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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->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 if (ir->return_deref != NULL) {
121 ir_variable *const var = ir->return_deref->variable_referenced();
123 if (strcmp(name, var->name) == 0) {
129 return visit_continue_with_parent;
132 bool variable_found()
138 const char *name; /**< Find writes to a variable with this name. */
139 bool found; /**< Was a write to the variable found? */
144 * Visitor that determines whether or not a variable is ever read.
146 class find_deref_visitor : public ir_hierarchical_visitor {
148 find_deref_visitor(const char *name)
149 : name(name), found(false)
154 virtual ir_visitor_status visit(ir_dereference_variable *ir)
156 if (strcmp(this->name, ir->var->name) == 0) {
161 return visit_continue;
164 bool variable_found() const
170 const char *name; /**< Find writes to a variable with this name. */
171 bool found; /**< Was a write to the variable found? */
176 linker_error(gl_shader_program *prog, const char *fmt, ...)
180 ralloc_strcat(&prog->InfoLog, "error: ");
182 ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
185 prog->LinkStatus = false;
190 linker_warning(gl_shader_program *prog, const char *fmt, ...)
194 ralloc_strcat(&prog->InfoLog, "error: ");
196 ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
203 link_invalidate_variable_locations(gl_shader *sh, enum ir_variable_mode mode,
206 foreach_list(node, sh->ir) {
207 ir_variable *const var = ((ir_instruction *) node)->as_variable();
209 if ((var == NULL) || (var->mode != (unsigned) mode))
212 /* Only assign locations for generic attributes / varyings / etc.
214 if ((var->location >= generic_base) && !var->explicit_location)
221 * Determine the number of attribute slots required for a particular type
223 * This code is here because it implements the language rules of a specific
224 * GLSL version. Since it's a property of the language and not a property of
225 * types in general, it doesn't really belong in glsl_type.
228 count_attribute_slots(const glsl_type *t)
230 /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec:
232 * "A scalar input counts the same amount against this limit as a vec4,
233 * so applications may want to consider packing groups of four
234 * unrelated float inputs together into a vector to better utilize the
235 * capabilities of the underlying hardware. A matrix input will use up
236 * multiple locations. The number of locations used will equal the
237 * number of columns in the matrix."
239 * The spec does not explicitly say how arrays are counted. However, it
240 * should be safe to assume the total number of slots consumed by an array
241 * is the number of entries in the array multiplied by the number of slots
242 * consumed by a single element of the array.
246 return t->array_size() * count_attribute_slots(t->element_type());
249 return t->matrix_columns;
256 * Verify that a vertex shader executable meets all semantic requirements.
258 * Also sets prog->Vert.UsesClipDistance and prog->Vert.ClipDistanceArraySize
261 * \param shader Vertex shader executable to be verified
264 validate_vertex_shader_executable(struct gl_shader_program *prog,
265 struct gl_shader *shader)
270 /* From the GLSL 1.10 spec, page 48:
272 * "The variable gl_Position is available only in the vertex
273 * language and is intended for writing the homogeneous vertex
274 * position. All executions of a well-formed vertex shader
275 * executable must write a value into this variable. [...] The
276 * variable gl_Position is available only in the vertex
277 * language and is intended for writing the homogeneous vertex
278 * position. All executions of a well-formed vertex shader
279 * executable must write a value into this variable."
281 * while in GLSL 1.40 this text is changed to:
283 * "The variable gl_Position is available only in the vertex
284 * language and is intended for writing the homogeneous vertex
285 * position. It can be written at any time during shader
286 * execution. It may also be read back by a vertex shader
287 * after being written. This value will be used by primitive
288 * assembly, clipping, culling, and other fixed functionality
289 * operations, if present, that operate on primitives after
290 * vertex processing has occurred. Its value is undefined if
291 * the vertex shader executable does not write gl_Position."
293 if (prog->Version < 140) {
294 find_assignment_visitor find("gl_Position");
295 find.run(shader->ir);
296 if (!find.variable_found()) {
297 linker_error(prog, "vertex shader does not write to `gl_Position'\n");
302 prog->Vert.ClipDistanceArraySize = 0;
304 if (prog->Version >= 130) {
305 /* From section 7.1 (Vertex Shader Special Variables) of the
308 * "It is an error for a shader to statically write both
309 * gl_ClipVertex and gl_ClipDistance."
311 find_assignment_visitor clip_vertex("gl_ClipVertex");
312 find_assignment_visitor clip_distance("gl_ClipDistance");
314 clip_vertex.run(shader->ir);
315 clip_distance.run(shader->ir);
316 if (clip_vertex.variable_found() && clip_distance.variable_found()) {
317 linker_error(prog, "vertex shader writes to both `gl_ClipVertex' "
318 "and `gl_ClipDistance'\n");
321 prog->Vert.UsesClipDistance = clip_distance.variable_found();
322 ir_variable *clip_distance_var =
323 shader->symbols->get_variable("gl_ClipDistance");
324 if (clip_distance_var)
325 prog->Vert.ClipDistanceArraySize = clip_distance_var->type->length;
333 * Verify that a fragment shader executable meets all semantic requirements
335 * \param shader Fragment shader executable to be verified
338 validate_fragment_shader_executable(struct gl_shader_program *prog,
339 struct gl_shader *shader)
344 find_assignment_visitor frag_color("gl_FragColor");
345 find_assignment_visitor frag_data("gl_FragData");
347 frag_color.run(shader->ir);
348 frag_data.run(shader->ir);
350 if (frag_color.variable_found() && frag_data.variable_found()) {
351 linker_error(prog, "fragment shader writes to both "
352 "`gl_FragColor' and `gl_FragData'\n");
361 * Generate a string describing the mode of a variable
364 mode_string(const ir_variable *var)
368 return (var->read_only) ? "global constant" : "global variable";
370 case ir_var_uniform: return "uniform";
371 case ir_var_in: return "shader input";
372 case ir_var_out: return "shader output";
373 case ir_var_inout: return "shader inout";
375 case ir_var_const_in:
376 case ir_var_temporary:
378 assert(!"Should not get here.");
379 return "invalid variable";
385 * Perform validation of global variables used across multiple shaders
388 cross_validate_globals(struct gl_shader_program *prog,
389 struct gl_shader **shader_list,
390 unsigned num_shaders,
393 /* Examine all of the uniforms in all of the shaders and cross validate
396 glsl_symbol_table variables;
397 for (unsigned i = 0; i < num_shaders; i++) {
398 if (shader_list[i] == NULL)
401 foreach_list(node, shader_list[i]->ir) {
402 ir_variable *const var = ((ir_instruction *) node)->as_variable();
407 if (uniforms_only && (var->mode != ir_var_uniform))
410 /* Don't cross validate temporaries that are at global scope. These
411 * will eventually get pulled into the shaders 'main'.
413 if (var->mode == ir_var_temporary)
416 /* If a global with this name has already been seen, verify that the
417 * new instance has the same type. In addition, if the globals have
418 * initializers, the values of the initializers must be the same.
420 ir_variable *const existing = variables.get_variable(var->name);
421 if (existing != NULL) {
422 if (var->type != existing->type) {
423 /* Consider the types to be "the same" if both types are arrays
424 * of the same type and one of the arrays is implicitly sized.
425 * In addition, set the type of the linked variable to the
426 * explicitly sized array.
428 if (var->type->is_array()
429 && existing->type->is_array()
430 && (var->type->fields.array == existing->type->fields.array)
431 && ((var->type->length == 0)
432 || (existing->type->length == 0))) {
433 if (var->type->length != 0) {
434 existing->type = var->type;
437 linker_error(prog, "%s `%s' declared as type "
438 "`%s' and type `%s'\n",
440 var->name, var->type->name,
441 existing->type->name);
446 if (var->explicit_location) {
447 if (existing->explicit_location
448 && (var->location != existing->location)) {
449 linker_error(prog, "explicit locations for %s "
450 "`%s' have differing values\n",
451 mode_string(var), var->name);
455 existing->location = var->location;
456 existing->explicit_location = true;
459 /* Validate layout qualifiers for gl_FragDepth.
