diff options
Diffstat (limited to 'mesalib/src/glsl/linker.cpp')
| -rw-r--r-- | mesalib/src/glsl/linker.cpp | 3624 |
1 files changed, 1812 insertions, 1812 deletions
diff --git a/mesalib/src/glsl/linker.cpp b/mesalib/src/glsl/linker.cpp index b54ef4108..0d4d5d88b 100644 --- a/mesalib/src/glsl/linker.cpp +++ b/mesalib/src/glsl/linker.cpp @@ -1,1812 +1,1812 @@ -/* - * Copyright © 2010 Intel Corporation - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice (including the next - * paragraph) shall be included in all copies or substantial portions of the - * Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER - * DEALINGS IN THE SOFTWARE. - */ - -/** - * \file linker.cpp - * GLSL linker implementation - * - * Given a set of shaders that are to be linked to generate a final program, - * there are three distinct stages. - * - * In the first stage shaders are partitioned into groups based on the shader - * type. All shaders of a particular type (e.g., vertex shaders) are linked - * together. - * - * - Undefined references in each shader are resolve to definitions in - * another shader. - * - Types and qualifiers of uniforms, outputs, and global variables defined - * in multiple shaders with the same name are verified to be the same. - * - Initializers for uniforms and global variables defined - * in multiple shaders with the same name are verified to be the same. - * - * The result, in the terminology of the GLSL spec, is a set of shader - * executables for each processing unit. - * - * After the first stage is complete, a series of semantic checks are performed - * on each of the shader executables. - * - * - Each shader executable must define a \c main function. - * - Each vertex shader executable must write to \c gl_Position. - * - Each fragment shader executable must write to either \c gl_FragData or - * \c gl_FragColor. - * - * In the final stage individual shader executables are linked to create a - * complete exectuable. - * - * - Types of uniforms defined in multiple shader stages with the same name - * are verified to be the same. - * - Initializers for uniforms defined in multiple shader stages with the - * same name are verified to be the same. - * - Types and qualifiers of outputs defined in one stage are verified to - * be the same as the types and qualifiers of inputs defined with the same - * name in a later stage. - * - * \author Ian Romanick <ian.d.romanick@intel.com> - */ - -#include "main/core.h" -#include "glsl_symbol_table.h" -#include "ir.h" -#include "program.h" -#include "program/hash_table.h" -#include "linker.h" -#include "ir_optimization.h" - -extern "C" { -#include "main/shaderobj.h" -} - -/** - * Visitor that determines whether or not a variable is ever written. - */ -class find_assignment_visitor : public ir_hierarchical_visitor { -public: - find_assignment_visitor(const char *name) - : name(name), found(false) - { - /* empty */ - } - - virtual ir_visitor_status visit_enter(ir_assignment *ir) - { - ir_variable *const var = ir->lhs->variable_referenced(); - - if (strcmp(name, var->name) == 0) { - found = true; - return visit_stop; - } - - return visit_continue_with_parent; - } - - virtual ir_visitor_status visit_enter(ir_call *ir) - { - exec_list_iterator sig_iter = ir->get_callee()->parameters.iterator(); - foreach_iter(exec_list_iterator, iter, *ir) { - ir_rvalue *param_rval = (ir_rvalue *)iter.get(); - ir_variable *sig_param = (ir_variable *)sig_iter.get(); - - if (sig_param->mode == ir_var_out || - sig_param->mode == ir_var_inout) { - ir_variable *var = param_rval->variable_referenced(); - if (var && strcmp(name, var->name) == 0) { - found = true; - return visit_stop; - } - } - sig_iter.next(); - } - - return visit_continue_with_parent; - } - - bool variable_found() - { - return found; - } - -private: - const char *name; /**< Find writes to a variable with this name. */ - bool found; /**< Was a write to the variable found? */ -}; - - -/** - * Visitor that determines whether or not a variable is ever read. - */ -class find_deref_visitor : public ir_hierarchical_visitor { -public: - find_deref_visitor(const char *name) - : name(name), found(false) - { - /* empty */ - } - - virtual ir_visitor_status visit(ir_dereference_variable *ir) - { - if (strcmp(this->name, ir->var->name) == 0) { - this->found = true; - return visit_stop; - } - - return visit_continue; - } - - bool variable_found() const - { - return this->found; - } - -private: - const char *name; /**< Find writes to a variable with this name. */ - bool found; /**< Was a write to the variable found? */ -}; - - -void -linker_error(gl_shader_program *prog, const char *fmt, ...) -{ - va_list ap; - - ralloc_strcat(&prog->InfoLog, "error: "); - va_start(ap, fmt); - ralloc_vasprintf_append(&prog->InfoLog, fmt, ap); - va_end(ap); - - prog->LinkStatus = false; -} - - -void -linker_warning(gl_shader_program *prog, const char *fmt, ...) -{ - va_list ap; - - ralloc_strcat(&prog->InfoLog, "error: "); - va_start(ap, fmt); - ralloc_vasprintf_append(&prog->InfoLog, fmt, ap); - va_end(ap); - -} - - -void -invalidate_variable_locations(gl_shader *sh, enum ir_variable_mode mode, - int generic_base) -{ - foreach_list(node, sh->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != (unsigned) mode)) - continue; - - /* Only assign locations for generic attributes / varyings / etc. - */ - if ((var->location >= generic_base) && !var->explicit_location) - var->location = -1; - } -} - - -/** - * Determine the number of attribute slots required for a particular type - * - * This code is here because it implements the language rules of a specific - * GLSL version. Since it's a property of the language and not a property of - * types in general, it doesn't really belong in glsl_type. - */ -unsigned -count_attribute_slots(const glsl_type *t) -{ - /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec: - * - * "A scalar input counts the same amount against this limit as a vec4, - * so applications may want to consider packing groups of four - * unrelated float inputs together into a vector to better utilize the - * capabilities of the underlying hardware. A matrix input will use up - * multiple locations. The number of locations used will equal the - * number of columns in the matrix." - * - * The spec does not explicitly say how arrays are counted. However, it - * should be safe to assume the total number of slots consumed by an array - * is the number of entries in the array multiplied by the number of slots - * consumed by a single element of the array. - */ - - if (t->is_array()) - return t->array_size() * count_attribute_slots(t->element_type()); - - if (t->is_matrix()) - return t->matrix_columns; - - return 1; -} - - -/** - * Verify that a vertex shader executable meets all semantic requirements - * - * \param shader Vertex shader executable to be verified - */ -bool -validate_vertex_shader_executable(struct gl_shader_program *prog, - struct gl_shader *shader) -{ - if (shader == NULL) - return true; - - find_assignment_visitor find("gl_Position"); - find.run(shader->ir); - if (!find.variable_found()) { - linker_error(prog, "vertex shader does not write to `gl_Position'\n"); - return false; - } - - return true; -} - - -/** - * Verify that a fragment shader executable meets all semantic requirements - * - * \param shader Fragment shader executable to be verified - */ -bool -validate_fragment_shader_executable(struct gl_shader_program *prog, - struct gl_shader *shader) -{ - if (shader == NULL) - return true; - - find_assignment_visitor frag_color("gl_FragColor"); - find_assignment_visitor frag_data("gl_FragData"); - - frag_color.run(shader->ir); - frag_data.run(shader->ir); - - if (frag_color.variable_found() && frag_data.variable_found()) { - linker_error(prog, "fragment shader writes to both " - "`gl_FragColor' and `gl_FragData'\n"); - return false; - } - - return true; -} - - -/** - * Generate a string describing the mode of a variable - */ -static const char * -mode_string(const ir_variable *var) -{ - switch (var->mode) { - case ir_var_auto: - return (var->read_only) ? "global constant" : "global variable"; - - case ir_var_uniform: return "uniform"; - case ir_var_in: return "shader input"; - case ir_var_out: return "shader output"; - case ir_var_inout: return "shader inout"; - - case ir_var_const_in: - case ir_var_temporary: - default: - assert(!"Should not get here."); - return "invalid variable"; - } -} - - -/** - * Perform validation of global variables used across multiple shaders - */ -bool -cross_validate_globals(struct gl_shader_program *prog, - struct gl_shader **shader_list, - unsigned num_shaders, - bool uniforms_only) -{ - /* Examine all of the uniforms in all of the shaders and cross validate - * them. - */ - glsl_symbol_table variables; - for (unsigned i = 0; i < num_shaders; i++) { - if (shader_list[i] == NULL) - continue; - - foreach_list(node, shader_list[i]->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if (var == NULL) - continue; - - if (uniforms_only && (var->mode != ir_var_uniform)) - continue; - - /* Don't cross validate temporaries that are at global scope. These - * will eventually get pulled into the shaders 'main'. - */ - if (var->mode == ir_var_temporary) - continue; - - /* If a global with this name has already been seen, verify that the - * new instance has the same type. In addition, if the globals have - * initializers, the values of the initializers must be the same. - */ - ir_variable *const existing = variables.get_variable(var->name); - if (existing != NULL) { - if (var->type != existing->type) { - /* Consider the types to be "the same" if both types are arrays - * of the same type and one of the arrays is implicitly sized. - * In addition, set the type of the linked variable to the - * explicitly sized array. - */ - if (var->type->is_array() - && existing->type->is_array() - && (var->type->fields.array == existing->type->fields.array) - && ((var->type->length == 0) - || (existing->type->length == 0))) { - if (var->type->length != 0) { - existing->type = var->type; - } - } else { - linker_error(prog, "%s `%s' declared as type " - "`%s' and type `%s'\n", - mode_string(var), - var->name, var->type->name, - existing->type->name); - return false; - } - } - - if (var->explicit_location) { - if (existing->explicit_location - && (var->location != existing->location)) { - linker_error(prog, "explicit locations for %s " - "`%s' have differing values\n", - mode_string(var), var->name); - return false; - } - - existing->location = var->location; - existing->explicit_location = true; - } - - /* Validate layout qualifiers for gl_FragDepth. - * - * From the AMD_conservative_depth spec: - * "If gl_FragDepth is redeclared in any fragment shader in - * a program, it must be redeclared in all fragment shaders in that - * program that have static assignments to gl_FragDepth. All - * redeclarations of gl_FragDepth in all fragment shaders in - * a single program must have the same set of qualifiers." - */ - if (strcmp(var->name, "gl_FragDepth") == 0) { - bool layout_declared = var->depth_layout != ir_depth_layout_none; - bool layout_differs = var->depth_layout != existing->depth_layout; - if (layout_declared && layout_differs) { - linker_error(prog, - "All redeclarations of gl_FragDepth in all fragment shaders " - "in a single program must have the same set of qualifiers."); - } - if (var->used && layout_differs) { - linker_error(prog, - "If gl_FragDepth is redeclared with a layout qualifier in" - "any fragment shader, it must be redeclared with the same" - "layout qualifier in all fragment shaders that have" - "assignments to gl_FragDepth"); - } - } - - /* FINISHME: Handle non-constant initializers. - */ - if (var->constant_value != NULL) { - if (existing->constant_value != NULL) { - if (!var->constant_value->has_value(existing->constant_value)) { - linker_error(prog, "initializers for %s " - "`%s' have differing values\n", - mode_string(var), var->name); - return false; - } - } else - /* If the first-seen instance of a particular uniform did not - * have an initializer but a later instance does, copy the - * initializer to the version stored in the symbol table. - */ - /* FINISHME: This is wrong. The constant_value field should - * FINISHME: not be modified! Imagine a case where a shader - * FINISHME: without an initializer is linked in two different - * FINISHME: programs with shaders that have differing - * FINISHME: initializers. Linking with the first will - * FINISHME: modify the shader, and linking with the second - * FINISHME: will fail. - */ - existing->constant_value = - var->constant_value->clone(ralloc_parent(existing), NULL); - } - - if (existing->invariant != var->invariant) { - linker_error(prog, "declarations for %s `%s' have " - "mismatching invariant qualifiers\n", - mode_string(var), var->name); - return false; - } - if (existing->centroid != var->centroid) { - linker_error(prog, "declarations for %s `%s' have " - "mismatching centroid qualifiers\n", - mode_string(var), var->name); - return false; - } - } else - variables.add_variable(var); - } - } - - return true; -} - - -/** - * Perform validation of uniforms used across multiple shader stages - */ -bool -cross_validate_uniforms(struct gl_shader_program *prog) -{ - return cross_validate_globals(prog, prog->_LinkedShaders, - MESA_SHADER_TYPES, true); -} - - -/** - * Validate that outputs from one stage match inputs of another - */ -bool -cross_validate_outputs_to_inputs(struct gl_shader_program *prog, - gl_shader *producer, gl_shader *consumer) -{ - glsl_symbol_table parameters; - /* FINISHME: Figure these out dynamically. */ - const