/* * 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 */ #include #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" #include "ir_uniform.h" #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->fields.array, 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->fields.array; return visit_continue; } }; /** * Visitor that determines the highest stream id to which a (geometry) shader * emits vertices. It also checks whether End{Stream}Primitive is ever called. */ class find_emit_vertex_visitor : public ir_hierarchical_visitor { public: find_emit_vertex_visitor(int max_allowed) : max_stream_allowed(max_allowed), invalid_stream_id(0), invalid_stream_id_from_emit_vertex(false), end_primitive_found(false), uses_non_zero_stream(false) { /* empty */ } virtual ir_visitor_status visit_leave(ir_emit_vertex *ir) { int stream_id = ir->stream_id(); if (stream_id < 0) { invalid_stream_id = stream_id; invalid_stream_id_from_emit_vertex = true; return visit_stop; } if (stream_id > max_stream_allowed) { invalid_stream_id = stream_id; invalid_stream_id_from_emit_vertex = true; return visit_stop; } if (stream_id != 0) uses_non_zero_stream = true; return visit_continue; } virtual ir_visitor_status visit_leave(ir_end_primitive *ir) { end_primitive_found = true; int stream_id = ir->stream_id(); if (stream_id < 0) { invalid_stream_id = stream_id; invalid_stream_id_from_emit_vertex = false; return visit_stop; } if (stream_id > max_stream_allowed) { invalid_stream_id = stream_id; invalid_stream_id_from_emit_vertex = false; return visit_stop; } if (stream_id != 0) uses_non_zero_stream = true; return visit_continue; } bool error() { return invalid_stream_id != 0; } const char *error_func() { return invalid_stream_id_from_emit_vertex ? "EmitStreamVertex" : "EndStreamPrimitive"; } int error_stream() { return invalid_stream_id; } bool uses_streams() { return uses_non_zero_stream; } bool uses_end_primitive() { return end_primitive_found; } private: int max_stream_allowed; int invalid_stream_id; bool invalid_stream_id_from_emit_vertex; bool end_primitive_found; bool uses_non_zero_stream; }; /* Class that finds array derefs and check if indexes are dynamic. */ class dynamic_sampler_array_indexing_visitor : public ir_hierarchical_visitor { public: dynamic_sampler_array_indexing_visitor() : dynamic_sampler_array_indexing(false) { } ir_visitor_status visit_enter(ir_dereference_array *ir) { if (!ir->variable_referenced()) return visit_continue; if (!ir->variable_referenced()->type->contains_sampler()) return visit_continue; if (!ir->array_index->constant_expression_value()) { dynamic_sampler_array_indexing = true; return visit_stop; } return visit_continue; } bool uses_dynamic_sampler_array_indexing() { return dynamic_sampler_array_indexing; } private: bool dynamic_sampler_array_indexing; }; } /* 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_in_list(ir_instruction, node, ir) { ir_variable *const var = 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." * * All GLSL ES Versions are 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()) { if (prog->IsES) { linker_warning(prog, "vertex shader does not write to `gl_Position'." "It's value is undefined. \n"); } else { 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); } /** * Check if geometry shaders emit to non-zero streams and do corresponding * validations. */ static void validate_geometry_shader_emissions(struct gl_context *ctx, struct gl_shader_program *prog) { if (prog->_LinkedShaders[MESA_SHADER_GEOMETRY] != NULL) { find_emit_vertex_visitor emit_vertex(ctx->Const.MaxVertexStreams - 1); emit_vertex.run(prog->_LinkedShaders[MESA_SHADER_GEOMETRY]->ir); if (emit_vertex.error()) { linker_error(prog, "Invalid call %s(%d). Accepted values for the " "stream parameter are in the range [0, %d].\n", emit_vertex.error_func(), emit_vertex.error_stream(), ctx->Const.MaxVertexStreams - 1); } prog->Geom.UsesStreams = emit_vertex.uses_streams(); prog->Geom.UsesEndPrimitive = emit_vertex.uses_end_primitive(); /* From the ARB_gpu_shader5 spec: * * "Multiple vertex streams are supported only if the output primitive * type is declared to be "points". A program will fail to link if it * contains a geometry shader calling EmitStreamVertex() or * EndStreamPrimitive() if its output primitive type is not "points". * * However, in the same spec: * * "The function EmitVertex() is equivalent to calling EmitStreamVertex() * with set to zero." * * And: * * "The function EndPrimitive() is equivalent to calling * EndStreamPrimitive() with set to zero." * * Since we can call EmitVertex() and EndPrimitive() when we output * primitives other than points, calling EmitStreamVertex(0) or * EmitEndPrimitive(0) should not produce errors. This it also what Nvidia * does. Currently we only set prog->Geom.UsesStreams to TRUE when * EmitStreamVertex() or EmitEndPrimitive() are called with a non-zero * stream. */ if (prog->Geom.UsesStreams && prog->Geom.OutputType != GL_POINTS) { linker_error(prog, "EmitStreamVertex(n) and EndStreamPrimitive(n) " "with n>0 requires point output\n"); } } } bool validate_intrastage_arrays(struct gl_shader_program *prog, ir_variable *const var, ir_variable *const existing) { /* 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) { if (var->type->length <= existing->data.max_array_access) { linker_error(prog, "%s `%s' declared as type " "`%s' but outermost dimension has an index" " of `%i'\n", mode_string(var), var->name, var->type->name, existing->data.max_array_access); } existing->type = var->type; return true; } else if (existing->type->length != 0) { if(existing->type->length <= var->data.max_array_access) { linker_error(prog, "%s `%s' declared as type " "`%s' but outermost dimension has an index" " of `%i'\n", mode_string(var), var->name, existing->type->name, var->data.max_array_access); } return true; } } return false; } /** * 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_in_list(ir_instruction, node, shader_list[i]->ir) { ir_variable *const var = 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) { /* Check if types match. Interface blocks have some special * rules so we handle those elsewhere. */ if (var->type != existing->type && !var->is_interface_instance()) { if (!validate_intrastage_arrays(prog, var, existing)) { 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.\n"); } 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\n"); } } /* 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\n", sh->UniformBlocks[j].Name); return false; } prog->UniformBlockStageIndex[i][index] = j; } } 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_in_list(ir_instruction, inst, sh->ir) { ir_variable *var; ir_function *func; if ((func = inst->as_function()) != NULL) { sh->symbols->add_function(func); } else if ((var = inst->as_variable()) != NULL) { if (var->data.mode != ir_var_temporary) 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_in_list_safe(ir_instruction, inst, instructions) { 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 */ ir_function_signature * link_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, false); 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->get_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->get_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." */ if ((linked_shader->redeclares_gl_fragcoord && !shader->redeclares_gl_fragcoord && shader->uses_gl_fragcoord) || (shader->redeclares_gl_fragcoord && !linked_shader->redeclares_gl_fragcoord && linked_shader->uses_gl_fragcoord)) { 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; } linked_shader->EarlyFragmentTests |= shader->EarlyFragmentTests; } } /** * 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); if (!prog->LinkStatus) 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_in_list(ir_instruction, node, shader_list[i]->ir) { ir_function *const f = 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_in_list(ir_function_signature, sig, &f->signatures) { 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\n", 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 (link_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 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 = link_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 *)); ok = linking_shaders != NULL; if (ok) { 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 { _mesa_error_no_memory(__func__); } } 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_in_list(ir_instruction, ir, linked->ir) { ir->accept(&input_resize_visitor); } } if (ctx->Const.VertexID_is_zero_based) lower_vertex_id(linked); /* 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_in_list(ir_instruction, node, prog->_LinkedShaders[i]->ir) { ir_variable *const var = 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_in_list(ir_instruction, node2, prog->_LinkedShaders[j]->ir) { ir_variable *other_var = 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. */ const unsigned num_slots = var->get_num_state_slots(); if (num_slots > 0) { var->set_num_state_slots((size + 1) * (num_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 or 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; unsigned total_attribs_size = 0; foreach_in_list(ir_instruction, node, sh->ir) { ir_variable *const var = 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; } } } const unsigned slots = var->type->count_attribute_slots(); /* From GL4.5 core spec, section 11.1.1 (Vertex Attributes): * * "A program with more than the value of MAX_VERTEX_ATTRIBS active * attribute variables may fail to link, unless device-dependent * optimizations are able to make the program fit within available * hardware resources. For the purposes of this test, attribute variables * of the type dvec3, dvec4, dmat2x3, dmat2x4, dmat3, dmat3x4, dmat4x3, * and