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 "ir_reader.h"
  25 #include "glsl_parser_extras.h"
  26 #include "glsl_types.h"
  27 #include "s_expression.h"
  28
  29 const static bool debug = false;
  30
  31 class ir_reader {
  32 public:
  33    ir_reader(_mesa_glsl_parse_state *);
  34
  35    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  36
  37 private:
  38    void *mem_ctx;
  39    _mesa_glsl_parse_state *state;
  40
  41    void ir_read_error(s_expression *, const char *fmt, ...);
  42
  43    const glsl_type *read_type(s_expression *);
  44
  45    void scan_for_prototypes(exec_list *, s_expression *);
  46    ir_function *read_function(s_expression *, bool skip_body);
  47    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  48
  49    void read_instructions(exec_list *, s_expression *, ir_loop *);
  50    ir_instruction *read_instruction(s_expression *, ir_loop *);
  51    ir_variable *read_declaration(s_expression *);
  52    ir_if *read_if(s_expression *, ir_loop *);
  53    ir_loop *read_loop(s_expression *);
  54    ir_call *read_call(s_expression *);
  55    ir_return *read_return(s_expression *);
  56    ir_rvalue *read_rvalue(s_expression *);
  57    ir_assignment *read_assignment(s_expression *);
  58    ir_expression *read_expression(s_expression *);
  59    ir_swizzle *read_swizzle(s_expression *);
  60    ir_constant *read_constant(s_expression *);
  61    ir_texture *read_texture(s_expression *);
  62
  63    ir_dereference *read_dereference(s_expression *);
  64    ir_dereference_variable *read_var_ref(s_expression *);
  65 };
  66
  67 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  68 {
  69    this->mem_ctx = state;
  70 }
  71
  72 void
  73 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  74                    const char *src, bool scan_for_protos)
  75 {
  76    ir_reader r(state);
  77    r.read(instructions, src, scan_for_protos);
  78 }
  79
  80 void
  81 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  82 {
  83    void *sx_mem_ctx = ralloc_context(NULL);
  84    s_expression *expr = s_expression::read_expression(sx_mem_ctx, src);
  85    if (expr == NULL) {
  86       ir_read_error(NULL, "couldn't parse S-Expression.");
  87       return;
  88    }
  89
  90    if (scan_for_protos) {
  91       scan_for_prototypes(instructions, expr);
  92       if (state->error)
  93          return;
  94    }
  95
  96    read_instructions(instructions, expr, NULL);
  97    ralloc_free(sx_mem_ctx);
  98
  99    if (debug)
 100       validate_ir_tree(instructions);
 101 }
 102
 103 void
 104 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 105 {
 106    va_list ap;
 107
 108    state->error = true;
 109
 110    if (state->current_function != NULL)
 111       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 112                              state->current_function->function_name());
 113    ralloc_strcat(&state->info_log, "error: ");
 114
 115    va_start(ap, fmt);
 116    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 117    va_end(ap);
 118    ralloc_strcat(&state->info_log, "\n");
 119
 120    if (expr != NULL) {
 121       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 122       expr->print();
 123       ralloc_strcat(&state->info_log, "\n\n");
 124    }
 125 }
 126
 127 const glsl_type *
 128 ir_reader::read_type(s_expression *expr)
 129 {
 130    s_expression *s_base_type;
 131    s_int *s_size;
 132
 133    s_pattern pat[] = { "array", s_base_type, s_size };
 134    if (MATCH(expr, pat)) {
 135       const glsl_type *base_type = read_type(s_base_type);
 136       if (base_type == NULL) {
 137          ir_read_error(NULL, "when reading base type of array type");
 138          return NULL;
 139       }
 140
 141       return glsl_type::get_array_instance(base_type, s_size->value());
 142    }
 143
 144    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 145    if (type_sym == NULL) {
 146       ir_read_error(expr, "expected <type>");
 147       return NULL;
 148    }
 149
 150    const glsl_type *type = state->symbols->get_type(type_sym->value());
 151    if (type == NULL)
 152       ir_read_error(expr, "invalid type: %s", type_sym->value());
 153
 154    return type;
 155 }
 156
 157
 158 void
 159 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 160 {
 161    s_list *list = SX_AS_LIST(expr);
 162    if (list == NULL) {
 163       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 164       return;
 165    }
 166
 167    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 168       s_list *sub = SX_AS_LIST(it.get());
 169       if (sub == NULL)
 170          continue; // not a (function ...); ignore it.
