Initial pass at resolving function calls

The code is still really rough and *REALLY* incomplete.  This at least
passes the first few trivially simple test cases.

Makefile.am

@@ -26,7 +26,7 @@ bin_PROGRAMS = glsl
 glsl_SOURCES = symbol_table.c hash_table.c glsl_types.cpp \
 	glsl_parser.ypp glsl_lexer.lpp glsl_parser_extras.cpp \
 	ast_expr.cpp ast_to_hir.cpp ir.cpp hir_field_selection.cpp \
-	ir_print_visitor.cpp ir_variable.cpp
+	ir_print_visitor.cpp ir_variable.cpp ir_function.cpp
 
 BUILT_SOURCES = glsl_parser.h builtin_types.h
 

ast_to_hir.cpp

@@ -720,11 +720,74 @@ ast_function_expression::hir(exec_list *instructions,
     * 2. methods - Only the .length() method of array types.
     * 3. functions - Calls to regular old functions.
     *
+    * There are two kinds of constructor call.  Constructors for built-in
+    * language types, such as mat4 and vec2, are free form.  The only
+    * requirement is that the parameters must provide enough values of the
+    * correct scalar type.  Constructors for arrays and structures must have
+    * the exact number of parameters with matching types in the correct order.
+    * These constructors follow essentially the same type matching rules as
+    * functions.
+    *
     * Method calls are actually detected when the ast_field_selection
     * expression is handled.
     */
-   (void) instructions;
-   (void) state;
+   if (is_constructor()) {
+      return ir_call::get_error_instruction();
+   } else {
+      const ast_expression *id = subexpressions[0];
+
+      ir_function *f = (ir_function *)
+	 _mesa_symbol_table_find_symbol(state->symbols, 0,
+					id->primary_expression.identifier);
+
+      if (f == NULL) {
+	 YYLTYPE loc = id->get_location();
+
+	 _mesa_glsl_error(& loc, state, "function `%s' undeclared",
+			  id->primary_expression.identifier);
+	 return ir_call::get_error_instruction();
+      }
+
+      /* Once we've determined that the function being called might exist,
+       * process the parameters.
+       */
+      exec_list actual_parameters;
+      simple_node *const first = subexpressions[1];
+      if (first != NULL) {
+	 simple_node *ptr = first;
+	 do {
+	    ir_instruction *const result =
+	       ((ast_node *) ptr)->hir(instructions, state);
+	    ptr = ptr->next;
+
+	    actual_parameters.push_tail(result);
+	 } while (ptr != first);
+      }
+
+      /* After processing the function's actual parameters, try to find an
+       * overload of the function that matches.
+       */
+      const ir_function_signature *sig =
+	 f->matching_signature(& actual_parameters);
+      if (sig != NULL) {
+	 /* FINISHME: The list of actual parameters needs to be modified to
+	  * FINISHME: include any necessary conversions.
+	  */
+	 return new ir_call(sig, & actual_parameters);
+      } else {
+	 YYLTYPE loc = id->get_location();
+
+	 /* FINISHME: Log a better error message here.  G++ will show the types
+	  * FINISHME: of the actual parameters and the set of candidate
+	  * FINISHME: functions.  A different error should also be logged when
+	  * FINISHME: multiple functions match.
+	  */
+	 _mesa_glsl_error(& loc, state, "no matching function for call to `%s'",
+			  id->primary_expression.identifier);
+	 return ir_call::get_error_instruction();
+      }
+   }
+
    return ir_call::get_error_instruction();
 }
 

ir.h

@@ -160,11 +160,19 @@ public:
       v->visit(this);
    }
 
+   /**
+    * Find a signature that matches a set of actual parameters.
+    */
+   const ir_function_signature *matching_signature(exec_list *actual_param);
+
    /**
     * Name of the function.
     */
    const char *name;
 
+   /**
+    * Set of overloaded functions with this name.
+    */
    struct exec_list signatures;
 };
 /*@}*/
@@ -283,10 +291,10 @@ public:
  */
 class ir_call : public ir_instruction {
 public:
-   ir_call()
-      : ir_instruction(ir_op_call), callee(NULL)
+   ir_call(const ir_function_signature *callee, exec_list *actual_parameters)
+      : ir_instruction(ir_op_call), callee(callee)
    {
-      /* empty */
+      actual_parameters->move_nodes_to(& this->actual_parameters);
    }
 
    virtual void accept(ir_visitor *v)
@@ -300,7 +308,13 @@ public:
    static ir_call *get_error_instruction();
 
 private:
-   ir_function_signature *callee;
+   ir_call()
+      : ir_instruction(ir_op_call), callee(NULL)
+   {
+      /* empty */
+   }
+
+   const ir_function_signature *callee;
    exec_list actual_parameters;
 };
 

