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     if (op >= INSTR_EQ_F && op <= INSTR_GT)
 174         self->expression.vtype = TYPE_FLOAT;
 175     else if (op == INSTR_AND || op == INSTR_OR ||
 176              op == INSTR_BITAND || op == INSTR_BITOR)
 177         self->expression.vtype = TYPE_FLOAT;
 178     else if (op == INSTR_MUL_VF || op == INSTR_MUL_FV)
 179         self->expression.vtype = TYPE_VECTOR;
 180     else if (op == INSTR_MUL_V)
 181         self->expression.vtype = TYPE_FLOAT;
 182     else
 183         self->expression.vtype = left->expression.vtype;
 184
 185     return self;
 186 }
 187
 188 void ast_binary_delete(ast_binary *self)
 189 {
 190     ast_unref(self->left);
 191     ast_unref(self->right);
 192     ast_expression_delete((ast_expression*)self);
 193     mem_d(self);
 194 }
 195
 196 ast_unary* ast_unary_new(lex_ctx ctx, int op,
 197                          ast_expression *expr)
 198 {
 199     ast_instantiate(ast_unary, ctx, ast_unary_delete);
 200     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_unary_codegen);
 201
 202     self->op = op;
 203     self->operand = expr;
 204
 205     return self;
 206 }
 207
 208 void ast_unary_delete(ast_unary *self)
 209 {
 210     ast_unref(self->operand);
 211     ast_expression_delete((ast_expression*)self);
 212     mem_d(self);
 213 }
 214
 215 ast_return* ast_return_new(lex_ctx ctx, int op,
 216                          ast_expression *expr)
 217 {
 218     ast_instantiate(ast_return, ctx, ast_return_delete);
 219     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_return_codegen);
 220
 221     self->operand = expr;
 222
 223     return self;
 224 }
 225
 226 void ast_return_delete(ast_return *self)
 227 {
 228     ast_unref(self->operand);
 229     ast_expression_delete((ast_expression*)self);
 230     mem_d(self);
 231 }
 232
 233 ast_entfield* ast_entfield_new(lex_ctx ctx, ast_expression *entity, ast_expression *field)
 234 {
 235     const ast_expression *outtype;
 236
 237     ast_instantiate(ast_entfield, ctx, ast_entfield_delete);
 238
 239     if (field->expression.vtype != TYPE_FIELD) {
 240         mem_d(self);
 241         return NULL;
 242     }
 243
 244     outtype = field->expression.next;
 245     if (!outtype) {
 246         mem_d(self);
 247         /* Error: field has no type... */
 248         return NULL;
 249     }
 250
 251     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_entfield_codegen);
 252
 253     self->expression.vtype = outtype->expression.vtype;
 254     self->expression.next  = ast_type_copy(ctx, outtype->expression.next);
 255
 256     self->entity = entity;
 257     self->field  = field;
 258
 259     return self;
 260 }
 261
 262 void ast_entfield_delete(ast_entfield *self)
 263 {
 264     ast_unref(self->entity);
 265     ast_unref(self->field);
 266     ast_expression_delete((ast_expression*)self);
 267     mem_d(self);
 268 }
 269
 270 ast_ifthen* ast_ifthen_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 271 {
 272     ast_instantiate(ast_ifthen, ctx, ast_ifthen_delete);
 273     if (!ontrue && !onfalse) {
 274         /* because it is invalid */
 275         mem_d(self);
 276         return NULL;
 277     }
 278     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ifthen_codegen);
 279
 280     self->cond     = cond;
 281     self->on_true  = ontrue;
 282     self->on_false = onfalse;
 283
 284     return self;
 285 }
 286
 287 void ast_ifthen_delete(ast_ifthen *self)
 288 {
 289     ast_unref(self->cond);
 290     if (self->on_true)
 291         ast_unref(self->on_true);
 292     if (self->on_false)
 293         ast_unref(self->on_false);
 294     ast_expression_delete((ast_expression*)self);
 295     mem_d(self);
 296 }
 297
 298 ast_ternary* ast_ternary_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 299 {
 300     ast_instantiate(ast_ternary, ctx, ast_ternary_delete);
 301     /* This time NEITHER must be NULL */
 302     if (!ontrue || !onfalse) {
 303         mem_d(self);
 304         return NULL;
 305     }
 306     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ternary_codegen);
 307
 308     self->cond     = cond;
 309     self->on_true  = ontrue;
 310     self->on_false = onfalse;
 311     self->phi_out  = NULL;
 312
 313     return self;
 314 }
 315
 316 void ast_ternary_delete(ast_ternary *self)
 317 {
 318     ast_unref(self->cond);
