Avoid sparse error or warning for sizeof(_Bool).

The sparse checker does not like taking sizeof(_Bool).  Older versions of
sparse output a hard error ("error: cannot size expression").  Newer
versions output a warning ("warning: expression using sizeof bool").  This
commit avoids the problem by not using sizeof(_Bool) anywhere.

The only place where OVS uses sizeof(_Bool) anyway is in code generated by
the OVSDB IDL.  It generates it for populating "optional bool" columns in
the database, that is, columns that are allowed to contain 0 or 1 instances
of a bool.  For these columns, it generates code that looks roughly like
this:
    row->column = xmalloc(sizeof *row->column);
    *row->column = value;
This commit changes these columns from type "bool *" to type "const bool *"
and changes the generated code to:
    static const bool true_value = true;
    static const bool false_value = false;

    row->column = value ? &true_value : &false_value;
which avoids the problem and saves a malloc() call at the same time.

The idltest code had a column with a slightly different type ("0, 1, or
2 bools") that didn't fit the revised pattern and is a fairly stupid type
anyhow, so I just changed it to "0 or 1 bools".

1 files changed, 32 insertions, 2 deletions

diff --git a/ovsdb/ovsdb-idlc.in b/ovsdb/ovsdb-idlc.in
index 2a4c67ca..e5c81832 100755
--- a/ovsdb/ovsdb-idlc.in
+++ b/ovsdb/ovsdb-idlc.in
@@ -27,6 +27,8 @@ def constify(cType, const):
 
 def cMembers(prefix, columnName, column, const):
     type = column.type
+    if is_optional_bool(type):
+        const = True
     if type.n_min == 1 and type.n_max == 1:
         singleton = True
         pointer = ''
@@ -165,6 +167,10 @@ def printEnum(members):
     print "    %s" % members[-1]
     print "};"
 
+def is_optional_bool(type):
+    return (type.key.type == ovs.db.types.BooleanType and not type.value
+            and type.n_min == 0 and type.n_max == 1)
+
 def printCIDLSource(schemaFile):
     schema = parseSchema(schemaFile)
     prefix = schema.idlPrefix
@@ -215,7 +221,23 @@ static void
                 keyVar = "row->%s" % columnName
                 valueVar = None
 
-            if (type.n_min == 1 and type.n_max == 1) or type.is_optional_pointer():
+            if is_optional_bool(type):
+                # Special case for an optional bool.  This is only here because
+                # sparse does not like the "normal" case below ("warning:
+                # expression using sizeof bool").
+                print
+                print "    assert(inited);"
+                print "    if (datum->n >= 1) {"
+                print "        static const bool false_value = false;"
+                print "        static const bool true_value = true;"
+                print
+                print "        row->n_%s = 1;" % columnName
+                print "        %s = datum->keys[0].boolean ? &true_value : &false_value;" % keyVar
+                print "    } else {"
+                print "        row->n_%s = 0;" % columnName
+                print "        %s = NULL;" % keyVar
+                print "    }"
+            elif (type.n_min == 1 and type.n_max == 1) or type.is_optional_pointer():
                 print
                 print "    assert(inited);"
                 print "    if (datum->n >= 1) {"
@@ -283,7 +305,15 @@ static void
         # Unparse functions.
         for columnName, column in sorted(table.columns.iteritems()):
             type = column.type
-            if (type.n_min != 1 or type.n_max != 1) and not type.is_optional_pointer():
+            if (type.key.type == ovs.db.types.BooleanType and not type.value
+                and type.n_min == 0 and type.n_max == 1):
+                print '''
+static void
+%(s)s_unparse_%(c)s(struct ovsdb_idl_row *row OVS_UNUSED)
+{
+    /* Nothing to do. */
+}''' % {'s': structName, 'c': columnName}
+            elif (type.n_min != 1 or type.n_max != 1) and not type.is_optional_pointer():
                 print '''
 static void
 %(s)s_unparse_%(c)s(struct ovsdb_idl_row *row_)