src/glsl/ir_reader.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include <cstdarg>
  25
  26 extern "C" {
  27 #include <talloc.h>
  28 }
  29
  30 #include "ir_reader.h"
  31 #include "glsl_parser_extras.h"
  32 #include "glsl_types.h"
  33 #include "s_expression.h"
  34
  35 const static bool debug = false;
  36
  37 static void ir_read_error(_mesa_glsl_parse_state *, s_expression *,
  38                           const char *fmt, ...);
  39 static const glsl_type *read_type(_mesa_glsl_parse_state *, s_expression *);
  40
  41 static void scan_for_prototypes(_mesa_glsl_parse_state *, exec_list *,
  42                                 s_expression *);
  43 static ir_function *read_function(_mesa_glsl_parse_state *, s_list *,
  44                                   bool skip_body);
  45 static void read_function_sig(_mesa_glsl_parse_state *, ir_function *,
  46                               s_list *, bool skip_body);
  47
  48 static void read_instructions(_mesa_glsl_parse_state *, exec_list *,
  49                               s_expression *, ir_loop *);
  50 static ir_instruction *read_instruction(_mesa_glsl_parse_state *,
  51                                         s_expression *, ir_loop *);
  52 static ir_variable *read_declaration(_mesa_glsl_parse_state *, s_list *);
  53 static ir_if *read_if(_mesa_glsl_parse_state *, s_list *, ir_loop *);
  54 static ir_loop *read_loop(_mesa_glsl_parse_state *st, s_list *list);
  55 static ir_return *read_return(_mesa_glsl_parse_state *, s_list *);
  56
  57 static ir_rvalue *read_rvalue(_mesa_glsl_parse_state *, s_expression *);
  58 static ir_assignment *read_assignment(_mesa_glsl_parse_state *, s_list *);
  59 static ir_expression *read_expression(_mesa_glsl_parse_state *, s_list *);
  60 static ir_call *read_call(_mesa_glsl_parse_state *, s_list *);
  61 static ir_swizzle *read_swizzle(_mesa_glsl_parse_state *, s_list *);
  62 static ir_constant *read_constant(_mesa_glsl_parse_state *, s_list *);
  63 static ir_texture *read_texture(_mesa_glsl_parse_state *, s_list *);
  64
  65 static ir_dereference *read_dereference(_mesa_glsl_parse_state *,
  66                                         s_expression *);
  67 static ir_dereference_variable *
  68 read_var_ref(_mesa_glsl_parse_state *, s_list *);
  69 static ir_dereference_array *
  70 read_array_ref(_mesa_glsl_parse_state *, s_list *);
  71 static ir_dereference_record *
  72 read_record_ref(_mesa_glsl_parse_state *, s_list *);
  73
  74 void
  75 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  76                    const char *src, bool scan_for_protos)
  77 {
  78    s_expression *expr = s_expression::read_expression(state, src);
  79    if (expr == NULL) {
  80       ir_read_error(state, NULL, "couldn't parse S-Expression.");
  81       return;
  82    }
  83
  84    if (scan_for_protos) {
  85       scan_for_prototypes(state, instructions, expr);
  86       if (state->error)
  87          return;
  88    }
  89
  90    read_instructions(state, instructions, expr, NULL);
  91    talloc_free(expr);
  92
  93    if (debug)
  94       validate_ir_tree(instructions);
  95 }
  96
  97 static void
  98 ir_read_error(_mesa_glsl_parse_state *state, s_expression *expr,
  99               const char *fmt, ...)
 100 {
 101    va_list ap;
 102
 103    state->error = true;
 104
 105    if (state->current_function != NULL)
 106       state->info_log = talloc_asprintf_append(state->info_log,
 107                            "In function %s:\n",
 108                            state->current_function->function_name());
 109    state->info_log = talloc_strdup_append(state->info_log, "error: ");
 110
 111    va_start(ap, fmt);
 112    state->info_log = talloc_vasprintf_append(state->info_log, fmt, ap);
 113    va_end(ap);
 114    state->info_log = talloc_strdup_append(state->info_log, "\n");
 115
 116    if (expr != NULL) {
 117       state->info_log = talloc_strdup_append(state->info_log,
 118                                              "...in this context:\n   ");
 119       expr->print();
 120       state->info_log = talloc_strdup_append(state->info_log, "\n\n");
 121    }
 122 }
 123
 124 static const glsl_type *
 125 read_type(_mesa_glsl_parse_state *st, s_expression *expr)
 126 {
 127    s_list *list = SX_AS_LIST(expr);
 128    if (list != NULL) {
 129       s_symbol *type_sym = SX_AS_SYMBOL(list->subexpressions.get_head());
 130       if (type_sym == NULL) {
 131          ir_read_error(st, expr, "expected type (array ...) or (struct ...)");
 132          return NULL;
 133       }
 134       if (strcmp(type_sym->value(), "array") == 0) {
 135          if (list->length() != 3) {
 136             ir_read_error(st, expr, "expected type (array <type> <int>)");
 137             return NULL;
 138          }
 139
 140          // Read base type
 141          s_expression *base_expr = (s_expression*) type_sym->next;
