aboutsummaryrefslogtreecommitdiff
path: root/mesalib/src/glsl/ast_array_index.cpp
blob: 50f9987c8afe5ae991015f5de9d9659b3363f27a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/*
 * Copyright © 2010 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "ast.h"
#include "glsl_types.h"
#include "ir.h"

void
ast_array_specifier::print(void) const
{
   if (this->is_unsized_array) {
      printf("[ ] ");
   }

   foreach_list_typed (ast_node, array_dimension, link, &this->array_dimensions) {
      printf("[ ");
      array_dimension->print();
      printf("] ");
   }
}

/**
 * If \c ir is a reference to an array for which we are tracking the max array
 * element accessed, track that the given element has been accessed.
 * Otherwise do nothing.
 *
 * This function also checks whether the array is a built-in array whose
 * maximum size is too small to accommodate the given index, and if so uses
 * loc and state to report the error.
 */
static void
update_max_array_access(ir_rvalue *ir, unsigned idx, YYLTYPE *loc,
                        struct _mesa_glsl_parse_state *state)
{
   if (ir_dereference_variable *deref_var = ir->as_dereference_variable()) {
      ir_variable *var = deref_var->var;
      if (idx > var->data.max_array_access) {
         var->data.max_array_access = idx;

         /* Check whether this access will, as a side effect, implicitly cause
          * the size of a built-in array to be too large.
          */
         check_builtin_array_max_size(var->name, idx+1, *loc, state);
      }
   } else if (ir_dereference_record *deref_record =
              ir->as_dereference_record()) {
      /* There are two possibilities we need to consider:
       *
       * - Accessing an element of an array that is a member of a named
       *   interface block (e.g. ifc.foo[i])
       *
       * - Accessing an element of an array that is a member of a named
       *   interface block array (e.g. ifc[j].foo[i]).
       */
      ir_dereference_variable *deref_var =
         deref_record->record->as_dereference_variable();
      if (deref_var == NULL) {
         if (ir_dereference_array *deref_array =
             deref_record->record->as_dereference_array()) {
            deref_var = deref_array->array->as_dereference_variable();
         }
      }

      if (deref_var != NULL) {
         if (deref_var->var->is_interface_instance()) {
            const glsl_type *interface_type =
               deref_var->var->get_interface_type();
            unsigned field_index =
               deref_record->record->type->field_index(deref_record->field);
            assert(field_index < interface_type->length);
            if (idx > deref_var->var->max_ifc_array_access[field_index]) {
               deref_var->var->max_ifc_array_access[field_index] = idx;

               /* Check whether this access will, as a side effect, implicitly
                * cause the size of a built-in array to be too large.
                */
               check_builtin_array_max_size(deref_record->field, idx+1, *loc,
                                            state);
            }
         }
      }
   }
}


ir_rvalue *
_mesa_ast_array_index_to_hir(void *mem_ctx,
			     struct _mesa_glsl_parse_state *state,
			     ir_rvalue *array, ir_rvalue *idx,
			     YYLTYPE &loc, YYLTYPE &idx_loc)
{
   if (!array->type->is_error()
       && !array->type->is_array()
       && !array->type->is_matrix()
       && !array->type->is_vector()) {
      _mesa_glsl_error(& idx_loc, state,
		       "cannot dereference non-array / non-matrix / "
		       "non-vector");
   }

   if (!idx->type->is_error()) {
      if (!idx->type->is_integer()) {
	 _mesa_glsl_error(& idx_loc, state, "array index must be integer type");
      } else if (!idx->type->is_scalar()) {
	 _mesa_glsl_error(& idx_loc, state, "array index must be scalar");
      }
   }

   /* If the array index is a constant expression and the array has a
    * declared size, ensure that the access is in-bounds.  If the array
    * index is not a constant expression, ensure that the array has a
    * declared size.
    */
   ir_constant *const const_index = idx->constant_expression_value();
   if (const_index != NULL && idx->type->is_integer()) {
      const int idx = const_index->value.i[0];
      const char *type_name = "error";
      unsigned bound = 0;

