Merge branch 'branch-2.6' into maint

* origin/branch-2.6:
  regen
  yacc.c: do not define location support when not using locations
  maint: be compilable with GCC 4.0
  tests: address a warning from GCC 4.4
  tests: don't use options that Clang does not support
  tests: restore the tests on -Werror
  regen
  parse-gram: update the Bison interface
  fix comment

diff --combined configure.ac
index 6a0e9c457b41632a3f509bb993b310f8c5fbcad6,651fa1397eab9c715ae1281b90cdc3a8cd25968d..955f56ef790afaf18d96dd625e155d2ea9c1af29
--- 1/configure.ac
--- 2/configure.ac
+++ b/configure.ac
@@@ -72,6 -72,18 +72,18 @@@ if test "$enable_gcc_warnings" = yes; t
      -Wshadow -Wstrict-prototypes'
    warn_cxx='-Wnoexcept'
    AC_LANG_PUSH([C])
+   # Clang supports many of GCC's -W options, but only issues warnings
+   # on the ones it does not recognize.  In that case, gl_WARN_ADD
+   # thinks the option is supported, and unknown options are then added
+   # to CFLAGS.  But then, when -Werror is added in the test suite for
+   # instance, the warning about the unknown option turns into an
+   # error.
+   #
+   # This should be addressed by gnulib's gl_WARN_ADD, but in the
+   # meanwhile, turn warnings about unknown options into errors in
+   # CFLAGS, and restore CFLAGS after the tests.
+   save_CFLAGS=$CFLAGS
+   gl_WARN_ADD([-Werror=unknown-warning-option], [CFLAGS])
    for i in $warn_common $warn_c;
    do
      gl_WARN_ADD([$i], [WARN_CFLAGS])
@@@ -80,19 -92,23 +92,23 @@@
    # Warnings for the test suite only.
    gl_WARN_ADD([-Wundef], [WARN_CFLAGS_TEST])
    gl_WARN_ADD([-pedantic], [WARN_CFLAGS_TEST])
+   CFLAGS=$save_CFLAGS
    AC_LANG_POP([C])
  
    AC_LANG_PUSH([C++])
+   save_CXXFLAGS=$CXXFLAGS
+   gl_WARN_ADD([-Werror=unknown-warning-option], [CXXFLAGS])
    for i in $warn_common $warn_cxx;
    do
      gl_WARN_ADD([$i], [WARN_CXXFLAGS])
    done
-   gl_WARN_ADD([ -Wzero-as-null-pointer-constant], [WARN_CXXFLAGS],
+   gl_WARN_ADD([-Wzero-as-null-pointer-constant], [WARN_CXXFLAGS],
                [AC_LANG_PROGRAM([], [nullptr])])
    gl_WARN_ADD([-Werror], [WERROR_CXXFLAGS])
    # Warnings for the test suite only.
    gl_WARN_ADD([-Wundef], [WARN_CXXFLAGS_TEST])
    gl_WARN_ADD([-pedantic], [WARN_CXXFLAGS_TEST])
+   CXXFLAGS=$save_CXXFLAGS
    AC_LANG_POP([C++])
  fi
  
@@@ -115,7 -131,6 +131,7 @@@ AC_SUBST([YACC_SCRIPT]
  AC_SUBST([YACC_LIBRARY])
  
  # Checks for programs.
 +AM_MISSING_PROG([DOT], [dot])
  AC_PROG_LEX
  $LEX_IS_FLEX || AC_MSG_ERROR([Flex is required])
  AC_PROG_YACC

diff --combined src/getargs.c
index 56d9724db5efa61a234ecf3c2b094c94575feca8,649056943d99bb5653a04aedab25fa0473e977d3..226e6de0f6aff21e43f0118f6cf3ce68606a835b
--- 1/src/getargs.c
--- 2/src/getargs.c
+++ b/src/getargs.c
@@@ -49,7 -49,7 +49,7 @@@
  #include "quote.h"
  #include "uniqstr.h"
  
