[patch] support argument dependent lookup (ADL)

[Sami Wagiaalla <swagiaal at redhat dot com>]

supports printing of variables in this manner:

namespace A 
{
 class B {}  

 void foo(B){}
}

int main(){
 A::B b;
 // (gdb) p foo(B)
 return 0;
}

foo is found by searching the namespaces which its arguments belong to.

   2010-03-22  Sami Wagiaalla  <swagiaal@redhat.com>
   
   	PR C++/7943:
   	* valops.c (find_overload_match): Handle fsym == NULL case.
   	(find_oload_champ_namespace_loop): Call make_symbol_overload_list_adl
   	when appropriate.
   	* parse.c (operator_length_standard): Return length for OP_ADL_FUNC
   	expression.
   	* expprint.c (op_name_standard): Added string for OP_ADL_FUNC case.
   	* eval.c (evaluate_subexp_standard): Added OP_ADL_FUNC case.
   	Evaluate arguments and use them to perform ADL lookup.
   	* cp-support.h: Added prototype for
   	make_symbol_overload_list_namespace.
   	* cp-support.c (make_symbol_overload_list_namespace): New function.
   	(make_symbol_overload_list_adl_namespace): New function.
   	(make_symbol_overload_list_adl): New function.
   	(make_symbol_overload_list_using): Moved code to add function to
   	overload set to make_symbol_overload_list_namespace.
   	* c-exp.y: create UNKNOWN_CPP_NAME token.
   	Add parse rule for ADL functions.
   	(classify_name): Recognize an UNKNOWN_CPP_NAME.
   
   2010-03-22  Sami Wagiaalla  <swagiaal@redhat.com>
   
   	* gdb.cp/koenig.exp: New test.
   	* gdb.cp/koenig.cc: New test program.

diff --git a/gdb/c-exp.y b/gdb/c-exp.y
index 1af76c9..d93815d 100644
--- a/gdb/c-exp.y
+++ b/gdb/c-exp.y
@@ -186,6 +186,7 @@ static struct stoken operator_stoken (const char *);
%token <tsval> STRING
%token <tsval> CHAR
%token <ssym> NAME /* BLOCKNAME defined below to give it higher precedence. */
+%token <ssym> UNKNOWN_CPP_NAME
%token <voidval> COMPLETE
%token <tsym> TYPENAME
%type <sval> name
@@ -391,6 +392,30 @@ exp	:	exp '('
			  write_exp_elt_opcode (OP_FUNCALL); }
	;

+exp	:	UNKNOWN_CPP_NAME '('
+			{
+
+			 /* This could potentially be a an argument defined
+			    lookup function (Koenig).  */
+			  write_exp_elt_opcode (OP_ADL_FUNC);
+			  write_exp_elt_block (expression_context_block);
+			  write_exp_elt_sym (NULL); /* Place holder */
+			  write_exp_string ($1.stoken);
+			  write_exp_elt_opcode (OP_ADL_FUNC);
+
+			/* This is to save the value of arglist_len
+			   being accumulated by an outer function call.  */
+
+			  start_arglist ();
+			}
+		arglist ')'	%prec ARROW
+			{
+			  write_exp_elt_opcode (OP_FUNCALL);
+			  write_exp_elt_longcst ((LONGEST) end_arglist ());
+			  write_exp_elt_opcode (OP_FUNCALL);
+			}
+	;
+
lcurly	:	'{'
			{ start_arglist (); }
	;
@@ -1224,6 +1249,7 @@ name	:	NAME { $$ = $1.stoken; }
	|	BLOCKNAME { $$ = $1.stoken; }
	|	TYPENAME { $$ = $1.stoken; }
	|	NAME_OR_INT  { $$ = $1.stoken; }
+	|	UNKNOWN_CPP_NAME  { $$ = $1.stoken; }
	|	operator { $$ = $1; }
	;

@@ -1236,6 +1262,7 @@ name_not_typename :	NAME
   context where only a name could occur, this might be useful.
  	|	NAME_OR_INT
 */
+	|	UNKNOWN_CPP_NAME
	;

