From ef133aa670db20d34177f674c927c2c82f3aeb54 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20=C5=9Aliwak?= <kamil.sliwak@codepoets.it>
Date: Fri, 29 May 2020 21:21:42 +0200
Subject: [PATCH 1/6] CommandLineInterface: Display an error instead of
 crashing when assembly variant has no Ewasm translation

---
 solc/CommandLineInterface.cpp                               | 6 ++++++
 test/cmdlineTests/evm_to_wasm_unsupported_translation/args  | 1 +
 test/cmdlineTests/evm_to_wasm_unsupported_translation/err   | 1 +
 test/cmdlineTests/evm_to_wasm_unsupported_translation/exit  | 1 +
 .../evm_to_wasm_unsupported_translation/input.yul           | 3 +++
 .../cmdlineTests/evm_to_wasm_unsupported_translation/output | 1 +
 6 files changed, 13 insertions(+)
 create mode 100644 test/cmdlineTests/evm_to_wasm_unsupported_translation/args
 create mode 100644 test/cmdlineTests/evm_to_wasm_unsupported_translation/err
 create mode 100644 test/cmdlineTests/evm_to_wasm_unsupported_translation/exit
 create mode 100644 test/cmdlineTests/evm_to_wasm_unsupported_translation/input.yul
 create mode 100644 test/cmdlineTests/evm_to_wasm_unsupported_translation/output

diff --git a/solc/CommandLineInterface.cpp b/solc/CommandLineInterface.cpp
index a8e5cc5b7..1cee24807 100644
--- a/solc/CommandLineInterface.cpp
+++ b/solc/CommandLineInterface.cpp
@@ -1172,6 +1172,12 @@ bool CommandLineInterface::processInput()
 				endl;
 			return false;
 		}
+		if (targetMachine == Machine::Ewasm && inputLanguage != Input::StrictAssembly && inputLanguage != Input::Ewasm)
+		{
+			serr() << "The selected input language is not directly supported when targeting the Ewasm machine ";
+			serr() << "and automatic translation is not available." << endl;
+			return false;
+		}
 		serr() <<
 			"Warning: Yul is still experimental. Please use the output with care." <<
 			endl;
diff --git a/test/cmdlineTests/evm_to_wasm_unsupported_translation/args b/test/cmdlineTests/evm_to_wasm_unsupported_translation/args
new file mode 100644
index 000000000..cc6c07083
--- /dev/null
+++ b/test/cmdlineTests/evm_to_wasm_unsupported_translation/args
@@ -0,0 +1 @@
+--assemble --machine ewasm
diff --git a/test/cmdlineTests/evm_to_wasm_unsupported_translation/err b/test/cmdlineTests/evm_to_wasm_unsupported_translation/err
new file mode 100644
index 000000000..5ef050f64
--- /dev/null
+++ b/test/cmdlineTests/evm_to_wasm_unsupported_translation/err
@@ -0,0 +1 @@
+The selected input language is not directly supported when targeting the Ewasm machine and automatic translation is not available.
diff --git a/test/cmdlineTests/evm_to_wasm_unsupported_translation/exit b/test/cmdlineTests/evm_to_wasm_unsupported_translation/exit
new file mode 100644
index 000000000..d00491fd7
--- /dev/null
+++ b/test/cmdlineTests/evm_to_wasm_unsupported_translation/exit
@@ -0,0 +1 @@
+1
diff --git a/test/cmdlineTests/evm_to_wasm_unsupported_translation/input.yul b/test/cmdlineTests/evm_to_wasm_unsupported_translation/input.yul
new file mode 100644
index 000000000..f21cd2b7e
--- /dev/null
+++ b/test/cmdlineTests/evm_to_wasm_unsupported_translation/input.yul
@@ -0,0 +1,3 @@
+{
+    sstore(0, 1)
+}
diff --git a/test/cmdlineTests/evm_to_wasm_unsupported_translation/output b/test/cmdlineTests/evm_to_wasm_unsupported_translation/output
new file mode 100644
index 000000000..8b1378917
--- /dev/null
+++ b/test/cmdlineTests/evm_to_wasm_unsupported_translation/output
@@ -0,0 +1 @@
+

From 37e8d78cff0fdfd93edf56b932476130c0ae8312 Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Thu, 28 May 2020 17:39:08 +0200
Subject: [PATCH 2/6] [Sol->Yul] Implement getters.

