ast.c

   1 /*
   2  * Copyright (C) 2012
   3  *     Wolfgang Bumiller
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy of
   6  * this software and associated documentation files (the "Software"), to deal in
   7  * the Software without restriction, including without limitation the rights to
   8  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   9  * of the Software, and to permit persons to whom the Software is furnished to do
  10  * so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in all
  13  * copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "gmqcc.h"
  28 #include "ast.h"
  29
  30 #define ast_instantiate(T, ctx, destroyfn)                          \
  31     T* self = (T*)mem_a(sizeof(T));                                 \
  32     if (!self) {                                                    \
  33         return NULL;                                                \
  34     }                                                               \
  35     ast_node_init((ast_node*)self, ctx);                            \
  36     ( (ast_node*)self )->node.destroy = (ast_node_delete*)destroyfn
  37
  38 /* It must not be possible to get here. */
  39 static GMQCC_NORETURN void _ast_node_destroy(ast_node *self)
  40 {
  41     fprintf(stderr, "ast node missing destroy()\n");
  42     abort();
  43 }
  44
  45 /* Initialize main ast node aprts */
  46 static void ast_node_init(ast_node *self, lex_ctx ctx)
  47 {
  48     self->node.context = ctx;
  49     self->node.destroy = &_ast_node_destroy;
  50     self->node.keep    = false;
  51 }
  52
  53 /* General expression initialization */
  54 static void ast_expression_init(ast_expression *self,
  55                                 ast_expression_codegen *codegen)
  56 {
  57     self->expression.codegen = codegen;
  58     self->expression.vtype   = TYPE_VOID;
  59     self->expression.next    = NULL;
  60 }
  61
  62 static void ast_expression_delete(ast_expression *self)
  63 {
  64     if (self->expression.next)
  65         ast_delete(self->expression.next);
  66 }
  67
  68 static void ast_expression_delete_full(ast_expression *self)
  69 {
  70     ast_expression_delete(self);
  71     mem_d(self);
  72 }
  73
  74 static ast_expression* ast_type_copy(lex_ctx ctx, const ast_expression *ex)
  75 {
  76     const ast_expression_common *cpex;
  77     ast_expression_common *selfex;
  78
  79     if (!ex)
  80         return NULL;
  81     else
  82     {
  83         ast_instantiate(ast_expression, ctx, ast_expression_delete_full);
  84
  85         cpex   = &ex->expression;
  86         selfex = &self->expression;
  87
  88         selfex->vtype = cpex->vtype;
  89         if (cpex->next)
  90         {
  91             selfex->next = ast_type_copy(ctx, cpex->next);
  92             if (!selfex->next) {
  93                 mem_d(self);
  94                 return NULL;
  95             }
  96         }
  97         else
  98             selfex->next = NULL;
  99
 100         /* This may never be codegen()d */
 101         selfex->codegen = NULL;
 102         return self;
 103     }
 104 }
 105
 106 ast_value* ast_value_new(lex_ctx ctx, const char *name, int t)
 107 {
 108     ast_instantiate(ast_value, ctx, ast_value_delete);
 109     ast_expression_init((ast_expression*)self,
 110                         (ast_expression_codegen*)&ast_value_codegen);
 111     self->expression.node.keep = true; /* keep */
 112
 113     self->name = name ? util_strdup(name) : NULL;
 114     self->expression.vtype = t;
 115     self->expression.next  = NULL;
 116     MEM_VECTOR_INIT(self, params);
 117     self->isconst = false;
 118     memset(&self->constval, 0, sizeof(self->constval));
 119
 120     self->ir_v    = NULL;
 121
 122     return self;
 123 }
 124 MEM_VEC_FUNCTIONS(ast_value, ast_value*, params)
 125
 126 void ast_value_delete(ast_value* self)
 127 {
 128     size_t i;
 129     if (self->name)
 130         mem_d((void*)self->name);
 131     for (i = 0; i < self->params_count; ++i)
 132         ast_value_delete(self->params[i]); /* delete, the ast_function is expected to die first */
 133     MEM_VECTOR_CLEAR(self, params);
 134     if (self->isconst) {
 135         switch (self->expression.vtype)
 136         {
 137         case TYPE_STRING:
 138             mem_d((void*)self->constval.vstring);
 139             break;
 140         case TYPE_FUNCTION:
 141             /* unlink us from the function node */
 142             self->constval.vfunc->vtype = NULL;
 143             break;
 144         /* NOTE: delete function? currently collected in
 145          * the parser structure
 146          */
 147         default:
 148             break;
 149         }
 150     }
 151     ast_expression_delete((ast_expression*)self);
 152     mem_d(self);
 153 }
 154
 155 bool ast_value_set_name(ast_value *self, const char *name)
 156 {
 157     if (self->name)
 158         mem_d((void*)self->name);
 159     self->name = util_strdup(name);
