Mercurial > lcfOS
annotate python/ppci/c3/codegenerator.py @ 393:6ae782a085e0
Added init program
| author | Windel Bouwman |
|---|---|
| date | Sat, 17 May 2014 21:17:40 +0200 |
| parents | 2ec730e45ea1 |
| children | 988f3fb861e4 |
| rev | line source |
|---|---|
| 255 | 1 import logging |
| 354 | 2 import struct |
| 301 | 3 from .. import ir |
| 307 | 4 from .. import irutils |
| 308 | 5 from . import astnodes as ast |
| 230 | 6 |
| 228 | 7 |
| 307 | 8 class SemanticError(Exception): |
| 308 | 9 """ Error thrown when a semantic issue is observed """ |
| 307 | 10 def __init__(self, msg, loc): |
| 308 | 11 super().__init__() |
| 307 | 12 self.msg = msg |
| 13 self.loc = loc | |
| 14 | |
| 15 | |
| 16 class CodeGenerator(irutils.Builder): | |
| 288 | 17 """ |
| 274 | 18 Generates intermediate (IR) code from a package. The entry function is |
| 19 'genModule'. The main task of this part is to rewrite complex control | |
| 20 structures, such as while and for loops into simple conditional | |
| 21 jump statements. Also complex conditional statements are simplified. | |
| 22 Such as 'and' and 'or' statements are rewritten in conditional jumps. | |
| 23 And structured datatypes are rewritten. | |
| 307 | 24 |
| 25 Type checking is done in one run with code generation. | |
| 274 | 26 """ |
| 307 | 27 def __init__(self, diag): |
| 261 | 28 self.logger = logging.getLogger('c3cgen') |
| 307 | 29 self.diag = diag |
| 261 | 30 |
| 217 | 31 def gencode(self, pkg): |
| 308 | 32 """ Generate code for a single module """ |
| 268 | 33 self.prepare() |
| 308 | 34 assert type(pkg) is ast.Package |
| 307 | 35 self.pkg = pkg |
| 36 self.intType = pkg.scope['int'] | |
| 37 self.boolType = pkg.scope['bool'] | |
| 389 | 38 self.pointerSize = 4 |
| 39 self.logger.debug('Generating ir-code for {}'.format(pkg.name), | |
| 40 extra={'c3_ast': pkg}) | |
| 288 | 41 self.varMap = {} # Maps variables to storage locations. |
| 268 | 42 self.m = ir.Module(pkg.name) |
| 307 | 43 try: |
| 389 | 44 for typ in pkg.Types: |
| 45 self.check_type(typ) | |
| 362 | 46 # Only generate function if function contains a body: |
| 389 | 47 real_functions = list(filter( |
| 48 lambda f: f.body, pkg.innerScope.Functions)) | |
| 307 | 49 for v in pkg.innerScope.Variables: |
| 364 | 50 v2 = ir.GlobalVariable(v.name) |
| 51 self.varMap[v] = v2 | |
| 363 | 52 if not v.isLocal: |
| 364 | 53 self.m.add_variable(v2) |
| 362 | 54 for s in real_functions: |
| 308 | 55 self.gen_function(s) |
| 307 | 56 except SemanticError as e: |
| 57 self.error(e.msg, e.loc) | |
| 313 | 58 if self.pkg.ok: |
| 59 return self.m | |
| 308 | 60 |
| 61 def error(self, msg, loc=None): | |
| 62 self.pkg.ok = False | |
| 63 self.diag.error(msg, loc) | |
| 307 | 64 |
| 308 | 65 def gen_function(self, fn): |
| 268 | 66 # TODO: handle arguments |
| 363 | 67 f = self.newFunction(fn.name) |
| 272 | 68 f.return_value = self.newTemp() |
| 268 | 69 self.setFunction(f) |
| 269 | 70 l2 = self.newBlock() |
| 71 self.emit(ir.Jump(l2)) | |
| 72 self.setBlock(l2) | |
| 268 | 73 # generate room for locals: |
| 174 | 74 |
| 268 | 75 for sym in fn.innerScope: |
| 389 | 76 self.check_type(sym.typ) |
| 272 | 77 if sym.isParameter: |
