ast.c

   1 /*
   2  * Copyright (C) 2012
   3  *     Wolfgang Bumiller
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of
   6  * this software and associated documentation files (the "Software"), to deal in
   7  * the Software without restriction, including without limitation the rights to
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   9  * of the Software, and to permit persons to whom the Software is furnished to do
  10  * so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in all
  13  * copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "gmqcc.h"
  28 #include "ast.h"
  29
  30 #define ast_instantiate(T, ctx, destroyfn)                          \
  31     T* self = (T*)mem_a(sizeof(T));                                 \
  32     if (!self) {                                                    \
  33         return NULL;                                                \
  34     }                                                               \
  35     ast_node_init((ast_node*)self, ctx);                            \
  36     ( (ast_node*)self )->node.destroy = (ast_node_delete*)destroyfn
  37
  38 /* It must not be possible to get here. */
  39 static void _ast_node_destroy(ast_node *self)
  40 {
  41     fprintf(stderr, "ast node missing destroy()\n");
  42     abort();
  43 }
  44
  45 /* Initialize main ast node aprts */
  46 static void ast_node_init(ast_node *self, lex_ctx ctx)
  47 {
  48     self->node.context = ctx;
  49     self->node.destroy = &_ast_node_destroy;
  50     self->node.keep    = false;
  51 }
  52
  53 /* General expression initialization */
  54 static void ast_expression_init(ast_expression *self,
  55                                 ast_expression_codegen *codegen)
  56 {
  57     self->expression.codegen = codegen;
  58     self->expression.vtype   = TYPE_VOID;
  59     self->expression.next    = NULL;
  60 }
  61
  62 static void ast_expression_delete(ast_expression *self)
  63 {
  64     if (self->expression.next)
  65         ast_delete(self->expression.next);
  66 }
  67
  68 static void ast_expression_delete_full(ast_expression *self)
  69 {
  70     ast_expression_delete(self);
  71     mem_d(self);
  72 }
  73
  74 static ast_expression* ast_type_copy(lex_ctx ctx, const ast_expression *ex)
  75 {
  76     const ast_expression_common *cpex;
  77     ast_expression_common *selfex;
  78
  79     if (!ex)
  80         return NULL;
  81     else
  82     {
  83         ast_instantiate(ast_expression, ctx, ast_expression_delete_full);
  84
  85         cpex   = &ex->expression;
  86         selfex = &self->expression;
  87
  88         selfex->vtype = cpex->vtype;
  89         if (cpex->next)
  90         {
  91             selfex->next = ast_type_copy(ctx, cpex->next);
  92             if (!selfex->next) {
  93                 mem_d(self);
  94                 return NULL;
  95             }
  96         }
  97         else
  98             selfex->next = NULL;
  99
 100         /* This may never be codegen()d */
 101         selfex->codegen = NULL;
 102         return self;
 103     }
 104 }
 105
 106 ast_value* ast_value_new(lex_ctx ctx, const char *name, int t)
 107 {
 108     ast_instantiate(ast_value, ctx, ast_value_delete);
 109     ast_expression_init((ast_expression*)self,
 110                         (ast_expression_codegen*)&ast_value_codegen);
 111     self->expression.node.keep = true; /* keep */
 112
 113     self->name = name ? util_strdup(name) : NULL;
 114     self->expression.vtype = t;
 115     self->expression.next  = NULL;
 116     MEM_VECTOR_INIT(self, params);
 117     self->isconst = false;
 118     memset(&self->constval, 0, sizeof(self->constval));
 119
 120     self->ir_v    = NULL;
 121
 122     return self;
 123 }
 124 MEM_VEC_FUNCTIONS(ast_value, ast_value*, params)
 125
 126 void ast_value_delete(ast_value* self)
 127 {
 128     size_t i;
 129     if (self->name)
 130         mem_d((void*)self->name);
 131     for (i = 0; i < self->params_count; ++i)
 132         ast_value_delete(self->params[i]); /* delete, the ast_function is expected to die first */
 133     MEM_VECTOR_CLEAR(self, params);
 134     if (self->isconst) {
 135         switch (self->expression.vtype)
 136         {
 137         case TYPE_STRING:
 138             mem_d((void*)self->constval.vstring);
 139             break;
 140         case TYPE_FUNCTION:
 141             /* unlink us from the function node */
 142             self->constval.vfunc->vtype = NULL;
 143             break;
 144         /* NOTE: delete function? currently collected in
