support: Implement TEST_COMPARE_STRING

support/tst-test_compare_string.c

@@ -0,0 +1,107 @@
+/* Basic test for the TEST_COMPARE_STRING macro.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+#include <support/check.h>
+#include <support/capture_subprocess.h>
+
+static void
+subprocess (void *closure)
+{
+  /* These tests should fail.  They were chosen to cover differences
+     in length (with the same contents), single-bit mismatches, and
+     mismatching null pointers.  */
+  TEST_COMPARE_STRING ("", NULL);             /* Line 29.  */
+  TEST_COMPARE_STRING ("X", "");              /* Line 30.  */
+  TEST_COMPARE_STRING (NULL, "X");            /* Line 31.  */
+  TEST_COMPARE_STRING ("abcd", "abcD");       /* Line 32.  */
+  TEST_COMPARE_STRING ("abcd", NULL);         /* Line 33.  */
+  TEST_COMPARE_STRING (NULL, "abcd");         /* Line 34.  */
+}
+
+/* Same contents, different addresses.  */
+char buffer_abc_1[] = "abc";
+char buffer_abc_2[] = "abc";
+
+static int
+do_test (void)
+{
+  /* This should succeed.  Even if the pointers and array contents are
+     different, zero-length inputs are not different.  */
+  TEST_COMPARE_STRING (NULL, NULL);
+  TEST_COMPARE_STRING ("", "");
+  TEST_COMPARE_STRING (buffer_abc_1, buffer_abc_2);
+  TEST_COMPARE_STRING (buffer_abc_1, "abc");
+
+  struct support_capture_subprocess proc = support_capture_subprocess
+    (&subprocess, NULL);
+
+  /* Discard the reported error.  */
+  support_record_failure_reset ();
+
+  puts ("info: *** subprocess output starts ***");
+  fputs (proc.out.buffer, stdout);
+  puts ("info: *** subprocess output ends ***");
+
+  TEST_VERIFY
+    (strcmp (proc.out.buffer,
+"tst-test_compare_string.c:29: error: blob comparison failed\n"
+"  left string: 0 bytes\n"
+"  right string: NULL\n"
+"tst-test_compare_string.c:30: error: blob comparison failed\n"
+"  left string: 1 bytes\n"
+"  right string: 0 bytes\n"
+"  left (evaluated from \"X\"):\n"
+"      \"X\"\n"
+"      58\n"
+"tst-test_compare_string.c:31: error: blob comparison failed\n"
+"  left string: NULL\n"
+"  right string: 1 bytes\n"
+"  right (evaluated from \"X\"):\n"
+"      \"X\"\n"
+"      58\n"
+"tst-test_compare_string.c:32: error: blob comparison failed\n"
+"  string length: 4 bytes\n"
+"  left (evaluated from \"abcd\"):\n"
+"      \"abcd\"\n"
+"      61 62 63 64\n"
+"  right (evaluated from \"abcD\"):\n"
+"      \"abcD\"\n"
+"      61 62 63 44\n"
+"tst-test_compare_string.c:33: error: blob comparison failed\n"
+"  left string: 4 bytes\n"
+"  right string: NULL\n"
+"  left (evaluated from \"abcd\"):\n"
+"      \"abcd\"\n"
+"      61 62 63 64\n"
+"tst-test_compare_string.c:34: error: blob comparison failed\n"
+"  left string: NULL\n"
+"  right string: 4 bytes\n"
+"  right (evaluated from \"abcd\"):\n"
+"      \"abcd\"\n"
+"      61 62 63 64\n"
+             ) == 0);
+
+  /* Check that there is no output on standard error.  */
+  support_capture_subprocess_check (&proc, "TEST_COMPARE_STRING",
+                                    0, sc_allow_stdout);
+
+  return 0;
+}
+
+#include <support/test-driver.c>