Re: FYI: Fix aliases properties consistency checks

[Akim Demaille]

I'm committing this version of the patch.

Index: ChangeLog
from  Akim Demaille  <address@hidden>

        * src/symtab.c (symbol_check_alias_consistency): Also check
        type names, destructors, and printers.
        Reported by Alexandre Duret-Lutz.
        Recode the handling of associativity and precedence in terms
        of symbol_precedence_set.
        Accept no redeclaration at all, not even equal to the previous
        value.
        (redeclaration): New.
        Use it to factor redeclaration complaints.
        (symbol_make_alias): Don't set the type of the alias, let
        symbol_check_alias_consistency do it as for other features.
        * src/symtab.h (symbol): Add new member prec_location, and
        type_location.
        * src/symtab.c (symbol_precedence_set, symbol_type_set): Set them.
        * tests/input.at (Incompatible Aliases): New.

Index: src/symtab.c
===================================================================
RCS file: /cvsroot/bison/bison/src/symtab.c,v
retrieving revision 1.56
diff -u -u -r1.56 symtab.c
--- src/symtab.c 7 May 2004 07:35:10 -0000 1.56
+++ src/symtab.c 11 Oct 2004 08:38:40 -0000
@@ -71,6 +71,19 @@
 }
 
 
+/*------------------------------------------------------------------.
+| Complain that S's WHAT is redeclared at SECOND, and was first set |
+| at FIRST.                                                         |
+`------------------------------------------------------------------*/
+
+static void
+redeclaration (symbol* s, const char *what, location first, location second)
+{
+  complain_at (second, _("%s redeclaration for %s"), what, s->tag);
+  complain_at (first, _("first declaration"));
+}
+
+
 /*-----------------------------------------------------------------.
 | Set the TYPE_NAME associated with SYM.  Does nothing if passed 0 |
 | as TYPE_NAME.                                                    |
@@ -82,9 +95,10 @@
   if (type_name)
     {
       if (sym->type_name)
-       complain_at (loc, _("type redeclaration for %s"), sym->tag);
+       redeclaration (sym, "%type", sym->type_location, loc);
       uniqstr_assert (type_name);
       sym->type_name = type_name;
+      sym->type_location = loc;
     }
 }
 
@@ -99,8 +113,7 @@
   if (destructor)
     {
       if (sym->destructor)
-       complain_at (loc, _("%s redeclaration for %s"),
-                    "%destructor", sym->tag);
+       redeclaration (sym, "%destructor", sym->destructor_location, loc);
       sym->destructor = destructor;
       sym->destructor_location = loc;
     }
@@ -117,8 +130,7 @@
   if (printer)
     {
       if (sym->printer)
-       complain_at (loc, _("%s redeclaration for %s"),
-                    "%printer", sym->tag);
+       redeclaration (sym, "%printer", sym->destructor_location, loc);
       sym->printer = printer;
       sym->printer_location = loc;
     }
@@ -136,9 +148,10 @@
   if (a != undef_assoc)
     {
       if (sym->prec != 0)
-       complain_at (loc, _("redefining precedence of %s"), sym->tag);
+       redeclaration (sym, assoc_to_string (a), sym->prec_location, loc);
       sym->prec = prec;
       sym->assoc = a;
+      sym->prec_location = loc;
     }
 
   /* Only terminals have a precedence. */
@@ -230,10 +243,10 @@
 {
   if (symval->alias)
     warn_at (loc, _("symbol `%s' used more than once as a literal string"),
-         symval->tag);
+            symval->tag);
   else if (sym->alias)
     warn_at (loc, _("symbol `%s' given more than one literal string"),
-         sym->tag);
+            sym->tag);
   else
     {
       symval->class = token_sym;
@@ -248,7 +261,6 @@
        abort ();
       sym->number = symval->number =
        (symval->number < sym->number) ? symval->number : sym->number;
-      symbol_type_set (symval, sym->type_name, loc);
     }
 }
 
@@ -258,45 +270,60 @@
 | associativity.                                           |
 `---------------------------------------------------------*/
 
-static inline bool
+static inline void
 symbol_check_alias_consistency (symbol *this)
 {
-  /* Check only those who _are_ the aliases. */
-  if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)
+  symbol *alias = this;
+  symbol *orig  = this->alias;
+
+  /* Check only those that _are_ the aliases.  */
+  if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
+    return;
+
+  if (orig->type_name || alias->type_name)
     {
-      if (this->prec != this->alias->prec)
-       {
-         if (this->prec != 0 && this->alias->prec != 0)
-           complain_at (this->alias->location,
-                        _("conflicting precedences for %s and %s"),
-                        this->tag, this->alias->tag);
-         if (this->prec != 0)
-           this->alias->prec = this->prec;
-         else
-           this->prec = this->alias->prec;
-       }
+      if (orig->type_name)
+       symbol_type_set (alias, orig->type_name, orig->type_location);
+      else
+       symbol_type_set (orig, alias->type_name, alias->type_location);
+    }
 
