Add Python parser C language-dependent part.

3 files changed, 1010 insertions, 11 deletions

diff --git a/configure.ac b/configure.ac
index 2fd3887..9b94392 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8,6 +8,8 @@ AC_INIT([libxcb],
 AC_CONFIG_SRCDIR([xcb.pc.in])
 AM_INIT_AUTOMAKE([foreign dist-bzip2])
 
+AM_PATH_PYTHON([2.5])
+
 PKG_CHECK_MODULES(CHECK, [check >= 0.9.4], [HAVE_CHECK=yes], [HAVE_CHECK=no])
 AM_CONDITIONAL(HAVE_CHECK, test x$HAVE_CHECK = xyes)
 
diff --git a/src/Makefile.am b/src/Makefile.am
index ae7f511..49ae77c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -263,23 +263,15 @@ noinst_HEADERS = xcbint.h
 BUILT_SOURCES = $(EXTSOURCES) $(EXTHEADERS)
 CLEANFILES = $(EXTSOURCES) $(EXTHEADERS) $(EXTENSION_XML)
 
-$(EXTHEADERS) $(EXTSOURCES): c-client.xsl
+$(EXTHEADERS) $(EXTSOURCES): c_client.py
 
 SUFFIXES = .xml
 
 .xml.h:
-	@n=`dirname $*`; test -d $$n || (echo mkdir $$n; mkdir $$n)
-	$(XSLTPROC) --stringparam mode header \
-	            --stringparam base-path $(XCBPROTO_XCBINCLUDEDIR)/ \
-	            --stringparam extension-path $(XCBPROTO_XCBINCLUDEDIR)/ \
-	            -o $@ $(srcdir)/c-client.xsl $< 
+	$(PYTHON) c_client.py $(XCBPROTO_XCBINCLUDEDIR)/$<
 
 .xml.c:
-	@n=`dirname $*`; test -d $$n || (echo mkdir $$n; mkdir $$n)
-	$(XSLTPROC) --stringparam mode source \
-	            --stringparam base-path $(XCBPROTO_XCBINCLUDEDIR)/ \
-	            --stringparam extension-path $(XCBPROTO_XCBINCLUDEDIR)/ \
-	            -o $@ $(srcdir)/c-client.xsl $< 
+	$(PYTHON) c_client.py $(XCBPROTO_XCBINCLUDEDIR)/$<
 
 $(EXTENSION_XML):
 	$(LN_S) -f $(XCBPROTO_XCBINCLUDEDIR)/$@ $@
diff --git a/src/c_client.py b/src/c_client.py
new file mode 100755
index 0000000..7bcf5e7
--- /dev/null
+++ b/src/c_client.py
@@ -0,0 +1,1005 @@
+#!/usr/bin/env python
+from xml.etree.cElementTree import *
+from sys import argv
+from os.path import basename
+import re
+
+# Jump to the bottom of this file for the main routine
+
+# Some hacks to make the API more readable, and to keep backwards compability
+_cname_re = re.compile('([A-Z0-9][a-z]+|[A-Z0-9]+(?![a-z])|[a-z]+)')
+_cname_special_cases = {'DECnet':'decnet'}
+
+_extension_special_cases = ['XPrint', 'XCMisc', 'BigRequests']
+
+_cplusplus_annoyances = {'class' : '_class',
+                         'new'   : '_new',
+                         'delete': '_delete'}
+
+_cardinal_types = ['CARD8', 'uint8_t',
+                   'CARD16','uint16_t',
+                   'CARD32','uint32_t',
+                   'INT8', 'int8_t',
+                   'INT16', 'int16_t',
+                   'INT32', 'int32_t',
+                   'BYTE',
+                   'BOOL',
+                   'char',
+                   'void',
+                   'float',
+                   'double']
+_hlines = []
+_hlevel = 0
+_clines = []
+_clevel = 0
+_ns = None
+
+def _h(fmt, *args):
+    '''
+    Writes the given line to the header file.
+    '''
+    _hlines[_hlevel].append(fmt % args)
+    
+def _c(fmt, *args):
+    '''
+    Writes the given line to the source file.
+    '''
+    _clines[_clevel].append(fmt % args)
+    
+def _hc(fmt, *args):
+    '''
+    Writes the given line to both the header and source files.
+    '''
+    _h(fmt, *args)
+    _c(fmt, *args)
+
+# XXX See if this level thing is really necessary.
+def _h_setlevel(idx):
+    '''
+    Changes the array that header lines are written to.
+    Supports writing different sections of the header file.
+    '''
+    global _hlevel
+    while len(_hlines) <= idx:
+        _hlines.append([])
+    _hlevel = idx
+    
+def _c_setlevel(idx):
+    '''
+    Changes the array that source lines are written to.
+    Supports writing to different sections of the source file.
+    '''
+    global _clevel
+    while len(_clines) <= idx:
+        _clines.append([])
+    _clevel = idx
+    
+def _n_item(str):
+    '''
+    Does C-name conversion on a single string fragment.
+    Uses a regexp with some hard-coded special cases.
