src/glsl/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
  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    void *ctx = talloc_parent(state);
  74    s_expression *expr = s_expression::read_expression(ctx, src);
  75    if (expr == NULL) {
  76       ir_read_error(state, NULL, "couldn't parse S-Expression.");
  77       return;
  78    }
  79
  80    scan_for_prototypes(state, instructions, expr);
  81    if (state->error)
  82       return;
  83
  84    read_instructions(state, instructions, expr, NULL);
  85 }
  86
  87 static void
  88 ir_read_error(_mesa_glsl_parse_state *state, s_expression *expr,
  89               const char *fmt, ...)
  90 {
  91    va_list ap;
  92
  93    state->error = true;
  94
  95    state->info_log = talloc_strdup_append(state->info_log, "error: ");
  96
  97    va_start(ap, fmt);
  98    state->info_log = talloc_vasprintf_append(state->info_log, fmt, ap);
  99    va_end(ap);
 100    state->info_log = talloc_strdup_append(state->info_log, "\n");
 101
 102    if (expr != NULL) {
 103       state->info_log = talloc_strdup_append(state->info_log,
 104                                              "...in this context:\n   ");
 105       expr->print();
 106       state->info_log = talloc_strdup_append(state->info_log, "\n\n");
 107    }
 108 }
 109
 110 static const glsl_type *
 111 read_type(_mesa_glsl_parse_state *st, s_expression *expr)
 112 {
 113    s_list *list = SX_AS_LIST(expr);
 114    if (list != NULL) {
 115       s_symbol *type_sym = SX_AS_SYMBOL(list->subexpressions.get_head());
 116       if (type_sym == NULL) {
 117          ir_read_error(st, expr, "expected type (array ...) or (struct ...)");
 118          return NULL;
 119       }
 120       if (strcmp(type_sym->value(), "array") == 0) {
 121          if (list->length() != 3) {
 122             ir_read_error(st, expr, "expected type (array <type> <int>)");
 123             return NULL;
 124          }
 125
 126          // Read base type
 127          s_expression *base_expr = (s_expression*) type_sym->next;
 128          const glsl_type *base_type = read_type(st, base_expr);
 129          if (base_type == NULL) {
 130             ir_read_error(st, NULL, "when reading base type of array");
 131             return NULL;
 132          }
 133
 134          // Read array size
 135          s_int *size = SX_AS_INT(base_expr->next);
 136          if (size == NULL) {
 137             ir_read_error(st, expr, "found non-integer array size");
 138             return NULL;
 139          }
 140
 141          return glsl_type::get_array_instance(st, base_type, size->value());
 142       } else if (strcmp(type_sym->value(), "struct") == 0) {
 143          assert(false); // FINISHME
 144       } else {
 145          ir_read_error(st, expr, "expected (array ...) or (struct ...); "
 146                                  "found (%s ...)", type_sym->value());
 147          return NULL;
 148       }
 149    }
 150
 151    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 152    if (type_sym == NULL) {
 153       ir_read_error(st, expr, "expected <type> (symbol or list)");
 154       return NULL;
 155    }
 156
 157    const glsl_type *type = st->symbols->get_type(type_sym->value());
 158    if (type == NULL)
 159       ir_read_error(st, expr, "invalid type: %s", type_sym->value());
 160
 161    return type;
 162 }
 163
 164
 165 static void
 166 scan_for_prototypes(_mesa_glsl_parse_state *st, exec_list *instructions,
 167                     s_expression *expr)
 168 {
 169    s_list *list = SX_AS_LIST(expr);
 170    if (list == NULL) {
 171       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 172       return;
 173    }
 174
 175    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 176       s_list *sub = SX_AS_LIST(it.get());
 177       if (sub == NULL)
 178          continue; // not a (function ...); ignore it.
 179
 180       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 181       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 182          continue; // not a (function ...); ignore it.
