src/separate_erasure_compiler.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Separate compilation of a Nit program with generic type erasure
  16 module separate_erasure_compiler
  17
  18
  19 import separate_compiler
  20
  21 redef class ToolContext
  22         # --erasure
  23         var opt_erasure: OptionBool = new OptionBool("Erase generic types", "--erasure")
  24
  25         # --no-check-erasure-cast
  26         var opt_no_check_erasure_cast: OptionBool = new OptionBool("Disable implicit casts on unsafe return with erasure-typing policy (dangerous)", "--no-check-erasure-cast")
  27
  28         redef init
  29         do
  30                 super
  31                 self.option_context.add_option(self.opt_erasure, self.opt_no_check_erasure_cast)
  32         end
  33 end
  34
  35 redef class ModelBuilder
  36         fun run_separate_erasure_compiler(mainmodule: MModule, runtime_type_analysis: RapidTypeAnalysis)
  37         do
  38                 var time0 = get_time
  39                 self.toolcontext.info("*** COMPILING TO C ***", 1)
  40
  41                 var compiler = new SeparateErasureCompiler(mainmodule, runtime_type_analysis, self)
  42                 compiler.compile_header
  43
  44                 # compile class structures
  45                 for m in mainmodule.in_importation.greaters do
  46                         for mclass in m.intro_mclasses do
  47                                 compiler.compile_class_to_c(mclass)
  48                         end
  49                 end
  50
  51                 # The main function of the C
  52                 compiler.compile_main_function
  53
  54                 # compile methods
  55                 for m in mainmodule.in_importation.greaters do
  56                         compiler.compile_module_to_c(m)
  57                 end
  58
  59                 compiler.display_stats
  60
  61                 write_and_make(compiler)
  62         end
  63 end
  64
  65 class SeparateErasureCompiler
  66         super SeparateCompiler
  67
  68         private var class_ids: HashMap[MClass, Int] = new HashMap[MClass, Int]
  69         private var class_colors: Map[MClass, Int]
  70         private var class_tables: Map[MClass, Array[nullable MClass]]
  71
  72         init(mainmodule: MModule, runtime_type_analysis: RapidTypeAnalysis, mmbuilder: ModelBuilder) do
  73                 var mclasses = new HashSet[MClass]
  74                 mclasses.add_all(mmbuilder.model.mclasses)
  75
  76                 # classes coloration
  77                 if modelbuilder.toolcontext.opt_phmod_typing.value then
  78                         # set type unique id
  79                         for mclass in mclasses do
  80                                 self.class_ids[mclass] = self.class_ids.length + 1
  81                         end
  82
  83                         var class_coloring = new ClassModPerfectHashing(mainmodule)
  84                         self.class_colors = class_coloring.compute_masks(mclasses, class_ids)
  85                         self.class_tables = class_coloring.hash_type_tables(mclasses, class_ids, class_colors)
  86
  87                         self.header.add_decl("#define HASH(mask, id) ((mask)%(id))")
  88                 else if modelbuilder.toolcontext.opt_phand_typing.value then
  89                         # set type unique id
  90                         for mclass in mclasses do
  91                                 self.class_ids[mclass] = self.class_ids.length + 1
  92                         end
  93
  94                         var class_coloring = new ClassAndPerfectHashing(mainmodule)
  95                         self.class_colors = class_coloring.compute_masks(mclasses, class_ids)
  96                         self.class_tables = class_coloring.hash_type_tables(mclasses, class_ids, class_colors)
  97
  98                         self.header.add_decl("#define HASH(mask, id) ((mask)&(id))")
  99                 else
 100                         var class_coloring
 101                         if modelbuilder.toolcontext.opt_bm_typing.value then
 102                                 class_coloring = new NaiveClassColoring(mainmodule)
 103                         else
 104                                 class_coloring = new ClassColoring(mainmodule)
 105                         end
 106                         # set type unique id
 107                         for mclass in mclasses do
 108                                 self.class_ids[mclass] = self.class_ids.length + 1
 109                         end
 110                         self.class_colors = class_coloring.colorize(modelbuilder.model.mclasses)
