add some ATTR_* (mostly)

mostly ATTR_PRINTFLIKE(*, 0) for functions with a va_list argument.

also, one ATTR_NORETURN and one ATTR_UNUSED, both on functions.

also, an explicit suppression for a format string stored in a variable.

src/common.h

@@ -122,8 +122,8 @@ void stats( void );
 
 /* util.c */
 
-void vdebug( int, const char *, va_list va );
-void vdebugn( int, const char *, va_list va );
+void ATTR_PRINTFLIKE(2, 0) vdebug( int, const char *, va_list va );
+void ATTR_PRINTFLIKE(2, 0) vdebugn( int, const char *, va_list va );
 void ATTR_PRINTFLIKE(1, 2) info( const char *, ... );
 void ATTR_PRINTFLIKE(1, 2) infon( const char *, ... );
 void ATTR_PRINTFLIKE(1, 2) progress( const char *, ... );
@@ -163,7 +163,7 @@ void *nfcalloc( size_t sz );
 void *nfrealloc( void *mem, size_t sz );
 char *nfstrndup( const char *str, size_t nchars );
 char *nfstrdup( const char *str );
-int nfvasprintf( char **str, const char *fmt, va_list va );
+int ATTR_PRINTFLIKE(2, 0) nfvasprintf( char **str, const char *fmt, va_list va );
 int ATTR_PRINTFLIKE(2, 3) nfasprintf( char **str, const char *fmt, ... );
 int ATTR_PRINTFLIKE(3, 4) nfsnprintf( char *buf, int blen, const char *fmt, ... );
 void ATTR_NORETURN oob( void );
@@ -244,7 +244,7 @@ typedef struct {
 void init_wakeup( wakeup_t *tmr, void (*cb)( void * ), void *aux );
 void conf_wakeup( wakeup_t *tmr, int timeout );
 void wipe_wakeup( wakeup_t *tmr );
-static INLINE int pending_wakeup( wakeup_t *tmr ) { return tmr->links.next != 0; }
+static INLINE int ATTR_UNUSED pending_wakeup( wakeup_t *tmr ) { return tmr->links.next != 0; }
 
 void main_loop( void );
 

src/drv_imap.c

@@ -306,8 +306,11 @@ send_imap_cmd( imap_store_t *ctx, imap_cmd_t *cmd )
 		buffmt = "%d %s{%d+}\r\n";
 		litplus = 1;
 	}
+DIAG_PUSH
+DIAG_DISABLE("-Wformat-nonliteral")
 	bufl = nfsnprintf( buf, sizeof(buf), buffmt,
 	                   cmd->tag, cmd->cmd, cmd->param.data_len );
+DIAG_POP
 	if (DFlags & DEBUG_NET) {
 		if (ctx->num_in_progress)
 			printf( "(%d in progress) ", ctx->num_in_progress );

src/main.c

@@ -136,7 +136,7 @@ debug( const char *msg, ... )
 }
 
 #ifdef __linux__
-static void
+static void ATTR_NORETURN
 crashHandler( int n )
 {
 	int dpid;

src/sync.c

@@ -74,7 +74,7 @@ Fclose( FILE *f, int safe )
 	}
 }
 
-void
+void ATTR_PRINTFLIKE(2, 0)
 vFprintf( FILE *f, const char *msg, va_list va )
 {
 	int r;
@@ -86,7 +86,7 @@ vFprintf( FILE *f, const char *msg, va_list va )
 	}
 }
 
-void
+void ATTR_PRINTFLIKE(2, 3)
 Fprintf( FILE *f, const char *msg, ... )
 {
 	va_list va;
@@ -217,7 +217,7 @@ static int check_cancel( sync_vars_t *svars );
 #define ST_SENDING_NEW     (1<<15)
 
 
-void
+void ATTR_PRINTFLIKE(2, 3)
 jFprintf( sync_vars_t *svars, const char *msg, ... )
 {
 	va_list va;

src/util.c

@@ -42,7 +42,7 @@ flushn( void )
 	}
 }
 
-static void
+static void ATTR_PRINTFLIKE(1, 0)
 printn( const char *msg, va_list va )
 {
 	if (*msg == '\v')