| 316 | 78 p = ir.Parameter(sym.name) |
| 79 variable = ir.LocalVariable(sym.name + '_copy') | |
| 80 f.addParameter(p) | |
| 81 f.addLocal(variable) | |
| 82 # Move parameter into local copy: | |
| 83 self.emit(ir.Move(ir.Mem(variable), p)) | |
| 274 | 84 elif sym.isLocal: |
| 308 | 85 variable = ir.LocalVariable(sym.name) |
| 86 f.addLocal(variable) | |
| 87 elif isinstance(sym, ast.Variable): | |
| 88 variable = ir.LocalVariable(sym.name) | |
| 89 f.addLocal(variable) | |
| 274 | 90 else: |
| 275 | 91 raise NotImplementedError('{}'.format(sym)) |
| 308 | 92 self.varMap[sym] = variable |
| 268 | 93 |
| 94 self.genCode(fn.body) | |
| 272 | 95 self.emit(ir.Move(f.return_value, ir.Const(0))) |
| 269 | 96 self.emit(ir.Jump(f.epiloog)) |
| 268 | 97 self.setFunction(None) |
| 158 | 98 |
| 217 | 99 def genCode(self, code): |
| 308 | 100 """ Wrapper around gen_stmt to catch errors """ |
| 307 | 101 try: |
| 308 | 102 self.gen_stmt(code) |
| 307 | 103 except SemanticError as e: |
| 104 self.error(e.msg, e.loc) | |
| 105 | |
| 308 | 106 def gen_stmt(self, code): |
| 107 """ Generate code for a statement """ | |
| 108 assert isinstance(code, ast.Statement) | |
| 268 | 109 self.setLoc(code.loc) |
| 308 | 110 if type(code) is ast.Compound: |
| 221 | 111 for s in code.statements: |
| 112 self.genCode(s) | |
| 308 | 113 elif type(code) is ast.Empty: |
| 306 | 114 pass |
| 308 | 115 elif type(code) is ast.Assignment: |
| 393 | 116 lval = self.gen_expr_code(code.lval) |
| 117 rval = self.gen_expr_code(code.rval) | |
| 389 | 118 if not self.equal_types(code.lval.typ, code.rval.typ): |
| 119 raise SemanticError('Cannot assign {} to {}' | |
| 120 .format(code.rval.typ, code.lval.typ), | |
| 121 code.loc) | |
| 307 | 122 if not code.lval.lvalue: |
| 389 | 123 raise SemanticError('No valid lvalue {}'.format(code.lval), |
| 124 code.lval.loc) | |
| 268 | 125 self.emit(ir.Move(lval, rval)) |
| 308 | 126 elif type(code) is ast.ExpressionStatement: |
| 393 | 127 self.emit(ir.Exp(self.gen_expr_code(code.ex))) |
| 308 | 128 elif type(code) is ast.If: |
| 268 | 129 bbtrue = self.newBlock() |
| 130 bbfalse = self.newBlock() | |
| 131 te = self.newBlock() | |
| 308 | 132 self.gen_cond_code(code.condition, bbtrue, bbfalse) |
| 268 | 133 self.setBlock(bbtrue) |
| 134 self.genCode(code.truestatement) | |
| 135 self.emit(ir.Jump(te)) | |
| 136 self.setBlock(bbfalse) | |
| 306 | 137 self.genCode(code.falsestatement) |
| 268 | 138 self.emit(ir.Jump(te)) |
| 139 self.setBlock(te) | |
| 308 | 140 elif type(code) is ast.Return: |
| 393 | 141 re = self.gen_expr_code(code.expr) |
| 303 | 142 self.emit(ir.Move(self.fn.return_value, re)) |
| 143 self.emit(ir.Jump(self.fn.epiloog)) | |
| 144 b = self.newBlock() | |
| 145 self.setBlock(b) | |
| 308 | 146 elif type(code) is ast.While: |
| 268 | 147 bbdo = self.newBlock() |
| 148 bbtest = self.newBlock() | |
| 149 te = self.newBlock() | |
| 150 self.emit(ir.Jump(bbtest)) | |
| 151 self.setBlock(bbtest) | |
| 308 | 152 self.gen_cond_code(code.condition, bbdo, te) |
| 268 | 153 self.setBlock(bbdo) |
| 228 | 154 self.genCode(code.statement) |
| 268 | 155 self.emit(ir.Jump(bbtest)) |
| 156 self.setBlock(te) | |
