src/glsl/link_uniform_block_active_visitor.cpp

   1 /*
   2  * Copyright © 2013 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 "link_uniform_block_active_visitor.h"
  25 #include "program.h"
  26
  27 link_uniform_block_active *
  28 process_block(void *mem_ctx, struct hash_table *ht, ir_variable *var)
  29 {
  30    const uint32_t h = _mesa_hash_string(var->get_interface_type()->name);
  31    const hash_entry *const existing_block =
  32       _mesa_hash_table_search(ht, h, var->get_interface_type()->name);
  33
  34    const glsl_type *const block_type = var->is_interface_instance()
  35       ? var->type : var->get_interface_type();
  36
  37
  38    /* If a block with this block-name has not previously been seen, add it.
  39     * If a block with this block-name has been seen, it must be identical to
  40     * the block currently being examined.
  41     */
  42    if (existing_block == NULL) {
  43       link_uniform_block_active *const b =
  44          rzalloc(mem_ctx, struct link_uniform_block_active);
  45
  46       b->type = block_type;
  47       b->has_instance_name = var->is_interface_instance();
  48
  49       if (var->data.explicit_binding) {
  50          b->has_binding = true;
  51          b->binding = var->data.binding;
  52       } else {
  53          b->has_binding = false;
  54          b->binding = 0;
  55       }
  56
  57       _mesa_hash_table_insert(ht, h, var->get_interface_type()->name,
  58                               (void *) b);
  59       return b;
  60    } else {
  61       link_uniform_block_active *const b =
  62          (link_uniform_block_active *) existing_block->data;
  63
  64       if (b->type != block_type
  65           || b->has_instance_name != var->is_interface_instance())
  66          return NULL;
  67       else
  68          return b;
  69    }
  70
  71    assert(!"Should not get here.");
  72    return NULL;
  73 }
  74
  75 ir_visitor_status
  76 link_uniform_block_active_visitor::visit_enter(ir_dereference_array *ir)
  77 {
  78    ir_dereference_variable *const d = ir->array->as_dereference_variable();
  79    ir_variable *const var = (d == NULL) ? NULL : d->var;
  80
  81    /* If the r-value being dereferenced is not a variable (e.g., a field of a
  82     * structure) or is not a uniform block instance, continue.
  83     *
  84     * WARNING: It is not enough for the variable to be part of uniform block.
  85     * It must represent the entire block.  Arrays (or matrices) inside blocks
  86     * that lack an instance name are handled by the ir_dereference_variable
  87     * function.
  88     */
  89    if (var == NULL
  90        || !var->is_in_uniform_block()
  91        || !var->is_interface_instance())
  92       return visit_continue;
  93
  94    /* Process the block.  Bail if there was an error.
  95     */
  96    link_uniform_block_active *const b =
  97       process_block(this->mem_ctx, this->ht, var);
  98    if (b == NULL) {
  99       linker_error(prog,
 100                    "uniform block `%s' has mismatching definitions",
 101                    var->get_interface_type()->name);
 102       this->success = false;
 103       return visit_stop;
 104    }
 105
 106    /* Block arrays must be declared with an instance name.
 107     */
 108    assert(b->has_instance_name);
 109    assert((b->num_array_elements == 0) == (b->array_elements == NULL));
 110    assert(b->type != NULL);
 111
 112    /* Determine whether or not this array index has already been added to the
 113     * list of active array indices.  At this point all constant folding must
 114     * have occured, and the array index must be a constant.
 115     */
 116    ir_constant *c = ir->array_index->as_constant();
 117    assert(c != NULL);
 118
 119    const unsigned idx = c->get_uint_component(0);
 120
 121    unsigned i;
 122    for (i = 0; i < b->num_array_elements; i++) {
 123       if (b->array_elements[i] == idx)
 124          break;
 125    }
 126
 127    assert(i <= b->num_array_elements);
 128
 129    if (i == b->num_array_elements) {
 130       b->array_elements = reralloc(this->mem_ctx,
 131                                    b->array_elements,
 132                                    unsigned,
 133                                    b->num_array_elements + 1);
 134
 135       b->array_elements[b->num_array_elements] = idx;
 136
 137       b->num_array_elements++;
 138    }
 139
 140    return visit_continue_with_parent;
 141 }
 142
 143 ir_visitor_status
 144 link_uniform_block_active_visitor::visit(ir_dereference_variable *ir)
 145 {
 146    ir_variable *var = ir->var;
 147
 148    if (!var->is_in_uniform_block())
 149       return visit_continue;
 150
 151    assert(!var->is_interface_instance() || !var->type->is_array());
 152
 153    /* Process the block.  Bail if there was an error.
 154     */
 155    link_uniform_block_active *const b =
 156       process_block(this->mem_ctx, this->ht, var);
 157    if (b == NULL) {
 158       linker_error(this->prog,
 159                    "uniform block `%s' has mismatching definitions",
 160                    var->get_interface_type()->name);
 161       this->success = false;
 162       return visit_stop;
 163    }
 164
 165    assert(b->num_array_elements == 0);
 166    assert(b->array_elements == NULL);
 167    assert(b->type != NULL);
 168
 169    return visit_continue;
 170 }