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 extern "C" {
  25 #include <talloc.h>
  26 }
  27
  28 #include "ir_reader.h"
  29 #include "glsl_parser_extras.h"
  30 #include "glsl_types.h"
  31 #include "s_expression.h"
  32
  33 const static bool debug = false;
  34
  35 class ir_reader {
  36 public:
  37    ir_reader(_mesa_glsl_parse_state *);
  38
  39    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  40
  41 private:
  42    void *mem_ctx;
  43    _mesa_glsl_parse_state *state;
  44
  45    void ir_read_error(s_expression *, const char *fmt, ...);
  46
  47    const glsl_type *read_type(s_expression *);
  48
  49    void scan_for_prototypes(exec_list *, s_expression *);
  50    ir_function *read_function(s_expression *, bool skip_body);
  51    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  52
  53    void read_instructions(exec_list *, s_expression *, ir_loop *);
  54    ir_instruction *read_instruction(s_expression *, ir_loop *);
  55    ir_variable *read_declaration(s_expression *);
  56    ir_if *read_if(s_expression *, ir_loop *);
  57    ir_loop *read_loop(s_expression *);
  58    ir_return *read_return(s_expression *);
  59    ir_rvalue *read_rvalue(s_expression *);
  60    ir_assignment *read_assignment(s_expression *);
  61    ir_expression *read_expression(s_expression *);
  62    ir_call *read_call(s_expression *);
  63    ir_swizzle *read_swizzle(s_expression *);
  64    ir_constant *read_constant(s_expression *);
  65    ir_texture *read_texture(s_expression *);
  66
  67    ir_dereference *read_dereference(s_expression *);
  68 };
  69
  70 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  71 {
  72    this->mem_ctx = state;
  73 }
  74
  75 void
  76 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  77                    const char *src, bool scan_for_protos)
  78 {
  79    ir_reader r(state);
  80    r.read(instructions, src, scan_for_protos);
  81 }
  82
  83 void
  84 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  85 {
  86    s_expression *expr = s_expression::read_expression(mem_ctx, src);
  87    if (expr == NULL) {
  88       ir_read_error(NULL, "couldn't parse S-Expression.");
  89       return;
  90    }
  91
  92    if (scan_for_protos) {
  93       scan_for_prototypes(instructions, expr);
  94       if (state->error)
  95          return;
  96    }
  97
  98    read_instructions(instructions, expr, NULL);
  99    talloc_free(expr);
 100
 101    if (debug)
 102       validate_ir_tree(instructions);
 103 }
 104
 105 void
 106 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 107 {
 108    va_list ap;
 109
 110    state->error = true;
 111
 112    if (state->current_function != NULL)
 113       state->info_log = talloc_asprintf_append(state->info_log,
 114                            "In function %s:\n",
 115                            state->current_function->function_name());
 116    state->info_log = talloc_strdup_append(state->info_log, "error: ");
 117
 118    va_start(ap, fmt);
 119    state->info_log = talloc_vasprintf_append(state->info_log, fmt, ap);
 120    va_end(ap);
 121    state->info_log = talloc_strdup_append(state->info_log, "\n");
 122
 123    if (expr != NULL) {
 124       state->info_log = talloc_strdup_append(state->info_log,
 125                                              "...in this context:\n   ");
 126       expr->print();
 127       state->info_log = talloc_strdup_append(state->info_log, "\n\n");
 128    }
 129 }
 130
 131 const glsl_type *
 132 ir_reader::read_type(s_expression *expr)
 133 {
 134    s_expression *s_base_type;
 135    s_int *s_size;
 136
 137    s_pattern pat[] = { "array", s_base_type, s_size };
 138    if (MATCH(expr, pat)) {
 139       const glsl_type *base_type = read_type(s_base_type);
 140       if (base_type == NULL) {
 141          ir_read_error(NULL, "when reading base type of array type");
 142          return NULL;
 143       }
 144
 145       return glsl_type::get_array_instance(base_type, s_size->value());
 146    }
 147
 148    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 149    if (type_sym == NULL) {
 150       ir_read_error(expr, "expected <type>");
 151       return NULL;
 152    }
 153
 154    const glsl_type *type = state->symbols->get_type(type_sym->value());
 155    if (type == NULL)
 156       ir_read_error(expr, "invalid type: %s", type_sym->value());
 157
 158    return type;
 159 }
 160
 161
 162 void
 163 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 164 {
 165    s_list *list = SX_AS_LIST(expr);
 166    if (list == NULL) {
 167       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 168       return;
 169    }
 170
 171    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 172       s_list *sub = SX_AS_LIST(it.get());
 173       if (sub == NULL)
 174          continue; // not a (function ...); ignore it.
