compiler: Bring over glsl compiler from alchemist-10.2.6+steamos-LunarG-1.1
diff --git a/icd/intel/compiler/shader/linker.cpp b/icd/intel/compiler/shader/linker.cpp
new file mode 100644
index 0000000..c448847
--- /dev/null
+++ b/icd/intel/compiler/shader/linker.cpp
@@ -0,0 +1,2644 @@
+/*
+ * 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 "glsl_parser_extras.h"
+#include "ir.h"
+#include "program.h"
+#include "program/hash_table.h"
+#include "linker.h"
+#include "link_varyings.h"
+#include "ir_optimization.h"
+#include "ir_rvalue_visitor.h"
+
+extern "C" {
+#include "main/shaderobj.h"
+#include "main/enums.h"
+}
+
+void linker_error(gl_shader_program *, const char *, ...);
+
+namespace {
+
+/**
+ * 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)
+ {
+ foreach_two_lists(formal_node, &ir->callee->parameters,
+ actual_node, &ir->actual_parameters) {
+ ir_rvalue *param_rval = (ir_rvalue *) actual_node;
+ ir_variable *sig_param = (ir_variable *) formal_node;
+
+ if (sig_param->data.mode == ir_var_function_out ||
+ sig_param->data.mode == ir_var_function_inout) {
+ ir_variable *var = param_rval->variable_referenced();
+ if (var && strcmp(name, var->name) == 0) {
+ found = true;
+ return visit_stop;
+ }
+ }
+ }
+
+ if (ir->return_deref != NULL) {
+ ir_variable *const var = ir->return_deref->variable_referenced();
+
+ if (strcmp(name, var->name) == 0) {
+ found = true;
+ return visit_stop;
+ }
+ }
+
+ 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? */
+};
+
+
+class geom_array_resize_visitor : public ir_hierarchical_visitor {
+public:
+ unsigned num_vertices;
+ gl_shader_program *prog;
+
+ geom_array_resize_visitor(unsigned num_vertices, gl_shader_program *prog)
+ {
+ this->num_vertices = num_vertices;
+ this->prog = prog;
+ }
+
+ virtual ~geom_array_resize_visitor()
+ {
+ /* empty */
+ }
+
+ virtual ir_visitor_status visit(ir_variable *var)
+ {
+ if (!var->type->is_array() || var->data.mode != ir_var_shader_in)
+ return visit_continue;
+
+ unsigned size = var->type->length;
+
+ /* Generate a link error if the shader has declared this array with an
+ * incorrect size.
+ */
+ if (size && size != this->num_vertices) {
+ linker_error(this->prog, "size of array %s declared as %u, "
+ "but number of input vertices is %u\n",
+ var->name, size, this->num_vertices);
+ return visit_continue;
+ }
+
+ /* Generate a link error if the shader attempts to access an input
+ * array using an index too large for its actual size assigned at link
+ * time.
+ */
+ if (var->data.max_array_access >= this->num_vertices) {
+ linker_error(this->prog, "geometry shader accesses element %i of "
+ "%s, but only %i input vertices\n",
+ var->data.max_array_access, var->name, this->num_vertices);
+ return visit_continue;
+ }
+
+ var->type = glsl_type::get_array_instance(var->type->element_type(),
+ this->num_vertices);
+ var->data.max_array_access = this->num_vertices - 1;
+
+ return visit_continue;
+ }
+
+ /* Dereferences of input variables need to be updated so that their type
+ * matches the newly assigned type of the variable they are accessing. */
+ virtual ir_visitor_status visit(ir_dereference_variable *ir)
+ {
+ ir->type = ir->var->type;
+ return visit_continue;
+ }
+
+ /* Dereferences of 2D input arrays need to be updated so that their type
+ * matches the newly assigned type of the array they are accessing. */
+ virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
+ {
+ const glsl_type *const vt = ir->array->type;
+ if (vt->is_array())
+ ir->type = vt->element_type();
+ return visit_continue;
+ }
+};
+
+
+/**
+ * Visitor that determines whether or not a shader uses ir_end_primitive.
+ */
+class find_end_primitive_visitor : public ir_hierarchical_visitor {
+public:
+ find_end_primitive_visitor()
+ : found(false)
+ {
+ /* empty */
+ }
+
+ virtual ir_visitor_status visit(ir_end_primitive *)
+ {
+ found = true;
+ return visit_stop;
+ }
+
+ bool end_primitive_found()
+ {
+ return found;
+ }
+
+private:
+ bool found;
+};
+
+} /* anonymous namespace */
+
+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, "warning: ");
+ va_start(ap, fmt);
+ ralloc_vasprintf_append(&prog->InfoLog, fmt, ap);
+ va_end(ap);
+
+}
+
+
+/**
+ * Given a string identifying a program resource, break it into a base name
+ * and an optional array index in square brackets.
+ *
+ * If an array index is present, \c out_base_name_end is set to point to the
+ * "[" that precedes the array index, and the array index itself is returned
+ * as a long.
+ *
+ * If no array index is present (or if the array index is negative or
+ * mal-formed), \c out_base_name_end, is set to point to the null terminator
+ * at the end of the input string, and -1 is returned.
+ *
+ * Only the final array index is parsed; if the string contains other array
+ * indices (or structure field accesses), they are left in the base name.
+ *
+ * No attempt is made to check that the base name is properly formed;
+ * typically the caller will look up the base name in a hash table, so
+ * ill-formed base names simply turn into hash table lookup failures.
+ */
+long
+parse_program_resource_name(const GLchar *name,
+ const GLchar **out_base_name_end)
+{
+ /* Section 7.3.1 ("Program Interfaces") of the OpenGL 4.3 spec says:
+ *
+ * "When an integer array element or block instance number is part of
+ * the name string, it will be specified in decimal form without a "+"
+ * or "-" sign or any extra leading zeroes. Additionally, the name
+ * string will not include white space anywhere in the string."
+ */
+
+ const size_t len = strlen(name);
+ *out_base_name_end = name + len;
+
+ if (len == 0 || name[len-1] != ']')
+ return -1;
+
+ /* Walk backwards over the string looking for a non-digit character. This
+ * had better be the opening bracket for an array index.
+ *
+ * Initially, i specifies the location of the ']'. Since the string may
+ * contain only the ']' charcater, walk backwards very carefully.
+ */
+ unsigned i;
+ for (i = len - 1; (i > 0) && isdigit(name[i-1]); --i)
+ /* empty */ ;
+
+ if ((i == 0) || name[i-1] != '[')
+ return -1;
+
+ long array_index = strtol(&name[i], NULL, 10);
+ if (array_index < 0)
+ return -1;
+
+ *out_base_name_end = name + (i - 1);
+ return array_index;
+}
+
+
+void
+link_invalidate_variable_locations(exec_list *ir)
+{
+ foreach_list(node, ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if (var == NULL)
+ continue;
+
+ /* Only assign locations for variables that lack an explicit location.
+ * Explicit locations are set for all built-in variables, generic vertex
+ * shader inputs (via layout(location=...)), and generic fragment shader
+ * outputs (also via layout(location=...)).
+ */
+ if (!var->data.explicit_location) {
+ var->data.location = -1;
+ var->data.location_frac = 0;
+ }
+
+ /* ir_variable::is_unmatched_generic_inout is used by the linker while
+ * connecting outputs from one stage to inputs of the next stage.
+ *
+ * There are two implicit assumptions here. First, we assume that any
+ * built-in variable (i.e., non-generic in or out) will have
+ * explicit_location set. Second, we assume that any generic in or out
+ * will not have explicit_location set.
+ *
+ * This second assumption will only be valid until
+ * GL_ARB_separate_shader_objects is supported. When that extension is
+ * implemented, this function will need some modifications.
+ */
+ if (!var->data.explicit_location) {
+ var->data.is_unmatched_generic_inout = 1;
+ } else {
+ var->data.is_unmatched_generic_inout = 0;
+ }
+ }
+}
+
+
+/**
+ * Set UsesClipDistance and ClipDistanceArraySize based on the given shader.
