posix/bits/unistd.h: Clearly separate declaration from definitions

This change is similar to what was done for bits/wchar2.h.
Routines declaration are moved into a dedicated bits/unistd-decl.h file
which is then included into the bits/unistd.h file.

This will allow to adapt the files so that PLT entries are not created when
_FORTIFY_SOURCE is enabled.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

3 files changed, 200 insertions, 153 deletions

diff --git a/posix/Makefile b/posix/Makefile
index 5113ee3b74..3d368b91f6 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -42,6 +42,7 @@ headers := \
   bits/types/idtype_t.h \
   bits/types/struct_sched_param.h \
   bits/typesizes.h \
+  bits/unistd-decl.h \
   bits/unistd.h \
   bits/unistd_ext.h \
   bits/utsname.h \
diff --git a/posix/bits/unistd-decl.h b/posix/bits/unistd-decl.h
new file mode 100644
index 0000000000..2d0f7a4456
--- /dev/null
+++ b/posix/bits/unistd-decl.h
@@ -0,0 +1,198 @@
+/* Checking routines for unistd functions. Declaration only.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_UNISTD_DECL_H
+#define _BITS_UNISTD_DECL_H 1
+
+#ifndef _UNISTD_H
+# error "Never include <bits/unistd-decl.h> directly; use <unistd.h> instead."
+#endif
+
+extern ssize_t __read_chk (int __fd, void *__buf, size_t __nbytes,
+			   size_t __buflen)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT (__read_alias, (int __fd, void *__buf,
+						  size_t __nbytes), read)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT (__read_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    size_t __buflen), __read_chk)
+     __wur __warnattr ("read called with bigger length than size of "
+		       "the destination buffer");
+
+#if defined __USE_UNIX98 || defined __USE_XOPEN2K8
+extern ssize_t __pread_chk (int __fd, void *__buf, size_t __nbytes,
+			    __off_t __offset, size_t __bufsize)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __pread64_chk (int __fd, void *__buf, size_t __nbytes,
+			      __off64_t __offset, size_t __bufsize)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT (__pread_alias,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off_t __offset), pread)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT (__pread64_alias,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off64_t __offset), pread64)
+     __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT (__pread_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off_t __offset, size_t __bufsize), __pread_chk)
+     __wur __warnattr ("pread called with bigger length than size of "
+		       "the destination buffer");
+extern ssize_t __REDIRECT (__pread64_chk_warn,
+			   (int __fd, void *__buf, size_t __nbytes,
+			    __off64_t __offset, size_t __bufsize),
+			    __pread64_chk)
+     __wur __warnattr ("pread64 called with bigger length than size of "
+		       "the destination buffer");
+#endif
+
+#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
+extern ssize_t __readlink_chk (const char *__restrict __path,
+			       char *__restrict __buf, size_t __len,
+			       size_t __buflen)
+     __THROW __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT_NTH (__readlink_alias,
+			       (const char *__restrict __path,
+				char *__restrict __buf, size_t __len), readlink)
+     __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
+extern ssize_t __REDIRECT_NTH (__readlink_chk_warn,
+			       (const char *__restrict __path,
+				char *__restrict __buf, size_t __len,
+				size_t __buflen), __readlink_chk)
+     __nonnull ((1, 2)) __wur __warnattr ("readlink called with bigger length "
+					  "than size of destination buffer");
+#endif
+
+#ifdef __USE_ATFILE
+extern ssize_t __readlinkat_chk (int __fd, const char *__restrict __path,
+				 char *__restrict __buf, size_t __len,
+				 size_t __buflen)
+     __THROW __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
+extern ssize_t __REDIRECT_NTH (__readlinkat_alias,
+			       (int __fd, const char *__restrict __path,
+				char *__restrict __buf, size_t __len),
+			       readlinkat)
+     __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
+extern ssize_t __REDIRECT_NTH (__readlinkat_chk_warn,
+			       (int __fd, const char *__restrict __path,
+				char *__restrict __buf, size_t __len,
+				size_t __buflen), __readlinkat_chk)
+     __nonnull ((2, 3)) __wur __warnattr ("readlinkat called with bigger "
+					  "length than size of destination "
+					  "buffer");
+#endif
+
+extern char *__getcwd_chk (char *__buf, size_t __size, size_t __buflen)
