From e07274a96f6e53a995d18cc92526239b9f20eb01 Mon Sep 17 00:00:00 2001
From: Daniel Kirchner <daniel@ekpyron.org>
Date: Thu, 6 Feb 2020 09:08:28 +0100
Subject: [PATCH] Disallow libraries as mapping keys.

---
 libsolidity/analysis/TypeChecker.cpp                | 13 +++++++++----
 .../mapping}/contract_mapping.sol                   |  0
 .../mapping}/contract_mapping_invalid.sol           |  0
 .../{mappings => types/mapping}/enum_mapping.sol    |  0
 .../mapping}/enum_mapping_invalid.sol               |  0
 .../syntaxTests/types/mapping/library_mapping.sol   |  4 ++++
 6 files changed, 13 insertions(+), 4 deletions(-)
 rename test/libsolidity/syntaxTests/{mappings => types/mapping}/contract_mapping.sol (100%)
 rename test/libsolidity/syntaxTests/{mappings => types/mapping}/contract_mapping_invalid.sol (100%)
 rename test/libsolidity/syntaxTests/{mappings => types/mapping}/enum_mapping.sol (100%)
 rename test/libsolidity/syntaxTests/{mappings => types/mapping}/enum_mapping_invalid.sol (100%)
 create mode 100644 test/libsolidity/syntaxTests/types/mapping/library_mapping.sol

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index f09c38832..4590bcdc2 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -2880,10 +2880,15 @@ bool TypeChecker::visit(Mapping const& _mapping)
 {
 	if (auto const* keyType = dynamic_cast<UserDefinedTypeName const*>(&_mapping.keyType()))
 	{
-		if (
-			keyType->annotation().type->category() != Type::Category::Contract &&
-			keyType->annotation().type->category() != Type::Category::Enum
-		)
+		if (auto const* contractType = dynamic_cast<ContractType const*>(keyType->annotation().type))
+		{
+			if (contractType->contractDefinition().isLibrary())
+				m_errorReporter.typeError(
+					keyType->location(),
+					"Library types cannot be used as mapping keys."
+				);
+		}
+		else if (keyType->annotation().type->category() != Type::Category::Enum)
 			m_errorReporter.typeError(
 				keyType->location(),
 				"Only elementary types, contract types or enums are allowed as mapping keys."
diff --git a/test/libsolidity/syntaxTests/mappings/contract_mapping.sol b/test/libsolidity/syntaxTests/types/mapping/contract_mapping.sol
similarity index 100%
rename from test/libsolidity/syntaxTests/mappings/contract_mapping.sol
rename to test/libsolidity/syntaxTests/types/mapping/contract_mapping.sol
diff --git a/test/libsolidity/syntaxTests/mappings/contract_mapping_invalid.sol b/test/libsolidity/syntaxTests/types/mapping/contract_mapping_invalid.sol
similarity index 100%
rename from test/libsolidity/syntaxTests/mappings/contract_mapping_invalid.sol
rename to test/libsolidity/syntaxTests/types/mapping/contract_mapping_invalid.sol
diff --git a/test/libsolidity/syntaxTests/mappings/enum_mapping.sol b/test/libsolidity/syntaxTests/types/mapping/enum_mapping.sol
similarity index 100%
rename from test/libsolidity/syntaxTests/mappings/enum_mapping.sol
rename to test/libsolidity/syntaxTests/types/mapping/enum_mapping.sol
diff --git a/test/libsolidity/syntaxTests/mappings/enum_mapping_invalid.sol b/test/libsolidity/syntaxTests/types/mapping/enum_mapping_invalid.sol
similarity index 100%
rename from test/libsolidity/syntaxTests/mappings/enum_mapping_invalid.sol
rename to test/libsolidity/syntaxTests/types/mapping/enum_mapping_invalid.sol
diff --git a/test/libsolidity/syntaxTests/types/mapping/library_mapping.sol b/test/libsolidity/syntaxTests/types/mapping/library_mapping.sol
new file mode 100644
index 000000000..b2512b47b
--- /dev/null
+++ b/test/libsolidity/syntaxTests/types/mapping/library_mapping.sol
@@ -0,0 +1,4 @@
+library L {}
+contract C { mapping(L => bool) i; }
+// ----
+// TypeError: (34-35): Library types cannot be used as mapping keys.