+ *
+ * Also check for errors based on incorrect usage of gl_ClipVertex and
+ * gl_ClipDistance.
+ *
+ * Return false if an error was reported.
+ */
+static void
+analyze_clip_usage(struct gl_shader_program *prog,
+ struct gl_shader *shader, GLboolean *UsesClipDistance,
+ GLuint *ClipDistanceArraySize)
+{
+ *ClipDistanceArraySize = 0;
+
+ if (!prog->IsES && prog->Version >= 130) {
+ /* From section 7.1 (Vertex Shader Special Variables) of the
+ * GLSL 1.30 spec:
+ *
+ * "It is an error for a shader to statically write both
+ * gl_ClipVertex and gl_ClipDistance."
+ *
+ * This does not apply to GLSL ES shaders, since GLSL ES defines neither
+ * gl_ClipVertex nor gl_ClipDistance.
+ */
+ find_assignment_visitor clip_vertex("gl_ClipVertex");
+ find_assignment_visitor clip_distance("gl_ClipDistance");
+
+ clip_vertex.run(shader->ir);
+ clip_distance.run(shader->ir);
+ if (clip_vertex.variable_found() && clip_distance.variable_found()) {
+ linker_error(prog, "%s shader writes to both `gl_ClipVertex' "
+ "and `gl_ClipDistance'\n",
+ _mesa_shader_stage_to_string(shader->Stage));
+ return;
+ }
+ *UsesClipDistance = clip_distance.variable_found();
+ ir_variable *clip_distance_var =
+ shader->symbols->get_variable("gl_ClipDistance");
+ if (clip_distance_var)
+ *ClipDistanceArraySize = clip_distance_var->type->length;
+ } else {
+ *UsesClipDistance = false;
+ }
+}
+
+
+/**
+ * Verify that a vertex shader executable meets all semantic requirements.
+ *
+ * Also sets prog->Vert.UsesClipDistance and prog->Vert.ClipDistanceArraySize
+ * as a side effect.
+ *
+ * \param shader Vertex shader executable to be verified
+ */
+void
+validate_vertex_shader_executable(struct gl_shader_program *prog,
+ struct gl_shader *shader)
+{
+ if (shader == NULL)
+ return;
+
+ /* From the GLSL 1.10 spec, page 48:
+ *
+ * "The variable gl_Position is available only in the vertex
+ * language and is intended for writing the homogeneous vertex
+ * position. All executions of a well-formed vertex shader
+ * executable must write a value into this variable. [...] The
+ * variable gl_Position is available only in the vertex
+ * language and is intended for writing the homogeneous vertex
+ * position. All executions of a well-formed vertex shader
+ * executable must write a value into this variable."
+ *
+ * while in GLSL 1.40 this text is changed to:
+ *
+ * "The variable gl_Position is available only in the vertex
+ * language and is intended for writing the homogeneous vertex
+ * position. It can be written at any time during shader
+ * execution. It may also be read back by a vertex shader
+ * after being written. This value will be used by primitive
+ * assembly, clipping, culling, and other fixed functionality
+ * operations, if present, that operate on primitives after
+ * vertex processing has occurred. Its value is undefined if
+ * the vertex shader executable does not write gl_Position."
+ *
+ * GLSL ES 3.00 is similar to GLSL 1.40--failing to write to gl_Position is
+ * not an error.
+ */
+ if (prog->Version < (prog->IsES ? 300 : 140)) {
+ 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;
+ }
+ }
+
+ analyze_clip_usage(prog, shader, &prog->Vert.UsesClipDistance,
+ &prog->Vert.ClipDistanceArraySize);
+}
+
+
+/**
+ * Verify that a fragment shader executable meets all semantic requirements
+ *
+ * \param shader Fragment shader executable to be verified
+ */
+void
+validate_fragment_shader_executable(struct gl_shader_program *prog,
+ struct gl_shader *shader)
+{
+ if (shader == NULL)
+ return;
+
+ 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");
+ }
+}
+
+/**
+ * Verify that a geometry shader executable meets all semantic requirements
+ *
+ * Also sets prog->Geom.VerticesIn, prog->Geom.UsesClipDistance, and
+ * prog->Geom.ClipDistanceArraySize as a side effect.
+ *
+ * \param shader Geometry shader executable to be verified
+ */
+void
+validate_geometry_shader_executable(struct gl_shader_program *prog,
+ struct gl_shader *shader)
+{
+ if (shader == NULL)
+ return;
+
+ unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
+ prog->Geom.VerticesIn = num_vertices;
+
+ analyze_clip_usage(prog, shader, &prog->Geom.UsesClipDistance,
+ &prog->Geom.ClipDistanceArraySize);
+
+ find_end_primitive_visitor end_primitive;
+ end_primitive.run(shader->ir);
+ prog->Geom.UsesEndPrimitive = end_primitive.end_primitive_found();
+}
+
+
+/**
+ * Perform validation of global variables used across multiple shaders
+ */
+void
+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->data.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->data.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 if (var->type->is_record()
+ && existing->type->is_record()
+ && existing->type->record_compare(var->type)) {
+ 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;
+ }
+ }
+
+ if (var->data.explicit_location) {
+ if (existing->data.explicit_location
+ && (var->data.location != existing->data.location)) {
+ linker_error(prog, "explicit locations for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return;
+ }
+
+ existing->data.location = var->data.location;
+ existing->data.explicit_location = true;
+ }
+
+ /* From the GLSL 4.20 specification:
+ * "A link error will result if two compilation units in a program
+ * specify different integer-constant bindings for the same
+ * opaque-uniform name. However, it is not an error to specify a
+ * binding on some but not all declarations for the same name"
+ */
+ if (var->data.explicit_binding) {
+ if (existing->data.explicit_binding &&
+ var->data.binding != existing->data.binding) {
+ linker_error(prog, "explicit bindings for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return;
+ }
+
+ existing->data.binding = var->data.binding;
+ existing->data.explicit_binding = true;
+ }
+
+ if (var->type->contains_atomic() &&
+ var->data.atomic.offset != existing->data.atomic.offset) {
+ linker_error(prog, "offset specifications for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return;
+ }
+
+ /* Validate layout qualifiers for gl_FragDepth.
+ *
+ * From the AMD/ARB_conservative_depth specs:
+ *
+ * "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->data.depth_layout != ir_depth_layout_none;
+ bool layout_differs =
+ var->data.depth_layout != existing->data.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->data.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");
+ }
+ }
+
+ /* Page 35 (page 41 of the PDF) of the GLSL 4.20 spec says:
+ *
+ * "If a shared global has multiple initializers, the
+ * initializers must all be constant expressions, and they
+ * must all have the same value. Otherwise, a link error will
+ * result. (A shared global having only one initializer does
+ * not require that initializer to be a constant expression.)"
+ *
+ * Previous to 4.20 the GLSL spec simply said that initializers
+ * must have the same value. In this case of non-constant
+ * initializers, this was impossible to determine. As a result,
+ * no vendor actually implemented that behavior. The 4.20
+ * behavior matches the implemented behavior of at least one other
+ * vendor, so we'll implement that for all GLSL versions.
+ */
+ if (var->constant_initializer != NULL) {
+ if (existing->constant_initializer != NULL) {
+ if (!var->constant_initializer->has_value(existing->constant_initializer)) {
+ linker_error(prog, "initializers for %s "
+ "`%s' have differing values\n",
+ mode_string(var), var->name);
+ return;
+ }
+ } 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_initializer =
+ var->constant_initializer->clone(ralloc_parent(existing),
+ NULL);
+ }
+ }
+
+ if (var->data.has_initializer) {
+ if (existing->data.has_initializer
+ && (var->constant_initializer == NULL
+ || existing->constant_initializer == NULL)) {
+ linker_error(prog,
+ "shared global variable `%s' has multiple "
+ "non-constant initializers.\n",
+ var->name);
+ return;
+ }
+
+ /* Some instance had an initializer, so keep track of that. In
+ * this location, all sorts of initializers (constant or
+ * otherwise) will propagate the existence to the variable
+ * stored in the symbol table.