---
 libsolidity/codegen/YulUtilFunctions.cpp      |  12 +-
 libsolidity/codegen/ir/IRGenerator.cpp        | 206 +++++++++++-------
 .../semanticTests/getters/arrays.sol          |  14 ++
 .../semanticTests/getters/mapping.sol         |  11 +
 .../semanticTests/getters/small_types.sol     |  19 ++
 .../storage/accessors_mapping_for_array.sol   |   2 +
 6 files changed, 179 insertions(+), 85 deletions(-)
 create mode 100644 test/libsolidity/semanticTests/getters/arrays.sol
 create mode 100644 test/libsolidity/semanticTests/getters/mapping.sol
 create mode 100644 test/libsolidity/semanticTests/getters/small_types.sol

diff --git a/libsolidity/codegen/YulUtilFunctions.cpp b/libsolidity/codegen/YulUtilFunctions.cpp
index 067fe3fea..87142099e 100644
--- a/libsolidity/codegen/YulUtilFunctions.cpp
+++ b/libsolidity/codegen/YulUtilFunctions.cpp
@@ -1276,7 +1276,8 @@ string YulUtilFunctions::mappingIndexAccessFunction(MappingType const& _mappingT
 
 string YulUtilFunctions::readFromStorage(Type const& _type, size_t _offset, bool _splitFunctionTypes)
 {
-	solUnimplementedAssert(!_splitFunctionTypes, "");
+	if (_type.category() == Type::Category::Function)
+		solUnimplementedAssert(!_splitFunctionTypes, "");
 	string functionName =
 		"read_from_storage_" +
 		string(_splitFunctionTypes ? "split_" : "") +
@@ -1299,7 +1300,8 @@ string YulUtilFunctions::readFromStorage(Type const& _type, size_t _offset, bool
 
 string YulUtilFunctions::readFromStorageDynamic(Type const& _type, bool _splitFunctionTypes)
 {
-	solUnimplementedAssert(!_splitFunctionTypes, "");
+	if (_type.category() == Type::Category::Function)
+		solUnimplementedAssert(!_splitFunctionTypes, "");
 	string functionName =
 		"read_from_storage_dynamic" +
 		string(_splitFunctionTypes ? "split_" : "") +
@@ -1429,7 +1431,8 @@ string YulUtilFunctions::writeToMemoryFunction(Type const& _type)
 
 string YulUtilFunctions::extractFromStorageValueDynamic(Type const& _type, bool _splitFunctionTypes)
 {
-	solUnimplementedAssert(!_splitFunctionTypes, "");
+	if (_type.category() == Type::Category::Function)
+		solUnimplementedAssert(!_splitFunctionTypes, "");
 
 	string functionName =
 		"extract_from_storage_value_dynamic" +
@@ -1474,7 +1477,8 @@ string YulUtilFunctions::extractFromStorageValue(Type const& _type, size_t _offs
 string YulUtilFunctions::cleanupFromStorageFunction(Type const& _type, bool _splitFunctionTypes)
 {
 	solAssert(_type.isValueType(), "");
-	solUnimplementedAssert(!_splitFunctionTypes, "");
+	if (_type.category() == Type::Category::Function)
+		solUnimplementedAssert(!_splitFunctionTypes, "");
 
 	string functionName = string("cleanup_from_storage_") + (_splitFunctionTypes ? "split_" : "") + _type.identifier();
 	return m_functionCollector.createFunction(functionName, [&] {
diff --git a/libsolidity/codegen/ir/IRGenerator.cpp b/libsolidity/codegen/ir/IRGenerator.cpp
index 1bb6c7089..92df1ba83 100644
--- a/libsolidity/codegen/ir/IRGenerator.cpp
+++ b/libsolidity/codegen/ir/IRGenerator.cpp
@@ -268,101 +268,145 @@ string IRGenerator::generateFunction(FunctionDefinition const& _function)
 string IRGenerator::generateGetter(VariableDeclaration const& _varDecl)
 {
 	string functionName = IRNames::function(_varDecl);
+	return m_context.functionCollector().createFunction(functionName, [&]() {
+		Type const* type = _varDecl.annotation().type;
 
