* src/symtab.h (SALIAS, SUNDEF): Rename as...

(USER_NUMBER_ALIAS, USER_NUMBER_UNDEFINED): these.
Adjust dependencies.
* src/output.c (token_definitions_output): Be sure not to output a
`#define 'a'' when fed with `%token 'a' "a"'.
* tests/regression.at (Token definitions): New.

diff --git a/ChangeLog b/ChangeLog
index 7bf7c436f50058c041529e4d3dae53d90b4e0d48..b53919882c744b1c3be16c979694d52226bc804d 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2002-05-04  Akim Demaille  <akim@epita.fr>
+
+       * src/symtab.h (SALIAS, SUNDEF): Rename as...
+       (USER_NUMBER_ALIAS, USER_NUMBER_UNDEFINED): these.
+       Adjust dependencies.
+       * src/output.c (token_definitions_output): Be sure not to output a
+       `#define 'a'' when fed with `%token 'a' "a"'.
+       * tests/regression.at (Token definitions): New.
+

 2002-05-03  Paul Eggert  <eggert@twinsun.com>
 
        * data/bison.simple (b4_token_defines): Also define YYTOKENTYPE
 2002-05-03  Paul Eggert  <eggert@twinsun.com>
 
        * data/bison.simple (b4_token_defines): Also define YYTOKENTYPE

diff --git a/NEWS b/NEWS
index ab991a8037fd056730b345718b0d23809146c3f0..98c7dad65eb3e1a2c08c29ebe696aef842b4ea41 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,9 @@ Changes in version 1.49b:
 * New tranlations
   Croatian, thanks to Denis Lackovic.
 
 * New tranlations
   Croatian, thanks to Denis Lackovic.
 

+* Token definitions
+  When fed with `%token 'a' "A"', Bison used to output `#define 'a' 65'.
+

 \f
 Changes in version 1.35, 2002-03-25:
 
 \f
 Changes in version 1.35, 2002-03-25:
 

diff --git a/TODO b/TODO
index 1c7c9f77f2bb62c9b23254e9fa695c873db3a767..bc474d21aee7183e7eeada910dd8e17485e51910 100644 (file)
--- a/TODO
+++ b/TODO
@@ -277,38 +277,6 @@ Rewrite the reader in Flex/Bison.  There will be delicate parts, in
 particular, expect the scanner to be hard to write.  Many interesting
 features cannot be implemented without such a new reader.
 
 particular, expect the scanner to be hard to write.  Many interesting
 features cannot be implemented without such a new reader.
 

-* Problems with aliases
-From: "Baum, Nathan I" <s0009525@chelt.ac.uk>
-Subject: Token Alias Bug
-To: "'bug-bison@gnu.org'" <bug-bison@gnu.org>
-
-I've noticed a bug in bison. Sadly, our eternally wise sysadmins won't let
-us use CVS, so I can't find out if it's been fixed already...
-
-Basically, I made a program (in flex) that went through a .y file looking
-for "..."-tokens, and then outputed a %token
-line for it. For single-character ""-tokens, I reasoned, I could just use
-[%token 'A' "A"]. However, this causes Bison to output a [#define 'A' 65],
-which cppp chokes on, not unreasonably. (And even if cppp didn't choke, I
-obviously wouldn't want (char)'A' to be replaced with (int)65 throughout my
-code.
-
-Bison normally forgoes outputing a #define for a character token. However,
-it always outputs an aliased token -- even if the token is an alias for a
-character token. We don't want that. The problem is in /output.c/, as I
-recall. When it outputs the token definitions, it checks for a character
-token, and then checks for an alias token. If the character token check is
-placed after the alias check, then it works correctly.
-
-Alias tokens seem to be something of a kludge. What about an [%alias "..."]
-command...
-
-       %alias T_IF "IF"
-
-Hmm. I can't help thinking... What about a --generate-lex option that
-creates an .l file for the alias tokens used... (Or an option to make a
-gperf file, etc...)
-

 * Presentation of the report file
 From: "Baum, Nathan I" <s0009525@chelt.ac.uk>
 Subject: Token Alias Bug
 * Presentation of the report file
 From: "Baum, Nathan I" <s0009525@chelt.ac.uk>
 Subject: Token Alias Bug

diff --git a/src/lex.c b/src/lex.c
index 516f799795fbc6cc5662d0daedf3042ec6a18f38..ad55f88e42665b5842134216cdee651ec3850db0 100644 (file)
--- a/src/lex.c
+++ b/src/lex.c
@@ -368,7 +368,7 @@ lex (void)
          {
            symval->number = ntokens++;
            symval->class = token_sym;
          {
            symval->number = ntokens++;
            symval->class = token_sym;