+     __THROW __wur;
+extern char *__REDIRECT_NTH (__getcwd_alias,
+			     (char *__buf, size_t __size), getcwd) __wur;
+extern char *__REDIRECT_NTH (__getcwd_chk_warn,
+			     (char *__buf, size_t __size, size_t __buflen),
+			     __getcwd_chk)
+     __wur __warnattr ("getcwd caller with bigger length than size of "
+		       "destination buffer");
+
+#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
+extern char *__getwd_chk (char *__buf, size_t buflen)
+     __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
+extern char *__REDIRECT_NTH (__getwd_warn, (char *__buf), getwd)
+     __nonnull ((1)) __wur __warnattr ("please use getcwd instead, as getwd "
+				       "doesn't specify buffer size");
+#endif
+
+extern size_t __confstr_chk (int __name, char *__buf, size_t __len,
+			     size_t __buflen) __THROW
+     __attr_access ((__write_only__, 2, 3));
+extern size_t __REDIRECT_NTH (__confstr_alias, (int __name, char *__buf,
+						size_t __len), confstr)
+     __attr_access ((__write_only__, 2, 3));
+extern size_t __REDIRECT_NTH (__confstr_chk_warn,
+			      (int __name, char *__buf, size_t __len,
+			       size_t __buflen), __confstr_chk)
+     __warnattr ("confstr called with bigger length than size of destination "
+		 "buffer");
+
+
+extern int __getgroups_chk (int __size, __gid_t __list[], size_t __listlen)
+     __THROW __wur __attr_access ((__write_only__, 2, 1));
+extern int __REDIRECT_NTH (__getgroups_alias, (int __size, __gid_t __list[]),
+			   getgroups) __wur __attr_access ((__write_only__, 2, 1));
+extern int __REDIRECT_NTH (__getgroups_chk_warn,
+			   (int __size, __gid_t __list[], size_t __listlen),
+			   __getgroups_chk)
+     __wur __warnattr ("getgroups called with bigger group count than what "
+		       "can fit into destination buffer");
+
+
+extern int __ttyname_r_chk (int __fd, char *__buf, size_t __buflen,
+			    size_t __nreal) __THROW __nonnull ((2))
+     __attr_access ((__write_only__, 2, 3));
+extern int __REDIRECT_NTH (__ttyname_r_alias, (int __fd, char *__buf,
+					       size_t __buflen), ttyname_r)
+     __nonnull ((2));
+extern int __REDIRECT_NTH (__ttyname_r_chk_warn,
+			   (int __fd, char *__buf, size_t __buflen,
+			    size_t __nreal), __ttyname_r_chk)
+     __nonnull ((2)) __warnattr ("ttyname_r called with bigger buflen than "
+				 "size of destination buffer");
+
+
+#ifdef __USE_POSIX199506
+extern int __getlogin_r_chk (char *__buf, size_t __buflen, size_t __nreal)
+     __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
+extern int __REDIRECT (__getlogin_r_alias, (char *__buf, size_t __buflen),
+		       getlogin_r) __nonnull ((1));
+extern int __REDIRECT (__getlogin_r_chk_warn,
+		       (char *__buf, size_t __buflen, size_t __nreal),
+		       __getlogin_r_chk)
+     __nonnull ((1)) __warnattr ("getlogin_r called with bigger buflen than "
+				 "size of destination buffer");
+#endif
+
+
+#if defined __USE_MISC || defined __USE_UNIX98
+extern int __gethostname_chk (char *__buf, size_t __buflen, size_t __nreal)
+     __THROW __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
+extern int __REDIRECT_NTH (__gethostname_alias, (char *__buf, size_t __buflen),
+			   gethostname)
+     __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
+extern int __REDIRECT_NTH (__gethostname_chk_warn,
+			   (char *__buf, size_t __buflen, size_t __nreal),
+			   __gethostname_chk)
+     __nonnull ((1)) __warnattr ("gethostname called with bigger buflen than "
+				 "size of destination buffer");
+#endif
+
+
+#if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_UNIX98)
+extern int __getdomainname_chk (char *__buf, size_t __buflen, size_t __nreal)
+     __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
+extern int __REDIRECT_NTH (__getdomainname_alias, (char *__buf,
+						   size_t __buflen),
+			   getdomainname) __nonnull ((1))
+     __wur __attr_access ((__write_only__, 1, 2));
+extern int __REDIRECT_NTH (__getdomainname_chk_warn,
+			   (char *__buf, size_t __buflen, size_t __nreal),
+			   __getdomainname_chk)
+     __nonnull ((1)) __wur __warnattr ("getdomainname called with bigger "
+				       "buflen than size of destination "
+				       "buffer");
+#endif
+#endif /* bits/unistd-decl.h.  */
diff --git a/posix/bits/unistd.h b/posix/bits/unistd.h
index 2a0782e6c8..6a381116a9 100644
--- a/posix/bits/unistd.h
+++ b/posix/bits/unistd.h
@@ -20,17 +20,7 @@
 # error "Never include <bits/unistd.h> directly; use <unistd.h> instead."
 #endif
 
