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