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_return *read_return(s_expression *);
  55    ir_rvalue *read_rvalue(s_expression *);
  56    ir_assignment *read_assignment(s_expression *);
  57    ir_expression *read_expression(s_expression *);
  58    ir_call *read_call(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 };
  65
  66 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  67 {
  68    this->mem_ctx = state;
  69 }
  70
  71 void
  72 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  73                    const char *src, bool scan_for_protos)
  74 {
  75    ir_reader r(state);
  76    r.read(instructions, src, scan_for_protos);
  77 }
  78
  79 void
  80 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  81 {
  82    void *sx_mem_ctx = ralloc_context(NULL);
  83    s_expression *expr = s_expression::read_expression(sx_mem_ctx, src);
  84    if (expr == NULL) {
  85       ir_read_error(NULL, "couldn't parse S-Expression.");
  86       return;
  87    }
  88
  89    if (scan_for_protos) {
  90       scan_for_prototypes(instructions, expr);
  91       if (state->error)
  92          return;
  93    }
  94
  95    read_instructions(instructions, expr, NULL);
  96    ralloc_free(sx_mem_ctx);
  97
  98    if (debug)
  99       validate_ir_tree(instructions);
 100 }
 101
 102 void
 103 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 104 {
 105    va_list ap;
 106
 107    state->error = true;
 108
 109    if (state->current_function != NULL)
 110       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 111                              state->current_function->function_name());
 112    ralloc_strcat(&state->info_log, "error: ");
 113
 114    va_start(ap, fmt);
 115    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 116    va_end(ap);
 117    ralloc_strcat(&state->info_log, "\n");
 118
 119    if (expr != NULL) {
 120       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 121       expr->print();
 122       ralloc_strcat(&state->info_log, "\n\n");
 123    }
 124 }
 125
 126 const glsl_type *
 127 ir_reader::read_type(s_expression *expr)
 128 {
 129    s_expression *s_base_type;
 130    s_int *s_size;
 131
 132    s_pattern pat[] = { "array", s_base_type, s_size };
 133    if (MATCH(expr, pat)) {
 134       const glsl_type *base_type = read_type(s_base_type);
 135       if (base_type == NULL) {
 136          ir_read_error(NULL, "when reading base type of array type");
 137          return NULL;
 138       }
 139
 140       return glsl_type::get_array_instance(base_type, s_size->value());
 141    }
 142
 143    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 144    if (type_sym == NULL) {
 145       ir_read_error(expr, "expected <type>");
 146       return NULL;
 147    }
 148
 149    const glsl_type *type = state->symbols->get_type(type_sym->value());
 150    if (type == NULL)
 151       ir_read_error(expr, "invalid type: %s", type_sym->value());
 152
 153    return type;
 154 }
 155
 156
 157 void
 158 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 159 {
 160    s_list *list = SX_AS_LIST(expr);
 161    if (list == NULL) {
 162       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 163       return;
 164    }
 165
 166    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 167       s_list *sub = SX_AS_LIST(it.get());
 168       if (sub == NULL)
 169          continue; // not a (function ...); ignore it.
 170
 171       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 172       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 173          continue; // not a (function ...); ignore it.
 174
 175       ir_function *f = read_function(sub, true);
 176       if (f == NULL)
 177          return;
 178       instructions->push_tail(f);
 179    }
 180 }
 181
 182 ir_function *
 183 ir_reader::read_function(s_expression *expr, bool skip_body)
 184 {
 185    bool added = false;
 186    s_symbol *name;
 187
 188    s_pattern pat[] = { "function", name };
 189    if (!PARTIAL_MATCH(expr, pat)) {
 190       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 191       return NULL;
 192    }
 193
 194    ir_function *f = state->symbols->get_function(name->value());
 195    if (f == NULL) {
 196       f = new(mem_ctx) ir_function(name->value());
 197       added = state->symbols->add_function(f);
 198       assert(added);
 199    }
 200
 201    exec_list_iterator it = ((s_list *) expr)->subexpressions.iterator();
 202    it.next(); // skip "function" tag
 203    it.next(); // skip function name
 204    for (/* nothing */; it.has_next(); it.next()) {
 205       s_expression *s_sig = (s_expression *) it.get();
 206       read_function_sig(f, s_sig, skip_body);
 207    }
 208    return added ? f : NULL;
 209 }
 210
 211 void
 212 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 213 {
 214    s_expression *type_expr;
 215    s_list *paramlist;
 216    s_list *body_list;
 217
 218    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 219    if (!MATCH(expr, pat)) {
 220       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 221                           "(<instruction> ...))");
 222       return;
 223    }
 224
 225    const glsl_type *return_type = read_type(type_expr);
 226    if (return_type == NULL)
 227       return;
 228
 229    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 230    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 231       ir_read_error(paramlist, "Expected (parameters ...)");
 232       return;
 233    }
 234
 235    // Read the parameters list into a temporary place.
