codegen: Add foreach support for strings

Fixes https://gitlab.gnome.org/GNOME/vala/issues/108

4 files changed, 80 insertions, 0 deletions

diff --git a/codegen/valaccodecontrolflowmodule.vala b/codegen/valaccodecontrolflowmodule.vala
index 9ecbced2f..9a68579b3 100644
--- a/codegen/valaccodecontrolflowmodule.vala
+++ b/codegen/valaccodecontrolflowmodule.vala
@@ -442,6 +442,40 @@ public abstract class Vala.CCodeControlFlowModule : CCodeMethodModule {
 			stmt.body.emit (this);
 
 			ccode.close ();
+		} else if (stmt.collection.value_type.compatible (string_type)) {
+			// iterating over a string
+
+			var validate = new CCodeFunctionCall (new CCodeIdentifier ("g_utf8_validate"));
+			validate.add_argument (get_variable_cexpression (get_local_cname (collection_backup)));
+			validate.add_argument (new CCodeConstant ("-1"));
+			validate.add_argument (new CCodeConstant ("NULL"));
+			var cassert = new CCodeFunctionCall (new CCodeIdentifier ("_vala_warn_if_fail"));
+			cassert.add_argument (validate);
+			cassert.add_argument (new CCodeConstant ("\"Invalid UTF-8 string\""));
+			requires_assert = true;
+			ccode.add_expression (cassert);
+
+			var iterator_variable = new LocalVariable (collection_type, "%s_iter".printf (stmt.variable_name));
+			visit_local_variable (iterator_variable);
+			var string_iter = get_variable_cname (get_local_cname (iterator_variable));
+
+			var ccond = new CCodeBinaryExpression (CCodeBinaryOperator.INEQUALITY, new CCodeUnaryExpression (CCodeUnaryOperator.POINTER_INDIRECTION, get_variable_cexpression (string_iter)), new CCodeConstant ("'\\0'"));
+			var next_char_call = new CCodeFunctionCall (new CCodeIdentifier ("g_utf8_next_char"));
+			next_char_call.add_argument (get_variable_cexpression (string_iter));
+
+			ccode.open_for (new CCodeAssignment (get_variable_cexpression (string_iter), get_variable_cexpression (collection_backup.name)),
+					ccond,
+					new CCodeAssignment (get_variable_cexpression (string_iter), next_char_call));
+
+			var element_expr = new CCodeFunctionCall (new CCodeIdentifier ("g_utf8_get_char"));
+			element_expr.add_argument (get_variable_cexpression (string_iter));
+
+			visit_local_variable (stmt.element_variable);
+			ccode.add_assignment (get_variable_cexpression (get_local_cname (stmt.element_variable)), element_expr);
+
+			stmt.body.emit (this);
+
+			ccode.close ();
 		} else {
 			Report.error (stmt.source_reference, "internal error: unsupported collection type");
 			stmt.error = true;
diff --git a/tests/control-flow/foreach.c-expected b/tests/control-flow/foreach.c-expected
index c402e1c12..3263a32ef 100644
--- a/tests/control-flow/foreach.c-expected
+++ b/tests/control-flow/foreach.c-expected
@@ -46,6 +46,7 @@ static void _vala_GValue_free_function_content_of (gpointer data);
 VALA_EXTERN void test_foreach_multidim_array (void);
 VALA_EXTERN void test_foreach_const_array (void);
 VALA_EXTERN void test_foreach_slice_array (void);
+VALA_EXTERN void test_foreach_string (void);
 static void _vala_main (void);
 
 const gint FOO[6] = {1, 2, 3, 4, 5, 6};
@@ -669,6 +670,36 @@ test_foreach_slice_array (void)
 	foo = (g_free (foo), NULL);
 }
 
+void
+test_foreach_string (void)
+{
+	guint i = 0U;
+	gchar* s = NULL;
+	gchar* _tmp0_;
+	const gchar* _tmp1_;
+	i = (guint) 0;
+	_tmp0_ = g_strdup ("abc àçêö 你好");
+	s = _tmp0_;
+	_tmp1_ = s;
+	{
+		const gchar* c_collection = NULL;
+		const gchar* c_iter = NULL;
+		c_collection = _tmp1_;
+		_vala_warn_if_fail (g_utf8_validate (c_collection, -1, NULL), "Invalid UTF-8 string");
+		for (c_iter = c_collection; (*c_iter) != '\0'; c_iter = g_utf8_next_char (c_iter)) {
+			gunichar c = 0U;
+			c = g_utf8_get_char (c_iter);
+			{
+				guint _tmp2_;
+				_tmp2_ = i;
+				i = _tmp2_ + 1;
+			}
+		}
+	}
+	_vala_assert (i == ((guint) 11), "i == 11");
+	_g_free0 (s);
+}
+
 static void
 _vala_main (void)
 {
@@ -679,6 +710,7 @@ _vala_main (void)
 	test_foreach_const_array ();
 	test_foreach_multidim_array ();
 	test_foreach_slice_array ();
+	test_foreach_string ();
 }
 
 int
diff --git a/tests/control-flow/foreach.vala b/tests/control-flow/foreach.vala
index 8689a18ad..83cef663a 100644
--- a/tests/control-flow/foreach.vala
+++ b/tests/control-flow/foreach.vala
@@ -173,6 +173,17 @@ void test_foreach_slice_array () {
 	assert (result == "2345");
 }
 
+void test_foreach_string () {
+	uint i = 0;
+	string s = "abc àçêö 你好"; // Ni hao
+
+	foreach (unichar c in s) {
+		i++;
+	}
+
+	assert (i == 11);
+}
+
 void main () {
 	test_foreach_gvaluearray ();
 	test_foreach_garray ();
@@ -181,4 +192,5 @@ void main () {
 	test_foreach_const_array ();
 	test_foreach_multidim_array ();
 	test_foreach_slice_array ();
+	test_foreach_string ();
 }
diff --git a/vala/valaforeachstatement.vala b/vala/valaforeachstatement.vala
index 84370e5b0..69d49eccb 100644
--- a/vala/valaforeachstatement.vala
+++ b/vala/valaforeachstatement.vala
@@ -194,6 +194,8 @@ public class Vala.ForeachStatement : Block {
 			return check_without_iterator (context, collection_type, collection_type.get_type_arguments ().get (0));
 		} else if (context.profile == Profile.GOBJECT && collection_type.compatible (context.analyzer.gvaluearray_type)) {
 			return check_without_iterator (context, collection_type, context.analyzer.gvalue_type);
+		} else if (context.profile == Profile.GOBJECT && collection_type.compatible (context.analyzer.string_type)) {
+			return check_without_iterator (context, collection_type, context.analyzer.unichar_type);
 		} else {
 			return check_with_iterator (context, collection_type);
 		}