 142          const glsl_type *base_type = read_type(st, base_expr);
 143          if (base_type == NULL) {
 144             ir_read_error(st, NULL, "when reading base type of array");
 145             return NULL;
 146          }
 147
 148          // Read array size
 149          s_int *size = SX_AS_INT(base_expr->next);
 150          if (size == NULL) {
 151             ir_read_error(st, expr, "found non-integer array size");
 152             return NULL;
 153          }
 154
 155          return glsl_type::get_array_instance(base_type, size->value());
 156       } else if (strcmp(type_sym->value(), "struct") == 0) {
 157          assert(false); // FINISHME
 158       } else {
 159          ir_read_error(st, expr, "expected (array ...) or (struct ...); "
 160                                  "found (%s ...)", type_sym->value());
 161          return NULL;
 162       }
 163    }
 164
 165    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 166    if (type_sym == NULL) {
 167       ir_read_error(st, expr, "expected <type> (symbol or list)");
 168       return NULL;
 169    }
 170
 171    const glsl_type *type = st->symbols->get_type(type_sym->value());
 172    if (type == NULL)
 173       ir_read_error(st, expr, "invalid type: %s", type_sym->value());
 174
 175    return type;
 176 }
 177
 178
 179 static void
 180 scan_for_prototypes(_mesa_glsl_parse_state *st, exec_list *instructions,
 181                     s_expression *expr)
 182 {
 183    s_list *list = SX_AS_LIST(expr);
 184    if (list == NULL) {
 185       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 186       return;
 187    }
 188
 189    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 190       s_list *sub = SX_AS_LIST(it.get());
 191       if (sub == NULL)
 192          continue; // not a (function ...); ignore it.
 193
 194       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 195       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 196          continue; // not a (function ...); ignore it.
 197
 198       ir_function *f = read_function(st, sub, true);
 199       if (f == NULL)
 200          return;
 201       instructions->push_tail(f);
 202    }
 203 }
 204
 205 static ir_function *
 206 read_function(_mesa_glsl_parse_state *st, s_list *list, bool skip_body)
 207 {
 208    void *ctx = st;
 209    bool added = false;
 210    if (list->length() < 3) {
 211       ir_read_error(st, list, "Expected (function <name> (signature ...) ...)");
 212       return NULL;
 213    }
 214
 215    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 216    if (name == NULL) {
 217       ir_read_error(st, list, "Expected (function <name> ...)");
 218       return NULL;
 219    }
 220
 221    ir_function *f = st->symbols->get_function(name->value());
 222    if (f == NULL) {
 223       f = new(ctx) ir_function(name->value());
 224       added = st->symbols->add_function(f);
 225       assert(added);
 226    }
 227
 228    exec_list_iterator it = list->subexpressions.iterator();
 229    it.next(); // skip "function" tag
 230    it.next(); // skip function name
 231    for (/* nothing */; it.has_next(); it.next()) {
 232       s_list *siglist = SX_AS_LIST(it.get());
 233       if (siglist == NULL) {
 234          ir_read_error(st, list, "Expected (function (signature ...) ...)");
 235          return NULL;
 236       }
 237
 238       s_symbol *tag = SX_AS_SYMBOL(siglist->subexpressions.get_head());
 239       if (tag == NULL || strcmp(tag->value(), "signature") != 0) {
 240          ir_read_error(st, siglist, "Expected (signature ...)");
 241          return NULL;
 242       }
 243
 244       read_function_sig(st, f, siglist, skip_body);
 245    }
 246    return added ? f : NULL;
 247 }
 248
 249 static void
 250 read_function_sig(_mesa_glsl_parse_state *st, ir_function *f, s_list *list,
 251                   bool skip_body)
 252 {
 253    void *ctx = st;
 254    if (list->length() != 4) {
 255       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 256                               "(<instruction> ...))");
 257       return;
 258    }
 259
 260    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 261    const glsl_type *return_type = read_type(st, type_expr);
 262    if (return_type == NULL)
 263       return;
 264
 265    s_list *paramlist = SX_AS_LIST(type_expr->next);
 266    s_list *body_list = SX_AS_LIST(type_expr->next->next);
 267    if (paramlist == NULL || body_list == NULL) {
 268       ir_read_error(st, list, "Expected (signature <type> (parameters ...) "
 269                               "(<instruction> ...))");
 270       return;
 271    }
 272    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 273    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 274       ir_read_error(st, paramlist, "Expected (parameters ...)");
 275       return;
 276    }
 277
 278    // Read the parameters list into a temporary place.