 145          * the parser structure
 146          */
 147         default:
 148             break;
 149         }
 150     }
 151     ast_expression_delete((ast_expression*)self);
 152     mem_d(self);
 153 }
 154
 155 bool ast_value_set_name(ast_value *self, const char *name)
 156 {
 157     if (self->name)
 158         mem_d((void*)self->name);
 159     self->name = util_strdup(name);
 160     return !!self->name;
 161 }
 162
 163 ast_binary* ast_binary_new(lex_ctx ctx, int op,
 164                            ast_expression* left, ast_expression* right)
 165 {
 166     ast_instantiate(ast_binary, ctx, ast_binary_delete);
 167     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_binary_codegen);
 168
 169     self->op = op;
 170     self->left = left;
 171     self->right = right;
 172
 173     return self;
 174 }
 175
 176 void ast_binary_delete(ast_binary *self)
 177 {
 178     ast_unref(self->left);
 179     ast_unref(self->right);
 180     ast_expression_delete((ast_expression*)self);
 181     mem_d(self);
 182 }
 183
 184 ast_entfield* ast_entfield_new(lex_ctx ctx, ast_expression *entity, ast_expression *field)
 185 {
 186     const ast_expression *outtype;
 187
 188     ast_instantiate(ast_entfield, ctx, ast_entfield_delete);
 189
 190     if (field->expression.vtype != TYPE_FIELD) {
 191         mem_d(self);
 192         return NULL;
 193     }
 194
 195     outtype = field->expression.next;
 196     if (!outtype) {
 197         mem_d(self);
 198         /* Error: field has no type... */
 199         return NULL;
 200     }
 201
 202     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_entfield_codegen);
 203
 204     self->expression.vtype = outtype->expression.vtype;
 205     self->expression.next  = ast_type_copy(ctx, outtype->expression.next);
 206
 207     self->entity = entity;
 208     self->field  = field;
 209
 210     return self;
 211 }
 212
 213 void ast_entfield_delete(ast_entfield *self)
 214 {
 215     ast_unref(self->entity);
 216     ast_unref(self->field);
 217     ast_expression_delete((ast_expression*)self);
 218     mem_d(self);
 219 }
 220
 221 ast_ifthen* ast_ifthen_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 222 {
 223     ast_instantiate(ast_ifthen, ctx, ast_ifthen_delete);
 224     if (!ontrue && !onfalse) {
 225         /* because it is invalid */
 226         mem_d(self);
 227         return NULL;
 228     }
 229     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ifthen_codegen);
 230
 231     self->cond     = cond;
 232     self->on_true  = ontrue;
 233     self->on_false = onfalse;
 234
 235     return self;
 236 }
 237
 238 void ast_ifthen_delete(ast_ifthen *self)
 239 {
 240     ast_unref(self->cond);
 241     if (self->on_true)
 242         ast_unref(self->on_true);
 243     if (self->on_false)
 244         ast_unref(self->on_false);
 245     ast_expression_delete((ast_expression*)self);
 246     mem_d(self);
 247 }
 248
 249 ast_ternary* ast_ternary_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 250 {
 251     ast_instantiate(ast_ternary, ctx, ast_ternary_delete);
 252     /* This time NEITHER must be NULL */
 253     if (!ontrue || !onfalse) {
 254         mem_d(self);
 255         return NULL;
 256     }
 257     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ternary_codegen);
 258
 259     self->cond     = cond;
 260     self->on_true  = ontrue;
 261     self->on_false = onfalse;
 262     self->phi_out  = NULL;
 263
 264     return self;
 265 }
 266
 267 void ast_ternary_delete(ast_ternary *self)
 268 {
 269     ast_unref(self->cond);
 270     ast_unref(self->on_true);
 271     ast_unref(self->on_false);
 272     ast_expression_delete((ast_expression*)self);
 273     mem_d(self);
 274 }
 275
 276 ast_loop* ast_loop_new(lex_ctx ctx,
 277                        ast_expression *initexpr,
 278                        ast_expression *precond,
 279                        ast_expression *postcond,
 280                        ast_expression *increment,
 281                        ast_expression *body)
 282 {
 283     ast_instantiate(ast_loop, ctx, ast_loop_delete);
 284     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_loop_codegen);
 285
 286     self->initexpr  = initexpr;
 287     self->precond   = precond;
 288     self->postcond  = postcond;
 289     self->increment = increment;
 290     self->body      = body;
 291
 292     return self;
 293 }
 294
 295 void ast_loop_delete(ast_loop *self)
 296 {
 297     if (self->initexpr)
 298         ast_unref(self->initexpr);