%%
@@ -2379,6 +2406,12 @@ classify_name (struct block *block)
  /* Any other kind of symbol */
  yylval.ssym.sym = sym;
  yylval.ssym.is_a_field_of_this = is_a_field_of_this;
+
+  if (sym == NULL
+      && parse_language->la_language == language_cplus
+      && !lookup_minimal_symbol (copy, NULL, NULL))
+    return UNKNOWN_CPP_NAME;
+
  return NAME;
}

diff --git a/gdb/cp-support.c b/gdb/cp-support.c
index d43d25f..8c18304 100644
--- a/gdb/cp-support.c
+++ b/gdb/cp-support.c
@@ -52,7 +52,7 @@ static void demangled_name_complaint (const char *name);

/* Functions/variables related to overload resolution.  */

-static int sym_return_val_size;
+static int sym_return_val_size = -1;
static int sym_return_val_index;
static struct symbol **sym_return_val;

@@ -712,6 +712,83 @@ make_symbol_overload_list (const char *func_name,
  return sym_return_val;
}

+/* Adds the function FUNC_NAME from NAMESPACE to the overload set.  */
+
+static void
+make_symbol_overload_list_namespace (const char *func_name,
+                                     const char *namespace)
+{
+
+  if (namespace[0] == '\0')
+    {
+      make_symbol_overload_list_qualified (func_name);
+    }
+  else
+    {
+      char *concatenated_name
+	= alloca (strlen (namespace) + 2 + strlen (func_name) + 1);
+      strcpy (concatenated_name, namespace);
+      strcat (concatenated_name, "::");
+      strcat (concatenated_name, func_name);
+      make_symbol_overload_list_qualified (concatenated_name);
+    }
+}
+
+/* Search the namespace of the given type and namespace of and public base
+ types.  */
+static void make_symbol_overload_list_adl_namespace (struct type *type,
+						     const char *func_name)
+{
+  char *namespace;
+  char *type_name;
+  int i, prefix_len;
+
+  if (TYPE_CODE (type) == TYPE_CODE_PTR || TYPE_CODE (type) == TYPE_CODE_REF
+      || TYPE_CODE (type) == TYPE_CODE_ARRAY)
+    return make_symbol_overload_list_adl_namespace (TYPE_TARGET_TYPE (type),
+                                                    func_name);
+
+  type_name = TYPE_NAME (type);
+
+  prefix_len = cp_entire_prefix_len (type_name);
+
+  if (prefix_len != 0)
+    {
+      namespace = alloca (prefix_len + 1);
+      strncpy (namespace, type_name, prefix_len);
+      namespace[prefix_len] = '\0';
+
+      make_symbol_overload_list_namespace (func_name, namespace);
+    }
+
+  /* Check public base type */
+  if (TYPE_CODE(type) == TYPE_CODE_CLASS)
+    for (i = 0; i < TYPE_N_BASECLASSES (type); i++)
+      {
+	if (BASETYPE_VIA_PUBLIC (type, i))
+	  make_symbol_overload_list_adl_namespace (TYPE_BASECLASS (type, i),
+						   func_name);
+      }
+
+}
+
+/* Adds the the overload list overload candidates for FUNC_NAME found through
+   argument dependent lookup.  */
+
+struct symbol **
+make_symbol_overload_list_adl (struct type **arg_types, int nargs,
+                               const char *func_name)
+{
+  int i;
+
+  gdb_assert (sym_return_val_size != -1);
+
+  for (i = 1; i <= nargs; i++)
+    make_symbol_overload_list_adl_namespace (arg_types[i - 1], func_name);
+
+  return sym_return_val;
+}
+
/* This applies the using directives to add namespaces to search in,
   and then searches for overloads in all of those namespaces.  It
   adds the symbols found to sym_return_val.  Arguments are as in
@@ -739,20 +816,7 @@ make_symbol_overload_list_using (const char *func_name,
    }