-extern ssize_t __read_chk (int __fd, void *__buf, size_t __nbytes,
-			   size_t __buflen)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT (__read_alias, (int __fd, void *__buf,
-					  size_t __nbytes), read)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT (__read_chk_warn,
-			   (int __fd, void *__buf, size_t __nbytes,
-			    size_t __buflen), __read_chk)
-     __wur __warnattr ("read called with bigger length than size of "
-		       "the destination buffer");
+# include <bits/unistd-decl.h>
 
 __fortify_function __wur ssize_t
 read (int __fd, void *__buf, size_t __nbytes)
@@ -41,32 +31,6 @@ read (int __fd, void *__buf, size_t __nbytes)
 }
 
 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
-extern ssize_t __pread_chk (int __fd, void *__buf, size_t __nbytes,
-			    __off_t __offset, size_t __bufsize)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __pread64_chk (int __fd, void *__buf, size_t __nbytes,
-			      __off64_t __offset, size_t __bufsize)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT (__pread_alias,
-			   (int __fd, void *__buf, size_t __nbytes,
-			    __off_t __offset), pread)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT (__pread64_alias,
-			   (int __fd, void *__buf, size_t __nbytes,
-			    __off64_t __offset), pread64)
-  __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT (__pread_chk_warn,
-			   (int __fd, void *__buf, size_t __nbytes,
-			    __off_t __offset, size_t __bufsize), __pread_chk)
-     __wur __warnattr ("pread called with bigger length than size of "
-		       "the destination buffer");
-extern ssize_t __REDIRECT (__pread64_chk_warn,
-			   (int __fd, void *__buf, size_t __nbytes,
-			    __off64_t __offset, size_t __bufsize),
-			    __pread64_chk)
-     __wur __warnattr ("pread64 called with bigger length than size of "
-		       "the destination buffer");
-
 # ifndef __USE_FILE_OFFSET64
 __fortify_function __wur ssize_t
 pread (int __fd, void *__buf, size_t __nbytes, __off_t __offset)
@@ -97,21 +61,6 @@ pread64 (int __fd, void *__buf, size_t __nbytes, __off64_t __offset)
 #endif
 
 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
-extern ssize_t __readlink_chk (const char *__restrict __path,
-			       char *__restrict __buf, size_t __len,
-			       size_t __buflen)
-     __THROW __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT_NTH (__readlink_alias,
-			       (const char *__restrict __path,
-				char *__restrict __buf, size_t __len), readlink)
-     __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
-extern ssize_t __REDIRECT_NTH (__readlink_chk_warn,
-			       (const char *__restrict __path,
-				char *__restrict __buf, size_t __len,
-				size_t __buflen), __readlink_chk)
-     __nonnull ((1, 2)) __wur __warnattr ("readlink called with bigger length "
-					  "than size of destination buffer");
-
 __fortify_function __nonnull ((1, 2)) __wur ssize_t
 __NTH (readlink (const char *__restrict __path, char *__restrict __buf,
 		 size_t __len))
@@ -123,23 +72,6 @@ __NTH (readlink (const char *__restrict __path, char *__restrict __buf,
 #endif
 
