From: Rico Tzschichholz <ricotz@ubuntu.com>
Date: Sat, 4 Jul 2020 14:04:22 +0000 (+0200)
Subject: vala: Recursive check of assignment target to recognize constants
X-Git-Tag: 0.49.1~59
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fbd40a292a2e491ba76dbd80de6ae428ac971b7e;p=thirdparty%2Fvala.git

vala: Recursive check of assignment target to recognize constants

See https://gitlab.gnome.org/GNOME/vala/issues/944
---

diff --git a/tests/Makefile.am b/tests/Makefile.am
index b6f9574e8..7d604cfbe 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -804,6 +804,8 @@ TESTS = \
 	semantic/class-too-many-type-arguments.test \
 	semantic/constant-extern.test \
 	semantic/constant-pointer.test \
+	semantic/constant-reassignment-element.test \
+	semantic/constant-reassignment-member.test \
 	semantic/constant-value.test \
 	semantic/constant-value-missing.test \
 	semantic/constant-value-type.test \
diff --git a/tests/semantic/constant-reassignment-element.test b/tests/semantic/constant-reassignment-element.test
new file mode 100644
index 000000000..4a87d7d6c
--- /dev/null
+++ b/tests/semantic/constant-reassignment-element.test
@@ -0,0 +1,10 @@
+Invalid Code
+
+struct Foo {
+	int i;
+}
+
+void main () {
+	const Foo[] foo = { { 23 } };
+	foo[0].i = 42;
+}
diff --git a/tests/semantic/constant-reassignment-member.test b/tests/semantic/constant-reassignment-member.test
new file mode 100644
index 000000000..bc53cd3fd
--- /dev/null
+++ b/tests/semantic/constant-reassignment-member.test
@@ -0,0 +1,10 @@
+Invalid Code
+
+struct Foo {
+	int i;
+}
+
+void main () {
+	const Foo foo = { 23 };
+	foo.i = 42;
+}
diff --git a/vala/valaassignment.vala b/vala/valaassignment.vala
index e67860825..f40bfd4e7 100644
--- a/vala/valaassignment.vala
+++ b/vala/valaassignment.vala
@@ -158,11 +158,7 @@ public class Vala.Assignment : Expression {
 		if (left is MemberAccess) {
 			unowned MemberAccess ma = (MemberAccess) left;
 
-			if (ma.symbol_reference is Constant) {
-				error = true;
-				Report.error (source_reference, "Assignment to constant after initialization");
-				return false;
-			}
+			check_constant_assignment (ma);
 
 			if ((!(ma.symbol_reference is DynamicProperty) && ma.value_type == null) ||
 			    (ma.inner == null && ma.member_name == "this" && context.analyzer.is_in_instance_method ())) {
@@ -191,6 +187,8 @@ public class Vala.Assignment : Expression {
 		} else if (left is ElementAccess) {
 			unowned ElementAccess ea = (ElementAccess) left;
 
+			check_constant_assignment (ea.container as MemberAccess);
+
 			if (ea.container.value_type.type_symbol == context.analyzer.string_type.type_symbol) {
 				error = true;
 				Report.error (ea.source_reference, "strings are immutable");
@@ -437,6 +435,23 @@ public class Vala.Assignment : Expression {
 		return false;
 	}
 
+	void check_constant_assignment (MemberAccess? inner) {
+		while (inner != null) {
+			if (inner.symbol_reference is Constant) {
+				error = true;
+				Report.error (source_reference, "Assignment to constant after initialization");
+				break;
+			}
+			if (inner.inner is MemberAccess) {
+				inner = (MemberAccess) inner.inner;
+			} else if (inner.inner is ElementAccess) {
+				inner = ((ElementAccess) inner.inner).container as MemberAccess;
+			} else {
+				inner = null;
+			}
+		}
+	}
+
 	public override void emit (CodeGenerator codegen) {
 		unowned MemberAccess? ma = left as MemberAccess;
 		unowned ElementAccess? ea = left as ElementAccess;