 175
 176       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 177       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 178          continue; // not a (function ...); ignore it.
 179
 180       ir_function *f = read_function(sub, true);
 181       if (f == NULL)
 182          return;
 183       instructions->push_tail(f);
 184    }
 185 }
 186
 187 ir_function *
 188 ir_reader::read_function(s_expression *expr, bool skip_body)
 189 {
 190    bool added = false;
 191    s_symbol *name;
 192
 193    s_pattern pat[] = { "function", name };
 194    if (!PARTIAL_MATCH(expr, pat)) {
 195       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 196       return NULL;
 197    }
 198
 199    ir_function *f = state->symbols->get_function(name->value());
 200    if (f == NULL) {
 201       f = new(mem_ctx) ir_function(name->value());
 202       added = state->symbols->add_function(f);
 203       assert(added);
 204    }
 205
 206    exec_list_iterator it = ((s_list *) expr)->subexpressions.iterator();
 207    it.next(); // skip "function" tag
 208    it.next(); // skip function name
 209    for (/* nothing */; it.has_next(); it.next()) {
 210       s_expression *s_sig = (s_expression *) it.get();
 211       read_function_sig(f, s_sig, skip_body);
 212    }
 213    return added ? f : NULL;
 214 }
 215
 216 void
 217 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 218 {
 219    s_expression *type_expr;
 220    s_list *paramlist;
 221    s_list *body_list;
 222
 223    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 224    if (!MATCH(expr, pat)) {
 225       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 226                           "(<instruction> ...))");
 227       return;
 228    }
 229
 230    const glsl_type *return_type = read_type(type_expr);
 231    if (return_type == NULL)
 232       return;
 233
 234    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 235    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 236       ir_read_error(paramlist, "Expected (parameters ...)");
 237       return;
 238    }
 239
 240    // Read the parameters list into a temporary place.
 241    exec_list hir_parameters;
 242    state->symbols->push_scope();
 243
 244    exec_list_iterator it = paramlist->subexpressions.iterator();
 245    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 246       ir_variable *var = read_declaration((s_expression *) it.get());
 247       if (var == NULL)
 248          return;
 249
 250       hir_parameters.push_tail(var);
 251    }
 252
 253    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 254    if (sig == NULL && skip_body) {
 255       /* If scanning for prototypes, generate a new signature. */
 256       sig = new(mem_ctx) ir_function_signature(return_type);
 257       sig->is_builtin = true;
 258       f->add_signature(sig);
 259    } else if (sig != NULL) {
 260       const char *badvar = sig->qualifiers_match(&hir_parameters);
 261       if (badvar != NULL) {
 262          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 263                        "don't match prototype", f->name, badvar);
 264          return;
 265       }
 266
 267       if (sig->return_type != return_type) {
 268          ir_read_error(expr, "function `%s' return type doesn't "
 269                        "match prototype", f->name);
 270          return;
 271       }
 272    } else {
 273       /* No prototype for this body exists - skip it. */
 274       state->symbols->pop_scope();
 275       return;
 276    }
 277    assert(sig != NULL);
 278
 279    sig->replace_parameters(&hir_parameters);
 280
 281    if (!skip_body && !body_list->subexpressions.is_empty()) {
 282       if (sig->is_defined) {
 283          ir_read_error(expr, "function %s redefined", f->name);
 284          return;
 285       }
 286       state->current_function = sig;
 287       read_instructions(&sig->body, body_list, NULL);
 288       state->current_function = NULL;
 289       sig->is_defined = true;
 290    }
 291
 292    state->symbols->pop_scope();
 293 }
 294
 295 void
 296 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 297                              ir_loop *loop_ctx)
 298 {
 299    // Read in a list of instructions
 300    s_list *list = SX_AS_LIST(expr);
 301    if (list == NULL) {
 302       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 303       return;
 304    }
 305
 306    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 307       s_expression *sub = (s_expression*) it.get();
 308       ir_instruction *ir = read_instruction(sub, loop_ctx);
 309       if (ir != NULL) {
 310          /* Global variable declarations should be moved to the top, before
 311           * any functions that might use them.  Functions are added to the
 312           * instruction stream when scanning for prototypes, so without this
 313           * hack, they always appear before variable declarations.