+    '''
+    if str in _cname_special_cases:
+        return _cname_special_cases[str]
+    else:
+        split = _cname_re.finditer(str)
+        name_parts = [match.group(0) for match in split]
+        return '_'.join(name_parts)
+    
+def _cpp(str):
+    '''
+    Checks for certain C++ reserved words and fixes them.
+    '''
+    if str in _cplusplus_annoyances:
+        return _cplusplus_annoyances[str]
+    else:
+        return str
+
+def _ext(str):
+    '''
+    Does C-name conversion on an extension name.
+    Has some additional special cases on top of _n_item.
+    '''
+    if str in _extension_special_cases:
+        return _n_item(str).lower()
+    else:
+        return str.lower()
+    
+def _n(list):
+    '''
+    Does C-name conversion on a tuple of strings.
+    Different behavior depending on length of tuple, extension/not extension, etc.
+    Basically C-name converts the individual pieces, then joins with underscores.
+    '''
+    if len(list) == 1:
+        parts = list
+    elif len(list) == 2:
+        parts = [list[0], _n_item(list[1])]
+    elif _ns.is_ext:
+        parts = [list[0], _ext(list[1])] + [_n_item(i) for i in list[2:]]
+    else:
+        parts = [list[0]] + [_n_item(i) for i in list[1:]]
+    return '_'.join(parts).lower()
+
+def _t(list):
+    '''
+    Does C-name conversion on a tuple of strings representing a type.
+    Same as _n but adds a "_t" on the end.
+    '''
+    if len(list) == 1:
+        parts = list
+    elif len(list) == 2:
+        parts = [list[0], _n_item(list[1]), 't']
+    elif _ns.is_ext:
+        parts = [list[0], _ext(list[1])] + [_n_item(i) for i in list[2:]] + ['t']
+    else:
+        parts = [list[0]] + [_n_item(i) for i in list[1:]] + ['t']
+    return '_'.join(parts).lower()
+        
+
+def c_open(self):
+    '''
+    Exported function that handles module open.
+    Opens the files and writes out the auto-generated comment, header file includes, etc.
+    '''
+    global _ns
+    _ns = self.namespace
+    _ns.c_ext_global_name = _n(_ns.prefix + ('id',))
+
+    _h_setlevel(0)
+    _c_setlevel(0)
+
+    _hc('/*')
+    _hc(' * This file generated automatically from %s by c_client.py.', _ns.file)
+    _hc(' * Edit at your peril.')
+    _hc(' */')
+    _hc('')
+
+    _h('/**')
+    _h(' * @defgroup XCB_%s_API XCB %s API', _ns.ext_name, _ns.ext_name)
+    _h(' * @brief %s XCB Protocol Implementation.', _ns.ext_name)
+    _h(' * @{')
+    _h(' **/')
+    _h('')
+    _h('#ifndef __%s_H', _ns.header.upper())
+    _h('#define __%s_H', _ns.header.upper())
+    _h('')
+    _h('#include "xcb.h"')
+
+    _c('#include <string.h>')
+    _c('#include <assert.h>')
+    _c('#include "xcbext.h"')
+    _c('#include "%s.h"', _ns.header)
+        
+    if _ns.is_ext:
+        for (n, h) in self.imports:
+            _hc('#include "%s.h"', h)
+
+        _h('')
+        _h('#define XCB_%s_MAJOR_VERSION %s', _ns.ext_name.upper(), _ns.major_version)
+        _h('#define XCB_%s_MINOR_VERSION %s', _ns.ext_name.upper(), _ns.minor_version)
+        _h('  ') #XXX
+        _h('extern xcb_extension_t %s;', _ns.c_ext_global_name)
+
+        _c('')
+        _c('xcb_extension_t %s = { "%s" };', _ns.c_ext_global_name, _ns.ext_xname)
+
+def c_close(self):
+    '''
+    Exported function that handles module close.
+    Writes out all the stored content lines, then closes the files.
+    '''
+    _h_setlevel(2)
+    _c_setlevel(2)
+    _hc('')
+    _h('')
+    _h('#endif')
+    _h('')
+    _h('/**')
+    _h(' * @}')
+    _h(' */')
+
+    # Write header file
+    hfile = open('%s.h' % _ns.header, 'w')
+    for list in _hlines:
+        for line in list:
+            hfile.write(line)
+            hfile.write('\n')
+    hfile.close()
+
+    # Write source file
+    cfile = open('%s.c' % _ns.header, 'w')
+    for list in _clines:
+        for line in list:
+            cfile.write(line)
+            cfile.write('\n')
+    cfile.close()
+
+def c_enum(self, name):
+    '''
+    Exported function that handles enum declarations.
+    '''
+    _h_setlevel(0)
+    _h('')
+    _h('typedef enum %s {', _t(name))
+
+    count = len(self.values)
+
+    for (enam, eval) in self.values:
+        count = count - 1
+        equals = ' = ' if eval != '' else ''
+        comma = ',' if count > 0 else ''
+        _h('    %s%s%s%s', _n(name + (enam,)).upper(), equals, eval, comma)
+
+    _h('} %s;', _t(name))
+
+def _c_type_setup(self, name, postfix):
+    '''
+    Sets up all the C-related state by adding additional data fields to
+    all Field and Type objects.  Here is where we figure out most of our
+    variable and function names.
+
+    Recurses into child fields and list member types.