| 315 | 157 elif type(code) is ast.For: |
| 158 bbdo = self.newBlock() | |
| 159 bbtest = self.newBlock() | |
| 160 te = self.newBlock() | |
| 161 self.genCode(code.init) | |
| 162 self.emit(ir.Jump(bbtest)) | |
| 163 self.setBlock(bbtest) | |
| 164 self.gen_cond_code(code.condition, bbdo, te) | |
| 165 self.setBlock(bbdo) | |
| 166 self.genCode(code.statement) | |
| 360 | 167 self.genCode(code.final) |
| 315 | 168 self.emit(ir.Jump(bbtest)) |
| 169 self.setBlock(te) | |
| 393 | 170 elif type(code) is ast.Switch: |
| 171 raise NotImplementedError('Unknown stmt {}'.format(code)) | |
| 222 | 172 else: |
| 268 | 173 raise NotImplementedError('Unknown stmt {}'.format(code)) |
| 230 | 174 |
| 308 | 175 def gen_cond_code(self, expr, bbtrue, bbfalse): |
| 176 """ Generate conditional logic. | |
| 177 Implement sequential logical operators. """ | |
| 178 if type(expr) is ast.Binop: | |
| 268 | 179 if expr.op == 'or': |
| 180 l2 = self.newBlock() | |
| 308 | 181 self.gen_cond_code(expr.a, bbtrue, l2) |
| 389 | 182 if not self.equal_types(expr.a.typ, self.boolType): |
| 307 | 183 raise SemanticError('Must be boolean', expr.a.loc) |
| 268 | 184 self.setBlock(l2) |
| 308 | 185 self.gen_cond_code(expr.b, bbtrue, bbfalse) |
| 389 | 186 if not self.equal_types(expr.b.typ, self.boolType): |
| 307 | 187 raise SemanticError('Must be boolean', expr.b.loc) |
| 268 | 188 elif expr.op == 'and': |
| 189 l2 = self.newBlock() | |
| 308 | 190 self.gen_cond_code(expr.a, l2, bbfalse) |
| 389 | 191 if not self.equal_types(expr.a.typ, self.boolType): |
| 307 | 192 self.error('Must be boolean', expr.a.loc) |
| 268 | 193 self.setBlock(l2) |
| 308 | 194 self.gen_cond_code(expr.b, bbtrue, bbfalse) |
| 389 | 195 if not self.equal_types(expr.b.typ, self.boolType): |
| 307 | 196 raise SemanticError('Must be boolean', expr.b.loc) |
| 305 | 197 elif expr.op in ['==', '>', '<', '!=', '<=', '>=']: |
| 393 | 198 ta = self.gen_expr_code(expr.a) |
| 199 tb = self.gen_expr_code(expr.b) | |
| 389 | 200 if not self.equal_types(expr.a.typ, expr.b.typ): |
| 307 | 201 raise SemanticError('Types unequal {} != {}' |
| 389 | 202 .format(expr.a.typ, expr.b.typ), |
| 203 expr.loc) | |
| 268 | 204 self.emit(ir.CJump(ta, expr.op, tb, bbtrue, bbfalse)) |
| 205 else: | |
| 311 | 206 raise SemanticError('non-bool: {}'.format(expr.op), expr.loc) |
| 307 | 207 expr.typ = self.boolType |
| 308 | 208 elif type(expr) is ast.Literal: |
| 393 | 209 self.gen_expr_code(expr) |
| 288 | 210 if expr.val: |
| 268 | 211 self.emit(ir.Jump(bbtrue)) |
| 288 | 212 else: |
| 268 | 213 self.emit(ir.Jump(bbfalse)) |
| 228 | 214 else: |
| 288 | 215 raise NotImplementedError('Unknown cond {}'.format(expr)) |
| 354 | 216 |
| 217 # Check that the condition is a boolean value: | |
| 389 | 218 if not self.equal_types(expr.typ, self.boolType): |
| 307 | 219 self.error('Condition must be boolean', expr.loc) |
| 230 | 220 |
| 393 | 221 def gen_expr_code(self, expr): |
| 308 | 222 """ Generate code for an expression. Return the generated ir-value """ |
| 223 assert isinstance(expr, ast.Expression) | |
| 224 if type(expr) is ast.Binop: | |
| 307 | 225 expr.lvalue = False |
| 226 if expr.op in ['+', '-', '*', '/', '<<', '>>', '|', '&']: | |