 183
 184       ir_function *f = read_function(st, sub, true);
 185       if (f == NULL)
 186          return;
 187       instructions->push_tail(f);
 188    }
 189 }
 190
 191 static ir_function *
 192 read_function(_mesa_glsl_parse_state *st, s_list *list, bool skip_body)
 193 {
 194    void *ctx = talloc_parent(st);
 195    if (list->length() < 3) {
 196       ir_read_error(st, list, "Expected (function <name> (signature ...) ...)");
 197       return NULL;
 198    }
 199
 200    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 201    if (name == NULL) {
 202       ir_read_error(st, list, "Expected (function <name> ...)");
 203       return NULL;
 204    }
 205
 206    ir_function *f = st->symbols->get_function(name->value());
 207    if (f == NULL) {
 208       f = new(ctx) ir_function(name->value());
 209       bool added = st->symbols->add_function(name->value(), f);
 210       assert(added);
 211    }
 212
 213    exec_list_iterator it = list->subexpressions.iterator();
 214    it.next(); // skip "function" tag
 215    it.next(); // skip function name
 216    for (/* nothing */; it.has_next(); it.next()) {
 217       s_list *siglist = SX_AS_LIST(it.get());
 218       if (siglist == NULL) {
 219          ir_read_error(st, list, "Expected (function (signature ...) ...)");
 220          return NULL;
 221       }
 222
 223       s_symbol *tag = SX_AS_SYMBOL(siglist->subexpressions.get_head());
 224       if (tag == NULL || strcmp(tag->value(), "signature") != 0) {
 225          ir_read_error(st, siglist, "Expected (signature ...)");
 226          return NULL;
 227       }
 228
 229       read_function_sig(st, f, siglist, skip_body);
 230    }
 231    return f;
 232 }
 233
 234 static void
 235 read_function_sig(_mesa_glsl_parse_state *st, ir_function *f, s_list *list,
 236                   bool skip_body)
 237 {
 238    void *ctx = talloc_parent(st);
 239    if (list->length() != 4) {
 240       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 241                               "(<instruction> ...))");
 242       return;
 243    }
 244
 245    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 246    const glsl_type *return_type = read_type(st, type_expr);
 247    if (return_type == NULL)
 248       return;
 249
 250    s_list *paramlist = SX_AS_LIST(type_expr->next);
 251    s_list *body_list = SX_AS_LIST(paramlist->next);
 252    if (paramlist == NULL || body_list == NULL) {
 253       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 254                               "(<instruction> ...))");
 255       return;
 256    }
 257    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 258    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 259       ir_read_error(st, paramlist, "Expected (parameters ...)");
 260       return;
 261    }
 262
 263    // Read the parameters list into a temporary place.
 264    exec_list hir_parameters;
 265    st->symbols->push_scope();
 266
 267    exec_list_iterator it = paramlist->subexpressions.iterator();
 268    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 269       s_list *decl = SX_AS_LIST(it.get());
 270       ir_variable *var = read_declaration(st, decl);
 271       if (var == NULL)
 272          return;
 273
 274       hir_parameters.push_tail(var);
 275    }
 276
 277    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 278    if (sig != NULL) {
 279       const char *badvar = sig->qualifiers_match(&hir_parameters);
 280       if (badvar != NULL) {
 281          ir_read_error(st, list, "function `%s' parameter `%s' qualifiers "
 282                        "don't match prototype", f->name, badvar);
 283          return;
 284       }
 285
 286       if (sig->return_type != return_type) {
 287          ir_read_error(st, list, "function `%s' return type doesn't "
 288                        "match prototype", f->name);
 289          return;
 290       }
 291    } else {
 292       sig = new(ctx) ir_function_signature(return_type);
 293       f->add_signature(sig);
 294    }
 295
 296    sig->replace_parameters(&hir_parameters);
 297
 298    if (!skip_body) {
 299       if (sig->is_defined) {
 300          ir_read_error(st, list, "function %s redefined", f->name);
 301          return;
 302       }
 303       read_instructions(st, &sig->body, body_list, NULL);
 304       sig->is_defined = true;
 305    }
 306
 307    st->symbols->pop_scope();
 308 }
 309
 310 static void
