cgen: fix chan autostr (fix #26337) (#26338)

Author: kbkpbot

vlib/sync/channels.c.v

@@ -118,10 +118,6 @@ fn new_channel_st_noscan(n u32, st u32) &Channel {
 	}
 }
 
-pub fn (ch &Channel) auto_str(typename string) string {
-	return 'chan ${typename}{cap: ${ch.cap}, closed: ${ch.closed}}'
-}
-
 pub fn (mut ch Channel) close() {
 	open_val := u16(0)
 	if !C.atomic_compare_exchange_strong_u16(&ch.closed, &open_val, 1) {

vlib/v/gen/c/auto_str_methods.v

@@ -565,7 +565,27 @@ fn (mut g Gen) gen_str_for_chan(info ast.Chan, styp string, str_fn_name string)
 	}
 	elem_type_name := util.strip_main_name(g.table.get_type_name(g.unwrap_generic(info.elem_type)))
 	g.definitions.writeln('${g.static_non_parallel}string ${str_fn_name}(${styp} x);')
-	g.auto_str_funcs.writeln('${g.static_non_parallel}string ${str_fn_name}(${styp} x) { return sync__Channel_auto_str(x, _S("${elem_type_name}")); }')
+	g.auto_str_funcs.writeln('${g.static_non_parallel}string ${str_fn_name}(${styp} x) { return indent_${str_fn_name}(x, 0);}')
+	g.definitions.writeln('${g.static_non_parallel}string indent_${str_fn_name}(${styp} x, ${ast.int_type_name} indent_count);')
+	g.auto_str_funcs.writeln('${g.static_non_parallel}string indent_${str_fn_name}(${styp} x, ${ast.int_type_name} indent_count) {')
+	g.auto_str_funcs.writeln('\tstring indents = builtin__string_repeat(_S("    "), indent_count);')
+	g.auto_str_funcs.writeln('\tstrings__Builder sb = strings__new_builder(64);')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("chan "));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("${elem_type_name}"));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("{\\n"));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, indents);')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("    cap: "));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, builtin__int_str(x->cap));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S(", closed: "));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, x->closed != 0 ? _S("true") : _S("false"));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("\\n"));')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, indents);')
+	g.auto_str_funcs.writeln('\tstrings__Builder_write_string(&sb, _S("}"));')
+	g.auto_str_funcs.writeln('\tstring res = strings__Builder_str(&sb);')
+	g.auto_str_funcs.writeln('\tstrings__Builder_free(&sb);')
+	g.auto_str_funcs.writeln('\tbuiltin__string_free(&indents);')
+	g.auto_str_funcs.writeln('\treturn res;')
+	g.auto_str_funcs.writeln('}')
 }
 
 fn (mut g Gen) gen_str_for_thread(info ast.Thread, styp string, str_fn_name string) {
@@ -1265,7 +1285,7 @@ fn data_str(x StrIntpType) string {
 }
 
 fn should_use_indent_func(kind ast.Kind) bool {
-	return kind in [.struct, .alias, .array, .array_fixed, .map, .sum_type, .interface]
+	return kind in [.struct, .alias, .array, .array_fixed, .map, .sum_type, .interface, .chan]
 }
 
 fn (mut g Gen) get_enum_type_idx_from_fn_name(fn_name string) (string, int) {

vlib/v/tests/concurrency/channels_test.v

@@ -21,11 +21,11 @@ fn test_printing_of_channels() {
 	res := (spawn fn1(ch)).wait()
 	println(res)
 	println(ch)
-	assert res.str().contains('another: chan f64{cap: 100, closed: 0}')
-	assert ch.str() == 'chan St1{cap: 10, closed: 0}'
-	assert fch.str() == 'chan f64{cap: 100, closed: 0}'
+	assert res.str().contains('another: chan f64{\n        cap: 100, closed: false\n    }')
+	assert ch.str() == 'chan St1{\n    cap: 10, closed: false\n}'
+	assert fch.str() == 'chan f64{\n    cap: 100, closed: false\n}'
 	fch.close()
-	assert fch.str() == 'chan f64{cap: 100, closed: 1}'
+	assert fch.str() == 'chan f64{\n    cap: 100, closed: true\n}'
 }
 
 struct Aa {}