| 393 | 227 ra = self.gen_expr_code(expr.a) |
| 228 rb = self.gen_expr_code(expr.b) | |
| 389 | 229 if self.equal_types(expr.a.typ, self.intType) and \ |
| 230 self.equal_types(expr.b.typ, self.intType): | |
| 307 | 231 expr.typ = expr.a.typ |
| 393 | 232 elif self.equal_types(expr.b.typ, self.intType) and \ |
| 233 type(expr.a.typ) is ast.PointerType: | |
| 234 # Special case for pointer arithmatic TODO: coerce! | |
| 235 expr.typ = expr.a.typ | |
| 307 | 236 else: |
| 237 raise SemanticError('Can only add integers', expr.loc) | |
| 238 else: | |
| 239 raise NotImplementedError("Cannot use equality as expressions") | |
| 268 | 240 return ir.Binop(ra, expr.op, rb) |
| 308 | 241 elif type(expr) is ast.Unop: |
| 307 | 242 if expr.op == '&': |
| 393 | 243 ra = self.gen_expr_code(expr.a) |
| 308 | 244 expr.typ = ast.PointerType(expr.a.typ) |
| 307 | 245 if not expr.a.lvalue: |
| 246 raise SemanticError('No valid lvalue', expr.a.loc) | |
| 247 expr.lvalue = False | |
| 248 assert type(ra) is ir.Mem | |
| 249 return ra.e | |
| 250 else: | |
| 251 raise NotImplementedError('Unknown unop {0}'.format(expr.op)) | |
| 308 | 252 elif type(expr) is ast.Identifier: |
| 307 | 253 # Generate code for this identifier. |
| 254 tg = self.resolveSymbol(expr) | |
| 255 expr.kind = type(tg) | |
| 256 expr.typ = tg.typ | |
| 279 | 257 # This returns the dereferenced variable. |
| 308 | 258 if isinstance(tg, ast.Variable): |
| 313 | 259 expr.lvalue = True |
| 307 | 260 return ir.Mem(self.varMap[tg]) |
| 313 | 261 elif isinstance(tg, ast.Constant): |
| 393 | 262 c_val = self.gen_expr_code(tg.value) |
| 313 | 263 return self.evalConst(c_val) |
|
280
02385f62f250
Rework from str interface to Instruction interface
Windel Bouwman
parents:
279
diff
changeset
|
264 else: |
| 308 | 265 raise NotImplementedError(str(tg)) |
| 266 elif type(expr) is ast.Deref: | |
| 222 | 267 # dereference pointer type: |
| 393 | 268 addr = self.gen_expr_code(expr.ptr) |
| 316 | 269 ptr_typ = self.the_type(expr.ptr.typ) |
| 307 | 270 expr.lvalue = True |
| 308 | 271 if type(ptr_typ) is ast.PointerType: |
| 307 | 272 expr.typ = ptr_typ.ptype |
| 273 return ir.Mem(addr) | |
| 274 else: | |
| 275 raise SemanticError('Cannot deref non-pointer', expr.loc) | |
| 308 | 276 elif type(expr) is ast.Member: |
| 393 | 277 base = self.gen_expr_code(expr.base) |
| 307 | 278 expr.lvalue = expr.base.lvalue |
| 316 | 279 basetype = self.the_type(expr.base.typ) |
| 308 | 280 if type(basetype) is ast.StructureType: |
| 307 | 281 if basetype.hasField(expr.field): |
| 282 expr.typ = basetype.fieldType(expr.field) | |
| 283 else: | |
| 284 raise SemanticError('{} does not contain field {}' | |
| 389 | 285 .format(basetype, expr.field), |
| 286 expr.loc) | |
| 307 | 287 else: |
| 308 | 288 raise SemanticError('Cannot select {} of non-structure type {}' |
| 289 .format(expr.field, basetype), expr.loc) | |
| 307 | 290 |
| 279 | 291 assert type(base) is ir.Mem, type(base) |
| 316 | 292 bt = self.the_type(expr.base.typ) |
| 268 | 293 offset = ir.Const(bt.fieldOffset(expr.field)) |
| 308 | 294 return ir.Mem(ir.Add(base.e, offset)) |
| 354 | 295 elif type(expr) is ast.Index: |