461 * From the AMD/ARB_conservative_depth specs:
463 * "If gl_FragDepth is redeclared in any fragment shader in a
464 * program, it must be redeclared in all fragment shaders in
465 * that program that have static assignments to
466 * gl_FragDepth. All redeclarations of gl_FragDepth in all
467 * fragment shaders in a single program must have the same set
470 if (strcmp(var->name, "gl_FragDepth") == 0) {
471 bool layout_declared = var->depth_layout != ir_depth_layout_none;
472 bool layout_differs =
473 var->depth_layout != existing->depth_layout;
475 if (layout_declared && layout_differs) {
477 "All redeclarations of gl_FragDepth in all "
478 "fragment shaders in a single program must have "
479 "the same set of qualifiers.");
482 if (var->used && layout_differs) {
484 "If gl_FragDepth is redeclared with a layout "
485 "qualifier in any fragment shader, it must be "
486 "redeclared with the same layout qualifier in "
487 "all fragment shaders that have assignments to "
492 /* Page 35 (page 41 of the PDF) of the GLSL 4.20 spec says:
494 * "If a shared global has multiple initializers, the
495 * initializers must all be constant expressions, and they
496 * must all have the same value. Otherwise, a link error will
497 * result. (A shared global having only one initializer does
498 * not require that initializer to be a constant expression.)"
500 * Previous to 4.20 the GLSL spec simply said that initializers
501 * must have the same value. In this case of non-constant
502 * initializers, this was impossible to determine. As a result,
503 * no vendor actually implemented that behavior. The 4.20
504 * behavior matches the implemented behavior of at least one other
505 * vendor, so we'll implement that for all GLSL versions.
507 if (var->constant_initializer != NULL) {
508 if (existing->constant_initializer != NULL) {
509 if (!var->constant_initializer->has_value(existing->constant_initializer)) {
510 linker_error(prog, "initializers for %s "
511 "`%s' have differing values\n",
512 mode_string(var), var->name);
516 /* If the first-seen instance of a particular uniform did not
517 * have an initializer but a later instance does, copy the
518 * initializer to the version stored in the symbol table.
520 /* FINISHME: This is wrong. The constant_value field should
521 * FINISHME: not be modified! Imagine a case where a shader
522 * FINISHME: without an initializer is linked in two different
523 * FINISHME: programs with shaders that have differing
524 * FINISHME: initializers. Linking with the first will
525 * FINISHME: modify the shader, and linking with the second
526 * FINISHME: will fail.
528 existing->constant_initializer =
529 var->constant_initializer->clone(ralloc_parent(existing),
534 if (var->has_initializer) {
535 if (existing->has_initializer
536 && (var->constant_initializer == NULL
537 || existing->constant_initializer == NULL)) {
539 "shared global variable `%s' has multiple "
540 "non-constant initializers.\n",
545 /* Some instance had an initializer, so keep track of that. In
546 * this location, all sorts of initializers (constant or
547 * otherwise) will propagate the existence to the variable
548 * stored in the symbol table.
550 existing->has_initializer = true;
553 if (existing->invariant != var->invariant) {
554 linker_error(prog, "declarations for %s `%s' have "
555 "mismatching invariant qualifiers\n",
556 mode_string(var), var->name);
559 if (existing->centroid != var->centroid) {
560 linker_error(prog, "declarations for %s `%s' have "
561 "mismatching centroid qualifiers\n",
562 mode_string(var), var->name);
566 variables.add_variable(var);
575 * Perform validation of uniforms used across multiple shader stages
578 cross_validate_uniforms(struct gl_shader_program *prog)
580 return cross_validate_globals(prog, prog->_LinkedShaders,
581 MESA_SHADER_TYPES, true);
585 * Accumulates the array of prog->UniformBlocks and checks that all
586 * definitons of blocks agree on their contents.
589 interstage_cross_validate_uniform_blocks(struct gl_shader_program *prog)
591 unsigned max_num_uniform_blocks = 0;
592 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
593 if (prog->_LinkedShaders[i])
594 max_num_uniform_blocks += prog->_LinkedShaders[i]->NumUniformBlocks;
597 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
598 struct gl_shader *sh = prog->_LinkedShaders[i];
600 prog->UniformBlockStageIndex[i] = ralloc_array(prog, int,
601 max_num_uniform_blocks);
602 for (unsigned int j = 0; j < max_num_uniform_blocks; j++)
603 prog->UniformBlockStageIndex[i][j] = -1;
608 for (unsigned int j = 0; j < sh->NumUniformBlocks; j++) {
609 int index = link_cross_validate_uniform_block(prog,
610 &prog->UniformBlocks,
611 &prog->NumUniformBlocks,
612 &sh->UniformBlocks[j]);
615 linker_error(prog, "uniform block `%s' has mismatching definitions",
616 sh->UniformBlocks[j].Name);
620 prog->UniformBlockStageIndex[i][index] = j;
628 * Validate that outputs from one stage match inputs of another
631 cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
632 gl_shader *producer, gl_shader *consumer)
634 glsl_symbol_table parameters;
635 /* FINISHME: Figure these out dynamically. */
636 const char *const producer_stage = "vertex";
637 const char *const consumer_stage = "fragment";
639 /* Find all shader outputs in the "producer" stage.
641 foreach_list(node, producer->ir) {
642 ir_variable *const var = ((ir_instruction *) node)->as_variable();
644 /* FINISHME: For geometry shaders, this should also look for inout
645 * FINISHME: variables.
647 if ((var == NULL) || (var->mode != ir_var_out))
650 parameters.add_variable(var);
654 /* Find all shader inputs in the "consumer" stage. Any variables that have
655 * matching outputs already in the symbol table must have the same type and
658 foreach_list(node, consumer->ir) {
659 ir_variable *const input = ((ir_instruction *) node)->as_variable();
661 /* FINISHME: For geometry shaders, this should also look for inout
662 * FINISHME: variables.
664 if ((input == NULL) || (input->mode != ir_var_in))
667 ir_variable *const output = parameters.get_variable(input->name);
668 if (output != NULL) {
669 /* Check that the types match between stages.
671 if (input->type != output->type) {
672 /* There is a bit of a special case for gl_TexCoord. This
673 * built-in is unsized by default. Applications that variable
674 * access it must redeclare it with a size. There is some
675 * language in the GLSL spec that implies the fragment shader
676 * and vertex shader do not have to agree on this size. Other
677 * driver behave this way, and one or two applications seem to
680 * Neither declaration needs to be modified here because the array
681 * sizes are fixed later when update_array_sizes is called.
683 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
685 * "Unlike user-defined varying variables, the built-in
686 * varying variables don't have a strict one-to-one
687 * correspondence between the vertex language and the
688 * fragment language."
690 if (!output->type->is_array()
691 || (strncmp("gl_", output->name, 3) != 0)) {
693 "%s shader output `%s' declared as type `%s', "
694 "but %s shader input declared as type `%s'\n",
695 producer_stage, output->name,
697 consumer_stage, input->type->name);
702 /* Check that all of the qualifiers match between stages.
704 if (input->centroid != output->centroid) {
706 "%s shader output `%s' %s centroid qualifier, "
707 "but %s shader input %s centroid qualifier\n",
710 (output->centroid) ? "has" : "lacks",
712 (input->centroid) ? "has" : "lacks");
716 if (input->invariant != output->invariant) {
718 "%s shader output `%s' %s invariant qualifier, "
719 "but %s shader input %s invariant qualifier\n",
722 (output->invariant) ? "has" : "lacks",
724 (input->invariant) ? "has" : "lacks");
728 if (input->interpolation != output->interpolation) {
730 "%s shader output `%s' specifies %s "
731 "interpolation qualifier, "
732 "but %s shader input specifies %s "
733 "interpolation qualifier\n",
736 output->interpolation_string(),
738 input->interpolation_string());
749 * Populates a shaders symbol table with all global declarations
752 populate_symbol_table(gl_shader *sh)
754 sh->symbols = new(sh) glsl_symbol_table;
756 foreach_list(node, sh->ir) {
757 ir_instruction *const inst = (ir_instruction *) node;
761 if ((func = inst->as_function()) != NULL) {
762 sh->symbols->add_function(func);
763 } else if ((var = inst->as_variable()) != NULL) {
764 sh->symbols->add_variable(var);
771 * Remap variables referenced in an instruction tree
773 * This is used when instruction trees are cloned from one shader and placed in
774 * another. These trees will contain references to \c ir_variable nodes that
775 * do not exist in the target shader. This function finds these \c ir_variable
776 * references and replaces the references with matching variables in the target
779 * If there is no matching variable in the target shader, a clone of the
780 * \c ir_variable is made and added to the target shader. The new variable is
781 * added to \b both the instruction stream and the symbol table.
783 * \param inst IR tree that is to be processed.