 171
 172       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 173       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 174          continue; // not a (function ...); ignore it.
 175
 176       ir_function *f = read_function(sub, true);
 177       if (f == NULL)
 178          return;
 179       instructions->push_tail(f);
 180    }
 181 }
 182
 183 ir_function *
 184 ir_reader::read_function(s_expression *expr, bool skip_body)
 185 {
 186    bool added = false;
 187    s_symbol *name;
 188
 189    s_pattern pat[] = { "function", name };
 190    if (!PARTIAL_MATCH(expr, pat)) {
 191       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 192       return NULL;
 193    }
 194
 195    ir_function *f = state->symbols->get_function(name->value());
 196    if (f == NULL) {
 197       f = new(mem_ctx) ir_function(name->value());
 198       added = state->symbols->add_function(f);
 199       assert(added);
 200    }
 201
 202    exec_list_iterator it = ((s_list *) expr)->subexpressions.iterator();
 203    it.next(); // skip "function" tag
 204    it.next(); // skip function name
 205    for (/* nothing */; it.has_next(); it.next()) {
 206       s_expression *s_sig = (s_expression *) it.get();
 207       read_function_sig(f, s_sig, skip_body);
 208    }
 209    return added ? f : NULL;
 210 }
 211
 212 void
 213 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 214 {
 215    s_expression *type_expr;
 216    s_list *paramlist;
 217    s_list *body_list;
 218
 219    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 220    if (!MATCH(expr, pat)) {
 221       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 222                           "(<instruction> ...))");
 223       return;
 224    }
 225
 226    const glsl_type *return_type = read_type(type_expr);
 227    if (return_type == NULL)
 228       return;
 229
 230    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 231    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 232       ir_read_error(paramlist, "Expected (parameters ...)");
 233       return;
 234    }
 235
 236    // Read the parameters list into a temporary place.
 237    exec_list hir_parameters;
 238    state->symbols->push_scope();
 239
 240    exec_list_iterator it = paramlist->subexpressions.iterator();
 241    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 242       ir_variable *var = read_declaration((s_expression *) it.get());
 243       if (var == NULL)
 244          return;
 245
 246       hir_parameters.push_tail(var);
 247    }
 248
 249    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 250    if (sig == NULL && skip_body) {
 251       /* If scanning for prototypes, generate a new signature. */
 252       sig = new(mem_ctx) ir_function_signature(return_type);
 253       sig->is_builtin = true;
 254       f->add_signature(sig);
 255    } else if (sig != NULL) {
 256       const char *badvar = sig->qualifiers_match(&hir_parameters);
 257       if (badvar != NULL) {
 258          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 259                        "don't match prototype", f->name, badvar);
 260          return;
 261       }
 262
 263       if (sig->return_type != return_type) {
 264          ir_read_error(expr, "function `%s' return type doesn't "
 265                        "match prototype", f->name);
 266          return;
 267       }
 268    } else {
 269       /* No prototype for this body exists - skip it. */
 270       state->symbols->pop_scope();
 271       return;
 272    }
 273    assert(sig != NULL);
 274
 275    sig->replace_parameters(&hir_parameters);
 276
 277    if (!skip_body && !body_list->subexpressions.is_empty()) {
 278       if (sig->is_defined) {
 279          ir_read_error(expr, "function %s redefined", f->name);
 280          return;
 281       }
 282       state->current_function = sig;
 283       read_instructions(&sig->body, body_list, NULL);
 284       state->current_function = NULL;
 285       sig->is_defined = true;
 286    }
 287
 288    state->symbols->pop_scope();
 289 }
 290
 291 void
 292 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 293                              ir_loop *loop_ctx)
 294 {
 295    // Read in a list of instructions
 296    s_list *list = SX_AS_LIST(expr);
 297    if (list == NULL) {
 298       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 299       return;
 300    }
 301
 302    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 303       s_expression *sub = (s_expression*) it.get();
 304       ir_instruction *ir = read_instruction(sub, loop_ctx);
 305       if (ir != NULL) {
 306          /* Global variable declarations should be moved to the top, before
 307           * any functions that might use them.  Functions are added to the
 308           * instruction stream when scanning for prototypes, so without this
 309           * hack, they always appear before variable declarations.