char *const producer_stage = "vertex"; - const char *const consumer_stage = "fragment"; - - /* Find all shader outputs in the "producer" stage. - */ - foreach_list(node, producer->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - /* FINISHME: For geometry shaders, this should also look for inout - * FINISHME: variables. - */ - if ((var == NULL) || (var->mode != ir_var_out)) - continue; - - parameters.add_variable(var); - } - - - /* Find all shader inputs in the "consumer" stage. Any variables that have - * matching outputs already in the symbol table must have the same type and - * qualifiers. - */ - foreach_list(node, consumer->ir) { - ir_variable *const input = ((ir_instruction *) node)->as_variable(); - - /* FINISHME: For geometry shaders, this should also look for inout - * FINISHME: variables. - */ - if ((input == NULL) || (input->mode != ir_var_in)) - continue; - - ir_variable *const output = parameters.get_variable(input->name); - if (output != NULL) { - /* Check that the types match between stages. - */ - if (input->type != output->type) { - /* There is a bit of a special case for gl_TexCoord. This - * built-in is unsized by default. Applications that variable - * access it must redeclare it with a size. There is some - * language in the GLSL spec that implies the fragment shader - * and vertex shader do not have to agree on this size. Other - * driver behave this way, and one or two applications seem to - * rely on it. - * - * Neither declaration needs to be modified here because the array - * sizes are fixed later when update_array_sizes is called. - * - * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec: - * - * "Unlike user-defined varying variables, the built-in - * varying variables don't have a strict one-to-one - * correspondence between the vertex language and the - * fragment language." - */ - if (!output->type->is_array() - || (strncmp("gl_", output->name, 3) != 0)) { - linker_error(prog, - "%s shader output `%s' declared as type `%s', " - "but %s shader input declared as type `%s'\n", - producer_stage, output->name, - output->type->name, - consumer_stage, input->type->name); - return false; - } - } - - /* Check that all of the qualifiers match between stages. - */ - if (input->centroid != output->centroid) { - linker_error(prog, - "%s shader output `%s' %s centroid qualifier, " - "but %s shader input %s centroid qualifier\n", - producer_stage, - output->name, - (output->centroid) ? "has" : "lacks", - consumer_stage, - (input->centroid) ? "has" : "lacks"); - return false; - } - - if (input->invariant != output->invariant) { - linker_error(prog, - "%s shader output `%s' %s invariant qualifier, " - "but %s shader input %s invariant qualifier\n", - producer_stage, - output->name, - (output->invariant) ? "has" : "lacks", - consumer_stage, - (input->invariant) ? "has" : "lacks"); - return false; - } - - if (input->interpolation != output->interpolation) { - linker_error(prog, - "%s shader output `%s' specifies %s " - "interpolation qualifier, " - "but %s shader input specifies %s " - "interpolation qualifier\n", - producer_stage, - output->name, - output->interpolation_string(), - consumer_stage, - input->interpolation_string()); - return false; - } - } - } - - return true; -} - - -/** - * Populates a shaders symbol table with all global declarations - */ -static void -populate_symbol_table(gl_shader *sh) -{ - sh->symbols = new(sh) glsl_symbol_table; - - foreach_list(node, sh->ir) { - ir_instruction *const inst = (ir_instruction *) node; - ir_variable *var; - ir_function *func; - - if ((func = inst->as_function()) != NULL) { - sh->symbols->add_function(func); - } else if ((var = inst->as_variable()) != NULL) { - sh->symbols->add_variable(var); - } - } -} - - -/** - * Remap variables referenced in an instruction tree - * - * This is used when instruction trees are cloned from one shader and placed in - * another. These trees will contain references to \c ir_variable nodes that - * do not exist in the target shader. This function finds these \c ir_variable - * references and replaces the references with matching variables in the target - * shader. - * - * If there is no matching variable in the target shader, a clone of the - * \c ir_variable is made and added to the target shader. The new variable is - * added to \b both the instruction stream and the symbol table. - * - * \param inst IR tree that is to be processed. - * \param symbols Symbol table containing global scope symbols in the - * linked shader. - * \param instructions Instruction stream where new variable declarations - * should be added. - */ -void -remap_variables(ir_instruction *inst, struct gl_shader *target, - hash_table *temps) -{ - class remap_visitor : public ir_hierarchical_visitor { - public: - remap_visitor(struct gl_shader *target, - hash_table *temps) - { - this->target = target; - this->symbols = target->symbols; - this->instructions = target->ir; - this->temps = temps; - } - - virtual ir_visitor_status visit(ir_dereference_variable *ir) - { - if (ir->var->mode == ir_var_temporary) { - ir_variable *var = (ir_variable *) hash_table_find(temps, ir->var); - - assert(var != NULL); - ir->var = var; - return visit_continue; - } - - ir_variable *const existing = - this->symbols->get_variable(ir->var->name); - if (existing != NULL) - ir->var = existing; - else { - ir_variable *copy = ir->var->clone(this->target, NULL); - - this->symbols->add_variable(copy); - this->instructions->push_head(copy); - ir->var = copy; - } - - return visit_continue; - } - - private: - struct gl_shader *target; - glsl_symbol_table *symbols; - exec_list *instructions; - hash_table *temps; - }; - - remap_visitor v(target, temps); - - inst->accept(&v); -} - - -/** - * Move non-declarations from one instruction stream to another - * - * The intended usage pattern of this function is to pass the pointer to the - * head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node - * pointer) for \c last and \c false for \c make_copies on the first - * call. Successive calls pass the return value of the previous call for - * \c last and \c true for \c make_copies. - * - * \param instructions Source instruction stream - * \param last Instruction after which new instructions should be - * inserted in the target instruction stream - * \param make_copies Flag selecting whether instructions in \c instructions - * should be copied (via \c ir_instruction::clone) into the - * target list or moved. - * - * \return - * The new "last" instruction in the target instruction stream. This pointer - * is suitable for use as the \c last parameter of a later call to this - * function. - */ -exec_node * -move_non_declarations(exec_list *instructions, exec_node *last, - bool make_copies, gl_shader *target) -{ - hash_table *temps = NULL; - - if (make_copies) - temps = hash_table_ctor(0, hash_table_pointer_hash, - hash_table_pointer_compare); - - foreach_list_safe(node, instructions) { - ir_instruction *inst = (ir_instruction *) node; - - if (inst->as_function()) - continue; - - ir_variable *var = inst->as_variable(); - if ((var != NULL) && (var->mode != ir_var_temporary)) - continue; - - assert(inst->as_assignment() - || ((var != NULL) && (var->mode == ir_var_temporary))); - - if (make_copies) { - inst = inst->clone(target, NULL); - - if (var != NULL) - hash_table_insert(temps, inst, var); - else - remap_variables(inst, target, temps); - } else { - inst->remove(); - } - - last->insert_after(inst); - last = inst; - } - - if (make_copies) - hash_table_dtor(temps); - - return last; -} - -/** - * Get the function signature for main from a shader - */ -static ir_function_signature * -get_main_function_signature(gl_shader *sh) -{ - ir_function *const f = sh->symbols->get_function("main"); - if (f != NULL) { - exec_list void_parameters; - - /* Look for the 'void main()' signature and ensure that it's defined. - * This keeps the linker from accidentally pick a shader that just - * contains a prototype for main. - * - * We don't have to check for multiple definitions of main (in multiple - * shaders) because that would have already been caught above. - */ - ir_function_signature *sig = f->matching_signature(&void_parameters); - if ((sig != NULL) && sig->is_defined) { - return sig; - } - } - - return NULL; -} - - -/** - * Combine a group of shaders for a single stage to generate a linked shader - * - * \note - * If this function is supplied a single shader, it is cloned, and the new - * shader is returned. - */ -static struct gl_shader * -link_intrastage_shaders(void *mem_ctx, - struct gl_context *ctx, - struct gl_shader_program *prog, - struct gl_shader **shader_list, - unsigned num_shaders) -{ - /* Check that global variables defined in multiple shaders are consistent. - */ - if (!cross_validate_globals(prog, shader_list, num_shaders, false)) - return NULL; - - /* Check that there is only a single definition of each function signature - * across all shaders. - */ - for (unsigned i = 0; i < (num_shaders - 1); i++) { - foreach_list(node, shader_list[i]->ir) { - ir_function *const f = ((ir_instruction *) node)->as_function(); - - if (f == NULL) - continue; - - for (unsigned j = i + 1; j < num_shaders; j++) { - ir_function *const other = - shader_list[j]->symbols->get_function(f->name); - - /* If the other shader has no function (and therefore no function - * signatures) with the same name, skip to the next shader. - */ - if (other == NULL) - continue; - - foreach_iter (exec_list_iterator, iter, *f) { - ir_function_signature *sig = - (ir_function_signature *) iter.get(); - - if (!sig->is_defined || sig->is_builtin) - continue; - - ir_function_signature *other_sig = - other->exact_matching_signature(& sig->parameters); - - if ((other_sig != NULL) && other_sig->is_defined - && !other_sig->is_builtin) { - linker_error(prog, "function `%s' is multiply defined", - f->name); - return NULL; - } - } - } - } - } - - /* Find the shader that defines main, and make a clone of it. - * - * Starting with the clone, search for undefined references. If one is - * found, find the shader that defines it. Clone the reference and add - * it to the shader. Repeat until there are no undefined references or - * until a reference cannot be resolved. - */ - gl_shader *main = NULL; - for (unsigned i = 0; i < num_shaders; i++) { - if (get_main_function_signature(shader_list[i]) != NULL) { - main = shader_list[i]; - break; - } - } - - if (main == NULL) { - linker_error(prog, "%s shader lacks `main'\n", - (shader_list[0]->Type == GL_VERTEX_SHADER) - ? "vertex" : "fragment"); - return NULL; - } - - gl_shader *linked = ctx->Driver.NewShader(NULL, 0, main->Type); - linked->ir = new(linked) exec_list; - clone_ir_list(mem_ctx, linked->ir, main->ir); - - populate_symbol_table(linked); - - /* The a pointer to the main function in the final linked shader (i.e., the - * copy of the original shader that contained the main function). - */ - ir_function_signature *const main_sig = get_main_function_signature(linked); - - /* Move any instructions other than variable declarations or function - * declarations into main. - */ - exec_node *insertion_point = - move_non_declarations(linked->ir, (exec_node *) &main_sig->body, false, - linked); - - for (unsigned i = 0; i < num_shaders; i++) { - if (shader_list[i] == main) - continue; - - insertion_point = move_non_declarations(shader_list[i]->ir, - insertion_point, true, linked); - } - - /* Resolve initializers for global variables in the linked shader. - */ - unsigned num_linking_shaders = num_shaders; - for (unsigned i = 0; i < num_shaders; i++) - num_linking_shaders += shader_list[i]->num_builtins_to_link; - - gl_shader **linking_shaders = - (gl_shader **) calloc(num_linking_shaders, sizeof(gl_shader *)); - - memcpy(linking_shaders, shader_list, - sizeof(linking_shaders[0]) * num_shaders); - - unsigned idx = num_shaders; - for (unsigned i = 0; i < num_shaders; i++) { - memcpy(&linking_shaders[idx], shader_list[i]->builtins_to_link, - sizeof(linking_shaders[0]) * shader_list[i]->num_builtins_to_link); - idx += shader_list[i]->num_builtins_to_link; - } - - assert(idx == num_linking_shaders); - - if (!link_function_calls(prog, linked, linking_shaders, - num_linking_shaders)) { - ctx->Driver.DeleteShader(ctx, linked); - linked = NULL; - } - - free(linking_shaders); - -#ifdef DEBUG - /* At this point linked should contain all of the linked IR, so - * validate it to make sure nothing went wrong. - */ - if (linked) - validate_ir_tree(linked->ir); -#endif - - /* Make a pass over all variable declarations to ensure that arrays with - * unspecified sizes have a size specified. The size is inferred from the - * max_array_access field. - */ - if (linked != NULL) { - class array_sizing_visitor : public ir_hierarchical_visitor { - public: - virtual ir_visitor_status visit(ir_variable *var) - { - if (var->type->is_array() && (var->type->length == 0)) { - const glsl_type *type = - glsl_type::get_array_instance(var->type->fields.array, - var->max_array_access + 1); - - assert(type != NULL); - var->type = type; - } - - return visit_continue; - } - } v; - - v.run(linked->ir); - } - - return linked; -} - - -struct uniform_node { - exec_node link; - struct gl_uniform *u; - unsigned slots; -}; - -/** - * Update the sizes of linked shader uniform arrays to the maximum - * array index used. - * - * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec: - * - * If one or more elements of an array are active, - * GetActiveUniform will return the name of the array in name, - * subject to the restrictions listed above. The type of the array - * is returned in type. The size parameter contains the highest - * array element index used, plus one. The compiler or linker - * determines the highest index used. There will be only one - * active uniform reported by the GL per uniform array. - - */ -static void -update_array_sizes(struct gl_shader_program *prog) -{ - for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - foreach_list(node, prog->_LinkedShaders[i]->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != ir_var_uniform && - var->mode != ir_var_in && - var->mode != ir_var_out) || - !var->type->is_array()) - continue; - - unsigned int size = var->max_array_access; - for (unsigned j = 0; j < MESA_SHADER_TYPES; j++) { - if (prog->_LinkedShaders[j] == NULL) - continue; - - foreach_list(node2, prog->_LinkedShaders[j]->ir) { - ir_variable *other_var = ((ir_instruction *) node2)->as_variable(); - if (!other_var) - continue; - - if (strcmp(var->name, other_var->name) == 0 && - other_var->max_array_access > size) { - size = other_var->max_array_access; - } - } - } - - if (size + 1 != var->type->fields.array->length) { - /* If this is a built-in uniform (i.e., it's backed by some - * fixed-function state), adjust the number of state slots to - * match the new array size. The number of slots per array entry - * is not known. It seems safe to assume that the total number of - * slots is an integer multiple of the number of array elements. - * Determine the number of slots per array element by dividing by - * the old (total) size. - */ - if (var->num_state_slots > 0) { - var->num_state_slots = (size + 1) - * (var->num_state_slots / var->type->length); - } - - var->type = glsl_type::get_array_instance(var->type->fields.array, - size + 1); - /* FINISHME: We should update the types of array - * dereferences of this variable now. - */ - } - } - } -} - -static void -add_uniform(void *mem_ctx, exec_list *uniforms, struct hash_table *ht, - const char *name, const glsl_type *type, GLenum shader_type, - unsigned *next_shader_pos, unsigned *total_uniforms) -{ - if (type->is_record()) { - for (unsigned int i = 0; i < type->length; i++) { - const glsl_type *field_type = type->fields.structure[i].type; - char *field_name = ralloc_asprintf(mem_ctx, "%s.%s", name, - type->fields.structure[i].name); - - add_uniform(mem_ctx, uniforms, ht, field_name, field_type, - shader_type, next_shader_pos, total_uniforms); - } - } else { - uniform_node *n = (uniform_node *) hash_table_find(ht, name); - unsigned int vec4_slots; - const glsl_type *array_elem_type = NULL; - - if (type->is_array()) { - array_elem_type = type->fields.array; - /* Array of structures. */ - if (array_elem_type->is_record()) { - for (unsigned int i = 0; i < type->length; i++) { - char *elem_name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i); - add_uniform(mem_ctx, uniforms, ht, elem_name, array_elem_type, - shader_type, next_shader_pos, total_uniforms); - } - return; - } - } - - /* Fix the storage size of samplers at 1 vec4 each. Be sure to pad out - * vectors to vec4 slots. - */ - if (type->is_array()) { - if (array_elem_type->is_sampler()) - vec4_slots = type->length; - else - vec4_slots = type->length * array_elem_type->matrix_columns; - } else if (type->is_sampler()) { - vec4_slots = 1; - } else { - vec4_slots = type->matrix_columns; - } - - if (n == NULL) { - n = (uniform_node *) calloc(1, sizeof(struct uniform_node)); - n->u = (gl_uniform *) calloc(1, sizeof(struct gl_uniform)); - n->slots = vec4_slots; - - n->u->Name = strdup(name); - n->u->Type = type; - n->u->VertPos = -1; - n->u->FragPos = -1; - n->u->GeomPos = -1; - (*total_uniforms)++; - - hash_table_insert(ht, n, name); - uniforms->push_tail(& n->link); - } - - switch (shader_type) { - case GL_VERTEX_SHADER: - n->u->VertPos = *next_shader_pos; - break; - case GL_FRAGMENT_SHADER: - n->u->FragPos = *next_shader_pos; - break; - case GL_GEOMETRY_SHADER: - n->u->GeomPos = *next_shader_pos; - break; - } - - (*next_shader_pos) += vec4_slots; - } -} - -void -assign_uniform_locations(struct gl_shader_program *prog) -{ - /* */ - exec_list uniforms; - unsigned total_uniforms = 0; - hash_table *ht = hash_table_ctor(32, hash_table_string_hash, - hash_table_string_compare); - void *mem_ctx = ralloc_context(NULL); - - for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - unsigned next_position = 0; - - foreach_list(node, prog->_LinkedShaders[i]->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != ir_var_uniform)) - continue; - - if (strncmp(var->name, "gl_", 3) == 0) { - /* At the moment, we don't allocate uniform locations for - * builtin uniforms. It's permitted by spec, and we'll - * likely switch to doing that at some point, but not yet. - */ - continue; - } - - var->location = next_position; - add_uniform(mem_ctx, &uniforms, ht, var->name, var->type, - prog->_LinkedShaders[i]->Type, - &next_position, &total_uniforms); - } - } - - ralloc_free(mem_ctx); - - gl_uniform_list *ul = (gl_uniform_list *) - calloc(1, sizeof(gl_uniform_list)); - - ul->Size = total_uniforms; - ul->NumUniforms = total_uniforms; - ul->Uniforms = (gl_uniform *) calloc(total_uniforms, sizeof(gl_uniform)); - - unsigned idx = 0; - uniform_node *next; - for (uniform_node *node = (uniform_node *) uniforms.head - ; node->link.next != NULL - ; node = next) { - next = (uniform_node *) node->link.next; - - node->link.remove(); - memcpy(&ul->Uniforms[idx], node->u, sizeof(gl_uniform)); - idx++; - - free(node->u); - free(node); - } - - hash_table_dtor(ht); - - prog->Uniforms = ul; -} - - -/** - * Find a contiguous set of available bits in a bitmask. - * - * \param used_mask Bits representing used (1) and unused (0) locations - * \param needed_count Number of contiguous bits needed. - * - * \return - * Base location of the available bits on success or -1 on failure. - */ -int -find_available_slots(unsigned used_mask, unsigned needed_count) -{ - unsigned needed_mask = (1 << needed_count) - 1; - const int max_bit_to_test = (8 * sizeof(used_mask)) - needed_count; - - /* The comparison to 32 is redundant, but without it GCC emits "warning: - * cannot optimize possibly infinite loops" for the loop below. - */ - if ((needed_count == 0) || (max_bit_to_test < 0) || (max_bit_to_test > 32)) - return -1; - - for (int i = 0; i <= max_bit_to_test; i++) { - if ((needed_mask & ~used_mask) == needed_mask) - return i; - - needed_mask <<= 1; - } - - return -1; -} - - -/** - * Assign locations for either VS inputs for FS outputs - * - * \param prog Shader program whose variables need locations assigned - * \param target_index Selector for the program target to receive location - * assignmnets. Must be either \c MESA_SHADER_VERTEX or - * \c MESA_SHADER_FRAGMENT. - * \param max_index Maximum number of generic locations. This corresponds - * to either the maximum number of draw buffers or the - * maximum number of generic attributes. - * - * \return - * If locations are successfully assigned, true is returned. Otherwise an - * error is emitted to the shader link log and false is returned. - * - * \bug - * Locations set via \c glBindFragDataLocation are not currently supported. - * Only locations assigned automatically by the linker, explicitly set by a - * layout qualifier, or explicitly set by a built-in variable (e.g., \c - * gl_FragColor) are supported for fragment shaders. - */ -bool -assign_attribute_or_color_locations(gl_shader_program *prog, - unsigned target_index, - unsigned max_index) -{ - /* Mark invalid locations as being used. - */ - unsigned used_locations = (max_index >= 32) - ? ~0 : ~((1 << max_index) - 1); - - assert((target_index == MESA_SHADER_VERTEX) - || (target_index == MESA_SHADER_FRAGMENT)); - - gl_shader *const sh = prog->_LinkedShaders[target_index]; - if (sh == NULL) - return true; - - /* Operate in a total of four passes. - * - * 1. Invalidate the location assignments for all vertex shader inputs. - * - * 2. Assign locations for inputs that have user-defined (via - * glBindVertexAttribLocation) locations. - * - * 3. Sort the attributes without assigned locations by number of slots - * required in decreasing order. Fragmentation caused by attribute - * locations assigned by the application may prevent large attributes - * from having enough contiguous space. - * - * 4. Assign locations to any inputs without assigned locations. - */ - - const int generic_base = (target_index == MESA_SHADER_VERTEX) - ? (int) VERT_ATTRIB_GENERIC0 : (int) FRAG_RESULT_DATA0; - - const enum ir_variable_mode direction = - (target_index == MESA_SHADER_VERTEX) ? ir_var_in : ir_var_out; - - - invalidate_variable_locations(sh, direction, generic_base); - - if ((target_index == MESA_SHADER_VERTEX) && (prog->Attributes != NULL)) { - for (unsigned i = 0; i < prog->Attributes->NumParameters; i++) { - ir_variable *const var = - sh->symbols->get_variable(prog->Attributes->Parameters[i].Name); - - /* Note: attributes that occupy multiple slots, such as arrays or - * matrices, may appear in the attrib array multiple times. - */ - if ((var == NULL) || (var->location != -1)) - continue; - - /* From page 61 of the OpenGL 4.0 spec: - * - * "LinkProgram will fail if the attribute bindings assigned by - * BindAttribLocation do not leave not enough space to assign a - * location for an active matrix attribute or an active attribute - * array, both of which require multiple contiguous generic - * attributes." - * - * Previous versions of the spec contain similar language but omit the - * bit about attribute arrays. - * - * Page 61 of the OpenGL 4.0 spec also says: - * - * "It is possible for an application to bind more than one - * attribute name to the same location. This is referred to as - * aliasing. This will only work if only one of the aliased - * attributes is active in the executable program, or if no path - * through the shader consumes more than one attribute of a set - * of attributes aliased to the same location. A link error can - * occur if the linker determines that every path through the - * shader consumes multiple aliased attributes, but - * implementations are not required to generate an error in this - * case." - * - * These two paragraphs are either somewhat contradictory, or I don't - * fully understand one or both of them. - */ - /* FINISHME: The code as currently written does not support attribute - * FINISHME: location aliasing (see comment above). - */ - const int attr = prog->Attributes->Parameters[i].StateIndexes[0]; - const unsigned slots = count_attribute_slots(var->type); - - /* Mask representing the contiguous slots that will be used by this - * attribute. - */ - const unsigned use_mask = (1 << slots) - 1; - - /* Generate a link error if the set of bits requested for this - * attribute overlaps any previously allocated bits. - */ - if ((~(use_mask << attr) & used_locations) != used_locations) { - linker_error(prog, - "insufficient contiguous attribute locations " - "available for vertex shader input `%s'", - var->name); - return false; - } - - var->location = VERT_ATTRIB_GENERIC0 + attr; - used_locations |= (use_mask << attr); - } - } - - /* Temporary storage for the set of attributes that need locations assigned. - */ - struct temp_attr { - unsigned slots; - ir_variable *var; - - /* Used below in the call to qsort. */ - static int compare(const void *a, const void *b) - { - const temp_attr *const l = (const temp_attr *) a; - const temp_attr *const r = (const temp_attr *) b; - - /* Reversed because we want a descending order sort below. */ - return r->slots - l->slots; - } - } to_assign[16]; - - unsigned num_attr = 0; - - foreach_list(node, sh->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != (unsigned) direction)) - continue; - - if (var->explicit_location) { - const unsigned slots = count_attribute_slots(var->type); - const unsigned use_mask = (1 << slots) - 1; - const int attr = var->location - generic_base; - - if ((var->location >= (int)(max_index + generic_base)) - || (var->location < 0)) { - linker_error(prog, - "invalid explicit location %d specified for `%s'\n", - (var->location < 0) ? var->location : attr, - var->name); - return false; - } else if (var->location >= generic_base) { - used_locations |= (use_mask << attr); - } - } - - /* The location was explicitly assigned, nothing to do here. - */ - if (var->location != -1) - continue; - - to_assign[num_attr].slots = count_attribute_slots(var->type); - to_assign[num_attr].var = var; - num_attr++; - } - - /* If all of the attributes were assigned locations by the application (or - * are built-in attributes with fixed locations), return early. This should - * be the common case. - */ - if (num_attr == 0) - return true; - - qsort(to_assign, num_attr, sizeof(to_assign[0]), temp_attr::compare); - - if (target_index == MESA_SHADER_VERTEX) { - /* VERT_ATTRIB_GENERIC0 is a pseudo-alias for VERT_ATTRIB_POS. It can - * only be explicitly assigned by via glBindAttribLocation. Mark it as - * reserved to prevent it from being automatically allocated below. - */ - find_deref_visitor find("gl_Vertex"); - find.run(sh->ir); - if (find.variable_found()) - used_locations |= (1 << 0); - } - - for (unsigned i = 0; i < num_attr; i++) { - /* Mask representing the contiguous slots that will be used by this - * attribute. - */ - const unsigned use_mask = (1 << to_assign[i].slots) - 1; - - int location = find_available_slots(used_locations, to_assign[i].slots); - - if (location < 0) { - const char *const string = (target_index == MESA_SHADER_VERTEX) - ? "vertex shader input" : "fragment shader output"; - - linker_error(prog, - "insufficient contiguous attribute locations " - "available for %s `%s'", - string, to_assign[i].var->name); - return false; - } - - to_assign[i].var->location = generic_base + location; - used_locations |= (use_mask << location); - } - - return true; -} - - -/** - * Demote shader inputs and outputs that are not used in other stages - */ -void -demote_shader_inputs_and_outputs(gl_shader *sh, enum ir_variable_mode mode) -{ - foreach_list(node, sh->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != int(mode))) - continue; - - /* A shader 'in' or 'out' variable is only really an input or output if - * its value is used by other shader stages. This will cause the variable - * to have a location assigned. - */ - if (var->location == -1) { - var->mode = ir_var_auto; - } - } -} - - -bool -assign_varying_locations(struct gl_context *ctx, - struct gl_shader_program *prog, - gl_shader *producer, gl_shader *consumer) -{ - /* FINISHME: Set dynamically when geometry shader support is added. */ - unsigned output_index = VERT_RESULT_VAR0; - unsigned input_index = FRAG_ATTRIB_VAR0; - - /* Operate in a total of three passes. - * - * 1. Assign locations for any matching inputs and outputs. - * - * 2. Mark output variables in the producer that do not have locations as - * not being outputs. This lets the optimizer eliminate them. - * - * 3. Mark input variables in the consumer that do not have locations as - * not being inputs. This lets the optimizer eliminate them. - */ - - invalidate_variable_locations(producer, ir_var_out, VERT_RESULT_VAR0); - invalidate_variable_locations(consumer, ir_var_in, FRAG_ATTRIB_VAR0); - - foreach_list(node, producer->ir) { - ir_variable *const output_var = ((ir_instruction *) node)->as_variable(); - - if ((output_var == NULL) || (output_var->mode != ir_var_out) - || (output_var->location != -1)) - continue; - - ir_variable *const input_var = - consumer->symbols->get_variable(output_var->name); - - if ((input_var == NULL) || (input_var->mode != ir_var_in)) - continue; - - assert(input_var->location == -1); - - output_var->location = output_index; - input_var->location = input_index; - - /* FINISHME: Support for "varying" records in GLSL 1.50. */ - assert(!output_var->type->is_record()); - - if (output_var->type->is_array()) { - const unsigned slots = output_var->type->length - * output_var->type->fields.array->matrix_columns; - - output_index += slots; - input_index += slots; - } else { - const unsigned slots = output_var->type->matrix_columns; - - output_index += slots; - input_index += slots; - } - } - - unsigned varying_vectors = 0; - - foreach_list(node, consumer->ir) { - ir_variable *const var = ((ir_instruction *) node)->as_variable(); - - if ((var == NULL) || (var->mode != ir_var_in)) - continue; - - if (var->location == -1) { - if (prog->Version <= 120) { - /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec: - * - * Only those varying variables used (i.e. read) in - * the fragment shader executable must be written to - * by the vertex shader executable; declaring - * superfluous varying variables in a vertex shader is - * permissible. - * - * We interpret this text as meaning that the VS must - * write the variable for the FS to read it. See - * "glsl1-varying read but not written" in piglit. - */ - - linker_error(prog, "fragment shader varying %s not written " - "by vertex shader\n.", var->name); - } - - /* An 'in' variable is only really a shader input if its - * value is written by the previous stage. - */ - var->mode = ir_var_auto; - } else { - /* The packing rules are used for vertex shader inputs are also used - * for fragment shader inputs. - */ - varying_vectors += count_attribute_slots(var->type); - } - } - - if (ctx->API == API_OPENGLES2 || prog->Version == 100) { - if (varying_vectors > ctx->Const.MaxVarying) { - linker_error(prog, "shader uses too many varying vectors " - "(%u > %u)\n", - varying_vectors, ctx->Const.MaxVarying); - return false; - } - } else { - const unsigned float_components = varying_vectors * 4; - if (float_components > ctx->Const.MaxVarying * 4) { - linker_error(prog, "shader uses too many varying components " - "(%u > %u)\n", - float_components, ctx->Const.MaxVarying * 4); - return false; - } - } - - return true; -} - - -void -link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) -{ - void *mem_ctx = ralloc_context(NULL); // temporary linker context - - prog->LinkStatus = false; - prog->Validated = false; - prog->_Used = false; - - if (prog->InfoLog != NULL) - ralloc_free(prog->InfoLog); - - prog->InfoLog = ralloc_strdup(NULL, ""); - - /* Separate the shaders into groups based on their type. - */ - struct gl_shader **vert_shader_list; - unsigned num_vert_shaders = 0; - struct gl_shader **frag_shader_list; - unsigned num_frag_shaders = 0; - - vert_shader_list = (struct gl_shader **) - calloc(2 * prog->NumShaders, sizeof(struct gl_shader *)); - frag_shader_list = &vert_shader_list[prog->NumShaders]; - - unsigned min_version = UINT_MAX; - unsigned max_version = 0; - for (unsigned i = 0; i < prog->NumShaders; i++) { - min_version = MIN2(min_version, prog->Shaders[i]->Version); - max_version = MAX2(max_version, prog->Shaders[i]->Version); - - switch (prog->Shaders[i]->Type) { - case GL_VERTEX_SHADER: - vert_shader_list[num_vert_shaders] = prog->Shaders[i]; - num_vert_shaders++; - break; - case GL_FRAGMENT_SHADER: - frag_shader_list[num_frag_shaders] = prog->Shaders[i]; - num_frag_shaders++; - break; - case GL_GEOMETRY_SHADER: - /* FINISHME: Support geometry shaders. */ - assert(prog->Shaders[i]->Type != GL_GEOMETRY_SHADER); - break; - } - } - - /* Previous to GLSL version 1.30, different compilation units could mix and - * match shading language versions. With GLSL 1.30 and later, the versions - * of all shaders must match. - */ - assert(min_version >= 100); - assert(max_version <= 130); - if ((max_version >= 130 || min_version == 100) - && min_version != max_version) { - linker_error(prog, "all shaders must use same shading " - "language version\n"); - goto done; - } - - prog->Version = max_version; - - for (unsigned int i = 0; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] != NULL) - ctx->Driver.DeleteShader(ctx, prog->_LinkedShaders[i]); - - prog->_LinkedShaders[i] = NULL; - } - - /* Link all shaders for a particular stage and validate the result. - */ - if (num_vert_shaders > 0) { - gl_shader *const sh = - link_intrastage_shaders(mem_ctx, ctx, prog, vert_shader_list, - num_vert_shaders); - - if (sh == NULL) - goto done; - - if (!validate_vertex_shader_executable(prog, sh)) - goto done; - - _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_VERTEX], - sh); - } - - if (num_frag_shaders > 0) { - gl_shader *const sh = - link_intrastage_shaders(mem_ctx, ctx, prog, frag_shader_list, - num_frag_shaders); - - if (sh == NULL) - goto done; - - if (!validate_fragment_shader_executable(prog, sh)) - goto done; - - _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_FRAGMENT], - sh); - } - - /* Here begins the inter-stage linking phase. Some initial validation is - * performed, then locations are assigned for uniforms, attributes, and - * varyings. - */ - if (cross_validate_uniforms(prog)) { - unsigned prev; - - for (prev = 0; prev < MESA_SHADER_TYPES; prev++) { - if (prog->_LinkedShaders[prev] != NULL) - break; - } - - /* Validate the inputs of each stage with the output of the preceding - * stage. - */ - for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - if (!cross_validate_outputs_to_inputs(prog, - prog->_LinkedShaders[prev], - prog->_LinkedShaders[i])) - goto done; - - prev = i; - } - - prog->LinkStatus = true; - } - - /* Do common optimization before assigning storage for attributes, - * uniforms, and varyings. Later optimization could possibly make - * some of that unused. - */ - for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - detect_recursion_linked(prog, prog->_LinkedShaders[i]->ir); - if (!prog->LinkStatus) - goto done; - - while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, 32)) - ; - } - - update_array_sizes(prog); - - assign_uniform_locations(prog); - - /* FINISHME: The value of the max_attribute_index parameter is - * FINISHME: implementation dependent based on the value of - * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be - * FINISHME: at least 16, so hardcode 16 for now. - */ - if (!assign_attribute_or_color_locations(prog, MESA_SHADER_VERTEX, 16)) { - goto done; - } - - if (!assign_attribute_or_color_locations(prog, MESA_SHADER_FRAGMENT, ctx->Const.MaxDrawBuffers)) { - goto done; - } - - unsigned prev; - for (prev = 0; prev < MESA_SHADER_TYPES; prev++) { - if (prog->_LinkedShaders[prev] != NULL) - break; - } - - for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - if (!assign_varying_locations(ctx, prog, - prog->_LinkedShaders[prev], - prog->_LinkedShaders[i])) { - goto done; - } - - prev = i; - } - - if (prog->_LinkedShaders[MESA_SHADER_VERTEX] != NULL) { - demote_shader_inputs_and_outputs(prog->_LinkedShaders[MESA_SHADER_VERTEX], - ir_var_out); - } - - if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) { - gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_GEOMETRY]; - - demote_shader_inputs_and_outputs(sh, ir_var_in); - demote_shader_inputs_and_outputs(sh, ir_var_inout); - demote_shader_inputs_and_outputs(sh, ir_var_out); - } - - if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] != NULL) { - gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT]; - - demote_shader_inputs_and_outputs(sh, ir_var_in); - } - - /* OpenGL ES requires that a vertex shader and a fragment shader both be - * present in a linked program. By checking for use of shading language - * version 1.00, we also catch the GL_ARB_ES2_compatibility case. - */ - if (ctx->API == API_OPENGLES2 || prog->Version == 100) { - if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) { - linker_error(prog, "program lacks a vertex shader\n"); - } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) { - linker_error(prog, "program lacks a fragment shader\n"); - } - } - - /* FINISHME: Assign fragment shader output locations. */ - -done: - free(vert_shader_list); - - for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) { - if (prog->_LinkedShaders[i] == NULL) - continue; - - /* Retain any live IR, but trash the rest. */ - reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir); - } - - ralloc_free(mem_ctx); -} +/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file linker.cpp
+ * GLSL linker implementation
+ *
+ * Given a set of shaders that are to be linked to generate a final program,
+ * there are three distinct stages.
+ *
+ * In the first stage shaders are partitioned into groups based on the shader
+ * type. All shaders of a particular type (e.g., vertex shaders) are linked
+ * together.
+ *
+ * - Undefined references in each shader are resolve to definitions in
+ * another shader.
+ * - Types and qualifiers of uniforms, outputs, and global variables defined
+ * in multiple shaders with the same name are verified to be the same.
+ * - Initializers for uniforms and global variables defined
+ * in multiple shaders with the same name are verified to be the same.
+ *
+ * The result, in the terminology of the GLSL spec, is a set of shader
+ * executables for each processing unit.
+ *
+ * After the first stage is complete, a series of semantic checks are performed
+ * on each of the shader executables.
+ *
+ * - Each shader executable must define a \c main function.
+ * - Each vertex shader executable must write to \c gl_Position.
+ * - Each fragment shader executable must write to either \c gl_FragData or
+ * \c gl_FragColor.
+ *
+ * In the final stage individual shader executables are linked to create a
+ * complete exectuable.
+ *
+ * - Types of uniforms defined in multiple shader stages with the same name
+ * are verified to be the same.
+ * - Initializers for uniforms defined in multiple shader stages with the
+ * same name are verified to be the same.
+ * - Types and qualifiers of outputs defined in one stage are verified to
+ * be the same as the types and qualifiers of inputs defined with the same
+ * name in a later stage.
+ *
+ * \author Ian Romanick <ian.d.romanick@intel.com>
+ */
+
+#include "main/core.h"
+#include "glsl_symbol_table.h"
+#include "ir.h"
+#include "program.h"
+#include "program/hash_table.h"
+#include "linker.h"
+#include "ir_optimization.h"
+
+extern "C" {
+#include "main/shaderobj.h"
+}
+
+/**
+ * Visitor that determines whether or not a variable is ever written.
+ */
+class find_assignment_visitor : public ir_hierarchical_visitor {
+public:
+ find_assignment_visitor(const char *name)
+ : name(name), found(false)
+ {
+ /* empty */
+ }
+
+ virtual ir_visitor_status visit_enter(ir_assignment *ir)
+ {
+ ir_variable *const var = ir->lhs->variable_referenced();
+
+ if (strcmp(name, var->name) == 0) {
+ found = true;
+ return visit_stop;
+ }
+
+ return visit_continue_with_parent;
+ }
+
+ virtual ir_visitor_status visit_enter(ir_call *ir)
+ {
+ exec_list_iterator sig_iter = ir->get_callee()->parameters.iterator();
+ foreach_iter(exec_list_iterator, iter, *ir) {
+ ir_rvalue *param_rval = (ir_rvalue *)iter.get();
+ ir_variable *sig_param = (ir_variable *)sig_iter.get();
+
+ if (sig_param->mode == ir_var_out ||
+ sig_param->mode == ir_var_inout) {
+ ir_variable *var = param_rval->variable_referenced();
+ if (var && strcmp(name, var->name) == 0) {
+ found = true;
+ return visit_stop;
+ }
+ }
+ sig_iter.next();
+ }
+
+ return visit_continue_with_parent;
+ }
+
+ bool variable_found()
+ {
+ return found;
+ }
+
+private:
+ const char *name; /**< Find writes to a variable with this name. */
+ bool found; /**< Was a write to the variable found? */
+};
+
+
+/**
+ * Visitor that determines whether or not a variable is ever read.
