version 3.5.3

* NEWS: Record release date.

.prev-version

@@ -1 +1 @@
-3.5.1
+3.5.2

NEWS

@@ -1,5 +1,15 @@
 GNU Bison NEWS
 
+* Noteworthy changes in release 3.5.3 (2020-03-08) [stable]
+
+** Bug fixes
+
+  Error messages could quote lines containing zero-width characters (such as
+  \005) with incorrect styling.  Fixes for similar issues with unexpectedly
+  short lines (e.g., the file was changed between parsing and diagnosing).
+
+  Several unlikely crashes found by fuzzing have been fixed.
+
 * Noteworthy changes in release 3.5.2 (2020-02-13) [stable]
 
 ** Bug fixes

README

@@ -17,13 +17,18 @@ See the file INSTALL for generic compilation and installation instructions.
 Bison requires GNU m4 1.4.6 or later.  See
 https://ftp.gnu.org/gnu/m4/m4-1.4.6.tar.gz.
 
+## Running a non installed bison
+Once you ran `make`, you might want to toy with this fresh bison before
+installing it.  In that case, do not use `src/bison`: it would use the
+*installed* files (skeletons, etc.), not the local ones.  Use `tests/bison`.
+
 ## Colored diagnostics
 As an experimental feature, diagnostics are now colored, controlled by the
 `--color` and `--style` options.
 
 To use them, install the libtextstyle library before configuring Bison.  It
 is available from https://alpha.gnu.org/gnu/gettext/, for instance
-https://alpha.gnu.org/gnu/gettext/libtextstyle-0.8.tar.gz.
+https://alpha.gnu.org/pub/gnu/gettext/libtextstyle-0.20.5.tar.gz.
 
 The option --color supports the following arguments:
 - always, yes: Enable colors.
@@ -85,18 +90,12 @@ Software Foundation, Inc.
 
 This file is part of GNU bison, the GNU Compiler Compiler.
 
-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
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
 
 Local Variables:
 mode: markdown

README-hacking.md

@@ -34,13 +34,28 @@ Only user visible strings are to be translated: error messages, bits of the
 assert/abort), and all the --trace output which is meant for the maintainers
 only.
 
-## Horizontal tabs
+## Coding style
+Follow the GNU Coding Standards.
+
+Don't reinvent the wheel: we use gnulib, which features many components.
+Actually, Bison has legacy code that we should replace with gnulib modules
+(e.g., many adhoc implementations of lists).
+
 Do not add horizontal tab characters to any file in Bison's repository
 except where required.  For example, do not use tabs to format C code.
 However, make files, ChangeLog, and some regular expressions require tabs.
 Also, test cases might need to contain tabs to check that Bison properly
 processes tabs in its input.
 
+## Commit messages
+Please, imitate the style we use.  Use `git log` to get sources of
+inspiration.
+
+## Debugging
+Bison supports tracing of its various steps, via the `--trace` option.
+Since it is not meant for the end user, it is not displayed by `bison
+--help`, nor is it documented in the manual.  Instead, run `bison
+--trace=help`.
 
 # Working from the repository
 

THANKS

@@ -4,8 +4,9 @@ it is today without the invaluable help of these people:
 Aaro Koskinen             [email protected]
 Аскар Сафин               [email protected]
 Adam Sampson              [email protected]
+Ahcheong Lee              [email protected]
 Airy Andre                [email protected]
-Akim Demaille             akim@lrde.epita.fr
+Akim Demaille             akim@gnu.org
 Albert Chin-A-Young       [email protected]
 Alexander Belopolsky      [email protected]
 Alexandre Duret-Lutz      [email protected]

TODO

@@ -315,13 +315,8 @@ It would be a very nice source of inspiration for the other languages.
 Valentin Tolmer is working on this.
 
