compiler_archs: gcc: Require gcc to retain variable order

Author: shaymargolis

shellblocks/compiler_archs/gcc.py

@@ -17,6 +17,7 @@ def get_gcc_flags(self):
         return [
             "-nostdlib",
             "-ffreestanding",
+            "-fno-toplevel-reorder",
         ]
 
     def compile_primitive(self, src_path: str) -> [str]:

shellblocks/src/memset.c

@@ -2,11 +2,6 @@
 #include "arch/utils.h"
 #include "memset.h"
 
-// Must be the first variable
-DECLARE_NOP_END(nop_end);
-
-const u8 items[] REL_ACCESS_STRING = MEMSET_ITEMS;
-
 void start(void) {
     u8 *items_rel;
 
@@ -23,3 +18,8 @@ void start(void) {
 
     JUMP_TO_NOP_END(nop_end);
 }
+
+const u8 items[] REL_ACCESS_STRING = MEMSET_ITEMS;
+
+// Must be the last variable
+DECLARE_NOP_END(nop_end);

shellblocks/src/print.c

@@ -2,11 +2,6 @@
 #include "arch/utils.h"
 #include "print.h"
 
-// Must be the first variable
-DECLARE_NOP_END(nop_end);
-
-const char print_string[] REL_ACCESS_STRING = PRINT_STRING;
-
 void start(void) {
     void (*print_func)(const char *) = (void (*)(const char *))PRINT_FUNCTION_ADDRESS;
     char *print_string_rel;
@@ -16,3 +11,8 @@ void start(void) {
 
     JUMP_TO_NOP_END(nop_end);
 }
+
+const char print_string[] REL_ACCESS_STRING = PRINT_STRING;
+
+// Must be the last variable
+DECLARE_NOP_END(nop_end);