784 * \param symbols Symbol table containing global scope symbols in the
786 * \param instructions Instruction stream where new variable declarations
790 remap_variables(ir_instruction *inst, struct gl_shader *target,
793 class remap_visitor : public ir_hierarchical_visitor {
795 remap_visitor(struct gl_shader *target,
798 this->target = target;
799 this->symbols = target->symbols;
800 this->instructions = target->ir;
804 virtual ir_visitor_status visit(ir_dereference_variable *ir)
806 if (ir->var->mode == ir_var_temporary) {
807 ir_variable *var = (ir_variable *) hash_table_find(temps, ir->var);
811 return visit_continue;
814 ir_variable *const existing =
815 this->symbols->get_variable(ir->var->name);
816 if (existing != NULL)
819 ir_variable *copy = ir->var->clone(this->target, NULL);
821 this->symbols->add_variable(copy);
822 this->instructions->push_head(copy);
826 return visit_continue;
830 struct gl_shader *target;
831 glsl_symbol_table *symbols;
832 exec_list *instructions;
836 remap_visitor v(target, temps);
843 * Move non-declarations from one instruction stream to another
845 * The intended usage pattern of this function is to pass the pointer to the
846 * head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node
847 * pointer) for \c last and \c false for \c make_copies on the first
848 * call. Successive calls pass the return value of the previous call for
849 * \c last and \c true for \c make_copies.
851 * \param instructions Source instruction stream
852 * \param last Instruction after which new instructions should be
853 * inserted in the target instruction stream
854 * \param make_copies Flag selecting whether instructions in \c instructions
855 * should be copied (via \c ir_instruction::clone) into the
856 * target list or moved.
859 * The new "last" instruction in the target instruction stream. This pointer
860 * is suitable for use as the \c last parameter of a later call to this
864 move_non_declarations(exec_list *instructions, exec_node *last,
865 bool make_copies, gl_shader *target)
867 hash_table *temps = NULL;
870 temps = hash_table_ctor(0, hash_table_pointer_hash,
871 hash_table_pointer_compare);
873 foreach_list_safe(node, instructions) {
874 ir_instruction *inst = (ir_instruction *) node;
876 if (inst->as_function())
879 ir_variable *var = inst->as_variable();
880 if ((var != NULL) && (var->mode != ir_var_temporary))
883 assert(inst->as_assignment()
885 || ((var != NULL) && (var->mode == ir_var_temporary)));
888 inst = inst->clone(target, NULL);
891 hash_table_insert(temps, inst, var);
893 remap_variables(inst, target, temps);
898 last->insert_after(inst);
903 hash_table_dtor(temps);
909 * Get the function signature for main from a shader
911 static ir_function_signature *
912 get_main_function_signature(gl_shader *sh)
914 ir_function *const f = sh->symbols->get_function("main");
916 exec_list void_parameters;
918 /* Look for the 'void main()' signature and ensure that it's defined.
919 * This keeps the linker from accidentally pick a shader that just
920 * contains a prototype for main.
922 * We don't have to check for multiple definitions of main (in multiple
923 * shaders) because that would have already been caught above.
925 ir_function_signature *sig = f->matching_signature(&void_parameters);
926 if ((sig != NULL) && sig->is_defined) {
936 * This class is only used in link_intrastage_shaders() below but declaring
937 * it inside that function leads to compiler warnings with some versions of
940 class array_sizing_visitor : public ir_hierarchical_visitor {
942 virtual ir_visitor_status visit(ir_variable *var)
944 if (var->type->is_array() && (var->type->length == 0)) {
945 const glsl_type *type =
946 glsl_type::get_array_instance(var->type->fields.array,
947 var->max_array_access + 1);
948 assert(type != NULL);
951 return visit_continue;
956 * Combine a group of shaders for a single stage to generate a linked shader
959 * If this function is supplied a single shader, it is cloned, and the new
960 * shader is returned.
962 static struct gl_shader *
963 link_intrastage_shaders(void *mem_ctx,
964 struct gl_context *ctx,
965 struct gl_shader_program *prog,
966 struct gl_shader **shader_list,
967 unsigned num_shaders)
969 struct gl_uniform_block *uniform_blocks = NULL;
970 unsigned num_uniform_blocks = 0;
972 /* Check that global variables defined in multiple shaders are consistent.
974 if (!cross_validate_globals(prog, shader_list, num_shaders, false))
977 /* Check that uniform blocks between shaders for a stage agree. */
978 for (unsigned i = 0; i < num_shaders; i++) {
979 struct gl_shader *sh = shader_list[i];
981 for (unsigned j = 0; j < shader_list[i]->NumUniformBlocks; j++) {
982 int index = link_cross_validate_uniform_block(mem_ctx,
985 &sh->UniformBlocks[j]);
987 linker_error(prog, "uniform block `%s' has mismatching definitions",
988 sh->UniformBlocks[j].Name);
994 /* Check that there is only a single definition of each function signature
995 * across all shaders.
997 for (unsigned i = 0; i < (num_shaders - 1); i++) {
998 foreach_list(node, shader_list[i]->ir) {
999 ir_function *const f = ((ir_instruction *) node)->as_function();
1004 for (unsigned j = i + 1; j < num_shaders; j++) {
1005 ir_function *const other =
1006 shader_list[j]->symbols->get_function(f->name);
1008 /* If the other shader has no function (and therefore no function
1009 * signatures) with the same name, skip to the next shader.
1014 foreach_iter (exec_list_iterator, iter, *f) {
1015 ir_function_signature *sig =
1016 (ir_function_signature *) iter.get();
1018 if (!sig->is_defined || sig->is_builtin)
1021 ir_function_signature *other_sig =
1022 other->exact_matching_signature(& sig->parameters);
1024 if ((other_sig != NULL) && other_sig->is_defined
1025 && !other_sig->is_builtin) {
1026 linker_error(prog, "function `%s' is multiply defined",
1035 /* Find the shader that defines main, and make a clone of it.
1037 * Starting with the clone, search for undefined references. If one is
1038 * found, find the shader that defines it. Clone the reference and add
1039 * it to the shader. Repeat until there are no undefined references or
1040 * until a reference cannot be resolved.
1042 gl_shader *main = NULL;
1043 for (unsigned i = 0; i < num_shaders; i++) {
1044 if (get_main_function_signature(shader_list[i]) != NULL) {
1045 main = shader_list[i];
1051 linker_error(prog, "%s shader lacks `main'\n",
1052 (shader_list[0]->Type == GL_VERTEX_SHADER)
1053 ? "vertex" : "fragment");
1057 gl_shader *linked = ctx->Driver.NewShader(NULL, 0, main->Type);
1058 linked->ir = new(linked) exec_list;
1059 clone_ir_list(mem_ctx, linked->ir, main->ir);
1061 linked->UniformBlocks = uniform_blocks;
1062 linked->NumUniformBlocks = num_uniform_blocks;
1063 ralloc_steal(linked, linked->UniformBlocks);
1065 populate_symbol_table(linked);
1067 /* The a pointer to the main function in the final linked shader (i.e., the
1068 * copy of the original shader that contained the main function).
1070 ir_function_signature *const main_sig = get_main_function_signature(linked);
1072 /* Move any instructions other than variable declarations or function
1073 * declarations into main.
1075 exec_node *insertion_point =
1076 move_non_declarations(linked->ir, (exec_node *) &main_sig->body, false,
1079 for (unsigned i = 0; i < num_shaders; i++) {
1080 if (shader_list[i] == main)
1083 insertion_point = move_non_declarations(shader_list[i]->ir,
1084 insertion_point, true, linked);
1087 /* Resolve initializers for global variables in the linked shader.
1089 unsigned num_linking_shaders = num_shaders;
1090 for (unsigned i = 0; i < num_shaders; i++)
1091 num_linking_shaders += shader_list[i]->num_builtins_to_link;
1093 gl_shader **linking_shaders =
1094 (gl_shader **) calloc(num_linking_shaders, sizeof(gl_shader *));
1096 memcpy(linking_shaders, shader_list,
1097 sizeof(linking_shaders[0]) * num_shaders);
1099 unsigned idx = num_shaders;
1100 for (unsigned i = 0; i < num_shaders; i++) {
1101 memcpy(&linking_shaders[idx], shader_list[i]->builtins_to_link,
1102 sizeof(linking_shaders[0]) * shader_list[i]->num_builtins_to_link);
1103 idx += shader_list[i]->num_builtins_to_link;
1106 assert(idx == num_linking_shaders);
1108 if (!link_function_calls(prog, linked, linking_shaders,
1109 num_linking_shaders)) {
1110 ctx->Driver.DeleteShader(ctx, linked);
1114 free(linking_shaders);
1117 /* At this point linked should contain all of the linked IR, so
1118 * validate it to make sure nothing went wrong.
1121 validate_ir_tree(linked->ir);
1124 /* Make a pass over all variable declarations to ensure that arrays with
1125 * unspecified sizes have a size specified. The size is inferred from the
1126 * max_array_access field.