 111                         self.class_tables = class_coloring.build_type_tables(modelbuilder.model.mclasses, class_colors)
 112                 end
 113         end
 114
 115         redef fun compile_header_structs do
 116                 self.header.add_decl("typedef void(*nitmethod_t)(void); /* general C type representing a Nit method. */")
 117                 self.compile_header_attribute_structs
 118                 self.header.add_decl("struct class \{ int id; const char *name; int box_kind; int color; struct vts_table *vts_table; struct type_table *type_table; nitmethod_t vft[1]; \}; /* general C type representing a Nit class. */")
 119                 self.header.add_decl("struct type_table \{ int size; int table[1]; \}; /* colorized type table. */")
 120                 self.header.add_decl("struct vts_entry \{ short int is_nullable; struct class *class; \}; /* link (nullable or not) between the vts and is bound. */")
 121
 122                 if modelbuilder.toolcontext.opt_phmod_typing.value or modelbuilder.toolcontext.opt_phand_typing.value then
 123                         self.header.add_decl("struct vts_table \{ int mask; struct vts_entry vts[1]; \}; /* vts list of a C type representation. */")
 124                 else
 125                         self.header.add_decl("struct vts_table \{ struct vts_entry vts[1]; \}; /* vts list of a C type representation. */")
 126                 end
 127
 128                 self.header.add_decl("typedef struct val \{ struct class *class; nitattribute_t attrs[1]; \} val; /* general C type representing a Nit instance. */")
 129         end
 130
 131         redef fun compile_class_to_c(mclass: MClass)
 132         do
 133                 var mtype = mclass.intro.bound_mtype
 134                 var c_name = mclass.c_name
 135
 136                 var vft = self.method_tables[mclass]
 137                 var attrs = self.attr_tables[mclass]
 138                 var class_table = self.class_tables[mclass]
 139                 var v = self.new_visitor
 140
 141                 v.add_decl("/* runtime class {c_name} */")
 142                 var idnum = classids.length
 143                 var idname = "ID_" + c_name
 144                 self.classids[mtype] = idname
 145                 #self.header.add_decl("#define {idname} {idnum} /* {c_name} */")
 146
 147                 self.header.add_decl("extern const struct class_{c_name} class_{c_name};")
 148                 self.header.add_decl("struct class_{c_name} \{")
 149                 self.header.add_decl("int id;")
 150                 self.header.add_decl("const char *name;")
 151                 self.header.add_decl("int box_kind;")
 152                 self.header.add_decl("int color;")
 153                 self.header.add_decl("const struct vts_table *vts_table;")
 154                 self.header.add_decl("struct type_table *type_table;")
 155                 self.header.add_decl("nitmethod_t vft[{vft.length}];")
 156                 self.header.add_decl("\};")
 157
 158                 # Build class vft
 159                 v.add_decl("const struct class_{c_name} class_{c_name} = \{")
 160                 v.add_decl("{self.class_ids[mclass]},")
 161                 v.add_decl("\"{mclass.name}\", /* class_name_string */")
 162                 v.add_decl("{self.box_kind_of(mclass)}, /* box_kind */")
 163                 v.add_decl("{self.class_colors[mclass]},")
 164                 if build_class_vts_table(mclass) then
 165                         v.add_decl("(const struct vts_table*) &vts_table_{c_name},")
 166                 else
 167                         v.add_decl("NULL,")
 168                 end
 169                 v.add_decl("(struct type_table*) &type_table_{c_name},")
 170                 v.add_decl("\{")
 171                 for i in [0 .. vft.length[ do
 172                         var mpropdef = vft[i]
 173                         if mpropdef == null then
 174                                 v.add_decl("NULL, /* empty */")
 175                         else
 176                                 if true or mpropdef.mclassdef.bound_mtype.ctype != "val*" then
 177                                         v.add_decl("(nitmethod_t)VIRTUAL_{mpropdef.c_name}, /* pointer to {mclass.intro_mmodule}:{mclass}:{mpropdef} */")
 178                                 else
 179                                         v.add_decl("(nitmethod_t){mpropdef.c_name}, /* pointer to {mclass.intro_mmodule}:{mclass}:{mpropdef} */")
 180                                 end
 181                         end
 182                 end
 183                 v.add_decl("\}")
 184                 v.add_decl("\};")
 185
