scripts/extgen.py

   1 #!/usr/bin/python
   2
   3 import sys
   4 import os
   5 import xml.dom
   6 import xml.dom.minidom
   7
   8 ### Command line processing ###
   9
  10 if len(sys.argv)<2:
  11         print """Usage:
  12   extgen.py <extension> [<core_version>] [<secondary> ...]
  13   extgen.py <extfile> [<outfile>]
  14
  15 Reads gl.xml and generates files to use <extension>.  Any promoted functions
  16 are exposed with their promoted names.  If <secondary> extensions are given,
  17 any promoted functions from those are pulled in as well.  <core_version> can
  18 be given to override the version where <extension> was promoted to core.
  19
  20 In the second form, the parameters are read from <extfile>.  If <outfile> is
  21 absent, the extension's lowercased name is used.  Anything after the last dot
  22 in <outfile> is removed and replaced with cpp and h."""
  23         sys.exit(0)
  24
  25 ext = sys.argv[1]
  26 out_base = None
  27 if ext.endswith(".glext"):
  28         fn = ext
  29         ext = None
  30         ver = None
  31         secondary = []
  32         for line in open(fn):
  33                 parts = line.split()
  34                 if parts[0]=="extension":
  35                         ext = parts[1]
  36                 elif parts[0]=="core_version":
  37                         ver = parts[1]
  38                 elif parts[0]=="secondary":
  39                         secondary.append(parts[1])
  40         if len(sys.argv)>=3:
  41                 out_base = os.path.splitext(sys.argv[2])[0]
  42 else:
  43         secondary = sys.argv[2:]
  44         ver = None
  45         if secondary and secondary[0][0].isdigit():
  46                 ver = secondary.pop(0)
  47
  48 exttype = ext.split('_')[0]
  49 backport_ext = None
  50
  51 if not out_base:
  52         out_base = ext.lower()
  53
  54 ### XML file parsing ###
  55
  56 class Function:
  57         def __init__(self, name):
  58                 self.name = name
  59                 self.typedef = None
  60                 self.version = None
  61                 self.extension = None
  62                 self.vectorequiv = None
  63                 self.aliases = []
  64                 self.extfunc = None
  65
  66 funcs = {}
  67
  68 def get_nested_elements(elem, path):
  69         if '/' in path:
  70                 head, tail = path.split('/', 1)
  71                 result = []
  72                 for e in elem.getElementsByTagName(head):
  73                         result += get_nested_elements(e, tail)
  74                 return result
  75         else:
  76                 return elem.getElementsByTagName(path)
  77
  78 def get_text_contents(node):
  79         result = ""
  80         for c in node.childNodes:
  81                 if c.nodeType==xml.dom.Node.TEXT_NODE or c.nodeType==xml.dom.Node.CDATA_SECTION_NODE:
  82                         result += c.data
  83                 else:
  84                         result += get_text_contents(c)
  85         return result
  86
  87 def parse_file(fn):
  88         doc = xml.dom.minidom.parse(fn)
  89         root = doc.documentElement
  90         commands = get_nested_elements(root, "commands/command")
  91         for cmd in commands:
  92                 name = get_text_contents(get_nested_elements(cmd, "proto/name")[0])
  93                 func = funcs.get(name)
  94                 if not func:
  95                         func = Function(name)
  96                         funcs[name] = func
  97
  98                 aliases = cmd.getElementsByTagName("alias")
  99                 for a in aliases:
 100                         func.aliases.append(a.getAttribute("name"))
 101
 102                 vec = cmd.getElementsByTagName("vecequiv")
 103                 if vec:
 104                         func.vectorequiv = vec[0].getAttribute("name")
 105
 106         features = root.getElementsByTagName("feature")
 107         for feat in features:
 108                 api = feat.getAttribute("api")
 109                 if api=="gl":
 110                         version = feat.getAttribute("number")
 111
 112                         commands = get_nested_elements(feat, "require/command")
 113                         for c in commands:
 114                                 name = c.getAttribute("name")
 115                                 func = funcs.get(name)
 116                                 if func:
 117                                         func.version = version
 118
 119                         if feat.getAttribute("name")=="MSPGL_REMOVE":
 120                                 commands = get_nested_elements(feat, "remove/command")
 121                                 for c in commands:
 122                                         name = c.getAttribute("name")
 123                                         if name in funcs:
 124                                                 del funcs[name]
 125
 126         extensions = get_nested_elements(root, "extensions/extension")
 127         for ext in extensions:
 128                 ext_name = ext.getAttribute("name")
 129                 if ext_name.startswith("GL_"):
 130                         ext_name = ext_name[3:]
 131                 supported = ext.getAttribute("supported").split('|')
 132                 if "gl" in supported:
 133                         commands = get_nested_elements(ext, "require/command")
 134                         for c in commands:
 135                                 name = c.getAttribute("name")
 136                                 func = funcs.get(name)
 137                                 if func:
 138                                         func.extension = ext_name
 139
 140 parse_file("gl.xml")
 141 parse_file("gl.fixes.xml")
 142
 143 ### Additional processing ###
 144
 145 # Create references from core functions to their extension counterparts
 146 for f in funcs.itervalues():
 147         if f.extension==ext or f.extension in secondary:
 148                 for a in f.aliases:
 149                         aliasfunc = funcs.get(a)
 150                         if aliasfunc:
 151                                 aliasfunc.extfunc = f
 152
 153 def is_relevant(f):
 154         # Unpromoted extension functions are relevant
 155         if f.extension==ext and not f.aliases:
 156                 return True
 157
 158         # Core functions promoted from the extension are also relevant
 159         if f.extfunc:
 160                 e = f.extfunc
 161                 if e.extension==ext or e.extension in secondary:
 162                         return True
 163
 164         return False
 165
 166 funcs = [f for f in funcs.itervalues() if is_relevant(f)]
 167 funcs.sort(key=(lambda f: f.name))
 168
 169 for f in funcs:
 170         if not ver:
 171                 ver = f.version
 172
 173         # Functions in backport extensions don't acquire an extension suffix
 174         if f.extension and not f.name.endswith(exttype):
 175                 backport_ext = f.extension
 176
 177         if f.extfunc:
 178                 # Typedefs for early core functions are not available in all
 179                 # implementations
 180                 f.typedef = "PFN%sPROC"%f.extfunc.name.upper()
 181         else:
 182                 f.typedef = "PFN%sPROC"%f.name.upper()
 183
 184 if ver:
 185         ver = map(int, ver.split('.'))
 186
 187 ### Output ###
 188
 189 out = file(out_base+".h", "w")
 190 out.write("#ifndef MSP_GL_%s_\n"%ext.upper())
 191 out.write("#define MSP_GL_%s_\n"%ext.upper())
 192
 193 out.write("""
 194 #include <msp/gl/extension.h>
 195 #include <msp/gl/gl.h>
 196
 197 namespace Msp {
 198 namespace GL {
 199 """)
 200
 201 if funcs:
 202         out.write("\n")
 203 for f in funcs:
 204         out.write("extern %s %s;\n"%(f.typedef, f.name))
 205
 206 out.write("\nextern Extension %s;\n"%ext)
 207
 208 out.write("""
 209 } // namespace GL
 210 } // namespace Msp
 211
 212 #endif
 213 """)
 214
 215 out = file(out_base+".cpp", "w")
 216 out.write("#include \"%s.h\"\n"%ext.lower())
 217
 218 out.write("""
 219 namespace Msp {
 220 namespace GL {
 221 """)
 222
 223 if funcs:
 224         out.write("\n")
 225 for f in funcs:
 226         out.write("%s %s = 0;\n"%(f.typedef, f.name))
 227
 228 out.write("\nExtension::SupportLevel init_%s()\n{\n"%ext.lower())
 229 if ver:
 230         out.write("\tif(is_version_at_least(%d, %d)"%tuple(ver))
 231         if backport_ext:
 232                 out.write(" || is_supported(\"GL_%s\")"%backport_ext)
 233         out.write(")\n\t{\n")
 234         for f in funcs:
 235                 out.write("\t\t%s = reinterpret_cast<%s>(get_proc_address(\"%s\"));\n"%(f.name, f.typedef, f.name))
 236         out.write("\t\treturn Extension::CORE;\n")
 237         out.write("\t}\n")
 238 if ext!=backport_ext:
 239         out.write("\tif(is_supported(\"GL_%s\"))\n\t{\n"%(ext))
 240         for f in funcs:
 241                 n = f.name
 242                 if f.extfunc:
 243                         n = f.extfunc.name
 244                 out.write("\t\t%s = reinterpret_cast<%s>(get_proc_address(\"%s\"));\n"%(f.name, f.typedef, n))
 245         out.write("\t\treturn Extension::EXTENSION;\n")
 246         out.write("\t}\n")
 247 out.write("\treturn Extension::UNSUPPORTED;\n")
 248 out.write("}\n")
 249
 250 out.write("\nExtension %s(\"GL_%s\", init_%s);\n"%(ext, ext, ext.lower()))
 251
 252 out.write("""
 253 } // namespace GL
 254 } // namespace Msp
 255 """)