 279    exec_list hir_parameters;
 280    st->symbols->push_scope();
 281
 282    exec_list_iterator it = paramlist->subexpressions.iterator();
 283    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 284       s_list *decl = SX_AS_LIST(it.get());
 285       ir_variable *var = read_declaration(st, decl);
 286       if (var == NULL)
 287          return;
 288
 289       hir_parameters.push_tail(var);
 290    }
 291
 292    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 293    if (sig == NULL && skip_body) {
 294       /* If scanning for prototypes, generate a new signature. */
 295       sig = new(ctx) ir_function_signature(return_type);
 296       sig->is_builtin = true;
 297       f->add_signature(sig);
 298    } else if (sig != NULL) {
 299       const char *badvar = sig->qualifiers_match(&hir_parameters);
 300       if (badvar != NULL) {
 301          ir_read_error(st, list, "function `%s' parameter `%s' qualifiers "
 302                        "don't match prototype", f->name, badvar);
 303          return;
 304       }
 305
 306       if (sig->return_type != return_type) {
 307          ir_read_error(st, list, "function `%s' return type doesn't "
 308                        "match prototype", f->name);
 309          return;
 310       }
 311    } else {
 312       /* No prototype for this body exists - skip it. */
 313       st->symbols->pop_scope();
 314       return;
 315    }
 316    assert(sig != NULL);
 317
 318    sig->replace_parameters(&hir_parameters);
 319
 320    if (!skip_body && !body_list->subexpressions.is_empty()) {
 321       if (sig->is_defined) {
 322          ir_read_error(st, list, "function %s redefined", f->name);
 323          return;
 324       }
 325       st->current_function = sig;
 326       read_instructions(st, &sig->body, body_list, NULL);
 327       st->current_function = NULL;
 328       sig->is_defined = true;
 329    }
 330
 331    st->symbols->pop_scope();
 332 }
 333
 334 static void
 335 read_instructions(_mesa_glsl_parse_state *st, exec_list *instructions,
 336                   s_expression *expr, ir_loop *loop_ctx)
 337 {
 338    // Read in a list of instructions
 339    s_list *list = SX_AS_LIST(expr);
 340    if (list == NULL) {
 341       ir_read_error(st, expr, "Expected (<instruction> ...); found an atom.");
 342       return;
 343    }
 344
 345    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 346       s_expression *sub = (s_expression*) it.get();
 347       ir_instruction *ir = read_instruction(st, sub, loop_ctx);
 348       if (ir != NULL) {
 349          /* Global variable declarations should be moved to the top, before
 350           * any functions that might use them.  Functions are added to the
 351           * instruction stream when scanning for prototypes, so without this
 352           * hack, they always appear before variable declarations.
 353           */
 354          if (st->current_function == NULL && ir->as_variable() != NULL)
 355             instructions->push_head(ir);
 356          else
 357             instructions->push_tail(ir);
 358       }
 359    }
 360 }
 361
 362
 363 static ir_instruction *
 364 read_instruction(_mesa_glsl_parse_state *st, s_expression *expr,
 365                  ir_loop *loop_ctx)
 366 {
 367    void *ctx = st;
 368    s_symbol *symbol = SX_AS_SYMBOL(expr);
 369    if (symbol != NULL) {
 370       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 371          return new(ctx) ir_loop_jump(ir_loop_jump::jump_break);
 372       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 373          return new(ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 374    }
 375
 376    s_list *list = SX_AS_LIST(expr);
 377    if (list == NULL || list->subexpressions.is_empty()) {
 378       ir_read_error(st, expr, "Invalid instruction.\n");
 379       return NULL;
 380    }
 381
 382    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 383    if (tag == NULL) {
 384       ir_read_error(st, expr, "expected instruction tag");
 385       return NULL;
 386    }
 387
 388    ir_instruction *inst = NULL;
 389    if (strcmp(tag->value(), "declare") == 0) {
 390       inst = read_declaration(st, list);
 391    } else if (strcmp(tag->value(), "assign") == 0) {
 392       inst = read_assignment(st, list);
 393    } else if (strcmp(tag->value(), "if") == 0) {
 394       inst = read_if(st, list, loop_ctx);
 395    } else if (strcmp(tag->value(), "loop") == 0) {
 396       inst = read_loop(st, list);
 397    } else if (strcmp(tag->value(), "return") == 0) {
 398       inst = read_return(st, list);
 399    } else if (strcmp(tag->value(), "function") == 0) {
 400       inst = read_function(st, list, false);
 401    } else {
 402       inst = read_rvalue(st, list);
 403       if (inst == NULL)
 404          ir_read_error(st, NULL, "when reading instruction");
 405    }
 406    return inst;
 407 }
 408
 409
 410 static ir_variable *
 411 read_declaration(_mesa_glsl_parse_state *st, s_list *list)
 412 {
 413    void *ctx = st;
 414    if (list->length() != 4) {
 415       ir_read_error(st, list, "expected (declare (<qualifiers>) <type> "
 416                               "<name>)");
 417       return NULL;
 418    }
 419
 420    s_list *quals = SX_AS_LIST(list->subexpressions.head->next);
 421    if (quals == NULL) {
 422       ir_read_error(st, list, "expected a list of variable qualifiers");
 423       return NULL;
 424    }
 425
 426    s_expression *type_expr = (s_expression*) quals->next;
 427    const glsl_type *type = read_type(st, type_expr);
 428    if (type == NULL)
 429       return NULL;
 430
 431    s_symbol *var_name = SX_AS_SYMBOL(type_expr->next);
 432    if (var_name == NULL) {
 433       ir_read_error(st, list, "expected variable name, found non-symbol");
 434       return NULL;
 435    }
 436
 437    ir_variable *var = new(ctx) ir_variable(type, var_name->value(),
 438                                            ir_var_auto);
 439
 440    foreach_iter(exec_list_iterator, it, quals->subexpressions) {
 441       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 442       if (qualifier == NULL) {
 443          ir_read_error(st, list, "qualifier list must contain only symbols");
 444          delete var;
 445          return NULL;
 446       }
 447
 448       // FINISHME: Check for duplicate/conflicting qualifiers.
