src/glsl/ir_reader.cpp

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "ir_reader.h"
  25 #include "glsl_parser_extras.h"
  26 #include "glsl_types.h"
  27 #include "s_expression.h"
  28
  29 const static bool debug = false;
  30
  31 class ir_reader {
  32 public:
  33    ir_reader(_mesa_glsl_parse_state *);
  34
  35    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  36
  37 private:
  38    void *mem_ctx;
  39    _mesa_glsl_parse_state *state;
  40
  41    void ir_read_error(s_expression *, const char *fmt, ...);
  42
  43    const glsl_type *read_type(s_expression *);
  44
  45    void scan_for_prototypes(exec_list *, s_expression *);
  46    ir_function *read_function(s_expression *, bool skip_body);
  47    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  48
  49    void read_instructions(exec_list *, s_expression *, ir_loop *);
  50    ir_instruction *read_instruction(s_expression *, ir_loop *);
  51    ir_variable *read_declaration(s_expression *);
  52    ir_if *read_if(s_expression *, ir_loop *);
  53    ir_loop *read_loop(s_expression *);
  54    ir_call *read_call(s_expression *);
  55    ir_return *read_return(s_expression *);
  56    ir_rvalue *read_rvalue(s_expression *);
  57    ir_assignment *read_assignment(s_expression *);
  58    ir_expression *read_expression(s_expression *);
  59    ir_swizzle *read_swizzle(s_expression *);
  60    ir_constant *read_constant(s_expression *);
  61    ir_texture *read_texture(s_expression *);
  62    ir_emit_vertex *read_emit_vertex(s_expression *);
  63    ir_end_primitive *read_end_primitive(s_expression *);
  64
  65    ir_dereference *read_dereference(s_expression *);
  66    ir_dereference_variable *read_var_ref(s_expression *);
  67 };
  68
  69 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  70 {
  71    this->mem_ctx = state;
  72 }
  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    ir_reader r(state);
  79    r.read(instructions, src, scan_for_protos);
  80 }
  81
  82 void
  83 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  84 {
  85    void *sx_mem_ctx = ralloc_context(NULL);
  86    s_expression *expr = s_expression::read_expression(sx_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    ralloc_free(sx_mem_ctx);
 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       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 114                              state->current_function->function_name());
 115    ralloc_strcat(&state->info_log, "error: ");
 116
 117    va_start(ap, fmt);
 118    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 119    va_end(ap);
 120    ralloc_strcat(&state->info_log, "\n");
 121
 122    if (expr != NULL) {
 123       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 124       expr->print();
 125       ralloc_strcat(&state->info_log, "\n\n");
 126    }
 127 }
 128
 129 const glsl_type *
 130 ir_reader::read_type(s_expression *expr)
 131 {
 132    s_expression *s_base_type;
 133    s_int *s_size;
 134
 135    s_pattern pat[] = { "array", s_base_type, s_size };
 136    if (MATCH(expr, pat)) {
 137       const glsl_type *base_type = read_type(s_base_type);
 138       if (base_type == NULL) {
 139          ir_read_error(NULL, "when reading base type of array type");
 140          return NULL;
 141       }
 142
 143       return glsl_type::get_array_instance(base_type, s_size->value());
 144    }
 145
 146    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 147    if (type_sym == NULL) {
 148       ir_read_error(expr, "expected <type>");
 149       return NULL;
 150    }
 151
 152    const glsl_type *type = state->symbols->get_type(type_sym->value());
 153    if (type == NULL)
 154       ir_read_error(expr, "invalid type: %s", type_sym->value());
 155
 156    return type;
 157 }
 158
 159
 160 void
 161 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 162 {
 163    s_list *list = SX_AS_LIST(expr);
 164    if (list == NULL) {
 165       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 166       return;
 167    }
 168
 169    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 170       s_list *sub = SX_AS_LIST(it.get());
 171       if (sub == NULL)
 172          continue; // not a (function ...); ignore it.
 173
 174       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 175       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 176          continue; // not a (function ...); ignore it.
