1 #!/usr/bin/env python 2 3 """ 4 Encoder functions, producing representations of program objects. 5 6 Copyright (C) 2016 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from common import first 23 24 # Output encoding and decoding for the summary files. 25 26 def encode_attrnames(attrnames): 27 28 "Encode the 'attrnames' representing usage." 29 30 return ", ".join(attrnames) or "{}" 31 32 def encode_constrained(constrained): 33 34 "Encode the 'constrained' status for program summaries." 35 36 return constrained and "constrained" or "deduced" 37 38 def encode_usage(usage): 39 40 "Encode attribute details from 'usage'." 41 42 all_attrnames = [] 43 for t in usage: 44 attrname, invocation, assignment = t 45 all_attrnames.append("%s%s" % (attrname, invocation and "!" or assignment and "=" or "")) 46 return ", ".join(all_attrnames) or "{}" 47 48 def decode_usage(s): 49 50 "Decode attribute details from 's'." 51 52 all_attrnames = set() 53 for attrname_str in s.split(", "): 54 all_attrnames.add((attrname_str.rstrip("!="), attrname_str.endswith("!"), attrname_str.endswith("="))) 55 56 all_attrnames = list(all_attrnames) 57 all_attrnames.sort() 58 return tuple(all_attrnames) 59 60 def encode_access_location(t): 61 62 "Encode the access location 't'." 63 64 path, name, attrname, version = t 65 return "%s %s %s:%d" % (path, name or "{}", attrname, version) 66 67 def encode_location(t): 68 69 "Encode the general location 't' in a concise form." 70 71 path, name, attrname, version = t 72 if name is not None and version is not None: 73 return "%s %s:%d" % (path, name, version) 74 elif name is not None: 75 return "%s %s" % (path, name) 76 else: 77 return "%s :%s" % (path, attrname) 78 79 def encode_modifiers(modifiers): 80 81 "Encode assignment details from 'modifiers'." 82 83 all_modifiers = [] 84 for t in modifiers: 85 all_modifiers.append(encode_modifier_term(t)) 86 return "".join(all_modifiers) 87 88 def encode_modifier_term(t): 89 90 "Encode modifier 't' representing assignment status." 91 92 assignment, invocation = t 93 return assignment and "=" or invocation and "!" or "_" 94 95 def decode_modifier_term(s): 96 97 "Decode modifier term 's' representing assignment status." 98 99 return (s == "=", s == "!") 100 101 102 103 # Test generation functions. 104 105 def get_kinds(all_types): 106 107 """ 108 Return object kind details for 'all_types', being a collection of 109 references for program types. 110 """ 111 112 return map(lambda ref: ref.get_kind(), all_types) 113 114 def test_for_kind(prefix, kind): 115 116 "Return a test condition identifier featuring 'prefix' and 'kind'." 117 118 return "%s-%s" % (prefix, kind == "<instance>" and "instance" or "type") 119 120 def test_for_kinds(prefix, all_kinds): 121 122 """ 123 Return an identifier describing test conditions incorporating the given 124 'prefix' and involving 'all_kinds', being a collection of object kinds. 125 """ 126 127 return test_for_kind(prefix, first(all_kinds)) 128 129 def test_for_type(prefix, ref): 130 131 """ 132 Return an identifier describing a test condition incorporating the given 133 'prefix' and involving 'ref', being a program type reference. The kind of 134 the reference is employed in the identifier. 135 """ 136 137 return test_for_kind(prefix, ref.get_kind()) 138 139 140 141 # Instruction representation encoding. 142 143 def encode_instruction(instruction): 144 145 """ 146 Encode the 'instruction' - a sequence starting with an operation and 147 followed by arguments, each of which may be an instruction sequence or a 148 plain value - to produce a function call string representation. 149 """ 150 151 op = instruction[0] 152 args = instruction[1:] 153 154 if args: 155 a = [] 156 for arg in args: 157 if isinstance(arg, tuple): 158 a.append(encode_instruction(arg)) 159 else: 160 a.append(arg or "{}") 161 argstr = "(%s)" % ", ".join(a) 162 return "%s%s" % (op, argstr) 163 else: 164 return op 165 166 167 168 # Output program encoding. 169 170 attribute_loading_ops = ( 171 "__load_via_class", "__load_via_object", "__get_class_and_load", 172 ) 173 174 attribute_ops = attribute_loading_ops + ( 175 "__store_via_object", 176 ) 177 178 checked_loading_ops = ( 179 "__check_and_load_via_class", "__check_and_load_via_object", "__check_and_load_via_any", 180 ) 181 182 checked_ops = checked_loading_ops + ( 183 "__check_and_store_via_class", "__check_and_store_via_object", "__check_and_store_via_any", 184 ) 185 186 typename_ops = ( 187 "__test_common_instance", "__test_common_object", "__test_common_type", 188 ) 189 190 static_ops = ( 191 "__load_static", 192 ) 193 194 reference_acting_ops = attribute_ops + checked_ops + typename_ops 195 attribute_producing_ops = attribute_loading_ops + checked_loading_ops 196 197 def encode_access_instruction(instruction, subs): 198 199 """ 200 Encode the 'instruction' - a sequence starting with an operation and 201 followed by arguments, each of which may be an instruction sequence or a 202 plain value - to produce a function call string representation. 203 204 The 'subs' parameter defines a mapping of substitutions for special values 205 used in instructions. 206 """ 207 208 op = instruction[0] 209 args = instruction[1:] 210 211 if not args: 212 argstr = "" 213 214 else: 215 # Encode the arguments. 