 236    exec_list hir_parameters;
 237    state->symbols->push_scope();
 238
 239    exec_list_iterator it = paramlist->subexpressions.iterator();
 240    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 241       ir_variable *var = read_declaration((s_expression *) it.get());
 242       if (var == NULL)
 243          return;
 244
 245       hir_parameters.push_tail(var);
 246    }
 247
 248    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 249    if (sig == NULL && skip_body) {
 250       /* If scanning for prototypes, generate a new signature. */
 251       sig = new(mem_ctx) ir_function_signature(return_type);
 252       sig->is_builtin = true;
 253       f->add_signature(sig);
 254    } else if (sig != NULL) {
 255       const char *badvar = sig->qualifiers_match(&hir_parameters);
 256       if (badvar != NULL) {
 257          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 258                        "don't match prototype", f->name, badvar);
 259          return;
 260       }
 261
 262       if (sig->return_type != return_type) {
 263          ir_read_error(expr, "function `%s' return type doesn't "
 264                        "match prototype", f->name);
 265          return;
 266       }
 267    } else {
 268       /* No prototype for this body exists - skip it. */
 269       state->symbols->pop_scope();
 270       return;
 271    }
 272    assert(sig != NULL);
 273
 274    sig->replace_parameters(&hir_parameters);
 275
 276    if (!skip_body && !body_list->subexpressions.is_empty()) {
 277       if (sig->is_defined) {
 278          ir_read_error(expr, "function %s redefined", f->name);
 279          return;
 280       }
 281       state->current_function = sig;
 282       read_instructions(&sig->body, body_list, NULL);
 283       state->current_function = NULL;
 284       sig->is_defined = true;
 285    }
 286
 287    state->symbols->pop_scope();
 288 }
 289
 290 void
 291 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 292                              ir_loop *loop_ctx)
 293 {
 294    // Read in a list of instructions
 295    s_list *list = SX_AS_LIST(expr);
 296    if (list == NULL) {
 297       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 298       return;
 299    }
 300
 301    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 302       s_expression *sub = (s_expression*) it.get();
 303       ir_instruction *ir = read_instruction(sub, loop_ctx);
 304       if (ir != NULL) {
 305          /* Global variable declarations should be moved to the top, before
 306           * any functions that might use them.  Functions are added to the
 307           * instruction stream when scanning for prototypes, so without this
 308           * hack, they always appear before variable declarations.
 309           */
 310          if (state->current_function == NULL && ir->as_variable() != NULL)
 311             instructions->push_head(ir);
 312          else
 313             instructions->push_tail(ir);
 314       }
 315    }
 316 }
 317
 318
 319 ir_instruction *
 320 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 321 {
 322    s_symbol *symbol = SX_AS_SYMBOL(expr);
 323    if (symbol != NULL) {
 324       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 325          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 326       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 327          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 328    }
 329
 330    s_list *list = SX_AS_LIST(expr);
 331    if (list == NULL || list->subexpressions.is_empty()) {
 332       ir_read_error(expr, "Invalid instruction.\n");
 333       return NULL;
 334    }
 335
 336    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 337    if (tag == NULL) {
 338       ir_read_error(expr, "expected instruction tag");
 339       return NULL;
 340    }
 341
 342    ir_instruction *inst = NULL;
 343    if (strcmp(tag->value(), "declare") == 0) {
 344       inst = read_declaration(list);
 345    } else if (strcmp(tag->value(), "assign") == 0) {
 346       inst = read_assignment(list);
 347    } else if (strcmp(tag->value(), "if") == 0) {
 348       inst = read_if(list, loop_ctx);
 349    } else if (strcmp(tag->value(), "loop") == 0) {
 350       inst = read_loop(list);
 351    } else if (strcmp(tag->value(), "return") == 0) {
 352       inst = read_return(list);
 353    } else if (strcmp(tag->value(), "function") == 0) {
 354       inst = read_function(list, false);
 355    } else {
 356       inst = read_rvalue(list);
 357       if (inst == NULL)
 358          ir_read_error(NULL, "when reading instruction");
 359    }
 360    return inst;
 361 }
 362
 363 ir_variable *
 364 ir_reader::read_declaration(s_expression *expr)
 365 {
 366    s_list *s_quals;
 367    s_expression *s_type;
 368    s_symbol *s_name;
 369
 370    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 371    if (!MATCH(expr, pat)) {
 372       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 373       return NULL;
 374    }
 375
 376    const glsl_type *type = read_type(s_type);
 377    if (type == NULL)
 378       return NULL;
 379
 380    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 381                                                ir_var_auto);
 382
 383    foreach_iter(exec_list_iterator, it, s_quals->subexpressions) {
 384       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 385       if (qualifier == NULL) {
 386          ir_read_error(expr, "qualifier list must contain only symbols");
 387          return NULL;
 388       }
 389
 390       // FINISHME: Check for duplicate/conflicting qualifiers.