| 296 """ Array indexing """ | |
| 393 | 297 base = self.gen_expr_code(expr.base) |
| 298 idx = self.gen_expr_code(expr.i) | |
| 354 | 299 base_typ = self.the_type(expr.base.typ) |
| 300 if not isinstance(base_typ, ast.ArrayType): | |
| 389 | 301 raise SemanticError('Cannot index non-array type {}' |
| 302 .format(base_typ), | |
| 303 expr.base.loc) | |
| 354 | 304 idx_type = self.the_type(expr.i.typ) |
| 389 | 305 if not self.equal_types(idx_type, self.intType): |
| 306 raise SemanticError('Index must be int not {}' | |
| 307 .format(idx_type), expr.i.loc) | |
| 354 | 308 assert type(base) is ir.Mem |
| 309 element_type = self.the_type(base_typ.element_type) | |
| 310 element_size = self.size_of(element_type) | |
| 311 expr.typ = base_typ.element_type | |
| 312 expr.lvalue = True | |
| 313 | |
| 314 return ir.Mem(ir.Add(base.e, ir.Mul(idx, ir.Const(element_size)))) | |
| 308 | 315 elif type(expr) is ast.Literal: |
| 307 | 316 expr.lvalue = False |
| 389 | 317 typemap = {int: 'int', |
| 318 float: 'double', | |
| 319 bool: 'bool', | |
| 320 str: 'string'} | |
| 307 | 321 if type(expr.val) in typemap: |
| 322 expr.typ = self.pkg.scope[typemap[type(expr.val)]] | |
| 323 else: | |
| 389 | 324 raise SemanticError('Unknown literal type {}' |
| 325 .format(expr.val), expr.loc) | |
| 354 | 326 # Construct correct const value: |
| 327 if type(expr.val) is str: | |
| 389 | 328 cval = self.pack_string(expr.val) |
| 354 | 329 return ir.Addr(ir.Const(cval)) |
| 330 else: | |
| 331 return ir.Const(expr.val) | |
| 308 | 332 elif type(expr) is ast.TypeCast: |
| 333 return self.gen_type_cast(expr) | |
| 393 | 334 elif type(expr) is ast.Sizeof: |
| 335 # The type of this expression is int: | |
| 336 expr.typ = self.intType | |
| 337 self.check_type(expr.query_typ) | |
| 338 type_size = self.size_of(expr.query_typ) | |
| 339 return ir.Const(type_size) | |
| 308 | 340 elif type(expr) is ast.FunctionCall: |
| 341 return self.gen_function_call(expr) | |
| 225 | 342 else: |
| 259 | 343 raise NotImplementedError('Unknown expr {}'.format(expr)) |
| 307 | 344 |
| 389 | 345 def pack_string(self, txt): |
| 346 """ Pack a string using 4 bytes length followed by text data """ | |
| 347 length = struct.pack('<I', len(txt)) | |
| 348 data = txt.encode('ascii') | |
| 349 return length + data | |
| 350 | |
| 308 | 351 def gen_type_cast(self, expr): |
| 352 """ Generate code for type casting """ | |
| 393 | 353 ar = self.gen_expr_code(expr.a) |
| 316 | 354 from_type = self.the_type(expr.a.typ) |
| 355 to_type = self.the_type(expr.to_type) | |
| 389 | 356 if isinstance(from_type, ast.PointerType) and \ |
| 308 | 357 isinstance(to_type, ast.PointerType): |
| 358 expr.typ = expr.to_type | |
| 359 return ar | |
| 389 | 360 elif self.equal_types(self.intType, from_type) and \ |
| 361 isinstance(to_type, ast.PointerType): | |
| 362 expr.typ = expr.to_type | |
| 363 return ar | |
| 364 elif self.equal_types(self.intType, to_type) \ | |
| 364 | 365 and isinstance(from_type, ast.PointerType): |
| 366 expr.typ = expr.to_type | |
| 367 return ar | |
| 354 | 368 elif type(from_type) is ast.BaseType and from_type.name == 'byte' and \ |
| 369 type(to_type) is ast.BaseType and to_type.name == 'int': | |
