Bump C std version to 11, and use static_assert

Makefile

@@ -2,7 +2,7 @@ MultiThread = Yes
 
 PROGNAME = torrent-verify
 CC = cc
-CFLAGS = -Wall -std=gnu99 -I./subm/heapless-bencode -Werror -O3
+CFLAGS = -Wall -std=gnu11 -I./subm/heapless-bencode -Werror -O3
 CPPFLAGS = -DPROGRAM_NAME='"$(PROGNAME)"' -DBUILD_INFO \
 		   -DBUILD_HASH="\"`git rev-parse --abbrev-ref HEAD` -> `git rev-parse --short HEAD`\"" -DBUILD_DATE="\"`date -I`\""
 

src/main.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <assert.h>
 #include "metainfo.h"
 #include "verify.h"
 #include "showinfo.h"
@@ -11,6 +12,8 @@
 #define PROGRAM_NAME "torrent-verify"
 #endif
 
+static_assert((sizeof(long long) >= 8), "Size of long long is less than 8, cannot compile");
+
 void usage() {
     fprintf(stderr, "Usage: " PROGRAM_NAME " [-h | -i | -s] [-n] [-v data_path] [--] .torrent_file...\n");
     exit(EXIT_FAILURE);
@@ -43,11 +46,6 @@ BUILD_HASH " (" BUILD_DATE ")\n"
 }
 
 int main(int argc, char** argv) {
-    if (sizeof(long int) < 8) {
-        fprintf(stderr, "long int is less than 8 bytes. Create an issue please.\n");
-        exit(1);
-    }
-    
     if (opts_parse(argc, argv) == -1)
         usage();