 310           */
 311          if (state->current_function == NULL && ir->as_variable() != NULL)
 312             instructions->push_head(ir);
 313          else
 314             instructions->push_tail(ir);
 315       }
 316    }
 317 }
 318
 319
 320 ir_instruction *
 321 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 322 {
 323    s_symbol *symbol = SX_AS_SYMBOL(expr);
 324    if (symbol != NULL) {
 325       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 326          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 327       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 328          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 329    }
 330
 331    s_list *list = SX_AS_LIST(expr);
 332    if (list == NULL || list->subexpressions.is_empty()) {
 333       ir_read_error(expr, "Invalid instruction.\n");
 334       return NULL;
 335    }
 336
 337    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 338    if (tag == NULL) {
 339       ir_read_error(expr, "expected instruction tag");
 340       return NULL;
 341    }
 342
 343    ir_instruction *inst = NULL;
 344    if (strcmp(tag->value(), "declare") == 0) {
 345       inst = read_declaration(list);
 346    } else if (strcmp(tag->value(), "assign") == 0) {
 347       inst = read_assignment(list);
 348    } else if (strcmp(tag->value(), "if") == 0) {
 349       inst = read_if(list, loop_ctx);
 350    } else if (strcmp(tag->value(), "loop") == 0) {
 351       inst = read_loop(list);
 352    } else if (strcmp(tag->value(), "call") == 0) {
 353       inst = read_call(list);
 354    } else if (strcmp(tag->value(), "return") == 0) {
 355       inst = read_return(list);
 356    } else if (strcmp(tag->value(), "function") == 0) {
 357       inst = read_function(list, false);
 358    } else {
 359       inst = read_rvalue(list);
 360       if (inst == NULL)
 361          ir_read_error(NULL, "when reading instruction");
 362    }
 363    return inst;
 364 }
 365
 366 ir_variable *
 367 ir_reader::read_declaration(s_expression *expr)
 368 {
 369    s_list *s_quals;
 370    s_expression *s_type;
 371    s_symbol *s_name;
 372
 373    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 374    if (!MATCH(expr, pat)) {
 375       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 376       return NULL;
 377    }
 378
 379    const glsl_type *type = read_type(s_type);
 380    if (type == NULL)
 381       return NULL;
 382
 383    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 384                                                ir_var_auto);
 385
 386    foreach_iter(exec_list_iterator, it, s_quals->subexpressions) {
 387       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 388       if (qualifier == NULL) {
 389          ir_read_error(expr, "qualifier list must contain only symbols");
 390          return NULL;
 391       }
 392
 393       // FINISHME: Check for duplicate/conflicting qualifiers.