+ */
+ existing->data.has_initializer = true;
+ }
+
+ if (existing->data.invariant != var->data.invariant) {
+ linker_error(prog, "declarations for %s `%s' have "
+ "mismatching invariant qualifiers\n",
+ mode_string(var), var->name);
+ return;
+ }
+ if (existing->data.centroid != var->data.centroid) {
+ linker_error(prog, "declarations for %s `%s' have "
+ "mismatching centroid qualifiers\n",
+ mode_string(var), var->name);
+ return;
+ }
+ if (existing->data.sample != var->data.sample) {
+ linker_error(prog, "declarations for %s `%s` have "
+ "mismatching sample qualifiers\n",
+ mode_string(var), var->name);
+ return;
+ }
+ } else
+ variables.add_variable(var);
+ }
+ }
+}
+
+
+/**
+ * Perform validation of uniforms used across multiple shader stages
+ */
+void
+cross_validate_uniforms(struct gl_shader_program *prog)
+{
+ cross_validate_globals(prog, prog->_LinkedShaders,
+ MESA_SHADER_STAGES, true);
+}
+
+/**
+ * Accumulates the array of prog->UniformBlocks and checks that all
+ * definitons of blocks agree on their contents.
+ */
+static bool
+interstage_cross_validate_uniform_blocks(struct gl_shader_program *prog)
+{
+ unsigned max_num_uniform_blocks = 0;
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ if (prog->_LinkedShaders[i])
+ max_num_uniform_blocks += prog->_LinkedShaders[i]->NumUniformBlocks;
+ }
+
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ struct gl_shader *sh = prog->_LinkedShaders[i];
+
+ prog->UniformBlockStageIndex[i] = ralloc_array(prog, int,
+ max_num_uniform_blocks);
+ for (unsigned int j = 0; j < max_num_uniform_blocks; j++)
+ prog->UniformBlockStageIndex[i][j] = -1;
+
+ if (sh == NULL)
+ continue;
+
+ for (unsigned int j = 0; j < sh->NumUniformBlocks; j++) {
+ int index = link_cross_validate_uniform_block(prog,
+ &prog->UniformBlocks,
+ &prog->NumUniformBlocks,
+ &sh->UniformBlocks[j]);
+
+ if (index == -1) {
+ linker_error(prog, "uniform block `%s' has mismatching definitions",
+ sh->UniformBlocks[j].Name);
+ return false;
+ }
+
+ prog->UniformBlockStageIndex[i][index] = j;
+ }
+ }
+
+ return true;
+}
+
+
+/**
+ * Populates a shaders symbol table with all global declarations
+ */
+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->data.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->data.mode != ir_var_temporary))
+ continue;
+
+ assert(inst->as_assignment()
+ || inst->as_call()
+ || inst->as_if() /* for initializers with the ?: operator */
+ || ((var != NULL) && (var->data.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(NULL, &void_parameters);
+ if ((sig != NULL) && sig->is_defined) {
+ return sig;
+ }
+ }
+
+ return NULL;
+}
+
+
+/**
+ * This class is only used in link_intrastage_shaders() below but declaring
+ * it inside that function leads to compiler warnings with some versions of
+ * gcc.
+ */
+class array_sizing_visitor : public ir_hierarchical_visitor {
+public:
+ array_sizing_visitor()
+ : mem_ctx(ralloc_context(NULL)),
+ unnamed_interfaces(hash_table_ctor(0, hash_table_pointer_hash,
+ hash_table_pointer_compare))
+ {
+ }
+
+ ~array_sizing_visitor()
+ {
+ hash_table_dtor(this->unnamed_interfaces);
+ ralloc_free(this->mem_ctx);
+ }
+
+ virtual ir_visitor_status visit(ir_variable *var)
+ {
+ fixup_type(&var->type, var->data.max_array_access);
+ if (var->type->is_interface()) {
+ if (interface_contains_unsized_arrays(var->type)) {
+ const glsl_type *new_type =
+ resize_interface_members(var->type, var->max_ifc_array_access);
+ var->type = new_type;
+ var->change_interface_type(new_type);
+ }
+ } else if (var->type->is_array() &&
+ var->type->fields.array->is_interface()) {
+ if (interface_contains_unsized_arrays(var->type->fields.array)) {
+ const glsl_type *new_type =
+ resize_interface_members(var->type->fields.array,
+ var->max_ifc_array_access);
+ var->change_interface_type(new_type);
+ var->type =
+ glsl_type::get_array_instance(new_type, var->type->length);
+ }
+ } else if (const glsl_type *ifc_type = var->get_interface_type()) {
+ /* Store a pointer to the variable in the unnamed_interfaces
+ * hashtable.
+ */
+ ir_variable **interface_vars = (ir_variable **)
+ hash_table_find(this->unnamed_interfaces, ifc_type);
+ if (interface_vars == NULL) {
+ interface_vars = rzalloc_array(mem_ctx, ir_variable *,
+ ifc_type->length);
+ hash_table_insert(this->unnamed_interfaces, interface_vars,
+ ifc_type);
+ }
+ unsigned index = ifc_type->field_index(var->name);
+ assert(index < ifc_type->length);
+ assert(interface_vars[index] == NULL);
+ interface_vars[index] = var;
+ }
+ return visit_continue;
+ }
+
+ /**
+ * For each unnamed interface block that was discovered while running the
+ * visitor, adjust the interface type to reflect the newly assigned array
+ * sizes, and fix up the ir_variable nodes to point to the new interface
+ * type.
+ */
+ void fixup_unnamed_interface_types()
+ {
+ hash_table_call_foreach(this->unnamed_interfaces,
+ fixup_unnamed_interface_type, NULL);
+ }
+
+private:
+ /**
+ * If the type pointed to by \c type represents an unsized array, replace
+ * it with a sized array whose size is determined by max_array_access.
+ */
+ static void fixup_type(const glsl_type **type, unsigned max_array_access)
+ {
+ if ((*type)->is_unsized_array()) {
+ *type = glsl_type::get_array_instance((*type)->fields.array,
+ max_array_access + 1);
+ assert(*type != NULL);
+ }
+ }
+
+ /**
+ * Determine whether the given interface type contains unsized arrays (if
+ * it doesn't, array_sizing_visitor doesn't need to process it).
+ */
+ static bool interface_contains_unsized_arrays(const glsl_type *type)
+ {
+ for (unsigned i = 0; i < type->length; i++) {
+ const glsl_type *elem_type = type->fields.structure[i].type;
+ if (elem_type->is_unsized_array())
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Create a new interface type based on the given type, with unsized arrays
+ * replaced by sized arrays whose size is determined by
+ * max_ifc_array_access.
+ */
+ static const glsl_type *
+ resize_interface_members(const glsl_type *type,
+ const unsigned *max_ifc_array_access)
+ {
+ unsigned num_fields = type->length;
+ glsl_struct_field *fields = new glsl_struct_field[num_fields];
+ memcpy(fields, type->fields.structure,
+ num_fields * sizeof(*fields));
+ for (unsigned i = 0; i < num_fields; i++) {
+ fixup_type(&fields[i].type, max_ifc_array_access[i]);
+ }
+ glsl_interface_packing packing =
+ (glsl_interface_packing) type->interface_packing;
+ const glsl_type *new_ifc_type =
+ glsl_type::get_interface_instance(fields, num_fields,
+ packing, type->name);
+ delete [] fields;
+ return new_ifc_type;
+ }
+
+ static void fixup_unnamed_interface_type(const void *key, void *data,
+ void *)
+ {
+ const glsl_type *ifc_type = (const glsl_type *) key;
+ ir_variable **interface_vars = (ir_variable **) data;
+ unsigned num_fields = ifc_type->length;
+ glsl_struct_field *fields = new glsl_struct_field[num_fields];
+ memcpy(fields, ifc_type->fields.structure,
+ num_fields * sizeof(*fields));
+ bool interface_type_changed = false;
+ for (unsigned i = 0; i < num_fields; i++) {
+ if (interface_vars[i] != NULL &&
+ fields[i].type != interface_vars[i]->type) {
+ fields[i].type = interface_vars[i]->type;
+ interface_type_changed = true;
+ }
+ }
+ if (!interface_type_changed) {
+ delete [] fields;
+ return;
+ }
+ glsl_interface_packing packing =
+ (glsl_interface_packing) ifc_type->interface_packing;
+ const glsl_type *new_ifc_type =
+ glsl_type::get_interface_instance(fields, num_fields, packing,
+ ifc_type->name);
+ delete [] fields;
+ for (unsigned i = 0; i < num_fields; i++) {
+ if (interface_vars[i] != NULL)
+ interface_vars[i]->change_interface_type(new_ifc_type);
+ }
+ }
+
+ /**
+ * Memory context used to allocate the data in \c unnamed_interfaces.