 449       if (strcmp(qualifier->value(), "centroid") == 0) {
 450          var->centroid = 1;
 451       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 452          var->invariant = 1;
 453       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 454          var->mode = ir_var_uniform;
 455       } else if (strcmp(qualifier->value(), "auto") == 0) {
 456          var->mode = ir_var_auto;
 457       } else if (strcmp(qualifier->value(), "in") == 0) {
 458          var->mode = ir_var_in;
 459       } else if (strcmp(qualifier->value(), "out") == 0) {
 460          var->mode = ir_var_out;
 461       } else if (strcmp(qualifier->value(), "inout") == 0) {
 462          var->mode = ir_var_inout;
 463       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 464          var->interpolation = ir_var_smooth;
 465       } else if (strcmp(qualifier->value(), "flat") == 0) {
 466          var->interpolation = ir_var_flat;
 467       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 468          var->interpolation = ir_var_noperspective;
 469       } else {
 470          ir_read_error(st, list, "unknown qualifier: %s", qualifier->value());
 471          delete var;
 472          return NULL;
 473       }
 474    }
 475
 476    // Add the variable to the symbol table
 477    st->symbols->add_variable(var);
 478
 479    return var;
 480 }
 481
 482
 483 static ir_if *
 484 read_if(_mesa_glsl_parse_state *st, s_list *list, ir_loop *loop_ctx)
 485 {
 486    void *ctx = st;
 487    if (list->length() != 4) {
 488       ir_read_error(st, list, "expected (if <condition> (<then> ...) "
 489                           "(<else> ...))");
 490       return NULL;
 491    }
 492
 493    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 494    ir_rvalue *condition = read_rvalue(st, cond_expr);
 495    if (condition == NULL) {
 496       ir_read_error(st, NULL, "when reading condition of (if ...)");
 497       return NULL;
 498    }
 499
 500    s_expression *then_expr = (s_expression*) cond_expr->next;
 501    s_expression *else_expr = (s_expression*) then_expr->next;
 502
 503    ir_if *iff = new(ctx) ir_if(condition);
 504
 505    read_instructions(st, &iff->then_instructions, then_expr, loop_ctx);
 506    read_instructions(st, &iff->else_instructions, else_expr, loop_ctx);
 507    if (st->error) {
 508       delete iff;
 509       iff = NULL;
 510    }
 511    return iff;
 512 }
 513
 514
 515 static ir_loop *
 516 read_loop(_mesa_glsl_parse_state *st, s_list *list)
 517 {
 518    void *ctx = st;
 519    if (list->length() != 6) {
 520       ir_read_error(st, list, "expected (loop <counter> <from> <to> "
 521                               "<increment> <body>)");
 522       return NULL;
 523    }
 524
 525    s_expression *count_expr = (s_expression*) list->subexpressions.head->next;
 526    s_expression *from_expr  = (s_expression*) count_expr->next;
 527    s_expression *to_expr    = (s_expression*) from_expr->next;
 528    s_expression *inc_expr   = (s_expression*) to_expr->next;
 529    s_expression *body_expr  = (s_expression*) inc_expr->next;
 530
 531    // FINISHME: actually read the count/from/to fields.
 532
 533    ir_loop *loop = new(ctx) ir_loop;
 534    read_instructions(st, &loop->body_instructions, body_expr, loop);
 535    if (st->error) {
 536       delete loop;
 537       loop = NULL;
 538    }
 539    return loop;
 540 }
 541
 542
 543 static ir_return *
 544 read_return(_mesa_glsl_parse_state *st, s_list *list)
 545 {
 546    void *ctx = st;
 547    if (list->length() != 2) {
 548       ir_read_error(st, list, "expected (return <rvalue>)");
 549       return NULL;
 550    }
 551
 552    s_expression *expr = (s_expression*) list->subexpressions.head->next;
 553
 554    ir_rvalue *retval = read_rvalue(st, expr);
 555    if (retval == NULL) {
 556       ir_read_error(st, NULL, "when reading return value");
 557       return NULL;
 558    }
 559
 560    return new(ctx) ir_return(retval);
 561 }
 562
 563
 564 static ir_rvalue *
 565 read_rvalue(_mesa_glsl_parse_state *st, s_expression *expr)
 566 {
 567    s_list *list = SX_AS_LIST(expr);
 568    if (list == NULL || list->subexpressions.is_empty())
 569       return NULL;
 570
 571    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 572    if (tag == NULL) {
 573       ir_read_error(st, expr, "expected rvalue tag");
 574       return NULL;
 575    }
 576
 577    ir_rvalue *rvalue = read_dereference(st, list);
 578    if (rvalue != NULL || st->error)
 579       return rvalue;
 580    else if (strcmp(tag->value(), "swiz") == 0) {
 581       rvalue = read_swizzle(st, list);
 582    } else if (strcmp(tag->value(), "expression") == 0) {
 583       rvalue = read_expression(st, list);
 584    } else if (strcmp(tag->value(), "call") == 0) {
 585       rvalue = read_call(st, list);
 586    } else if (strcmp(tag->value(), "constant") == 0) {
