ir_reader.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * 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
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23 #include <cstdio>
  24 #include <cstdarg>
  25
  26 extern "C" {
  27 #include <talloc.h>
  28 }
  29
  30 #include "ir_reader.h"
  31 #include "glsl_parser_extras.h"
  32 #include "glsl_types.h"
  33 #include "s_expression.h"
  34
  35 static void ir_read_error(_mesa_glsl_parse_state *, s_expression *,
  36                           const char *fmt, ...);
  37 static const glsl_type *read_type(_mesa_glsl_parse_state *, s_expression *);
  38
  39 static void scan_for_prototypes(_mesa_glsl_parse_state *, exec_list *,
  40                                 s_expression *);
  41 static ir_function *read_function(_mesa_glsl_parse_state *, s_list *,
  42                                   bool skip_body);
  43 static void read_function_sig(_mesa_glsl_parse_state *, ir_function *,
  44                               s_list *, bool skip_body);
  45
  46 static void read_instructions(_mesa_glsl_parse_state *, exec_list *,
  47                               s_expression *, ir_loop *);
  48 static ir_instruction *read_instruction(_mesa_glsl_parse_state *,
  49                                         s_expression *, ir_loop *);
  50 static ir_variable *read_declaration(_mesa_glsl_parse_state *, s_list *);
  51 static ir_if *read_if(_mesa_glsl_parse_state *, s_list *, ir_loop *);
  52 static ir_loop *read_loop(_mesa_glsl_parse_state *st, s_list *list);
  53 static ir_return *read_return(_mesa_glsl_parse_state *, s_list *);
  54
  55 static ir_rvalue *read_rvalue(_mesa_glsl_parse_state *, s_expression *);
  56 static ir_assignment *read_assignment(_mesa_glsl_parse_state *, s_list *);
  57 static ir_expression *read_expression(_mesa_glsl_parse_state *, s_list *);
  58 static ir_call *read_call(_mesa_glsl_parse_state *, s_list *);
  59 static ir_swizzle *read_swizzle(_mesa_glsl_parse_state *, s_list *);
  60 static ir_constant *read_constant(_mesa_glsl_parse_state *, s_list *);
  61 static ir_texture *read_texture(_mesa_glsl_parse_state *, s_list *);
  62
  63 static ir_dereference *read_dereference(_mesa_glsl_parse_state *,
  64                                         s_expression *);
  65 static ir_dereference *read_var_ref(_mesa_glsl_parse_state *, s_list *);
  66 static ir_dereference *read_array_ref(_mesa_glsl_parse_state *, s_list *);
  67 static ir_dereference *read_record_ref(_mesa_glsl_parse_state *, s_list *);
  68
  69 void
  70 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  71                    const char *src)
  72 {
  73    s_expression *expr = s_expression::read_expression(src);
  74    if (expr == NULL) {
  75       ir_read_error(state, NULL, "couldn't parse S-Expression.");
  76       return;
  77    }
  78
  79    scan_for_prototypes(state, instructions, expr);
  80    if (state->error)
  81       return;
  82
  83    read_instructions(state, instructions, expr, NULL);
  84 }
  85
  86 static void
  87 ir_read_error(_mesa_glsl_parse_state *state, s_expression *expr,
  88               const char *fmt, ...)
  89 {
  90    va_list ap;
  91
  92    state->error = true;
  93
  94    state->info_log = talloc_strdup_append(state->info_log, "error: ");
  95
  96    va_start(ap, fmt);
  97    state->info_log = talloc_vasprintf_append(state->info_log, fmt, ap);
  98    va_end(ap);
  99    state->info_log = talloc_strdup_append(state->info_log, "\n");
 100
 101    if (expr != NULL) {
 102       state->info_log = talloc_strdup_append(state->info_log,
 103                                              "...in this context:\n   ");
 104       expr->print();
 105       state->info_log = talloc_strdup_append(state->info_log, "\n\n");
 106    }
 107 }
 108
 109 static const glsl_type *
 110 read_type(_mesa_glsl_parse_state *st, s_expression *expr)
 111 {
 112    s_list *list = SX_AS_LIST(expr);
 113    if (list != NULL) {
 114       s_symbol *type_sym = SX_AS_SYMBOL(list->subexpressions.get_head());
 115       if (type_sym == NULL) {
 116          ir_read_error(st, expr, "expected type (array ...) or (struct ...)");
 117          return NULL;
 118       }
 119       if (strcmp(type_sym->value(), "array") == 0) {
 120          if (list->length() != 3) {
 121             ir_read_error(st, expr, "expected type (array <type> <int>)");
 122             return NULL;
 123          }
 124
 125          // Read base type
 126          s_expression *base_expr = (s_expression*) type_sym->next;
 127          const glsl_type *base_type = read_type(st, base_expr);
 128          if (base_type == NULL) {