 299     if (self->precond)
 300         ast_unref(self->precond);
 301     if (self->postcond)
 302         ast_unref(self->postcond);
 303     if (self->increment)
 304         ast_unref(self->increment);
 305     if (self->body)
 306         ast_unref(self->body);
 307     ast_expression_delete((ast_expression*)self);
 308     mem_d(self);
 309 }
 310
 311 ast_store* ast_store_new(lex_ctx ctx, int op,
 312                          ast_value *dest, ast_expression *source)
 313 {
 314     ast_instantiate(ast_store, ctx, ast_store_delete);
 315     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);
 316
 317     self->op = op;
 318     self->dest = dest;
 319     self->source = source;
 320
 321     return self;
 322 }
 323
 324 void ast_store_delete(ast_store *self)
 325 {
 326     ast_unref(self->dest);
 327     ast_unref(self->source);
 328     ast_expression_delete((ast_expression*)self);
 329     mem_d(self);
 330 }
 331
 332 ast_block* ast_block_new(lex_ctx ctx)
 333 {
 334     ast_instantiate(ast_block, ctx, ast_block_delete);
 335     ast_expression_init((ast_expression*)self,
 336                         (ast_expression_codegen*)&ast_block_codegen);
 337
 338     MEM_VECTOR_INIT(self, locals);
 339     MEM_VECTOR_INIT(self, exprs);
 340
 341     return self;
 342 }
 343 MEM_VEC_FUNCTIONS(ast_block, ast_value*, locals)
 344 MEM_VEC_FUNCTIONS(ast_block, ast_expression*, exprs)
 345
 346 void ast_block_delete(ast_block *self)
 347 {
 348     size_t i;
 349     for (i = 0; i < self->exprs_count; ++i)
 350         ast_unref(self->exprs[i]);
 351     MEM_VECTOR_CLEAR(self, exprs);
 352     for (i = 0; i < self->locals_count; ++i)
 353         ast_delete(self->locals[i]);
 354     MEM_VECTOR_CLEAR(self, locals);
 355     ast_expression_delete((ast_expression*)self);
 356     mem_d(self);
 357 }
 358
 359 ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
 360 {
 361     ast_instantiate(ast_function, ctx, ast_function_delete);
 362
 363     if (!vtype ||
 364         vtype->isconst ||
 365         vtype->expression.vtype != TYPE_FUNCTION)
 366     {
 367         mem_d(self);
 368         return NULL;
 369     }
 370
 371     self->vtype = vtype;
 372     self->name = name ? util_strdup(name) : NULL;
 373     MEM_VECTOR_INIT(self, blocks);
 374
 375     self->labelcount = 0;
 376
 377     self->ir_func = NULL;
 378     self->curblock = NULL;
 379
 380     self->breakblock    = NULL;
 381     self->continueblock = NULL;
 382
 383     vtype->isconst = true;
 384     vtype->constval.vfunc = self;
 385
 386     return self;
 387 }
 388
 389 MEM_VEC_FUNCTIONS(ast_function, ast_block*, blocks)
 390
 391 void ast_function_delete(ast_function *self)
 392 {
 393     size_t i;
 394     if (self->name)
 395         mem_d((void*)self->name);
 396     if (self->vtype) {
 397         /* ast_value_delete(self->vtype); */
 398         self->vtype->isconst = false;
 399         self->vtype->constval.vfunc = NULL;
 400         /* We use unref - if it was stored in a global table it is supposed
 401          * to be deleted from *there*
 402          */
 403         ast_unref(self->vtype);
 404     }
 405     for (i = 0; i < self->blocks_count; ++i)
 406         ast_delete(self->blocks[i]);
 407     MEM_VECTOR_CLEAR(self, blocks);
 408     mem_d(self);
 409 }
 410
 411 static void ast_util_hexitoa(char *buf, size_t size, unsigned int num)
 412 {
 413     unsigned int base = 10;
 414 #define checknul() do { if (size == 1) { *buf = 0; return; } } while (0)
 415 #define addch(x) do { *buf++ = (x); --size; checknul(); } while (0)
 416     if (size < 1)
 417         return;
 418     checknul();
 419     if (!num)
 420         addch('0');
 421     else {
 422         while (num)
 423         {
 424             int digit = num % base;
 425             num /= base;
 426             addch('0' + digit);
 427         }
 428     }
 429
 430     *buf = 0;
 431 #undef addch
 432 #undef checknul
 433 }
 434
 435 const char* ast_function_label(ast_function *self, const char *prefix)
 436 {
 437     size_t id = (self->labelcount++);
 438     size_t len = strlen(prefix);
 439     strncpy(self->labelbuf, prefix, sizeof(self->labelbuf));
 440     ast_util_hexitoa(self->labelbuf + len, sizeof(self->labelbuf)-len, id);
 441     return self->labelbuf;
 442 }
 443
 444 /*********************************************************************/
 445 /* AST codegen part
 446  * by convention you must never pass NULL to the 'ir_value **out'
 447  * parameter. If you really don't care about the output, pass a dummy.