 160     return !!self->name;
 161 }
 162
 163 ast_binary* ast_binary_new(lex_ctx ctx, int op,
 164                            ast_expression* left, ast_expression* right)
 165 {
 166     ast_instantiate(ast_binary, ctx, ast_binary_delete);
 167     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_binary_codegen);
 168
 169     self->op = op;
 170     self->left = left;
 171     self->right = right;
 172
 173     return self;
 174 }
 175
 176 void ast_binary_delete(ast_binary *self)
 177 {
 178     ast_unref(self->left);
 179     ast_unref(self->right);
 180     ast_expression_delete((ast_expression*)self);
 181     mem_d(self);
 182 }
 183
 184 ast_entfield* ast_entfield_new(lex_ctx ctx, ast_expression *entity, ast_expression *field)
 185 {
 186     const ast_expression *outtype;
 187
 188     ast_instantiate(ast_entfield, ctx, ast_entfield_delete);
 189
 190     if (field->expression.vtype != TYPE_FIELD) {
 191         mem_d(self);
 192         return NULL;
 193     }
 194
 195     outtype = field->expression.next;
 196     if (!outtype) {
 197         mem_d(self);
 198         /* Error: field has no type... */
 199         return NULL;
 200     }
 201
 202     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_entfield_codegen);
 203
 204     self->expression.vtype = outtype->expression.vtype;
 205     self->expression.next  = ast_type_copy(ctx, outtype->expression.next);
 206
 207     self->entity = entity;
 208     self->field  = field;
 209
 210     return self;
 211 }
 212
 213 void ast_entfield_delete(ast_entfield *self)
 214 {
 215     ast_unref(self->entity);
 216     ast_unref(self->field);
 217     ast_expression_delete((ast_expression*)self);
 218     mem_d(self);
 219 }
 220
 221 ast_ifthen* ast_ifthen_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 222 {
 223     ast_instantiate(ast_ifthen, ctx, ast_ifthen_delete);
 224     if (!ontrue && !onfalse) {
 225         /* because it is invalid */
 226         mem_d(self);
 227         return NULL;
 228     }
 229     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ifthen_codegen);
 230
 231     self->cond     = cond;
 232     self->on_true  = ontrue;
 233     self->on_false = onfalse;
 234
 235     return self;
 236 }
 237
 238 void ast_ifthen_delete(ast_ifthen *self)
 239 {
 240     ast_unref(self->cond);
 241     if (self->on_true)
 242         ast_unref(self->on_true);
 243     if (self->on_false)
 244         ast_unref(self->on_false);
 245     ast_expression_delete((ast_expression*)self);
 246     mem_d(self);
 247 }
 248
 249 ast_ternary* ast_ternary_new(lex_ctx ctx, ast_expression *cond, ast_expression *ontrue, ast_expression *onfalse)
 250 {
 251     ast_instantiate(ast_ternary, ctx, ast_ternary_delete);
 252     /* This time NEITHER must be NULL */
 253     if (!ontrue || !onfalse) {
 254         mem_d(self);
 255         return NULL;
 256     }
 257     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_ternary_codegen);
 258
 259     self->cond     = cond;
 260     self->on_true  = ontrue;
 261     self->on_false = onfalse;
 262     self->phi_out  = NULL;
 263
 264     return self;
 265 }
 266
 267 void ast_ternary_delete(ast_ternary *self)
 268 {
 269     ast_unref(self->cond);
 270     ast_unref(self->on_true);
 271     ast_unref(self->on_false);
 272     ast_expression_delete((ast_expression*)self);
 273     mem_d(self);
 274 }
 275
 276 ast_loop* ast_loop_new(lex_ctx ctx,
 277                        ast_expression *initexpr,
 278                        ast_expression *precond,
 279                        ast_expression *postcond,
 280                        ast_expression *increment,
 281                        ast_expression *body)
 282 {
 283     ast_instantiate(ast_loop, ctx, ast_loop_delete);
 284     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_loop_codegen);
 285
 286     self->initexpr  = initexpr;
 287     self->precond   = precond;
 288     self->postcond  = postcond;
 289     self->increment = increment;
 290     self->body      = body;
 291
 292     return self;
 293 }
 294
 295 void ast_loop_delete(ast_loop *self)
 296 {
 297     if (self->initexpr)
 298         ast_unref(self->initexpr);
 299     if (self->precond)
 300         ast_unref(self->precond);
 301     if (self->postcond)
 302         ast_unref(self->postcond);
 303     if (self->increment)
 304         ast_unref(self->increment);
 305     if (self->body)
 306         ast_unref(self->body);
 307     ast_expression_delete((ast_expression*)self);
 308     mem_d(self);
 309 }
 310
 311 ast_call* ast_call_new(lex_ctx ctx,
 312                        ast_expression *funcexpr)
 313 {
 314     ast_instantiate(ast_call, ctx, ast_call_delete);
 315     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_call_codegen);
 316
 317     MEM_VECTOR_INIT(self, params);
 318
 319     self->func = funcexpr;
 320
 321     return self;
 322 }
 323 MEM_VEC_FUNCTIONS(ast_call, ast_expression*, params)
 324
 325 void ast_call_delete(ast_call *self)
