[common] provide debug print methods for dependent libraries to use

common/CMakeLists.txt

@@ -34,6 +34,7 @@ set(COMMON_SOURCES
   src/ringbuffer.c
   src/vector.c
   src/cpuinfo.c
+  src/debug.c
 )
 
 add_library(lg_common STATIC ${COMMON_SOURCES})

common/include/common/debug.h

@@ -131,4 +131,13 @@ void printBacktrace(void);
   #define DEBUG_PROTO(fmt, ...) do {} while(0)
 #endif
 
+void debug_info(const char * file, unsigned int line, const char * function,
+    const char * format, ...) __attribute__((format (printf, 4, 5)));
+
+void debug_warn(const char * file, unsigned int line, const char * function,
+    const char * format, ...) __attribute__((format (printf, 4, 5)));
+
+void debug_error(const char * file, unsigned int line, const char * function,
+    const char * format, ...) __attribute__((format (printf, 4, 5)));
+
 #endif

common/src/debug.c

@@ -0,0 +1,63 @@
+/* Looking Glass
+ * Copyright © 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "common/debug.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+inline static void debug_level(enum DebugLevel level, const char * file,
+    unsigned int line, const char * function, const char * format, va_list va)
+{
+  const char * f = strrchr(file, DIRECTORY_SEPARATOR) + 1;
+  fprintf(stderr, "%s%12" PRId64 "%20s:%-4u | %-30s | ",
+      debug_lookup[level], microtime(), f,
+      line, function);
+  vfprintf(stderr, format, va);
+  fprintf(stderr, "%s\n", debug_lookup[DEBUG_LEVEL_NONE]);
+}
+
+
+void debug_info(const char * file, unsigned int line, const char * function,
+    const char * format, ...)
+{
+  va_list va;
+  va_start(va, format);
+  debug_level(DEBUG_LEVEL_INFO, file, line, function, format, va);
+  va_end(va);
+}
+
+void debug_warn(const char * file, unsigned int line, const char * function,
+    const char * format, ...)
+{
+  va_list va;
+  va_start(va, format);
+  debug_level(DEBUG_LEVEL_WARN, file, line, function, format, va);
+  va_end(va);
+}
+
+void debug_error(const char * file, unsigned int line, const char * function,
+    const char * format, ...)
+{
+  va_list va;
+  va_start(va, format);
+  debug_level(DEBUG_LEVEL_ERROR, file, line, function, format, va);
+  va_end(va);
+}