  /* Now, add names for this namespace.  */
-  
-  if (namespace[0] == '\0')
-    {
-      make_symbol_overload_list_qualified (func_name);
-    }
-  else
-    {
-      char *concatenated_name
-	= alloca (strlen (namespace) + 2 + strlen (func_name) + 1);
-      strcpy (concatenated_name, namespace);
-      strcat (concatenated_name, "::");
-      strcat (concatenated_name, func_name);
-      make_symbol_overload_list_qualified (concatenated_name);
-    }
+  make_symbol_overload_list_namespace (func_name, namespace);
}

/* This does the bulk of the work of finding overloaded symbols.
diff --git a/gdb/cp-support.h b/gdb/cp-support.h
index e10f5a9..f92ca67 100644
--- a/gdb/cp-support.h
+++ b/gdb/cp-support.h
@@ -79,6 +79,10 @@ extern char *cp_remove_params (const char *demangled_name);
extern struct symbol **make_symbol_overload_list (const char *,
						  const char *);

+extern struct symbol **make_symbol_overload_list_adl (struct type **arg_types,
+                                                      int nargs,
+                                                      const char *func_name);
+
extern struct type *cp_lookup_rtti_type (const char *name,
					 struct block *block);

diff --git a/gdb/eval.c b/gdb/eval.c
index 3bcd417..1e1ed0e 100644
--- a/gdb/eval.c
+++ b/gdb/eval.c
@@ -731,6 +731,7 @@ evaluate_subexp_standard (struct type *expect_type,
      return value_from_decfloat (exp->elts[pc + 1].type,
				  exp->elts[pc + 2].decfloatconst);

+    case OP_ADL_FUNC:
    case OP_VAR_VALUE:
      (*pos) += 3;
      if (noside == EVAL_SKIP)
@@ -1453,6 +1454,17 @@ evaluate_subexp_standard (struct type *expect_type,
	      tem = 2;
	    }
	}
+      else if (op == OP_ADL_FUNC)
+        {
+          /* Save the function position and move pos so that the arguments
+             can be evaluated.  */
+          int func_name_len;
+          save_pos1 = *pos;
+          tem = 1;
+
+          func_name_len = longest_to_int (exp->elts[save_pos1 + 3].longconst);
+          (*pos) += 6 + BYTES_TO_EXP_ELEM (func_name_len + 1);
+        }
      else
	{
	  /* Non-method function call */
@@ -1483,6 +1495,32 @@ evaluate_subexp_standard (struct type *expect_type,

      /* signal end of arglist */
      argvec[tem] = 0;
+      if (op == OP_ADL_FUNC)
+        {
+          struct symbol *symp;
+          char *func_name;
+          int  name_len;
+          int string_pc = save_pos1 + 3;
+
+          /* Extract the function name.  */
+          name_len = longest_to_int (exp->elts[string_pc].longconst);
+          func_name = (char *) alloca (name_len + 1);
+          strcpy (func_name, &exp->elts[string_pc + 1].string);
+
+          /* Prepare list of argument types for overload resolution */
+          arg_types = (struct type **) alloca (nargs * (sizeof (struct type *)));
+          for (ix = 1; ix <= nargs; ix++)
+            arg_types[ix - 1] = value_type (argvec[ix]);
+
+          find_overload_match (arg_types, nargs, func_name,
+                               0 /* not method */ , 0 /* strict match */ ,
+                               NULL, NULL /* pass NULL symbol since symbol is unknown */ ,
+                               NULL, &symp, NULL);
+
+          /* Now fix the expression being evaluated.  */
+          exp->elts[save_pos1 + 2].symbol = symp;
+          argvec[0] = evaluate_subexp_with_coercion (exp, &save_pos1, noside);
+        }

      if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR
	  || (op == OP_SCOPE && function_name != NULL))
diff --git a/gdb/expprint.c b/gdb/expprint.c
index e378831..45deffe 100644
--- a/gdb/expprint.c
+++ b/gdb/expprint.c
@@ -816,6 +816,8 @@ op_name_standard (enum exp_opcode opcode)
      return "OP_TYPE";
    case OP_LABELED:
      return "OP_LABELED";
+    case OP_ADL_FUNC:
+      return "OP_ADL_FUNC";
    }
}

diff --git a/gdb/expression.h b/gdb/expression.h
index ca216cf..29ebde4 100644
--- a/gdb/expression.h
+++ b/gdb/expression.h
@@ -347,6 +347,10 @@ enum exp_opcode
       Then comes another OP_DECFLOAT.  */
    OP_DECFLOAT,