+ */
+class find_deref_visitor : public ir_hierarchical_visitor {
+public:
+ find_deref_visitor(const char *name)
+ : name(name), found(false)
+ {
+ /* empty */
+ }
+
+ virtual ir_visitor_status visit(ir_dereference_variable *ir)
+ {
+ if (strcmp(this->name, ir->var->name) == 0) {
+ this->found = true;
+ return visit_stop;
+ }
+
+ return visit_continue;
+ }
+
+ bool variable_found() const
+ {
+ return this->found;
+ }
+
+private:
+ const char *name; /**< Find writes to a variable with this name. */
+ bool found; /**< Was a write to the variable found? */
+};
+
+
+void
+linker_error(gl_shader_program *prog, const char *fmt, ...)
+{
+ va_list ap;
+
+ ralloc_strcat(&prog->InfoLog, "error: ");
+ va_start(ap, fmt);
+ ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
+ va_end(ap);
+
+ prog->LinkStatus = false;
+}
+
+
+void
+linker_warning(gl_shader_program *prog, const char *fmt, ...)
+{
+ va_list ap;
+
+ ralloc_strcat(&prog->InfoLog, "error: ");
+ va_start(ap, fmt);
+ ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
+ va_end(ap);
+
+}
+
+
+void
+invalidate_variable_locations(gl_shader *sh, enum ir_variable_mode mode,
+ int generic_base)
+{
+ foreach_list(node, sh->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != (unsigned) mode))
+ continue;
+
+ /* Only assign locations for generic attributes / varyings / etc.
+ */
+ if ((var->location >= generic_base) && !var->explicit_location)
+ var->location = -1;
+ }
+}
+
+
+/**
+ * Determine the number of attribute slots required for a particular type
+ *
+ * This code is here because it implements the language rules of a specific
+ * GLSL version. Since it's a property of the language and not a property of
+ * types in general, it doesn't really belong in glsl_type.
+ */
+unsigned
+count_attribute_slots(const glsl_type *t)
+{
+ /* From page 31 (page 37 of the PDF) of the GLSL 1.50 spec:
+ *
+ * "A scalar input counts the same amount against this limit as a vec4,
+ * so applications may want to consider packing groups of four
+ * unrelated float inputs together into a vector to better utilize the
+ * capabilities of the underlying hardware. A matrix input will use up
+ * multiple locations. The number of locations used will equal the
+ * number of columns in the matrix."
+ *
+ * The spec does not explicitly say how arrays are counted. However, it
+ * should be safe to assume the total number of slots consumed by an array
+ * is the number of entries in the array multiplied by the number of slots
+ * consumed by a single element of the array.
+ */
+
+ if (t->is_array())
+ return t->array_size() * count_attribute_slots(t->element_type());
+
+ if (t->is_matrix())
+ return t->matrix_columns;
+
+ return 1;
+}
+
+
+/**
+ * Verify that a vertex shader executable meets all semantic requirements
+ *
+ * \param shader Vertex shader executable to be verified
+ */
+bool
+validate_vertex_shader_executable(struct gl_shader_program *prog,
+ struct gl_shader *shader)
+{
+ if (shader == NULL)
+ return true;
+
+ find_assignment_visitor find("gl_Position");
+ find.run(shader->ir);
+ if (!find.variable_found()) {
+ linker_error(prog, "vertex shader does not write to `gl_Position'\n");
+ return false;
+ }
+
+ return true;
+}
+
+
+/**
+ * Verify that a fragment shader executable meets all semantic requirements
+ *
+ * \param shader Fragment shader executable to be verified
+ */
+bool
+validate_fragment_shader_executable(struct gl_shader_program *prog,
+ struct gl_shader *shader)
+{
+ if (shader == NULL)
+ return true;
+
+ find_assignment_visitor frag_color("gl_FragColor");
+ find_assignment_visitor frag_data("gl_FragData");
+
+ frag_color.run(shader->ir);
+ frag_data.run(shader->ir);
+
+ if (frag_color.variable_found() && frag_data.variable_found()) {
+ linker_error(prog, "fragment shader writes to both "
+ "`gl_FragColor' and `gl_FragData'\n");
+ return false;
+ }
+
+ return true;
+}
+
+
+/**
+ * Generate a string describing the mode of a variable
+ */
+static const char *
+mode_string(const ir_variable *var)
+{
+ switch (var->mode) {
+ case ir_var_auto:
+ return (var->read_only) ? "global constant" : "global variable";
+
+ case ir_var_uniform: return "uniform";
+ case ir_var_in: return "shader input";
+ case ir_var_out: return "shader output";
+ case ir_var_inout: return "shader inout";
+
+ case ir_var_const_in:
+ case ir_var_temporary:
+ default:
+ assert(!"Should not get here.");
+ return "invalid variable";
+ }
+}
+
+
+/**
+ * Perform validation of global variables used across multiple shaders
+ */
+bool
+cross_validate_globals(struct gl_shader_program *prog,
+ struct gl_shader **shader_list,
+ unsigned num_shaders,
+ bool uniforms_only)
+{
+ /* Examine all of the uniforms in all of the shaders and cross validate
+ * them.
+ */
+ glsl_symbol_table variables;
+ for (unsigned i = 0; i < num_shaders; i++) {
+ if (shader_list[i] == NULL)
+ continue;
+
+ foreach_list(node, shader_list[i]->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if (var == NULL)
+ continue;
+
+ if (uniforms_only && (var->mode != ir_var_uniform))
+ continue;
+
+ /* Don't cross validate temporaries that are at global scope. These
+ * will eventually get pulled into the shaders 'main'.
+ */
+ if (var->mode == ir_var_temporary)
+ continue;
+
+ /* If a global with this name has already been seen, verify that the
+ * new instance has the same type. In addition, if the globals have
+ * initializers, the values of the initializers must be the same.
+ */
+ ir_variable *const existing = variables.get_variable(var->name);
+ if (existing != NULL) {
+ if (var->type != existing->type) {
+ /* Consider the types to be "the same" if both types are arrays
+ * of the same type and one of the arrays is implicitly sized.
+ * In addition, set the type of the linked variable to the
+ * explicitly sized array.
+ */
+ if (var->type->is_array()
+ && existing->type->is_array()
+ && (var->type->fields.array == existing->type->fields.array)
+ && ((var->type->length == 0)
+ || (existing->type->length == 0))) {
+ if (var->type->length != 0) {
+ existing->type = var->type;
+ }
+ } else {
+ linker_error(prog, "%s `%s' declared as type "
+ "`%s' and type `%s'\n",
+ mode_string(var),
+ var->name, var->type->name,
+ existing->type->name);
+ return false;
+ }
+ }
+
+ if (var->explicit_location) {
+ if (existing->explicit_location
+ && (var->location != existing->location)) {
+ linker_error(prog, "explicit locations for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return false;
+ }
+
+ existing->location = var->location;
+ existing->explicit_location = true;
+ }
+
+ /* Validate layout qualifiers for gl_FragDepth.
+ *
+ * From the AMD_conservative_depth spec:
+ * "If gl_FragDepth is redeclared in any fragment shader in
+ * a program, it must be redeclared in all fragment shaders in that
+ * program that have static assignments to gl_FragDepth. All
+ * redeclarations of gl_FragDepth in all fragment shaders in
+ * a single program must have the same set of qualifiers."
+ */
+ if (strcmp(var->name, "gl_FragDepth") == 0) {
+ bool layout_declared = var->depth_layout != ir_depth_layout_none;
+ bool layout_differs = var->depth_layout != existing->depth_layout;
+ if (layout_declared && layout_differs) {
+ linker_error(prog,
+ "All redeclarations of gl_FragDepth in all fragment shaders "
+ "in a single program must have the same set of qualifiers.");
+ }
+ if (var->used && layout_differs) {
+ linker_error(prog,
+ "If gl_FragDepth is redeclared with a layout qualifier in"
+ "any fragment shader, it must be redeclared with the same"
+ "layout qualifier in all fragment shaders that have"
+ "assignments to gl_FragDepth");
+ }
+ }
+
+ /* FINISHME: Handle non-constant initializers.
+ */
+ if (var->constant_value != NULL) {
+ if (existing->constant_value != NULL) {
+ if (!var->constant_value->has_value(existing->constant_value)) {
+ linker_error(prog, "initializers for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return false;
+ }
+ } else
+ /* If the first-seen instance of a particular uniform did not
+ * have an initializer but a later instance does, copy the
+ * initializer to the version stored in the symbol table.
+ */
+ /* FINISHME: This is wrong. The constant_value field should
+ * FINISHME: not be modified! Imagine a case where a shader
+ * FINISHME: without an initializer is linked in two different
+ * FINISHME: programs with shaders that have differing
+ * FINISHME: initializers. Linking with the first will
+ * FINISHME: modify the shader, and linking with the second
+ * FINISHME: will fail.
+ */
+ existing->constant_value =
+ var->constant_value->clone(ralloc_parent(existing), NULL);
+ }
+
+ if (existing->invariant != var->invariant) {
+ linker_error(prog, "declarations for %s `%s' have "
+ "mismatching invariant qualifiers\n",
+ mode_string(var), var->name);
+ return false;
+ }
+ if (existing->centroid != var->centroid) {
+ linker_error(prog, "declarations for %s `%s' have "
+ "mismatching centroid qualifiers\n",
+ mode_string(var), var->name);
+ return false;
+ }
+ } else
+ variables.add_variable(var);
+ }
+ }
+
+ return true;
+}
+
+
+/**
+ * Perform validation of uniforms used across multiple shader stages
+ */
+bool
+cross_validate_uniforms(struct gl_shader_program *prog)
+{
+ return cross_validate_globals(prog, prog->_LinkedShaders,
+ MESA_SHADER_TYPES, true);
+}
+
+
+/**
+ * Validate that outputs from one stage match inputs of another
+ */
+bool
+cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer)
+{
+ glsl_symbol_table parameters;
+ /* FINISHME: Figure these out dynamically. */
+ const char *const producer_stage = "vertex";
+ const char *const consumer_stage = "fragment";
+
+ /* Find all shader outputs in the "producer" stage.
+ */
+ foreach_list(node, producer->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((var == NULL) || (var->mode != ir_var_out))
+ continue;
+
+ parameters.add_variable(var);
+ }
+
+
+ /* Find all shader inputs in the "consumer" stage. Any variables that have
+ * matching outputs already in the symbol table must have the same type and
+ * qualifiers.
+ */
+ foreach_list(node, consumer->ir) {
+ ir_variable *const input = ((ir_instruction *) node)->as_variable();
+
+ /* FINISHME: For geometry shaders, this should also look for inout
+ * FINISHME: variables.
+ */
+ if ((input == NULL) || (input->mode != ir_var_in))
+ continue;
+
+ ir_variable *const output = parameters.get_variable(input->name);
+ if (output != NULL) {
+ /* Check that the types match between stages.
+ */
+ if (input->type != output->type) {
+ /* There is a bit of a special case for gl_TexCoord. This
+ * built-in is unsized by default. Applications that variable
+ * access it must redeclare it with a size. There is some
+ * language in the GLSL spec that implies the fragment shader
+ * and vertex shader do not have to agree on this size. Other
+ * driver behave this way, and one or two applications seem to
+ * rely on it.
+ *
+ * Neither declaration needs to be modified here because the array
+ * sizes are fixed later when update_array_sizes is called.
+ *
+ * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
+ *
+ * "Unlike user-defined varying variables, the built-in
+ * varying variables don't have a strict one-to-one
+ * correspondence between the vertex language and the
+ * fragment language."
+ */
+ if (!output->type->is_array()
+ || (strncmp("gl_", output->name, 3) != 0)) {
+ linker_error(prog,
+ "%s shader output `%s' declared as type `%s', "
+ "but %s shader input declared as type `%s'\n",
+ producer_stage, output->name,
+ output->type->name,
+ consumer_stage, input->type->name);
+ return false;
+ }
+ }
+
+ /* Check that all of the qualifiers match between stages.