 ** YYERRCODE
-Defined to 256, but not used, not documented.  Probably the token
-number for the error token, which POSIX wants to be 256, but which
-Bison might renumber if the user used number 256.  Keep fix and doc?
-Throw away?
-
-Also, why don't we output the token name of the error token in the
-output?  It is explicitly skipped:
+Why don't we output the token name of the error token in the output?  It is
+explicitly skipped:
 
       /* Skip error token and tokens without identifier.  */
       if (sym != errtoken && id)

build-aux/cross-options.pl

@@ -17,7 +17,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #
-# Written by Akimn Demaille.
+# Written by Akim Demaille.
 
 use warnings;
 use 5.005;

data/skeletons/lalr1.cc

@@ -1340,7 +1340,7 @@ b4_error_verbose_if([state_type yystate, const symbol_type& yyla],
         yyarg[yycount++] = yytname_[yytoken];]b4_lac_if([[
 
 #if ]b4_api_PREFIX[DEBUG
-        // Execute LAC once. We don't care if it is succesful, we
+        // Execute LAC once. We don't care if it is successful, we
         // only do it for the sake of debugging output.
         if (!yy_lac_established_)
           yy_lac_check_ (yytoken);

data/skeletons/yacc.c

@@ -673,7 +673,7 @@ static const ]b4_int_type_for([b4_toknum])[ yytoknum[] =
 
 /* Error token number */
 #define YYTERROR        1
-#define YYERRCODE       256
+#define YYERRCODE       ]b4_symbol(1, user_number)[
 
 ]b4_locations_if([[
 ]b4_yylloc_default_define[

etc/bench.pl.in

@@ -100,7 +100,7 @@ Artificial grammar with very long rules.
 
 =item B<-h>, B<--help>
 
-Display this message and exit succesfully.  The more verbose, the more
+Display this message and exit successfully.  The more verbose, the more
 details.
 
 =item B<-i>, B<--iterations>=I<integer>

examples/c++/README.md

@@ -55,5 +55,5 @@ Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
 Texts.  A copy of the license is included in the "GNU Free
 Documentation License" file as part of this distribution.
 
-# LocalWords:  mfcalc calc parsers yy ispell american
+LocalWords:  mfcalc calc parsers yy ispell american
 --->

examples/c++/calc++/README.md

@@ -38,20 +38,12 @@ End:
 
 Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
-This file is part of Bison, the GNU Compiler Compiler.
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
 
-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
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-# LocalWords:  calc parsers yy MERCHANTABILITY Ctrl ispell american
+LocalWords:  calc parsers yy MERCHANTABILITY Ctrl ispell american
 --->

examples/c/README.md

@@ -47,6 +47,8 @@ End:
 
 Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
+This file is part of GNU bison, the GNU Compiler Compiler.
+
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
 any later version published by the Free Software Foundation; with no

examples/c/calc/README.md

@@ -13,16 +13,11 @@ Copyright (C) 2019-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 
-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
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
 
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
 --->

examples/c/lexcalc/README.md

@@ -13,16 +13,10 @@ Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
 This file is part of Bison, the GNU Compiler Compiler.
 
-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
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
 --->

examples/c/reccalc/README.md

@@ -28,18 +28,11 @@ End:
 
 Copyright (C) 2018-2020 Free Software Foundation, Inc.
 
-This file is part of Bison, the GNU Compiler Compiler.
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts.  A copy of the license is included in the "GNU Free
+Documentation License" file as part of this distribution.
 
-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
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program.  If not, see <http://www.gnu.org/licenses/>.
 --->

src/gram.h

@@ -42,9 +42,9 @@
 
    Internally, we cannot use the number 0 for a rule because for
    instance RITEM stores both symbol (the RHS) and rule numbers: the
-   symbols are shorts >= 0, and rule number are stored negative.
+   symbols are integers >= 0, and rule numbers are stored negative.
    Therefore 0 cannot be used, since it would be both the rule number
-   0, and the token $end).
+   0, and the token $end.
 
    Actions are accessed via the rule number.
 
@@ -55,8 +55,7 @@
 
    RULES[R].lhs -- the symbol of the left hand side of rule R.
 
-   RULES[R].rhs -- the index in RITEM of the beginning of the portion
-   for rule R.
+   RULES[R].rhs -- the beginning of the portion of RITEM for rule R.
 
    RULES[R].prec -- the symbol providing the precedence level of R.
 
@@ -75,16 +74,16 @@
 
    RULES[R].line -- the line where R was defined.
 
