elf: Move ld.so error/help output to _dl_usage

Also add a comment to elf/Makefile, explaining why we cannot use
config.status for autoconf template processing.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/elf/dl-usage.c b/elf/dl-usage.c
new file mode 100644
index 0000000000..f3d89d22b7
--- /dev/null
+++ b/elf/dl-usage.c
@@ -0,0 +1,51 @@
+/* Print usage information and help for ld.so.
+   Copyright (C) 1995-2020 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-cache.h>
+#include <dl-main.h>
+#include <ldsodefs.h>
+
+void
+_dl_usage (void)
+{
+  _dl_fatal_printf ("\
+Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
+You have invoked `ld.so', the helper program for shared library executables.\n\
+This program usually lives in the file `/lib/ld.so', and special directives\n\
+in executable files using ELF shared libraries tell the system's program\n\
+loader to load the helper program from this file.  This helper program loads\n\
+the shared libraries needed by the program executable, prepares the program\n\
+to run, and runs it.  You may invoke this helper program directly from the\n\
+command line to load and run an ELF executable file; this is like executing\n\
+that file itself, but always uses this helper program from the file you\n\
+specified, instead of the helper program file specified in the executable\n\
+file you run.  This is mostly of use for maintainers to test new versions\n\
+of this helper program; chances are you did not intend to run this program.\n\
+\n\
+  --list                list all dependencies and how they are resolved\n\
+  --verify              verify that given object really is a dynamically linked\n\
+                        object we can handle\n\
+  --inhibit-cache       Do not use " LD_SO_CACHE "\n\
+  --library-path PATH   use given PATH instead of content of the environment\n\
+                        variable LD_LIBRARY_PATH\n\
+  --inhibit-rpath LIST  ignore RUNPATH and RPATH information in object names\n\
+                        in LIST\n\
+  --audit LIST          use objects named in LIST as auditors\n\
+  --preload LIST        preload objects named in LIST\n\
+  --argv0 STRING        set argv[0] to STRING before running\n");
+}