2 * Copyright © 2010 Intel Corporation
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:
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
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.
26 * GLSL linker implementation
28 * Given a set of shaders that are to be linked to generate a final program,
29 * there are three distinct stages.
31 * In the first stage shaders are partitioned into groups based on the shader
32 * type. All shaders of a particular type (e.g., vertex shaders) are linked
35 * - Undefined references in each shader are resolve to definitions in
37 * - Types and qualifiers of uniforms, outputs, and global variables defined
38 * in multiple shaders with the same name are verified to be the same.
39 * - Initializers for uniforms and global variables defined
40 * in multiple shaders with the same name are verified to be the same.
42 * The result, in the terminology of the GLSL spec, is a set of shader
43 * executables for each processing unit.
45 * After the first stage is complete, a series of semantic checks are performed
46 * on each of the shader executables.
48 * - Each shader executable must define a \c main function.
49 * - Each vertex shader executable must write to \c gl_Position.
50 * - Each fragment shader executable must write to either \c gl_FragData or
53 * In the final stage individual shader executables are linked to create a
54 * complete exectuable.
56 * - Types of uniforms defined in multiple shader stages with the same name
57 * are verified to be the same.
58 * - Initializers for uniforms defined in multiple shader stages with the
59 * same name are verified to be the same.
60 * - Types and qualifiers of outputs defined in one stage are verified to
61 * be the same as the types and qualifiers of inputs defined with the same
62 * name in a later stage.
64 * \author Ian Romanick <ian.d.romanick@intel.com>
75 #include "main/core.h"
76 #include "glsl_symbol_table.h"
79 #include "program/hash_table.h"
81 #include "ir_optimization.h"
84 #include "main/shaderobj.h"
88 * Visitor that determines whether or not a variable is ever written.
90 class find_assignment_visitor
: public ir_hierarchical_visitor
{
92 find_assignment_visitor(const char *name
)
93 : name(name
), found(false)
98 virtual ir_visitor_status
visit_enter(ir_assignment
*ir
)
100 ir_variable
*const var
= ir
->lhs
->variable_referenced();
102 if (strcmp(name
, var
->name
) == 0) {
107 return visit_continue_with_parent
;
110 virtual ir_visitor_status
visit_enter(ir_call
*ir
)
112 exec_list_iterator sig_iter
= ir
->get_callee()->parameters
.iterator();
113 foreach_iter(exec_list_iterator
, iter
, *ir
) {
114 ir_rvalue
*param_rval
= (ir_rvalue
*)iter
.get();
115 ir_variable
*sig_param
= (ir_variable
*)sig_iter
.get();
117 if (sig_param
->mode
== ir_var_out
||
118 sig_param
->mode
== ir_var_inout
) {
119 ir_variable
*var
= param_rval
->variable_referenced();
120 if (var
&& strcmp(name
, var
->name
) == 0) {
128 return visit_continue_with_parent
;
131 bool variable_found()
137 const char *name
; /**< Find writes to a variable with this name. */
138 bool found
; /**< Was a write to the variable found? */
143 * Visitor that determines whether or not a variable is ever read.
145 class find_deref_visitor
: public ir_hierarchical_visitor
{
147 find_deref_visitor(const char *name
)
148 : name(name
), found(false)
153 virtual ir_visitor_status
visit(ir_dereference_variable
*ir
)
155 if (strcmp(this->name
, ir
->var
->name
) == 0) {
160 return visit_continue
;
163 bool variable_found() const
169 const char *name
; /**< Find writes to a variable with this name. */
170 bool found
; /**< Was a write to the variable found? */
175 linker_error_printf(gl_shader_program
*prog
, const char *fmt
, ...)
179 prog
->InfoLog
= talloc_strdup_append(prog
->InfoLog
, "error: ");
181 prog
->InfoLog
= talloc_vasprintf_append(prog
->InfoLog
, fmt
, ap
);
187 invalidate_variable_locations(gl_shader
*sh
, enum ir_variable_mode mode
,
190 foreach_list(node
, sh
->ir
) {
191 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
193 if ((var
== NULL
) || (var
->mode
!= (unsigned) mode
))
196 /* Only assign locations for generic attributes / varyings / etc.
198 if ((var
->location
>= generic_base
) && !var
->explicit_location
)
205 * Determine the number of attribute slots required for a particular type
207 * This code is here because it implements the language rules of a specific
208 * GLSL version. Since it's a property of the language and not a property of
209 * types in general, it doesn't really belong in glsl_type.
212 count_attribute_slots(const glsl_type
*t
)
214 /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec:
216 * "A scalar input counts the same amount against this limit as a vec4,
217 * so applications may want to consider packing groups of four
218 * unrelated float inputs together into a vector to better utilize the
219 * capabilities of the underlying hardware. A matrix input will use up
220 * multiple locations. The number of locations used will equal the
221 * number of columns in the matrix."
223 * The spec does not explicitly say how arrays are counted. However, it
224 * should be safe to assume the total number of slots consumed by an array
225 * is the number of entries in the array multiplied by the number of slots
226 * consumed by a single element of the array.