 326 {
 327     size_t i;
 328     for (i = 0; i < self->params_count; ++i)
 329         ast_unref(self->params[i]);
 330     MEM_VECTOR_CLEAR(self, params);
 331
 332     if (self->func)
 333         ast_unref(self->func);
 334
 335     ast_expression_delete((ast_expression*)self);
 336     mem_d(self);
 337 }
 338
 339 ast_store* ast_store_new(lex_ctx ctx, int op,
 340                          ast_value *dest, ast_expression *source)
 341 {
 342     ast_instantiate(ast_store, ctx, ast_store_delete);
 343     ast_expression_init((ast_expression*)self, (ast_expression_codegen*)&ast_store_codegen);
 344
 345     self->op = op;
 346     self->dest = dest;
 347     self->source = source;
 348
 349     return self;
 350 }
 351
 352 void ast_store_delete(ast_store *self)
 353 {
 354     ast_unref(self->dest);
 355     ast_unref(self->source);
 356     ast_expression_delete((ast_expression*)self);
 357     mem_d(self);
 358 }
 359
 360 ast_block* ast_block_new(lex_ctx ctx)
 361 {
 362     ast_instantiate(ast_block, ctx, ast_block_delete);
 363     ast_expression_init((ast_expression*)self,
 364                         (ast_expression_codegen*)&ast_block_codegen);
 365
 366     MEM_VECTOR_INIT(self, locals);
 367     MEM_VECTOR_INIT(self, exprs);
 368
 369     return self;
 370 }
 371 MEM_VEC_FUNCTIONS(ast_block, ast_value*, locals)
 372 MEM_VEC_FUNCTIONS(ast_block, ast_expression*, exprs)
 373
 374 void ast_block_delete(ast_block *self)
 375 {
 376     size_t i;
 377     for (i = 0; i < self->exprs_count; ++i)
 378         ast_unref(self->exprs[i]);
 379     MEM_VECTOR_CLEAR(self, exprs);
 380     for (i = 0; i < self->locals_count; ++i)
 381         ast_delete(self->locals[i]);
 382     MEM_VECTOR_CLEAR(self, locals);
 383     ast_expression_delete((ast_expression*)self);
 384     mem_d(self);
 385 }
 386
 387 ast_function* ast_function_new(lex_ctx ctx, const char *name, ast_value *vtype)
 388 {
 389     ast_instantiate(ast_function, ctx, ast_function_delete);
 390
 391     if (!vtype ||
 392         vtype->isconst ||
 393         vtype->expression.vtype != TYPE_FUNCTION)
 394     {
 395         mem_d(self);
 396         return NULL;
 397     }
 398
 399     self->vtype = vtype;
 400     self->name = name ? util_strdup(name) : NULL;
 401     MEM_VECTOR_INIT(self, blocks);
 402     MEM_VECTOR_INIT(self, params);
 403
 404     self->labelcount = 0;
 405     self->builtin = 0;
 406
 407     self->ir_func = NULL;
 408     self->curblock = NULL;
 409
 410     self->breakblock    = NULL;
 411     self->continueblock = NULL;
 412
 413     vtype->isconst = true;
 414     vtype->constval.vfunc = self;
 415
 416     return self;
 417 }
 418
 419 MEM_VEC_FUNCTIONS(ast_function, ast_block*, blocks)
 420 MEM_VEC_FUNCTIONS(ast_function, ast_value*, params)
 421
 422 void ast_function_delete(ast_function *self)
 423 {
 424     size_t i;
 425     if (self->name)
 426         mem_d((void*)self->name);
 427     if (self->vtype) {
 428         /* ast_value_delete(self->vtype); */
 429         self->vtype->isconst = false;
 430         self->vtype->constval.vfunc = NULL;
 431         /* We use unref - if it was stored in a global table it is supposed
 432          * to be deleted from *there*
 433          */
 434         ast_unref(self->vtype);
 435     }
 436     for (i = 0; i < self->blocks_count; ++i)
 437         ast_delete(self->blocks[i]);
 438     MEM_VECTOR_CLEAR(self, blocks);
 439     /* ast_delete, not unref, there must only have been references
 440      * to the parameter values inside the blocks deleted above.
 441      */
 442     for (i = 0; i < self->params_count; ++i)
 443         ast_delete(self->params[i]);
 444     MEM_VECTOR_CLEAR(self, params);
 445     mem_d(self);
 446 }
 447
 448 static void ast_util_hexitoa(char *buf, size_t size, unsigned int num)
 449 {
 450     unsigned int base = 10;
 451 #define checknul() do { if (size == 1) { *buf = 0; return; } } while (0)
 452 #define addch(x) do { *buf++ = (x); --size; checknul(); } while (0)
 453     if (size < 1)
 454         return;
 455     checknul();
 456     if (!num)
 457         addch('0');
 458     else {
 459         while (num)
 460         {
 461             int digit = num % base;
 462             num /= base;
 463             addch('0' + digit);
 464         }
 465     }
 466
 467     *buf = 0;
 468 #undef addch
 469 #undef checknul
 470 }
 471
 472 const char* ast_function_label(ast_function *self, const char *prefix)
 473 {
 474     size_t id = (self->labelcount++);
 475     size_t len = strlen(prefix);
 476     strncpy(self->labelbuf, prefix, sizeof(self->labelbuf));
 477     ast_util_hexitoa(self->labelbuf + len, sizeof(self->labelbuf)-len, id);
 478     return self->labelbuf;
 479 }
 480
 481 /*********************************************************************/
 482 /* AST codegen part
 483  * by convention you must never pass NULL to the 'ir_value **out'
 484  * parameter. If you really don't care about the output, pass a dummy.
