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 GMQCC_NORETURN 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_call* ast_call_new(lex_ctx ctx,
 312                        ast_expression *funcexpr)
 313 {
 314     ast_instantiate(ast_call, ctx, ast_call_delete);
 315     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_call_codegen);
 316
 317     MEM_VECTOR_INIT(self, params);
 318
 319     return self;
 320 }
 321
 322 void ast_call_delete(ast_call *self)
 323 {
 324     size_t i;
 325     for (i = 0; i < self->params_count; ++i)
 326         ast_unref(self->params[i]);
 327     MEM_VECTOR_CLEAR(self, params);
 328
 329     if (self->func)
 330         ast_unref(self->func);
 331
 332     ast_expression_delete((ast_expression*)self);
 333     mem_d(self);
 334 }
 335
 336 ast_store* ast_store_new(lex_ctx ctx, int op,
 337                          ast_value *dest, ast_expression *source)
 338 {
 339     ast_instantiate(ast_store, ctx, ast_store_delete);
 340     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);
 341
 342     self->op = op;
 343     self->dest = dest;
 344     self->source = source;
 345
 346     return self;
 347 }
 348
 349 void ast_store_delete(ast_store *self)
 350 {
 351     ast_unref(self->dest);
 352     ast_unref(self->source);
 353     ast_expression_delete((ast_expression*)self);
 354     mem_d(self);
 355 }
 356
 357 ast_block* ast_block_new(lex_ctx ctx)
 358 {
 359     ast_instantiate(ast_block, ctx, ast_block_delete);
 360     ast_expression_init((ast_expression*)self,
 361                         (ast_expression_codegen*)&ast_block_codegen);
 362
 363     MEM_VECTOR_INIT(self, locals);
 364     MEM_VECTOR_INIT(self, exprs);
 365
 366     return self;
 367 }
 368 MEM_VEC_FUNCTIONS(ast_block, ast_value*, locals)
 369 MEM_VEC_FUNCTIONS(ast_block, ast_expression*, exprs)
 370
 371 void ast_block_delete(ast_block *self)
 372 {
 373     size_t i;
 374     for (i = 0; i < self->exprs_count; ++i)
 375         ast_unref(self->exprs[i]);
 376     MEM_VECTOR_CLEAR(self, exprs);
 377     for (i = 0; i < self->locals_count; ++i)
 378         ast_delete(self->locals[i]);
 379     MEM_VECTOR_CLEAR(self, locals);
 380     ast_expression_delete((ast_expression*)self);
 381     mem_d(self);
 382 }
 383
 384 ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
 385 {
 386     ast_instantiate(ast_function, ctx, ast_function_delete);
 387
 388     if (!vtype ||
 389         vtype->isconst ||
 390         vtype->expression.vtype != TYPE_FUNCTION)
 391     {
 392         mem_d(self);
 393         return NULL;
 394     }
 395
 396     self->vtype = vtype;
 397     self->name = name ? util_strdup(name) : NULL;
 398     MEM_VECTOR_INIT(self, blocks);
 399
 400     self->labelcount = 0;
 401
 402     self->ir_func = NULL;
 403     self->curblock = NULL;
 404
 405     self->breakblock    = NULL;
 406     self->continueblock = NULL;
 407
 408     vtype->isconst = true;
 409     vtype->constval.vfunc = self;
 410
 411     return self;
 412 }
 413
 414 MEM_VEC_FUNCTIONS(ast_function, ast_block*, blocks)
 415
 416 void ast_function_delete(ast_function *self)
 417 {
 418     size_t i;
 419     if (self->name)
 420         mem_d((void*)self->name);
 421     if (self->vtype) {
 422         /* ast_value_delete(self->vtype); */
 423         self->vtype->isconst = false;
 424         self->vtype->constval.vfunc = NULL;
 425         /* We use unref - if it was stored in a global table it is supposed
 426          * to be deleted from *there*
 427          */
 428         ast_unref(self->vtype);
 429     }
 430     for (i = 0; i < self->blocks_count; ++i)
 431         ast_delete(self->blocks[i]);
 432     MEM_VECTOR_CLEAR(self, blocks);
 433     mem_d(self);
 434 }
 435
 436 static void ast_util_hexitoa(char *buf, size_t size, unsigned int num)
 437 {
 438     unsigned int base = 10;
 439 #define checknul() do { if (size == 1) { *buf = 0; return; } } while (0)
 440 #define addch(x) do { *buf++ = (x); --size; checknul(); } while (0)
 441     if (size < 1)
 442         return;
 443     checknul();
 444     if (!num)
 445         addch('0');
 446     else {
 447         while (num)
 448         {
 449             int digit = num % base;
 450             num /= base;
 451             addch('0' + digit);
 452         }
 453     }
 454
 455     *buf = 0;
 456 #undef addch
 457 #undef checknul
 458 }
 459
 460 const char* ast_function_label(ast_function *self, const char *prefix)
 461 {
 462     size_t id = (self->labelcount++);
 463     size_t len = strlen(prefix);
 464     strncpy(self->labelbuf, prefix, sizeof(self->labelbuf));
 465     ast_util_hexitoa(self->labelbuf + len, sizeof(self->labelbuf)-len, id);
 466     return self->labelbuf;
 467 }
 468
 469 /*********************************************************************/
 470 /* AST codegen part
 471  * by convention you must never pass NULL to the 'ir_value **out'
 472  * parameter. If you really don't care about the output, pass a dummy.
