style: no longer use backquotes

* README, REFERENCES, TODO, configure.ac, data/README, data/bison.m4,
* data/c++.m4, data/c.m4, data/java.m4, data/lalr1.cc,
* data/lalr1.java, data/yacc.c, doc/local.mk, etc/bench.pl.in,
* src/conflicts.c, src/files.c, src/getargs.c, src/gram.h, src/lalr.c,
* src/location.c, src/location.h, src/muscle-tab.c, src/muscle-tab.h,
* src/output.c, src/parse-gram.c, src/parse-gram.y, src/print-xml.c,
* src/print.c, src/reader.c, src/reduce.c, src/scan-skel.l,
* src/symtab.h, src/system.h, src/tables.c:
Use single quotes, as currently recommended by the GNU Coding Standards.

34 files changed, 87 insertions, 87 deletions

diff --git a/README b/README
index ad667a23..ed393c28 100644
--- a/README
+++ b/README
@@ -30,7 +30,7 @@ not answer them, please send mail to <help-bison@gnu.org>.
 
 * Bug reports
 Please send bug reports to <bug-bison@gnu.org>.  Please include the
-version number from `bison --version', and a complete, self-contained
+version number from 'bison --version', and a complete, self-contained
 test case in each bug report.
 
 * Copyright statements
diff --git a/REFERENCES b/REFERENCES
index d55cdae8..9af36731 100644
--- a/REFERENCES
+++ b/REFERENCES
@@ -9,7 +9,7 @@ Bison supports the @N construction, which gives you access to
 the starting and ending line number and character number associated
 with any of the symbols in the current rule.
 
-Also, Bison supports the command `%expect N' which says not to mention
+Also, Bison supports the command '%expect N' which says not to mention
 the conflicts if there are N shift/reduce conflicts and no reduce/reduce
 conflicts.
 
diff --git a/TODO b/TODO
index bba43c29..09fce089 100644
--- a/TODO
+++ b/TODO
@@ -176,13 +176,13 @@ part of $default.  Should we make the two reductions explicit, or just
 keep $default?  See the following point.
 
 ** Disabled Reductions
-See `tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
+See 'tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
 what we want to do.
 
 ** Documentation
 Extend with error productions.  The hard part will probably be finding
 the right rule so that a single state does not exhibit too many yet
-undocumented ``features''.  Maybe an empty action ought to be
+undocumented ''features''.  Maybe an empty action ought to be
 presented too.  Shall we try to make a single grammar with all these
 features, or should we have several very small grammars?
 
@@ -243,9 +243,9 @@ into
         exp: exp '+' exp | exp '&' exp;
 
 when there are no actions.  This can significantly speed up some
-grammars.  I can't find the papers.  In particular the book `LR
+grammars.  I can't find the papers.  In particular the book 'LR
 parsing: Theory and Practice' is impossible to find, but according to
-`Parsing Techniques: a Practical Guide', it includes information about
+'Parsing Techniques: a Practical Guide', it includes information about
 this issue.  Does anybody have it?
 
 
diff --git a/configure.ac b/configure.ac
index 05a8d920..8f96e546 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@
 # In order for some versions of Sun Studio to compile our C++ test cases
 # correctly, we need Autoconf 2.64 or better to handle the restrict
 # keyword in at least string.h from gnulib.  We need Autoconf 2.68 or
-# better to avoid a typo in the `configure --help' entry for the YACC
+# better to avoid a typo in the 'configure --help' entry for the YACC
 # environment variable.
 AC_PREREQ([2.68])
 m4_pattern_forbid([^gl_[A-Z]])
diff --git a/data/README b/data/README
index 9dc9ca6e..842c0041 100644
--- a/data/README
+++ b/data/README
@@ -27,7 +27,7 @@ Currently, the supported skeletons are:
 These skeletons are the only ones supported by the Bison team.
 Because the interface between skeletons and the bison program is not
 finished, *we are not bound to it*.  In particular, Bison is not
-mature enough for us to consider that ``foreign skeletons'' are
+mature enough for us to consider that "foreign skeletons" are
 supported.
 
