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, 34 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/print-file-var.h b/gdb/testsuite/gdb.base/print-file-var.h
new file mode 100644
index 0000000..c44e484
--- /dev/null
+++ b/gdb/testsuite/gdb.base/print-file-var.h
@@ -0,0 +1,34 @@
+/* This testcase is part of GDB, the GNU debugger.
+   Copyright 2019 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef PRINT_FILE_VAR_H
+#define PRINT_FILE_VAR_H
+
+#if HIDDEN
+# define ATTRIBUTE_VISIBILITY __attribute__((visibility ("hidden")))
+#else
+# define ATTRIBUTE_VISIBILITY
+#endif
+
+#ifdef __cplusplus
+# define START_EXTERN_C extern "C" {
+# define END_EXTERN_C }
+#else
+# define START_EXTERN_C
+# define END_EXTERN_C
+#endif
+
+#endif /* PRINT_FILE_VAR_H */