 473  * But I can't imagine a pituation where the output is truly unnecessary.
 474  */
 475
 476 bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
 477 {
 478     /* NOTE: This is the codegen for a variable used in an expression.
 479      * It is not the codegen to generate the value. For this purpose,
 480      * ast_local_codegen and ast_global_codegen are to be used before this
 481      * is executed. ast_function_codegen should take care of its locals,
 482      * and the ast-user should take care of ast_global_codegen to be used
 483      * on all the globals.
 484      */
 485     if (!self->ir_v)
 486         return false;
 487     *out = self->ir_v;
 488     return true;
 489 }
 490
 491 bool ast_global_codegen(ast_value *self, ir_builder *ir)
 492 {
 493     ir_value *v = NULL;
 494     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 495     {
 496         ir_function *func = ir_builder_create_function(ir, self->name);
 497         if (!func)
 498             return false;
 499
 500         self->constval.vfunc->ir_func = func;
 501         /* The function is filled later on ast_function_codegen... */
 502         return true;
 503     }
 504
 505     v = ir_builder_create_global(ir, self->name, self->expression.vtype);
 506     if (!v)
 507         return false;
 508
 509     if (self->isconst) {
 510         switch (self->expression.vtype)
 511         {
 512             case TYPE_FLOAT:
 513                 if (!ir_value_set_float(v, self->constval.vfloat))
 514                     goto error;
 515                 break;
 516             case TYPE_VECTOR:
 517                 if (!ir_value_set_vector(v, self->constval.vvec))
 518                     goto error;
 519                 break;
 520             case TYPE_STRING:
 521                 if (!ir_value_set_string(v, self->constval.vstring))
 522                     goto error;
 523                 break;
 524             case TYPE_FUNCTION:
 525                 /* Cannot generate an IR value for a function,
 526                  * need a pointer pointing to a function rather.
 527                  */
 528                 goto error;
 529             default:
 530                 printf("TODO: global constant type %i\n", self->expression.vtype);
 531                 break;
 532         }
 533     }
 534
 535     /* link us to the ir_value */
 536     self->ir_v = v;
 537     return true;
 538
 539 error: /* clean up */
 540     ir_value_delete(v);
 541     return false;
 542 }
 543
 544 bool ast_local_codegen(ast_value *self, ir_function *func)
 545 {
 546     ir_value *v = NULL;
 547     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 548     {
 549         /* Do we allow local functions? I think not...
 550          * this is NOT a function pointer atm.
 551          */
 552         return false;
 553     }
 554
 555     v = ir_function_create_local(func, self->name, self->expression.vtype);
 556     if (!v)
 557         return false;
 558
 559     /* A constant local... hmmm...