1128 if (linked != NULL) {
1129 array_sizing_visitor v;
1138 * Update the sizes of linked shader uniform arrays to the maximum
1141 * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
1143 * If one or more elements of an array are active,
1144 * GetActiveUniform will return the name of the array in name,
1145 * subject to the restrictions listed above. The type of the array
1146 * is returned in type. The size parameter contains the highest
1147 * array element index used, plus one. The compiler or linker
1148 * determines the highest index used. There will be only one
1149 * active uniform reported by the GL per uniform array.
1153 update_array_sizes(struct gl_shader_program *prog)
1155 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
1156 if (prog->_LinkedShaders[i] == NULL)
1159 foreach_list(node, prog->_LinkedShaders[i]->ir) {
1160 ir_variable *const var = ((ir_instruction *) node)->as_variable();
1162 if ((var == NULL) || (var->mode != ir_var_uniform &&
1163 var->mode != ir_var_in &&
1164 var->mode != ir_var_out) ||
1165 !var->type->is_array())
1168 /* GL_ARB_uniform_buffer_object says that std140 uniforms
1169 * will not be eliminated. Since we always do std140, just
1170 * don't resize arrays in UBOs.
1172 if (var->uniform_block != -1)
1175 unsigned int size = var->max_array_access;
1176 for (unsigned j = 0; j < MESA_SHADER_TYPES; j++) {
1177 if (prog->_LinkedShaders[j] == NULL)
1180 foreach_list(node2, prog->_LinkedShaders[j]->ir) {
1181 ir_variable *other_var = ((ir_instruction *) node2)->as_variable();
1185 if (strcmp(var->name, other_var->name) == 0 &&
1186 other_var->max_array_access > size) {
1187 size = other_var->max_array_access;
1192 if (size + 1 != var->type->fields.array->length) {
1193 /* If this is a built-in uniform (i.e., it's backed by some
1194 * fixed-function state), adjust the number of state slots to
1195 * match the new array size. The number of slots per array entry
1196 * is not known. It seems safe to assume that the total number of
1197 * slots is an integer multiple of the number of array elements.
1198 * Determine the number of slots per array element by dividing by
1199 * the old (total) size.
1201 if (var->num_state_slots > 0) {
1202 var->num_state_slots = (size + 1)
1203 * (var->num_state_slots / var->type->length);
1206 var->type = glsl_type::get_array_instance(var->type->fields.array,
1208 /* FINISHME: We should update the types of array
1209 * dereferences of this variable now.
1217 * Find a contiguous set of available bits in a bitmask.
1219 * \param used_mask Bits representing used (1) and unused (0) locations
1220 * \param needed_count Number of contiguous bits needed.
1223 * Base location of the available bits on success or -1 on failure.
1226 find_available_slots(unsigned used_mask, unsigned needed_count)
1228 unsigned needed_mask = (1 << needed_count) - 1;
1229 const int max_bit_to_test = (8 * sizeof(used_mask)) - needed_count;
1231 /* The comparison to 32 is redundant, but without it GCC emits "warning:
1232 * cannot optimize possibly infinite loops" for the loop below.
1234 if ((needed_count == 0) || (max_bit_to_test < 0) || (max_bit_to_test > 32))
1237 for (int i = 0; i <= max_bit_to_test; i++) {
1238 if ((needed_mask & ~used_mask) == needed_mask)
1249 * Assign locations for either VS inputs for FS outputs
1251 * \param prog Shader program whose variables need locations assigned
1252 * \param target_index Selector for the program target to receive location
1253 * assignmnets. Must be either \c MESA_SHADER_VERTEX or
1254 * \c MESA_SHADER_FRAGMENT.
1255 * \param max_index Maximum number of generic locations. This corresponds
1256 * to either the maximum number of draw buffers or the
1257 * maximum number of generic attributes.
1260 * If locations are successfully assigned, true is returned. Otherwise an
1261 * error is emitted to the shader link log and false is returned.
1264 assign_attribute_or_color_locations(gl_shader_program *prog,
1265 unsigned target_index,
1268 /* Mark invalid locations as being used.
1270 unsigned used_locations = (max_index >= 32)
1271 ? ~0 : ~((1 << max_index) - 1);
1273 assert((target_index == MESA_SHADER_VERTEX)
1274 || (target_index == MESA_SHADER_FRAGMENT));
1276 gl_shader *const sh = prog->_LinkedShaders[target_index];
1280 /* Operate in a total of four passes.
1282 * 1. Invalidate the location assignments for all vertex shader inputs.
1284 * 2. Assign locations for inputs that have user-defined (via
1285 * glBindVertexAttribLocation) locations and outputs that have
1286 * user-defined locations (via glBindFragDataLocation).
1288 * 3. Sort the attributes without assigned locations by number of slots
1289 * required in decreasing order. Fragmentation caused by attribute
1290 * locations assigned by the application may prevent large attributes
1291 * from having enough contiguous space.
1293 * 4. Assign locations to any inputs without assigned locations.
1296 const int generic_base = (target_index == MESA_SHADER_VERTEX)
1297 ? (int) VERT_ATTRIB_GENERIC0 : (int) FRAG_RESULT_DATA0;
1299 const enum ir_variable_mode direction =
1300 (target_index == MESA_SHADER_VERTEX) ? ir_var_in : ir_var_out;
1303 link_invalidate_variable_locations(sh, direction, generic_base);
1305 /* Temporary storage for the set of attributes that need locations assigned.
1311 /* Used below in the call to qsort. */
1312 static int compare(const void *a, const void *b)
1314 const temp_attr *const l = (const temp_attr *) a;
1315 const temp_attr *const r = (const temp_attr *) b;
1317 /* Reversed because we want a descending order sort below. */
1318 return r->slots - l->slots;
1322 unsigned num_attr = 0;
1324 foreach_list(node, sh->ir) {
1325 ir_variable *const var = ((ir_instruction *) node)->as_variable();
1327 if ((var == NULL) || (var->mode != (unsigned) direction))
1330 if (var->explicit_location) {
1331 if ((var->location >= (int)(max_index + generic_base))
1332 || (var->location < 0)) {
1334 "invalid explicit location %d specified for `%s'\n",
1336 ? var->location : var->location - generic_base,
1340 } else if (target_index == MESA_SHADER_VERTEX) {
1343 if (prog->AttributeBindings->get(binding, var->name)) {
1344 assert(binding >= VERT_ATTRIB_GENERIC0);
1345 var->location = binding;
1347 } else if (target_index == MESA_SHADER_FRAGMENT) {
1351 if (prog->FragDataBindings->get(binding, var->name)) {
1352 assert(binding >= FRAG_RESULT_DATA0);
1353 var->location = binding;
1355 if (prog->FragDataIndexBindings->get(index, var->name)) {
1361 /* If the variable is not a built-in and has a location statically
1362 * assigned in the shader (presumably via a layout qualifier), make sure
1363 * that it doesn't collide with other assigned locations. Otherwise,
1364 * add it to the list of variables that need linker-assigned locations.
1366 const unsigned slots = count_attribute_slots(var->type);
1367 if (var->location != -1) {
1368 if (var->location >= generic_base && var->index < 1) {
1369 /* From page 61 of the OpenGL 4.0 spec:
1371 * "LinkProgram will fail if the attribute bindings assigned
1372 * by BindAttribLocation do not leave not enough space to
1373 * assign a location for an active matrix attribute or an
1374 * active attribute array, both of which require multiple
1375 * contiguous generic attributes."
1377 * Previous versions of the spec contain similar language but omit
1378 * the bit about attribute arrays.
1380 * Page 61 of the OpenGL 4.0 spec also says:
1382 * "It is possible for an application to bind more than one
1383 * attribute name to the same location. This is referred to as
1384 * aliasing. This will only work if only one of the aliased
1385 * attributes is active in the executable program, or if no
1386 * path through the shader consumes more than one attribute of
1387 * a set of attributes aliased to the same location. A link
1388 * error can occur if the linker determines that every path
1389 * through the shader consumes multiple aliased attributes,
1390 * but implementations are not required to generate an error
1393 * These two paragraphs are either somewhat contradictory, or I
1394 * don't fully understand one or both of them.
1396 /* FINISHME: The code as currently written does not support
1397 * FINISHME: attribute location aliasing (see comment above).
1399 /* Mask representing the contiguous slots that will be used by
1402 const unsigned attr = var->location - generic_base;
1403 const unsigned use_mask = (1 << slots) - 1;
1405 /* Generate a link error if the set of bits requested for this
1406 * attribute overlaps any previously allocated bits.
