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     self->func = funcexpr;
 320
 321     return self;
 322 }
 323 MEM_VEC_FUNCTIONS(ast_call, ast_expression*, params)
 324
 325 void ast_call_delete(ast_call *self)
 326 {
 327     size_t i;
 328     for (i = 0; i < self->params_count; ++i)
 329         ast_unref(self->params[i]);
 330     MEM_VECTOR_CLEAR(self, params);
 331
 332     if (self->func)
 333         ast_unref(self->func);
 334
 335     ast_expression_delete((ast_expression*)self);
 336     mem_d(self);
 337 }
 338
 339 ast_store* ast_store_new(lex_ctx ctx, int op,
 340                          ast_value *dest, ast_expression *source)
 341 {
 342     ast_instantiate(ast_store, ctx, ast_store_delete);
 343     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);
 344
 345     self->op = op;
 346     self->dest = dest;
 347     self->source = source;
 348
 349     return self;
 350 }
 351
 352 void ast_store_delete(ast_store *self)
 353 {
 354     ast_unref(self->dest);
 355     ast_unref(self->source);
 356     ast_expression_delete((ast_expression*)self);
 357     mem_d(self);
 358 }
 359
 360 ast_block* ast_block_new(lex_ctx ctx)
 361 {
 362     ast_instantiate(ast_block, ctx, ast_block_delete);
 363     ast_expression_init((ast_expression*)self,
 364                         (ast_expression_codegen*)&ast_block_codegen);
 365
 366     MEM_VECTOR_INIT(self, locals);
 367     MEM_VECTOR_INIT(self, exprs);
 368
 369     return self;
 370 }
 371 MEM_VEC_FUNCTIONS(ast_block, ast_value*, locals)
 372 MEM_VEC_FUNCTIONS(ast_block, ast_expression*, exprs)
 373
 374 void ast_block_delete(ast_block *self)
 375 {
 376     size_t i;
 377     for (i = 0; i < self->exprs_count; ++i)
 378         ast_unref(self->exprs[i]);
 379     MEM_VECTOR_CLEAR(self, exprs);
 380     for (i = 0; i < self->locals_count; ++i)
 381         ast_delete(self->locals[i]);
 382     MEM_VECTOR_CLEAR(self, locals);
 383     ast_expression_delete((ast_expression*)self);
 384     mem_d(self);
 385 }
 386
 387 ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
 388 {
 389     ast_instantiate(ast_function, ctx, ast_function_delete);
 390
 391     if (!vtype ||
 392         vtype->isconst ||
 393         vtype->expression.vtype != TYPE_FUNCTION)
 394     {
 395         mem_d(self);
 396         return NULL;
 397     }
 398
 399     self->vtype = vtype;
 400     self->name = name ? util_strdup(name) : NULL;
 401     MEM_VECTOR_INIT(self, blocks);
 402
 403     self->labelcount = 0;
 404     self->builtin = 0;
 405
 406     self->ir_func = NULL;
 407     self->curblock = NULL;
 408
 409     self->breakblock    = NULL;
 410     self->continueblock = NULL;
 411
 412     vtype->isconst = true;
 413     vtype->constval.vfunc = self;
 414
 415     return self;
 416 }
 417
 418 MEM_VEC_FUNCTIONS(ast_function, ast_block*, blocks)
 419
 420 void ast_function_delete(ast_function *self)
 421 {
 422     size_t i;
 423     if (self->name)
 424         mem_d((void*)self->name);
 425     if (self->vtype) {
 426         /* ast_value_delete(self->vtype); */
 427         self->vtype->isconst = false;
 428         self->vtype->constval.vfunc = NULL;
 429         /* We use unref - if it was stored in a global table it is supposed
 430          * to be deleted from *there*
 431          */
 432         ast_unref(self->vtype);
 433     }
 434     for (i = 0; i < self->blocks_count; ++i)
 435         ast_delete(self->blocks[i]);
 436     MEM_VECTOR_CLEAR(self, blocks);
 437     mem_d(self);
 438 }
 439
 440 static void ast_util_hexitoa(char *buf, size_t size, unsigned int num)
 441 {
 442     unsigned int base = 10;
 443 #define checknul() do { if (size == 1) { *buf = 0; return; } } while (0)
 444 #define addch(x) do { *buf++ = (x); --size; checknul(); } while (0)
 445     if (size < 1)
 446         return;
 447     checknul();
 448     if (!num)
 449         addch('0');
 450     else {