-	Type const* type = _varDecl.annotation().type;
-
-	solAssert(_varDecl.isStateVariable(), "");
-
-	if (auto const* mappingType = dynamic_cast<MappingType const*>(type))
-		return m_context.functionCollector().createFunction(functionName, [&]() {
-			solAssert(!_varDecl.isConstant() && !_varDecl.immutable(), "");
-			pair<u256, unsigned> slot_offset = m_context.storageLocationOfVariable(_varDecl);
-			solAssert(slot_offset.second == 0, "");
-			FunctionType funType(_varDecl);
-			solUnimplementedAssert(funType.returnParameterTypes().size() == 1, "");
-			TypePointer returnType = funType.returnParameterTypes().front();
-			unsigned num_keys = 0;
-			stringstream indexAccesses;
-			string slot = m_context.newYulVariable();
-			do
-			{
-				solUnimplementedAssert(
-					mappingType->keyType()->sizeOnStack() == 1,
-					"Multi-slot mapping key unimplemented - might not be a problem"
-				);
-				indexAccesses <<
-					slot <<
-					" := " <<
-					m_utils.mappingIndexAccessFunction(*mappingType, *mappingType->keyType()) <<
-					"(" <<
-					slot;
-				if (mappingType->keyType()->sizeOnStack() > 0)
-					indexAccesses <<
-						", " <<
-						suffixedVariableNameList("key", num_keys, num_keys + mappingType->keyType()->sizeOnStack());
-				indexAccesses << ")\n";
-				num_keys += mappingType->keyType()->sizeOnStack();
-			}
-			while ((mappingType = dynamic_cast<MappingType const*>(mappingType->valueType())));
+		solAssert(_varDecl.isStateVariable(), "");
 
+		FunctionType accessorType(_varDecl);
+		TypePointers paramTypes = accessorType.parameterTypes();
+		if (_varDecl.immutable())
+		{
+			solAssert(paramTypes.empty(), "");
+			solUnimplementedAssert(type->sizeOnStack() == 1, "");
 			return Whiskers(R"(
-				function <functionName>(<keys>) -> rval {
-					let <slot> := <base>
-					<indexAccesses>
-					rval := <readStorage>(<slot>)
+				function <functionName>() -> rval {
+					rval := loadimmutable("<id>")
 				}
 			)")
 			("functionName", functionName)
-			("keys", suffixedVariableNameList("key", 0, num_keys))
-			("readStorage", m_utils.readFromStorage(*returnType, 0, false))
-			("indexAccesses", indexAccesses.str())
-			("slot", slot)
-			("base", slot_offset.first.str())
+			("id", to_string(_varDecl.id()))
 			.render();
-		});
-	else
-	{
-		solUnimplementedAssert(type->isValueType(), "");
+		}
+		else if (_varDecl.isConstant())
+		{
+			solAssert(paramTypes.empty(), "");
+			return Whiskers(R"(
+				function <functionName>() -> <ret> {
+					<ret> := <constantValueFunction>()
+				}
+			)")
+			("functionName", functionName)
+			("constantValueFunction", IRGeneratorForStatements(m_context, m_utils).constantValueFunction(_varDecl))
+			("ret", suffixedVariableNameList("ret_", 0, _varDecl.type()->sizeOnStack()))
+			.render();
+		}
 