 587       rvalue = read_constant(st, list);
 588    } else {
 589       rvalue = read_texture(st, list);
 590       if (rvalue == NULL && !st->error)
 591          ir_read_error(st, expr, "unrecognized rvalue tag: %s", tag->value());
 592    }
 593
 594    return rvalue;
 595 }
 596
 597 static ir_assignment *
 598 read_assignment(_mesa_glsl_parse_state *st, s_list *list)
 599 {
 600    void *ctx = st;
 601    if (list->length() != 5) {
 602       ir_read_error(st, list, "expected (assign <condition> (<write mask>) "
 603                               "<lhs> <rhs>)");
 604       return NULL;
 605    }
 606
 607    s_expression *cond_expr = (s_expression*) list->subexpressions.head->next;
 608    s_list       *mask_list = SX_AS_LIST(cond_expr->next);
 609    s_expression *lhs_expr  = (s_expression*) cond_expr->next->next;
 610    s_expression *rhs_expr  = (s_expression*) lhs_expr->next;
 611
 612    ir_rvalue *condition = read_rvalue(st, cond_expr);
 613    if (condition == NULL) {
 614       ir_read_error(st, NULL, "when reading condition of assignment");
 615       return NULL;
 616    }
 617
 618    if (mask_list == NULL || mask_list->length() > 1) {
 619       ir_read_error(st, mask_list, "expected () or (<write mask>)");
 620       return NULL;
 621    }
 622
 623    unsigned mask = 0;
 624    if (mask_list->length() == 1) {
 625       s_symbol *mask_symbol = SX_AS_SYMBOL(mask_list->subexpressions.head);
 626       if (mask_symbol == NULL) {
 627          ir_read_error(st, list, "expected a write mask; found non-symbol");
 628          return NULL;
 629       }
 630
 631       const char *mask_str = mask_symbol->value();
 632       unsigned mask_length = strlen(mask_str);
 633       if (mask_length > 4) {
 634          ir_read_error(st, list, "invalid write mask: %s", mask_str);
 635          return NULL;
 636       }
 637
 638       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 639
 640       for (unsigned i = 0; i < mask_length; i++) {
 641          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 642             ir_read_error(st, list, "write mask contains invalid character: %c",
 643                           mask_str[i]);
 644             return NULL;
 645          }
 646          mask |= 1 << idx_map[mask_str[i] - 'w'];
 647       }
 648    }
 649
 650    ir_dereference *lhs = read_dereference(st, lhs_expr);
 651    if (lhs == NULL) {
 652       ir_read_error(st, NULL, "when reading left-hand side of assignment");
 653       return NULL;
 654    }
 655
 656    ir_rvalue *rhs = read_rvalue(st, rhs_expr);
 657    if (rhs == NULL) {
 658       ir_read_error(st, NULL, "when reading right-hand side of assignment");
 659       return NULL;
 660    }
 661
 662    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 663       ir_read_error(st, list, "non-zero write mask required.");
 664       return NULL;
 665    }
 666
 667    return new(ctx) ir_assignment(lhs, rhs, condition, mask);
 668 }
 669
 670 static ir_call *
 671 read_call(_mesa_glsl_parse_state *st, s_list *list)
 672 {
 673    void *ctx = st;
 674    if (list->length() != 3) {
 675       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 676       return NULL;
 677    }
 678
 679    s_symbol *name = SX_AS_SYMBOL(list->subexpressions.head->next);
 680    s_list *params = SX_AS_LIST(list->subexpressions.head->next->next);
 681    if (name == NULL || params == NULL) {
 682       ir_read_error(st, list, "expected (call <name> (<param> ...))");
 683       return NULL;
 684    }
 685
 686    exec_list parameters;
 687
 688    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 689       s_expression *expr = (s_expression*) it.get();
 690       ir_rvalue *param = read_rvalue(st, expr);
 691       if (param == NULL) {
 692          ir_read_error(st, list, "when reading parameter to function call");
 693          return NULL;
 694       }
 695       parameters.push_tail(param);
 696    }
 697
 698    ir_function *f = st->symbols->get_function(name->value());
 699    if (f == NULL) {
 700       ir_read_error(st, list, "found call to undefined function %s",
 701                     name->value());
 702       return NULL;
 703    }
 704
 705    ir_function_signature *callee = f->matching_signature(&parameters);
 706    if (callee == NULL) {
 707       ir_read_error(st, list, "couldn't find matching signature for function "
 708                     "%s", name->value());
 709       return NULL;
 710    }
 711
 712    return new(ctx) ir_call(callee, &parameters);
 713 }
 714
 715 static ir_expression *
 716 read_expression(_mesa_glsl_parse_state *st, s_list *list)
 717 {
 718    void *ctx = st;
 719    const unsigned list_length = list->length();
 720    if (list_length < 4) {
 721       ir_read_error(st, list, "expected (expression <type> <operator> "
 722                               "<operand> [<operand>])");
 723       return NULL;