 451         while (num)
 452         {
 453             int digit = num % base;
 454             num /= base;
 455             addch('0' + digit);
 456         }
 457     }
 458
 459     *buf = 0;
 460 #undef addch
 461 #undef checknul
 462 }
 463
 464 const char* ast_function_label(ast_function *self, const char *prefix)
 465 {
 466     size_t id = (self->labelcount++);
 467     size_t len = strlen(prefix);
 468     strncpy(self->labelbuf, prefix, sizeof(self->labelbuf));
 469     ast_util_hexitoa(self->labelbuf + len, sizeof(self->labelbuf)-len, id);
 470     return self->labelbuf;
 471 }
 472
 473 /*********************************************************************/
 474 /* AST codegen part
 475  * by convention you must never pass NULL to the 'ir_value **out'
 476  * parameter. If you really don't care about the output, pass a dummy.
 477  * But I can't imagine a pituation where the output is truly unnecessary.
 478  */
 479
 480 bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
 481 {
 482     /* NOTE: This is the codegen for a variable used in an expression.
 483      * It is not the codegen to generate the value. For this purpose,
 484      * ast_local_codegen and ast_global_codegen are to be used before this
 485      * is executed. ast_function_codegen should take care of its locals,
 486      * and the ast-user should take care of ast_global_codegen to be used
 487      * on all the globals.
 488      */
 489     if (!self->ir_v) {
 490         printf("ast_value used before generated (%s)\n", self->name);
 491         return false;
 492     }
 493     *out = self->ir_v;
 494     return true;
 495 }
 496
 497 bool ast_global_codegen(ast_value *self, ir_builder *ir)
 498 {
 499     ir_value *v = NULL;
 500     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 501     {
 502         ir_function *func = ir_builder_create_function(ir, self->name, self->expression.next->expression.vtype);
 503         if (!func)
 504             return false;
 505
 506         self->constval.vfunc->ir_func = func;
 507         self->ir_v = func->value;
 508         /* The function is filled later on ast_function_codegen... */
 509         return true;
 510     }
 511
 512     v = ir_builder_create_global(ir, self->name, self->expression.vtype);
 513     if (!v) {
 514         printf("ir_builder_create_global failed\n");
 515         return false;
 516     }
 517
 518     if (self->isconst) {
 519         switch (self->expression.vtype)
 520         {
 521             case TYPE_FLOAT:
 522                 if (!ir_value_set_float(v, self->constval.vfloat))
 523                     goto error;
 524                 break;
 525             case TYPE_VECTOR:
 526                 if (!ir_value_set_vector(v, self->constval.vvec))
 527                     goto error;
 528                 break;
 529             case TYPE_STRING:
 530                 if (!ir_value_set_string(v, self->constval.vstring))
 531                     goto error;
 532                 break;
 533             case TYPE_FUNCTION:
 534                 printf("global of type function not properly generated\n");
 535                 goto error;
 536                 /* Cannot generate an IR value for a function,
 537                  * need a pointer pointing to a function rather.
 538                  */
 539             default:
 540                 printf("TODO: global constant type %i\n", self->expression.vtype);
 541                 break;
 542         }
 543     }
 544
 545     /* link us to the ir_value */
 546     self->ir_v = v;
 547     return true;
 548
 549 error: /* clean up */
 550     ir_value_delete(v);
 551     return false;
 552 }
 553
 554 bool ast_local_codegen(ast_value *self, ir_function *func)
 555 {
 556     ir_value *v = NULL;
 557     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 558     {
 559         /* Do we allow local functions? I think not...
