+#define L_DEBUG 'D' /* Debugging messages */
+#define L_INFO 'I' /* Informational msgs, warnings and errors */
+#define L_WARN 'W'
+#define L_ERROR 'E'
+#define L_INFO_R 'i' /* Errors caused by external events */
+#define L_WARN_R 'w'
+#define L_ERROR_R 'e'
+#define L_FATAL '!' /* die() */
+
+extern char *log_title; /* NULL - print no title, default is log_progname */
+extern char *log_filename; /* Expanded name of the current log file */
+extern volatile int log_switch_nest; /* log_switch() nesting counter, increment to disable automatic switches */
+extern int log_pid; /* 0 if shouldn't be logged */
+extern int log_precise_timings; /* Include microsecond timestamps in log messages */
+extern void (*log_die_hook)(void);
+struct tm;
+extern void (*log_switch_hook)(struct tm *tm);
+
+void log_msg(unsigned int cat, const char *msg, ...) FORMAT_CHECK(printf,2,3);
+#define log log_msg
+void vlog_msg(unsigned int cat, const char *msg, va_list args);
+void die(const char *, ...) NONRET FORMAT_CHECK(printf,1,2);
+void log_init(byte *argv0);
+void log_file(byte *name);
+void log_fork(void);
+int log_switch(void);
+
+void assert_failed(char *assertion, char *file, int line) NONRET;
+void assert_failed_noinfo(void) NONRET;
+
+#ifdef DEBUG_ASSERTS
+#define ASSERT(x) do { if (unlikely(!(x))) assert_failed(#x, __FILE__, __LINE__); } while(0)
+#else
+#define ASSERT(x) do { if (__builtin_constant_p(x) && !(x)) assert_failed_noinfo(); } while(0)
+#endif
+
+#define COMPILE_ASSERT(name,x) typedef char _COMPILE_ASSERT_##name[!!(x)-1]
+
+#ifdef LOCAL_DEBUG
+#define DBG(x,y...) log(L_DEBUG, x,##y)
+#else
+#define DBG(x,y...) do { } while(0)
+#endif
+
+static inline void log_switch_disable(void) { log_switch_nest++; }
+static inline void log_switch_enable(void) { ASSERT(log_switch_nest); log_switch_nest--; }
+
+/* Memory allocation */
+
+#define xmalloc sh_xmalloc
+#define xrealloc sh_xrealloc
+#define xfree sh_xfree
+
+#ifdef DEBUG_DMALLOC
+/*
+ * The standard dmalloc macros tend to produce lots of namespace
+ * conflicts and we use only xmalloc and xfree, so we can define
+ * the stubs ourselves.
+ */
+#define DMALLOC_DISABLE
+#include <dmalloc.h>
+#define sh_xmalloc(size) _xmalloc_leap(__FILE__, __LINE__, size)
+#define sh_xrealloc(ptr,size) _xrealloc_leap(__FILE__, __LINE__, ptr, size)
+#define sh_xfree(ptr) _xfree_leap(__FILE__, __LINE__, ptr)
+#else
+/*
+ * Unfortunately, several libraries we might want to link to define
+ * their own xmalloc and we don't want to interfere with them, hence
+ * the renaming.
+ */
+void *xmalloc(unsigned);
+void *xrealloc(void *, unsigned);
+void xfree(void *);
+#endif