[Xcb-commit] libxcb: 3 commits - src

Peter Harris peterh at kemper.freedesktop.org
Mon Aug 25 16:17:17 PDT 2014


 src/c_client.py |   55 +++++++++++++++++++++++++++++++++----------------------
 src/xcb_conn.c  |   26 +++++++++++++++++++++++---
 2 files changed, 56 insertions(+), 25 deletions(-)

New commits:
commit b0e6c2de09c7474868dd7185674fa113a5c2e0aa
Author: Uli Schlachter <psychon at znc.in>
Date:   Mon Aug 18 10:38:48 2014 +0200

    xcb_get_setup(): Never return NULL
    
    The documentation doesn't mention it and it's unlikely that a lot of code out
    there handles this case correctly. So, instead of returning NULL, let
    xcb_get_setup() return a pointer to a static, invalid, all-zero setup
    information structure.
    
    Signed-off-by: Uli Schlachter <psychon at znc.in>

diff --git a/src/xcb_conn.c b/src/xcb_conn.c
index 15f707a..7d09637 100644
--- a/src/xcb_conn.c
+++ b/src/xcb_conn.c
@@ -64,6 +64,26 @@ typedef struct {
     uint16_t length;
 } xcb_setup_generic_t;
 
+static const xcb_setup_t xcb_error_setup = {
+    0,     /* status: failed (but we wouldn't have a xcb_setup_t in this case) */
+    0,     /* pad0 */
+    0, 0,  /* protocol version, should be 11.0, but isn't */
+    0,     /* length, invalid value */
+    0,     /* release_number */
+    0, 0,  /* resource_id_{base,mask} */
+    0,     /* motion_buffer_size */
+    0,     /* vendor_len */
+    0,     /* maximum_request_length */
+    0,     /* roots_len */
+    0,     /* pixmap_formats_len */
+    0,     /* image_byte_order */
+    0,     /* bitmap_format_bit_order */
+    0,     /* bitmap_format_scanline_unit */
+    0,     /* bitmap_format_scanline_pad */
+    0, 0,  /* {min,max}_keycode */
+    { 0, 0, 0, 0 } /* pad1 */
+};
+
 /* Keep this list in sync with is_static_error_conn()! */
 static const int xcb_con_error = XCB_CONN_ERROR;
 static const int xcb_con_closed_mem_er = XCB_CONN_CLOSED_MEM_INSUFFICIENT;
@@ -289,7 +309,7 @@ static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
 const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
 {
     if(is_static_error_conn(c))
-        return 0;
+        return &xcb_error_setup;
     /* doesn't need locking because it's never written to. */
     return c->setup;
 }
commit c4e40f646b8da4fd112ea54a612c880be5e942a8
Author: Uli Schlachter <psychon at znc.in>
Date:   Mon Aug 18 10:38:41 2014 +0200

    Make some functions also work on error connections
    
    There is no technical reason why xcb_get_setup() and xcb_get_file_descriptor()
    shouldn't work on non-static error connections. They cannot be used for many
    useful things, but at least they work.
    
    This works around bugs in lots of programs out there which assume that
    xcb_get_setup() does not return NULL and which just happily dereference the
    results. Since xcb_connect() never returns NULL, it's a bit weird that
    xcb_get_setup() can do so. xcb_get_file_descriptor() is just modified since this
    can be done here equally easily and because the fd isn't closed until the final
    xcb_disconnect() on the error connection.
    
    Non-static error connections are connections which entered an error state after
    xcb_connect() succeeded. If something goes wrong in establishing a connection,
    xcb_connect() will return a static error connection which doesn't have the
    fields used here.
    
    Signed-off-by: Uli Schlachter <psychon at znc.in>

diff --git a/src/xcb_conn.c b/src/xcb_conn.c
index fa50985..15f707a 100644
--- a/src/xcb_conn.c
+++ b/src/xcb_conn.c
@@ -288,7 +288,7 @@ static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
 
 const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
 {
-    if(c->has_error)
+    if(is_static_error_conn(c))
         return 0;
     /* doesn't need locking because it's never written to. */
     return c->setup;
@@ -296,7 +296,7 @@ const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
 
 int xcb_get_file_descriptor(xcb_connection_t *c)
 {
-    if(c->has_error)
+    if(is_static_error_conn(c))
         return -1;
     /* doesn't need locking because it's never written to. */
     return c->fd;
commit 355d4d6ab9f5c12c2ee4a91e8cf6eb4a2854d73c
Author: Christian Linhart <chris at demorecorder.com>
Date:   Tue Aug 19 15:57:34 2014 +0200

    support switch case in the generator
    
    The implementation is rather simple:
    When a <case> is used instead of a <bitcase>
    then operator "==" is used instead of "&" in the if-condition.
    
    So it creates a series of "if" statements
    (instead of a switch-case statement in C )
    
    In practice this does not matter because a good
    optimizing compiler will create the same code
    as for a switch-case.
    