 560      * I suppose the IR will have to deal with this
 561      */
 562     if (self->isconst) {
 563         switch (self->expression.vtype)
 564         {
 565             case TYPE_FLOAT:
 566                 if (!ir_value_set_float(v, self->constval.vfloat))
 567                     goto error;
 568                 break;
 569             case TYPE_VECTOR:
 570                 if (!ir_value_set_vector(v, self->constval.vvec))
 571                     goto error;
 572                 break;
 573             case TYPE_STRING:
 574                 if (!ir_value_set_string(v, self->constval.vstring))
 575                     goto error;
 576                 break;
 577             default:
 578                 printf("TODO: global constant type %i\n", self->expression.vtype);
 579                 break;
 580         }
 581     }
 582
 583     /* link us to the ir_value */
 584     self->ir_v = v;
 585     return true;
 586
 587 error: /* clean up */
 588     ir_value_delete(v);
 589     return false;
 590 }
 591
 592 bool ast_function_codegen(ast_function *self, ir_builder *ir)
 593 {
 594     ir_function *irf;
 595     ir_value    *dummy;
 596     size_t    i;
 597
 598     irf = self->ir_func;
 599     if (!irf) {
 600         printf("ast_function's related ast_value was not generated yet\n");
 601         return false;
 602     }
 603
 604     self->curblock = ir_function_create_block(irf, "entry");
 605     if (!self->curblock)
 606         return false;
 607
 608     for (i = 0; i < self->blocks_count; ++i) {
 609         ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
 610         if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
 611             return false;
 612     }
 613
 614     /* TODO: check return types */
 615     if (!self->curblock->is_return)
 616     {
 617         if (!self->vtype->expression.next ||
 618             self->vtype->expression.next->expression.vtype == TYPE_VOID)
 619             return ir_block_create_return(self->curblock, NULL);
 620         else
 621         {
 622             /* error("missing return"); */
 623             return false;
 624         }
 625     }
 626     return true;
 627 }
 628
 629 /* Note, you will not see ast_block_codegen generate ir_blocks.
 630  * To the AST and the IR, blocks are 2 different things.
 631  * In the AST it represents a block of code, usually enclosed in
 632  * curly braces {...}.
 633  * While in the IR it represents a block in terms of control-flow.
 634  */
 635 bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
 636 {
 637     size_t i;
 638
 639     /* We don't use this
 640      * Note: an ast-representation using the comma-operator
 641      * of the form: (a, b, c) = x should not assign to c...
 642      */
 643     (void)lvalue;
 644
 645     /* output is NULL at first, we'll have each expression
 646      * assign to out output, thus, a comma-operator represention
 647      * using an ast_block will return the last generated value,
 648      * so: (b, c) + a  executed both b and c, and returns c,
 649      * which is then added to a.
 650      */
 651     *out = NULL;
 652
 653     /* generate locals */
 654     for (i = 0; i < self->locals_count; ++i)
 655     {
 656         if (!ast_local_codegen(self->locals[i], func->ir_func))
 657             return false;
 658     }
 659
 660     for (i = 0; i < self->exprs_count; ++i)
 661     {
 662         ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
 663         if (!(*gen)(self->exprs[i], func, false, out))
 664             return false;
 665     }
 666
 667     return true;
 668 }
 669
 670 bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
 671 {
 672     ast_expression_codegen *cgen;
 673     ir_value *left, *right;
 674
 675     cgen = self->dest->expression.codegen;
 676     /* lvalue! */
 677     if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
 678         return false;
 679
 680     cgen = self->source->expression.codegen;
 681     /* rvalue! */
 682     if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
 683         return false;
 684
 685     if (!ir_block_create_store_op(func->curblock, self->op, left, right))
 686         return false;
 687
 688     /* Theoretically, an assinment returns its left side as an
 689      * lvalue, if we don't need an lvalue though, we return
 690      * the right side as an rvalue, otherwise we have to
 691      * somehow know whether or not we need to dereference the pointer
 692      * on the left side - that is: OP_LOAD if it was an address.
 693      * Also: in original QC we cannot OP_LOADP *anyway*.
 694      */
 695     *out = (lvalue ? left : right);
 696
 697     return true;
 698 }
 699
 700 bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
 701 {
 702     ast_expression_codegen *cgen;
 703     ir_value *left, *right;
 704
 705     /* In the context of a binary operation, we can disregard
 706      * the lvalue flag.
 707      */
 708      (void)lvalue;
 709
 710     cgen = self->left->expression.codegen;
 711     /* lvalue! */
 712     if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
 713         return false;
 714
 715     cgen = self->right->expression.codegen;
 716     /* rvalue! */
 717     if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
 718         return false;
 719
 720     *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
 721                                  self->op, left, right);
 722     if (!*out)
 723         return false;
 724
 725     return true;
 726 }
 727
 728 bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
 729 {
 730     ast_expression_codegen *cgen;
 731     ir_value *ent, *field;
 732
 733     /* This function needs to take the 'lvalue' flag into account!