 560          * this is NOT a function pointer atm.
 561          */
 562         return false;
 563     }
 564
 565     v = ir_function_create_local(func, self->name, self->expression.vtype);
 566     if (!v)
 567         return false;
 568
 569     /* A constant local... hmmm...
 570      * I suppose the IR will have to deal with this
 571      */
 572     if (self->isconst) {
 573         switch (self->expression.vtype)
 574         {
 575             case TYPE_FLOAT:
 576                 if (!ir_value_set_float(v, self->constval.vfloat))
 577                     goto error;
 578                 break;
 579             case TYPE_VECTOR:
 580                 if (!ir_value_set_vector(v, self->constval.vvec))
 581                     goto error;
 582                 break;
 583             case TYPE_STRING:
 584                 if (!ir_value_set_string(v, self->constval.vstring))
 585                     goto error;
 586                 break;
 587             default:
 588                 printf("TODO: global constant type %i\n", self->expression.vtype);
 589                 break;
 590         }
 591     }
 592
 593     /* link us to the ir_value */
 594     self->ir_v = v;
 595     return true;
 596
 597 error: /* clean up */
 598     ir_value_delete(v);
 599     return false;
 600 }
 601
 602 bool ast_function_codegen(ast_function *self, ir_builder *ir)
 603 {
 604     ir_function *irf;
 605     ir_value    *dummy;
 606     size_t    i;
 607
 608     irf = self->ir_func;
 609     if (!irf) {
 610         printf("ast_function's related ast_value was not generated yet\n");
 611         return false;
 612     }
 613
 614     for (i = 0; i < self->vtype->params_count; ++i)
 615     {
 616         if (!ir_function_params_add(irf, self->vtype->params[i]->expression.vtype))
 617             return false;
 618     }
 619
 620     if (self->builtin) {
 621         irf->builtin = self->builtin;
 622         return true;
 623     }
 624
 625     self->curblock = ir_function_create_block(irf, "entry");
 626     if (!self->curblock)
 627         return false;
 628
 629     for (i = 0; i < self->blocks_count; ++i) {
 630         ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
 631         if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
 632             return false;
 633     }
 634
 635     /* TODO: check return types */
 636     if (!self->curblock->is_return)
 637     {
 638         if (!self->vtype->expression.next ||
 639             self->vtype->expression.next->expression.vtype == TYPE_VOID)
 640         {
 641             return ir_block_create_return(self->curblock, NULL);
 642         }
 643         else
 644         {
 645             /* error("missing return"); */
 646             return false;
 647         }
 648     }
 649     return true;
 650 }
 651
 652 /* Note, you will not see ast_block_codegen generate ir_blocks.
 653  * To the AST and the IR, blocks are 2 different things.
 654  * In the AST it represents a block of code, usually enclosed in
 655  * curly braces {...}.
 656  * While in the IR it represents a block in terms of control-flow.
 657  */
 658 bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
 659 {
 660     size_t i;
 661
 662     /* We don't use this
 663      * Note: an ast-representation using the comma-operator
 664      * of the form: (a, b, c) = x should not assign to c...
 665      */
 666     (void)lvalue;
 667
 668     /* output is NULL at first, we'll have each expression
 669      * assign to out output, thus, a comma-operator represention
 670      * using an ast_block will return the last generated value,
 671      * so: (b, c) + a  executed both b and c, and returns c,
 672      * which is then added to a.