-		return m_context.functionCollector().createFunction(functionName, [&]() {
-			if (_varDecl.immutable())
+		string code;
+
+		auto const& location = m_context.storageLocationOfVariable(_varDecl);
+		code += Whiskers(R"(
+			let slot := <slot>
+			let offset := <offset>
+		)")
+		("slot", location.first.str())
+		("offset", to_string(location.second))
+		.render();
+
+		if (!paramTypes.empty())
+			solAssert(
+				location.second == 0,
+				"If there are parameters, we are dealing with structs or mappings and thus should have offset zero."
+			);
+
+		// The code of an accessor is of the form `x[a][b][c]` (it is slightly more complicated
+		// if the final type is a struct).
+		// In each iteration of the loop below, we consume one parameter, perform an
+		// index access, reassign the yul variable `slot` and move @a currentType further "down".
+		// The initial value of @a currentType is only used if we skip the loop completely.
+		TypePointer currentType = _varDecl.annotation().type;
+
+		vector<string> parameters;
+		vector<string> returnVariables;
+
+		for (size_t i = 0; i < paramTypes.size(); ++i)
+		{
+			MappingType const* mappingType = dynamic_cast<MappingType const*>(currentType);
+			ArrayType const* arrayType = dynamic_cast<ArrayType const*>(currentType);
+			solAssert(mappingType || arrayType, "");
+
+			vector<string> keys = IRVariable("key_" + to_string(i),
+				mappingType ? *mappingType->keyType() : *TypeProvider::uint256()
+			).stackSlots();
+			parameters += keys;
+			code += Whiskers(R"(
+				slot<?array>, offset</array> := <indexAccess>(slot<?+keys>, <keys></+keys>)
+			)")
+			(
+				"indexAccess",
+				mappingType ?
+				m_utils.mappingIndexAccessFunction(*mappingType, *mappingType->keyType()) :
+				m_utils.storageArrayIndexAccessFunction(*arrayType)
+			)
+			("array", arrayType != nullptr)
+			("keys", joinHumanReadable(keys))
+			.render();
+
+			currentType = mappingType ? mappingType->valueType() : arrayType->baseType();
+		}
+
+		auto returnTypes = accessorType.returnParameterTypes();
+		solAssert(returnTypes.size() >= 1, "");
+		if (StructType const* structType = dynamic_cast<StructType const*>(currentType))
+		{
+			solAssert(location.second == 0, "");
+			auto const& names = accessorType.returnParameterNames();
+			for (size_t i = 0; i < names.size(); ++i)
 			{
-				solUnimplementedAssert(type->sizeOnStack() == 1, "");
-				return Whiskers(R"(
-					function <functionName>() -> rval {
-						rval := loadimmutable("<id>")
-					}
+				if (returnTypes[i]->category() == Type::Category::Mapping)
+					continue;
+				if (auto arrayType = dynamic_cast<ArrayType const*>(returnTypes[i]))
+					if (!arrayType->isByteArray())
+						continue;
+
+				// TODO conversion from storage byte arrays is not yet implemented.
+				pair<u256, unsigned> const& offsets = structType->storageOffsetsOfMember(names[i]);
+				vector<string> retVars = IRVariable("ret_" + to_string(returnVariables.size()), *returnTypes[i]).stackSlots();
+				returnVariables += retVars;
+				code += Whiskers(R"(
+					<ret> := <readStorage>(add(slot, <slotOffset>))
 				)")
-				("functionName", functionName)
-				("id", to_string(_varDecl.id()))
+				("ret", joinHumanReadable(retVars))
+				("readStorage", m_utils.readFromStorage(*returnTypes[i], offsets.second, true))
+				("slotOffset", offsets.first.str())
 				.render();
 			}
-			else if (_varDecl.isConstant())
-				return Whiskers(R"(
-					function <functionName>() -> <ret> {
-						<ret> := <constantValueFunction>()
-					}
-				)")
-				("functionName", functionName)
-				("constantValueFunction", IRGeneratorForStatements(m_context, m_utils).constantValueFunction(_varDecl))
-				("ret", suffixedVariableNameList("ret_", 0, _varDecl.type()->sizeOnStack()))
-				.render();
-			else
-			{
-				pair<u256, unsigned> slot_offset = m_context.storageLocationOfVariable(_varDecl);
+		}
+		else
+		{
+			solAssert(returnTypes.size() == 1, "");
+			vector<string> retVars = IRVariable("ret", *returnTypes.front()).stackSlots();
+			returnVariables += retVars;
+			// TODO conversion from storage byte arrays is not yet implemented.
+			code += Whiskers(R"(
+				<ret> := <readStorage>(slot, offset)
+			)")
+			("ret", joinHumanReadable(retVars))
+			("readStorage", m_utils.readFromStorageDynamic(*returnTypes.front(), true))
+			.render();
+		}
 
-				return Whiskers(R"(
-					function <functionName>() -> rval {
-						rval := <readStorage>(<slot>)
-					}
-				)")
-				("functionName", functionName)
-				("readStorage", m_utils.readFromStorage(*type, slot_offset.second, false))
-				("slot", slot_offset.first.str())
-				.render();
+		return Whiskers(R"(
+			function <functionName>(<params>) -> <retVariables> {
+				<code>
 			}
-		});
-	}
+		)")
+		("functionName", functionName)
+		("params", joinHumanReadable(parameters))
+		("retVariables", joinHumanReadable(returnVariables))
+		("code", std::move(code))
+		.render();
+	});
 }
 