+ */
+ if (input->centroid != output->centroid) {
+ linker_error(prog,
+ "%s shader output `%s' %s centroid qualifier, "
+ "but %s shader input %s centroid qualifier\n",
+ producer_stage,
+ output->name,
+ (output->centroid) ? "has" : "lacks",
+ consumer_stage,
+ (input->centroid) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->invariant != output->invariant) {
+ linker_error(prog,
+ "%s shader output `%s' %s invariant qualifier, "
+ "but %s shader input %s invariant qualifier\n",
+ producer_stage,
+ output->name,
+ (output->invariant) ? "has" : "lacks",
+ consumer_stage,
+ (input->invariant) ? "has" : "lacks");
+ return false;
+ }
+
+ if (input->interpolation != output->interpolation) {
+ linker_error(prog,
+ "%s shader output `%s' specifies %s "
+ "interpolation qualifier, "
+ "but %s shader input specifies %s "
+ "interpolation qualifier\n",
+ producer_stage,
+ output->name,
+ output->interpolation_string(),
+ consumer_stage,
+ input->interpolation_string());
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+
+/**
+ * Populates a shaders symbol table with all global declarations
+ */
+static void
+populate_symbol_table(gl_shader *sh)
+{
+ sh->symbols = new(sh) glsl_symbol_table;
+
+ foreach_list(node, sh->ir) {
+ ir_instruction *const inst = (ir_instruction *) node;
+ ir_variable *var;
+ ir_function *func;
+
+ if ((func = inst->as_function()) != NULL) {
+ sh->symbols->add_function(func);
+ } else if ((var = inst->as_variable()) != NULL) {
+ sh->symbols->add_variable(var);
+ }
+ }
+}
+
+
+/**
+ * Remap variables referenced in an instruction tree
+ *
+ * This is used when instruction trees are cloned from one shader and placed in
+ * another. These trees will contain references to \c ir_variable nodes that
+ * do not exist in the target shader. This function finds these \c ir_variable
+ * references and replaces the references with matching variables in the target
+ * shader.
+ *
+ * If there is no matching variable in the target shader, a clone of the
+ * \c ir_variable is made and added to the target shader. The new variable is
+ * added to \b both the instruction stream and the symbol table.
+ *
+ * \param inst IR tree that is to be processed.
+ * \param symbols Symbol table containing global scope symbols in the
+ * linked shader.
+ * \param instructions Instruction stream where new variable declarations
+ * should be added.
+ */
+void
+remap_variables(ir_instruction *inst, struct gl_shader *target,
+ hash_table *temps)
+{
+ class remap_visitor : public ir_hierarchical_visitor {
+ public:
+ remap_visitor(struct gl_shader *target,
+ hash_table *temps)
+ {
+ this->target = target;
+ this->symbols = target->symbols;
+ this->instructions = target->ir;
+ this->temps = temps;
+ }
+
+ virtual ir_visitor_status visit(ir_dereference_variable *ir)
+ {
+ if (ir->var->mode == ir_var_temporary) {
+ ir_variable *var = (ir_variable *) hash_table_find(temps, ir->var);
+
+ assert(var != NULL);
+ ir->var = var;
+ return visit_continue;
+ }
+
+ ir_variable *const existing =
+ this->symbols->get_variable(ir->var->name);
+ if (existing != NULL)
+ ir->var = existing;
+ else {
+ ir_variable *copy = ir->var->clone(this->target, NULL);
+
+ this->symbols->add_variable(copy);
+ this->instructions->push_head(copy);
+ ir->var = copy;
+ }
+
+ return visit_continue;
+ }
+
+ private:
+ struct gl_shader *target;
+ glsl_symbol_table *symbols;
+ exec_list *instructions;
+ hash_table *temps;
+ };
+
+ remap_visitor v(target, temps);
+
+ inst->accept(&v);
+}
+
+
+/**
+ * Move non-declarations from one instruction stream to another
+ *
+ * The intended usage pattern of this function is to pass the pointer to the
+ * head sentinel of a list (i.e., a pointer to the list cast to an \c exec_node
+ * pointer) for \c last and \c false for \c make_copies on the first
+ * call. Successive calls pass the return value of the previous call for
+ * \c last and \c true for \c make_copies.
+ *
+ * \param instructions Source instruction stream
+ * \param last Instruction after which new instructions should be
+ * inserted in the target instruction stream
+ * \param make_copies Flag selecting whether instructions in \c instructions
+ * should be copied (via \c ir_instruction::clone) into the
+ * target list or moved.
+ *
+ * \return
+ * The new "last" instruction in the target instruction stream. This pointer
+ * is suitable for use as the \c last parameter of a later call to this
+ * function.
+ */
+exec_node *
+move_non_declarations(exec_list *instructions, exec_node *last,
+ bool make_copies, gl_shader *target)
+{
+ hash_table *temps = NULL;
+
+ if (make_copies)
+ temps = hash_table_ctor(0, hash_table_pointer_hash,
+ hash_table_pointer_compare);
+
+ foreach_list_safe(node, instructions) {
+ ir_instruction *inst = (ir_instruction *) node;
+
+ if (inst->as_function())
+ continue;
+
+ ir_variable *var = inst->as_variable();
+ if ((var != NULL) && (var->mode != ir_var_temporary))
+ continue;
+
+ assert(inst->as_assignment()
+ || ((var != NULL) && (var->mode == ir_var_temporary)));
+
+ if (make_copies) {
+ inst = inst->clone(target, NULL);
+
+ if (var != NULL)
+ hash_table_insert(temps, inst, var);
+ else
+ remap_variables(inst, target, temps);
+ } else {
+ inst->remove();
+ }
+
+ last->insert_after(inst);
+ last = inst;
+ }
+
+ if (make_copies)
+ hash_table_dtor(temps);
+
+ return last;
+}
+
+/**
+ * Get the function signature for main from a shader
+ */
+static ir_function_signature *
+get_main_function_signature(gl_shader *sh)
+{
+ ir_function *const f = sh->symbols->get_function("main");
+ if (f != NULL) {
+ exec_list void_parameters;
+
+ /* Look for the 'void main()' signature and ensure that it's defined.
+ * This keeps the linker from accidentally pick a shader that just
+ * contains a prototype for main.
+ *
+ * We don't have to check for multiple definitions of main (in multiple
+ * shaders) because that would have already been caught above.
+ */
+ ir_function_signature *sig = f->matching_signature(&void_parameters);
+ if ((sig != NULL) && sig->is_defined) {
+ return sig;
+ }
+ }
+
+ return NULL;
+}
+
+
+/**
+ * Combine a group of shaders for a single stage to generate a linked shader
+ *
+ * \note
+ * If this function is supplied a single shader, it is cloned, and the new
+ * shader is returned.
+ */
+static struct gl_shader *
+link_intrastage_shaders(void *mem_ctx,
+ struct gl_context *ctx,
+ struct gl_shader_program *prog,
+ struct gl_shader **shader_list,
+ unsigned num_shaders)
+{
+ /* Check that global variables defined in multiple shaders are consistent.
+ */
+ if (!cross_validate_globals(prog, shader_list, num_shaders, false))
+ return NULL;
+
+ /* Check that there is only a single definition of each function signature
+ * across all shaders.
+ */
+ for (unsigned i = 0; i < (num_shaders - 1); i++) {
+ foreach_list(node, shader_list[i]->ir) {
+ ir_function *const f = ((ir_instruction *) node)->as_function();
+
+ if (f == NULL)
+ continue;
+
+ for (unsigned j = i + 1; j < num_shaders; j++) {
+ ir_function *const other =
+ shader_list[j]->symbols->get_function(f->name);
+
+ /* If the other shader has no function (and therefore no function
+ * signatures) with the same name, skip to the next shader.
+ */
+ if (other == NULL)
+ continue;
+
+ foreach_iter (exec_list_iterator, iter, *f) {
+ ir_function_signature *sig =
+ (ir_function_signature *) iter.get();
+
+ if (!sig->is_defined || sig->is_builtin)
+ continue;
+
+ ir_function_signature *other_sig =
+ other->exact_matching_signature(& sig->parameters);
+
+ if ((other_sig != NULL) && other_sig->is_defined
+ && !other_sig->is_builtin) {
+ linker_error(prog, "function `%s' is multiply defined",
+ f->name);
+ return NULL;
+ }
+ }
+ }
+ }
+ }
+
+ /* Find the shader that defines main, and make a clone of it.
+ *
+ * Starting with the clone, search for undefined references. If one is
+ * found, find the shader that defines it. Clone the reference and add
+ * it to the shader. Repeat until there are no undefined references or
+ * until a reference cannot be resolved.
+ */
+ gl_shader *main = NULL;
+ for (unsigned i = 0; i < num_shaders; i++) {
+ if (get_main_function_signature(shader_list[i]) != NULL) {
+ main = shader_list[i];
+ break;
+ }
+ }
+
+ if (main == NULL) {
+ linker_error(prog, "%s shader lacks `main'\n",
+ (shader_list[0]->Type == GL_VERTEX_SHADER)
+ ? "vertex" : "fragment");
+ return NULL;
+ }
+
+ gl_shader *linked = ctx->Driver.NewShader(NULL, 0, main->Type);
+ linked->ir = new(linked) exec_list;
+ clone_ir_list(mem_ctx, linked->ir, main->ir);
+
+ populate_symbol_table(linked);
+
+ /* The a pointer to the main function in the final linked shader (i.e., the
+ * copy of the original shader that contained the main function).
+ */
+ ir_function_signature *const main_sig = get_main_function_signature(linked);
+
+ /* Move any instructions other than variable declarations or function
+ * declarations into main.
+ */
+ exec_node *insertion_point =
+ move_non_declarations(linked->ir, (exec_node *) &main_sig->body, false,
+ linked);
+
+ for (unsigned i = 0; i < num_shaders; i++) {
+ if (shader_list[i] == main)
+ continue;
+
+ insertion_point = move_non_declarations(shader_list[i]->ir,
+ insertion_point, true, linked);
+ }
+
+ /* Resolve initializers for global variables in the linked shader.
+ */
+ unsigned num_linking_shaders = num_shaders;
+ for (unsigned i = 0; i < num_shaders; i++)
+ num_linking_shaders += shader_list[i]->num_builtins_to_link;
+
+ gl_shader **linking_shaders =
+ (gl_shader **) calloc(num_linking_shaders, sizeof(gl_shader *));
+
+ memcpy(linking_shaders, shader_list,
+ sizeof(linking_shaders[0]) * num_shaders);
+
+ unsigned idx = num_shaders;
+ for (unsigned i = 0; i < num_shaders; i++) {
+ memcpy(&linking_shaders[idx], shader_list[i]->builtins_to_link,
+ sizeof(linking_shaders[0]) * shader_list[i]->num_builtins_to_link);
+ idx += shader_list[i]->num_builtins_to_link;
+ }
+
+ assert(idx == num_linking_shaders);
+
+ if (!link_function_calls(prog, linked, linking_shaders,
+ num_linking_shaders)) {
+ ctx->Driver.DeleteShader(ctx, linked);
+ linked = NULL;
+ }
+
+ free(linking_shaders);
+
+#ifdef DEBUG
+ /* At this point linked should contain all of the linked IR, so
+ * validate it to make sure nothing went wrong.
+ */
+ if (linked)
+ validate_ir_tree(linked->ir);
+#endif
+
+ /* Make a pass over all variable declarations to ensure that arrays with
+ * unspecified sizes have a size specified. The size is inferred from the
+ * max_array_access field.
+ */
+ if (linked != NULL) {
+ class array_sizing_visitor : public ir_hierarchical_visitor {
+ public:
+ virtual ir_visitor_status visit(ir_variable *var)
+ {
+ if (var->type->is_array() && (var->type->length == 0)) {
+ const glsl_type *type =
+ glsl_type::get_array_instance(var->type->fields.array,
+ var->max_array_access + 1);
+
+ assert(type != NULL);
+ var->type = type;
+ }
+
+ return visit_continue;
+ }
+ } v;
+
+ v.run(linked->ir);
+ }
+
+ return linked;
+}
+
+
+struct uniform_node {
+ exec_node link;
+ struct gl_uniform *u;
+ unsigned slots;
+};
+
+/**
+ * Update the sizes of linked shader uniform arrays to the maximum
+ * array index used.
+ *
+ * From page 81 (page 95 of the PDF) of the OpenGL 2.1 spec:
+ *
+ * If one or more elements of an array are active,
+ * GetActiveUniform will return the name of the array in name,
+ * subject to the restrictions listed above. The type of the array
+ * is returned in type. The size parameter contains the highest
+ * array element index used, plus one. The compiler or linker
+ * determines the highest index used. There will be only one
+ * active uniform reported by the GL per uniform array.
