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