 314           */
 315          if (state->current_function == NULL && ir->as_variable() != NULL)
 316             instructions->push_head(ir);
 317          else
 318             instructions->push_tail(ir);
 319       }
 320    }
 321 }
 322
 323
 324 ir_instruction *
 325 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 326 {
 327    s_symbol *symbol = SX_AS_SYMBOL(expr);
 328    if (symbol != NULL) {
 329       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 330          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 331       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 332          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 333    }
 334
 335    s_list *list = SX_AS_LIST(expr);
 336    if (list == NULL || list->subexpressions.is_empty()) {
 337       ir_read_error(expr, "Invalid instruction.\n");
 338       return NULL;
 339    }
 340
 341    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 342    if (tag == NULL) {
 343       ir_read_error(expr, "expected instruction tag");
 344       return NULL;
 345    }
 346
 347    ir_instruction *inst = NULL;
 348    if (strcmp(tag->value(), "declare") == 0) {
 349       inst = read_declaration(list);
 350    } else if (strcmp(tag->value(), "assign") == 0) {
 351       inst = read_assignment(list);
 352    } else if (strcmp(tag->value(), "if") == 0) {
 353       inst = read_if(list, loop_ctx);
 354    } else if (strcmp(tag->value(), "loop") == 0) {
 355       inst = read_loop(list);
 356    } else if (strcmp(tag->value(), "return") == 0) {
 357       inst = read_return(list);
 358    } else if (strcmp(tag->value(), "function") == 0) {
 359       inst = read_function(list, false);
 360    } else {
 361       inst = read_rvalue(list);
 362       if (inst == NULL)
 363          ir_read_error(NULL, "when reading instruction");
 364    }
 365    return inst;
 366 }
 367
 368 ir_variable *
 369 ir_reader::read_declaration(s_expression *expr)
 370 {
 371    s_list *s_quals;
 372    s_expression *s_type;
 373    s_symbol *s_name;
 374
 375    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 376    if (!MATCH(expr, pat)) {
 377       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 378       return NULL;
 379    }
 380
 381    const glsl_type *type = read_type(s_type);
 382    if (type == NULL)
 383       return NULL;
 384
 385    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 386                                                ir_var_auto);
 387
 388    foreach_iter(exec_list_iterator, it, s_quals->subexpressions) {
 389       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 390       if (qualifier == NULL) {
 391          ir_read_error(expr, "qualifier list must contain only symbols");
 392          return NULL;
 393       }
 394
 395       // FINISHME: Check for duplicate/conflicting qualifiers.
