tests: headers.at: strengthen.

[bison.git] / src / reader.c

diff --git a/src/reader.c b/src/reader.c
index ec560aa55a266638e2cadf499ce6376b1e608051..7dd0aaa46c7b13d528e31a18746a4501175bd945 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -1,7 +1,7 @@
 /* Input parser for Bison
 
 /* Input parser for Bison
 

-   Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000, 2001, 2002, 2003,
-   2005, 2006, 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 1992, 1998, 2000-2003, 2005-2007,
+   2009-2012 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -22,20 +22,20 @@
 #include "system.h"
 
 #include <quote.h>
 #include "system.h"
 
 #include <quote.h>

-#include <quotearg.h>

 
 #include "complain.h"
 #include "conflicts.h"
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"
 
 #include "complain.h"
 #include "conflicts.h"
 #include "files.h"
 #include "getargs.h"
 #include "gram.h"

-#include "muscle_tab.h"
+#include "muscle-tab.h"

 #include "reader.h"
 #include "symlist.h"
 #include "symtab.h"
 #include "scan-gram.h"
 #include "scan-code.h"
 
 #include "reader.h"
 #include "symlist.h"
 #include "symtab.h"
 #include "scan-gram.h"
 #include "scan-code.h"
 

+static void prepare_percent_define_front_end_variables (void);

 static void check_and_convert_grammar (void);
 
 static symbol_list *grammar = NULL;
 static void check_and_convert_grammar (void);
 
 static symbol_list *grammar = NULL;


@@ -129,8 +129,8 @@ record_merge_function_type (int merger, uniqstr type, location declaration_loc)
   if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
     {
       complain_at (declaration_loc,
   if (merge_function->type != NULL && !UNIQSTR_EQ (merge_function->type, type))
     {
       complain_at (declaration_loc,

-                  _("result type clash on merge function `%s': <%s> != <%s>"),
-                  merge_function->name, type, merge_function->type);
+                   _("result type clash on merge function %s: <%s> != <%s>"),
+                   quote (merge_function->name), type, merge_function->type);

       complain_at (merge_function->type_declaration_location,
                   _("previous declaration"));
     }
       complain_at (merge_function->type_declaration_location,
                   _("previous declaration"));
     }


@@ -190,6 +190,23 @@ grammar_symbol_append (symbol *sym, location loc)
   return p;
 }
 
   return p;
 }
 

+static void
+assign_named_ref (symbol_list *p, named_ref *name)
+{
+  symbol *sym = p->content.sym;
+
+  if (name->id == sym->tag)
+    {
+      warn_at (name->loc,
+              _("duplicated symbol name for %s ignored"),
+              quote (sym->tag));
+      named_ref_free (name);
+    }
+  else
+    p->named_ref = name;
+}
+
+

 /* The rule currently being defined, and the previous rule.
    CURRENT_RULE points to the first LHS of the current rule, while
    PREVIOUS_RULE_END points to the *end* of the previous rule (NULL).  */
 /* The rule currently being defined, and the previous rule.
    CURRENT_RULE points to the first LHS of the current rule, while
    PREVIOUS_RULE_END points to the *end* of the previous rule (NULL).  */


@@ -203,7 +220,7 @@ static symbol_list *previous_rule_end = NULL;
 
 void
 grammar_current_rule_begin (symbol *lhs, location loc,
 
 void
 grammar_current_rule_begin (symbol *lhs, location loc,

-                           named_ref *lhs_named_ref)
+                           named_ref *lhs_name)

 {
   symbol_list* p;
 
 {
   symbol_list* p;
 


@@ -212,18 +229,8 @@ grammar_current_rule_begin (symbol *lhs, location loc,
   previous_rule_end = grammar_end;
 
   p = grammar_symbol_append (lhs, loc);
   previous_rule_end = grammar_end;
 
   p = grammar_symbol_append (lhs, loc);