 * m4sugar
diff --git a/data/bison.m4 b/data/bison.m4
index d01124bb..9c5d48f5 100644
--- a/data/bison.m4
+++ b/data/bison.m4
@@ -313,7 +313,7 @@ m4_define([b4_define_flag_if],
 # _b4_define_flag_if($1, $2, FLAG)
 # --------------------------------
 # Work around the impossibility to define macros inside macros,
-# because issuing `[$1]' is not possible in M4.  GNU M4 should provide
+# because issuing '[$1]' is not possible in M4.  GNU M4 should provide
 # $$1 a la M5/TeX.
 m4_define([_b4_define_flag_if],
 [m4_if([$1$2], $[1]$[2], [],
@@ -772,8 +772,8 @@ m4_define([b4_percent_define_default],
 # b4_percent_define_if_define(NAME, [VARIABLE = NAME])
 # ----------------------------------------------------
 # Define b4_NAME_if that executes its $1 or $2 depending whether
-# VARIABLE was %defined.  The characters `.' and `-' in VARIABLE are mapped
-# to `_'.
+# VARIABLE was %defined.  The characters '.' and `-' in VARIABLE are mapped
+# to '_'.
 m4_define([b4_percent_define_if_define_],
 [m4_define(m4_bpatsubst([b4_$1_if], [[-.]], [_]),
            [b4_percent_define_flag_if(m4_default([$2], [$1]),
diff --git a/data/c++.m4 b/data/c++.m4
index a63cbce4..3fc67509 100644
--- a/data/c++.m4
+++ b/data/c++.m4
@@ -54,8 +54,8 @@ b4_percent_define_default([[define_location_comparison]],
 m4_define([b4_namespace_ref], [b4_percent_define_get([[api.namespace]])])
 
 
-# Don't permit an empty b4_namespace_ref.  Any `::parser::foo' appended to it
-# would compile as an absolute reference with `parser' in the global namespace.
+# Don't permit an empty b4_namespace_ref.  Any '::parser::foo' appended to it
+# would compile as an absolute reference with 'parser' in the global namespace.
 # b4_namespace_open would open an anonymous namespace and thus establish
 # internal linkage.  This would compile.  However, it's cryptic, and internal
 # linkage for the parser would be specified in all translation units that
diff --git a/data/c.m4 b/data/c.m4
index f145c737..9405ae34 100644
--- a/data/c.m4
+++ b/data/c.m4
@@ -150,7 +150,7 @@ m4_popdef([$1])dnl
 
 # b4_parse_param_use([VAL], [LOC])
 # --------------------------------
-# `YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
+# 'YYUSE' VAL, LOC if locations are enabled, and all the parse-params.
 m4_define([b4_parse_param_use],
 [m4_ifvaln([$1], [  YYUSE ([$1]);])dnl
 b4_locations_if([m4_ifvaln([$2], [  YYUSE ([$2]);])])dnl
@@ -182,7 +182,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])
 
diff --git a/data/java.m4 b/data/java.m4
index 7a9bcc19..cff774d8 100644
--- a/data/java.m4
+++ b/data/java.m4
@@ -103,7 +103,7 @@ m4_define([b4_int_type],
 # b4_int_type_for(NAME)
 # ---------------------
 # Return the smallest int type able to handle numbers ranging from
-# `NAME_min' to `NAME_max' (included).
+# 'NAME_min' to 'NAME_max' (included).
 m4_define([b4_int_type_for],
 [b4_int_type($1_min, $1_max)])
 
diff --git a/data/lalr1.cc b/data/lalr1.cc
index eb488355..53e7455a 100644
--- a/data/lalr1.cc
+++ b/data/lalr1.cc
@@ -824,7 +824,7 @@ b4_dollar_popdef])[]dnl
        variants.  */
     b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])],[
     /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.
 
        Otherwise, the following line sets YYLHS.VALUE to garbage.
        This behavior is undocumented and Bison
diff --git a/data/lalr1.java b/data/lalr1.java
index 187580a2..204c03fc 100644
--- a/data/lalr1.java
+++ b/data/lalr1.java
@@ -375,7 +375,7 @@ b4_lexer_if([[
     ]b4_locations_if([b4_location_type[ yyloc = yylloc (yystack, yylen);]])[
 
     /* If YYLEN is nonzero, implement the default value of the action:
-       `$$ = $1'.  Otherwise, use the top of the stack.
+       '$$ = $1'.  Otherwise, use the top of the stack.
 