+    '''
+    # Do all the various names in advance
+    self.c_type = _t(name + postfix)
+    self.c_wiretype = 'char' if self.c_type == 'void' else self.c_type
+
+    self.c_iterator_type = _t(name + ('iterator',))
+    self.c_next_name = _n(name + ('next',))
+    self.c_end_name = _n(name + ('end',))
+
+    self.c_request_name = _n(name)
+    self.c_checked_name = _n(name + ('checked',))
+    self.c_unchecked_name = _n(name + ('unchecked',))
+    self.c_reply_name = _n(name + ('reply',))
+    self.c_reply_type = _t(name + ('reply',))
+    self.c_cookie_type = _t(name + ('cookie',))
+
+    if self.is_container:
+
+        self.c_container = 'union' if self.is_union else 'struct'
+        prev_varsized_field = None
+        prev_varsized_offset = 0
+        first_field_after_varsized = None
+
+        for field in self.fields:
+            _c_type_setup(field.type, field.field_type, ())
+            if field.type.is_list:
+                _c_type_setup(field.type.member, field.field_type, ())
+
+            field.c_field_type = _t(field.field_type)
+            field.c_field_const_type = ('' if field.type.nmemb == 1 else 'const ') + field.c_field_type
+            field.c_field_name = _cpp(field.field_name)
+            field.c_subscript = '[%d]' % field.type.nmemb if (field.type.nmemb > 1) else ''
+            field.c_pointer = ' ' if field.type.nmemb == 1 else '*'
+
+            field.c_iterator_type = _t(field.field_type + ('iterator',))      # xcb_fieldtype_iterator_t
+            field.c_iterator_name = _n(name + (field.field_name, 'iterator')) # xcb_container_field_iterator
+            field.c_accessor_name = _n(name + (field.field_name,))            # xcb_container_field
+            field.c_length_name = _n(name + (field.field_name, 'length'))     # xcb_container_field_length
+            field.c_end_name = _n(name + (field.field_name, 'end'))           # xcb_container_field_end
+
+            field.prev_varsized_field = prev_varsized_field
+            field.prev_varsized_offset = prev_varsized_offset
+
+            if prev_varsized_offset == 0:
+                first_field_after_varsized = field
+            field.first_field_after_varsized = first_field_after_varsized
+
+            if field.type.fixed_size():
+                prev_varsized_offset += field.type.size
+            else:
+                self.last_varsized_field = field
+                prev_varsized_field = field
+                prev_varsized_offset = 0
+
+def _c_iterator_get_end(field, accum):
+    '''
+    Figures out what C code is needed to find the end of a variable-length structure field.
+    For nested structures, recurses into its last variable-sized field.
+    For lists, calls the end function
+    '''
+    if field.type.is_container:
+        accum = field.c_accessor_name + '(' + accum + ')'
+        # XXX there could be fixed-length fields at the end
+        return _c_iterator_get_end(field.type.last_varsized_field, accum)
+    if field.type.is_list:
+        # XXX we can always use the first way
+        if field.type.c_type in _cardinal_types:
+            return field.c_end_name + '(' + accum + ')'
+        else:
+            return field.type.member.c_end_name + '(' + field.c_iterator_name + '(' + accum + '))'
+
+def _c_iterator(self, name):
+    '''
+    Declares the iterator structure and next/end functions for a given type.
+    '''
+    _h_setlevel(0)
+    _h('')
+    _h('/**')
+    _h(' * @brief %s', self.c_iterator_type)
+    _h(' **/')
+    _h('typedef struct %s {', self.c_iterator_type)
+    _h('    %s *data; /**<  */', self.c_type)
+    _h('    int%s rem; /**<  */', ' ' * (len(self.c_type) - 2))
+    _h('    int%s index; /**<  */', ' ' * (len(self.c_type) - 2))
+    _h('} %s;', self.c_iterator_type)
+
+    _h_setlevel(1)
+    _c_setlevel(1)
+    _h('')
+    _h('/**')
+    _h(' * Get the next element of the iterator')
+    _h(' * @param i Pointer to a %s', self.c_iterator_type)
+    _h(' *')
+    _h(' * Get the next element in the iterator. The member rem is')
+    _h(' * decreased by one. The member data points to the next')
+    _h(' * element. The member index is increased by sizeof(%s)', self.c_type)
+    _h(' */')
+    _c('')
+    _hc('')
+    _hc('/*****************************************************************************')
+    _hc(' **')
+    _hc(' ** void %s', self.c_next_name)
+    _hc(' ** ')
+    _hc(' ** @param %s *i', self.c_iterator_type)
+    _hc(' ** @returns void')
+    _hc(' **')
+    _hc(' *****************************************************************************/')
+    _hc(' ')
+    _hc('void')
+    _h('%s (%s *i  /**< */);', self.c_next_name, self.c_iterator_type)
+    _c('%s (%s *i  /**< */)', self.c_next_name, self.c_iterator_type)
+    _c('{')
+
+    if not self.fixed_size():
+        _c('    %s *R = i->data;', self.c_type)
+        _c('    xcb_generic_iterator_t child = %s;', _c_iterator_get_end(self.last_varsized_field, 'R'))
+        _c('    --i->rem;')
+        _c('    i->data = (%s *) child.data;', self.c_type)
+        _c('    i->index = child.index;')
+    else:
+        _c('    --i->rem;')
+        _c('    ++i->data;')
+        _c('    i->index += sizeof(%s);', self.c_type)
+
+    _c('}')
+
+    _h('')
+    _h('/**')
+    _h(' * Return the iterator pointing to the last element')
+    _h(' * @param i An %s', self.c_iterator_type)
+    _h(' * @return  The iterator pointing to the last element')
+    _h(' *')
+    _h(' * Set the current element in the iterator to the last element.')
