feat: set log level in runtime

Author: erhankur

example/stub_main.c

@@ -155,11 +155,13 @@ static __attribute__((unused)) int handle_test1(va_list ap)
     STUB_LOG("stub command test:%c\n", 'A');
     STUB_LOG("stub command test:%l\n", 10); // not supported
 
-    STUB_LOGE("stub command test\n");
-    STUB_LOGW("stub command test\n");
-    STUB_LOGI("stub command test\n");
-    STUB_LOGD("stub command test\n");
-    STUB_LOGV("stub command test\n");
+    STUB_LOGE("This is an error message\n");
+    STUB_LOGW("This is a warning message\n");
+    STUB_LOGI("This is an info message\n");
+
+    stub_lib_log_set_level(STUB_LOG_LEVEL_V);
+    STUB_LOGD("This is a debug message\n");
+    STUB_LOGV("This is a verbose message\n");
     STUB_LOG_TRACE();
     STUB_LOG_TRACEF("foo:%u\n", 0x2A);
 
@@ -230,7 +232,7 @@ int stub_main(int cmd, ...)
 
     va_start(ap, cmd);
 
-    STUB_LOG_INIT();
+    STUB_LOG_INIT(STUB_LIB_LOG_LEVEL);
 
     STUB_LOGI("Command: 0x%x\n", cmd);
 

include/esp-stub-lib/log.h

@@ -6,39 +6,97 @@
 
 #pragma once
 
+typedef enum {
+    STUB_LOG_LEVEL_NONE = 0,
+    STUB_LOG_LEVEL_E = 1,
+    STUB_LOG_LEVEL_W = 2,
+    STUB_LOG_LEVEL_I = 3,
+    STUB_LOG_LEVEL_D = 4,
+    STUB_LOG_LEVEL_T = 5,
+    STUB_LOG_LEVEL_TRACE = STUB_LOG_LEVEL_T,
+    STUB_LOG_LEVEL_V = 6,
+} stub_lib_log_level_t;
+
+#if !defined(STUB_LIB_LOG_LEVEL)
+#define STUB_LIB_LOG_LEVEL STUB_LOG_LEVEL_I
+#endif
+
 #if defined(STUB_LOG_ENABLED)
 
 #ifdef __cplusplus
 extern "C" {
 #endif // __cplusplus
 
-void stub_lib_log_init();
+/**
+ * @brief Initialize logging backend and set the initial log level.
+ *
+ * @param level Initial log level.
+ */
+void stub_lib_log_init(stub_lib_log_level_t level);
+
+/**
+ * @brief Set the current runtime log level.
+ *
+ * @param level New log level.
+ */
+void stub_lib_log_set_level(stub_lib_log_level_t level);
+
+/**
+ * @brief Check whether a log level is currently enabled.
+ *
+ * @param level Log level to check.
+ * @return Non-zero if enabled, zero otherwise.
+ */
+int stub_lib_log_level_enabled(stub_lib_log_level_t level);
+
+/**
+ * @brief Print a formatted log message.
+ *
+ * @param fmt Format string.
+ *
+ * @note Supported format specifiers are: `%s`, `%d`, `%u`, `%x`, `%X`, `%c`.
+ *       Other specifiers are not supported.
+ */
 void stub_lib_log_printf(const char *fmt, ...);
 
 #ifdef __cplusplus
 }
 #endif // __cplusplus
 
-#define STUB_LOG_INIT()    stub_lib_log_init()
-#define STUB_LOG(fmt, ...) stub_lib_log_printf(fmt, ##__VA_ARGS__)
+#define STUB_LOG_INIT(level) stub_lib_log_init(level)
+#define STUB_LOG(fmt, ...)   stub_lib_log_printf(fmt, ##__VA_ARGS__)
 
 #else // defined(STUB_LOG_ENABLED)
 
-#define STUB_LOG_INIT()                                                                                                \
+#define STUB_LOG_INIT(level)                                                                                           \
     do {                                                                                                               \
+        (void)(level);                                                                                                 \
     } while (0)
 #define STUB_LOG(fmt, ...)                                                                                             \
     do {                                                                                                               \
     } while (0)
 
 #endif // defined(STUB_LOG_ENABLED)
 
