1 files changed, 51 insertions, 13 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index b123efeb..df1cacf2 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1,4 +1,4 @@
-dnl $LynxId: aclocal.m4,v 1.270 2020/09/01 08:19:14 tom Exp $
+dnl $LynxId: aclocal.m4,v 1.271 2020/11/26 22:37:55 tom Exp $
 dnl Macros for auto-configure script.
 dnl by Thomas E. Dickey <dickey@invisible-island.net>
 dnl and Jim Spath <jspath@mail.bcpl.lib.md.us>
@@ -1742,7 +1742,7 @@ if test $ac_cv_type_$1 = no; then
 fi
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_CLANG_COMPILER version: 3 updated: 2020/08/28 04:10:22
+dnl CF_CLANG_COMPILER version: 6 updated: 2020/11/26 17:37:55
 dnl -----------------
 dnl Check if the given compiler is really clang.  clang's C driver defines
 dnl __GNUC__ (fooling the configure script into setting $GCC to yes) but does
@@ -1761,21 +1761,52 @@ ifelse([$2],,CLANG_COMPILER,[$2])=no
 if test "$ifelse([$1],,[$1],GCC)" = yes ; then
 	AC_MSG_CHECKING(if this is really Clang ifelse([$1],GXX,C++,C) compiler)
 	cf_save_CFLAGS="$ifelse([$3],,CFLAGS,[$3])"
-	ifelse([$3],,CFLAGS,[$3])="$ifelse([$3],,CFLAGS,[$3]) -Qunused-arguments"
 	AC_TRY_COMPILE([],[
 #ifdef __clang__
 #else
 make an error
 #endif
 ],[ifelse([$2],,CLANG_COMPILER,[$2])=yes
-cf_save_CFLAGS="$cf_save_CFLAGS -Qunused-arguments"
 ],[])
 	ifelse([$3],,CFLAGS,[$3])="$cf_save_CFLAGS"
 	AC_MSG_RESULT($ifelse([$2],,CLANG_COMPILER,[$2]))
 fi
 
-if test "x$CLANG_COMPILER" = "xyes" ; then
-	CF_APPEND_TEXT(CFLAGS,-Wno-error=implicit-function-declaration)
+CLANG_VERSION=none
+
+if test "x$ifelse([$2],,CLANG_COMPILER,[$2])" = "xyes" ; then
+	case "$CC" in
+	(c[[1-9]][[0-9]]|*/c[[1-9]][[0-9]])
+		AC_MSG_WARN(replacing broken compiler alias $CC)
+		CFLAGS="$CFLAGS -std=`echo "$CC" | sed -e 's%.*/%%'`"
+		CC=clang
+		;;
+	esac
+
+	AC_MSG_CHECKING(version of $CC)
+	CLANG_VERSION="`$CC --version 2>/dev/null | sed -e '2,$d' -e 's/^.*(CLANG[[^)]]*) //' -e 's/^.*(Debian[[^)]]*) //' -e 's/^[[^0-9.]]*//' -e 's/[[^0-9.]].*//'`"
+	test -z "$CLANG_VERSION" && CLANG_VERSION=unknown
+	AC_MSG_RESULT($CLANG_VERSION)
+
+	for cf_clang_opt in \
+		-Qunused-arguments \
+		-Wno-error=implicit-function-declaration
+	do
+		AC_MSG_CHECKING(if option $cf_clang_opt works)
+		cf_save_CFLAGS="$CFLAGS"
+		CFLAGS="$CFLAGS $cf_clang_opt"
+		AC_TRY_LINK([
+			#include <stdio.h>],[
+			printf("hello!\n");],[
+			cf_clang_optok=yes],[
+			cf_clang_optok=no])
+		AC_MSG_RESULT($cf_clang_optok)
+		CFLAGS="$cf_save_CFLAGS"
+		if test $cf_clang_optok = yes; then
+			CF_VERBOSE(adding option $cf_clang_opt)
+			CF_APPEND_TEXT(CFLAGS,$cf_clang_opt)
+		fi
+	done
 fi
 ])
 dnl ---------------------------------------------------------------------------
@@ -2400,9 +2431,15 @@ if test "$cf_disable_rpath_hack" = no ; then
 fi
 ])
 dnl ---------------------------------------------------------------------------