216 217 a = [] 218 converting_op = op 219 for arg in args: 220 a.append(encode_access_instruction_arg(arg, subs, converting_op)) 221 converting_op = None 222 223 # Modify certain arguments. 224 225 # Convert attribute name arguments to position symbols. 226 227 if op in attribute_ops: 228 arg = a[1] 229 a[1] = encode_symbol("pos", arg) 230 231 # Convert attribute name arguments to position and code symbols. 232 233 elif op in checked_ops: 234 arg = a[1] 235 a[1] = encode_symbol("pos", arg) 236 a.insert(2, encode_symbol("code", arg)) 237 238 # Convert type name arguments to position and code symbols. 239 240 elif op in typename_ops: 241 arg = encode_type_attribute(a[1]) 242 a[1] = encode_symbol("pos", arg) 243 a.insert(2, encode_symbol("code", arg)) 244 245 # Obtain addresses of static objects. 246 247 elif op in static_ops: 248 a[0] = "&%s" % a[0] 249 a[1] = "&%s" % a[1] 250 251 argstr = "(%s)" % ", ".join(a) 252 253 # Substitute the first element of the instruction, which may not be an 254 # operation at all. 255 256 if subs.has_key(op): 257 op = subs[op] 258 elif not args: 259 op = "&%s" % encode_path(op) 260 261 return "%s%s" % (op, argstr) 262 263 def encode_access_instruction_arg(arg, subs, op): 264 265 "Encode 'arg' using 'subs' to define substitutions." 266 267 if isinstance(arg, tuple): 268 encoded = encode_access_instruction(arg, subs) 269 270 # Convert attribute results to references where required. 271 272 if op and op in reference_acting_ops and arg[0] in attribute_producing_ops: 273 return "%s.value" % encoded 274 else: 275 return encoded 276 277 # Special values only need replacing, not encoding. 278 279 elif subs.has_key(arg): 280 return subs.get(arg) 281 282 # Other values may need encoding. 283 284 else: 285 return encode_path(arg) 286 287 def encode_bound_reference(path): 288 289 "Encode 'path' as a bound method name." 290 291 return "__bound_%s" % encode_path(path) 292 293 def encode_function_pointer(path): 294 295 "Encode 'path' as a reference to an output program function." 296 297 return "__fn_%s" % encode_path(path) 298 299 def encode_initialiser_pointer(path): 300 301 "Encode 'path' as a reference to an initialiser function structure." 302 303 return encode_path("%s.__init__" % path) 304 305 def encode_instantiator_pointer(path): 306 307 "Encode 'path' as a reference to an output program instantiator." 308 309 return "__new_%s" % encode_path(path) 310 311 def encode_literal_constant(n): 312 313 "Encode a name for the literal constant with the number 'n'." 314 315 return "__const%d" % n 316 317 def encode_literal_constant_member(value): 318 319 "Encode the member name for the 'value' in the final program." 320 321 return "%svalue" % value.__class__.__name__ 322 323 def encode_literal_constant_value(value): 324 325 "Encode the given 'value' in the final program." 326 327 if isinstance(value, (int, float)): 328 return str(value) 329 else: 330 return '"%s"' % str(value).replace('"', '\\"').replace("\n", "\\n").replace("\t", "\\t").replace("\r", "\\r") 331 332 def encode_literal_instantiator(path): 333 334 """ 335 Encode a reference to an instantiator for a literal having the given 'path'. 336 """ 337 338 return "__newliteral_%s" % encode_path(path) 339 340 def encode_literal_reference(n): 341 342 "Encode a reference to a literal constant with the number 'n'." 343 344 return "__constvalue%d" % n 345 346 def encode_path(path): 347 348 "Encode 'path' as an output program object, translating special symbols." 349 350 if path in reserved_words: 351 return "__%s" % path 352 else: 353 return path.replace("#", "__").replace("$", "__").replace(".", "_") 354 355 def encode_predefined_reference(path): 356 357 "Encode a reference to a predefined constant value for 'path'." 358 359 return "__predefined_%s" % encode_path(path) 360 361 def encode_size(kind, path=None): 362 363 """ 364 Encode a structure size reference for the given 'kind' of structure, with 365 'path' indicating a specific structure name. 366 """ 367 368 return "__%ssize%s" % (structure_size_prefixes.get(kind, kind), path and "_%s" % encode_path(path) or "") 369 370 def encode_symbol(symbol_type, path=None): 371 372 "Encode a symbol with the given 'symbol_type' and optional 'path'." 373 374 return "__%s%s" % (symbol_type, path and "_%s" % encode_path(path) or "") 375 376 def encode_tablename(kind, path): 377 378 """ 379 Encode a table reference for the given 'kind' of table structure, indicating 380 a 'path' for the specific object concerned. 381 """ 382 383 return "__%sTable_%s" % (table_name_prefixes[kind], encode_path(path)) 384 385 def encode_type_attribute(path): 386 387 "Encode the special type attribute for 'path'." 388 389 return "#%s" % path 390 391 392 393 # A mapping from kinds to structure size reference prefixes. 394 395 structure_size_prefixes = { 396 "<class>" : "c", 397 "<module>" : "m", 398 "<instance>" : "i" 399 } 400 401 # A mapping from kinds to table name prefixes. 402 403 table_name_prefixes = { 404 "<class>" : "Class", 405 "<function>" : "Function", 406 "<module>" : "Module", 407 "<instance>" : "Instance" 408 } 409 410 411 412 # Output language reserved words. 413 414 reserved_words = [ 415 "break", "char", "const", "continue", 416 "default", "double", "else", 417 "float", "for", 418 "if", "int", "long", 419 "NULL", 420 "return", "struct", 421 "typedef", 422 "void", "while", 423 ] 424 425 # vim: tabstop=4 expandtab shiftwidth=4