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 namespace {
  32
  33 class ir_reader {
  34 public:
  35    ir_reader(_mesa_glsl_parse_state *);
  36
  37    void read(exec_list *instructions, const char *src, bool scan_for_protos);
  38
  39 private:
  40    void *mem_ctx;
  41    _mesa_glsl_parse_state *state;
  42
  43    void ir_read_error(s_expression *, const char *fmt, ...);
  44
  45    const glsl_type *read_type(s_expression *);
  46
  47    void scan_for_prototypes(exec_list *, s_expression *);
  48    ir_function *read_function(s_expression *, bool skip_body);
  49    void read_function_sig(ir_function *, s_expression *, bool skip_body);
  50
  51    void read_instructions(exec_list *, s_expression *, ir_loop *);
  52    ir_instruction *read_instruction(s_expression *, ir_loop *);
  53    ir_variable *read_declaration(s_expression *);
  54    ir_if *read_if(s_expression *, ir_loop *);
  55    ir_loop *read_loop(s_expression *);
  56    ir_call *read_call(s_expression *);
  57    ir_return *read_return(s_expression *);
  58    ir_rvalue *read_rvalue(s_expression *);
  59    ir_assignment *read_assignment(s_expression *);
  60    ir_expression *read_expression(s_expression *);
  61    ir_swizzle *read_swizzle(s_expression *);
  62    ir_constant *read_constant(s_expression *);
  63    ir_texture *read_texture(s_expression *);
  64    ir_emit_vertex *read_emit_vertex(s_expression *);
  65    ir_end_primitive *read_end_primitive(s_expression *);
  66
  67    ir_dereference *read_dereference(s_expression *);
  68    ir_dereference_variable *read_var_ref(s_expression *);
  69 };
  70
  71 } /* anonymous namespace */
  72
  73 ir_reader::ir_reader(_mesa_glsl_parse_state *state) : state(state)
  74 {
  75    this->mem_ctx = state;
  76 }
  77
  78 void
  79 _mesa_glsl_read_ir(_mesa_glsl_parse_state *state, exec_list *instructions,
  80                    const char *src, bool scan_for_protos)
  81 {
  82    ir_reader r(state);
  83    r.read(instructions, src, scan_for_protos);
  84 }
  85
  86 void
  87 ir_reader::read(exec_list *instructions, const char *src, bool scan_for_protos)
  88 {
  89    void *sx_mem_ctx = ralloc_context(NULL);
  90    s_expression *expr = s_expression::read_expression(sx_mem_ctx, src);
  91    if (expr == NULL) {
  92       ir_read_error(NULL, "couldn't parse S-Expression.");
  93       return;
  94    }
  95
  96    if (scan_for_protos) {
  97       scan_for_prototypes(instructions, expr);
  98       if (state->error)
  99          return;
 100    }
 101
 102    read_instructions(instructions, expr, NULL);
 103    ralloc_free(sx_mem_ctx);
 104
 105    if (debug)
 106       validate_ir_tree(instructions);
 107 }
 108
 109 void
 110 ir_reader::ir_read_error(s_expression *expr, const char *fmt, ...)
 111 {
 112    va_list ap;
 113
 114    state->error = true;
 115
 116    if (state->current_function != NULL)
 117       ralloc_asprintf_append(&state->info_log, "In function %s:\n",
 118                              state->current_function->function_name());
 119    ralloc_strcat(&state->info_log, "error: ");
 120
 121    va_start(ap, fmt);
 122    ralloc_vasprintf_append(&state->info_log, fmt, ap);
 123    va_end(ap);
 124    ralloc_strcat(&state->info_log, "\n");
 125
 126    if (expr != NULL) {
 127       ralloc_strcat(&state->info_log, "...in this context:\n   ");
 128       expr->print();
 129       ralloc_strcat(&state->info_log, "\n\n");
 130    }
 131 }
 132
 133 const glsl_type *
 134 ir_reader::read_type(s_expression *expr)
 135 {
 136    s_expression *s_base_type;
 137    s_int *s_size;
 138
 139    s_pattern pat[] = { "array", s_base_type, s_size };
 140    if (MATCH(expr, pat)) {
 141       const glsl_type *base_type = read_type(s_base_type);
 142       if (base_type == NULL) {
 143          ir_read_error(NULL, "when reading base type of array type");
 144          return NULL;
 145       }
 146
 147       return glsl_type::get_array_instance(base_type, s_size->value());
 148    }
 149
 150    s_symbol *type_sym = SX_AS_SYMBOL(expr);
 151    if (type_sym == NULL) {
 152       ir_read_error(expr, "expected <type>");
 153       return NULL;
 154    }
 155
 156    const glsl_type *type = state->symbols->get_type(type_sym->value());
 157    if (type == NULL)
 158       ir_read_error(expr, "invalid type: %s", type_sym->value());
 159
 160    return type;
 161 }
 162
 163
 164 void
 165 ir_reader::scan_for_prototypes(exec_list *instructions, s_expression *expr)
 166 {
 167    s_list *list = SX_AS_LIST(expr);
 168    if (list == NULL) {
 169       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 170       return;
 171    }
 172
 173    foreach_list(n, &list->subexpressions) {
 174       s_list *sub = SX_AS_LIST(n);
 175       if (sub == NULL)
 176          continue; // not a (function ...); ignore it.