 177
 178       ir_function *f = read_function(sub, true);
 179       if (f == NULL)
 180          return;
 181       instructions->push_tail(f);
 182    }
 183 }
 184
 185 ir_function *
 186 ir_reader::read_function(s_expression *expr, bool skip_body)
 187 {
 188    bool added = false;
 189    s_symbol *name;
 190
 191    s_pattern pat[] = { "function", name };
 192    if (!PARTIAL_MATCH(expr, pat)) {
 193       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 194       return NULL;
 195    }
 196
 197    ir_function *f = state->symbols->get_function(name->value());
 198    if (f == NULL) {
 199       f = new(mem_ctx) ir_function(name->value());
 200       added = state->symbols->add_function(f);
 201       assert(added);
 202    }
 203
 204    exec_list_iterator it = ((s_list *) expr)->subexpressions.iterator();
 205    it.next(); // skip "function" tag
 206    it.next(); // skip function name
 207    for (/* nothing */; it.has_next(); it.next()) {
 208       s_expression *s_sig = (s_expression *) it.get();
 209       read_function_sig(f, s_sig, skip_body);
 210    }
 211    return added ? f : NULL;
 212 }
 213
 214 static bool
 215 always_available(const _mesa_glsl_parse_state *)
 216 {
 217    return true;
 218 }
 219
 220 void
 221 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 222 {
 223    s_expression *type_expr;
 224    s_list *paramlist;
 225    s_list *body_list;
 226
 227    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 228    if (!MATCH(expr, pat)) {
 229       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 230                           "(<instruction> ...))");
 231       return;
 232    }
 233
 234    const glsl_type *return_type = read_type(type_expr);
 235    if (return_type == NULL)
 236       return;
 237
 238    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 239    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 240       ir_read_error(paramlist, "Expected (parameters ...)");
 241       return;
 242    }
 243
 244    // Read the parameters list into a temporary place.
 245    exec_list hir_parameters;
 246    state->symbols->push_scope();
 247
 248    exec_list_iterator it = paramlist->subexpressions.iterator();
 249    for (it.next() /* skip "parameters" */; it.has_next(); it.next()) {
 250       ir_variable *var = read_declaration((s_expression *) it.get());
 251       if (var == NULL)
 252          return;
 253
 254       hir_parameters.push_tail(var);
 255    }
 256
 257    ir_function_signature *sig = f->exact_matching_signature(&hir_parameters);
 258    if (sig == NULL && skip_body) {
 259       /* If scanning for prototypes, generate a new signature. */
 260       /* ir_reader doesn't know what languages support a given built-in, so
 261        * just say that they're always available.  For now, other mechanisms
 262        * guarantee the right built-ins are available.
 263        */
 264       sig = new(mem_ctx) ir_function_signature(return_type, always_available);
 265       f->add_signature(sig);
 266    } else if (sig != NULL) {
 267       const char *badvar = sig->qualifiers_match(&hir_parameters);
 268       if (badvar != NULL) {
 269          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 270                        "don't match prototype", f->name, badvar);
 271          return;
 272       }
 273
 274       if (sig->return_type != return_type) {
 275          ir_read_error(expr, "function `%s' return type doesn't "
 276                        "match prototype", f->name);
 277          return;
 278       }
 279    } else {
 280       /* No prototype for this body exists - skip it. */
 281       state->symbols->pop_scope();
 282       return;
 283    }
 284    assert(sig != NULL);
 285
 286    sig->replace_parameters(&hir_parameters);
 287
 288    if (!skip_body && !body_list->subexpressions.is_empty()) {
 289       if (sig->is_defined) {
 290          ir_read_error(expr, "function %s redefined", f->name);
 291          return;
 292       }
 293       state->current_function = sig;
 294       read_instructions(&sig->body, body_list, NULL);
 295       state->current_function = NULL;
 296       sig->is_defined = true;
 297    }
 298
 299    state->symbols->pop_scope();
 300 }
 301
 302 void
 303 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 304                              ir_loop *loop_ctx)
 305 {
 306    // Read in a list of instructions
 307    s_list *list = SX_AS_LIST(expr);
 308    if (list == NULL) {
 309       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 310       return;
 311    }
 312
 313    foreach_iter(exec_list_iterator, it, list->subexpressions) {
 314       s_expression *sub = (s_expression*) it.get();
 315       ir_instruction *ir = read_instruction(sub, loop_ctx);
 316       if (ir != NULL) {
 317          /* Global variable declarations should be moved to the top, before
 318           * any functions that might use them.  Functions are added to the
 319           * instruction stream when scanning for prototypes, so without this
 320           * hack, they always appear before variable declarations.