 #ifdef __USE_ATFILE
-extern ssize_t __readlinkat_chk (int __fd, const char *__restrict __path,
-				 char *__restrict __buf, size_t __len,
-				 size_t __buflen)
-     __THROW __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
-extern ssize_t __REDIRECT_NTH (__readlinkat_alias,
-			       (int __fd, const char *__restrict __path,
-				char *__restrict __buf, size_t __len),
-			       readlinkat)
-     __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
-extern ssize_t __REDIRECT_NTH (__readlinkat_chk_warn,
-			       (int __fd, const char *__restrict __path,
-				char *__restrict __buf, size_t __len,
-				size_t __buflen), __readlinkat_chk)
-     __nonnull ((2, 3)) __wur __warnattr ("readlinkat called with bigger "
-					  "length than size of destination "
-					  "buffer");
-
 __fortify_function __nonnull ((2, 3)) __wur ssize_t
 __NTH (readlinkat (int __fd, const char *__restrict __path,
 		   char *__restrict __buf, size_t __len))
@@ -150,16 +82,6 @@ __NTH (readlinkat (int __fd, const char *__restrict __path,
 }
 #endif
 
-extern char *__getcwd_chk (char *__buf, size_t __size, size_t __buflen)
-     __THROW __wur;
-extern char *__REDIRECT_NTH (__getcwd_alias,
-			     (char *__buf, size_t __size), getcwd) __wur;
-extern char *__REDIRECT_NTH (__getcwd_chk_warn,
-			     (char *__buf, size_t __size, size_t __buflen),
-			     __getcwd_chk)
-     __wur __warnattr ("getcwd caller with bigger length than size of "
-		       "destination buffer");
-
 __fortify_function __wur char *
 __NTH (getcwd (char *__buf, size_t __size))
 {
@@ -169,12 +91,6 @@ __NTH (getcwd (char *__buf, size_t __size))
 }
 
 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
-extern char *__getwd_chk (char *__buf, size_t buflen)
-     __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
-extern char *__REDIRECT_NTH (__getwd_warn, (char *__buf), getwd)
-     __nonnull ((1)) __wur __warnattr ("please use getcwd instead, as getwd "
-				       "doesn't specify buffer size");
-
 __fortify_function __nonnull ((1)) __attribute_deprecated__ __wur char *
 __NTH (getwd (char *__buf))
 {
@@ -184,18 +100,6 @@ __NTH (getwd (char *__buf))
 }
 #endif
 
-extern size_t __confstr_chk (int __name, char *__buf, size_t __len,
-			     size_t __buflen) __THROW
-  __attr_access ((__write_only__, 2, 3));
-extern size_t __REDIRECT_NTH (__confstr_alias, (int __name, char *__buf,
-						size_t __len), confstr)
-   __attr_access ((__write_only__, 2, 3));
-extern size_t __REDIRECT_NTH (__confstr_chk_warn,
-			      (int __name, char *__buf, size_t __len,
-			       size_t __buflen), __confstr_chk)
-     __warnattr ("confstr called with bigger length than size of destination "
-		 "buffer");
-
 __fortify_function size_t
 __NTH (confstr (int __name, char *__buf, size_t __len))
 {
@@ -205,16 +109,6 @@ __NTH (confstr (int __name, char *__buf, size_t __len))
 }
 
