[Ada] Tighten crtbegin files for VxWorks

Enforce a more explicit distinction of crtbegin objects holding
either functions with ctor/dtor attributes or _ctors/_dtors arrays,
or none of the two (no array, no attributes). Then allow/enforce
different linking strategies for VxWorks 7.

2018-05-29  Olivier Hainque  <hainque@adacore.com>

gcc/ada/

	* vx_crtbegin.inc: Use a consistent naming convention for the
	registration/deregistration functions across RTP or kernel.  Remove the
	ctor/dtor attribute setting based on RTP/kernel, expect the optional
	attribute extension to be provided by includers instead.
	* vx_crtbegin.c: Mere inclusion of vx_crtbegin.inc with empty attribute
	extension for the registration/deregistration functions.
	* vx_crtbegin_attr.c: New file. Include vx_crtbegin.inc with explicit
	constructor/destructor attribute extensions.
	* vx_crtbegin_array.c: New file. Include vx_crtbegin.inc with empty
	attribute extensions and declare _ctors/_dtors arrays.
	* vx_crtbegin_auto.c: Remove.
	* libgnat/system-vxworks7-aarch64-rtp-smp.ads: Use
	vxworks7-gnat-crtbe-link.spec.
	* libgnat/system-vxworks7-aarch64.ads: Likewise.
	* libgnat/system-vxworks7-e500-rtp-smp.ads: Likewise.
	* libgnat/system-vxworks7-ppc-rtp-smp.ads: Likewise.
	* libgnat/system-vxworks7-ppc64-rtp-smp.ads: Likewise.
	* libgnat/system-vxworks7-x86-kernel.ads: Likewise.
	* libgnat/system-vxworks7-x86-rtp-smp.ads: Likewise.
	* libgnat/system-vxworks7-x86_64-kernel.ads: Likewise.
	* libgnat/system-vxworks7-x86_64-rtp-smp.ads: Likewise.

From-SVN: r260876

gcc/ada/ChangeLog

+2018-05-29  Olivier Hainque  <hainque@adacore.com>
+
+	* vx_crtbegin.inc: Use a consistent naming convention for the
+	registration/deregistration functions across RTP or kernel.  Remove the
+	ctor/dtor attribute setting based on RTP/kernel, expect the optional
+	attribute extension to be provided by includers instead.
+	* vx_crtbegin.c: Mere inclusion of vx_crtbegin.inc with empty attribute
+	extension for the registration/deregistration functions.
+	* vx_crtbegin_attr.c: New file. Include vx_crtbegin.inc with explicit
+	constructor/destructor attribute extensions.
+	* vx_crtbegin_array.c: New file. Include vx_crtbegin.inc with empty
+	attribute extensions and declare _ctors/_dtors arrays.
+	* vx_crtbegin_auto.c: Remove.
+	* libgnat/system-vxworks7-aarch64-rtp-smp.ads: Use
+	vxworks7-gnat-crtbe-link.spec.
+	* libgnat/system-vxworks7-aarch64.ads: Likewise.
+	* libgnat/system-vxworks7-e500-rtp-smp.ads: Likewise.
+	* libgnat/system-vxworks7-ppc-rtp-smp.ads: Likewise.
+	* libgnat/system-vxworks7-ppc64-rtp-smp.ads: Likewise.
+	* libgnat/system-vxworks7-x86-kernel.ads: Likewise.
+	* libgnat/system-vxworks7-x86-rtp-smp.ads: Likewise.
+	* libgnat/system-vxworks7-x86_64-kernel.ads: Likewise.
+	* libgnat/system-vxworks7-x86_64-rtp-smp.ads: Likewise.
+
 2018-05-29  Piotr Trojanek  <trojanek@adacore.com>
 
 	* ali.adb: Minor reformatting.

gcc/ada/libgnat/system-vxworks7-aarch64-rtp-smp.ads

@@ -120,7 +120,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-aarch64.ads

@@ -120,7 +120,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-e500-rtp-smp.ads

@@ -120,7 +120,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-ppc-rtp-smp.ads

@@ -120,7 +120,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-ppc64-rtp-smp.ads

@@ -120,7 +120,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-x86-kernel.ads

@@ -118,7 +118,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-x86-rtp-smp.ads

@@ -118,7 +118,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-x86_64-kernel.ads

@@ -118,7 +118,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/libgnat/system-vxworks7-x86_64-rtp-smp.ads

@@ -118,7 +118,7 @@ package System is
 
 private
 
-   pragma Linker_Options ("--specs=vxworks-gnat-crtbe-link.spec");
+   pragma Linker_Options ("--specs=vxworks7-gnat-crtbe-link.spec");
    --  Pull in crtbegin/crtend objects and register exceptions for ZCX.
    --  This is commented out by our Makefile for SJLJ runtimes.
 

gcc/ada/vx_crtbegin.c

@@ -30,10 +30,10 @@
  ****************************************************************************/
 