 391       if (strcmp(qualifier->value(), "centroid") == 0) {
 392          var->centroid = 1;
 393       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 394          var->invariant = 1;
 395       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 396          var->mode = ir_var_uniform;
 397       } else if (strcmp(qualifier->value(), "auto") == 0) {
 398          var->mode = ir_var_auto;
 399       } else if (strcmp(qualifier->value(), "in") == 0) {
 400          var->mode = ir_var_in;
 401       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 402          var->mode = ir_var_const_in;
 403       } else if (strcmp(qualifier->value(), "out") == 0) {
 404          var->mode = ir_var_out;
 405       } else if (strcmp(qualifier->value(), "inout") == 0) {
 406          var->mode = ir_var_inout;
 407       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 408          var->interpolation = INTERP_QUALIFIER_SMOOTH;
 409       } else if (strcmp(qualifier->value(), "flat") == 0) {
 410          var->interpolation = INTERP_QUALIFIER_FLAT;
 411       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 412          var->interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 413       } else {
 414          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 415          return NULL;
 416       }
 417    }
 418
 419    // Add the variable to the symbol table
 420    state->symbols->add_variable(var);
 421
 422    return var;
 423 }
 424
 425
 426 ir_if *
 427 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 428 {
 429    s_expression *s_cond;
 430    s_expression *s_then;
 431    s_expression *s_else;
 432
 433    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 434    if (!MATCH(expr, pat)) {
 435       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 436       return NULL;
 437    }
 438
 439    ir_rvalue *condition = read_rvalue(s_cond);
 440    if (condition == NULL) {
 441       ir_read_error(NULL, "when reading condition of (if ...)");
 442       return NULL;
 443    }
 444
 445    ir_if *iff = new(mem_ctx) ir_if(condition);
 446
 447    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 448    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 449    if (state->error) {
 450       delete iff;
 451       iff = NULL;
 452    }
 453    return iff;
 454 }
 455
 456
 457 ir_loop *
 458 ir_reader::read_loop(s_expression *expr)
 459 {
 460    s_expression *s_counter, *s_from, *s_to, *s_inc, *s_body;
 461
 462    s_pattern pat[] = { "loop", s_counter, s_from, s_to, s_inc, s_body };
 463    if (!MATCH(expr, pat)) {
 464       ir_read_error(expr, "expected (loop <counter> <from> <to> "
 465                           "<increment> <body>)");
 466       return NULL;
 467    }
 468
 469    // FINISHME: actually read the count/from/to fields.