 734      * As lvalue we provide a field-pointer, as rvalue we provide the
 735      * value in a temp.
 736      */
 737
 738     cgen = self->entity->expression.codegen;
 739     if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
 740         return false;
 741
 742     cgen = self->field->expression.codegen;
 743     if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
 744         return false;
 745
 746     if (lvalue) {
 747         /* address! */
 748         *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
 749                                             ent, field);
 750     } else {
 751         *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
 752                                              ent, field, self->expression.vtype);
 753     }
 754     if (!*out)
 755         return false;
 756
 757     /* Hm that should be it... */
 758     return true;
 759 }
 760
 761 bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
 762 {
 763     ast_expression_codegen *cgen;
 764
 765     ir_value *condval;
 766     ir_value *dummy;
 767
 768     ir_block *cond = func->curblock;
 769     ir_block *ontrue;
 770     ir_block *onfalse;
 771     ir_block *merge;
 772
 773     /* We don't output any value, thus also don't care about r/lvalue */
 774     (void)out;
 775     (void)lvalue;
 776
 777     /* generate the condition */
 778     func->curblock = cond;
 779     cgen = self->cond->expression.codegen;
 780     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 781         return false;
 782
 783     /* on-true path */
 784
 785     if (self->on_true) {
 786         /* create on-true block */
 787         ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
 788         if (!ontrue)
 789             return false;
 790
 791         /* enter the block */
 792         func->curblock = ontrue;
 793
 794         /* generate */
 795         cgen = self->on_true->expression.codegen;
 796         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
 797             return false;
 798     } else
 799         ontrue = NULL;
 800
 801     /* on-false path */
 802     if (self->on_false) {
 803         /* create on-false block */
 804         onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
 805         if (!onfalse)
 806             return false;
 807
 808         /* enter the block */
 809         func->curblock = onfalse;
 810
 811         /* generate */
 812         cgen = self->on_false->expression.codegen;
 813         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
 814             return false;
 815     } else
 816         onfalse = NULL;
 817
 818     /* Merge block were they all merge in to */
 819     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
 820     if (!merge)
 821         return false;
 822
 823     /* add jumps ot the merge block */
 824     if (ontrue && !ir_block_create_jump(ontrue, merge))
 825         return false;
 826     if (onfalse && !ir_block_create_jump(onfalse, merge))
 827         return false;
 828
 829     /* we create the if here, that way all blocks are ordered :)
 830      */
 831     if (!ir_block_create_if(cond, condval,
 832                             (ontrue  ? ontrue  : merge),
 833                             (onfalse ? onfalse : merge)))
 834     {
 835         return false;
 836     }
 837
 838     /* Now enter the merge block */
 839     func->curblock = merge;
 840
 841     return true;
 842 }
 843
 844 bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
 845 {
 846     ast_expression_codegen *cgen;
 847
 848     ir_value *condval;
 849     ir_value *trueval, *falseval;
 850     ir_instr *phi;
 851
 852     ir_block *cond = func->curblock;
 853     ir_block *ontrue;
 854     ir_block *onfalse;
 855     ir_block *merge;
 856
 857     /* In theory it shouldn't be possible to pass through a node twice, but
 858      * in case we add any kind of optimization pass for the AST itself, it
 859      * may still happen, thus we remember a created ir_value and simply return one
 860      * if it already exists.
 861      */
 862     if (self->phi_out) {
 863         *out = self->phi_out;
 864         return true;
 865     }
 866
 867     /* Ternary can never create an lvalue... */
 868     if (lvalue)
 869         return false;
 870
 871     /* In the following, contraty to ast_ifthen, we assume both paths exist. */
 872
 873     /* generate the condition */
 874     func->curblock = cond;
 875     cgen = self->cond->expression.codegen;
 876     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 877         return false;
 878
 879     /* create on-true block */
 880     ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
 881     if (!ontrue)
 882         return false;
 883     else
 884     {
 885         /* enter the block */
 886         func->curblock = ontrue;
 887
 888         /* generate */
 889         cgen = self->on_true->expression.codegen;
 890         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
 891             return false;
 892     }
 893
 894     /* create on-false block */
 895     onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
 896     if (!onfalse)
 897         return false;
 898     else
 899     {
 900         /* enter the block */
 901         func->curblock = onfalse;
 902
 903         /* generate */
 904         cgen = self->on_false->expression.codegen;
 905         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &falseval))
 906             return false;
 907     }
 908
 909     /* create merge block */
 910     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
 911     if (!merge)
 912         return false;
 913     /* jump to merge block */
 914     if (!ir_block_create_jump(ontrue, merge))
 915         return false;
 916     if (!ir_block_create_jump(onfalse, merge))
 917         return false;
 918
 919     /* create if instruction */
 920     if (!ir_block_create_if(cond, condval, ontrue, onfalse))
 921         return false;
 922
 923     /* Now enter the merge block */
 924     func->curblock = merge;
 925
 926     /* Here, now, we need a PHI node
 927      * but first some sanity checking...