 724    }
 725
 726    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 727    const glsl_type *type = read_type(st, type_expr);
 728    if (type == NULL)
 729       return NULL;
 730
 731    /* Read the operator */
 732    s_symbol *op_sym = SX_AS_SYMBOL(type_expr->next);
 733    if (op_sym == NULL) {
 734       ir_read_error(st, list, "expected operator, found non-symbol");
 735       return NULL;
 736    }
 737
 738    ir_expression_operation op = ir_expression::get_operator(op_sym->value());
 739    if (op == (ir_expression_operation) -1) {
 740       ir_read_error(st, list, "invalid operator: %s", op_sym->value());
 741       return NULL;
 742    }
 743
 744    /* Now that we know the operator, check for the right number of operands */
 745    if (ir_expression::get_num_operands(op) == 2) {
 746       if (list_length != 5) {
 747          ir_read_error(st, list, "expected (expression <type> %s <operand> "
 748                                  " <operand>)", op_sym->value());
 749          return NULL;
 750       }
 751    } else {
 752       if (list_length != 4) {
 753          ir_read_error(st, list, "expected (expression <type> %s <operand>)",
 754                        op_sym->value());
 755          return NULL;
 756       }
 757    }
 758
 759    s_expression *exp1 = (s_expression*) (op_sym->next);
 760    ir_rvalue *arg1 = read_rvalue(st, exp1);
 761    if (arg1 == NULL) {
 762       ir_read_error(st, NULL, "when reading first operand of %s",
 763                     op_sym->value());
 764       return NULL;
 765    }
 766
 767    ir_rvalue *arg2 = NULL;
 768    if (ir_expression::get_num_operands(op) == 2) {
 769       s_expression *exp2 = (s_expression*) (exp1->next);
 770       arg2 = read_rvalue(st, exp2);
 771       if (arg2 == NULL) {
 772          ir_read_error(st, NULL, "when reading second operand of %s",
 773                        op_sym->value());
 774          return NULL;
 775       }
 776    }
 777
 778    return new(ctx) ir_expression(op, type, arg1, arg2);
 779 }
 780
 781 static ir_swizzle *
 782 read_swizzle(_mesa_glsl_parse_state *st, s_list *list)
 783 {
 784    if (list->length() != 3) {
 785       ir_read_error(st, list, "expected (swiz <swizzle> <rvalue>)");
 786       return NULL;
 787    }
 788
 789    s_symbol *swiz = SX_AS_SYMBOL(list->subexpressions.head->next);
 790    if (swiz == NULL) {
 791       ir_read_error(st, list, "expected a valid swizzle; found non-symbol");
 792       return NULL;
 793    }
 794
 795    if (strlen(swiz->value()) > 4) {
 796       ir_read_error(st, list, "expected a valid swizzle; found %s",
 797                     swiz->value());
 798       return NULL;
 799    }
 800
 801    s_expression *sub = (s_expression*) swiz->next;
 802    ir_rvalue *rvalue = read_rvalue(st, sub);
 803    if (rvalue == NULL)
 804       return NULL;
 805
 806    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 807                                        rvalue->type->vector_elements);
 808    if (ir == NULL)
 809       ir_read_error(st, list, "invalid swizzle");
 810
 811    return ir;
 812 }
 813
 814 static ir_constant *
 815 read_constant(_mesa_glsl_parse_state *st, s_list *list)
 816 {
 817    void *ctx = st;
 818    if (list->length() != 3) {
 819       ir_read_error(st, list, "expected (constant <type> (...))");
 820       return NULL;
 821    }
 822
 823    s_expression *type_expr = (s_expression*) list->subexpressions.head->next;
 824    const glsl_type *type = read_type(st, type_expr);
 825    if (type == NULL)
 826       return NULL;
 827
 828    s_list *values = SX_AS_LIST(type_expr->next);
 829    if (values == NULL) {
 830       ir_read_error(st, list, "expected (constant <type> (...))");
 831       return NULL;
 832    }
 833
 834    if (type->is_array()) {
 835       const unsigned elements_supplied = values->length();
 836       if (elements_supplied != type->length) {
 837          ir_read_error(st, values, "expected exactly %u array elements, "
 838                        "given %u", type->length, elements_supplied);
 839          return NULL;
 840       }
 841
 842       exec_list elements;
 843       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 844          s_expression *expr = (s_expression *) it.get();
 845          s_list *elt = SX_AS_LIST(expr);
 846          if (elt == NULL) {
 847             ir_read_error(st, expr, "expected (constant ...) array element");
 848             return NULL;
 849          }
 850
 851          ir_constant *ir_elt = read_constant(st, elt);
 852          if (ir_elt == NULL)
 853             return NULL;
 854          elements.push_tail(ir_elt);
 855       }
 856       return new(ctx) ir_constant(type, &elements);
 857    }
 858
 859    const glsl_type *const base_type = type->get_base_type();
 860
 861    ir_constant_data data = { { 0 } };
 862
 863    // Read in list of values (at most 16).