 485  * But I can't imagine a pituation where the output is truly unnecessary.
 486  */
 487
 488 bool ast_value_codegen(ast_value *self, ast_function *func, bool lvalue, ir_value **out)
 489 {
 490     /* NOTE: This is the codegen for a variable used in an expression.
 491      * It is not the codegen to generate the value. For this purpose,
 492      * ast_local_codegen and ast_global_codegen are to be used before this
 493      * is executed. ast_function_codegen should take care of its locals,
 494      * and the ast-user should take care of ast_global_codegen to be used
 495      * on all the globals.
 496      */
 497     if (!self->ir_v) {
 498         printf("ast_value used before generated (%s)\n", self->name);
 499         return false;
 500     }
 501     *out = self->ir_v;
 502     return true;
 503 }
 504
 505 bool ast_global_codegen(ast_value *self, ir_builder *ir)
 506 {
 507     ir_value *v = NULL;
 508     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 509     {
 510         ir_function *func = ir_builder_create_function(ir, self->name, self->expression.next->expression.vtype);
 511         if (!func)
 512             return false;
 513
 514         self->constval.vfunc->ir_func = func;
 515         self->ir_v = func->value;
 516         /* The function is filled later on ast_function_codegen... */
 517         return true;
 518     }
 519
 520     v = ir_builder_create_global(ir, self->name, self->expression.vtype);
 521     if (!v)
 522         return false;
 523
 524     if (self->isconst) {
 525         switch (self->expression.vtype)
 526         {
 527             case TYPE_FLOAT:
 528                 if (!ir_value_set_float(v, self->constval.vfloat))
 529                     goto error;
 530                 break;
 531             case TYPE_VECTOR:
 532                 if (!ir_value_set_vector(v, self->constval.vvec))
 533                     goto error;
 534                 break;
 535             case TYPE_STRING:
 536                 if (!ir_value_set_string(v, self->constval.vstring))
 537                     goto error;
 538                 break;
 539             case TYPE_FUNCTION:
 540                 printf("global of type function not properly generated\n");
 541                 goto error;
 542                 /* Cannot generate an IR value for a function,
 543                  * need a pointer pointing to a function rather.
 544                  */
 545             default:
 546                 printf("TODO: global constant type %i\n", self->expression.vtype);
 547                 break;
 548         }
 549     }
 550
 551     /* link us to the ir_value */
 552     self->ir_v = v;
 553     return true;
 554
 555 error: /* clean up */
 556     ir_value_delete(v);
 557     return false;
 558 }
 559
 560 bool ast_local_codegen(ast_value *self, ir_function *func)
 561 {
 562     ir_value *v = NULL;
 563     if (self->isconst && self->expression.vtype == TYPE_FUNCTION)
 564     {
 565         /* Do we allow local functions? I think not...
 566          * this is NOT a function pointer atm.
 567          */
 568         return false;
 569     }
 570
 571     v = ir_function_create_local(func, self->name, self->expression.vtype);
 572     if (!v)
 573         return false;
 574
 575     /* A constant local... hmmm...
 576      * I suppose the IR will have to deal with this
 577      */
 578     if (self->isconst) {
 579         switch (self->expression.vtype)
 580         {
 581             case TYPE_FLOAT:
 582                 if (!ir_value_set_float(v, self->constval.vfloat))
 583                     goto error;
 584                 break;
 585             case TYPE_VECTOR:
 586                 if (!ir_value_set_vector(v, self->constval.vvec))
 587                     goto error;
 588                 break;
 589             case TYPE_STRING:
 590                 if (!ir_value_set_string(v, self->constval.vstring))
 591                     goto error;
 592                 break;
 593             default:
 594                 printf("TODO: global constant type %i\n", self->expression.vtype);
 595                 break;
 596         }
 597     }
 598
 599     /* link us to the ir_value */
 600     self->ir_v = v;
 601     return true;
 602
 603 error: /* clean up */
 604     ir_value_delete(v);
 605     return false;
 606 }
 607
 608 bool ast_function_codegen(ast_function *self, ir_builder *ir)
 609 {
 610     ir_function *irf;
 611     ir_value    *dummy;
 612     size_t    i;
 613
 614     irf = self->ir_func;
 615     if (!irf) {
 616         printf("ast_function's related ast_value was not generated yet\n");
 617         return false;
 618     }
 619
 620     for (i = 0; i < self->vtype->params_count; ++i)
 621     {
 622         if (!ir_function_params_add(irf, self->vtype->params[i]->expression.vtype))
 623             return false;
 624     }
 625
 626     if (self->builtin) {
 627         irf->builtin = self->builtin;
 628         return true;
 629     }
 630
 631     self->curblock = ir_function_create_block(irf, "entry");
 632     if (!self->curblock)
 633         return false;
 634
 635     for (i = 0; i < self->blocks_count; ++i) {
 636         ast_expression_codegen *gen = self->blocks[i]->expression.codegen;
 637         if (!(*gen)((ast_expression*)self->blocks[i], self, false, &dummy))
 638             return false;
 639     }
 640
 641     /* TODO: check return types */
 642     if (!self->curblock->is_return)
 643     {
 644         if (!self->vtype->expression.next ||
 645             self->vtype->expression.next->expression.vtype == TYPE_VOID)
 646         {
 647             return ir_block_create_return(self->curblock, NULL);
 648         }
 649         else
 650         {
 651             /* error("missing return"); */
 652             return false;
 653         }
 654     }
 655     return true;
 656 }
 657
 658 /* Note, you will not see ast_block_codegen generate ir_blocks.