ir_function.cpp

@@ -0,0 +1,185 @@
+/*
+ * 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 "glsl_types.h"
+#include "ir.h"
+
+int
+type_compare(const glsl_type *a, const glsl_type *b)
+{
+   switch (a->base_type) {
+   case GLSL_TYPE_UINT:
+   case GLSL_TYPE_INT:
+   case GLSL_TYPE_FLOAT:
+   case GLSL_TYPE_BOOL:
+      if ((a->vector_elements != b->vector_elements)
+	  || (a->matrix_rows != b->matrix_rows))
+	 return -1;
+
+      if (a->base_type == b->base_type)
+	 return 0;
+
+      /* There is no implicit conversion to or from bool.
+       */
+      if ((a->base_type == GLSL_TYPE_BOOL)
+	  || (b->base_type == GLSL_TYPE_BOOL))
+	 return -1;
+
+      return 1;
+
+   case GLSL_TYPE_SAMPLER:
+      return ((a->sampler_dimensionality == b->sampler_dimensionality)
+	      && (a->sampler_shadow == b->sampler_shadow)
+	      && (a->sampler_array == b->sampler_array)
+	      && (a->sampler_type == b->sampler_type))
+	 ? 0 : -1;
+
+   case GLSL_TYPE_STRUCT:
+      return (strcmp(a->name, b->name) == 0) ? 0 : -1;
+
+   case GLSL_TYPE_ARRAY:
+      if ((b->base_type != GLSL_TYPE_ARRAY)
+	  || (a->length != b->length))
+	 return -1;
+
+      /* From GLSL 1.50 spec, page 27 (page 33 of the PDF):
+       *    "There are no implicit array or structure conversions."
+       *
+       * If the comparison of the array element types detects that a conversion
+       * would be required, the array types do not match.
+       */
+      return (type_compare(a->fields.array, b->fields.array) == 0) ? 0 : -1;
+
+   case GLSL_TYPE_FUNCTION:
+   case GLSL_TYPE_VOID:
+   case GLSL_TYPE_ERROR:
+   default:
+      /* These are all error conditions.  It is invalid for a parameter to
+       * a function to be declared as error, void, or a function.
+       */
+      return -1;
+   }
+
+   /* This point should be unreachable.
+    */
+   assert(0);
+}
+
+
+static int
+parameter_lists_match(exec_list *list_a, exec_list *list_b)
+{
+   exec_list_iterator iter_a = list_a->iterator();
+   exec_list_iterator iter_b = list_b->iterator();
+   int total_score = 0;
+
+   for (/* empty */ ; iter_a.has_next(); iter_a.next(), iter_b.next()) {
+      /* If all of the parameters from the other parameter list have been
+       * exhausted, the lists have different length and, by definition,
+       * do not match.
+       */
+      if (!iter_b.has_next())
+	 return -1;
+
+
+      const ir_variable *const param = (ir_variable *) iter_a.get();
+      const ir_instruction *const actual = (ir_instruction *) iter_b.get();
+
+      /* Determine whether or not the types match.  If the types are an
+       * exact match, the match score is zero.  If the types don't match
+       * but the actual parameter can be coerced to the type of the declared
+       * parameter, the match score is one.
+       */
+      int score;
+      switch ((enum ir_variable_mode)(param->mode)) {
+      case ir_var_auto:
+      case ir_var_uniform:
+	 /* These are all error conditions.  It is invalid for a parameter to
+	  * a function to be declared as auto (not in, out, or inout) or
+	  * as uniform.
+	  */
+	 assert(0);
+	 return -1;
+
+      case ir_var_in:
+	 score = type_compare(param->type, actual->type);
+	 break;
+
+      case ir_var_out:
+	 /* FINISHME: Make sure that actual is a valid lvalue. */
+	 score = type_compare(actual->type, param->type);
+	 break;
+
+      case ir_var_inout:
+	 /* FINISHME: Make sure that actual is a valid lvalue. */
+
+	 /* Since there are no bi-directional automatic conversions (e.g.,
+	  * there is int -> float but no float -> int), inout parameters must
+	  * be exact matches.
+	  */
+	 score = (type_compare(actual->type, param->type) == 0) ? 0 : -1;
+	 break;
+      }
+
+      if (score < 0)
+	 return -1;
+
+      total_score += score;
+   }
+
+   /* If all of the parameters from the other parameter list have been
+    * exhausted, the lists have different length and, by definition, do not
+    * match.
+    */
+   if (iter_b.has_next())
+      return -1;
+
+   return total_score;
+}
+
+
+const ir_function_signature *
+ir_function::matching_signature(exec_list *actual_parameters)
+{
+   ir_function_signature *match = NULL;
+
+   foreach_iter(exec_list_iterator, iter, signatures) {
+      ir_function_signature *const sig =
+	 (ir_function_signature *) iter.get();
+
+      const int score = parameter_lists_match(& sig->parameters,
+					      actual_parameters);
+
+      if (score == 0)
+	 return sig;
+
+      if (score > 0) {
+	 if (match != NULL)
+	    return NULL;
+
+	 match = sig;
+      }
+   }
+
+   return match;
+}