Propagate purity information for member access to foreign pure variables

Author: StrongerXi

Changelog.md

@@ -8,6 +8,7 @@ Language Features:
 Compiler Features:
  * LSP: Add rudimentary support for semantic highlighting.
  * Yul Optimizer: Improve inlining heuristics for via IR code generation and pure Yul compilation.
+ * TypeChecker: Support using library constants in initializers of other constants
 
 
 Bugfixes:

libsolidity/analysis/TypeChecker.cpp

@@ -3158,6 +3158,13 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 
 			annotation.isPure = isPure;
 		}
+	if (
+		auto const* varDecl = dynamic_cast<VariableDeclaration const*>(annotation.referencedDeclaration);
+		!annotation.isPure.set() &&
+		varDecl &&
+		varDecl->isConstant()
+	)
+		annotation.isPure = true;
 
 	if (auto magicType = dynamic_cast<MagicType const*>(exprType))
 	{

test/libsolidity/syntaxTests/constants/constant_with_dependencies_on_constants.sol

@@ -0,0 +1,35 @@
+uint256 constant MAX = 1;
+
+library L1 {
+    uint256 internal constant INT = 100;
+}
+
+contract C1 {
+    uint256 internal constant CONST = 20 + L2.INT; // forward reference
+    uint256 internal constant LIMIT = MAX * L1.INT;  // same file & external library constant
+    uint256 internal constant NESTED = LIMIT + CONST; // nested & same contract constant
+
+    uint256[L1.INT] internal arr1; // error, backward reference
+    uint256[L2.INT] internal arr2; // error, forward reference
+}
+
+contract C2 is C1 {
+    uint256 internal constant INHERITED = NESTED + CONST * LIMIT; // inherited constants
+}
+
+contract C3 is C2 {
+    uint256 internal constant NESTED_INHERITED = INHERITED + NESTED + CONST * LIMIT; // nest-inherited constants
+
+    uint256[CONST] internal arr3;            // error, nest-inherited constants
+    uint256[NESTED_INHERITED] internal arr4; // error, same contract constant
+}
+
+library L2 {
+    uint256 internal constant INT = 100;
+}
+
+// ----
+// TypeError 5462: (366-372): Invalid array length, expected integer literal or constant expression.
+// TypeError 5462: (430-436): Invalid array length, expected integer literal or constant expression.
+// TypeError 5462: (742-747): Invalid array length, expected integer literal or constant expression.
+// TypeError 5462: (822-838): Invalid array length, expected integer literal or constant expression.

test/libsolidity/syntaxTests/constants/constant_with_dependencies_on_file_level_constants.sol

@@ -0,0 +1,11 @@
+==== Source: A.sol ====
+import "B.sol" as B;
+
+uint constant X = 1;
+uint constant Y = B.Y;
+
+==== Source: B.sol ====
+import "A.sol" as A;
+
+uint constant X = A.X;
+uint constant Y = 2;

test/libsolidity/syntaxTests/constants/constants_with_dependencies_on_library_constants_multi_file.sol

@@ -0,0 +1,17 @@
+==== Source: A.sol ====
+import "B.sol";
+
+library L {
+    uint constant X = 1;
+    uint constant Y = K.Y;
+}
+
+==== Source: B.sol ====
+import "A.sol";
+
+library K {
+    uint constant X = L.X;
+    uint constant Y = 2;
+}
+
+// ====

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.