 673      */
 674     *out = NULL;
 675
 676     /* generate locals */
 677     for (i = 0; i < self->locals_count; ++i)
 678     {
 679         if (!ast_local_codegen(self->locals[i], func->ir_func))
 680             return false;
 681     }
 682
 683     for (i = 0; i < self->exprs_count; ++i)
 684     {
 685         ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
 686         if (!(*gen)(self->exprs[i], func, false, out))
 687             return false;
 688     }
 689
 690     return true;
 691 }
 692
 693 bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
 694 {
 695     ast_expression_codegen *cgen;
 696     ir_value *left, *right;
 697
 698     cgen = self->dest->expression.codegen;
 699     /* lvalue! */
 700     if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
 701         return false;
 702
 703     cgen = self->source->expression.codegen;
 704     /* rvalue! */
 705     if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
 706         return false;
 707
 708     if (!ir_block_create_store_op(func->curblock, self->op, left, right))
 709         return false;
 710
 711     /* Theoretically, an assinment returns its left side as an
 712      * lvalue, if we don't need an lvalue though, we return
 713      * the right side as an rvalue, otherwise we have to
 714      * somehow know whether or not we need to dereference the pointer
 715      * on the left side - that is: OP_LOAD if it was an address.
 716      * Also: in original QC we cannot OP_LOADP *anyway*.
 717      */
 718     *out = (lvalue ? left : right);
 719
 720     return true;
 721 }
 722
 723 bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
 724 {
 725     ast_expression_codegen *cgen;
 726     ir_value *left, *right;
 727
 728     /* In the context of a binary operation, we can disregard
 729      * the lvalue flag.
 730      */
 731      (void)lvalue;
 732
 733     cgen = self->left->expression.codegen;
 734     /* lvalue! */
 735     if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
 736         return false;
 737
 738     cgen = self->right->expression.codegen;
 739     /* rvalue! */
 740     if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
 741         return false;
 742
 743     *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
 744                                  self->op, left, right);
 745     if (!*out)
 746         return false;
 747
 748     return true;
 749 }
 750
 751 bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
 752 {
 753     ast_expression_codegen *cgen;
 754     ir_value *ent, *field;
 755
 756     /* This function needs to take the 'lvalue' flag into account!
 757      * As lvalue we provide a field-pointer, as rvalue we provide the
 758      * value in a temp.
 759      */
 760
 761     cgen = self->entity->expression.codegen;
 762     if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
 763         return false;
 764
 765     cgen = self->field->expression.codegen;
 766     if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
 767         return false;
 768
 769     if (lvalue) {
 770         /* address! */
 771         *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
 772                                             ent, field);
 773     } else {
 774         *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
 775                                              ent, field, self->expression.vtype);
 776     }
 777     if (!*out)
 778         return false;
 779
 780     /* Hm that should be it... */
 781     return true;
 782 }
 783
 784 bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
 785 {
 786     ast_expression_codegen *cgen;
 787
 788     ir_value *condval;
 789     ir_value *dummy;
 790
 791     ir_block *cond = func->curblock;
 792     ir_block *ontrue;
 793     ir_block *onfalse;
 794     ir_block *merge;
 795
 796     /* We don't output any value, thus also don't care about r/lvalue */
 797     (void)out;
 798     (void)lvalue;
 799
 800     /* generate the condition */
 801     func->curblock = cond;
 802     cgen = self->cond->expression.codegen;
 803     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 804         return false;
 805
 806     /* on-true path */
 807
 808     if (self->on_true) {
 809         /* create on-true block */
 810         ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
 811         if (!ontrue)
 812             return false;
 813
 814         /* enter the block */
 815         func->curblock = ontrue;
 816
 817         /* generate */
 818         cgen = self->on_true->expression.codegen;
 819         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
 820             return false;
 821     } else
 822         ontrue = NULL;
 823
 824     /* on-false path */
 825     if (self->on_false) {
 826         /* create on-false block */
 827         onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
 828         if (!onfalse)
 829             return false;
 830
 831         /* enter the block */
 832         func->curblock = onfalse;
 833
 834         /* generate */
 835         cgen = self->on_false->expression.codegen;
 836         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
 837             return false;
 838     } else
 839         onfalse = NULL;
 840
 841     /* Merge block were they all merge in to */
 842     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
 843     if (!merge)
 844         return false;
 845
 846     /* add jumps ot the merge block */
 847     if (ontrue && !ir_block_create_jump(ontrue, merge))
 848         return false;
 849     if (onfalse && !ir_block_create_jump(onfalse, merge))
 850         return false;
 851
 852     /* we create the if here, that way all blocks are ordered :)
 853      */
 854     if (!ir_block_create_if(cond, condval,
 855                             (ontrue  ? ontrue  : merge),
 856                             (onfalse ? onfalse : merge)))
 857     {
 858         return false;
 859     }
 860
 861     /* Now enter the merge block */
 862     func->curblock = merge;
 863
 864     return true;
 865 }
 866
 867 bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
 868 {
 869     ast_expression_codegen *cgen;
 870
 871     ir_value *condval;
 872     ir_value *trueval, *falseval;
 873     ir_instr *phi;
 874
 875     ir_block *cond = func->curblock;
 876     ir_block *ontrue;
 877     ir_block *onfalse;
 878     ir_block *merge;
 879
 880     /* In theory it shouldn't be possible to pass through a node twice, but
 881      * in case we add any kind of optimization pass for the AST itself, it
 882      * may still happen, thus we remember a created ir_value and simply return one
 883      * if it already exists.