 129             ir_read_error(st, NULL, "when reading base type of array");
 130             return NULL;
 131          }
 132
 133          // Read array size
 134          s_int *size = SX_AS_INT(base_expr->next);
 135          if (size == NULL) {
 136             ir_read_error(st, expr, "found non-integer array size");
 137             return NULL;
 138          }
 139
 140          return glsl_type::get_array_instance(base_type, size->value());
 141       } else if (strcmp(type_sym->value(), "struct") == 0) {
 142          assert(false); // FINISHME
 143       } else {
 144          ir_read_error(st, expr, "expected (array ...) or (struct ...); "
 145                                  "found (%s ...)", type_sym->value());
 146          return NULL;
 147       }
 148    }
 149
 150    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 151    if (type_sym == NULL) {
 152       ir_read_error(st, expr, "expected <type> (symbol or list)");
 153       return NULL;
 154    }
 155
 156    const glsl_type *type = st->symbols->get_type(type_sym->value());
 157    if (type == NULL)
 158       ir_read_error(st, expr, "invalid type: %s", type_sym->value());
 159
 160    return type;
 161 }
 162
 163
 164 static void
 165 scan_for_prototypes(_mesa_glsl_parse_state *st, exec_list *instructions,
 166                     s_expression *expr)
 167 {
 168    s_list *list = SX_AS_LIST(expr);
 169    if (list == NULL) {
 170       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 171       return;
 172    }
 173
 174    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 175       s_list *sub = SX_AS_LIST(it.get());
 176       if (sub == NULL)
 177          continue; // not a (function ...); ignore it.
 178
 179       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 180       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 181          continue; // not a (function ...); ignore it.
 182
 183       ir_function *f = read_function(st, sub, true);
 184       if (f == NULL)
 185          return;
 186       instructions->push_tail(f);
 187    }
 188 }
 189
 190 static ir_function *
 191 read_function(_mesa_glsl_parse_state *st, s_list *list, bool skip_body)
 192 {
 193    if (list->length() < 3) {
 194       ir_read_error(st, list, "Expected (function <name> (signature ...) ...)");
 195       return NULL;
 196    }
 197
 198    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 199    if (name == NULL) {
 200       ir_read_error(st, list, "Expected (function <name> ...)");
 201       return NULL;
 202    }
 203
 204    ir_function *f = st->symbols->get_function(name->value());
 205    if (f == NULL) {
 206       f = new ir_function(name->value());
 207       bool added = st->symbols->add_function(name->value(), f);
 208       assert(added);
 209    }
 210
 211    exec_list_iterator it = list->subexpressions.iterator();
 212    it.next(); // skip "function" tag
 213    it.next(); // skip function name
 214    for (/* nothing */; it.has_next(); it.next()) {
 215       s_list *siglist = SX_AS_LIST(it.get());
 216       if (siglist == NULL) {
 217          ir_read_error(st, list, "Expected (function (signature ...) ...)");
 218          return NULL;
 219       }
 220
 221       s_symbol *tag = SX_AS_SYMBOL(siglist->subexpressions.get_head());
 222       if (tag == NULL || strcmp(tag->value(), "signature") != 0) {
 223          ir_read_error(st, siglist, "Expected (signature ...)");
 224          return NULL;
 225       }
 226
 227       read_function_sig(st, f, siglist, skip_body);
 228    }
 229    return f;
 230 }
 231
 232 static void
 233 read_function_sig(_mesa_glsl_parse_state *st, ir_function *f, s_list *list,
 234                   bool skip_body)
 235 {
 236    if (list->length() != 4) {
 237       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 238                               "(<instruction> ...))");
 239       return;
 240    }
 241
 242    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 243    const glsl_type *return_type = read_type(st, type_expr);
 244    if (return_type == NULL)
 245       return;
 246
 247    s_list *paramlist = SX_AS_LIST(type_expr->next);
 248    s_list *body_list = SX_AS_LIST(paramlist->next);
 249    if (paramlist == NULL || body_list == NULL) {
 250       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 251                               "(<instruction> ...))");
 252       return;
 253    }
 254    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 255    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 256       ir_read_error(st, paramlist, "Expected (parameters ...)");
 257       return;
 258    }
 259
 260    // Read the parameters list into a temporary place.
