Test assumptions we make about the platform
Things that are not guaranteed by the standard but should be true of all
platforms of interest to us:
- 8-bit chars
- NULL pointers represented by all-bits-zero
diff --git a/programs/test/selftest.c b/programs/test/selftest.c
index 902225e..5c1d354 100644
--- a/programs/test/selftest.c
+++ b/programs/test/selftest.c
@@ -72,6 +72,19 @@
#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
unsigned char buf[1000000];
#endif
+ void *pointer;
+
+ /*
+ * The C standard doesn't guarantee that all-bits-0 is the representation
+ * of a NULL pointer. We do however use that in our code for initializing
+ * structures, which should work on every modern platform. Let's be sure.
+ */
+ memset( &pointer, 0, sizeof( void * ) );
+ if( pointer != NULL )
+ {
+ mbedtls_printf( "all-bits-zero is not a NULL pointer\n" );
+ return( 1 );
+ }
if( argc == 2 && strcmp( argv[1], "-quiet" ) == 0 )
v = 0;