 659  * To the AST and the IR, blocks are 2 different things.
 660  * In the AST it represents a block of code, usually enclosed in
 661  * curly braces {...}.
 662  * While in the IR it represents a block in terms of control-flow.
 663  */
 664 bool ast_block_codegen(ast_block *self, ast_function *func, bool lvalue, ir_value **out)
 665 {
 666     size_t i;
 667
 668     /* We don't use this
 669      * Note: an ast-representation using the comma-operator
 670      * of the form: (a, b, c) = x should not assign to c...
 671      */
 672     (void)lvalue;
 673
 674     /* output is NULL at first, we'll have each expression
 675      * assign to out output, thus, a comma-operator represention
 676      * using an ast_block will return the last generated value,
 677      * so: (b, c) + a  executed both b and c, and returns c,
 678      * which is then added to a.
 679      */
 680     *out = NULL;
 681
 682     /* generate locals */
 683     for (i = 0; i < self->locals_count; ++i)
 684     {
 685         if (!ast_local_codegen(self->locals[i], func->ir_func))
 686             return false;
 687     }
 688
 689     for (i = 0; i < self->exprs_count; ++i)
 690     {
 691         ast_expression_codegen *gen = self->exprs[i]->expression.codegen;
 692         if (!(*gen)(self->exprs[i], func, false, out))
 693             return false;
 694     }
 695
 696     return true;
 697 }
 698
 699 bool ast_store_codegen(ast_store *self, ast_function *func, bool lvalue, ir_value **out)
 700 {
 701     ast_expression_codegen *cgen;
 702     ir_value *left, *right;
 703
 704     cgen = self->dest->expression.codegen;
 705     /* lvalue! */
 706     if (!(*cgen)((ast_expression*)(self->dest), func, true, &left))
 707         return false;
 708
 709     cgen = self->source->expression.codegen;
 710     /* rvalue! */
 711     if (!(*cgen)((ast_expression*)(self->source), func, false, &right))
 712         return false;
 713
 714     if (!ir_block_create_store_op(func->curblock, self->op, left, right))
 715         return false;
 716
 717     /* Theoretically, an assinment returns its left side as an
 718      * lvalue, if we don't need an lvalue though, we return
 719      * the right side as an rvalue, otherwise we have to
 720      * somehow know whether or not we need to dereference the pointer
 721      * on the left side - that is: OP_LOAD if it was an address.
 722      * Also: in original QC we cannot OP_LOADP *anyway*.
 723      */
 724     *out = (lvalue ? left : right);
 725
 726     return true;
 727 }
 728
 729 bool ast_binary_codegen(ast_binary *self, ast_function *func, bool lvalue, ir_value **out)
 730 {
 731     ast_expression_codegen *cgen;
 732     ir_value *left, *right;
 733
 734     /* In the context of a binary operation, we can disregard
 735      * the lvalue flag.
 736      */
 737      (void)lvalue;
 738
 739     cgen = self->left->expression.codegen;
 740     /* lvalue! */
 741     if (!(*cgen)((ast_expression*)(self->left), func, false, &left))
 742         return false;
 743
 744     cgen = self->right->expression.codegen;
 745     /* rvalue! */
 746     if (!(*cgen)((ast_expression*)(self->right), func, false, &right))
 747         return false;
 748
 749     *out = ir_block_create_binop(func->curblock, ast_function_label(func, "bin"),
 750                                  self->op, left, right);
 751     if (!*out)
 752         return false;
 753
 754     return true;
 755 }
 756
 757 bool ast_entfield_codegen(ast_entfield *self, ast_function *func, bool lvalue, ir_value **out)
 758 {
 759     ast_expression_codegen *cgen;
 760     ir_value *ent, *field;
 761
 762     /* This function needs to take the 'lvalue' flag into account!
 763      * As lvalue we provide a field-pointer, as rvalue we provide the
 764      * value in a temp.