 319     ast_unref(self->on_true);
 320     ast_unref(self->on_false);
 321     ast_expression_delete((ast_expression*)self);
 322     mem_d(self);
 323 }
 324
 325 ast_loop* ast_loop_new(lex_ctx ctx,
 326                        ast_expression *initexpr,
 327                        ast_expression *precond,
 328                        ast_expression *postcond,
 329                        ast_expression *increment,
 330                        ast_expression *body)
 331 {
 332     ast_instantiate(ast_loop, ctx, ast_loop_delete);
 333     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_loop_codegen);
 334
 335     self->initexpr  = initexpr;
 336     self->precond   = precond;
 337     self->postcond  = postcond;
 338     self->increment = increment;
 339     self->body      = body;
 340
 341     return self;
 342 }
 343
 344 void ast_loop_delete(ast_loop *self)
 345 {
 346     if (self->initexpr)
 347         ast_unref(self->initexpr);
 348     if (self->precond)
 349         ast_unref(self->precond);
 350     if (self->postcond)
 351         ast_unref(self->postcond);
 352     if (self->increment)
 353         ast_unref(self->increment);
 354     if (self->body)
 355         ast_unref(self->body);
 356     ast_expression_delete((ast_expression*)self);
 357     mem_d(self);
 358 }
 359
 360 ast_call* ast_call_new(lex_ctx ctx,
 361                        ast_expression *funcexpr)
 362 {
 363     ast_instantiate(ast_call, ctx, ast_call_delete);
 364     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_call_codegen);
 365
 366     MEM_VECTOR_INIT(self, params);
 367
 368     self->func = funcexpr;
 369
 370     return self;
 371 }
 372 MEM_VEC_FUNCTIONS(ast_call, ast_expression*, params)
 373
 374 void ast_call_delete(ast_call *self)
 375 {
 376     size_t i;
 377     for (i = 0; i < self->params_count; ++i)
 378         ast_unref(self->params[i]);
 379     MEM_VECTOR_CLEAR(self, params);
 380
 381     if (self->func)
 382         ast_unref(self->func);
 383
 384     ast_expression_delete((ast_expression*)self);
 385     mem_d(self);
 386 }
 387
 388 ast_store* ast_store_new(lex_ctx ctx, int op,
 389                          ast_value *dest, ast_expression *source)
 390 {
 391     ast_instantiate(ast_store, ctx, ast_store_delete);
 392     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);
 393
 394     self->op = op;
 395     self->dest = dest;
 396     self->source = source;
 397
 398     return self;
 399 }
 400
 401 void ast_store_delete(ast_store *self)
 402 {
 403     ast_unref(self->dest);
 404     ast_unref(self->source);
 405     ast_expression_delete((ast_expression*)self);
 406     mem_d(self);
 407 }
 408
 409 ast_block* ast_block_new(lex_ctx ctx)
 410 {
 411     ast_instantiate(ast_block, ctx, ast_block_delete);
 412     ast_expression_init((ast_expression*)self,
 413                         (ast_expression_codegen*)&ast_block_codegen);
 414
 415     MEM_VECTOR_INIT(self, locals);
 416     MEM_VECTOR_INIT(self, exprs);
 417
 418     return self;
 419 }
 420 MEM_VEC_FUNCTIONS(ast_block, ast_value*, locals)
 421 MEM_VEC_FUNCTIONS(ast_block, ast_expression*, exprs)
 422
 423 void ast_block_delete(ast_block *self)
 424 {
 425     size_t i;
 426     for (i = 0; i < self->exprs_count; ++i)
 427         ast_unref(self->exprs[i]);
 428     MEM_VECTOR_CLEAR(self, exprs);
 429     for (i = 0; i < self->locals_count; ++i)
 430         ast_delete(self->locals[i]);
 431     MEM_VECTOR_CLEAR(self, locals);
 432     ast_expression_delete((ast_expression*)self);
 433     mem_d(self);
 434 }
 435
 436 ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
 437 {
 438     ast_instantiate(ast_function, ctx, ast_function_delete);
 439
 440     if (!vtype ||
 441         vtype->isconst ||
 442         vtype->expression.vtype != TYPE_FUNCTION)
 443     {
 444         mem_d(self);
 445         return NULL;
 446     }
 447
 448     self->vtype = vtype;
 449     self->name = name ? util_strdup(name) : NULL;
 450     MEM_VECTOR_INIT(self, blocks);
 451
 452     self->labelcount = 0;
 453     self->builtin = 0;
 454
 455     self->ir_func = NULL;
 456     self->curblock = NULL;
 457
 458     self->breakblock    = NULL;
 459     self->continueblock = NULL;
 460
 461     vtype->isconst = true;
 462     vtype->constval.vfunc = self;
 463
 464     return self;
 465 }
 466
 467 MEM_VEC_FUNCTIONS(ast_function, ast_block*, blocks)
