elf: Generalize name-based DSO recognition in ldconfig

This introduces <dl-is_dso.h> and the _dl_is_dso function.  A
test ensures that the official names of libc.so, ld.so, and their
versioned names are recognized.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/elf/tst-dl-is_dso.c b/elf/tst-dl-is_dso.c
new file mode 100644
index 0000000..48d2cc9
--- /dev/null
+++ b/elf/tst-dl-is_dso.c
@@ -0,0 +1,35 @@
+/* Test heuristic for recognizing DSO file names.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <dl-is_dso.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+  /* Official ABI names.  */
+  TEST_VERIFY (_dl_is_dso (LIBC_SO));
+  TEST_VERIFY (_dl_is_dso (LD_SO));
+  /* Version-based names.  The version number does not matter.  */
+  TEST_VERIFY (_dl_is_dso ("libc-2.12.so"));
+  TEST_VERIFY (_dl_is_dso ("ld-2.12.so"));
+  return 0;
+}
+
+#include <support/test-driver.c>