dmat4 may count as consuming twice as many attributes as equivalent * single-precision types. While these types use the same number of * generic attributes as their single-precision equivalents, * implementations are permitted to consume two single-precision vectors * of internal storage for each three- or four-component double-precision * vector." * Until someone has a good reason in Mesa, enforce that now. */ if (target_index == MESA_SHADER_VERTEX) { total_attribs_size += slots; if (var->type->without_array() == glsl_type::dvec3_type || var->type->without_array() == glsl_type::dvec4_type || var->type->without_array() == glsl_type::dmat2x3_type || var->type->without_array() == glsl_type::dmat2x4_type || var->type->without_array() == glsl_type::dmat3_type || var->type->without_array() == glsl_type::dmat3x4_type || var->type->without_array() == glsl_type::dmat4x3_type || var->type->without_array() == glsl_type::dmat4_type) total_attribs_size += slots; } /* 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. */ 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\n", 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 (target_index == MESA_SHADER_VERTEX) { if (total_attribs_size > max_index) { linker_error(prog, "attempt to use %d vertex attribute slots only %d available ", total_attribs_size, max_index); return false; } } /* 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'\n", 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_in_list(ir_instruction, node, sh->ir) { ir_variable *const var = 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) { assert(var->data.mode != ir_var_temporary); 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_in_list(ir_instruction, node, ir) { ir_variable *const var = 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\n", _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\n", _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\n", _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++) { if (prog->UniformBlocks[i].UniformBufferSize > ctx->Const.MaxUniformBlockSize) { linker_error(prog, "Uniform block %s too big (%d/%d)\n", prog->UniformBlocks[i].Name, prog->UniformBlocks[i].UniformBufferSize, ctx->Const.MaxUniformBlockSize); } 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)\n", 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)\n", _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\n", _mesa_shader_stage_to_string(i)); total_image_units += sh->NumImages; if (i == MESA_SHADER_FRAGMENT) { foreach_in_list(ir_instruction, node, sh->ir) { ir_variable *var = 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\n"); if (total_image_units + fragment_outputs > ctx->Const.MaxCombinedImageUnitsAndFragmentOutputs) linker_error(prog, "Too many combined image uniforms and fragment outputs\n"); } /** * Initializes explicit location slots to INACTIVE_UNIFORM_EXPLICIT_LOCATION * for a variable, checks for overlaps between other uniforms using explicit * locations. */ static bool reserve_explicit_locations(struct gl_shader_program *prog, string_to_uint_map *map, ir_variable *var) { unsigned slots = var->type->uniform_locations(); unsigned max_loc = var->data.location + slots - 1; /* Resize remap table if locations do not fit in the current one. */ if (max_loc + 1 > prog->NumUniformRemapTable) { prog->UniformRemapTable = reralloc(prog, prog->UniformRemapTable, gl_uniform_storage *, max_loc + 1); if (!prog->UniformRemapTable) { linker_error(prog, "Out of memory during linking.\n"); return false; } /* Initialize allocated space. */ for (unsigned i = prog->NumUniformRemapTable; i < max_loc + 1; i++) prog->UniformRemapTable[i] = NULL; prog->NumUniformRemapTable = max_loc + 1; } for (unsigned i = 0; i < slots; i++) { unsigned loc = var->data.location + i; /* Check if location is already used. */ if (prog->UniformRemapTable[loc] == INACTIVE_UNIFORM_EXPLICIT_LOCATION) { /* Possibly same uniform from a different stage, this is ok. */ unsigned hash_loc; if (map->get(hash_loc, var->name) && hash_loc == loc - i) continue; /* ARB_explicit_uniform_location specification states: * * "No two default-block uniform variables in the program can have * the same location, even if they are unused, otherwise a compiler * or linker error will be generated." */ linker_error(prog, "location qualifier for uniform %s overlaps " "previously used location\n", var->name); return false; } /* Initialize location as inactive before optimization * rounds and location assignment. */ prog->UniformRemapTable[loc] = INACTIVE_UNIFORM_EXPLICIT_LOCATION; } /* Note, base location used for arrays. */ map->put(var->data.location, var->name); return true; } /** * Check and reserve all explicit uniform locations, called before * any optimizations happen to handle also inactive uniforms and * inactive array elements that may get trimmed away. */ static void check_explicit_uniform_locations(struct gl_context *ctx, struct gl_shader_program *prog) { if (!ctx->Extensions.ARB_explicit_uniform_location) return; /* This map is used to detect if overlapping explicit locations * occur with the same uniform (from different stage) or a different one. */ string_to_uint_map *uniform_map = new string_to_uint_map; if (!uniform_map) { linker_error(prog, "Out of memory during linking.