log: initial framework for logging things

CMakeLists.txt

@@ -26,6 +26,7 @@ add_executable(f00bar
   bar.c bar.h
   config.c config.h
   font.c font.h
+  log.c log.h
   main.c
   module.c module.h
   particle.c particle.h

log.c

@@ -0,0 +1,45 @@
+#include "log.h"
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <stdbool.h>
+
+static void
+_log(enum log_class log_class, const char *module, const char *file, int lineno,
+     const char *fmt, va_list va)
+{
+    bool colorize = true;
+
+    const char *class;
+    int class_clr;
+    switch (log_class) {
+    case LOG_CLASS_ERROR:    class = "error"; class_clr = 31; break;
+    case LOG_CLASS_WARNING:  class = "warning"; class_clr = 33; break;
+    case LOG_CLASS_INFO:     class = "info"; class_clr = 97; break;
+    case LOG_CLASS_DEBUG:    class = "debug"; class_clr = 36; break;
+    }
+
+    char clr[16];
+    snprintf(clr, sizeof(clr), "\e[%dm", class_clr);
+    printf("%s%s%s: ", colorize ? clr : "", class, colorize ? "\e[0m" : "");
+
+#if defined(_DEBUG)
+    printf("%s:%d: ", file, lineno);
+#else
+    printf("%s: ", module);
+#endif
+
+    //printf("%%s\n", buf);
+    vprintf(fmt, va);
+    printf("\n");
+}
+
+void
+log_class(enum log_class log_class, const char *module,
+          const char *file, int lineno, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    _log(log_class, module, file, lineno, fmt, ap);
+    va_end(ap);
+}

log.h

@@ -0,0 +1,16 @@
+#pragma once
+
+enum log_class { LOG_CLASS_ERROR, LOG_CLASS_WARNING, LOG_CLASS_INFO, LOG_CLASS_DEBUG };
+
+void log_class(enum log_class log_class, const char *module,
+               const char *file, int lineno,
+               const char *fmt, ...) __attribute__((format (printf, 5, 6)));
+
+#define LOG_ERR(fmt, ...)  \
+    log_class(LOG_CLASS_ERROR, LOG_MODULE, __FILE__, __LINE__, fmt, __VA_ARGS__)
+#define LOG_WARN(fmt, ...)  \
+    log_class(LOG_CLASS_WARNING, LOG_MODULE, __FILE__, __LINE__, fmt, __VA_ARGS__)
+#define LOG_INFO(fmt, ...)  \
+    log_class(LOG_CLASS_INFO, LOG_MODULE, __FILE__, __LINE__, fmt, __VA_ARGS__)
+#define LOG_DBG(fmt, ...)  \
+    log_class(LOG_CLASS_DEBUG, LOG_MODULE, __FILE__, __LINE__, fmt, __VA_ARGS__)