Don't allow an undeclared string literal, but allow a string literal to

be used before its declaration.
* src/reader.c (check_and_convert_grammar): Don't invoke packgram if
symbols_pack complained.
* src/symtab.c (symbol_new): Don't count a string literal as a new
symbol.
(symbol_class_set): Don't count a string literal as a new token, and
don't assign it a symbol number since symbol_make_alias does that.
(symbol_make_alias): It's not necessary to decrement the symbol and
token counts anymore.  Don't assume that an alias declaration occurs
before any uses of the identifier or string, and thus don't assert that
one of them has the highest symbol number so far.
(symbol_check_alias_consistency): Complain if there's a string literal
that wasn't declared as an alias.
(symbols_pack): Bail if symbol_check_alias_consistency failed since
symbol_pack asserts that every token has been assigned a symbol number
although undeclared string literals have not.
* tests/regression.at (String alias declared after use, Undeclared
string literal): New test case.
(Characters Escapes, Web2c Actions): Declare string literals as
aliases.
* tests/sets.at (Firsts): Likewise.

diff --git a/ChangeLog b/ChangeLog
index 8fa4385859795e42e59b7094a594c3c9cf788031..3a683551af51aa2e672a215285b1d303b8880fa5 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,28 @@
+2006-08-18  Joel E. Denny  <jdenny@ces.clemson.edu>
+
+       Don't allow an undeclared string literal, but allow a string literal to
+       be used before its declaration.
+       * src/reader.c (check_and_convert_grammar): Don't invoke packgram if
+       symbols_pack complained.
+       * src/symtab.c (symbol_new): Don't count a string literal as a new
+       symbol.
+       (symbol_class_set): Don't count a string literal as a new token, and
+       don't assign it a symbol number since symbol_make_alias does that.
+       (symbol_make_alias): It's not necessary to decrement the symbol and
+       token counts anymore.  Don't assume that an alias declaration occurs
+       before any uses of the identifier or string, and thus don't assert that
+       one of them has the highest symbol number so far.
+       (symbol_check_alias_consistency): Complain if there's a string literal
+       that wasn't declared as an alias.
+       (symbols_pack): Bail if symbol_check_alias_consistency failed since
+       symbol_pack asserts that every token has been assigned a symbol number
+       although undeclared string literals have not.
+       * tests/regression.at (String alias declared after use, Undeclared
+       string literal): New test case.
+       (Characters Escapes, Web2c Actions): Declare string literals as
+       aliases.
+       * tests/sets.at (Firsts): Likewise.
+
 2006-08-14  Joel E. Denny  <jdenny@ces.clemson.edu>
 
        In the grammar scanner, STRING_FINISH unclosed constructs and return

diff --git a/src/reader.c b/src/reader.c
index 5084618ffb4a5ba465db4dce995620e32ea84574..e31fe4c5dc4ece1b0e7f8cadbd42b60814a30362 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -630,7 +630,8 @@ check_and_convert_grammar (void)
   symbols_pack ();
 
   /* Convert the grammar into the format described in gram.h.  */
-  packgram ();
+  if (!complaint_issued)
+    packgram ();
 
   /* The grammar as a symbol_list is no longer needed. */
   LIST_FREE (symbol_list, grammar);

diff --git a/src/symtab.c b/src/symtab.c
index 8b3e30d37e0dd69b2f5376dc3325b8a66f003495..28f49fb4b72cb8f55a8bfb1e44286450304d5708 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -79,7 +79,8 @@ symbol_new (uniqstr tag, location loc)
   if (nsyms == SYMBOL_NUMBER_MAXIMUM)
     fatal (_("too many symbols in input grammar (limit is %d)"),
           SYMBOL_NUMBER_MAXIMUM);
-  nsyms++;
+  if (tag[0] != '"')
+    nsyms++;
   return res;
 }
 