        Otherwise, the following line sets YYVAL to garbage.
        This behavior is undocumented and Bison
diff --git a/data/yacc.c b/data/yacc.c
index 88277a91..c341a70d 100644
--- a/data/yacc.c
+++ b/data/yacc.c
@@ -223,9 +223,9 @@ m4_define([b4_declare_parser_state_variables], [b4_pure_if([[
     int yyerrstatus;
 
     /* The stacks and their tools:
-       `yyss': related to states.
-       `yyvs': related to semantic values.]b4_locations_if([[
-       `yyls': related to locations.]])[
+       'yyss': related to states.
+       'yyvs': related to semantic values.]b4_locations_if([[
+       'yyls': related to locations.]])[
 
        Refer to the stacks through separate pointers, to allow yyoverflow
        to reallocate them elsewhere.  */
@@ -468,7 +468,7 @@ b4_push_if([], [b4_lac_if([], [[
 # endif]])])[
 
 # ifdef YYSTACK_ALLOC
-   /* Pacify GCC's `empty if-body' warning.  */
+   /* Pacify GCC's 'empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
 #  ifndef YYSTACK_ALLOC_MAXIMUM
     /* The OS might guarantee only one guard page at the bottom of the stack,
@@ -1654,7 +1654,7 @@ yyreduce:
   yylen = yyr2[yyn];
 
   /* If YYLEN is nonzero, implement the default value of the action:
-     `$$ = $1'.
+     '$$ = $1'.
 
      Otherwise, the following line sets YYVAL to garbage.
      This behavior is undocumented and Bison
@@ -1702,7 +1702,7 @@ yyreduce:
   *++yyvsp = yyval;]b4_locations_if([
   *++yylsp = yyloc;])[
 
-  /* Now `shift' the result of the reduction.  Determine what state
+  /* Now 'shift' the result of the reduction.  Determine what state
      that goes to, based on the state we popped back to and the rule
      number reduced by.  */
 
diff --git a/doc/local.mk b/doc/local.mk
index 30ef3389..afd50dd1 100644
--- a/doc/local.mk
+++ b/doc/local.mk
@@ -37,7 +37,7 @@ MOSTLYCLEANFILES += $(top_srcdir)/doc/*.t
 CROSS_OPTIONS_PL = $(top_srcdir)/build-aux/cross-options.pl
 CROSS_OPTIONS_TEXI = $(top_srcdir)/doc/cross-options.texi
 $(CROSS_OPTIONS_TEXI): doc/bison.help $(CROSS_OPTIONS_PL)
-# Create $@~ which is the previous contents.  Don't use `mv' here so
+# Create $@~ which is the previous contents.  Don't use 'mv' here so
 # that even if we are interrupted, the file is still available for
 # diff in the next run.  Note that $@ might not exist yet.
 	$(AM_V_GEN){ test ! -f $@ || cat $@; } >$@~
diff --git a/etc/bench.pl.in b/etc/bench.pl.in
index aaaf1430..30d0a996 100755
--- a/etc/bench.pl.in
+++ b/etc/bench.pl.in
@@ -204,9 +204,9 @@ Format the list of directives for Bison for bench named C<$bench>.
 sub directives($@)
 {
   my ($bench, @directive) = @_;
-  my $res = "/* Directives for bench `$bench'. */\n";
+  my $res = "/* Directives for bench '$bench'. */\n";
   $res .= join ("\n", @directive) . "\n";
-  $res .= "/* End of directives for bench `$bench'. */\n";
+  $res .= "/* End of directives for bench '$bench'. */\n";
   return $res;
 }
 
diff --git a/src/conflicts.c b/src/conflicts.c
index 80ea74a8..18404736 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -403,7 +403,7 @@ conflicts_solve (void)
       set_conflicts (states[i], errors);
 
       /* For uniformity of the code, make sure all the states have a valid
-         `errs' member.  */
+         'errs' member.  */
       if (!states[i]->errs)
         states[i]->errs = errs_new (0, 0);
     }
diff --git a/src/files.c b/src/files.c
index bc8a4e51..76aa7fe3 100644
--- a/src/files.c
+++ b/src/files.c
@@ -34,7 +34,7 @@
 #include "getargs.h"
 #include "gram.h"
 
-/* Initializing some values below (such SPEC_NAME_PREFIX to `yy') is
+/* Initializing some values below (such SPEC_NAME_PREFIX to 'yy') is
    tempting, but don't do that: for the time being our handling of the
    %directive vs --option leaves precedence to the options by deciding
    that if a %directive sets a variable which is really set (i.e., not
@@ -58,20 +58,20 @@ uniqstr grammar_file = NULL;
 uniqstr current_file = NULL;
 
 /* If --output=dir/foo.c was specified,
-   DIR_PREFIX is `dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are `dir/foo'.
+   DIR_PREFIX is 'dir/' and ALL_BUT_EXT and ALL_BUT_TAB_EXT are 'dir/foo'.
 