230 return t
->array_size() * count_attribute_slots(t
->element_type());
233 return t
->matrix_columns
;
240 * Verify that a vertex shader executable meets all semantic requirements
242 * \param shader Vertex shader executable to be verified
245 validate_vertex_shader_executable(struct gl_shader_program
*prog
,
246 struct gl_shader
*shader
)
251 find_assignment_visitor
find("gl_Position");
252 find
.run(shader
->ir
);
253 if (!find
.variable_found()) {
254 linker_error_printf(prog
,
255 "vertex shader does not write to `gl_Position'\n");
264 * Verify that a fragment shader executable meets all semantic requirements
266 * \param shader Fragment shader executable to be verified
269 validate_fragment_shader_executable(struct gl_shader_program
*prog
,
270 struct gl_shader
*shader
)
275 find_assignment_visitor
frag_color("gl_FragColor");
276 find_assignment_visitor
frag_data("gl_FragData");
278 frag_color
.run(shader
->ir
);
279 frag_data
.run(shader
->ir
);
281 if (frag_color
.variable_found() && frag_data
.variable_found()) {
282 linker_error_printf(prog
, "fragment shader writes to both "
283 "`gl_FragColor' and `gl_FragData'\n");
292 * Generate a string describing the mode of a variable
295 mode_string(const ir_variable
*var
)
299 return (var
->read_only
) ? "global constant" : "global variable";
301 case ir_var_uniform
: return "uniform";
302 case ir_var_in
: return "shader input";
303 case ir_var_out
: return "shader output";
304 case ir_var_inout
: return "shader inout";
306 case ir_var_temporary
:
308 assert(!"Should not get here.");
309 return "invalid variable";
315 * Perform validation of global variables used across multiple shaders
318 cross_validate_globals(struct gl_shader_program
*prog
,
319 struct gl_shader
**shader_list
,
320 unsigned num_shaders
,
323 /* Examine all of the uniforms in all of the shaders and cross validate
326 glsl_symbol_table variables
;
327 for (unsigned i
= 0; i
< num_shaders
; i
++) {
328 if (shader_list
[i
] == NULL
)
331 foreach_list(node
, shader_list
[i
]->ir
) {
332 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
337 if (uniforms_only
&& (var
->mode
!= ir_var_uniform
))
340 /* Don't cross validate temporaries that are at global scope. These
341 * will eventually get pulled into the shaders 'main'.
343 if (var
->mode
== ir_var_temporary
)
346 /* If a global with this name has already been seen, verify that the
347 * new instance has the same type. In addition, if the globals have
348 * initializers, the values of the initializers must be the same.
350 ir_variable
*const existing
= variables
.get_variable(var
->name
);
351 if (existing
!= NULL
) {
352 if (var
->type
!= existing
->type
) {
353 /* Consider the types to be "the same" if both types are arrays
354 * of the same type and one of the arrays is implicitly sized.
355 * In addition, set the type of the linked variable to the
356 * explicitly sized array.
358 if (var
->type
->is_array()
359 && existing
->type
->is_array()
360 && (var
->type
->fields
.array
== existing
->type
->fields
.array
)
361 && ((var
->type
->length
== 0)
362 || (existing
->type
->length
== 0))) {
363 if (existing
->type
->length
== 0)
364 existing
->type
= var
->type
;
366 linker_error_printf(prog
, "%s `%s' declared as type "
367 "`%s' and type `%s'\n",
369 var
->name
, var
->type
->name
,
370 existing
->type
->name
);
375 if (var
->explicit_location
) {
376 if (existing
->explicit_location
377 && (var
->location
!= existing
->location
)) {
378 linker_error_printf(prog
, "explicit locations for %s "
379 "`%s' have differing values\n",
380 mode_string(var
), var
->name
);
384 existing
->location
= var
->location
;
385 existing
->explicit_location
= true;
388 /* FINISHME: Handle non-constant initializers.
390 if (var
->constant_value
!= NULL
) {
391 if (existing
->constant_value
!= NULL
) {
392 if (!var
->constant_value
->has_value(existing
->constant_value
)) {
393 linker_error_printf(prog
, "initializers for %s "
394 "`%s' have differing values\n",
395 mode_string(var
), var
->name
);
399 /* If the first-seen instance of a particular uniform did not
400 * have an initializer but a later instance does, copy the
401 * initializer to the version stored in the symbol table.
403 /* FINISHME: This is wrong. The constant_value field should
404 * FINISHME: not be modified! Imagine a case where a shader
405 * FINISHME: without an initializer is linked in two different
406 * FINISHME: programs with shaders that have differing
407 * FINISHME: initializers. Linking with the first will
408 * FINISHME: modify the shader, and linking with the second
409 * FINISHME: will fail.
411 existing
->constant_value
=
412 var
->constant_value
->clone(talloc_parent(existing
), NULL
);
415 if (existing
->invariant
!= var
->invariant
) {
416 linker_error_printf(prog
, "declarations for %s `%s' have "
417 "mismatching invariant qualifiers\n",
418 mode_string(var
), var
->name
);
422 variables
.add_variable(var
);
431 * Perform validation of uniforms used across multiple shader stages
434 cross_validate_uniforms(struct gl_shader_program
*prog
)
436 return cross_validate_globals(prog
, prog
->_LinkedShaders
,
437 MESA_SHADER_TYPES
, true);
442 * Validate that outputs from one stage match inputs of another
445 cross_validate_outputs_to_inputs(struct gl_shader_program
*prog
,
446 gl_shader
*producer
, gl_shader
*consumer
)
448 glsl_symbol_table parameters
;
449 /* FINISHME: Figure these out dynamically. */
450 const char *const producer_stage
= "vertex";
451 const char *const consumer_stage
= "fragment";
453 /* Find all shader outputs in the "producer" stage.
455 foreach_list(node
, producer
->ir
) {
456 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
458 /* FINISHME: For geometry shaders, this should also look for inout
459 * FINISHME: variables.
461 if ((var
== NULL
) || (var
->mode
!= ir_var_out
))
464 parameters
.add_variable(var
);
468 /* Find all shader inputs in the "consumer" stage. Any variables that have
469 * matching outputs already in the symbol table must have the same type and
472 foreach_list(node
, consumer
->ir
) {
473 ir_variable
*const input
= ((ir_instruction
*) node
)->as_variable();
475 /* FINISHME: For geometry shaders, this should also look for inout
476 * FINISHME: variables.