 311 read_instructions(_mesa_glsl_parse_state *st, exec_list *instructions,
 312                   s_expression *expr, ir_loop *loop_ctx)
 313 {
 314    // Read in a list of instructions
 315    s_list *list = SX_AS_LIST(expr);
 316    if (list == NULL) {
 317       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 318       return;
 319    }
 320
 321    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 322       s_expression *sub = (s_expression*) it.get();
 323       ir_instruction *ir = read_instruction(st, sub, loop_ctx);
 324       if (ir == NULL) {
 325          ir_read_error(st, sub, "Invalid instruction.\n");
 326          return;
 327       }
 328       instructions->push_tail(ir);
 329    }
 330 }
 331
 332
 333 static ir_instruction *
 334 read_instruction(_mesa_glsl_parse_state *st, s_expression *expr,
 335                  ir_loop *loop_ctx)
 336 {
 337    void *ctx = talloc_parent(st);
 338    s_symbol *symbol = SX_AS_SYMBOL(expr);
 339    if (symbol != NULL) {
 340       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 341          return new(ctx) ir_loop_jump(ir_loop_jump::jump_break);
 342       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 343          return new(ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 344    }
 345
 346    s_list *list = SX_AS_LIST(expr);
 347    if (list == NULL || list->subexpressions.is_empty())
 348       return NULL;
 349
 350    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 351    if (tag == NULL) {
 352       ir_read_error(st, expr, "expected instruction tag");
 353       return NULL;
 354    }
 355
 356    ir_instruction *inst = NULL;
 357    if (strcmp(tag->value(), "declare") == 0) {
 358       inst = read_declaration(st, list);
 359    } else if (strcmp(tag->value(), "if") == 0) {
 360       inst = read_if(st, list, loop_ctx);
 361    } else if (strcmp(tag->value(), "loop") == 0) {
 362       inst = read_loop(st, list);
 363    } else if (strcmp(tag->value(), "return") == 0) {
 364       inst = read_return(st, list);
 365    } else if (strcmp(tag->value(), "function") == 0) {
 366       inst = read_function(st, list, false);
 367    } else {
 368       inst = read_rvalue(st, list);
 369       if (inst == NULL)
 370          ir_read_error(st, NULL, "when reading instruction");
 371    }
 372    return inst;
 373 }
 374
 375
 376 static ir_variable *
 377 read_declaration(_mesa_glsl_parse_state *st, s_list *list)
 378 {
 379    void *ctx = talloc_parent(st);
 380    if (list->length() != 4) {
 381       ir_read_error(st, list, "expected (declare (<qualifiers>) <type> "
 382                               "<name>)");
 383       return NULL;
 384    }
 385
 386    s_list *quals = SX_AS_LIST(list->subexpressions.head->next);
 387    if (quals == NULL) {
 388       ir_read_error(st, list, "expected a list of variable qualifiers");
 389       return NULL;
 390    }
 391
 392    s_expression *type_expr = (s_expression*) quals->next;
 393    const glsl_type *type = read_type(st, type_expr);
 394    if (type == NULL)
 395       return NULL;
 396
 397    s_symbol *var_name = SX_AS_SYMBOL(type_expr->next);
 398    if (var_name == NULL) {
 399       ir_read_error(st, list, "expected variable name, found non-symbol");
 400       return NULL;
 401    }
 402
 403    ir_variable *var = new(ctx) ir_variable(type, var_name->value());
 404
 405    foreach_iter(exec_list_iterator, it, quals->subexpressions) {
 406       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 407       if (qualifier == NULL) {
 408          ir_read_error(st, list, "qualifier list must contain only symbols");
 409          delete var;
 410          return NULL;
 411       }
 412
 413       // FINISHME: Check for duplicate/conflicting qualifiers.
 414       if (strcmp(qualifier->value(), "centroid") == 0) {
 415          var->centroid = 1;
 416       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 417          var->invariant = 1;
 418       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 419          var->mode = ir_var_uniform;
 420       } else if (strcmp(qualifier->value(), "auto") == 0) {
 421          var->mode = ir_var_auto;
 422       } else if (strcmp(qualifier->value(), "in") == 0) {
 423          var->mode = ir_var_in;
 424       } else if (strcmp(qualifier->value(), "out") == 0) {
 425          var->mode = ir_var_out;
 426       } else if (strcmp(qualifier->value(), "inout") == 0) {