-   If --output=dir/foo.tab.c was specified, DIR_PREFIX is `dir/',
-   ALL_BUT_EXT is `dir/foo.tab', and ALL_BUT_TAB_EXT is `dir/foo'.
+   If --output=dir/foo.tab.c was specified, DIR_PREFIX is 'dir/',
+   ALL_BUT_EXT is 'dir/foo.tab', and ALL_BUT_TAB_EXT is 'dir/foo'.
 
    If --output was not specified but --file-prefix=dir/foo was specified,
-   ALL_BUT_EXT = `foo.tab' and ALL_BUT_TAB_EXT = `foo'.
+   ALL_BUT_EXT = 'foo.tab' and ALL_BUT_TAB_EXT = 'foo'.
 
    If neither --output nor --file was specified but the input grammar
-   is name dir/foo.y, ALL_BUT_EXT and ALL_BUT_TAB_EXT are `foo'.
+   is name dir/foo.y, ALL_BUT_EXT and ALL_BUT_TAB_EXT are 'foo'.
 
    If neither --output nor --file was specified, DIR_PREFIX is the
    empty string (meaning the current directory); otherwise it is
-   `dir/'.  */
+   'dir/'.  */
 
 char *all_but_ext;
 static char *all_but_tab_ext;
@@ -79,7 +79,7 @@ char *dir_prefix;
 
 /* C source file extension (the parser source).  */
 static char *src_extension = NULL;
-/* Header file extension (if option ``-d'' is specified).  */
+/* Header file extension (if option '`-d'' is specified).  */
 static char *header_extension = NULL;
 
 /*-----------------------------------------------------------------.
@@ -191,7 +191,7 @@ compute_exts_from_src (const char *ext)
    *EXT points to the last period in the basename, or NULL if none.
 
    If there is no *EXT, *TAB is NULL.  Otherwise, *TAB points to
-   `.tab' or `_tab' if present right before *EXT, or is NULL. *TAB
+   '.tab' or '_tab' if present right before *EXT, or is NULL. *TAB
    cannot be equal to *BASE.
 
    None are allocated, they are simply pointers to parts of FILE_NAME.
@@ -222,7 +222,7 @@ file_name_split (const char *file_name,
   *ext = strrchr (*base, '.');
   *tab = NULL;
 
-  /* If there is an extension, check if there is a `.tab' part right
+  /* If there is an extension, check if there is a '.tab' part right
      before.  */
   if (*ext)
     {
@@ -270,7 +270,7 @@ compute_file_name_parts (void)
 
       if (spec_file_prefix)
         {
-          /* If --file-prefix=foo was specified, ALL_BUT_TAB_EXT = `foo'.  */
+          /* If --file-prefix=foo was specified, ALL_BUT_TAB_EXT = 'foo'.  */
           dir_prefix =
             xstrndup (spec_file_prefix,
                       last_component (spec_file_prefix) - spec_file_prefix);
@@ -278,14 +278,14 @@ compute_file_name_parts (void)
         }
       else if (yacc_flag)
         {
-          /* If --yacc, then the output is `y.tab.c'.  */
+          /* If --yacc, then the output is 'y.tab.c'.  */
           dir_prefix = xstrdup ("");
           all_but_tab_ext = xstrdup ("y");
         }
       else
         {
           /* Otherwise, ALL_BUT_TAB_EXT is computed from the input
-             grammar: `foo/bar.yy' => `bar'.  */
+             grammar: 'foo/bar.yy' => 'bar'.  */
           dir_prefix = xstrdup ("");
           all_but_tab_ext =
             xstrndup (base, (strlen (base) - (ext ? strlen (ext) : 0)));
diff --git a/src/getargs.c b/src/getargs.c
index 03a7339b..e4ffc02e 100644
--- a/src/getargs.c
+++ b/src/getargs.c
@@ -538,7 +538,7 @@ static struct option const long_options[] =
 };
 