 396       if (strcmp(qualifier->value(), "centroid") == 0) {
 397          var->centroid = 1;
 398       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 399          var->invariant = 1;
 400       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 401          var->mode = ir_var_uniform;
 402       } else if (strcmp(qualifier->value(), "auto") == 0) {
 403          var->mode = ir_var_auto;
 404       } else if (strcmp(qualifier->value(), "in") == 0) {
 405          var->mode = ir_var_in;
 406       } else if (strcmp(qualifier->value(), "out") == 0) {
 407          var->mode = ir_var_out;
 408       } else if (strcmp(qualifier->value(), "inout") == 0) {
 409          var->mode = ir_var_inout;
 410       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 411          var->interpolation = ir_var_smooth;
 412       } else if (strcmp(qualifier->value(), "flat") == 0) {
 413          var->interpolation = ir_var_flat;
 414       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 415          var->interpolation = ir_var_noperspective;
 416       } else {
 417          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 418          return NULL;
 419       }
 420    }
 421
 422    // Add the variable to the symbol table
 423    state->symbols->add_variable(var);
 424
 425    return var;
 426 }
 427
 428
 429 ir_if *
 430 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 431 {
 432    s_expression *s_cond;
 433    s_expression *s_then;
 434    s_expression *s_else;
 435
 436    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 437    if (!MATCH(expr, pat)) {
 438       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 439       return NULL;
 440    }
 441
 442    ir_rvalue *condition = read_rvalue(s_cond);
 443    if (condition == NULL) {
 444       ir_read_error(NULL, "when reading condition of (if ...)");
 445       return NULL;
 446    }
 447
 448    ir_if *iff = new(mem_ctx) ir_if(condition);
 449
 450    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 451    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 452    if (state->error) {
 453       delete iff;
 454       iff = NULL;
 455    }
 456    return iff;
 457 }
 458
 459
 460 ir_loop *
 461 ir_reader::read_loop(s_expression *expr)
 462 {
 463    s_expression *s_counter, *s_from, *s_to, *s_inc, *s_body;
 464
 465    s_pattern pat[] = { "loop", s_counter, s_from, s_to, s_inc, s_body };
 466    if (!MATCH(expr, pat)) {
 467       ir_read_error(expr, "expected (loop <counter> <from> <to> "
 468                           "<increment> <body>)");
 469       return NULL;
 470    }
 471
 472    // FINISHME: actually read the count/from/to fields.
 473
 474    ir_loop *loop = new(mem_ctx) ir_loop;
 475    read_instructions(&loop->body_instructions, s_body, loop);
 476    if (state->error) {
 477       delete loop;
 478       loop = NULL;
 479    }
 480    return loop;
 481 }
 482
 483
 484 ir_return *
 485 ir_reader::read_return(s_expression *expr)
 486 {
 487    s_expression *s_retval;
 488
 489    s_pattern pat[] = { "return", s_retval};
 490    if (!MATCH(expr, pat)) {
 491       ir_read_error(expr, "expected (return <rvalue>)");
 492       return NULL;
 493    }
 494
 495    ir_rvalue *retval = read_rvalue(s_retval);
 496    if (retval == NULL) {
 497       ir_read_error(NULL, "when reading return value");
 498       return NULL;
 499    }
 500
 501    return new(mem_ctx) ir_return(retval);
 502 }
 503
 504
 505 ir_rvalue *
 506 ir_reader::read_rvalue(s_expression *expr)
 507 {
 508    s_list *list = SX_AS_LIST(expr);
 509    if (list == NULL || list->subexpressions.is_empty())
 510       return NULL;
 511
 512    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 513    if (tag == NULL) {
 514       ir_read_error(expr, "expected rvalue tag");
 515       return NULL;
 516    }
 517
 518    ir_rvalue *rvalue = read_dereference(list);
 519    if (rvalue != NULL || state->error)
 520       return rvalue;
 521    else if (strcmp(tag->value(), "swiz") == 0) {
 522       rvalue = read_swizzle(list);
 523    } else if (strcmp(tag->value(), "expression") == 0) {
 524       rvalue = read_expression(list);
 525    } else if (strcmp(tag->value(), "call") == 0) {
 526       rvalue = read_call(list);