 177
 178       s_symbol *tag = SX_AS_SYMBOL(sub->subexpressions.get_head());
 179       if (tag == NULL || strcmp(tag->value(), "function") != 0)
 180          continue; // not a (function ...); ignore it.
 181
 182       ir_function *f = read_function(sub, true);
 183       if (f == NULL)
 184          return;
 185       instructions->push_tail(f);
 186    }
 187 }
 188
 189 ir_function *
 190 ir_reader::read_function(s_expression *expr, bool skip_body)
 191 {
 192    bool added = false;
 193    s_symbol *name;
 194
 195    s_pattern pat[] = { "function", name };
 196    if (!PARTIAL_MATCH(expr, pat)) {
 197       ir_read_error(expr, "Expected (function <name> (signature ...) ...)");
 198       return NULL;
 199    }
 200
 201    ir_function *f = state->symbols->get_function(name->value());
 202    if (f == NULL) {
 203       f = new(mem_ctx) ir_function(name->value());
 204       added = state->symbols->add_function(f);
 205       assert(added);
 206    }
 207
 208    /* Skip over "function" tag and function name (which are guaranteed to be
 209     * present by the above PARTIAL_MATCH call).
 210     */
 211    exec_node *node = ((s_list *) expr)->subexpressions.head->next->next;
 212    for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
 213       s_expression *s_sig = (s_expression *) node;
 214       read_function_sig(f, s_sig, skip_body);
 215    }
 216    return added ? f : NULL;
 217 }
 218
 219 static bool
 220 always_available(const _mesa_glsl_parse_state *)
 221 {
 222    return true;
 223 }
 224
 225 void
 226 ir_reader::read_function_sig(ir_function *f, s_expression *expr, bool skip_body)
 227 {
 228    s_expression *type_expr;
 229    s_list *paramlist;
 230    s_list *body_list;
 231
 232    s_pattern pat[] = { "signature", type_expr, paramlist, body_list };
 233    if (!MATCH(expr, pat)) {
 234       ir_read_error(expr, "Expected (signature <type> (parameters ...) "
 235                           "(<instruction> ...))");
 236       return;
 237    }
 238
 239    const glsl_type *return_type = read_type(type_expr);
 240    if (return_type == NULL)
 241       return;
 242
 243    s_symbol *paramtag = SX_AS_SYMBOL(paramlist->subexpressions.get_head());
 244    if (paramtag == NULL || strcmp(paramtag->value(), "parameters") != 0) {
 245       ir_read_error(paramlist, "Expected (parameters ...)");
 246       return;
 247    }
 248
 249    // Read the parameters list into a temporary place.
 250    exec_list hir_parameters;
 251    state->symbols->push_scope();
 252
 253    /* Skip over the "parameters" tag. */
 254    exec_node *node = paramlist->subexpressions.head->next;
 255    for (/* nothing */; !node->is_tail_sentinel(); node = node->next) {
 256       ir_variable *var = read_declaration((s_expression *) node);
 257       if (var == NULL)
 258          return;
 259
 260       hir_parameters.push_tail(var);
 261    }
 262
 263    ir_function_signature *sig =
 264       f->exact_matching_signature(state, &hir_parameters);
 265    if (sig == NULL && skip_body) {
 266       /* If scanning for prototypes, generate a new signature. */
 267       /* ir_reader doesn't know what languages support a given built-in, so
 268        * just say that they're always available.  For now, other mechanisms
 269        * guarantee the right built-ins are available.
 270        */
 271       sig = new(mem_ctx) ir_function_signature(return_type, always_available);
 272       f->add_signature(sig);
 273    } else if (sig != NULL) {
 274       const char *badvar = sig->qualifiers_match(&hir_parameters);
 275       if (badvar != NULL) {
 276          ir_read_error(expr, "function `%s' parameter `%s' qualifiers "
 277                        "don't match prototype", f->name, badvar);
 278          return;
 279       }
 280
 281       if (sig->return_type != return_type) {
 282          ir_read_error(expr, "function `%s' return type doesn't "
 283                        "match prototype", f->name);
 284          return;
 285       }
 286    } else {
 287       /* No prototype for this body exists - skip it. */
 288       state->symbols->pop_scope();
 289       return;
 290    }
 291    assert(sig != NULL);
 292
 293    sig->replace_parameters(&hir_parameters);
 294
 295    if (!skip_body && !body_list->subexpressions.is_empty()) {
 296       if (sig->is_defined) {
 297          ir_read_error(expr, "function %s redefined", f->name);
 298          return;
 299       }
 300       state->current_function = sig;
 301       read_instructions(&sig->body, body_list, NULL);
 302       state->current_function = NULL;
 303       sig->is_defined = true;
 304    }
 305
 306    state->symbols->pop_scope();
 307 }
 308
 309 void
 310 ir_reader::read_instructions(exec_list *instructions, s_expression *expr,
 311                              ir_loop *loop_ctx)
 312 {
 313    // Read in a list of instructions
 314    s_list *list = SX_AS_LIST(expr);
 315    if (list == NULL) {
 316       ir_read_error(expr, "Expected (<instruction> ...); found an atom.");
 317       return;
 318    }
 319
 320    foreach_list(n, &list->subexpressions) {
 321       s_expression *sub = (s_expression *) n;
 322       ir_instruction *ir = read_instruction(sub, loop_ctx);
 323       if (ir != NULL) {
 324          /* Global variable declarations should be moved to the top, before
 325           * any functions that might use them.  Functions are added to the
 326           * instruction stream when scanning for prototypes, so without this
 327           * hack, they always appear before variable declarations.