 470
 471    ir_loop *loop = new(mem_ctx) ir_loop;
 472    read_instructions(&loop->body_instructions, s_body, loop);
 473    if (state->error) {
 474       delete loop;
 475       loop = NULL;
 476    }
 477    return loop;
 478 }
 479
 480
 481 ir_return *
 482 ir_reader::read_return(s_expression *expr)
 483 {
 484    s_expression *s_retval;
 485
 486    s_pattern return_value_pat[] = { "return", s_retval};
 487    s_pattern return_void_pat[] = { "return" };
 488    if (MATCH(expr, return_value_pat)) {
 489       ir_rvalue *retval = read_rvalue(s_retval);
 490       if (retval == NULL) {
 491          ir_read_error(NULL, "when reading return value");
 492          return NULL;
 493       }
 494       return new(mem_ctx) ir_return(retval);
 495    } else if (MATCH(expr, return_void_pat)) {
 496       return new(mem_ctx) ir_return;
 497    } else {
 498       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 499       return NULL;
 500    }
 501 }
 502
 503
 504 ir_rvalue *
 505 ir_reader::read_rvalue(s_expression *expr)
 506 {
 507    s_list *list = SX_AS_LIST(expr);
 508    if (list == NULL || list->subexpressions.is_empty())
 509       return NULL;
 510
 511    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 512    if (tag == NULL) {
 513       ir_read_error(expr, "expected rvalue tag");
 514       return NULL;
 515    }
 516
 517    ir_rvalue *rvalue = read_dereference(list);
 518    if (rvalue != NULL || state->error)
 519       return rvalue;
 520    else if (strcmp(tag->value(), "swiz") == 0) {
 521       rvalue = read_swizzle(list);
 522    } else if (strcmp(tag->value(), "expression") == 0) {
 523       rvalue = read_expression(list);
 524    } else if (strcmp(tag->value(), "call") == 0) {
 525       rvalue = read_call(list);
 526    } else if (strcmp(tag->value(), "constant") == 0) {
 527       rvalue = read_constant(list);
 528    } else {
 529       rvalue = read_texture(list);
 530       if (rvalue == NULL && !state->error)
 531          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 532    }
 533
 534    return rvalue;
 535 }
 536
 537 ir_assignment *
 538 ir_reader::read_assignment(s_expression *expr)
 539 {
 540    s_expression *cond_expr = NULL;
 541    s_expression *lhs_expr, *rhs_expr;
 542    s_list       *mask_list;
 543
 544    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 545    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 546    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 547       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 548                           "<lhs> <rhs>)");
 549       return NULL;
 550    }
 551
 552    ir_rvalue *condition = NULL;
 553    if (cond_expr != NULL) {
 554       condition = read_rvalue(cond_expr);
 555       if (condition == NULL) {
 556          ir_read_error(NULL, "when reading condition of assignment");
 557          return NULL;
 558       }
 559    }
 560
 561    unsigned mask = 0;
 562
 563    s_symbol *mask_symbol;
 564    s_pattern mask_pat[] = { mask_symbol };
 565    if (MATCH(mask_list, mask_pat)) {
 566       const char *mask_str = mask_symbol->value();
 567       unsigned mask_length = strlen(mask_str);
 568       if (mask_length > 4) {
 569          ir_read_error(expr, "invalid write mask: %s", mask_str);
 570          return NULL;
 571       }
 572
 573       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 574
 575       for (unsigned i = 0; i < mask_length; i++) {
 576          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 577             ir_read_error(expr, "write mask contains invalid character: %c",
 578                           mask_str[i]);
 579             return NULL;
 580          }
 581          mask |= 1 << idx_map[mask_str[i] - 'w'];
 582       }
 583    } else if (!mask_list->subexpressions.is_empty()) {
 584       ir_read_error(mask_list, "expected () or (<write mask>)");
 585       return NULL;
 586    }
 587
 588    ir_dereference *lhs = read_dereference(lhs_expr);
 589    if (lhs == NULL) {
 590       ir_read_error(NULL, "when reading left-hand side of assignment");
 591       return NULL;
 592    }
 593
 594    ir_rvalue *rhs = read_rvalue(rhs_expr);
 595    if (rhs == NULL) {
 596       ir_read_error(NULL, "when reading right-hand side of assignment");
 597       return NULL;
 598    }
 599
 600    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 601       ir_read_error(expr, "non-zero write mask required.");
 602       return NULL;
 603    }
 604
 605    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 606 }
 607
 608 ir_call *
 609 ir_reader::read_call(s_expression *expr)
 610 {
 611    s_symbol *name;
 612    s_list *params;
 613
 614    s_pattern pat[] = { "call", name, params };
 615    if (!MATCH(expr, pat)) {
 616       ir_read_error(expr, "expected (call <name> (<param> ...))");
 617       return NULL;
 618    }
 619
 620    exec_list parameters;
 621
 622    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 623       s_expression *expr = (s_expression*) it.get();
 624       ir_rvalue *param = read_rvalue(expr);