+ */
+ void *mem_ctx;
+
+ /**
+ * Hash table from const glsl_type * to an array of ir_variable *'s
+ * pointing to the ir_variables constituting each unnamed interface block.
+ */
+ hash_table *unnamed_interfaces;
+};
+
+/**
+ * Performs the cross-validation of layout qualifiers specified in
+ * redeclaration of gl_FragCoord for the attached fragment shaders,
+ * and propagates them to the linked FS and linked shader program.
+ */
+static void
+link_fs_input_layout_qualifiers(struct gl_shader_program *prog,
+ struct gl_shader *linked_shader,
+ struct gl_shader **shader_list,
+ unsigned num_shaders)
+{
+ linked_shader->redeclares_gl_fragcoord = false;
+ linked_shader->uses_gl_fragcoord = false;
+ linked_shader->origin_upper_left = false;
+ linked_shader->pixel_center_integer = false;
+
+ if (linked_shader->Stage != MESA_SHADER_FRAGMENT ||
+ (prog->Version < 150 && !prog->ARB_fragment_coord_conventions_enable))
+ return;
+
+ for (unsigned i = 0; i < num_shaders; i++) {
+ struct gl_shader *shader = shader_list[i];
+ /* From the GLSL 1.50 spec, page 39:
+ *
+ * "If gl_FragCoord is redeclared in any fragment shader in a program,
+ * it must be redeclared in all the fragment shaders in that program
+ * that have a static use gl_FragCoord."
+ *
+ * Exclude the case when one of the 'linked_shader' or 'shader' redeclares
+ * gl_FragCoord with no layout qualifiers but the other one doesn't
+ * redeclare it. If we strictly follow GLSL 1.50 spec's language, it
+ * should be a link error. But, generating link error for this case will
+ * be a wrong behaviour which spec didn't intend to do and it could also
+ * break some applications.
+ */
+ if ((linked_shader->redeclares_gl_fragcoord
+ && !shader->redeclares_gl_fragcoord
+ && shader->uses_gl_fragcoord
+ && (linked_shader->origin_upper_left
+ || linked_shader->pixel_center_integer))
+ || (shader->redeclares_gl_fragcoord
+ && !linked_shader->redeclares_gl_fragcoord
+ && linked_shader->uses_gl_fragcoord
+ && (shader->origin_upper_left
+ || shader->pixel_center_integer))) {
+ linker_error(prog, "fragment shader defined with conflicting "
+ "layout qualifiers for gl_FragCoord\n");
+ }
+
+ /* From the GLSL 1.50 spec, page 39:
+ *
+ * "All redeclarations of gl_FragCoord in all fragment shaders in a
+ * single program must have the same set of qualifiers."
+ */
+ if (linked_shader->redeclares_gl_fragcoord && shader->redeclares_gl_fragcoord
+ && (shader->origin_upper_left != linked_shader->origin_upper_left
+ || shader->pixel_center_integer != linked_shader->pixel_center_integer)) {
+ linker_error(prog, "fragment shader defined with conflicting "
+ "layout qualifiers for gl_FragCoord\n");
+ }
+
+ /* Update the linked shader state. Note that uses_gl_fragcoord should
+ * accumulate the results. The other values should replace. If there
+ * are multiple redeclarations, all the fields except uses_gl_fragcoord
+ * are already known to be the same.
+ */
+ if (shader->redeclares_gl_fragcoord || shader->uses_gl_fragcoord) {
+ linked_shader->redeclares_gl_fragcoord =
+ shader->redeclares_gl_fragcoord;
+ linked_shader->uses_gl_fragcoord = linked_shader->uses_gl_fragcoord
+ || shader->uses_gl_fragcoord;
+ linked_shader->origin_upper_left = shader->origin_upper_left;
+ linked_shader->pixel_center_integer = shader->pixel_center_integer;
+ }
+ }
+}
+
+/**
+ * Performs the cross-validation of geometry shader max_vertices and
+ * primitive type layout qualifiers for the attached geometry shaders,
+ * and propagates them to the linked GS and linked shader program.
+ */
+static void
+link_gs_inout_layout_qualifiers(struct gl_shader_program *prog,
+ struct gl_shader *linked_shader,
+ struct gl_shader **shader_list,
+ unsigned num_shaders)
+{
+ linked_shader->Geom.VerticesOut = 0;
+ linked_shader->Geom.Invocations = 0;
+ linked_shader->Geom.InputType = PRIM_UNKNOWN;
+ linked_shader->Geom.OutputType = PRIM_UNKNOWN;
+
+ /* No in/out qualifiers defined for anything but GLSL 1.50+
+ * geometry shaders so far.
+ */
+ if (linked_shader->Stage != MESA_SHADER_GEOMETRY || prog->Version < 150)
+ return;
+
+ /* From the GLSL 1.50 spec, page 46:
+ *
+ * "All geometry shader output layout declarations in a program
+ * must declare the same layout and same value for
+ * max_vertices. There must be at least one geometry output
+ * layout declaration somewhere in a program, but not all
+ * geometry shaders (compilation units) are required to
+ * declare it."
+ */
+
+ for (unsigned i = 0; i < num_shaders; i++) {
+ struct gl_shader *shader = shader_list[i];
+
+ if (shader->Geom.InputType != PRIM_UNKNOWN) {
+ if (linked_shader->Geom.InputType != PRIM_UNKNOWN &&
+ linked_shader->Geom.InputType != shader->Geom.InputType) {
+ linker_error(prog, "geometry shader defined with conflicting "
+ "input types\n");
+ return;
+ }
+ linked_shader->Geom.InputType = shader->Geom.InputType;
+ }
+
+ if (shader->Geom.OutputType != PRIM_UNKNOWN) {
+ if (linked_shader->Geom.OutputType != PRIM_UNKNOWN &&
+ linked_shader->Geom.OutputType != shader->Geom.OutputType) {
+ linker_error(prog, "geometry shader defined with conflicting "
+ "output types\n");
+ return;
+ }
+ linked_shader->Geom.OutputType = shader->Geom.OutputType;
+ }
+
+ if (shader->Geom.VerticesOut != 0) {
+ if (linked_shader->Geom.VerticesOut != 0 &&
+ linked_shader->Geom.VerticesOut != shader->Geom.VerticesOut) {
+ linker_error(prog, "geometry shader defined with conflicting "
+ "output vertex count (%d and %d)\n",
+ linked_shader->Geom.VerticesOut,
+ shader->Geom.VerticesOut);
+ return;
+ }
+ linked_shader->Geom.VerticesOut = shader->Geom.VerticesOut;
+ }
+
+ if (shader->Geom.Invocations != 0) {
+ if (linked_shader->Geom.Invocations != 0 &&
+ linked_shader->Geom.Invocations != shader->Geom.Invocations) {
+ linker_error(prog, "geometry shader defined with conflicting "
+ "invocation count (%d and %d)\n",
+ linked_shader->Geom.Invocations,
+ shader->Geom.Invocations);
+ return;
+ }
+ linked_shader->Geom.Invocations = shader->Geom.Invocations;
+ }
+ }
+
+ /* Just do the intrastage -> interstage propagation right now,
+ * since we already know we're in the right type of shader program
+ * for doing it.