| 370 expr.typ = expr.to_type | |
| 371 return ar | |
| 308 | 372 else: |
| 373 raise SemanticError('Cannot cast {} to {}' | |
| 374 .format(from_type, to_type), expr.loc) | |
| 353 | 375 |
| 308 | 376 def gen_function_call(self, expr): |
| 377 """ Generate code for a function call """ | |
| 378 # Evaluate the arguments: | |
| 393 | 379 args = [self.gen_expr_code(e) for e in expr.args] |
| 308 | 380 # Check arguments: |
| 381 tg = self.resolveSymbol(expr.proc) | |
| 382 if type(tg) is not ast.Function: | |
| 383 raise SemanticError('cannot call {}'.format(tg)) | |
| 384 ftyp = tg.typ | |
|
336
d1ecc493384e
Added spiffy armtoken class for bit fiddeling. Added cool test that checks for build repeatability
Windel Bouwman
parents:
334
diff
changeset
|
385 fname = tg.package.name + '_' + tg.name |
| 308 | 386 ptypes = ftyp.parametertypes |
| 387 if len(expr.args) != len(ptypes): | |
| 388 raise SemanticError('{} requires {} arguments, {} given' | |
| 389 | 389 .format(fname, len(ptypes), len(expr.args)), |
| 390 expr.loc) | |
| 308 | 391 for arg, at in zip(expr.args, ptypes): |
| 389 | 392 if not self.equal_types(arg.typ, at): |
| 308 | 393 raise SemanticError('Got {}, expected {}' |
| 389 | 394 .format(arg.typ, at), arg.loc) |
| 308 | 395 # determine return type: |
| 396 expr.typ = ftyp.returntype | |
| 397 return ir.Call(fname, args) | |
| 398 | |
| 313 | 399 def evalConst(self, c): |
| 400 if isinstance(c, ir.Const): | |
| 401 return c | |
| 402 else: | |
| 403 raise SemanticError('Cannot evaluate constant {}'.format(c)) | |
| 404 | |
| 307 | 405 def resolveSymbol(self, sym): |
| 308 | 406 if type(sym) is ast.Member: |
| 307 | 407 base = self.resolveSymbol(sym.base) |
| 308 | 408 if type(base) is not ast.Package: |
| 409 raise SemanticError('Base is not a package', sym.loc) | |
| 307 | 410 scope = base.innerScope |
| 411 name = sym.field | |
| 308 | 412 elif type(sym) is ast.Identifier: |
| 307 | 413 scope = sym.scope |
| 414 name = sym.target | |
| 415 else: | |
| 416 raise NotImplementedError(str(sym)) | |
| 417 if name in scope: | |
| 418 s = scope[name] | |
| 419 else: | |
| 420 raise SemanticError('{} undefined'.format(name), sym.loc) | |
| 308 | 421 assert isinstance(s, ast.Symbol) |
| 307 | 422 return s |
| 423 | |
| 316 | 424 def size_of(self, t): |
| 425 """ Determine the byte size of a type """ | |
| 426 t = self.the_type(t) | |
| 427 if type(t) is ast.BaseType: | |
| 428 return t.bytesize | |
| 429 elif type(t) is ast.StructureType: | |
| 430 return sum(self.size_of(mem.typ) for mem in t.mems) | |
| 354 | 431 elif type(t) is ast.ArrayType: |
| 432 return t.size * self.size_of(t.element_type) | |
| 389 | 433 elif type(t) is ast.PointerType: |
| 434 return self.pointerSize | |
| 316 | 435 else: |
| 436 raise NotImplementedError(str(t)) | |
| 437 | |
| 389 | 438 def the_type(self, t, reveil_defined=True): |
| 439 """ Recurse until a 'real' type is found | |
| 440 When reveil_defined is True, defined types are resolved to | |
| 441 their backing types. | |
| 442 """ | |
| 308 | 443 if type(t) is ast.DefinedType: |
| 389 | 444 if reveil_defined: |
| 445 t = self.the_type(t.typ) | |