 864    int k = 0;
 865    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 866       if (k >= 16) {
 867          ir_read_error(st, values, "expected at most 16 numbers");
 868          return NULL;
 869       }
 870
 871       s_expression *expr = (s_expression*) it.get();
 872
 873       if (base_type->base_type == GLSL_TYPE_FLOAT) {
 874          s_number *value = SX_AS_NUMBER(expr);
 875          if (value == NULL) {
 876             ir_read_error(st, values, "expected numbers");
 877             return NULL;
 878          }
 879          data.f[k] = value->fvalue();
 880       } else {
 881          s_int *value = SX_AS_INT(expr);
 882          if (value == NULL) {
 883             ir_read_error(st, values, "expected integers");
 884             return NULL;
 885          }
 886
 887          switch (base_type->base_type) {
 888          case GLSL_TYPE_UINT: {
 889             data.u[k] = value->value();
 890             break;
 891          }
 892          case GLSL_TYPE_INT: {
 893             data.i[k] = value->value();
 894             break;
 895          }
 896          case GLSL_TYPE_BOOL: {
 897             data.b[k] = value->value();
 898             break;
 899          }
 900          default:
 901             ir_read_error(st, values, "unsupported constant type");
 902             return NULL;
 903          }
 904       }
 905       ++k;
 906    }
 907
 908    return new(ctx) ir_constant(type, &data);
 909 }
 910
 911 static ir_dereference *
 912 read_dereference(_mesa_glsl_parse_state *st, s_expression *expr)
 913 {
 914    s_list *list = SX_AS_LIST(expr);
 915    if (list == NULL || list->subexpressions.is_empty())
 916       return NULL;
 917
 918    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
 919    assert(tag != NULL);
 920
 921    if (strcmp(tag->value(), "var_ref") == 0)
 922       return read_var_ref(st, list);
 923    if (strcmp(tag->value(), "array_ref") == 0)
 924       return read_array_ref(st, list);
 925    if (strcmp(tag->value(), "record_ref") == 0)
 926       return read_record_ref(st, list);
 927    return NULL;
 928 }
 929
 930 static ir_dereference_variable *
 931 read_var_ref(_mesa_glsl_parse_state *st, s_list *list)
 932 {
 933    void *ctx = st;
 934    if (list->length() != 2) {
 935       ir_read_error(st, list, "expected (var_ref <variable name>)");
 936       return NULL;
 937    }
 938    s_symbol *var_name = SX_AS_SYMBOL(list->subexpressions.head->next);
 939    if (var_name == NULL) {
 940       ir_read_error(st, list, "expected (var_ref <variable name>)");
 941       return NULL;
 942    }
 943
 944    ir_variable *var = st->symbols->get_variable(var_name->value());
 945    if (var == NULL) {
 946       ir_read_error(st, list, "undeclared variable: %s", var_name->value());
 947       return NULL;
 948    }
 949
 950    return new(ctx) ir_dereference_variable(var);
 951 }
 952
 953 static ir_dereference_array *
 954 read_array_ref(_mesa_glsl_parse_state *st, s_list *list)
 955 {
 956    void *ctx = st;
 957    if (list->length() != 3) {
 958       ir_read_error(st, list, "expected (array_ref <rvalue> <index>)");
 959       return NULL;
 960    }
 961
 962    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 963    ir_rvalue *subject = read_rvalue(st, subj_expr);
 964    if (subject == NULL) {
 965       ir_read_error(st, NULL, "when reading the subject of an array_ref");
 966       return NULL;
 967    }
 968
 969    s_expression *idx_expr = (s_expression*) subj_expr->next;
 970    ir_rvalue *idx = read_rvalue(st, idx_expr);
 971    return new(ctx) ir_dereference_array(subject, idx);
 972 }
 973
 974 static ir_dereference_record *
 975 read_record_ref(_mesa_glsl_parse_state *st, s_list *list)
 976 {
 977    void *ctx = st;
 978    if (list->length() != 3) {
 979       ir_read_error(st, list, "expected (record_ref <rvalue> <field>)");
 980       return NULL;
 981    }
 982
 983    s_expression *subj_expr = (s_expression*) list->subexpressions.head->next;
 984    ir_rvalue *subject = read_rvalue(st, subj_expr);
 985    if (subject == NULL) {
 986       ir_read_error(st, NULL, "when reading the subject of a record_ref");
 987       return NULL;
 988    }
 989
 990    s_symbol *field = SX_AS_SYMBOL(subj_expr->next);
 991    if (field == NULL) {
 992       ir_read_error(st, list, "expected (record_ref ... <field name>)");
 993       return NULL;
 994    }
 995    return new(ctx) ir_dereference_record(subject, field->value());
 996 }
 997
 998 static bool
 999 valid_texture_list_length(ir_texture_opcode op, s_list *list)
1000 {
1001    unsigned required_length = 7;
1002    if (op == ir_txf)
1003       required_length = 5;
1004    else if (op == ir_tex)
1005       required_length = 6;
1006
1007    return list->length() == required_length;
1008 }
1009
1010 static ir_texture *
1011 read_texture(_mesa_glsl_parse_state *st, s_list *list)
1012 {
1013    void *ctx = st;
1014    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.head);
1015    assert(tag != NULL);
1016
1017    ir_texture_opcode op = ir_texture::get_opcode(tag->value());
1018    if (op == (ir_texture_opcode) -1)