 186                 # Build class type table
 187                 self.header.add_decl("extern const struct type_table_{c_name} type_table_{c_name};")
 188                 self.header.add_decl("struct type_table_{c_name} \{")
 189                 self.header.add_decl("int size;")
 190                 self.header.add_decl("int table[{class_table.length}];")
 191                 self.header.add_decl("\};")
 192
 193                 v.add_decl("const struct type_table_{c_name} type_table_{c_name} = \{")
 194                 v.add_decl("{class_table.length},")
 195                 v.add_decl("\{")
 196                 for msuper in class_table do
 197                         if msuper == null then
 198                                 v.add_decl("-1, /* empty */")
 199                         else
 200                                 v.add_decl("{self.class_ids[msuper]}, /* {msuper} */")
 201                         end
 202                 end
 203                 v.add_decl("\}")
 204                 v.add_decl("\};")
 205
 206                 #Build instance struct
 207                 if mtype.ctype != "val*" then
 208                         self.header.add_decl("struct instance_{c_name} \{")
 209                         self.header.add_decl("const struct class *class;")
 210                         self.header.add_decl("{mtype.ctype} value;")
 211                         self.header.add_decl("\};")
 212
 213                         self.header.add_decl("val* BOX_{c_name}({mtype.ctype});")
 214                         v.add_decl("/* allocate {mtype} */")
 215                         v.add_decl("val* BOX_{mtype.c_name}({mtype.ctype} value) \{")
 216                         v.add("struct instance_{c_name}*res = GC_MALLOC(sizeof(struct instance_{c_name}));")
 217                         v.add("res->class = (struct class*) &class_{c_name};")
 218                         v.add("res->value = value;")
 219                         v.add("return (val*)res;")
 220                         v.add("\}")
 221                         return
 222                 end
 223
 224                 var is_native_array = mclass.name == "NativeArray"
 225
 226                 var sig
 227                 if is_native_array then
 228                         sig = "int length"
 229                 else
 230                         sig = ""
 231                 end
 232
 233                 #Build instance struct
 234                 #extern const struct instance_array__NativeArray instance_array__NativeArray;
 235                 self.header.add_decl("struct instance_{c_name} \{")
 236                 self.header.add_decl("const struct class *class;")
 237                 self.header.add_decl("nitattribute_t attrs[{attrs.length}];")
 238                 if is_native_array then
 239                         # NativeArrays are just a instance header followed by an array of values
 240                         self.header.add_decl("val* values[0];")
 241                 end
 242                 self.header.add_decl("\};")
 243
 244
 245                 self.header.add_decl("{mtype.ctype} NEW_{c_name}({sig});")
 246                 v.add_decl("/* allocate {mtype} */")
 247                 v.add_decl("{mtype.ctype} NEW_{c_name}({sig}) \{")
 248                 var res = v.new_named_var(mtype, "self")
 249                 res.is_exact = true
 250                 if is_native_array then
 251                         var mtype_elt = mtype.arguments.first
 252                         v.add("{res} = GC_MALLOC(sizeof(struct instance_{c_name}) + length*sizeof({mtype_elt.ctype}));")
 253                 else
 254                         v.add("{res} = GC_MALLOC(sizeof(struct instance_{c_name}));")
 255                 end
 256                 v.add("{res}->class = (struct class*) &class_{c_name};")
 257
 258                 self.generate_init_attr(v, res, mtype)
 259                 v.add("return {res};")
 260                 v.add("\}")
 261
 262                 generate_check_init_instance(mtype)
 263         end
 264
 265         private fun build_class_vts_table(mclass: MClass): Bool do
 266                 if self.vt_tables[mclass].is_empty then return false
 267
 268                 self.header.add_decl("extern const struct vts_table_{mclass.c_name} vts_table_{mclass.c_name};")
 269                 self.header.add_decl("struct vts_table_{mclass.c_name} \{")
 270                 if modelbuilder.toolcontext.opt_phmod_typing.value or modelbuilder.toolcontext.opt_phand_typing.value then
 271                         self.header.add_decl("int mask;")
 272                 end
 273                 self.header.add_decl("struct vts_entry vts[{self.vt_tables[mclass].length}];")
