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