 321           */
 322          if (state->current_function == NULL && ir->as_variable() != NULL)
 323             instructions->push_head(ir);
 324          else
 325             instructions->push_tail(ir);
 326       }
 327    }
 328 }
 329
 330
 331 ir_instruction *
 332 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 333 {
 334    s_symbol *symbol = SX_AS_SYMBOL(expr);
 335    if (symbol != NULL) {
 336       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 337          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 338       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 339          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 340    }
 341
 342    s_list *list = SX_AS_LIST(expr);
 343    if (list == NULL || list->subexpressions.is_empty()) {
 344       ir_read_error(expr, "Invalid instruction.\n");
 345       return NULL;
 346    }
 347
 348    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 349    if (tag == NULL) {
 350       ir_read_error(expr, "expected instruction tag");
 351       return NULL;
 352    }
 353
 354    ir_instruction *inst = NULL;
 355    if (strcmp(tag->value(), "declare") == 0) {
 356       inst = read_declaration(list);
 357    } else if (strcmp(tag->value(), "assign") == 0) {
 358       inst = read_assignment(list);
 359    } else if (strcmp(tag->value(), "if") == 0) {
 360       inst = read_if(list, loop_ctx);
 361    } else if (strcmp(tag->value(), "loop") == 0) {
 362       inst = read_loop(list);
 363    } else if (strcmp(tag->value(), "call") == 0) {
 364       inst = read_call(list);
 365    } else if (strcmp(tag->value(), "return") == 0) {
 366       inst = read_return(list);
 367    } else if (strcmp(tag->value(), "function") == 0) {
 368       inst = read_function(list, false);
 369    } else if (strcmp(tag->value(), "emit-vertex") == 0) {
 370       inst = read_emit_vertex(list);
 371    } else if (strcmp(tag->value(), "end-primitive") == 0) {
 372       inst = read_end_primitive(list);
 373    } else {
 374       inst = read_rvalue(list);
 375       if (inst == NULL)
 376          ir_read_error(NULL, "when reading instruction");
 377    }
 378    return inst;
 379 }
 380
 381 ir_variable *
 382 ir_reader::read_declaration(s_expression *expr)
 383 {
 384    s_list *s_quals;
 385    s_expression *s_type;
 386    s_symbol *s_name;
 387
 388    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 389    if (!MATCH(expr, pat)) {
 390       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 391       return NULL;
 392    }
 393
 394    const glsl_type *type = read_type(s_type);
 395    if (type == NULL)
 396       return NULL;
 397
 398    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 399                                                ir_var_auto);
 400
 401    foreach_iter(exec_list_iterator, it, s_quals->subexpressions) {
 402       s_symbol *qualifier = SX_AS_SYMBOL(it.get());
 403       if (qualifier == NULL) {
 404          ir_read_error(expr, "qualifier list must contain only symbols");
 405          return NULL;
 406       }
 407
 408       // FINISHME: Check for duplicate/conflicting qualifiers.
 409       if (strcmp(qualifier->value(), "centroid") == 0) {
 410          var->centroid = 1;
 411       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 412          var->invariant = 1;
 413       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 414          var->mode = ir_var_uniform;
 415       } else if (strcmp(qualifier->value(), "auto") == 0) {
 416          var->mode = ir_var_auto;
 417       } else if (strcmp(qualifier->value(), "in") == 0) {
 418          var->mode = ir_var_function_in;
 419       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
 420          var->mode = ir_var_shader_in;
 421       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 422          var->mode = ir_var_const_in;
 423       } else if (strcmp(qualifier->value(), "out") == 0) {
 424          var->mode = ir_var_function_out;
 425       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
 426          var->mode = ir_var_shader_out;
 427       } else if (strcmp(qualifier->value(), "inout") == 0) {
 428          var->mode = ir_var_function_inout;
 429       } else if (strcmp(qualifier->value(), "temporary") == 0) {
 430          var->mode = ir_var_temporary;
 431       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 432          var->interpolation = INTERP_QUALIFIER_SMOOTH;
 433       } else if (strcmp(qualifier->value(), "flat") == 0) {
 434          var->interpolation = INTERP_QUALIFIER_FLAT;
 435       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 436          var->interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 437       } else {