 468
 469 void ast_function_delete(ast_function *self)
 470 {
 471     size_t i;
 472     if (self->name)
 473         mem_d((void*)self->name);
 474     if (self->vtype) {
 475         /* ast_value_delete(self->vtype); */
 476         self->vtype->isconst = false;
 477         self->vtype->constval.vfunc = NULL;
 478         /* We use unref - if it was stored in a global table it is supposed
 479          * to be deleted from *there*
 480          */
 481         ast_unref(self->vtype);
 482     }
 483     for (i = 0; i < self->blocks_count; ++i)
 484         ast_delete(self->blocks[i]);
 485     MEM_VECTOR_CLEAR(self, blocks);
 486     mem_d(self);
 487 }
 488
 489 static void ast_util_hexitoa(char *buf, size_t size, unsigned int num)
 490 {
 491     unsigned int base = 10;
 492 #define checknul() do { if (size == 1) { *buf = 0; return; } } while (0)
 493 #define addch(x) do { *buf++ = (x); --size; checknul(); } while (0)
 494     if (size < 1)
 495         return;
 496     checknul();
 497     if (!num)
 498         addch('0');
 499     else {
 500         while (num)
 501         {
 502             int digit = num % base;
 503             num /= base;
 504             addch('0' + digit);
 505         }
 506     }
 507
 508     *buf = 0;
 509 #undef addch
 510 #undef checknul
 511 }
 512
 513 const char* ast_function_label(ast_function *self, const char *prefix)
 514 {
 515     size_t id = (self->labelcount++);
 516     size_t len = strlen(prefix);
 517     strncpy(self->labelbuf, prefix, sizeof(self->labelbuf));
 518     ast_util_hexitoa(self->labelbuf + len, sizeof(self->labelbuf)-len, id);
 519     return self->labelbuf;
 520 }
 521
 522 /*********************************************************************/
 523 /* AST codegen part
 524  * by convention you must never pass NULL to the 'ir_value **out'
 525  * parameter. If you really don't care about the output, pass a dummy.
 526  * But I can't imagine a pituation where the output is truly unnecessary.
 527  */
 528
 529 bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
 530 {
 531     /* NOTE: This is the codegen for a variable used in an expression.
 532      * It is not the codegen to generate the value. For this purpose,
 533      * ast_local_codegen and ast_global_codegen are to be used before this
 534      * is executed. ast_function_codegen should take care of its locals,
 535      * and the ast-user should take care of ast_global_codegen to be used
 536      * on all the globals.
 537      */
 538     if (!self->ir_v) {
 539         printf("ast_value used before generated (%s)\n", self->name);
 540         return false;
 541     }
 542     *out = self->ir_v;
 543     return true;
 544 }
 545
 546 bool ast_global_codegen(ast_value *self, ir_builder *ir)
 547 {
 548     ir_value *v = NULL;
 549     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 550     {
 551         ir_function *func = ir_builder_create_function(ir, self->name, self->expression.next->expression.vtype);
 552         if (!func)
 553             return false;
 554
 555         self->constval.vfunc->ir_func = func;
 556         self->ir_v = func->value;
 557         /* The function is filled later on ast_function_codegen... */
 558         return true;
 559     }
 560
 561     v = ir_builder_create_global(ir, self->name, self->expression.vtype);
 562     if (!v) {
 563         printf("ir_builder_create_global failed\n");
 564         return false;
 565     }
 566
 567     if (self->isconst) {
 568         switch (self->expression.vtype)
 569         {
 570             case TYPE_FLOAT:
 571                 if (!ir_value_set_float(v, self->constval.vfloat))
 572                     goto error;
 573                 break;
 574             case TYPE_VECTOR:
 575                 if (!ir_value_set_vector(v, self->constval.vvec))
 576                     goto error;
 577                 break;
 578             case TYPE_STRING:
 579                 if (!ir_value_set_string(v, self->constval.vstring))
 580                     goto error;
 581                 break;
 582             case TYPE_FUNCTION:
 583                 printf("global of type function not properly generated\n");
 584                 goto error;
 585                 /* Cannot generate an IR value for a function,
 586                  * need a pointer pointing to a function rather.