 /* Under DOS, there is no difference on the case.  This can be
-   troublesome when looking for `.tab' etc.  */
+   troublesome when looking for '.tab' etc.  */
 #ifdef MSDOS
 # define AS_FILE_NAME(File) (strlwr (File), (File))
 #else
diff --git a/src/gram.h b/src/gram.h
index 35e8be4a..c1dd9a64 100644
--- a/src/gram.h
+++ b/src/gram.h
@@ -35,7 +35,7 @@
 
    The rules receive rule numbers 1 to NRULES in the order they are
    written.  More precisely Bison augments the grammar with the
-   initial rule, `$accept: START-SYMBOL $end', which is numbered 1,
+   initial rule, '$accept: START-SYMBOL $end', which is numbered 1,
    all the user rules are 2, 3 etc.  Each time a rule number is
    presented to the user, we subtract 1, so *displayed* rule numbers
    are 0, 1, 2...
@@ -61,7 +61,7 @@
    RULES[R].prec -- the symbol providing the precedence level of R.
 
    RULES[R].precsym -- the symbol attached (via %prec) to give its
-   precedence to R.  Of course, if set, it is equal to `prec', but we
+   precedence to R.  Of course, if set, it is equal to 'prec', but we
    need to distinguish one from the other when reducing: a symbol used
    in a %prec is not useless.
 
@@ -205,11 +205,11 @@ extern rule *rules;
 /* A function that selects a rule.  */
 typedef bool (*rule_filter) (rule const *);
 
-/* Return true IFF the rule has a `number' smaller than NRULES.  That is, it is
+/* Return true IFF the rule has a 'number' smaller than NRULES.  That is, it is
    useful in the grammar.  */
 bool rule_useful_in_grammar_p (rule const *r);
 
-/* Return true IFF the rule has a `number' higher than NRULES.  That is, it is
+/* Return true IFF the rule has a 'number' higher than NRULES.  That is, it is
    useless in the grammar.  */
 bool rule_useless_in_grammar_p (rule const *r);
 
@@ -262,8 +262,8 @@ void grammar_rules_print_xml (FILE *out, int level);
 void grammar_dump (FILE *out, const char *title);
 
 /* Report on STDERR the rules that are not flagged USEFUL, using the
-   MESSAGE (which can be `rule useless in grammar' when invoked after grammar
-   reduction, or `rule useless in parser due to conflicts' after conflicts
+   MESSAGE (which can be 'rule useless in grammar' when invoked after grammar
+   reduction, or 'rule useless in parser due to conflicts' after conflicts
    were taken into account).  */
 void grammar_rules_useless_report (const char *message);
 
diff --git a/src/lalr.c b/src/lalr.c
index 5e155749..d99f960f 100644
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -342,7 +342,7 @@ state_lookahead_tokens_count (state *s, bool default_reduction_only_for_accept)
   /* We need a lookahead either to distinguish different reductions
      (i.e., there are two or more), or to distinguish a reduction from a
      shift.  Otherwise, it is straightforward, and the state is
-     `consistent'.  However, do not treat a state with any reductions as
+     'consistent'.  However, do not treat a state with any reductions as
      consistent unless it is the accepting state (because there is never
      a lookahead token that makes sense there, and so no lookahead token
      should be read) if the user has otherwise disabled default
diff --git a/src/location.c b/src/location.c
index dd4bd043..662b2a12 100644
--- a/src/location.c
+++ b/src/location.c
@@ -219,7 +219,7 @@ void
 boundary_set_from_string (boundary *bound, char *loc_str)
 {
   /* Must search in reverse since the file name field may
-   * contain `.' or `:'.  */
+   * contain '.' or ':'.  */
   char *delim = strrchr (loc_str, '.');
   aver (delim);
   *delim = '\0';
diff --git a/src/location.h b/src/location.h
index 5c57d307..8f1c5ae1 100644
--- a/src/location.h
+++ b/src/location.h
@@ -121,7 +121,7 @@ location_cmp (location a, location b)
   return res;
 }
 
-/* LOC_STR must be formatted as `file:line.column', it will be modified.  */
+/* LOC_STR must be formatted as 'file:line.column', it will be modified.  */
 void boundary_set_from_string (boundary *bound, char *loc_str);
 
 #endif /* ! defined LOCATION_H_ */
diff --git a/src/muscle-tab.c b/src/muscle-tab.c
index 490dadae..8060a2c2 100644
--- a/src/muscle-tab.c
+++ b/src/muscle-tab.c
@@ -254,7 +254,7 @@ muscle_find (char const *key)
 }
 