 884      */
 885     if (self->phi_out) {
 886         *out = self->phi_out;
 887         return true;
 888     }
 889
 890     /* Ternary can never create an lvalue... */
 891     if (lvalue)
 892         return false;
 893
 894     /* In the following, contraty to ast_ifthen, we assume both paths exist. */
 895
 896     /* generate the condition */
 897     func->curblock = cond;
 898     cgen = self->cond->expression.codegen;
 899     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 900         return false;
 901
 902     /* create on-true block */
 903     ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
 904     if (!ontrue)
 905         return false;
 906     else
 907     {
 908         /* enter the block */
 909         func->curblock = ontrue;
 910
 911         /* generate */
 912         cgen = self->on_true->expression.codegen;
 913         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
 914             return false;
 915     }
 916
 917     /* create on-false block */
 918     onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
 919     if (!onfalse)
 920         return false;
 921     else
 922     {
 923         /* enter the block */
 924         func->curblock = onfalse;
 925
 926         /* generate */
 927         cgen = self->on_false->expression.codegen;
 928         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &falseval))
 929             return false;
 930     }
 931
 932     /* create merge block */
 933     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
 934     if (!merge)
 935         return false;
 936     /* jump to merge block */
 937     if (!ir_block_create_jump(ontrue, merge))
 938         return false;
 939     if (!ir_block_create_jump(onfalse, merge))
 940         return false;
 941
 942     /* create if instruction */
 943     if (!ir_block_create_if(cond, condval, ontrue, onfalse))
 944         return false;
 945
 946     /* Now enter the merge block */
 947     func->curblock = merge;
 948
 949     /* Here, now, we need a PHI node
 950      * but first some sanity checking...
 951      */
 952     if (trueval->vtype != falseval->vtype) {
 953         /* error("ternary with different types on the two sides"); */
 954         return false;
 955     }
 956
 957     /* create PHI */
 958     phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
 959     if (!phi ||
 960         !ir_phi_add(phi, ontrue,  trueval) ||
 961         !ir_phi_add(phi, onfalse, falseval))
 962     {
 963         return false;
 964     }
 965
 966     self->phi_out = ir_phi_value(phi);
 967     *out = self->phi_out;
 968
 969     return true;
 970 }
 971
 972 bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
 973 {
 974     ast_expression_codegen *cgen;
 975
 976     ir_value *dummy      = NULL;
 977     ir_value *precond    = NULL;
 978     ir_value *postcond   = NULL;
 979
 980     /* Since we insert some jumps "late" so we have blocks
 981      * ordered "nicely", we need to keep track of the actual end-blocks
 982      * of expressions to add the jumps to.