1408 if ((~(use_mask << attr) & used_locations) != used_locations) {
1409 const char *const string = (target_index == MESA_SHADER_VERTEX)
1410 ? "vertex shader input" : "fragment shader output";
1412 "insufficient contiguous locations "
1413 "available for %s `%s' %d %d %d", string,
1414 var->name, used_locations, use_mask, attr);
1418 used_locations |= (use_mask << attr);
1424 to_assign[num_attr].slots = slots;
1425 to_assign[num_attr].var = var;
1429 /* If all of the attributes were assigned locations by the application (or
1430 * are built-in attributes with fixed locations), return early. This should
1431 * be the common case.
1436 qsort(to_assign, num_attr, sizeof(to_assign[0]), temp_attr::compare);
1438 if (target_index == MESA_SHADER_VERTEX) {
1439 /* VERT_ATTRIB_GENERIC0 is a pseudo-alias for VERT_ATTRIB_POS. It can
1440 * only be explicitly assigned by via glBindAttribLocation. Mark it as
1441 * reserved to prevent it from being automatically allocated below.
1443 find_deref_visitor find("gl_Vertex");
1445 if (find.variable_found())
1446 used_locations |= (1 << 0);
1449 for (unsigned i = 0; i < num_attr; i++) {
1450 /* Mask representing the contiguous slots that will be used by this
1453 const unsigned use_mask = (1 << to_assign[i].slots) - 1;
1455 int location = find_available_slots(used_locations, to_assign[i].slots);
1458 const char *const string = (target_index == MESA_SHADER_VERTEX)
1459 ? "vertex shader input" : "fragment shader output";
1462 "insufficient contiguous locations "
1463 "available for %s `%s'",
1464 string, to_assign[i].var->name);
1468 to_assign[i].var->location = generic_base + location;
1469 used_locations |= (use_mask << location);
1477 * Demote shader inputs and outputs that are not used in other stages
1480 demote_shader_inputs_and_outputs(gl_shader *sh, enum ir_variable_mode mode)
1482 foreach_list(node, sh->ir) {
1483 ir_variable *const var = ((ir_instruction *) node)->as_variable();
1485 if ((var == NULL) || (var->mode != int(mode)))
1488 /* A shader 'in' or 'out' variable is only really an input or output if
1489 * its value is used by other shader stages. This will cause the variable
1490 * to have a location assigned.
1492 if (var->location == -1) {
1493 var->mode = ir_var_auto;
1500 * Data structure tracking information about a transform feedback declaration
1503 class tfeedback_decl
1506 bool init(struct gl_context *ctx, struct gl_shader_program *prog,
1507 const void *mem_ctx, const char *input);
1508 static bool is_same(const tfeedback_decl &x, const tfeedback_decl &y);
1509 bool assign_location(struct gl_context *ctx, struct gl_shader_program *prog,
1510 ir_variable *output_var);
1511 bool accumulate_num_outputs(struct gl_shader_program *prog, unsigned *count);
1512 bool store(struct gl_context *ctx, struct gl_shader_program *prog,
1513 struct gl_transform_feedback_info *info, unsigned buffer,
1514 const unsigned max_outputs) const;
1517 * True if assign_location() has been called for this object.
1519 bool is_assigned() const
1521 return this->location != -1;
1524 bool is_next_buffer_separator() const
1526 return this->next_buffer_separator;
1529 bool is_varying() const
1531 return !this->next_buffer_separator && !this->skip_components;
1535 * Determine whether this object refers to the variable var.
1537 bool matches_var(ir_variable *var) const
1539 if (this->is_clip_distance_mesa)
1540 return strcmp(var->name, "gl_ClipDistanceMESA") == 0;
1542 return strcmp(var->name, this->var_name) == 0;
1546 * The total number of varying components taken up by this variable. Only
1547 * valid if is_assigned() is true.
1549 unsigned num_components() const
1551 if (this->is_clip_distance_mesa)
1554 return this->vector_elements * this->matrix_columns * this->size;
1559 * The name that was supplied to glTransformFeedbackVaryings. Used for
1560 * error reporting and glGetTransformFeedbackVarying().
1562 const char *orig_name;
1565 * The name of the variable, parsed from orig_name.
1567 const char *var_name;
1570 * True if the declaration in orig_name represents an array.
1572 bool is_subscripted;
1575 * If is_subscripted is true, the subscript that was specified in orig_name.
1577 unsigned array_subscript;
1580 * True if the variable is gl_ClipDistance and the driver lowers
1581 * gl_ClipDistance to gl_ClipDistanceMESA.
1583 bool is_clip_distance_mesa;
1586 * The vertex shader output location that the linker assigned for this
1587 * variable. -1 if a location hasn't been assigned yet.
1592 * If location != -1, the number of vector elements in this variable, or 1
1593 * if this variable is a scalar.
1595 unsigned vector_elements;
1598 * If location != -1, the number of matrix columns in this variable, or 1
1599 * if this variable is not a matrix.
1601 unsigned matrix_columns;
1603 /** Type of the varying returned by glGetTransformFeedbackVarying() */
1607 * If location != -1, the size that should be returned by
1608 * glGetTransformFeedbackVarying().
1613 * How many components to skip. If non-zero, this is
1614 * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
1616 unsigned skip_components;
1619 * Whether this is gl_NextBuffer from ARB_transform_feedback3.
1621 bool next_buffer_separator;
1626 * Initialize this object based on a string that was passed to
1627 * glTransformFeedbackVaryings. If there is a parse error, the error is
1628 * reported using linker_error(), and false is returned.
1631 tfeedback_decl::init(struct gl_context *ctx, struct gl_shader_program *prog,
1632 const void *mem_ctx, const char *input)
1634 /* We don't have to be pedantic about what is a valid GLSL variable name,
1635 * because any variable with an invalid name can't exist in the IR anyway.
1638 this->location = -1;
1639 this->orig_name = input;
1640 this->is_clip_distance_mesa = false;
1641 this->skip_components = 0;
1642 this->next_buffer_separator = false;
1644 if (ctx->Extensions.ARB_transform_feedback3) {
1645 /* Parse gl_NextBuffer. */
1646 if (strcmp(input, "gl_NextBuffer") == 0) {
1647 this->next_buffer_separator = true;
1651 /* Parse gl_SkipComponents. */
1652 if (strcmp(input, "gl_SkipComponents1") == 0)
1653 this->skip_components = 1;
1654 else if (strcmp(input, "gl_SkipComponents2") == 0)
1655 this->skip_components = 2;
1656 else if (strcmp(input, "gl_SkipComponents3") == 0)
1657 this->skip_components = 3;
1658 else if (strcmp(input, "gl_SkipComponents4") == 0)
1659 this->skip_components = 4;
1661 if (this->skip_components)
1665 /* Parse a declaration. */
1666 const char *bracket = strrchr(input, '[');
1669 this->var_name = ralloc_strndup(mem_ctx, input, bracket - input);
1670 if (sscanf(bracket, "[%u]", &this->array_subscript) != 1) {
1671 linker_error(prog, "Cannot parse transform feedback varying %s", input);
1674 this->is_subscripted = true;
1676 this->var_name = ralloc_strdup(mem_ctx, input);
1677 this->is_subscripted = false;
1680 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
1681 * class must behave specially to account for the fact that gl_ClipDistance
1682 * is converted from a float[8] to a vec4[2].
1684 if (ctx->ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerClipDistance &&
1685 strcmp(this->var_name, "gl_ClipDistance") == 0) {
1686 this->is_clip_distance_mesa = true;
1694 * Determine whether two tfeedback_decl objects refer to the same variable and
1695 * array index (if applicable).
1698 tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y)
1700 assert(x.is_varying() && y.is_varying());
1702 if (strcmp(x.var_name, y.var_name) != 0)
1704 if (x.is_subscripted != y.is_subscripted)
1706 if (x.is_subscripted && x.array_subscript != y.array_subscript)
1713 * Assign a location for this tfeedback_decl object based on the location
1714 * assignment in output_var.
1716 * If an error occurs, the error is reported through linker_error() and false
1720 tfeedback_decl::assign_location(struct gl_context *ctx,
1721 struct gl_shader_program *prog,
1722 ir_variable *output_var)
1724 assert(this->is_varying());
1726 if (output_var->type->is_array()) {
1727 /* Array variable */
1728 const unsigned matrix_cols =
1729 output_var->type->fields.array->matrix_columns;
1730 unsigned actual_array_size = this->is_clip_distance_mesa ?