-  if (lhs_named_ref)
-    {
-      if (lhs_named_ref->id == lhs->tag)
-       {
-         warn_at (lhs_named_ref->loc,
-                  _("duplicated symbol name for %s ignored"),
-                  quote (lhs->tag));
-         named_ref_free (lhs_named_ref);
-       }
-      else
-       p->named_ref = lhs_named_ref;
-    }
+  if (lhs_name)
+    assign_named_ref (p, named_ref_copy (lhs_name));

 
   current_rule = grammar_end;
 
 
   current_rule = grammar_end;
 


@@ -242,22 +249,25 @@ grammar_current_rule_begin (symbol *lhs, location loc,
 /*----------------------------------------------------------------------.
 | A symbol should be used if either:                                    |
 |   1. It has a destructor.                                             |
 /*----------------------------------------------------------------------.
 | A symbol should be used if either:                                    |
 |   1. It has a destructor.                                             |

-|   2. --warnings=midrule-values and the symbol is a mid-rule symbol    |
-|      (i.e., the generated LHS replacing a mid-rule action) that was   |
-|      assigned to or used, as in "exp: { $$ = 1; } { $$ = $1; }".      |
+|   2. The symbol is a mid-rule symbol (i.e., the generated LHS         |
+|      replacing a mid-rule action) that was assigned to or used, as in |
+|      "exp: { $$ = 1; } { $$ = $1; }".                                 |

 `----------------------------------------------------------------------*/
 
 static bool
 `----------------------------------------------------------------------*/
 
 static bool

-symbol_should_be_used (symbol_list const *s)
+symbol_should_be_used (symbol_list const *s, bool *midrule_warning)

 {
   if (symbol_destructor_get (s->content.sym)->code)
     return true;
 {
   if (symbol_destructor_get (s->content.sym)->code)
     return true;

-  if (warnings_flag & warnings_midrule_values)
-    return ((s->midrule && s->midrule->action_props.is_value_used)
-           || (s->midrule_parent_rule
-               && symbol_list_n_get (s->midrule_parent_rule,
-                                     s->midrule_parent_rhs_index)
-                     ->action_props.is_value_used));
+  if ((s->midrule && s->midrule->action_props.is_value_used)
+      || (s->midrule_parent_rule
+          && symbol_list_n_get (s->midrule_parent_rule,
+                                s->midrule_parent_rhs_index)
+               ->action_props.is_value_used))
+    {
+      *midrule_warning = true;
+      return true;
+    }

   return false;
 }
 
   return false;
 }
 


@@ -301,17 +311,31 @@ grammar_rule_check (const symbol_list *r)
     symbol_list const *l = r;
     int n = 0;
     for (; l && l->content.sym; l = l->next, ++n)
     symbol_list const *l = r;
     int n = 0;
     for (; l && l->content.sym; l = l->next, ++n)

-      if (! (l->action_props.is_value_used
-            || !symbol_should_be_used (l)
-            /* The default action, $$ = $1, `uses' both.  */
-            || (!r->action_props.code && (n == 0 || n == 1))))
-       {
-         if (n)
-           warn_at (r->location, _("unused value: $%d"), n);
-         else
-           warn_at (r->location, _("unset value: $$"));
-       }
+      {
+        bool midrule_warning = false;
+        if (!l->action_props.is_value_used
+            && symbol_should_be_used (l, &midrule_warning)
+            /* The default action, $$ = $1, `uses' both.  */
+            && (r->action_props.code || (n != 0 && n != 1)))
+          {
+            void (*warn_at_ptr)(location, char const*, ...) =
+              midrule_warning ? midrule_value_at : warn_at;
+            if (n)
+              warn_at_ptr (r->location, _("unused value: $%d"), n);
+            else
+              warn_at_ptr (r->location, _("unset value: $$"));
+          }
+      }

   }
   }

+
+  /* See comments in grammar_current_rule_prec_set for how POSIX
+     mandates this complaint.  It's only for identifiers, so skip
+     it for char literals and strings, which are always tokens.  */
+  if (r->ruleprec
+      && r->ruleprec->tag[0] != '\'' && r->ruleprec->tag[0] != '"'
+      && !r->ruleprec->declared && !r->ruleprec->prec)
+    warn_at (r->location, _("token for %%prec is not defined: %s"),
+             r->ruleprec->tag);