 394       if (strcmp(qualifier->value(), "centroid") == 0) {
 395          var->centroid = 1;
 396       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 397          var->invariant = 1;
 398       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 399          var->mode = ir_var_uniform;
 400       } else if (strcmp(qualifier->value(), "auto") == 0) {
 401          var->mode = ir_var_auto;
 402       } else if (strcmp(qualifier->value(), "in") == 0) {
 403          var->mode = ir_var_function_in;
 404       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
 405          var->mode = ir_var_shader_in;
 406       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 407          var->mode = ir_var_const_in;
 408       } else if (strcmp(qualifier->value(), "out") == 0) {
 409          var->mode = ir_var_function_out;
 410       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
 411          var->mode = ir_var_shader_out;
 412       } else if (strcmp(qualifier->value(), "inout") == 0) {
 413          var->mode = ir_var_function_inout;
 414       } else if (strcmp(qualifier->value(), "temporary") == 0) {
 415          var->mode = ir_var_temporary;
 416       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 417          var->interpolation = INTERP_QUALIFIER_SMOOTH;
 418       } else if (strcmp(qualifier->value(), "flat") == 0) {
 419          var->interpolation = INTERP_QUALIFIER_FLAT;
 420       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 421          var->interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 422       } else {
 423          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 424          return NULL;
 425       }
 426    }
 427
 428    // Add the variable to the symbol table
 429    state->symbols->add_variable(var);
 430
 431    return var;
 432 }
 433
 434
 435 ir_if *
 436 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 437 {
 438    s_expression *s_cond;
 439    s_expression *s_then;
 440    s_expression *s_else;
 441
 442    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 443    if (!MATCH(expr, pat)) {
 444       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 445       return NULL;
 446    }
 447
 448    ir_rvalue *condition = read_rvalue(s_cond);
 449    if (condition == NULL) {
 450       ir_read_error(NULL, "when reading condition of (if ...)");
 451       return NULL;
 452    }
 453
 454    ir_if *iff = new(mem_ctx) ir_if(condition);
 455
 456    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 457    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 458    if (state->error) {
 459       delete iff;
 460       iff = NULL;
 461    }
 462    return iff;
 463 }
 464
 465
 466 ir_loop *
 467 ir_reader::read_loop(s_expression *expr)
 468 {
 469    s_expression *s_counter, *s_from, *s_to, *s_inc, *s_body;
 470
 471    s_pattern pat[] = { "loop", s_counter, s_from, s_to, s_inc, s_body };
 472    if (!MATCH(expr, pat)) {
 473       ir_read_error(expr, "expected (loop <counter> <from> <to> "
 474                           "<increment> <body>)");
 475       return NULL;
 476    }
 477
 478    // FINISHME: actually read the count/from/to fields.
 479
 480    ir_loop *loop = new(mem_ctx) ir_loop;
 481    read_instructions(&loop->body_instructions, s_body, loop);
 482    if (state->error) {
 483       delete loop;
 484       loop = NULL;
 485    }
 486    return loop;
 487 }
 488
 489
 490 ir_return *
 491 ir_reader::read_return(s_expression *expr)
 492 {
 493    s_expression *s_retval;
 494
 495    s_pattern return_value_pat[] = { "return", s_retval};
 496    s_pattern return_void_pat[] = { "return" };
 497    if (MATCH(expr, return_value_pat)) {
 498       ir_rvalue *retval = read_rvalue(s_retval);
 499       if (retval == NULL) {
 500          ir_read_error(NULL, "when reading return value");
 501          return NULL;
 502       }
 503       return new(mem_ctx) ir_return(retval);
 504    } else if (MATCH(expr, return_void_pat)) {
 505       return new(mem_ctx) ir_return;
 506    } else {
 507       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 508       return NULL;
 509    }
 510 }
 511
 512
 513 ir_rvalue *
 514 ir_reader::read_rvalue(s_expression *expr)
 515 {
 516    s_list *list = SX_AS_LIST(expr);
 517    if (list == NULL || list->subexpressions.is_empty())
 518       return NULL;
 519
 520    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 521    if (tag == NULL) {
 522       ir_read_error(expr, "expected rvalue tag");
 523       return NULL;
 524    }
 525
 526    ir_rvalue *rvalue = read_dereference(list);
 527    if (rvalue != NULL || state->error)
