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 "ast.h"
25 #include "compiler/glsl_types.h"
26 #include "ir.h"
27
28 void
print(void) const29 ast_array_specifier::print(void) const
30 {
31 foreach_list_typed (ast_node, array_dimension, link, &this->array_dimensions) {
32 printf("[ ");
33 if (((ast_expression*)array_dimension)->oper != ast_unsized_array_dim)
34 array_dimension->print();
35 printf("] ");
36 }
37 }
38
39 /**
40 * If \c ir is a reference to an array for which we are tracking the max array
41 * element accessed, track that the given element has been accessed.
42 * Otherwise do nothing.
43 *
44 * This function also checks whether the array is a built-in array whose
45 * maximum size is too small to accommodate the given index, and if so uses
46 * loc and state to report the error.
47 */
48 static void
update_max_array_access(ir_rvalue * ir,int idx,YYLTYPE * loc,struct _mesa_glsl_parse_state * state)49 update_max_array_access(ir_rvalue *ir, int idx, YYLTYPE *loc,
50 struct _mesa_glsl_parse_state *state)
51 {
52 if (ir_dereference_variable *deref_var = ir->as_dereference_variable()) {
53 ir_variable *var = deref_var->var;
54 if (idx > (int)var->data.max_array_access) {
55 var->data.max_array_access = idx;
56
57 /* Check whether this access will, as a side effect, implicitly cause
58 * the size of a built-in array to be too large.
59 */
60 check_builtin_array_max_size(var->name, idx+1, *loc, state);
61 }
62 } else if (ir_dereference_record *deref_record =
63 ir->as_dereference_record()) {
64 /* There are three possibilities we need to consider:
65 *
66 * - Accessing an element of an array that is a member of a named
67 * interface block (e.g. ifc.foo[i])
68 *
69 * - Accessing an element of an array that is a member of a named
70 * interface block array (e.g. ifc[j].foo[i]).
71 *
72 * - Accessing an element of an array that is a member of a named
73 * interface block array of arrays (e.g. ifc[j][k].foo[i]).
74 */
75 ir_dereference_variable *deref_var =
76 deref_record->record->as_dereference_variable();
77 if (deref_var == NULL) {
78 ir_dereference_array *deref_array =
79 deref_record->record->as_dereference_array();
80 ir_dereference_array *deref_array_prev = NULL;
81 while (deref_array != NULL) {
82 deref_array_prev = deref_array;
83 deref_array = deref_array->array->as_dereference_array();
84 }
85 if (deref_array_prev != NULL)
86 deref_var = deref_array_prev->array->as_dereference_variable();
87 }
88
89 if (deref_var != NULL) {
90 if (deref_var->var->is_interface_instance()) {
91 unsigned field_idx = deref_record->field_idx;
92 assert(field_idx < deref_var->var->get_interface_type()->length);
93
94 int *const max_ifc_array_access =
95 deref_var->var->get_max_ifc_array_access();
96
97 assert(max_ifc_array_access != NULL);
98
99 if (idx > max_ifc_array_access[field_idx]) {
100 max_ifc_array_access[field_idx] = idx;
101
102 /* Check whether this access will, as a side effect, implicitly
103 * cause the size of a built-in array to be too large.
104 */
105 const char *field_name =
106 deref_record->record->type->fields.structure[field_idx].name;
107 check_builtin_array_max_size(field_name, idx+1, *loc, state);
108 }
109 }
110 }
111 }
112 }
113
114
115 static int
get_implicit_array_size(struct _mesa_glsl_parse_state * state,ir_rvalue * array)116 get_implicit_array_size(struct _mesa_glsl_parse_state *state,
117 ir_rvalue *array)
118 {
119 ir_variable *var = array->variable_referenced();
120
121 /* Inputs in control shader are implicitly sized
122 * to the maximum patch size.
123 */
124 if (state->stage == MESA_SHADER_TESS_CTRL &&
125 var->data.mode == ir_var_shader_in) {
126 return state->Const.MaxPatchVertices;
127 }
128
129 /* Non-patch inputs in evaluation shader are implicitly sized
130 * to the maximum patch size.