 
-/* In the format `file_name:line.column', append BOUND to MUSCLE.  Use
+/* In the format 'file_name:line.column', append BOUND to MUSCLE.  Use
    digraphs for special characters in the file name.  */
 
 static void
@@ -270,7 +270,7 @@ muscle_boundary_grow (char const *key, boundary bound)
 }
 
 
-/* In the format `[[file_name:line.column]], [[file_name:line.column]]',
+/* In the format '[[file_name:line.column]], [[file_name:line.column]]',
    append LOC to MUSCLE.  Use digraphs for special characters in each
    file name.  */
 
@@ -523,8 +523,8 @@ muscle_percent_define_ensure (char const *variable, location loc,
   char const *val = value ? "" : "false";
   char const *name = UNIQSTR_CONCAT ("percent_define(", variable, ")");
 
-  /* %pure-parser is deprecated in favor of `%define api.pure', so use
-     `%define api.pure' in a backward-compatible manner here.  First,
+  /* %pure-parser is deprecated in favor of '%define api.pure', so use
+     '%define api.pure' in a backward-compatible manner here.  First,
      don't complain if %pure-parser is specified multiple times.  */
   if (!muscle_find_const (name))
     muscle_percent_define_insert (variable, loc, val,
diff --git a/src/muscle-tab.h b/src/muscle-tab.h
index 66975624..deeb076f 100644
--- a/src/muscle-tab.h
+++ b/src/muscle-tab.h
@@ -92,7 +92,7 @@ void muscle_pair_list_grow (const char *muscle,
 
 /* Grow KEY for the occurrence of the name USER_NAME at LOC appropriately for
    use with b4_check_user_names in ../data/bison.m4.  USER_NAME is not escaped
-   with digraphs, so it must not contain `[' or `]'.  */
+   with digraphs, so it must not contain '[' or ']'.  */
 void muscle_user_name_list_grow (char const *key, char const *user_name,
                                  location loc);
 
diff --git a/src/output.c b/src/output.c
index 2b6842d7..b543cbab 100644
--- a/src/output.c
+++ b/src/output.c
@@ -90,7 +90,7 @@ Name (char const *name,                                                 \
                                                                         \
   lmin = min;                                                           \
   lmax = max;                                                           \
-  /* Build `NAME_min' and `NAME_max' in the obstack. */                 \
+  /* Build 'NAME_min' and 'NAME_max' in the obstack. */                 \
   obstack_printf (&format_obstack, "%s_min", name);                     \
   MUSCLE_INSERT_LONG_INT (obstack_finish0 (&format_obstack), lmin);     \
   obstack_printf (&format_obstack, "%s_max", name);                     \
diff --git a/src/parse-gram.c b/src/parse-gram.c
index 032dabf5..c87bad87 100644
--- a/src/parse-gram.c
+++ b/src/parse-gram.c
@@ -464,7 +464,7 @@ typedef short int yytype_int16;
 /* The parser invokes alloca or malloc; define the necessary symbols.  */
 
 # ifdef YYSTACK_ALLOC
-   /* Pacify GCC's `empty if-body' warning.  */
+   /* Pacify GCC's 'empty if-body' warning.  */
 #  define YYSTACK_FREE(Ptr) do { /* empty */; } while (0)
 #  ifndef YYSTACK_ALLOC_MAXIMUM
     /* The OS might guarantee only one guard page at the bottom of the stack,
@@ -1794,9 +1794,9 @@ YYLTYPE yylloc = yyloc_default;
     int yyerrstatus;
 
     /* The stacks and their tools:
-       `yyss': related to states.
-       `yyvs': related to semantic values.
-       `yyls': related to locations.
+       'yyss': related to states.
+       'yyvs': related to semantic values.
+       'yyls': related to locations.
 
        Refer to the stacks through separate pointers, to allow yyoverflow
        to reallocate them elsewhere.  */
@@ -2050,7 +2050,7 @@ yyreduce:
   yylen = yyr2[yyn];
 
   /* If YYLEN is nonzero, implement the default value of the action:
-     `$$ = $1'.
+     '$$ = $1'.
 
