c++: expose the type used to store line and column numbers

* data/skeletons/location.cc (position::counter_type)
(location::counter_type): New.
Use them.
* doc/bison.texi (C++ position, C++ location): Adjust.

NEWS

@@ -14,7 +14,8 @@ GNU Bison NEWS
   In C++, line numbers and columns are now represented as 'int' not
   'unsigned', so that integer overflow on positions is easily checkable via
   'gcc -fsanitize=undefined' and the like.  This affects the API for
-  positions.
+  positions.  The default position and location classes now expose
+  'counter_type' (int), used to define line and column numbers.
 
 ** Bug fixes
 

data/skeletons/location.cc

@@ -62,11 +62,14 @@ m4_define([b4_location_define],
 [[  /// A point in a source file.
   class position
   {
-  public:]m4_ifdef([b4_location_constructors], [[
+  public:
+    /// Type for line and column numbers.
+    typedef int counter_type;
+]m4_ifdef([b4_location_constructors], [[
     /// Construct a position.
     explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
-                       int l = ]b4_location_initial_line[,
+                       counter_type l = ]b4_location_initial_line[,
-                       int c = ]b4_location_initial_column[)
+                       counter_type c = ]b4_location_initial_column[)
       : filename (f)
       , line (l)
       , column (c)
@@ -75,8 +78,8 @@ m4_define([b4_location_define],
 ]])[
     /// Initialization.
     void initialize (]b4_percent_define_get([[filename_type]])[* fn = YY_NULLPTR,
-                     int l = ]b4_location_initial_line[,
+                     counter_type l = ]b4_location_initial_line[,
-                     int c = ]b4_location_initial_column[)
+                     counter_type c = ]b4_location_initial_column[)
     {
       filename = fn;
       line = l;
@@ -86,7 +89,7 @@ m4_define([b4_location_define],
     /** \name Line and Column related manipulators
      ** \{ */
     /// (line related) Advance to the COUNT next lines.
-    void lines (int count = 1)
+    void lines (counter_type count = 1)
     {
       if (count)
         {
@@ -96,7 +99,7 @@ m4_define([b4_location_define],
     }
 
     /// (column related) Advance to the COUNT next columns.
-    void columns (int count = 1)
+    void columns (counter_type count = 1)
     {
       column = add_ (column, count, ]b4_location_initial_column[);
     }
@@ -105,13 +108,13 @@ m4_define([b4_location_define],
     /// File name to which this position refers.
     ]b4_percent_define_get([[filename_type]])[* filename;
     /// Current line number.
-    int line;
+    counter_type line;
     /// Current column number.
-    int column;
+    counter_type column;
 
   private:
     /// Compute max (min, lhs+rhs).
-    static int add_ (int lhs, int rhs, int min)
+    static counter_type add_ (counter_type lhs, counter_type rhs, counter_type min)
     {
       return lhs + rhs < min ? min : lhs + rhs;
     }
@@ -119,7 +122,7 @@ m4_define([b4_location_define],
 
   /// Add \a width columns, in place.
   inline position&
-  operator+= (position& res, int width)
+  operator+= (position& res, position::counter_type width)
   {
     res.columns (width);
     return res;
@@ -127,21 +130,21 @@ m4_define([b4_location_define],
 
   /// Add \a width columns.
   inline position
-  operator+ (position res, int width)
+  operator+ (position res, position::counter_type width)
   {
     return res += width;
   }
 
   /// Subtract \a width columns, in place.
   inline position&
-  operator-= (position& res, int width)
+  operator-= (position& res, position::counter_type width)
   {
     return res += -width;
   }
 
   /// Subtract \a width columns.
   inline position
-  operator- (position res, int width)
+  operator- (position res, position::counter_type width)
   {
     return res -= width;
   }
@@ -181,6 +184,8 @@ m4_define([b4_location_define],
   class location
   {
   public:
+    /// Type for line and column numbers.
+    typedef position::counter_type counter_type;
 ]m4_ifdef([b4_location_constructors], [
     /// Construct a location from \a b to \a e.
     location (const position& b, const position& e)
@@ -196,8 +201,8 @@ m4_define([b4_location_define],
 