 328           */
 329          if (state->current_function == NULL && ir->as_variable() != NULL)
 330             instructions->push_head(ir);
 331          else
 332             instructions->push_tail(ir);
 333       }
 334    }
 335 }
 336
 337
 338 ir_instruction *
 339 ir_reader::read_instruction(s_expression *expr, ir_loop *loop_ctx)
 340 {
 341    s_symbol *symbol = SX_AS_SYMBOL(expr);
 342    if (symbol != NULL) {
 343       if (strcmp(symbol->value(), "break") == 0 && loop_ctx != NULL)
 344          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_break);
 345       if (strcmp(symbol->value(), "continue") == 0 && loop_ctx != NULL)
 346          return new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
 347    }
 348
 349    s_list *list = SX_AS_LIST(expr);
 350    if (list == NULL || list->subexpressions.is_empty()) {
 351       ir_read_error(expr, "Invalid instruction.\n");
 352       return NULL;
 353    }
 354
 355    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 356    if (tag == NULL) {
 357       ir_read_error(expr, "expected instruction tag");
 358       return NULL;
 359    }
 360
 361    ir_instruction *inst = NULL;
 362    if (strcmp(tag->value(), "declare") == 0) {
 363       inst = read_declaration(list);
 364    } else if (strcmp(tag->value(), "assign") == 0) {
 365       inst = read_assignment(list);
 366    } else if (strcmp(tag->value(), "if") == 0) {
 367       inst = read_if(list, loop_ctx);
 368    } else if (strcmp(tag->value(), "loop") == 0) {
 369       inst = read_loop(list);
 370    } else if (strcmp(tag->value(), "call") == 0) {
 371       inst = read_call(list);
 372    } else if (strcmp(tag->value(), "return") == 0) {
 373       inst = read_return(list);
 374    } else if (strcmp(tag->value(), "function") == 0) {
 375       inst = read_function(list, false);
 376    } else if (strcmp(tag->value(), "emit-vertex") == 0) {
 377       inst = read_emit_vertex(list);
 378    } else if (strcmp(tag->value(), "end-primitive") == 0) {
 379       inst = read_end_primitive(list);
 380    } else {
 381       inst = read_rvalue(list);
 382       if (inst == NULL)
 383          ir_read_error(NULL, "when reading instruction");
 384    }
 385    return inst;
 386 }
 387
 388 ir_variable *
 389 ir_reader::read_declaration(s_expression *expr)
 390 {
 391    s_list *s_quals;
 392    s_expression *s_type;
 393    s_symbol *s_name;
 394
 395    s_pattern pat[] = { "declare", s_quals, s_type, s_name };
 396    if (!MATCH(expr, pat)) {
 397       ir_read_error(expr, "expected (declare (<qualifiers>) <type> <name>)");
 398       return NULL;
 399    }
 400
 401    const glsl_type *type = read_type(s_type);
 402    if (type == NULL)
 403       return NULL;
 404
 405    ir_variable *var = new(mem_ctx) ir_variable(type, s_name->value(),
 406                                                ir_var_auto);
 407
 408    foreach_list(n, &s_quals->subexpressions) {
 409       s_symbol *qualifier = SX_AS_SYMBOL(n);
 410       if (qualifier == NULL) {
 411          ir_read_error(expr, "qualifier list must contain only symbols");
 412          return NULL;
 413       }
 414
 415       // FINISHME: Check for duplicate/conflicting qualifiers.
 416       if (strcmp(qualifier->value(), "centroid") == 0) {
 417          var->data.centroid = 1;
 418       } else if (strcmp(qualifier->value(), "sample") == 0) {
 419          var->data.sample = 1;
 420       } else if (strcmp(qualifier->value(), "invariant") == 0) {
 421          var->data.invariant = 1;
 422       } else if (strcmp(qualifier->value(), "uniform") == 0) {
 423          var->data.mode = ir_var_uniform;
 424       } else if (strcmp(qualifier->value(), "auto") == 0) {
 425          var->data.mode = ir_var_auto;
 426       } else if (strcmp(qualifier->value(), "in") == 0) {
 427          var->data.mode = ir_var_function_in;
 428       } else if (strcmp(qualifier->value(), "shader_in") == 0) {
 429          var->data.mode = ir_var_shader_in;
 430       } else if (strcmp(qualifier->value(), "const_in") == 0) {
 431          var->data.mode = ir_var_const_in;
 432       } else if (strcmp(qualifier->value(), "out") == 0) {
 433          var->data.mode = ir_var_function_out;
 434       } else if (strcmp(qualifier->value(), "shader_out") == 0) {
 435          var->data.mode = ir_var_shader_out;
 436       } else if (strcmp(qualifier->value(), "inout") == 0) {
 437          var->data.mode = ir_var_function_inout;
 438       } else if (strcmp(qualifier->value(), "temporary") == 0) {
 439          var->data.mode = ir_var_temporary;
 440       } else if (strcmp(qualifier->value(), "stream1") == 0) {
 441          var->data.stream = 1;
 442       } else if (strcmp(qualifier->value(), "stream2") == 0) {
 443          var->data.stream = 2;
 444       } else if (strcmp(qualifier->value(), "stream3") == 0) {
 445          var->data.stream = 3;
