2000-logging-base.patch

--- a/libkvmchan/util.c
+++ b/libkvmchan/util.c
@@ -0,0 +1,27 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+
+#include "util.h"
+
+const char *debug_level_names[] = {
+    "[INFO]",
+    "[WARN]",
+    "[ERROR]",
+    "[BUG]"
+};
+
+void debug_impl(enum debug_level level, const char *file, int line, const char *fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+
+    fprintf(stderr, "%s %s:%d: ", debug_level_names[level], file, line);
+    vfprintf(stderr, fmt, args);
+    fputc('\n', stderr);
+
+    va_end(args);
+}
+
--- a/libkvmchan/util.h
+++ b/libkvmchan/util.h
@@ -0,0 +1,15 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+enum debug_level {
+    LOGL_INFO,
+    LOGL_WARN,
+    LOGL_ERROR,
+    LOGL_BUG // Internal use only through log_BUG
+};
+
+#define debug(level, fmt, ...) debug_impl(level, __FILE__, __LINE__, fmt, ##__VA_ARGS__)
+void debug_impl(enum debug_level level, const char *file, int line, const char *fmt, ...);
+
--- a/libkvmchan/Makefile
+++ b/libkvmchan/Makefile
@@ -1,4 +1,4 @@
-SRCS:=library.c ringbuf.c
+SRCS:=library.c ringbuf.c util.c
 DEPS:=$(SRCS:.c=.o)
 BIN:=libkvmchan.so
 LIBS=-lrt -pthread