[libc] ensure bool, true and false are not macros when in C++ mode

share/libc/stdbool.h

@@ -22,8 +22,11 @@
 
 #ifndef __FC_STDBOOL
 #define __FC_STDBOOL
+// In C++, bool, true and false are native values
+#ifndef __cplusplus
 #define bool _Bool
 #define true 1
 #define false 0
+#endif
 #define __bool_true_false_are_defined 1
 #endif

tests/libc/oracle/stdbool_as_cpp.res.oracle

+[kernel] Parsing tests/libc/stdbool_as_cpp.c (with preprocessing)
+/* Generated by Frama-C */
+int main(void)
+{
+  int __retres;
+  __retres = 0;
+  return __retres;
+}
+
+

tests/libc/stdbool_as_cpp.c

+/* run.config*
+OPT: -print
+*/
+// announce that we are a non-conforming C++ compiler
+#define __cplusplus 1L
+#include <stdbool.h>
+#ifdef bool
+#error bool should not be defined in C++ mode
+#endif
+#ifdef true
+#error true should not be defined in C++ mode
+#endif
+#ifdef false
+#error false should not be defined in C++ mode
+#endif
+int main() { return 0; }