 261    exec_list hir_parameters;
 262    st->symbols->push_scope();
 263
 264    exec_list_iterator it = paramlist->subexpressions.iterator();
 265    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 266       s_list *decl = SX_AS_LIST(it.get());
 267       ir_variable *var = read_declaration(st, decl);
 268       if (var == NULL)
 269          return;
 270
 271       hir_parameters.push_tail(var);
 272    }
 273
 274    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 275    if (sig != NULL) {
 276       const char *badvar = sig->qualifiers_match(&hir_parameters);
 277       if (badvar != NULL) {
 278          ir_read_error(st, list, "function `%s' parameter `%s' qualifiers "
 279                        "don't match prototype", f->name, badvar);
 280          return;
 281       }
 282
 283       if (sig->return_type != return_type) {
 284          ir_read_error(st, list, "function `%s' return type doesn't "
 285                        "match prototype", f->name);
 286          return;
 287       }
 288    } else {
 289       sig = new ir_function_signature(return_type);
 290       f->add_signature(sig);
 291    }
 292
 293    sig->replace_parameters(&hir_parameters);
 294
 295    if (!skip_body) {
 296       if (sig->is_defined) {
 297          ir_read_error(st, list, "function %s redefined", f->name);
 298          return;
 299       }
 300       read_instructions(st, &sig->body, body_list, NULL);
 301       sig->is_defined = true;
 302    }
 303
 304    st->symbols->pop_scope();
 305 }
 306
 307 static void
 308 read_instructions(_mesa_glsl_parse_state *st, exec_list *instructions,
 309                   s_expression *expr, ir_loop *loop_ctx)
 310 {
 311    // Read in a list of instructions
 312    s_list *list = SX_AS_LIST(expr);
 313    if (list == NULL) {
 314       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 315       return;
 316    }
 317
 318    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 319       s_expression *sub = (s_expression*) it.get();
 320       ir_instruction *ir = read_instruction(st, sub, loop_ctx);
 321       if (ir == NULL) {
 322          ir_read_error(st, sub, "Invalid instruction.\n");
 323          return;
 324       }
 325       instructions->push_tail(ir);
 326    }
 327 }
 328
 329
 330 static ir_instruction *
 331 read_instruction(_mesa_glsl_parse_state *st, s_expression *expr,
 332                  ir_loop *loop_ctx)
 333 {
 334    s_symbol *symbol = SX_AS_SYMBOL(expr);
 335    if (symbol != NULL) {
 336       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 337          return new ir_loop_jump(loop_ctx, ir_loop_jump::jump_break);
 338       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 339          return new ir_loop_jump(loop_ctx, ir_loop_jump::jump_continue);
 340    }
 341
 342    s_list *list = SX_AS_LIST(expr);
 343    if (list == NULL || list->subexpressions.is_empty())
 344       return NULL;
 345
 346    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 347    if (tag == NULL) {
 348       ir_read_error(st, expr, "expected instruction tag");
 349       return NULL;
 350    }
 351
 352    ir_instruction *inst = NULL;
 353    if (strcmp(tag->value(), "declare") == 0) {
 354       inst = read_declaration(st, list);
 355    } else if (strcmp(tag->value(), "if") == 0) {
 356       inst = read_if(st, list, loop_ctx);
 357    } else if (strcmp(tag->value(), "loop") == 0) {
 358       inst = read_loop(st, list);
 359    } else if (strcmp(tag->value(), "return") == 0) {
 360       inst = read_return(st, list);
 361    } else if (strcmp(tag->value(), "function") == 0) {
 362       inst = read_function(st, list, false);
 363    } else {
 364       inst = read_rvalue(st, list);
 365       if (inst == NULL)
 366          ir_read_error(st, NULL, "when reading instruction");
 367    }
 368    return inst;
 369 }
 370
 371
 372 static ir_variable *
 373 read_declaration(_mesa_glsl_parse_state *st, s_list *list)
 374 {
 375    if (list->length() != 4) {
 376       ir_read_error(st, list, "expected (declare (<qualifiers>) <type> "
 377                               "<name>)");
 378       return NULL;
 379    }
 380
 381    s_list *quals = SX_AS_LIST(list->subexpressions.head->next);
 382    if (quals == NULL) {
 383       ir_read_error(st, list, "expected a list of variable qualifiers");
 384       return NULL;
 385    }
 386
 387    s_expression *type_expr = (s_expression*) quals->next;
 388    const glsl_type *type = read_type(st, type_expr);
 389    if (type == NULL)
 390       return NULL;
 391
 392    s_symbol *var_name = SX_AS_SYMBOL(type_expr->next);
 393    if (var_name == NULL) {
 394       ir_read_error(st, list, "expected variable name, found non-symbol");
 395       return NULL;
 396    }
 397
 398    ir_variable *var = new ir_variable(type, var_name->value());
 399
 400    foreach_iter(exec_list_iterator, it, quals->subexpressions) {
 401       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 402       if (qualifier == NULL) {
 403          ir_read_error(st, list, "qualifier list must contain only symbols");
 404          delete var;
 405          return NULL;
 406       }
 407
 408       // FINISHME: Check for duplicate/conflicting qualifiers.