 }
 
 
 }
 
 


@@ -348,8 +372,8 @@ grammar_midrule_action (void)
   symbol *dummy = dummy_symbol_get (dummy_location);
   symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
 
   symbol *dummy = dummy_symbol_get (dummy_location);
   symbol_list *midrule = symbol_list_sym_new (dummy, dummy_location);
 

-  /* Remember named_ref of previous action */
-  named_ref *named_ref = current_rule->action_props.named_ref;
+  /* Remember named_ref of previous action. */
+  named_ref *action_name = current_rule->action_props.named_ref;

 
   /* Make a new rule, whose body is empty, before the current one, so
      that the action just read can belong to it.  */
 
   /* Make a new rule, whose body is empty, before the current one, so
      that the action just read can belong to it.  */


@@ -376,7 +400,8 @@ grammar_midrule_action (void)
 
   /* Insert the dummy nonterminal replacing the midrule action into
      the current rule.  Bind it to its dedicated rule.  */
 
   /* Insert the dummy nonterminal replacing the midrule action into
      the current rule.  Bind it to its dedicated rule.  */

-  grammar_current_rule_symbol_append (dummy, dummy_location, named_ref);
+  grammar_current_rule_symbol_append (dummy, dummy_location,
+                                      action_name);

   grammar_end->midrule = midrule;
   midrule->midrule_parent_rule = current_rule;
   midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);
   grammar_end->midrule = midrule;
   midrule->midrule_parent_rule = current_rule;
   midrule->midrule_parent_rhs_index = symbol_list_length (current_rule->next);


@@ -387,6 +412,16 @@ grammar_midrule_action (void)
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {
 void
 grammar_current_rule_prec_set (symbol *precsym, location loc)
 {

+  /* POSIX says that any identifier is a nonterminal if it does not
+     appear on the LHS of a grammar rule and is not defined by %token
+     or by one of the directives that assigns precedence to a token.  We
+     ignore this here because the only kind of identifier that POSIX
+     allows to follow a %prec is a token and because assuming it's a
+     token now can produce more logical error messages.  Nevertheless,
+     grammar_rule_check does obey what we believe is the real intent of
+     POSIX here: that an error be reported for any identifier that
+     appears after %prec but that is not defined separately as a
+     token.  */

   symbol_class_set (precsym, token_sym, loc, false);
   if (current_rule->ruleprec)
     complain_at (loc, _("only one %s allowed per rule"), "%prec");
   symbol_class_set (precsym, token_sym, loc, false);
   if (current_rule->ruleprec)
     complain_at (loc, _("only one %s allowed per rule"), "%prec");


@@ -426,39 +461,28 @@ grammar_current_rule_merge_set (uniqstr name, location loc)
 
 void
 grammar_current_rule_symbol_append (symbol *sym, location loc,
 
 void
 grammar_current_rule_symbol_append (symbol *sym, location loc,

-                                   named_ref *named_ref)
+                                   named_ref *name)

 {
   symbol_list *p;
   if (current_rule->action_props.code)
     grammar_midrule_action ();
   p = grammar_symbol_append (sym, loc);
 {
   symbol_list *p;
   if (current_rule->action_props.code)
     grammar_midrule_action ();
   p = grammar_symbol_append (sym, loc);

-
-  if (named_ref)
-    {
-       if (named_ref->id == sym->tag)
-       {
-         warn_at (named_ref->loc,
-                  _("duplicated symbol name for %s ignored"),
-                  quote (sym->tag));
-         named_ref_free (named_ref);
-       }
-       else
-        p->named_ref = named_ref;
-    }
+  if (name)
+    assign_named_ref(p, name);

 }
 
 /* Attach an ACTION to the current rule.  */
 
 void
 grammar_current_rule_action_append (const char *action, location loc,
 }
 
 /* Attach an ACTION to the current rule.  */
 
 void
 grammar_current_rule_action_append (const char *action, location loc,

-                                   named_ref *named_ref)
+                                   named_ref *name)