+ */
+ if (linked_shader->Geom.InputType == PRIM_UNKNOWN) {
+ linker_error(prog,
+ "geometry shader didn't declare primitive input type\n");
+ return;
+ }
+ prog->Geom.InputType = linked_shader->Geom.InputType;
+
+ if (linked_shader->Geom.OutputType == PRIM_UNKNOWN) {
+ linker_error(prog,
+ "geometry shader didn't declare primitive output type\n");
+ return;
+ }
+ prog->Geom.OutputType = linked_shader->Geom.OutputType;
+
+ if (linked_shader->Geom.VerticesOut == 0) {
+ linker_error(prog,
+ "geometry shader didn't declare max_vertices\n");
+ return;
+ }
+ prog->Geom.VerticesOut = linked_shader->Geom.VerticesOut;
+
+ if (linked_shader->Geom.Invocations == 0)
+ linked_shader->Geom.Invocations = 1;
+
+ prog->Geom.Invocations = linked_shader->Geom.Invocations;
+}
+
+
+/**
+ * Perform cross-validation of compute shader local_size_{x,y,z} layout
+ * qualifiers for the attached compute shaders, and propagate them to the
+ * linked CS and linked shader program.
+ */
+static void
+link_cs_input_layout_qualifiers(struct gl_shader_program *prog,
+ struct gl_shader *linked_shader,
+ struct gl_shader **shader_list,
+ unsigned num_shaders)
+{
+ for (int i = 0; i < 3; i++)
+ linked_shader->Comp.LocalSize[i] = 0;
+
+ /* This function is called for all shader stages, but it only has an effect
+ * for compute shaders.
+ */
+ if (linked_shader->Stage != MESA_SHADER_COMPUTE)
+ return;
+
+ /* From the ARB_compute_shader spec, in the section describing local size
+ * declarations:
+ *
+ * If multiple compute shaders attached to a single program object
+ * declare local work-group size, the declarations must be identical;
+ * otherwise a link-time error results. Furthermore, if a program
+ * object contains any compute shaders, at least one must contain an
+ * input layout qualifier specifying the local work sizes of the
+ * program, or a link-time error will occur.
+ */
+ for (unsigned sh = 0; sh < num_shaders; sh++) {
+ struct gl_shader *shader = shader_list[sh];
+
+ if (shader->Comp.LocalSize[0] != 0) {
+ if (linked_shader->Comp.LocalSize[0] != 0) {
+ for (int i = 0; i < 3; i++) {
+ if (linked_shader->Comp.LocalSize[i] !=
+ shader->Comp.LocalSize[i]) {
+ linker_error(prog, "compute shader defined with conflicting "
+ "local sizes\n");
+ return;
+ }
+ }
+ }
+ for (int i = 0; i < 3; i++)
+ linked_shader->Comp.LocalSize[i] = shader->Comp.LocalSize[i];
+ }
+ }
+
+ /* Just do the intrastage -> interstage propagation right now,
+ * since we already know we're in the right type of shader program
+ * for doing it.
+ */
+ if (linked_shader->Comp.LocalSize[0] == 0) {
+ linker_error(prog, "compute shader didn't declare local size\n");
+ return;
+ }
+ for (int i = 0; i < 3; i++)
+ prog->Comp.LocalSize[i] = linked_shader->Comp.LocalSize[i];
+}
+
+
+/**
+ * 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)
+{
+ struct gl_uniform_block *uniform_blocks = NULL;
+
+ /* Check that global variables defined in multiple shaders are consistent.
+ */
+ cross_validate_globals(prog, shader_list, num_shaders, false);
+ if (!prog->LinkStatus)
+ return NULL;
+
+ /* Check that interface blocks defined in multiple shaders are consistent.
+ */
+ validate_intrastage_interface_blocks(prog, (const gl_shader **)shader_list,
+ num_shaders);
+ if (!prog->LinkStatus)
+ return NULL;
+
+ /* Link up uniform blocks defined within this stage. */
+ const unsigned num_uniform_blocks =
+ link_uniform_blocks(mem_ctx, prog, shader_list, num_shaders,
+ &uniform_blocks);
+
+ /* 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_list(n, &f->signatures) {
+ ir_function_signature *sig = (ir_function_signature *) n;
+
+ if (!sig->is_defined || sig->is_builtin())
+ continue;
+
+ ir_function_signature *other_sig =
+ other->exact_matching_signature(NULL, &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",
+ _mesa_shader_stage_to_string(shader_list[0]->Stage));
+ 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);
+
+ linked->UniformBlocks = uniform_blocks;
+ linked->NumUniformBlocks = num_uniform_blocks;
+ ralloc_steal(linked, linked->UniformBlocks);
+
+ link_fs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
+ link_gs_inout_layout_qualifiers(prog, linked, shader_list, num_shaders);
+ link_cs_input_layout_qualifiers(prog, linked, shader_list, num_shaders);
+
+ 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);
+ }
+
+ /* Check if any shader needs built-in functions. */
+ bool need_builtins = false;
+ for (unsigned i = 0; i < num_shaders; i++) {
+ if (shader_list[i]->uses_builtin_functions) {
+ need_builtins = true;
+ break;
+ }
+ }
+
+ bool ok;
+ if (need_builtins) {
+ /* Make a temporary array one larger than shader_list, which will hold
+ * the built-in function shader as well.
+ */
+ gl_shader **linking_shaders = (gl_shader **)
+ calloc(num_shaders + 1, sizeof(gl_shader *));
+ memcpy(linking_shaders, shader_list, num_shaders * sizeof(gl_shader *));
+ linking_shaders[num_shaders] = _mesa_glsl_get_builtin_function_shader();
+
+ ok = link_function_calls(prog, linked, linking_shaders, num_shaders + 1);
+
+ free(linking_shaders);
+ } else {
+ ok = link_function_calls(prog, linked, shader_list, num_shaders);
+ }
+
+
+ if (!ok) {
+ ctx->Driver.DeleteShader(ctx, linked);
+ return NULL;
+ }
+
+ /* At this point linked should contain all of the linked IR, so
+ * validate it to make sure nothing went wrong.
+ */
+ validate_ir_tree(linked->ir);
+
+ /* Set the size of geometry shader input arrays */
+ if (linked->Stage == MESA_SHADER_GEOMETRY) {
+ unsigned num_vertices = vertices_per_prim(prog->Geom.InputType);
+ geom_array_resize_visitor input_resize_visitor(num_vertices, prog);
+ foreach_list(n, linked->ir) {
+ ir_instruction *ir = (ir_instruction *) n;
+ ir->accept(&input_resize_visitor);
+ }
+ }
+
+ /* 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.
+ */
+ array_sizing_visitor v;
+ v.run(linked->ir);
+ v.fixup_unnamed_interface_types();
+
+ return linked;
+}
+
+/**
+ * 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_STAGES; 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->data.mode != ir_var_uniform) ||
+ !var->type->is_array())
+ continue;
+
+ /* GL_ARB_uniform_buffer_object says that std140 uniforms
+ * will not be eliminated. Since we always do std140, just
+ * don't resize arrays in UBOs.
+ *
+ * Atomic counters are supposed to get deterministic
+ * locations assigned based on the declaration ordering and
+ * sizes, array compaction would mess that up.
+ */
+ if (var->is_in_uniform_block() || var->type->contains_atomic())
+ continue;
+
+ unsigned int size = var->data.max_array_access;
+ for (unsigned j = 0; j < MESA_SHADER_STAGES; 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->data.max_array_access > size) {
+ size = other_var->data.max_array_access;
+ }
+ }
+ }
+
+ if (size + 1 != var->type->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.
+ */
+ }
+ }
+ }
+}
+
+/**
+ * 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.
+ */
+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 and outputs that have
+ * user-defined locations (via glBindFragDataLocation).
