call.c (maybe_print_user_conv_context): New.

	* call.c (maybe_print_user_conv_context): New.
	(convert_like_real): Use it.  Print call context for bad
	user-defined conversion.
	(build_over_call): Print call context for bad 'this' conversion.

From-SVN: r210350

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 15dc0b6..ca07527 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,10 @@
 2014-05-12  Jason Merrill  <jason@redhat.com>
 
+       * call.c (maybe_print_user_conv_context): New.
+       (convert_like_real): Use it.  Print call context for bad
+       user-defined conversion.
+       (build_over_call): Print call context for bad 'this' conversion.
+
        * call.c (convert_like_real): Use inform for identifying the
        declaration point.
 

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index f2ceef2..7b8bc09 100644 (file)
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -5942,6 +5942,23 @@ conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
     }
 }
 
+/* We gave a diagnostic during a conversion.  If this was in the second
+   standard conversion sequence of a user-defined conversion sequence, say
+   which user-defined conversion.  */
+
+static void
+maybe_print_user_conv_context (conversion *convs)
+{
+  if (convs->user_conv_p)
+    for (conversion *t = convs; t; t = next_conversion (t))
+      if (t->kind == ck_user)
+       {
+         print_z_candidate (0, "  after user-defined conversion:",
+                            t->cand);
+         break;
+       }
+}
+
 /* Perform the conversions in CONVS on the expression EXPR.  FN and
    ARGNUM are used for diagnostics.  ARGNUM is zero based, -1
    indicates the `this' argument of a method.  INNER is nonzero when
@@ -6003,11 +6020,15 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
                                        /*c_cast_p=*/false,
                                        complain);
              if (convs->kind == ck_ref_bind)
-               return convert_to_reference (totype, expr, CONV_IMPLICIT,
+               expr = convert_to_reference (totype, expr, CONV_IMPLICIT,
                                             LOOKUP_NORMAL, NULL_TREE,
                                             complain);
              else
-               return cp_convert (totype, expr, complain);
+               expr = cp_convert (totype, expr, complain);
+             if (fn)
+               inform (DECL_SOURCE_LOCATION (fn),
+                       "  initializing argument %P of %qD", argnum, fn);
+             return expr;
            }
          else if (t->kind == ck_user || !t->bad_p)
            {
@@ -6030,7 +6051,7 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
                                TREE_TYPE (expr), totype);
       if (complained && fn)
        inform (DECL_SOURCE_LOCATION (fn),
-               "initializing argument %P of %qD", argnum, fn);
+               "  initializing argument %P of %qD", argnum, fn);
 
       return cp_convert (totype, expr, complain);
     }
@@ -6135,7 +6156,7 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
          build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL,
                                      complain);
          if (fn)
-           inform (input_location, "initializing argument %P of %q+D",
+           inform (input_location, "  initializing argument %P of %q+D",
                    argnum, fn);
        }
       return error_mark_node;
@@ -6255,9 +6276,14 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
        /* Copy-list-initialization doesn't actually involve a copy.  */
        return expr;
       expr = build_temp (expr, totype, flags, &diag_kind, complain);
-      if (diag_kind && fn && complain)
-       inform (DECL_SOURCE_LOCATION (fn),
-               "  initializing argument %P of %qD", argnum, fn);
+      if (diag_kind && complain)
+       {
+         maybe_print_user_conv_context (convs);
+         if (fn)
+           inform (DECL_SOURCE_LOCATION (fn),
+                   "  initializing argument %P of %qD", argnum, fn);
+       }
+
       return build_cplus_new (totype, expr, complain);
 
     case ck_ref_bind:
@@ -6272,9 +6298,10 @@ convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
 
            error_at (loc, "cannot bind %qT lvalue to %qT",
                      TREE_TYPE (expr), totype);
+           maybe_print_user_conv_context (convs);
            if (fn)
              inform (input_location,
-                     "initializing argument %P of %q+D", argnum, fn);
+                     "  initializing argument %P of %q+D", argnum, fn);
            return error_mark_node;
          }
 
@@ -6935,8 +6962,12 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
       if (convs[i]->bad_p)
        {
          if (complain & tf_error)
-           permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
-                      TREE_TYPE (argtype), fn);
+           {
+             if (permerror (input_location, "passing %qT as %<this%> "
+                            "argument discards qualifiers",
+                            TREE_TYPE (argtype)))
+               inform (DECL_SOURCE_LOCATION (fn), "  in call to %qD", fn);
+           }
          else
            return error_mark_node;
        }