     /// Construct a 0-width location in \a f, \a l, \a c.
     explicit location (]b4_percent_define_get([[filename_type]])[* f,
-                       int l = ]b4_location_initial_line[,
+                       counter_type l = ]b4_location_initial_line[,
-                       int c = ]b4_location_initial_column[)
+                       counter_type c = ]b4_location_initial_column[)
       : begin (f, l, c)
       , end (f, l, c)
     {}
@@ -205,8 +210,8 @@ m4_define([b4_location_define],
 ])[
     /// Initialization.
     void initialize (]b4_percent_define_get([[filename_type]])[* f = YY_NULLPTR,
-                     int l = ]b4_location_initial_line[,
+                     counter_type l = ]b4_location_initial_line[,
-                     int c = ]b4_location_initial_column[)
+                     counter_type c = ]b4_location_initial_column[)
     {
       begin.initialize (f, l, c);
       end = begin;
@@ -222,13 +227,13 @@ m4_define([b4_location_define],
     }
 
     /// Extend the current location to the COUNT next columns.
-    void columns (int count = 1)
+    void columns (counter_type count = 1)
     {
       end += count;
     }
 
     /// Extend the current location to the COUNT next lines.
-    void lines (int count = 1)
+    void lines (counter_type count = 1)
     {
       end.lines (count);
     }
@@ -243,39 +248,45 @@ m4_define([b4_location_define],
   };
 
   /// Join two locations, in place.
-  inline location& operator+= (location& res, const location& end)
+  inline location&
+  operator+= (location& res, const location& end)
   {
     res.end = end.end;
     return res;
   }
 
   /// Join two locations.
-  inline location operator+ (location res, const location& end)
+  inline location
+  operator+ (location res, const location& end)
   {
     return res += end;
   }
 
   /// Add \a width columns to the end position, in place.
-  inline location& operator+= (location& res, int width)
+  inline location&
+  operator+= (location& res, location::counter_type width)
   {
     res.columns (width);
     return res;
   }
 
   /// Add \a width columns to the end position.
-  inline location operator+ (location res, int width)
+  inline location
+  operator+ (location res, location::counter_type width)
   {
     return res += width;
   }
 
   /// Subtract \a width columns to the end position, in place.
-  inline location& operator-= (location& res, int width)
+  inline location&
+  operator-= (location& res, location::counter_type width)
   {
     return res += -width;
   }
 
   /// Subtract \a width columns to the end position.
-  inline location operator- (location res, int width)
+  inline location
+  operator- (location res, location::counter_type width)
   {
     return res -= width;
   }
@@ -304,7 +315,8 @@ m4_define([b4_location_define],
   std::basic_ostream<YYChar>&
   operator<< (std::basic_ostream<YYChar>& ostr, const location& loc)
   {
-    int end_col = 0 < loc.end.column ? loc.end.column - 1 : 0;
+    location::counter_type end_col
+      = 0 < loc.end.column ? loc.end.column - 1 : 0;
     ostr << loc.begin;
     if (loc.end.filename
         && (!loc.begin.filename

doc/bison.texi

@@ -11453,8 +11453,8 @@ is some time and/or some talented C++ hacker willing to contribute to Bison.
 @node C++ Location Values
 @subsection C++ Location Values
 @c - %locations
-@c - class Position
+@c - class position
-@c - class Location
+@c - class location
 @c - %define filename_type "const symbol::Symbol"
 
 When the directive @code{%locations} is used, the C++ parser supports
@@ -11462,9 +11462,9 @@ location tracking, see @ref{Tracking Locations}.
 
 By default, two auxiliary classes define a @code{position}, a single point
 in a file, and a @code{location}, a range composed of a pair of
-@code{position}s (possibly spanning several files).  But if the
+@code{position}s (possibly spanning several files).  If the @code{%define}
-@code{%define} variable @code{api.location.type} is defined, then these
+variable @code{api.location.type} is defined, then these classes will not be
-classes will not be generated, and the user defined type will be used.
+generated, and the user defined type will be used.
 