+ *
+ * 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_shader_in : ir_var_shader_out;
+
+
+ /* 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->data.mode != (unsigned) direction))
+ continue;
+
+ if (var->data.explicit_location) {
+ if ((var->data.location >= (int)(max_index + generic_base))
+ || (var->data.location < 0)) {
+ linker_error(prog,
+ "invalid explicit location %d specified for `%s'\n",
+ (var->data.location < 0)
+ ? var->data.location
+ : var->data.location - generic_base,
+ var->name);
+ return false;
+ }
+ } else if (target_index == MESA_SHADER_VERTEX) {
+ unsigned binding;
+
+ if (prog->AttributeBindings->get(binding, var->name)) {
+ assert(binding >= VERT_ATTRIB_GENERIC0);
+ var->data.location = binding;
+ var->data.is_unmatched_generic_inout = 0;
+ }
+ } else if (target_index == MESA_SHADER_FRAGMENT) {
+ unsigned binding;
+ unsigned index;
+
+ if (prog->FragDataBindings->get(binding, var->name)) {
+ assert(binding >= FRAG_RESULT_DATA0);
+ var->data.location = binding;
+ var->data.is_unmatched_generic_inout = 0;
+
+ if (prog->FragDataIndexBindings->get(index, var->name)) {
+ var->data.index = index;
+ }
+ }
+ }
+
+ /* If the variable is not a built-in and has a location statically
+ * assigned in the shader (presumably via a layout qualifier), make sure
+ * that it doesn't collide with other assigned locations. Otherwise,
+ * add it to the list of variables that need linker-assigned locations.
+ */
+ const unsigned slots = var->type->count_attribute_slots();
+ if (var->data.location != -1) {
+ if (var->data.location >= generic_base && var->data.index < 1) {
+ /* 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."
+ *
+ * I think above text prohibits the aliasing of explicit and
+ * automatic assignments. But, aliasing is allowed in manual
+ * assignments of attribute locations. See below comments for
+ * the details.
+ *
+ * From OpenGL 4.0 spec, page 61:
+ *
+ * "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."
+ *
+ * From GLSL 4.30 spec, page 54:
+ *
+ * "A program will fail to link if any two non-vertex shader
+ * input variables are assigned to the same location. For
+ * vertex shaders, multiple input variables may be assigned
+ * to the same location using either layout qualifiers or via
+ * the OpenGL API. However, such aliasing is intended only to
+ * support vertex shaders where each execution path accesses
+ * at most one input per each location. Implementations are
+ * permitted, but not required, to generate link-time errors
+ * if they detect that every path through the vertex shader
+ * executable accesses multiple inputs assigned to any single
+ * location. For all shader types, a program will fail to link
+ * if explicit location assignments leave the linker unable
+ * to find space for other variables without explicit
+ * assignments."
+ *
+ * From OpenGL ES 3.0 spec, page 56:
+ *
+ * "Binding more than one attribute name to the same location
+ * is referred to as aliasing, and is not permitted in OpenGL
+ * ES Shading Language 3.00 vertex shaders. LinkProgram will
+ * fail when this condition exists. However, aliasing is
+ * possible in OpenGL ES Shading Language 1.00 vertex shaders.
+ * 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 implemen-
+ * tations are not required to generate an error in this case."
+ *
+ * After looking at above references from OpenGL, OpenGL ES and
+ * GLSL specifications, we allow aliasing of vertex input variables
+ * in: OpenGL 2.0 (and above) and OpenGL ES 2.0.
+ *
+ * NOTE: This is not required by the spec but its worth mentioning
+ * here that we're not doing anything to make sure that no path
+ * through the vertex shader executable accesses multiple inputs
+ * assigned to any single location.
+ */
+
+ /* Mask representing the contiguous slots that will be used by
+ * this attribute.
+ */
+ const unsigned attr = var->data.location - generic_base;
+ const unsigned use_mask = (1 << slots) - 1;
+ const char *const string = (target_index == MESA_SHADER_VERTEX)
+ ? "vertex shader input" : "fragment shader output";
+
+ /* Generate a link error if the requested locations for this
+ * attribute exceed the maximum allowed attribute location.
+ */
+ if (attr + slots > max_index) {
+ linker_error(prog,
+ "insufficient contiguous locations "
+ "available for %s `%s' %d %d %d", string,
+ var->name, used_locations, use_mask, attr);
+ return false;
+ }
+
+ /* 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) {
+ if (target_index == MESA_SHADER_FRAGMENT ||
+ (prog->IsES && prog->Version >= 300)) {
+ linker_error(prog,
+ "overlapping location is assigned "
+ "to %s `%s' %d %d %d\n", string,
+ var->name, used_locations, use_mask, attr);
+ return false;
+ } else {
+ linker_warning(prog,
+ "overlapping location is assigned "
+ "to %s `%s' %d %d %d\n", string,
+ var->name, used_locations, use_mask, attr);
+ }
+ }
+
+ used_locations |= (use_mask << attr);
+ }
+
+ continue;
+ }
+
+ to_assign[num_attr].slots = slots;
+ 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 locations "
+ "available for %s `%s'",
+ string, to_assign[i].var->name);
+ return false;
+ }
+
+ to_assign[i].var->data.location = generic_base + location;
+ to_assign[i].var->data.is_unmatched_generic_inout = 0;
+ 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->data.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->data.is_unmatched_generic_inout) {
+ var->data.mode = ir_var_auto;
+ }
+ }
+}
+
+
+/**
+ * Store the gl_FragDepth layout in the gl_shader_program struct.
+ */
+static void
+store_fragdepth_layout(struct gl_shader_program *prog)
+{
+ if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) {
+ return;
+ }
+
+ struct exec_list *ir = prog->_LinkedShaders[MESA_SHADER_FRAGMENT]->ir;
+
+ /* We don't look up the gl_FragDepth symbol directly because if
+ * gl_FragDepth is not used in the shader, it's removed from the IR.
+ * However, the symbol won't be removed from the symbol table.
+ *
+ * We're only interested in the cases where the variable is NOT removed
+ * from the IR.
+ */
+ foreach_list(node, ir) {
+ ir_variable *const var = ((ir_instruction *) node)->as_variable();
+
+ if (var == NULL || var->data.mode != ir_var_shader_out) {
+ continue;
+ }
+
+ if (strcmp(var->name, "gl_FragDepth") == 0) {
+ switch (var->data.depth_layout) {
+ case ir_depth_layout_none:
+ prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_NONE;
+ return;
+ case ir_depth_layout_any:
+ prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_ANY;
+ return;
+ case ir_depth_layout_greater:
+ prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_GREATER;
+ return;
+ case ir_depth_layout_less:
+ prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_LESS;
+ return;
+ case ir_depth_layout_unchanged:
+ prog->FragDepthLayout = FRAG_DEPTH_LAYOUT_UNCHANGED;
+ return;
+ default:
+ assert(0);
+ return;
+ }
+ }
+ }
+}
+
+/**
+ * Validate the resources used by a program versus the implementation limits
+ */
+static void
+check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ struct gl_shader *sh = prog->_LinkedShaders[i];
+
+ if (sh == NULL)
+ continue;
+
+ if (sh->num_samplers > ctx->Const.Program[i].MaxTextureImageUnits) {
+ linker_error(prog, "Too many %s shader texture samplers",
+ _mesa_shader_stage_to_string(i));
+ }
+
+ if (sh->num_uniform_components >
+ ctx->Const.Program[i].MaxUniformComponents) {
+ if (ctx->Const.GLSLSkipStrictMaxUniformLimitCheck) {
+ linker_warning(prog, "Too many %s shader default uniform block "
+ "components, but the driver will try to optimize "
+ "them out; this is non-portable out-of-spec "
+ "behavior\n",
+ _mesa_shader_stage_to_string(i));
+ } else {
+ linker_error(prog, "Too many %s shader default uniform block "
+ "components",
+ _mesa_shader_stage_to_string(i));
+ }
+ }
+
+ if (sh->num_combined_uniform_components >
+ ctx->Const.Program[i].MaxCombinedUniformComponents) {
+ if (ctx->Const.GLSLSkipStrictMaxUniformLimitCheck) {
+ linker_warning(prog, "Too many %s shader uniform components, "
+ "but the driver will try to optimize them out; "
+ "this is non-portable out-of-spec behavior\n",
+ _mesa_shader_stage_to_string(i));
+ } else {
+ linker_error(prog, "Too many %s shader uniform components",
+ _mesa_shader_stage_to_string(i));
+ }
+ }
+ }
+
+ unsigned blocks[MESA_SHADER_STAGES] = {0};
+ unsigned total_uniform_blocks = 0;
+
+ for (unsigned i = 0; i < prog->NumUniformBlocks; i++) {
+ for (unsigned j = 0; j < MESA_SHADER_STAGES; j++) {
+ if (prog->UniformBlockStageIndex[j][i] != -1) {
+ blocks[j]++;
+ total_uniform_blocks++;
+ }
+ }
+
+ if (total_uniform_blocks > ctx->Const.MaxCombinedUniformBlocks) {
+ linker_error(prog, "Too many combined uniform blocks (%d/%d)",
+ prog->NumUniformBlocks,
+ ctx->Const.MaxCombinedUniformBlocks);
+ } else {
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ const unsigned max_uniform_blocks =
+ ctx->Const.Program[i].MaxUniformBlocks;
+ if (blocks[i] > max_uniform_blocks) {
+ linker_error(prog, "Too many %s uniform blocks (%d/%d)",
+ _mesa_shader_stage_to_string(i),
+ blocks[i],
+ max_uniform_blocks);
+ break;
+ }
+ }
+ }
+ }
+}
+
+/**
+ * Validate shader image resources.
