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5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
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11 * The above copyright notice and this permission notice (including the next
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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
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19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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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>
67 #include "main/core.h"
68 #include "glsl_symbol_table.h"
71 #include "program/hash_table.h"
73 #include "ir_optimization.h"
76 #include "main/shaderobj.h"
80 * Visitor that determines whether or not a variable is ever written.
82 class find_assignment_visitor
: public ir_hierarchical_visitor
{
84 find_assignment_visitor(const char *name
)
85 : name(name
), found(false)
90 virtual ir_visitor_status
visit_enter(ir_assignment
*ir
)
92 ir_variable
*const var
= ir
->lhs
->variable_referenced();
94 if (strcmp(name
, var
->name
) == 0) {
99 return visit_continue_with_parent
;
102 virtual ir_visitor_status
visit_enter(ir_call
*ir
)
104 exec_list_iterator sig_iter
= ir
->get_callee()->parameters
.iterator();
105 foreach_iter(exec_list_iterator
, iter
, *ir
) {
106 ir_rvalue
*param_rval
= (ir_rvalue
*)iter
.get();
107 ir_variable
*sig_param
= (ir_variable
*)sig_iter
.get();
109 if (sig_param
->mode
== ir_var_out
||
110 sig_param
->mode
== ir_var_inout
) {
111 ir_variable
*var
= param_rval
->variable_referenced();
112 if (var
&& strcmp(name
, var
->name
) == 0) {
120 return visit_continue_with_parent
;
123 bool variable_found()
129 const char *name
; /**< Find writes to a variable with this name. */
130 bool found
; /**< Was a write to the variable found? */
135 * Visitor that determines whether or not a variable is ever read.
137 class find_deref_visitor
: public ir_hierarchical_visitor
{
139 find_deref_visitor(const char *name
)
140 : name(name
), found(false)
145 virtual ir_visitor_status
visit(ir_dereference_variable
*ir
)
147 if (strcmp(this->name
, ir
->var
->name
) == 0) {
152 return visit_continue
;
155 bool variable_found() const
161 const char *name
; /**< Find writes to a variable with this name. */
162 bool found
; /**< Was a write to the variable found? */
167 linker_error(gl_shader_program
*prog
, const char *fmt
, ...)
171 ralloc_strcat(&prog
->InfoLog
, "error: ");
173 ralloc_vasprintf_append(&prog
->InfoLog
, fmt
, ap
);
176 prog
->LinkStatus
= false;
181 linker_warning(gl_shader_program
*prog
, const char *fmt
, ...)
185 ralloc_strcat(&prog
->InfoLog
, "error: ");
187 ralloc_vasprintf_append(&prog
->InfoLog
, fmt
, ap
);
194 link_invalidate_variable_locations(gl_shader
*sh
, enum ir_variable_mode mode
,
197 foreach_list(node
, sh
->ir
) {
198 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
200 if ((var
== NULL
) || (var
->mode
!= (unsigned) mode
))
203 /* Only assign locations for generic attributes / varyings / etc.
205 if ((var
->location
>= generic_base
) && !var
->explicit_location
)
212 * Determine the number of attribute slots required for a particular type
214 * This code is here because it implements the language rules of a specific
215 * GLSL version. Since it's a property of the language and not a property of
216 * types in general, it doesn't really belong in glsl_type.
219 count_attribute_slots(const glsl_type
*t
)
221 /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec:
223 * "A scalar input counts the same amount against this limit as a vec4,
224 * so applications may want to consider packing groups of four
225 * unrelated float inputs together into a vector to better utilize the
226 * capabilities of the underlying hardware. A matrix input will use up
227 * multiple locations. The number of locations used will equal the
228 * number of columns in the matrix."
230 * The spec does not explicitly say how arrays are counted. However, it
231 * should be safe to assume the total number of slots consumed by an array
232 * is the number of entries in the array multiplied by the number of slots
233 * consumed by a single element of the array.
237 return t
->array_size() * count_attribute_slots(t
->element_type());
240 return t
->matrix_columns
;
247 * Verify that a vertex shader executable meets all semantic requirements.
249 * Also sets prog->Vert.UsesClipDistance and prog->Vert.ClipDistanceArraySize
252 * \param shader Vertex shader executable to be verified
255 validate_vertex_shader_executable(struct gl_shader_program
*prog
,
256 struct gl_shader
*shader
)
261 find_assignment_visitor
find("gl_Position");
262 find
.run(shader
->ir
);
263 if (!find
.variable_found()) {
264 linker_error(prog
, "vertex shader does not write to `gl_Position'\n");
268 prog
->Vert
.ClipDistanceArraySize
= 0;
270 if (prog
->Version
>= 130) {
271 /* From section 7.1 (Vertex Shader Special Variables) of the
274 * "It is an error for a shader to statically write both
275 * gl_ClipVertex and gl_ClipDistance."
277 find_assignment_visitor
clip_vertex("gl_ClipVertex");
278 find_assignment_visitor
clip_distance("gl_ClipDistance");
280 clip_vertex
.run(shader
->ir
);
281 clip_distance
.run(shader
->ir
);
282 if (clip_vertex
.variable_found() && clip_distance
.variable_found()) {
283 linker_error(prog
, "vertex shader writes to both `gl_ClipVertex' "
284 "and `gl_ClipDistance'\n");
287 prog
->Vert
.UsesClipDistance
= clip_distance
.variable_found();
288 ir_variable
*clip_distance_var
=
289 shader
->symbols
->get_variable("gl_ClipDistance");
290 if (clip_distance_var
)
291 prog
->Vert
.ClipDistanceArraySize
= clip_distance_var
->type
->length
;
299 * Verify that a fragment shader executable meets all semantic requirements
301 * \param shader Fragment shader executable to be verified
304 validate_fragment_shader_executable(struct gl_shader_program
*prog
,
305 struct gl_shader
*shader
)
310 find_assignment_visitor
frag_color("gl_FragColor");
311 find_assignment_visitor
frag_data("gl_FragData");
313 frag_color
.run(shader
->ir
);
314 frag_data
.run(shader
->ir
);
316 if (frag_color
.variable_found() && frag_data
.variable_found()) {
317 linker_error(prog
, "fragment shader writes to both "
318 "`gl_FragColor' and `gl_FragData'\n");
327 * Generate a string describing the mode of a variable
330 mode_string(const ir_variable
*var
)
334 return (var
->read_only
) ? "global constant" : "global variable";
336 case ir_var_uniform
: return "uniform";
337 case ir_var_in
: return "shader input";
338 case ir_var_out
: return "shader output";
339 case ir_var_inout
: return "shader inout";
341 case ir_var_const_in
:
342 case ir_var_temporary
:
344 assert(!"Should not get here.");
345 return "invalid variable";
351 * Perform validation of global variables used across multiple shaders
354 cross_validate_globals(struct gl_shader_program
*prog
,
355 struct gl_shader
**shader_list
,
356 unsigned num_shaders
,
359 /* Examine all of the uniforms in all of the shaders and cross validate
362 glsl_symbol_table variables
;
363 for (unsigned i
= 0; i
< num_shaders
; i
++) {
364 if (shader_list
[i
] == NULL
)
367 foreach_list(node
, shader_list
[i
]->ir
) {
368 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
373 if (uniforms_only
&& (var
->mode
!= ir_var_uniform
))
376 /* Don't cross validate temporaries that are at global scope. These
377 * will eventually get pulled into the shaders 'main'.
379 if (var
->mode
== ir_var_temporary
)
382 /* If a global with this name has already been seen, verify that the
383 * new instance has the same type. In addition, if the globals have
384 * initializers, the values of the initializers must be the same.
386 ir_variable
*const existing
= variables
.get_variable(var
->name
);
387 if (existing
!= NULL
) {
388 if (var
->type
!= existing
->type
) {
389 /* Consider the types to be "the same" if both types are arrays
390 * of the same type and one of the arrays is implicitly sized.
391 * In addition, set the type of the linked variable to the
392 * explicitly sized array.
394 if (var
->type
->is_array()
395 && existing
->type
->is_array()
396 && (var
->type
->fields
.array
== existing
->type
->fields
.array
)
397 && ((var
->type
->length
== 0)
398 || (existing
->type
->length
== 0))) {
399 if (var
->type
->length
!= 0) {
400 existing
->type
= var
->type
;
403 linker_error(prog
, "%s `%s' declared as type "
404 "`%s' and type `%s'\n",
406 var
->name
, var
->type
->name
,
407 existing
->type
->name
);
412 if (var
->explicit_location
) {
413 if (existing
->explicit_location
414 && (var
->location
!= existing
->location
)) {
415 linker_error(prog
, "explicit locations for %s "
416 "`%s' have differing values\n",
417 mode_string(var
), var
->name
);
421 existing
->location
= var
->location
;
422 existing
->explicit_location
= true;
425 /* Validate layout qualifiers for gl_FragDepth.