+    _h(' * The member rem is set to 0. The member data points to the')
+    _h(' * last element.')
+    _h(' */')
+    _c('')
+    _hc('')
+    _hc('/*****************************************************************************')
+    _hc(' **')
+    _hc(' ** xcb_generic_iterator_t %s', self.c_end_name)
+    _hc(' ** ')
+    _hc(' ** @param %s i', self.c_iterator_type)
+    _hc(' ** @returns xcb_generic_iterator_t')
+    _hc(' **')
+    _hc(' *****************************************************************************/')
+    _hc(' ')
+    _hc('xcb_generic_iterator_t')
+    _h('%s (%s i  /**< */);', self.c_end_name, self.c_iterator_type)
+    _c('%s (%s i  /**< */)', self.c_end_name, self.c_iterator_type)
+    _c('{')
+    _c('    xcb_generic_iterator_t ret;')
+
+    if self.fixed_size():
+        _c('    ret.data = i.data + i.rem;')
+        _c('    ret.index = i.index + ((char *) ret.data - (char *) i.data);')
+        _c('    ret.rem = 0;')
+    else:
+        _c('    while(i.rem > 0)')
+        _c('        %s(&i);', self.c_next_name)
+        _c('    ret.data = i.data;')
+        _c('    ret.rem = i.rem;')
+        _c('    ret.index = i.index;')
+
+    _c('    return ret;')
+    _c('}')
+
+def _c_accessor_get_length(expr, prefix=''):
+    '''
+    Figures out what C code is needed to get a length field.
+    For fields that follow a variable-length field, use the accessor.
+    Otherwise, just reference the structure field directly.
+    '''
+    prefarrow = '' if prefix == '' else prefix + '->'
+
+    if expr.lenfield != None and expr.lenfield.prev_varsized_field != None:
+        return expr.lenfield.c_accessor_name + '(' + prefix + ')'
+    elif expr.lenfield_name != None:
+        return prefarrow + expr.lenfield_name
+    else:
+        return str(expr.nmemb)
+
+def _c_accessor_get_expr(expr, prefix=''):
+    '''
+    Figures out what C code is needed to get the length of a list field.
+    Recurses for math operations.
+    Returns bitcount for value-mask fields.
+    Otherwise, uses the value of the length field.
+    '''
+    lenexp = _c_accessor_get_length(expr, prefix)
+
+    if expr.op != None:
+        return '(' + _c_accessor_get_expr(expr.lhs, prefix) + ' ' + expr.op + ' ' + _c_accessor_get_expr(expr.rhs, prefix) + ')'
+    elif expr.bitfield:
+        return 'xcb_popcount(' + lenexp + ')'
+    else:
+        return lenexp
+
+def _c_accessors_field(self, field):
+    '''
+    Declares the accessor functions for a non-list field that follows a variable-length field.
+    '''
+    if field.field_type[0] in _cardinal_types:
+        _hc('')
+        _hc('')
+        _hc('/*****************************************************************************')
+        _hc(' **')
+        _hc(' ** %s %s', field.c_field_type, field.c_accessor_name)
+        _hc(' ** ')
+        _hc(' ** @param const %s *R', self.c_type)
+        _hc(' ** @returns %s', field.c_field_type)
+        _hc(' **')
+        _hc(' *****************************************************************************/')
+        _hc(' ')
+        _hc('%s', field.c_field_type)
+        _h('%s (const %s *R  /**< */);', field.c_accessor_name, self.c_type)
+        _c('%s (const %s *R  /**< */)', field.c_accessor_name, self.c_type)
+        _c('{')
+        _c('    xcb_generic_iterator_t prev = %s;', _c_iterator_get_end(field.prev_varsized_field, 'R'))
+        _c('    return * (%s *) ((char *) prev.data + XCB_TYPE_PAD(%s, prev.index) + %d);', field.c_field_type, field.first_field_after_varsized.type.c_type, field.prev_varsized_offset)
+        _c('}')
+    else:
+        _hc('')
+        _hc('')
+        _hc('/*****************************************************************************')
+        _hc(' **')
+        _hc(' ** %s * %s', field.c_field_type, field.c_accessor_name)
+        _hc(' ** ')
+        _hc(' ** @param const %s *R', self.c_type)
+        _hc(' ** @returns %s *', field.c_field_type)
+        _hc(' **')
+        _hc(' *****************************************************************************/')
+        _hc(' ')
+        _hc('%s *', field.c_field_type)
+        _h('%s (const %s *R  /**< */);', field.c_accessor_name, self.c_type)
+        _c('%s (const %s *R  /**< */)', field.c_accessor_name, self.c_type)
+        _c('{')
+        _c('    xcb_generic_iterator_t prev = %s;', _c_iterator_get_end(field.prev_varsized_field, 'R'))
+        _c('    return (%s *) ((char *) prev.data + XCB_TYPE_PAD(%s, prev.index) + %d);', field.c_field_type, field.first_field_after_varsized.type.c_type, field.prev_varsized_offset)
+        _c('}')
+    
+def _c_accessors_list(self, field):
+    '''
+    Declares the accessor functions for a list field.