 983      */
 984     ir_block *bbody      = NULL, *end_bbody      = NULL;
 985     ir_block *bprecond   = NULL, *end_bprecond   = NULL;
 986     ir_block *bpostcond  = NULL, *end_bpostcond  = NULL;
 987     ir_block *bincrement = NULL, *end_bincrement = NULL;
 988     ir_block *bout       = NULL, *bin            = NULL;
 989
 990     /* let's at least move the outgoing block to the end */
 991     size_t    bout_id;
 992
 993     /* 'break' and 'continue' need to be able to find the right blocks */
 994     ir_block *bcontinue     = NULL;
 995     ir_block *bbreak        = NULL;
 996
 997     ir_block *old_bcontinue = NULL;
 998     ir_block *old_bbreak    = NULL;
 999
1000     ir_block *tmpblock      = NULL;
1001
1002     (void)lvalue;
1003     (void)out;
1004
1005     /* NOTE:
1006      * Should we ever need some kind of block ordering, better make this function
1007      * move blocks around than write a block ordering algorithm later... after all
1008      * the ast and ir should work together, not against each other.
1009      */
1010
1011     /* initexpr doesn't get its own block, it's pointless, it could create more blocks
1012      * anyway if for example it contains a ternary.
1013      */
1014     if (self->initexpr)
1015     {
1016         cgen = self->initexpr->expression.codegen;
1017         if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
1018             return false;
1019     }
1020
1021     /* Store the block from which we enter this chaos */
1022     bin = func->curblock;
1023
1024     /* The pre-loop condition needs its own block since we
1025      * need to be able to jump to the start of that expression.
1026      */
1027     if (self->precond)
1028     {
1029         bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
1030         if (!bprecond)
1031             return false;
1032
1033         /* the pre-loop-condition the least important place to 'continue' at */
1034         bcontinue = bprecond;
1035
1036         /* enter */
1037         func->curblock = bprecond;
1038
1039         /* generate */
1040         cgen = self->precond->expression.codegen;
1041         if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
1042             return false;
1043
1044         end_bprecond = func->curblock;
1045     } else {
1046         bprecond = end_bprecond = NULL;
1047     }
1048
1049     /* Now the next blocks won't be ordered nicely, but we need to
1050      * generate them this early for 'break' and 'continue'.
1051      */
1052     if (self->increment) {
1053         bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
1054         if (!bincrement)
1055             return false;
1056         bcontinue = bincrement; /* increment comes before the pre-loop-condition */
1057     } else {
1058         bincrement = end_bincrement = NULL;
1059     }
1060
1061     if (self->postcond) {
1062         bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
1063         if (!bpostcond)
1064             return false;
1065         bcontinue = bpostcond; /* postcond comes before the increment */
1066     } else {
1067         bpostcond = end_bpostcond = NULL;
1068     }
1069
1070     bout_id = func->ir_func->blocks_count;
1071     bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
1072     if (!bout)
1073         return false;
1074     bbreak = bout;
1075
1076     /* The loop body... */
1077     if (self->body)
1078     {
1079         bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
1080         if (!bbody)
1081             return false;
1082
1083         /* enter */
1084         func->curblock = bbody;
1085
1086         old_bbreak          = func->breakblock;
1087         old_bcontinue       = func->continueblock;
1088         func->breakblock    = bbreak;
1089         func->continueblock = bcontinue;
1090
1091         /* generate */
1092         cgen = self->body->expression.codegen;
1093         if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
1094             return false;
1095
1096         end_bbody = func->curblock;
1097         func->breakblock    = old_bbreak;
1098         func->continueblock = old_bcontinue;
1099     }
1100
1101     /* post-loop-condition */
1102     if (self->postcond)
1103     {
1104         /* enter */
1105         func->curblock = bpostcond;
1106
1107         /* generate */
1108         cgen = self->postcond->expression.codegen;
1109         if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
1110             return false;