 527    } else if (strcmp(tag->value(), "constant") == 0) {
 528       rvalue = read_constant(list);
 529    } else {
 530       rvalue = read_texture(list);
 531       if (rvalue == NULL && !state->error)
 532          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 533    }
 534
 535    return rvalue;
 536 }
 537
 538 ir_assignment *
 539 ir_reader::read_assignment(s_expression *expr)
 540 {
 541    s_expression *cond_expr = NULL;
 542    s_expression *lhs_expr, *rhs_expr;
 543    s_list       *mask_list;
 544
 545    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 546    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 547    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 548       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 549                           "<lhs> <rhs>)");
 550       return NULL;
 551    }
 552
 553    ir_rvalue *condition = NULL;
 554    if (cond_expr != NULL) {
 555       condition = read_rvalue(cond_expr);
 556       if (condition == NULL) {
 557          ir_read_error(NULL, "when reading condition of assignment");
 558          return NULL;
 559       }
 560    }
 561
 562    unsigned mask = 0;
 563
 564    s_symbol *mask_symbol;
 565    s_pattern mask_pat[] = { mask_symbol };
 566    if (MATCH(mask_list, mask_pat)) {
 567       const char *mask_str = mask_symbol->value();
 568       unsigned mask_length = strlen(mask_str);
 569       if (mask_length > 4) {
 570          ir_read_error(expr, "invalid write mask: %s", mask_str);
 571          return NULL;
 572       }
 573
 574       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 575
 576       for (unsigned i = 0; i < mask_length; i++) {
 577          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 578             ir_read_error(expr, "write mask contains invalid character: %c",
 579                           mask_str[i]);
 580             return NULL;
 581          }
 582          mask |= 1 << idx_map[mask_str[i] - 'w'];
 583       }
 584    } else if (!mask_list->subexpressions.is_empty()) {
 585       ir_read_error(mask_list, "expected () or (<write mask>)");
 586       return NULL;
 587    }
 588
 589    ir_dereference *lhs = read_dereference(lhs_expr);
 590    if (lhs == NULL) {
 591       ir_read_error(NULL, "when reading left-hand side of assignment");
 592       return NULL;
 593    }
 594
 595    ir_rvalue *rhs = read_rvalue(rhs_expr);
 596    if (rhs == NULL) {
 597       ir_read_error(NULL, "when reading right-hand side of assignment");
 598       return NULL;
 599    }
 600
 601    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 602       ir_read_error(expr, "non-zero write mask required.");
 603       return NULL;
 604    }
 605
 606    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 607 }
 608
 609 ir_call *
 610 ir_reader::read_call(s_expression *expr)
 611 {
 612    s_symbol *name;
 613    s_list *params;
 614
 615    s_pattern pat[] = { "call", name, params };
 616    if (!MATCH(expr, pat)) {
 617       ir_read_error(expr, "expected (call <name> (<param> ...))");
 618       return NULL;
 619    }
 620
 621    exec_list parameters;
 622
 623    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 624       s_expression *expr = (s_expression*) it.get();
 625       ir_rvalue *param = read_rvalue(expr);
 626       if (param == NULL) {
 627          ir_read_error(expr, "when reading parameter to function call");
 628          return NULL;
 629       }
 630       parameters.push_tail(param);
 631    }
 632
 633    ir_function *f = state->symbols->get_function(name->value());
 634    if (f == NULL) {
 635       ir_read_error(expr, "found call to undefined function %s",
 636                     name->value());
 637       return NULL;
 638    }
 639
 640    ir_function_signature *callee = f->matching_signature(&parameters);
 641    if (callee == NULL) {
 642       ir_read_error(expr, "couldn't find matching signature for function "
 643                     "%s", name->value());
 644       return NULL;
 645    }
 646
 647    return new(mem_ctx) ir_call(callee, &parameters);
 648 }
 649
 650 ir_expression *
 651 ir_reader::read_expression(s_expression *expr)
 652 {
 653    s_expression *s_type;