427 * From the AMD/ARB_conservative_depth specs:
429 * "If gl_FragDepth is redeclared in any fragment shader in a
430 * program, it must be redeclared in all fragment shaders in
431 * that program that have static assignments to
432 * gl_FragDepth. All redeclarations of gl_FragDepth in all
433 * fragment shaders in a single program must have the same set
436 if (strcmp(var
->name
, "gl_FragDepth") == 0) {
437 bool layout_declared
= var
->depth_layout
!= ir_depth_layout_none
;
438 bool layout_differs
=
439 var
->depth_layout
!= existing
->depth_layout
;
441 if (layout_declared
&& layout_differs
) {
443 "All redeclarations of gl_FragDepth in all "
444 "fragment shaders in a single program must have "
445 "the same set of qualifiers.");
448 if (var
->used
&& layout_differs
) {
450 "If gl_FragDepth is redeclared with a layout "
451 "qualifier in any fragment shader, it must be "
452 "redeclared with the same layout qualifier in "
453 "all fragment shaders that have assignments to "
458 /* Page 35 (page 41 of the PDF) of the GLSL 4.20 spec says:
460 * "If a shared global has multiple initializers, the
461 * initializers must all be constant expressions, and they
462 * must all have the same value. Otherwise, a link error will
463 * result. (A shared global having only one initializer does
464 * not require that initializer to be a constant expression.)"
466 * Previous to 4.20 the GLSL spec simply said that initializers
467 * must have the same value. In this case of non-constant
468 * initializers, this was impossible to determine. As a result,
469 * no vendor actually implemented that behavior. The 4.20
470 * behavior matches the implemented behavior of at least one other
471 * vendor, so we'll implement that for all GLSL versions.
473 if (var
->constant_initializer
!= NULL
) {
474 if (existing
->constant_initializer
!= NULL
) {
475 if (!var
->constant_initializer
->has_value(existing
->constant_initializer
)) {
476 linker_error(prog
, "initializers for %s "
477 "`%s' have differing values\n",
478 mode_string(var
), var
->name
);
482 /* If the first-seen instance of a particular uniform did not
483 * have an initializer but a later instance does, copy the
484 * initializer to the version stored in the symbol table.
486 /* FINISHME: This is wrong. The constant_value field should
487 * FINISHME: not be modified! Imagine a case where a shader
488 * FINISHME: without an initializer is linked in two different
489 * FINISHME: programs with shaders that have differing
490 * FINISHME: initializers. Linking with the first will
491 * FINISHME: modify the shader, and linking with the second
492 * FINISHME: will fail.
494 existing
->constant_initializer
=
495 var
->constant_initializer
->clone(ralloc_parent(existing
),
500 if (var
->has_initializer
) {
501 if (existing
->has_initializer
502 && (var
->constant_initializer
== NULL
503 || existing
->constant_initializer
== NULL
)) {
505 "shared global variable `%s' has multiple "
506 "non-constant initializers.\n",
511 /* Some instance had an initializer, so keep track of that. In
512 * this location, all sorts of initializers (constant or
513 * otherwise) will propagate the existence to the variable
514 * stored in the symbol table.
516 existing
->has_initializer
= true;
519 if (existing
->invariant
!= var
->invariant
) {
520 linker_error(prog
, "declarations for %s `%s' have "
521 "mismatching invariant qualifiers\n",
522 mode_string(var
), var
->name
);
525 if (existing
->centroid
!= var
->centroid
) {
526 linker_error(prog
, "declarations for %s `%s' have "
527 "mismatching centroid qualifiers\n",
528 mode_string(var
), var
->name
);
532 variables
.add_variable(var
);
541 * Perform validation of uniforms used across multiple shader stages
544 cross_validate_uniforms(struct gl_shader_program
*prog
)
546 return cross_validate_globals(prog
, prog
->_LinkedShaders
,
547 MESA_SHADER_TYPES
, true);
552 * Validate that outputs from one stage match inputs of another
555 cross_validate_outputs_to_inputs(struct gl_shader_program
*prog
,
556 gl_shader
*producer
, gl_shader
*consumer
)
558 glsl_symbol_table parameters
;
559 /* FINISHME: Figure these out dynamically. */
560 const char *const producer_stage
= "vertex";
561 const char *const consumer_stage
= "fragment";
563 /* Find all shader outputs in the "producer" stage.
565 foreach_list(node
, producer
->ir
) {
566 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
568 /* FINISHME: For geometry shaders, this should also look for inout
569 * FINISHME: variables.
571 if ((var
== NULL
) || (var
->mode
!= ir_var_out
))
574 parameters
.add_variable(var
);
578 /* Find all shader inputs in the "consumer" stage. Any variables that have
579 * matching outputs already in the symbol table must have the same type and
582 foreach_list(node
, consumer
->ir
) {
583 ir_variable
*const input
= ((ir_instruction
*) node
)->as_variable();
585 /* FINISHME: For geometry shaders, this should also look for inout
586 * FINISHME: variables.
588 if ((input
== NULL
) || (input
->mode
!= ir_var_in
))
591 ir_variable
*const output
= parameters
.get_variable(input
->name
);
592 if (output
!= NULL
) {
593 /* Check that the types match between stages.
595 if (input
->type
!= output
->type
) {
596 /* There is a bit of a special case for gl_TexCoord. This
597 * built-in is unsized by default. Applications that variable
598 * access it must redeclare it with a size. There is some
599 * language in the GLSL spec that implies the fragment shader
600 * and vertex shader do not have to agree on this size. Other
601 * driver behave this way, and one or two applications seem to
604 * Neither declaration needs to be modified here because the array
605 * sizes are fixed later when update_array_sizes is called.
607 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
609 * "Unlike user-defined varying variables, the built-in
610 * varying variables don't have a strict one-to-one
611 * correspondence between the vertex language and the
612 * fragment language."
614 if (!output
->type
->is_array()
615 || (strncmp("gl_", output
->name
, 3) != 0)) {
617 "%s shader output `%s' declared as type `%s', "
618 "but %s shader input declared as type `%s'\n",
619 producer_stage
, output
->name
,
621 consumer_stage
, input
->type
->name
);
626 /* Check that all of the qualifiers match between stages.
628 if (input
->centroid
!= output
->centroid
) {
630 "%s shader output `%s' %s centroid qualifier, "
631 "but %s shader input %s centroid qualifier\n",
634 (output
->centroid
) ? "has" : "lacks",
636 (input
->centroid
) ? "has" : "lacks");
640 if (input
->invariant
!= output
->invariant
) {
642 "%s shader output `%s' %s invariant qualifier, "
643 "but %s shader input %s invariant qualifier\n",
646 (output
->invariant
) ? "has" : "lacks",
648 (input
->invariant
) ? "has" : "lacks");
652 if (input
->interpolation
!= output
->interpolation
) {
654 "%s shader output `%s' specifies %s "
655 "interpolation qualifier, "
656 "but %s shader input specifies %s "
657 "interpolation qualifier\n",
660 output
->interpolation_string(),
662 input
->interpolation_string());
673 * Populates a shaders symbol table with all global declarations
676 populate_symbol_table(gl_shader
*sh
)
678 sh
->symbols
= new(sh
) glsl_symbol_table
;
680 foreach_list(node
, sh
->ir
) {
681 ir_instruction
*const inst
= (ir_instruction
*) node
;
685 if ((func
= inst
->as_function()) != NULL
) {
686 sh
->symbols
->add_function(func
);
687 } else if ((var
= inst
->as_variable()) != NULL
) {
688 sh
->symbols
->add_variable(var
);
695 * Remap variables referenced in an instruction tree
697 * This is used when instruction trees are cloned from one shader and placed in
698 * another. These trees will contain references to \c ir_variable nodes that
699 * do not exist in the target shader. This function finds these \c ir_variable
700 * references and replaces the references with matching variables in the target
703 * If there is no matching variable in the target shader, a clone of the
704 * \c ir_variable is made and added to the target shader. The new variable is
705 * added to \b both the instruction stream and the symbol table.
707 * \param inst IR tree that is to be processed.
