[Qemu-devel] [PATCH 05/26] qapi: qapi_visit.py, support arrays and complex qapi definitions

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Add support for arrays in the code generators.

Complex field descriptions can now be used to provide additional
information to the visitor generators, such as the max size of an array,
or the field within a struct to use to determine how many elements are
present in the array to avoid serializing uninitialized elements.

Add handling for these in the code generators as well.

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 scripts/qapi.py          |    8 +++-
 scripts/qapi_commands.py |    8 ++--
 scripts/qapi_types.py    |    2 +-
 scripts/qapi_visit.py    |  102 ++++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 106 insertions(+), 14 deletions(-)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index afc5f32..555d823 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -110,12 +110,16 @@ def parse_args(typeinfo):
         argentry = typeinfo[member]
         optional = False
         structured = False
+        annotated = False
         if member.startswith('*'):
             argname = member[1:]
             optional = True
         if isinstance(argentry, OrderedDict):
-            structured = True
-        yield (argname, argentry, optional, structured)
+            if argentry.has_key('<annotated>'):
+                annotated = True
+            else:
+                structured = True
+        yield (argname, argentry, optional, structured, annotated)
 
 def de_camel_case(name):
     new_name = ''
diff --git a/scripts/qapi_commands.py b/scripts/qapi_commands.py
index 3c4678d..a2e0c23 100644
--- a/scripts/qapi_commands.py
+++ b/scripts/qapi_commands.py
@@ -32,7 +32,7 @@ void %(visitor)s(Visitor *m, %(name)s * obj, const char *name, Error **errp);
 
 def generate_command_decl(name, args, ret_type):
     arglist=""
-    for argname, argtype, optional, structured in parse_args(args):
+    for argname, argtype, optional, structured, annotated in parse_args(args):
         argtype = c_type(argtype)
         if argtype == "char *":
             argtype = "const char *"
@@ -50,7 +50,7 @@ def gen_sync_call(name, args, ret_type, indent=0):
     retval=""
     if ret_type:
         retval = "retval = "
-    for argname, argtype, optional, structured in parse_args(args):
+    for argname, argtype, optional, structured, annotated in parse_args(args):
         if optional:
             arglist += "has_%s, " % c_var(argname)
         arglist += "%s, " % (c_var(argname))
@@ -106,7 +106,7 @@ Visitor *v;
 def gen_visitor_input_vars_decl(args):
     ret = ""
     push_indent()
-    for argname, argtype, optional, structured in parse_args(args):
+    for argname, argtype, optional, structured, annotated in parse_args(args):
         if optional:
             ret += mcgen('''
 bool has_%(argname)s = false;
@@ -145,7 +145,7 @@ v = qmp_input_get_visitor(mi);
 ''',
                      obj=obj)
 
-    for argname, argtype, optional, structured in parse_args(args):
+    for argname, argtype, optional, structured, annotated in parse_args(args):
         if optional:
             ret += mcgen('''
 visit_start_optional(v, &has_%(c_name)s, "%(name)s", errp);
diff --git a/scripts/qapi_types.py b/scripts/qapi_types.py
index 1b84834..87d0218 100644
--- a/scripts/qapi_types.py
+++ b/scripts/qapi_types.py
@@ -45,7 +45,7 @@ struct %(name)s
 ''',
           name=structname)
 