478 if ((input
== NULL
) || (input
->mode
!= ir_var_in
))
481 ir_variable
*const output
= parameters
.get_variable(input
->name
);
482 if (output
!= NULL
) {
483 /* Check that the types match between stages.
485 if (input
->type
!= output
->type
) {
486 linker_error_printf(prog
,
487 "%s shader output `%s' declared as "
488 "type `%s', but %s shader input declared "
490 producer_stage
, output
->name
,
492 consumer_stage
, input
->type
->name
);
496 /* Check that all of the qualifiers match between stages.
498 if (input
->centroid
!= output
->centroid
) {
499 linker_error_printf(prog
,
500 "%s shader output `%s' %s centroid qualifier, "
501 "but %s shader input %s centroid qualifier\n",
504 (output
->centroid
) ? "has" : "lacks",
506 (input
->centroid
) ? "has" : "lacks");
510 if (input
->invariant
!= output
->invariant
) {
511 linker_error_printf(prog
,
512 "%s shader output `%s' %s invariant qualifier, "
513 "but %s shader input %s invariant qualifier\n",
516 (output
->invariant
) ? "has" : "lacks",
518 (input
->invariant
) ? "has" : "lacks");
522 if (input
->interpolation
!= output
->interpolation
) {
523 linker_error_printf(prog
,
524 "%s shader output `%s' specifies %s "
525 "interpolation qualifier, "
526 "but %s shader input specifies %s "
527 "interpolation qualifier\n",
530 output
->interpolation_string(),
532 input
->interpolation_string());
543 * Populates a shaders symbol table with all global declarations
546 populate_symbol_table(gl_shader
*sh
)
548 sh
->symbols
= new(sh
) glsl_symbol_table
;
550 foreach_list(node
, sh
->ir
) {
551 ir_instruction
*const inst
= (ir_instruction
*) node
;
555 if ((func
= inst
->as_function()) != NULL
) {
556 sh
->symbols
->add_function(func
);
557 } else if ((var
= inst
->as_variable()) != NULL
) {
558 sh
->symbols
->add_variable(var
);
565 * Remap variables referenced in an instruction tree
567 * This is used when instruction trees are cloned from one shader and placed in
568 * another. These trees will contain references to \c ir_variable nodes that
569 * do not exist in the target shader. This function finds these \c ir_variable
570 * references and replaces the references with matching variables in the target
573 * If there is no matching variable in the target shader, a clone of the
574 * \c ir_variable is made and added to the target shader. The new variable is
575 * added to \b both the instruction stream and the symbol table.
577 * \param inst IR tree that is to be processed.
578 * \param symbols Symbol table containing global scope symbols in the
580 * \param instructions Instruction stream where new variable declarations
584 remap_variables(ir_instruction
*inst
, struct gl_shader
*target
,
587 class remap_visitor
: public ir_hierarchical_visitor
{
589 remap_visitor(struct gl_shader
*target
,
592 this->target
= target
;
593 this->symbols
= target
->symbols
;
594 this->instructions
= target
->ir
;
598 virtual ir_visitor_status
visit(ir_dereference_variable
*ir
)
600 if (ir
->var
->mode
== ir_var_temporary
) {
601 ir_variable
*var
= (ir_variable
*) hash_table_find(temps
, ir
->var
);
605 return visit_continue
;
608 ir_variable
*const existing
=
609 this->symbols
->get_variable(ir
->var
->name
);
610 if (existing
!= NULL
)
613 ir_variable
*copy
= ir
->var
->clone(this->target
, NULL
);
615 this->symbols
->add_variable(copy
);
616 this->instructions
->push_head(copy
);
620 return visit_continue
;
624 struct gl_shader
*target
;
625 glsl_symbol_table
*symbols
;
626 exec_list
*instructions
;
630 remap_visitor
v(target
, temps
);
637 * Move non-declarations from one instruction stream to another
639 * The intended usage pattern of this function is to pass the pointer to the
640 * head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node
641 * pointer) for \c last and \c false for \c make_copies on the first
642 * call. Successive calls pass the return value of the previous call for
643 * \c last and \c true for \c make_copies.
645 * \param instructions Source instruction stream
646 * \param last Instruction after which new instructions should be
647 * inserted in the target instruction stream
648 * \param make_copies Flag selecting whether instructions in \c instructions
649 * should be copied (via \c ir_instruction::clone) into the
650 * target list or moved.
653 * The new "last" instruction in the target instruction stream. This pointer
654 * is suitable for use as the \c last parameter of a later call to this
658 move_non_declarations(exec_list
*instructions
, exec_node
*last
,
659 bool make_copies
, gl_shader
*target
)
661 hash_table
*temps
= NULL
;
664 temps
= hash_table_ctor(0, hash_table_pointer_hash
,
665 hash_table_pointer_compare
);
667 foreach_list_safe(node
, instructions
) {
668 ir_instruction
*inst
= (ir_instruction
*) node
;
670 if (inst
->as_function())
673 ir_variable
*var
= inst
->as_variable();
674 if ((var
!= NULL
) && (var
->mode
!= ir_var_temporary
))
677 assert(inst
->as_assignment()
678 || ((var
!= NULL
) && (var
->mode
== ir_var_temporary
)));
681 inst
= inst
->clone(target
, NULL
);
684 hash_table_insert(temps
, inst
, var
);
686 remap_variables(inst
, target
, temps
);
691 last
->insert_after(inst
);
696 hash_table_dtor(temps
);
702 * Get the function signature for main from a shader
704 static ir_function_signature
*
705 get_main_function_signature(gl_shader
*sh
)
707 ir_function
*const f
= sh
->symbols
->get_function("main");
709 exec_list void_parameters
;
711 /* Look for the 'void main()' signature and ensure that it's defined.
712 * This keeps the linker from accidentally pick a shader that just
713 * contains a prototype for main.