1019       return NULL;
1020
1021    if (!valid_texture_list_length(op, list)) {
1022       ir_read_error(st, NULL, "invalid list size in (%s ...)", tag->value());
1023       return NULL;
1024    }
1025
1026    ir_texture *tex = new(ctx) ir_texture(op);
1027
1028    // Read sampler (must be a deref)
1029    s_expression *sampler_expr = (s_expression *) tag->next;
1030    ir_dereference *sampler = read_dereference(st, sampler_expr);
1031    if (sampler == NULL) {
1032       ir_read_error(st, NULL, "when reading sampler in (%s ...)", tag->value());
1033       return NULL;
1034    }
1035    tex->set_sampler(sampler);
1036
1037    // Read coordinate (any rvalue)
1038    s_expression *coordinate_expr = (s_expression *) sampler_expr->next;
1039    tex->coordinate = read_rvalue(st, coordinate_expr);
1040    if (tex->coordinate == NULL) {
1041       ir_read_error(st, NULL, "when reading coordinate in (%s ...)",
1042                     tag->value());
1043       return NULL;
1044    }
1045
1046    // Read texel offset, i.e. (0 0 0)
1047    s_list *offset_list = SX_AS_LIST(coordinate_expr->next);
1048    if (offset_list == NULL || offset_list->length() != 3) {
1049       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
1050       return NULL;
1051    }
1052    s_int *offset_x = SX_AS_INT(offset_list->subexpressions.head);
1053    s_int *offset_y = SX_AS_INT(offset_list->subexpressions.head->next);
1054    s_int *offset_z = SX_AS_INT(offset_list->subexpressions.head->next->next);
1055    if (offset_x == NULL || offset_y == NULL || offset_z == NULL) {
1056       ir_read_error(st, offset_list, "expected (<int> <int> <int>)");
1057       return NULL;
1058    }
1059    tex->offsets[0] = offset_x->value();
1060    tex->offsets[1] = offset_y->value();
1061    tex->offsets[2] = offset_z->value();
1062
1063    if (op == ir_txf) {
1064       s_expression *lod_expr = (s_expression *) offset_list->next;
1065       tex->lod_info.lod = read_rvalue(st, lod_expr);
1066       if (tex->lod_info.lod == NULL) {
1067          ir_read_error(st, NULL, "when reading LOD in (txf ...)");
1068          return NULL;
1069       }
1070    } else {
1071       s_expression *proj_expr = (s_expression *) offset_list->next;
1072       s_int *proj_as_int = SX_AS_INT(proj_expr);
1073       if (proj_as_int && proj_as_int->value() == 1) {
1074          tex->projector = NULL;
1075       } else {
1076          tex->projector = read_rvalue(st, proj_expr);
1077          if (tex->projector == NULL) {
1078             ir_read_error(st, NULL, "when reading projective divide in (%s ..)",
1079                           tag->value());
1080             return NULL;
1081          }
1082       }
1083
1084       s_list *shadow_list = SX_AS_LIST(proj_expr->next);
1085       if (shadow_list == NULL) {
1086          ir_read_error(st, NULL, "shadow comparitor must be a list");
1087          return NULL;
1088       }
1089       if (shadow_list->subexpressions.is_empty()) {
1090          tex->shadow_comparitor= NULL;
1091       } else {
1092          tex->shadow_comparitor = read_rvalue(st, shadow_list);
1093          if (tex->shadow_comparitor == NULL) {
1094             ir_read_error(st, NULL, "when reading shadow comparitor in (%s ..)",
1095                           tag->value());
1096             return NULL;
1097          }
1098       }
1099       s_expression *lod_expr = (s_expression *) shadow_list->next;
1100
1101       switch (op) {
1102       case ir_txb:
1103          tex->lod_info.bias = read_rvalue(st, lod_expr);
1104          if (tex->lod_info.bias == NULL) {
1105             ir_read_error(st, NULL, "when reading LOD bias in (txb ...)");
1106             return NULL;
1107          }
1108          break;
1109       case ir_txl:
1110          tex->lod_info.lod = read_rvalue(st, lod_expr);
1111          if (tex->lod_info.lod == NULL) {
1112             ir_read_error(st, NULL, "when reading LOD in (txl ...)");
1113             return NULL;
1114          }
1115          break;
1116       case ir_txd: {
1117          s_list *lod_list = SX_AS_LIST(lod_expr);
1118          if (lod_list->length() != 2) {
1119             ir_read_error(st, lod_expr, "expected (dPdx dPdy) in (txd ...)");
1120             return NULL;
1121          }
1122          s_expression *dx_expr = (s_expression *) lod_list->subexpressions.head;
1123          s_expression *dy_expr = (s_expression *) dx_expr->next;
1124
1125          tex->lod_info.grad.dPdx = read_rvalue(st, dx_expr);
1126          if (tex->lod_info.grad.dPdx == NULL) {
1127             ir_read_error(st, NULL, "when reading dPdx in (txd ...)");
1128             return NULL;
1129          }
1130          tex->lod_info.grad.dPdy = read_rvalue(st, dy_expr);
1131          if (tex->lod_info.grad.dPdy == NULL) {
1132             ir_read_error(st, NULL, "when reading dPdy in (txd ...)");
1133             return NULL;
1134          }
1135          break;
1136       }
1137       default:
1138          // tex doesn't have any extra parameters and txf was handled earlier.
1139          break;
1140       };
1141    }
1142    return tex;
1143 }