elf: Add test case for LD_PROFILE/LD_PROFILE_OUTPUT interaction

This verifies that LD_PROFILE is correctly ignored if LD_PROFILE_OUTPUT
is not set.

The test was initially auto-generated, then heavily edited and re-edited
for brevity and clarity.  The test uses glibc-specific interfaces
(including one that did not exist at all a couple of hours ago), so
this should be unproblematic.

diff --git a/elf/Makefile b/elf/Makefile
index 01cc51636eee412b5877df183038504cdb2269e1..30ac283186bb02b99c1d1bc146881f00c74de797 100644 (file)
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -452,6 +452,7 @@ tests += \
   tst-initorder \
   tst-initorder2 \
   tst-latepthread \
+  tst-ld_profile \
   tst-main1 \
   tst-next-ver \
   tst-nodelete-dlclose \

diff --git a/elf/tst-ld_profile.c b/elf/tst-ld_profile.c
new file mode 100644 (file)
index 0000000..6c392f6
--- /dev/null
+++ b/elf/tst-ld_profile.c
@@ -0,0 +1,139 @@
+/* Test LD_PROFILE/LD_PROFILE_OUTPUT interaction (bug 33797).
+   Copyright (C) 2026 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 <gnu/lib-names.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/capture_subprocess.h>
+#include <support/check.h>
+#include <support/subprocess.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <unistd.h>
+
+/* Expected profile file path (based on LD_PROFILE_OUTPUT and LIBC_SO).  */
+static char *profile_file_path;
+
+/* Path to this test program for recursive invocation.  */
+static char *program;
+
+/* LD_PROFILE_OUTPUT environment variable setting.  */
+static char *ld_profile_output_env;
+
+/* Run the test program with the specified environment array.  */
+static struct support_capture_subprocess
+run_test_program (char *env[])
+{
+  /* Make sure the the potential output file does not exist.  */
+  unlink (profile_file_path);
+
+/* Command line arguments for recursive invocation.  This turns the
+   test program in a no-op (with LD_PROFILE output the only side effect).  */
+  static char *recurse_argv[] =
+    {
+      (char *) "tst-ld_profile", (char *) "recurse", NULL
+    };
+  struct support_spawn_wrapped *w
+    = support_spawn_wrap (program, recurse_argv, env, 0);
+  struct support_capture_subprocess proc
+    = support_capture_subprogram (w->path, w->argv, w->envp);
+  support_spawn_wrapped_free (w);
+
+  return proc;
+}
+
+static void
+test_profile_without_output (void)
+{
+  char *env[] = { (char *) "LD_PROFILE=" LIBC_SO, NULL };
+  struct support_capture_subprocess proc = run_test_program (env);
+  const char *expected_warning =
+    "warning: LD_PROFILE ignored because LD_PROFILE_OUTPUT not specified\n";
+  TEST_COMPARE_STRING (proc.err.buffer, expected_warning);
+  support_capture_subprocess_check (&proc,
+                                    "LD_PROFILE without LD_PROFILE_OUTPUT",
+                                    0, sc_allow_stderr);
+  support_capture_subprocess_free (&proc);
+
+  TEST_VERIFY (access (profile_file_path, F_OK) != 0);
+  /* Also check the old /var/tmp path.  */
+  TEST_VERIFY (access ("/var/tmp/" LIBC_SO ".profile", F_OK) != 0);
+}
+
+static void
+test_profile_with_output (void)
+{
+  char *env[] = { (char *) "LD_PROFILE=" LIBC_SO, ld_profile_output_env, NULL };
+  struct support_capture_subprocess proc = run_test_program (env);
+  support_capture_subprocess_check (&proc, "LD_PROFILE with LD_PROFILE_OUTPUT",
+                                    0, sc_allow_none);
+  support_capture_subprocess_free (&proc);
+
+  /* This asserts that the file was created.  */
+  TEST_COMPARE (unlink (profile_file_path), 0);
+}
+
+static void
+test_output_without_profile (void)
+{
+  char *env[] = { ld_profile_output_env, NULL };
+  struct support_capture_subprocess proc = run_test_program (env);
+  support_capture_subprocess_check (&proc,
+                                    "LD_PROFILE_OUTPUT without LD_PROFILE",
+                                    0, sc_allow_none);
+  support_capture_subprocess_free (&proc);
+
+  TEST_VERIFY (access (profile_file_path, F_OK) != 0);
+}
+
+static void
+prepare (int argc, char **argv)
+{
+  /* Do nothing on recursive invocation.  */
+  if (argc >= 2 && strcmp (argv[1], "recurse") == 0)
+    exit (0);
+}
+
+#define PREPARE prepare
+
+static int
+do_test (void)
+{
+  if (access ("/var/tmp/" LIBC_SO ".profile", F_OK) == 0)
+    FAIL_UNSUPPORTED ("/var/tmp/" LIBC_SO ".profile exists");
+
+  /* Temporary directory for the profile output.  */
+  char *profile_output_dir = support_create_temp_directory ("tst-ld_profile");
+  profile_file_path = xasprintf ("%s/%s.profile", profile_output_dir, LIBC_SO);
+  ld_profile_output_env = xasprintf ("LD_PROFILE_OUTPUT=%s",
+                                     profile_output_dir);
+  program = xasprintf ("%s/elf/tst-ld_profile", support_objdir_root);
+
+  test_profile_without_output ();
+  test_profile_with_output ();
+  test_output_without_profile ();
+
+  free (program);
+  free (ld_profile_output_env);
+  free (profile_file_path);
+  free (profile_output_dir);
+
+  return 0;
+}
+
+#include <support/test-driver.c>