+ */
+static void
+check_image_resources(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+ unsigned total_image_units = 0;
+ unsigned fragment_outputs = 0;
+
+ if (!ctx->Extensions.ARB_shader_image_load_store)
+ return;
+
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ struct gl_shader *sh = prog->_LinkedShaders[i];
+
+ if (sh) {
+ if (sh->NumImages > ctx->Const.Program[i].MaxImageUniforms)
+ linker_error(prog, "Too many %s shader image uniforms",
+ _mesa_shader_stage_to_string(i));
+
+ total_image_units += sh->NumImages;
+
+ if (i == MESA_SHADER_FRAGMENT) {
+ foreach_list(node, sh->ir) {
+ ir_variable *var = ((ir_instruction *)node)->as_variable();
+ if (var && var->data.mode == ir_var_shader_out)
+ fragment_outputs += var->type->count_attribute_slots();
+ }
+ }
+ }
+ }
+
+ if (total_image_units > ctx->Const.MaxCombinedImageUniforms)
+ linker_error(prog, "Too many combined image uniforms");
+
+ if (total_image_units + fragment_outputs >
+ ctx->Const.MaxCombinedImageUnitsAndFragmentOutputs)
+ linker_error(prog, "Too many combined image uniforms and fragment outputs");
+}
+
+void
+link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+ tfeedback_decl *tfeedback_decls = NULL;
+ unsigned num_tfeedback_decls = prog->TransformFeedback.NumVarying;
+
+ void *mem_ctx = ralloc_context(NULL); // temporary linker context
+
+ prog->LinkStatus = true; /* All error paths will set this to false */
+ prog->Validated = false;
+ prog->_Used = false;
+
+ ralloc_free(prog->InfoLog);
+ prog->InfoLog = ralloc_strdup(NULL, "");
+
+ ralloc_free(prog->UniformBlocks);
+ prog->UniformBlocks = NULL;
+ prog->NumUniformBlocks = 0;
+ for (int i = 0; i < MESA_SHADER_STAGES; i++) {
+ ralloc_free(prog->UniformBlockStageIndex[i]);
+ prog->UniformBlockStageIndex[i] = NULL;
+ }
+
+ ralloc_free(prog->AtomicBuffers);
+ prog->AtomicBuffers = NULL;
+ prog->NumAtomicBuffers = 0;
+ prog->ARB_fragment_coord_conventions_enable = false;
+
+ /* Separate the shaders into groups based on their type.
+ */
+ struct gl_shader **shader_list[MESA_SHADER_STAGES];
+ unsigned num_shaders[MESA_SHADER_STAGES];
+
+ for (int i = 0; i < MESA_SHADER_STAGES; i++) {
+ shader_list[i] = (struct gl_shader **)
+ calloc(prog->NumShaders, sizeof(struct gl_shader *));
+ num_shaders[i] = 0;
+ }
+
+ unsigned min_version = UINT_MAX;
+ unsigned max_version = 0;
+ const bool is_es_prog =
+ (prog->NumShaders > 0 && prog->Shaders[0]->IsES) ? true : false;
+ 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);
+
+ if (prog->Shaders[i]->IsES != is_es_prog) {
+ linker_error(prog, "all shaders must use same shading "
+ "language version\n");
+ goto done;
+ }
+
+ prog->ARB_fragment_coord_conventions_enable |=
+ prog->Shaders[i]->ARB_fragment_coord_conventions_enable;
+
+ gl_shader_stage shader_type = prog->Shaders[i]->Stage;
+ shader_list[shader_type][num_shaders[shader_type]] = prog->Shaders[i];
+ num_shaders[shader_type]++;
+ }
+
+ /* In desktop GLSL, different shader versions may be linked together. In
+ * GLSL ES, all shader versions must be the same.
+ */
+ if (is_es_prog && min_version != max_version) {
+ linker_error(prog, "all shaders must use same shading "
+ "language version\n");
+ goto done;
+ }
+
+ prog->Version = max_version;
+ prog->IsES = is_es_prog;
+
+ /* Geometry shaders have to be linked with vertex shaders.
+ */
+ if (num_shaders[MESA_SHADER_GEOMETRY] > 0 &&
+ num_shaders[MESA_SHADER_VERTEX] == 0 &&
+ !prog->SeparateShader) {
+ linker_error(prog, "Geometry shader must be linked with "
+ "vertex shader\n");
+ goto done;
+ }
+
+ /* Compute shaders have additional restrictions. */
+ if (num_shaders[MESA_SHADER_COMPUTE] > 0 &&
+ num_shaders[MESA_SHADER_COMPUTE] != prog->NumShaders) {
+ linker_error(prog, "Compute shaders may not be linked with any other "
+ "type of shader\n");
+ }
+
+ for (unsigned int i = 0; i < MESA_SHADER_STAGES; 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.
+ */
+ for (int stage = 0; stage < MESA_SHADER_STAGES; stage++) {
+ if (num_shaders[stage] > 0) {
+ gl_shader *const sh =
+ link_intrastage_shaders(mem_ctx, ctx, prog, shader_list[stage],
+ num_shaders[stage]);
+
+ if (!prog->LinkStatus)
+ goto done;
+
+ switch (stage) {
+ case MESA_SHADER_VERTEX:
+ validate_vertex_shader_executable(prog, sh);
+ break;
+ case MESA_SHADER_GEOMETRY:
+ validate_geometry_shader_executable(prog, sh);
+ break;
+ case MESA_SHADER_FRAGMENT:
+ validate_fragment_shader_executable(prog, sh);
+ break;
+ }
+ if (!prog->LinkStatus)
+ goto done;
+
+ _mesa_reference_shader(ctx, &prog->_LinkedShaders[stage], sh);
+ }
+ }
+
+ if (num_shaders[MESA_SHADER_GEOMETRY] > 0)
+ prog->LastClipDistanceArraySize = prog->Geom.ClipDistanceArraySize;
+ else if (num_shaders[MESA_SHADER_VERTEX] > 0)
+ prog->LastClipDistanceArraySize = prog->Vert.ClipDistanceArraySize;
+ else
+ prog->LastClipDistanceArraySize = 0; /* Not used */
+
+ /* Here begins the inter-stage linking phase. Some initial validation is
+ * performed, then locations are assigned for uniforms, attributes, and
+ * varyings.
+ */
+ cross_validate_uniforms(prog);
+ if (!prog->LinkStatus)
+ goto done;
+
+ unsigned prev;
+
+ for (prev = 0; prev <= MESA_SHADER_FRAGMENT; 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_FRAGMENT; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ validate_interstage_inout_blocks(prog, prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]);
+ if (!prog->LinkStatus)
+ goto done;
+
+ cross_validate_outputs_to_inputs(prog,
+ prog->_LinkedShaders[prev],
+ prog->_LinkedShaders[i]);
+ if (!prog->LinkStatus)
+ goto done;
+
+ prev = i;
+ }
+
+ /* Cross-validate uniform blocks between shader stages */
+ validate_interstage_uniform_blocks(prog, prog->_LinkedShaders,
+ MESA_SHADER_STAGES);
+ if (!prog->LinkStatus)
+ goto done;
+
+ for (unsigned int i = 0; i < MESA_SHADER_STAGES; i++) {
+ if (prog->_LinkedShaders[i] != NULL)
+ lower_named_interface_blocks(mem_ctx, prog->_LinkedShaders[i]);
+ }
+
+ /* Implement the GLSL 1.30+ rule for discard vs infinite loops Do
+ * it before optimization because we want most of the checks to get
+ * dropped thanks to constant propagation.
