cleanup: Use static_assert instead of preprocessor #error.

`ccompat.h` ensures that if it doesn't exist, then `static_assert` has no
effect.

toxcore/Messenger.c

@@ -24,6 +24,11 @@
 #include "state.h"
 #include "util.h"
 
+//!TOKSTYLE-
+static_assert(MAX_CONCURRENT_FILE_PIPES <= UINT8_MAX + 1,
+              "uint8_t cannot represent all file transfer numbers");
+//!TOKSTYLE+
+
 static int write_cryptpacket_id(const Messenger *m, int32_t friendnumber, uint8_t packet_id, const uint8_t *data,
                                 uint32_t length, uint8_t congestion_control);
 static void m_register_default_plugins(Messenger *m);

toxcore/Messenger.h

@@ -24,10 +24,6 @@
 /* This cannot be bigger than 256 */
 #define MAX_CONCURRENT_FILE_PIPES 256
 
-#if !defined(__SPLINT__) && MAX_CONCURRENT_FILE_PIPES > UINT8_MAX + 1
-#error "uint8_t cannot represent all file transfer numbers"
-#endif
-
 
 #define FRIEND_ADDRESS_SIZE (CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint32_t) + sizeof(uint16_t))
 

toxcore/network.c

@@ -194,13 +194,12 @@ static int inet_pton6(const char *addrString, struct in6_addr *addrbuf)
 #endif
 #endif
 
-#if TOX_INET6_ADDRSTRLEN < INET6_ADDRSTRLEN
+//!TOKSTYLE-
-#error "TOX_INET6_ADDRSTRLEN should be greater or equal to INET6_ADDRSTRLEN (#INET6_ADDRSTRLEN)"
+static_assert(TOX_INET6_ADDRSTRLEN >= INET6_ADDRSTRLEN,
-#endif
+              "TOX_INET6_ADDRSTRLEN should be greater or equal to INET6_ADDRSTRLEN (#INET6_ADDRSTRLEN)");
-
+static_assert(TOX_INET_ADDRSTRLEN >= INET_ADDRSTRLEN,
-#if TOX_INET_ADDRSTRLEN < INET_ADDRSTRLEN
+              "TOX_INET_ADDRSTRLEN should be greater or equal to INET_ADDRSTRLEN (#INET_ADDRSTRLEN)");
-#error "TOX_INET_ADDRSTRLEN should be greater or equal to INET_ADDRSTRLEN (#INET_ADDRSTRLEN)"
+//!TOKSTYLE+
-#endif
 
 static int make_proto(int proto)
 {

toxcore/onion_announce.c

@@ -26,6 +26,11 @@
 #define DATA_REQUEST_MIN_SIZE ONION_DATA_REQUEST_MIN_SIZE
 #define DATA_REQUEST_MIN_SIZE_RECV (DATA_REQUEST_MIN_SIZE + ONION_RETURN_3)
 
+//!TOKSTYLE-
+static_assert(ONION_PING_ID_SIZE == CRYPTO_PUBLIC_KEY_SIZE,
+              "announce response packets assume that ONION_PING_ID_SIZE is equal to CRYPTO_PUBLIC_KEY_SIZE");
+//!TOKSTYLE+
+
 typedef struct Onion_Announce_Entry {
     uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE];
     IP_Port ret_ip_port;

toxcore/onion_announce.h

@@ -25,10 +25,6 @@
 
 #define ONION_DATA_RESPONSE_MIN_SIZE (1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_MAC_SIZE)
 
-#if ONION_PING_ID_SIZE != CRYPTO_PUBLIC_KEY_SIZE
-#error "announce response packets assume that ONION_PING_ID_SIZE is equal to CRYPTO_PUBLIC_KEY_SIZE"
-#endif
-
 #define ONION_DATA_REQUEST_MIN_SIZE (1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_MAC_SIZE)
 #define MAX_DATA_REQUEST_SIZE (ONION_MAX_DATA_SIZE - ONION_DATA_REQUEST_MIN_SIZE)
 

toxcore/tox.c

@@ -32,37 +32,24 @@
 
 #define SET_ERROR_PARAMETER(param, x) do { if (param) { *param = x; } } while (0)
 