 765      */
 766
 767     cgen = self->entity->expression.codegen;
 768     if (!(*cgen)((ast_expression*)(self->entity), func, false, &ent))
 769         return false;
 770
 771     cgen = self->field->expression.codegen;
 772     if (!(*cgen)((ast_expression*)(self->field), func, false, &field))
 773         return false;
 774
 775     if (lvalue) {
 776         /* address! */
 777         *out = ir_block_create_fieldaddress(func->curblock, ast_function_label(func, "efa"),
 778                                             ent, field);
 779     } else {
 780         *out = ir_block_create_load_from_ent(func->curblock, ast_function_label(func, "efv"),
 781                                              ent, field, self->expression.vtype);
 782     }
 783     if (!*out)
 784         return false;
 785
 786     /* Hm that should be it... */
 787     return true;
 788 }
 789
 790 bool ast_ifthen_codegen(ast_ifthen *self, ast_function *func, bool lvalue, ir_value **out)
 791 {
 792     ast_expression_codegen *cgen;
 793
 794     ir_value *condval;
 795     ir_value *dummy;
 796
 797     ir_block *cond = func->curblock;
 798     ir_block *ontrue;
 799     ir_block *onfalse;
 800     ir_block *merge;
 801
 802     /* We don't output any value, thus also don't care about r/lvalue */
 803     (void)out;
 804     (void)lvalue;
 805
 806     /* generate the condition */
 807     func->curblock = cond;
 808     cgen = self->cond->expression.codegen;
 809     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 810         return false;
 811
 812     /* on-true path */
 813
 814     if (self->on_true) {
 815         /* create on-true block */
 816         ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "ontrue"));
 817         if (!ontrue)
 818             return false;
 819
 820         /* enter the block */
 821         func->curblock = ontrue;
 822
 823         /* generate */
 824         cgen = self->on_true->expression.codegen;
 825         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &dummy))
 826             return false;
 827     } else
 828         ontrue = NULL;
 829
 830     /* on-false path */
 831     if (self->on_false) {
 832         /* create on-false block */
 833         onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "onfalse"));
 834         if (!onfalse)
 835             return false;
 836
 837         /* enter the block */
 838         func->curblock = onfalse;
 839
 840         /* generate */
 841         cgen = self->on_false->expression.codegen;
 842         if (!(*cgen)((ast_expression*)(self->on_false), func, false, &dummy))
 843             return false;
 844     } else
 845         onfalse = NULL;
 846
 847     /* Merge block were they all merge in to */
 848     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "endif"));
 849     if (!merge)
 850         return false;
 851
 852     /* add jumps ot the merge block */
 853     if (ontrue && !ir_block_create_jump(ontrue, merge))
 854         return false;
 855     if (onfalse && !ir_block_create_jump(onfalse, merge))
 856         return false;
 857
 858     /* we create the if here, that way all blocks are ordered :)
 859      */
 860     if (!ir_block_create_if(cond, condval,
 861                             (ontrue  ? ontrue  : merge),
 862                             (onfalse ? onfalse : merge)))
 863     {
 864         return false;
 865     }
 866
 867     /* Now enter the merge block */
 868     func->curblock = merge;
 869
 870     return true;
 871 }
 872
 873 bool ast_ternary_codegen(ast_ternary *self, ast_function *func, bool lvalue, ir_value **out)
 874 {
 875     ast_expression_codegen *cgen;
 876
 877     ir_value *condval;
 878     ir_value *trueval, *falseval;
 879     ir_instr *phi;
 880
 881     ir_block *cond = func->curblock;
 882     ir_block *ontrue;
 883     ir_block *onfalse;
 884     ir_block *merge;
 885
 886     /* In theory it shouldn't be possible to pass through a node twice, but
 887      * in case we add any kind of optimization pass for the AST itself, it
 888      * may still happen, thus we remember a created ir_value and simply return one
 889      * if it already exists.
 890      */
 891     if (self->phi_out) {
 892         *out = self->phi_out;
 893         return true;
 894     }
 895
 896     /* Ternary can never create an lvalue... */
 897     if (lvalue)
 898         return false;
 899
 900     /* In the following, contraty to ast_ifthen, we assume both paths exist. */
 901
 902     /* generate the condition */
 903     func->curblock = cond;
 904     cgen = self->cond->expression.codegen;
 905     if (!(*cgen)((ast_expression*)(self->cond), func, false, &condval))
 906         return false;
 907
 908     /* create on-true block */
 909     ontrue = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_T"));
 910     if (!ontrue)
 911         return false;
 912     else
 913     {
 914         /* enter the block */
 915         func->curblock = ontrue;
 916
 917         /* generate */
 918         cgen = self->on_true->expression.codegen;
 919         if (!(*cgen)((ast_expression*)(self->on_true), func, false, &trueval))
 920             return false;
 921     }
 922
 923     /* create on-false block */
 924     onfalse = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_F"));
 925     if (!onfalse)
 926         return false;
 927     else
 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, &falseval))
 935             return false;
 936     }
 937
 938     /* create merge block */
 939     merge = ir_function_create_block(func->ir_func, ast_function_label(func, "tern_out"));
 940     if (!merge)
 941         return false;
 942     /* jump to merge block */
 943     if (!ir_block_create_jump(ontrue, merge))
 944         return false;
 945     if (!ir_block_create_jump(onfalse, merge))
 946         return false;
 947
 948     /* create if instruction */
 949     if (!ir_block_create_if(cond, condval, ontrue, onfalse))
 950         return false;
 951
 952     /* Now enter the merge block */
 953     func->curblock = merge;
 954
 955     /* Here, now, we need a PHI node
 956      * but first some sanity checking...