 625       if (param == NULL) {
 626          ir_read_error(expr, "when reading parameter to function call");
 627          return NULL;
 628       }
 629       parameters.push_tail(param);
 630    }
 631
 632    ir_function *f = state->symbols->get_function(name->value());
 633    if (f == NULL) {
 634       ir_read_error(expr, "found call to undefined function %s",
 635                     name->value());
 636       return NULL;
 637    }
 638
 639    ir_function_signature *callee = f->matching_signature(&parameters);
 640    if (callee == NULL) {
 641       ir_read_error(expr, "couldn't find matching signature for function "
 642                     "%s", name->value());
 643       return NULL;
 644    }
 645
 646    return new(mem_ctx) ir_call(callee, &parameters);
 647 }
 648
 649 ir_expression *
 650 ir_reader::read_expression(s_expression *expr)
 651 {
 652    s_expression *s_type;
 653    s_symbol *s_op;
 654    s_expression *s_arg1;
 655
 656    s_pattern pat[] = { "expression", s_type, s_op, s_arg1 };
 657    if (!PARTIAL_MATCH(expr, pat)) {
 658       ir_read_error(expr, "expected (expression <type> <operator> "
 659                           "<operand> [<operand>])");
 660       return NULL;
 661    }
 662    s_expression *s_arg2 = (s_expression *) s_arg1->next; // may be tail sentinel
 663
 664    const glsl_type *type = read_type(s_type);
 665    if (type == NULL)
 666       return NULL;
 667
 668    /* Read the operator */
 669    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 670    if (op == (ir_expression_operation) -1) {
 671       ir_read_error(expr, "invalid operator: %s", s_op->value());
 672       return NULL;
 673    }
 674
 675    unsigned num_operands = ir_expression::get_num_operands(op);
 676    if (num_operands == 1 && !s_arg1->next->is_tail_sentinel()) {
 677       ir_read_error(expr, "expected (expression <type> %s <operand>)",
 678                     s_op->value());
 679       return NULL;
 680    }
 681
 682    ir_rvalue *arg1 = read_rvalue(s_arg1);
 683    ir_rvalue *arg2 = NULL;
 684    if (arg1 == NULL) {
 685       ir_read_error(NULL, "when reading first operand of %s", s_op->value());
 686       return NULL;
 687    }
 688
 689    if (num_operands == 2) {
 690       if (s_arg2->is_tail_sentinel() || !s_arg2->next->is_tail_sentinel()) {
 691          ir_read_error(expr, "expected (expression <type> %s <operand> "
 692                              "<operand>)", s_op->value());
 693          return NULL;
 694       }
 695       arg2 = read_rvalue(s_arg2);
 696       if (arg2 == NULL) {
 697          ir_read_error(NULL, "when reading second operand of %s",
 698                        s_op->value());
 699          return NULL;
 700       }
 701    }
 702
 703    return new(mem_ctx) ir_expression(op, type, arg1, arg2);
 704 }
 705
 706 ir_swizzle *
 707 ir_reader::read_swizzle(s_expression *expr)
 708 {
 709    s_symbol *swiz;
 710    s_expression *sub;
 711
 712    s_pattern pat[] = { "swiz", swiz, sub };
 713    if (!MATCH(expr, pat)) {
 714       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 715       return NULL;
 716    }
 717
 718    if (strlen(swiz->value()) > 4) {
 719       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 720       return NULL;
 721    }
 722
 723    ir_rvalue *rvalue = read_rvalue(sub);
 724    if (rvalue == NULL)
 725       return NULL;
 726
 727    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 728                                        rvalue->type->vector_elements);
 729    if (ir == NULL)
 730       ir_read_error(expr, "invalid swizzle");
 731
 732    return ir;
 733 }
 734
 735 ir_constant *
 736 ir_reader::read_constant(s_expression *expr)
 737 {
 738    s_expression *type_expr;
 739    s_list *values;
 740
 741    s_pattern pat[] = { "constant", type_expr, values };
 742    if (!MATCH(expr, pat)) {
 743       ir_read_error(expr, "expected (constant <type> (...))");
 744       return NULL;
 745    }
 746
 747    const glsl_type *type = read_type(type_expr);
 748    if (type == NULL)
 749       return NULL;
 750
 751    if (values == NULL) {
 752       ir_read_error(expr, "expected (constant <type> (...))");
 753       return NULL;
 754    }
 755
 756    if (type->is_array()) {
 757       unsigned elements_supplied = 0;
 758       exec_list elements;
 759       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 760          s_expression *elt = (s_expression *) it.get();
 761          ir_constant *ir_elt = read_constant(elt);
 762          if (ir_elt == NULL)
 763             return NULL;
 764          elements.push_tail(ir_elt);
 765          elements_supplied++;
 766       }
 767
 768       if (elements_supplied != type->length) {
 769          ir_read_error(values, "expected exactly %u array elements, "
 770                        "given %u", type->length, elements_supplied);
 771          return NULL;
 772       }
 773       return new(mem_ctx) ir_constant(type, &elements);
 774    }
 775
 776    ir_constant_data data = { { 0 } };
 777
 778    // Read in list of values (at most 16).
