[gcc r16-5900] Ada, Darwin: Implement OSLock for Darwin [PR115305].

[Iain D Sandoe]

https://gcc.gnu.org/g:bdf293a112d293cee8bca0ae2e3944eba36e8005

commit r16-5900-gbdf293a112d293cee8bca0ae2e3944eba36e8005
Author: Iain Sandoe <iain@sandoe.co.uk>
Date:   Wed Dec 3 07:44:53 2025 +0000

    Ada, Darwin: Implement OSLock for Darwin [PR115305].
    
    The generic Posix code does not match the layout of the pthread entities
    in the Darwin _pthread_types.h.  So, let's make a Darwin-specific version
    and use it.
    
            PR ada/115305
    
    gcc/ada/ChangeLog:
    
            * Makefile.rtl: Use s-oslock__darwin instead of the Posix version.
            * libgnat/s-oslock__darwin.ads: New file.
    
    Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

Diff:
---
 gcc/ada/Makefile.rtl                 |  2 +-
 gcc/ada/libgnat/s-oslock__darwin.ads | 57 ++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/gcc/ada/Makefile.rtl b/gcc/ada/Makefile.rtl
index 0fa2c51ceb6c..2c3891dc4645 100644
--- a/gcc/ada/Makefile.rtl
+++ b/gcc/ada/Makefile.rtl
@@ -3036,7 +3036,7 @@ ifeq ($(strip $(filter-out darwin%,$(target_os))),)
     s-inmaop.adb<libgnarl/s-inmaop__posix.adb \
     s-osinte.adb<libgnarl/s-osinte__darwin.adb \
     s-osinte.ads<libgnarl/s-osinte__darwin.ads \
-    s-oslock.ads<libgnat/s-oslock__posix.ads \
+    s-oslock.ads<libgnat/s-oslock__darwin.ads \
     s-taprop.adb<libgnarl/s-taprop__posix.adb \
     s-taspri.ads<libgnarl/s-taspri__posix.ads \
     g-sercom.adb<libgnat/g-sercom__linux.adb \
diff --git a/gcc/ada/libgnat/s-oslock__darwin.ads b/gcc/ada/libgnat/s-oslock__darwin.ads
new file mode 100644
index 000000000000..98b9fa6d282e
--- /dev/null
+++ b/gcc/ada/libgnat/s-oslock__darwin.ads
@@ -0,0 +1,57 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                 GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS                 --
+--                                                                          --
+--                       S Y S T E M . O S _ L O C K S                      --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--              Copyright (C) 2025, Free Software Foundation, Inc.          --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNARL was developed by the GNARL team at Florida State University.       --
+-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This is a Darwin version of this package
+
+with Interfaces.C;
+with System.OS_Constants;
+
+package System.OS_Locks is
+   pragma Preelaborate;
+
+   type pthread_mutex_t is limited private;
+
+   subtype RTS_Lock is pthread_mutex_t;
+   --  Should be used inside the runtime system. The difference between Lock
+   --  and the RTS_Lock is that the latter serves only as a semaphore so that
+   --  we do not check for ceiling violations.
+
+private
+
+   subtype char_array is Interfaces.C.char_array;
+
+   type pthread_mutex_t is record
+      Sig  : Interfaces.C.long;
+      Data : char_array (1 .. OS_Constants.PTHREAD_MUTEX_SIZE);
+   end record;
+   pragma Convention (C, pthread_mutex_t);
+
+end System.OS_Locks;