 427          var->mode = ir_var_inout;
 428       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 429          var->interpolation = ir_var_smooth;
 430       } else if (strcmp(qualifier->value(), "flat") == 0) {
 431          var->interpolation = ir_var_flat;
 432       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 433          var->interpolation = ir_var_noperspective;
 434       } else {
 435          ir_read_error(st, list, "unknown qualifier: %s", qualifier->value());
 436          delete var;
 437          return NULL;
 438       }
 439    }
 440
 441    // Add the variable to the symbol table
 442    st->symbols->add_variable(var_name->value(), var);
 443
 444    return var;
 445 }
 446
 447
 448 static ir_if *
 449 read_if(_mesa_glsl_parse_state *st, s_list *list, ir_loop *loop_ctx)
 450 {
 451    void *ctx = talloc_parent(st);
 452    if (list->length() != 4) {
 453       ir_read_error(st, list, "expected (if <condition> (<then> ...) "
 454                           "(<else> ...))");
 455       return NULL;
 456    }
 457
 458    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 459    ir_rvalue *condition = read_rvalue(st, cond_expr);
 460    if (condition == NULL) {
 461       ir_read_error(st, NULL, "when reading condition of (if ...)");
 462       return NULL;
 463    }
 464
 465    s_expression *then_expr = (s_expression*) cond_expr->next;
 466    s_expression *else_expr = (s_expression*) then_expr->next;
 467
 468    ir_if *iff = new(ctx) ir_if(condition);
 469
 470    read_instructions(st, &iff->then_instructions, then_expr, loop_ctx);
 471    read_instructions(st, &iff->else_instructions, else_expr, loop_ctx);
 472    if (st->error) {
 473       delete iff;
 474       iff = NULL;
 475    }
 476    return iff;
 477 }
 478
 479
 480 static ir_loop *
 481 read_loop(_mesa_glsl_parse_state *st, s_list *list)
 482 {
 483    void *ctx = talloc_parent(st);
 484    if (list->length() != 6) {
 485       ir_read_error(st, list, "expected (loop <counter> <from> <to> "
 486                               "<increment> <body>)");
 487       return NULL;
 488    }
 489
 490    s_expression *count_expr = (s_expression*) list->subexpressions.head->next;
 491    s_expression *from_expr  = (s_expression*) count_expr->next;
 492    s_expression *to_expr    = (s_expression*) from_expr->next;
 493    s_expression *inc_expr   = (s_expression*) to_expr->next;
 494    s_expression *body_expr  = (s_expression*) inc_expr->next;
 495
 496    // FINISHME: actually read the count/from/to fields.
 497
 498    ir_loop *loop = new(ctx) ir_loop;
 499    read_instructions(st, &loop->body_instructions, body_expr, loop);
 500    if (st->error) {
 501       delete loop;
 502       loop = NULL;
 503    }
 504    return loop;
 505 }
 506
 507
 508 static ir_return *
 509 read_return(_mesa_glsl_parse_state *st, s_list *list)
 510 {
 511    void *ctx = talloc_parent(st);
 512    if (list->length() != 2) {
 513       ir_read_error(st, list, "expected (return <rvalue>)");
 514       return NULL;
 515    }
 516
 517    s_expression *expr = (s_expression*) list->subexpressions.head->next;
 518
 519    ir_rvalue *retval = read_rvalue(st, expr);
 520    if (retval == NULL) {
 521       ir_read_error(st, NULL, "when reading return value");
 522       return NULL;
 523    }
 524
 525    return new(ctx) ir_return(retval);
 526 }
 527
 528
 529 static ir_rvalue *
 530 read_rvalue(_mesa_glsl_parse_state *st, s_expression *expr)
 531 {
 532    s_list *list = SX_AS_LIST(expr);
 533    if (list == NULL || list->subexpressions.is_empty())
 534       return NULL;
 535
 536    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 537    if (tag == NULL) {
 538       ir_read_error(st, expr, "expected rvalue tag");
 539       return NULL;
 540    }
 541
 542    ir_rvalue *rvalue = read_dereference(st, list);
 543    if (rvalue != NULL || st->error)
 544       return rvalue;
 545    else if (strcmp(tag->value(), "swiz") == 0) {
 546       rvalue = read_swizzle(st, list);
 547    } else if (strcmp(tag->value(), "assign") == 0) {
 548       rvalue = read_assignment(st, list);
 549    } else if (strcmp(tag->value(), "expression") == 0) {
 550       rvalue = read_expression(st, list);
 551    } else if (strcmp(tag->value(), "call") == 0) {
 552       rvalue = read_call(st, list);
 553    } else if (strcmp(tag->value(), "constant") == 0) {
 554       rvalue = read_constant(st, list);
