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
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+++ 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;
+}