+    Declares a direct-accessor function only if the list members are fixed size.
+    Declares length and get-iterator functions always.
+    '''
+    list = field.type
+
+    _h_setlevel(1)
+    _c_setlevel(1)
+    if list.member.fixed_size():
+        _hc('')
+        _hc('')
+        _hc('/*****************************************************************************')
+        _hc(' **')
+        _hc(' ** %s * %s', field.c_field_type, field.c_accessor_name)
+        _hc(' ** ')
+        _hc(' ** @param const %s *R', self.c_type)
+        _hc(' ** @returns %s *', field.c_field_type)
+        _hc(' **')
+        _hc(' *****************************************************************************/')
+        _hc(' ')
+        _hc('%s *', field.c_field_type)
+        _h('%s (const %s *R  /**< */);', field.c_accessor_name, self.c_type)
+        _c('%s (const %s *R  /**< */)', field.c_accessor_name, self.c_type)
+        _c('{')
+
+        if field.prev_varsized_field == None:
+            _c('    return (%s *) (R + 1);', field.c_field_type)
+        else:
+            _c('    xcb_generic_iterator_t prev = %s;', _c_iterator_get_end(field.prev_varsized_field, 'R'))
+            _c('    return (%s *) ((char *) prev.data + XCB_TYPE_PAD(%s, prev.index) + %d);', field.c_field_type, field.first_field_after_varsized.type.c_type, field.prev_varsized_offset)
+
+        _c('}')
+
+    _hc('')
+    _hc('')
+    _hc('/*****************************************************************************')
+    _hc(' **')
+    _hc(' ** int %s', field.c_length_name)
+    _hc(' ** ')
+    _hc(' ** @param const %s *R', self.c_type)
+    _hc(' ** @returns int')
+    _hc(' **')
+    _hc(' *****************************************************************************/')
+    _hc(' ')
+    _hc('int')
+    _h('%s (const %s *R  /**< */);', field.c_length_name, self.c_type)
+    _c('%s (const %s *R  /**< */)', field.c_length_name, self.c_type)
+    _c('{')
+    _c('    return %s;', _c_accessor_get_expr(field.type.expr, 'R'))
+    _c('}')
+
+    if field.field_type[0] in _cardinal_types:
+        _hc('')
+        _hc('')
+        _hc('/*****************************************************************************')
+        _hc(' **')
+        _hc(' ** xcb_generic_iterator_t %s', field.c_end_name)
+        _hc(' ** ')
+        _hc(' ** @param const %s *R', self.c_type)
+        _hc(' ** @returns xcb_generic_iterator_t')
+        _hc(' **')
+        _hc(' *****************************************************************************/')
+        _hc(' ')
+        _hc('xcb_generic_iterator_t')
+        _h('%s (const %s *R  /**< */);', field.c_end_name, self.c_type)
+        _c('%s (const %s *R  /**< */)', field.c_end_name, self.c_type)
+        _c('{')
+        _c('    xcb_generic_iterator_t i;')
+
+        if field.prev_varsized_field == None:
+            _c('    i.data = ((%s *) (R + 1)) + (%s);', field.type.c_wiretype, _c_accessor_get_expr(field.type.expr, 'R'))
+        else:
+            _c('    xcb_generic_iterator_t child = %s;', _c_iterator_get_end(field.prev_varsized_field, 'R'))
+            _c('    i.data = ((%s *) child.data) + (%s);', field.type.c_wiretype, _c_accessor_get_expr(field.type.expr, 'R'))
+
+        _c('    i.rem = 0;')
+        _c('    i.index = (char *) i.data - (char *) R;')
+        _c('    return i;')
+        _c('}')
+
+    else:
+        _hc('')
+        _hc('')
+        _hc('/*****************************************************************************')
+        _hc(' **')
+        _hc(' ** %s %s', field.c_iterator_type, field.c_iterator_name)
+        _hc(' ** ')
+        _hc(' ** @param const %s *R', self.c_type)
+        _hc(' ** @returns %s', field.c_iterator_type)
+        _hc(' **')
+        _hc(' *****************************************************************************/')
+        _hc(' ')
+        _hc('%s', field.c_iterator_type)
+        _h('%s (const %s *R  /**< */);', field.c_iterator_name, self.c_type)
+        _c('%s (const %s *R  /**< */)', field.c_iterator_name, self.c_type)
+        _c('{')
+        _c('    %s i;', field.c_iterator_type)
+
+        if field.prev_varsized_field == None:
+            _c('    i.data = (%s *) (R + 1);', field.c_field_type)
+        else:
+            _c('    xcb_generic_iterator_t prev = %s;', _c_iterator_get_end(field.prev_varsized_field, 'R'))
+            _c('    i.data = (%s *) ((char *) prev.data + XCB_TYPE_PAD(%s, prev.index));', field.c_field_type, field.c_field_type)
+
+        _c('    i.rem = %s;', _c_accessor_get_expr(field.type.expr, 'R'))
+        _c('    i.index = (char *) i.data - (char *) R;')
+        _c('    return i;')
+        _c('}')
+
+def _c_accessors(self, name, base):
+    '''
+    Declares the accessor functions for the fields of a structure.
