From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Sun, 10 May 2020 06:46:33 +0000 (+0200)
Subject: codegen: Correctly handle cast-expression of real struct to nullable struct
X-Git-Tag: 0.49.1~136
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c49d45a4e52d5a572ca6e10ecdd5c475eb768720;p=thirdparty%2Fvala.git

codegen: Correctly handle cast-expression of real struct to nullable struct

Don't generate invalid c-code leading to "cannot convert to a pointer type"

Fix https://gitlab.gnome.org/GNOME/vala/issues/991
---

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index fb3c70154..b4a65dd77 100644
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -5342,6 +5342,10 @@ public abstract class Vala.CCodeBaseModule : CodeGenerator {
 			expr.inner.value_type is ValueType && expr.inner.value_type.nullable) {
 			// nullable integer or float or boolean or struct or enum cast to non-nullable
 			innercexpr = new CCodeUnaryExpression (CCodeUnaryOperator.POINTER_INDIRECTION, innercexpr);
+		} else if (expr.type_reference is ValueType && expr.type_reference.nullable &&
+			expr.inner.value_type.is_real_non_null_struct_type ()) {
+			// real non-null struct cast to nullable
+			innercexpr = new CCodeUnaryExpression (CCodeUnaryOperator.ADDRESS_OF, innercexpr);
 		} else if (expr.type_reference is ArrayType && !(expr.inner is Literal)
 		    && expr.inner.value_type is ValueType && !expr.inner.value_type.nullable) {
 			// integer or float or boolean or struct or enum to array cast
diff --git a/tests/Makefile.am b/tests/Makefile.am
index d5038fd9d..7a99b0af2 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -267,6 +267,7 @@ TESTS = \
 	enums/bug780050.vala \
 	structs/struct_only.vala \
 	structs/struct-base-types.vala \
+	structs/struct-boxed-cast.vala \
 	structs/struct-empty-still.test \
 	structs/struct-initializer-list-in-array.vala \
 	structs/struct-no-gtype.vala \
diff --git a/tests/structs/struct-boxed-cast.vala b/tests/structs/struct-boxed-cast.vala
new file mode 100644
index 000000000..260819dcf
--- /dev/null
+++ b/tests/structs/struct-boxed-cast.vala
@@ -0,0 +1,21 @@
+void foo<T> (T t) {
+	assert (((Bar?) t).s == "foo");
+	assert (((Bar?) t).i == 23);
+}
+
+struct Bar {
+	public string s;
+	public int i;
+}
+
+void main () {
+	Bar f = { "bar", 42 };
+	var cast = (Bar?) f;
+	assert (cast.s == "bar");
+	assert (cast.i == 42);
+
+	Bar arg = { "foo", 23 };
+	foo ((Bar?) arg);
+	foo<Bar?> (arg);
+	foo<Bar?> ((Bar?) arg);
+}