 587                  */
 588             default:
 589                 printf("TODO: global constant type %i\n", self->expression.vtype);
 590                 break;
 591         }
 592     }
 593
 594     /* link us to the ir_value */
 595     self->ir_v = v;
 596     return true;
 597
 598 error: /* clean up */
 599     ir_value_delete(v);
 600     return false;
 601 }
 602
 603 bool ast_local_codegen(ast_value *self, ir_function *func, bool param)
 604 {
 605     ir_value *v = NULL;
 606     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 607     {
 608         /* Do we allow local functions? I think not...
 609          * this is NOT a function pointer atm.
 610          */
 611         return false;
 612     }
 613
 614     v = ir_function_create_local(func, self->name, self->expression.vtype, param);
 615     if (!v)
 616         return false;
 617
 618     /* A constant local... hmmm...
 619      * I suppose the IR will have to deal with this
 620      */
 621     if (self->isconst) {
 622         switch (self->expression.vtype)
 623         {
 624             case TYPE_FLOAT:
 625                 if (!ir_value_set_float(v, self->constval.vfloat))
 626                     goto error;
 627                 break;
 628             case TYPE_VECTOR:
 629                 if (!ir_value_set_vector(v, self->constval.vvec))
 630                     goto error;
 631                 break;
 632             case TYPE_STRING:
 633                 if (!ir_value_set_string(v, self->constval.vstring))
 634                     goto error;
 635                 break;
 636             default:
 637                 printf("TODO: global constant type %i\n", self->expression.vtype);
 638                 break;
 639         }
 640     }
 641
 642     /* link us to the ir_value */
 643     self->ir_v = v;
 644     return true;
 645
 646 error: /* clean up */
 647     ir_value_delete(v);
 648     return false;
 649 }
 650
 651 bool ast_function_codegen(ast_function *self, ir_builder *ir)
 652 {
 653     ir_function *irf;
 654     ir_value    *dummy;
 655     size_t    i;
 656
 657     irf = self->ir_func;
 658     if (!irf) {
 659         printf("ast_function's related ast_value was not generated yet\n");
 660         return false;
 661     }
 662
 663     /* fill the parameter list */
 664     for (i = 0; i < self->vtype->params_count; ++i)
 665     {
 666         if (!ir_function_params_add(irf, self->vtype->params[i]->expression.vtype))
 667             return false;
 668         if (!self->builtin) {
 669             if (!ast_local_codegen(self->vtype->params[i], self->ir_func, true))
 670                 return false;
 671         }
 672     }
 673
 674     if (self->builtin) {
 675         irf->builtin = self->builtin;
 676         return true;
 677     }
 678
 679     self->curblock = ir_function_create_block(irf, "entry");
 680     if (!self->curblock)
 681         return false;
 682
 683     for (i = 0; i < self->blocks_count; ++i) {
 684         ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
 685         if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
 686             return false;
 687     }
 688
 689     /* TODO: check return types */
 690     if (!self->curblock->is_return)
 691     {
 692         if (!self->vtype->expression.next ||
 693             self->vtype->expression.next->expression.vtype == TYPE_VOID)
 694         {
 695             return ir_block_create_return(self->curblock, NULL);
 696         }
 697         else
 698         {
 699             /* error("missing return"); */
 700             return false;
 701         }
 702     }
 703     return true;
 704 }
 705
 706 /* Note, you will not see ast_block_codegen generate ir_blocks.
 707  * To the AST and the IR, blocks are 2 different things.
 708  * In the AST it represents a block of code, usually enclosed in
 709  * curly braces {...}.
 710  * While in the IR it represents a block in terms of control-flow.
 711  */
 712 bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
 713 {
 714     size_t i;
 715
 716     /* We don't use this
 717      * Note: an ast-representation using the comma-operator
 718      * of the form: (a, b, c) = x should not assign to c...
 719      */
 720     (void)lvalue;
 721
 722     /* output is NULL at first, we'll have each expression
 723      * assign to out output, thus, a comma-operator represention
 724      * using an ast_block will return the last generated value,
 725      * so: (b, c) + a  executed both b and c, and returns c,
 726      * which is then added to a.