 
-extern int __getgroups_chk (int __size, __gid_t __list[], size_t __listlen)
-  __THROW __wur __attr_access ((__write_only__, 2, 1));
-extern int __REDIRECT_NTH (__getgroups_alias, (int __size, __gid_t __list[]),
-			   getgroups) __wur __attr_access ((__write_only__, 2, 1));
-extern int __REDIRECT_NTH (__getgroups_chk_warn,
-			   (int __size, __gid_t __list[], size_t __listlen),
-			   __getgroups_chk)
-     __wur __warnattr ("getgroups called with bigger group count than what "
-		       "can fit into destination buffer");
-
 __fortify_function int
 __NTH (getgroups (int __size, __gid_t __list[]))
 {
@@ -224,18 +118,6 @@ __NTH (getgroups (int __size, __gid_t __list[]))
 }
 
 
-extern int __ttyname_r_chk (int __fd, char *__buf, size_t __buflen,
-			    size_t __nreal) __THROW __nonnull ((2))
-   __attr_access ((__write_only__, 2, 3));
-extern int __REDIRECT_NTH (__ttyname_r_alias, (int __fd, char *__buf,
-					       size_t __buflen), ttyname_r)
-     __nonnull ((2));
-extern int __REDIRECT_NTH (__ttyname_r_chk_warn,
-			   (int __fd, char *__buf, size_t __buflen,
-			    size_t __nreal), __ttyname_r_chk)
-     __nonnull ((2)) __warnattr ("ttyname_r called with bigger buflen than "
-				 "size of destination buffer");
-
 __fortify_function int
 __NTH (ttyname_r (int __fd, char *__buf, size_t __buflen))
 {
@@ -246,16 +128,6 @@ __NTH (ttyname_r (int __fd, char *__buf, size_t __buflen))
 
 
 #ifdef __USE_POSIX199506
-extern int __getlogin_r_chk (char *__buf, size_t __buflen, size_t __nreal)
-     __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
-extern int __REDIRECT (__getlogin_r_alias, (char *__buf, size_t __buflen),
-		       getlogin_r) __nonnull ((1));
-extern int __REDIRECT (__getlogin_r_chk_warn,
-		       (char *__buf, size_t __buflen, size_t __nreal),
-		       __getlogin_r_chk)
-     __nonnull ((1)) __warnattr ("getlogin_r called with bigger buflen than "
-				 "size of destination buffer");
-
 __fortify_function int
 getlogin_r (char *__buf, size_t __buflen)
 {
@@ -267,17 +139,6 @@ getlogin_r (char *__buf, size_t __buflen)
 
 
 #if defined __USE_MISC || defined __USE_UNIX98
-extern int __gethostname_chk (char *__buf, size_t __buflen, size_t __nreal)
-     __THROW __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
-extern int __REDIRECT_NTH (__gethostname_alias, (char *__buf, size_t __buflen),
-			   gethostname)
-  __nonnull ((1)) __attr_access ((__write_only__, 1, 2));
-extern int __REDIRECT_NTH (__gethostname_chk_warn,
-			   (char *__buf, size_t __buflen, size_t __nreal),
-			   __gethostname_chk)
-     __nonnull ((1)) __warnattr ("gethostname called with bigger buflen than "
-				 "size of destination buffer");
-
 __fortify_function int
 __NTH (gethostname (char *__buf, size_t __buflen))
 {
@@ -289,19 +150,6 @@ __NTH (gethostname (char *__buf, size_t __buflen))
 
 
 #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_UNIX98)
-extern int __getdomainname_chk (char *__buf, size_t __buflen, size_t __nreal)
-     __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
-extern int __REDIRECT_NTH (__getdomainname_alias, (char *__buf,
-						   size_t __buflen),
-			   getdomainname) __nonnull ((1))
-  __wur __attr_access ((__write_only__, 1, 2));
-extern int __REDIRECT_NTH (__getdomainname_chk_warn,
-			   (char *__buf, size_t __buflen, size_t __nreal),
-			   __getdomainname_chk)
-     __nonnull ((1)) __wur __warnattr ("getdomainname called with bigger "
-				       "buflen than size of destination "
-				       "buffer");
-
 __fortify_function int
 __NTH (getdomainname (char *__buf, size_t __buflen))
 {