 438          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 439          return NULL;
 440       }
 441    }
 442
 443    // Add the variable to the symbol table
 444    state->symbols->add_variable(var);
 445
 446    return var;
 447 }
 448
 449
 450 ir_if *
 451 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 452 {
 453    s_expression *s_cond;
 454    s_expression *s_then;
 455    s_expression *s_else;
 456
 457    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 458    if (!MATCH(expr, pat)) {
 459       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 460       return NULL;
 461    }
 462
 463    ir_rvalue *condition = read_rvalue(s_cond);
 464    if (condition == NULL) {
 465       ir_read_error(NULL, "when reading condition of (if ...)");
 466       return NULL;
 467    }
 468
 469    ir_if *iff = new(mem_ctx) ir_if(condition);
 470
 471    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 472    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 473    if (state->error) {
 474       delete iff;
 475       iff = NULL;
 476    }
 477    return iff;
 478 }
 479
 480
 481 ir_loop *
 482 ir_reader::read_loop(s_expression *expr)
 483 {
 484    s_expression *s_counter, *s_from, *s_to, *s_inc, *s_body;
 485
 486    s_pattern pat[] = { "loop", s_counter, s_from, s_to, s_inc, s_body };
 487    if (!MATCH(expr, pat)) {
 488       ir_read_error(expr, "expected (loop <counter> <from> <to> "
 489                           "<increment> <body>)");
 490       return NULL;
 491    }
 492
 493    // FINISHME: actually read the count/from/to fields.
 494
 495    ir_loop *loop = new(mem_ctx) ir_loop;
 496    read_instructions(&loop->body_instructions, s_body, loop);
 497    if (state->error) {
 498       delete loop;
 499       loop = NULL;
 500    }
 501    return loop;
 502 }
 503
 504
 505 ir_return *
 506 ir_reader::read_return(s_expression *expr)
 507 {
 508    s_expression *s_retval;
 509
 510    s_pattern return_value_pat[] = { "return", s_retval};
 511    s_pattern return_void_pat[] = { "return" };
 512    if (MATCH(expr, return_value_pat)) {
 513       ir_rvalue *retval = read_rvalue(s_retval);
 514       if (retval == NULL) {
 515          ir_read_error(NULL, "when reading return value");
 516          return NULL;
 517       }
 518       return new(mem_ctx) ir_return(retval);
 519    } else if (MATCH(expr, return_void_pat)) {
 520       return new(mem_ctx) ir_return;
 521    } else {
 522       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 523       return NULL;
 524    }
 525 }
 526
 527
 528 ir_rvalue *
 529 ir_reader::read_rvalue(s_expression *expr)
 530 {
 531    s_list *list = SX_AS_LIST(expr);
 532    if (list == NULL || list->subexpressions.is_empty())
 533       return NULL;
 534
 535    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 536    if (tag == NULL) {
 537       ir_read_error(expr, "expected rvalue tag");
 538       return NULL;
 539    }
 540
 541    ir_rvalue *rvalue = read_dereference(list);
 542    if (rvalue != NULL || state->error)
 543       return rvalue;
 544    else if (strcmp(tag->value(), "swiz") == 0) {
 545       rvalue = read_swizzle(list);
 546    } else if (strcmp(tag->value(), "expression") == 0) {
 547       rvalue = read_expression(list);
 548    } else if (strcmp(tag->value(), "constant") == 0) {
 549       rvalue = read_constant(list);
 550    } else {
 551       rvalue = read_texture(list);
 552       if (rvalue == NULL && !state->error)
 553          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 554    }
 555
 556    return rvalue;
 557 }
 558
 559 ir_assignment *
 560 ir_reader::read_assignment(s_expression *expr)
 561 {
 562    s_expression *cond_expr = NULL;
 563    s_expression *lhs_expr, *rhs_expr;
 564    s_list       *mask_list;
 565
 566    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 567    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 568    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 569       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 570                           "<lhs> <rhs>)");
 571       return NULL;
 572    }
 573
 574    ir_rvalue *condition = NULL;
 575    if (cond_expr != NULL) {
 576       condition = read_rvalue(cond_expr);
 577       if (condition == NULL) {
 578          ir_read_error(NULL, "when reading condition of assignment");
 579          return NULL;
 580       }
 581    }
 582
 583    unsigned mask = 0;
 584
 585    s_symbol *mask_symbol;
 586    s_pattern mask_pat[] = { mask_symbol };
 587    if (MATCH(mask_list, mask_pat)) {