 409       if (strcmp(qualifier->value(), "centroid") == 0) {
 410          var->centroid = 1;
 411       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 412          var->invariant = 1;
 413       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 414          var->mode = ir_var_uniform;
 415       } else if (strcmp(qualifier->value(), "auto") == 0) {
 416          var->mode = ir_var_auto;
 417       } else if (strcmp(qualifier->value(), "in") == 0) {
 418          var->mode = ir_var_in;
 419       } else if (strcmp(qualifier->value(), "out") == 0) {
 420          var->mode = ir_var_out;
 421       } else if (strcmp(qualifier->value(), "inout") == 0) {
 422          var->mode = ir_var_inout;
 423       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 424          var->interpolation = ir_var_smooth;
 425       } else if (strcmp(qualifier->value(), "flat") == 0) {
 426          var->interpolation = ir_var_flat;
 427       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 428          var->interpolation = ir_var_noperspective;
 429       } else {
 430          ir_read_error(st, list, "unknown qualifier: %s", qualifier->value());
 431          delete var;
 432          return NULL;
 433       }
 434    }
 435
 436    // Add the variable to the symbol table
 437    st->symbols->add_variable(var_name->value(), var);
 438
 439    return var;
 440 }
 441
 442
 443 static ir_if *
 444 read_if(_mesa_glsl_parse_state *st, s_list *list, ir_loop *loop_ctx)
 445 {
 446    if (list->length() != 4) {
 447       ir_read_error(st, list, "expected (if <condition> (<then> ...) "
 448                           "(<else> ...))");
 449       return NULL;
 450    }
 451
 452    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 453    ir_rvalue *condition = read_rvalue(st, cond_expr);
 454    if (condition == NULL) {
 455       ir_read_error(st, NULL, "when reading condition of (if ...)");
 456       return NULL;
 457    }
 458
 459    s_expression *then_expr = (s_expression*) cond_expr->next;
 460    s_expression *else_expr = (s_expression*) then_expr->next;
 461
 462    ir_if *iff = new ir_if(condition);
 463
 464    read_instructions(st, &iff->then_instructions, then_expr, loop_ctx);
 465    read_instructions(st, &iff->else_instructions, else_expr, loop_ctx);
 466    if (st->error) {
 467       delete iff;
 468       iff = NULL;
 469    }
 470    return iff;
 471 }
 472
 473
 474 static ir_loop *
 475 read_loop(_mesa_glsl_parse_state *st, s_list *list)
 476 {
 477    if (list->length() != 6) {
 478       ir_read_error(st, list, "expected (loop <counter> <from> <to> "
 479                               "<increment> <body>)");
 480       return NULL;
 481    }
 482
 483    s_expression *count_expr = (s_expression*) list->subexpressions.head->next;
 484    s_expression *from_expr  = (s_expression*) count_expr->next;
 485    s_expression *to_expr    = (s_expression*) from_expr->next;
 486    s_expression *inc_expr   = (s_expression*) to_expr->next;
 487    s_expression *body_expr  = (s_expression*) inc_expr->next;
 488
 489    // FINISHME: actually read the count/from/to fields.
