gcc: Add 'mcf' thread model support from mcfgthread

This patch adds the new thread model `mcf`, which implements mutexes
and condition variables with the mcfgthread library.

Source code for mcfgthread is available at <https://github.com/lhmouse/mcfgthread>.

config/ChangeLog:
	* gthr.m4 (GCC_AC_THREAD_HEADER): Add new case for `mcf` thread
	model

gcc/ChangeLog:
	* config/i386/mingw-mcfgthread.h: New file
	* config/i386/mingw32.h: Add builtin macro and default libraries
	for mcfgthread when thread model is `mcf`
	* config.gcc: Include 'i386/mingw-mcfgthread.h' when thread model
	is `mcf`
	* configure.ac: Recognize `mcf` as a valid thread model
	* config.in: Regenerate
	* configure: Regenerate

libatomic/ChangeLog:
	* configure.tgt: Add new case for `mcf` thread model

libgcc/ChangeLog:
	* config.host: Add new cases for `mcf` thread model
	* config/i386/gthr-mcf.h: New file
	* config/i386/t-mingw-mcfgthread: New file
	* config/i386/t-slibgcc-cygming: Add mcfgthread for libgcc DLL
	* configure: Regenerate

libstdc++-v3/ChangeLog:
	* libsupc++/atexit_thread.cc (__cxa_thread_atexit): Use
	implementation from mcfgthread if available
	* libsupc++/guard.cc (__cxa_guard_acquire, __cxa_guard_release,
	__cxa_guard_abort): Use implementations from mcfgthread if
	available
	* configure: Regenerate

6 files changed, 24 insertions, 7 deletions

diff --git a/gcc/config.gcc b/gcc/config.gcc
index 2af30b4..2fbf2e6 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -2096,6 +2096,9 @@ i[34567]86-*-mingw* | x86_64-*-mingw*)
 	if test x$enable_threads = xposix ; then
 		tm_file="${tm_file} i386/mingw-pthread.h"
 	fi
+	if test x$enable_threads = xmcf ; then
+		tm_file="${tm_file} i386/mingw-mcfgthread.h"
+	fi
 	tm_file="${tm_file} i386/mingw32.h"
 	# This makes the logic if mingw's or the w64 feature set has to be used
 	case ${target} in
diff --git a/gcc/config.in b/gcc/config.in
index cc217b9..5e41748 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -1451,6 +1451,12 @@
 #endif
 
 
+/* Define to 1 if you have the `getauxval' function. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GETAUXVAL
+#endif
+
+
 /* Define to 1 if you have the `getchar_unlocked' function. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_GETCHAR_UNLOCKED
@@ -2678,7 +2684,3 @@
 #undef vfork
 #endif
 
-/* Define to 1 if you have the `getauxval' function. */
-#ifndef USED_FOR_TARGET
-#undef HAVE_GETAUXVAL
-#endif
diff --git a/gcc/config/i386/mingw-mcfgthread.h b/gcc/config/i386/mingw-mcfgthread.h
new file mode 100644
index 0000000..7d4eda3
--- /dev/null
+++ b/gcc/config/i386/mingw-mcfgthread.h
@@ -0,0 +1 @@
+#define TARGET_USING_MCFGTHREAD  1
diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h
index d3ca0cd..b5f31c3 100644
--- a/gcc/config/i386/mingw32.h
+++ b/gcc/config/i386/mingw32.h
@@ -32,6 +32,10 @@ along with GCC; see the file COPYING3.  If not see
 	 | MASK_STACK_PROBE | MASK_ALIGN_DOUBLE \
 	 | MASK_MS_BITFIELD_LAYOUT)
 
+#ifndef TARGET_USING_MCFGTHREAD
+#define TARGET_USING_MCFGTHREAD  0
+#endif
+
 /* See i386/crtdll.h for an alternative definition. _INTEGRAL_MAX_BITS
    is for compatibility with native compiler.  */
 #define EXTRA_OS_CPP_BUILTINS()					\
@@ -50,6 +54,8 @@ along with GCC; see the file COPYING3.  If not see
 	  builtin_define_std ("WIN64");				\
 	  builtin_define ("_WIN64");				\
 	}							\
+      if (TARGET_USING_MCFGTHREAD)				\
+	builtin_define ("__USING_MCFGTHREAD__");		\
     }								\
   while (0)
 
@@ -181,11 +187,16 @@ along with GCC; see the file COPYING3.  If not see
 #else
 #define SHARED_LIBGCC_SPEC " -lgcc "
 #endif
+#if TARGET_USING_MCFGTHREAD
+#define MCFGTHREAD_SPEC  " -lmcfgthread -lkernel32 -lntdll "
+#else
+#define MCFGTHREAD_SPEC  ""
+#endif
 #undef REAL_LIBGCC_SPEC
 #define REAL_LIBGCC_SPEC \
   "%{mthreads:-lmingwthrd} -lmingw32 \
    " SHARED_LIBGCC_SPEC " \
-   -lmoldname -lmingwex -lmsvcrt -lkernel32"
+   -lmoldname -lmingwex -lmsvcrt -lkernel32 " MCFGTHREAD_SPEC
 
 #undef STARTFILE_SPEC
 #define STARTFILE_SPEC "%{shared|mdll:dllcrt2%O%s} \
diff --git a/gcc/configure b/gcc/configure
index 99ba76522..2ce51a8 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -12900,7 +12900,7 @@ case ${enable_threads} in
     target_thread_file='single'
     ;;
   aix | dce | lynx | mipssde | posix | rtems | \
-  single | tpf | vxworks | win32)
+  single | tpf | vxworks | win32 | mcf)
     target_thread_file=${enable_threads}
     ;;
   *)
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e48fcbf..e1ef2ec 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1991,7 +1991,7 @@ case ${enable_threads} in
     target_thread_file='single'
     ;;
   aix | dce | lynx | mipssde | posix | rtems | \
-  single | tpf | vxworks | win32)
+  single | tpf | vxworks | win32 | mcf)
     target_thread_file=${enable_threads}
     ;;
   *)