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Diffstat (limited to 'src/glsl/link_functions.cpp')
| -rw-r--r-- | src/glsl/link_functions.cpp | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/glsl/link_functions.cpp b/src/glsl/link_functions.cpp new file mode 100644 index 00000000000..dfda05fcbe5 --- /dev/null +++ b/src/glsl/link_functions.cpp @@ -0,0 +1,262 @@ +/* + * 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 <cstdlib> +#include <cstdio> +#include <cstdarg> + +extern "C" { +#include <talloc.h> +} + +#include "main/mtypes.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); + +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->get_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); + if (sig != NULL) { + ir->set_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); + if (sig == NULL) { + /* FINISHME: Log the full signature of unresolved function. + */ + linker_error_printf(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); + + ir_function_signature *linked_sig = + f->matching_signature(&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 = 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->set_callee(linked_sig); + + 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->name, var); + linked->ir->push_head(var); + } + + 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) +{ + 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(actual_parameters); + + if ((sig == NULL) || !sig->is_defined) + 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; +} |