 727      */
 728     *out = NULL;
 729
 730     /* generate locals */
 731     for (i = 0; i < self->locals_count; ++i)
 732     {
 733         if (!ast_local_codegen(self->locals[i], func->ir_func, false))
 734             return false;
 735     }
 736
 737     for (i = 0; i < self->exprs_count; ++i)
 738     {
 739         ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
 740         if (!(*gen)(self->exprs[i], func, false, out))
 741             return false;
 742     }
 743
 744     return true;
 745 }
 746
 747 bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
 748 {
 749     ast_expression_codegen *cgen;
 750     ir_value *left, *right;
 751
 752     cgen = self->dest->expression.codegen;
 753     /* lvalue! */
 754     if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
 755         return false;
 756
 757     cgen = self->source->expression.codegen;
 758     /* rvalue! */
 759     if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
 760         return false;
 761
 762     if (!ir_block_create_store_op(func->curblock, self->op, left, right))
 763         return false;
 764
 765     /* Theoretically, an assinment returns its left side as an
 766      * lvalue, if we don't need an lvalue though, we return
 767      * the right side as an rvalue, otherwise we have to
 768      * somehow know whether or not we need to dereference the pointer
 769      * on the left side - that is: OP_LOAD if it was an address.
 770      * Also: in original QC we cannot OP_LOADP *anyway*.
 771      */
 772     *out = (lvalue ? left : right);
 773
 774     return true;
 775 }
 776
 777 bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
 778 {
 779     ast_expression_codegen *cgen;
 780     ir_value *left, *right;
 781
 782     /* In the context of a binary operation, we can disregard
 783      * the lvalue flag.
 784      */
 785      (void)lvalue;
 786
 787     cgen = self->left->expression.codegen;
 788     /* lvalue! */
 789     if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
 790         return false;
 791
 792     cgen = self->right->expression.codegen;
 793     /* rvalue! */
 794     if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
 795         return false;
 796
 797     *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
 798                                  self->op, left, right);
 799     if (!*out)
 800         return false;
 801
 802     return true;
 803 }
 804
 805 bool ast_unary_codegen(ast_unary *self, ast_function *func, bool lvalue, ir_value **out)
 806 {
 807     ast_expression_codegen *cgen;
 808     ir_value *operand;
 809
 810     /* In the context of a unary operation, we can disregard
 811      * the lvalue flag.
 812      */
 813     (void)lvalue;
 814
 815     cgen = self->operand->expression.codegen;
 816     /* lvalue! */
 817     if (!(*cgen)((ast_expression*)(self->operand), func, false, &operand))
 818         return false;
 819
 820     *out = ir_block_create_unary(func->curblock, ast_function_label(func, "unary"),
 821                                  self->op, operand);
 822     if (!*out)
 823         return false;
 824
 825     return true;
 826 }
 827
 828 bool ast_return_codegen(ast_return *self, ast_function *func, bool lvalue, ir_value **out)
 829 {
 830     ast_expression_codegen *cgen;
 831     ir_value *operand;
 832
 833     /* In the context of a return operation, we can disregard
 834      * the lvalue flag.
 835      */
 836     (void)lvalue;
 837
 838     cgen = self->operand->expression.codegen;
 839     /* lvalue! */
 840     if (!(*cgen)((ast_expression*)(self->operand), func, false, &operand))
 841         return false;
 842
 843     if (!ir_block_create_return(func->curblock, operand))
 844         return false;
 845
 846     return true;
 847 }
 848
 849 bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
 850 {
 851     ast_expression_codegen *cgen;
 852     ir_value *ent, *field;
 853
 854     /* This function needs to take the 'lvalue' flag into account!
 855      * As lvalue we provide a field-pointer, as rvalue we provide the
 856      * value in a temp.
