Use bool literal in while loop

This avoids some warnings when converting an int to a bool.

Author: romainbrenguier

src/util/invariant.h

@@ -202,19 +202,21 @@ inline void invariant_violated_string(
 #define __this_function__ __func__
 #endif
 
-#define INVARIANT(CONDITION, REASON) \
-  do /* NOLINT */ \
-  { \
-  if(!(CONDITION)) \
-    invariant_violated_string(__FILE__, __this_function__, __LINE__, (REASON)); /* NOLINT */  \
-  } while(0)
+#define INVARIANT(CONDITION, REASON)                                           \
+  do /* NOLINT */                                                              \
+  {                                                                            \
+    if(!(CONDITION))                                                           \
+      invariant_violated_string(                                               \
+        __FILE__, __this_function__, __LINE__, (REASON)); /* NOLINT */         \
+  } while(false)
 
-#define INVARIANT_STRUCTURED(CONDITION, TYPENAME, ...) \
-  do /* NOLINT */ \
-  { \
-  if(!(CONDITION)) \
-    invariant_violated_structured<TYPENAME>(__FILE__, __this_function__, __LINE__, __VA_ARGS__); /* NOLINT */ \
-  } while(0)
+#define INVARIANT_STRUCTURED(CONDITION, TYPENAME, ...)                         \
+  do /* NOLINT */                                                              \
+  {                                                                            \
+    if(!(CONDITION))                                                           \
+      invariant_violated_structured<TYPENAME>(                                 \
+        __FILE__, __this_function__, __LINE__, __VA_ARGS__); /* NOLINT */      \
+  } while(false)
 
 #endif // End CPROVER_DO_NOT_CHECK / CPROVER_ASSERT / ... if block