* c-exp.y: Add new rule for resolving method overloads.

* eval.c (make_params): New function.
	(free_param_types): New function.
	(evaluate_subexp_standard): Pass expect_type to value_aggregate_elt.
	Handle case TYPE_INSTANCE.
	(evaluate_subexp_for_address): Pass expect_type to value_aggregate_elt.
	* expression.h (enum exp_opcode): Add TYPE_INSTANCE.
	(compare_parameters): Add declaration.
	* parse.c (operator_length_standard): Add TYPE_INSTANCE.
	* valops.c (value_aggregate_elt): Add new expect_type parameter.
	Pass expect_type to value_struct_elt_for_reference.
	(value_struct_elt_for_reference): Add expect_type parameter and use
	compare_parameters.
	Check for overload matches with and without artificial parameters.
	Skip artificial methods.
	(compare_parameters): New function.
	* value.h (value_aggregate_elt): Add new expect_type parameter.

gdb/ChangeLog

@@ -1,3 +1,23 @@
+2009-11-10  Keith Seitz  <keiths@redhat.com>
+
+	* c-exp.y: Add new rule for resolving method overloads.
+	* eval.c (make_params): New function.
+	(free_param_types): New function.
+	(evaluate_subexp_standard): Pass expect_type to value_aggregate_elt.
+	Handle case TYPE_INSTANCE.
+	(evaluate_subexp_for_address): Pass expect_type to value_aggregate_elt.
+	* expression.h (enum exp_opcode): Add TYPE_INSTANCE.
+	(compare_parameters): Add declaration.
+	* parse.c (operator_length_standard): Add TYPE_INSTANCE.
+	* valops.c (value_aggregate_elt): Add new expect_type parameter.
+	Pass expect_type to value_struct_elt_for_reference.
+	(value_struct_elt_for_reference): Add expect_type parameter and use
+	compare_parameters.
+	Check for overload matches with and without artificial parameters.
+	Skip artificial methods.
+	(compare_parameters): New function.
+	* value.h (value_aggregate_elt): Add new expect_type parameter.
+
 2009-11-10  Joseph Myers  <joseph@codesourcery.com>
 
 	* solib-svr4.c (enable_break): Call

gdb/c-exp.y

@@ -401,6 +401,18 @@ arglist	:	arglist ',' exp   %prec ABOVE_COMMA
 			{ arglist_len++; }
 	;
 
+exp     :       exp '(' nonempty_typelist ')' const_or_volatile
+			{ int i;
+			  write_exp_elt_opcode (TYPE_INSTANCE);
+			  write_exp_elt_longcst ((LONGEST) $<ivec>3[0]);
+			  for (i = 0; i < $<ivec>3[0]; ++i)
+			    write_exp_elt_type ($<tvec>3[i + 1]);
+			  write_exp_elt_longcst((LONGEST) $<ivec>3[0]);
+			  write_exp_elt_opcode (TYPE_INSTANCE);
+			  free ($3);
+			}
+	;
+
 rcurly	:	'}'
 			{ $$ = end_arglist () - 1; }
 	;

gdb/eval.c

@@ -40,6 +40,8 @@
 #include "regcache.h"
 #include "user-regs.h"
 #include "valprint.h"
+#include "gdb_obstack.h"
+#include "objfiles.h"
 #include "python/python.h"
 
 #include "gdb_assert.h"
@@ -651,6 +653,29 @@ ptrmath_type_p (struct type *type)
     }
 }
 