-      if (this->assoc != this->alias->assoc)
-       {
-         if (this->assoc != undef_assoc && this->alias->assoc != undef_assoc)
-           complain_at (this->alias->location,
-                        _("conflicting associativities for %s (%s) and %s 
(%s)"),
-                        this->tag, assoc_to_string (this->assoc),
-                        this->alias->tag, assoc_to_string 
(this->alias->assoc));
-         if (this->assoc != undef_assoc)
-           this->alias->assoc = this->assoc;
-         else
-           this->assoc = this->alias->assoc;
-       }
+
+  if (orig->destructor || alias->destructor)
+    {
+      if (orig->destructor)
+       symbol_destructor_set (alias, orig->destructor,
+                              orig->destructor_location);
+      else
+       symbol_destructor_set (orig, alias->destructor,
+                              alias->destructor_location);
+    }
+
+  if (orig->printer || alias->printer)
+    {
+      if (orig->printer)
+       symbol_printer_set (alias, orig->printer, orig->printer_location);
+      else
+       symbol_printer_set (orig, alias->printer, alias->printer_location);
+    }
+
+  if (alias->prec || orig->prec)
+    {
+      if (orig->prec)
+       symbol_precedence_set (alias, orig->prec, orig->assoc,
+                              orig->prec_location);
+      else
+       symbol_precedence_set (orig, alias->prec, alias->assoc,
+                              alias->prec_location);
     }
-  return true;
 }
 
 static bool
 symbol_check_alias_consistency_processor (void *this,
                                          void *null ATTRIBUTE_UNUSED)
 {
-  return symbol_check_alias_consistency (this);
+  symbol_check_alias_consistency (this);
+  return true;
 }
 
 
Index: src/symtab.h
===================================================================
RCS file: /cvsroot/bison/bison/src/symtab.h,v
retrieving revision 1.52
diff -u -u -r1.52 symtab.h
--- src/symtab.h 31 Mar 2004 00:37:21 -0000 1.52
+++ src/symtab.h 11 Oct 2004 08:38:40 -0000
@@ -46,6 +46,9 @@
 
 
 typedef struct symbol symbol;
+
+/* When extending this structure, be sure to complete
+   symbol_check_alias_consistency.  */
 struct symbol
 {
   /* The key, name of the symbol.  */
@@ -55,12 +58,16 @@
 
   /* Its %type and associated printer and destructor.  */
   uniqstr type_name;
+  location type_location;
+
   char *destructor;
   location destructor_location;
+
   char *printer;
   location printer_location;
 
   symbol_number number;
+  location prec_location;
   short int prec;
   assoc assoc;
   int user_token_number;
Index: tests/input.at
===================================================================
RCS file: /cvsroot/bison/bison/tests/input.at,v
retrieving revision 1.28
diff -u -u -r1.28 input.at
--- tests/input.at 24 Dec 2003 08:17:05 -0000 1.28
+++ tests/input.at 11 Oct 2004 08:38:40 -0000
@@ -1,5 +1,5 @@
 # Checking the Bison scanner.                    -*- Autotest -*-
-# Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+# Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -82,6 +82,43 @@
 AT_CLEANUP
 
 
+## ---------------------- ##
+## Incompatible Aliases.  ##
+## ---------------------- ##
+
+AT_SETUP([Incompatible Aliases])
+
+AT_DATA([input.y],
+[[%token foo "foo"
+
+%type <bar>       foo
+%printer {bar}    foo
+%destructor {bar} foo
+%left             foo
+
+%type <baz>       "foo"
+%printer {baz}    "foo"
+%destructor {baz} "foo"
+%left             "foo"
+
+%%
+exp: foo;
+]])
+
+AT_CHECK([bison input.y], [1], [],
+[[input.y:8.7-11: %type redeclaration for foo
+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:9.19-23: %printer redeclaration for foo
+input.y:10.13-17: first declaration
+input.y:11.1-5: %left redeclaration for foo
+input.y:6.1-5: first declaration
+]])
+
+AT_CLEANUP
+
+
 
 ## ----------------------- ##
 ## Torturing the Scanner.  ##