      Otherwise, the following line sets YYVAL to garbage.
      This behavior is undocumented and Bison
@@ -2780,7 +2780,7 @@ yyreduce:
   *++yyvsp = yyval;
   *++yylsp = yyloc;
 
-  /* Now `shift' the result of the reduction.  Determine what state
+  /* Now 'shift' the result of the reduction.  Determine what state
      that goes to, based on the state we popped back to and the rule
      number reduced by.  */
 
diff --git a/src/parse-gram.y b/src/parse-gram.y
index 2f66e412..4e887e81 100644
--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -636,7 +636,7 @@ named_ref.opt:
 `---------------------------*/
 
 /* The STRING form of variable is deprecated and is not M4-friendly.
-   For example, M4 fails for `%define "[" "value"'.  */
+   For example, M4 fails for '%define "[" "value"'.  */
 variable:
   ID
 | STRING { $$ = uniqstr_new ($1); }
diff --git a/src/print-xml.c b/src/print-xml.c
index 441af920..a3ef1511 100644
--- a/src/print-xml.c
+++ b/src/print-xml.c
@@ -209,7 +209,7 @@ print_errs (FILE *out, int level, state *s)
 
 
 /*-------------------------------------------------------------------------.
-| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default').  |
+| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be 'default').  |
 | If not ENABLED, the rule is masked by a shift or a reduce (S/R and       |
 | R/R conflicts).                                                          |
 `-------------------------------------------------------------------------*/
diff --git a/src/print.c b/src/print.c
index e795e456..824bb4ae 100644
--- a/src/print.c
+++ b/src/print.c
@@ -206,7 +206,7 @@ print_errs (FILE *out, state *s)
 
 
 /*-------------------------------------------------------------------------.
-| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default').  |
+| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be 'default').  |
 | If not ENABLED, the rule is masked by a shift or a reduce (S/R and       |
 | R/R conflicts).                                                          |
 `-------------------------------------------------------------------------*/
@@ -514,7 +514,7 @@ print_results (void)
   print_grammar (out);
 
   /* If the whole state item sets, not only the kernels, are wanted,
-     `closure' will be run, which needs memory allocation/deallocation.   */
+     'closure' will be run, which needs memory allocation/deallocation.   */
   if (report_flag & report_itemsets)
     new_closure (nritems);
   /* Storage for print_reductions.  */
diff --git a/src/reader.c b/src/reader.c
index c83fc52a..5960e243 100644
--- a/src/reader.c
+++ b/src/reader.c
@@ -321,7 +321,7 @@ grammar_rule_check (const symbol_list *r)
         bool midrule_warning = false;
         if (!l->action_props.is_value_used
             && symbol_should_be_used (l, &midrule_warning)
-            /* The default action, $$ = $1, `uses' both.  */
+            /* The default action, $$ = $1, 'uses' both.  */
             && (r->action_props.code || (n != 0 && n != 1)))
           {
             warnings warn_flag = midrule_warning ? Wmidrule_values : Wother;
@@ -562,7 +562,7 @@ packgram (void)
       rules[ruleno].action_location = p->action_props.location;
       rules[ruleno].is_predicate = p->action_props.is_predicate;
 
-      /* If the midrule's $$ is set or its $n is used, remove the `$' from the
+      /* If the midrule's $$ is set or its $n is used, remove the '$' from the
          symbol name so that it's a user-defined symbol so that the default
          %destructor and %printer apply.  */
       if (p->midrule_parent_rule
@@ -764,11 +764,11 @@ check_and_convert_grammar (void)
      action type checking.
 
      Before invoking grammar_rule_check (in packgram below) on any rule, make
-     sure all actions have already been scanned in order to set `used' flags.
+     sure all actions have already been scanned in order to set 'used' flags.
      Otherwise, checking that a midrule's $$ should be set will not always work
      properly because the check must forward-reference the midrule's parent
-     rule.  For the same reason, all the `used' flags must be set before
-     checking whether to remove `$' from any midrule symbol name (also in
+     rule.  For the same reason, all the 'used' flags must be set before
+     checking whether to remove '$' from any midrule symbol name (also in
      packgram).  */
   {
     symbol_list *sym;
diff --git a/src/reduce.c b/src/reduce.c
index 9f9a82d2..eea11b1e 100644
--- a/src/reduce.c
+++ b/src/reduce.c
@@ -49,7 +49,7 @@ static bitset P;
 static bitset V;
 