\n"); return; } for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { struct gl_shader *sh = prog->_LinkedShaders[i]; if (!sh) continue; foreach_in_list(ir_instruction, node, sh->ir) { ir_variable *var = node->as_variable(); if ((var && var->data.mode == ir_var_uniform) && var->data.explicit_location) { if (!reserve_explicit_locations(prog, uniform_map, var)) { delete uniform_map; return; } } } } delete uniform_map; } static bool add_program_resource(struct gl_shader_program *prog, GLenum type, const void *data, uint8_t stages) { assert(data); /* If resource already exists, do not add it again. */ for (unsigned i = 0; i < prog->NumProgramResourceList; i++) if (prog->ProgramResourceList[i].Data == data) return true; prog->ProgramResourceList = reralloc(prog, prog->ProgramResourceList, gl_program_resource, prog->NumProgramResourceList + 1); if (!prog->ProgramResourceList) { linker_error(prog, "Out of memory during linking.\n"); return false; } struct gl_program_resource *res = &prog->ProgramResourceList[prog->NumProgramResourceList]; res->Type = type; res->Data = data; res->StageReferences = stages; prog->NumProgramResourceList++; return true; } /** * Function builds a stage reference bitmask from variable name. */ static uint8_t build_stageref(struct gl_shader_program *shProg, const char *name) { uint8_t stages = 0; /* Note, that we assume MAX 8 stages, if there will be more stages, type * used for reference mask in gl_program_resource will need to be changed. */ assert(MESA_SHADER_STAGES < 8); for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { struct gl_shader *sh = shProg->_LinkedShaders[i]; if (!sh) continue; ir_variable *var = sh->symbols->get_variable(name); if (var) stages |= (1 << i); } return stages; } static bool add_interface_variables(struct gl_shader_program *shProg, struct gl_shader *sh, GLenum programInterface) { foreach_in_list(ir_instruction, node, sh->ir) { ir_variable *var = node->as_variable(); uint8_t mask = 0; if (!var) continue; switch (var->data.mode) { /* From GL 4.3 core spec, section 11.1.1 (Vertex Attributes): * "For GetActiveAttrib, all active vertex shader input variables * are enumerated, including the special built-in inputs gl_VertexID * and gl_InstanceID." */ case ir_var_system_value: if (var->data.location != SYSTEM_VALUE_VERTEX_ID && var->data.location != SYSTEM_VALUE_VERTEX_ID_ZERO_BASE && var->data.location != SYSTEM_VALUE_INSTANCE_ID) continue; /* Mark special built-in inputs referenced by the vertex stage so * that they are considered active by the shader queries. */ mask = (1 << (MESA_SHADER_VERTEX)); /* FALLTHROUGH */ case ir_var_shader_in: if (programInterface != GL_PROGRAM_INPUT) continue; break; case ir_var_shader_out: if (programInterface != GL_PROGRAM_OUTPUT) continue; break; default: continue; }; if (!add_program_resource(shProg, programInterface, var, build_stageref(shProg, var->name) | mask)) return false; } return true; } /** * Builds up a list of program resources that point to existing * resource data. */ static void build_program_resource_list(struct gl_context *ctx, struct gl_shader_program *shProg) { /* Rebuild resource list. */ if (shProg->ProgramResourceList) { ralloc_free(shProg->ProgramResourceList); shProg->ProgramResourceList = NULL; shProg->NumProgramResourceList = 0; } int input_stage = MESA_SHADER_STAGES, output_stage = 0; /* Determine first input and final output stage. These are used to * detect which variables should be enumerated in the resource list * for GL_PROGRAM_INPUT and GL_PROGRAM_OUTPUT. */ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { if (!shProg->_LinkedShaders[i]) continue; if (input_stage == MESA_SHADER_STAGES) input_stage = i; output_stage = i; } /* Empty shader, no resources. */ if (input_stage == MESA_SHADER_STAGES && output_stage == 0) return; /* Add inputs and outputs to the resource list. */ if (!add_interface_variables(shProg, shProg->_LinkedShaders[input_stage], GL_PROGRAM_INPUT)) return; if (!add_interface_variables(shProg, shProg->_LinkedShaders[output_stage], GL_PROGRAM_OUTPUT)) return; /* Add transform feedback varyings. */ if (shProg->LinkedTransformFeedback.NumVarying > 0) { for (int i = 0; i < shProg->LinkedTransformFeedback.NumVarying; i++) { uint8_t stageref = build_stageref(shProg, shProg->LinkedTransformFeedback.Varyings[i].Name); if (!add_program_resource(shProg, GL_TRANSFORM_FEEDBACK_VARYING, &shProg->LinkedTransformFeedback.Varyings[i], stageref)) return; } } /* Add uniforms from uniform storage. */ for (unsigned i = 0; i < shProg->NumUniformStorage; i++) { /* Do not add uniforms internally used by Mesa. */ if (shProg->UniformStorage[i].hidden) continue; uint8_t stageref = build_stageref(shProg, shProg->UniformStorage[i].name); /* Add stagereferences for uniforms in a uniform block. */ int block_index = shProg->UniformStorage[i].block_index; if (block_index != -1) { for (unsigned j = 0; j < MESA_SHADER_STAGES; j++) { if (shProg->UniformBlockStageIndex[j][block_index] != -1) stageref |= (1 << j); } } if (!add_program_resource(shProg, GL_UNIFORM, &shProg->UniformStorage[i], stageref)) return; } /* Add program uniform blocks. */ for (unsigned i = 0; i < shProg->NumUniformBlocks; i++) { if (!add_program_resource(shProg, GL_UNIFORM_BLOCK, &shProg->UniformBlocks[i], 0)) return; } /* Add atomic counter buffers. */ for (unsigned i = 0; i < shProg->NumAtomicBuffers; i++) { if (!add_program_resource(shProg, GL_ATOMIC_COUNTER_BUFFER, &shProg->AtomicBuffers[i], 0)) return; } /* TODO - following extensions will require more resource types: * * GL_ARB_shader_storage_buffer_object * GL_ARB_shader_subroutine */ } /** * This check is done to make sure we allow only constant expression * indexing and "constant-index-expression" (indexing with an expression * that includes loop induction variable). */ static bool validate_sampler_array_indexing(struct gl_context *ctx, struct gl_shader_program *prog) { dynamic_sampler_array_indexing_visitor v; for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { if (prog->_LinkedShaders[i] == NULL) continue; bool no_dynamic_indexing = ctx->Const.ShaderCompilerOptions[i].EmitNoIndirectSampler; /* Search for array derefs in shader. */ v.run(prog->_LinkedShaders[i]->ir); if (v.uses_dynamic_sampler_array_indexing()) { const char *msg = "sampler arrays indexed with non-constant " "expressions is forbidden in GLSL %s %u"; /* Backend has indicated that it has no dynamic indexing support. */ if (no_dynamic_indexing) { linker_error(prog, msg, prog->IsES ? "ES" : "", prog->Version); return false; } else { linker_warning(prog, msg, prog->IsES ? "ES" : "", prog->Version); } } } return true; } 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; 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; } if (prog->Shaders[i]->ARB_fragment_coord_conventions_enable) { prog->ARB_fragment_coord_conventions_enable = true; } 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) { if (sh) ctx->Driver.DeleteShader(ctx, sh); 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) { if (sh) ctx->Driver.DeleteShader(ctx, sh); 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; } check_explicit_uniform_locations(ctx, prog); if (!prog->LinkStatus) goto done; /* 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->Const.ShaderCompilerOptions[i].LowerClipDistance) { lower_clip_distance(prog->_LinkedShaders[i]); } while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, &ctx->Const.ShaderCompilerOptions[i], ctx->Const.NativeIntegers)) ; lower_const_arrays_to_uniforms(prog->_LinkedShaders[i]->ir); } /* Validation for special cases where we allow sampler array indexing * with loop induction variable. This check emits a warning or error * depending if backend can handle dynamic indexing. */ if ((!prog->IsES && prog->Version < 130) || (prog->IsES && prog->Version < 300)) { if (!validate_sampler_array_indexing(ctx, prog)) goto done; } /* Check and validate stream emissions in geometry shaders */ validate_geometry_shader_emissions(ctx, prog); /* 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, last; first = MESA_SHADER_STAGES; last = 0; /* Determine first and last stage. */ for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { if (!prog->_LinkedShaders[i]) continue; if (first == MESA_SHADER_STAGES) first = i; last = i; } if (num_tfeedback_decls != 0) { /* From GL_EXT_transform_feedback: * A program will fail to link if: * * * the 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.\n"); 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 next; if (first < MESA_SHADER_FRAGMENT) { gl_shader *const sh = prog->_LinkedShaders[last]; if (first == MESA_SHADER_GEOMETRY) { /* There was no vertex shader, but we still have to assign varying * locations for use by geometry shader inputs in SSO. * * If the shader is not separable (i.e., prog->SeparateShader is * false), linking will have already failed when first is * MESA_SHADER_GEOMETRY. */ if (!assign_varying_locations(ctx, mem_ctx, prog, NULL, prog->_LinkedShaders[first], num_tfeedback_decls, tfeedback_decls, prog->Geom.VerticesIn)) goto done; } if (last != MESA_SHADER_FRAGMENT && (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, ctx->Const.UniformBooleanTrue); 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"); } } build_program_resource_list(ctx, prog); if (!prog->LinkStatus) goto done; /* 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); }