+
+ */
+static void
+update_array_sizes(struct gl_shader_program *prog)
+{
+ for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ foreach_list(node, prog->_LinkedShaders[i]->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != ir_var_uniform &&
+ var->mode != ir_var_in &&
+ var->mode != ir_var_out) ||
+ !var->type->is_array())
+ continue;
+
+ unsigned int size = var->max_array_access;
+ for (unsigned j = 0; j < MESA_SHADER_TYPES; j++) {
+ if (prog->_LinkedShaders[j] == NULL)
+ continue;
+
+ foreach_list(node2, prog->_LinkedShaders[j]->ir) {
+ ir_variable *other_var = ((ir_instruction *) node2)->as_variable();
+ if (!other_var)
+ continue;
+
+ if (strcmp(var->name, other_var->name) == 0 &&
+ other_var->max_array_access > size) {
+ size = other_var->max_array_access;
+ }
+ }
+ }
+
+ if (size + 1 != var->type->fields.array->length) {
+ /* If this is a built-in uniform (i.e., it's backed by some
+ * fixed-function state), adjust the number of state slots to
+ * match the new array size. The number of slots per array entry
+ * is not known. It seems safe to assume that the total number of
+ * slots is an integer multiple of the number of array elements.
+ * Determine the number of slots per array element by dividing by
+ * the old (total) size.
+ */
+ if (var->num_state_slots > 0) {
+ var->num_state_slots = (size + 1)
+ * (var->num_state_slots / var->type->length);
+ }
+
+ var->type = glsl_type::get_array_instance(var->type->fields.array,
+ size + 1);
+ /* FINISHME: We should update the types of array
+ * dereferences of this variable now.
+ */
+ }
+ }
+ }
+}
+
+static void
+add_uniform(void *mem_ctx, exec_list *uniforms, struct hash_table *ht,
+ const char *name, const glsl_type *type, GLenum shader_type,
+ unsigned *next_shader_pos, unsigned *total_uniforms)
+{
+ if (type->is_record()) {
+ for (unsigned int i = 0; i < type->length; i++) {
+ const glsl_type *field_type = type->fields.structure[i].type;
+ char *field_name = ralloc_asprintf(mem_ctx, "%s.%s", name,
+ type->fields.structure[i].name);
+
+ add_uniform(mem_ctx, uniforms, ht, field_name, field_type,
+ shader_type, next_shader_pos, total_uniforms);
+ }
+ } else {
+ uniform_node *n = (uniform_node *) hash_table_find(ht, name);
+ unsigned int vec4_slots;
+ const glsl_type *array_elem_type = NULL;
+
+ if (type->is_array()) {
+ array_elem_type = type->fields.array;
+ /* Array of structures. */
+ if (array_elem_type->is_record()) {
+ for (unsigned int i = 0; i < type->length; i++) {
+ char *elem_name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i);
+ add_uniform(mem_ctx, uniforms, ht, elem_name, array_elem_type,
+ shader_type, next_shader_pos, total_uniforms);
+ }
+ return;
+ }
+ }
+
+ /* Fix the storage size of samplers at 1 vec4 each. Be sure to pad out
+ * vectors to vec4 slots.
+ */
+ if (type->is_array()) {
+ if (array_elem_type->is_sampler())
+ vec4_slots = type->length;
+ else
+ vec4_slots = type->length * array_elem_type->matrix_columns;
+ } else if (type->is_sampler()) {
+ vec4_slots = 1;
+ } else {
+ vec4_slots = type->matrix_columns;
+ }
+
+ if (n == NULL) {
+ n = (uniform_node *) calloc(1, sizeof(struct uniform_node));
+ n->u = (gl_uniform *) calloc(1, sizeof(struct gl_uniform));
+ n->slots = vec4_slots;
+
+ n->u->Name = strdup(name);
+ n->u->Type = type;
+ n->u->VertPos = -1;
+ n->u->FragPos = -1;
+ n->u->GeomPos = -1;
+ (*total_uniforms)++;
+
+ hash_table_insert(ht, n, name);
+ uniforms->push_tail(& n->link);
+ }
+
+ switch (shader_type) {
+ case GL_VERTEX_SHADER:
+ n->u->VertPos = *next_shader_pos;
+ break;
+ case GL_FRAGMENT_SHADER:
+ n->u->FragPos = *next_shader_pos;
+ break;
+ case GL_GEOMETRY_SHADER:
+ n->u->GeomPos = *next_shader_pos;
+ break;
+ }
+
+ (*next_shader_pos) += vec4_slots;
+ }
+}
+
+void
+assign_uniform_locations(struct gl_shader_program *prog)
+{
+ /* */
+ exec_list uniforms;
+ unsigned total_uniforms = 0;
+ hash_table *ht = hash_table_ctor(32, hash_table_string_hash,
+ hash_table_string_compare);
+ void *mem_ctx = ralloc_context(NULL);
+
+ for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ unsigned next_position = 0;
+
+ foreach_list(node, prog->_LinkedShaders[i]->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != ir_var_uniform))
+ continue;
+
+ if (strncmp(var->name, "gl_", 3) == 0) {
+ /* At the moment, we don't allocate uniform locations for
+ * builtin uniforms. It's permitted by spec, and we'll
+ * likely switch to doing that at some point, but not yet.
+ */
+ continue;
+ }
+
+ var->location = next_position;
+ add_uniform(mem_ctx, &uniforms, ht, var->name, var->type,
+ prog->_LinkedShaders[i]->Type,
+ &next_position, &total_uniforms);
+ }
+ }
+
+ ralloc_free(mem_ctx);
+
+ gl_uniform_list *ul = (gl_uniform_list *)
+ calloc(1, sizeof(gl_uniform_list));
+
+ ul->Size = total_uniforms;
+ ul->NumUniforms = total_uniforms;
+ ul->Uniforms = (gl_uniform *) calloc(total_uniforms, sizeof(gl_uniform));
+
+ unsigned idx = 0;
+ uniform_node *next;
+ for (uniform_node *node = (uniform_node *) uniforms.head
+ ; node->link.next != NULL
+ ; node = next) {
+ next = (uniform_node *) node->link.next;
+
+ node->link.remove();
+ memcpy(&ul->Uniforms[idx], node->u, sizeof(gl_uniform));
+ idx++;
+
+ free(node->u);
+ free(node);
+ }
+
+ hash_table_dtor(ht);
+
+ prog->Uniforms = ul;
+}
+
+
+/**
+ * Find a contiguous set of available bits in a bitmask.
+ *
+ * \param used_mask Bits representing used (1) and unused (0) locations
+ * \param needed_count Number of contiguous bits needed.
+ *
+ * \return
+ * Base location of the available bits on success or -1 on failure.
+ */
+int
+find_available_slots(unsigned used_mask, unsigned needed_count)
+{
+ unsigned needed_mask = (1 << needed_count) - 1;
+ const int max_bit_to_test = (8 * sizeof(used_mask)) - needed_count;
+
+ /* The comparison to 32 is redundant, but without it GCC emits "warning:
+ * cannot optimize possibly infinite loops" for the loop below.
+ */
+ if ((needed_count == 0) || (max_bit_to_test < 0) || (max_bit_to_test > 32))
+ return -1;
+
+ for (int i = 0; i <= max_bit_to_test; i++) {
+ if ((needed_mask & ~used_mask) == needed_mask)
+ return i;
+
+ needed_mask <<= 1;
+ }
+
+ return -1;
+}
+
+
+/**
+ * Assign locations for either VS inputs for FS outputs
+ *
+ * \param prog Shader program whose variables need locations assigned
+ * \param target_index Selector for the program target to receive location
+ * assignmnets. Must be either \c MESA_SHADER_VERTEX or
+ * \c MESA_SHADER_FRAGMENT.
+ * \param max_index Maximum number of generic locations. This corresponds
+ * to either the maximum number of draw buffers or the
+ * maximum number of generic attributes.
+ *
+ * \return
+ * If locations are successfully assigned, true is returned. Otherwise an
+ * error is emitted to the shader link log and false is returned.
+ *
+ * \bug
+ * Locations set via \c glBindFragDataLocation are not currently supported.
+ * Only locations assigned automatically by the linker, explicitly set by a
+ * layout qualifier, or explicitly set by a built-in variable (e.g., \c
+ * gl_FragColor) are supported for fragment shaders.
+ */
+bool
+assign_attribute_or_color_locations(gl_shader_program *prog,
+ unsigned target_index,
+ unsigned max_index)
+{
+ /* Mark invalid locations as being used.
+ */
+ unsigned used_locations = (max_index >= 32)
+ ? ~0 : ~((1 << max_index) - 1);
+
+ assert((target_index == MESA_SHADER_VERTEX)
+ || (target_index == MESA_SHADER_FRAGMENT));
+
+ gl_shader *const sh = prog->_LinkedShaders[target_index];
+ if (sh == NULL)
+ return true;
+
+ /* Operate in a total of four passes.
+ *
+ * 1. Invalidate the location assignments for all vertex shader inputs.
+ *
+ * 2. Assign locations for inputs that have user-defined (via
+ * glBindVertexAttribLocation) locations.
+ *
+ * 3. Sort the attributes without assigned locations by number of slots
+ * required in decreasing order. Fragmentation caused by attribute
+ * locations assigned by the application may prevent large attributes
+ * from having enough contiguous space.
+ *
+ * 4. Assign locations to any inputs without assigned locations.
+ */
+
+ const int generic_base = (target_index == MESA_SHADER_VERTEX)
+ ? (int) VERT_ATTRIB_GENERIC0 : (int) FRAG_RESULT_DATA0;
+
+ const enum ir_variable_mode direction =
+ (target_index == MESA_SHADER_VERTEX) ? ir_var_in : ir_var_out;
+
+
+ invalidate_variable_locations(sh, direction, generic_base);
+
+ if ((target_index == MESA_SHADER_VERTEX) && (prog->Attributes != NULL)) {
+ for (unsigned i = 0; i < prog->Attributes->NumParameters; i++) {
+ ir_variable *const var =
+ sh->symbols->get_variable(prog->Attributes->Parameters[i].Name);
+
+ /* Note: attributes that occupy multiple slots, such as arrays or
+ * matrices, may appear in the attrib array multiple times.
+ */
+ if ((var == NULL) || (var->location != -1))
+ continue;
+
+ /* From page 61 of the OpenGL 4.0 spec:
+ *
+ * "LinkProgram will fail if the attribute bindings assigned by
+ * BindAttribLocation do not leave not enough space to assign a
+ * location for an active matrix attribute or an active attribute
+ * array, both of which require multiple contiguous generic
+ * attributes."
+ *
+ * Previous versions of the spec contain similar language but omit the
+ * bit about attribute arrays.
+ *
+ * Page 61 of the OpenGL 4.0 spec also says:
+ *
+ * "It is possible for an application to bind more than one
+ * attribute name to the same location. This is referred to as
+ * aliasing. This will only work if only one of the aliased
+ * attributes is active in the executable program, or if no path
+ * through the shader consumes more than one attribute of a set
+ * of attributes aliased to the same location. A link error can
+ * occur if the linker determines that every path through the
+ * shader consumes multiple aliased attributes, but
+ * implementations are not required to generate an error in this
+ * case."
+ *
+ * These two paragraphs are either somewhat contradictory, or I don't
+ * fully understand one or both of them.
+ */
+ /* FINISHME: The code as currently written does not support attribute
+ * FINISHME: location aliasing (see comment above).
+ */
+ const int attr = prog->Attributes->Parameters[i].StateIndexes[0];
+ const unsigned slots = count_attribute_slots(var->type);
+
+ /* Mask representing the contiguous slots that will be used by this
+ * attribute.
+ */
+ const unsigned use_mask = (1 << slots) - 1;
+
+ /* Generate a link error if the set of bits requested for this
+ * attribute overlaps any previously allocated bits.
+ */
+ if ((~(use_mask << attr) & used_locations) != used_locations) {
+ linker_error(prog,
+ "insufficient contiguous attribute locations "
+ "available for vertex shader input `%s'",
+ var->name);
+ return false;
+ }
+
+ var->location = VERT_ATTRIB_GENERIC0 + attr;
+ used_locations |= (use_mask << attr);
+ }
+ }
+
+ /* Temporary storage for the set of attributes that need locations assigned.
+ */
+ struct temp_attr {
+ unsigned slots;
+ ir_variable *var;
+
+ /* Used below in the call to qsort. */
+ static int compare(const void *a, const void *b)
+ {
+ const temp_attr *const l = (const temp_attr *) a;
+ const temp_attr *const r = (const temp_attr *) b;
+
+ /* Reversed because we want a descending order sort below. */
+ return r->slots - l->slots;
+ }
+ } to_assign[16];
+
+ unsigned num_attr = 0;
+
+ foreach_list(node, sh->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != (unsigned) direction))
+ continue;
+
+ if (var->explicit_location) {
+ const unsigned slots = count_attribute_slots(var->type);
+ const unsigned use_mask = (1 << slots) - 1;
+ const int attr = var->location - generic_base;
+
+ if ((var->location >= (int)(max_index + generic_base))
+ || (var->location < 0)) {
+ linker_error(prog,
+ "invalid explicit location %d specified for `%s'\n",
+ (var->location < 0) ? var->location : attr,
+ var->name);
+ return false;
+ } else if (var->location >= generic_base) {
+ used_locations |= (use_mask << attr);
+ }
+ }
+
+ /* The location was explicitly assigned, nothing to do here.
