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