 857      */
 858
 859     cgen = self->entity->expression.codegen;
 860     if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
 861         return false;
 862
 863     cgen = self->field->expression.codegen;
 864     if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
 865         return false;
 866
 867     if (lvalue) {
 868         /* address! */
 869         *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
 870                                             ent, field);
 871     } else {
 872         *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
 873                                              ent, field, self->expression.vtype);
 874     }
 875     if (!*out)
 876         return false;
 877
 878     /* Hm that should be it... */
 879     return true;
 880 }
 881
 882 bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
 883 {
 884     ast_expression_codegen *cgen;
 885
 886     ir_value *condval;
 887     ir_value *dummy;
 888
 889     ir_block *cond = func->curblock;
 890     ir_block *ontrue;
 891     ir_block *onfalse;
 892     ir_block *merge;
 893
 894     /* We don't output any value, thus also don't care about r/lvalue */
 895     (void)out;
 896     (void)lvalue;
 897
 898     /* generate the condition */
 899     func->curblock = cond;
 900     cgen = self->cond->expression.codegen;
 901     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 902         return false;
 903
 904     /* on-true path */
 905
 906     if (self->on_true) {
 907         /* create on-true block */
 908         ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
 909         if (!ontrue)
 910             return false;
 911
 912         /* enter the block */
 913         func->curblock = ontrue;
 914
 915         /* generate */
 916         cgen = self->on_true->expression.codegen;
 917         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
 918             return false;
 919     } else
 920         ontrue = NULL;
 921
 922     /* on-false path */
 923     if (self->on_false) {
 924         /* create on-false block */
 925         onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
 926         if (!onfalse)
 927             return false;
 928
 929         /* enter the block */
 930         func->curblock = onfalse;
 931
 932         /* generate */
 933         cgen = self->on_false->expression.codegen;
 934         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
 935             return false;
 936     } else
 937         onfalse = NULL;
 938
 939     /* Merge block were they all merge in to */
 940     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
 941     if (!merge)
 942         return false;
 943
 944     /* add jumps ot the merge block */
 945     if (ontrue && !ir_block_create_jump(ontrue, merge))
 946         return false;
 947     if (onfalse && !ir_block_create_jump(onfalse, merge))
 948         return false;
 949
 950     /* we create the if here, that way all blocks are ordered :)
 951      */
 952     if (!ir_block_create_if(cond, condval,
 953                             (ontrue  ? ontrue  : merge),
 954                             (onfalse ? onfalse : merge)))
 955     {
 956         return false;
 957     }
 958
 959     /* Now enter the merge block */
 960     func->curblock = merge;
 961
 962     return true;
 963 }
 964
 965 bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
 966 {
 967     ast_expression_codegen *cgen;
 968
 969     ir_value *condval;
 970     ir_value *trueval, *falseval;
 971     ir_instr *phi;
 972
 973     ir_block *cond = func->curblock;
 974     ir_block *ontrue;
 975     ir_block *onfalse;
 976     ir_block *merge;
 977
 978     /* In theory it shouldn't be possible to pass through a node twice, but
 979      * in case we add any kind of optimization pass for the AST itself, it
 980      * may still happen, thus we remember a created ir_value and simply return one
 981      * if it already exists.
 982      */
 983     if (self->phi_out) {
 984         *out = self->phi_out;
 985         return true;
 986     }
 987
 988     /* Ternary can never create an lvalue... */
 989     if (lvalue)
 990         return false;
 991
 992     /* In the following, contraty to ast_ifthen, we assume both paths exist. */
 993
 994     /* generate the condition */
 995     func->curblock = cond;
 996     cgen = self->cond->expression.codegen;
 997     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 998         return false;
 999
1000     /* create on-true block */
1001     ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
1002     if (!ontrue)
1003         return false;
1004     else
1005     {
1006         /* enter the block */
1007         func->curblock = ontrue;
1008
1009         /* generate */
1010         cgen = self->on_true->expression.codegen;
1011         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
1012             return false;
1013     }
1014
1015     /* create on-false block */
1016     onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
1017     if (!onfalse)
1018         return false;
1019     else
1020     {
1021         /* enter the block */
1022         func->curblock = onfalse;
1023
1024         /* generate */
1025         cgen = self->on_false->expression.codegen;
1026         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &falseval))
1027             return false;
1028     }
1029
1030     /* create merge block */
1031     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
1032     if (!merge)
1033         return false;
1034     /* jump to merge block */
1035     if (!ir_block_create_jump(ontrue, merge))
1036         return false;
1037     if (!ir_block_create_jump(onfalse, merge))
1038         return false;
1039
1040     /* create if instruction */
1041     if (!ir_block_create_if(cond, condval, ontrue, onfalse))
1042         return false;
1043
1044     /* Now enter the merge block */
1045     func->curblock = merge;
1046
1047     /* Here, now, we need a PHI node
1048      * but first some sanity checking...
