lib/bug: Small utilities to say there is a warning, or a todo, or a bug on condition

Modelled by ones used in Linux kernel.

include/wendelin/bug.h

+#ifndef _WENDELIN_BUG_H_
+#define _WENDELIN_BUG_H_
+
+/* Wendelin. Utilities for handling assertions and bugs
+ * Copyright (C) 2014-2015  Nexedi SA and Contributors.
+ *                          Kirill Smelkov <kirr@nexedi.com>
+ *
+ * This program is free software: you can Use, Study, Modify and Redistribute
+ * it under the terms of the GNU General Public License version 3, or (at your
+ * option) any later version, as published by the Free Software Foundation.
+ *
+ * You can also Link and Combine this program with other software covered by
+ * the terms of any of the Open Source Initiative approved licenses and Convey
+ * the resulting work. Corresponding source of such a combination shall include
+ * the source code for all other software used.
+ *
+ * This program is distributed WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See COPYING file for full licensing terms.
+ */
+
+
+// XXX maybe not needed - just go with std assert()
+
+#define TODO(expr)  do {                                    \
+    if (expr)                                               \
+        __todo(#expr, __FILE__, __LINE__, __func__);        \
+} while (0)
+
+#define WARN(msg) do {                              \
+    __warn(__FILE__, __LINE__, __func__, msg);      \
+} while (0)
+
+#define BUG() do {                                  \
+    __bug(__FILE__, __LINE__, __func__);            \
+} while (0)
+
+#define BUGe() do {                                 \
+    __bug_errno(__FILE__, __LINE__, __func__);      \
+} while (0)
+
+/* like assert(expr) but works indepenently of NDEBUG */
+// TODO unlikely
+#define ASSERT(expr)    do {                                \
+    if (!(expr))                                            \
+        __bug_fail(#expr, __FILE__, __LINE__, __func__);    \
+} while (0)
+
+/* =ASSERT(!expr) */
+#define BUG_ON(expr)    ASSERT(!(expr))
+
+
+
+void __todo(const char *, const char *, unsigned, const char *)
+    __attribute__((noreturn));
+void __warn(const char *, unsigned, const char *, const char *);
+void __bug(const char *, unsigned, const char *)
+    __attribute__((noreturn));
+void __bug_errno(const char *, unsigned, const char *)
+    __attribute__((noreturn));
+void __bug_fail(const char *, const char *, unsigned, const char *)
+    __attribute__((noreturn));
+
+
+#endif

lib/bug.c

+/* Wendelin. Utilities for handling assertions and bugs
+ * Copyright (C) 2014-2015  Nexedi SA and Contributors.
+ *                          Kirill Smelkov <kirr@nexedi.com>
+ *
+ * This program is free software: you can Use, Study, Modify and Redistribute
+ * it under the terms of the GNU General Public License version 3, or (at your
+ * option) any later version, as published by the Free Software Foundation.
+ *
+ * You can also Link and Combine this program with other software covered by
+ * the terms of any of the Open Source Initiative approved licenses and Convey
+ * the resulting work. Corresponding source of such a combination shall include
+ * the source code for all other software used.
+ *
+ * This program is distributed WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See COPYING file for full licensing terms.
+ */
+
+/* first include with NDEBUG unset to get __assert_* prototypes */
+#undef NDEBUG
+#include <assert.h>
+
+#include <wendelin/bug.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+void __bug_fail(const char *expr, const char *file, unsigned line, const char *func)
+{
+    /* just tail to libc */
+    __assert_fail(expr, file, line, func);
+}
+
+
+void __bug(const char *file, unsigned line, const char *func)
+{
+    fprintf(stderr, "%s:%u %s\tBUG!\n", file, line, func);
+    abort();
+}
+
+
+void __bug_errno(const char *file, unsigned line, const char *func)
+{
+    char errno_buf[128];
+    char *errno_str;
+
+    errno_str = strerror_r(errno, errno_buf, sizeof(errno_buf));
+    fprintf(stderr, "%s:%u %s\tBUG! (%s)\n", file, line, func, errno_str);
+    abort();
+}
+
+
+void __warn(const char *file, unsigned line, const char *func, const char *msg)
+{
+    fprintf(stderr, "%s:%u %s WARN: %s\n", file, line, func, msg);
+}
+
+
+void __todo(const char *expr, const char *file, unsigned line, const char *func)
+{
+    fprintf(stderr, "%s:%u %s\tTODO %s\n", file, line, func, expr);
+    abort();
+}

setup.py

@@ -27,6 +27,7 @@ import os
 _bigfile = Extension('wendelin.bigfile._bigfile',
             sources = [
                 'bigfile/_bigfile.c',
+                'lib/bug.c',
             ],
             include_dirs = [
                 './include',