 448  * But I can't imagine a pituation where the output is truly unnecessary.
 449  */
 450
 451 bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
 452 {
 453     /* NOTE: This is the codegen for a variable used in an expression.
 454      * It is not the codegen to generate the value. For this purpose,
 455      * ast_local_codegen and ast_global_codegen are to be used before this
 456      * is executed. ast_function_codegen should take care of its locals,
 457      * and the ast-user should take care of ast_global_codegen to be used
 458      * on all the globals.
 459      */
 460     if (!self->ir_v)
 461         return false;
 462     *out = self->ir_v;
 463     return true;
 464 }
 465
 466 bool ast_global_codegen(ast_value *self, ir_builder *ir)
 467 {
 468     ir_value *v = NULL;
 469     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 470     {
 471         ir_function *func = ir_builder_create_function(ir, self->name);
 472         if (!func)
 473             return false;
 474
 475         self->constval.vfunc->ir_func = func;
 476         /* The function is filled later on ast_function_codegen... */
 477         return true;
 478     }
 479
 480     v = ir_builder_create_global(ir, self->name, self->expression.vtype);
 481     if (!v)
 482         return false;
 483
 484     if (self->isconst) {
 485         switch (self->expression.vtype)
 486         {
 487             case TYPE_FLOAT:
 488                 if (!ir_value_set_float(v, self->constval.vfloat))
 489                     goto error;
 490                 break;
 491             case TYPE_VECTOR:
 492                 if (!ir_value_set_vector(v, self->constval.vvec))
 493                     goto error;
 494                 break;
 495             case TYPE_STRING:
 496                 if (!ir_value_set_string(v, self->constval.vstring))
 497                     goto error;
 498                 break;
 499             case TYPE_FUNCTION:
 500                 /* Cannot generate an IR value for a function,
 501                  * need a pointer pointing to a function rather.
 502                  */
 503                 goto error;
 504             default:
 505                 printf("TODO: global constant type %i\n", self->expression.vtype);
 506                 break;
 507         }
 508     }
 509
 510     /* link us to the ir_value */
 511     self->ir_v = v;
 512     return true;
 513
 514 error: /* clean up */
 515     ir_value_delete(v);
 516     return false;
 517 }
 518
 519 bool ast_local_codegen(ast_value *self, ir_function *func)
 520 {
 521     ir_value *v = NULL;
 522     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 523     {
 524         /* Do we allow local functions? I think not...
 525          * this is NOT a function pointer atm.
 526          */
 527         return false;
 528     }
 529
 530     v = ir_function_create_local(func, self->name, self->expression.vtype);
 531     if (!v)
 532         return false;
 533
 534     /* A constant local... hmmm...