 779    unsigned k = 0;
 780    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 781       if (k >= 16) {
 782          ir_read_error(values, "expected at most 16 numbers");
 783          return NULL;
 784       }
 785
 786       s_expression *expr = (s_expression*) it.get();
 787
 788       if (type->base_type == GLSL_TYPE_FLOAT) {
 789          s_number *value = SX_AS_NUMBER(expr);
 790          if (value == NULL) {
 791             ir_read_error(values, "expected numbers");
 792             return NULL;
 793          }
 794          data.f[k] = value->fvalue();
 795       } else {
 796          s_int *value = SX_AS_INT(expr);
 797          if (value == NULL) {
 798             ir_read_error(values, "expected integers");
 799             return NULL;
 800          }
 801
 802          switch (type->base_type) {
 803          case GLSL_TYPE_UINT: {
 804             data.u[k] = value->value();
 805             break;
 806          }
 807          case GLSL_TYPE_INT: {
 808             data.i[k] = value->value();
 809             break;
 810          }
 811          case GLSL_TYPE_BOOL: {
 812             data.b[k] = value->value();
 813             break;
 814          }
 815          default:
 816             ir_read_error(values, "unsupported constant type");
 817             return NULL;
 818          }
 819       }
 820       ++k;
 821    }
 822    if (k != type->components()) {
 823       ir_read_error(values, "expected %u constant values, found %u",
 824                     type->components(), k);
 825       return NULL;
 826    }
 827
 828    return new(mem_ctx) ir_constant(type, &data);
 829 }
 830
 831 ir_dereference *
 832 ir_reader::read_dereference(s_expression *expr)
 833 {
 834    s_symbol *s_var;
 835    s_expression *s_subject;
 836    s_expression *s_index;
 837    s_symbol *s_field;
 838
 839    s_pattern var_pat[] = { "var_ref", s_var };
 840    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 841    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 842
 843    if (MATCH(expr, var_pat)) {
 844       ir_variable *var = state->symbols->get_variable(s_var->value());
 845       if (var == NULL) {
 846          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 847          return NULL;
 848       }
 849       return new(mem_ctx) ir_dereference_variable(var);
 850    } else if (MATCH(expr, array_pat)) {
 851       ir_rvalue *subject = read_rvalue(s_subject);
 852       if (subject == NULL) {
 853          ir_read_error(NULL, "when reading the subject of an array_ref");
 854          return NULL;
 855       }
 856
 857       ir_rvalue *idx = read_rvalue(s_index);
 858       if (subject == NULL) {
 859          ir_read_error(NULL, "when reading the index of an array_ref");
 860          return NULL;
 861       }
 862       return new(mem_ctx) ir_dereference_array(subject, idx);
 863    } else if (MATCH(expr, record_pat)) {
 864       ir_rvalue *subject = read_rvalue(s_subject);
 865       if (subject == NULL) {
 866          ir_read_error(NULL, "when reading the subject of a record_ref");
 867          return NULL;
 868       }
 869       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 870    }
 871    return NULL;
 872 }
 873
 874 ir_texture *
 875 ir_reader::read_texture(s_expression *expr)
 876 {
 877    s_symbol *tag = NULL;
 878    s_expression *s_type = NULL;
 879    s_expression *s_sampler = NULL;
 880    s_expression *s_coord = NULL;
 881    s_expression *s_offset = NULL;
 882    s_expression *s_proj = NULL;
 883    s_list *s_shadow = NULL;
 884    s_expression *s_lod = NULL;
 885
 886    ir_texture_opcode op = ir_tex; /* silence warning */
 887
 888    s_pattern tex_pattern[] =
 889       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 890    s_pattern txf_pattern[] =
 891       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 892    s_pattern txs_pattern[] =
 893       { "txs", s_type, s_sampler, s_lod };
 894    s_pattern other_pattern[] =
 895       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 896
 897    if (MATCH(expr, tex_pattern)) {
 898       op = ir_tex;
 899    } else if (MATCH(expr, txf_pattern)) {