 588       const char *mask_str = mask_symbol->value();
 589       unsigned mask_length = strlen(mask_str);
 590       if (mask_length > 4) {
 591          ir_read_error(expr, "invalid write mask: %s", mask_str);
 592          return NULL;
 593       }
 594
 595       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 596
 597       for (unsigned i = 0; i < mask_length; i++) {
 598          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 599             ir_read_error(expr, "write mask contains invalid character: %c",
 600                           mask_str[i]);
 601             return NULL;
 602          }
 603          mask |= 1 << idx_map[mask_str[i] - 'w'];
 604       }
 605    } else if (!mask_list->subexpressions.is_empty()) {
 606       ir_read_error(mask_list, "expected () or (<write mask>)");
 607       return NULL;
 608    }
 609
 610    ir_dereference *lhs = read_dereference(lhs_expr);
 611    if (lhs == NULL) {
 612       ir_read_error(NULL, "when reading left-hand side of assignment");
 613       return NULL;
 614    }
 615
 616    ir_rvalue *rhs = read_rvalue(rhs_expr);
 617    if (rhs == NULL) {
 618       ir_read_error(NULL, "when reading right-hand side of assignment");
 619       return NULL;
 620    }
 621
 622    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 623       ir_read_error(expr, "non-zero write mask required.");
 624       return NULL;
 625    }
 626
 627    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 628 }
 629
 630 ir_call *
 631 ir_reader::read_call(s_expression *expr)
 632 {
 633    s_symbol *name;
 634    s_list *params;
 635    s_list *s_return = NULL;
 636
 637    ir_dereference_variable *return_deref = NULL;
 638
 639    s_pattern void_pat[] = { "call", name, params };
 640    s_pattern non_void_pat[] = { "call", name, s_return, params };
 641    if (MATCH(expr, non_void_pat)) {
 642       return_deref = read_var_ref(s_return);
 643       if (return_deref == NULL) {
 644          ir_read_error(s_return, "when reading a call's return storage");
 645          return NULL;
 646       }
 647    } else if (!MATCH(expr, void_pat)) {
 648       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
 649       return NULL;
 650    }
 651
 652    exec_list parameters;
 653
 654    foreach_iter(exec_list_iterator, it, params->subexpressions) {
 655       s_expression *expr = (s_expression*) it.get();
 656       ir_rvalue *param = read_rvalue(expr);
 657       if (param == NULL) {
 658          ir_read_error(expr, "when reading parameter to function call");
 659          return NULL;
 660       }
 661       parameters.push_tail(param);
 662    }
 663
 664    ir_function *f = state->symbols->get_function(name->value());
 665    if (f == NULL) {
 666       ir_read_error(expr, "found call to undefined function %s",
 667                     name->value());
 668       return NULL;
 669    }
 670
 671    ir_function_signature *callee = f->matching_signature(&parameters);
 672    if (callee == NULL) {
 673       ir_read_error(expr, "couldn't find matching signature for function "
 674                     "%s", name->value());
 675       return NULL;
 676    }
 677
 678    if (callee->return_type == glsl_type::void_type && return_deref) {
 679       ir_read_error(expr, "call has return value storage but void type");
 680       return NULL;
 681    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
 682       ir_read_error(expr, "call has non-void type but no return value storage");
 683       return NULL;
 684    }
 685
 686    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
 687 }
 688
 689 ir_expression *
 690 ir_reader::read_expression(s_expression *expr)
 691 {
 692    s_expression *s_type;
 693    s_symbol *s_op;
 694    s_expression *s_arg[4] = {NULL};
 695
 696    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
 697    if (!PARTIAL_MATCH(expr, pat)) {
 698       ir_read_error(expr, "expected (expression <type> <operator> "
 699                           "<operand> [<operand>] [<operand>] [<operand>])");
 700       return NULL;
 701    }
 702    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
 703    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
 704    if (s_arg[2])
 705       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
 706
 707    const glsl_type *type = read_type(s_type);
 708    if (type == NULL)
 709       return NULL;
 710
 711    /* Read the operator */
 712    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 713    if (op == (ir_expression_operation) -1) {
 714       ir_read_error(expr, "invalid operator: %s", s_op->value());
 715       return NULL;
 716    }
 717