1111
1112         end_bpostcond = func->curblock;
1113     }
1114
1115     /* The incrementor */
1116     if (self->increment)
1117     {
1118         /* enter */
1119         func->curblock = bincrement;
1120
1121         /* generate */
1122         cgen = self->increment->expression.codegen;
1123         if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
1124             return false;
1125
1126         end_bincrement = func->curblock;
1127     }
1128
1129     /* In any case now, we continue from the outgoing block */
1130     func->curblock = bout;
1131
1132     /* Now all blocks are in place */
1133     /* From 'bin' we jump to whatever comes first */
1134     if      (bprecond)   tmpblock = bprecond;
1135     else if (bbody)      tmpblock = bbody;
1136     else if (bpostcond)  tmpblock = bpostcond;
1137     else                 tmpblock = bout;
1138     if (!ir_block_create_jump(bin, tmpblock))
1139         return false;
1140
1141     /* From precond */
1142     if (bprecond)
1143     {
1144         ir_block *ontrue, *onfalse;
1145         if      (bbody)      ontrue = bbody;
1146         else if (bincrement) ontrue = bincrement;
1147         else if (bpostcond)  ontrue = bpostcond;
1148         else                 ontrue = bprecond;
1149         onfalse = bout;
1150         if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
1151             return false;
1152     }
1153
1154     /* from body */
1155     if (bbody)
1156     {
1157         if      (bincrement) tmpblock = bincrement;
1158         else if (bpostcond)  tmpblock = bpostcond;
1159         else if (bprecond)   tmpblock = bprecond;
1160         else                 tmpblock = bout;
1161         if (!ir_block_create_jump(end_bbody, tmpblock))
1162             return false;
1163     }
1164
1165     /* from increment */
1166     if (bincrement)
1167     {
1168         if      (bpostcond)  tmpblock = bpostcond;
1169         else if (bprecond)   tmpblock = bprecond;
1170         else if (bbody)      tmpblock = bbody;
1171         else                 tmpblock = bout;
1172         if (!ir_block_create_jump(end_bincrement, tmpblock))
1173             return false;
1174     }
1175
1176     /* from postcond */
1177     if (bpostcond)
1178     {
1179         ir_block *ontrue, *onfalse;
1180         if      (bprecond)   ontrue = bprecond;
1181         else if (bbody)      ontrue = bbody;
1182         else if (bincrement) ontrue = bincrement;
1183         else                 ontrue = bpostcond;
1184         onfalse = bout;
1185         if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
1186             return false;
1187     }
1188
1189     /* Move 'bout' to the end */
1190     if (!ir_function_blocks_remove(func->ir_func, bout_id) ||
1191         !ir_function_blocks_add(func->ir_func, bout))
1192     {
1193         ir_block_delete(bout);
1194         return false;
1195     }
1196
1197     return true;
1198 }
1199
1200 bool ast_call_codegen(ast_call *self, ast_function *func, bool lvalue, ir_value **out)
1201 {
1202     ast_expression_codegen *cgen;
1203     ir_value_vector         params;
1204     ir_instr               *callinstr;
1205     size_t i;
1206
1207     ir_value *funval = NULL;
1208
1209     /* return values are never rvalues */
1210     (void)lvalue;
1211
1212     cgen = self->func->expression.codegen;
1213     if (!(*cgen)((ast_expression*)(self->func), func, false, &funval))
1214         return false;
1215     if (!funval)
1216         return false;
1217
1218     MEM_VECTOR_INIT(&params, v);
1219
1220     /* parameters */
1221     for (i = 0; i < self->params_count; ++i)
1222     {
1223         ir_value *param;
1224         ast_expression *expr = self->params[i];
1225
1226         cgen = expr->expression.codegen;
1227         if (!(*cgen)(expr, func, false, &param))
1228             goto error;
1229         if (!param)
1230             goto error;
1231         if (!ir_value_vector_v_add(&params, param))
1232             goto error;
1233     }
1234
1235     callinstr = ir_block_create_call(func->curblock, ast_function_label(func, "call"), funval);
1236     if (!callinstr)
1237         goto error;
1238
1239     for (i = 0; i < params.v_count; ++i) {
1240         if (!ir_call_param(callinstr, params.v[i]))
1241             goto error;
1242     }
1243
1244     *out = ir_call_value(callinstr);
1245
1246     return true;
1247 error:
1248     MEM_VECTOR_CLEAR(&params, v);
1249     return false;
1250 }