    With this simple implementation we get additional
    flexibility in the following forms:
    * a case value may appear in multiple case branches.
      for example:
    	case C1 will be selected by values 1, 4, or 5
    	case C2 will be selected by values 3, 4, or 7
    
    * mixing of bitcase and case is possible
    	(this will usually make no sense but there may
    	be protocol specs where this is needed)
    
    details of the impl:
    * replaced "is_bitcase" with "is_case_or_bitcase" in all places
      so that cases are treated like bitcases.
    
    * In function "_c_serialize_helper_switch": write operator "=="
      instead of operator "&" if it is a case.

diff --git a/src/c_client.py b/src/c_client.py
index 54e56c4..87f268b 100644
--- a/src/c_client.py
+++ b/src/c_client.py
@@ -358,7 +358,7 @@ def _c_type_setup(self, name, postfix):
                 field.c_pointer = '*'
                 field.c_field_const_type = 'const ' + field.c_field_type
                 self.c_need_aux = True
-            elif not field.type.fixed_size() and not field.type.is_bitcase:
+            elif not field.type.fixed_size() and not field.type.is_case_or_bitcase:
                 self.c_need_sizeof = True
 
             field.c_iterator_type = _t(field.field_type + ('iterator',))      # xcb_fieldtype_iterator_t
@@ -407,7 +407,7 @@ def _c_type_setup(self, name, postfix):
                 # no list with switch as element, so no call to
                 # _c_iterator(field.type, field_name) necessary
 
-    if not self.is_bitcase:
+    if not self.is_case_or_bitcase:
         if self.c_need_serialize:
             if self.c_serialize_name not in finished_serializers:
                 finished_serializers.append(self.c_serialize_name)
@@ -437,7 +437,7 @@ def _c_helper_absolute_name(prefix, field=None):
         prefix_str += name
         if '' == sep:
             sep = '->'
-            if ((obj.is_bitcase and obj.has_name) or     # named bitcase
+            if ((obj.is_case_or_bitcase and obj.has_name) or     # named bitcase
                 (obj.is_switch and len(obj.parents)>1)):
                 sep = '.'
         prefix_str += sep
@@ -470,7 +470,7 @@ def _c_helper_field_mapping(complex_type, prefix, flat=False):
 
             all_fields[f.field_name] = (fname, f)
             if f.type.is_container and flat==False:
-                if f.type.is_bitcase and not f.type.has_name:
+                if f.type.is_case_or_bitcase and not f.type.has_name:
                     new_prefix = prefix
                 elif f.type.is_switch and len(f.type.parents)>1:
                     # nested switch gets another separator
@@ -493,10 +493,10 @@ def _c_helper_resolve_field_names (prefix):
         name, sep, obj = p
         if ''==sep:
             # sep can be preset in prefix, if not, make a sensible guess
-            sep = '.' if (obj.is_switch or obj.is_bitcase) else '->'
+            sep = '.' if (obj.is_switch or obj.is_case_or_bitcase) else '->'
             # exception: 'toplevel' object (switch as well!) always have sep '->'
             sep = '->' if idx<1 else sep
-        if not obj.is_bitcase or (obj.is_bitcase and obj.has_name):
+        if not obj.is_case_or_bitcase or (obj.is_case_or_bitcase and obj.has_name):
             tmp_prefix.append((name, sep, obj))
         all_fields.update(_c_helper_field_mapping(obj, tmp_prefix, flat=True))
 
@@ -689,18 +689,29 @@ def _c_serialize_helper_switch(context, self, complex_name,
 
     for b in self.bitcases:
         len_expr = len(b.type.expr)
+
+        compare_operator = '&'
+        if b.type.is_case:
+            compare_operator = '=='
+        else:
+            compare_operator = '&'
+
         for n, expr in enumerate(b.type.expr):
             bitcase_expr = _c_accessor_get_expr(expr, None)
             # only one <enumref> in the <bitcase>
             if len_expr == 1:
-                code_lines.append('    if(%s & %s) {' % (switch_expr, bitcase_expr))
+                code_lines.append(
+                    '    if(%s %s %s) {' % (switch_expr, compare_operator, bitcase_expr))
             # multiple <enumref> in the <bitcase>
             elif n == 0: # first
-                code_lines.append('    if((%s & %s) ||' % (switch_expr, bitcase_expr))
+                code_lines.append(
+                    '    if((%s %s %s) ||' % (switch_expr, compare_operator, bitcase_expr))
             elif len_expr == (n + 1): # last
-                code_lines.append('       (%s & %s)) {' % (switch_expr, bitcase_expr))
+                code_lines.append(
+                    '       (%s %s %s)) {' % (switch_expr, compare_operator, bitcase_expr))
             else: # between first and last
-                code_lines.append('       (%s & %s) ||' % (switch_expr, bitcase_expr))
+                code_lines.append(
+                    '       (%s %s %s) ||' % (switch_expr, compare_operator, bitcase_expr))
 
         b_prefix = prefix
         if b.type.has_name:
@@ -710,7 +721,7 @@ def _c_serialize_helper_switch(context, self, complex_name,
                                             code_lines, temp_vars,
                                             "%s    " % space,
                                             b_prefix,
-                                            is_bitcase = True)
+                                            is_case_or_bitcase = True)
         code_lines.append('    }')
 