+    '''
+    for field in self.fields:
+        if field.type.is_list and not field.type.fixed_size():
+            _c_accessors_list(self, field)
+        elif field.prev_varsized_field != None:
+            _c_accessors_field(self, field)
+
+def c_simple(self, name):
+    '''
+    Exported function that handles cardinal type declarations.
+    These are types which are typedef'd to one of the CARDx's, char, float, etc.
+    '''
+    _c_type_setup(self, name, ())
+
+    if (self.name != name):
+        # Typedef
+        _h_setlevel(0)
+        my_name = _t(name)
+        _h('')
+        _h('typedef %s %s;', _t(self.name), my_name)
+
+        # Iterator
+        _c_iterator(self, name)
+
+def _c_complex(self):
+    '''
+    Helper function for handling all structure types.
+    Called for all structs, requests, replies, events, errors.
+    '''
+    _h_setlevel(0)
+    _h('')
+    _h('/**')
+    _h(' * @brief %s', self.c_type)
+    _h(' **/')
+    _h('typedef %s %s {', self.c_container, self.c_type)
+
+    struct_fields = []
+    maxtypelen = 0
+
+    for field in self.fields:
+        if not field.type.fixed_size():
+            break
+        if field.wire:
+            struct_fields.append(field)
+        
+    for field in struct_fields:
+        if len(field.c_field_type) > maxtypelen:
+            maxtypelen = len(field.c_field_type)
+
+    for field in struct_fields:
+        spacing = ' ' * (maxtypelen - len(field.c_field_type))
+        _h('    %s%s %s%s; /**<  */', field.c_field_type, spacing, field.c_field_name, field.c_subscript)
+
+    _h('} %s;', self.c_type)
+
+def c_struct(self, name):
+    '''
+    Exported function that handles structure declarations.
+    '''
+    _c_type_setup(self, name, ())
+    _c_complex(self)
+    _c_accessors(self, name, name)
+    _c_iterator(self, name)
+
+def c_union(self, name):
+    '''
+    Exported function that handles union declarations.
+    '''
+    _c_type_setup(self, name, ())
+    _c_complex(self)
+    _c_iterator(self, name)
+
+def _c_request_helper(self, name, cookie_type, void, regular):
+    '''
+    Declares a request function.
+    '''
+
+    # Four stunningly confusing possibilities here:
+    #
+    #   Void            Non-void
+    # ------------------------------
+    # "req"            "req"
+    # 0 flag           CHECKED flag   Normal Mode
+    # void_cookie      req_cookie
+    # ------------------------------
+    # "req_checked"    "req_unchecked"
+    # CHECKED flag     0 flag         Abnormal Mode
+    # void_cookie      req_cookie
+    # ------------------------------
+
+
+    # Whether we are _checked or _unchecked
+    checked = void and not regular
+    unchecked = not void and not regular
+
+    # What kind of cookie we return
+    func_cookie = 'xcb_void_cookie_t' if void else self.c_cookie_type
+
+    # What flag is passed to xcb_request
+    func_flags = '0' if (void and regular) or (not void and not regular) else 'XCB_REQUEST_CHECKED'
+
+    # Global extension id variable or NULL for xproto
+    func_ext_global = '&' + _ns.c_ext_global_name if _ns.is_ext else '0'
+
+    # What our function name is
+    func_name = self.c_request_name
+    if checked:
+        func_name = self.c_checked_name
+    if unchecked:
+        func_name = self.c_unchecked_name
+
+    param_fields = []
+    wire_fields = []
+    maxtypelen = len('xcb_connection_t')
+
+    for field in self.fields:
+        if field.visible:
+            # The field should appear as a call parameter
+            param_fields.append(field)
+        if field.wire and not field.auto:
+            # We need to set the field up in the structure
+            wire_fields.append(field)
+        
+    for field in param_fields:
+        if len(field.c_field_const_type) > maxtypelen:
+            maxtypelen = len(field.c_field_const_type)
+
+    _h_setlevel(1)
+    _c_setlevel(1)
+    _h('')
+    _h('/**')
+    _h(' * Delivers a request to the X server')
+    _h(' * @param c The connection')
+    _h(' * @return A cookie')
+    _h(' *')
+    _h(' * Delivers a request to the X server.')
+    _h(' * ')
+    if checked:
+        _h(' * This form can be used only if the request will not cause')
+        _h(' * a reply to be generated. Any returned error will be')
+        _h(' * saved for handling by xcb_request_check().')
+    if unchecked:
+        _h(' * This form can be used only if the request will cause')
+        _h(' * a reply to be generated. Any returned error will be')
+        _h(' * placed in the event queue.')
