added syntaxt tests and updated the TypeChecker logic.

libsolidity/analysis/TypeChecker.cpp

@@ -3393,7 +3393,31 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 		else if (magicType->kind() == MagicType::Kind::MetaType && memberName == "interfaceId")
 			annotation.isPure = true;
 		else if (magicType->kind() == MagicType::Kind::MetaType && memberName == "typehash")
+		{
 			annotation.isPure = true;
+			auto accessedStructType = dynamic_cast<StructType const*>(magicType->typeArgument());
+			solAssert(accessedStructType, "typehash requested on a non struct type.");
+
+			if (accessedStructType->recursive()) {
+				m_errorReporter.typeError(
+					9298_error,
+					_memberAccess.location(),
+					"\"typehash\" cannot be used for recursive structs."
+				);
+			}
+
+			for (auto const& member: accessedStructType->members(currentDefinitionScope()))
+			{
+				if (!member.type->isEIP712AllowedStructMemberType())
+				{
+					m_errorReporter.typeError(
+						9518_error,
+						_memberAccess.location(),
+						"\"typehash\" cannot be used for structs with members of \"" + member.type->humanReadableName() + "\" type."
+					);
+				}
+			}
+		}
 		else if (
 			magicType->kind() == MagicType::Kind::MetaType &&
 			(memberName == "min" ||	memberName == "max")

libsolidity/ast/Types.h

@@ -358,6 +358,7 @@ public:
 	virtual std::string canonicalName() const { return toString(true); }
 	virtual std::string humanReadableName() const { return toString(); }
 	virtual std::string eip712TypeName() const { return encodingType()->toString(true); }
+	virtual bool isEIP712AllowedStructMemberType() const { return false; }
 	/// @returns the signature of this type in external functions, i.e. `uint256` for integers
 	/// or `(uint256,bytes8)[2]` for an array of structs. If @a _structsByName,
 	/// structs are given by canonical name like `ContractName.StructName[2]`.
@@ -458,6 +459,7 @@ public:
 	bool leftAligned() const override { return false; }
 	bool isValueType() const override { return true; }
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 
 	MemberList::MemberMap nativeMembers(ASTNode const*) const override;
 
@@ -503,6 +505,7 @@ public:
 	bool leftAligned() const override { return false; }
 	bool isValueType() const override { return true; }
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 
 	std::string toString(bool _withoutDataLocation) const override;
 
@@ -662,6 +665,8 @@ public:
 		return nullptr;
 	}
 
+	bool isEIP712AllowedStructMemberType() const override { return true; }
+
 	std::string richIdentifier() const override;
 	bool operator==(Type const& _other) const override;
 
@@ -700,6 +705,7 @@ public:
 	bool leftAligned() const override { return true; }
 	bool isValueType() const override { return true; }
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 
 	std::string toString(bool) const override { return "bytes" + util::toString(m_bytes); }
 	MemberList::MemberMap nativeMembers(ASTNode const*) const override;
@@ -728,6 +734,7 @@ public:
 	bool leftAligned() const override { return false; }
 	bool isValueType() const override { return true; }
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 
 	std::string toString(bool) const override { return "bool"; }
 	u256 literalValue(Literal const* _literal) const override;
@@ -865,6 +872,7 @@ public:
 	u256 storageSize() const override;
 	bool containsNestedMapping() const override { return m_baseType->containsNestedMapping(); }
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 
 	std::string toString(bool _withoutDataLocation) const override;
 	std::string humanReadableName() const override;
@@ -978,6 +986,7 @@ public:
 	bool leftAligned() const override { solAssert(!isSuper(), ""); return false; }
 	bool isValueType() const override { return !isSuper(); }
 	bool nameable() const override { return !isSuper(); }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 	std::string toString(bool _withoutDataLocation) const override;
 	std::string canonicalName() const override;
 
@@ -1040,6 +1049,7 @@ public:
 	u256 storageSize() const override;
 	bool containsNestedMapping() const override;
 	bool nameable() const override { return true; }
+	bool isEIP712AllowedStructMemberType() const override { return true; }
 	std::string toString(bool _withoutDataLocation) const override;
 
 	MemberList::MemberMap nativeMembers(ASTNode const* _currentScope) const override;

test/libsolidity/syntaxTests/types/struct/typehash_const.sol

@@ -0,0 +1,7 @@
+contract C {
+    struct S {
+        uint256[][10][] x;
+    }
+
+    bytes32 constant h = type(S).typehash;
+}

test/libsolidity/syntaxTests/types/struct/typehash_contract.sol

@@ -0,0 +1,5 @@
+contract C {
+    bytes32 x = type(C).typehash;
+}
+// ----
+// TypeError 9582: (29-45): Member "typehash" not found or not visible after argument-dependent lookup in type(contract C).