 490
 491    ir_loop *loop = new ir_loop;
 492    read_instructions(st, &loop->body_instructions, body_expr, loop);
 493    if (st->error) {
 494       delete loop;
 495       loop = NULL;
 496    }
 497    return loop;
 498 }
 499
 500
 501 static ir_return *
 502 read_return(_mesa_glsl_parse_state *st, s_list *list)
 503 {
 504    if (list->length() != 2) {
 505       ir_read_error(st, list, "expected (return <rvalue>)");
 506       return NULL;
 507    }
 508
 509    s_expression *expr = (s_expression*) list->subexpressions.head->next;
 510
 511    ir_rvalue *retval = read_rvalue(st, expr);
 512    if (retval == NULL) {
 513       ir_read_error(st, NULL, "when reading return value");
 514       return NULL;
 515    }
 516
 517    return new ir_return(retval);
 518 }
 519
 520
 521 static ir_rvalue *
 522 read_rvalue(_mesa_glsl_parse_state *st, s_expression *expr)
 523 {
 524    s_list *list = SX_AS_LIST(expr);
 525    if (list == NULL || list->subexpressions.is_empty())
 526       return NULL;
 527
 528    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 529    if (tag == NULL) {
 530       ir_read_error(st, expr, "expected rvalue tag");
 531       return NULL;
 532    }
 533
 534    ir_rvalue *rvalue = read_dereference(st, list);
 535    if (rvalue != NULL || st->error)
 536       return rvalue;
 537    else if (strcmp(tag->value(), "swiz") == 0) {
 538       rvalue = read_swizzle(st, list);
 539    } else if (strcmp(tag->value(), "assign") == 0) {
 540       rvalue = read_assignment(st, list);
 541    } else if (strcmp(tag->value(), "expression") == 0) {
 542       rvalue = read_expression(st, list);
 543    } else if (strcmp(tag->value(), "call") == 0) {
 544       rvalue = read_call(st, list);
 545    } else if (strcmp(tag->value(), "constant") == 0) {
 546       rvalue = read_constant(st, list);
 547    } else {
 548       rvalue = read_texture(st, list);
 549       if (rvalue == NULL && !st->error)
 550          ir_read_error(st, expr, "unrecognized rvalue tag: %s", tag->value());
 551    }
 552
 553    return rvalue;
 554 }
 555
 556 static ir_assignment *
 557 read_assignment(_mesa_glsl_parse_state *st, s_list *list)
 558 {
 559    if (list->length() != 4) {
 560       ir_read_error(st, list, "expected (assign <condition> <lhs> <rhs>)");
 561       return NULL;
 562    }
 563
 564    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 565    s_expression *lhs_expr  = (s_expression*) cond_expr->next;
 566    s_expression *rhs_expr  = (s_expression*) lhs_expr->next;
 567
 568    // FINISHME: Deal with "true" condition
 569    ir_rvalue *condition = read_rvalue(st, cond_expr);
 570    if (condition == NULL) {
 571       ir_read_error(st, NULL, "when reading condition of assignment");
 572       return NULL;
 573    }
 574
 575    ir_rvalue *lhs = read_rvalue(st, lhs_expr);
 576    if (lhs == NULL) {
 577       ir_read_error(st, NULL, "when reading left-hand side of assignment");
 578       return NULL;
 579    }
 580
 581    ir_rvalue *rhs = read_rvalue(st, rhs_expr);
 582    if (rhs == NULL) {
 583       ir_read_error(st, NULL, "when reading right-hand side of assignment");
 584       return NULL;
 585    }
 586
 587    return new ir_assignment(lhs, rhs, condition);
 588 }
 589
 590 static ir_call *
 591 read_call(_mesa_glsl_parse_state *st, s_list *list)
 592 {
 593    if (list->length() != 3) {
 594       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 595       return NULL;
 596    }
 597
 598    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 599    s_list *params = SX_AS_LIST(name->next);
 600    if (name == NULL || params == NULL) {
 601       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 602       return NULL;
 603    }
 604
 605    exec_list parameters;
 606
 607    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 608       s_expression *expr = (s_expression*) it.get();
 609       ir_rvalue *param = read_rvalue(st, expr);
 610       if (param == NULL) {
 611          ir_read_error(st, list, "when reading parameter to function call");
 612          return NULL;
 613       }
 614       parameters.push_tail(param);
 615    }
 616
 617    ir_function *f = st->symbols->get_function(name->value());
 618    if (f == NULL) {
 619       ir_read_error(st, list, "found call to undefined function %s",
 620                     name->value());
 621       return NULL;
 622    }
 623
 624    const ir_function_signature *callee = f->matching_signature(&parameters);
 625    if (callee == NULL) {
 626       ir_read_error(st, list, "couldn't find matching signature for function "