1049      */
1050     if (trueval->vtype != falseval->vtype) {
1051         /* error("ternary with different types on the two sides"); */
1052         return false;
1053     }
1054
1055     /* create PHI */
1056     phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
1057     if (!phi ||
1058         !ir_phi_add(phi, ontrue,  trueval) ||
1059         !ir_phi_add(phi, onfalse, falseval))
1060     {
1061         return false;
1062     }
1063
1064     self->phi_out = ir_phi_value(phi);
1065     *out = self->phi_out;
1066
1067     return true;
1068 }
1069
1070 bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
1071 {
1072     ast_expression_codegen *cgen;
1073
1074     ir_value *dummy      = NULL;
1075     ir_value *precond    = NULL;
1076     ir_value *postcond   = NULL;
1077
1078     /* Since we insert some jumps "late" so we have blocks
1079      * ordered "nicely", we need to keep track of the actual end-blocks
1080      * of expressions to add the jumps to.
1081      */
1082     ir_block *bbody      = NULL, *end_bbody      = NULL;
1083     ir_block *bprecond   = NULL, *end_bprecond   = NULL;
1084     ir_block *bpostcond  = NULL, *end_bpostcond  = NULL;
1085     ir_block *bincrement = NULL, *end_bincrement = NULL;
1086     ir_block *bout       = NULL, *bin            = NULL;
1087
1088     /* let's at least move the outgoing block to the end */
1089     size_t    bout_id;
1090
1091     /* 'break' and 'continue' need to be able to find the right blocks */
1092     ir_block *bcontinue     = NULL;
1093     ir_block *bbreak        = NULL;
1094
1095     ir_block *old_bcontinue = NULL;
1096     ir_block *old_bbreak    = NULL;
1097
1098     ir_block *tmpblock      = NULL;
1099
1100     (void)lvalue;
1101     (void)out;
1102
1103     /* NOTE:
1104      * Should we ever need some kind of block ordering, better make this function
1105      * move blocks around than write a block ordering algorithm later... after all
1106      * the ast and ir should work together, not against each other.
1107      */
1108
1109     /* initexpr doesn't get its own block, it's pointless, it could create more blocks
1110      * anyway if for example it contains a ternary.
1111      */
1112     if (self->initexpr)
1113     {
1114         cgen = self->initexpr->expression.codegen;
1115         if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
1116             return false;
1117     }
1118
1119     /* Store the block from which we enter this chaos */
1120     bin = func->curblock;
1121
1122     /* The pre-loop condition needs its own block since we
1123      * need to be able to jump to the start of that expression.
1124      */
1125     if (self->precond)
1126     {
1127         bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
1128         if (!bprecond)
1129             return false;
1130
1131         /* the pre-loop-condition the least important place to 'continue' at */
1132         bcontinue = bprecond;
1133
1134         /* enter */
1135         func->curblock = bprecond;
1136
1137         /* generate */
1138         cgen = self->precond->expression.codegen;
1139         if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
1140             return false;
1141
1142         end_bprecond = func->curblock;
1143     } else {
1144         bprecond = end_bprecond = NULL;
1145     }
1146
1147     /* Now the next blocks won't be ordered nicely, but we need to
1148      * generate them this early for 'break' and 'continue'.
1149      */
1150     if (self->increment) {
1151         bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
1152         if (!bincrement)
1153             return false;
1154         bcontinue = bincrement; /* increment comes before the pre-loop-condition */
1155     } else {
1156         bincrement = end_bincrement = NULL;
1157     }
1158
1159     if (self->postcond) {
1160         bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
1161         if (!bpostcond)
1162             return false;
1163         bcontinue = bpostcond; /* postcond comes before the increment */
1164     } else {
1165         bpostcond = end_bpostcond = NULL;
1166     }
1167
1168     bout_id = func->ir_func->blocks_count;
1169     bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
1170     if (!bout)
1171         return false;
1172     bbreak = bout;
1173
1174     /* The loop body... */
1175     if (self->body)
1176     {
1177         bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
1178         if (!bbody)
1179             return false;
1180
1181         /* enter */
1182         func->curblock = bbody;
1183
1184         old_bbreak          = func->breakblock;
1185         old_bcontinue       = func->continueblock;
1186         func->breakblock    = bbreak;
1187         func->continueblock = bcontinue;
1188
1189         /* generate */
1190         cgen = self->body->expression.codegen;
1191         if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
1192             return false;
