Define macros that will become the new logging API (Eduardo Habkost)

These macros are NOT a proposal for a definitive new logging API. They
are just a step for it: a way to mark all usage patterns of the
logfile/loglevel variables on a single place.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6333 c046a42c-6fe2-441c-8c8c-71466251a162

qemu-log.h

 #ifndef QEMU_LOG_H
 #define QEMU_LOG_H
 
+/* The deprecated global variables: */
 extern FILE *logfile;
 extern int loglevel;
 
+
+/* 
+ * The new API:
+ *
+ */
+
+/* Log settings checking macros: */
+
+/* Returns true if qemu_log() will really write somewhere
+ */
+#define qemu_log_enabled() (logfile != NULL)
+
+/* Returns true if a bit is set in the current loglevel mask
+ */
+#define qemu_loglevel_mask(b) ((loglevel & (b)) != 0)
+
+
+/* Logging functions: */
+
+/* main logging function
+ */
+#define qemu_log(...) do {                 \
+        if (logfile)                       \
+            fprintf(logfile, ## __VA_ARGS__); \
+    } while (0)
+
+/* vfprintf-like logging function
+ */
+#define qemu_log_vprintf(fmt, va) do {     \
+        if (logfile)                       \
+            vfprintf(logfile, fmt, va);    \
+    } while (0)
+
+/* log only if a bit is set on the current loglevel mask
+ */
+#define qemu_log_mask(b, ...) do {         \
+        if (loglevel & (b))                \
+            fprintf(logfile, ## __VA_ARGS__); \
+    } while (0)
+
+
+
+
+/* Special cases: */
+
+/* cpu_dump_state() logging functions: */
+#define log_cpu_state(env, f) cpu_dump_state((env), logfile, fprintf, (f));
+#define log_cpu_state_mask(b, env, f) do {           \
+      if (loglevel & (b)) log_cpu_state((env), (f)); \
+  } while (0)
+
+/* disas() and target_disas() to logfile: */
+#define log_target_disas(start, len, flags) \
+        target_disas(logfile, (start), (len), (flags))
+#define log_disas(start, len) \
+        disas(logfile, (start), (len))
+
+/* page_dump() output to the log file: */
+#define log_page_dump() page_dump(logfile)
+
+
+
+/* Maintenance: */
+
+/* fflush() the log file */
+#define qemu_log_flush() fflush(logfile)
+
+/* Close the log file */
+#define qemu_log_close() do { \
+        fclose(logfile);      \
+        logfile = NULL;       \
+    } while (0)
+
+/* Set up a new log file */
+#define qemu_log_set_file(f) do { \
+        logfile = (f);            \
+    } while (0)
+
+/* Set up a new log file, only if none is set */
+#define qemu_log_try_set_file(f) do { \
+        if (!logfile)                 \
+            logfile = (f);            \
+    } while (0)
+
+
 #endif