+    _h(' */')
+    _c('')
+    _hc('')
+    _hc('/*****************************************************************************')
+    _hc(' **')
+    _hc(' ** %s %s', cookie_type, func_name)
+    _hc(' ** ')
+
+    spacing = ' ' * (maxtypelen - len('xcb_connection_t'))
+    _hc(' ** @param xcb_connection_t%s *c', spacing)
+
+    for field in param_fields:
+        spacing = ' ' * (maxtypelen - len(field.c_field_const_type))
+        _hc(' ** @param %s%s %s%s', field.c_field_const_type, spacing, field.c_pointer, field.c_field_name)
+
+    _hc(' ** @returns %s', cookie_type)
+    _hc(' **')
+    _hc(' *****************************************************************************/')
+    _hc(' ')
+    _hc('%s', cookie_type)
+
+    spacing = ' ' * (maxtypelen - len('xcb_connection_t'))
+    comma = ',' if len(param_fields) else ');'
+    _h('%s (xcb_connection_t%s *c  /**< */%s', func_name, spacing, comma)
+    comma = ',' if len(param_fields) else ')'
+    _c('%s (xcb_connection_t%s *c  /**< */%s', func_name, spacing, comma)
+
+    func_spacing = ' ' * (len(func_name) + 2)
+    count = len(param_fields)
+    for field in param_fields:
+        count = count - 1
+        spacing = ' ' * (maxtypelen - len(field.c_field_const_type))
+        comma = ',' if count else ');'
+        _h('%s%s%s %s%s  /**< */%s', func_spacing, field.c_field_const_type, spacing, field.c_pointer, field.c_field_name, comma)
+        comma = ',' if count else ')'
+        _c('%s%s%s %s%s  /**< */%s', func_spacing, field.c_field_const_type, spacing, field.c_pointer, field.c_field_name, comma)
+
+    count = 2
+    for field in param_fields:
+        if not field.type.fixed_size():
+            count = count + 2
+
+    _c('{')
+    _c('    static const xcb_protocol_request_t xcb_req = {')
+    _c('        /* count */ %d,', count)
+    _c('        /* ext */ %s,', func_ext_global)
+    _c('        /* opcode */ %s,', self.c_request_name.upper())
+    _c('        /* isvoid */ %d', 1 if void else 0)
+    _c('    };')
+    _c('    ')
+    _c('    struct iovec xcb_parts[%d];', count + 2)
+    _c('    %s xcb_ret;', func_cookie)
+    _c('    %s xcb_out;', self.c_type)
+    _c('    ')
+
+    for field in wire_fields:
+        if field.type.fixed_size():
+            if field.type.is_expr:
+                _c('    xcb_out.%s = %s;', field.c_field_name, _c_accessor_get_expr(field.type.expr))
+
+            elif field.type.is_pad:
+                if field.type.nmemb == 1:
+                    _c('    xcb_out.%s = 0;', field.c_field_name)
+                else:
+                    _c('    memset(xcb_out.%s, 0, %d);', field.c_field_name, field.type.nmemb)
+            else:
+                if field.type.nmemb == 1:
+                    _c('    xcb_out.%s = %s;', field.c_field_name, field.c_field_name)
+                else:
+                    _c('    memcpy(xcb_out.%s, %s, %d);', field.c_field_name, field.c_field_name, field.type.nmemb)
+
+    _c('    ')
+    _c('    xcb_parts[2].iov_base = (char *) &xcb_out;')
+    _c('    xcb_parts[2].iov_len = sizeof(xcb_out);')
+    _c('    xcb_parts[3].iov_base = 0;')
+    _c('    xcb_parts[3].iov_len = -xcb_parts[2].iov_len & 3;')
+
+    count = 4
+    for field in param_fields:
+        if not field.type.fixed_size():
+            _c('    xcb_parts[%d].iov_base = (char *) %s;', count, field.c_field_name)
+            if field.type.is_list:
+                _c('    xcb_parts[%d].iov_len = %s * sizeof(%s);', count, _c_accessor_get_expr(field.type.expr), field.type.member.c_wiretype)
+            else:
+                _c('    xcb_parts[%d].iov_len = %s * sizeof(%s);', count, 'Uh oh', field.type.c_wiretype)
+            _c('    xcb_parts[%d].iov_base = 0;', count + 1)
+            _c('    xcb_parts[%d].iov_len = -xcb_parts[%d].iov_len & 3;', count + 1, count)
+            count = count + 2
+
+    _c('    xcb_ret.sequence = xcb_send_request(c, %s, xcb_parts + 2, &xcb_req);', func_flags)
+    _c('    return xcb_ret;')
+    _c('}')
+
+def _c_reply(self, name):
+    '''
+    Declares the function that returns the reply structure.
+    '''
+    spacing1 = ' ' * (len(self.c_cookie_type) - len('xcb_connection_t'))
+    spacing2 = ' ' * (len(self.c_cookie_type) - len('xcb_generic_error_t'))
+    spacing3 = ' ' * (len(self.c_reply_name) + 2)
+
+    _h('')
+    _h('/**')
+    _h(' * Return the reply')
+    _h(' * @param c      The connection')
+    _h(' * @param cookie The cookie')
+    _h(' * @param e      The xcb_generic_error_t supplied')
+    _h(' *')
+    _h(' * Returns the reply of the request asked by')
+    _h(' * ')
+    _h(' * The parameter @p e supplied to this function must be NULL if')
+    _h(' * %s(). is used.', self.c_unchecked_name)
+    _h(' * Otherwise, it stores the error if any.')