 627                     "%s", name->value());
 628       return NULL;
 629    }
 630
 631    return new ir_call(callee, &parameters);
 632 }
 633
 634 static ir_expression *
 635 read_expression(_mesa_glsl_parse_state *st, s_list *list)
 636 {
 637    const unsigned list_length = list->length();
 638    if (list_length < 4) {
 639       ir_read_error(st, list, "expected (expression <type> <operator> "
 640                               "<operand> [<operand>])");
 641       return NULL;
 642    }
 643
 644    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 645    const glsl_type *type = read_type(st, type_expr);
 646    if (type == NULL)
 647       return NULL;
 648
 649    /* Read the operator */
 650    s_symbol *op_sym = SX_AS_SYMBOL(type_expr->next);
 651    if (op_sym == NULL) {
 652       ir_read_error(st, list, "expected operator, found non-symbol");
 653       return NULL;
 654    }
 655
 656    ir_expression_operation op = ir_expression::get_operator(op_sym->value());
 657    if (op == (ir_expression_operation) -1) {
 658       ir_read_error(st, list, "invalid operator: %s", op_sym->value());
 659       return NULL;
 660    }
 661
 662    /* Now that we know the operator, check for the right number of operands */
 663    if (ir_expression::get_num_operands(op) == 2) {
 664       if (list_length != 5) {
 665          ir_read_error(st, list, "expected (expression <type> %s <operand> "
 666                                  " <operand>)", op_sym->value());
 667          return NULL;
 668       }
 669    } else {
 670       if (list_length != 4) {
 671          ir_read_error(st, list, "expected (expression <type> %s <operand>)",
 672                        op_sym->value());
 673          return NULL;
 674       }
 675    }
 676
 677    s_expression *exp1 = (s_expression*) (op_sym->next);
 678    ir_rvalue *arg1 = read_rvalue(st, exp1);
 679    if (arg1 == NULL) {
 680       ir_read_error(st, NULL, "when reading first operand of %s",
 681                     op_sym->value());
 682       return NULL;
 683    }
 684
 685    ir_rvalue *arg2 = NULL;
 686    if (ir_expression::get_num_operands(op) == 2) {
 687       s_expression *exp2 = (s_expression*) (exp1->next);
 688       arg2 = read_rvalue(st, exp2);
 689       if (arg2 == NULL) {
 690          ir_read_error(st, NULL, "when reading second operand of %s",
 691                        op_sym->value());
 692          return NULL;
 693       }
 694    }
 695
 696    return new ir_expression(op, type, arg1, arg2);
 697 }
 698
 699 static ir_swizzle *
 700 read_swizzle(_mesa_glsl_parse_state *st, s_list *list)
 701 {
 702    if (list->length() != 3) {
 703       ir_read_error(st, list, "expected (swiz <swizzle> <rvalue>)");
 704       return NULL;
 705    }
 706
 707    s_symbol *swiz = SX_AS_SYMBOL(list->subexpressions.head->next);
 708    if (swiz == NULL) {
 709       ir_read_error(st, list, "expected a valid swizzle; found non-symbol");
 710       return NULL;
 711    }
 712
 713    if (strlen(swiz->value()) > 4) {
 714       ir_read_error(st, list, "expected a valid swizzle; found %s",
 715                     swiz->value());
 716       return NULL;
 717    }
 718
 719    s_expression *sub = (s_expression*) swiz->next;
 720    if (sub == NULL) {
 721       ir_read_error(st, list, "expected rvalue: (swizzle %s <rvalue>)",
 722                     swiz->value());
 723       return NULL;
 724    }
 725
 726    ir_rvalue *rvalue = read_rvalue(st, sub);
 727    if (rvalue == NULL)
 728       return NULL;
 729
 730    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 731                                        rvalue->type->vector_elements);
 732    if (ir == NULL)
 733       ir_read_error(st, list, "invalid swizzle");
 734
 735    return ir;
 736 }
 737
 738 static ir_constant *
 739 read_constant(_mesa_glsl_parse_state *st, s_list *list)
 740 {
 741    if (list->length() != 3) {
 742       ir_read_error(st, list, "expected (constant <type> (<num> ... <num>))");
 743       return NULL;
 744    }
 745
 746    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 747    const glsl_type *type = read_type(st, type_expr);
 748    if (type == NULL)
 749       return NULL;
 750
 751    s_list *values = SX_AS_LIST(type_expr->next);
 752    if (values == NULL) {
 753       ir_read_error(st, list, "expected (constant <type> (<num> ... <num>))");
 754       return NULL;
 755    }
 756
 757    const glsl_type *const base_type = type->get_base_type();
 758
 759    ir_constant_data data;
 760
 761    // Read in list of values (at most 16).
