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(ir_variable *var)
  77 {
  78    if (!var->is_in_uniform_block())
  79       return visit_continue;
  80
  81    const glsl_type *const block_type = var->is_interface_instance()
  82       ? var->type : var->get_interface_type();
  83
  84    /* Section 2.11.6 (Uniform Variables) of the OpenGL ES 3.0.3 spec says:
  85     *
  86     *     "All members of a named uniform block declared with a shared or
  87     *     std140 layout qualifier are considered active, even if they are not
  88     *     referenced in any shader in the program. The uniform block itself is
  89     *     also considered active, even if no member of the block is
  90     *     referenced."
  91     */
  92    if (block_type->interface_packing == GLSL_INTERFACE_PACKING_PACKED)
  93       return visit_continue;
  94
  95    /* Process the block.  Bail if there was an error.
  96     */
  97    link_uniform_block_active *const b =
  98       process_block(this->mem_ctx, this->ht, var);
  99    if (b == NULL) {
 100       linker_error(this->prog,
 101                    "uniform block `%s' has mismatching definitions",
 102                    var->get_interface_type()->name);
 103       this->success = false;
 104       return visit_stop;
 105    }
 106
 107    assert(b->num_array_elements == 0);
 108    assert(b->array_elements == NULL);
 109    assert(b->type != NULL);
 110
 111    return visit_continue;
 112 }
 113
 114 ir_visitor_status
 115 link_uniform_block_active_visitor::visit_enter(ir_dereference_array *ir)
 116 {
 117    ir_dereference_variable *const d = ir->array->as_dereference_variable();
 118    ir_variable *const var = (d == NULL) ? NULL : d->var;
 119
 120    /* If the r-value being dereferenced is not a variable (e.g., a field of a
 121     * structure) or is not a uniform block instance, continue.
 122     *
 123     * WARNING: It is not enough for the variable to be part of uniform block.
 124     * It must represent the entire block.  Arrays (or matrices) inside blocks
 125     * that lack an instance name are handled by the ir_dereference_variable
 126     * function.
 127     */
 128    if (var == NULL
 129        || !var->is_in_uniform_block()
 130        || !var->is_interface_instance())
 131       return visit_continue;
 132
 133    /* Process the block.  Bail if there was an error.
 134     */
 135    link_uniform_block_active *const b =
 136       process_block(this->mem_ctx, this->ht, var);
 137    if (b == NULL) {
 138       linker_error(prog,
 139                    "uniform block `%s' has mismatching definitions",
 140                    var->get_interface_type()->name);
 141       this->success = false;
 142       return visit_stop;
 143    }
 144
 145    /* Block arrays must be declared with an instance name.
 146     */
 147    assert(b->has_instance_name);
 148    assert((b->num_array_elements == 0) == (b->array_elements == NULL));
 149    assert(b->type != NULL);
 150
 151    ir_constant *c = ir->array_index->as_constant();
 152
 153    if (c) {
 154       /* Index is a constant, so mark just that element used, if not already */
 155       const unsigned idx = c->get_uint_component(0);
 156
 157       unsigned i;
 158       for (i = 0; i < b->num_array_elements; i++) {
 159          if (b->array_elements[i] == idx)
 160             break;
 161       }
 162
 163       assert(i <= b->num_array_elements);
 164
 165       if (i == b->num_array_elements) {
 166          b->array_elements = reralloc(this->mem_ctx,
 167                                       b->array_elements,
 168                                       unsigned,
 169                                       b->num_array_elements + 1);
 170
 171          b->array_elements[b->num_array_elements] = idx;
 172
 173          b->num_array_elements++;
 174       }
 175    } else {
 176       /* The array index is not a constant, so mark the entire array used. */
 177       assert(b->type->is_array());
 178       if (b->num_array_elements < b->type->length) {
 179          b->num_array_elements = b->type->length;
 180          b->array_elements = reralloc(this->mem_ctx,
 181                                       b->array_elements,
 182                                       unsigned,
 183                                       b->num_array_elements);
 184
 185          for (unsigned i = 0; i < b->num_array_elements; i++) {
 186             b->array_elements[i] = i;
 187          }
 188       }
 189    }
 190
 191    return visit_continue_with_parent;
 192 }
 193
 194 ir_visitor_status
 195 link_uniform_block_active_visitor::visit(ir_dereference_variable *ir)
 196 {
 197    ir_variable *var = ir->var;
 198
 199    if (!var->is_in_uniform_block())
 200       return visit_continue;
 201
 202    assert(!var->is_interface_instance() || !var->type->is_array());
 203
 204    /* Process the block.  Bail if there was an error.
 205     */
 206    link_uniform_block_active *const b =
 207       process_block(this->mem_ctx, this->ht, var);
 208    if (b == NULL) {
 209       linker_error(this->prog,
 210                    "uniform block `%s' has mismatching definitions",
 211                    var->get_interface_type()->name);
 212       this->success = false;
 213       return visit_stop;
 214    }
 215
 216    assert(b->num_array_elements == 0);
 217    assert(b->array_elements == NULL);
 218    assert(b->type != NULL);
 219
 220    return visit_continue;
 221 }