 /* crtbegin kind of file for ehframe registration/deregistration
-   purposes on VxWorks.  This variant exposes the ctor/dtor functions
-   as visible entities so they're picked by the WRS muncher.  */
-
-#define CDTOR_VISIBILITY
-#include "vx_crtbegin.inc"
+   purposes on VxWorks.  This variant exposes just the ctor/dtor functions
+   without any particular attribute.  */
 
+#define CTOR_ATTRIBUTE
+#define DTOR_ATTRIBUTE
 
+#include "vx_crtbegin.inc"

gcc/ada/vx_crtbegin.inc

@@ -39,37 +39,29 @@
 #include "tm.h"
 #include "unwind-dw2-fde.h"
 
-/* Pick names that the VxWorks muncher will get if involved.
-   Note: ppc64-vx7 diab uses "_STI_15..." for C++ in kernel mode,
-   not "_GLOBAL__{I,D}...". ???  */
+/* Pick names that the VxWorks muncher will get if involved and leave the
+   symbols with public visibility.  Hiding by default is pointless and even
+   problematic in some configurations.  When the presence of these
+   constructors is an issue, best is not to include the crt object files at
+   all.  */
 
-#ifdef __RTP__
-/* 101 is the highest user level priority allowed by VxWorks.  */
-#define CTOR_NAME _STI__101____crtbe_register_frame
-#define DTOR_NAME _STI__101____crtbe_deregister_frame
-#define CTOR_ATTRIBUTE __attribute__((constructor(101)))
-#define DTOR_ATTRIBUTE __attribute__((destructor(101)))
-#else
-#define CTOR_NAME _GLOBAL__I___crtbe_register_frame
-#define DTOR_NAME _GLOBAL__D___crtbe_deregister_frame
-#define CTOR_ATTRIBUTE __attribute__((unused))
-#define DTOR_ATTRIBUTE __attribute__((unused))
-#endif
+#define CTOR_NAME _STI__101___crtbe_register_frame
+#define DTOR_NAME _STD__101___crtbe_deregister_frame
 
-CDTOR_VISIBILITY void CTOR_NAME (void) CTOR_ATTRIBUTE;
-CDTOR_VISIBILITY void DTOR_NAME (void) DTOR_ATTRIBUTE;
+void CTOR_NAME (void) CTOR_ATTRIBUTE;
+void DTOR_NAME (void) DTOR_ATTRIBUTE;
 
 static const char __EH_FRAME_BEGIN__[]
 __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
   = { };
 
-CDTOR_VISIBILITY void CTOR_NAME (void)
+void CTOR_NAME (void)
 {
   static struct object object;
   __register_frame_info (__EH_FRAME_BEGIN__, &object);
 }
 
-CDTOR_VISIBILITY void DTOR_NAME (void)
+void DTOR_NAME (void)
 {
   __deregister_frame_info (__EH_FRAME_BEGIN__);
 }

gcc/ada/vx_crtbegin_auto.c → gcc/ada/vx_crtbegin_array.c

@@ -33,15 +33,12 @@
    purposes on VxWorks.  This variant provides _ctors and _dtors
    arrays that the kernel module loader knows to process when it has
    been configured for this purpose (c++ constructor strategy set to
-   automatic).  The ctor/dtor functions need not be visible in this
-   case.  */
+   automatic).  */
 
-#define CDTOR_VISIBILITY static
-#include "vx_crtbegin.inc"
+#define CTOR_ATTRIBUTE
+#define DTOR_ATTRIBUTE
 
-/* Diab C++ for ppc64-vx7 crtbegin wants to declare a
-   char dso_handle = 0;
-   here. ???  */
+#include "vx_crtbegin.inc"
 
 typedef void (*func_ptr) (void);
 func_ptr _dtors [] = {DTOR_NAME, 0};

gcc/ada/vx_crtbegin_attr.c

+/****************************************************************************
+ *                                                                          *
+ *                         GNAT COMPILER COMPONENTS                         *
+ *                                                                          *
+ *                          V X _ C R T B E G I N                           *
+ *                                                                          *
+ *                          C Implementation File                           *
+ *                                                                          *
+ *              Copyright (C) 2016-2018, 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/>.                                          *
+ *                                                                          *
+ * GNAT was originally developed  by the GNAT team at  New York University. *
+ * Extensive contributions were provided by Ada Core Technologies Inc.      *
+ *                                                                          *
+ ****************************************************************************/
+
+/* crtbegin kind of file for ehframe registration/deregistration
+   purposes on VxWorks.  This variant exposes the ctor/dtor functions
+   as explicit constructors, expected to be placed in a .ctors/.dtors
+   section.  */
+
+/* 101 is the highest user level priority allowed by VxWorks.  */
+
+#define CTOR_ATTRIBUTE __attribute__((constructor(101)))
+#define DTOR_ATTRIBUTE __attribute__((destructor(101)))
+
+#include "vx_crtbegin.inc"