-#if TOX_HASH_LENGTH != CRYPTO_SHA256_SIZE
+//!TOKSTYLE-
-#error "TOX_HASH_LENGTH is assumed to be equal to CRYPTO_SHA256_SIZE"
+static_assert(TOX_HASH_LENGTH == CRYPTO_SHA256_SIZE,
-#endif
+              "TOX_HASH_LENGTH is assumed to be equal to CRYPTO_SHA256_SIZE");
-
+static_assert(FILE_ID_LENGTH == CRYPTO_SYMMETRIC_KEY_SIZE,
-#if FILE_ID_LENGTH != CRYPTO_SYMMETRIC_KEY_SIZE
+              "FILE_ID_LENGTH is assumed to be equal to CRYPTO_SYMMETRIC_KEY_SIZE");
-#error "FILE_ID_LENGTH is assumed to be equal to CRYPTO_SYMMETRIC_KEY_SIZE"
+static_assert(TOX_FILE_ID_LENGTH == CRYPTO_SYMMETRIC_KEY_SIZE,
-#endif
+              "TOX_FILE_ID_LENGTH is assumed to be equal to CRYPTO_SYMMETRIC_KEY_SIZE");
-
+static_assert(TOX_FILE_ID_LENGTH == TOX_HASH_LENGTH,
-#if TOX_FILE_ID_LENGTH != CRYPTO_SYMMETRIC_KEY_SIZE
+              "TOX_FILE_ID_LENGTH is assumed to be equal to TOX_HASH_LENGTH");
-#error "TOX_FILE_ID_LENGTH is assumed to be equal to CRYPTO_SYMMETRIC_KEY_SIZE"
+static_assert(TOX_PUBLIC_KEY_SIZE == CRYPTO_PUBLIC_KEY_SIZE,
-#endif
+              "TOX_PUBLIC_KEY_SIZE is assumed to be equal to CRYPTO_PUBLIC_KEY_SIZE");
-
+static_assert(TOX_SECRET_KEY_SIZE == CRYPTO_SECRET_KEY_SIZE,
-#if TOX_FILE_ID_LENGTH != TOX_HASH_LENGTH
+              "TOX_SECRET_KEY_SIZE is assumed to be equal to CRYPTO_SECRET_KEY_SIZE");
-#error "TOX_FILE_ID_LENGTH is assumed to be equal to TOX_HASH_LENGTH"
+static_assert(TOX_MAX_NAME_LENGTH == MAX_NAME_LENGTH,
-#endif
+              "TOX_MAX_NAME_LENGTH is assumed to be equal to MAX_NAME_LENGTH");
-
+static_assert(TOX_MAX_STATUS_MESSAGE_LENGTH == MAX_STATUSMESSAGE_LENGTH,
-#if TOX_PUBLIC_KEY_SIZE != CRYPTO_PUBLIC_KEY_SIZE
+              "TOX_MAX_STATUS_MESSAGE_LENGTH is assumed to be equal to MAX_STATUSMESSAGE_LENGTH");
-#error "TOX_PUBLIC_KEY_SIZE is assumed to be equal to CRYPTO_PUBLIC_KEY_SIZE"
+//!TOKSTYLE+
-#endif
-
-#if TOX_SECRET_KEY_SIZE != CRYPTO_SECRET_KEY_SIZE
-#error "TOX_SECRET_KEY_SIZE is assumed to be equal to CRYPTO_SECRET_KEY_SIZE"
-#endif
-
-#if TOX_MAX_NAME_LENGTH != MAX_NAME_LENGTH
-#error "TOX_MAX_NAME_LENGTH is assumed to be equal to MAX_NAME_LENGTH"
-#endif
-
-#if TOX_MAX_STATUS_MESSAGE_LENGTH != MAX_STATUSMESSAGE_LENGTH
-#error "TOX_MAX_STATUS_MESSAGE_LENGTH is assumed to be equal to MAX_STATUSMESSAGE_LENGTH"
-#endif
 
 struct Tox {
     // XXX: Messenger *must* be the first member, because toxav casts its