1731 prog->Vert.ClipDistanceArraySize : output_var->type->array_size();
1733 if (this->is_subscripted) {
1734 /* Check array bounds. */
1735 if (this->array_subscript >= actual_array_size) {
1736 linker_error(prog, "Transform feedback varying %s has index "
1737 "%i, but the array size is %u.",
1738 this->orig_name, this->array_subscript,
1742 if (this->is_clip_distance_mesa) {
1744 output_var->location + this->array_subscript / 4;
1747 output_var->location + this->array_subscript * matrix_cols;
1751 this->location = output_var->location;
1752 this->size = actual_array_size;
1754 this->vector_elements = output_var->type->fields.array->vector_elements;
1755 this->matrix_columns = matrix_cols;
1756 if (this->is_clip_distance_mesa)
1757 this->type = GL_FLOAT;
1759 this->type = output_var->type->fields.array->gl_type;
1761 /* Regular variable (scalar, vector, or matrix) */
1762 if (this->is_subscripted) {
1763 linker_error(prog, "Transform feedback varying %s requested, "
1764 "but %s is not an array.",
1765 this->orig_name, this->var_name);
1768 this->location = output_var->location;
1770 this->vector_elements = output_var->type->vector_elements;
1771 this->matrix_columns = output_var->type->matrix_columns;
1772 this->type = output_var->type->gl_type;
1775 /* From GL_EXT_transform_feedback:
1776 * A program will fail to link if:
1778 * * the total number of components to capture in any varying
1779 * variable in <varyings> is greater than the constant
1780 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
1781 * buffer mode is SEPARATE_ATTRIBS_EXT;
1783 if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS &&
1784 this->num_components() >
1785 ctx->Const.MaxTransformFeedbackSeparateComponents) {
1786 linker_error(prog, "Transform feedback varying %s exceeds "
1787 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
1797 tfeedback_decl::accumulate_num_outputs(struct gl_shader_program *prog,
1800 if (!this->is_varying()) {
1804 if (!this->is_assigned()) {
1805 /* From GL_EXT_transform_feedback:
1806 * A program will fail to link if:
1808 * * any variable name specified in the <varyings> array is not
1809 * declared as an output in the geometry shader (if present) or
1810 * the vertex shader (if no geometry shader is present);
1812 linker_error(prog, "Transform feedback varying %s undeclared.",
1817 unsigned translated_size = this->size;
1818 if (this->is_clip_distance_mesa)
1819 translated_size = (translated_size + 3) / 4;
1821 *count += translated_size * this->matrix_columns;
1828 * Update gl_transform_feedback_info to reflect this tfeedback_decl.
1830 * If an error occurs, the error is reported through linker_error() and false
1834 tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog,
1835 struct gl_transform_feedback_info *info,
1836 unsigned buffer, const unsigned max_outputs) const
1838 assert(!this->next_buffer_separator);
1840 /* Handle gl_SkipComponents. */
1841 if (this->skip_components) {
1842 info->BufferStride[buffer] += this->skip_components;
1846 /* From GL_EXT_transform_feedback:
1847 * A program will fail to link if:
1849 * * the total number of components to capture is greater than
1850 * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
1851 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
1853 if (prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS &&
1854 info->BufferStride[buffer] + this->num_components() >
1855 ctx->Const.MaxTransformFeedbackInterleavedComponents) {
1856 linker_error(prog, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
1857 "limit has been exceeded.");
1861 unsigned translated_size = this->size;
1862 if (this->is_clip_distance_mesa)
1863 translated_size = (translated_size + 3) / 4;
1864 unsigned components_so_far = 0;
1865 for (unsigned index = 0; index < translated_size; ++index) {
1866 for (unsigned v = 0; v < this->matrix_columns; ++v) {
1867 unsigned num_components = this->vector_elements;
1868 assert(info->NumOutputs < max_outputs);
1869 info->Outputs[info->NumOutputs].ComponentOffset = 0;
1870 if (this->is_clip_distance_mesa) {
1871 if (this->is_subscripted) {
1873 info->Outputs[info->NumOutputs].ComponentOffset =
1874 this->array_subscript % 4;
1876 num_components = MIN2(4, this->size - components_so_far);
1879 info->Outputs[info->NumOutputs].OutputRegister =
1880 this->location + v + index * this->matrix_columns;
1881 info->Outputs[info->NumOutputs].NumComponents = num_components;
1882 info->Outputs[info->NumOutputs].OutputBuffer = buffer;
1883 info->Outputs[info->NumOutputs].DstOffset = info->BufferStride[buffer];
1885 info->BufferStride[buffer] += num_components;
1886 components_so_far += num_components;
1889 assert(components_so_far == this->num_components());
1891 info->Varyings[info->NumVarying].Name = ralloc_strdup(prog, this->orig_name);
1892 info->Varyings[info->NumVarying].Type = this->type;
1893 info->Varyings[info->NumVarying].Size = this->size;
1901 * Parse all the transform feedback declarations that were passed to
1902 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
1904 * If an error occurs, the error is reported through linker_error() and false
1908 parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog,
1909 const void *mem_ctx, unsigned num_names,
1910 char **varying_names, tfeedback_decl *decls)
1912 for (unsigned i = 0; i < num_names; ++i) {
1913 if (!decls[i].init(ctx, prog, mem_ctx, varying_names[i]))
1916 if (!decls[i].is_varying())
1919 /* From GL_EXT_transform_feedback:
1920 * A program will fail to link if:
1922 * * any two entries in the <varyings> array specify the same varying
1925 * We interpret this to mean "any two entries in the <varyings> array
1926 * specify the same varying variable and array index", since transform
1927 * feedback of arrays would be useless otherwise.
1929 for (unsigned j = 0; j < i; ++j) {
1930 if (!decls[j].is_varying())
1933 if (tfeedback_decl::is_same(decls[i], decls[j])) {
1934 linker_error(prog, "Transform feedback varying %s specified "
1935 "more than once.", varying_names[i]);
1945 * Assign a location for a variable that is produced in one pipeline stage
1946 * (the "producer") and consumed in the next stage (the "consumer").
1948 * \param input_var is the input variable declaration in the consumer.
1950 * \param output_var is the output variable declaration in the producer.
1952 * \param input_index is the counter that keeps track of assigned input
1953 * locations in the consumer.
1955 * \param output_index is the counter that keeps track of assigned output
1956 * locations in the producer.
1958 * It is permissible for \c input_var to be NULL (this happens if a variable
1959 * is output by the producer and consumed by transform feedback, but not
1960 * consumed by the consumer).
1962 * If the variable has already been assigned a location, this function has no
1966 assign_varying_location(ir_variable *input_var, ir_variable *output_var,
1967 unsigned *input_index, unsigned *output_index)
1969 if (output_var->location != -1) {
1970 /* Location already assigned. */
1975 assert(input_var->location == -1);
1976 input_var->location = *input_index;
1979 output_var->location = *output_index;
1981 /* FINISHME: Support for "varying" records in GLSL 1.50. */
1982 assert(!output_var->type->is_record());
1984 if (output_var->type->is_array()) {
1985 const unsigned slots = output_var->type->length
1986 * output_var->type->fields.array->matrix_columns;
1988 *output_index += slots;
1989 *input_index += slots;
1991 const unsigned slots = output_var->type->matrix_columns;
1993 *output_index += slots;
1994 *input_index += slots;
2000 * Is the given variable a varying variable to be counted against the
2001 * limit in ctx->Const.MaxVarying?
2002 * This includes variables such as texcoords, colors and generic
2003 * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
2006 is_varying_var(GLenum shaderType, const ir_variable *var)
2008 /* Only fragment shaders will take a varying variable as an input */
2009 if (shaderType == GL_FRAGMENT_SHADER &&
2010 var->mode == ir_var_in &&
2011 var->explicit_location) {
2012 switch (var->location) {
2013 case FRAG_ATTRIB_WPOS:
2014 case FRAG_ATTRIB_FACE:
2015 case FRAG_ATTRIB_PNTC:
2026 * Assign locations for all variables that are produced in one pipeline stage
2027 * (the "producer") and consumed in the next stage (the "consumer").
2029 * Variables produced by the producer may also be consumed by transform
2032 * \param num_tfeedback_decls is the number of declarations indicating
2033 * variables that may be consumed by transform feedback.
2035 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
2036 * representing the result of parsing the strings passed to
2037 * glTransformFeedbackVaryings(). assign_location() will be called for
2038 * each of these objects that matches one of the outputs of the
2041 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
2042 * be NULL. In this case, varying locations are assigned solely based on the
2043 * requirements of transform feedback.
2046 assign_varying_locations(struct gl_context *ctx,
2047 struct gl_shader_program *prog,
2048 gl_shader *producer, gl_shader *consumer,
2049 unsigned num_tfeedback_decls,
2050 tfeedback_decl *tfeedback_decls)
2052 /* FINISHME: Set dynamically when geometry shader support is added. */
2053 unsigned output_index = VERT_RESULT_VAR0;
2054 unsigned input_index = FRAG_ATTRIB_VAR0;
2056 /* Operate in a total of three passes.
2058 * 1. Assign locations for any matching inputs and outputs.