708 * \param symbols Symbol table containing global scope symbols in the
710 * \param instructions Instruction stream where new variable declarations
714 remap_variables(ir_instruction
*inst
, struct gl_shader
*target
,
717 class remap_visitor
: public ir_hierarchical_visitor
{
719 remap_visitor(struct gl_shader
*target
,
722 this->target
= target
;
723 this->symbols
= target
->symbols
;
724 this->instructions
= target
->ir
;
728 virtual ir_visitor_status
visit(ir_dereference_variable
*ir
)
730 if (ir
->var
->mode
== ir_var_temporary
) {
731 ir_variable
*var
= (ir_variable
*) hash_table_find(temps
, ir
->var
);
735 return visit_continue
;
738 ir_variable
*const existing
=
739 this->symbols
->get_variable(ir
->var
->name
);
740 if (existing
!= NULL
)
743 ir_variable
*copy
= ir
->var
->clone(this->target
, NULL
);
745 this->symbols
->add_variable(copy
);
746 this->instructions
->push_head(copy
);
750 return visit_continue
;
754 struct gl_shader
*target
;
755 glsl_symbol_table
*symbols
;
756 exec_list
*instructions
;
760 remap_visitor
v(target
, temps
);
767 * Move non-declarations from one instruction stream to another
769 * The intended usage pattern of this function is to pass the pointer to the
770 * head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node
771 * pointer) for \c last and \c false for \c make_copies on the first
772 * call. Successive calls pass the return value of the previous call for
773 * \c last and \c true for \c make_copies.
775 * \param instructions Source instruction stream
776 * \param last Instruction after which new instructions should be
777 * inserted in the target instruction stream
778 * \param make_copies Flag selecting whether instructions in \c instructions
779 * should be copied (via \c ir_instruction::clone) into the
780 * target list or moved.
783 * The new "last" instruction in the target instruction stream. This pointer
784 * is suitable for use as the \c last parameter of a later call to this
788 move_non_declarations(exec_list
*instructions
, exec_node
*last
,
789 bool make_copies
, gl_shader
*target
)
791 hash_table
*temps
= NULL
;
794 temps
= hash_table_ctor(0, hash_table_pointer_hash
,
795 hash_table_pointer_compare
);
797 foreach_list_safe(node
, instructions
) {
798 ir_instruction
*inst
= (ir_instruction
*) node
;
800 if (inst
->as_function())
803 ir_variable
*var
= inst
->as_variable();
804 if ((var
!= NULL
) && (var
->mode
!= ir_var_temporary
))
807 assert(inst
->as_assignment()
808 || ((var
!= NULL
) && (var
->mode
== ir_var_temporary
)));
811 inst
= inst
->clone(target
, NULL
);
814 hash_table_insert(temps
, inst
, var
);
816 remap_variables(inst
, target
, temps
);
821 last
->insert_after(inst
);
826 hash_table_dtor(temps
);
832 * Get the function signature for main from a shader
834 static ir_function_signature
*
835 get_main_function_signature(gl_shader
*sh
)
837 ir_function
*const f
= sh
->symbols
->get_function("main");
839 exec_list void_parameters
;
841 /* Look for the 'void main()' signature and ensure that it's defined.
842 * This keeps the linker from accidentally pick a shader that just
843 * contains a prototype for main.
845 * We don't have to check for multiple definitions of main (in multiple
846 * shaders) because that would have already been caught above.
848 ir_function_signature
*sig
= f
->matching_signature(&void_parameters
);
849 if ((sig
!= NULL
) && sig
->is_defined
) {
859 * Combine a group of shaders for a single stage to generate a linked shader
862 * If this function is supplied a single shader, it is cloned, and the new
863 * shader is returned.
865 static struct gl_shader
*
866 link_intrastage_shaders(void *mem_ctx
,
867 struct gl_context
*ctx
,
868 struct gl_shader_program
*prog
,
869 struct gl_shader
**shader_list
,
870 unsigned num_shaders
)
872 /* Check that global variables defined in multiple shaders are consistent.
874 if (!cross_validate_globals(prog
, shader_list
, num_shaders
, false))
877 /* Check that there is only a single definition of each function signature
878 * across all shaders.
880 for (unsigned i
= 0; i
< (num_shaders
- 1); i
++) {
881 foreach_list(node
, shader_list
[i
]->ir
) {
882 ir_function
*const f
= ((ir_instruction
*) node
)->as_function();
887 for (unsigned j
= i
+ 1; j
< num_shaders
; j
++) {
888 ir_function
*const other
=
889 shader_list
[j
]->symbols
->get_function(f
->name
);
891 /* If the other shader has no function (and therefore no function
892 * signatures) with the same name, skip to the next shader.
897 foreach_iter (exec_list_iterator
, iter
, *f
) {
898 ir_function_signature
*sig
=
899 (ir_function_signature
*) iter
.get();
901 if (!sig
->is_defined
|| sig
->is_builtin
)
904 ir_function_signature
*other_sig
=
905 other
->exact_matching_signature(& sig
->parameters
);
907 if ((other_sig
!= NULL
) && other_sig
->is_defined
908 && !other_sig
->is_builtin
) {
909 linker_error(prog
, "function `%s' is multiply defined",
918 /* Find the shader that defines main, and make a clone of it.
920 * Starting with the clone, search for undefined references. If one is
921 * found, find the shader that defines it. Clone the reference and add
922 * it to the shader. Repeat until there are no undefined references or
923 * until a reference cannot be resolved.
925 gl_shader
*main
= NULL
;
926 for (unsigned i
= 0; i
< num_shaders
; i
++) {
927 if (get_main_function_signature(shader_list
[i
]) != NULL
) {
928 main
= shader_list
[i
];
934 linker_error(prog
, "%s shader lacks `main'\n",
935 (shader_list
[0]->Type
== GL_VERTEX_SHADER
)
936 ? "vertex" : "fragment");
940 gl_shader
*linked
= ctx
->Driver
.NewShader(NULL
, 0, main
->Type
);
941 linked
->ir
= new(linked
) exec_list
;
942 clone_ir_list(mem_ctx
, linked
->ir
, main
->ir
);
944 populate_symbol_table(linked
);
946 /* The a pointer to the main function in the final linked shader (i.e., the
947 * copy of the original shader that contained the main function).
949 ir_function_signature
*const main_sig
= get_main_function_signature(linked
);
951 /* Move any instructions other than variable declarations or function
952 * declarations into main.
954 exec_node
*insertion_point
=
955 move_non_declarations(linked
->ir
, (exec_node
*) &main_sig
->body
, false,
958 for (unsigned i
= 0; i
< num_shaders
; i
++) {
959 if (shader_list
[i
] == main
)
962 insertion_point
= move_non_declarations(shader_list
[i
]->ir
,
963 insertion_point
, true, linked
);
966 /* Resolve initializers for global variables in the linked shader.
968 unsigned num_linking_shaders
= num_shaders
;
969 for (unsigned i
= 0; i
< num_shaders
; i
++)
970 num_linking_shaders
+= shader_list
[i
]->num_builtins_to_link
;
972 gl_shader
**linking_shaders
=
973 (gl_shader
**) calloc(num_linking_shaders
, sizeof(gl_shader
*));
975 memcpy(linking_shaders
, shader_list
,
976 sizeof(linking_shaders
[0]) * num_shaders
);
978 unsigned idx
= num_shaders
;
979 for (unsigned i
= 0; i
< num_shaders
; i
++) {
980 memcpy(&linking_shaders
[idx
], shader_list
[i
]->builtins_to_link
,
981 sizeof(linking_shaders
[0]) * shader_list
[i
]->num_builtins_to_link
);
982 idx
+= shader_list
[i
]->num_builtins_to_link
;
985 assert(idx
== num_linking_shaders
);
987 if (!link_function_calls(prog
, linked
, linking_shaders
,
988 num_linking_shaders
)) {
989 ctx
->Driver
.DeleteShader(ctx
, linked
);
993 free(linking_shaders
);
996 /* At this point linked should contain all of the linked IR, so
997 * validate it to make sure nothing went wrong.
1000 validate_ir_tree(linked
->ir
);
1003 /* Make a pass over all variable declarations to ensure that arrays with
1004 * unspecified sizes have a size specified. The size is inferred from the
1005 * max_array_access field.
1007 if (linked
!= NULL
) {
1008 class array_sizing_visitor
: public ir_hierarchical_visitor
{
1010 virtual ir_visitor_status
visit(ir_variable
*var
)
1012 if (var
->type
->is_array() && (var
->type
->length
== 0)) {
1013 const glsl_type
*type
=
1014 glsl_type::get_array_instance(var
->type
->fields
.array
,
1015 var
->max_array_access
+ 1);
1017 assert(type
!= NULL
);
1021 return visit_continue
;
1032 * Update the sizes of linked shader uniform arrays to the maximum
1035 * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
1037 * If one or more elements of an array are active,
1038 * GetActiveUniform will return the name of the array in name,
1039 * subject to the restrictions listed above. The type of the array
1040 * is returned in type. The size parameter contains the highest
1041 * array element index used, plus one. The compiler or linker
1042 * determines the highest index used. There will be only one
1043 * active uniform reported by the GL per uniform array.