 928      */
 929     if (trueval->vtype != falseval->vtype) {
 930         /* error("ternary with different types on the two sides"); */
 931         return false;
 932     }
 933
 934     /* create PHI */
 935     phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
 936     if (!phi ||
 937         !ir_phi_add(phi, ontrue,  trueval) ||
 938         !ir_phi_add(phi, onfalse, falseval))
 939     {
 940         return false;
 941     }
 942
 943     self->phi_out = ir_phi_value(phi);
 944     *out = self->phi_out;
 945
 946     return true;
 947 }
 948
 949 bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
 950 {
 951     ast_expression_codegen *cgen;
 952
 953     ir_value *dummy      = NULL;
 954     ir_value *precond    = NULL;
 955     ir_value *postcond   = NULL;
 956
 957     /* Since we insert some jumps "late" so we have blocks
 958      * ordered "nicely", we need to keep track of the actual end-blocks
 959      * of expressions to add the jumps to.
 960      */
 961     ir_block *bbody      = NULL, *end_bbody      = NULL;
 962     ir_block *bprecond   = NULL, *end_bprecond   = NULL;
 963     ir_block *bpostcond  = NULL, *end_bpostcond  = NULL;
 964     ir_block *bincrement = NULL, *end_bincrement = NULL;
 965     ir_block *bout       = NULL, *bin            = NULL;
 966
 967     /* let's at least move the outgoing block to the end */
 968     size_t    bout_id;
 969
 970     /* 'break' and 'continue' need to be able to find the right blocks */
 971     ir_block *bcontinue     = NULL;
 972     ir_block *bbreak        = NULL;
 973
 974     ir_block *old_bcontinue = NULL;
 975     ir_block *old_bbreak    = NULL;
 976
 977     ir_block *tmpblock      = NULL;
 978
 979     (void)lvalue;
 980     (void)out;
 981
 982     /* NOTE:
 983      * Should we ever need some kind of block ordering, better make this function
 984      * move blocks around than write a block ordering algorithm later... after all
 985      * the ast and ir should work together, not against each other.
 986      */
 987
 988     /* initexpr doesn't get its own block, it's pointless, it could create more blocks
 989      * anyway if for example it contains a ternary.
 990      */
 991     if (self->initexpr)
 992     {
 993         cgen = self->initexpr->expression.codegen;
 994         if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
 995             return false;
 996     }
 997
 998     /* Store the block from which we enter this chaos */
 999     bin = func->curblock;
1000
1001     /* The pre-loop condition needs its own block since we
1002      * need to be able to jump to the start of that expression.
1003      */
1004     if (self->precond)
1005     {
1006         bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
1007         if (!bprecond)
1008             return false;
1009
1010         /* the pre-loop-condition the least important place to 'continue' at */
1011         bcontinue = bprecond;
1012
1013         /* enter */
1014         func->curblock = bprecond;
1015
1016         /* generate */
1017         cgen = self->precond->expression.codegen;
1018         if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
1019             return false;
1020
1021         end_bprecond = func->curblock;
1022     } else {
1023         bprecond = end_bprecond = NULL;
1024     }
1025
1026     /* Now the next blocks won't be ordered nicely, but we need to
1027      * generate them this early for 'break' and 'continue'.