1193
1194         end_bbody = func->curblock;
1195         func->breakblock    = old_bbreak;
1196         func->continueblock = old_bcontinue;
1197     }
1198
1199     /* post-loop-condition */
1200     if (self->postcond)
1201     {
1202         /* enter */
1203         func->curblock = bpostcond;
1204
1205         /* generate */
1206         cgen = self->postcond->expression.codegen;
1207         if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
1208             return false;
1209
1210         end_bpostcond = func->curblock;
1211     }
1212
1213     /* The incrementor */
1214     if (self->increment)
1215     {
1216         /* enter */
1217         func->curblock = bincrement;
1218
1219         /* generate */
1220         cgen = self->increment->expression.codegen;
1221         if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
1222             return false;
1223
1224         end_bincrement = func->curblock;
1225     }
1226
1227     /* In any case now, we continue from the outgoing block */
1228     func->curblock = bout;
1229
1230     /* Now all blocks are in place */
1231     /* From 'bin' we jump to whatever comes first */
1232     if      (bprecond)   tmpblock = bprecond;
1233     else if (bbody)      tmpblock = bbody;
1234     else if (bpostcond)  tmpblock = bpostcond;
1235     else                 tmpblock = bout;
1236     if (!ir_block_create_jump(bin, tmpblock))
1237         return false;
1238
1239     /* From precond */
1240     if (bprecond)
1241     {
1242         ir_block *ontrue, *onfalse;
1243         if      (bbody)      ontrue = bbody;
1244         else if (bincrement) ontrue = bincrement;
1245         else if (bpostcond)  ontrue = bpostcond;
1246         else                 ontrue = bprecond;
1247         onfalse = bout;
1248         if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
1249             return false;
1250     }
1251
1252     /* from body */
1253     if (bbody)
1254     {
1255         if      (bincrement) tmpblock = bincrement;
1256         else if (bpostcond)  tmpblock = bpostcond;
1257         else if (bprecond)   tmpblock = bprecond;
1258         else                 tmpblock = bout;
1259         if (!ir_block_create_jump(end_bbody, tmpblock))
1260             return false;
1261     }
1262
1263     /* from increment */
1264     if (bincrement)
1265     {
1266         if      (bpostcond)  tmpblock = bpostcond;
1267         else if (bprecond)   tmpblock = bprecond;
1268         else if (bbody)      tmpblock = bbody;
1269         else                 tmpblock = bout;
1270         if (!ir_block_create_jump(end_bincrement, tmpblock))
1271             return false;
1272     }
1273
1274     /* from postcond */
1275     if (bpostcond)
1276     {
1277         ir_block *ontrue, *onfalse;
1278         if      (bprecond)   ontrue = bprecond;
1279         else if (bbody)      ontrue = bbody;
1280         else if (bincrement) ontrue = bincrement;
1281         else                 ontrue = bpostcond;
1282         onfalse = bout;
1283         if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
1284             return false;
1285     }
1286
1287     /* Move 'bout' to the end */
1288     if (!ir_function_blocks_remove(func->ir_func, bout_id) ||
1289         !ir_function_blocks_add(func->ir_func, bout))
1290     {
1291         ir_block_delete(bout);
1292         return false;
1293     }
1294
1295     return true;
1296 }
1297
1298 bool ast_call_codegen(ast_call *self, ast_function *func, bool lvalue, ir_value **out)
1299 {
1300     ast_expression_codegen *cgen;
1301     ir_value_vector         params;
1302     ir_instr               *callinstr;
1303     size_t i;
1304
1305     ir_value *funval = NULL;
1306
1307     /* return values are never rvalues */
1308     (void)lvalue;
1309
1310     cgen = self->func->expression.codegen;
1311     if (!(*cgen)((ast_expression*)(self->func), func, false, &funval))
1312         return false;
1313     if (!funval)
1314         return false;
1315
1316     MEM_VECTOR_INIT(&params, v);
1317
1318     /* parameters */
1319     for (i = 0; i < self->params_count; ++i)
1320     {
1321         ir_value *param;
1322         ast_expression *expr = self->params[i];
1323
1324         cgen = expr->expression.codegen;
1325         if (!(*cgen)(expr, func, false, &param))
1326             goto error;
1327         if (!param)
1328             goto error;
1329         if (!ir_value_vector_v_add(&params, param))
1330             goto error;
1331     }
1332
1333     callinstr = ir_block_create_call(func->curblock, ast_function_label(func, "call"), funval);
1334     if (!callinstr)
1335         goto error;
1336
1337     for (i = 0; i < params.v_count; ++i) {
1338         if (!ir_call_param(callinstr, params.v[i]))
1339             goto error;
1340     }
1341
1342     *out = ir_call_value(callinstr);
1343
1344     return true;
1345 error:
1346     MEM_VECTOR_CLEAR(&params, v);
1347     return false;
1348 }