Resolve conflicts for functions introduced in Android API level 21.

* m4/execvpe.m4 (gl_FUNC_EXECVPE): Conditionally set REPLACE_EXECVPE.
* m4/linkat.m4 (gl_FUNC_LINKAT): Conditionally set REPLACE_LINKAT.
* m4/readlinkat.m4 (gl_FUNC_READLINKAT): Conditionally set
REPLACE_READLINKAT.
* m4/symlinkat.m4 (gl_FUNC_SYMLINKAT): Conditionally set
REPLACE_SYMLINKAT.
* m4/truncate.m4 (gl_FUNC_TRUNCATE): Conditionally set REPLACE_TRUNCATE.
* lib/unistd.in.h (execvpe, linkat, readlinkat, symlinkat, truncate):
Disable _GL_CXXALIASWARN invocation on non-glibc systems.

5 files changed, 20 insertions, 8 deletions

diff --git a/m4/execvpe.m4 b/m4/execvpe.m4
index 6c0a0e9b7d..3f211049b8 100644
--- a/m4/execvpe.m4
+++ b/m4/execvpe.m4
@@ -1,4 +1,4 @@
-# execvpe.m4 serial 2
+# execvpe.m4 serial 3
 dnl Copyright (C) 2020-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -18,6 +18,9 @@ AC_DEFUN([gl_FUNC_EXECVPE],
       gl_CHECK_FUNCS_ANDROID([execvpe], [[#include <unistd.h>]])
       if test $ac_cv_func_execvpe != yes; then
         HAVE_EXECVPE=0
+        case "$gl_cv_onwards_func_execvpe" in
+          future*) REPLACE_EXECVPE=1 ;;
+        esac
       fi
       ;;
   esac
diff --git a/m4/linkat.m4 b/m4/linkat.m4
index 9b35fc14e3..032e89bb54 100644
--- a/m4/linkat.m4
+++ b/m4/linkat.m4
@@ -1,4 +1,4 @@
-# serial 15
+# serial 16
 # See if we need to provide linkat replacement.
 
 dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
@@ -19,6 +19,9 @@ AC_DEFUN([gl_FUNC_LINKAT],
   gl_CHECK_FUNCS_ANDROID([linkat], [[#include <unistd.h>]])
   if test $ac_cv_func_linkat = no; then
     HAVE_LINKAT=0
+    case "$gl_cv_onwards_func_linkat" in
+      future*) REPLACE_LINKAT=1 ;;
+    esac
   else
     dnl OS X Yosemite has linkat() but it's not sufficient
     dnl to our needs since it doesn't support creating
diff --git a/m4/readlinkat.m4 b/m4/readlinkat.m4
index 416f9c0d64..5c51356291 100644
--- a/m4/readlinkat.m4
+++ b/m4/readlinkat.m4
@@ -1,4 +1,4 @@
-# serial 7
+# serial 8
 # See if we need to provide readlinkat replacement.
 
 dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
@@ -16,6 +16,9 @@ AC_DEFUN([gl_FUNC_READLINKAT],
   AC_REQUIRE([gl_FUNC_READLINK])
   if test $ac_cv_func_readlinkat = no; then
     HAVE_READLINKAT=0
+    case "$gl_cv_onwards_func_readlinkat" in
+      future*) REPLACE_READLINKAT=1 ;;
+    esac
   else
     AC_CACHE_CHECK([whether readlinkat signature is correct],
       [gl_cv_decl_readlinkat_works],
diff --git a/m4/symlinkat.m4 b/m4/symlinkat.m4
index d12f91997c..dc3dd323aa 100644
--- a/m4/symlinkat.m4
+++ b/m4/symlinkat.m4
@@ -1,4 +1,4 @@
-# serial 11
+# serial 12
 # See if we need to provide symlinkat replacement.
 
 dnl Copyright (C) 2009-2023 Free Software Foundation, Inc.
@@ -17,6 +17,9 @@ AC_DEFUN([gl_FUNC_SYMLINKAT],
   gl_CHECK_FUNCS_ANDROID([symlinkat], [[#include <unistd.h>]])
   if test $ac_cv_func_symlinkat = no; then
     HAVE_SYMLINKAT=0
+    case "$gl_cv_onwards_func_symlinkat" in
+      future*) REPLACE_SYMLINKAT=1 ;;
+    esac
   else
     AC_CACHE_CHECK([whether symlinkat handles trailing slash correctly],
       [gl_cv_func_symlinkat_works],
diff --git a/m4/truncate.m4 b/m4/truncate.m4
index b047af34c9..fe9fdbf408 100644
--- a/m4/truncate.m4
+++ b/m4/truncate.m4
@@ -1,4 +1,4 @@
-# truncate.m4 serial 4   -*- Autoconf -*-
+# truncate.m4 serial 5   -*- Autoconf -*-
 dnl Copyright (C) 2017-2023 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -71,10 +71,10 @@ AC_DEFUN([gl_FUNC_TRUNCATE],
     fi
   else
     HAVE_DECL_TRUNCATE=0
-    if test $ac_cv_func_truncate = yes; then
+    case "$gl_cv_onwards_func_truncate" in
       dnl Avoid a conflict with the 'truncate' in libc.
-      REPLACE_TRUNCATE=1
-    fi
+      yes | future*) REPLACE_TRUNCATE=1 ;;
+    esac
   fi
 ])