+    /* OP_ADL_FUNC specifies that the function is to be looked up in an
+       Argument Dependent manner (Koenig lookup).  */
+    OP_ADL_FUNC,
+
     /* First extension operator.  Individual language modules define
	extra operators in *.inc include files below always starting with
	numbering at OP_EXTENDED0:
diff --git a/gdb/parse.c b/gdb/parse.c
index aabc461..b607c71 100644
--- a/gdb/parse.c
+++ b/gdb/parse.c
@@ -889,6 +889,13 @@ operator_length_standard (struct expression *expr, int endpos,
      args = 1;
      break;

+    case OP_ADL_FUNC:
+      oplen = longest_to_int (expr->elts[endpos - 2].longconst);
+      oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
+      oplen++;
+      oplen++;
+      break;
+
    case OP_LABELED:
    case STRUCTOP_STRUCT:
    case STRUCTOP_PTR:
diff --git a/gdb/testsuite/gdb.cp/koenig.cc b/gdb/testsuite/gdb.cp/koenig.cc
new file mode 100644
index 0000000..6c2c01d
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/koenig.cc
@@ -0,0 +1,188 @@
+namespace A
+{
+  class C
+  {
+  public:
+    static const int x = 11;
+  };
+
+  int
+  first (C c)
+  {
+    return 11;
+  }
+
+  int
+  first (int a, C c)
+  {
+    return 22;
+  }
+
+  int
+  second (int a, int b, C cc, int c, int d)
+  {
+    return 33;
+  }
+
+}
+
+struct B
+{
+  A::C c;
+};
+
+//------------
+
+namespace E
+{
+  class O{};
+  int foo (O o){return 1; }
+  int foo (O o, O o2){return 2; }
+  int foo (O o, O o2, int i){return 3; }
+}
+
+namespace F
+{
+  class O{};
+  int foo (       O fo, ::E::O eo){ return 4;}
+  int foo (int i, O fo, ::E::O eo){ return 5;}
+}
+
+namespace G
+{
+  class O{};
+  int foo (O go, ::F::O fo, ::E::O eo){ return 6; }
+}
+
+//------------
+
+namespace H
+{
+  class O{};
+  int foo (O){ return 7;}
+}
+
+namespace I
+{
+  class O: public H::O {};
+  class X: H::O{};
+}
+
+//------------
+
+namespace J
+{
+  union U{};
+  struct S{};
+  enum E{};
+
+  class A{
+  public:
+    class B{};
+  };
+
+  class C{};
+
+  int foo (U){ return 8;}
+  int foo (S){ return 9;}
+  int foo (E){ return 10;}
+  int foo (A::B){ return 11;}
+  int foo (A*){ return 12;}
+  int foo (A**){ return 13;}
+  int foo (C[]){ return 14;}
+
+}
+//------------
+
+namespace K{
+  class O{};
+
+  int foo(O, int){
+    return 15;
+  }
+
+  int bar(O, int){
+    return 15;
+  }
+}
+
+int foo(K::O, float){
+  return 16;
+}
+
+int bar(K::O, int){
+  return 16;
+}
+//------------
+
+namespace L {
+  namespace A{
+    namespace B{
+    class O {};
+
+    int foo (O){
+      return 17;
+    }
+
+    }
+  }
+}
+
+//------------
+int
+main ()
+{
+  A::C c;
+  B b;
+
+  A::first (c);
+  first (0, c);
+  second (0, 0, c, 0, 0);
+  A::first (b.c);
+
+  E::O eo;
+  F::O fo;
+  G::O go;
+
+  foo (eo);
+  foo (eo, eo);
+  foo (eo, eo, 1);
+  foo (fo, eo);
+  foo (1  ,fo, eo);
+  foo (go, fo, eo);
+
+  I::O io;
+  I::X ix;
+
+  foo (io);
+//foo (ix);
+
+  J::U ju;
+  J::S js;
+  J::E je;
+  J::A::B jab;
+  J::A *jap;
+  J::A **japp;
+  J::C jca[3];
+
+  foo (ju);