-dnl CF_ENABLE_WARNINGS version: 6 updated: 2020/08/28 04:10:22
+dnl CF_ENABLE_WARNINGS version: 7 updated: 2020/08/29 09:05:21
 dnl ------------------
 dnl Configure-option to enable gcc warnings
+dnl
+dnl $1 = extra options to add, if supported
+dnl $2 = option for checking attributes.  By default, this is done when
+dnl      warnings are enabled.  For other values:
+dnl      yes: always do this, e.g., to use in generated library-headers
+dnl      no: never do this
 AC_DEFUN([CF_ENABLE_WARNINGS],[
 if ( test "$GCC" = yes || test "$GXX" = yes )
 then
@@ -2417,9 +2454,10 @@ CF_ARG_ENABLE(warnings,
 AC_MSG_RESULT($with_warnings)
 if test "$with_warnings" = "yes"
 then
-	CF_GCC_ATTRIBUTES
+	ifelse($2,,[CF_GCC_ATTRIBUTES])
 	CF_GCC_WARNINGS($1)
 fi
+ifelse($2,yes,[CF_GCC_ATTRIBUTES])
 fi
 ])dnl
 dnl ---------------------------------------------------------------------------
@@ -3088,14 +3126,14 @@ if test $cf_cv_type_unionwait = yes; then
 fi
 ])dnl
 dnl ---------------------------------------------------------------------------
-dnl CF_GCC_ATTRIBUTES version: 18 updated: 2020/03/10 18:53:47
+dnl CF_GCC_ATTRIBUTES version: 19 updated: 2020/08/29 09:05:21
 dnl -----------------
 dnl Test for availability of useful gcc __attribute__ directives to quiet
 dnl compiler warnings.  Though useful, not all are supported -- and contrary
 dnl to documentation, unrecognized directives cause older compilers to barf.
 AC_DEFUN([CF_GCC_ATTRIBUTES],
 [
-if test "$GCC" = yes
+if ( test "$GCC" = yes || test "$GXX" = yes )
 then
 cat > conftest.i <<EOF
 #ifndef GCC_PRINTF
@@ -3976,7 +4014,7 @@ ifelse($1,,[
 fi
 ])
 dnl ---------------------------------------------------------------------------
-dnl CF_MERGE_EXTRA_CFLAGS version: 1 updated: 2020/09/01 04:00:32
+dnl CF_MERGE_EXTRA_CFLAGS version: 1 updated: 2020/09/01 04:19:14
 dnl ---------------------
 dnl CF_FIX_WARNINGS moves problematic flags into EXTRA_CFLAGS, but some scripts
 dnl may depend on being able to override that variable at build-time.  Move it
@@ -3989,7 +4027,7 @@ then
 fi
 ])
 dnl ---------------------------------------------------------------------------
-dnl CF_MIXEDCASE_FILENAMES version: 7 updated: 2015/04/12 15:39:00
+dnl CF_MIXEDCASE_FILENAMES version: 8 updated: 2020/11/14 10:12:15
 dnl ----------------------
 dnl Check if the file-system supports mixed-case filenames.  If we're able to
 dnl create a lowercase name and see it as uppercase, it doesn't support that.
@@ -3998,7 +4036,7 @@ AC_DEFUN([CF_MIXEDCASE_FILENAMES],
 AC_CACHE_CHECK(if filesystem supports mixed-case filenames,cf_cv_mixedcase,[
 if test "$cross_compiling" = yes ; then
 	case $target_alias in
-	(*-os2-emx*|*-msdosdjgpp*|*-cygwin*|*-msys*|*-mingw*|*-uwin*)
+	(*-os2-emx*|*-msdosdjgpp*|*-cygwin*|*-msys*|*-mingw*|*-uwin*|darwin*)
 		cf_cv_mixedcase=no
 		;;
 	(*)