 555    } else {
 556       rvalue = read_texture(st, list);
 557       if (rvalue == NULL && !st->error)
 558          ir_read_error(st, expr, "unrecognized rvalue tag: %s", tag->value());
 559    }
 560
 561    return rvalue;
 562 }
 563
 564 static ir_assignment *
 565 read_assignment(_mesa_glsl_parse_state *st, s_list *list)
 566 {
 567    void *ctx = talloc_parent(st);
 568    if (list->length() != 4) {
 569       ir_read_error(st, list, "expected (assign <condition> <lhs> <rhs>)");
 570       return NULL;
 571    }
 572
 573    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 574    s_expression *lhs_expr  = (s_expression*) cond_expr->next;
 575    s_expression *rhs_expr  = (s_expression*) lhs_expr->next;
 576
 577    // FINISHME: Deal with "true" condition
 578    ir_rvalue *condition = read_rvalue(st, cond_expr);
 579    if (condition == NULL) {
 580       ir_read_error(st, NULL, "when reading condition of assignment");
 581       return NULL;
 582    }
 583
 584    ir_rvalue *lhs = read_rvalue(st, lhs_expr);
 585    if (lhs == NULL) {
 586       ir_read_error(st, NULL, "when reading left-hand side of assignment");
 587       return NULL;
 588    }
 589
 590    ir_rvalue *rhs = read_rvalue(st, rhs_expr);
 591    if (rhs == NULL) {
 592       ir_read_error(st, NULL, "when reading right-hand side of assignment");
 593       return NULL;
 594    }
 595
 596    return new(ctx) ir_assignment(lhs, rhs, condition);
 597 }
 598
 599 static ir_call *
 600 read_call(_mesa_glsl_parse_state *st, s_list *list)
 601 {
 602    void *ctx = talloc_parent(st);
 603    if (list->length() != 3) {
 604       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 605       return NULL;
 606    }
 607
 608    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 609    s_list *params = SX_AS_LIST(name->next);
 610    if (name == NULL || params == NULL) {
 611       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 612       return NULL;
 613    }
 614
 615    exec_list parameters;
 616
 617    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 618       s_expression *expr = (s_expression*) it.get();
 619       ir_rvalue *param = read_rvalue(st, expr);
 620       if (param == NULL) {
 621          ir_read_error(st, list, "when reading parameter to function call");
 622          return NULL;
 623       }
 624       parameters.push_tail(param);
 625    }
 626
 627    ir_function *f = st->symbols->get_function(name->value());
 628    if (f == NULL) {
 629       ir_read_error(st, list, "found call to undefined function %s",
 630                     name->value());
 631       return NULL;
 632    }
 633
 634    const ir_function_signature *callee = f->matching_signature(&parameters);
 635    if (callee == NULL) {
 636       ir_read_error(st, list, "couldn't find matching signature for function "
 637                     "%s", name->value());
 638       return NULL;
 639    }
 640
 641    return new(ctx) ir_call(callee, &parameters);
 642 }
 643
 644 static ir_expression *
 645 read_expression(_mesa_glsl_parse_state *st, s_list *list)
 646 {
 647    void *ctx = talloc_parent(st);
 648    const unsigned list_length = list->length();
 649    if (list_length < 4) {
 650       ir_read_error(st, list, "expected (expression <type> <operator> "
 651                               "<operand> [<operand>])");
 652       return NULL;
 653    }
 654
 655    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 656    const glsl_type *type = read_type(st, type_expr);
 657    if (type == NULL)
 658       return NULL;
 659
 660    /* Read the operator */
 661    s_symbol *op_sym = SX_AS_SYMBOL(type_expr->next);
 662    if (op_sym == NULL) {
 663       ir_read_error(st, list, "expected operator, found non-symbol");
 664       return NULL;
 665    }
 666
 667    ir_expression_operation op = ir_expression::get_operator(op_sym->value());
 668    if (op == (ir_expression_operation) -1) {
 669       ir_read_error(st, list, "invalid operator: %s", op_sym->value());
 670       return NULL;
 671    }
 672
 673    /* Now that we know the operator, check for the right number of operands */
 674    if (ir_expression::get_num_operands(op) == 2) {
 675       if (list_length != 5) {
 676          ir_read_error(st, list, "expected (expression <type> %s <operand> "
 677                                  " <operand>)", op_sym->value());
 678          return NULL;