 274                 self.header.add_decl("\};")
 275
 276                 var v = new_visitor
 277                 v.add_decl("const struct vts_table_{mclass.c_name} vts_table_{mclass.c_name} = \{")
 278                 if modelbuilder.toolcontext.opt_phmod_typing.value or modelbuilder.toolcontext.opt_phand_typing.value then
 279                         v.add_decl("{vt_masks[mclass]},")
 280                 end
 281                 v.add_decl("\{")
 282
 283                 for vt in self.vt_tables[mclass] do
 284                         if vt == null then
 285                                 v.add_decl("\{-1, NULL\}, /* empty */")
 286                         else
 287                                 var is_null = 0
 288                                 var bound = retrieve_vt_bound(mclass.intro.bound_mtype, vt.bound)
 289                                 while bound isa MNullableType do
 290                                         bound = retrieve_vt_bound(mclass.intro.bound_mtype, bound.mtype)
 291                                         is_null = 1
 292                                 end
 293                                 v.add_decl("\{{is_null}, (struct class*)&class_{bound.as(MClassType).mclass.c_name}\}, /* {vt} */")
 294                         end
 295                 end
 296                 v.add_decl("\},")
 297                 v.add_decl("\};")
 298                 return true
 299         end
 300
 301         private fun retrieve_vt_bound(anchor: MClassType, mtype: nullable MType): MType do
 302                 if mtype == null then
 303                         print "NOT YET IMPLEMENTED: retrieve_vt_bound on null"
 304                         abort
 305                 end
 306                 if mtype isa MVirtualType then
 307                         return mtype.anchor_to(mainmodule, anchor)
 308                 else if mtype isa MParameterType then
 309                         return mtype.anchor_to(mainmodule, anchor)
 310                 else
 311                         return mtype
 312                 end
 313         end
 314
 315         redef fun new_visitor do return new SeparateErasureCompilerVisitor(self)
 316 end
 317
 318 class SeparateErasureCompilerVisitor
 319         super SeparateCompilerVisitor
 320
 321         redef fun compile_callsite(callsite, arguments)
 322         do
 323                 var res = super
 324                 if callsite.erasure_cast and not self.compiler.as(SeparateErasureCompiler).modelbuilder.toolcontext.opt_no_check_erasure_cast.value then
 325                         assert res != null
 326                         var mtype = callsite.msignature.return_mtype
 327                         assert mtype != null
 328                         self.add("/* Erasure cast for return {res} isa {mtype} */")
 329                         var cond = self.type_test(res, mtype, "erasure")
 330                         self.add("if (!{cond}) \{")
 331                         #var x = self.class_name_string(res)
 332                         #var y = self.class_name_string(arguments.first)
 333                         #self.add("fprintf(stderr, \"Erasure cast: expected {mtype} (self is %s), got %s for {res}\\n\", {y}, {x});")
 334                         self.add_abort("Cast failed")
 335                         self.add("\}")
 336                 end
 337                 return res
 338         end
 339
 340         redef fun init_instance(mtype)
 341         do
 342                 return self.new_expr("NEW_{mtype.mclass.c_name}()", mtype)
 343         end
 344
 345         redef fun type_test(value, mtype, tag)
 346         do
 347                 self.add("/* type test for {value.inspect} isa {mtype} */")
 348
 349                 var res = self.new_var(bool_type)
 350
 351                 var cltype = self.get_name("cltype")
 352                 self.add_decl("int {cltype};")
 353                 var idtype = self.get_name("idtype")
 354                 self.add_decl("int {idtype};")
 355                 var is_nullable = self.get_name("is_nullable")
 356                 self.add_decl("short int {is_nullable};")
 357                 var is_null = self.get_name("is_null")
 358                 self.add_decl("short int {is_null};")
 359
 360                 var maybe_null = 0
 361                 if mtype isa MNullableType then
 362                         mtype = mtype.mtype
 363                         maybe_null = 1
 364                         self.add("{is_nullable} = 1;")
 365                 end
 366                 if mtype isa MParameterType then
 367                         # Here we get the bound of the the formal type (eh, erasure...)