 900       op = ir_txf;
 901    } else if (MATCH(expr, txs_pattern)) {
 902       op = ir_txs;
 903    } else if (MATCH(expr, other_pattern)) {
 904       op = ir_texture::get_opcode(tag->value());
 905       if (op == -1)
 906          return NULL;
 907    } else {
 908       ir_read_error(NULL, "unexpected texture pattern");
 909       return NULL;
 910    }
 911
 912    ir_texture *tex = new(mem_ctx) ir_texture(op);
 913
 914    // Read return type
 915    const glsl_type *type = read_type(s_type);
 916    if (type == NULL) {
 917       ir_read_error(NULL, "when reading type in (%s ...)",
 918                     tex->opcode_string());
 919       return NULL;
 920    }
 921
 922    // Read sampler (must be a deref)
 923    ir_dereference *sampler = read_dereference(s_sampler);
 924    if (sampler == NULL) {
 925       ir_read_error(NULL, "when reading sampler in (%s ...)",
 926                     tex->opcode_string());
 927       return NULL;
 928    }
 929    tex->set_sampler(sampler, type);
 930
 931    if (op != ir_txs) {
 932       // Read coordinate (any rvalue)
 933       tex->coordinate = read_rvalue(s_coord);
 934       if (tex->coordinate == NULL) {
 935          ir_read_error(NULL, "when reading coordinate in (%s ...)",
 936                        tex->opcode_string());
 937          return NULL;
 938       }
 939
 940       // Read texel offset - either 0 or an rvalue.
 941       s_int *si_offset = SX_AS_INT(s_offset);
 942       if (si_offset == NULL || si_offset->value() != 0) {
 943          tex->offset = read_rvalue(s_offset);
 944          if (tex->offset == NULL) {
 945             ir_read_error(s_offset, "expected 0 or an expression");
 946             return NULL;
 947          }
 948       }
 949    }
 950
 951    if (op != ir_txf && op != ir_txs) {
 952       s_int *proj_as_int = SX_AS_INT(s_proj);
 953       if (proj_as_int && proj_as_int->value() == 1) {
 954          tex->projector = NULL;
 955       } else {
 956          tex->projector = read_rvalue(s_proj);
 957          if (tex->projector == NULL) {
 958             ir_read_error(NULL, "when reading projective divide in (%s ..)",
 959                           tex->opcode_string());
 960             return NULL;
 961          }
 962       }
 963
 964       if (s_shadow->subexpressions.is_empty()) {
 965          tex->shadow_comparitor = NULL;
 966       } else {
 967          tex->shadow_comparitor = read_rvalue(s_shadow);
 968          if (tex->shadow_comparitor == NULL) {
 969             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
 970                           tex->opcode_string());
 971             return NULL;
 972          }
 973       }
 974    }
 975
 976    switch (op) {
 977    case ir_txb:
 978       tex->lod_info.bias = read_rvalue(s_lod);
 979       if (tex->lod_info.bias == NULL) {
 980          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
 981          return NULL;
 982       }
 983       break;
 984    case ir_txl:
 985    case ir_txf:
 986    case ir_txs:
 987       tex->lod_info.lod = read_rvalue(s_lod);
 988       if (tex->lod_info.lod == NULL) {
 989          ir_read_error(NULL, "when reading LOD in (%s ...)",
 990                        tex->opcode_string());
 991          return NULL;
 992       }
 993       break;
 994    case ir_txd: {
 995       s_expression *s_dx, *s_dy;
 996       s_pattern dxdy_pat[] = { s_dx, s_dy };
 997       if (!MATCH(s_lod, dxdy_pat)) {
 998          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
 999          return NULL;
1000       }
1001       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1002       if (tex->lod_info.grad.dPdx == NULL) {
1003          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1004          return NULL;
1005       }
1006       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1007       if (tex->lod_info.grad.dPdy == NULL) {
1008          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1009          return NULL;
1010       }
1011       break;
1012    }
1013    default:
1014       // tex doesn't have any extra parameters.
1015       break;
1016    };
1017    return tex;
1018 }