-   RULES[R].useful -- whether the rule is used (i.e., false if thrown
-   away by reduce).
+   RULES[R].useful -- whether the rule is used.  False if thrown away
+   by reduce().
 
    The right hand side is stored as symbol numbers in a portion of
    RITEM.
 
    The length of the portion is one greater than the number of symbols
    in the rule's right hand side.  The last element in the portion
-   contains minus R, which identifies it as the end of a portion and
-   says which rule it is for.
+   contains -R, which identifies it as the end of a portion and says
+   which rule it is for.
 
    The portions of RITEM come in order of increasing rule number.
    NRITEMS is the total length of RITEM.  Each element of RITEM is

src/location.c

@@ -175,6 +175,8 @@ location_print (location loc, FILE *out)
     }
   else
     {
+      aver (loc.start.file);
+      aver (loc.end.file);
       int end_col = 0 != loc.end.column ? loc.end.column - 1 : 0;
       res += fprintf (out, "%s",
                       quotearg_n_style (3, escape_quoting_style, loc.start.file));
@@ -317,7 +319,7 @@ caret_getc_internal (mbchar_t *res)
 
 /* Move CARET_INFO (which has a valid FILE) to the line number LINE.
    Compute and cache that line's length in CARET_INFO.LINE_LEN.
-   Return whether succesful.*/
+   Return whether successful.  */
 static bool
 caret_set_line (int line)
 {
@@ -421,12 +423,14 @@ location_caret (location loc, const char *style, FILE *out)
       {
         /* The last column to highlight.  Only the first line of
            multiline locations are quoted, in which case the ending
-           column is the end of line.  Single point locations (with
-           equal boundaries) denote the character that they
-           follow.  */
-        int col_end
+           column is the end of line.
+
+           We used to work with byte offsets, and that was much
+           easier.  However, we went back to using (visual) columns to
+           support truncating of long lines.  */
+        const int col_end
           = loc.start.line == loc.end.line
-          ? loc.end.column + (loc.start.column == loc.end.column)
+          ? loc.end.column
           : caret_info.line_len;
         /* Quote the file (at most the first line in the case of
            multiline locations).  */
@@ -436,24 +440,28 @@ location_caret (location loc, const char *style, FILE *out)
              expected (maybe the file was changed since the scanner
              ran), we might reach the end before we actually saw the
              opening column.  */
-          bool opened = false;
+          enum { before, inside, after } state = before;
           while (!mb_iseof (c) && !mb_iseq (c, '\n'))
             {
-              if (caret_info.pos.column == loc.start.column)
+              // We might have already opened (and even closed!) the
+              // style and yet have the equality of the columns if we
+              // just saw zero-width characters.
+              if (state == before
+                  && caret_info.pos.column == loc.start.column)
                 {
                   begin_use_class (style, out);
-                  opened = true;
+                  state = inside;
                 }
               if (skip < caret_info.pos.column)
                 mb_putc (c, out);
               boundary_compute (&caret_info.pos, mb_ptr (c), mb_len (c));
               caret_getc (c);
-              if (opened
+              if (state == inside
                   && (caret_info.pos.column == col_end
                       || width < caret_info.pos.column - skip))
                 {
                   end_use_class (style, out);
-                  opened = false;
+                  state = after;
                 }
               if (width < caret_info.pos.column - skip)
                 {
@@ -461,6 +469,12 @@ location_caret (location loc, const char *style, FILE *out)
                   break;
                 }
             }
+          if (state == inside)
+            {
+              // The line is shorter than expected.
+              end_use_class (style, out);
+              state = after;
+            }
           putc ('\n', out);
         }
 

src/location.h

@@ -42,16 +42,14 @@ typedef struct
 
   /* If positive, the column (starting at 1) just after the boundary.
      This is neither a byte count, nor a character count; it is a
-     column count.  If this is INT_MAX, the column number has
+     (visual) column count.  If this is INT_MAX, the column number has
      overflowed.
 