 718    int num_operands = -3; /* skip "expression" <type> <operation> */
 719    foreach_list(n, &((s_list *) expr)->subexpressions)
 720       ++num_operands;
 721
 722    int expected_operands = ir_expression::get_num_operands(op);
 723    if (num_operands != expected_operands) {
 724       ir_read_error(expr, "found %d expression operands, expected %d",
 725                     num_operands, expected_operands);
 726       return NULL;
 727    }
 728
 729    ir_rvalue *arg[4] = {NULL};
 730    for (int i = 0; i < num_operands; i++) {
 731       arg[i] = read_rvalue(s_arg[i]);
 732       if (arg[i] == NULL) {
 733          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
 734          return NULL;
 735       }
 736    }
 737
 738    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
 739 }
 740
 741 ir_swizzle *
 742 ir_reader::read_swizzle(s_expression *expr)
 743 {
 744    s_symbol *swiz;
 745    s_expression *sub;
 746
 747    s_pattern pat[] = { "swiz", swiz, sub };
 748    if (!MATCH(expr, pat)) {
 749       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 750       return NULL;
 751    }
 752
 753    if (strlen(swiz->value()) > 4) {
 754       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 755       return NULL;
 756    }
 757
 758    ir_rvalue *rvalue = read_rvalue(sub);
 759    if (rvalue == NULL)
 760       return NULL;
 761
 762    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 763                                        rvalue->type->vector_elements);
 764    if (ir == NULL)
 765       ir_read_error(expr, "invalid swizzle");
 766
 767    return ir;
 768 }
 769
 770 ir_constant *
 771 ir_reader::read_constant(s_expression *expr)
 772 {
 773    s_expression *type_expr;
 774    s_list *values;
 775
 776    s_pattern pat[] = { "constant", type_expr, values };
 777    if (!MATCH(expr, pat)) {
 778       ir_read_error(expr, "expected (constant <type> (...))");
 779       return NULL;
 780    }
 781
 782    const glsl_type *type = read_type(type_expr);
 783    if (type == NULL)
 784       return NULL;
 785
 786    if (values == NULL) {
 787       ir_read_error(expr, "expected (constant <type> (...))");
 788       return NULL;
 789    }
 790
 791    if (type->is_array()) {
 792       unsigned elements_supplied = 0;
 793       exec_list elements;
 794       foreach_iter(exec_list_iterator, it, values->subexpressions) {
 795          s_expression *elt = (s_expression *) it.get();
 796          ir_constant *ir_elt = read_constant(elt);
 797          if (ir_elt == NULL)
 798             return NULL;
 799          elements.push_tail(ir_elt);
 800          elements_supplied++;
 801       }
 802
 803       if (elements_supplied != type->length) {
 804          ir_read_error(values, "expected exactly %u array elements, "
 805                        "given %u", type->length, elements_supplied);
 806          return NULL;
 807       }
 808       return new(mem_ctx) ir_constant(type, &elements);
 809    }
 810
 811    ir_constant_data data = { { 0 } };
 812
 813    // Read in list of values (at most 16).
 814    unsigned k = 0;
 815    foreach_iter(exec_list_iterator, it, values->subexpressions) {
 816       if (k >= 16) {
 817          ir_read_error(values, "expected at most 16 numbers");
 818          return NULL;
 819       }
 820
 821       s_expression *expr = (s_expression*) it.get();
 822
 823       if (type->base_type == GLSL_TYPE_FLOAT) {
 824          s_number *value = SX_AS_NUMBER(expr);
 825          if (value == NULL) {
 826             ir_read_error(values, "expected numbers");
 827             return NULL;
 828          }
 829          data.f[k] = value->fvalue();
 830       } else {
 831          s_int *value = SX_AS_INT(expr);
 832          if (value == NULL) {
 833             ir_read_error(values, "expected integers");
 834             return NULL;
 835          }
 836
 837          switch (type->base_type) {
 838          case GLSL_TYPE_UINT: {
 839             data.u[k] = value->value();
 840             break;
 841          }
 842          case GLSL_TYPE_INT: {
 843             data.i[k] = value->value();
 844             break;
 845          }
 846          case GLSL_TYPE_BOOL: {
 847             data.b[k] = value->value();
 848             break;
 849          }
 850          default:
 851             ir_read_error(values, "unsupported constant type");
 852             return NULL;
 853          }
 854       }
 855       ++k;
 856    }
 857    if (k != type->components()) {
 858       ir_read_error(values, "expected %u constant values, found %u",
 859                     type->components(), k);
 860       return NULL;
 861    }
 862