1028      */
1029     if (self->increment) {
1030         bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
1031         if (!bincrement)
1032             return false;
1033         bcontinue = bincrement; /* increment comes before the pre-loop-condition */
1034     } else {
1035         bincrement = end_bincrement = NULL;
1036     }
1037
1038     if (self->postcond) {
1039         bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
1040         if (!bpostcond)
1041             return false;
1042         bcontinue = bpostcond; /* postcond comes before the increment */
1043     } else {
1044         bpostcond = end_bpostcond = NULL;
1045     }
1046
1047     bout_id = func->ir_func->blocks_count;
1048     bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
1049     if (!bout)
1050         return false;
1051     bbreak = bout;
1052
1053     /* The loop body... */
1054     if (self->body)
1055     {
1056         bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
1057         if (!bbody)
1058             return false;
1059
1060         /* enter */
1061         func->curblock = bbody;
1062
1063         old_bbreak          = func->breakblock;
1064         old_bcontinue       = func->continueblock;
1065         func->breakblock    = bbreak;
1066         func->continueblock = bcontinue;
1067
1068         /* generate */
1069         cgen = self->body->expression.codegen;
1070         if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
1071             return false;
1072
1073         end_bbody = func->curblock;
1074         func->breakblock    = old_bbreak;
1075         func->continueblock = old_bcontinue;
1076     }
1077
1078     /* post-loop-condition */
1079     if (self->postcond)
1080     {
1081         /* enter */
1082         func->curblock = bpostcond;
1083
1084         /* generate */
1085         cgen = self->postcond->expression.codegen;
1086         if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
1087             return false;
1088
1089         end_bpostcond = func->curblock;
1090     }
1091
1092     /* The incrementor */
1093     if (self->increment)
1094     {
1095         /* enter */
1096         func->curblock = bincrement;
1097
1098         /* generate */
1099         cgen = self->increment->expression.codegen;
1100         if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
1101             return false;
1102
1103         end_bincrement = func->curblock;
1104     }
1105
1106     /* In any case now, we continue from the outgoing block */
1107     func->curblock = bout;
1108
1109     /* Now all blocks are in place */
1110     /* From 'bin' we jump to whatever comes first */
1111     if      (bprecond)   tmpblock = bprecond;
1112     else if (bbody)      tmpblock = bbody;
1113     else if (bpostcond)  tmpblock = bpostcond;
1114     else                 tmpblock = bout;
1115     if (!ir_block_create_jump(bin, tmpblock))
1116         return false;
1117
1118     /* From precond */
1119     if (bprecond)
1120     {
1121         ir_block *ontrue, *onfalse;
1122         if      (bbody)      ontrue = bbody;
1123         else if (bincrement) ontrue = bincrement;
1124         else if (bpostcond)  ontrue = bpostcond;
1125         else                 ontrue = bprecond;
1126         onfalse = bout;
1127         if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
1128             return false;
1129     }
1130
1131     /* from body */
1132     if (bbody)
1133     {
1134         if      (bincrement) tmpblock = bincrement;
1135         else if (bpostcond)  tmpblock = bpostcond;
1136         else if (bprecond)   tmpblock = bprecond;
1137         else                 tmpblock = bout;
1138         if (!ir_block_create_jump(end_bbody, tmpblock))
1139             return false;
1140     }
1141
1142     /* from increment */
1143     if (bincrement)
1144     {
1145         if      (bpostcond)  tmpblock = bpostcond;
1146         else if (bprecond)   tmpblock = bprecond;
1147         else if (bbody)      tmpblock = bbody;
1148         else                 tmpblock = bout;
1149         if (!ir_block_create_jump(end_bincrement, tmpblock))
1150             return false;
1151     }
1152
1153     /* from postcond */
1154     if (bpostcond)
1155     {
1156         ir_block *ontrue, *onfalse;
1157         if      (bprecond)   ontrue = bprecond;
1158         else if (bbody)      ontrue = bbody;
1159         else if (bincrement) ontrue = bincrement;
1160         else                 ontrue = bpostcond;
1161         onfalse = bout;
1162         if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
1163             return false;
1164     }
1165
1166     /* Move 'bout' to the end */
1167     if (!ir_function_blocks_remove(func->ir_func, bout_id) ||
1168         !ir_function_blocks_add(func->ir_func, bout))
1169     {
1170         ir_block_delete(bout);
1171         return false;
1172     }
1173
1174     return true;
1175 }
1176
1177 bool ast_call_codegen(ast_call *self, ast_function *func, bool lvalue, ir_value **out)
1178 {
1179     /* TODO: call ir codegen */
1180     return false;
1181 }