Introduce an internal API for VxWorks version checks

This changes introduces an internal API for VxWorks version checks
within runtime files, a prerequisite to a few fixes coming up for libstdc++
builds on more recent versions of the OS.

2019-12-30  Olivier Hainque  <hainque@adacore.com>

	gcc/
	* config/vxworks/_vxworks-versions.h: New file.
	* config.gcc (*-*-vxworks*): Add it to extra_headers.

	libgcc/
	* config/gthr-vxworks.h: Use _vxworks-versions.h.
	* config/gthr-vxworks-tls.c: Likewise.

From-SVN: r279783

gcc/ChangeLog

 2019-12-30  Olivier Hainque  <hainque@adacore.com>
 
+	* config/vxworks/_vxworks-versions.h: New file.
+	* config.gcc (*-*-vxworks*): Add it to extra_headers.
+
+2019-12-30  Olivier Hainque  <hainque@adacore.com>
+
 	* config/t-vxworks: Rework the vxworks.o compilation
 	rules to use $(COMPILE).
 

gcc/config.gcc

@@ -961,6 +961,13 @@ case ${target} in
   target_has_targetcm="yes"
   use_gcc_stdint=provide
   tm_file="${tm_file} vxworks-stdint.h"
+
+  # This private header exposes a consistent interface for checks on
+  # the VxWorks version our runtime header files need to perform, based on
+  # what the system headers adverstise:
+
+  extra_headers="${extra_headers} ../vxworks/_vxworks-versions.h"
+
   case ${enable_threads} in
     no) ;;
     "" | yes | vxworks) thread_file='vxworks' ;;

libgcc/ChangeLog

 2019-12-30  Olivier Hainque  <hainque@adacore.com>
 
+	* config/gthr-vxworks.h: Use _vxworks-versions.h.
+	* config/gthr-vxworks-tls.c: Likewise.
+
+2019-12-30  Olivier Hainque  <hainque@adacore.com>
+
 	* config/gthr-vxworks.h (GTHREAD_ONCE_INIT): Use
 	standard zero-initializer syntax.
 

libgcc/config/gthr-vxworks-tls.c

@@ -45,6 +45,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #include <errno.h>
 #endif
 
+#include <_vxworks-versions.h>
+
 /* Thread-local storage.
 
    A gthread TLS key is simply an offset in an array, the address of which
@@ -91,10 +93,10 @@ static int self_owner;
    it is only removed when unloading this module.  */
 static volatile int delete_hook_installed;
 
-/* TLS data access internal API.  A straight __thread variable on VxWorks 7,
-   a pointer returned by kernel provided routines otherwise.  */
+/* TLS data access internal API.  A straight __thread variable starting with
+   VxWorks 7, a pointer returned by kernel provided routines otherwise.  */
 
-#ifdef __VXWORKS7__
+#if _VXWORKS_MAJOR_GE(7)
 
 static __thread struct tls_data *__gthread_tls_data;
 
@@ -118,7 +120,7 @@ extern void __gthread_leave_tls_dtor_context (void);
 #define VX_ENTER_TLS_DTOR() __gthread_enter_tls_dtor_context ()
 #define VX_LEAVE_TLS_DTOR() __gthread_leave_tls_dtor_context ()
 
-#endif /* __VXWORKS7__ */
+#endif
 
 /* This is a global structure which records all of the active keys.
 

libgcc/config/gthr-vxworks.h

@@ -35,13 +35,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #else
 
 #include <vxWorks.h>
-#include <version.h>
-
-/* Conditional compilation directives are easier to read when they fit on a
-   single line, which is helped by macros with shorter names.  */
-#define _VXW_MAJOR _WRS_VXWORKS_MAJOR
-#define _VXW_MINOR _WRS_VXWORKS_MINOR
-#define _VXW_PRE_69 (_VXW_MAJOR  < 6 || (_VXW_MAJOR == 6 && _VXW_MINOR < 9))
+#include <_vxworks-versions.h>
 
 /* Some VxWorks headers profusely use typedefs of a pointer to a function with
    undefined number of arguments.  */
@@ -62,7 +56,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 /* RTP, pre 6.9.  */
 
-#if defined(__RTP__) && _VXW_PRE_69
+#if defined(__RTP__) && _VXWORKS_PRE(6,9)
 
 #define __TAS(x) vxCas ((x), 0, 1)
 typedef volatile unsigned char __vx_tas_t;
@@ -71,7 +65,7 @@ typedef volatile unsigned char __vx_tas_t;
 
 /* RTP, 6.9 and beyond.  */
 
-#if defined(__RTP__) && !_VXW_PRE_69
+#if defined(__RTP__) && !_VXWORKS_PRE(6,9)
 
 #define __TAS(x) vxAtomicCas ((x), 0, 1)
 typedef atomic_t __vx_tas_t;