[ddk] Add zxlog_level_enabled(...)
Add a small macro which allows drivers to test to see if a given log
level is currently enabled.
Change-Id: I7321ea90b80f8d33eb2b3a6b6d9c5ec2b6c6962e
diff --git a/system/ulib/ddk/include/ddk/debug.h b/system/ulib/ddk/include/ddk/debug.h
index 4a709c9..7d0a158 100644
--- a/system/ulib/ddk/include/ddk/debug.h
+++ b/system/ulib/ddk/include/ddk/debug.h
@@ -69,6 +69,27 @@
#define DDK_LOG_LDEBUG3 (ZX_LOG_DEBUG3 | ZX_LOG_LOCAL)
#define DDK_LOG_LDEBUG4 (ZX_LOG_DEBUG4 | ZX_LOG_LOCAL)
+// zxlog_level_enabled_etc(...) is an internal macro which tests to see if a
+// given log level is currently enabled. Users should not use this macro, they
+// should use zxlog_level_enabled(...) instead.
+#define zxlog_level_enabled_etc(flag) \
+ (((flag & ZX_LOG_LEVEL_MASK) & __zircon_driver_rec__.log_flags) != 0)
+
+// zxlog_level_enabled(...) provides a way for a driver to test to see if a
+// particular log level is currently enabled. This allows for patterns where a
+// driver might want to log something at trace or spew level, but the something
+// that they want to log might involve a computation or for loop which cannot be
+// embedded into the log macro and therefor disabled without cost.
+//
+// Example:
+// if (zxlog_level_enabled(TRACE)) {
+// zxlogf(TRACE, "Scatter gather table has %u entries\n", sg_table.count);
+// for (uint32_t i = 0; i < sg_table.count; ++i) {
+// zxlogf(TRACE, "[%u] : 0x%08x, %u\n",
+// i, sg_table.entry[i].base, sg_table.entry[i].base);
+// }
+// }
+#define zxlog_level_enabled(flag) zxlog_level_enabled_etc(DDK_LOG_##flag)
void driver_printf(uint32_t flags, const char* fmt, ...) __PRINTFLIKE(2, 3);
@@ -87,7 +108,7 @@
//
#define zxlogf(flag, fmt...) \
do { \
- if ((DDK_LOG_##flag & ZX_LOG_LEVEL_MASK) & __zircon_driver_rec__.log_flags) { \
+ if (zxlog_level_enabled_etc(DDK_LOG_##flag)) { \
driver_printf(DDK_LOG_##flag, fmt); \
} \
} while (0)
@@ -103,7 +124,7 @@
typedef uint32_t DPRINTF_IS_DEPRECATED_USE_ZXLOGF __attribute__((deprecated));
#define dprintf(flag, fmt...) \
do { \
- if ((DDK_LOG_##flag & ZX_LOG_LEVEL_MASK) & __zircon_driver_rec__.log_flags) { \
+ if (zxlog_level_enabled_etc(DDK_LOG_##flag)) { \
driver_printf((DPRINTF_IS_DEPRECATED_USE_ZXLOGF)(DDK_LOG_##flag), fmt); \
} \
} while (0)