+    _h(' *')
+    _h(' * The returned value must be freed by the caller using free().')
+    _h(' */')
+    _c('')
+    _hc('')
+    _hc('/*****************************************************************************')
+    _hc(' **')
+    _hc(' ** %s * %s', self.c_reply_type, self.c_reply_name)
+    _hc(' ** ')
+    _hc(' ** @param xcb_connection_t%s  *c', spacing1)
+    _hc(' ** @param %s   cookie', self.c_cookie_type)
+    _hc(' ** @param xcb_generic_error_t%s **e', spacing2)
+    _hc(' ** @returns %s *', self.c_reply_type)
+    _hc(' **')
+    _hc(' *****************************************************************************/')
+    _hc(' ')
+    _hc('%s *', self.c_reply_type)
+    _hc('%s (xcb_connection_t%s  *c  /**< */,', self.c_reply_name, spacing1)
+    _hc('%s%s   cookie  /**< */,', spacing3, self.c_cookie_type)
+    _h('%sxcb_generic_error_t%s **e  /**< */);', spacing3, spacing2)
+    _c('%sxcb_generic_error_t%s **e  /**< */)', spacing3, spacing2)
+    _c('{')
+    _c('    return (%s *) xcb_wait_for_reply(c, cookie.sequence, e);', self.c_reply_type)
+    _c('}')
+
+def _c_opcode(name, opcode):
+    '''
+    Declares the opcode define for requests, events, and errors.
+    '''
+    _h_setlevel(0)
+    _h('')
+    _h('/** Opcode for %s. */', _n(name))
+    _h('#define %s %s', _n(name).upper(), opcode)
+    
+def _c_cookie(self, name):
+    '''
+    Declares the cookie type for a non-void request.
+    '''
+    _h_setlevel(0)
+    _h('')
+    _h('/**')
+    _h(' * @brief %s', self.c_cookie_type)
+    _h(' **/')
+    _h('typedef struct %s {', self.c_cookie_type)
+    _h('    unsigned int sequence; /**<  */')
+    _h('} %s;', self.c_cookie_type)
+
+def c_request(self, name):
+    '''
+    Exported function that handles request declarations.
+    '''
+    _c_type_setup(self, name, ('request',))
+
+    if self.reply:
+        # Cookie type declaration
+        _c_cookie(self, name)
+
+    # Opcode define
+    _c_opcode(name, self.opcode)
+
+    # Request structure declaration
+    _c_complex(self)
+
+    if self.reply:
+        _c_type_setup(self.reply, name, ('reply',))
+        # Reply structure definition
+        _c_complex(self.reply)
+        # Request prototypes
+        _c_request_helper(self, name, self.c_cookie_type, False, True)
+        _c_request_helper(self, name, self.c_cookie_type, False, False)
+        # Reply accessors
+        _c_accessors(self.reply, name + ('reply',), name)
+        _c_reply(self, name)
+    else:
+        # Request prototypes
+        _c_request_helper(self, name, 'xcb_void_cookie_t', True, False)
+        _c_request_helper(self, name, 'xcb_void_cookie_t', True, True)
+
+def c_event(self, name):
+    '''
+    Exported function that handles event declarations.
+    '''
+    _c_type_setup(self, name, ('event',))
+
+    # Opcode define
+    _c_opcode(name, self.opcodes[name])
+
+    if self.name == name:
+        # Structure definition
+        _c_complex(self)
+    else:
+        # Typedef
+        _h('')
+        _h('typedef %s %s;', _t(self.name + ('event',)), _t(name + ('event',)))
+
+def c_error(self, name):
+    '''
+    Exported function that handles error declarations.
+    '''
+    _c_type_setup(self, name, ('error',))
+
+    # Opcode define
+    _c_opcode(name, self.opcodes[name])
+
+    if self.name == name:
+        # Structure definition
+        _c_complex(self)
+    else:
+        # Typedef
+        _h('')
+        _h('typedef %s %s;', _t(self.name + ('error',)), _t(name + ('error',)))
+
+
+# Main routine starts here
+
+# Must create an "output" dictionary before any xcbgen imports.
+output = {'open'    : c_open,
+          'close'   : c_close,
+          'simple'  : c_simple,
+          'enum'    : c_enum,
+          'struct'  : c_struct,
+          'union'   : c_union,
+          'request' : c_request,
+          'event'   : c_event,
+          'error'   : c_error
+          }
+
+# Boilerplate below this point
+
+# Import the module class
+try:
+    from xcbgen.state import Module
+except ImportError:
+    print ''
+    print 'Failed to load the xcbgen Python package!'
+    print 'Make sure that xcb/proto installed it on your Python path.'
+    print 'If not, you will need to create a .pth file to extend the path.'
+    print 'Refer to the README file in xcb/proto for more info.'
+    print ''
+    raise
+
+# Parse the xml header
+module = Module(argv[1], output)
+
+# Build type-registry and resolve type dependencies
+module.register()
+module.resolve()
+
+# Output the code
+module.generate()