715 * We don't have to check for multiple definitions of main (in multiple
716 * shaders) because that would have already been caught above.
718 ir_function_signature
*sig
= f
->matching_signature(&void_parameters
);
719 if ((sig
!= NULL
) && sig
->is_defined
) {
729 * Combine a group of shaders for a single stage to generate a linked shader
732 * If this function is supplied a single shader, it is cloned, and the new
733 * shader is returned.
735 static struct gl_shader
*
736 link_intrastage_shaders(void *mem_ctx
,
737 struct gl_context
*ctx
,
738 struct gl_shader_program
*prog
,
739 struct gl_shader
**shader_list
,
740 unsigned num_shaders
)
742 /* Check that global variables defined in multiple shaders are consistent.
744 if (!cross_validate_globals(prog
, shader_list
, num_shaders
, false))
747 /* Check that there is only a single definition of each function signature
748 * across all shaders.
750 for (unsigned i
= 0; i
< (num_shaders
- 1); i
++) {
751 foreach_list(node
, shader_list
[i
]->ir
) {
752 ir_function
*const f
= ((ir_instruction
*) node
)->as_function();
757 for (unsigned j
= i
+ 1; j
< num_shaders
; j
++) {
758 ir_function
*const other
=
759 shader_list
[j
]->symbols
->get_function(f
->name
);
761 /* If the other shader has no function (and therefore no function
762 * signatures) with the same name, skip to the next shader.
767 foreach_iter (exec_list_iterator
, iter
, *f
) {
768 ir_function_signature
*sig
=
769 (ir_function_signature
*) iter
.get();
771 if (!sig
->is_defined
|| sig
->is_builtin
)
774 ir_function_signature
*other_sig
=
775 other
->exact_matching_signature(& sig
->parameters
);
777 if ((other_sig
!= NULL
) && other_sig
->is_defined
778 && !other_sig
->is_builtin
) {
779 linker_error_printf(prog
,
780 "function `%s' is multiply defined",
789 /* Find the shader that defines main, and make a clone of it.
791 * Starting with the clone, search for undefined references. If one is
792 * found, find the shader that defines it. Clone the reference and add
793 * it to the shader. Repeat until there are no undefined references or
794 * until a reference cannot be resolved.
796 gl_shader
*main
= NULL
;
797 for (unsigned i
= 0; i
< num_shaders
; i
++) {
798 if (get_main_function_signature(shader_list
[i
]) != NULL
) {
799 main
= shader_list
[i
];
805 linker_error_printf(prog
, "%s shader lacks `main'\n",
806 (shader_list
[0]->Type
== GL_VERTEX_SHADER
)
807 ? "vertex" : "fragment");
811 gl_shader
*linked
= ctx
->Driver
.NewShader(NULL
, 0, main
->Type
);
812 linked
->ir
= new(linked
) exec_list
;
813 clone_ir_list(mem_ctx
, linked
->ir
, main
->ir
);
815 populate_symbol_table(linked
);
817 /* The a pointer to the main function in the final linked shader (i.e., the
818 * copy of the original shader that contained the main function).
820 ir_function_signature
*const main_sig
= get_main_function_signature(linked
);
822 /* Move any instructions other than variable declarations or function
823 * declarations into main.
825 exec_node
*insertion_point
=
826 move_non_declarations(linked
->ir
, (exec_node
*) &main_sig
->body
, false,
829 for (unsigned i
= 0; i
< num_shaders
; i
++) {
830 if (shader_list
[i
] == main
)
833 insertion_point
= move_non_declarations(shader_list
[i
]->ir
,
834 insertion_point
, true, linked
);
837 /* Resolve initializers for global variables in the linked shader.
839 unsigned num_linking_shaders
= num_shaders
;
840 for (unsigned i
= 0; i
< num_shaders
; i
++)
841 num_linking_shaders
+= shader_list
[i
]->num_builtins_to_link
;
843 gl_shader
**linking_shaders
=
844 (gl_shader
**) calloc(num_linking_shaders
, sizeof(gl_shader
*));
846 memcpy(linking_shaders
, shader_list
,
847 sizeof(linking_shaders
[0]) * num_shaders
);
849 unsigned idx
= num_shaders
;
850 for (unsigned i
= 0; i
< num_shaders
; i
++) {
851 memcpy(&linking_shaders
[idx
], shader_list
[i
]->builtins_to_link
,
852 sizeof(linking_shaders
[0]) * shader_list
[i
]->num_builtins_to_link
);
853 idx
+= shader_list
[i
]->num_builtins_to_link
;
856 assert(idx
== num_linking_shaders
);
858 if (!link_function_calls(prog
, linked
, linking_shaders
,
859 num_linking_shaders
)) {
860 ctx
->Driver
.DeleteShader(ctx
, linked
);
864 free(linking_shaders
);
870 struct uniform_node
{
872 struct gl_uniform
*u
;
877 * Update the sizes of linked shader uniform arrays to the maximum
880 * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
882 * If one or more elements of an array are active,
883 * GetActiveUniform will return the name of the array in name,
884 * subject to the restrictions listed above. The type of the array
885 * is returned in type. The size parameter contains the highest
886 * array element index used, plus one. The compiler or linker
887 * determines the highest index used. There will be only one
888 * active uniform reported by the GL per uniform array.
