vala: Fix assignment operators for element access

This transforms an assignment to element access other than `=' to a
binary expression i.e. `a[b] += 1' will become `a.set(a.get(b) + 1)'

Fixes https://gitlab.gnome.org/GNOME/vala/issues/135

3 files changed, 176 insertions, 0 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index b93d4963c..4536dcb3b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1045,6 +1045,7 @@ TESTS = \
 	semantic/array-length-nullable.test \
 	semantic/array-too-few-type-arguments.test \
 	semantic/array-too-many-type-arguments.test \
+	semantic/assignment-element-getter-setter.vala \
 	semantic/assignment-element-incompatible-ownership.test \
 	semantic/assignment-element-incompatible-type.test \
 	semantic/assignment-fixed-array-length.test \
diff --git a/tests/semantic/assignment-element-getter-setter.c-expected b/tests/semantic/assignment-element-getter-setter.c-expected
new file mode 100644
index 000000000..b0abb879d
--- /dev/null
+++ b/tests/semantic/assignment-element-getter-setter.c-expected
@@ -0,0 +1,140 @@
+/* semantic_assignment_element_getter_setter.c generated by valac, the Vala compiler
+ * generated from semantic_assignment_element_getter_setter.vala, do not modify */
+
+#include <glib.h>
+
+#if !defined(VALA_EXTERN)
+#if defined(_MSC_VER)
+#define VALA_EXTERN __declspec(dllexport) extern
+#elif __GNUC__ >= 4
+#define VALA_EXTERN __attribute__((visibility("default"))) extern
+#else
+#define VALA_EXTERN extern
+#endif
+#endif
+
+typedef struct _Foo Foo;
+#define _foo_free0(var) ((var == NULL) ? NULL : (var = (foo_free (var), NULL)))
+#define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+#define _vala_return_if_fail(expr, msg) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return; }
+#define _vala_return_val_if_fail(expr, msg, val) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return val; }
+#define _vala_warn_if_fail(expr, msg) if G_LIKELY (expr) ; else g_warn_message (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+
+struct _Foo {
+	gpointer* elements;
+	gint elements_length1;
+};
+
+VALA_EXTERN void foo_free (Foo * self);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Foo, foo_free)
+static void foo_instance_init (Foo * self);
+VALA_EXTERN Foo* foo_new (void);
+VALA_EXTERN gpointer foo_get (Foo* self,
+                  gint idx);
+VALA_EXTERN void foo_set (Foo* self,
+              gint idx,
+              gconstpointer val);
+static void _vala_main (void);
+
+Foo*
+foo_new (void)
+{
+	Foo* self;
+	gpointer* _tmp0_;
+	self = g_slice_new0 (Foo);
+	foo_instance_init (self);
+	_tmp0_ = g_new0 (gpointer, 1);
+	_tmp0_[0] = NULL;
+	self->elements = (g_free (self->elements), NULL);
+	self->elements = _tmp0_;
+	self->elements_length1 = 1;
+	return self;
+}
+
+gpointer
+foo_get (Foo* self,
+         gint idx)
+{
+	gpointer* _tmp0_;
+	gint _tmp0__length1;
+	gconstpointer _tmp1_;
+	gpointer result;
+	g_return_val_if_fail (self != NULL, NULL);
+	_tmp0_ = self->elements;
+	_tmp0__length1 = self->elements_length1;
+	_tmp1_ = _tmp0_[idx];
+	result = _tmp1_;
+	return result;
+}
+
+void
+foo_set (Foo* self,
+         gint idx,
+         gconstpointer val)
+{
+	gpointer* _tmp0_;
+	gint _tmp0__length1;
+	g_return_if_fail (self != NULL);
+	_tmp0_ = self->elements;
+	_tmp0__length1 = self->elements_length1;
+	_tmp0_[idx] = val;
+}
+
+static void
+foo_instance_init (Foo * self)
+{
+}
+
+void
+foo_free (Foo * self)
+{
+	self->elements = (g_free (self->elements), NULL);
+	g_slice_free (Foo, self);
+}
+
+static void
+_vala_main (void)
+{
+	Foo* foo = NULL;
+	Foo* _tmp0_;
+	gpointer _tmp1_;
+	gpointer _tmp2_;
+	gpointer _tmp3_;
+	gpointer _tmp4_;
+	gpointer _tmp5_;
+	gpointer _tmp6_;
+	gpointer _tmp7_;
+	gpointer _tmp8_;
+	gpointer _tmp9_;
+	_tmp0_ = foo_new ();
+	foo = _tmp0_;
+	foo_set (foo, 0, (gpointer) ((gintptr) 23));
+	_tmp1_ = foo_get (foo, 0);
+	_vala_assert (((gint) ((gintptr) _tmp1_)) == 23, "foo[0] == 23");
+	_tmp2_ = foo_get (foo, 0);
+	foo_set (foo, 0, (gpointer) ((gintptr) (((gint) ((gintptr) _tmp2_)) + 42)));
+	_tmp3_ = foo_get (foo, 0);
+	_vala_assert (((gint) ((gintptr) _tmp3_)) == 65, "foo[0] == 65");
+	_tmp4_ = foo_get (foo, 0);
+	foo_set (foo, 0, (gpointer) ((gintptr) (((gint) ((gintptr) _tmp4_)) * 2)));
+	_tmp5_ = foo_get (foo, 0);
+	_vala_assert (((gint) ((gintptr) _tmp5_)) == 130, "foo[0] == 130");
+	_tmp6_ = foo_get (foo, 0);
+	foo_set (foo, 0, (gpointer) ((gintptr) (((gint) ((gintptr) _tmp6_)) / 5)));
+	_tmp7_ = foo_get (foo, 0);
+	_vala_assert (((gint) ((gintptr) _tmp7_)) == 26, "foo[0] == 26");
+	_tmp8_ = foo_get (foo, 0);
+	foo_set (foo, 0, (gpointer) ((gintptr) (((gint) ((gintptr) _tmp8_)) - 4711)));
+	_tmp9_ = foo_get (foo, 0);
+	_vala_assert (((gint) ((gintptr) _tmp9_)) == -4685, "foo[0] == -4685");
+	_foo_free0 (foo);
+}
+
+int
+main (int argc,
+      char ** argv)
+{
+	_vala_main ();
+	return 0;
+}
+
diff --git a/tests/semantic/assignment-element-getter-setter.vala b/tests/semantic/assignment-element-getter-setter.vala
new file mode 100644
index 000000000..8399dc0d6
--- /dev/null
+++ b/tests/semantic/assignment-element-getter-setter.vala
@@ -0,0 +1,35 @@
+[Compact]
+public class Foo<G> {
+	public G[] elements;
+
+	public Foo () {
+		elements = new G[] { null };
+	}
+
+	public G get (int idx) {
+		return elements[idx];
+	}
+
+	public void set (int idx, G val) {
+		elements[idx] = val;
+	}
+}
+
+void main () {
+	var foo = new Foo<int> ();
+
+	foo[0] = 23;
+	assert (foo[0] == 23);
+
+	foo[0] += 42;
+	assert (foo[0] == 65);
+
+	foo[0] *= 2;
+	assert (foo[0] == 130);
+
+	foo[0] /= 5;
+	assert (foo[0] == 26);
+
+	foo[0] -= 4711;
+	assert (foo[0] == -4685);
+}