- bool debug_flag;
+ bool debug;
  bool defines_flag;
  bool graph_flag;
  bool xml_flag;
@@@ -343,14 -343,13 +343,14 @@@ Warning categories include:\n
    `yacc'            incompatibilities with POSIX Yacc\n\
    `conflicts-sr'    S/R conflicts (enabled by default)\n\
    `conflicts-rr'    R/R conflicts (enabled by default)\n\
 +  `deprecated'      obsolete constructs\n\
    `other'           all other warnings (enabled by default)\n\
    `all'             all the warnings\n\
    `no-CATEGORY'     turn off warnings in CATEGORY\n\
    `none'            turn off all the warnings\n\
    `error'           treat warnings as errors\n\
 -\n\
  "), stdout);
 +      putc ('\n', stdout);
  
        fputs (_("\
  THINGS is a list of comma separated words that can include:\n\
@@@ -665,7 -664,7 +665,7 @@@ getargs (int argc, char *argv[]
        break;
  
        case 't':
-       debug_flag = true;
+       debug = true;
        break;
  
        case 'v':

diff --combined src/output.c
index a99ef4cddaeb3fc6a12b5af0fcec14cefe14d61e,4a4d62d1a8ece8d4d208b7d3c98c5e1a1e1d2405..3852729bb7694436a238e282c1c33fa6c83cd4f9
--- 1/src/output.c
--- 2/src/output.c
+++ b/src/output.c
@@@ -41,6 -41,8 +41,6 @@@
  #include "symtab.h"
  #include "tables.h"
  
 -# define ARRAY_CARDINALITY(Array) (sizeof (Array) / sizeof *(Array))
 -
  static struct obstack format_obstack;
  
  
@@@ -626,7 -628,7 +626,7 @@@ prepare (void
      use_push_for_pull_flag = true;
  
    /* Flags. */
-   MUSCLE_INSERT_BOOL ("debug_flag", debug_flag);
+   MUSCLE_INSERT_BOOL ("debug_flag", debug);
    MUSCLE_INSERT_BOOL ("defines_flag", defines_flag);
    MUSCLE_INSERT_BOOL ("error_verbose_flag", error_verbose);
    MUSCLE_INSERT_BOOL ("glr_flag", glr_parser);

diff --combined tests/local.at
index 65ff8870461f80af0b6d4308a8e669347af459dd,97107a550a05afc13e6a13216aad70445064ff0c..f172b2445055dc87b7d1deefff793024c3b5f865
--- 1/tests/local.at
--- 2/tests/local.at
+++ b/tests/local.at
@@@ -137,7 -137,7 +137,7 @@@ m4_pushdef([AT_LEXPARAM_IF]
  m4_pushdef([AT_LOCATION_IF],
  [m4_bmatch([$3], [%locations], [$1], [$2])])
  m4_pushdef([AT_LOCATION_TYPE_IF],
 -[m4_bmatch([$3], [%define location_type], [$1], [$2])])
 +[m4_bmatch([$3], [%define \(api\.location\.type\|location_type\)], [$1], [$2])])
  m4_pushdef([AT_PARAM_IF],
  [m4_bmatch([$3], [%parse-param], [$1], [$2])])
  m4_pushdef([AT_PURE_IF],
@@@ -462,10 -462,14 +462,14 @@@ m4_define([AT_BISON_CHECK_WARNINGS]
        [m4_null_if([$2], [AT_BISON_CHECK_WARNINGS_($@)])])])
  
  m4_define([AT_BISON_CHECK_WARNINGS_],
- [[# Defining POSIXLY_CORRECT causes bison to complain if options
- # are added after the grammar file name, so skip these checks
- # in that case.
- if test -z "${POSIXLY_CORRECT+set}"; then
+ [[# Defining POSIXLY_CORRECT causes bison to complain if options are
+ # added after the grammar file name, so skip these checks in that
+ # case.
+ #
+ # Don't just check if $POSIXLY_CORRECT is set, as Bash, when launched
+ # as /bin/sh, sets the shell variable POSIXLY_CORRECT to y, but not
+ # the environment variable.
+ if env | grep '^POSIXLY_CORRECT=' >/dev/null; then :; else
    ]AT_SAVE_SPECIAL_FILES[
  
    # To avoid expanding it repeatedly, store specified stdout.