>From 6d4b69053bdeb5798069fd52cba2807b3f938828 Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sun, 26 Jul 2020 12:00:38 +0200
Subject: [PATCH 1/2] iconv: Change configure message.

* m4/iconv.m4 (AM_ICONV): Say "checking whether iconv is compatible
with its POSIX signature..." instead of "checking for iconv
declaration...". Remove K&R C support.
---
 ChangeLog   |  7 +++++++
 m4/iconv.m4 | 44 +++++++++++++++++++++++---------------------
 2 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index fc4b46e..87b873b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2020-07-26  Bruno Haible  <bruno@clisp.org>
 
+	iconv: Change configure message.
+	* m4/iconv.m4 (AM_ICONV): Say "checking whether iconv is compatible
+	with its POSIX signature..." instead of "checking for iconv
+	declaration...". Remove K&R C support.
+
+2020-07-26  Bruno Haible  <bruno@clisp.org>
+
 	expl: Simplify autoconf test.
 	* m4/expl.m4 (gl_FUNC_EXPL): Merge the "checking whether expl() breaks
 	with small values..." test into the "checking whether expl works..."
diff --git a/m4/iconv.m4 b/m4/iconv.m4
index e593b72..cd2fd23 100644
--- a/m4/iconv.m4
+++ b/m4/iconv.m4
@@ -1,4 +1,4 @@
-# iconv.m4 serial 21
+# iconv.m4 serial 22
 dnl Copyright (C) 2000-2002, 2007-2014, 2016-2020 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -7,6 +7,10 @@ dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Bruno Haible.
 
+dnl Note: AM_ICONV is documented in the GNU gettext manual
+dnl <https://www.gnu.org/software/gettext/manual/html_node/AM_005fICONV.html>.
+dnl Don't make changes that are incompatible with that documentation!
+
 AC_DEFUN([AM_ICONV_LINKFLAGS_BODY],
 [
   dnl Prerequisites of AC_LIB_LINKFLAGS_BODY.
@@ -247,41 +251,39 @@ gl_iconv_AC_DEFUN([AM_ICONV],
 [
   AM_ICONV_LINK
   if test "$am_cv_func_iconv" = yes; then
-    AC_MSG_CHECKING([for iconv declaration])
-    AC_CACHE_VAL([am_cv_proto_iconv], [
-      AC_COMPILE_IFELSE(
-        [AC_LANG_PROGRAM(
-           [[
+    AC_CACHE_CHECK([whether iconv is compatible with its POSIX signature],
+      [gl_cv_iconv_nonconst],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[
 #include <stdlib.h>
 #include <iconv.h>
 extern
 #ifdef __cplusplus
 "C"
 #endif
-#if defined(__STDC__) || defined(_MSC_VER) || defined(__cplusplus)
 size_t iconv (iconv_t cd, char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);
-#else
-size_t iconv();
-#endif
-           ]],
-           [[]])],
-        [am_cv_proto_iconv_arg1=""],
-        [am_cv_proto_iconv_arg1="const"])
-      am_cv_proto_iconv="extern size_t iconv (iconv_t cd, $am_cv_proto_iconv_arg1 char * *inbuf, size_t *inbytesleft, char * *outbuf, size_t *outbytesleft);"])
-    am_cv_proto_iconv=`echo "[$]am_cv_proto_iconv" | tr -s ' ' | sed -e 's/( /(/'`
-    AC_MSG_RESULT([
-         $am_cv_proto_iconv])
+            ]],
+            [[]])],
+         [gl_cv_iconv_nonconst=yes],
+         [gl_cv_iconv_nonconst=no])
+      ])
   else
     dnl When compiling GNU libiconv on a system that does not have iconv yet,
     dnl pick the POSIX compliant declaration without 'const'.
-    am_cv_proto_iconv_arg1=""
+    gl_cv_iconv_nonconst=yes
+  fi
+  if test $gl_cv_iconv_nonconst = yes; then
+    iconv_arg1=""
+  else
+    iconv_arg1="const"
   fi
-  AC_DEFINE_UNQUOTED([ICONV_CONST], [$am_cv_proto_iconv_arg1],
+  AC_DEFINE_UNQUOTED([ICONV_CONST], [$iconv_arg1],
     [Define as const if the declaration of iconv() needs const.])
   dnl Also substitute ICONV_CONST in the gnulib generated <iconv.h>.
   m4_ifdef([gl_ICONV_H_DEFAULTS],
     [AC_REQUIRE([gl_ICONV_H_DEFAULTS])
-     if test -n "$am_cv_proto_iconv_arg1"; then
+     if test $gl_cv_iconv_nonconst != yes; then
        ICONV_CONST="const"
      fi
     ])
-- 
2.7.4