cgen: fix address violations for error propagation (#7972)

vlib/sync/channel_opt_propagate_test.v

@@ -4,13 +4,13 @@ const (
 	num_iterations = 10000
 )
 
-fn get_val_from_chan(ch chan int) ?int {
+fn get_val_from_chan(ch chan i64) ?i64 {
 	r := <-ch ?
 	return r
 }
 
-// this function gets an array of channels for `int`
+// this function gets an array of channels for `i64`
-fn do_rec_calc_send(chs []chan int, sem sync.Semaphore) {
+fn do_rec_calc_send(chs []chan i64, sem sync.Semaphore) {
 	mut msg := ''
 	for {
 		mut s := get_val_from_chan(chs[0]) or {
@@ -25,10 +25,10 @@ fn do_rec_calc_send(chs []chan int, sem sync.Semaphore) {
 }
 
 fn test_channel_array_mut() {
-	mut chs := [chan int{}, chan int{cap: 10}]
+	mut chs := [chan i64{}, chan i64{cap: 10}]
 	sem := sync.new_semaphore()
 	go do_rec_calc_send(chs, sem)
-	mut t := int(100)
+	mut t := i64(100)
 	for _ in 0 .. num_iterations {
 		chs[0] <- t
 		t = <-chs[1]

vlib/sync/channel_push_or_2_test.v

@@ -1,27 +1,27 @@
 const n = 1000
 
-fn f(ch chan int) {
+fn f(ch chan f64) {
-	mut s := 0
+	mut s := 0.
 	for _ in 0 .. n {
 		s += <-ch
 	}
-	assert s == n * (n + 1) / 2
+	assert s == f64(n * (n + 1) / 2)
 	ch.close()
 }
 
-fn do_send(ch chan int, val int) ?int {
+fn do_send(ch chan f64, val f64) ?f64 {
 	ch <- val ?
-	return val + 1
+	return val + 1.0
 }
 
 fn test_push_propargate() {
-	ch := chan int{}
+	ch := chan f64{}
 	go f(ch)
-	mut s := 1
+	mut s := 1.0
 	for {
 		s = do_send(ch, s) or {
 			break
 		}
 	}
-	assert s == n + 1
+	assert s == f64(n + 1)
 }

vlib/v/gen/cgen.v

@@ -5045,7 +5045,10 @@ fn (mut g Gen) or_block(var_name string, or_block ast.OrExpr, return_type table.
 			g.write_defer_stmts()
 			// Now that option types are distinct we need a cast here
 			styp := g.typ(g.fn_decl.return_type)
-			g.writeln('\treturn *($styp *)&$cvar_name;')
+			err_obj := g.new_tmp_var()
+			g.writeln('\t$styp $err_obj;')
+			g.writeln('\tmemcpy(&$err_obj, &$cvar_name, sizeof(Option));')
+			g.writeln('\treturn $err_obj;')
 		}
 	}
 	g.write('}')