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-rw-r--r--mesalib/src/glsl/linker.cpp3608
1 files changed, 1804 insertions, 1804 deletions
diff --git a/mesalib/src/glsl/linker.cpp b/mesalib/src/glsl/linker.cpp
index 19eb9b5ff..cb4083b29 100644
--- a/mesalib/src/glsl/linker.cpp
+++ b/mesalib/src/glsl/linker.cpp
@@ -1,1804 +1,1804 @@
-/*
- * 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);
-
- /* 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);
+
+ /* 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);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 02:52:23 +0000