131 */
132 if (state->stage == MESA_SHADER_TESS_EVAL &&
133 var->data.mode == ir_var_shader_in &&
134 !var->data.patch) {
135 return state->Const.MaxPatchVertices;
136 }
137
138 return 0;
139 }
140
141
142 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)143 _mesa_ast_array_index_to_hir(void *mem_ctx,
144 struct _mesa_glsl_parse_state *state,
145 ir_rvalue *array, ir_rvalue *idx,
146 YYLTYPE &loc, YYLTYPE &idx_loc)
147 {
148 if (!array->type->is_error()
149 && !array->type->is_array()
150 && !array->type->is_matrix()
151 && !array->type->is_vector()) {
152 _mesa_glsl_error(& idx_loc, state,
153 "cannot dereference non-array / non-matrix / "
154 "non-vector");
155 }
156
157 if (!idx->type->is_error()) {
158 if (!idx->type->is_integer()) {
159 _mesa_glsl_error(& idx_loc, state, "array index must be integer type");
160 } else if (!idx->type->is_scalar()) {
161 _mesa_glsl_error(& idx_loc, state, "array index must be scalar");
162 }
163 }
164
165 /* If the array index is a constant expression and the array has a
166 * declared size, ensure that the access is in-bounds. If the array
167 * index is not a constant expression, ensure that the array has a
168 * declared size.
169 */
170 ir_constant *const const_index = idx->constant_expression_value(mem_ctx);
171 if (const_index != NULL && idx->type->is_integer()) {
172 const int idx = const_index->value.i[0];
173 const char *type_name = "error";
174 unsigned bound = 0;
175
176 /* From page 24 (page 30 of the PDF) of the GLSL 1.50 spec:
177 *
178 * "It is illegal to declare an array with a size, and then
179 * later (in the same shader) index the same array with an
180 * integral constant expression greater than or equal to the
181 * declared size. It is also illegal to index an array with a
182 * negative constant expression."
183 */
184 if (array->type->is_matrix()) {
185 if (array->type->row_type()->vector_elements <= idx) {
186 type_name = "matrix";
187 bound = array->type->row_type()->vector_elements;
188 }
189 } else if (array->type->is_vector()) {
190 if (array->type->vector_elements <= idx) {
191 type_name = "vector";
192 bound = array->type->vector_elements;
193 }
194 } else {
195 /* glsl_type::array_size() returns -1 for non-array types. This means
196 * that we don't need to verify that the type is an array before
197 * doing the bounds checking.
198 */
199 if ((array->type->array_size() > 0)
200 && (array->type->array_size() <= idx)) {
201 type_name = "array";
202 bound = array->type->array_size();
203 }
204 }
205
206 if (bound > 0) {
207 _mesa_glsl_error(& loc, state, "%s index must be < %u",
208 type_name, bound);
209 } else if (idx < 0) {
210 _mesa_glsl_error(& loc, state, "%s index must be >= 0", type_name);
211 }
212
213 if (array->type->is_array())
214 update_max_array_access(array, idx, &loc, state);
215 } else if (const_index == NULL && array->type->is_array()) {
216 if (array->type->is_unsized_array()) {
217 int implicit_size = get_implicit_array_size(state, array);
218 if (implicit_size) {
219 ir_variable *v = array->whole_variable_referenced();
220 if (v != NULL)
221 v->data.max_array_access = implicit_size - 1;
222 }
223 else if (state->stage == MESA_SHADER_TESS_CTRL &&
224 array->variable_referenced()->data.mode == ir_var_shader_out &&
225 !array->variable_referenced()->data.patch) {
226 /* Tessellation control shader output non-patch arrays are
227 * initially unsized. Despite that, they are allowed to be
228 * indexed with a non-constant expression (typically
229 * "gl_InvocationID"). The array size will be determined
230 * by the linker.
231 */
232 }
233 else if (array->variable_referenced()->data.mode !=
234 ir_var_shader_storage) {
235 _mesa_glsl_error(&loc, state, "unsized array index must be constant");
236 } else {
237 /* Unsized array non-constant indexing on SSBO is allowed only for
238 * the last member of the SSBO definition.
239 */
240 ir_variable *var = array->variable_referenced();
241 const glsl_type *iface_type = var->get_interface_type();
242 int field_index = iface_type->field_index(var->name);
243 /* Field index can be < 0 for instance arrays */
244 if (field_index >= 0 &&
245 field_index != (int) iface_type->length - 1) {
246 _mesa_glsl_error(&loc, state, "Indirect access on unsized "
247 "array is limited to the last member of "
248 "SSBO.");
249 }
250 }
251 } else if (array->type->without_array()->is_interface()
252 && ((array->variable_referenced()->data.mode == ir_var_uniform
253 && !state->is_version(400, 320)
254 && !state->ARB_gpu_shader5_enable
255 && !state->EXT_gpu_shader5_enable
256 && !state->OES_gpu_shader5_enable) ||
257 (array->variable_referenced()->data.mode == ir_var_shader_storage
258 && !state->is_version(400, 0)
259 && !state->ARB_gpu_shader5_enable))) {
260 /* Page 50 in section 4.3.9 of the OpenGL ES 3.10 spec says:
261 *
262 * "All indices used to index a uniform or shader storage block
263 * array must be constant integral expressions."
