Fix view/pure checker for access to base.

Changelog.md

@@ -15,6 +15,7 @@ Compiler Features:
 
 
 Bugfixes:
+ * View/Pure Checker: Properly detect state variable access through base class.
 
 
 

libsolidity/analysis/ViewPureChecker.cpp

@@ -389,8 +389,15 @@ void ViewPureChecker::endVisit(MemberAccess const& _memberAccess)
 		break;
 	}
 	default:
+	{
+		if (VariableDeclaration const* varDecl = dynamic_cast<VariableDeclaration const*>(
+			_memberAccess.annotation().referencedDeclaration
+		))
+			if (varDecl->isStateVariable() && !varDecl->isConstant())
+				mutability = writes ? StateMutability::NonPayable : StateMutability::View;
 		break;
 	}
+	}
 	reportMutability(mutability, _memberAccess.location());
 }
 

test/libsolidity/syntaxTests/nameAndTypeResolution/069_base_class_state_variable_accessor.sol

@@ -6,4 +6,4 @@ contract Child is Parent {
     function foo() public returns (uint256) { return Parent.m_aMember; }
 }
 // ----
-// Warning: (158-226): Function state mutability can be restricted to pure
+// Warning: (158-226): Function state mutability can be restricted to view

test/libsolidity/syntaxTests/nameAndTypeResolution/071_base_class_state_variable_internal_member.sol

@@ -5,4 +5,4 @@ contract Child is Parent {
     function foo() public returns (uint256) { return Parent.m_aMember; }
 }
 // ----
-// Warning: (83-151): Function state mutability can be restricted to pure
+// Warning: (83-151): Function state mutability can be restricted to view

test/libsolidity/syntaxTests/viewPureChecker/access_to_base_member_array.sol

@@ -0,0 +1,21 @@
+contract A {
+    uint[] x;
+}
+
+contract B is A {
+    function f() public view {
+        A.x.length = 2;
+    }
+    function g() public pure returns (uint) {
+        return A.x.length;
+    }
+    function h() public pure returns (uint) {
+        return A.x[2];
+    }
+}
+// ----
+// TypeError: (87-97): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (170-173): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (170-180): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (249-252): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (249-255): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/access_to_base_member_constant.sol

@@ -0,0 +1,10 @@
+contract A {
+    uint constant x = 2;
+}
+
+contract B is A {
+    function f() public pure returns (uint) {
+        return A.x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/viewPureChecker/access_to_base_member_function.sol

@@ -0,0 +1,11 @@
+contract A {
+    function x() public {}
+}
+
+contract B is A {
+    function f() public view {
+        A.x();
+    }
+}
+// ----
+// TypeError: (100-105): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.

test/libsolidity/syntaxTests/viewPureChecker/access_to_base_member_struct.sol

@@ -0,0 +1,21 @@
+contract A {
+    struct S { uint x; }
+    S s;
+}
+
+contract B is A {
+    function f() public view {
+        A.s = A.S(2);
+    }
+    function g() public view {
+        A.s.x = 2;
+    }
+    function h() public pure returns (uint) {
+        return A.s.x;
+    }
+}
+// ----
+// TypeError: (107-110): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (166-171): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.
+// TypeError: (244-247): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (244-249): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/access_to_base_members.sol

@@ -0,0 +1,15 @@
+contract A {
+    uint x;
+}
+
+contract B is A {
+    function f() public pure returns (uint) {
+        return A.x;
+    }
+    function g() public view {
+        A.x = 5;
+    }
+}
+// ----
+// TypeError: (107-110): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError: (157-160): Function declared as view, but this expression (potentially) modifies the state and thus requires non-payable (the default) or payable.