From: wxx <769218589@qq.com>
Date: Tue, 30 Nov 2021 18:54:04 +0000 (+0800)
Subject: vala: Transform assignment of an array element as needed
X-Git-Tag: 0.52.11~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5bab6ff1872610e6b6afe0b23ceeda7b2ca364f;p=thirdparty%2Fvala.git

vala: Transform assignment of an array element as needed

Fixes https://gitlab.gnome.org/GNOME/vala/issues/889
Fixes https://gitlab.gnome.org/GNOME/vala/issues/1258
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 69f687dc1..48369672a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -50,6 +50,7 @@ TESTS = \
 	basic-types/custom-types.vala \
 	basic-types/default-gtype.vala \
 	basic-types/strings.vala \
+	basic-types/string-array-append.vala \
 	basic-types/string-concat-null.test \
 	basic-types/arrays.vala \
 	basic-types/arrays-generics.vala \
@@ -111,6 +112,7 @@ TESTS = \
 	arrays/class-field-initializer.vala \
 	arrays/class-field-length-cname.vala \
 	arrays/constant-element-access.vala \
+	arrays/element-nullable-assignment.vala \
 	arrays/empty-length-0.vala \
 	arrays/expression-bracket.test \
 	arrays/fixed-length-init0-not-allowed.vala \
diff --git a/tests/arrays/element-nullable-assignment.vala b/tests/arrays/element-nullable-assignment.vala
new file mode 100644
index 000000000..29dc2950e
--- /dev/null
+++ b/tests/arrays/element-nullable-assignment.vala
@@ -0,0 +1,11 @@
+void main () {
+	int?[] foo = { 23, 42, 4711 };
+
+	foo[0] += 1;
+	foo[1] *= 3;
+	foo[2] -= 2;
+
+	assert (foo[0] == 24);
+	assert (foo[1] == 126);
+	assert (foo[2] == 4709);
+}
diff --git a/tests/basic-types/string-array-append.vala b/tests/basic-types/string-array-append.vala
new file mode 100644
index 000000000..4b1ae328e
--- /dev/null
+++ b/tests/basic-types/string-array-append.vala
@@ -0,0 +1,12 @@
+void main () {
+	string[] foo = { "foo", "bar", "foo bar" };
+
+	foo[0] += "abc";
+	foo[1] += 123.to_string ();
+	foo[2] += " abc" + 123.to_string ();
+
+	assert (foo[0] == "fooabc");
+	assert (foo[1] == "bar123");
+	assert (foo[2] == "foo bar abc123");
+}
+
diff --git a/vala/valaassignment.vala b/vala/valaassignment.vala
index 8c0948ef3..150c34723 100644
--- a/vala/valaassignment.vala
+++ b/vala/valaassignment.vala
@@ -229,13 +229,36 @@ public class Vala.Assignment : Expression {
 		}
 
 		unowned MemberAccess? ma = left as MemberAccess;
-		if (operator != AssignmentOperator.SIMPLE && ma != null
-		    && !(left.value_type.is_non_null_simple_type () && ma.symbol_reference is LocalVariable)) {
+		unowned ElementAccess? ea = left as ElementAccess;
+		bool transform_assignment = false;
+
+		if (ma != null && !(ma.symbol_reference is LocalVariable)) {
+			transform_assignment = true;
+		} else if (left.value_type != null && !left.value_type.is_non_null_simple_type ()) {
+			transform_assignment = true;
+		} else if (ea != null && ea.container.value_type is ArrayType) {
+			// check if the left is an array and its element is non-null simple type
+			unowned ArrayType array_type = (ArrayType) ea.container.value_type;
+			transform_assignment = !array_type.element_type.is_non_null_simple_type ();
+		}
+
+		if ((operator != AssignmentOperator.SIMPLE) && transform_assignment) {
 			// transform into simple assignment
 			// FIXME: only do this if the backend doesn't support
 			// the assignment natively
-
-			var old_value = new MemberAccess (ma.inner, ma.member_name, source_reference);
+			Expression old_value = null;
+
+			if (ma != null) {
+				old_value = new MemberAccess (ma.inner, ma.member_name, left.source_reference);
+			} else if (ea !=null) {
+				old_value = new ElementAccess (ea.container, left.source_reference);
+				var indices = ea.get_indices ();
+				foreach (var index in indices) {
+					((ElementAccess) old_value).append_index (index);
+				}
+			} else {
+				assert_not_reached ();
+			}
 
 			BinaryOperator bop;
 
@@ -361,9 +384,7 @@ public class Vala.Assignment : Expression {
 					}
 				}
 			}
-		} else if (left is ElementAccess) {
-			unowned ElementAccess ea = (ElementAccess) left;
-
+		} else if (ea != null) {
 			if (!right.value_type.compatible (left.value_type)) {
 				error = true;
 				Report.error (source_reference, "Assignment: Cannot convert from `%s' to `%s'", right.value_type.to_string (), left.value_type.to_string ());