Re: C++ comparison operators for location

[Joel E. Denny]

On Wed, 21 Jun 2006, Joel E. Denny wrote:

> On Wed, 21 Jun 2006, Akim Demaille wrote:
> 
> > Yes.  For a start, as a simple Boolean (%define
> > "define_position_comparison"), until we find something smarter.
> 
> How about define_location_comparison?  I see location as the more general 
> concept (maybe it's just me), and this boolean will affect both location 
> and position.

I went ahead and committed this.  We can adjust the name later if need be.

I'm not sure how you want to handle %define booleans in general.  For now, 
`1' is the only true value.

Joel

Index: ChangeLog
===================================================================
RCS file: /sources/bison/bison/ChangeLog,v
retrieving revision 1.1510
diff -p -u -r1.1510 ChangeLog
--- ChangeLog   21 Jun 2006 01:37:00 -0000      1.1510
+++ ChangeLog   22 Jun 2006 19:24:20 -0000
@@ -1,3 +1,22 @@
+2006-06-22  Joel E. Denny  <address@hidden>
+
+       Add comparison operators for C++ location classes.  Discussed at
+       <http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00092.html>.
+       * data/c++.m4 (b4_define_location_comparison): New boolean %define
+       declaration indicating whether filename_type has an operator==.  If
+       filename_type is `std::string', it defaults to `1', `0' otherwise.
+       * data/location.cc: Iff b4_define_location_comparison is `1', add
+       operator== and operator!= for class position and for class location.
+
+       Some minor fixes.
+       * src/scan-action.l: Remove unused file.
+       * src/symtab.c (symbol_printer_set): Use printer_location not
+       destructor_location.
+       * src/symtab.h (struct symbol): Replace incorrect source comment for
+       printer members.
+       * tests/input.at (Incompatible Aliases): Update output with correct
+       printer location.
+
 2006-06-20  Joel E. Denny  <address@hidden>
 
        Don't put the pre-prologue in the header file.  For the yacc.c code
Index: data/c++.m4
===================================================================
RCS file: /sources/bison/bison/data/c++.m4,v
retrieving revision 1.7
diff -p -u -r1.7 c++.m4
--- data/c++.m4 20 Jun 2006 11:32:19 -0000      1.7
+++ data/c++.m4 22 Jun 2006 19:24:20 -0000
@@ -30,6 +30,8 @@ m4_define_default([b4_parser_class_name]
 m4_define_default([b4_location_type], [location])
 m4_define_default([b4_filename_type], [std::string])
 m4_define_default([b4_namespace], m4_defn([b4_prefix]))
+m4_define_default([b4_define_location_comparison],
+                 m4_if(b4_filename_type, [std::string], [1], [0]))
 
 
 # b4_token_enums(LIST-OF-PAIRS-TOKEN-NAME-TOKEN-NUMBER)
Index: data/location.cc
===================================================================
RCS file: /sources/bison/bison/data/location.cc,v
retrieving revision 1.11
diff -p -u -r1.11 location.cc
--- data/location.cc    20 Jun 2006 11:32:19 -0000      1.11
+++ data/location.cc    22 Jun 2006 19:24:20 -0000
@@ -119,7 +119,24 @@ namespace ]b4_namespace[
   {
     return begin + -width;
   }
+]m4_if(b4_define_location_comparison, [1], [[
+  /// Compare two position objects.
+  inline bool
+  operator== (const position& pos1, const position& pos2)
+  {
+    return
+      (pos1.filename == pos2.filename
+       || pos1.filename && pos2.filename && *pos1.filename == *pos2.filename)
+      && pos1.line == pos2.line && pos1.column == pos2.column;
+  }
 
+  /// Compare two position objects.
+  inline bool
+  operator!= (const position& pos1, const position& pos2)
+  {
+    return !(pos1 == pos2);
+  }
+]])[
   /** \brief Intercept output stream redirection.
    ** \param ostr the destination output stream
    ** \param pos a reference to the position to redirect
@@ -224,7 +241,21 @@ namespace ]b4_namespace[
     res.columns (width);
     return res;
   }
+]m4_if(b4_define_location_comparison, [1], [[
+  /// Compare two location objects.
+  inline bool
+  operator== (const location& loc1, const location& loc2)
+  {
+    return loc1.begin == loc2.begin && loc1.end == loc2.end;
+  }
 
+  /// Compare two location objects.
+  inline bool
+  operator!= (const location& loc1, const location& loc2)
+  {
+    return !(loc1 == loc2);
+  }
+]])[
   /** \brief Intercept output stream redirection.
    ** \param ostr the destination output stream
    ** \param loc a reference to the location to redirect
Index: src/symtab.c
===================================================================
RCS file: /sources/bison/bison/src/symtab.c,v
retrieving revision 1.71
diff -p -u -r1.71 symtab.c
--- src/symtab.c        20 Jun 2006 11:39:22 -0000      1.71
+++ src/symtab.c        22 Jun 2006 19:24:20 -0000
@@ -158,7 +158,7 @@ symbol_printer_set (symbol *sym, const c
   if (printer)
     {
       if (sym->printer)
-       redeclaration (sym, "%printer", sym->destructor_location, loc);
+       redeclaration (sym, "%printer", sym->printer_location, loc);
       sym->printer = printer;
       sym->printer_location = loc;
     }
Index: src/symtab.h
===================================================================
RCS file: /sources/bison/bison/src/symtab.h,v
retrieving revision 1.60
diff -p -u -r1.60 symtab.h
--- src/symtab.h        20 Jun 2006 11:39:22 -0000      1.60
+++ src/symtab.h        22 Jun 2006 19:24:20 -0000
@@ -64,7 +64,7 @@ struct symbol
   const char *destructor;
   location destructor_location;
 
-  /* Does not own the memory. */
+  /* Printer. */
   const char *printer;
   location printer_location;
 
Index: tests/input.at
===================================================================
RCS file: /sources/bison/bison/tests/input.at,v
retrieving revision 1.45
diff -p -u -r1.45 input.at
--- tests/input.at      7 Jun 2006 07:09:32 -0000       1.45
+++ tests/input.at      22 Jun 2006 19:24:20 -0000
@@ -163,7 +163,7 @@ input.y:3.7-11: first declaration
 input.y:10.13-17: %destructor redeclaration for foo
 input.y:5.13-17: first declaration
 input.y:9.10-14: %printer redeclaration for foo
-input.y:10.13-17: first declaration
+input.y:4.10-14: first declaration
 input.y:11.1-5: %left redeclaration for foo
 input.y:6.1-5: first declaration
 ]])