 679       }
 680    } else {
 681       if (list_length != 4) {
 682          ir_read_error(st, list, "expected (expression <type> %s <operand>)",
 683                        op_sym->value());
 684          return NULL;
 685       }
 686    }
 687
 688    s_expression *exp1 = (s_expression*) (op_sym->next);
 689    ir_rvalue *arg1 = read_rvalue(st, exp1);
 690    if (arg1 == NULL) {
 691       ir_read_error(st, NULL, "when reading first operand of %s",
 692                     op_sym->value());
 693       return NULL;
 694    }
 695
 696    ir_rvalue *arg2 = NULL;
 697    if (ir_expression::get_num_operands(op) == 2) {
 698       s_expression *exp2 = (s_expression*) (exp1->next);
 699       arg2 = read_rvalue(st, exp2);
 700       if (arg2 == NULL) {
 701          ir_read_error(st, NULL, "when reading second operand of %s",
 702                        op_sym->value());
 703          return NULL;
 704       }
 705    }
 706
 707    return new(ctx) ir_expression(op, type, arg1, arg2);
 708 }
 709
 710 static ir_swizzle *
 711 read_swizzle(_mesa_glsl_parse_state *st, s_list *list)
 712 {
 713    if (list->length() != 3) {
 714       ir_read_error(st, list, "expected (swiz <swizzle> <rvalue>)");
 715       return NULL;
 716    }
 717
 718    s_symbol *swiz = SX_AS_SYMBOL(list->subexpressions.head->next);
 719    if (swiz == NULL) {
 720       ir_read_error(st, list, "expected a valid swizzle; found non-symbol");
 721       return NULL;
 722    }
 723
 724    if (strlen(swiz->value()) > 4) {
 725       ir_read_error(st, list, "expected a valid swizzle; found %s",
 726                     swiz->value());
 727       return NULL;
 728    }
 729
 730    s_expression *sub = (s_expression*) swiz->next;
 731    if (sub == NULL) {
 732       ir_read_error(st, list, "expected rvalue: (swizzle %s <rvalue>)",
 733                     swiz->value());
 734       return NULL;
 735    }
 736
 737    ir_rvalue *rvalue = read_rvalue(st, sub);
 738    if (rvalue == NULL)
 739       return NULL;
 740
 741    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 742                                        rvalue->type->vector_elements);
 743    if (ir == NULL)
 744       ir_read_error(st, list, "invalid swizzle");
 745
 746    return ir;
 747 }
 748
 749 static ir_constant *
 750 read_constant(_mesa_glsl_parse_state *st, s_list *list)
 751 {
 752    void *ctx = talloc_parent(st);
 753    if (list->length() != 3) {
 754       ir_read_error(st, list, "expected (constant <type> (<num> ... <num>))");
 755       return NULL;
 756    }
 757
 758    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 759    const glsl_type *type = read_type(st, type_expr);
 760    if (type == NULL)
 761       return NULL;
 762
 763    s_list *values = SX_AS_LIST(type_expr->next);
 764    if (values == NULL) {
 765       ir_read_error(st, list, "expected (constant <type> (<num> ... <num>))");
 766       return NULL;
 767    }
 768
 769    const glsl_type *const base_type = type->get_base_type();
 770
 771    ir_constant_data data;
 772
 773    // Read in list of values (at most 16).
 774    int k = 0;
 775    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 776       if (k >= 16) {
 777          ir_read_error(st, values, "expected at most 16 numbers");
 778          return NULL;
 779       }
 780
 781       s_expression *expr = (s_expression*) it.get();
 782
 783       if (base_type->base_type == GLSL_TYPE_FLOAT) {
 784          s_number *value = SX_AS_NUMBER(expr);
 785          if (value == NULL) {
 786             ir_read_error(st, values, "expected numbers");
 787             return NULL;
 788          }
 789          data.f[k] = value->fvalue();
 790       } else {
 791          s_int *value = SX_AS_INT(expr);
 792          if (value == NULL) {
 793             ir_read_error(st, values, "expected integers");
 794             return NULL;
 795          }
 796
 797          switch (base_type->base_type) {
 798          case GLSL_TYPE_UINT: {
 799             data.u[k] = value->value();
 800             break;
 801          }
 802          case GLSL_TYPE_INT: {
 803             data.i[k] = value->value();
 804             break;
 805          }
 806          case GLSL_TYPE_BOOL: {
 807             data.b[k] = value->value();
 808             break;
 809          }
 810          default:
 811             ir_read_error(st, values, "unsupported constant type");
 812             return NULL;