| 308 | 446 elif type(t) in [ast.Identifier, ast.Member]: |
| 389 | 447 t = self.the_type(self.resolveSymbol(t), reveil_defined) |
| 308 | 448 elif isinstance(t, ast.Type): |
| 307 | 449 pass |
| 450 else: | |
| 451 raise NotImplementedError(str(t)) | |
| 308 | 452 assert isinstance(t, ast.Type) |
| 307 | 453 return t |
| 454 | |
| 389 | 455 def equal_types(self, a, b, byname=False): |
| 456 """ Compare types a and b for structural equavalence. | |
| 457 if byname is True stop on defined types. | |
| 458 """ | |
| 307 | 459 # Recurse into named types: |
| 389 | 460 a = self.the_type(a, not byname) |
| 461 b = self.the_type(b, not byname) | |
| 307 | 462 |
| 389 | 463 # Check types for sanity: |
| 464 self.check_type(a) | |
| 465 self.check_type(b) | |
| 466 | |
| 467 # Do structural equivalence check: | |
| 307 | 468 if type(a) is type(b): |
| 308 | 469 if type(a) is ast.BaseType: |
| 307 | 470 return a.name == b.name |
| 308 | 471 elif type(a) is ast.PointerType: |
| 389 | 472 # If a pointed type is detected, stop structural |
| 473 # equivalence: | |
| 474 return self.equal_types(a.ptype, b.ptype, byname=True) | |
| 308 | 475 elif type(a) is ast.StructureType: |
| 307 | 476 if len(a.mems) != len(b.mems): |
| 477 return False | |
| 389 | 478 return all(self.equal_types(am.typ, bm.typ) for am, bm in |
| 307 | 479 zip(a.mems, b.mems)) |
| 354 | 480 elif type(a) is ast.ArrayType: |
| 389 | 481 return self.equal_types(a.element_type, b.element_type) |
| 482 elif type(a) is ast.DefinedType: | |
| 483 # Try by name in case of defined types: | |
| 484 return a.name == b.name | |
| 307 | 485 else: |
| 486 raise NotImplementedError('{} not implemented'.format(type(a))) | |
| 487 return False | |
| 389 | 488 |
| 489 def check_type(self, t, first=True, byname=False): | |
| 490 """ Determine struct offsets and check for recursiveness by using | |
| 491 mark and sweep algorithm. | |
| 492 The calling function could call this function with first set | |
| 493 to clear the marks. | |
| 494 """ | |
| 495 | |
| 496 # Reset the mark and sweep: | |
| 497 if first: | |
| 498 self.got_types = set() | |
| 499 | |
| 500 # Resolve the type: | |
| 501 t = self.the_type(t, not byname) | |
| 502 | |
| 503 # Check for recursion: | |
| 504 if t in self.got_types: | |
| 505 raise SemanticError('Recursive data type {}'.format(t), None) | |
| 506 | |
| 507 if type(t) is ast.BaseType: | |
| 508 pass | |
| 509 elif type(t) is ast.PointerType: | |
| 510 # If a pointed type is detected, stop structural | |
| 511 # equivalence: | |
| 512 self.check_type(t.ptype, first=False, byname=True) | |
| 513 elif type(t) is ast.StructureType: | |
| 514 self.got_types.add(t) | |
| 515 # Setup offsets of fields. Is this the right place?: | |
| 516 offset = 0 | |
| 517 for struct_member in t.mems: | |
| 518 self.check_type(struct_member.typ, first=False) | |
| 519 struct_member.offset = offset | |
| 520 offset = offset + self.size_of(struct_member.typ) | |
| 521 elif type(t) is ast.ArrayType: | |
| 522 self.check_type(t.element_type, first=False) | |
| 523 elif type(t) is ast.DefinedType: | |
| 524 pass | |
| 525 else: | |
| 526 raise NotImplementedError('{} not implemented'.format(type(t))) |