/* * 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 "program/hash_table.h" #include "linker.h" static ir_function_signature * find_matching_signature(const char *name, const exec_list *actual_parameters, gl_shader **shader_list, unsigned num_shaders, bool use_builtin); class call_link_visitor : public ir_hierarchical_visitor { public: call_link_visitor(gl_shader_program *prog, gl_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 = hash_table_ctor(0, hash_table_pointer_hash, hash_table_pointer_compare); } ~call_link_visitor() { hash_table_dtor(this->locals); } virtual ir_visitor_status visit(ir_variable *ir) { hash_table_insert(locals, ir, 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(); /* 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, 1, ir->use_builtin); 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. */ sig = find_matching_signature(name, &ir->actual_parameters, shader_list, num_shaders, ir->use_builtin); 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 != NULL) && (linked_sig->is_builtin() != ir->use_builtin))) { 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 = hash_table_ctor(0, hash_table_pointer_hash, hash_table_pointer_compare); exec_list formal_parameters; foreach_list_const(node, &sig->parameters) { const ir_instruction *const original = (ir_instruction *) node; 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); foreach_list_const(node, &sig->body) { const ir_instruction *const original = (ir_instruction *) node; ir_instruction *copy = original->clone(linked, ht); linked_sig->body.push_tail(copy); } linked_sig->is_defined = true; hash_table_dtor(ht); /* 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->max_array_access = MAX2(formal_param->max_array_access, deref->var->max_array_access); } } } } return visit_continue; } virtual ir_visitor_status visit(ir_dereference_variable *ir) { if (hash_table_find(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->max_array_access = MAX2(var->max_array_access, ir->var->max_array_access); if (var->type->length == 0 && ir->var->type->length != 0) var->type = ir->var->type; } 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_shader *linked; /** * Table of variables local to the function. */ hash_table *locals; }; /** * Searches a list of shaders for a particular function definition */ ir_function_signature * find_matching_signature(const char *name, const exec_list *actual_parameters, gl_shader **shader_list, unsigned num_shaders, bool use_builtin) { for (unsigned i = 0; i < num_shaders; i++) { ir_function *const f = shader_list[i]->symbols->get_function(name); if (f == NULL) continue; ir_function_signature *sig = f->matching_signature(NULL, actual_parameters); if ((sig == NULL) || !sig->is_defined) continue; /* If this function expects to bind to a built-in function and the * signature that we found isn't a built-in, keep looking. Also keep * looking if we expect a non-built-in but found a built-in. */ if (use_builtin != sig->is_builtin()) continue; return sig; } return NULL; } bool link_function_calls(gl_shader_program *prog, gl_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; }