1047 update_array_sizes(struct gl_shader_program
*prog
)
1049 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
1050 if (prog
->_LinkedShaders
[i
] == NULL
)
1053 foreach_list(node
, prog
->_LinkedShaders
[i
]->ir
) {
1054 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1056 if ((var
== NULL
) || (var
->mode
!= ir_var_uniform
&&
1057 var
->mode
!= ir_var_in
&&
1058 var
->mode
!= ir_var_out
) ||
1059 !var
->type
->is_array())
1062 unsigned int size
= var
->max_array_access
;
1063 for (unsigned j
= 0; j
< MESA_SHADER_TYPES
; j
++) {
1064 if (prog
->_LinkedShaders
[j
] == NULL
)
1067 foreach_list(node2
, prog
->_LinkedShaders
[j
]->ir
) {
1068 ir_variable
*other_var
= ((ir_instruction
*) node2
)->as_variable();
1072 if (strcmp(var
->name
, other_var
->name
) == 0 &&
1073 other_var
->max_array_access
> size
) {
1074 size
= other_var
->max_array_access
;
1079 if (size
+ 1 != var
->type
->fields
.array
->length
) {
1080 /* If this is a built-in uniform (i.e., it's backed by some
1081 * fixed-function state), adjust the number of state slots to
1082 * match the new array size. The number of slots per array entry
1083 * is not known. It seems safe to assume that the total number of
1084 * slots is an integer multiple of the number of array elements.
1085 * Determine the number of slots per array element by dividing by
1086 * the old (total) size.
1088 if (var
->num_state_slots
> 0) {
1089 var
->num_state_slots
= (size
+ 1)
1090 * (var
->num_state_slots
/ var
->type
->length
);
1093 var
->type
= glsl_type::get_array_instance(var
->type
->fields
.array
,
1095 /* FINISHME: We should update the types of array
1096 * dereferences of this variable now.
1104 * Find a contiguous set of available bits in a bitmask.
1106 * \param used_mask Bits representing used (1) and unused (0) locations
1107 * \param needed_count Number of contiguous bits needed.
1110 * Base location of the available bits on success or -1 on failure.
1113 find_available_slots(unsigned used_mask
, unsigned needed_count
)
1115 unsigned needed_mask
= (1 << needed_count
) - 1;
1116 const int max_bit_to_test
= (8 * sizeof(used_mask
)) - needed_count
;
1118 /* The comparison to 32 is redundant, but without it GCC emits "warning:
1119 * cannot optimize possibly infinite loops" for the loop below.
1121 if ((needed_count
== 0) || (max_bit_to_test
< 0) || (max_bit_to_test
> 32))
1124 for (int i
= 0; i
<= max_bit_to_test
; i
++) {
1125 if ((needed_mask
& ~used_mask
) == needed_mask
)
1136 * Assign locations for either VS inputs for FS outputs
1138 * \param prog Shader program whose variables need locations assigned
1139 * \param target_index Selector for the program target to receive location
1140 * assignmnets. Must be either \c MESA_SHADER_VERTEX or
1141 * \c MESA_SHADER_FRAGMENT.
1142 * \param max_index Maximum number of generic locations. This corresponds
1143 * to either the maximum number of draw buffers or the
1144 * maximum number of generic attributes.
1147 * If locations are successfully assigned, true is returned. Otherwise an
1148 * error is emitted to the shader link log and false is returned.
1151 assign_attribute_or_color_locations(gl_shader_program
*prog
,
1152 unsigned target_index
,
1155 /* Mark invalid locations as being used.
1157 unsigned used_locations
= (max_index
>= 32)
1158 ? ~0 : ~((1 << max_index
) - 1);
1160 assert((target_index
== MESA_SHADER_VERTEX
)
1161 || (target_index
== MESA_SHADER_FRAGMENT
));
1163 gl_shader
*const sh
= prog
->_LinkedShaders
[target_index
];
1167 /* Operate in a total of four passes.
1169 * 1. Invalidate the location assignments for all vertex shader inputs.
1171 * 2. Assign locations for inputs that have user-defined (via
1172 * glBindVertexAttribLocation) locations and outputs that have
1173 * user-defined locations (via glBindFragDataLocation).
1175 * 3. Sort the attributes without assigned locations by number of slots
1176 * required in decreasing order. Fragmentation caused by attribute
1177 * locations assigned by the application may prevent large attributes
1178 * from having enough contiguous space.
1180 * 4. Assign locations to any inputs without assigned locations.
1183 const int generic_base
= (target_index
== MESA_SHADER_VERTEX
)
1184 ? (int) VERT_ATTRIB_GENERIC0
: (int) FRAG_RESULT_DATA0
;
1186 const enum ir_variable_mode direction
=
1187 (target_index
== MESA_SHADER_VERTEX
) ? ir_var_in
: ir_var_out
;
1190 link_invalidate_variable_locations(sh
, direction
, generic_base
);
1192 /* Temporary storage for the set of attributes that need locations assigned.
1198 /* Used below in the call to qsort. */
1199 static int compare(const void *a
, const void *b
)
1201 const temp_attr
*const l
= (const temp_attr
*) a
;
1202 const temp_attr
*const r
= (const temp_attr
*) b
;
1204 /* Reversed because we want a descending order sort below. */
1205 return r
->slots
- l
->slots
;
1209 unsigned num_attr
= 0;
1211 foreach_list(node
, sh
->ir
) {
1212 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1214 if ((var
== NULL
) || (var
->mode
!= (unsigned) direction
))
1217 if (var
->explicit_location
) {
1218 if ((var
->location
>= (int)(max_index
+ generic_base
))
1219 || (var
->location
< 0)) {
1221 "invalid explicit location %d specified for `%s'\n",
1223 ? var
->location
: var
->location
- generic_base
,
1227 } else if (target_index
== MESA_SHADER_VERTEX
) {
1230 if (prog
->AttributeBindings
->get(binding
, var
->name
)) {
1231 assert(binding
>= VERT_ATTRIB_GENERIC0
);
1232 var
->location
= binding
;
1234 } else if (target_index
== MESA_SHADER_FRAGMENT
) {
1237 if (prog
->FragDataBindings
->get(binding
, var
->name
)) {
1238 assert(binding
>= FRAG_RESULT_DATA0
);
1239 var
->location
= binding
;
1243 /* If the variable is not a built-in and has a location statically
1244 * assigned in the shader (presumably via a layout qualifier), make sure
1245 * that it doesn't collide with other assigned locations. Otherwise,
1246 * add it to the list of variables that need linker-assigned locations.
1248 const unsigned slots
= count_attribute_slots(var
->type
);
1249 if (var
->location
!= -1) {
1250 if (var
->location
>= generic_base
) {
1251 /* From page 61 of the OpenGL 4.0 spec:
1253 * "LinkProgram will fail if the attribute bindings assigned
1254 * by BindAttribLocation do not leave not enough space to
1255 * assign a location for an active matrix attribute or an
1256 * active attribute array, both of which require multiple
1257 * contiguous generic attributes."
1259 * Previous versions of the spec contain similar language but omit
1260 * the bit about attribute arrays.
1262 * Page 61 of the OpenGL 4.0 spec also says:
1264 * "It is possible for an application to bind more than one
1265 * attribute name to the same location. This is referred to as
1266 * aliasing. This will only work if only one of the aliased
1267 * attributes is active in the executable program, or if no
1268 * path through the shader consumes more than one attribute of
1269 * a set of attributes aliased to the same location. A link
1270 * error can occur if the linker determines that every path
1271 * through the shader consumes multiple aliased attributes,
1272 * but implementations are not required to generate an error
1275 * These two paragraphs are either somewhat contradictory, or I
1276 * don't fully understand one or both of them.
1278 /* FINISHME: The code as currently written does not support
1279 * FINISHME: attribute location aliasing (see comment above).
1281 /* Mask representing the contiguous slots that will be used by
1284 const unsigned attr
= var
->location
- generic_base
;
1285 const unsigned use_mask
= (1 << slots
) - 1;
1287 /* Generate a link error if the set of bits requested for this
1288 * attribute overlaps any previously allocated bits.
1290 if ((~(use_mask
<< attr
) & used_locations
) != used_locations
) {
1292 "insufficient contiguous attribute locations "
1293 "available for vertex shader input `%s'",
1298 used_locations
|= (use_mask
<< attr
);
1304 to_assign
[num_attr
].slots
= slots
;
1305 to_assign
[num_attr
].var
= var
;
1309 /* If all of the attributes were assigned locations by the application (or
1310 * are built-in attributes with fixed locations), return early. This should
1311 * be the common case.