 957      */
 958     if (trueval->vtype != falseval->vtype) {
 959         /* error("ternary with different types on the two sides"); */
 960         return false;
 961     }
 962
 963     /* create PHI */
 964     phi = ir_block_create_phi(merge, ast_function_label(func, "phi"), trueval->vtype);
 965     if (!phi ||
 966         !ir_phi_add(phi, ontrue,  trueval) ||
 967         !ir_phi_add(phi, onfalse, falseval))
 968     {
 969         return false;
 970     }
 971
 972     self->phi_out = ir_phi_value(phi);
 973     *out = self->phi_out;
 974
 975     return true;
 976 }
 977
 978 bool ast_loop_codegen(ast_loop *self, ast_function *func, bool lvalue, ir_value **out)
 979 {
 980     ast_expression_codegen *cgen;
 981
 982     ir_value *dummy      = NULL;
 983     ir_value *precond    = NULL;
 984     ir_value *postcond   = NULL;
 985
 986     /* Since we insert some jumps "late" so we have blocks
 987      * ordered "nicely", we need to keep track of the actual end-blocks
 988      * of expressions to add the jumps to.
 989      */
 990     ir_block *bbody      = NULL, *end_bbody      = NULL;
 991     ir_block *bprecond   = NULL, *end_bprecond   = NULL;
 992     ir_block *bpostcond  = NULL, *end_bpostcond  = NULL;
 993     ir_block *bincrement = NULL, *end_bincrement = NULL;
 994     ir_block *bout       = NULL, *bin            = NULL;
 995
 996     /* let's at least move the outgoing block to the end */
 997     size_t    bout_id;
 998
 999     /* 'break' and 'continue' need to be able to find the right blocks */
1000     ir_block *bcontinue     = NULL;
1001     ir_block *bbreak        = NULL;
1002
1003     ir_block *old_bcontinue = NULL;
1004     ir_block *old_bbreak    = NULL;
1005
1006     ir_block *tmpblock      = NULL;
1007
1008     (void)lvalue;
1009     (void)out;
1010
1011     /* NOTE:
1012      * Should we ever need some kind of block ordering, better make this function
1013      * move blocks around than write a block ordering algorithm later... after all
1014      * the ast and ir should work together, not against each other.
1015      */
1016
1017     /* initexpr doesn't get its own block, it's pointless, it could create more blocks
1018      * anyway if for example it contains a ternary.
1019      */
1020     if (self->initexpr)
1021     {
1022         cgen = self->initexpr->expression.codegen;
1023         if (!(*cgen)((ast_expression*)(self->initexpr), func, false, &dummy))
1024             return false;
1025     }
1026
1027     /* Store the block from which we enter this chaos */
1028     bin = func->curblock;
1029
1030     /* The pre-loop condition needs its own block since we
1031      * need to be able to jump to the start of that expression.
1032      */
1033     if (self->precond)
1034     {
1035         bprecond = ir_function_create_block(func->ir_func, ast_function_label(func, "pre_loop_cond"));
1036         if (!bprecond)
1037             return false;
1038
1039         /* the pre-loop-condition the least important place to 'continue' at */
1040         bcontinue = bprecond;
1041
1042         /* enter */
1043         func->curblock = bprecond;
1044
1045         /* generate */
1046         cgen = self->precond->expression.codegen;
1047         if (!(*cgen)((ast_expression*)(self->precond), func, false, &precond))
1048             return false;
1049
1050         end_bprecond = func->curblock;
1051     } else {
1052         bprecond = end_bprecond = NULL;
1053     }
1054
1055     /* Now the next blocks won't be ordered nicely, but we need to
1056      * generate them this early for 'break' and 'continue'.
1057      */
1058     if (self->increment) {
1059         bincrement = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_increment"));
1060         if (!bincrement)
1061             return false;
1062         bcontinue = bincrement; /* increment comes before the pre-loop-condition */
1063     } else {
1064         bincrement = end_bincrement = NULL;
1065     }
1066
1067     if (self->postcond) {
1068         bpostcond = ir_function_create_block(func->ir_func, ast_function_label(func, "post_loop_cond"));
1069         if (!bpostcond)
1070             return false;
1071         bcontinue = bpostcond; /* postcond comes before the increment */
1072     } else {
1073         bpostcond = end_bpostcond = NULL;
1074     }
1075
1076     bout_id = func->ir_func->blocks_count;
1077     bout = ir_function_create_block(func->ir_func, ast_function_label(func, "after_loop"));
1078     if (!bout)
1079         return false;
1080     bbreak = bout;
1081
1082     /* The loop body... */
1083     if (self->body)
1084     {
1085         bbody = ir_function_create_block(func->ir_func, ast_function_label(func, "loop_body"));
1086         if (!bbody)
1087             return false;
1088
1089         /* enter */
1090         func->curblock = bbody;
1091
1092         old_bbreak          = func->breakblock;
1093         old_bcontinue       = func->continueblock;
1094         func->breakblock    = bbreak;
1095         func->continueblock = bcontinue;
1096
1097         /* generate */
1098         cgen = self->body->expression.codegen;