892 update_array_sizes(struct gl_shader_program
*prog
)
894 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
895 if (prog
->_LinkedShaders
[i
] == NULL
)
898 foreach_list(node
, prog
->_LinkedShaders
[i
]->ir
) {
899 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
901 if ((var
== NULL
) || (var
->mode
!= ir_var_uniform
&&
902 var
->mode
!= ir_var_in
&&
903 var
->mode
!= ir_var_out
) ||
904 !var
->type
->is_array())
907 unsigned int size
= var
->max_array_access
;
908 for (unsigned j
= 0; j
< MESA_SHADER_TYPES
; j
++) {
909 if (prog
->_LinkedShaders
[j
] == NULL
)
912 foreach_list(node2
, prog
->_LinkedShaders
[j
]->ir
) {
913 ir_variable
*other_var
= ((ir_instruction
*) node2
)->as_variable();
917 if (strcmp(var
->name
, other_var
->name
) == 0 &&
918 other_var
->max_array_access
> size
) {
919 size
= other_var
->max_array_access
;
924 if (size
+ 1 != var
->type
->fields
.array
->length
) {
925 var
->type
= glsl_type::get_array_instance(var
->type
->fields
.array
,
927 /* FINISHME: We should update the types of array
928 * dereferences of this variable now.
936 add_uniform(void *mem_ctx
, exec_list
*uniforms
, struct hash_table
*ht
,
937 const char *name
, const glsl_type
*type
, GLenum shader_type
,
938 unsigned *next_shader_pos
, unsigned *total_uniforms
)
940 if (type
->is_record()) {
941 for (unsigned int i
= 0; i
< type
->length
; i
++) {
942 const glsl_type
*field_type
= type
->fields
.structure
[i
].type
;
943 char *field_name
= talloc_asprintf(mem_ctx
, "%s.%s", name
,
944 type
->fields
.structure
[i
].name
);
946 add_uniform(mem_ctx
, uniforms
, ht
, field_name
, field_type
,
947 shader_type
, next_shader_pos
, total_uniforms
);
950 uniform_node
*n
= (uniform_node
*) hash_table_find(ht
, name
);
951 unsigned int vec4_slots
;
952 const glsl_type
*array_elem_type
= NULL
;
954 if (type
->is_array()) {
955 array_elem_type
= type
->fields
.array
;
956 /* Array of structures. */
957 if (array_elem_type
->is_record()) {
958 for (unsigned int i
= 0; i
< type
->length
; i
++) {
959 char *elem_name
= talloc_asprintf(mem_ctx
, "%s[%d]", name
, i
);
960 add_uniform(mem_ctx
, uniforms
, ht
, elem_name
, array_elem_type
,
961 shader_type
, next_shader_pos
, total_uniforms
);
967 /* Fix the storage size of samplers at 1 vec4 each. Be sure to pad out
968 * vectors to vec4 slots.
970 if (type
->is_array()) {
971 if (array_elem_type
->is_sampler())
972 vec4_slots
= type
->length
;
974 vec4_slots
= type
->length
* array_elem_type
->matrix_columns
;
975 } else if (type
->is_sampler()) {
978 vec4_slots
= type
->matrix_columns
;
982 n
= (uniform_node
*) calloc(1, sizeof(struct uniform_node
));
983 n
->u
= (gl_uniform
*) calloc(1, sizeof(struct gl_uniform
));
984 n
->slots
= vec4_slots
;
986 n
->u
->Name
= strdup(name
);
993 hash_table_insert(ht
, n
, name
);
994 uniforms
->push_tail(& n
->link
);
997 switch (shader_type
) {
998 case GL_VERTEX_SHADER
:
999 n
->u
->VertPos
= *next_shader_pos
;
1001 case GL_FRAGMENT_SHADER
:
1002 n
->u
->FragPos
= *next_shader_pos
;
1004 case GL_GEOMETRY_SHADER
:
1005 n
->u
->GeomPos
= *next_shader_pos
;
1009 (*next_shader_pos
) += vec4_slots
;
1014 assign_uniform_locations(struct gl_shader_program
*prog
)
1018 unsigned total_uniforms
= 0;
1019 hash_table
*ht
= hash_table_ctor(32, hash_table_string_hash
,
1020 hash_table_string_compare
);
1021 void *mem_ctx
= talloc_new(NULL
);
1023 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
1024 if (prog
->_LinkedShaders
[i
] == NULL
)
1027 unsigned next_position
= 0;
1029 foreach_list(node
, prog
->_LinkedShaders
[i
]->ir
) {
1030 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1032 if ((var
== NULL
) || (var
->mode
!= ir_var_uniform
))
1035 if (strncmp(var
->name
, "gl_", 3) == 0) {
1036 /* At the moment, we don't allocate uniform locations for
1037 * builtin uniforms. It's permitted by spec, and we'll
1038 * likely switch to doing that at some point, but not yet.
1043 var
->location
= next_position
;
1044 add_uniform(mem_ctx
, &uniforms
, ht
, var
->name
, var
->type
,
1045 prog
->_LinkedShaders
[i
]->Type
,
1046 &next_position
, &total_uniforms
);
1050 talloc_free(mem_ctx
);
1052 gl_uniform_list
*ul
= (gl_uniform_list
*)
1053 calloc(1, sizeof(gl_uniform_list
));
1055 ul
->Size
= total_uniforms
;
1056 ul
->NumUniforms
= total_uniforms
;
1057 ul
->Uniforms
= (gl_uniform
*) calloc(total_uniforms
, sizeof(gl_uniform
));
1061 for (uniform_node
*node
= (uniform_node
*) uniforms
.head
1062 ; node
->link
.next
!= NULL
1064 next
= (uniform_node
*) node
->link
.next
;
1066 node
->link
.remove();
1067 memcpy(&ul
->Uniforms
[idx
], node
->u
, sizeof(gl_uniform
));
1074 hash_table_dtor(ht
);
1076 prog
->Uniforms
= ul
;
1081 * Find a contiguous set of available bits in a bitmask
1083 * \param used_mask Bits representing used (1) and unused (0) locations
1084 * \param needed_count Number of contiguous bits needed.
1087 * Base location of the available bits on success or -1 on failure.