 446       } else if (strcmp(qualifier->value(), "smooth") == 0) {
 447          var->data.interpolation = INTERP_QUALIFIER_SMOOTH;
 448       } else if (strcmp(qualifier->value(), "flat") == 0) {
 449          var->data.interpolation = INTERP_QUALIFIER_FLAT;
 450       } else if (strcmp(qualifier->value(), "noperspective") == 0) {
 451          var->data.interpolation = INTERP_QUALIFIER_NOPERSPECTIVE;
 452       } else {
 453          ir_read_error(expr, "unknown qualifier: %s", qualifier->value());
 454          return NULL;
 455       }
 456    }
 457
 458    // Add the variable to the symbol table
 459    state->symbols->add_variable(var);
 460
 461    return var;
 462 }
 463
 464
 465 ir_if *
 466 ir_reader::read_if(s_expression *expr, ir_loop *loop_ctx)
 467 {
 468    s_expression *s_cond;
 469    s_expression *s_then;
 470    s_expression *s_else;
 471
 472    s_pattern pat[] = { "if", s_cond, s_then, s_else };
 473    if (!MATCH(expr, pat)) {
 474       ir_read_error(expr, "expected (if <condition> (<then>...) (<else>...))");
 475       return NULL;
 476    }
 477
 478    ir_rvalue *condition = read_rvalue(s_cond);
 479    if (condition == NULL) {
 480       ir_read_error(NULL, "when reading condition of (if ...)");
 481       return NULL;
 482    }
 483
 484    ir_if *iff = new(mem_ctx) ir_if(condition);
 485
 486    read_instructions(&iff->then_instructions, s_then, loop_ctx);
 487    read_instructions(&iff->else_instructions, s_else, loop_ctx);
 488    if (state->error) {
 489       delete iff;
 490       iff = NULL;
 491    }
 492    return iff;
 493 }
 494
 495
 496 ir_loop *
 497 ir_reader::read_loop(s_expression *expr)
 498 {
 499    s_expression *s_body;
 500
 501    s_pattern loop_pat[] = { "loop", s_body };
 502    if (!MATCH(expr, loop_pat)) {
 503       ir_read_error(expr, "expected (loop <body>)");
 504       return NULL;
 505    }
 506
 507    ir_loop *loop = new(mem_ctx) ir_loop;
 508
 509    read_instructions(&loop->body_instructions, s_body, loop);
 510    if (state->error) {
 511       delete loop;
 512       loop = NULL;
 513    }
 514    return loop;
 515 }
 516
 517
 518 ir_return *
 519 ir_reader::read_return(s_expression *expr)
 520 {
 521    s_expression *s_retval;
 522
 523    s_pattern return_value_pat[] = { "return", s_retval};
 524    s_pattern return_void_pat[] = { "return" };
 525    if (MATCH(expr, return_value_pat)) {
 526       ir_rvalue *retval = read_rvalue(s_retval);
 527       if (retval == NULL) {
 528          ir_read_error(NULL, "when reading return value");
 529          return NULL;
 530       }
 531       return new(mem_ctx) ir_return(retval);
 532    } else if (MATCH(expr, return_void_pat)) {
 533       return new(mem_ctx) ir_return;
 534    } else {
 535       ir_read_error(expr, "expected (return <rvalue>) or (return)");
 536       return NULL;
 537    }
 538 }
 539
 540
 541 ir_rvalue *
 542 ir_reader::read_rvalue(s_expression *expr)
 543 {
 544    s_list *list = SX_AS_LIST(expr);
 545    if (list == NULL || list->subexpressions.is_empty())
 546       return NULL;
 547
 548    s_symbol *tag = SX_AS_SYMBOL(list->subexpressions.get_head());
 549    if (tag == NULL) {
 550       ir_read_error(expr, "expected rvalue tag");
 551       return NULL;
 552    }
 553
 554    ir_rvalue *rvalue = read_dereference(list);
 555    if (rvalue != NULL || state->error)
 556       return rvalue;
 557    else if (strcmp(tag->value(), "swiz") == 0) {
 558       rvalue = read_swizzle(list);
 559    } else if (strcmp(tag->value(), "expression") == 0) {
 560       rvalue = read_expression(list);
 561    } else if (strcmp(tag->value(), "constant") == 0) {
 562       rvalue = read_constant(list);
 563    } else {
 564       rvalue = read_texture(list);
 565       if (rvalue == NULL && !state->error)
 566          ir_read_error(expr, "unrecognized rvalue tag: %s", tag->value());
 567    }
 568
 569    return rvalue;
 570 }
 571
 572 ir_assignment *
 573 ir_reader::read_assignment(s_expression *expr)
 574 {
 575    s_expression *cond_expr = NULL;
 576    s_expression *lhs_expr, *rhs_expr;
 577    s_list       *mask_list;
 578
 579    s_pattern pat4[] = { "assign",            mask_list, lhs_expr, rhs_expr };
 580    s_pattern pat5[] = { "assign", cond_expr, mask_list, lhs_expr, rhs_expr };
 581    if (!MATCH(expr, pat4) && !MATCH(expr, pat5)) {
 582       ir_read_error(expr, "expected (assign [<condition>] (<write mask>) "
 583                           "<lhs> <rhs>)");
 584       return NULL;
 585    }
 586
 587    ir_rvalue *condition = NULL;
 588    if (cond_expr != NULL) {
 589       condition = read_rvalue(cond_expr);
 590       if (condition == NULL) {
 591          ir_read_error(NULL, "when reading condition of assignment");
 592          return NULL;
 593       }
 594    }
 595
 596    unsigned mask = 0;
 597
 598    s_symbol *mask_symbol;
 599    s_pattern mask_pat[] = { mask_symbol };