 368                         mtype = mtype.resolve_for(self.frame.mpropdef.mclassdef.bound_mtype, self.frame.mpropdef.mclassdef.bound_mtype, self.frame.mpropdef.mclassdef.mmodule, false)
 369                         if mtype isa MNullableType then
 370                                 mtype = mtype.mtype
 371                                 maybe_null = 1
 372                                 self.add("{is_nullable} = 1;")
 373                         end
 374                 end
 375                 if mtype isa MVirtualType then
 376                         # FIXME virtual types should not be erased but got from the class table of the current receiver (self.frame.arguments.first)
 377                         #mtype = mtype.resolve_for(self.frame.mpropdef.mclassdef.bound_mtype, self.frame.mpropdef.mclassdef.bound_mtype, self.frame.mpropdef.mclassdef.mmodule, true)
 378                         #if mtype isa MNullableType then
 379                         #       mtype = mtype.mtype
 380                         #       maybe_null = true
 381                         #end
 382                 end
 383
 384                 if value.mcasttype.is_subtype(self.frame.mpropdef.mclassdef.mmodule, self.frame.mpropdef.mclassdef.bound_mtype, mtype) then
 385                         self.add("{res} = 1; /* easy {value.inspect} isa {mtype}*/")
 386                         if compiler.modelbuilder.toolcontext.opt_typing_test_metrics.value then
 387                                 self.compiler.count_type_test_skipped[tag] += 1
 388                                 self.add("count_type_test_skipped_{tag}++;")
 389                         end
 390                         return res
 391                 end
 392
 393                 var class_ptr
 394                 var type_table
 395                 if value.mtype.ctype == "val*" then
 396                         class_ptr = "{value}->class->"
 397                         self.add("{is_null} = {value} == NULL;")
 398                 else
 399                         var mclass = value.mtype.as(MClassType).mclass
 400                         class_ptr = "class_{mclass.c_name}."
 401                         self.add("{is_null} = 0;")
 402                 end
 403
 404                 if mtype isa MClassType then
 405                         self.add("{cltype} = class_{mtype.mclass.c_name}.color;")
 406                         self.add("{idtype} = class_{mtype.mclass.c_name}.id;")
 407                         if maybe_null == 0 then
 408                                 self.add("{is_nullable} = 0;")
 409                         end
 410                         if compiler.modelbuilder.toolcontext.opt_typing_test_metrics.value then
 411                                 self.compiler.count_type_test_resolved[tag] += 1
 412                                 self.add("count_type_test_resolved_{tag}++;")
 413                         end
 414                 else if mtype isa MVirtualType then
 415                         var recv = self.frame.arguments.first
 416                         var recv_ptr
 417                         if recv.mtype.ctype == "val*" then
 418                                 recv_ptr = "{recv}->class->"
 419                         else
 420                                 var mclass = recv.mtype.as(MClassType).mclass
 421                                 recv_ptr = "class_{mclass.c_name}."