-           if (symval->user_token_number == SUNDEF)
+           if (symval->user_token_number == USER_NUMBER_UNDEFINED)

              symval->user_token_number = code;
          }
        return tok_identifier;
              symval->user_token_number = code;
          }
        return tok_identifier;

diff --git a/src/output.c b/src/output.c
index f92b6646306b5c656e3b4263f446d444561044b0..10ed907b7966e44947e74d29b7d58546ec3fb824 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -582,21 +582,25 @@ token_definitions_output (FILE *out)
       symbol_t *symbol = symbols[i];
       int number = symbol->user_token_number;
 
       symbol_t *symbol = symbols[i];
       int number = symbol->user_token_number;
 

-      if (number == SALIAS)
-       continue;
+      /* At this stage, if there are literal aliases, they are part of
+        SYMBOLS, so we should not find symbols which are the aliases
+        here.  */
+      assert (number != USER_NUMBER_ALIAS);
+

       /* Skip error token.  */
       if (symbol == errtoken)
        continue;
       /* Skip error token.  */
       if (symbol == errtoken)
        continue;

-      if (symbol->tag[0] == '\'')
-       continue;               /* skip literal character */
-      if (symbol->tag[0] == '\"')
-       {
-         /* use literal string only if given a symbol with an alias */
-         if (symbol->alias)
-           symbol = symbol->alias;
-         else
-           continue;
-       }
+
+      /* If this string has an alias, then it is necessarily the alias
+        which is to be output.  */
+      if (symbol->alias)
+       symbol = symbol->alias;
+
+      /* Don't output literal chars or strings (when defined only as a
+        string).  Note that must be done after the alias resolution:
+        think about `%token 'f' "f"'.  */
+      if (symbol->tag[0] == '\'' || symbol->tag[0] == '\"')
+       continue;

 
       /* Don't #define nonliteral tokens whose names contain periods
         or '$' (as does the default value of the EOF token).  */
 
       /* Don't #define nonliteral tokens whose names contain periods
         or '$' (as does the default value of the EOF token).  */


@@ -605,6 +609,7 @@ token_definitions_output (FILE *out)
 
       fprintf (out, "%s[[[%s]], [%d]]",
               first ? "" : ",\n", symbol->tag, number);
 
       fprintf (out, "%s[[[%s]], [%d]]",
               first ? "" : ",\n", symbol->tag, number);

+

       first = 0;
     }
 }
       first = 0;
     }
 }

diff --git a/src/reader.c b/src/reader.c
index da97aa415ff179fa6c0e87487a06f4691f72cb9d..75957010632f83d9c95c4132521535c48eaec0a3 100644 (file)
--- a/src/reader.c
+++ b/src/reader.c
@@ -126,7 +126,7 @@ symbol_make_alias (symbol_t *symbol, char *typename)
       symval->class = token_sym;
       symval->type_name = typename;
       symval->user_token_number = symbol->user_token_number;
       symval->class = token_sym;
       symval->type_name = typename;
       symval->user_token_number = symbol->user_token_number;

-      symbol->user_token_number = SALIAS;
+      symbol->user_token_number = USER_NUMBER_ALIAS;

       symval->alias = symbol;
       symbol->alias = symval;
       /* symbol and symval combined are only one symbol */
       symval->alias = symbol;
       symbol->alias = symval;
       /* symbol and symval combined are only one symbol */


@@ -149,7 +149,7 @@ static bool
 symbol_check_alias_consistence (symbol_t *this)
 {
   /* Check only those who _are_ the aliases. */
 symbol_check_alias_consistence (symbol_t *this)
 {
   /* Check only those who _are_ the aliases. */

-  if (this->alias && this->user_token_number == SALIAS)
+  if (this->alias && this->user_token_number == USER_NUMBER_ALIAS)

     {
       if (this->prec != this->alias->prec)
        {
     {
       if (this->prec != this->alias->prec)
        {


@@ -204,8 +204,8 @@ symbol_pack (symbol_t *this)
              this->number = this->alias->number;
            }
        }
              this->number = this->alias->number;
            }
        }