 813          }
 814       }
 815       ++k;
 816    }
 817
 818    return new(ctx) ir_constant(type, &data);
 819 }
 820
 821 static ir_dereference *
 822 read_dereference(_mesa_glsl_parse_state *st, s_expression *expr)
 823 {
 824    s_list *list = SX_AS_LIST(expr);
 825    if (list == NULL || list->subexpressions.is_empty())
 826       return NULL;
 827
 828    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
 829    assert(tag != NULL);
 830
 831    if (strcmp(tag->value(), "var_ref") == 0)
 832       return read_var_ref(st, list);
 833    if (strcmp(tag->value(), "array_ref") == 0)
 834       return read_array_ref(st, list);
 835    if (strcmp(tag->value(), "record_ref") == 0)
 836       return read_record_ref(st, list);
 837    return NULL;
 838 }
 839
 840 static ir_dereference *
 841 read_var_ref(_mesa_glsl_parse_state *st, s_list *list)
 842 {
 843    void *ctx = talloc_parent(st);
 844    if (list->length() != 2) {
 845       ir_read_error(st, list, "expected (var_ref <variable name>)");
 846       return NULL;
 847    }
 848    s_symbol *var_name = SX_AS_SYMBOL(list->subexpressions.head->next);
 849    if (var_name == NULL) {
 850       ir_read_error(st, list, "expected (var_ref <variable name>)");
 851       return NULL;
 852    }
 853
 854    ir_variable *var = st->symbols->get_variable(var_name->value());
 855    if (var == NULL) {
 856       ir_read_error(st, list, "undeclared variable: %s", var_name->value());
 857       return NULL;
 858    }
 859
 860    return new(ctx) ir_dereference_variable(var);
 861 }
 862
 863 static ir_dereference *
 864 read_array_ref(_mesa_glsl_parse_state *st, s_list *list)
 865 {
 866    void *ctx = talloc_parent(st);
 867    if (list->length() != 3) {
 868       ir_read_error(st, list, "expected (array_ref <rvalue> <index>)");
 869       return NULL;
 870    }
 871
 872    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 873    ir_rvalue *subject = read_rvalue(st, subj_expr);
 874    if (subject == NULL) {
 875       ir_read_error(st, NULL, "when reading the subject of an array_ref");
 876       return NULL;
 877    }
 878
 879    s_expression *idx_expr = (s_expression*) subj_expr->next;
 880    ir_rvalue *idx = read_rvalue(st, idx_expr);
 881    return new(ctx) ir_dereference_array(subject, idx);
 882 }
 883
 884 static ir_dereference *
 885 read_record_ref(_mesa_glsl_parse_state *st, s_list *list)
 886 {
 887    void *ctx = talloc_parent(st);
 888    if (list->length() != 3) {
 889       ir_read_error(st, list, "expected (record_ref <rvalue> <field>)");
 890       return NULL;
 891    }
 892
 893    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 894    ir_rvalue *subject = read_rvalue(st, subj_expr);
 895    if (subject == NULL) {
 896       ir_read_error(st, NULL, "when reading the subject of a record_ref");
 897       return NULL;
 898    }
 899
 900    s_symbol *field = SX_AS_SYMBOL(subj_expr->next);
 901    if (field == NULL) {
 902       ir_read_error(st, list, "expected (record_ref ... <field name>)");
 903       return NULL;
 904    }
 905    return new(ctx) ir_dereference_record(subject, field->value());
 906 }
 907
 908 static bool
 909 valid_texture_list_length(ir_texture_opcode op, s_list *list)
 910 {
 911    unsigned required_length = 7;
 912    if (op == ir_txf)
 913       required_length = 5;
 914    else if (op == ir_tex)
 915       required_length = 6;
 916
 917    return list->length() == required_length;
 918 }
 919
 920 static ir_texture *
 921 read_texture(_mesa_glsl_parse_state *st, s_list *list)
 922 {
 923    void *ctx = talloc_parent(st);
 924    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
 925    assert(tag != NULL);
 926
 927    ir_texture_opcode op = ir_texture::get_opcode(tag->value());
 928    if (op == (ir_texture_opcode) -1)
 929       return NULL;
 930
 931    if (!valid_texture_list_length(op, list)) {
 932       ir_read_error(st, NULL, "invalid list size in (%s ...)", tag->value());
 933       return NULL;
 934    }
 935
 936    ir_texture *tex = new(ctx) ir_texture(op);
 937
 938    // Read sampler (must be a deref)
 939    s_expression *sampler_expr = (s_expression *) tag->next;
 940    ir_dereference *sampler = read_dereference(st, sampler_expr);
 941    if (sampler == NULL) {
 942       ir_read_error(st, NULL, "when reading sampler in (%s ...)", tag->value());
 943       return NULL;
 944    }
 945    tex->set_sampler(sampler);
