Make print-file-var.exp test attribute visibility hidden, dlopen, and main symbol

Make gdb.base/print-file-var.exp test all combinations of:

  - attribute hidden in the this_version_id symbols or not
  - dlopen or not
  - this_version_id symbol in main file or not
  - C++

gdb/testsuite/ChangeLog
2019-10-02  Pedro Alves  <palves@redhat.com>
	    Andrew Burgess  <andrew.burgess@embecosm.com>

	* gdb.base/print-file-var-lib1.c: Include <stdio.h> and
	"print-file-var.h".
	(this_version_id) Use ATTRIBUTE_VISIBILITY.
	(get_version_1): Print this_version_id and its address.
	Add extern "C" wrappers around interface functions.
	* gdb.base/print-file-var-lib2.c: Include <stdio.h> and
	"print-file-var.h".
	(this_version_id) Use ATTRIBUTE_VISIBILITY.
	(get_version_2): Print this_version_id and its address.
	Add extern "C" wrappers around interface functions.
	* gdb.base/print-file-var-main.c: Include <dlfcn.h>, <assert.h>,
	<stddef.h> and "print-file-var.h".
	Add extern "C" wrappers around interface functions.
	[VERSION_ID_MAIN] (this_version_id): Define.
	(main): Define v0.  Use dlopen if SHLIB_NAME is defined.
	* gdb.base/print-file-var.h: Add some #defines to simplify setting
	up extern "C" blocks.
	* gdb.base/print-file-var.exp (test): New, factored out from top
	level.
	(top level): Test all combinations of attribute hidden or not,
	dlopen or not, and this_version_id symbol in main file or not.
	Compile tests as both C++ and C, make test names unique.

1 files changed, 35 insertions, 7 deletions

diff --git a/gdb/testsuite/gdb.base/print-file-var-main.c b/gdb/testsuite/gdb.base/print-file-var-main.c
index ddc54f1..1472bd4 100644
--- a/gdb/testsuite/gdb.base/print-file-var-main.c
+++ b/gdb/testsuite/gdb.base/print-file-var-main.c
@@ -14,21 +14,49 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+#ifdef SHLIB_NAME
+# include <dlfcn.h>
+#endif
+
+#include <assert.h>
+#include <stddef.h>
+
+#include "print-file-var.h"
+
+START_EXTERN_C
+
 extern int get_version_1 (void);
 extern int get_version_2 (void);
 
+END_EXTERN_C
+
+#if VERSION_ID_MAIN
+ATTRIBUTE_VISIBILITY int this_version_id = 55;
+#endif
+
 int
 main (void)
 {
+#if VERSION_ID_MAIN
+  int vm = this_version_id;
+#endif
   int v1 = get_version_1 ();
-  int v2 = get_version_2 ();
+  int v2;
+
+#ifdef SHLIB_NAME
+  {
+    void *handle = dlopen (SHLIB_NAME, RTLD_LAZY);
+    int (*getver2) (void);
+
+    assert (handle != NULL);
 
-  if (v1 != 104)
-    return 1;
-  /* The value returned by get_version_2 depends on the target system.  */
-  if (v2 != 104 && v2 != 203)
-    return 2;
+    getver2 = (int (*)(void)) dlsym (handle, "get_version_2");
+
+    v2 = getver2 ();
+  }
+#else
+  v2 = get_version_2 ();
+#endif
 
   return 0; /* STOP */
 }
-