cgen: fix array_sort_by_references (fix #8390) (#8403)

vlib/v/gen/array.v

@@ -253,17 +253,18 @@ fn (mut g Gen) gen_array_sort(node ast.CallExpr) {
 		// `users.sort(a.age > b.age)`
 		// Generate a comparison function for a custom type
 		tmp_name := g.new_tmp_var()
-		compare_fn = 'compare_${tmp_name}_' + g.typ(typ)
+		styp := g.typ(typ).trim('*')
+		compare_fn = 'compare_${tmp_name}_$styp'
 		if is_reverse {
 			compare_fn += '_reverse'
 		}
 		// Register a new custom `compare_xxx` function for qsort()
 		g.table.register_fn(name: compare_fn, return_type: table.int_type)
 		infix_expr := node.args[0].expr as ast.InfixExpr
-		styp := g.typ(typ)
 		// Variables `a` and `b` are used in the `.sort(a < b)` syntax, so we can reuse them
 		// when generating the function as long as the args are named the same.
-		g.definitions.writeln('int $compare_fn ($styp* a, $styp* b) {')
+		styp_arg := g.typ(typ)
+		g.definitions.writeln('int $compare_fn ($styp_arg* a, $styp_arg* b) {')
 		sym := g.table.get_type_symbol(typ)
 		if !is_reverse && sym.has_method('<') && infix_expr.left.str().len == 1 {
 			g.definitions.writeln('\tif (${styp}__lt(*a, *b)) { return -1; } else { return 1; }}')
@@ -271,8 +272,12 @@ fn (mut g Gen) gen_array_sort(node ast.CallExpr) {
 			g.definitions.writeln('\tif (${styp}__gt(*a, *b)) { return -1; } else { return 1; }}')
 		} else {
 			field_type := g.typ(infix_expr.left_type)
-			left_expr_str := g.write_expr_to_string(infix_expr.left)
+			mut left_expr_str := g.write_expr_to_string(infix_expr.left)
-			right_expr_str := g.write_expr_to_string(infix_expr.right)
+			mut right_expr_str := g.write_expr_to_string(infix_expr.right)
+			if typ.is_ptr() {
+				left_expr_str = left_expr_str.replace_once('a', '(*a)')
+				right_expr_str = right_expr_str.replace_once('b', '(*b)')
+			}
 			g.definitions.writeln('$field_type a_ = $left_expr_str;')
 			g.definitions.writeln('$field_type b_ = $right_expr_str;')
 			mut op1, mut op2 := '', ''

vlib/v/tests/sorting_by_references_test.v

@@ -0,0 +1,22 @@
+struct Container {
+mut:
+	name string
+}
+
+fn test_array_sort_by_references() {
+	mut a := []&Container{}
+
+	a << &Container{ name: 'a' }
+	a << &Container{ name: 'b' }
+	a << &Container{ name: 'c' }
+	a << &Container{ name: 'd' }
+	a << &Container{ name: 'e' }
+
+	a.sort(a.name > b.name)
+	println(a)
+	assert a[0].name == 'e'
+	assert a[1].name == 'd'
+	assert a[2].name == 'c'
+	assert a[3].name == 'b'
+	assert a[4].name == 'a'
+}