Fix fallthrough test on macOS

tests/output/c-backend/fallthrough.c

@@ -10,12 +10,12 @@ int func(int arg)
 #line 9 "/home/novikov/work/cif/tests/input/c-backend/fallthrough.c"
     case 2:;
     ret += 20;
-    goto ldv_1320;
+    goto ldv_1;
     default:;
-    goto ldv_1320;
+    goto ldv_1;
   }
 #line 16 "/home/novikov/work/cif/tests/input/c-backend/fallthrough.c"
-  ldv_1320:;
+  ldv_1:;
 #line 16 "/home/novikov/work/cif/tests/input/c-backend/fallthrough.c"
   return ret;
 }

tests/test_c_backend.py

@@ -138,6 +138,7 @@ def test_may_alias(self):
 
     def test_fallthrough(self):
         self.cif.run(cif_input='input/c-backend/fallthrough.c', stage='C-backend', cif_output='work/fallthrough.c')
+        self.replace_gotos('work/fallthrough.c')
         self.compare(output='work/fallthrough.c', expected='output/c-backend/fallthrough.c')
 
     def test___func__(self):

tests/utils.py

@@ -1,4 +1,5 @@
 import os
+import re
 import subprocess
 import shutil
 import unittest
@@ -93,6 +94,36 @@ def skip_os_specific_defines(self, output):
                 if not line.startswith('/usr/include/stdc-predef.h'):
                     fp.write(line)
 
+    def replace_gotos(self, output):
+        self.check_cif_status()
+
+        with open(output) as fp:
+            lines = fp.readlines()
+
+        goto_ids = dict()
+        counter = 1
+        for line in lines:
+            m = re.search(r"goto ldv_(\d*);", line)
+
+            if not m:
+                continue
+
+            old_id = m.group(1)
+
+            if old_id not in goto_ids:
+                goto_ids[old_id] = str(counter)
+                counter += 1
+
+        with open(output, 'w') as fp:
+            for line in lines:
+                m = re.search(r"ldv_(\d*)[;:]", line)
+
+                if m:
+                    old_id = m.group(1)
+                    line = line.replace(old_id, goto_ids[old_id])
+
+                fp.write(line)
+
     def make_relpath(self, output):
         with open(output) as fp:
             lines = fp.readlines()