 600    if (MATCH(mask_list, mask_pat)) {
 601       const char *mask_str = mask_symbol->value();
 602       unsigned mask_length = strlen(mask_str);
 603       if (mask_length > 4) {
 604          ir_read_error(expr, "invalid write mask: %s", mask_str);
 605          return NULL;
 606       }
 607
 608       const unsigned idx_map[] = { 3, 0, 1, 2 }; /* w=bit 3, x=0, y=1, z=2 */
 609
 610       for (unsigned i = 0; i < mask_length; i++) {
 611          if (mask_str[i] < 'w' || mask_str[i] > 'z') {
 612             ir_read_error(expr, "write mask contains invalid character: %c",
 613                           mask_str[i]);
 614             return NULL;
 615          }
 616          mask |= 1 << idx_map[mask_str[i] - 'w'];
 617       }
 618    } else if (!mask_list->subexpressions.is_empty()) {
 619       ir_read_error(mask_list, "expected () or (<write mask>)");
 620       return NULL;
 621    }
 622
 623    ir_dereference *lhs = read_dereference(lhs_expr);
 624    if (lhs == NULL) {
 625       ir_read_error(NULL, "when reading left-hand side of assignment");
 626       return NULL;
 627    }
 628
 629    ir_rvalue *rhs = read_rvalue(rhs_expr);
 630    if (rhs == NULL) {
 631       ir_read_error(NULL, "when reading right-hand side of assignment");
 632       return NULL;
 633    }
 634
 635    if (mask == 0 && (lhs->type->is_vector() || lhs->type->is_scalar())) {
 636       ir_read_error(expr, "non-zero write mask required.");
 637       return NULL;
 638    }
 639
 640    return new(mem_ctx) ir_assignment(lhs, rhs, condition, mask);
 641 }
 642
 643 ir_call *
 644 ir_reader::read_call(s_expression *expr)
 645 {
 646    s_symbol *name;
 647    s_list *params;
 648    s_list *s_return = NULL;
 649
 650    ir_dereference_variable *return_deref = NULL;
 651
 652    s_pattern void_pat[] = { "call", name, params };
 653    s_pattern non_void_pat[] = { "call", name, s_return, params };
 654    if (MATCH(expr, non_void_pat)) {
 655       return_deref = read_var_ref(s_return);
 656       if (return_deref == NULL) {
 657          ir_read_error(s_return, "when reading a call's return storage");
 658          return NULL;
 659       }
 660    } else if (!MATCH(expr, void_pat)) {
 661       ir_read_error(expr, "expected (call <name> [<deref>] (<param> ...))");
 662       return NULL;
 663    }
 664
 665    exec_list parameters;
 666
 667    foreach_list(n, &params->subexpressions) {
 668       s_expression *expr = (s_expression *) n;
 669       ir_rvalue *param = read_rvalue(expr);
 670       if (param == NULL) {
 671          ir_read_error(expr, "when reading parameter to function call");
 672          return NULL;
 673       }
 674       parameters.push_tail(param);
 675    }
 676
 677    ir_function *f = state->symbols->get_function(name->value());
 678    if (f == NULL) {
 679       ir_read_error(expr, "found call to undefined function %s",
 680                     name->value());
 681       return NULL;
 682    }
 683
 684    ir_function_signature *callee = f->matching_signature(state, &parameters);
 685    if (callee == NULL) {
 686       ir_read_error(expr, "couldn't find matching signature for function "
 687                     "%s", name->value());
 688       return NULL;
 689    }
 690
 691    if (callee->return_type == glsl_type::void_type && return_deref) {
 692       ir_read_error(expr, "call has return value storage but void type");
 693       return NULL;
 694    } else if (callee->return_type != glsl_type::void_type && !return_deref) {
 695       ir_read_error(expr, "call has non-void type but no return value storage");
 696       return NULL;
 697    }
 698
 699    return new(mem_ctx) ir_call(callee, return_deref, &parameters);
 700 }
 701
 702 ir_expression *
 703 ir_reader::read_expression(s_expression *expr)
 704 {
 705    s_expression *s_type;
 706    s_symbol *s_op;
 707    s_expression *s_arg[4] = {NULL};
 708
 709    s_pattern pat[] = { "expression", s_type, s_op, s_arg[0] };
 710    if (!PARTIAL_MATCH(expr, pat)) {
 711       ir_read_error(expr, "expected (expression <type> <operator> "
 712                           "<operand> [<operand>] [<operand>] [<operand>])");
 713       return NULL;
 714    }
 715    s_arg[1] = (s_expression *) s_arg[0]->next; // may be tail sentinel
 716    s_arg[2] = (s_expression *) s_arg[1]->next; // may be tail sentinel or NULL
 717    if (s_arg[2])
 718       s_arg[3] = (s_expression *) s_arg[2]->next; // may be tail sentinel or NULL
 719
 720    const glsl_type *type = read_type(s_type);
 721    if (type == NULL)
 722       return NULL;
 723
 724    /* Read the operator */
 725    ir_expression_operation op = ir_expression::get_operator(s_op->value());
 726    if (op == (ir_expression_operation) -1) {
 727       ir_read_error(expr, "invalid operator: %s", s_op->value());
 728       return NULL;
 729    }
 730
 731    int num_operands = -3; /* skip "expression" <type> <operation> */