 535      * I suppose the IR will have to deal with this
 536      */
 537     if (self->isconst) {
 538         switch (self->expression.vtype)
 539         {
 540             case TYPE_FLOAT:
 541                 if (!ir_value_set_float(v, self->constval.vfloat))
 542                     goto error;
 543                 break;
 544             case TYPE_VECTOR:
 545                 if (!ir_value_set_vector(v, self->constval.vvec))
 546                     goto error;
 547                 break;
 548             case TYPE_STRING:
 549                 if (!ir_value_set_string(v, self->constval.vstring))
 550                     goto error;
 551                 break;
 552             default:
 553                 printf("TODO: global constant type %i\n", self->expression.vtype);
 554                 break;
 555         }
 556     }
 557
 558     /* link us to the ir_value */
 559     self->ir_v = v;
 560     return true;
 561
 562 error: /* clean up */
 563     ir_value_delete(v);
 564     return false;
 565 }
 566
 567 bool ast_function_codegen(ast_function *self, ir_builder *ir)
 568 {
 569     ir_function *irf;
 570     ir_value    *dummy;
 571     size_t    i;
 572
 573     irf = self->ir_func;
 574     if (!irf) {
 575         printf("ast_function's related ast_value was not generated yet\n");
 576         return false;
 577     }
 578
 579     self->curblock = ir_function_create_block(irf, "entry");
 580     if (!self->curblock)
 581         return false;
 582
 583     for (i = 0; i < self->blocks_count; ++i) {
 584         ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
 585         if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
 586             return false;
 587     }
 588
 589     /* TODO: check return types */
 590     if (!self->curblock->is_return)
 591     {
 592         if (!self->vtype->expression.next ||
 593             self->vtype->expression.next->expression.vtype == TYPE_VOID)
 594             return ir_block_create_return(self->curblock, NULL);
 595         else
 596         {
 597             /* error("missing return"); */
 598             return false;
 599         }
 600     }
 601     return true;
 602 }
 603
 604 /* Note, you will not see ast_block_codegen generate ir_blocks.
 605  * To the AST and the IR, blocks are 2 different things.
 606  * In the AST it represents a block of code, usually enclosed in
 607  * curly braces {...}.
 608  * While in the IR it represents a block in terms of control-flow.
 609  */
 610 bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
 611 {
 612     size_t i;
 613
 614     /* We don't use this
 615      * Note: an ast-representation using the comma-operator
 616      * of the form: (a, b, c) = x should not assign to c...
 617      */
 618     (void)lvalue;
 619
 620     /* output is NULL at first, we'll have each expression
 621      * assign to out output, thus, a comma-operator represention
 622      * using an ast_block will return the last generated value,
 623      * so: (b, c) + a  executed both b and c, and returns c,
 624      * which is then added to a.
 625      */
 626     *out = NULL;
 627
 628     /* generate locals */
 629     for (i = 0; i < self->locals_count; ++i)
 630     {
 631         if (!ast_local_codegen(self->locals[i], func->ir_func))
 632             return false;
 633     }
 634
 635     for (i = 0; i < self->exprs_count; ++i)
 636     {
 637         ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
 638         if (!(*gen)(self->exprs[i], func, false, out))
 639             return false;
 640     }
 641
 642     return true;
 643 }
 644
 645 bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
 646 {
 647     ast_expression_codegen *cgen;
 648     ir_value *left, *right;
 649
 650     cgen = self->dest->expression.codegen;
 651     /* lvalue! */
 652     if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
 653         return false;
 654
 655     cgen = self->source->expression.codegen;
 656     /* rvalue! */
 657     if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
 658         return false;
 659
 660     if (!ir_block_create_store_op(func->curblock, self->op, left, right))
 661         return false;
 662
 663     /* Theoretically, an assinment returns its left side as an
 664      * lvalue, if we don't need an lvalue though, we return
 665      * the right side as an rvalue, otherwise we have to
 666      * somehow know whether or not we need to dereference the pointer
 667      * on the left side - that is: OP_LOAD if it was an address.
 668      * Also: in original QC we cannot OP_LOADP *anyway*.
 669      */
 670     *out = (lvalue ? left : right);
 671
 672     return true;
 673 }
 674
 675 bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
 676 {
 677     ast_expression_codegen *cgen;
 678     ir_value *left, *right;
 679
 680     /* In the context of a binary operation, we can disregard
 681      * the lvalue flag.