1090 find_available_slots(unsigned used_mask
, unsigned needed_count
)
1092 unsigned needed_mask
= (1 << needed_count
) - 1;
1093 const int max_bit_to_test
= (8 * sizeof(used_mask
)) - needed_count
;
1095 /* The comparison to 32 is redundant, but without it GCC emits "warning:
1096 * cannot optimize possibly infinite loops" for the loop below.
1098 if ((needed_count
== 0) || (max_bit_to_test
< 0) || (max_bit_to_test
> 32))
1101 for (int i
= 0; i
<= max_bit_to_test
; i
++) {
1102 if ((needed_mask
& ~used_mask
) == needed_mask
)
1113 assign_attribute_locations(gl_shader_program
*prog
, unsigned max_attribute_index
)
1115 /* Mark invalid attribute locations as being used.
1117 unsigned used_locations
= (max_attribute_index
>= 32)
1118 ? ~0 : ~((1 << max_attribute_index
) - 1);
1120 gl_shader
*const sh
= prog
->_LinkedShaders
[0];
1121 assert(sh
->Type
== GL_VERTEX_SHADER
);
1123 /* Operate in a total of four passes.
1125 * 1. Invalidate the location assignments for all vertex shader inputs.
1127 * 2. Assign locations for inputs that have user-defined (via
1128 * glBindVertexAttribLocation) locatoins.
1130 * 3. Sort the attributes without assigned locations by number of slots
1131 * required in decreasing order. Fragmentation caused by attribute
1132 * locations assigned by the application may prevent large attributes
1133 * from having enough contiguous space.
1135 * 4. Assign locations to any inputs without assigned locations.
1138 invalidate_variable_locations(sh
, ir_var_in
, VERT_ATTRIB_GENERIC0
);
1140 if (prog
->Attributes
!= NULL
) {
1141 for (unsigned i
= 0; i
< prog
->Attributes
->NumParameters
; i
++) {
1142 ir_variable
*const var
=
1143 sh
->symbols
->get_variable(prog
->Attributes
->Parameters
[i
].Name
);
1145 /* Note: attributes that occupy multiple slots, such as arrays or
1146 * matrices, may appear in the attrib array multiple times.
1148 if ((var
== NULL
) || (var
->location
!= -1))
1151 /* From page 61 of the OpenGL 4.0 spec:
1153 * "LinkProgram will fail if the attribute bindings assigned by
1154 * BindAttribLocation do not leave not enough space to assign a
1155 * location for an active matrix attribute or an active attribute
1156 * array, both of which require multiple contiguous generic
1159 * Previous versions of the spec contain similar language but omit the
1160 * bit about attribute arrays.
1162 * Page 61 of the OpenGL 4.0 spec also says:
1164 * "It is possible for an application to bind more than one
1165 * attribute name to the same location. This is referred to as
1166 * aliasing. This will only work if only one of the aliased
1167 * attributes is active in the executable program, or if no path
1168 * through the shader consumes more than one attribute of a set
1169 * of attributes aliased to the same location. A link error can
1170 * occur if the linker determines that every path through the
1171 * shader consumes multiple aliased attributes, but
1172 * implementations are not required to generate an error in this
1175 * These two paragraphs are either somewhat contradictory, or I don't
1176 * fully understand one or both of them.
1178 /* FINISHME: The code as currently written does not support attribute
1179 * FINISHME: location aliasing (see comment above).
1181 const int attr
= prog
->Attributes
->Parameters
[i
].StateIndexes
[0];
1182 const unsigned slots
= count_attribute_slots(var
->type
);
1184 /* Mask representing the contiguous slots that will be used by this
1187 const unsigned use_mask
= (1 << slots
) - 1;
1189 /* Generate a link error if the set of bits requested for this
1190 * attribute overlaps any previously allocated bits.
1192 if ((~(use_mask
<< attr
) & used_locations
) != used_locations
) {
1193 linker_error_printf(prog
,
1194 "insufficient contiguous attribute locations "
1195 "available for vertex shader input `%s'",
1200 var
->location
= VERT_ATTRIB_GENERIC0
+ attr
;
1201 used_locations
|= (use_mask
<< attr
);
1205 /* Temporary storage for the set of attributes that need locations assigned.
1211 /* Used below in the call to qsort. */
1212 static int compare(const void *a
, const void *b
)
1214 const temp_attr
*const l
= (const temp_attr
*) a
;
1215 const temp_attr
*const r
= (const temp_attr
*) b
;
1217 /* Reversed because we want a descending order sort below. */
1218 return r
->slots
- l
->slots
;
1222 unsigned num_attr
= 0;
1224 foreach_list(node
, sh
->ir
) {
1225 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1227 if ((var
== NULL
) || (var
->mode
!= ir_var_in
))
1230 if (var
->explicit_location
) {
1231 const unsigned slots
= count_attribute_slots(var
->type
);
1232 const unsigned use_mask
= (1 << slots
) - 1;
1233 const int attr
= var
->location
- VERT_ATTRIB_GENERIC0
;
1235 if ((var
->location
>= (int)(max_attribute_index
+ VERT_ATTRIB_GENERIC0
))
1236 || (var
->location
< 0)) {
1237 linker_error_printf(prog
,
1238 "invalid explicit location %d specified for "
1240 (var
->location
< 0) ? var
->location
: attr
,
1243 } else if (var
->location
>= VERT_ATTRIB_GENERIC0
) {
1244 used_locations
|= (use_mask
<< attr
);
1248 /* The location was explicitly assigned, nothing to do here.
1250 if (var
->location
!= -1)
1253 to_assign
[num_attr
].slots
= count_attribute_slots(var
->type
);
1254 to_assign
[num_attr
].var
= var
;
1258 /* If all of the attributes were assigned locations by the application (or
1259 * are built-in attributes with fixed locations), return early. This should
1260 * be the common case.