 732    foreach_list(n, &((s_list *) expr)->subexpressions)
 733       ++num_operands;
 734
 735    int expected_operands = ir_expression::get_num_operands(op);
 736    if (num_operands != expected_operands) {
 737       ir_read_error(expr, "found %d expression operands, expected %d",
 738                     num_operands, expected_operands);
 739       return NULL;
 740    }
 741
 742    ir_rvalue *arg[4] = {NULL};
 743    for (int i = 0; i < num_operands; i++) {
 744       arg[i] = read_rvalue(s_arg[i]);
 745       if (arg[i] == NULL) {
 746          ir_read_error(NULL, "when reading operand #%d of %s", i, s_op->value());
 747          return NULL;
 748       }
 749    }
 750
 751    return new(mem_ctx) ir_expression(op, type, arg[0], arg[1], arg[2], arg[3]);
 752 }
 753
 754 ir_swizzle *
 755 ir_reader::read_swizzle(s_expression *expr)
 756 {
 757    s_symbol *swiz;
 758    s_expression *sub;
 759
 760    s_pattern pat[] = { "swiz", swiz, sub };
 761    if (!MATCH(expr, pat)) {
 762       ir_read_error(expr, "expected (swiz <swizzle> <rvalue>)");
 763       return NULL;
 764    }
 765
 766    if (strlen(swiz->value()) > 4) {
 767       ir_read_error(expr, "expected a valid swizzle; found %s", swiz->value());
 768       return NULL;
 769    }
 770
 771    ir_rvalue *rvalue = read_rvalue(sub);
 772    if (rvalue == NULL)
 773       return NULL;
 774
 775    ir_swizzle *ir = ir_swizzle::create(rvalue, swiz->value(),
 776                                        rvalue->type->vector_elements);
 777    if (ir == NULL)
 778       ir_read_error(expr, "invalid swizzle");
 779
 780    return ir;
 781 }
 782
 783 ir_constant *
 784 ir_reader::read_constant(s_expression *expr)
 785 {
 786    s_expression *type_expr;
 787    s_list *values;
 788
 789    s_pattern pat[] = { "constant", type_expr, values };
 790    if (!MATCH(expr, pat)) {
 791       ir_read_error(expr, "expected (constant <type> (...))");
 792       return NULL;
 793    }
 794
 795    const glsl_type *type = read_type(type_expr);
 796    if (type == NULL)
 797       return NULL;
 798
 799    if (values == NULL) {
 800       ir_read_error(expr, "expected (constant <type> (...))");
 801       return NULL;
 802    }
 803
 804    if (type->is_array()) {
 805       unsigned elements_supplied = 0;
 806       exec_list elements;
 807       foreach_list(n, &values->subexpressions) {
 808          s_expression *elt = (s_expression *) n;
 809          ir_constant *ir_elt = read_constant(elt);
 810          if (ir_elt == NULL)
 811             return NULL;
 812          elements.push_tail(ir_elt);
 813          elements_supplied++;
 814       }
 815
 816       if (elements_supplied != type->length) {
 817          ir_read_error(values, "expected exactly %u array elements, "
 818                        "given %u", type->length, elements_supplied);
 819          return NULL;
 820       }
 821       return new(mem_ctx) ir_constant(type, &elements);
 822    }
 823
 824    ir_constant_data data = { { 0 } };
 825
 826    // Read in list of values (at most 16).
 827    unsigned k = 0;
 828    foreach_list(n, &values->subexpressions) {
 829       if (k >= 16) {
 830          ir_read_error(values, "expected at most 16 numbers");
 831          return NULL;
 832       }
 833
 834       s_expression *expr = (s_expression *) n;
 835
 836       if (type->base_type == GLSL_TYPE_FLOAT) {
 837          s_number *value = SX_AS_NUMBER(expr);
 838          if (value == NULL) {
 839             ir_read_error(values, "expected numbers");
 840             return NULL;
 841          }
 842          data.f[k] = value->fvalue();
 843       } else {
 844          s_int *value = SX_AS_INT(expr);
 845          if (value == NULL) {
 846             ir_read_error(values, "expected integers");
 847             return NULL;
 848          }
 849
 850          switch (type->base_type) {
 851          case GLSL_TYPE_UINT: {
 852             data.u[k] = value->value();
 853             break;
 854          }
 855          case GLSL_TYPE_INT: {
 856             data.i[k] = value->value();
 857             break;
 858          }
 859          case GLSL_TYPE_BOOL: {
 860             data.b[k] = value->value();
 861             break;
 862          }
 863          default:
 864             ir_read_error(values, "unsupported constant type");
 865             return NULL;
 866          }
 867       }
 868       ++k;
 869    }
 870    if (k != type->components()) {
 871       ir_read_error(values, "expected %u constant values, found %u",
 872                     type->components(), k);
 873       return NULL;
 874    }
 875
 876    return new(mem_ctx) ir_constant(type, &data);
 877 }
 878
 879 ir_dereference_variable *
 880 ir_reader::read_var_ref(s_expression *expr)
 881 {
 882    s_symbol *s_var;
 883    s_pattern var_pat[] = { "var_ref", s_var };
 884
 885    if (MATCH(expr, var_pat)) {