1316 qsort(to_assign
, num_attr
, sizeof(to_assign
[0]), temp_attr::compare
);
1318 if (target_index
== MESA_SHADER_VERTEX
) {
1319 /* VERT_ATTRIB_GENERIC0 is a pseudo-alias for VERT_ATTRIB_POS. It can
1320 * only be explicitly assigned by via glBindAttribLocation. Mark it as
1321 * reserved to prevent it from being automatically allocated below.
1323 find_deref_visitor
find("gl_Vertex");
1325 if (find
.variable_found())
1326 used_locations
|= (1 << 0);
1329 for (unsigned i
= 0; i
< num_attr
; i
++) {
1330 /* Mask representing the contiguous slots that will be used by this
1333 const unsigned use_mask
= (1 << to_assign
[i
].slots
) - 1;
1335 int location
= find_available_slots(used_locations
, to_assign
[i
].slots
);
1338 const char *const string
= (target_index
== MESA_SHADER_VERTEX
)
1339 ? "vertex shader input" : "fragment shader output";
1342 "insufficient contiguous attribute locations "
1343 "available for %s `%s'",
1344 string
, to_assign
[i
].var
->name
);
1348 to_assign
[i
].var
->location
= generic_base
+ location
;
1349 used_locations
|= (use_mask
<< location
);
1357 * Demote shader inputs and outputs that are not used in other stages
1360 demote_shader_inputs_and_outputs(gl_shader
*sh
, enum ir_variable_mode mode
)
1362 foreach_list(node
, sh
->ir
) {
1363 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1365 if ((var
== NULL
) || (var
->mode
!= int(mode
)))
1368 /* A shader 'in' or 'out' variable is only really an input or output if
1369 * its value is used by other shader stages. This will cause the variable
1370 * to have a location assigned.
1372 if (var
->location
== -1) {
1373 var
->mode
= ir_var_auto
;
1380 * Data structure tracking information about a transform feedback declaration
1383 class tfeedback_decl
1386 bool init(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1387 const void *mem_ctx
, const char *input
);
1388 static bool is_same(const tfeedback_decl
&x
, const tfeedback_decl
&y
);
1389 bool assign_location(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1390 ir_variable
*output_var
);
1391 bool store(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1392 struct gl_transform_feedback_info
*info
, unsigned buffer
,
1393 unsigned varying
) const;
1397 * True if assign_location() has been called for this object.
1399 bool is_assigned() const
1401 return this->location
!= -1;
1405 * Determine whether this object refers to the variable var.
1407 bool matches_var(ir_variable
*var
) const
1409 if (this->is_clip_distance_mesa
)
1410 return strcmp(var
->name
, "gl_ClipDistanceMESA") == 0;
1412 return strcmp(var
->name
, this->var_name
) == 0;
1416 * The total number of varying components taken up by this variable. Only
1417 * valid if is_assigned() is true.
1419 unsigned num_components() const
1421 if (this->is_clip_distance_mesa
)
1424 return this->vector_elements
* this->matrix_columns
* this->size
;
1429 * The name that was supplied to glTransformFeedbackVaryings. Used for
1430 * error reporting and glGetTransformFeedbackVarying().
1432 const char *orig_name
;
1435 * The name of the variable, parsed from orig_name.
1437 const char *var_name
;
1440 * True if the declaration in orig_name represents an array.
1442 bool is_subscripted
;
1445 * If is_subscripted is true, the subscript that was specified in orig_name.
1447 unsigned array_subscript
;
1450 * True if the variable is gl_ClipDistance and the driver lowers
1451 * gl_ClipDistance to gl_ClipDistanceMESA.
1453 bool is_clip_distance_mesa
;
1456 * The vertex shader output location that the linker assigned for this
1457 * variable. -1 if a location hasn't been assigned yet.
1462 * If location != -1, the number of vector elements in this variable, or 1
1463 * if this variable is a scalar.
1465 unsigned vector_elements
;
1468 * If location != -1, the number of matrix columns in this variable, or 1
1469 * if this variable is not a matrix.
1471 unsigned matrix_columns
;
1473 /** Type of the varying returned by glGetTransformFeedbackVarying() */
1477 * If location != -1, the size that should be returned by
1478 * glGetTransformFeedbackVarying().
1485 * Initialize this object based on a string that was passed to
1486 * glTransformFeedbackVaryings. If there is a parse error, the error is
1487 * reported using linker_error(), and false is returned.
1490 tfeedback_decl::init(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1491 const void *mem_ctx
, const char *input
)
1493 /* We don't have to be pedantic about what is a valid GLSL variable name,
1494 * because any variable with an invalid name can't exist in the IR anyway.
1497 this->location
= -1;
1498 this->orig_name
= input
;
1499 this->is_clip_distance_mesa
= false;
1501 const char *bracket
= strrchr(input
, '[');
1504 this->var_name
= ralloc_strndup(mem_ctx
, input
, bracket
- input
);
1505 if (sscanf(bracket
, "[%u]", &this->array_subscript
) != 1) {
1506 linker_error(prog
, "Cannot parse transform feedback varying %s", input
);
1509 this->is_subscripted
= true;
1511 this->var_name
= ralloc_strdup(mem_ctx
, input
);
1512 this->is_subscripted
= false;
1515 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
1516 * class must behave specially to account for the fact that gl_ClipDistance
1517 * is converted from a float[8] to a vec4[2].
1519 if (ctx
->ShaderCompilerOptions
[MESA_SHADER_VERTEX
].LowerClipDistance
&&
1520 strcmp(this->var_name
, "gl_ClipDistance") == 0) {
1521 this->is_clip_distance_mesa
= true;
1529 * Determine whether two tfeedback_decl objects refer to the same variable and
1530 * array index (if applicable).
1533 tfeedback_decl::is_same(const tfeedback_decl
&x
, const tfeedback_decl
&y
)
1535 if (strcmp(x
.var_name
, y
.var_name
) != 0)
1537 if (x
.is_subscripted
!= y
.is_subscripted
)
1539 if (x
.is_subscripted
&& x
.array_subscript
!= y
.array_subscript
)
1546 * Assign a location for this tfeedback_decl object based on the location
1547 * assignment in output_var.
1549 * If an error occurs, the error is reported through linker_error() and false
1553 tfeedback_decl::assign_location(struct gl_context
*ctx
,
1554 struct gl_shader_program
*prog
,
1555 ir_variable
*output_var
)
1557 if (output_var
->type
->is_array()) {
1558 /* Array variable */
1559 const unsigned matrix_cols
=
1560 output_var
->type
->fields
.array
->matrix_columns
;
1561 unsigned actual_array_size
= this->is_clip_distance_mesa
?
1562 prog
->Vert
.ClipDistanceArraySize
: output_var
->type
->array_size();
1564 if (this->is_subscripted
) {
1565 /* Check array bounds. */
1566 if (this->array_subscript
>= actual_array_size
) {
1567 linker_error(prog
, "Transform feedback varying %s has index "
1568 "%i, but the array size is %u.",
1569 this->orig_name
, this->array_subscript
,
1573 if (this->is_clip_distance_mesa
) {
1575 output_var
->location
+ this->array_subscript
/ 4;
1578 output_var
->location
+ this->array_subscript
* matrix_cols
;
1582 this->location
= output_var
->location
;
1583 this->size
= actual_array_size
;
1585 this->vector_elements
= output_var
->type
->fields
.array
->vector_elements
;
1586 this->matrix_columns
= matrix_cols
;
1587 if (this->is_clip_distance_mesa
)
1588 this->type
= GL_FLOAT
;
1590 this->type
= output_var
->type
->fields
.array
->gl_type
;
1592 /* Regular variable (scalar, vector, or matrix) */
1593 if (this->is_subscripted
) {
1594 linker_error(prog
, "Transform feedback varying %s requested, "
1595 "but %s is not an array.",
1596 this->orig_name
, this->var_name
);
1599 this->location
= output_var
->location
;
1601 this->vector_elements
= output_var
->type
->vector_elements
;
1602 this->matrix_columns
= output_var
->type
->matrix_columns
;
1603 this->type
= output_var
->type
->gl_type
;
1606 /* From GL_EXT_transform_feedback:
1607 * A program will fail to link if:
1609 * * the total number of components to capture in any varying
1610 * variable in <varyings> is greater than the constant
1611 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
1612 * buffer mode is SEPARATE_ATTRIBS_EXT;
1614 if (prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
&&
1615 this->num_components() >
1616 ctx
->Const
.MaxTransformFeedbackSeparateComponents
) {
1617 linker_error(prog
, "Transform feedback varying %s exceeds "
1618 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
1628 * Update gl_transform_feedback_info to reflect this tfeedback_decl.