 682      */
 683      (void)lvalue;
 684
 685     cgen = self->left->expression.codegen;
 686     /* lvalue! */
 687     if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
 688         return false;
 689
 690     cgen = self->right->expression.codegen;
 691     /* rvalue! */
 692     if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
 693         return false;
 694
 695     *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
 696                                  self->op, left, right);
 697     if (!*out)
 698         return false;
 699
 700     return true;
 701 }
 702
 703 bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
 704 {
 705     ast_expression_codegen *cgen;
 706     ir_value *ent, *field;
 707
 708     /* This function needs to take the 'lvalue' flag into account!
 709      * As lvalue we provide a field-pointer, as rvalue we provide the
 710      * value in a temp.
 711      */
 712
 713     cgen = self->entity->expression.codegen;
 714     if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
 715         return false;
 716
 717     cgen = self->field->expression.codegen;
 718     if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
 719         return false;
 720
 721     if (lvalue) {
 722         /* address! */
 723         *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
 724                                             ent, field);
 725     } else {
 726         *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
 727                                              ent, field, self->expression.vtype);
 728     }
 729     if (!*out)
 730         return false;
 731
 732     /* Hm that should be it... */
 733     return true;
 734 }
 735
 736 bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
 737 {
 738     ast_expression_codegen *cgen;
 739
 740     ir_value *condval;
 741     ir_value *dummy;
 742
 743     ir_block *cond = func->curblock;
 744     ir_block *ontrue;
 745     ir_block *onfalse;
 746     ir_block *merge;
 747
 748     /* We don't output any value, thus also don't care about r/lvalue */
 749     (void)out;
 750     (void)lvalue;
 751
 752     /* generate the condition */
 753     func->curblock = cond;
 754     cgen = self->cond->expression.codegen;
 755     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 756         return false;
 757
 758     /* on-true path */
 759
 760     if (self->on_true) {
 761         /* create on-true block */
 762         ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
 763         if (!ontrue)
 764             return false;
 765
 766         /* enter the block */
 767         func->curblock = ontrue;
 768
 769         /* generate */
 770         cgen = self->on_true->expression.codegen;
 771         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
 772             return false;
 773     } else
 774         ontrue = NULL;
 775
 776     /* on-false path */
 777     if (self->on_false) {
 778         /* create on-false block */
 779         onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
 780         if (!onfalse)
 781             return false;
 782
 783         /* enter the block */
 784         func->curblock = onfalse;
 785
 786         /* generate */
 787         cgen = self->on_false->expression.codegen;
 788         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
 789             return false;
 790     } else
 791         onfalse = NULL;
 792
 793     /* Merge block were they all merge in to */
 794     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
 795     if (!merge)
 796         return NULL;
 797
 798     /* add jumps ot the merge block */
 799     if (ontrue && !ir_block_create_jump(ontrue, merge))
 800         return false;
 801     if (onfalse && !ir_block_create_jump(onfalse, merge))
 802         return false;
 803
 804     /* we create the if here, that way all blocks are ordered :)
 805      */
 806     if (!ir_block_create_if(cond, condval,
 807                             (ontrue  ? ontrue  : merge),
 808                             (onfalse ? onfalse : merge)))
 809     {
 810         return false;
 811     }
 812
 813     /* Now enter the merge block */
 814     func->curblock = merge;
 815
 816     return true;
 817 }
 818
 819 bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
 820 {
 821     ast_expression_codegen *cgen;
 822
 823     ir_value *condval;
 824     ir_value *trueval, *falseval;
 825     ir_instr *phi;
 826
 827     ir_block *cond = func->curblock;
 828     ir_block *ontrue;
 829     ir_block *onfalse;
 830     ir_block *merge;
 831
 832     /* In theory it shouldn't be possible to pass through a node twice, but
 833      * in case we add any kind of optimization pass for the AST itself, it
 834      * may still happen, thus we remember a created ir_value and simply return one
 835      * if it already exists.
