Propagate purity information for member access to foreign pure variables

Author: StrongerXi

libsolidity/analysis/TypeChecker.cpp

@@ -3158,6 +3158,14 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 
 			annotation.isPure = isPure;
 		}
+	if (
+		VariableDeclaration const* varDecl = dynamic_cast<decltype(varDecl)>(annotation.referencedDeclaration);
+		!annotation.isPure.set() &&
+		varDecl &&
+		varDecl->isConstant()
+	) {
+		annotation.isPure = true;
+	}
 
 	if (auto magicType = dynamic_cast<MagicType const*>(exprType))
 	{

test/libsolidity/syntaxTests/constants/cyclic_dependency_file_and_library_constants.sol

@@ -0,0 +1,15 @@
+==== Source: A.sol ====
+import "B.sol";
+
+uint256 constant A = B.VAL + 1;
+
+==== Source: B.sol ====
+import "A.sol";
+
+library B {
+    uint256 constant VAL = A + 1;
+}
+
+// ----
+// TypeError 6161: (B.sol:33-61): The value of the constant VAL has a cyclic dependency via A.
+// TypeError 6161: (A.sol:17-47): The value of the constant A has a cyclic dependency via VAL.

test/libsolidity/syntaxTests/constants/cyclic_dependency_file_constants.sol

@@ -0,0 +1,13 @@
+==== Source: A.sol ====
+import "B.sol";
+
+uint256 constant A = B + 1;
+
+==== Source: B.sol ====
+import "A.sol";
+
+uint256 constant B = A + 1;
+
+// ----
+// TypeError 6161: (B.sol:17-43): The value of the constant B has a cyclic dependency via A.
+// TypeError 6161: (A.sol:17-43): The value of the constant A has a cyclic dependency via B.

test/libsolidity/syntaxTests/constants/cyclic_dependency_library_constants.sol

@@ -0,0 +1,11 @@
+library A {
+    uint256 constant VAL = B.VAL + 1;
+}
+
+library B {
+    uint256 constant VAL = A.VAL + 1;
+}
+
+// ----
+// TypeError 6161: (16-48): The value of the constant VAL has a cyclic dependency via VAL.
+// TypeError 6161: (69-101): The value of the constant VAL has a cyclic dependency via VAL.

test/libsolidity/syntaxTests/constants/define_constants_with_external_constant_member_var.sol

@@ -0,0 +1,11 @@
+uint256 constant MAX = 1;
+
+library Internal {
+    uint256 internal constant SCALE = 100;
+}
+
+contract Usage {
+    uint256 private constant LIMIT = MAX * Internal.SCALE;
+}
+
+// ====