-#define STUB_LOGE(fmt, ...)       STUB_LOG("STUB_E: " fmt, ##__VA_ARGS__)
-#define STUB_LOGW(fmt, ...)       STUB_LOG("STUB_W: " fmt, ##__VA_ARGS__)
-#define STUB_LOGI(fmt, ...)       STUB_LOG("STUB_I: " fmt, ##__VA_ARGS__)
-#define STUB_LOGD(fmt, ...)       STUB_LOG("STUB_D: " fmt, ##__VA_ARGS__)
-#define STUB_LOGV(fmt, ...)       STUB_LOG("STUB_V: " fmt, ##__VA_ARGS__)
+#if defined(STUB_LOG_ENABLED)
+#define STUB_LOG_AT_LEVEL(level, fmt, ...)                                                                             \
+    do {                                                                                                               \
+        if (stub_lib_log_level_enabled(level)) {                                                                       \
+            STUB_LOG(fmt, ##__VA_ARGS__);                                                                              \
+        }                                                                                                              \
+    } while (0)
+#else
+#define STUB_LOG_AT_LEVEL(level, fmt, ...)                                                                             \
+    do {                                                                                                               \
+    } while (0)
+#endif
+
+#define STUB_LOGE(fmt, ...)       STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_E, "STUB_E: " fmt, ##__VA_ARGS__)
+#define STUB_LOGW(fmt, ...)       STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_W, "STUB_W: " fmt, ##__VA_ARGS__)
+#define STUB_LOGI(fmt, ...)       STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_I, "STUB_I: " fmt, ##__VA_ARGS__)
+#define STUB_LOGD(fmt, ...)       STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_D, "STUB_D: " fmt, ##__VA_ARGS__)
+#define STUB_LOGV(fmt, ...)       STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_V, "STUB_V: " fmt, ##__VA_ARGS__)
 // trace only function name
-#define STUB_LOG_TRACE()          STUB_LOG("STUB_T: %s()\n", __func__)
+#define STUB_LOG_TRACE()          STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_T, "STUB_T: %s()\n", __func__)
 // trace with format
-#define STUB_LOG_TRACEF(fmt, ...) STUB_LOG("STUB_T: %s(): " fmt, __func__, ##__VA_ARGS__)
+#define STUB_LOG_TRACEF(fmt, ...) STUB_LOG_AT_LEVEL(STUB_LOG_LEVEL_T, "STUB_T: %s(): " fmt, __func__, ##__VA_ARGS__)

src/log_buf.c

@@ -26,7 +26,7 @@ static void stub_lib_log_buf_write_char(char c)
     g_stub_lib_log_buf.count = (g_stub_lib_log_buf.count + 1) % STUB_LIB_LOG_BUF_SIZE;
 }
 
-void stub_lib_log_init()
+void stub_lib_log_backend_init(void)
 {
     ets_install_putc1(stub_lib_log_buf_write_char);
     ets_install_putc2(NULL);

src/log_common.c

@@ -5,7 +5,41 @@
  */
 #include <stdarg.h>
 
+#include <esp-stub-lib/log.h>
+
 extern void ets_printf(const char *fmt, ...);
+extern void stub_lib_log_backend_init(void);
+
+static stub_lib_log_level_t g_stub_lib_log_level = STUB_LIB_LOG_LEVEL;
+
+static stub_lib_log_level_t stub_lib_log_level_normalize(stub_lib_log_level_t level)
+{
+    if (level < STUB_LOG_LEVEL_NONE) {
+        return STUB_LOG_LEVEL_NONE;
+    }
+
+    if (level > STUB_LOG_LEVEL_V) {
+        return STUB_LOG_LEVEL_V;
+    }
+
+    return level;
+}
+
+void stub_lib_log_set_level(stub_lib_log_level_t level)
+{
+    g_stub_lib_log_level = stub_lib_log_level_normalize(level);
+}
+
+int stub_lib_log_level_enabled(stub_lib_log_level_t level)
+{
+    return g_stub_lib_log_level >= level;
+}
+
+void stub_lib_log_init(stub_lib_log_level_t level)
+{
+    stub_lib_log_set_level(level);
+    stub_lib_log_backend_init();
+}
 
 // This function is designed to avoid implementing vprintf() to reduce code size.
 // It only supports a subset of format specifiers: %s, %d, %u, %x, %X, %c.

src/log_uart.c

@@ -12,7 +12,7 @@ extern void ets_install_putc1(void (*p)(char c));
 extern void ets_install_putc2(void (*p)(char c));
 extern void ets_install_uart_printf(void);
 
-void stub_lib_log_init()
+void stub_lib_log_backend_init(void)
 {
     stub_target_uart_init(0);
     ets_install_putc1(NULL);