[glibc/azanella/clang] debug: Improve mqueue.h fortify warnings with clang

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=a040289c87f3be67ed5f304db2d0bb256b83448c

commit a040289c87f3be67ed5f304db2d0bb256b83448c
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Dec 5 16:18:54 2023 -0300

    debug: Improve mqueue.h fortify warnings with clang
    
    It improve mq_open.  The compile and runtime checks have similar
    coverage as with GCC.
    
    Checked on aarch64, armhf, x86_64, and i686.

Diff:
---
 rt/bits/mqueue2.h | 29 +++++++++++++++++++++++++++++
 rt/mqueue.h       |  3 +--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/rt/bits/mqueue2.h b/rt/bits/mqueue2.h
index c1d86662dc..69897fd578 100644
--- a/rt/bits/mqueue2.h
+++ b/rt/bits/mqueue2.h
@@ -29,6 +29,8 @@ extern mqd_t __mq_open_2 (const char *__name, int __oflag)
 extern mqd_t __REDIRECT_NTH (__mq_open_alias, (const char *__name,
 					       int __oflag, ...), mq_open)
      __nonnull ((1));
+
+#ifdef __va_arg_pack_len
 __errordecl (__mq_open_wrong_number_of_args,
 	     "mq_open can be called either with 2 or 4 arguments");
 __errordecl (__mq_open_missing_mode_and_attr,
@@ -55,3 +57,30 @@ __NTH (mq_open (const char *__name, int __oflag, ...))
 
   return __mq_open_alias (__name, __oflag, __va_arg_pack ());
 }
+#elif __fortify_use_clang
+__fortify_function_error_function __attribute_overloadable__ mqd_t
+__NTH (mq_open (const char *__name, int __oflag, mode_t mode))
+     __fortify_clang_unavailable ("mq_open can be called either with 2 or 4 arguments");
+
+__fortify_function_error_function __attribute_overloadable__ mqd_t
+__NTH (mq_open (const char *__name, int __oflag, mode_t mode,
+		struct mq_attr *attr, ...))
+     __fortify_clang_unavailable ("mq_open can be called either with 2 or 4 arguments");
+
+__fortify_function __attribute_overloadable__ mqd_t
+__NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
+		int __oflag))
+     __fortify_clang_prefer_this_overload
+     __fortify_clang_error ((__oflag & O_CREAT),
+			     "mq_open with O_CREAT in second argument needs 4 arguments")
+{
+  return __mq_open_alias (__name, __oflag);
+}
+
+__fortify_function __attribute_overloadable__ mqd_t
+__NTH (mq_open (__fortify_clang_overload_arg (const char *, ,__name),
+		int __oflag, int __mode, struct mq_attr *__attr))
+{
+  return __mq_open_alias (__name, __oflag, __mode, __attr);
+}
+#endif
diff --git a/rt/mqueue.h b/rt/mqueue.h
index 126a6b54b3..9279763841 100644
--- a/rt/mqueue.h
+++ b/rt/mqueue.h
@@ -110,8 +110,7 @@ extern int __REDIRECT (mq_timedsend, (mqd_t __mqdes,
 #endif
 
 /* Define some inlines helping to catch common problems.  */
-#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
-    && defined __va_arg_pack_len
+#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
 # include <bits/mqueue2.h>
 #endif