 422                         end
 423                         var entry = self.get_name("entry")
 424                         self.add("struct vts_entry {entry};")
 425                         if compiler.modelbuilder.toolcontext.opt_phmod_typing.value or compiler.modelbuilder.toolcontext.opt_phand_typing.value then
 426                                 self.add("{entry} = {recv_ptr}vts_table->vts[HASH({recv_ptr}vts_table->mask, {mtype.mproperty.const_color})];")
 427                         else
 428                                 self.add("{entry} = {recv_ptr}vts_table->vts[{mtype.mproperty.const_color}];")
 429                         end
 430                         self.add("{cltype} = {entry}.class->color;")
 431                         self.add("{idtype} = {entry}.class->id;")
 432                         if maybe_null == 0 then
 433                                 self.add("{is_nullable} = {entry}.is_nullable;")
 434                         end
 435                         if compiler.modelbuilder.toolcontext.opt_typing_test_metrics.value then
 436                                 self.compiler.count_type_test_unresolved[tag] += 1
 437                                 self.add("count_type_test_unresolved_{tag}++;")
 438                         end
 439                 else
 440                         self.debug("type_test({value.inspect}, {mtype})")
 441                         abort
 442                 end
 443
 444                 # check color is in table
 445                 self.add("if({is_null}) \{")
 446                 self.add("{res} = {is_nullable};")
 447                 self.add("\} else \{")
 448                 if compiler.modelbuilder.toolcontext.opt_phmod_typing.value or compiler.modelbuilder.toolcontext.opt_phand_typing.value then
 449                         self.add("{cltype} = HASH({class_ptr}color, {idtype});")
 450                 end
 451                 self.add("if({cltype} >= {class_ptr}type_table->size) \{")
 452                 self.add("{res} = 0;")
 453                 self.add("\} else \{")
 454                 self.add("{res} = {class_ptr}type_table->table[{cltype}] == {idtype};")
 455                 self.add("\}")
 456                 self.add("\}")
 457
 458                 return res
 459         end
 460
 461         redef fun class_name_string(value)
 462         do
 463                 var res = self.get_name("var_class_name")
 464                 self.add_decl("const char* {res};")
 465                 if value.mtype.ctype == "val*" then
 466                         self.add "{res} = {value} == NULL ? \"null\" : {value}->class->name;"
 467                 else
 468                         self.add "{res} = class_{value.mtype.c_name}.name;"
 469                 end
 470                 return res
 471         end
 472
 473         redef fun array_instance(array, elttype)
 474         do
 475                 var nclass = self.get_class("NativeArray")
 476                 elttype = self.anchor(elttype)
 477                 var arraytype = self.get_class("Array").get_mtype([elttype])
 478                 var res = self.init_instance(arraytype)
 479                 self.add("\{ /* {res} = array_instance Array[{elttype}] */")
 480                 var nat = self.new_var(self.get_class("NativeArray").get_mtype([elttype]))
 481                 nat.is_exact = true
 482                 self.add("{nat} = NEW_{nclass.c_name}({array.length});")
 483                 for i in [0..array.length[ do
 484                         var r = self.autobox(array[i], self.object_type)
 485                         self.add("((struct instance_{nclass.c_name}*){nat})->values[{i}] = (val*) {r};")
 486                 end
 487                 var length = self.int_instance(array.length)
 488                 self.send(self.get_property("with_native", arraytype), [res, nat, length])
 489                 self.check_init_instance(res, arraytype)
 490                 self.add("\}")
 491                 return res
 492         end
 493
 494         redef fun calloc_array(ret_type, arguments)
 495         do
 496                 var ret = ret_type.as(MClassType)
 497                 self.ret(self.new_expr("NEW_{ret.mclass.c_name}({arguments[1]})", ret_type))
 498         end
 499 end