1630 * If an error occurs, the error is reported through linker_error() and false
1634 tfeedback_decl::store(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1635 struct gl_transform_feedback_info
*info
,
1636 unsigned buffer
, unsigned varying
) const
1638 if (!this->is_assigned()) {
1639 /* From GL_EXT_transform_feedback:
1640 * A program will fail to link if:
1642 * * any variable name specified in the <varyings> array is not
1643 * declared as an output in the geometry shader (if present) or
1644 * the vertex shader (if no geometry shader is present);
1646 linker_error(prog
, "Transform feedback varying %s undeclared.",
1651 /* From GL_EXT_transform_feedback:
1652 * A program will fail to link if:
1654 * * the total number of components to capture is greater than
1655 * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
1656 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
1658 if (prog
->TransformFeedback
.BufferMode
== GL_INTERLEAVED_ATTRIBS
&&
1659 info
->BufferStride
[buffer
] + this->num_components() >
1660 ctx
->Const
.MaxTransformFeedbackInterleavedComponents
) {
1661 linker_error(prog
, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
1662 "limit has been exceeded.");
1666 /* Verify that the checks on MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS
1667 * and MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS are sufficient to prevent
1668 * overflow of info->Outputs[]. In worst case we generate one entry in
1669 * Outputs[] per component so a conservative check is to verify that the
1670 * size of the array is greater than or equal to both
1671 * MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS and
1672 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.
1674 assert(Elements(info
->Outputs
) >=
1675 ctx
->Const
.MaxTransformFeedbackInterleavedComponents
);
1676 assert(Elements(info
->Outputs
) >=
1677 ctx
->Const
.MaxTransformFeedbackSeparateComponents
);
1679 unsigned translated_size
= this->size
;
1680 if (this->is_clip_distance_mesa
)
1681 translated_size
= (translated_size
+ 3) / 4;
1682 unsigned components_so_far
= 0;
1683 for (unsigned index
= 0; index
< translated_size
; ++index
) {
1684 for (unsigned v
= 0; v
< this->matrix_columns
; ++v
) {
1685 unsigned num_components
= this->vector_elements
;
1686 info
->Outputs
[info
->NumOutputs
].ComponentOffset
= 0;
1687 if (this->is_clip_distance_mesa
) {
1688 if (this->is_subscripted
) {
1690 info
->Outputs
[info
->NumOutputs
].ComponentOffset
=
1691 this->array_subscript
% 4;
1693 num_components
= MIN2(4, this->size
- components_so_far
);
1696 info
->Outputs
[info
->NumOutputs
].OutputRegister
=
1697 this->location
+ v
+ index
* this->matrix_columns
;
1698 info
->Outputs
[info
->NumOutputs
].NumComponents
= num_components
;
1699 info
->Outputs
[info
->NumOutputs
].OutputBuffer
= buffer
;
1700 info
->Outputs
[info
->NumOutputs
].DstOffset
= info
->BufferStride
[buffer
];
1702 info
->BufferStride
[buffer
] += num_components
;
1703 components_so_far
+= num_components
;
1706 assert(components_so_far
== this->num_components());
1708 info
->Varyings
[varying
].Name
= ralloc_strdup(prog
, this->orig_name
);
1709 info
->Varyings
[varying
].Type
= this->type
;
1710 info
->Varyings
[varying
].Size
= this->size
;
1718 * Parse all the transform feedback declarations that were passed to
1719 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
1721 * If an error occurs, the error is reported through linker_error() and false
1725 parse_tfeedback_decls(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1726 const void *mem_ctx
, unsigned num_names
,
1727 char **varying_names
, tfeedback_decl
*decls
)
1729 for (unsigned i
= 0; i
< num_names
; ++i
) {
1730 if (!decls
[i
].init(ctx
, prog
, mem_ctx
, varying_names
[i
]))
1732 /* From GL_EXT_transform_feedback:
1733 * A program will fail to link if:
1735 * * any two entries in the <varyings> array specify the same varying
1738 * We interpret this to mean "any two entries in the <varyings> array
1739 * specify the same varying variable and array index", since transform
1740 * feedback of arrays would be useless otherwise.
1742 for (unsigned j
= 0; j
< i
; ++j
) {
1743 if (tfeedback_decl::is_same(decls
[i
], decls
[j
])) {
1744 linker_error(prog
, "Transform feedback varying %s specified "
1745 "more than once.", varying_names
[i
]);
1755 * Assign a location for a variable that is produced in one pipeline stage
1756 * (the "producer") and consumed in the next stage (the "consumer").
1758 * \param input_var is the input variable declaration in the consumer.
1760 * \param output_var is the output variable declaration in the producer.
1762 * \param input_index is the counter that keeps track of assigned input
1763 * locations in the consumer.
1765 * \param output_index is the counter that keeps track of assigned output
1766 * locations in the producer.
1768 * It is permissible for \c input_var to be NULL (this happens if a variable
1769 * is output by the producer and consumed by transform feedback, but not
1770 * consumed by the consumer).
1772 * If the variable has already been assigned a location, this function has no
1776 assign_varying_location(ir_variable
*input_var
, ir_variable
*output_var
,
1777 unsigned *input_index
, unsigned *output_index
)
1779 if (output_var
->location
!= -1) {
1780 /* Location already assigned. */
1785 assert(input_var
->location
== -1);
1786 input_var
->location
= *input_index
;
1789 output_var
->location
= *output_index
;
1791 /* FINISHME: Support for "varying" records in GLSL 1.50. */
1792 assert(!output_var
->type
->is_record());
1794 if (output_var
->type
->is_array()) {
1795 const unsigned slots
= output_var
->type
->length
1796 * output_var
->type
->fields
.array
->matrix_columns
;
1798 *output_index
+= slots
;
1799 *input_index
+= slots
;
1801 const unsigned slots
= output_var
->type
->matrix_columns
;
1803 *output_index
+= slots
;
1804 *input_index
+= slots
;
1810 * Assign locations for all variables that are produced in one pipeline stage
1811 * (the "producer") and consumed in the next stage (the "consumer").
1813 * Variables produced by the producer may also be consumed by transform
1816 * \param num_tfeedback_decls is the number of declarations indicating
1817 * variables that may be consumed by transform feedback.
1819 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
1820 * representing the result of parsing the strings passed to
1821 * glTransformFeedbackVaryings(). assign_location() will be called for
1822 * each of these objects that matches one of the outputs of the
1825 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
1826 * be NULL. In this case, varying locations are assigned solely based on the
1827 * requirements of transform feedback.
1830 assign_varying_locations(struct gl_context
*ctx
,
1831 struct gl_shader_program
*prog
,
1832 gl_shader
*producer
, gl_shader
*consumer
,
1833 unsigned num_tfeedback_decls
,
1834 tfeedback_decl
*tfeedback_decls
)
1836 /* FINISHME: Set dynamically when geometry shader support is added. */
1837 unsigned output_index
= VERT_RESULT_VAR0
;
1838 unsigned input_index
= FRAG_ATTRIB_VAR0
;
1840 /* Operate in a total of three passes.
1842 * 1. Assign locations for any matching inputs and outputs.
1844 * 2. Mark output variables in the producer that do not have locations as
1845 * not being outputs. This lets the optimizer eliminate them.
1847 * 3. Mark input variables in the consumer that do not have locations as
1848 * not being inputs. This lets the optimizer eliminate them.
1851 link_invalidate_variable_locations(producer
, ir_var_out
, VERT_RESULT_VAR0
);
1853 link_invalidate_variable_locations(consumer
, ir_var_in
, FRAG_ATTRIB_VAR0
);
1855 foreach_list(node
, producer
->ir
) {
1856 ir_variable
*const output_var
= ((ir_instruction
*) node
)->as_variable();
1858 if ((output_var
== NULL
) || (output_var
->mode
!= ir_var_out
))
1861 ir_variable
*input_var
=
1862 consumer
? consumer
->symbols
->get_variable(output_var
->name
) : NULL
;
1864 if (input_var
&& input_var
->mode
!= ir_var_in
)
1868 assign_varying_location(input_var
, output_var
, &input_index
,
1872 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1873 if (!tfeedback_decls
[i
].is_assigned() &&
1874 tfeedback_decls
[i
].matches_var(output_var
)) {
1875 if (output_var
->location
== -1) {
1876 assign_varying_location(input_var
, output_var
, &input_index
,
1879 if (!tfeedback_decls
[i
].assign_location(ctx
, prog
, output_var
))
1885 unsigned varying_vectors
= 0;
1888 foreach_list(node
, consumer
->ir
) {
1889 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
1891 if ((var
== NULL
) || (var
->mode
!= ir_var_in
))
1894 if (var
->location
== -1) {
1895 if (prog
->Version
<= 120) {
1896 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
1898 * Only those varying variables used (i.e. read) in
1899 * the fragment shader executable must be written to
1900 * by the vertex shader executable; declaring
1901 * superfluous varying variables in a vertex shader is
1904 * We interpret this text as meaning that the VS must
1905 * write the variable for the FS to read it. See
1906 * "glsl1-varying read but not written" in piglit.