@@ -266,7 +267,8 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
 
   if (class == nterm_sym && sym->class != nterm_sym)
     sym->number = nvars++;
-  else if (class == token_sym && sym->number == NUMBER_UNDEFINED)
+  else if (class == token_sym && sym->number == NUMBER_UNDEFINED
+           && sym->tag[0] != '"')
     sym->number = ntokens++;
 
   sym->class = class;
@@ -361,12 +363,7 @@ symbol_make_alias (symbol *sym, symbol *symval, location loc)
       sym->user_token_number = USER_NUMBER_ALIAS;
       symval->alias = sym;
       sym->alias = symval;
-      /* sym and symval combined are only one symbol.  */
-      nsyms--;
-      ntokens--;
-      assert (ntokens == sym->number || ntokens == symval->number);
-      sym->number = symval->number =
-       (symval->number < sym->number) ? symval->number : sym->number;
+      symval->number = sym->number;
       symbol_type_set (symval, sym->type_name, loc);
     }
 }
@@ -383,6 +380,9 @@ symbol_check_alias_consistency (symbol *this)
   symbol *alias = this;
   symbol *orig  = this->alias;
 
+  if (this->tag[0] == '"' && !this->alias)
+    complain_at (this->location, _("%s undeclared"), this->tag);
+
   /* Check only those that _are_ the aliases.  */
   if (!(this->alias && this->user_token_number == USER_NUMBER_ALIAS))
     return;
@@ -723,6 +723,8 @@ symbols_pack (void)
   symbols = xcalloc (nsyms, sizeof *symbols);
 
   symbols_do (symbol_check_alias_consistency_processor, NULL);
+  if (complaint_issued)
+    return;
   symbols_do (symbol_pack_processor, NULL);
 
   symbols_token_translations_init ();

diff --git a/tests/regression.at b/tests/regression.at
index 923a8933949f26b885873cf6c37fa45423f8e6fc..1c5ccbbf370766306713828ff23c5d6d2f1ee7dd 100644 (file)
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -489,7 +489,9 @@ AT_DATA_GRAMMAR([input.y],
 void yyerror (const char *s);
 int yylex (void);
 %}
-[%%
+[%token QUOTES "\""
+%token TICK "'"
+%%
 exp:
   '\'' "\'"
 | '\"' "\""
@@ -700,6 +702,10 @@ statement:  struct_stat;
 struct_stat:  /* empty. */ | if else;
 if: "if" "const" "then" statement;
 else: "else" statement;
+%token IF "if";
+%token CONST "const";
+%token THEN "then";
+%token ELSE "else";
 %%
 ]])
 
@@ -1108,3 +1114,48 @@ Stack now 0
 ]])
 
 AT_CLEANUP
+
+
+
+## --------------------------------- ##
+## String alias declared after use.  ##
+## --------------------------------- ##
+
+AT_SETUP([String alias declared after use])
+
+# Bison once incorrectly asserted that the symbol number for either a token or
+# its alias was the highest symbol number so far at the point of the alias
+# declaration.  That was true unless the declaration appeared after their first
+# uses.
+
+AT_DATA([input.y],
+[[%%
+start: 'a' "A" 'b';
+%token 'a' "A";
+]])
+
+AT_CHECK([bison -t -o input.c input.y])
+
+AT_CLEANUP
+
+
+
+## --------------------------- ##
+## Undeclared string literal.  ##
+## --------------------------- ##
+
+AT_SETUP([Undeclared string literal])
+
+# Bison once allowed a string literal to be used in the grammar without any
+# declaration assigning it as an alias of another token.
+
+AT_DATA([input.y],
+[[%%
+start: "abc";
+]])
+
+AT_CHECK([bison -t -o input.c input.y], [1], [],
+[[input.y:2.8-12: "abc" undeclared
+]])
+
+AT_CLEANUP

diff --git a/tests/sets.at b/tests/sets.at
index a731315b231e06386a62f5e5e8cd6f3565e93b85..941d0cc257a42d7c0f30e2d705995019e1905c63 100644 (file)
--- a/tests/sets.at
+++ b/tests/sets.at
@@ -196,6 +196,7 @@ AT_DATA([input.y],
 [[%nonassoc '<' '>'
 %left '+' '-'
 %right '^' '='
+%token EXP "exp"
 %%
 exp:
    exp '<' exp