 863    return new(mem_ctx) ir_constant(type, &data);
 864 }
 865
 866 ir_dereference_variable *
 867 ir_reader::read_var_ref(s_expression *expr)
 868 {
 869    s_symbol *s_var;
 870    s_pattern var_pat[] = { "var_ref", s_var };
 871
 872    if (MATCH(expr, var_pat)) {
 873       ir_variable *var = state->symbols->get_variable(s_var->value());
 874       if (var == NULL) {
 875          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 876          return NULL;
 877       }
 878       return new(mem_ctx) ir_dereference_variable(var);
 879    }
 880    return NULL;
 881 }
 882
 883 ir_dereference *
 884 ir_reader::read_dereference(s_expression *expr)
 885 {
 886    s_expression *s_subject;
 887    s_expression *s_index;
 888    s_symbol *s_field;
 889
 890    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 891    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 892
 893    ir_dereference_variable *var_ref = read_var_ref(expr);
 894    if (var_ref != NULL) {
 895       return var_ref;
 896    } else if (MATCH(expr, array_pat)) {
 897       ir_rvalue *subject = read_rvalue(s_subject);
 898       if (subject == NULL) {
 899          ir_read_error(NULL, "when reading the subject of an array_ref");
 900          return NULL;
 901       }
 902
 903       ir_rvalue *idx = read_rvalue(s_index);
 904       if (idx == NULL) {
 905          ir_read_error(NULL, "when reading the index of an array_ref");
 906          return NULL;
 907       }
 908       return new(mem_ctx) ir_dereference_array(subject, idx);
 909    } else if (MATCH(expr, record_pat)) {
 910       ir_rvalue *subject = read_rvalue(s_subject);
 911       if (subject == NULL) {
 912          ir_read_error(NULL, "when reading the subject of a record_ref");
 913          return NULL;
 914       }
 915       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 916    }
 917    return NULL;
 918 }
 919
 920 ir_texture *
 921 ir_reader::read_texture(s_expression *expr)
 922 {
 923    s_symbol *tag = NULL;
 924    s_expression *s_type = NULL;
 925    s_expression *s_sampler = NULL;
 926    s_expression *s_coord = NULL;
 927    s_expression *s_offset = NULL;
 928    s_expression *s_proj = NULL;
 929    s_list *s_shadow = NULL;
 930    s_expression *s_lod = NULL;
 931    s_expression *s_sample_index = NULL;
 932
 933    ir_texture_opcode op = ir_tex; /* silence warning */
 934
 935    s_pattern tex_pattern[] =
 936       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 937    s_pattern lod_pattern[] =
 938       { "lod", s_type, s_sampler, s_coord };
 939    s_pattern txf_pattern[] =
 940       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 941    s_pattern txf_ms_pattern[] =
 942       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
 943    s_pattern txs_pattern[] =
 944       { "txs", s_type, s_sampler, s_lod };
 945    s_pattern other_pattern[] =
 946       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 947
 948    if (MATCH(expr, lod_pattern)) {
 949       op = ir_lod;
 950    } else if (MATCH(expr, tex_pattern)) {
 951       op = ir_tex;
 952    } else if (MATCH(expr, txf_pattern)) {
 953       op = ir_txf;
 954    } else if (MATCH(expr, txf_ms_pattern)) {
 955       op = ir_txf_ms;
 956    } else if (MATCH(expr, txs_pattern)) {
 957       op = ir_txs;
 958    } else if (MATCH(expr, other_pattern)) {
 959       op = ir_texture::get_opcode(tag->value());
 960       if (op == -1)
 961          return NULL;
 962    } else {
 963       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
 964       return NULL;
 965    }
 966
 967    ir_texture *tex = new(mem_ctx) ir_texture(op);
 968
 969    // Read return type
 970    const glsl_type *type = read_type(s_type);
 971    if (type == NULL) {
 972       ir_read_error(NULL, "when reading type in (%s ...)",
 973                     tex->opcode_string());
 974       return NULL;
 975    }
 976
 977    // Read sampler (must be a deref)
 978    ir_dereference *sampler = read_dereference(s_sampler);
 979    if (sampler == NULL) {
 980       ir_read_error(NULL, "when reading sampler in (%s ...)",
 981                     tex->opcode_string());
 982       return NULL;
 983    }
 984    tex->set_sampler(sampler, type);
 985
 986    if (op != ir_txs) {
 987       // Read coordinate (any rvalue)
 988       tex->coordinate = read_rvalue(s_coord);
 989       if (tex->coordinate == NULL) {
 990          ir_read_error(NULL, "when reading coordinate in (%s ...)",
 991                        tex->opcode_string());
 992          return NULL;
 993       }
 994
 995       if (op != ir_txf_ms && op != ir_lod) {
 996          // Read texel offset - either 0 or an rvalue.