1909 linker_error(prog
, "fragment shader varying %s not written "
1910 "by vertex shader\n.", var
->name
);
1913 /* An 'in' variable is only really a shader input if its
1914 * value is written by the previous stage.
1916 var
->mode
= ir_var_auto
;
1918 /* The packing rules are used for vertex shader inputs are also
1919 * used for fragment shader inputs.
1921 varying_vectors
+= count_attribute_slots(var
->type
);
1926 if (ctx
->API
== API_OPENGLES2
|| prog
->Version
== 100) {
1927 if (varying_vectors
> ctx
->Const
.MaxVarying
) {
1928 if (ctx
->Const
.GLSLSkipStrictMaxVaryingLimitCheck
) {
1929 linker_warning(prog
, "shader uses too many varying vectors "
1930 "(%u > %u), but the driver will try to optimize "
1931 "them out; this is non-portable out-of-spec "
1933 varying_vectors
, ctx
->Const
.MaxVarying
);
1935 linker_error(prog
, "shader uses too many varying vectors "
1937 varying_vectors
, ctx
->Const
.MaxVarying
);
1942 const unsigned float_components
= varying_vectors
* 4;
1943 if (float_components
> ctx
->Const
.MaxVarying
* 4) {
1944 if (ctx
->Const
.GLSLSkipStrictMaxVaryingLimitCheck
) {
1945 linker_warning(prog
, "shader uses too many varying components "
1946 "(%u > %u), but the driver will try to optimize "
1947 "them out; this is non-portable out-of-spec "
1949 float_components
, ctx
->Const
.MaxVarying
* 4);
1951 linker_error(prog
, "shader uses too many varying components "
1953 float_components
, ctx
->Const
.MaxVarying
* 4);
1964 * Store transform feedback location assignments into
1965 * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
1967 * If an error occurs, the error is reported through linker_error() and false
1971 store_tfeedback_info(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1972 unsigned num_tfeedback_decls
,
1973 tfeedback_decl
*tfeedback_decls
)
1975 bool separate_attribs_mode
=
1976 prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
;
1978 ralloc_free(prog
->LinkedTransformFeedback
.Varyings
);
1980 memset(&prog
->LinkedTransformFeedback
, 0,
1981 sizeof(prog
->LinkedTransformFeedback
));
1983 prog
->LinkedTransformFeedback
.NumBuffers
=
1984 separate_attribs_mode
? num_tfeedback_decls
: 1;
1986 prog
->LinkedTransformFeedback
.Varyings
=
1987 rzalloc_array(prog
->LinkedTransformFeedback
.Varyings
,
1988 struct gl_transform_feedback_varying_info
,
1989 num_tfeedback_decls
);
1991 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1992 unsigned buffer
= separate_attribs_mode
? i
: 0;
1993 if (!tfeedback_decls
[i
].store(ctx
, prog
, &prog
->LinkedTransformFeedback
,
2002 * Store the gl_FragDepth layout in the gl_shader_program struct.
2005 store_fragdepth_layout(struct gl_shader_program
*prog
)
2007 if (prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
] == NULL
) {
2011 struct exec_list
*ir
= prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
]->ir
;
2013 /* We don't look up the gl_FragDepth symbol directly because if
2014 * gl_FragDepth is not used in the shader, it's removed from the IR.
2015 * However, the symbol won't be removed from the symbol table.
2017 * We're only interested in the cases where the variable is NOT removed
2020 foreach_list(node
, ir
) {
2021 ir_variable
*const var
= ((ir_instruction
*) node
)->as_variable();
2023 if (var
== NULL
|| var
->mode
!= ir_var_out
) {
2027 if (strcmp(var
->name
, "gl_FragDepth") == 0) {
2028 switch (var
->depth_layout
) {
2029 case ir_depth_layout_none
:
2030 prog
->FragDepthLayout
= FRAG_DEPTH_LAYOUT_NONE
;
2032 case ir_depth_layout_any
:
2033 prog
->FragDepthLayout
= FRAG_DEPTH_LAYOUT_ANY
;
2035 case ir_depth_layout_greater
:
2036 prog
->FragDepthLayout
= FRAG_DEPTH_LAYOUT_GREATER
;
2038 case ir_depth_layout_less
:
2039 prog
->FragDepthLayout
= FRAG_DEPTH_LAYOUT_LESS
;
2041 case ir_depth_layout_unchanged
:
2042 prog
->FragDepthLayout
= FRAG_DEPTH_LAYOUT_UNCHANGED
;
2053 * Validate the resources used by a program versus the implementation limits
2056 check_resources(struct gl_context
*ctx
, struct gl_shader_program
*prog
)
2058 static const char *const shader_names
[MESA_SHADER_TYPES
] = {
2059 "vertex", "fragment", "geometry"
2062 const unsigned max_samplers
[MESA_SHADER_TYPES
] = {
2063 ctx
->Const
.MaxVertexTextureImageUnits
,
2064 ctx
->Const
.MaxTextureImageUnits
,
2065 ctx
->Const
.MaxGeometryTextureImageUnits
2068 const unsigned max_uniform_components
[MESA_SHADER_TYPES
] = {
2069 ctx
->Const
.VertexProgram
.MaxUniformComponents
,
2070 ctx
->Const
.FragmentProgram
.MaxUniformComponents
,
2071 0 /* FINISHME: Geometry shaders. */
2074 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
2075 struct gl_shader
*sh
= prog
->_LinkedShaders
[i
];
2080 if (sh
->num_samplers
> max_samplers
[i
]) {
2081 linker_error(prog
, "Too many %s shader texture samplers",
2085 if (sh
->num_uniform_components
> max_uniform_components
[i
]) {
2086 if (ctx
->Const
.GLSLSkipStrictMaxUniformLimitCheck
) {
2087 linker_warning(prog
, "Too many %s shader uniform components, "
2088 "but the driver will try to optimize them out; "
2089 "this is non-portable out-of-spec behavior\n",
2092 linker_error(prog
, "Too many %s shader uniform components",
2098 return prog
->LinkStatus
;
2102 link_shaders(struct gl_context
*ctx
, struct gl_shader_program
*prog
)
2104 tfeedback_decl
*tfeedback_decls
= NULL
;
2105 unsigned num_tfeedback_decls
= prog
->TransformFeedback
.NumVarying
;
2107 void *mem_ctx
= ralloc_context(NULL
); // temporary linker context
2109 prog
->LinkStatus
= false;
2110 prog
->Validated
= false;
2111 prog
->_Used
= false;
2113 if (prog
->InfoLog
!= NULL
)
2114 ralloc_free(prog
->InfoLog
);
2116 prog
->InfoLog
= ralloc_strdup(NULL
, "");
2118 /* Separate the shaders into groups based on their type.
2120 struct gl_shader
**vert_shader_list
;
2121 unsigned num_vert_shaders
= 0;
2122 struct gl_shader
**frag_shader_list
;
2123 unsigned num_frag_shaders
= 0;
2125 vert_shader_list
= (struct gl_shader
**)
2126 calloc(2 * prog
->NumShaders
, sizeof(struct gl_shader
*));
2127 frag_shader_list
= &vert_shader_list
[prog
->NumShaders
];
2129 unsigned min_version
= UINT_MAX
;
2130 unsigned max_version
= 0;
2131 for (unsigned i
= 0; i
< prog
->NumShaders
; i
++) {
2132 min_version
= MIN2(min_version
, prog
->Shaders
[i
]->Version
);
2133 max_version
= MAX2(max_version
, prog
->Shaders
[i
]->Version
);
2135 switch (prog
->Shaders
[i
]->Type
) {
2136 case GL_VERTEX_SHADER
:
2137 vert_shader_list
[num_vert_shaders
] = prog
->Shaders
[i
];
2140 case GL_FRAGMENT_SHADER
:
2141 frag_shader_list
[num_frag_shaders
] = prog
->Shaders
[i
];
2144 case GL_GEOMETRY_SHADER
:
2145 /* FINISHME: Support geometry shaders. */
2146 assert(prog
->Shaders
[i
]->Type
!= GL_GEOMETRY_SHADER
);
2151 /* Previous to GLSL version 1.30, different compilation units could mix and
2152 * match shading language versions. With GLSL 1.30 and later, the versions
2153 * of all shaders must match.