      /* From page 24 (page 30 of the PDF) of the GLSL 1.50 spec:
       *
       *    "It is illegal to declare an array with a size, and then
       *    later (in the same shader) index the same array with an
       *    integral constant expression greater than or equal to the
       *    declared size. It is also illegal to index an array with a
       *    negative constant expression."
       */
      if (array->type->is_matrix()) {
	 if (array->type->row_type()->vector_elements <= idx) {
	    type_name = "matrix";
	    bound = array->type->row_type()->vector_elements;
	 }
      } else if (array->type->is_vector()) {
	 if (array->type->vector_elements <= idx) {
	    type_name = "vector";
	    bound = array->type->vector_elements;
	 }
      } else {
	 /* glsl_type::array_size() returns -1 for non-array types.  This means
	  * that we don't need to verify that the type is an array before
	  * doing the bounds checking.
	  */
	 if ((array->type->array_size() > 0)
	     && (array->type->array_size() <= idx)) {
	    type_name = "array";
	    bound = array->type->array_size();
	 }
      }

      if (bound > 0) {
	 _mesa_glsl_error(& loc, state, "%s index must be < %u",
			  type_name, bound);
      } else if (idx < 0) {
	 _mesa_glsl_error(& loc, state, "%s index must be >= 0",
			  type_name);
      }

      if (array->type->is_array())
         update_max_array_access(array, idx, &loc, state);
   } else if (const_index == NULL && array->type->is_array()) {
      if (array->type->is_unsized_array()) {
	 _mesa_glsl_error(&loc, state, "unsized array index must be constant");
      } else if (array->type->fields.array->is_interface()
                 && array->variable_referenced()->data.mode == ir_var_uniform
                 && !state->is_version(400, 0) && !state->ARB_gpu_shader5_enable) {
	 /* Page 46 in section 4.3.7 of the OpenGL ES 3.00 spec says:
	  *
	  *     "All indexes used to index a uniform block array must be
	  *     constant integral expressions."
	  */
	 _mesa_glsl_error(&loc, state,
			  "uniform block array index must be constant");
      } else {
	 /* whole_variable_referenced can return NULL if the array is a
	  * member of a structure.  In this case it is safe to not update
	  * the max_array_access field because it is never used for fields
	  * of structures.
	  */
	 ir_variable *v = array->whole_variable_referenced();
	 if (v != NULL)
	    v->data.max_array_access = array->type->array_size() - 1;
      }

      /* From page 23 (29 of the PDF) of the GLSL 1.30 spec:
       *
       *    "Samplers aggregated into arrays within a shader (using square
       *    brackets [ ]) can only be indexed with integral constant
       *    expressions [...]."
       *
       * This restriction was added in GLSL 1.30.  Shaders using earlier
       * version of the language should not be rejected by the compiler
       * front-end for using this construct.  This allows useful things such
       * as using a loop counter as the index to an array of samplers.  If the
       * loop in unrolled, the code should compile correctly.  Instead, emit a
       * warning.
       */
      if (array->type->element_type()->is_sampler()) {
	 if (!state->is_version(130, 100)) {
	    if (state->es_shader) {
	       _mesa_glsl_warning(&loc, state,
				  "sampler arrays indexed with non-constant "
				  "expressions is optional in %s",
				  state->get_version_string());
	    } else {
	       _mesa_glsl_warning(&loc, state,
				  "sampler arrays indexed with non-constant "
				  "expressions will be forbidden in GLSL 1.30 "
				  "and later");
	    }
	 } else {
	    _mesa_glsl_error(&loc, state,
			     "sampler arrays indexed with non-constant "
			     "expressions is forbidden in GLSL 1.30 and "
			     "later");
	 }
      }
   }

   /* After performing all of the error checking, generate the IR for the
    * expression.
    */
   if (array->type->is_array()
       || array->type->is_matrix()) {
      return new(mem_ctx) ir_dereference_array(array, idx);
   } else if (array->type->is_vector()) {
      return new(mem_ctx) ir_expression(ir_binop_vector_extract, array, idx);
   } else if (array->type->is_error()) {
      return array;
   } else {
      ir_rvalue *result = new(mem_ctx) ir_dereference_array(array, idx);
      result->type = glsl_type::error_type;

      return result;
   }
}