1265 qsort(to_assign
, num_attr
, sizeof(to_assign
[0]), temp_attr::compare
);
1267 /* VERT_ATTRIB_GENERIC0 is a psdueo-alias for VERT_ATTRIB_POS. It can only
1268 * be explicitly assigned by via glBindAttribLocation. Mark it as reserved
1269 * to prevent it from being automatically allocated below.
1271 find_deref_visitor
find("gl_Vertex");
1273 if (find
.variable_found())
1274 used_locations
|= (1 << 0);
1276 for (unsigned i
= 0; i
< num_attr
; i
++) {
1277 /* Mask representing the contiguous slots that will be used by this
1280 const unsigned use_mask
= (1 << to_assign
[i
].slots
) - 1;
1282 int location
= find_available_slots(used_locations
, to_assign
[i
].slots
);
1285 linker_error_printf(prog
,
1286 "insufficient contiguous attribute locations "
1287 "available for vertex shader input `%s'",
1288 to_assign
[i
].var
->name
);
1292 to_assign
[i
].var
->location
= VERT_ATTRIB_GENERIC0
+ location
;
1293 used_locations
|= (use_mask
<< location
);
1301 * Demote shader inputs and outputs that are not used in other stages
1304 demote_shader_inputs_and_outputs(gl_shader
*sh
, enum ir_variable_mode mode
)
1306 foreach_list(node
, sh
->ir
) {
1307 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1309 if ((var
== NULL
) || (var
->mode
!= int(mode
)))
1312 /* A shader 'in' or 'out' variable is only really an input or output if
1313 * its value is used by other shader stages. This will cause the variable
1314 * to have a location assigned.
1316 if (var
->location
== -1) {
1317 var
->mode
= ir_var_auto
;
1324 assign_varying_locations(struct gl_shader_program
*prog
,
1325 gl_shader
*producer
, gl_shader
*consumer
)
1327 /* FINISHME: Set dynamically when geometry shader support is added. */
1328 unsigned output_index
= VERT_RESULT_VAR0
;
1329 unsigned input_index
= FRAG_ATTRIB_VAR0
;
1331 /* Operate in a total of three passes.
1333 * 1. Assign locations for any matching inputs and outputs.
1335 * 2. Mark output variables in the producer that do not have locations as
1336 * not being outputs. This lets the optimizer eliminate them.
1338 * 3. Mark input variables in the consumer that do not have locations as
1339 * not being inputs. This lets the optimizer eliminate them.
1342 invalidate_variable_locations(producer
, ir_var_out
, VERT_RESULT_VAR0
);
1343 invalidate_variable_locations(consumer
, ir_var_in
, FRAG_ATTRIB_VAR0
);
1345 foreach_list(node
, producer
->ir
) {
1346 ir_variable
*const output_var
= ((ir_instruction
*) node
)->as_variable();
1348 if ((output_var
== NULL
) || (output_var
->mode
!= ir_var_out
)
1349 || (output_var
->location
!= -1))
1352 ir_variable
*const input_var
=
1353 consumer
->symbols
->get_variable(output_var
->name
);
1355 if ((input_var
== NULL
) || (input_var
->mode
!= ir_var_in
))
1358 assert(input_var
->location
== -1);
1360 output_var
->location
= output_index
;
1361 input_var
->location
= input_index
;
1363 /* FINISHME: Support for "varying" records in GLSL 1.50. */
1364 assert(!output_var
->type
->is_record());
1366 if (output_var
->type
->is_array()) {
1367 const unsigned slots
= output_var
->type
->length
1368 * output_var
->type
->fields
.array
->matrix_columns
;
1370 output_index
+= slots
;
1371 input_index
+= slots
;
1373 const unsigned slots
= output_var
->type
->matrix_columns
;
1375 output_index
+= slots
;
1376 input_index
+= slots
;
1380 foreach_list(node
, consumer
->ir
) {
1381 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1383 if ((var
== NULL
) || (var
->mode
!= ir_var_in
))
1386 if (var
->location
== -1) {
1387 if (prog
->Version
<= 120) {
1388 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
1390 * Only those varying variables used (i.e. read) in
1391 * the fragment shader executable must be written to
1392 * by the vertex shader executable; declaring
1393 * superfluous varying variables in a vertex shader is
1396 * We interpret this text as meaning that the VS must
1397 * write the variable for the FS to read it. See
1398 * "glsl1-varying read but not written" in piglit.
1401 linker_error_printf(prog
, "fragment shader varying %s not written "
1402 "by vertex shader\n.", var
->name
);
1403 prog
->LinkStatus
= false;
1406 /* An 'in' variable is only really a shader input if its
1407 * value is written by the previous stage.
1409 var
->mode
= ir_var_auto
;
1416 link_shaders(struct gl_context
*ctx
, struct gl_shader_program
*prog
)
1418 void *mem_ctx
= talloc_init("temporary linker context");
1420 prog
->LinkStatus
= false;
1421 prog
->Validated
= false;
1422 prog
->_Used
= false;
1424 if (prog
->InfoLog
!= NULL
)
1425 talloc_free(prog
->InfoLog
);
1427 prog
->InfoLog
= talloc_strdup(NULL
, "");
1429 /* Separate the shaders into groups based on their type.