 997          s_int *si_offset = SX_AS_INT(s_offset);
 998          if (si_offset == NULL || si_offset->value() != 0) {
 999             tex->offset = read_rvalue(s_offset);
1000             if (tex->offset == NULL) {
1001                ir_read_error(s_offset, "expected 0 or an expression");
1002                return NULL;
1003             }
1004          }
1005       }
1006    }
1007
1008    if (op != ir_txf && op != ir_txf_ms && op != ir_txs && op != ir_lod) {
1009       s_int *proj_as_int = SX_AS_INT(s_proj);
1010       if (proj_as_int && proj_as_int->value() == 1) {
1011          tex->projector = NULL;
1012       } else {
1013          tex->projector = read_rvalue(s_proj);
1014          if (tex->projector == NULL) {
1015             ir_read_error(NULL, "when reading projective divide in (%s ..)",
1016                           tex->opcode_string());
1017             return NULL;
1018          }
1019       }
1020
1021       if (s_shadow->subexpressions.is_empty()) {
1022          tex->shadow_comparitor = NULL;
1023       } else {
1024          tex->shadow_comparitor = read_rvalue(s_shadow);
1025          if (tex->shadow_comparitor == NULL) {
1026             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
1027                           tex->opcode_string());
1028             return NULL;
1029          }
1030       }
1031    }
1032
1033    switch (op) {
1034    case ir_txb:
1035       tex->lod_info.bias = read_rvalue(s_lod);
1036       if (tex->lod_info.bias == NULL) {
1037          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
1038          return NULL;
1039       }
1040       break;
1041    case ir_txl:
1042    case ir_txf:
1043    case ir_txs:
1044       tex->lod_info.lod = read_rvalue(s_lod);
1045       if (tex->lod_info.lod == NULL) {
1046          ir_read_error(NULL, "when reading LOD in (%s ...)",
1047                        tex->opcode_string());
1048          return NULL;
1049       }
1050       break;
1051    case ir_txf_ms:
1052       tex->lod_info.sample_index = read_rvalue(s_sample_index);
1053       if (tex->lod_info.sample_index == NULL) {
1054          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
1055          return NULL;
1056       }
1057       break;
1058    case ir_txd: {
1059       s_expression *s_dx, *s_dy;
1060       s_pattern dxdy_pat[] = { s_dx, s_dy };
1061       if (!MATCH(s_lod, dxdy_pat)) {
1062          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
1063          return NULL;
1064       }
1065       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1066       if (tex->lod_info.grad.dPdx == NULL) {
1067          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1068          return NULL;
1069       }
1070       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1071       if (tex->lod_info.grad.dPdy == NULL) {
1072          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1073          return NULL;
1074       }
1075       break;
1076    }
1077    default:
1078       // tex and lod don't have any extra parameters.
1079       break;
1080    };
1081    return tex;
1082 }
1083
1084 ir_emit_vertex *
1085 ir_reader::read_emit_vertex(s_expression *expr)
1086 {
1087    s_pattern pat[] = { "emit-vertex" };
1088
1089    if (MATCH(expr, pat)) {
1090       return new(mem_ctx) ir_emit_vertex();
1091    }
1092    ir_read_error(NULL, "when reading emit-vertex");
1093    return NULL;
1094 }
1095
1096 ir_end_primitive *
1097 ir_reader::read_end_primitive(s_expression *expr)
1098 {
1099    s_pattern pat[] = { "end-primitive" };
1100
1101    if (MATCH(expr, pat)) {
1102       return new(mem_ctx) ir_end_primitive();
1103    }
1104    ir_read_error(NULL, "when reading end-primitive");
1105    return NULL;
1106 }