Allow access to the original type in the XML

xcbgen 'helpfully' transforms things to C types already so that libxcb
does not have to do so. Thus, even though the XML says that a field has
type CARD8, xcbgen will claim uint8_t. This might be a bit weird, but is
so far totally fine.

However, the type mapping that xcbgen uses is not injective. All of
CARD8, BYTE and BOOL get turned into uint8_t and the original type is
lost.

This is totally fine for libxcb, but programming languages other than C
do have built in boolean types. My personal problem is with Rust, where
providing a boolean for an integer argument causes a compiler error.
This results in (relatively) ugly "0 / 1" instead of "false / true".

This commit adds a new xml_type member to SimpleType. This type contains
the original string that appeared in the XML file.

Since libxcb creates instances of SimpleType itself and to avoid
breaking the API, the new argument to SimpleType.__init__ defaults to
None.

Signed-off-by: Uli Schlachter <psychon@znc.in>

xcbgen/state.py

@@ -100,12 +100,12 @@ class Module(object):
         self.add_type('INT16', '', ('int16_t',), tint16)
         self.add_type('INT32', '', ('int32_t',), tint32)
         self.add_type('INT64', '', ('int64_t',), tint64)
-        self.add_type('BYTE', '', ('uint8_t',), tcard8)
-        self.add_type('BOOL', '', ('uint8_t',), tcard8)
+        self.add_type('BYTE', '', ('uint8_t',), tbyte)
+        self.add_type('BOOL', '', ('uint8_t',), tbool)
         self.add_type('char', '', ('char',), tchar)
         self.add_type('float', '', ('float',), tfloat)
         self.add_type('double', '', ('double',), tdouble)
-        self.add_type('void', '', ('void',), tcard8)
+        self.add_type('void', '', ('void',), tvoid)
 
     # This goes out and parses the rest of the XML
     def register(self):

xcbgen/xtypes.py

@@ -192,12 +192,12 @@ class SimpleType(PrimitiveType):
     Any type which is typedef'ed to cardinal will be one of these.
 
     Public fields added:
-    none
+    xml_type is the original string describing the type in the XML
     '''
-    def __init__(self, name, size):
+    def __init__(self, name, size, xml_type=None):
         PrimitiveType.__init__(self, name, size)
         self.is_simple = True
-
+        self.xml_type = xml_type
 
     def resolve(self, module):
         self.resolved = True
@@ -206,24 +206,27 @@ class SimpleType(PrimitiveType):
 
 
 # Cardinal datatype globals.  See module __init__ method.
-tcard8 = SimpleType(('uint8_t',), 1)
-tcard16 = SimpleType(('uint16_t',), 2)
-tcard32 = SimpleType(('uint32_t',), 4)
-tcard64 = SimpleType(('uint64_t',), 8)
-tint8 =  SimpleType(('int8_t',), 1)
-tint16 = SimpleType(('int16_t',), 2)
-tint32 = SimpleType(('int32_t',), 4)
-tint64 = SimpleType(('int64_t',), 8)
-tchar =  SimpleType(('char',), 1)
-tfloat = SimpleType(('float',), 4)
-tdouble = SimpleType(('double',), 8)
+tcard8 = SimpleType(('uint8_t',), 1, 'CARD8')
+tcard16 = SimpleType(('uint16_t',), 2, 'CARD16')
+tcard32 = SimpleType(('uint32_t',), 4, 'CARD32')
+tcard64 = SimpleType(('uint64_t',), 8, 'CARD64')
+tint8 =  SimpleType(('int8_t',), 1, 'INT8')
+tint16 = SimpleType(('int16_t',), 2, 'INT16')
+tint32 = SimpleType(('int32_t',), 4, 'INT32')
+tint64 = SimpleType(('int64_t',), 8, 'INT64')
+tchar =  SimpleType(('char',), 1, 'char')
+tfloat = SimpleType(('float',), 4, 'float')
+tdouble = SimpleType(('double',), 8, 'double')
+tbyte = SimpleType(('uint8_t',), 1, 'BYTE')
+tbool = SimpleType(('uint8_t',), 1, 'BOOL')
+tvoid = SimpleType(('uint8_t',), 1, 'void')
 
 class FileDescriptor(SimpleType):
     '''
     Derived class which represents a file descriptor.
     '''
     def __init__(self):
-        SimpleType.__init__(self, ('int'), 4)
+        SimpleType.__init__(self, ('int'), 4, 'fd')
         self.is_fd = True
 
     def fixed_size(self):
@@ -240,7 +243,7 @@ class Enum(SimpleType):
     bits contains a list of (name, bitnum) tuples.  items only appear if specified as a bit. bitnum is a number.
     '''
     def __init__(self, name, elt):
-        SimpleType.__init__(self, name, 4)
+        SimpleType.__init__(self, name, 4, 'enum')
         self.values = []
         self.bits = []
         self.doc = None