diff --git a/configure.ac b/configure.ac
index 83e2c972..a9dad57c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -192,7 +192,7 @@ BISON_CXX_COMPILER_POSIXLY_CORRECT
 
 # D.
 AC_CHECK_PROGS([DC], [dmd])
-AC_CHECK_PROGS([DCFLAGS], [])
+AC_CHECK_PROGS([DCFLAGS], [-g])
 AM_CONDITIONAL([ENABLE_D], [test x"$DC" != x])
 
 # Java.
diff --git a/data/skeletons/d.m4 b/data/skeletons/d.m4
index 109c3a01..2d29127c 100644
--- a/data/skeletons/d.m4
+++ b/data/skeletons/d.m4
@@ -100,12 +100,6 @@ m4_define([b4_location_type_if],
 [b4_percent_define_ifdef([[location_type]], [$1], [$2])])
 
 
-# b4_locations_if(TRUE, FALSE)
-# ----------------------------
-m4_define([b4_locations_if],
-[m4_if(b4_locations_flag, 1, [$1], [$2])])
-
-
 # b4_identification
 # -----------------
 m4_define([b4_identification],
diff --git a/data/skeletons/lalr1.d b/data/skeletons/lalr1.d
index 087b3a06..dc155ef4 100644
--- a/data/skeletons/lalr1.d
+++ b/data/skeletons/lalr1.d
@@ -97,12 +97,15 @@ public struct ]b4_position_type[ {
   /** The line number within an input file.  */
   public int line = 1;
   /** The name of the input file.  */
-  public string filename = "(unspecified file)";
+  public string filename = null;
 
   /**
    * A string representation of the position. */
   public string toString() const {
-    return format("%s:%d.%d", filename, line, column);
+    if (filename)
+      return format("%s:%d.%d", filename, line, column);
+    else
+      return format("%d.%d", line, column);
   }
 }
 ]])b4_location_type_if([[
@@ -141,6 +144,9 @@ public class ]b4_location_type[
     this.begin = this.end = loc;
   }
 
+  public this () {
+  }
+
   /**
    * Create a <code>]b4_location_type[</code> from the endpoints of the range.
    * @@param begin The first position included in the range.
@@ -156,10 +162,15 @@ public class ]b4_location_type[
    * <code>]b4_position_type[</code> should override the <code>toString</code>
    * method.  */
   public override string toString () const {
-    if (begin == end)
-      return begin.toString ();
-    else
-      return begin.toString () ~ "-" ~ end.toString ();
+    auto end_col = 0 < end.column ? end.column - 1 : 0;
+    auto res = begin.toString ();
+    if (end.filename && begin.filename != end.filename)
+      res ~= "-" ~ format("%s:%d.%d", end.filename, end.line, end_col);
+    else if (begin.line < end.line)
+      res ~= "-" ~ format("%d.%d", end.line, end_col);
+    else if (begin.column < end_col)
+      res ~= "-" ~ format("%d", end_col);
+    return res;
   }
 }
 
@@ -289,7 +300,7 @@ b4_user_union_members
   private static immutable int YYERRLAB1 = 7;
   private static immutable int YYRETURN = 8;
 ]b4_locations_if([
-  private static immutable YYSemanticType yy_semantic_null = cast(YYSemanticType)null;])[
+  private static immutable YYSemanticType yy_semantic_null;])[
   private int yyerrstatus_ = 0;
 
   /**
diff --git a/tests/calc.at b/tests/calc.at
index 0036c10e..77537610 100644
--- a/tests/calc.at
+++ b/tests/calc.at
@@ -141,27 +141,56 @@ class CalcLexer(R) : Lexer
 {
   R input;
 
-  this(R r) { input = r; }
-
-  public void yyerror (string s)
-  {
-    stderr.writeln (s);
+  this(R r) {
+    input = r;
   }
 
-  YYSemanticType semanticVal_;
+  ]AT_YYERROR_DEFINE[
 
+  YYSemanticType semanticVal_;]AT_LOCATION_IF([[
+  YYLocation location = new YYLocation;
+
+  public final @property YYPosition startPos()
+  {
+    return location.begin;
+  }
+
+  public final @property YYPosition endPos()
+  {
+    return location.end;
+  }
+]])[
   public final @property YYSemanticType semanticVal()
   {
     return semanticVal_;
   }
 
-  int yylex ()
+  int parseInt ()
   {
+    auto res = 0;
+    import std.uni : isNumber;
+    while (input.front.isNumber)
+      {
+        res = res * 10 + (input.front - '0');]AT_LOCATION_IF([[
+        location.end.column += 1;]])[
+        input.popFront;
+      }
+    return res;
+  }
+
+  int yylex ()
+  {]AT_LOCATION_IF([[
+    location.begin = location.end;]])[
+
     import std.uni : isWhite, isNumber;
 
     // Skip initial spaces
     while (!input.empty && input.front != '\n' && isWhite (input.front))
-      input.popFront;
+      {
+        input.popFront;]AT_LOCATION_IF([[
+        location.begin.column += 1;
+        location.end.column += 1;]])[
+      }
 
     // Handle EOF.
     if (input.empty)
@@ -170,13 +199,19 @@ class CalcLexer(R) : Lexer
     // Numbers.
     if (input.front.isNumber)
       {
-        import std.conv : parse;
-        semanticVal_.ival = input.parse!int;
+        semanticVal_.ival = parseInt;
         return YYTokenType.NUM;
       }
 
     // Individual characters
-    auto c = input.front;
+    auto c = input.front;]AT_LOCATION_IF([[
+    if (c == '\n')
+      {
+        location.end.line += 1;
+        location.end.column = 1;
+      }
+    else
+      location.end.column += 1;]])[
     input.popFront;
     return c;
   }
@@ -856,13 +891,13 @@ m4_define([AT_CHECK_CALC_LALR1_D],
 [AT_CHECK_CALC([%language "D" $1], [$2])])
 
 AT_CHECK_CALC_LALR1_D([])
-#AT_CHECK_CALC_LALR1_D([%locations])
+AT_CHECK_CALC_LALR1_D([%locations])
 #AT_CHECK_CALC_LALR1_D([%locations %define api.location.type {Span}])
 AT_CHECK_CALC_LALR1_D([%define parse.error verbose %define api.prefix {calc} %verbose])
 
-#AT_CHECK_CALC_LALR1_D([%debug])
+AT_CHECK_CALC_LALR1_D([%debug])
 
-#AT_CHECK_CALC_LALR1_D([%define parse.error verbose %debug %verbose])
+AT_CHECK_CALC_LALR1_D([%define parse.error verbose %debug %verbose])
 #AT_CHECK_CALC_LALR1_D([%define parse.error verbose %debug %define api.token.prefix {TOK_} %verbose])
 
 #AT_CHECK_CALC_LALR1_D([%locations %define parse.error verbose %debug %verbose %parse-param {semantic_value *result} %parse-param {int *count}])
diff --git a/tests/local.at b/tests/local.at
index 2b331cc9..48b65114 100644
--- a/tests/local.at
+++ b/tests/local.at
@@ -672,10 +672,9 @@ m4_define([AT_YYERROR_DECLARE_EXTERN(d)], [])
 
 m4_define([AT_YYERROR_DEFINE(d)],
 [[/* An error reporting function.  */
-public void error (]AT_LOCATION_IF([[location_type l, ]])[string m)
+public void yyerror (]AT_LOCATION_IF([[YYLocation l, ]])[string m)
 {
-  // FIXME: location.
-  stderr.writeln (m);
+  stderr.writeln (]AT_LOCATION_IF([[l, ": ", ]])[m);
 }]])