+ *
+ * This rule also applies to GLSL ES 3.00.
+ */
+ if (max_version >= (is_es_prog ? 300 : 130)) {
+ struct gl_shader *sh = prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
+ if (sh) {
+ lower_discard_flow(sh->ir);
+ }
+ }
+
+ if (!interstage_cross_validate_uniform_blocks(prog))
+ goto done;
+
+ /* 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_STAGES; i++) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ detect_recursion_linked(prog, prog->_LinkedShaders[i]->ir);
+ if (!prog->LinkStatus)
+ goto done;
+
+ if (ctx->ShaderCompilerOptions[i].LowerClipDistance) {
+ lower_clip_distance(prog->_LinkedShaders[i]);
+ }
+
+ while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false,
+ &ctx->ShaderCompilerOptions[i],
+ ctx->Const.NativeIntegers))
+ ;
+ }
+
+ /* Mark all generic shader inputs and outputs as unpaired. */
+ for (unsigned i = MESA_SHADER_VERTEX; i <= MESA_SHADER_FRAGMENT; i++) {
+ if (prog->_LinkedShaders[i] != NULL) {
+ link_invalidate_variable_locations(prog->_LinkedShaders[i]->ir);
+ }
+ }
+
+ /* 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, MAX2(ctx->Const.MaxDrawBuffers, ctx->Const.MaxDualSourceDrawBuffers))) {
+ goto done;
+ }
+
+ unsigned first;
+ for (first = 0; first <= MESA_SHADER_FRAGMENT; first++) {
+ if (prog->_LinkedShaders[first] != NULL)
+ break;
+ }
+
+ if (num_tfeedback_decls != 0) {
+ /* From GL_EXT_transform_feedback:
+ * A program will fail to link if:
+ *
+ * * the <count> specified by TransformFeedbackVaryingsEXT is
+ * non-zero, but the program object has no vertex or geometry
+ * shader;
+ */
+ if (first == MESA_SHADER_FRAGMENT) {
+ linker_error(prog, "Transform feedback varyings specified, but "
+ "no vertex or geometry shader is present.");
+ goto done;
+ }
+
+ tfeedback_decls = ralloc_array(mem_ctx, tfeedback_decl,
+ prog->TransformFeedback.NumVarying);
+ if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls,
+ prog->TransformFeedback.VaryingNames,
+ tfeedback_decls))
+ goto done;
+ }
+
+ /* Linking the stages in the opposite order (from fragment to vertex)
+ * ensures that inter-shader outputs written to in an earlier stage are
+ * eliminated if they are (transitively) not used in a later stage.
+ */
+ int last, next;
+ for (last = MESA_SHADER_FRAGMENT; last >= 0; last--) {
+ if (prog->_LinkedShaders[last] != NULL)
+ break;
+ }
+
+ if (last >= 0 && last < MESA_SHADER_FRAGMENT) {
+ gl_shader *const sh = prog->_LinkedShaders[last];
+
+ if (num_tfeedback_decls != 0 || prog->SeparateShader) {
+ /* There was no fragment shader, but we still have to assign varying
+ * locations for use by transform feedback.
+ */
+ if (!assign_varying_locations(ctx, mem_ctx, prog,
+ sh, NULL,
+ num_tfeedback_decls, tfeedback_decls,
+ 0))
+ goto done;
+ }
+
+ do_dead_builtin_varyings(ctx, sh, NULL,
+ num_tfeedback_decls, tfeedback_decls);
+
+ if (!prog->SeparateShader)
+ demote_shader_inputs_and_outputs(sh, ir_var_shader_out);
+
+ /* Eliminate code that is now dead due to unused outputs being demoted.
+ */
+ while (do_dead_code(sh->ir, false))
+ ;
+ }
+ else if (first == MESA_SHADER_FRAGMENT) {
+ /* If the program only contains a fragment shader...
+ */
+ gl_shader *const sh = prog->_LinkedShaders[first];
+
+ do_dead_builtin_varyings(ctx, NULL, sh,
+ num_tfeedback_decls, tfeedback_decls);
+
+ if (prog->SeparateShader) {
+ if (!assign_varying_locations(ctx, mem_ctx, prog,
+ NULL /* producer */,
+ sh /* consumer */,
+ 0 /* num_tfeedback_decls */,
+ NULL /* tfeedback_decls */,
+ 0 /* gs_input_vertices */))
+ goto done;
+ } else
+ demote_shader_inputs_and_outputs(sh, ir_var_shader_in);
+
+ while (do_dead_code(sh->ir, false))
+ ;
+ }
+
+ next = last;
+ for (int i = next - 1; i >= 0; i--) {
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ gl_shader *const sh_i = prog->_LinkedShaders[i];
+ gl_shader *const sh_next = prog->_LinkedShaders[next];
+ unsigned gs_input_vertices =
+ next == MESA_SHADER_GEOMETRY ? prog->Geom.VerticesIn : 0;
+
+ if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next,
+ next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
+ tfeedback_decls, gs_input_vertices))
+ goto done;
+
+ do_dead_builtin_varyings(ctx, sh_i, sh_next,
+ next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
+ tfeedback_decls);
+
+ demote_shader_inputs_and_outputs(sh_i, ir_var_shader_out);
+ demote_shader_inputs_and_outputs(sh_next, ir_var_shader_in);
+
+ /* Eliminate code that is now dead due to unused outputs being demoted.
+ */
+ while (do_dead_code(sh_i->ir, false))
+ ;
+ while (do_dead_code(sh_next->ir, false))
+ ;
+
+ /* This must be done after all dead varyings are eliminated. */
+ if (!check_against_output_limit(ctx, prog, sh_i))
+ goto done;
+ if (!check_against_input_limit(ctx, prog, sh_next))
+ goto done;
+
+ next = i;
+ }
+
+ if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls))
+ goto done;
+
+ update_array_sizes(prog);
+ link_assign_uniform_locations(prog);
+ link_assign_atomic_counter_resources(ctx, prog);
+ store_fragdepth_layout(prog);
+
+ check_resources(ctx, prog);
+ check_image_resources(ctx, prog);
+ link_check_atomic_counter_resources(ctx, prog);
+
+ if (!prog->LinkStatus)
+ goto done;
+
+ /* OpenGL ES requires that a vertex shader and a fragment shader both be
+ * present in a linked program. GL_ARB_ES2_compatibility doesn't say
+ * anything about shader linking when one of the shaders (vertex or
+ * fragment shader) is absent. So, the extension shouldn't change the
+ * behavior specified in GLSL specification.
+ */
+ if (!prog->SeparateShader && ctx->API == API_OPENGLES2) {
+ 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:
+ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
+ free(shader_list[i]);
+ if (prog->_LinkedShaders[i] == NULL)
+ continue;
+
+ /* Do a final validation step to make sure that the IR wasn't
+ * invalidated by any modifications performed after intrastage linking.
+ */
+ validate_ir_tree(prog->_LinkedShaders[i]->ir);
+
+ /* Retain any live IR, but trash the rest. */
+ reparent_ir(prog->_LinkedShaders[i]->ir, prog->_LinkedShaders[i]->ir);
+
+ /* The symbol table in the linked shaders may contain references to
+ * variables that were removed (e.g., unused uniforms). Since it may
+ * contain junk, there is no possible valid use. Delete it and set the
+ * pointer to NULL.
+ */
+ delete prog->_LinkedShaders[i]->symbols;
+ prog->_LinkedShaders[i]->symbols = NULL;
+ }
+
+ ralloc_free(mem_ctx);
+}