 762    int k = 0;
 763    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 764       if (k >= 16) {
 765          ir_read_error(st, values, "expected at most 16 numbers");
 766          return NULL;
 767       }
 768
 769       s_expression *expr = (s_expression*) it.get();
 770
 771       if (base_type->base_type == GLSL_TYPE_FLOAT) {
 772          s_number *value = SX_AS_NUMBER(expr);
 773          if (value == NULL) {
 774             ir_read_error(st, values, "expected numbers");
 775             return NULL;
 776          }
 777          data.f[k] = value->fvalue();
 778       } else {
 779          s_int *value = SX_AS_INT(expr);
 780          if (value == NULL) {
 781             ir_read_error(st, values, "expected integers");
 782             return NULL;
 783          }
 784
 785          switch (base_type->base_type) {
 786          case GLSL_TYPE_UINT: {
 787             data.u[k] = value->value();
 788             break;
 789          }
 790          case GLSL_TYPE_INT: {
 791             data.i[k] = value->value();
 792             break;
 793          }
 794          case GLSL_TYPE_BOOL: {
 795             data.b[k] = value->value();
 796             break;
 797          }
 798          default:
 799             ir_read_error(st, values, "unsupported constant type");
 800             return NULL;
 801          }
 802       }
 803       ++k;
 804    }
 805
 806    return new ir_constant(type, &data);
 807 }
 808
 809 static ir_dereference *
 810 read_dereference(_mesa_glsl_parse_state *st, s_expression *expr)
 811 {
 812    s_list *list = SX_AS_LIST(expr);
 813    if (list == NULL || list->subexpressions.is_empty())
 814       return NULL;
 815
 816    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
 817    assert(tag != NULL);
 818
 819    if (strcmp(tag->value(), "var_ref") == 0)
 820       return read_var_ref(st, list);
 821    if (strcmp(tag->value(), "array_ref") == 0)
 822       return read_array_ref(st, list);
 823    if (strcmp(tag->value(), "record_ref") == 0)
 824       return read_record_ref(st, list);
 825    return NULL;
 826 }
 827
 828 static ir_dereference *
 829 read_var_ref(_mesa_glsl_parse_state *st, s_list *list)
 830 {
 831    if (list->length() != 2) {
 832       ir_read_error(st, list, "expected (var_ref <variable name>)");
 833       return NULL;
 834    }
 835    s_symbol *var_name = SX_AS_SYMBOL(list->subexpressions.head->next);
 836    if (var_name == NULL) {
 837       ir_read_error(st, list, "expected (var_ref <variable name>)");
 838       return NULL;
 839    }
 840
 841    ir_variable *var = st->symbols->get_variable(var_name->value());
 842    if (var == NULL) {
 843       ir_read_error(st, list, "undeclared variable: %s", var_name->value());
 844       return NULL;
 845    }
 846
 847    return new ir_dereference_variable(var);
 848 }
 849
 850 static ir_dereference *
 851 read_array_ref(_mesa_glsl_parse_state *st, s_list *list)
 852 {
 853    if (list->length() != 3) {
 854       ir_read_error(st, list, "expected (array_ref <rvalue> <index>)");
 855       return NULL;
 856    }
 857
 858    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 859    ir_rvalue *subject = read_rvalue(st, subj_expr);
 860    if (subject == NULL) {
 861       ir_read_error(st, NULL, "when reading the subject of an array_ref");
 862       return NULL;
 863    }
 864
 865    s_expression *idx_expr = (s_expression*) subj_expr->next;
 866    ir_rvalue *idx = read_rvalue(st, idx_expr);
 867    return new ir_dereference_array(subject, idx);
 868 }
 869
 870 static ir_dereference *
 871 read_record_ref(_mesa_glsl_parse_state *st, s_list *list)
 872 {
 873    if (list->length() != 3) {
 874       ir_read_error(st, list, "expected (record_ref <rvalue> <field>)");
 875       return NULL;
 876    }
 877
 878    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 879    ir_rvalue *subject = read_rvalue(st, subj_expr);
 880    if (subject == NULL) {
 881       ir_read_error(st, NULL, "when reading the subject of a record_ref");
 882       return NULL;
 883    }
 884
 885    s_symbol *field = SX_AS_SYMBOL(subj_expr->next);
 886    if (field == NULL) {
 887       ir_read_error(st, list, "expected (record_ref ... <field name>)");
 888       return NULL;
 889    }
 890    return new ir_dereference_record(subject, field->value());
 891 }
 892
 893 static bool
 894 valid_texture_list_length(ir_texture_opcode op, s_list *list)
 895 {
 896    unsigned required_length = 7;
 897    if (op == ir_txf)
 898       required_length = 5;
 899    else if (op == ir_tex)
 900       required_length = 6;
 901
 902    return list->length() == required_length;
 903 }
 904
 905 static ir_texture *
 906 read_texture(_mesa_glsl_parse_state *st, s_list *list)
 907 {
 908    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
 909    assert(tag != NULL);
 910
 911    ir_texture_opcode op = ir_texture::get_opcode(tag->value());
 912    if (op == (ir_texture_opcode) -1)
 913       return NULL;
 914