test/libsolidity/syntaxTests/types/struct/typehash_enum.sol

@@ -0,0 +1,9 @@
+contract C {
+    enum E {
+        VALUE
+    }
+
+    bytes32 h = type(E).typehash;
+}
+// ----
+// TypeError 9582: (63-79): Member "typehash" not found or not visible after argument-dependent lookup in type(enum C.E).

test/libsolidity/syntaxTests/types/struct/typehash_member_enum.sol

@@ -0,0 +1,14 @@
+contract C {
+    enum E {
+        VALUE
+    }
+
+    struct S {
+        E e;
+    }
+
+    bytes32 h = type(S).typehash;
+}
+
+// ----
+// TypeError 9518: (98-114): "typehash" cannot be used for structs with members of "enum C.E" type.

test/libsolidity/syntaxTests/types/struct/typehash_member_fixed128x18.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S {
+        fixed128x18 x;
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9518: (74-90): "typehash" cannot be used for structs with members of "fixed128x18" type.

test/libsolidity/syntaxTests/types/struct/typehash_member_function.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S {
+        function(uint256) internal returns(uint256) f;
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9518: (106-122): "typehash" cannot be used for structs with members of "function (uint256) returns (uint256)" type.

test/libsolidity/syntaxTests/types/struct/typehash_member_mapping.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S {
+        mapping (uint256 => uint256) x; 
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9518: (92-108): "typehash" cannot be used for structs with members of "mapping(uint256 => uint256)" type.

test/libsolidity/syntaxTests/types/struct/typehash_member_ufixed128x18.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S {
+        ufixed128x18 x;
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9518: (75-91): "typehash" cannot be used for structs with members of "ufixed128x18" type.

test/libsolidity/syntaxTests/types/struct/typehash_member_userdefined.sol

@@ -0,0 +1,10 @@
+type T is uint256;
+contract C {
+    struct S {
+        T t;
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9518: (83-99): "typehash" cannot be used for structs with members of "T" type.

test/libsolidity/syntaxTests/types/struct/typehash_pure.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S {
+        uint256 x;
+    }
+
+    function f() public pure returns(bytes32) {
+        return type(S).typehash;
+    }
+}

test/libsolidity/syntaxTests/types/struct/typehash_recursive_struct.sol

@@ -0,0 +1,9 @@
+contract C {
+    struct S { 
+        S[] s; 
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9298: (68-84): "typehash" cannot be used for recursive structs.

test/libsolidity/syntaxTests/types/struct/typehash_recursive_struct_2.sol

@@ -0,0 +1,14 @@
+contract A {
+    struct S {
+        C.S[] s;
+    }
+}
+contract C {
+    struct S { 
+        A.S s; 
+    }
+
+    bytes32 h = type(S).typehash;
+}
+// ----
+// TypeError 9298: (121-137): "typehash" cannot be used for recursive structs.

test/libsolidity/syntaxTests/types/struct/typehash_struct_variable.sol

@@ -0,0 +1,15 @@
+contract C {
+    struct S {
+        uint256 x;
+    }
+
+    function f1(S calldata s) public pure returns(bytes32 h) {
+        h = type(s).typehash; // should fail
+    }
+
+    function f3(S calldata s) public pure returns(bytes32 h) {
+        h = type(S).typehash;
+    }
+}
+// ----
+// TypeError 4259: (134-135): Invalid type for argument in the function call. An enum type, contract type, struct type or an integer type is required, but struct C.S calldata provided.

test/libsolidity/syntaxTests/types/struct/typehash_struct_variable_2.sol

@@ -0,0 +1,15 @@
+contract C {
+    struct S {
+        uint256 x;
+    }
+
+    function f1(S memory s) public pure returns(bytes32 h) {
+        h = type(s).typehash; // should fail
+    }
+
+    function f3(S calldata s) public pure returns(bytes32 h) {
+        h = type(S).typehash;
+    }
+}
+// ----
+// TypeError 4259: (132-133): Invalid type for argument in the function call. An enum type, contract type, struct type or an integer type is required, but struct C.S memory provided.

test/libsolidity/syntaxTests/types/struct/typehash_uint256.sol

@@ -0,0 +1,5 @@
+contract C {
+    bytes32 h = type(uint256).typehash;
+}
+// ----
+// TypeError 9582: (29-51): Member "typehash" not found or not visible after argument-dependent lookup in type(uint256).

test/libsolidity/syntaxTests/types/struct/typehash_viewpure.sol

@@ -0,0 +1,11 @@
+contract C {
+    struct S {
+        uint256 x;
+    }
+
+    function f() public view returns(bytes32) { // can be pure
+        return type(S).typehash;
+    }
+}
+// ----
+// Warning 2018: (58-155): Function state mutability can be restricted to pure