2060 * 2. Mark output variables in the producer that do not have locations as
2061 * not being outputs. This lets the optimizer eliminate them.
2063 * 3. Mark input variables in the consumer that do not have locations as
2064 * not being inputs. This lets the optimizer eliminate them.
2067 link_invalidate_variable_locations(producer, ir_var_out, VERT_RESULT_VAR0);
2069 link_invalidate_variable_locations(consumer, ir_var_in, FRAG_ATTRIB_VAR0);
2071 foreach_list(node, producer->ir) {
2072 ir_variable *const output_var = ((ir_instruction *) node)->as_variable();
2074 if ((output_var == NULL) || (output_var->mode != ir_var_out))
2077 ir_variable *input_var =
2078 consumer ? consumer->symbols->get_variable(output_var->name) : NULL;
2080 if (input_var && input_var->mode != ir_var_in)
2084 assign_varying_location(input_var, output_var, &input_index,
2088 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
2089 if (!tfeedback_decls[i].is_varying())
2092 if (!tfeedback_decls[i].is_assigned() &&
2093 tfeedback_decls[i].matches_var(output_var)) {
2094 if (output_var->location == -1) {
2095 assign_varying_location(input_var, output_var, &input_index,
2098 if (!tfeedback_decls[i].assign_location(ctx, prog, output_var))
2104 unsigned varying_vectors = 0;
2107 foreach_list(node, consumer->ir) {
2108 ir_variable *const var = ((ir_instruction *) node)->as_variable();
2110 if ((var == NULL) || (var->mode != ir_var_in))
2113 if (var->location == -1) {
2114 if (prog->Version <= 120) {
2115 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
2117 * Only those varying variables used (i.e. read) in
2118 * the fragment shader executable must be written to
2119 * by the vertex shader executable; declaring
2120 * superfluous varying variables in a vertex shader is
2123 * We interpret this text as meaning that the VS must
2124 * write the variable for the FS to read it. See
2125 * "glsl1-varying read but not written" in piglit.
2128 linker_error(prog, "fragment shader varying %s not written "
2129 "by vertex shader\n.", var->name);
2132 /* An 'in' variable is only really a shader input if its
2133 * value is written by the previous stage.
2135 var->mode = ir_var_auto;
2136 } else if (is_varying_var(consumer->Type, var)) {
2137 /* The packing rules are used for vertex shader inputs are also
2138 * used for fragment shader inputs.
2140 varying_vectors += count_attribute_slots(var->type);
2145 if (ctx->API == API_OPENGLES2 || prog->Version == 100) {
2146 if (varying_vectors > ctx->Const.MaxVarying) {
2147 if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
2148 linker_warning(prog, "shader uses too many varying vectors "
2149 "(%u > %u), but the driver will try to optimize "
2150 "them out; this is non-portable out-of-spec "
2152 varying_vectors, ctx->Const.MaxVarying);
2154 linker_error(prog, "shader uses too many varying vectors "
2156 varying_vectors, ctx->Const.MaxVarying);
2161 const unsigned float_components = varying_vectors * 4;
2162 if (float_components > ctx->Const.MaxVarying * 4) {
2163 if (ctx->Const.GLSLSkipStrictMaxVaryingLimitCheck) {
2164 linker_warning(prog, "shader uses too many varying components "
2165 "(%u > %u), but the driver will try to optimize "
2166 "them out; this is non-portable out-of-spec "
2168 float_components, ctx->Const.MaxVarying * 4);
2170 linker_error(prog, "shader uses too many varying components "
2172 float_components, ctx->Const.MaxVarying * 4);
2183 * Store transform feedback location assignments into
2184 * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
2186 * If an error occurs, the error is reported through linker_error() and false
2190 store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
2191 unsigned num_tfeedback_decls,
2192 tfeedback_decl *tfeedback_decls)
2194 bool separate_attribs_mode =
2195 prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS;
2197 ralloc_free(prog->LinkedTransformFeedback.Varyings);
2198 ralloc_free(prog->LinkedTransformFeedback.Outputs);
2200 memset(&prog->LinkedTransformFeedback, 0,
2201 sizeof(prog->LinkedTransformFeedback));
2203 prog->LinkedTransformFeedback.Varyings =
2205 struct gl_transform_feedback_varying_info,
2206 num_tfeedback_decls);
2208 unsigned num_outputs = 0;
2209 for (unsigned i = 0; i < num_tfeedback_decls; ++i)
2210 if (!tfeedback_decls[i].accumulate_num_outputs(prog, &num_outputs))
2213 prog->LinkedTransformFeedback.Outputs =
2215 struct gl_transform_feedback_output,
2218 unsigned num_buffers = 0;
2220 if (separate_attribs_mode) {
2221 /* GL_SEPARATE_ATTRIBS */
2222 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
2223 if (!tfeedback_decls[i].store(ctx, prog, &prog->LinkedTransformFeedback,
2224 num_buffers, num_outputs))
2231 /* GL_INVERLEAVED_ATTRIBS */
2232 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
2233 if (tfeedback_decls[i].is_next_buffer_separator()) {
2238 if (!tfeedback_decls[i].store(ctx, prog,
2239 &prog->LinkedTransformFeedback,
2240 num_buffers, num_outputs))
2246 assert(prog->LinkedTransformFeedback.NumOutputs == num_outputs);
2248 prog->LinkedTransformFeedback.NumBuffers = num_buffers;
2253 * Store the gl_FragDepth layout in the gl_shader_program struct.
2256 store_fragdepth_layout(struct gl_shader_program *prog)
2258 if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
2262 struct exec_list *ir = prog->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir;
2264 /* We don't look up the gl_FragDepth symbol directly because if
2265 * gl_FragDepth is not used in the shader, it's removed from the IR.
2266 * However, the symbol won't be removed from the symbol table.
2268 * We're only interested in the cases where the variable is NOT removed
2271 foreach_list(node, ir) {
2272 ir_variable *const var = ((ir_instruction *) node)->as_variable();
2274 if (var == NULL || var->mode != ir_var_out) {
2278 if (strcmp(var->name, "gl_FragDepth") == 0) {
2279 switch (var->depth_layout) {
2280 case ir_depth_layout_none:
2281 prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_NONE;
2283 case ir_depth_layout_any:
2284 prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_ANY;
2286 case ir_depth_layout_greater:
2287 prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_GREATER;
2289 case ir_depth_layout_less:
2290 prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_LESS;
2292 case ir_depth_layout_unchanged:
2293 prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_UNCHANGED;
2304 * Validate the resources used by a program versus the implementation limits
2307 check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
2309 static const char *const shader_names[MESA_SHADER_TYPES] = {
2310 "vertex", "fragment", "geometry"
2313 const unsigned max_samplers[MESA_SHADER_TYPES] = {
2314 ctx->Const.MaxVertexTextureImageUnits,
2315 ctx->Const.MaxTextureImageUnits,
2316 ctx->Const.MaxGeometryTextureImageUnits
2319 const unsigned max_uniform_components[MESA_SHADER_TYPES] = {
2320 ctx->Const.VertexProgram.MaxUniformComponents,
2321 ctx->Const.FragmentProgram.MaxUniformComponents,
2322 0 /* FINISHME: Geometry shaders. */
2325 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
2326 struct gl_shader *sh = prog->_LinkedShaders[i];
2331 if (sh->num_samplers > max_samplers[i]) {
2332 linker_error(prog, "Too many %s shader texture samplers",
2336 if (sh->num_uniform_components > max_uniform_components[i]) {
2337 if (ctx->Const.GLSLSkipStrictMaxUniformLimitCheck) {
2338 linker_warning(prog, "Too many %s shader uniform components, "
2339 "but the driver will try to optimize them out; "
2340 "this is non-portable out-of-spec behavior\n",
2343 linker_error(prog, "Too many %s shader uniform components",
2349 return prog->LinkStatus;
2353 link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
2355 tfeedback_decl *tfeedback_decls = NULL;
2356 unsigned num_tfeedback_decls = prog->TransformFeedback.NumVarying;
2358 void *mem_ctx = ralloc_context(NULL); // temporary linker context
2360 prog->LinkStatus = false;
2361 prog->Validated = false;
2362 prog->_Used = false;
2364 ralloc_free(prog->InfoLog);
2365 prog->InfoLog = ralloc_strdup(NULL, "");
2367 ralloc_free(prog->UniformBlocks);
2368 prog->UniformBlocks = NULL;
2369 prog->NumUniformBlocks = 0;
2370 for (int i = 0; i < MESA_SHADER_TYPES; i++) {
2371 ralloc_free(prog->UniformBlockStageIndex[i]);
2372 prog->UniformBlockStageIndex[i] = NULL;
2375 /* Separate the shaders into groups based on their type.