-     Meaningless and not displayed if nonpositive.
-  */
+     Meaningless and not displayed if nonpositive.  */
   int column;
 
-  /* If nonnegative, the byte number (starting at 0) in the current line.
-     Never displayed, used when printing error messages with colors to
-     know where colors start and end.  */
+  /* If nonnegative, the byte number (starting at 0) in the current
+     line.  Not displayed (unless --trace=location).  */
   int byte;
 
 } boundary;

src/lr0.c

@@ -58,10 +58,11 @@ core_print (size_t core_size, item_number *core, FILE *out)
     }
 }
 
-/*------------------------------------------------------------------.
-| A state was just discovered from another state.  Queue it for     |
-| later examination, in order to find its transitions.  Return it.  |
-`------------------------------------------------------------------*/
+/*-----------------------------------------------------------------.
+| A state was just discovered by transitioning on SYM from another |
+| state.  Queue this state for later examination, in order to find |
+| its outgoing transitions.  Return it.                            |
+`-----------------------------------------------------------------*/
 
 static state *
 state_list_append (symbol_number sym, size_t core_size, item_number *core)
@@ -98,7 +99,7 @@ static state **shiftset;
 
 
 /* KERNEL_BASE[symbol-number] -> list of item numbers (offsets inside
-   RITEM) of lenngth KERNEL_SIZE[symbol-number]. */
+   RITEM) of length KERNEL_SIZE[symbol-number]. */
 static item_number **kernel_base;
 static int *kernel_size;
 

src/lr0.h

@@ -21,8 +21,6 @@
 #ifndef LR0_H_
 # define LR0_H_
 
-# include "state.h"
-
 void generate_states (void);
 
 #endif /* !LR0_H_ */

src/muscle-tab.c

@@ -292,7 +292,6 @@ muscle_location_grow (char const *key, location loc)
 
 #define COMMON_DECODE(Value)                                    \
   case '$':                                                     \
-    ++(Value); aver (*(Value) == '[');                          \
     ++(Value); aver (*(Value) == ']');                          \
     ++(Value); aver (*(Value) == '[');                          \
     obstack_sgrow (&muscle_obstack, "$");                       \

src/reader.c

@@ -610,7 +610,7 @@ packgram (void)
 {
   int itemno = 0;
   ritem = xnmalloc (nritems + 1, sizeof *ritem);
-  /* This sentinel is used by build_relations in gram.c.  */
+  /* This sentinel is used by build_relations() in lalr.c.  */
   *ritem++ = 0;
 
   rule_number ruleno = 0;

src/reader.h

@@ -35,12 +35,6 @@ typedef struct merger_list
   location type_declaration_loc;
 } merger_list;
 
-/* From the parser.  */
-extern int gram_debug;
-int gram_parse (void);
-
-
-/* From reader.c. */
 void grammar_start_symbol_set (symbol *sym, location loc);
 void grammar_current_rule_begin (symbol *lhs, location loc,
                                  named_ref *lhs_named_ref);

src/scan-code.l

@@ -81,7 +81,7 @@ static bool untyped_var_seen;
    historically almost any character is allowed in a tag.  We disallow
    NUL and newline, as this simplifies our implementation.  We allow
    "->" as a means to dereference a pointer.  */
-tag      ([^\0\n>]|->)+
+tag      ([^\0\n>]|->)*[^-]
 
 /* Zero or more instances of backslash-newline.  Following GCC, allow
    white space between the backslash and the newline.  */

src/symtab.c

@@ -77,10 +77,12 @@ sym_content_new (symbol *s)
   res->symbol = s;
 
   res->type_name = NULL;
+  res->type_loc = empty_loc;
   for (int i = 0; i < CODE_PROPS_SIZE; ++i)
     code_props_none_init (&res->props[i]);
 
   res->number = NUMBER_UNDEFINED;
+  res->prec_loc = empty_loc;
   res->prec = 0;
   res->assoc = undef_assoc;
   res->user_token_number = USER_NUMBER_UNDEFINED;
@@ -553,7 +555,10 @@ symbol_class_set (symbol *sym, symbol_class class, location loc, bool declaring)
                                _("previous declaration"));
             }
           else
-            s->status = declared;
+            {
+              sym->location = loc;
+              s->status = declared;
+            }
         }
     }
 }

src/symtab.h

@@ -225,7 +225,8 @@ void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 /** Set the \c class associated with \c sym.
 