 /* Set of symbols used to define rule precedence (so they are
-   `useless', but no warning should be issued).  */
+   'useless', but no warning should be issued).  */
 static bitset V1;
 
 static rule_number nuseful_productions;
diff --git a/src/scan-skel.l b/src/scan-skel.l
index c7e7190f..654491ef 100644
--- a/src/scan-skel.l
+++ b/src/scan-skel.l
@@ -72,7 +72,7 @@ static void fail_for_invalid_at (char const *at);
 "@@" fputc ('@', yyout);
 "@{" fputc ('[', yyout);
 "@}" fputc (']', yyout);
-"@`" continue;  /* Used by b4_cat in ../data/bison.m4.  */
+"@'" continue;  /* Used by b4_cat in ../data/bison.m4.  */
 @\n  continue;
 
 "@oline@"  fprintf (yyout, "%d", out_lineno + 1);
@@ -83,7 +83,7 @@ static void fail_for_invalid_at (char const *at);
 "@output("      at_init (&argc, argv, &at_ptr, &at_output);
 
   /* This pattern must not match more than the previous @ patterns. */
-@[^@{}`(\n]*    fail_for_invalid_at (yytext);
+@[^@{}'(\n]*    fail_for_invalid_at (yytext);
 \n              out_lineno++; ECHO;
 [^@\n]+         ECHO;
 
@@ -103,7 +103,7 @@ static void fail_for_invalid_at (char const *at);
   "@@"   obstack_1grow (&obstack_for_string, '@');
   "@{"   obstack_1grow (&obstack_for_string, '[');
   "@}"   obstack_1grow (&obstack_for_string, ']');
-  "@`"   continue; /* For starting an argument that begins with whitespace. */
+  "@'"   continue; /* For starting an argument that begins with whitespace. */
   @\n    continue;
 
   @[,)] {
diff --git a/src/symtab.h b/src/symtab.h
index f585fd7b..bcc74951 100644
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -128,9 +128,9 @@ struct symbol
 /** Undefined user number.  */
 # define USER_NUMBER_UNDEFINED -1
 
-/* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
-   this symbol has a literal string alias.  For instance, `%token foo
-   "foo"' has `"foo"' numbered regularly, and `foo' numbered as
+/* 'symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
+   this symbol has a literal string alias.  For instance, '%token foo
+   "foo"' has '"foo"' numbered regularly, and 'foo' numbered as
    USER_NUMBER_HAS_STRING_ALIAS.  */
 # define USER_NUMBER_HAS_STRING_ALIAS -9991
 
diff --git a/src/system.h b/src/system.h
index 736fd700..3267f2d2 100644
--- a/src/system.h
+++ b/src/system.h
@@ -99,7 +99,7 @@ typedef size_t uintptr_t;
 #  endif
 # endif
 
-/* The __-protected variants of `format' and `printf' attributes
+/* The __-protected variants of 'format' and 'printf' attributes
    are accepted by gcc versions 2.6.4 (effectively 2.7) and later.  */
 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
 #  define __format__ format
diff --git a/src/tables.c b/src/tables.c
index 87b6b76d..f06cba86 100644
--- a/src/tables.c
+++ b/src/tables.c
@@ -35,7 +35,7 @@
 #include "tables.h"
 
 /* Several tables are indexed both by state and nonterminal numbers.
-   We call such an index a `vector'; i.e., a vector is either a state
+   We call such an index a 'vector'; i.e., a vector is either a state
    or a nonterminal number.
 
    Of course vector_number_t ought to be wide enough to contain
@@ -90,18 +90,18 @@ static base_number *width;
 
 /* For a given state, N = ACTROW[SYMBOL]:
 
-   If N = 0, stands for `run the default action'.
-   If N = MIN, stands for `raise a syntax error'.
-   If N > 0, stands for `shift SYMBOL and go to n'.
-   If N < 0, stands for `reduce -N'.  */
+   If N = 0, stands for 'run the default action'.
+   If N = MIN, stands for 'raise a syntax error'.
+   If N > 0, stands for 'shift SYMBOL and go to n'.
+   If N < 0, stands for 'reduce -N'.  */
 typedef int action_number;
 #define ACTION_NUMBER_MINIMUM INT_MIN
 
 static action_number *actrow;
 
 /* FROMS and TOS are reordered to be compressed.  ORDER[VECTOR] is the
-   new vector number of VECTOR.  We skip `empty' vectors (i.e.,
-   TALLY[VECTOR] = 0), and call these `entries'.  */
+   new vector number of VECTOR.  We skip 'empty' vectors (i.e.,
+   TALLY[VECTOR] = 0), and call these 'entries'.  */
 static vector_number *order;
 static int nentries;