 {
   if (current_rule->action_props.code)
     grammar_midrule_action ();
   /* After all symbol declarations have been parsed, packgram invokes
      code_props_translate_code.  */
   code_props_rule_action_init (&current_rule->action_props, action, loc,
 {
   if (current_rule->action_props.code)
     grammar_midrule_action ();
   /* After all symbol declarations have been parsed, packgram invokes
      code_props_translate_code.  */
   code_props_rule_action_init (&current_rule->action_props, action, loc,

-                               current_rule, named_ref);
+                               current_rule, name);

 }
 
 \f
 }
 
 \f


@@ -593,36 +617,41 @@ reader (void)
   gram_debug = trace_flag & trace_parse;
   gram_scanner_initialize ();
   gram_parse ();
   gram_debug = trace_flag & trace_parse;
   gram_scanner_initialize ();
   gram_parse ();

+  prepare_percent_define_front_end_variables ();
+
+  if (! complaint_issued)
+    check_and_convert_grammar ();

 
 

-  /* Set front-end %define variable defaults.  */
+  xfclose (gram_in);
+}
+
+static void
+prepare_percent_define_front_end_variables (void)
+{
+  /* Set %define front-end variable defaults.  */

   muscle_percent_define_default ("lr.keep-unreachable-states", "false");
   {
     char *lr_type;
     /* IELR would be a better default, but LALR is historically the
        default.  */
   muscle_percent_define_default ("lr.keep-unreachable-states", "false");
   {
     char *lr_type;
     /* IELR would be a better default, but LALR is historically the
        default.  */

-    muscle_percent_define_default ("lr.type", "LALR");
+    muscle_percent_define_default ("lr.type", "lalr");

     lr_type = muscle_percent_define_get ("lr.type");
     lr_type = muscle_percent_define_get ("lr.type");

-    if (0 != strcmp (lr_type, "canonical LR"))
-      muscle_percent_define_default ("lr.default-reductions", "all");
+    if (0 != strcmp (lr_type, "canonical-lr"))
+      muscle_percent_define_default ("lr.default-reductions", "most");

     else
       muscle_percent_define_default ("lr.default-reductions", "accepting");
     free (lr_type);
   }
 
     else
       muscle_percent_define_default ("lr.default-reductions", "accepting");
     free (lr_type);
   }
 

-  /* Check front-end %define variables.  */
+  /* Check %define front-end variables.  */

   {
     static char const * const values[] = {
   {
     static char const * const values[] = {

-      "lr.type", "LALR", "IELR", "canonical LR", NULL,
-      "lr.default-reductions", "all", "consistent", "accepting", NULL,
+      "lr.type", "lalr", "ielr", "canonical-lr", NULL,
+      "lr.default-reductions", "most", "consistent", "accepting", NULL,

       NULL
     };
     muscle_percent_define_check_values (values);
   }
       NULL
     };
     muscle_percent_define_check_values (values);
   }

-
-  if (! complaint_issued)
-    check_and_convert_grammar ();
-
-  xfclose (gram_in);

 }
 
 
 }
 
 


@@ -638,9 +667,6 @@ check_and_convert_grammar (void)
   if (nrules == 0)
     fatal (_("no rules in the input grammar"));
 
   if (nrules == 0)
     fatal (_("no rules in the input grammar"));
 

-  /* Report any undefined symbols and consider them nonterminals.  */
-  symbols_check_defined ();
-

   /* If the user did not define her ENDTOKEN, do it now. */
   if (!endtoken)
     {
   /* If the user did not define her ENDTOKEN, do it now. */
   if (!endtoken)
     {


@@ -651,6 +677,9 @@ check_and_convert_grammar (void)
       endtoken->user_token_number = 0;
     }
 
       endtoken->user_token_number = 0;
     }
 

+  /* Report any undefined symbols and consider them nonterminals.  */
+  symbols_check_defined ();
+

   /* Find the start symbol if no %start.  */
   if (!start_flag)
     {
   /* Find the start symbol if no %start.  */
   if (!start_flag)
     {