Statics are always writeable. Statics are always meaningful.
Chris Pressey
4 years ago
| 50 | 50 | |
| 51 | 51 | class IncompatibleConstraintsError(ConstraintsError): |
| 52 | 52 | pass |
| 53 | ||
| 54 | ||
| 55 | def routine_has_static(routine, ref): | |
| 56 | if not hasattr(routine, 'statics'): | |
| 57 | return False | |
| 58 | return ref in [static.location for static in routine.statics] | |
| 53 | 59 | |
| 54 | 60 | |
| 55 | 61 | class Context(object): |
| 111 | 117 | def assert_meaningful(self, *refs, **kwargs): |
| 112 | 118 | exception_class = kwargs.get('exception_class', UnmeaningfulReadError) |
| 113 | 119 | for ref in refs: |
| 120 | # statics are always meaningful | |
| 121 | if routine_has_static(self.routine, ref): | |
| 122 | continue | |
| 114 | 123 | if ref.is_constant() or ref in self.routines: |
| 115 | 124 | pass |
| 116 | 125 | elif isinstance(ref, LocationRef): |
| 128 | 137 | def assert_writeable(self, *refs, **kwargs): |
| 129 | 138 | exception_class = kwargs.get('exception_class', ForbiddenWriteError) |
| 130 | 139 | for ref in refs: |
| 140 | # statics are always writeable | |
| 141 | if routine_has_static(self.routine, ref): | |
| 142 | continue | |
| 131 | 143 | if ref not in self._writeable: |
| 132 | 144 | message = '%s in %s' % (ref.name, self.routine.name) |
| 133 | 145 | if kwargs.get('message'): |
| 230 | 242 | for ref in type_.outputs: |
| 231 | 243 | context.assert_meaningful(ref, exception_class=UnmeaningfulOutputError) |
| 232 | 244 | for ref in context.each_touched(): |
| 233 | if ref not in type_.outputs and ref not in type_.trashes: | |
| 245 | if ref not in type_.outputs and ref not in type_.trashes and not routine_has_static(routine, ref): | |
| 234 | 246 | message = '%s in %s' % (ref.name, routine.name) |
| 235 | 247 | raise ForbiddenWriteError(message) |
| 236 | 248 | self.current_routine = None |
| 144 | 144 | # just to be sure. |
| 145 | 145 | equal = isinstance(other, self.__class__) and other.name == self.name |
| 146 | 146 | if equal: |
| 147 | assert other.type == self.type | |
| 147 | assert other.type == self.type, repr((self, other)) | |
| 148 | 148 | return equal |
| 149 | 149 | |
| 150 | 150 | def __hash__(self): |
| 12 | 12 | def __init__(self, ast_node, model): |
| 13 | 13 | self.ast_node = ast_node |
| 14 | 14 | self.model = model |
| 15 | ||
| 16 | def __repr__(self): | |
| 17 | return "%s(%r, %r)" % (self.__class__.__name__, self.ast_node, self.model) | |
| 15 | 18 | |
| 16 | 19 | |
| 17 | 20 | class Parser(object): |
| 220 | 223 | else: |
| 221 | 224 | statics = self.statics() |
| 222 | 225 | |
| 223 | self.current_statics = {} | |
| 224 | for defn in statics: | |
| 225 | name = defn.name | |
| 226 | if name in self.symbols or name in self.current_statics: | |
| 227 | raise SyntaxError('Symbol "%s" already declared' % name) | |
| 228 | self.current_statics[name] = SymEntry(defn, defn.location) | |
| 226 | self.current_statics = self.compose_statics_dict(statics) | |
| 229 | 227 | block = self.block() |
| 230 | 228 | self.current_statics = {} |
| 231 | 229 | |
| 235 | 233 | name=name, block=block, addr=addr, |
| 236 | 234 | location=location, statics=statics |
| 237 | 235 | ) |
| 236 | ||
| 237 | def compose_statics_dict(self, statics): | |
| 238 | c = {} | |
| 239 | for defn in statics: | |
| 240 | name = defn.name | |
| 241 | if name in self.symbols or name in self.current_statics: | |
| 242 | raise SyntaxError('Symbol "%s" already declared' % name) | |
| 243 | c[name] = SymEntry(defn, defn.location) | |
| 244 | return c | |
| 238 | 245 | |
| 239 | 246 | def labels(self): |
| 240 | 247 | accum = [] |
| 2282 | 2282 | | copy foo, vec |
| 2283 | 2283 | | } |
| 2284 | 2284 | = ok |
| 2285 | ||
| 2286 | ### static ### | |
| 2287 | ||
| 2288 | When memory locations are defined static to a routine, they cannot be | |
| 2289 | directly input, nor directly output; and since they are always initialized, | |
| 2290 | they cannot be trashed. Thus, they really don't participate in the analysis. | |
| 2291 | ||
| 2292 | | define foo routine | |
| 2293 | | inputs x | |
| 2294 | | outputs x | |
| 2295 | | trashes z, n | |
| 2296 | | static byte t : 0 | |
| 2297 | | { | |
| 2298 | | st x, t | |
| 2299 | | inc t | |
| 2300 | | ld x, t | |
| 2301 | | } | |
| 2302 | | | |
| 2303 | | define main routine | |
| 2304 | | trashes a, x, z, n | |
| 2305 | | static byte t : 0 | |
| 2306 | | { | |
| 2307 | | ld x, t | |
| 2308 | | call foo | |
| 2309 | | } | |
| 2310 | = ok |