 836      */
 837     if (self->phi_out) {
 838         *out = self->phi_out;
 839         return true;
 840     }
 841
 842     /* Ternary can never create an lvalue... */
 843     if (lvalue)
 844         return false;
 845
 846     /* In the following, contraty to ast_ifthen, we assume both paths exist. */
 847
 848     /* generate the condition */
 849     func->curblock = cond;
 850     cgen = self->cond->expression.codegen;
 851     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 852         return false;
 853
 854     /* create on-true block */
 855     ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
 856     if (!ontrue)
 857         return false;
 858     else
 859     {
 860         /* enter the block */
 861         func->curblock = ontrue;
 862
 863         /* generate */
 864         cgen = self->on_true->expression.codegen;
 865         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
 866             return false;
 867     }
 868
 869     /* create on-false block */
 870     onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
 871     if (!onfalse)
 872         return false;
 873     else
 874     {
 875         /* enter the block */
 876         func->curblock = onfalse;
 877
 878         /* generate */
 879         cgen = self->on_false->expression.codegen;
 880         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &falseval))
 881             return false;
 882     }
 883
 884     /* create merge block */
 885     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
 886     if (!merge)
 887         return NULL;
 888     /* jump to merge block */
 889     if (!ir_block_create_jump(ontrue, merge))
 890         return false;
 891     if (!ir_block_create_jump(onfalse, merge))
 892         return false;
 893
 894     /* create if instruction */
 895     if (!ir_block_create_if(cond, condval, ontrue, onfalse))
 896         return false;
 897
 898     /* Now enter the merge block */
 899     func->curblock = merge;
 900
 901     /* Here, now, we need a PHI node
 902      * but first some sanity checking...
 903      */
 904     if (trueval->vtype != falseval->vtype) {
 905         /* error("ternary with different types on the two sides"); */
 906         return false;
 907     }
 908
 909     /* create PHI */
 910     phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
 911     if (!phi ||
 912         !ir_phi_add(phi, ontrue,  trueval) ||
 913         !ir_phi_add(phi, onfalse, falseval))
 914     {
 915         return false;
 916     }
 917
 918     self->phi_out = ir_phi_value(phi);
 919     *out = self->phi_out;
 920
 921     return true;
 922 }
 923
 924 bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
 925 {
 926     ast_expression_codegen *cgen;
 927
 928     ir_value *dummy;
 929     ir_value *precond;
 930     ir_value *postcond;
 931
 932     /* Since we insert some jumps "late" so we have blocks
 933      * ordered "nicely", we need to keep track of the actual end-blocks
 934      * of expressions to add the jumps to.
 935      */
 936     ir_block *bbody,      *end_bbody;
 937     ir_block *bprecond,   *end_bprecond;
 938     ir_block *bpostcond,  *end_bpostcond;
 939     ir_block *bincrement, *end_bincrement;
 940     ir_block *bout, *bin;
 941
 942     /* let's at least move the outgoing block to the end */
 943     size_t    bout_id;
 944
 945     /* 'break' and 'continue' need to be able to find the right blocks */
 946     ir_block *bcontinue = NULL;
 947     ir_block *bbreak    = NULL;
 948
 949     ir_block *old_bcontinue;
 950     ir_block *old_bbreak;
 951
 952     ir_block *tmpblock;
 953
 954     (void)lvalue;
 955     (void)out;
 956
 957     /* NOTE:
 958      * Should we ever need some kind of block ordering, better make this function
 959      * move blocks around than write a block ordering algorithm later... after all
 960      * the ast and ir should work together, not against each other.
 961      */
 962
 963     /* initexpr doesn't get its own block, it's pointless, it could create more blocks
 964      * anyway if for example it contains a ternary.
 965      */
 966     if (self->initexpr)
 967     {
 968         cgen = self->initexpr->expression.codegen;
 969         if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
 970             return false;
 971     }
 972
 973     /* Store the block from which we enter this chaos */
 974     bin = func->curblock;
 975
 976     /* The pre-loop condition needs its own block since we
 977      * need to be able to jump to the start of that expression.
 978      */
 979     if (self->precond)
 980     {
 981         bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
 982         if (!bprecond)
 983             return false;
 984
 985         /* the pre-loop-condition the least important place to 'continue' at */
 986         bcontinue = bprecond;
 987
 988         /* enter */
 989         func->curblock = bprecond;
 990
 991         /* generate */
 992         cgen = self->precond->expression.codegen;
 993         if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
 994             return false;
 995
 996         end_bprecond = func->curblock;
 997     } else {
 998         bprecond = end_bprecond = NULL;
 999     }
1000
1001     /* Now the next blocks won't be ordered nicely, but we need to
1002      * generate them this early for 'break' and 'continue'.