+ */
+ if (var->location != -1)
+ continue;
+
+ to_assign[num_attr].slots = count_attribute_slots(var->type);
+ to_assign[num_attr].var = var;
+ num_attr++;
+ }
+
+ /* If all of the attributes were assigned locations by the application (or
+ * are built-in attributes with fixed locations), return early. This should
+ * be the common case.
+ */
+ if (num_attr == 0)
+ return true;
+
+ qsort(to_assign, num_attr, sizeof(to_assign[0]), temp_attr::compare);
+
+ if (target_index == MESA_SHADER_VERTEX) {
+ /* VERT_ATTRIB_GENERIC0 is a pseudo-alias for VERT_ATTRIB_POS. It can
+ * only be explicitly assigned by via glBindAttribLocation. Mark it as
+ * reserved to prevent it from being automatically allocated below.
+ */
+ find_deref_visitor find("gl_Vertex");
+ find.run(sh->ir);
+ if (find.variable_found())
+ used_locations |= (1 << 0);
+ }
+
+ for (unsigned i = 0; i < num_attr; i++) {
+ /* Mask representing the contiguous slots that will be used by this
+ * attribute.
+ */
+ const unsigned use_mask = (1 << to_assign[i].slots) - 1;
+
+ int location = find_available_slots(used_locations, to_assign[i].slots);
+
+ if (location < 0) {
+ const char *const string = (target_index == MESA_SHADER_VERTEX)
+ ? "vertex shader input" : "fragment shader output";
+
+ linker_error(prog,
+ "insufficient contiguous attribute locations "
+ "available for %s `%s'",
+ string, to_assign[i].var->name);
+ return false;
+ }
+
+ to_assign[i].var->location = generic_base + location;
+ used_locations |= (use_mask << location);
+ }
+
+ return true;
+}
+
+
+/**
+ * Demote shader inputs and outputs that are not used in other stages
+ */
+void
+demote_shader_inputs_and_outputs(gl_shader *sh, enum ir_variable_mode mode)
+{
+ foreach_list(node, sh->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != int(mode)))
+ continue;
+
+ /* A shader 'in' or 'out' variable is only really an input or output if
+ * its value is used by other shader stages. This will cause the variable
+ * to have a location assigned.
+ */
+ if (var->location == -1) {
+ var->mode = ir_var_auto;
+ }
+ }
+}
+
+
+bool
+assign_varying_locations(struct gl_context *ctx,
+ struct gl_shader_program *prog,
+ gl_shader *producer, gl_shader *consumer)
+{
+ /* FINISHME: Set dynamically when geometry shader support is added. */
+ unsigned output_index = VERT_RESULT_VAR0;
+ unsigned input_index = FRAG_ATTRIB_VAR0;
+
+ /* Operate in a total of three passes.
+ *
+ * 1. Assign locations for any matching inputs and outputs.
+ *
+ * 2. Mark output variables in the producer that do not have locations as
+ * not being outputs. This lets the optimizer eliminate them.
+ *
+ * 3. Mark input variables in the consumer that do not have locations as
+ * not being inputs. This lets the optimizer eliminate them.
+ */
+
+ invalidate_variable_locations(producer, ir_var_out, VERT_RESULT_VAR0);
+ invalidate_variable_locations(consumer, ir_var_in, FRAG_ATTRIB_VAR0);
+
+ foreach_list(node, producer->ir) {
+ ir_variable *const output_var = ((ir_instruction *) node)->as_variable();
+
+ if ((output_var == NULL) || (output_var->mode != ir_var_out)
+ || (output_var->location != -1))
+ continue;
+
+ ir_variable *const input_var =
+ consumer->symbols->get_variable(output_var->name);
+
+ if ((input_var == NULL) || (input_var->mode != ir_var_in))
+ continue;
+
+ assert(input_var->location == -1);
+
+ output_var->location = output_index;
+ input_var->location = input_index;
+
+ /* FINISHME: Support for "varying" records in GLSL 1.50. */
+ assert(!output_var->type->is_record());
+
+ if (output_var->type->is_array()) {
+ const unsigned slots = output_var->type->length
+ * output_var->type->fields.array->matrix_columns;
+
+ output_index += slots;
+ input_index += slots;
+ } else {
+ const unsigned slots = output_var->type->matrix_columns;
+
+ output_index += slots;
+ input_index += slots;
+ }
+ }
+
+ unsigned varying_vectors = 0;
+
+ foreach_list(node, consumer->ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if ((var == NULL) || (var->mode != ir_var_in))
+ continue;
+
+ if (var->location == -1) {
+ if (prog->Version <= 120) {
+ /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
+ *
+ * Only those varying variables used (i.e. read) in
+ * the fragment shader executable must be written to
+ * by the vertex shader executable; declaring
+ * superfluous varying variables in a vertex shader is
+ * permissible.
+ *
+ * We interpret this text as meaning that the VS must
+ * write the variable for the FS to read it. See
+ * "glsl1-varying read but not written" in piglit.
+ */
+
+ linker_error(prog, "fragment shader varying %s not written "
+ "by vertex shader\n.", var->name);
+ }
+
+ /* An 'in' variable is only really a shader input if its
+ * value is written by the previous stage.
+ */
+ var->mode = ir_var_auto;
+ } else {
+ /* The packing rules are used for vertex shader inputs are also used
+ * for fragment shader inputs.
+ */
+ varying_vectors += count_attribute_slots(var->type);
+ }
+ }
+
+ if (ctx->API == API_OPENGLES2 || prog->Version == 100) {
+ if (varying_vectors > ctx->Const.MaxVarying) {
+ linker_error(prog, "shader uses too many varying vectors "
+ "(%u > %u)\n",
+ varying_vectors, ctx->Const.MaxVarying);
+ return false;
+ }
+ } else {
+ const unsigned float_components = varying_vectors * 4;
+ if (float_components > ctx->Const.MaxVarying * 4) {
+ linker_error(prog, "shader uses too many varying components "
+ "(%u > %u)\n",
+ float_components, ctx->Const.MaxVarying * 4);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+
+void
+link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+ void *mem_ctx = ralloc_context(NULL); // temporary linker context
+
+ prog->LinkStatus = false;
+ prog->Validated = false;
+ prog->_Used = false;
+
+ if (prog->InfoLog != NULL)
+ ralloc_free(prog->InfoLog);
+
+ prog->InfoLog = ralloc_strdup(NULL, "");
+
+ /* Separate the shaders into groups based on their type.
+ */
+ struct gl_shader **vert_shader_list;
+ unsigned num_vert_shaders = 0;
+ struct gl_shader **frag_shader_list;
+ unsigned num_frag_shaders = 0;
+
+ vert_shader_list = (struct gl_shader **)
+ calloc(2 * prog->NumShaders, sizeof(struct gl_shader *));
+ frag_shader_list = &vert_shader_list[prog->NumShaders];
+
+ unsigned min_version = UINT_MAX;
+ unsigned max_version = 0;
+ for (unsigned i = 0; i < prog->NumShaders; i++) {
+ min_version = MIN2(min_version, prog->Shaders[i]->Version);
+ max_version = MAX2(max_version, prog->Shaders[i]->Version);
+
+ switch (prog->Shaders[i]->Type) {
+ case GL_VERTEX_SHADER:
+ vert_shader_list[num_vert_shaders] = prog->Shaders[i];
+ num_vert_shaders++;
+ break;
+ case GL_FRAGMENT_SHADER:
+ frag_shader_list[num_frag_shaders] = prog->Shaders[i];
+ num_frag_shaders++;
+ break;
+ case GL_GEOMETRY_SHADER:
+ /* FINISHME: Support geometry shaders. */
+ assert(prog->Shaders[i]->Type != GL_GEOMETRY_SHADER);
+ break;
+ }
+ }
+
+ /* Previous to GLSL version 1.30, different compilation units could mix and
+ * match shading language versions. With GLSL 1.30 and later, the versions
+ * of all shaders must match.
+ */
+ assert(min_version >= 100);
+ assert(max_version <= 130);
+ if ((max_version >= 130 || min_version == 100)
+ && min_version != max_version) {
+ linker_error(prog, "all shaders must use same shading "
+ "language version\n");
+ goto done;
+ }
+
+ prog->Version = max_version;
+
+ for (unsigned int i = 0; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] != NULL)
+ ctx->Driver.DeleteShader(ctx, prog->_LinkedShaders[i]);
+
+ prog->_LinkedShaders[i] = NULL;
+ }
+
+ /* Link all shaders for a particular stage and validate the result.
+ */
+ if (num_vert_shaders > 0) {
+ gl_shader *const sh =
+ link_intrastage_shaders(mem_ctx, ctx, prog, vert_shader_list,
+ num_vert_shaders);
+
+ if (sh == NULL)
+ goto done;
+
+ if (!validate_vertex_shader_executable(prog, sh))
+ goto done;
+
+ _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_VERTEX],
+ sh);
+ }
+
+ if (num_frag_shaders > 0) {
+ gl_shader *const sh =
+ link_intrastage_shaders(mem_ctx, ctx, prog, frag_shader_list,
+ num_frag_shaders);
+
+ if (sh == NULL)
+ goto done;
+
+ if (!validate_fragment_shader_executable(prog, sh))
+ goto done;
+
+ _mesa_reference_shader(ctx, &prog->_LinkedShaders[MESA_SHADER_FRAGMENT],
+ sh);
+ }
+
+ /* Here begins the inter-stage linking phase. Some initial validation is
+ * performed, then locations are assigned for uniforms, attributes, and
+ * varyings.
+ */
+ if (cross_validate_uniforms(prog)) {
+ unsigned prev;
+
+ for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
+ if (prog->_LinkedShaders[prev] != NULL)
+ break;
+ }
+
+ /* Validate the inputs of each stage with the output of the preceding
+ * stage.
+ */
+ for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ if (!cross_validate_outputs_to_inputs(prog,
+ prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]))
+ goto done;
+
+ prev = i;
+ }
+
+ prog->LinkStatus = true;
+ }
+
+ /* Do common optimization before assigning storage for attributes,
+ * uniforms, and varyings. Later optimization could possibly make
+ * some of that unused.
+ */
+ for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ detect_recursion_linked(prog, prog->_LinkedShaders[i]->ir);
+ if (!prog->LinkStatus)
+ goto done;
+
+ while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, 32))
+ ;
+ }
+
+ update_array_sizes(prog);
+
+ assign_uniform_locations(prog);
+
+ /* FINISHME: The value of the max_attribute_index parameter is
+ * FINISHME: implementation dependent based on the value of
+ * FINISHME: GL_MAX_VERTEX_ATTRIBS. GL_MAX_VERTEX_ATTRIBS must be
+ * FINISHME: at least 16, so hardcode 16 for now.
+ */
+ if (!assign_attribute_or_color_locations(prog, MESA_SHADER_VERTEX, 16)) {
+ goto done;
+ }
+
+ if (!assign_attribute_or_color_locations(prog, MESA_SHADER_FRAGMENT, ctx->Const.MaxDrawBuffers)) {
+ goto done;
+ }
+
+ unsigned prev;
+ for (prev = 0; prev < MESA_SHADER_TYPES; prev++) {
+ if (prog->_LinkedShaders[prev] != NULL)
+ break;
+ }
+
+ for (unsigned i = prev + 1; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ if (!assign_varying_locations(ctx, prog,
+ prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i])) {
+ goto done;
+ }
+
+ prev = i;
+ }
+
+ if (prog->_LinkedShaders[MESA_SHADER_VERTEX] != NULL) {
+ demote_shader_inputs_and_outputs(prog->_LinkedShaders[MESA_SHADER_VERTEX],
+ ir_var_out);
+ }
+
+ if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) {
+ gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
+
+ demote_shader_inputs_and_outputs(sh, ir_var_in);
+ demote_shader_inputs_and_outputs(sh, ir_var_inout);
+ demote_shader_inputs_and_outputs(sh, ir_var_out);
+ }
+
+ if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] != NULL) {
+ gl_shader *const sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
+
+ demote_shader_inputs_and_outputs(sh, ir_var_in);
+ }
+
+ /* OpenGL ES requires that a vertex shader and a fragment shader both be
+ * present in a linked program. By checking for use of shading language
+ * version 1.00, we also catch the GL_ARB_ES2_compatibility case.
+ */
+ if (ctx->API == API_OPENGLES2 || prog->Version == 100) {
+ if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) {
+ linker_error(prog, "program lacks a vertex shader\n");
+ } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
+ linker_error(prog, "program lacks a fragment shader\n");
+ }
+ }
+
+ /* FINISHME: Assign fragment shader output locations. */
+
+done:
+ free(vert_shader_list);
+
+ for (unsigned i = 0; i < MESA_SHADER_TYPES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ /* Retain any live IR, but trash the rest. */
+ reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir);
+ }
+
+ ralloc_free(mem_ctx);
+}
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