2155 assert(min_version
>= 100);
2156 assert(max_version
<= 130);
2157 if ((max_version
>= 130 || min_version
== 100)
2158 && min_version
!= max_version
) {
2159 linker_error(prog
, "all shaders must use same shading "
2160 "language version\n");
2164 prog
->Version
= max_version
;
2166 for (unsigned int i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
2167 if (prog
->_LinkedShaders
[i
] != NULL
)
2168 ctx
->Driver
.DeleteShader(ctx
, prog
->_LinkedShaders
[i
]);
2170 prog
->_LinkedShaders
[i
] = NULL
;
2173 /* Link all shaders for a particular stage and validate the result.
2175 if (num_vert_shaders
> 0) {
2176 gl_shader
*const sh
=
2177 link_intrastage_shaders(mem_ctx
, ctx
, prog
, vert_shader_list
,
2183 if (!validate_vertex_shader_executable(prog
, sh
))
2186 _mesa_reference_shader(ctx
, &prog
->_LinkedShaders
[MESA_SHADER_VERTEX
],
2190 if (num_frag_shaders
> 0) {
2191 gl_shader
*const sh
=
2192 link_intrastage_shaders(mem_ctx
, ctx
, prog
, frag_shader_list
,
2198 if (!validate_fragment_shader_executable(prog
, sh
))
2201 _mesa_reference_shader(ctx
, &prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
],
2205 /* Here begins the inter-stage linking phase. Some initial validation is
2206 * performed, then locations are assigned for uniforms, attributes, and
2209 if (cross_validate_uniforms(prog
)) {
2212 for (prev
= 0; prev
< MESA_SHADER_TYPES
; prev
++) {
2213 if (prog
->_LinkedShaders
[prev
] != NULL
)
2217 /* Validate the inputs of each stage with the output of the preceding
2220 for (unsigned i
= prev
+ 1; i
< MESA_SHADER_TYPES
; i
++) {
2221 if (prog
->_LinkedShaders
[i
] == NULL
)
2224 if (!cross_validate_outputs_to_inputs(prog
,
2225 prog
->_LinkedShaders
[prev
],
2226 prog
->_LinkedShaders
[i
]))
2232 prog
->LinkStatus
= true;
2235 /* Do common optimization before assigning storage for attributes,
2236 * uniforms, and varyings. Later optimization could possibly make
2237 * some of that unused.
2239 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
2240 if (prog
->_LinkedShaders
[i
] == NULL
)
2243 detect_recursion_linked(prog
, prog
->_LinkedShaders
[i
]->ir
);
2244 if (!prog
->LinkStatus
)
2247 if (ctx
->ShaderCompilerOptions
[i
].LowerClipDistance
)
2248 lower_clip_distance(prog
->_LinkedShaders
[i
]->ir
);
2250 while (do_common_optimization(prog
->_LinkedShaders
[i
]->ir
, true, false, 32))
2254 /* FINISHME: The value of the max_attribute_index parameter is
2255 * FINISHME: implementation dependent based on the value of
2256 * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be
2257 * FINISHME: at least 16, so hardcode 16 for now.
2259 if (!assign_attribute_or_color_locations(prog
, MESA_SHADER_VERTEX
, 16)) {
2263 if (!assign_attribute_or_color_locations(prog
, MESA_SHADER_FRAGMENT
, ctx
->Const
.MaxDrawBuffers
)) {
2268 for (prev
= 0; prev
< MESA_SHADER_TYPES
; prev
++) {
2269 if (prog
->_LinkedShaders
[prev
] != NULL
)
2273 if (num_tfeedback_decls
!= 0) {
2274 /* From GL_EXT_transform_feedback:
2275 * A program will fail to link if:
2277 * * the <count> specified by TransformFeedbackVaryingsEXT is
2278 * non-zero, but the program object has no vertex or geometry
2281 if (prev
>= MESA_SHADER_FRAGMENT
) {
2282 linker_error(prog
, "Transform feedback varyings specified, but "
2283 "no vertex or geometry shader is present.");
2287 tfeedback_decls
= ralloc_array(mem_ctx
, tfeedback_decl
,
2288 prog
->TransformFeedback
.NumVarying
);
2289 if (!parse_tfeedback_decls(ctx
, prog
, mem_ctx
, num_tfeedback_decls
,
2290 prog
->TransformFeedback
.VaryingNames
,
2295 for (unsigned i
= prev
+ 1; i
< MESA_SHADER_TYPES
; i
++) {
2296 if (prog
->_LinkedShaders
[i
] == NULL
)
2299 if (!assign_varying_locations(
2300 ctx
, prog
, prog
->_LinkedShaders
[prev
], prog
->_LinkedShaders
[i
],
2301 i
== MESA_SHADER_FRAGMENT
? num_tfeedback_decls
: 0,
2308 if (prev
!= MESA_SHADER_FRAGMENT
&& num_tfeedback_decls
!= 0) {
2309 /* There was no fragment shader, but we still have to assign varying
2310 * locations for use by transform feedback.
2312 if (!assign_varying_locations(
2313 ctx
, prog
, prog
->_LinkedShaders
[prev
], NULL
, num_tfeedback_decls
,
2318 if (!store_tfeedback_info(ctx
, prog
, num_tfeedback_decls
, tfeedback_decls
))
2321 if (prog
->_LinkedShaders
[MESA_SHADER_VERTEX
] != NULL
) {
2322 demote_shader_inputs_and_outputs(prog
->_LinkedShaders
[MESA_SHADER_VERTEX
],
2325 /* Eliminate code that is now dead due to unused vertex outputs being
2328 while (do_dead_code(prog
->_LinkedShaders
[MESA_SHADER_VERTEX
]->ir
, false))
2332 if (prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
] != NULL
) {
2333 gl_shader
*const sh
= prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
];
2335 demote_shader_inputs_and_outputs(sh
, ir_var_in
);
2336 demote_shader_inputs_and_outputs(sh
, ir_var_inout
);
2337 demote_shader_inputs_and_outputs(sh
, ir_var_out
);
2339 /* Eliminate code that is now dead due to unused geometry outputs being
2342 while (do_dead_code(prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
]->ir
, false))
2346 if (prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
] != NULL
) {
2347 gl_shader
*const sh
= prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
];
2349 demote_shader_inputs_and_outputs(sh
, ir_var_in
);
2351 /* Eliminate code that is now dead due to unused fragment inputs being
2352 * demoted. This shouldn't actually do anything other than remove
2353 * declarations of the (now unused) global variables.
2355 while (do_dead_code(prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
]->ir
, false))
2359 update_array_sizes(prog
);
2360 link_assign_uniform_locations(prog
);
2361 store_fragdepth_layout(prog
);
2363 if (!check_resources(ctx
, prog
))
2366 /* OpenGL ES requires that a vertex shader and a fragment shader both be
2367 * present in a linked program. By checking for use of shading language
2368 * version 1.00, we also catch the GL_ARB_ES2_compatibility case.
2370 if (!prog
->InternalSeparateShader
&&
2371 (ctx
->API
== API_OPENGLES2
|| prog
->Version
== 100)) {
2372 if (prog
->_LinkedShaders
[MESA_SHADER_VERTEX
] == NULL
) {
2373 linker_error(prog
, "program lacks a vertex shader\n");
2374 } else if (prog
->_LinkedShaders
[MESA_SHADER_FRAGMENT
] == NULL
) {
2375 linker_error(prog
, "program lacks a fragment shader\n");
2379 /* FINISHME: Assign fragment shader output locations. */
2382 free(vert_shader_list
);
2384 for (unsigned i
= 0; i
< MESA_SHADER_TYPES
; i
++) {
2385 if (prog
->_LinkedShaders
[i
] == NULL
)
2388 /* Retain any live IR, but trash the rest. */
2389 reparent_ir(prog
->_LinkedShaders
[i
]->ir
, prog
->_LinkedShaders
[i
]->ir
);
2391 /* The symbol table in the linked shaders may contain references to
2392 * variables that were removed (e.g., unused uniforms). Since it may
2393 * contain junk, there is no possible valid use. Delete it and set the
2396 delete prog
->_LinkedShaders
[i
]->symbols
;
2397 prog
->_LinkedShaders
[i
]->symbols
= NULL
;
2400 ralloc_free(mem_ctx
);