1003      */
1004     if (self->increment) {
1005         bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
1006         if (!bincrement)
1007             return false;
1008         bcontinue = bincrement; /* increment comes before the pre-loop-condition */
1009     } else {
1010         bincrement = end_bincrement = NULL;
1011     }
1012
1013     if (self->postcond) {
1014         bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
1015         if (!bpostcond)
1016             return false;
1017         bcontinue = bpostcond; /* postcond comes before the increment */
1018     } else {
1019         bpostcond = end_bpostcond = NULL;
1020     }
1021
1022     bout_id = func->ir_func->blocks_count;
1023     bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
1024     if (!bout)
1025         return false;
1026     bbreak = bout;
1027
1028     /* The loop body... */
1029     if (self->body)
1030     {
1031         bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
1032         if (!bbody)
1033             return false;
1034
1035         /* enter */
1036         func->curblock = bbody;
1037
1038         old_bbreak          = func->breakblock;
1039         old_bcontinue       = func->continueblock;
1040         func->breakblock    = bbreak;
1041         func->continueblock = bcontinue;
1042
1043         /* generate */
1044         cgen = self->body->expression.codegen;
1045         if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
1046             return false;
1047
1048         end_bbody = func->curblock;
1049         func->breakblock    = old_bbreak;
1050         func->continueblock = old_bcontinue;
1051     }
1052
1053     /* post-loop-condition */
1054     if (self->postcond)
1055     {
1056         /* enter */
1057         func->curblock = bpostcond;
1058
1059         /* generate */
1060         cgen = self->postcond->expression.codegen;
1061         if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
1062             return false;
1063
1064         end_bpostcond = func->curblock;
1065     }
1066
1067     /* The incrementor */
1068     if (self->increment)
1069     {
1070         /* enter */
1071         func->curblock = bincrement;
1072
1073         /* generate */
1074         cgen = self->increment->expression.codegen;
1075         if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
1076             return false;
1077
1078         end_bincrement = func->curblock;
1079     }
1080
1081     /* In any case now, we continue from the outgoing block */
1082     func->curblock = bout;
1083
1084     /* Now all blocks are in place */
1085     /* From 'bin' we jump to whatever comes first */
1086     if      (bprecond)   tmpblock = bprecond;
1087     else if (bbody)      tmpblock = bbody;
1088     else if (bpostcond)  tmpblock = bpostcond;
1089     else                 tmpblock = bout;
1090     if (!ir_block_create_jump(bin, tmpblock))
1091         return false;
1092
1093     /* From precond */
1094     if (bprecond)
1095     {
1096         ir_block *ontrue, *onfalse;
1097         if      (bbody)      ontrue = bbody;
1098         else if (bincrement) ontrue = bincrement;
1099         else if (bpostcond)  ontrue = bpostcond;
1100         else                 ontrue = bprecond;
1101         onfalse = bout;
1102         if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
1103             return false;
1104     }
1105
1106     /* from body */
1107     if (bbody)
1108     {
1109         if      (bincrement) tmpblock = bincrement;
1110         else if (bpostcond)  tmpblock = bpostcond;
1111         else if (bprecond)   tmpblock = bprecond;
1112         else                 tmpblock = bout;
1113         if (!ir_block_create_jump(end_bbody, tmpblock))
1114             return false;
1115     }
1116
1117     /* from increment */
1118     if (bincrement)
1119     {
1120         if      (bpostcond)  tmpblock = bpostcond;
1121         else if (bprecond)   tmpblock = bprecond;
1122         else if (bbody)      tmpblock = bbody;
1123         else                 tmpblock = bout;
1124         if (!ir_block_create_jump(end_bincrement, tmpblock))
1125             return false;
1126     }
1127
1128     /* from postcond */
1129     if (bpostcond)
1130     {
1131         ir_block *ontrue, *onfalse;
1132         if      (bprecond)   ontrue = bprecond;
1133         else if (bbody)      ontrue = bbody;
1134         else if (bincrement) ontrue = bincrement;
1135         else                 ontrue = bpostcond;
1136         onfalse = bout;
1137         if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
1138             return false;
1139     }
1140
1141     /* Move 'bout' to the end */
1142     if (!ir_function_blocks_remove(func->ir_func, bout_id) ||
1143         !ir_function_blocks_add(func->ir_func, bout))
1144     {
1145         ir_block_delete(bout);
1146         return false;
1147     }
1148
1149     return true;
1150 }