 654    s_symbol *s_op;
 655    s_expression *s_arg1;
 656
 657    s_pattern pat[] = { "expression", s_type, s_op, s_arg1 };
 658    if (!PARTIAL_MATCH(expr, pat)) {
 659       ir_read_error(expr, "expected (expression <type> <operator> "
 660                           "<operand> [<operand>])");
 661       return NULL;
 662    }
 663    s_expression *s_arg2 = (s_expression *) s_arg1->next; // may be tail sentinel
 664
 665    const glsl_type *type = read_type(s_type);
 666    if (type == NULL)
 667       return NULL;
 668
 669    /* Read the operator */
 670    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 671    if (op == (ir_expression_operation) -1) {
 672       ir_read_error(expr, "invalid operator: %s", s_op->value());
 673       return NULL;
 674    }
 675
 676    unsigned num_operands = ir_expression::get_num_operands(op);
 677    if (num_operands == 1 && !s_arg1->next->is_tail_sentinel()) {
 678       ir_read_error(expr, "expected (expression <type> %s <operand>)",
 679                     s_op->value());
 680       return NULL;
 681    }
 682
 683    ir_rvalue *arg1 = read_rvalue(s_arg1);
 684    ir_rvalue *arg2 = NULL;
 685    if (arg1 == NULL) {
 686       ir_read_error(NULL, "when reading first operand of %s", s_op->value());
 687       return NULL;
 688    }
 689
 690    if (num_operands == 2) {
 691       if (s_arg2->is_tail_sentinel() || !s_arg2->next->is_tail_sentinel()) {
 692          ir_read_error(expr, "expected (expression <type> %s <operand> "
 693                              "<operand>)", s_op->value());
 694          return NULL;
 695       }
 696       arg2 = read_rvalue(s_arg2);
 697       if (arg2 == NULL) {
 698          ir_read_error(NULL, "when reading second operand of %s",
 699                        s_op->value());
 700          return NULL;
 701       }
 702    }
 703
 704    return new(mem_ctx) ir_expression(op, type, arg1, arg2);
 705 }
 706
 707 ir_swizzle *
 708 ir_reader::read_swizzle(s_expression *expr)
 709 {
 710    s_symbol *swiz;
 711    s_expression *sub;
 712
 713    s_pattern pat[] = { "swiz", swiz, sub };
 714    if (!MATCH(expr, pat)) {
 715       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 716       return NULL;
 717    }
 718
 719    if (strlen(swiz->value()) > 4) {
 720       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 721       return NULL;
 722    }
 723
 724    ir_rvalue *rvalue = read_rvalue(sub);
 725    if (rvalue == NULL)
 726       return NULL;
 727
 728    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 729                                        rvalue->type->vector_elements);
 730    if (ir == NULL)
 731       ir_read_error(expr, "invalid swizzle");
 732
 733    return ir;
 734 }
 735
 736 ir_constant *
 737 ir_reader::read_constant(s_expression *expr)
 738 {
 739    s_expression *type_expr;
 740    s_list *values;
 741
 742    s_pattern pat[] = { "constant", type_expr, values };
 743    if (!MATCH(expr, pat)) {
 744       ir_read_error(expr, "expected (constant <type> (...))");
 745       return NULL;
 746    }
 747
 748    const glsl_type *type = read_type(type_expr);
 749    if (type == NULL)
 750       return NULL;
 751
 752    if (values == NULL) {
 753       ir_read_error(expr, "expected (constant <type> (...))");
 754       return NULL;
 755    }
 756
 757    if (type->is_array()) {
 758       unsigned elements_supplied = 0;
 759       exec_list elements;
 760       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 761          s_expression *elt = (s_expression *) it.get();
 762          ir_constant *ir_elt = read_constant(elt);
 763          if (ir_elt == NULL)
 764             return NULL;
 765          elements.push_tail(ir_elt);
 766          elements_supplied++;
 767       }
 768
 769       if (elements_supplied != type->length) {
 770          ir_read_error(values, "expected exactly %u array elements, "
 771                        "given %u", type->length, elements_supplied);
 772          return NULL;
 773       }
 774       return new(mem_ctx) ir_constant(type, &elements);
 775    }
 776
 777    const glsl_type *const base_type = type->get_base_type();
 778
 779    ir_constant_data data = { { 0 } };
 780
 781    // Read in list of values (at most 16).
