cgen: fix a buggy comparison, add ability to do println(sym.debug())

vlib/v/checker/comparing_typesymbol_to_a_type_should_not_compile.vv

@@ -0,0 +1,17 @@
+import v.table
+
+fn main() {
+	t := table.new_table()
+	ityp := table.int_type
+	isym := t.get_type_symbol(ityp)
+	println(ityp.debug())
+	println(isym)
+	println(isym.debug())
+	x := ityp == table.string_type
+	// the next line should produce at least a warning, or even an error, without an explicit cast:
+	z := isym == table.string_type
+	println(typeof(isym))
+	println(typeof(table.string_type))
+	println(x)
+	println(z)
+}

vlib/v/gen/cgen.v

@@ -1678,7 +1678,7 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 						if left.left_type.is_ptr() {
 							g.write('*')
 						}
-						needs_clone := elem_typ == table.string_type && g.pref.autofree
+						needs_clone := info.elem_type == table.string_type && g.pref.autofree
 						if needs_clone {
 							g.write('/*1*/string_clone(')
 						}

vlib/v/table/types.v

@@ -183,6 +183,21 @@ pub fn (t Type) has_flag(flag TypeFlag) bool {
 	return int(t) & (1 << (int(flag) + 24)) > 0
 }
 
+pub fn (ts TypeSymbol) debug() []string {
+	mut res := []string{}
+	res << 'parent_idx: $ts.parent_idx'
+	res << 'mod: $ts.mod'
+	res << 'name: $ts.name'
+	res << 'source_name: $ts.source_name'
+	res << 'info: $ts.info'
+	res << 'kind: $ts.kind'
+	res << 'is_public: $ts.is_public'
+	res << 'is_written: $ts.is_written'
+	res << 'language: $ts.language'
+	res << 'methods ($ts.methods.len): ' + ts.methods.map(it.str()).join(', ')
+	return res
+}
+
 pub fn (t Type) debug() []string {
 	mut res := []string{}
 	res << 'idx: ${t.idx():5}'