 946
 947    // Read coordinate (any rvalue)
 948    s_expression *coordinate_expr = (s_expression *) sampler_expr->next;
 949    tex->coordinate = read_rvalue(st, coordinate_expr);
 950    if (tex->coordinate == NULL) {
 951       ir_read_error(st, NULL, "when reading coordinate in (%s ...)",
 952                     tag->value());
 953       return NULL;
 954    }
 955
 956    // Read texel offset, i.e. (0 0 0)
 957    s_list *offset_list = SX_AS_LIST(coordinate_expr->next);
 958    if (offset_list == NULL || offset_list->length() != 3) {
 959       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
 960       return NULL;
 961    }
 962    s_int *offset_x = SX_AS_INT(offset_list->subexpressions.head);
 963    s_int *offset_y = SX_AS_INT(offset_x->next);
 964    s_int *offset_z = SX_AS_INT(offset_y->next);
 965    if (offset_x == NULL || offset_y == NULL || offset_z == NULL) {
 966       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
 967       return NULL;
 968    }
 969    tex->offsets[0] = offset_x->value();
 970    tex->offsets[1] = offset_y->value();
 971    tex->offsets[2] = offset_z->value();
 972
 973    if (op == ir_txf) {
 974       s_expression *lod_expr = (s_expression *) offset_list->next;
 975       tex->lod_info.lod = read_rvalue(st, lod_expr);
 976       if (tex->lod_info.lod == NULL) {
 977          ir_read_error(st, NULL, "when reading LOD in (txf ...)");
 978          return NULL;
 979       }
 980    } else {
 981       s_expression *proj_expr = (s_expression *) offset_list->next;
 982       s_int *proj_as_int = SX_AS_INT(proj_expr);
 983       if (proj_as_int && proj_as_int->value() == 1) {
 984          tex->projector = NULL;
 985       } else {
 986          tex->projector = read_rvalue(st, proj_expr);
 987          if (tex->projector == NULL) {
 988             ir_read_error(st, NULL, "when reading projective divide in (%s ..)",
 989                           tag->value());
 990             return NULL;
 991          }
 992       }
 993
 994       s_list *shadow_list = SX_AS_LIST(proj_expr->next);
 995       if (shadow_list == NULL) {
 996          ir_read_error(st, NULL, "shadow comparitor must be a list");
 997          return NULL;
 998       }
 999       if (shadow_list->subexpressions.is_empty()) {
1000          tex->shadow_comparitor= NULL;
1001       } else {
1002          tex->shadow_comparitor = read_rvalue(st, shadow_list);
1003          if (tex->shadow_comparitor == NULL) {
1004             ir_read_error(st, NULL, "when reading shadow comparitor in (%s ..)",
1005                           tag->value());
1006             return NULL;
1007          }
1008       }
1009       s_expression *lod_expr = (s_expression *) shadow_list->next;
1010
1011       switch (op) {
1012       case ir_txb:
1013          tex->lod_info.bias = read_rvalue(st, lod_expr);
1014          if (tex->lod_info.bias == NULL) {
1015             ir_read_error(st, NULL, "when reading LOD bias in (txb ...)");
1016             return NULL;
1017          }
1018          break;
1019       case ir_txl:
1020          tex->lod_info.lod = read_rvalue(st, lod_expr);
1021          if (tex->lod_info.lod == NULL) {
1022             ir_read_error(st, NULL, "when reading LOD in (txl ...)");
1023             return NULL;
1024          }
1025          break;
1026       case ir_txd: {
1027          s_list *lod_list = SX_AS_LIST(lod_expr);
1028          if (lod_list->length() != 2) {
1029             ir_read_error(st, lod_expr, "expected (dPdx dPdy) in (txd ...)");
1030             return NULL;
1031          }
1032          s_expression *dx_expr = (s_expression *) lod_list->subexpressions.head;
1033          s_expression *dy_expr = (s_expression *) dx_expr->next;
1034
1035          tex->lod_info.grad.dPdx = read_rvalue(st, dx_expr);
1036          if (tex->lod_info.grad.dPdx == NULL) {
1037             ir_read_error(st, NULL, "when reading dPdx in (txd ...)");
1038             return NULL;
1039          }
1040          tex->lod_info.grad.dPdy = read_rvalue(st, dy_expr);
1041          if (tex->lod_info.grad.dPdy == NULL) {
1042             ir_read_error(st, NULL, "when reading dPdy in (txd ...)");
1043             return NULL;
1044          }
1045          break;
1046       }
1047       default:
1048          // tex doesn't have any extra parameters and txf was handled earlier.
1049          break;
1050       };
1051    }
1052    return tex;
1053 }