 886       ir_variable *var = state->symbols->get_variable(s_var->value());
 887       if (var == NULL) {
 888          ir_read_error(expr, "undeclared variable: %s", s_var->value());
 889          return NULL;
 890       }
 891       return new(mem_ctx) ir_dereference_variable(var);
 892    }
 893    return NULL;
 894 }
 895
 896 ir_dereference *
 897 ir_reader::read_dereference(s_expression *expr)
 898 {
 899    s_expression *s_subject;
 900    s_expression *s_index;
 901    s_symbol *s_field;
 902
 903    s_pattern array_pat[] = { "array_ref", s_subject, s_index };
 904    s_pattern record_pat[] = { "record_ref", s_subject, s_field };
 905
 906    ir_dereference_variable *var_ref = read_var_ref(expr);
 907    if (var_ref != NULL) {
 908       return var_ref;
 909    } else if (MATCH(expr, array_pat)) {
 910       ir_rvalue *subject = read_rvalue(s_subject);
 911       if (subject == NULL) {
 912          ir_read_error(NULL, "when reading the subject of an array_ref");
 913          return NULL;
 914       }
 915
 916       ir_rvalue *idx = read_rvalue(s_index);
 917       if (idx == NULL) {
 918          ir_read_error(NULL, "when reading the index of an array_ref");
 919          return NULL;
 920       }
 921       return new(mem_ctx) ir_dereference_array(subject, idx);
 922    } else if (MATCH(expr, record_pat)) {
 923       ir_rvalue *subject = read_rvalue(s_subject);
 924       if (subject == NULL) {
 925          ir_read_error(NULL, "when reading the subject of a record_ref");
 926          return NULL;
 927       }
 928       return new(mem_ctx) ir_dereference_record(subject, s_field->value());
 929    }
 930    return NULL;
 931 }
 932
 933 ir_texture *
 934 ir_reader::read_texture(s_expression *expr)
 935 {
 936    s_symbol *tag = NULL;
 937    s_expression *s_type = NULL;
 938    s_expression *s_sampler = NULL;
 939    s_expression *s_coord = NULL;
 940    s_expression *s_offset = NULL;
 941    s_expression *s_proj = NULL;
 942    s_list *s_shadow = NULL;
 943    s_expression *s_lod = NULL;
 944    s_expression *s_sample_index = NULL;
 945    s_expression *s_component = NULL;
 946
 947    ir_texture_opcode op = ir_tex; /* silence warning */
 948
 949    s_pattern tex_pattern[] =
 950       { "tex", s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow };
 951    s_pattern lod_pattern[] =
 952       { "lod", s_type, s_sampler, s_coord };
 953    s_pattern txf_pattern[] =
 954       { "txf", s_type, s_sampler, s_coord, s_offset, s_lod };
 955    s_pattern txf_ms_pattern[] =
 956       { "txf_ms", s_type, s_sampler, s_coord, s_sample_index };
 957    s_pattern txs_pattern[] =
 958       { "txs", s_type, s_sampler, s_lod };
 959    s_pattern tg4_pattern[] =
 960       { "tg4", s_type, s_sampler, s_coord, s_offset, s_component };
 961    s_pattern query_levels_pattern[] =
 962       { "query_levels", s_type, s_sampler };
 963    s_pattern other_pattern[] =
 964       { tag, s_type, s_sampler, s_coord, s_offset, s_proj, s_shadow, s_lod };
 965
 966    if (MATCH(expr, lod_pattern)) {
 967       op = ir_lod;
 968    } else if (MATCH(expr, tex_pattern)) {
 969       op = ir_tex;
 970    } else if (MATCH(expr, txf_pattern)) {
 971       op = ir_txf;
 972    } else if (MATCH(expr, txf_ms_pattern)) {
 973       op = ir_txf_ms;
 974    } else if (MATCH(expr, txs_pattern)) {
 975       op = ir_txs;
 976    } else if (MATCH(expr, tg4_pattern)) {
 977       op = ir_tg4;
 978    } else if (MATCH(expr, query_levels_pattern)) {
 979       op = ir_query_levels;
 980    } else if (MATCH(expr, other_pattern)) {
 981       op = ir_texture::get_opcode(tag->value());
 982       if (op == -1)
 983          return NULL;
 984    } else {
 985       ir_read_error(NULL, "unexpected texture pattern %s", tag->value());
 986       return NULL;
 987    }
 988
 989    ir_texture *tex = new(mem_ctx) ir_texture(op);
 990
 991    // Read return type
 992    const glsl_type *type = read_type(s_type);
 993    if (type == NULL) {
 994       ir_read_error(NULL, "when reading type in (%s ...)",
 995                     tex->opcode_string());
 996       return NULL;
 997    }
 998
 999    // Read sampler (must be a deref)
1000    ir_dereference *sampler = read_dereference(s_sampler);
1001    if (sampler == NULL) {
1002       ir_read_error(NULL, "when reading sampler in (%s ...)",
1003                     tex->opcode_string());
1004       return NULL;
1005    }
1006    tex->set_sampler(sampler, type);
1007
1008    if (op != ir_txs) {
1009       // Read coordinate (any rvalue)
1010       tex->coordinate = read_rvalue(s_coord);
1011       if (tex->coordinate == NULL) {
1012          ir_read_error(NULL, "when reading coordinate in (%s ...)",
1013                        tex->opcode_string());
1014          return NULL;
1015       }
1016
1017       if (op != ir_txf_ms && op != ir_lod) {
1018          // Read texel offset - either 0 or an rvalue.