264 *
265 * But OES_gpu_shader5 (and ESSL 3.20) relax this to allow indexing
266 * on uniform blocks but not shader storage blocks.
267 *
268 */
269 _mesa_glsl_error(&loc, state, "%s block array index must be constant",
270 array->variable_referenced()->data.mode
271 == ir_var_uniform ? "uniform" : "shader storage");
272 } else {
273 /* whole_variable_referenced can return NULL if the array is a
274 * member of a structure. In this case it is safe to not update
275 * the max_array_access field because it is never used for fields
276 * of structures.
277 */
278 ir_variable *v = array->whole_variable_referenced();
279 if (v != NULL)
280 v->data.max_array_access = array->type->array_size() - 1;
281 }
282
283 /* From page 23 (29 of the PDF) of the GLSL 1.30 spec:
284 *
285 * "Samplers aggregated into arrays within a shader (using square
286 * brackets [ ]) can only be indexed with integral constant
287 * expressions [...]."
288 *
289 * This restriction was added in GLSL 1.30. Shaders using earlier
290 * version of the language should not be rejected by the compiler
291 * front-end for using this construct. This allows useful things such
292 * as using a loop counter as the index to an array of samplers. If the
293 * loop in unrolled, the code should compile correctly. Instead, emit a
294 * warning.
295 *
296 * In GLSL 4.00 / ARB_gpu_shader5, this requirement is relaxed again to allow
297 * indexing with dynamically uniform expressions. Note that these are not
298 * required to be uniforms or expressions based on them, but merely that the
299 * values must not diverge between shader invocations run together. If the
300 * values *do* diverge, then the behavior of the operation requiring a
301 * dynamically uniform expression is undefined.
302 *
303 * From section 4.1.7 of the ARB_bindless_texture spec:
304 *
305 * "Samplers aggregated into arrays within a shader (using square
306 * brackets []) can be indexed with arbitrary integer expressions."
307 */
308 if (array->type->without_array()->is_sampler()) {
309 if (!state->is_version(400, 320) &&
310 !state->ARB_gpu_shader5_enable &&
311 !state->EXT_gpu_shader5_enable &&
312 !state->OES_gpu_shader5_enable &&
313 !state->has_bindless()) {
314 if (state->is_version(130, 300))
315 _mesa_glsl_error(&loc, state,
316 "sampler arrays indexed with non-constant "
317 "expressions are forbidden in GLSL %s "
318 "and later",
319 state->es_shader ? "ES 3.00" : "1.30");
320 else if (state->es_shader)
321 _mesa_glsl_warning(&loc, state,
322 "sampler arrays indexed with non-constant "
323 "expressions will be forbidden in GLSL "
324 "3.00 and later");
325 else
326 _mesa_glsl_warning(&loc, state,
327 "sampler arrays indexed with non-constant "
328 "expressions will be forbidden in GLSL "
329 "1.30 and later");
330 }
331 }
332
333 /* From page 27 of the GLSL ES 3.1 specification:
334 *
335 * "When aggregated into arrays within a shader, images can only be
336 * indexed with a constant integral expression."
337 *
338 * On the other hand the desktop GL specification extension allows
339 * non-constant indexing of image arrays, but behavior is left undefined
340 * in cases where the indexing expression is not dynamically uniform.
341 */
342 if (state->es_shader && array->type->without_array()->is_image()) {
343 _mesa_glsl_error(&loc, state,
344 "image arrays indexed with non-constant "
345 "expressions are forbidden in GLSL ES.");
346 }
347 }
348
349 /* After performing all of the error checking, generate the IR for the
350 * expression.
351 */
352 if (array->type->is_array()
353 || array->type->is_matrix()
354 || array->type->is_vector()) {
355 return new(mem_ctx) ir_dereference_array(array, idx);
356 } else if (array->type->is_error()) {
357 return array;
358 } else {
359 ir_rvalue *result = new(mem_ctx) ir_dereference_array(array, idx);
360 result->type = glsl_type::error_type;
361
362 return result;
363 }
364 }
365