 528       return rvalue;
 529    else if (strcmp(tag->value(), "swiz") == 0) {
 530       rvalue = read_swizzle(list);
 531    } else if (strcmp(tag->value(), "expression") == 0) {
 532       rvalue = read_expression(list);
 533    } else if (strcmp(tag->value(), "constant") == 0) {
 534       rvalue = read_constant(list);
 535    } else {
 536       rvalue = read_texture(list);
 537       if (rvalue == NULL && !state->error)
 538          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 539    }
 540
 541    return rvalue;
 542 }
 543
 544 ir_assignment *
 545 ir_reader::read_assignment(s_expression *expr)
 546 {
 547    s_expression *cond_expr = NULL;
 548    s_expression *lhs_expr, *rhs_expr;
 549    s_list       *mask_list;
 550
 551    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 552    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 553    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 554       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 555                           "<lhs> <rhs>)");
 556       return NULL;
 557    }
 558
 559    ir_rvalue *condition = NULL;
 560    if (cond_expr != NULL) {
 561       condition = read_rvalue(cond_expr);
 562       if (condition == NULL) {
 563          ir_read_error(NULL, "when reading condition of assignment");
 564          return NULL;
 565       }
 566    }
 567
 568    unsigned mask = 0;
 569
 570    s_symbol *mask_symbol;
 571    s_pattern mask_pat[] = { mask_symbol };
 572    if (MATCH(mask_list, mask_pat)) {
 573       const char *mask_str = mask_symbol->value();
 574       unsigned mask_length = strlen(mask_str);
 575       if (mask_length > 4) {
 576          ir_read_error(expr, "invalid write mask: %s", mask_str);
 577          return NULL;
 578       }
 579
 580       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 581
 582       for (unsigned i = 0; i < mask_length; i++) {
 583          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 584             ir_read_error(expr, "write mask contains invalid character: %c",
 585                           mask_str[i]);
 586             return NULL;
 587          }
 588          mask |= 1 << idx_map[mask_str[i] - 'w'];
 589       }
 590    } else if (!mask_list->subexpressions.is_empty()) {
 591       ir_read_error(mask_list, "expected () or (<write mask>)");
 592       return NULL;
 593    }
 594
 595    ir_dereference *lhs = read_dereference(lhs_expr);
 596    if (lhs == NULL) {
 597       ir_read_error(NULL, "when reading left-hand side of assignment");
 598       return NULL;
 599    }
 600
 601    ir_rvalue *rhs = read_rvalue(rhs_expr);
 602    if (rhs == NULL) {
 603       ir_read_error(NULL, "when reading right-hand side of assignment");
 604       return NULL;
 605    }
 606
 607    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 608       ir_read_error(expr, "non-zero write mask required.");
 609       return NULL;
 610    }
 611
 612    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 613 }
 614
 615 ir_call *
 616 ir_reader::read_call(s_expression *expr)
 617 {
 618    s_symbol *name;
 619    s_list *params;
 620    s_list *s_return = NULL;
 621
 622    ir_dereference_variable *return_deref = NULL;
 623
 624    s_pattern void_pat[] = { "call", name, params };
 625    s_pattern non_void_pat[] = { "call", name, s_return, params };
 626    if (MATCH(expr, non_void_pat)) {
 627       return_deref = read_var_ref(s_return);
 628       if (return_deref == NULL) {
 629          ir_read_error(s_return, "when reading a call's return storage");
 630          return NULL;
 631       }
 632    } else if (!MATCH(expr, void_pat)) {
 633       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
 634       return NULL;
 635    }
 636
 637    exec_list parameters;
 638
 639    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 640       s_expression *expr = (s_expression*) it.get();
 641       ir_rvalue *param = read_rvalue(expr);
 642       if (param == NULL) {
 643          ir_read_error(expr, "when reading parameter to function call");
 644          return NULL;
 645       }
 646       parameters.push_tail(param);
 647    }
 648
 649    ir_function *f = state->symbols->get_function(name->value());
 650    if (f == NULL) {
 651       ir_read_error(expr, "found call to undefined function %s",
 652                     name->value());
 653       return NULL;
 654    }
 655
 656    ir_function_signature *callee = f->matching_signature(&parameters);
 657    if (callee == NULL) {
 658       ir_read_error(expr, "couldn't find matching signature for function "
