Merge remote-tracking branch 'origin/maint'

* origin/maint:
  news: prepare for forthcoming release
  doc: explain how mid-rule actions are translated
  error: use better locations for unused midrule values
  doc: various minor improvements and fixes
  tests: ignore more useless compiler warnings
  tests: be robust to C being compiled with a C++11 compiler
  build: beware of Clang++ not supporting POSIXLY_CORRECT
  maint: post-release administrivia
  version 2.6.90
  build: fix syntax-check error.
  cpp: simplify the Flex version checking macro
  news: improve the carets example and fix a typo
  cpp: improve the Flex version checking macro
  carets: improve the code
  maint: update news
  build: keep -Wmissing-declarations and -Wmissing-prototypes for modern GCCs
  build: drop -Wcast-qual
  gnulib: update

Conflicts:
	NEWS
	doc/Makefile.am
	doc/bison.texi
	gnulib
	src/reader.c
	tests/actions.at
	tests/atlocal.in
	tests/input.at

2 files changed, 34 insertions, 17 deletions

diff --git a/m4/c-working.m4 b/m4/c-working.m4
index ee84acf9..999c52de 100644
--- a/m4/c-working.m4
+++ b/m4/c-working.m4
@@ -24,6 +24,7 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_C_COMPILER], [
          int test_array[CHAR_BIT];]])],
     [],
     [AC_MSG_FAILURE([cannot compile a simple C program])])
+   AC_SUBST([BISON_C_WORKS], [:])
 ])
 
 # BISON_CHECK_WITH_POSIXLY_CORRECT(CODE)
@@ -47,25 +48,32 @@ case $gl_had_POSIXLY_CORRECT in
 esac
 ])
 
+# BISON_LANG_COMPILER_POSIXLY_CORRECT
+# -----------------------------------
+# Whether the compiler for the current language supports -g in
+# POSIXLY_CORRECT mode.  clang-2.9 on OS X does not, because
+# "clang-mp-2.9 -o test -g test.c" launches "/usr/bin/dsymutil test -o
+# test.dSYM" which fails with "error: unable to open executable '-o'".
+#
+# Sets <LANG>_COMPILER_POSIXLY_CORRECT to true/false.
+AC_DEFUN([BISON_LANG_COMPILER_POSIXLY_CORRECT],
+[AC_CACHE_CHECK([whether $_AC_CC supports POSIXLY_CORRECT=1],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct],
+[BISON_CHECK_WITH_POSIXLY_CORRECT(
+[AC_LINK_IFELSE([AC_LANG_PROGRAM],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=yes],
+                [bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct=no])])])
+case $bison_cv_[]_AC_LANG_ABBREV[]_supports_posixly_correct in
+  yes) AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [true]) ;;
+  no)  AC_SUBST(_AC_LANG_PREFIX[_COMPILER_POSIXLY_CORRECT], [false]);;
+esac
+])
+
 # BISON_C_COMPILER_POSIXLY_CORRECT
 # --------------------------------
-# Whether the compiler supports -g in POSIXLY_CORRECT mode.  clang-2.9
-# on OS X does not, because "clang-mp-2.9 -o test -g test.c" launches
-# "/usr/bin/dsymutil test -o test.dSYM" which fails with "error:
-# unable to open executable '-o'".
-#
-# Sets C_COMPILER_POSIXLY_CORRECT to true/false.
+# Whether the C compiler supports -g in POSIXLY_CORRECT mode.
 AC_DEFUN([BISON_C_COMPILER_POSIXLY_CORRECT],
-[AC_CACHE_CHECK([whether $CC supports POSIXLY_CORRECT=1],
-                [bison_cv_cc_supports_posixly_correct],
-[BISON_CHECK_WITH_POSIXLY_CORRECT(
 [AC_LANG_PUSH([C])
-AC_LINK_IFELSE([AC_LANG_PROGRAM],
-                [bison_cv_cc_supports_posixly_correct=yes],
-                [bison_cv_cc_supports_posixly_correct=no])
-AC_LANG_POP([C])])])
-case $bison_cv_cc_supports_posixly_correct in
-  yes) AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [true]) ;;
-  no)  AC_SUBST([C_COMPILER_POSIXLY_CORRECT], [false]);;
-esac
+BISON_LANG_COMPILER_POSIXLY_CORRECT
+AC_LANG_POP([C])
 ])
diff --git a/m4/cxx.m4 b/m4/cxx.m4
index 8ef1a250..f9f06092 100644
--- a/m4/cxx.m4
+++ b/m4/cxx.m4
@@ -58,3 +58,12 @@ AC_DEFUN([BISON_TEST_FOR_WORKING_CXX_COMPILER],
  AC_SUBST([BISON_CXX_WORKS])
  AM_CONDITIONAL(BISON_CXX_WORKS, test $bison_cv_cxx_works = yes)
 ])
+
+# BISON_CXX_COMPILER_POSIXLY_CORRECT
+# ----------------------------------
+# Whether the C++ compiler supports -g in POSIXLY_CORRECT mode.
+AC_DEFUN([BISON_CXX_COMPILER_POSIXLY_CORRECT],
+[AC_LANG_PUSH([C++])
+BISON_LANG_COMPILER_POSIXLY_CORRECT
+AC_LANG_POP([C++])
+])