/* * 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. */ #include "main/core.h" #include "glsl_symbol_table.h" #include "glsl_parser_extras.h" #include "ir.h" #include "program.h" #include "util/set.h" #include "util/hash_table.h" #include "linker.h" static ir_function_signature * find_matching_signature(const char *name, const exec_list *actual_parameters, glsl_symbol_table *symbols); namespace { class call_link_visitor : public ir_hierarchical_visitor { public: call_link_visitor(gl_shader_program *prog, gl_linked_shader *linked, gl_shader **shader_list, unsigned num_shaders) { this->prog = prog; this->shader_list = shader_list; this->num_shaders = num_shaders; this->success = true; this->linked = linked; this->locals = _mesa_set_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal); } ~call_link_visitor() { _mesa_set_destroy(this->locals, NULL); } virtual ir_visitor_status visit(ir_variable *ir) { _mesa_set_add(locals, ir); return visit_continue; } virtual ir_visitor_status visit_enter(ir_call *ir) { /* If ir is an ir_call from a function that was imported from another * shader callee will point to an ir_function_signature in the original * shader. In this case the function signature MUST NOT BE MODIFIED. * Doing so will modify the original shader. This may prevent that * shader from being linkable in other programs. */ const ir_function_signature *const callee = ir->callee; assert(callee != NULL); const char *const name = callee->function_name(); /* We don't actually need to find intrinsics; they're not real */ if (callee->is_intrinsic()) return visit_continue; /* Determine if the requested function signature already exists in the * final linked shader. If it does, use it as the target of the call. */ ir_function_signature *sig = find_matching_signature(name, &callee->parameters, linked->symbols); if (sig != NULL) { ir->callee = sig; return visit_continue; } /* Try to find the signature in one of the other shaders that is being * linked. If it's not found there, return an error. */ for (unsigned i = 0; i < num_shaders; i++) { sig = find_matching_signature(name, &ir->actual_parameters, shader_list[i]->symbols); if (sig) break; } if (sig == NULL) { /* FINISHME: Log the full signature of unresolved function. */ linker_error(this->prog, "unresolved reference to function `%s'\n", name); this->success = false; return visit_stop; } /* Find the prototype information in the linked shader. Generate any * details that may be missing. */ ir_function *f = linked->symbols->get_function(name); if (f == NULL) { f = new(linked) ir_function(name); /* Add the new function to the linked IR. Put it at the end * so that it comes after any global variable declarations * that it refers to. */ linked->symbols->add_function(f); linked->ir->push_tail(f); } ir_function_signature *linked_sig = f->exact_matching_signature(NULL, &callee->parameters); if (linked_sig == NULL) { linked_sig = new(linked) ir_function_signature(callee->return_type); f->add_signature(linked_sig); } /* At this point linked_sig and called may be the same. If ir is an * ir_call from linked then linked_sig and callee will be * ir_function_signatures that have no definitions (is_defined is false). */ assert(!linked_sig->is_defined); assert(linked_sig->body.is_empty()); /* Create an in-place clone of the function definition. This multistep * process introduces some complexity here, but it has some advantages. * The parameter list and the and function body are cloned separately. * The clone of the parameter list is used to prime the hashtable used * to replace variable references in the cloned body. * * The big advantage is that the ir_function_signature does not change. * This means that we don't have to process the rest of the IR tree to * patch ir_call nodes. In addition, there is no way to remove or * replace signature stored in a function. One could easily be added, * but this avoids the need. */ struct hash_table *ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal); exec_list formal_parameters; foreach_in_list(const ir_instruction, original, &sig->parameters) { assert(const_cast<ir_instruction *>(original)->as_variable()); ir_instruction *copy = original->clone(linked, ht); formal_parameters.push_tail(copy); } linked_sig->replace_parameters(&formal_parameters); linked_sig->intrinsic_id = sig->intrinsic_id; if (sig->is_defined) { foreach_in_list(const ir_instruction, original, &sig->body) { ir_instruction *copy = original->clone(linked, ht); linked_sig->body.push_tail(copy); } linked_sig->is_defined = true; } _mesa_hash_table_destroy(ht, NULL); /* Patch references inside the function to things outside the function * (i.e., function calls and global variables). */ linked_sig->accept(this); ir->callee = linked_sig; return visit_continue; } virtual ir_visitor_status visit_leave(ir_call *ir) { /* Traverse list of function parameters, and for array parameters * propagate max_array_access. Otherwise arrays that are only referenced * from inside functions via function parameters will be incorrectly * optimized. This will lead to incorrect code being generated (or worse). * Do it when leaving the node so the children would propagate their * array accesses first. */ const exec_node *formal_param_node = ir->callee->parameters.get_head(); if (formal_param_node) { const exec_node *actual_param_node = ir->actual_parameters.get_head(); while (!actual_param_node->is_tail_sentinel()) { ir_variable *formal_param = (ir_variable *) formal_param_node; ir_rvalue *actual_param = (ir_rvalue *) actual_param_node; formal_param_node = formal_param_node->get_next(); actual_param_node = actual_param_node->get_next(); if (formal_param->type->is_array()) { ir_dereference_variable *deref = actual_param->as_dereference_variable(); if (deref && deref->var && deref->var->type->is_array()) { deref->var->data.max_array_access = MAX2(formal_param->data.max_array_access, deref->var->data.max_array_access); } } } } return visit_continue; } virtual ir_visitor_status visit(ir_dereference_variable *ir) { if (_mesa_set_search(locals, ir->var) == NULL) { /* The non-function variable must be a global, so try to find the * variable in the shader's symbol table. If the variable is not * found, then it's a global that *MUST* be defined in the original * shader. */ ir_variable *var = linked->symbols->get_variable(ir->var->name); if (var == NULL) { /* Clone the ir_variable that the dereference already has and add * it to the linked shader. */ var = ir->var->clone(linked, NULL); linked->symbols->add_variable(var); linked->ir->push_head(var); } else { if (var->type->is_array()) { /* It is possible to have a global array declared in multiple * shaders without a size. The array is implicitly sized by * the maximal access to it in *any* shader. Because of this, * we need to track the maximal access to the array as linking * pulls more functions in that access the array. */ var->data.max_array_access = MAX2(var->data.max_array_access, ir->var->data.max_array_access); if (var->type->length == 0 && ir->var->type->length != 0) var->type = ir->var->type; } if (var->is_interface_instance()) { /* Similarly, we need implicit sizes of arrays within interface * blocks to be sized by the maximal access in *any* shader. */ int *const linked_max_ifc_array_access = var->get_max_ifc_array_access(); int *const ir_max_ifc_array_access = ir->var->get_max_ifc_array_access(); assert(linked_max_ifc_array_access != NULL); assert(ir_max_ifc_array_access != NULL); for (unsigned i = 0; i < var->get_interface_type()->length; i++) { linked_max_ifc_array_access[i] = MAX2(linked_max_ifc_array_access[i], ir_max_ifc_array_access[i]); } } } ir->var = var; } return visit_continue; } /** Was function linking successful? */ bool success; private: /** * Shader program being linked * * This is only used for logging error messages. */ gl_shader_program *prog; /** List of shaders available for linking. */ gl_shader **shader_list; /** Number of shaders available for linking. */ unsigned num_shaders; /** * Final linked shader * * This is used two ways. It is used to find global variables in the * linked shader that are accessed by the function. It is also used to add * global variables from the shader where the function originated. */ gl_linked_shader *linked; /** * Table of variables local to the function. */ set *locals; }; } /* anonymous namespace */ /** * Searches a list of shaders for a particular function definition */ ir_function_signature * find_matching_signature(const char *name, const exec_list *actual_parameters, glsl_symbol_table *symbols) { ir_function *const f = symbols->get_function(name); if (f) { ir_function_signature *sig = f->matching_signature(NULL, actual_parameters, false); if (sig && (sig->is_defined || sig->is_intrinsic())) return sig; } return NULL; } bool link_function_calls(gl_shader_program *prog, gl_linked_shader *main, gl_shader **shader_list, unsigned num_shaders) { call_link_visitor v(prog, main, shader_list, num_shaders); v.run(main->ir); return v.success; }