1019          s_int *si_offset = SX_AS_INT(s_offset);
1020          if (si_offset == NULL || si_offset->value() != 0) {
1021             tex->offset = read_rvalue(s_offset);
1022             if (tex->offset == NULL) {
1023                ir_read_error(s_offset, "expected 0 or an expression");
1024                return NULL;
1025             }
1026          }
1027       }
1028    }
1029
1030    if (op != ir_txf && op != ir_txf_ms &&
1031        op != ir_txs && op != ir_lod && op != ir_tg4 &&
1032        op != ir_query_levels) {
1033       s_int *proj_as_int = SX_AS_INT(s_proj);
1034       if (proj_as_int && proj_as_int->value() == 1) {
1035          tex->projector = NULL;
1036       } else {
1037          tex->projector = read_rvalue(s_proj);
1038          if (tex->projector == NULL) {
1039             ir_read_error(NULL, "when reading projective divide in (%s ..)",
1040                           tex->opcode_string());
1041             return NULL;
1042          }
1043       }
1044
1045       if (s_shadow->subexpressions.is_empty()) {
1046          tex->shadow_comparitor = NULL;
1047       } else {
1048          tex->shadow_comparitor = read_rvalue(s_shadow);
1049          if (tex->shadow_comparitor == NULL) {
1050             ir_read_error(NULL, "when reading shadow comparitor in (%s ..)",
1051                           tex->opcode_string());
1052             return NULL;
1053          }
1054       }
1055    }
1056
1057    switch (op) {
1058    case ir_txb:
1059       tex->lod_info.bias = read_rvalue(s_lod);
1060       if (tex->lod_info.bias == NULL) {
1061          ir_read_error(NULL, "when reading LOD bias in (txb ...)");
1062          return NULL;
1063       }
1064       break;
1065    case ir_txl:
1066    case ir_txf:
1067    case ir_txs:
1068       tex->lod_info.lod = read_rvalue(s_lod);
1069       if (tex->lod_info.lod == NULL) {
1070          ir_read_error(NULL, "when reading LOD in (%s ...)",
1071                        tex->opcode_string());
1072          return NULL;
1073       }
1074       break;
1075    case ir_txf_ms:
1076       tex->lod_info.sample_index = read_rvalue(s_sample_index);
1077       if (tex->lod_info.sample_index == NULL) {
1078          ir_read_error(NULL, "when reading sample_index in (txf_ms ...)");
1079          return NULL;
1080       }
1081       break;
1082    case ir_txd: {
1083       s_expression *s_dx, *s_dy;
1084       s_pattern dxdy_pat[] = { s_dx, s_dy };
1085       if (!MATCH(s_lod, dxdy_pat)) {
1086          ir_read_error(s_lod, "expected (dPdx dPdy) in (txd ...)");
1087          return NULL;
1088       }
1089       tex->lod_info.grad.dPdx = read_rvalue(s_dx);
1090       if (tex->lod_info.grad.dPdx == NULL) {
1091          ir_read_error(NULL, "when reading dPdx in (txd ...)");
1092          return NULL;
1093       }
1094       tex->lod_info.grad.dPdy = read_rvalue(s_dy);
1095       if (tex->lod_info.grad.dPdy == NULL) {
1096          ir_read_error(NULL, "when reading dPdy in (txd ...)");
1097          return NULL;
1098       }
1099       break;
1100    }
1101    case ir_tg4:
1102       tex->lod_info.component = read_rvalue(s_component);
1103       if (tex->lod_info.component == NULL) {
1104          ir_read_error(NULL, "when reading component in (tg4 ...)");
1105          return NULL;
1106       }
1107       break;
1108    default:
1109       // tex and lod don't have any extra parameters.
1110       break;
1111    };
1112    return tex;
1113 }
1114
1115 ir_emit_vertex *
1116 ir_reader::read_emit_vertex(s_expression *expr)
1117 {
1118    s_expression *s_stream = NULL;
1119
1120    s_pattern pat[] = { "emit-vertex", s_stream };
1121
1122    if (MATCH(expr, pat)) {
1123       ir_rvalue *stream = read_dereference(s_stream);
1124       if (stream == NULL) {
1125          ir_read_error(NULL, "when reading stream info in emit-vertex");
1126          return NULL;
1127       }
1128       return new(mem_ctx) ir_emit_vertex(stream);
1129    }
1130    ir_read_error(NULL, "when reading emit-vertex");
1131    return NULL;
1132 }
1133
1134 ir_end_primitive *
1135 ir_reader::read_end_primitive(s_expression *expr)
1136 {
1137    s_expression *s_stream = NULL;
1138
1139    s_pattern pat[] = { "end-primitive", s_stream };
1140
1141    if (MATCH(expr, pat)) {
1142       ir_rvalue *stream = read_dereference(s_stream);
1143       if (stream == NULL) {
1144          ir_read_error(NULL, "when reading stream info in end-primitive");
1145          return NULL;
1146       }
1147       return new(mem_ctx) ir_end_primitive(stream);
1148    }
1149    ir_read_error(NULL, "when reading end-primitive");
1150    return NULL;
1151 }