 782    int k = 0;
 783    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 784       if (k >= 16) {
 785          ir_read_error(values, "expected at most 16 numbers");
 786          return NULL;
 787       }
 788
 789       s_expression *expr = (s_expression*) it.get();
 790
 791       if (base_type->base_type == GLSL_TYPE_FLOAT) {
 792          s_number *value = SX_AS_NUMBER(expr);
 793          if (value == NULL) {
 794             ir_read_error(values, "expected numbers");
 795             return NULL;
 796          }
 797          data.f[k] = value->fvalue();
 798       } else {
 799          s_int *value = SX_AS_INT(expr);
 800          if (value == NULL) {
 801             ir_read_error(values, "expected integers");
 802             return NULL;
 803          }
 804
 805          switch (base_type->base_type) {
 806          case GLSL_TYPE_UINT: {
 807             data.u[k] = value->value();
 808             break;
 809          }
 810          case GLSL_TYPE_INT: {
 811             data.i[k] = value->value();
 812             break;
 813          }
 814          case GLSL_TYPE_BOOL: {
 815             data.b[k] = value->value();
 816             break;
 817          }
 818          default:
 819             ir_read_error(values, "unsupported constant type");
 820             return NULL;
 821          }
 822       }
 823       ++k;
 824    }
 825
 826    return new(mem_ctx) ir_constant(type, &data);
 827 }
 828
 829 ir_dereference *
 830 ir_reader::read_dereference(s_expression *expr)
 831 {
 832    s_symbol *s_var;
 833    s_expression *s_subject;
 834    s_expression *s_index;
 835    s_symbol *s_field;
 836
 837    s_pattern var_pat[] = { "var_ref", s_var };
 838    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 839    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 840
 841    if (MATCH(expr, var_pat)) {
 842       ir_variable *var = state->symbols->get_variable(s_var->value());
 843       if (var == NULL) {
 844          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 845          return NULL;
 846       }
 847       return new(mem_ctx) ir_dereference_variable(var);
 848    } else if (MATCH(expr, array_pat)) {
 849       ir_rvalue *subject = read_rvalue(s_subject);
 850       if (subject == NULL) {
 851          ir_read_error(NULL, "when reading the subject of an array_ref");
 852          return NULL;
 853       }
 854
 855       ir_rvalue *idx = read_rvalue(s_index);
 856       if (subject == NULL) {
 857          ir_read_error(NULL, "when reading the index of an array_ref");
 858          return NULL;
 859       }
 860       return new(mem_ctx) ir_dereference_array(subject, idx);
 861    } else if (MATCH(expr, record_pat)) {
 862       ir_rvalue *subject = read_rvalue(s_subject);
 863       if (subject == NULL) {
 864          ir_read_error(NULL, "when reading the subject of a record_ref");
 865          return NULL;
 866       }
 867       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 868    }
 869    return NULL;
 870 }
 871
 872 ir_texture *
 873 ir_reader::read_texture(s_expression *expr)
 874 {
 875    s_symbol *tag = NULL;
 876    s_expression *s_sampler = NULL;
 877    s_expression *s_coord = NULL;
 878    s_list *s_offset = NULL;
 879    s_expression *s_proj = NULL;
 880    s_list *s_shadow = NULL;
 881    s_expression *s_lod = NULL;
 882
 883    ir_texture_opcode op;
 884
 885    s_pattern tex_pattern[] =
 886       { "tex", s_sampler, s_coord, s_offset, s_proj, s_shadow };
 887    s_pattern txf_pattern[] =
 888       { "txf", s_sampler, s_coord, s_offset, s_lod };
 889    s_pattern other_pattern[] =
 890       { tag, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 891
 892    if (MATCH(expr, tex_pattern)) {
 893       op = ir_tex;