+/* Constructs a fake method with the given parameter types.
+   This function is used by the parser to construct an "expected"
+   type for method overload resolution.  */
+
+static struct type *
+make_params (int num_types, struct type **param_types)
+{
+  struct type *type = XZALLOC (struct type);
+  TYPE_MAIN_TYPE (type) = XZALLOC (struct main_type);
+  TYPE_LENGTH (type) = 1;
+  TYPE_CODE (type) = TYPE_CODE_METHOD;
+  TYPE_VPTR_FIELDNO (type) = -1;
+  TYPE_CHAIN (type) = type;
+  TYPE_NFIELDS (type) = num_types;
+  TYPE_FIELDS (type) = (struct field *)
+    TYPE_ZALLOC (type, sizeof (struct field) * num_types);
+
+  while (num_types-- > 0)
+    TYPE_FIELD_TYPE (type, num_types) = param_types[num_types];
+
+  return type;
+}
+
 struct value *
 evaluate_subexp_standard (struct type *expect_type,
 			  struct expression *exp, int *pos,
@@ -684,7 +709,7 @@ evaluate_subexp_standard (struct type *expect_type,
 	goto nosideret;
       arg1 = value_aggregate_elt (exp->elts[pc + 1].type,
 				  &exp->elts[pc + 3].string,
-				  0, noside);
+				  expect_type, 0, noside);
       if (arg1 == NULL)
 	error (_("There is no field named %s"), &exp->elts[pc + 3].string);
       return arg1;
@@ -1730,6 +1755,20 @@ evaluate_subexp_standard (struct type *expect_type,
 	  error (_("non-pointer-to-member value used in pointer-to-member construct"));
 	}
 
+    case TYPE_INSTANCE:
+      nargs = longest_to_int (exp->elts[pc + 1].longconst);
+      arg_types = (struct type **) alloca (nargs * sizeof (struct type *));
+      for (ix = 0; ix < nargs; ++ix)
+	arg_types[ix] = exp->elts[pc + 1 + ix + 1].type;
+
+      expect_type = make_params (nargs, arg_types);
+      *(pos) += 3 + nargs;
+      arg1 = evaluate_subexp_standard (expect_type, exp, pos, noside);
+      xfree (TYPE_FIELDS (expect_type));
+      xfree (TYPE_MAIN_TYPE (expect_type));
+      xfree (expect_type);
+      return arg1;
+
     case BINOP_CONCAT:
       arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
       arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
@@ -2612,7 +2651,7 @@ evaluate_subexp_for_address (struct expression *exp, int *pos,
       (*pos) += 5 + BYTES_TO_EXP_ELEM (tem + 1);
       x = value_aggregate_elt (exp->elts[pc + 1].type,
 			       &exp->elts[pc + 3].string,
-			       1, noside);
+			       NULL, 1, noside);
       if (x == NULL)
 	error (_("There is no field named %s"), &exp->elts[pc + 3].string);
       return x;

gdb/expression.h

@@ -88,6 +88,13 @@ enum exp_opcode
        when X is a pointer instead of an aggregate.  */
     STRUCTOP_MPTR,
 
+    /* TYPE_INSTANCE is used when the user specifies a specific
+       type instantiation for overloaded methods/functions.
+
+       The format is:
+       TYPE_INSTANCE num_types type0 ... typeN num_types TYPE_INSTANCE  */
+    TYPE_INSTANCE,
+
     /* end of C++.  */
 
     /* For Modula-2 integer division DIV */

gdb/parse.c

@@ -837,6 +837,11 @@ operator_length_standard (struct expression *expr, int endpos,
       args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
       break;
 
+    case TYPE_INSTANCE:
+      oplen = 4 + longest_to_int (expr->elts[endpos - 2].longconst);
+      args = 1;
+      break;
+
     case OP_OBJC_MSGCALL:	/* Objective C message (method) call */
       oplen = 4;
       args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);

gdb/valops.c

@@ -2536,8 +2536,8 @@ check_field (struct type *type, const char *name)
    the comment before value_struct_elt_for_reference.  */
 
 struct value *
-value_aggregate_elt (struct type *curtype,
+value_aggregate_elt (struct type *curtype, char *name,
-		     char *name, int want_address,
+		     struct type *expect_type, int want_address,
 		     enum noside noside)
 {
   switch (TYPE_CODE (curtype))
@@ -2545,7 +2545,7 @@ value_aggregate_elt (struct type *curtype,
     case TYPE_CODE_STRUCT:
     case TYPE_CODE_UNION:
       return value_struct_elt_for_reference (curtype, 0, curtype, 
-					     name, NULL,
+					     name, expect_type,
 					     want_address, noside);
     case TYPE_CODE_NAMESPACE:
       return value_namespace_elt (curtype, name, 
@@ -2556,6 +2556,57 @@ value_aggregate_elt (struct type *curtype,
     }
 }
 