+  foo (js);
+  foo (je);
+  foo (jab);
+  foo (jap);
+  foo (japp);
+  foo (jca);
+
+  K::O ko;
+  foo (ko, 1);
+  foo (ko, 1.0f);
+  //bar(ko,1);
+
+  L::A::B::O labo;
+  foo (labo);
+  
+  return first (0, c) + foo (eo) +
+         foo (eo, eo) + foo (eo, eo, 1)  +
+         foo (fo, eo) + foo (1  ,fo, eo) +
+         foo (go, fo, eo);
+}
diff --git a/gdb/testsuite/gdb.cp/koenig.exp b/gdb/testsuite/gdb.cp/koenig.exp
new file mode 100644
index 0000000..cebf045
--- /dev/null
+++ b/gdb/testsuite/gdb.cp/koenig.exp
@@ -0,0 +1,95 @@
+# Copyright 2008 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile koenig
+set srcfile ${testfile}.cc
+set binfile ${objdir}/${subdir}/${testfile}
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
+    untested "Couldn't compile test program"
+    return -1
+}
+
+# Get things started.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+############################################
+
+if ![runto_main] then {
+    perror "couldn't run to breakpoint main"
+    continue
+}
+
+# Test that koenig lookup finds correct function
+gdb_test "p first(c)" "= 11"
+
+# Change the number of parameters and position of
+# the qualifying parameter
+gdb_test "p second(0,0,c,0,0)" "= 33"
+
+# Test that koenig lookup finds correct function
+# even if it is overloaded
+gdb_test "p first(0,c)" "= 22"
+
+# Test that koenig lookup finds correct function
+# when the argument is an expression
+gdb_test "p first(b.c)" "= 11"
+
+# test that resolutions can be made across namespaces
+gdb_test "p foo(eo)"         "= 1"
+gdb_test "p foo(eo, eo)"     "= 2"
+gdb_test "p foo(eo, eo, 1)"  "= 3"
+gdb_test "p foo(fo, eo)"     "= 4"
+gdb_test "p foo(1 ,fo, eo)"  "= 5"
+gdb_test "p foo(go, fo, eo)" "= 6"
+
+#test that gdb fails gracefully
+gdb_test "p fake(eo)" "No symbol \"fake\" in current context."
+
+#test that namespaces of base classes are searched
+gdb_test "p foo(io)" "= 7"
+gdb_test "p foo(ix)" "Cannot resolve function foo to any overloaded instance"
+
+#test for other types
+gdb_test "p foo(ju)" "= 8"
+gdb_test "p foo(js)" "= 9"
+gdb_test "p foo(je)" "= 10"
+
+#test for class members
+setup_xfail "*-*-*"
+gdb_test "p foo(jab)" "= 11"
+
+gdb_test "p foo(jap)" "= 12"
+gdb_test "p foo(japp)" "= 13"
+gdb_test "p foo(jca)" "= 14"
+
+#test overload resolution
+gdb_test "p foo(ko,1)" "= 15"
+gdb_test "p foo(ko,1.0f)" "= 16"
+setup_xfail "*-*-*"
+gdb_test "p bar(ko,1)" "= -1"
+
+#test lookup of objects belonging to nested namespaces
+gdb_test "p foo(labo)" "= 17"
diff --git a/gdb/valops.c b/gdb/valops.c
index 4a7a334..1cd44f8 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -2336,10 +2336,10 @@ find_overload_match (struct type **arg_types, int nargs,
  int boffset;
  int ix;
  int static_offset;
-  struct cleanup *old_cleanups = NULL;
+  struct cleanup *all_cleanups = make_cleanup (null_cleanup, NULL);

  const char *obj_type_name = NULL;
-  char *func_name = NULL;
+  const char *func_name = NULL;
  enum oload_classification match_quality;