-      /* Do not do processing below for SALIASs.  */
-      if (this->user_token_number == SALIAS)
+      /* Do not do processing below for USER_NUMBER_ALIASs.  */
+      if (this->user_token_number == USER_NUMBER_ALIAS)

        return TRUE;
     }
   else /* this->class == token_sym */
        return TRUE;
     }
   else /* this->class == token_sym */


@@ -229,7 +229,7 @@ symbol_translation (symbol_t *this)
 {
   /* Non-terminal? */
   if (this->class == token_sym
 {
   /* Non-terminal? */
   if (this->class == token_sym

-      && this->user_token_number != SALIAS)
+      && this->user_token_number != USER_NUMBER_ALIAS)

     {
       /* A token which translation has already been set? */
       if (token_translations[this->user_token_number] != undeftoken->number)
     {
       /* A token which translation has already been set? */
       if (token_translations[this->user_token_number] != undeftoken->number)


@@ -998,10 +998,10 @@ parse_expect_decl (void)
 |                                                                    |
 | Two symbols are entered in the table, one for the token symbol and |
 | one for the literal.  Both are given the <type>, if any, from the  |
 |                                                                    |
 | Two symbols are entered in the table, one for the token symbol and |
 | one for the literal.  Both are given the <type>, if any, from the  |

-| declaration.  The ->user_token_number of the first is SALIAS and   |
-| the ->user_token_number of the second is set to the number, if     |
-| any, from the declaration.  The two symbols are linked via         |
-| pointers in their ->alias fields.                                  |
+| declaration.  The ->user_token_number of the first is              |
+| USER_NUMBER_ALIAS and the ->user_token_number of the second is set |
+| to the number, if any, from the declaration.  The two symbols are  |
+| linked via pointers in their ->alias fields.                       |

 |                                                                    |
 | During OUTPUT_DEFINES_TABLE, the symbol is reported thereafter,    |
 | only the literal string is retained it is the literal string that  |
 |                                                                    |
 | During OUTPUT_DEFINES_TABLE, the symbol is reported thereafter,    |
 | only the literal string is retained it is the literal string that  |


@@ -1014,7 +1014,7 @@ parse_thong_decl (void)
   token_t token;
   symbol_t *symbol;
   char *typename = 0;
   token_t token;
   symbol_t *symbol;
   char *typename = 0;

-  int usrtoknum = SUNDEF;
+  int usrtoknum = USER_NUMBER_UNDEFINED;

 
   token = lex ();              /* fetch typename or first token */
   if (token == tok_typename)
 
   token = lex ();              /* fetch typename or first token */
   if (token == tok_typename)


@@ -1035,7 +1035,7 @@ parse_thong_decl (void)
     }
   symval->class = token_sym;
   symval->type_name = typename;
     }
   symval->class = token_sym;
   symval->type_name = typename;

-  symval->user_token_number = SALIAS;
+  symval->user_token_number = USER_NUMBER_ALIAS;

   symbol = symval;
 
   token = lex ();              /* get number or literal string */
   symbol = symval;
 
   token = lex ();              /* get number or literal string */


@@ -1666,7 +1666,7 @@ token_translations_init (void)
   for (i = 0; i < ntokens; ++i)
     {
       symbol_t *this = symbols[i];
   for (i = 0; i < ntokens; ++i)
     {
       symbol_t *this = symbols[i];

-      if (this->user_token_number != SUNDEF)
+      if (this->user_token_number != USER_NUMBER_UNDEFINED)

        {
          if (this->user_token_number > max_user_token_number)
            max_user_token_number = this->user_token_number;
        {
          if (this->user_token_number > max_user_token_number)
            max_user_token_number = this->user_token_number;


@@ -1676,7 +1676,8 @@ token_translations_init (void)
     }
 
   /* If 256 is not used, assign it to error, to follow POSIX.  */
     }
 
   /* If 256 is not used, assign it to error, to follow POSIX.  */

-  if (num_256_available_p && errtoken->user_token_number == SUNDEF)
+  if (num_256_available_p
+      && errtoken->user_token_number == USER_NUMBER_UNDEFINED)

     errtoken->user_token_number = 256;
 
   /* Set the missing user numbers. */
     errtoken->user_token_number = 256;
 
   /* Set the missing user numbers. */


@@ -1686,7 +1687,7 @@ token_translations_init (void)
   for (i = 0; i < ntokens; ++i)
     {
       symbol_t *this = symbols[i];
   for (i = 0; i < ntokens; ++i)
     {
       symbol_t *this = symbols[i];