     Whether \c declaring means whether this class definition comes
-    from %nterm or %token (but not %type, prec/assoc, etc.).  */
+    from %nterm or %token (but not %type, prec/assoc, etc.).  A symbol
+    can have "declaring" set only at most once.  */
 void symbol_class_set (symbol *sym, symbol_class class, location loc,
                        bool declaring);
 

src/system.h

@@ -209,10 +209,10 @@ typedef size_t uintptr_t;
 
 /* Output Str both quoted for M4 (i.e., embed in [[...]]), and escaped
    for our postprocessing (i.e., escape M4 special characters).  If
-   Str is empty (or NULL), output "[]" instead of "[[]]" as it make M4
-   programming easier (m4_ifval can be used).
+   Str is empty (or NULL), output "[]" instead of "[[]]" as it makes
+   M4 programming easier (m4_ifval can be used).
 
-   For instance "[foo]" -> "[[@{foo@}]]", "$$" -> "[[$][$][]]". */
+   For instance "[foo]" -> "[[@{foo@}]]", "$$" -> "[[$][$][]]".  */
 
 # define obstack_quote(Obs, Str)                \
   do {                                          \

tests/diagnostics.at

@@ -37,15 +37,15 @@ AT_BISON_OPTION_PUSHDEFS
 
 AT_DATA_GRAMMAR([[input.y]], [$2])
 
+AT_DATA([experr], [$4])
+
 # For some reason, literal ^M in the input are removed and don't end
 # in `input.y`.  So use the two-character ^M represent it, and let
 # Perl insert real CR characters.
-if grep '\^M' input.y >/dev/null; then
-  AT_PERL_REQUIRE([-pi -e 's{\^M}{\r}gx' input.y])
+if $EGREP ['\^M|\\[0-9][0-9][0-9]'] input.y experr >/dev/null; then
+  AT_PERL_REQUIRE([-pi -e 's{\^M}{\r}g;s{\\(\d{3}|.)}{$v = $[]1; $v =~ /\A\d+\z/ ? chr($v) : $v}ge' input.y experr])
 fi
 
-AT_DATA([experr], [$4])
-
 AT_CHECK([LC_ALL="$locale" $5 bison -fcaret --color=debug -Wall input.y], [$3], [], [experr])
 
 # When no style, same messages, but without style.
@@ -152,6 +152,65 @@ input.y: <warning>warning:</warning> fix-its can be applied.  Rerun with option
 ]])
 
 
+
+## ------------------------------------- ##
+## Line is too short, and then you die.  ##
+## ------------------------------------- ##
+
+# We trust the "#line", since that's what allows us to quote the
+# actual source from which the gramar file was generated.  But #line
+# can also be wrong, and point to a line which is shorter that the bad
+# one.  In which case we can easily forget to close the styling.
+#
+# Be sure to have #line point to a line long enough to open the
+# styling, but not enough to close it.
+
+AT_TEST([[Line is too short, and then you die]],
+[[// Beware that there are 9 lines inserted before (including this one).
+#line 12
+%token foo 123
+%token foo 123123
+%token foo 123
+%%
+exp:
+]],
+[1],
+[[input.y:13.8-10: <warning>warning:</warning> symbol foo redeclared [<warning>-Wother</warning>]
+   13 | %token <warning>foo</warning> 123
+      |        <warning>^~~</warning>
+input.y:12.8-10:     previous declaration
+   12 | %token <note>foo</note> 123123
+      |        <note>^~~</note>
+input.y:13.12-17: <error>error:</error> redefining user token number of foo
+   13 | %token foo <error>123</error>
+      |            <error>^~~~~~</error>
+input.y:14.8-10: <warning>warning:</warning> symbol foo redeclared [<warning>-Wother</warning>]
+   14 | %%
+      |        <warning>^~~</warning>
+input.y:12.8-10:     previous declaration
+   12 | %token <note>foo</note> 123123
+      |        <note>^~~</note>
+]])
+
+
+## ----------------------- ##
+## Zero-width characters.  ##
+## ----------------------- ##
+
+# We used to open twice the styling for characters that have a
+# zero-width on display (e.g., \005).
+
+AT_TEST([[Zero-width characters]],
+[[%%
+exp: an\005error.
+]],
+[1],
+[[input.y:10.8: <error>error:</error> invalid character: '\\005'
+   10 | exp: an<error>\005</error>error.
+      |        <error>^</error>
+]])
+
+
 ## -------------------------------------- ##
 ## Tabulations and multibyte characters.  ##
 ## -------------------------------------- ##
@@ -262,7 +321,7 @@ input.y:10.1-27: <error>error:</error> %define variable 'error2' is not used
 ## ----------------- ##
 
