Move DEBUG macro to own header to be a standalone helper

checkrt.c

@@ -18,6 +18,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
+#include "debug.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -47,7 +48,6 @@
 
 char *optional = NULL;
 char *optional_ld_preload = NULL;
-int debug_flag = 0;
 
 void checkrt(char *usr_in_appdir)
 {
@@ -63,8 +63,6 @@ void checkrt(char *usr_in_appdir)
     char *gcc_bundle_lib = "./" GCCDIR "/libgcc_s.so.1";
     const char *format = "tr '\\0' '\\n' < '%s' | grep -e '%s' | tail -n1";
 
-    debug_flag = getenv("APPIMAGE_CHECKRT_DEBUG") ? 1 : 0;
-
     if (access(stdcxx_bundle_lib, F_OK) == 0) {
         f = popen("ldconfig -p | grep 'libstdc++.so.6 (" LIBC6_ARCH ")' | awk 'NR==1{print $NF}'", "r");
         ret = fscanf(f, "%s", stdcxx_sys_lib); (void)ret;

checkrt.h

@@ -1,9 +1,8 @@
+#ifndef CHEKRT_H
+#define CHECKRT_H
+
 extern char *optional;
 extern char *optional_ld_preload;
 extern void checkrt(char *usr_in_appdir);
-extern int debug_flag;
 
-#define DEBUG(...) do { \
-    if (debug_flag) \
-        printf(__VA_ARGS__); \
-} while (0)
+#endif

debug.h

@@ -0,0 +1,11 @@
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include <stdlib.h>
+
+#define DEBUG(...) do { \
+    if (getenv("APPIMAGE_CHECKRT_DEBUG")) \
+        printf(__VA_ARGS__); \
+} while (0)
+
+#endif // DEBUG_H

exec.c

@@ -42,7 +42,7 @@ variable (e.g. "PATH"):
 
 #define _GNU_SOURCE
 
-#include "checkrt.h"
+#include "debug.h"
 
 #include <unistd.h>
 #include <dlfcn.h>