 915    if (!valid_texture_list_length(op, list)) {
 916       ir_read_error(st, NULL, "invalid list size in (%s ...)", tag->value());
 917       return NULL;
 918    }
 919
 920    ir_texture *tex = new ir_texture(op);
 921
 922    // Read sampler (must be a deref)
 923    s_expression *sampler_expr = (s_expression *) tag->next;
 924    ir_dereference *sampler = read_dereference(st, sampler_expr);
 925    if (sampler == NULL) {
 926       ir_read_error(st, NULL, "when reading sampler in (%s ...)", tag->value());
 927       return NULL;
 928    }
 929    tex->set_sampler(sampler);
 930
 931    // Read coordinate (any rvalue)
 932    s_expression *coordinate_expr = (s_expression *) sampler_expr->next;
 933    tex->coordinate = read_rvalue(st, coordinate_expr);
 934    if (tex->coordinate == NULL) {
 935       ir_read_error(st, NULL, "when reading coordinate in (%s ...)",
 936                     tag->value());
 937       return NULL;
 938    }
 939
 940    // Read texel offset, i.e. (0 0 0)
 941    s_list *offset_list = SX_AS_LIST(coordinate_expr->next);
 942    if (offset_list == NULL || offset_list->length() != 3) {
 943       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
 944       return NULL;
 945    }
 946    s_int *offset_x = SX_AS_INT(offset_list->subexpressions.head);
 947    s_int *offset_y = SX_AS_INT(offset_x->next);
 948    s_int *offset_z = SX_AS_INT(offset_y->next);
 949    if (offset_x == NULL || offset_y == NULL || offset_z == NULL) {
 950       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
 951       return NULL;
 952    }
 953    tex->offsets[0] = offset_x->value();
 954    tex->offsets[1] = offset_y->value();
 955    tex->offsets[2] = offset_z->value();
 956
 957    if (op == ir_txf) {
 958       s_expression *lod_expr = (s_expression *) offset_list->next;
 959       tex->lod_info.lod = read_rvalue(st, lod_expr);
 960       if (tex->lod_info.lod == NULL) {
 961          ir_read_error(st, NULL, "when reading LOD in (txf ...)");
 962          return NULL;
 963       }
 964    } else {
 965       s_expression *proj_expr = (s_expression *) offset_list->next;
 966       s_int *proj_as_int = SX_AS_INT(proj_expr);
 967       if (proj_as_int && proj_as_int->value() == 1) {
 968          tex->projector = NULL;
 969       } else {
 970          tex->projector = read_rvalue(st, proj_expr);
 971          if (tex->projector == NULL) {
 972             ir_read_error(st, NULL, "when reading projective divide in (%s ..)",
 973                           tag->value());
 974             return NULL;
 975          }
 976       }
 977
 978       s_list *shadow_list = SX_AS_LIST(proj_expr->next);
 979       if (shadow_list == NULL) {
 980          ir_read_error(st, NULL, "shadow comparitor must be a list");
 981          return NULL;
 982       }
 983       if (shadow_list->subexpressions.is_empty()) {
 984          tex->shadow_comparitor= NULL;
 985       } else {
 986          tex->shadow_comparitor = read_rvalue(st, shadow_list);
 987          if (tex->shadow_comparitor == NULL) {
 988             ir_read_error(st, NULL, "when reading shadow comparitor in (%s ..)",
 989                           tag->value());
 990             return NULL;
 991          }
 992       }
 993       s_expression *lod_expr = (s_expression *) shadow_list->next;
 994
 995       switch (op) {
 996       case ir_txb:
 997          tex->lod_info.bias = read_rvalue(st, lod_expr);
 998          if (tex->lod_info.bias == NULL) {
 999             ir_read_error(st, NULL, "when reading LOD bias in (txb ...)");
1000             return NULL;
1001          }
1002          break;
1003       case ir_txl:
1004          tex->lod_info.lod = read_rvalue(st, lod_expr);
1005          if (tex->lod_info.lod == NULL) {
1006             ir_read_error(st, NULL, "when reading LOD in (txl ...)");
1007             return NULL;
1008          }
1009          break;
1010       case ir_txd: {
1011          s_list *lod_list = SX_AS_LIST(lod_expr);
1012          if (lod_list->length() != 2) {
1013             ir_read_error(st, lod_expr, "expected (dPdx dPdy) in (txd ...)");
1014             return NULL;
1015          }
1016          s_expression *dx_expr = (s_expression *) lod_list->subexpressions.head;
1017          s_expression *dy_expr = (s_expression *) dx_expr->next;
1018
1019          tex->lod_info.grad.dPdx = read_rvalue(st, dx_expr);
1020          if (tex->lod_info.grad.dPdx == NULL) {
1021             ir_read_error(st, NULL, "when reading dPdx in (txd ...)");
1022             return NULL;
1023          }
1024          tex->lod_info.grad.dPdy = read_rvalue(st, dy_expr);
1025          if (tex->lod_info.grad.dPdy == NULL) {
1026             ir_read_error(st, NULL, "when reading dPdy in (txd ...)");
1027             return NULL;
1028          }
1029          break;
1030       }
1031       default:
1032          // tex doesn't have any extra parameters and txf was handled earlier.
1033          break;
1034       };
1035    }
1036    return tex;
1037 }