 #    if 'serialize' == context:
@@ -834,7 +845,7 @@ def _c_serialize_helper_fields_fixed_size(context, self, field,
                                           code_lines, temp_vars,
                                           space, prefix):
     # keep the C code a bit more readable by giving the field name
-    if not self.is_bitcase:
+    if not self.is_case_or_bitcase:
         code_lines.append('%s    /* %s.%s */' % (space, self.c_type, field.c_field_name))
     else:
         scoped_name = [p[2].c_type if idx==0 else p[0] for idx, p in enumerate(prefix)]
@@ -951,7 +962,7 @@ def _c_serialize_helper_fields_variable_size(context, self, field,
 
 def _c_serialize_helper_fields(context, self,
                                code_lines, temp_vars,
-                               space, prefix, is_bitcase):
+                               space, prefix, is_case_or_bitcase):
     count = 0
     need_padding = False
     prev_field_was_variable = False
@@ -963,7 +974,7 @@ def _c_serialize_helper_fields(context, self,
 
         # switch/bitcase: fixed size fields must be considered explicitly
         if field.type.fixed_size():
-            if self.is_bitcase or self.c_var_followed_by_fixed_fields:
+            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,
@@ -989,7 +1000,7 @@ def _c_serialize_helper_fields(context, self,
                 continue
             else:
                 # switch/bitcase: always calculate padding before and after variable sized fields
-                if need_padding or is_bitcase:
+                if need_padding or is_case_or_bitcase:
                     count += _c_serialize_helper_insert_padding(context, code_lines, space,
                                                             self.c_var_followed_by_fixed_fields)
 
@@ -1003,7 +1014,7 @@ def _c_serialize_helper_fields(context, self,
             code_lines.append('%s%s' % (space, value))
 
         if field.type.fixed_size():
-            if is_bitcase or self.c_var_followed_by_fixed_fields:
+            if is_case_or_bitcase or self.c_var_followed_by_fixed_fields:
                 # keep track of (un)serialized object's size
                 code_lines.append('%s    xcb_block_len += %s;' % (space, length))
                 if context in ('unserialize', 'unpack', 'sizeof'):
@@ -1461,7 +1472,7 @@ def _c_accessors_field(self, field):
 
     # special case: switch
     switch_obj = self if self.is_switch else None
-    if self.is_bitcase:
+    if self.is_case_or_bitcase:
         switch_obj = self.parents[-1]
     if switch_obj is not None:
         c_type = switch_obj.c_type
@@ -1529,7 +1540,7 @@ def _c_accessors_list(self, field):
     # the reason is that switch is either a child of a request/reply or nested in another switch,
     # so whenever we need to access a length field, we might need to refer to some anchestor type
     switch_obj = self if self.is_switch else None
-    if self.is_bitcase:
+    if self.is_case_or_bitcase:
         switch_obj = self.parents[-1]
     if switch_obj is not None:
         c_type = switch_obj.c_type
@@ -1561,7 +1572,7 @@ def _c_accessors_list(self, field):
         for p in parents[2:] + [self]:
             # the separator between parent and child is always '.' here,
             # because of nested switch statements
-            if not p.is_bitcase or (p.is_bitcase and p.has_name):
+            if not p.is_case_or_bitcase or (p.is_case_or_bitcase and p.has_name):
                 prefix.append((p.name[-1], '.', p))
             fields.update(_c_helper_field_mapping(p, prefix, flat=True))
 
@@ -2364,7 +2375,7 @@ def _man_request(self, name, cookie_type, void, aux):
 
             # special case: switch
             switch_obj = self if self.is_switch else None
-            if self.is_bitcase:
+            if self.is_case_or_bitcase:
                 switch_obj = self.parents[-1]
             if switch_obj is not None:
                 c_type = switch_obj.c_type
@@ -2392,7 +2403,7 @@ def _man_request(self, name, cookie_type, void, aux):
             # the reason is that switch is either a child of a request/reply or nested in another switch,
             # so whenever we need to access a length field, we might need to refer to some anchestor type
             switch_obj = self if self.is_switch else None
-            if self.is_bitcase:
+            if self.is_case_or_bitcase:
                 switch_obj = self.parents[-1]
             if switch_obj is not None:
                 c_type = switch_obj.c_type
@@ -2424,7 +2435,7 @@ def _man_request(self, name, cookie_type, void, aux):
                 for p in parents[2:] + [self]:
                     # the separator between parent and child is always '.' here,
                     # because of nested switch statements
-                    if not p.is_bitcase or (p.is_bitcase and p.has_name):
+                    if not p.is_case_or_bitcase or (p.is_case_or_bitcase and p.has_name):
                         prefix.append((p.name[-1], '.', p))
                     fields.update(_c_helper_field_mapping(p, prefix, flat=True))
 


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