1431 struct gl_shader
**vert_shader_list
;
1432 unsigned num_vert_shaders
= 0;
1433 struct gl_shader
**frag_shader_list
;
1434 unsigned num_frag_shaders
= 0;
1436 vert_shader_list
= (struct gl_shader
**)
1437 calloc(2 * prog
->NumShaders
, sizeof(struct gl_shader
*));
1438 frag_shader_list
= &vert_shader_list
[prog
->NumShaders
];
1440 unsigned min_version
= UINT_MAX
;
1441 unsigned max_version
= 0;
1442 for (unsigned i
= 0; i
< prog
->NumShaders
; i
++) {
1443 min_version
= MIN2(min_version
, prog
->Shaders
[i
]->Version
);
1444 max_version
= MAX2(max_version
, prog
->Shaders
[i
]->Version
);
1446 switch (prog
->Shaders
[i
]->Type
) {
1447 case GL_VERTEX_SHADER
:
1448 vert_shader_list
[num_vert_shaders
] = prog
->Shaders
[i
];
1451 case GL_FRAGMENT_SHADER
:
1452 frag_shader_list
[num_frag_shaders
] = prog
->Shaders
[i
];
1455 case GL_GEOMETRY_SHADER
:
1456 /* FINISHME: Support geometry shaders. */
1457 assert(prog
->Shaders
[i
]->Type
!= GL_GEOMETRY_SHADER
);
1462 /* Previous to GLSL version 1.30, different compilation units could mix and
1463 * match shading language versions. With GLSL 1.30 and later, the versions
1464 * of all shaders must match.
1466 assert(min_version
>= 100);
1467 assert(max_version
<= 130);
1468 if ((max_version
>= 130 || min_version
== 100)
1469 && min_version
!= max_version
) {
1470 linker_error_printf(prog
, "all shaders must use same shading "
1471 "language version\n");
1475 prog
->Version
= max_version
;
1477 for (unsigned int i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
1478 if (prog
->_LinkedShaders
[i
] != NULL
)
1479 ctx
->Driver
.DeleteShader(ctx
, prog
->_LinkedShaders
[i
]);
1481 prog
->_LinkedShaders
[i
] = NULL
;
1484 /* Link all shaders for a particular stage and validate the result.
1486 if (num_vert_shaders
> 0) {
1487 gl_shader
*const sh
=
1488 link_intrastage_shaders(mem_ctx
, ctx
, prog
, vert_shader_list
,
1494 if (!validate_vertex_shader_executable(prog
, sh
))
1497 _mesa_reference_shader(ctx
, &prog
->_LinkedShaders
[MESA_SHADER_VERTEX
],
1501 if (num_frag_shaders
> 0) {
1502 gl_shader
*const sh
=
1503 link_intrastage_shaders(mem_ctx
, ctx
, prog
, frag_shader_list
,
1509 if (!validate_fragment_shader_executable(prog
, sh
))
1512 _mesa_reference_shader(ctx
, &prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
],
1516 /* Here begins the inter-stage linking phase. Some initial validation is
1517 * performed, then locations are assigned for uniforms, attributes, and
1520 if (cross_validate_uniforms(prog
)) {
1523 for (prev
= 0; prev
< MESA_SHADER_TYPES
; prev
++) {
1524 if (prog
->_LinkedShaders
[prev
] != NULL
)
1528 /* Validate the inputs of each stage with the output of the preceeding
1531 for (unsigned i
= prev
+ 1; i
< MESA_SHADER_TYPES
; i
++) {
1532 if (prog
->_LinkedShaders
[i
] == NULL
)
1535 if (!cross_validate_outputs_to_inputs(prog
,
1536 prog
->_LinkedShaders
[prev
],
1537 prog
->_LinkedShaders
[i
]))
1543 prog
->LinkStatus
= true;
1546 /* Do common optimization before assigning storage for attributes,
1547 * uniforms, and varyings. Later optimization could possibly make
1548 * some of that unused.
1550 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
1551 if (prog
->_LinkedShaders
[i
] == NULL
)
1554 while (do_common_optimization(prog
->_LinkedShaders
[i
]->ir
, true, 32))
1558 update_array_sizes(prog
);
1560 assign_uniform_locations(prog
);
1562 if (prog
->_LinkedShaders
[MESA_SHADER_VERTEX
] != NULL
) {
1563 /* FINISHME: The value of the max_attribute_index parameter is
1564 * FINISHME: implementation dependent based on the value of
1565 * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be
1566 * FINISHME: at least 16, so hardcode 16 for now.
1568 if (!assign_attribute_locations(prog
, 16)) {
1569 prog
->LinkStatus
= false;
1575 for (prev
= 0; prev
< MESA_SHADER_TYPES
; prev
++) {
1576 if (prog
->_LinkedShaders
[prev
] != NULL
)
1580 for (unsigned i
= prev
+ 1; i
< MESA_SHADER_TYPES
; i
++) {
1581 if (prog
->_LinkedShaders
[i
] == NULL
)
1584 assign_varying_locations(prog
,
1585 prog
->_LinkedShaders
[prev
],
1586 prog
->_LinkedShaders
[i
]);
1590 if (prog
->_LinkedShaders
[MESA_SHADER_VERTEX
] != NULL
) {
1591 demote_shader_inputs_and_outputs(prog
->_LinkedShaders
[MESA_SHADER_VERTEX
],
1595 if (prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
] != NULL
) {
1596 gl_shader
*const sh
= prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
];
1598 demote_shader_inputs_and_outputs(sh
, ir_var_in
);
1599 demote_shader_inputs_and_outputs(sh
, ir_var_inout
);
1600 demote_shader_inputs_and_outputs(sh
, ir_var_out
);
1603 if (prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
] != NULL
) {
1604 gl_shader
*const sh
= prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
];
1606 demote_shader_inputs_and_outputs(sh
, ir_var_in
);
1609 /* FINISHME: Assign fragment shader output locations. */
1612 free(vert_shader_list
);
1614 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
1615 if (prog
->_LinkedShaders
[i
] == NULL
)
1618 /* Retain any live IR, but trash the rest. */
1619 reparent_ir(prog
->_LinkedShaders
[i
]->ir
, prog
->_LinkedShaders
[i
]->ir
);
1622 talloc_free(mem_ctx
);