 894    } else if (MATCH(expr, txf_pattern)) {
 895       op = ir_txf;
 896    } else if (MATCH(expr, other_pattern)) {
 897       op = ir_texture::get_opcode(tag->value());
 898       if (op == -1)
 899          return NULL;
 900    }
 901
 902    ir_texture *tex = new(mem_ctx) ir_texture(op);
 903
 904    // Read sampler (must be a deref)
 905    ir_dereference *sampler = read_dereference(s_sampler);
 906    if (sampler == NULL) {
 907       ir_read_error(NULL, "when reading sampler in (%s ...)",
 908                     tex->opcode_string());
 909       return NULL;
 910    }
 911    tex->set_sampler(sampler);
 912
 913    // Read coordinate (any rvalue)
 914    tex->coordinate = read_rvalue(s_coord);
 915    if (tex->coordinate == NULL) {
 916       ir_read_error(NULL, "when reading coordinate in (%s ...)",
 917                     tex->opcode_string());
 918       return NULL;
 919    }
 920
 921    // Read texel offset, i.e. (0 0 0)
 922    s_int *offset_x;
 923    s_int *offset_y;
 924    s_int *offset_z;
 925    s_pattern offset_pat[] = { offset_x, offset_y, offset_z };
 926    if (!MATCH(s_offset, offset_pat)) {
 927       ir_read_error(s_offset, "expected (<int> <int> <int>)");
 928       return NULL;
 929    }
 930    tex->offsets[0] = offset_x->value();
 931    tex->offsets[1] = offset_y->value();
 932    tex->offsets[2] = offset_z->value();
 933
 934    if (op != ir_txf) {
 935       s_int *proj_as_int = SX_AS_INT(s_proj);
 936       if (proj_as_int && proj_as_int->value() == 1) {
 937          tex->projector = NULL;
 938       } else {
 939          tex->projector = read_rvalue(s_proj);
 940          if (tex->projector == NULL) {
 941             ir_read_error(NULL, "when reading projective divide in (%s ..)",
 942                           tex->opcode_string());
 943             return NULL;
 944          }
 945       }
 946
 947       if (s_shadow->subexpressions.is_empty()) {
 948          tex->shadow_comparitor = NULL;
 949       } else {
 950          tex->shadow_comparitor = read_rvalue(s_shadow);
 951          if (tex->shadow_comparitor == NULL) {
 952             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
 953                           tex->opcode_string());
 954             return NULL;
 955          }
 956       }
 957    }
 958
 959    switch (op) {
 960    case ir_txb:
 961       tex->lod_info.bias = read_rvalue(s_lod);
 962       if (tex->lod_info.bias == NULL) {
 963          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
 964          return NULL;
 965       }
 966       break;
 967    case ir_txl:
 968    case ir_txf:
 969       tex->lod_info.lod = read_rvalue(s_lod);
 970       if (tex->lod_info.lod == NULL) {
 971          ir_read_error(NULL, "when reading LOD in (%s ...)",
 972                        tex->opcode_string());
 973          return NULL;
 974       }
 975       break;
 976    case ir_txd: {
 977       s_expression *s_dx, *s_dy;
 978       s_pattern dxdy_pat[] = { s_dx, s_dy };
 979       if (!MATCH(s_lod, dxdy_pat)) {
 980          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
 981          return NULL;
 982       }
 983       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
 984       if (tex->lod_info.grad.dPdx == NULL) {
 985          ir_read_error(NULL, "when reading dPdx in (txd ...)");
 986          return NULL;
 987       }
 988       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
 989       if (tex->lod_info.grad.dPdy == NULL) {
 990          ir_read_error(NULL, "when reading dPdy in (txd ...)");
 991          return NULL;
 992       }
 993       break;
 994    }
 995    default:
 996       // tex doesn't have any extra parameters.
 997       break;
 998    };
 999    return tex;
1000 }