Resolve conflicts for functions introduced in Android API level 34.

* lib/string.in.h (memset_explicit): Consider REPLACE_MEMSET_EXPLICIT.
* m4/string_h.m4 (gl_STRING_H_DEFAULTS): Initialize
REPLACE_MEMSET_EXPLICIT.
* modules/string (Makefile.am): Substitute REPLACE_MEMSET_EXPLICIT.
* m4/memset_explicit.m4 (gl_FUNC_MEMSET_EXPLICIT): Test for
memset_explicit using gl_CHECK_FUNCS_ANDROID instead of
AC_CHECK_FUNCS_ONCE. Conditionally set REPLACE_MEMSET_EXPLICIT.
* modules/memset_explicit (configure.ac): Consider
REPLACE_MEMSET_EXPLICIT.
* doc/posix-functions/memset_explicit.texi: Mention the Android API
levels.

ChangeLog

@@ -2,6 +2,18 @@
 
 	Resolve conflicts for functions introduced in Android API level 34.
 
+	* lib/string.in.h (memset_explicit): Consider REPLACE_MEMSET_EXPLICIT.
+	* m4/string_h.m4 (gl_STRING_H_DEFAULTS): Initialize
+	REPLACE_MEMSET_EXPLICIT.
+	* modules/string (Makefile.am): Substitute REPLACE_MEMSET_EXPLICIT.
+	* m4/memset_explicit.m4 (gl_FUNC_MEMSET_EXPLICIT): Test for
+	memset_explicit using gl_CHECK_FUNCS_ANDROID instead of
+	AC_CHECK_FUNCS_ONCE. Conditionally set REPLACE_MEMSET_EXPLICIT.
+	* modules/memset_explicit (configure.ac): Consider
+	REPLACE_MEMSET_EXPLICIT.
+	* doc/posix-functions/memset_explicit.texi: Mention the Android API
+	levels.
+
 	* m4/freadahead.m4 (gl_FUNC_FREADAHEAD): Test for __freadahead using
 	gl_CHECK_FUNCS_ANDROID instead of AC_CHECK_FUNCS_ONCE.
 	* lib/freadahead.h: Update comment.

doc/posix-functions/memset_explicit.texi

@@ -29,7 +29,7 @@ Portability problems fixed by Gnulib:
 @itemize
 @item
 This function is missing on some platforms:
-glibc 2.36, FreeBSD 13.1, NetBSD 9.3, OpenBSD 7.2, macOS 13, Solaris 11.4, Android 13,
+glibc 2.36, FreeBSD 13.1, NetBSD 9.3, OpenBSD 7.2, macOS 13, Solaris 11.4, Android API level 33,
 and many other systems.
 @end itemize
 

lib/string.in.h

@@ -414,11 +414,21 @@ _GL_WARN_ON_USE (memrchr, "memrchr is unportable - "
 /* Overwrite a block of memory.  The compiler will not optimize
    effects away, even if the block is dead after the call.  */
 #if @GNULIB_MEMSET_EXPLICIT@
-# if ! @HAVE_MEMSET_EXPLICIT@
+# if @REPLACE_MEMSET_EXPLICIT@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef memset_explicit
+#   define memset_explicit rpl_memset_explicit
+#  endif
+_GL_FUNCDECL_RPL (memset_explicit, void *,
+                  (void *__dest, int __c, size_t __n) _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (memset_explicit, void *, (void *__dest, int __c, size_t __n));
+# else
+#  if !@HAVE_MEMSET_EXPLICIT@
 _GL_FUNCDECL_SYS (memset_explicit, void *,
                   (void *__dest, int __c, size_t __n) _GL_ARG_NONNULL ((1)));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (memset_explicit, void *, (void *__dest, int __c, size_t __n));
+# endif
 _GL_CXXALIASWARN (memset_explicit);
 #elif defined GNULIB_POSIXCHECK
 # undef memset_explicit

m4/memset_explicit.m4

@@ -1,3 +1,4 @@
+# memset_explicit.m4 serial 2
 dnl Copyright 2022-2024 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -7,9 +8,12 @@ AC_DEFUN([gl_FUNC_MEMSET_EXPLICIT],
 [
   AC_REQUIRE([gl_STRING_H_DEFAULTS])
 
-  AC_CHECK_FUNCS_ONCE([memset_explicit])
+  gl_CHECK_FUNCS_ANDROID([memset_explicit], [[#include <string.h>]])
   if test $ac_cv_func_memset_explicit = no; then
     HAVE_MEMSET_EXPLICIT=0
+    case "$gl_cv_onwards_func_memset_explicit" in
+      future*) REPLACE_MEMSET_EXPLICIT=1 ;;
+    esac
   fi
 ])
 

m4/string_h.m4

@@ -5,7 +5,7 @@
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
-# serial 38
+# serial 39
 
 # Written by Paul Eggert.
 
@@ -132,6 +132,7 @@ AC_DEFUN([gl_STRING_H_DEFAULTS],
   REPLACE_MEMCHR=0;             AC_SUBST([REPLACE_MEMCHR])
   REPLACE_MEMMEM=0;             AC_SUBST([REPLACE_MEMMEM])
   REPLACE_MEMPCPY=0;            AC_SUBST([REPLACE_MEMPCPY])
+  REPLACE_MEMSET_EXPLICIT=0;    AC_SUBST([REPLACE_MEMSET_EXPLICIT])
   REPLACE_STPCPY=0;             AC_SUBST([REPLACE_STPCPY])
   REPLACE_STPNCPY=0;            AC_SUBST([REPLACE_STPNCPY])
   REPLACE_STRCHRNUL=0;          AC_SUBST([REPLACE_STRCHRNUL])

modules/memset_explicit

@@ -10,7 +10,8 @@ string
 
 configure.ac:
 gl_FUNC_MEMSET_EXPLICIT
-gl_CONDITIONAL([GL_COND_OBJ_MEMSET_EXPLICIT], [test $HAVE_MEMSET_EXPLICIT = 0])
+gl_CONDITIONAL([GL_COND_OBJ_MEMSET_EXPLICIT],
+               [test $HAVE_MEMSET_EXPLICIT = 0 || test $REPLACE_MEMSET_EXPLICIT = 1])
 AM_COND_IF([GL_COND_OBJ_MEMSET_EXPLICIT], [
   gl_PREREQ_MEMSET_EXPLICIT
 ])

modules/string

@@ -110,6 +110,7 @@ string.h: string.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H
 	      -e 's|@''REPLACE_MEMCHR''@|$(REPLACE_MEMCHR)|g' \
 	      -e 's|@''REPLACE_MEMMEM''@|$(REPLACE_MEMMEM)|g' \
 	      -e 's|@''REPLACE_MEMPCPY''@|$(REPLACE_MEMPCPY)|g' \
+	      -e 's|@''REPLACE_MEMSET_EXPLICIT''@|$(REPLACE_MEMSET_EXPLICIT)|g' \
 	      -e 's|@''REPLACE_FREE''@|$(REPLACE_FREE)|g' \
 	      -e 's|@''REPLACE_STPCPY''@|$(REPLACE_STPCPY)|g' \
 	      -e 's|@''REPLACE_STPNCPY''@|$(REPLACE_STPNCPY)|g' \