[Xcb] [PATCH libxcb 1/1] set the align-offset as provided by proto

Christian Linhart chris at demorecorder.com
Sun Nov 1 09:35:35 PST 2015


instead of using the lower bits of the pointer address.
This fixes a bug reported by Peter Hutterer in off-list communication
back in June 2015.

This requires the alignment-checker patches in xcb/proto.

Signed-off-by: Christian Linhart <chris at demorecorder.com>
---
 src/c_client.py | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/c_client.py b/src/c_client.py
index c38b434..fc34bbe 100644
--- a/src/c_client.py
+++ b/src/c_client.py
@@ -815,15 +815,15 @@ def get_serialize_params(context, self, buffer_var='_buffer', aux_var='_aux'):
     if not self.is_switch and 'serialize' == context:
         for p in param_fields:
             if not p.type.fixed_size():
                 add_param(params, (p.c_field_const_type, '*', p.c_field_name))
 
     return (param_fields, wire_fields, params)
 
-def _c_serialize_helper_insert_padding(context, code_lines, space, postpone, is_case_or_bitcase):
+def _c_serialize_helper_insert_padding(context, complex_type, code_lines, space, postpone, is_case_or_bitcase):
     code_lines.append('%s    /* insert padding */' % space)
     if is_case_or_bitcase:
         code_lines.append(
             '%s    xcb_pad = -(xcb_block_len + xcb_padding_offset) & (xcb_align_to - 1);'
             % space)
     else:
         code_lines.append(
@@ -890,15 +890,15 @@ def _c_serialize_helper_switch(context, self, complex_name,
                                             code_lines, temp_vars,
                                             "%s    " % space,
                                             b_prefix,
                                             is_case_or_bitcase = True)
         code_lines.append('    }')
 
 #    if 'serialize' == context:
-#        count += _c_serialize_helper_insert_padding(context, code_lines, space, False)
+#        count += _c_serialize_helper_insert_padding(context, self, code_lines, space, False)
 #    elif context in ('unserialize', 'unpack', 'sizeof'):
 #        # padding
 #        code_lines.append('%s    xcb_pad = -xcb_block_len & 3;' % space)
 #        code_lines.append('%s    xcb_buffer_len += xcb_block_len + xcb_pad;' % space)
 
     return count
 
@@ -1164,15 +1164,15 @@ def _c_serialize_helper_fields(context, self,
                 continue
 
         # switch/bitcase: fixed size fields must be considered explicitly
         if field.type.fixed_size():
             if self.is_case_or_bitcase or self.c_var_followed_by_fixed_fields:
                 if prev_field_was_variable and need_padding:
                     # insert padding
-#                    count += _c_serialize_helper_insert_padding(context, code_lines, space,
+#                    count += _c_serialize_helper_insert_padding(context, self, code_lines, space,
 #                                                                self.c_var_followed_by_fixed_fields)
                     prev_field_was_variable = False
 
                 # prefix for fixed size fields
                 fixed_prefix = prefix
 
                 value, length = _c_serialize_helper_fields_fixed_size(context, self, field,
@@ -1182,22 +1182,22 @@ def _c_serialize_helper_fields(context, self,
                 continue
 
         # fields with variable size
         else:
             if field.type.is_pad:
                 # Variable length pad is <pad align= />
                 code_lines.append('%s    xcb_align_to = %d;' % (space, field.type.align))
-                count += _c_serialize_helper_insert_padding(context, code_lines, space,
+                count += _c_serialize_helper_insert_padding(context, self, code_lines, space,
                                                             self.c_var_followed_by_fixed_fields,
                                                             is_case_or_bitcase)
                 continue
             else:
                 # switch/bitcase: always calculate padding before and after variable sized fields
                 if need_padding or is_case_or_bitcase:
-                    count += _c_serialize_helper_insert_padding(context, code_lines, space,
+                    count += _c_serialize_helper_insert_padding(context, self, code_lines, space,
                                                                 self.c_var_followed_by_fixed_fields,
                                                                 is_case_or_bitcase)
 
                 value, length = _c_serialize_helper_fields_variable_size(context, self, field,
                                                                          code_lines, temp_vars,
                                                                          space, prefix)
                 prev_field_was_variable = True
@@ -1281,15 +1281,15 @@ def _c_serialize_helper(context, complex_type,
             code_lines.append('%s    xcb_buffer_len += xcb_block_len;' % space)
             code_lines.append('%s    xcb_block_len = 0;' % space)
 
         count += _c_serialize_helper_fields(context, self,
                                             code_lines, temp_vars,
                                             space, prefix, False)
     # "final padding"
-    count += _c_serialize_helper_insert_padding(context, code_lines, space, False, self.is_switch)
+    count += _c_serialize_helper_insert_padding(context, complex_type, code_lines, space, False, self.is_switch)
 
     return count
 
 def _c_serialize(context, self):
     """
     depending on the context variable, generate _serialize(), _unserialize(), _unpack(), or _sizeof()
     for the ComplexType variable self
@@ -1352,15 +1352,16 @@ def _c_serialize(context, self):
             _c('    unsigned int xcb_buffer_len = sizeof(%s) + xcb_out_pad;', self.c_type)
             _c('    unsigned int xcb_align_to = 0;')
         else:
             _c('    char *xcb_out = *_buffer;')
             _c('    unsigned int xcb_buffer_len = 0;')
             _c('    unsigned int xcb_align_to = 0;')
         if self.is_switch:
-            _c('    unsigned int xcb_padding_offset = ((size_t)xcb_out) & 7;')
+            _c('    unsigned int xcb_padding_offset = %d;',
+	       self.get_align_offset() )
         prefix = [('_aux', '->', self)]
         aux_ptr = 'xcb_out'
 
     elif context in ('unserialize', 'unpack'):
         _c('    char *xcb_tmp = (char *)_buffer;')
         if not self.is_switch:
             if not self.c_var_followed_by_fixed_fields:
@@ -1377,15 +1378,16 @@ def _c_serialize(context, self):
             prefix = [(aux_var, '->', self)]
         aux_ptr = '*_aux'
         _c('    unsigned int xcb_buffer_len = 0;')
         _c('    unsigned int xcb_block_len = 0;')
         _c('    unsigned int xcb_pad = 0;')
         _c('    unsigned int xcb_align_to = 0;')
         if self.is_switch:
-            _c('    unsigned int xcb_padding_offset = ((size_t)_buffer) & 7;')
+            _c('    unsigned int xcb_padding_offset = %d;',
+	       self.get_align_offset() )
 
     elif 'sizeof' == context:
         param_names = [p[2] for p in params]
         if self.is_switch:
             # switch: call _unpack()
             _c('    %s _aux;', self.c_type)
             _c('    return %s(%s, &_aux);', self.c_unpack_name, ", ".join(param_names))
-- 
2.1.4



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