X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/cc8962bdde81b04aa728aef21e53b4a08a0debfe..026816664ff8283a55f91915843a8ff0ac5cf86c:/data/location.cc?ds=sidebyside

diff --git a/data/location.cc b/data/location.cc
index 987843b2..9a60f250 100644
--- a/data/location.cc
+++ b/data/location.cc
@@ -25,8 +25,7 @@ m4_define([b4_position_define],
 [[  /// Abstract a position.
   class position
   {
-  public:
-]m4_ifdef([b4_location_constructors], [[
+  public:]m4_ifdef([b4_location_constructors], [[
     /// Construct a position.
     explicit position (]b4_percent_define_get([[filename_type]])[* f = YY_NULL,
                        unsigned int l = ]b4_location_initial_line[u,
@@ -53,14 +52,17 @@ m4_define([b4_position_define],
     /// (line related) Advance to the COUNT next lines.
     void lines (int count = 1)
     {
-      column = ]b4_location_initial_column[u;
-      line += count;
+      if (count)
+        {
+          column = ]b4_location_initial_column[u;
+          line = add_ (line, count, ]b4_location_initial_line[);
+        }
     }
 
     /// (column related) Advance to the COUNT next columns.
     void columns (int count = 1)
     {
-      column = std::max (]b4_location_initial_column[u, column + count);
+      column = add_ (column, count, ]b4_location_initial_column[);
     }
     /** \} */
 
@@ -70,36 +72,44 @@ m4_define([b4_position_define],
     unsigned int line;
     /// Current column number.
     unsigned int column;
+
+  private:
+    /// Compute max(min, lhs+rhs) (provided min <= lhs).
+    static unsigned int add_ (unsigned int lhs, int rhs, unsigned int min)
+    {
+      return (0 < rhs || -static_cast<unsigned int>(rhs) < lhs
+              ? rhs + lhs
+              : min);
+    }
   };
 
   /// Add and assign a position.
   inline position&
-  operator+= (position& res, const int width)
+  operator+= (position& res, int width)
   {
     res.columns (width);
     return res;
   }
 
   /// Add two position objects.
-  inline const position
-  operator+ (const position& begin, const int width)
+  inline position
+  operator+ (position res, int width)
   {
-    position res = begin;
     return res += width;
   }
 
   /// Add and assign a position.
   inline position&
-  operator-= (position& res, const int width)
+  operator-= (position& res, int width)
   {
     return res += -width;
   }
 
   /// Add two position objects.
-  inline const position
-  operator- (const position& begin, const int width)
+  inline position
+  operator- (position res, int width)
   {
-    return begin + -width;
+    return res -= width;
   }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
   /// Compare two position objects.
@@ -186,13 +196,13 @@ m4_define([b4_location_define],
     }
 
     /// Extend the current location to the COUNT next columns.
-    void columns (unsigned int count = 1)
+    void columns (int count = 1)
     {
       end += count;
     }
 
     /// Extend the current location to the COUNT next lines.
-    void lines (unsigned int count = 1)
+    void lines (int count = 1)
     {
       end.lines (count);
     }
@@ -207,26 +217,35 @@ m4_define([b4_location_define],
   };
 
   /// Join two location objects to create a location.
-  inline const location operator+ (const location& begin, const location& end)
+  inline location operator+ (location res, const location& end)
   {
-    location res = begin;
     res.end = end.end;
     return res;
   }
 
-  /// Add two location objects.
-  inline const location operator+ (const location& begin, unsigned int width)
+  /// Change end position in place.
+  inline location& operator+= (location& res, int width)
   {
-    location res = begin;
     res.columns (width);
     return res;
   }
 
-  /// Add and assign a location.
-  inline location& operator+= (location& res, unsigned int width)
+  /// Change end position.
+  inline location operator+ (location res, int width)
   {
-    res.columns (width);
-    return res;
+    return res += width;
+  }
+
+  /// Change end position in place.
+  inline location& operator-= (location& res, int width)
+  {
+    return res += -width;
+  }
+
+  /// Change end position.
+  inline location operator- (const location& begin, int width)
+  {
+    return begin + -width;
   }
 ]b4_percent_define_flag_if([[define_location_comparison]], [[
   /// Compare two location objects.