[Qemu-devel] [RFC PATCH v2 6/7] qapi: Initialize argument value in generated code if has 'default'

[Fam Zheng]

Input marshalling code generation is modified.

If an argument has default, initialize its value in generated code to
that default. If this argument is specified by user input, visit
argument with deallocate visitor, before input visitor, so that the
initial value is deallocated.

This moves initialization of md, mi, vd, vi before input block as
necessary, and moves cleanup of mi aside cleanup of md, for symmetry.

Signed-off-by: Fam Zheng <address@hidden>
---
 scripts/qapi-commands.py | 47 +++++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 05904f9..62ab51a 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -87,8 +87,8 @@ def gen_visitor_input_containers_decl(args, obj):
     if len(args) > 0:
         ret += mcgen('''
 QmpInputVisitor *mi = qmp_input_visitor_new_strict(%(obj)s);
-QapiDeallocVisitor *md;
-Visitor *v;
+QapiDeallocVisitor *md = qapi_dealloc_visitor_new();
+Visitor *vi, *vd;
 ''',
                      obj=obj)
     pop_indent()
@@ -99,12 +99,19 @@ def gen_visitor_input_vars_decl(args):
     ret = ""
     push_indent()
     for argname, argtype, optional, structured, default in parse_args(args):
-        if optional:
+        has_default = default is not None
+        if optional or has_default:
             ret += mcgen('''
 bool has_%(argname)s = false;
 ''',
                          argname=c_var(argname))
-        if c_type(argtype).endswith("*"):
+        if has_default:
+            ret += mcgen('''
+%(argtype)s %(argname)s = %(argval)s;
+''',
+                         argname=c_var(argname), argtype=c_type(argtype),
+                         argval=c_val(argtype, default))
+        elif c_type(argtype).endswith("*"):
             ret += mcgen('''
 %(argtype)s %(argname)s = NULL;
 ''',
@@ -122,6 +129,7 @@ def gen_visitor_input_block(args, dealloc=False):
     ret = ""
     errparg = '&local_err'
     errarg = 'local_err'
+    vvar = 'vi'
 
     if len(args) == 0:
         return ret
@@ -131,35 +139,41 @@ def gen_visitor_input_block(args, dealloc=False):
     if dealloc:
         errparg = 'NULL'
         errarg = None;
-        ret += mcgen('''
-qmp_input_visitor_cleanup(mi);
-md = qapi_dealloc_visitor_new();
-v = qapi_dealloc_get_visitor(md);
-''')
+        vvar = 'vd'
     else:
         ret += mcgen('''
-v = qmp_input_get_visitor(mi);
+vi = qmp_input_get_visitor(mi);
+vd = qapi_dealloc_get_visitor(md);
 ''')
 
     for argname, argtype, optional, structured, default in parse_args(args):
-        if optional:
+        has_default = default is not None
+        if optional or has_default:
             ret += mcgen('''
-visit_optional(v, &has_%(c_name)s, "%(name)s", %(errp)s);
+visit_optional(%(v)s, &has_%(c_name)s, "%(name)s", %(errp)s);
 ''',
-                         c_name=c_var(argname), name=argname, errp=errparg)
+                         v=vvar, c_name=c_var(argname), name=argname, 
errp=errparg)
             ret += gen_err_check(errarg)
             ret += mcgen('''
 if (has_%(c_name)s) {
 ''',
                          c_name=c_var(argname))
             push_indent()
+            if not dealloc and has_default:
+                # For input block, we should deallocate argument that is
+                # initialized with a defualt value, before reading in from 
input
+                ret += mcgen('''
+%(visitor)s(vd, &%(c_name)s, "%(name)s", NULL);
+''',
+                         c_name=c_var(argname), name=argname, argtype=argtype,
+                         visitor=type_visitor(argtype), errp=errparg)
         ret += mcgen('''
-%(visitor)s(v, &%(c_name)s, "%(name)s", %(errp)s);
+%(visitor)s(%(v)s, &%(c_name)s, "%(name)s", %(errp)s);
 ''',
-                     c_name=c_var(argname), name=argname, argtype=argtype,
+                     v=vvar, c_name=c_var(argname), name=argname, 
argtype=argtype,
                      visitor=type_visitor(argtype), errp=errparg)
         ret += gen_err_check(errarg)
-        if optional:
+        if optional or has_default:
             pop_indent()
             ret += mcgen('''
 }
@@ -167,6 +181,7 @@ if (has_%(c_name)s) {
 
     if dealloc:
         ret += mcgen('''
+qmp_input_visitor_cleanup(mi);
 qapi_dealloc_visitor_cleanup(md);
 ''')
     pop_indent()
-- 
1.9.2