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Re: [PATCH] support: Add TEST_COMPARE macro
On 11/23/2017 11:52 AM, Siddhesh Poyarekar wrote:
On Thursday 23 November 2017 03:49 PM, Florian Weimer wrote:
This is currently bundled with the MPK changes, but it is useful
separately, so I'm submitting it here as well.
I tried to expand the comments regarding the use of de-facto 65-bit
integers, as Adhemerval suggested before.
ENOPATCH
Uh-oh. Next try.
Thanks,
Florian
Subject: [PATCH] support: Add TEST_COMPARE macro
To: libc-alpha@sourceware.org
2017-11-23 Florian Weimer <fweimer@redhat.com>
* support/check.h (TEST_COMPARE): Define.
(support_test_compare_failure): Declare.
* support/Makefile (libsupport-routines): Add
support_test_compare_failure.
(tests): Add tst-test_compare.
* support /support_test_compare_failure.c: New file.
* support/tst-test_compare.c: Likewise.
diff --git a/support/Makefile b/support/Makefile
index 384fecb65a..bb81825fc2 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -54,6 +54,7 @@ libsupport-routines = \
support_record_failure \
support_run_diff \
support_shared_allocate \
+ support_test_compare_failure \
support_write_file_string \
support_test_main \
support_test_verify_impl \
@@ -143,6 +144,7 @@ tests = \
tst-support_capture_subprocess \
tst-support_format_dns_packet \
tst-support_record_failure \
+ tst-test_compare \
tst-xreadlink \
ifeq ($(run-built-tests),yes)
diff --git a/support/check.h b/support/check.h
index bdcd12952a..eb02d81077 100644
--- a/support/check.h
+++ b/support/check.h
@@ -86,6 +86,40 @@ void support_test_verify_exit_impl (int status, const char *file, int line,
does not support reporting failures from a DSO. */
void support_record_failure (void);
+/* Compare the two integers LEFT and RIGHT and report failure if they
+ are different. */
+#define TEST_COMPARE(left, right) \
+ ({ \
+ __typeof__ (left) __left_value = (left); \
+ __typeof__ (right) __right_value = (right); \
+ /* Prevent accidental use with larger-than-long long types. */ \
+ _Static_assert (sizeof (__left_value) <= sizeof (long long), \
+ "left value fits into long long"); \
+ _Static_assert (sizeof (__right_value) <= sizeof (long long), \
+ "right value fits into long long"); \
+ /* Compare the value and the sign, to avoid false equality. */ \
+ /* (A signed value could be converted to an unsigned type.) */ \
+ if (__left_value != __right_value \
+ || ((__left_value > 0) != (__right_value > 0))) \
+ support_test_compare_failure \
+ (__FILE__, __LINE__, \
+ #left, __left_value, __left_value > 0, \
+ #right, __right_value, __right_value > 0); \
+ })
+
+/* Internal implementation of TEST_COMPARE. LEFT_POSITIVE and
+ RIGHT_POSITIVE are used to store the sign separately, so that both
+ unsigned long long and long long arguments fit into LEFT_VALUE and
+ RIGHT_VALUE, and the function can still print the original
+ value. */
+void support_test_compare_failure (const char *file, int line,
+ const char *left_expr,
+ long long left_value,
+ int left_positive,
+ const char *right_expr,
+ long long right_value,
+ int right_positive);
+
/* Internal function called by the test driver. */
int support_report_failure (int status)
__attribute__ ((weak, warn_unused_result));
diff --git a/support/support_test_compare_failure.c b/support/support_test_compare_failure.c
new file mode 100644
index 0000000000..007f0154f0
--- /dev/null
+++ b/support/support_test_compare_failure.c
@@ -0,0 +1,46 @@
+/* Reporting a numeric comparison failure.
+ Copyright (C) 2017 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 <stdio.h>
+#include <support/check.h>
+
+static void
+report (const char *which, const char *expr, long long value, int positive)
+{
+ printf (" %s: ", which);
+ if (positive)
+ printf ("%llu", (unsigned long long) value);
+ else
+ printf ("%lld", value);
+ printf (" (0x%llx); from: %s\n", (unsigned long long) value, expr);
+}
+
+void
+support_test_compare_failure (const char *file, int line,
+ const char *left_expr,
+ long long left_value,
+ int left_positive,
+ const char *right_expr,
+ long long right_value,
+ int right_positive)
+{
+ support_record_failure ();
+ printf ("%s:%d: numeric comparison failure\n", file, line);
+ report (" left", left_expr, left_value, left_positive);
+ report ("right", right_expr, right_value, right_positive);
+}
diff --git a/support/tst-test_compare.c b/support/tst-test_compare.c
new file mode 100644
index 0000000000..fc1d6a7095
--- /dev/null
+++ b/support/tst-test_compare.c
@@ -0,0 +1,61 @@
+/* Basic test for the TEST_COMPARE macro.
+ Copyright (C) 2017 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)
+{
+ unsigned long long left = -1;
+ long long right = -1;
+ /* This should fail. */
+ TEST_COMPARE (left, right); /* Line 29. */
+}
+
+static int
+do_test (void)
+{
+ /* This should succeed. */
+ TEST_COMPARE (1, 1);
+ TEST_COMPARE (0ULL, 0LL);
+
+ 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.c:29: numeric comparison failure\n"
+ " left: 18446744073709551615 (0xffffffffffffffff); from: left\n"
+ " right: -1 (0xffffffffffffffff); from: right\n") == 0);
+
+ /* Check that there is no output on standard error. */
+ support_capture_subprocess_check (&proc, "TEST_COMPARE", 0, sc_allow_stdout);
+
+ return 0;
+}
+
+#include <support/test-driver.c>