  /* Get the list of overloaded methods or functions.  */
@@ -2384,24 +2384,39 @@ find_overload_match (struct type **arg_types, int nargs,
    }
  else
    {
-      const char *qualified_name = SYMBOL_NATURAL_NAME (fsym);
+      const char *qualified_name = NULL;

-      /* If we have a function with a C++ name, try to extract just
-	 the function part.  Do not try this for non-functions (e.g.
-	 function pointers).  */
-      if (qualified_name
-	  && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym))) == TYPE_CODE_FUNC)
+      if (fsym)
+        {
+          qualified_name = SYMBOL_NATURAL_NAME (fsym);
+
+          /* If we have a function with a C++ name, try to extract just
+	     the function part.  Do not try this for non-functions (e.g.
+	     function pointers).  */
+          if (qualified_name
+              && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym))) == TYPE_CODE_FUNC)
+            {
+	      char *temp;
+
+	      temp = cp_func_name (qualified_name);
+
+	      /* If cp_func_name did not remove anything, the name of the
+	         symbol did not include scope or argument types - it was
+	         probably a C-style function.  */
+	      if (temp)
+		{
+		  make_cleanup (xfree, temp);
+		  if (strcmp (temp, qualified_name) == 0)
+		    func_name = NULL;
+		  else
+		    func_name = temp;
+		}
+            }
+        }
+      else
	{
-	  func_name = cp_func_name (qualified_name);
-
-	  /* If cp_func_name did not remove anything, the name of the
-	     symbol did not include scope or argument types - it was
-	     probably a C-style function.  */
-	  if (func_name && strcmp (func_name, qualified_name) == 0)
-	    {
-	      xfree (func_name);
-	      func_name = NULL;
-	    }
+	  func_name = name;
+	  qualified_name = name;
	}

      /* If there was no C++ name, this must be a C-style function or
@@ -2413,7 +2428,6 @@ find_overload_match (struct type **arg_types, int nargs,
          return 0;
        }

-      old_cleanups = make_cleanup (xfree, func_name);
      make_cleanup (xfree, oload_syms);
      make_cleanup (xfree, oload_champ_bv);

@@ -2424,8 +2438,11 @@ find_overload_match (struct type **arg_types, int nargs,
						&oload_champ_bv);
    }

-  /* Check how bad the best match is.  */
+  /* Did we find a match ?  */
+  if (oload_champ == -1)
+    error ("No symbol \"%s\" in current context.", name);

+  /* Check how bad the best match is.  */
  match_quality =
    classify_oload_match (oload_champ_bv, nargs,
			  oload_method_static (method, fns_ptr,
@@ -2482,8 +2499,8 @@ find_overload_match (struct type **arg_types, int nargs,
	}
      *objp = temp;
    }
-  if (old_cleanups != NULL)
-    do_cleanups (old_cleanups);
+
+  do_cleanups (all_cleanups);

  switch (match_quality)
    {
@@ -2591,6 +2608,12 @@ find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
  new_namespace[namespace_len] = '\0';
  new_oload_syms = make_symbol_overload_list (func_name,
					      new_namespace);
+
+  /* If we have reached the deepesst level perform argument
+     determined lookup.  */
+  if (!searched_deeper)
+    make_symbol_overload_list_adl (arg_types, nargs, func_name);
+
  while (new_oload_syms[num_fns])
    ++num_fns;

@@ -2623,7 +2646,6 @@ find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
    }
  else
    {
-      gdb_assert (new_oload_champ != -1);
      *oload_syms = new_oload_syms;
      *oload_champ = new_oload_champ;
      *oload_champ_bv = new_oload_champ_bv;

Attachment: adl.patch
Description: Text document