1099         if (!(*cgen)((ast_expression*)(self->body), func, false, &dummy))
1100             return false;
1101
1102         end_bbody = func->curblock;
1103         func->breakblock    = old_bbreak;
1104         func->continueblock = old_bcontinue;
1105     }
1106
1107     /* post-loop-condition */
1108     if (self->postcond)
1109     {
1110         /* enter */
1111         func->curblock = bpostcond;
1112
1113         /* generate */
1114         cgen = self->postcond->expression.codegen;
1115         if (!(*cgen)((ast_expression*)(self->postcond), func, false, &postcond))
1116             return false;
1117
1118         end_bpostcond = func->curblock;
1119     }
1120
1121     /* The incrementor */
1122     if (self->increment)
1123     {
1124         /* enter */
1125         func->curblock = bincrement;
1126
1127         /* generate */
1128         cgen = self->increment->expression.codegen;
1129         if (!(*cgen)((ast_expression*)(self->increment), func, false, &dummy))
1130             return false;
1131
1132         end_bincrement = func->curblock;
1133     }
1134
1135     /* In any case now, we continue from the outgoing block */
1136     func->curblock = bout;
1137
1138     /* Now all blocks are in place */
1139     /* From 'bin' we jump to whatever comes first */
1140     if      (bprecond)   tmpblock = bprecond;
1141     else if (bbody)      tmpblock = bbody;
1142     else if (bpostcond)  tmpblock = bpostcond;
1143     else                 tmpblock = bout;
1144     if (!ir_block_create_jump(bin, tmpblock))
1145         return false;
1146
1147     /* From precond */
1148     if (bprecond)
1149     {
1150         ir_block *ontrue, *onfalse;
1151         if      (bbody)      ontrue = bbody;
1152         else if (bincrement) ontrue = bincrement;
1153         else if (bpostcond)  ontrue = bpostcond;
1154         else                 ontrue = bprecond;
1155         onfalse = bout;
1156         if (!ir_block_create_if(end_bprecond, precond, ontrue, onfalse))
1157             return false;
1158     }
1159
1160     /* from body */
1161     if (bbody)
1162     {
1163         if      (bincrement) tmpblock = bincrement;
1164         else if (bpostcond)  tmpblock = bpostcond;
1165         else if (bprecond)   tmpblock = bprecond;
1166         else                 tmpblock = bout;
1167         if (!ir_block_create_jump(end_bbody, tmpblock))
1168             return false;
1169     }
1170
1171     /* from increment */
1172     if (bincrement)
1173     {
1174         if      (bpostcond)  tmpblock = bpostcond;
1175         else if (bprecond)   tmpblock = bprecond;
1176         else if (bbody)      tmpblock = bbody;
1177         else                 tmpblock = bout;
1178         if (!ir_block_create_jump(end_bincrement, tmpblock))
1179             return false;
1180     }
1181
1182     /* from postcond */
1183     if (bpostcond)
1184     {
1185         ir_block *ontrue, *onfalse;
1186         if      (bprecond)   ontrue = bprecond;
1187         else if (bbody)      ontrue = bbody;
1188         else if (bincrement) ontrue = bincrement;
1189         else                 ontrue = bpostcond;
1190         onfalse = bout;
1191         if (!ir_block_create_if(end_bpostcond, postcond, ontrue, onfalse))
1192             return false;
1193     }
1194
1195     /* Move 'bout' to the end */
1196     if (!ir_function_blocks_remove(func->ir_func, bout_id) ||
1197         !ir_function_blocks_add(func->ir_func, bout))
1198     {
1199         ir_block_delete(bout);
1200         return false;
1201     }
1202
1203     return true;
1204 }
1205
1206 bool ast_call_codegen(ast_call *self, ast_function *func, bool lvalue, ir_value **out)
1207 {
1208     ast_expression_codegen *cgen;
1209     ir_value_vector         params;
1210     ir_instr               *callinstr;
1211     size_t i;
1212
1213     ir_value *funval = NULL;
1214
1215     /* return values are never rvalues */
1216     (void)lvalue;
1217
1218     cgen = self->func->expression.codegen;
1219     if (!(*cgen)((ast_expression*)(self->func), func, false, &funval))
1220         return false;
1221     if (!funval)
1222         return false;
1223
1224     MEM_VECTOR_INIT(&params, v);
1225
1226     /* parameters */
1227     for (i = 0; i < self->params_count; ++i)
1228     {
1229         ir_value *param;
1230         ast_expression *expr = self->params[i];
1231
1232         cgen = expr->expression.codegen;
1233         if (!(*cgen)(expr, func, false, &param))
1234             goto error;
1235         if (!param)
1236             goto error;
1237         if (!ir_value_vector_v_add(&params, param))
1238             goto error;
1239     }
1240
1241     callinstr = ir_block_create_call(func->curblock, ast_function_label(func, "call"), funval);
1242     if (!callinstr)
1243         goto error;
1244
1245     for (i = 0; i < params.v_count; ++i) {
1246         if (!ir_call_param(callinstr, params.v[i]))
1247             goto error;
1248     }
1249
1250     *out = ir_call_value(callinstr);
1251
1252     return true;
1253 error:
1254     MEM_VECTOR_CLEAR(&params, v);
1255     return false;
1256 }