2377 struct gl_shader **vert_shader_list;
2378 unsigned num_vert_shaders = 0;
2379 struct gl_shader **frag_shader_list;
2380 unsigned num_frag_shaders = 0;
2382 vert_shader_list = (struct gl_shader **)
2383 calloc(2 * prog->NumShaders, sizeof(struct gl_shader *));
2384 frag_shader_list = &vert_shader_list[prog->NumShaders];
2386 unsigned min_version = UINT_MAX;
2387 unsigned max_version = 0;
2388 for (unsigned i = 0; i < prog->NumShaders; i++) {
2389 min_version = MIN2(min_version, prog->Shaders[i]->Version);
2390 max_version = MAX2(max_version, prog->Shaders[i]->Version);
2392 switch (prog->Shaders[i]->Type) {
2393 case GL_VERTEX_SHADER:
2394 vert_shader_list[num_vert_shaders] = prog->Shaders[i];
2397 case GL_FRAGMENT_SHADER:
2398 frag_shader_list[num_frag_shaders] = prog->Shaders[i];
2401 case GL_GEOMETRY_SHADER:
2402 /* FINISHME: Support geometry shaders. */
2403 assert(prog->Shaders[i]->Type != GL_GEOMETRY_SHADER);
2408 /* Previous to GLSL version 1.30, different compilation units could mix and
2409 * match shading language versions. With GLSL 1.30 and later, the versions
2410 * of all shaders must match.
2412 assert(min_version >= 100);
2413 assert(max_version <= 140);
2414 if ((max_version >= 130 || min_version == 100)
2415 && min_version != max_version) {
2416 linker_error(prog, "all shaders must use same shading "
2417 "language version\n");
2421 prog->Version = max_version;
2423 for (unsigned int i = 0; i < MESA_SHADER_TYPES; i++) {
2424 if (prog->_LinkedShaders[i] != NULL)
2425 ctx->Driver.DeleteShader(ctx, prog->_LinkedShaders[i]);
2427 prog->_LinkedShaders[i] = NULL;
2430 /* Link all shaders for a particular stage and validate the result.
2432 if (num_vert_shaders > 0) {
2433 gl_shader *const sh =
2434 link_intrastage_shaders(mem_ctx, ctx, prog, vert_shader_list,
2440 if (!validate_vertex_shader_executable(prog, sh))
2443 _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_VERTEX],
2447 if (num_frag_shaders > 0) {
2448 gl_shader *const sh =
2449 link_intrastage_shaders(mem_ctx, ctx, prog, frag_shader_list,
2455 if (!validate_fragment_shader_executable(prog, sh))
2458 _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_FRAGMENT],
2462 /* Here begins the inter-stage linking phase. Some initial validation is
2463 * performed, then locations are assigned for uniforms, attributes, and
2466 if (cross_validate_uniforms(prog)) {
2469 for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
2470 if (prog->_LinkedShaders[prev] != NULL)
2474 /* Validate the inputs of each stage with the output of the preceding
2477 for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
2478 if (prog->_LinkedShaders[i] == NULL)
2481 if (!cross_validate_outputs_to_inputs(prog,
2482 prog->_LinkedShaders[prev],
2483 prog->_LinkedShaders[i]))
2489 prog->LinkStatus = true;
2492 /* Implement the GLSL 1.30+ rule for discard vs infinite loops Do
2493 * it before optimization because we want most of the checks to get
2494 * dropped thanks to constant propagation.
2496 if (max_version >= 130) {
2497 struct gl_shader *sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
2499 lower_discard_flow(sh->ir);
2503 if (!interstage_cross_validate_uniform_blocks(prog))
2506 /* Do common optimization before assigning storage for attributes,
2507 * uniforms, and varyings. Later optimization could possibly make
2508 * some of that unused.
2510 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
2511 if (prog->_LinkedShaders[i] == NULL)
2514 detect_recursion_linked(prog, prog->_LinkedShaders[i]->ir);
2515 if (!prog->LinkStatus)
2518 if (ctx->ShaderCompilerOptions[i].LowerClipDistance)
2519 lower_clip_distance(prog->_LinkedShaders[i]->ir);
2521 unsigned max_unroll = ctx->ShaderCompilerOptions[i].MaxUnrollIterations;
2523 while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, max_unroll))
2527 /* FINISHME: The value of the max_attribute_index parameter is
2528 * FINISHME: implementation dependent based on the value of
2529 * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be
2530 * FINISHME: at least 16, so hardcode 16 for now.
2532 if (!assign_attribute_or_color_locations(prog, MESA_SHADER_VERTEX, 16)) {
2536 if (!assign_attribute_or_color_locations(prog, MESA_SHADER_FRAGMENT, MAX2(ctx->Const.MaxDrawBuffers, ctx->Const.MaxDualSourceDrawBuffers))) {
2541 for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
2542 if (prog->_LinkedShaders[prev] != NULL)
2546 if (num_tfeedback_decls != 0) {
2547 /* From GL_EXT_transform_feedback:
2548 * A program will fail to link if:
2550 * * the <count> specified by TransformFeedbackVaryingsEXT is
2551 * non-zero, but the program object has no vertex or geometry
2554 if (prev >= MESA_SHADER_FRAGMENT) {
2555 linker_error(prog, "Transform feedback varyings specified, but "
2556 "no vertex or geometry shader is present.");
2560 tfeedback_decls = ralloc_array(mem_ctx, tfeedback_decl,
2561 prog->TransformFeedback.NumVarying);
2562 if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls,
2563 prog->TransformFeedback.VaryingNames,
2568 for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
2569 if (prog->_LinkedShaders[i] == NULL)
2572 if (!assign_varying_locations(
2573 ctx, prog, prog->_LinkedShaders[prev], prog->_LinkedShaders[i],
2574 i == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
2581 if (prev != MESA_SHADER_FRAGMENT && num_tfeedback_decls != 0) {
2582 /* There was no fragment shader, but we still have to assign varying
2583 * locations for use by transform feedback.
2585 if (!assign_varying_locations(
2586 ctx, prog, prog->_LinkedShaders[prev], NULL, num_tfeedback_decls,
2591 if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls))
2594 if (prog->_LinkedShaders[MESA_SHADER_VERTEX] != NULL) {
2595 demote_shader_inputs_and_outputs(prog->_LinkedShaders[MESA_SHADER_VERTEX],
2598 /* Eliminate code that is now dead due to unused vertex outputs being
2601 while (do_dead_code(prog->_LinkedShaders[MESA_SHADER_VERTEX]->ir, false))
2605 if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) {
2606 gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
2608 demote_shader_inputs_and_outputs(sh, ir_var_in);
2609 demote_shader_inputs_and_outputs(sh, ir_var_inout);
2610 demote_shader_inputs_and_outputs(sh, ir_var_out);
2612 /* Eliminate code that is now dead due to unused geometry outputs being
2615 while (do_dead_code(prog->_LinkedShaders[MESA_SHADER_GEOMETRY]->ir, false))
2619 if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] != NULL) {
2620 gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
2622 demote_shader_inputs_and_outputs(sh, ir_var_in);
2624 /* Eliminate code that is now dead due to unused fragment inputs being
2625 * demoted. This shouldn't actually do anything other than remove
2626 * declarations of the (now unused) global variables.
2628 while (do_dead_code(prog->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir, false))
2632 update_array_sizes(prog);
2633 link_assign_uniform_locations(prog);
2634 store_fragdepth_layout(prog);
2636 if (!check_resources(ctx, prog))
2639 /* OpenGL ES requires that a vertex shader and a fragment shader both be
2640 * present in a linked program. By checking for use of shading language
2641 * version 1.00, we also catch the GL_ARB_ES2_compatibility case.
2643 if (!prog->InternalSeparateShader &&
2644 (ctx->API == API_OPENGLES2 || prog->Version == 100)) {
2645 if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) {
2646 linker_error(prog, "program lacks a vertex shader\n");
2647 } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
2648 linker_error(prog, "program lacks a fragment shader\n");
2652 /* FINISHME: Assign fragment shader output locations. */
2655 free(vert_shader_list);
2657 for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
2658 if (prog->_LinkedShaders[i] == NULL)
2661 /* Retain any live IR, but trash the rest. */
2662 reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir);
2664 /* The symbol table in the linked shaders may contain references to
2665 * variables that were removed (e.g., unused uniforms). Since it may
2666 * contain junk, there is no possible valid use. Delete it and set the
2669 delete prog->_LinkedShaders[i]->symbols;
2670 prog->_LinkedShaders[i]->symbols = NULL;
2673 ralloc_free(mem_ctx);