+/* Compares the two method/function types T1 and T2 for "equality" 
+   with respect to the the methods' parameters.  If the types of the
+   two parameter lists are the same, returns 1; 0 otherwise.  This
+   comparison may ignore any artificial parameters in T1 if
+   SKIP_ARTIFICIAL is non-zero.  This function will ALWAYS skip
+   the first artificial parameter in T1, assumed to be a 'this' pointer.
+
+   The type T2 is expected to have come from make_params (in eval.c).  */
+
+static int
+compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
+{
+  int start = 0;
+
+  if (TYPE_FIELD_ARTIFICIAL (t1, 0))
+    ++start;
+
+  /* If skipping artificial fields, find the first real field
+     in T1. */
+  if (skip_artificial)
+    {
+      while (start < TYPE_NFIELDS (t1)
+	     && TYPE_FIELD_ARTIFICIAL (t1, start))
+	++start;
+    }
+
+  /* Now compare parameters */
+
+  /* Special case: a method taking void.  T1 will contain no
+     non-artificial fields, and T2 will contain TYPE_CODE_VOID.  */
+  if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
+      && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
+    return 1;
+
+  if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
+    {
+      int i;
+      for (i = 0; i < TYPE_NFIELDS (t2); ++i)
+	{
+	  if (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
+			      TYPE_FIELD_TYPE (t2, i))
+	      != 0)
+	    return 0;
+	}
+
+      return 1;
+    }
+
+  return 0;
+}
+
 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
    return the address of this member as a "pointer to member" type.
    If INTYPE is non-null, then it will be the type of the member we
@@ -2633,23 +2684,46 @@ value_struct_elt_for_reference (struct type *domain, int offset,
 	}
       if (t_field_name && strcmp (t_field_name, name) == 0)
 	{
-	  int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
+	  int j;
+	  int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
 	  struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
 
 	  check_stub_method_group (t, i);
 
-	  if (intype == 0 && j > 1)
-	    error (_("non-unique member `%s' requires type instantiation"), name);
 	  if (intype)
 	    {
-	      while (j--)
+	      for (j = 0; j < len; ++j)
-		if (TYPE_FN_FIELD_TYPE (f, j) == intype)
+		{
-		  break;
+		  if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
-	      if (j < 0)
+		      || compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 1))
-		error (_("no member function matches that type instantiation"));
+		    break;
-	    }
+		}
+
+	      if (j == len)
+		error (_("no member function matches that type instantiation"));	    }
 	  else
-	    j = 0;
+	    {
+	      int ii;
+	      /* Skip artificial methods.  This is necessary if, for example,
+		 the user wants to "print subclass::subclass" with only
+		 one user-defined constructor.  There is no ambiguity in this
+		 case.  */
+	      for (ii = 0; ii < TYPE_FN_FIELDLIST_LENGTH (t, i);
+		   ++ii)
+		{
+		  if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
+		    --len;
+		}
+
+	      /* Desired method is ambiguous if more than one method is
+		 defined.  */
+	      if (len > 1)
+		error (_("non-unique member `%s' requires type instantiation"), name);
+
+	      /* This assumes, of course, that all artificial methods appear
+		 BEFORE any concrete methods.  */
+	      j = TYPE_FN_FIELDLIST_LENGTH (t, i) - 1;
+	    }
 
 	  if (TYPE_FN_FIELD_STATIC_P (f, j))
 	    {

gdb/value.h

@@ -436,6 +436,7 @@ extern struct value *value_struct_elt (struct value **argp,
 
 extern struct value *value_aggregate_elt (struct type *curtype,
 					  char *name,
+					  struct type *expect_type,
 					  int want_address,
 					  enum noside noside);