 # Carriage-return used to count as a newline in the scanner, and not
-# in diagnostics.  Resulting in all sort of nice bugs.
+# in diagnostics.  Resulting in all kinds of nice bugs.
 
 AT_TEST([[Carriage return]],
 [[^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M^M

tests/input.at

@@ -298,6 +298,52 @@ input.y:8.14: error: syntax error, unexpected integer
 AT_CLEANUP
 
 
+## ---------------------------- ##
+## Redefining the error token.  ##
+## ---------------------------- ##
+
+AT_SETUP([Redefining the error token])
+
+# We used to crash when trying to display the original definition of
+# "error", which is a builtin without any location.
+
+AT_DATA([input.y],
+[[%token error 123
+%token error 124
+%%
+exp:
+]])
+
+AT_BISON_CHECK([-fcaret input.y], [1], [],
+[[input.y:2.8-12: warning: symbol error redeclared [-Wother]
+    2 | %token error 124
+      |        ^~~~~
+input.y:1.8-12:     previous declaration
+    1 | %token error 123
+      |        ^~~~~
+input.y:2.14-16: error: redefining user token number of error
+    2 | %token error 124
+      |              ^~~
+]])
+
+# While at it, make sure we properly used the user's number for
+# "error".
+AT_DATA([input.y],
+[[%token error 123
+%%
+exp:
+]])
+
+AT_BISON_CHECK([input.y])
+
+AT_CHECK([$EGREP -E '123|256' input.tab.c], [],
+[[       0,   123,   257
+#define YYERRCODE       123
+]])
+
+AT_CLEANUP
+
+
 ## ------------------ ##
 ## Dangling aliases.  ##
 ## ------------------ ##
@@ -2069,6 +2115,25 @@ input.y:1.1-34:     accepted value: 'consistent'
 input.y:1.1-34:     accepted value: 'accepting'
 ]])
 
+# Check escapes.
+AT_DATA([[input.y]],
+[[%define lr.default-reduction {[$@]}
+%%
+start: %empty;
+]])
+AT_BISON_CHECK([[-fcaret input.y]], [[1]], [[]],
+[[input.y:1.1-35: warning: %define variable 'lr.default-reduction' requires keyword values [-Wdeprecated]
+    1 | %define lr.default-reduction {[$@]}
+      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+input.y:1.1-35: error: invalid value for %define variable 'lr.default-reduction': '[$@]'
+    1 | %define lr.default-reduction {[$@]}
+      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+input.y:1.1-35:     accepted value: 'most'
+input.y:1.1-35:     accepted value: 'consistent'
+input.y:1.1-35:     accepted value: 'accepting'
+]])
+
+
 # Back-end.
 AT_DATA([[input.y]],
 [[%define api.push-pull neither
@@ -2548,7 +2613,9 @@ AT_DATA_GRAMMAR([[input.y]],
 %printer        { $%; @%; } <*> exp TOK;
 %{ $ @ %} // Should not warn.
 %%
-exp: TOK        { $%; @%; $$ = $1; };
+exp: TOK        { $%; @%; $$ = $1; }
+   | 'a'        { $<->1; $$ = 1; }
+   | 'b'        { $<foo->bar>$; }
 %%
 $ @ // Should not warn.
 ]])
@@ -2562,6 +2629,7 @@ input.y:13.19: warning: stray '$' [-Wother]
 input.y:13.23: warning: stray '@' [-Wother]
 input.y:16.19: warning: stray '$' [-Wother]
 input.y:16.23: warning: stray '@' [-Wother]
+input.y:17.19: warning: stray '$' [-Wother]
 ]])
 
 AT_BISON_OPTION_POPDEFS