 659                     "%s", name->value());
 660       return NULL;
 661    }
 662
 663    if (callee->return_type == glsl_type::void_type && return_deref) {
 664       ir_read_error(expr, "call has return value storage but void type");
 665       return NULL;
 666    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
 667       ir_read_error(expr, "call has non-void type but no return value storage");
 668       return NULL;
 669    }
 670
 671    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
 672 }
 673
 674 ir_expression *
 675 ir_reader::read_expression(s_expression *expr)
 676 {
 677    s_expression *s_type;
 678    s_symbol *s_op;
 679    s_expression *s_arg[4] = {NULL};
 680
 681    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
 682    if (!PARTIAL_MATCH(expr, pat)) {
 683       ir_read_error(expr, "expected (expression <type> <operator> "
 684                           "<operand> [<operand>] [<operand>] [<operand>])");
 685       return NULL;
 686    }
 687    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
 688    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
 689    if (s_arg[2])
 690       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
 691
 692    const glsl_type *type = read_type(s_type);
 693    if (type == NULL)
 694       return NULL;
 695
 696    /* Read the operator */
 697    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 698    if (op == (ir_expression_operation) -1) {
 699       ir_read_error(expr, "invalid operator: %s", s_op->value());
 700       return NULL;
 701    }
 702
 703    int num_operands = -3; /* skip "expression" <type> <operation> */
 704    foreach_list(n, &((s_list *) expr)->subexpressions)
 705       ++num_operands;
 706
 707    int expected_operands = ir_expression::get_num_operands(op);
 708    if (num_operands != expected_operands) {
 709       ir_read_error(expr, "found %d expression operands, expected %d",
 710                     num_operands, expected_operands);
 711       return NULL;
 712    }
 713
 714    ir_rvalue *arg[4] = {NULL};
 715    for (int i = 0; i < num_operands; i++) {
 716       arg[i] = read_rvalue(s_arg[i]);
 717       if (arg[i] == NULL) {
 718          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
 719          return NULL;
 720       }
 721    }
 722
 723    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
 724 }
 725
 726 ir_swizzle *
 727 ir_reader::read_swizzle(s_expression *expr)
 728 {
 729    s_symbol *swiz;
 730    s_expression *sub;
 731
 732    s_pattern pat[] = { "swiz", swiz, sub };
 733    if (!MATCH(expr, pat)) {
 734       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 735       return NULL;
 736    }
 737
 738    if (strlen(swiz->value()) > 4) {
 739       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 740       return NULL;
 741    }
 742
 743    ir_rvalue *rvalue = read_rvalue(sub);
 744    if (rvalue == NULL)
 745       return NULL;
 746
 747    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 748                                        rvalue->type->vector_elements);
 749    if (ir == NULL)
 750       ir_read_error(expr, "invalid swizzle");
 751
 752    return ir;
 753 }
 754
 755 ir_constant *
 756 ir_reader::read_constant(s_expression *expr)
 757 {
 758    s_expression *type_expr;
 759    s_list *values;
 760
 761    s_pattern pat[] = { "constant", type_expr, values };
 762    if (!MATCH(expr, pat)) {
 763       ir_read_error(expr, "expected (constant <type> (...))");
 764       return NULL;
 765    }
 766
 767    const glsl_type *type = read_type(type_expr);
 768    if (type == NULL)
 769       return NULL;
 770
 771    if (values == NULL) {
 772       ir_read_error(expr, "expected (constant <type> (...))");
 773       return NULL;
 774    }
 775
 776    if (type->is_array()) {
 777       unsigned elements_supplied = 0;
 778       exec_list elements;
 779       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 780          s_expression *elt = (s_expression *) it.get();
 781          ir_constant *ir_elt = read_constant(elt);
 782          if (ir_elt == NULL)
 783             return NULL;
 784          elements.push_tail(ir_elt);
 785          elements_supplied++;
 786       }
 787
 788       if (elements_supplied != type->length) {
 789          ir_read_error(values, "expected exactly %u array elements, "
 790                        "given %u", type->length, elements_supplied);
 791          return NULL;
 792       }
 793       return new(mem_ctx) ir_constant(type, &elements);
 794    }
 795
 796    ir_constant_data data = { { 0 } };
 797
 798    // Read in list of values (at most 16).
