[gdb] Fix 'not in executable format' error message

With trying to load a non-executable file into gdb, we run into PR26880:
...
$ gdb -q -batch test.c
"0x7ffc87bfc8d0s": not in executable format: \
  file format not recognized
...

The problem is caused by using %ps in combination with the error function
(note that confusingly, it does work in combination with the warning
function).

Fix this by using plain "%s" instead.

Tested on x86_64-linux.

gdb/ChangeLog:

2021-08-22  Tom de Vries  <tdevries@suse.de>

	PR gdb/26880
	* gdb/exec.c (exec_file_attach): Use %s instead of %ps in call to
	error function.

gdb/testsuite/ChangeLog:

2021-08-22  Tom de Vries  <tdevries@suse.de>

	PR gdb/26880
	* gdb.base/non-executable.exp: New file.

2 files changed, 35 insertions, 5 deletions

diff --git a/gdb/exec.c b/gdb/exec.c
index 6f936c9..1be5147 100644
--- a/gdb/exec.c
+++ b/gdb/exec.c
@@ -453,9 +453,8 @@ exec_file_attach (const char *filename, int from_tty)
 
       if (!current_program_space->exec_bfd ())
 	{
-	  error (_("\"%ps\": could not open as an executable file: %s."),
-		 styled_string (file_name_style.style (), scratch_pathname),
-		 bfd_errmsg (bfd_get_error ()));
+	  error (_("\"%s\": could not open as an executable file: %s."),
+		 scratch_pathname, bfd_errmsg (bfd_get_error ()));
 	}
 
       /* gdb_realpath_keepfile resolves symlinks on the local
@@ -475,8 +474,7 @@ exec_file_attach (const char *filename, int from_tty)
 	  /* Make sure to close exec_bfd, or else "run" might try to use
 	     it.  */
 	  current_program_space->exec_close ();
-	  error (_("\"%ps\": not in executable format: %s"),
-		 styled_string (file_name_style.style (), scratch_pathname),
+	  error (_("\"%s\": not in executable format: %s"), scratch_pathname,
 		 gdb_bfd_errmsg (bfd_get_error (), matching).c_str ());
 	}
 
diff --git a/gdb/testsuite/gdb.base/non-executable.exp b/gdb/testsuite/gdb.base/non-executable.exp
new file mode 100644
index 0000000..4ae123a
--- /dev/null
+++ b/gdb/testsuite/gdb.base/non-executable.exp
@@ -0,0 +1,32 @@
+# Copyright 2021 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/>.
+
+# Check that loading an existing but non-executable file
+# results in the correct error message.
+
+set binfile "$srcdir/$subdir/$gdb_test_file_name.exp"
+
+clean_restart
+
+set re \
+    [list \
+	 "\"[string_to_regexp $binfile]\"" \
+	 "not in executable format" \
+	 "file format not recognized"]
+set re [join $re ": "]
+
+# Using gdb_load will generate a dejagnu ERROR, so use
+# plain file command instead.
+gdb_test "file $binfile" $re "error message"