-      if (this->user_token_number == SUNDEF)
+      if (this->user_token_number == USER_NUMBER_UNDEFINED)

        this->user_token_number = ++max_user_token_number;
       if (this->user_token_number > max_user_token_number)
        max_user_token_number = this->user_token_number;
        this->user_token_number = ++max_user_token_number;
       if (this->user_token_number > max_user_token_number)
        max_user_token_number = this->user_token_number;

diff --git a/src/symtab.c b/src/symtab.c
index 598f8ee2b415d46a2802856e194ab51732b39ebd..c255a8f3c00df8be16fd8d2ea258ec01a46840d3 100644 (file)
--- a/src/symtab.c
+++ b/src/symtab.c
@@ -38,7 +38,7 @@ symbol_new (const char *tag)
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;
   res->assoc = right_assoc;
   res->number = NUMBER_UNDEFINED;
   res->prec = 0;
   res->assoc = right_assoc;

-  res->user_token_number = SUNDEF;
+  res->user_token_number = USER_NUMBER_UNDEFINED;

   res->alias = NULL;
   res->class = unknown_sym;
 
   res->alias = NULL;
   res->class = unknown_sym;
 

diff --git a/src/symtab.h b/src/symtab.h
index 591c6b8e4057b87dc21ab7d7e88a3b2cc618485b..fd7f495cf5018d6a295c90b4dc7a89bf5788cd2b 100644 (file)
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -41,14 +41,12 @@ typedef enum
   nterm_sym            /* non-terminal */
 } symbol_class;
 
   nterm_sym            /* non-terminal */
 } symbol_class;
 

+

 /* Internal token numbers. */
 typedef short token_number_t;
 
 /* Internal token numbers. */
 typedef short token_number_t;
 

-#define SUNDEF  -1              /* For undefined user number. */
-#define SALIAS -9991           /* for symbol generated with an alias */
-
-#define NUMBER_UNDEFINED ((token_number_t) -1)

 
 

+typedef struct symbol_s symbol_t;

 struct symbol_s
 {
   /* The key, name of the symbol. */
 struct symbol_s
 {
   /* The key, name of the symbol. */


@@ -61,14 +59,25 @@ struct symbol_s
   associativity assoc;
   int user_token_number;
 
   associativity assoc;
   int user_token_number;
 

-  /* Points to the other in the identifier-symbol pair for an
-     alias. Special value SALIAS in the identifier half of the
+  /* Points to the other in the identifier-symbol pair for an alias.
+     Special value USER_NUMBER_ALIAS in the identifier half of the

      identifier-symbol pair for an alias.  */
      identifier-symbol pair for an alias.  */

-  struct symbol_s *alias;
+  symbol_t *alias;

   symbol_class class;
 };
 
   symbol_class class;
 };
 

-typedef struct symbol_s symbol_t;
+/* Undefined user number.  */
+#define USER_NUMBER_UNDEFINED -1
+
+/* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
+   *has* (not is) a string literal alias.  For instance, `%token foo
+   "foo"' has `"foo"' numbered regularly, and `foo' numbered as
+   USER_NUMBER_ALIAS.  */
+#define USER_NUMBER_ALIAS -9991
+
+/* Undefined internal token number.  */
+#define NUMBER_UNDEFINED ((token_number_t) -1)
+

 
 /* A function to apply to each symbol. */
 typedef bool (*symbol_processor) PARAMS ((symbol_t *));
 
 /* A function to apply to each symbol. */
 typedef bool (*symbol_processor) PARAMS ((symbol_t *));

diff --git a/tests/regression.at b/tests/regression.at
index f97b710a97b15c406801a0b49b01b5420f5cbe46..8fb6ac9116fe2a50c68f3e5bc9067066600812f3 100644 (file)
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -287,6 +287,32 @@ AT_CLEANUP
 
 
 
 
 
 

+## ------------------- ##
+## Token definitions.  ##
+## ------------------- ##
+
+
+AT_SETUP([Token definitions])
+
+# Bison managed, when fed with `%token 'f' "f"' to #define 'f'!
+AT_DATA([input.y],
+[[%token "end of file"
+%token 'a' "a"
+%token "b" 'b'
+%token "c" c
+%token d "d"
+%token e 'e'
+%token 'f' e
+%%
+exp: "a";
+]])
+
+AT_CHECK([bison input.y -o input.c])
+AT_CHECK([$CC $CFLAGS $CPPFLAGS input.c -c])
+AT_CLEANUP
+
+
+

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