 799    unsigned k = 0;
 800    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 801       if (k >= 16) {
 802          ir_read_error(values, "expected at most 16 numbers");
 803          return NULL;
 804       }
 805
 806       s_expression *expr = (s_expression*) it.get();
 807
 808       if (type->base_type == GLSL_TYPE_FLOAT) {
 809          s_number *value = SX_AS_NUMBER(expr);
 810          if (value == NULL) {
 811             ir_read_error(values, "expected numbers");
 812             return NULL;
 813          }
 814          data.f[k] = value->fvalue();
 815       } else {
 816          s_int *value = SX_AS_INT(expr);
 817          if (value == NULL) {
 818             ir_read_error(values, "expected integers");
 819             return NULL;
 820          }
 821
 822          switch (type->base_type) {
 823          case GLSL_TYPE_UINT: {
 824             data.u[k] = value->value();
 825             break;
 826          }
 827          case GLSL_TYPE_INT: {
 828             data.i[k] = value->value();
 829             break;
 830          }
 831          case GLSL_TYPE_BOOL: {
 832             data.b[k] = value->value();
 833             break;
 834          }
 835          default:
 836             ir_read_error(values, "unsupported constant type");
 837             return NULL;
 838          }
 839       }
 840       ++k;
 841    }
 842    if (k != type->components()) {
 843       ir_read_error(values, "expected %u constant values, found %u",
 844                     type->components(), k);
 845       return NULL;
 846    }
 847
 848    return new(mem_ctx) ir_constant(type, &data);
 849 }
 850
 851 ir_dereference_variable *
 852 ir_reader::read_var_ref(s_expression *expr)
 853 {
 854    s_symbol *s_var;
 855    s_pattern var_pat[] = { "var_ref", s_var };
 856
 857    if (MATCH(expr, var_pat)) {
 858       ir_variable *var = state->symbols->get_variable(s_var->value());
 859       if (var == NULL) {
 860          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 861          return NULL;
 862       }
 863       return new(mem_ctx) ir_dereference_variable(var);
 864    }
 865    return NULL;
 866 }
 867
 868 ir_dereference *
 869 ir_reader::read_dereference(s_expression *expr)
 870 {
 871    s_expression *s_subject;
 872    s_expression *s_index;
 873    s_symbol *s_field;
 874
 875    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 876    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 877
 878    ir_dereference_variable *var_ref = read_var_ref(expr);
 879    if (var_ref != NULL) {
 880       return var_ref;
 881    } else if (MATCH(expr, array_pat)) {
 882       ir_rvalue *subject = read_rvalue(s_subject);
 883       if (subject == NULL) {
 884          ir_read_error(NULL, "when reading the subject of an array_ref");
 885          return NULL;
 886       }
 887
 888       ir_rvalue *idx = read_rvalue(s_index);
 889       if (subject == NULL) {
 890          ir_read_error(NULL, "when reading the index of an array_ref");
 891          return NULL;
 892       }
 893       return new(mem_ctx) ir_dereference_array(subject, idx);
 894    } else if (MATCH(expr, record_pat)) {
 895       ir_rvalue *subject = read_rvalue(s_subject);
 896       if (subject == NULL) {
 897          ir_read_error(NULL, "when reading the subject of a record_ref");
 898          return NULL;
 899       }
 900       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 901    }
 902    return NULL;
 903 }
 904
 905 ir_texture *
 906 ir_reader::read_texture(s_expression *expr)
 907 {
 908    s_symbol *tag = NULL;
 909    s_expression *s_type = NULL;
 910    s_expression *s_sampler = NULL;
 911    s_expression *s_coord = NULL;
 912    s_expression *s_offset = NULL;
 913    s_expression *s_proj = NULL;
 914    s_list *s_shadow = NULL;
 915    s_expression *s_lod = NULL;
 916    s_expression *s_sample_index = NULL;
 917
 918    ir_texture_opcode op = ir_tex; /* silence warning */
 919
 920    s_pattern tex_pattern[] =
 921       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 922    s_pattern lod_pattern[] =
 923       { "lod", s_type, s_sampler, s_coord };
 924    s_pattern txf_pattern[] =
 925       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 926    s_pattern txf_ms_pattern[] =
 927       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
 928    s_pattern txs_pattern[] =
 929       { "txs", s_type, s_sampler, s_lod };
 930    s_pattern other_pattern[] =
 931       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 932
 933    if (MATCH(expr, lod_pattern)) {
 934       op = ir_lod;
 935    } else if (MATCH(expr, tex_pattern)) {
 936       op = ir_tex;