 @menu
 * C++ position::         One point in the source file
@@ -11477,13 +11477,17 @@ classes will not be generated, and the user defined type will be used.
 @node C++ position
 @subsubsection C++ @code{position}
 
-@deftypeop {Constructor} {position} {} position (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
+@defcv {Type} {position} {counter_type}
+The type used to store line and column numbers.  Defined as @code{int}.
+@end defcv
+
+@deftypeop {Constructor} {position} {} position (std::string* @var{file} = nullptr, counter_type @var{line} = 1, counter_type @var{col} = 1)
 Create a @code{position} denoting a given point.  Note that @code{file} is
 not reclaimed when the @code{position} is destroyed: memory managed must be
 handled elsewhere.
 @end deftypeop
 
-@deftypemethod {position} {void} initialize (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
+@deftypemethod {position} {void} initialize (std::string* @var{file} = nullptr, counter_type @var{line} = 1, counter_type @var{col} = 1)
 Reset the position to the given values.
 @end deftypemethod
 
@@ -11494,28 +11498,28 @@ change it to @samp{@var{type}*} using @samp{%define filename_type
 "@var{type}"}.
 @end deftypeivar
 
-@deftypeivar {position} {int} line
+@deftypeivar {position} {counter_type} line
 The line, starting at 1.
 @end deftypeivar
 
-@deftypemethod {position} {void} lines (int @var{height} = 1)
+@deftypemethod {position} {void} lines (counter_type @var{height} = 1)
 If @var{height} is not null, advance by @var{height} lines, resetting the
 column number.  The resulting line number cannot be less than 1.
 @end deftypemethod
 
-@deftypeivar {position} {int} column
+@deftypeivar {position} {counter_type} column
 The column, starting at 1.
 @end deftypeivar
 
-@deftypemethod {position} {void} columns (int @var{width} = 1)
+@deftypemethod {position} {void} columns (counter_type @var{width} = 1)
 Advance by @var{width} columns, without changing the line number. The
 resulting column number cannot be less than 1.
 @end deftypemethod
 
-@deftypemethod {position} {position&} operator+= (int @var{width})
+@deftypemethod {position} {position&} operator+= (counter_type @var{width})
-@deftypemethodx {position} {position} operator+ (int @var{width})
+@deftypemethodx {position} {position} operator+ (counter_type @var{width})
-@deftypemethodx {position} {position&} operator-= (int @var{width})
+@deftypemethodx {position} {position&} operator-= (counter_type @var{width})
-@deftypemethodx {position} {position} operator- (int @var{width})
+@deftypemethodx {position} {position} operator- (counter_type @var{width})
 Various forms of syntactic sugar for @code{columns}.
 @end deftypemethod
 
@@ -11538,11 +11542,11 @@ Create a @code{Location} from the endpoints of the range.
 @end deftypeop
 
 @deftypeop {Constructor} {location} {} location (const position& @var{pos} = position())
-@deftypeopx {Constructor} {location} {} location (std::string* @var{file}, int @var{line}, int @var{col})
+@deftypeopx {Constructor} {location} {} location (std::string* @var{file}, counter_type @var{line}, counter_type @var{col})
 Create a @code{Location} denoting an empty range located at a given point.
 @end deftypeop
 
-@deftypemethod {location} {void} initialize (std::string* @var{file} = nullptr, int @var{line} = 1, int @var{col} = 1)
+@deftypemethod {location} {void} initialize (std::string* @var{file} = nullptr, counter_type @var{line} = 1, counter_type @var{col} = 1)
 Reset the location to an empty range at the given values.
 @end deftypemethod
 
@@ -11551,15 +11555,15 @@ Reset the location to an empty range at the given values.
 The first, inclusive, position of the range, and the first beyond.
 @end deftypeivar
 
-@deftypemethod {location} {void} columns (int @var{width} = 1)
+@deftypemethod {location} {void} columns (counter_type @var{width} = 1)
-@deftypemethodx {location} {void} lines (int @var{height} = 1)
+@deftypemethodx {location} {void} lines (counter_type @var{height} = 1)
 Forwarded to the @code{end} position.
 @end deftypemethod
 
-@deftypemethod  {location} {location} operator+  (int @var{width})
+@deftypemethod  {location} {location} operator+  (counter_type @var{width})
-@deftypemethodx {location} {location} operator+= (int @var{width})
+@deftypemethodx {location} {location} operator+= (counter_type @var{width})
-@deftypemethodx {location} {location} operator-  (int @var{width})
+@deftypemethodx {location} {location} operator-  (counter_type @var{width})
-@deftypemethodx {location} {location} operator-= (int @var{width})
+@deftypemethodx {location} {location} operator-= (counter_type @var{width})
 Various forms of syntactic sugar for @code{columns}.
 @end deftypemethod