-    for argname, argentry, optional, structured in parse_args(members):
+    for argname, argentry, optional, structured, annotated in parse_args(members):
         if optional:
             ret += mcgen('''
     bool has_%(c_name)s;
diff --git a/scripts/qapi_visit.py b/scripts/qapi_visit.py
index f98abf2..d80d3d8 100644
--- a/scripts/qapi_visit.py
+++ b/scripts/qapi_visit.py
@@ -16,6 +16,90 @@ import sys
 import os
 import getopt
 import errno
+import types
+
+def generate_visit_carray_body(name, info):
+    if info['array_size'][0].isdigit():
+        array_size = info['array_size']
+    elif info['array_size'][0] == '(' and info['array_size'][-1] == ')':
+        array_size = info['array_size']
+    else:
+        array_size = "(*obj)->%s" % info['array_size']
+
+    if info.has_key('array_capacity'):
+        array_capacity = info['array_capacity']
+    else:
+        array_capacity = array_size
+
+    # Visitors for "objects" (qidl-generated visitors for structs or
+    # qapi-defined types) expect a <type>** argument so that, in some
+    # cases, memory can be allocated for the object and a pointer to that
+    # memory can be assigned to the location/pointer passed to the visitor
+    # call.
+    #
+    # For other cases, "primitive" types, we don't do allocations and thus
+    # expect a <type>*.
+    #
+    # So we use special handling for the former case, below, to get the
+    # arguments right. We identify these cases by checking if the type
+    # uses camel-case, which is reserved for typedef'd structs/objects as
+    # per QEMU coding standards and QAPI convention.
+    if camel_case(de_camel_case(info['type'][0])) == info['type'][0]:
+        ret = mcgen('''
+
+if (!error_is_set(errp)) {
+    Error *%(local_err)s = NULL;
+    visit_start_carray(m, (void **)obj, "%(name)s", %(array_capacity)s, sizeof(%(type)s), &%(local_err)s);
+    if (!%(local_err)s) {
+        int %(name)s_i;
+        for (%(name)s_i = 0; %(name)s_i < %(array_size)s; %(name)s_i++) {
+            %(type)s %(name)s_ptr = &(*obj)->%(name)s[%(name)s_i];
+            visit_next_carray(m, &%(local_err)s);
+            visit_type_%(type_short)s(m, &%(name)s_ptr, NULL, &%(local_err)s);
+        }
+
+        error_propagate(errp, %(local_err)s);
+        %(local_err)s = NULL;
+
+        /* Always call end_carry if start_carray succeeded.  */
+        visit_end_carray(m, &%(local_err)s);
+    }
+    error_propagate(errp, %(local_err)s);
+}
+''',
+                    name=name, type=c_type(info['type'][0]),
+                    type_short=info['type'][0],
+                    array_size=str(array_size),
+                    array_capacity=str(array_capacity),
+                    local_err=name + "_err")
+    else:
+        ret = mcgen('''
+if (!error_is_set(errp)) {
+    Error *%(local_err)s = NULL;
+    visit_start_carray(m, (void **)obj, "%(name)s", %(array_capacity)s, sizeof(%(type)s), &%(local_err)s);
+    if (!%(local_err)s) {
+        int %(name)s_i;
+        for (%(name)s_i = 0; %(name)s_i < %(array_size)s; %(name)s_i++) {
+            %(type)s *%(name)s_ptr = (%(type)s *)&(*obj)->%(name)s[%(name)s_i];
+            visit_next_carray(m, &%(local_err)s);
+            visit_type_%(type_short)s(m, %(name)s_ptr, NULL, &%(local_err)s);
+        }
+
+        error_propagate(errp, %(local_err)s);
+        %(local_err)s = NULL;
+
+        /* Always call end_carry if start_carray succeeded.  */
+        visit_end_carray(m, &%(local_err)s);
+    }
+    error_propagate(errp, %(local_err)s);
+}
+''',
+                    name=name, type=c_type(info['type'][0]),
+                    type_short=info['type'][0],
+                    array_size=str(array_size),
+                    array_capacity=str(array_capacity),
+                    local_err=name + "_err")
+    return ret
 
 def generate_visit_struct_body(field_prefix, name, members):
     ret = mcgen('''
@@ -45,10 +129,10 @@ if (!err) {
 
     push_indent()
     push_indent()
-    for argname, argentry, optional, structured in parse_args(members):
+    for argname, argentry, optional, structured, annotated in parse_args(members):
         if optional:
             ret += mcgen('''
-visit_start_optional(m, obj ? &(*obj)->%(c_prefix)shas_%(c_name)s : NULL, "%(name)s", &err);
+visit_start_optional(m, obj ? &(*obj)->%(c_prefix)shas_%(c_name)s : NULL, "%(name)s", errp);
 if (obj && (*obj)->%(prefix)shas_%(c_name)s) {
 ''',
                          c_prefix=c_var(field_prefix), prefix=field_prefix,
@@ -58,12 +142,16 @@ if (obj && (*obj)->%(prefix)shas_%(c_name)s) {
         if structured:
             ret += generate_visit_struct_body(field_prefix + argname, argname, argentry)
         else:
-            ret += mcgen('''
-visit_type_%(type)s(m, obj ? &(*obj)->%(c_prefix)s%(c_name)s : NULL, "%(name)s", &err);
+            if annotated:
+                if isinstance(argentry['type'], types.ListType):
+                    ret += generate_visit_carray_body(argname, argentry)
+            else:
+                ret += mcgen('''
+visit_type_%(type)s(m, obj ? &(*obj)->%(c_prefix)s%(c_name)s : NULL, "%(name)s", errp);
 ''',
-                         c_prefix=c_var(field_prefix), prefix=field_prefix,
-                         type=type_name(argentry), c_name=c_var(argname),
-                         name=argname)
+                             c_prefix=c_var(field_prefix), prefix=field_prefix,
+                             type=type_name(argentry), c_name=c_var(argname),
+                             name=argname)
 
         if optional:
             pop_indent()
-- 
1.7.9.5