 937    } else if (MATCH(expr, txf_pattern)) {
 938       op = ir_txf;
 939    } else if (MATCH(expr, txf_ms_pattern)) {
 940       op = ir_txf_ms;
 941    } else if (MATCH(expr, txs_pattern)) {
 942       op = ir_txs;
 943    } else if (MATCH(expr, other_pattern)) {
 944       op = ir_texture::get_opcode(tag->value());
 945       if (op == -1)
 946          return NULL;
 947    } else {
 948       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
 949       return NULL;
 950    }
 951
 952    ir_texture *tex = new(mem_ctx) ir_texture(op);
 953
 954    // Read return type
 955    const glsl_type *type = read_type(s_type);
 956    if (type == NULL) {
 957       ir_read_error(NULL, "when reading type in (%s ...)",
 958                     tex->opcode_string());
 959       return NULL;
 960    }
 961
 962    // Read sampler (must be a deref)
 963    ir_dereference *sampler = read_dereference(s_sampler);
 964    if (sampler == NULL) {
 965       ir_read_error(NULL, "when reading sampler in (%s ...)",
 966                     tex->opcode_string());
 967       return NULL;
 968    }
 969    tex->set_sampler(sampler, type);
 970
 971    if (op != ir_txs) {
 972       // Read coordinate (any rvalue)
 973       tex->coordinate = read_rvalue(s_coord);
 974       if (tex->coordinate == NULL) {
 975          ir_read_error(NULL, "when reading coordinate in (%s ...)",
 976                        tex->opcode_string());
 977          return NULL;
 978       }
 979
 980       if (op != ir_txf_ms && op != ir_lod) {
 981          // Read texel offset - either 0 or an rvalue.
 982          s_int *si_offset = SX_AS_INT(s_offset);
 983          if (si_offset == NULL || si_offset->value() != 0) {
 984             tex->offset = read_rvalue(s_offset);
 985             if (tex->offset == NULL) {
 986                ir_read_error(s_offset, "expected 0 or an expression");
 987                return NULL;
 988             }
 989          }
 990       }
 991    }
 992
 993    if (op != ir_txf && op != ir_txf_ms && op != ir_txs && op != ir_lod) {
 994       s_int *proj_as_int = SX_AS_INT(s_proj);
 995       if (proj_as_int && proj_as_int->value() == 1) {
 996          tex->projector = NULL;
 997       } else {
 998          tex->projector = read_rvalue(s_proj);
 999          if (tex->projector == NULL) {
1000             ir_read_error(NULL, "when reading projective divide in (%s ..)",
1001                           tex->opcode_string());
1002             return NULL;
1003          }
1004       }
1005
1006       if (s_shadow->subexpressions.is_empty()) {
1007          tex->shadow_comparitor = NULL;
1008       } else {
1009          tex->shadow_comparitor = read_rvalue(s_shadow);
1010          if (tex->shadow_comparitor == NULL) {
1011             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
1012                           tex->opcode_string());
1013             return NULL;
1014          }
1015       }
1016    }
1017
1018    switch (op) {
1019    case ir_txb:
1020       tex->lod_info.bias = read_rvalue(s_lod);
1021       if (tex->lod_info.bias == NULL) {
1022          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
1023          return NULL;
1024       }
1025       break;
1026    case ir_txl:
1027    case ir_txf:
1028    case ir_txs:
1029       tex->lod_info.lod = read_rvalue(s_lod);
1030       if (tex->lod_info.lod == NULL) {
1031          ir_read_error(NULL, "when reading LOD in (%s ...)",
1032                        tex->opcode_string());
1033          return NULL;
1034       }
1035       break;
1036    case ir_txf_ms:
1037       tex->lod_info.sample_index = read_rvalue(s_sample_index);
1038       if (tex->lod_info.sample_index == NULL) {
1039          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
1040          return NULL;
1041       }
1042       break;
1043    case ir_txd: {
1044       s_expression *s_dx, *s_dy;
1045       s_pattern dxdy_pat[] = { s_dx, s_dy };
1046       if (!MATCH(s_lod, dxdy_pat)) {
1047          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
1048          return NULL;
1049       }
1050       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1051       if (tex->lod_info.grad.dPdx == NULL) {
1052          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1053          return NULL;
1054       }
1055       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1056       if (tex->lod_info.grad.dPdy == NULL) {
1057          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1058          return NULL;
1059       }
1060       break;
1061    }
1062    default:
1063       // tex and lod don't have any extra parameters.
1064       break;
1065    };
1066    return tex;
1067 }