 'base', its value must name a struct,
     # and there must be a discriminator.
     if base is not None:
         if discriminator is None:
@@ -448,18 +448,18 @@ def check_union(expr, expr_info):
         base_fields = find_base_fields(base)
         if not base_fields:
             raise QAPIExprError(expr_info,
-                                "Base '%s' is not a valid type"
+                                "Base '%s' is not a valid struct"
                                 % base)
 
         # The value of member 'discriminator' must name a non-optional
-        # member of the base type.
+        # member of the base struct.
         check_name(expr_info, "Discriminator of flat union '%s'" % name,
                    discriminator)
         discriminator_type = base_fields.get(discriminator)
         if not discriminator_type:
             raise QAPIExprError(expr_info,
                                 "Discriminator '%s' is not a member of base "
-                                "type '%s'"
+                                "struct '%s'"
                                 % (discriminator, base))
         enum_define = find_enum(discriminator_type)
         allow_metas=['struct']
@@ -546,12 +546,12 @@ def check_enum(expr, expr_info):
         values[key] = member
 
 def check_struct(expr, expr_info):
-    name = expr['type']
+    name = expr['struct']
     members = expr['data']
 
-    check_type(expr_info, "'data' for type '%s'" % name, members,
+    check_type(expr_info, "'data' for struct '%s'" % name, members,
                allow_dict=True, allow_optional=True)
-    check_type(expr_info, "'base' for type '%s'" % name, expr.get('base'),
+    check_type(expr_info, "'base' for struct '%s'" % name, expr.get('base'),
                allow_metas=['struct'])
 
 def check_exprs(schema):
@@ -565,7 +565,7 @@ def check_exprs(schema):
             check_union(expr, info)
         elif expr.has_key('alternate'):
             check_alternate(expr, info)
-        elif expr.has_key('type'):
+        elif expr.has_key('struct'):
             check_struct(expr, info)
         elif expr.has_key('command'):
             check_command(expr, info)
@@ -617,6 +617,20 @@ def parse_schema(input_file):
         for expr_elem in schema.exprs:
             expr = expr_elem['expr']
             info = expr_elem['info']
+
+            # back-compat hack until all schemas have been converted;
+            # preserve the ordering of the original expression
+            if expr.has_key('type'):
+                seen_type = False
+                for (key, value) in expr.items():
+                    if key == 'type':
+                        seen_type = True
+                        del expr['type']
+                        expr['struct'] = value
+                    elif seen_type:
+                        del expr[key]
+                        expr[key] = value
+
             if expr.has_key('enum'):
                 check_keys(expr_elem, 'enum', ['data'])
                 add_enum(expr['enum'], info, expr['data'])
@@ -627,8 +641,8 @@ def parse_schema(input_file):
             elif expr.has_key('alternate'):
                 check_keys(expr_elem, 'alternate', ['data'])
                 add_name(expr['alternate'], info, 'alternate')
-            elif expr.has_key('type'):
-                check_keys(expr_elem, 'type', ['data'], ['base'])
+            elif expr.has_key('struct'):
+                check_keys(expr_elem, 'struct', ['data'], ['base'])
                 add_struct(expr, info)
             elif expr.has_key('command'):
                 check_keys(expr_elem, 'command', [],
@@ -745,11 +759,9 @@ def type_name(name):
         return c_list_type(name[0])
     return name
 
-def add_name(name, info, meta, implicit = False, source = None):
+def add_name(name, info, meta, implicit = False):
     global all_names
-    if not source:
-        source = "'%s'" % meta
-    check_name(info, source, name)
+    check_name(info, "'%s'" % meta, name)
     if name in all_names:
         raise QAPIExprError(info,
                             "%s '%s' is already defined"
@@ -762,14 +774,14 @@ def add_name(name, info, meta, implicit = False, source = None):
 
 def add_struct(definition, info):
     global struct_types
-    name = definition['type']
-    add_name(name, info, 'struct', source="'type'")
+    name = definition['struct']
+    add_name(name, info, 'struct')
     struct_types.append(definition)
 
 def find_struct(name):
     global struct_types
     for struct in struct_types:
-        if struct['type'] == name:
+        if struct['struct'] == name:
             return struct
     return None