 string IRGenerator::generateInitialAssignment(VariableDeclaration const& _varDecl)
diff --git a/test/libsolidity/semanticTests/getters/arrays.sol b/test/libsolidity/semanticTests/getters/arrays.sol
new file mode 100644
index 000000000..2a8641a9b
--- /dev/null
+++ b/test/libsolidity/semanticTests/getters/arrays.sol
@@ -0,0 +1,14 @@
+contract C {
+    uint8[][2] public a;
+    constructor() public {
+        a[1].push(3);
+        a[1].push(4);
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// a(uint256,uint256): 0, 0 -> FAILURE
+// a(uint256,uint256): 1, 0 -> 3
+// a(uint256,uint256): 1, 1 -> 4
+// a(uint256,uint256): 2, 0 -> FAILURE
diff --git a/test/libsolidity/semanticTests/getters/mapping.sol b/test/libsolidity/semanticTests/getters/mapping.sol
new file mode 100644
index 000000000..5b28a0f06
--- /dev/null
+++ b/test/libsolidity/semanticTests/getters/mapping.sol
@@ -0,0 +1,11 @@
+contract C {
+    mapping(uint => mapping(uint => uint)) public x;
+    constructor() public {
+        x[1][2] = 3;
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// x(uint256,uint256): 1, 2 -> 3
+// x(uint256,uint256): 0, 0 -> 0
\ No newline at end of file
diff --git a/test/libsolidity/semanticTests/getters/small_types.sol b/test/libsolidity/semanticTests/getters/small_types.sol
new file mode 100644
index 000000000..d970f9138
--- /dev/null
+++ b/test/libsolidity/semanticTests/getters/small_types.sol
@@ -0,0 +1,19 @@
+contract C {
+    uint8 public a;
+    uint16 public b;
+    uint128 public c;
+    uint public d;
+    constructor() public {
+        a = 3;
+        b = 4;
+        c = 5;
+        d = 6;
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// a() -> 3
+// b() -> 4
+// c() -> 5
+// d() -> 6
diff --git a/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol b/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
index 94bc11ff0..e7f43d48d 100644
--- a/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
+++ b/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
@@ -8,6 +8,8 @@ contract test {
         dynamicData[2][2] = 8;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // data(uint256,uint256): 2, 2 -> 8
 // data(uint256,uint256): 2, 8 -> FAILURE  # NB: the original code contained a bug here #

From e7f3c042b6923ddd5f51665ef22c2ea7ca1d585e Mon Sep 17 00:00:00 2001
From: chriseth <chris@ethereum.org>
Date: Thu, 28 May 2020 21:11:06 +0200
Subject: [PATCH 3/6] Struct member access for storage and memory.

---
 .../codegen/ir/IRGeneratorForStatements.cpp   | 38 ++++++++++++++++++-
 .../getters/mapping_to_struct.sol             | 20 ++++++++++
 .../storage/accessors_mapping_for_array.sol   |  2 +-
 .../semanticTests/storage/struct_accessor.sol |  2 +
 4 files changed, 60 insertions(+), 2 deletions(-)
 create mode 100644 test/libsolidity/semanticTests/getters/mapping_to_struct.sol

diff --git a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
index 2924ea535..075cad1f3 100644
--- a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
+++ b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
@@ -1467,7 +1467,43 @@ void IRGeneratorForStatements::endVisit(MemberAccess const& _memberAccess)
 		break;
 	case Type::Category::Struct:
 	{
-		solUnimplementedAssert(false, "");
+		auto const& structType = dynamic_cast<StructType const&>(*_memberAccess.expression().annotation().type);
+
+		IRVariable expression(_memberAccess.expression());
+		switch (structType.location())
+		{
+		case DataLocation::Storage:
+		{
+			pair<u256, unsigned> const& offsets = structType.storageOffsetsOfMember(member);
+			string slot = m_context.newYulVariable();
+			m_code << "let " << slot << " := " <<
+				("add(" + expression.name() + ", " + offsets.first.str() + ")\n");
+			setLValue(_memberAccess, IRLValue{
+				type(_memberAccess),
+				IRLValue::Storage{slot, offsets.second}
+			});
+			break;
+		}
+		case DataLocation::Memory:
+		{
+			string pos = m_context.newYulVariable();
+			m_code << "let " << pos << " := " <<
+				("add(" + expression.part("mpos").name() + ", " + structType.memoryOffsetOfMember(member).str() + ")\n");
+			setLValue(_memberAccess, IRLValue{
+				type(_memberAccess),
+				IRLValue::Memory{pos}
+			});
+			break;
+		}
+		case DataLocation::CallData:
+		{
+			solUnimplementedAssert(false, "");
+			break;
+		}
+		default:
+			solAssert(false, "Illegal data location for struct.");
+		}
+		break;
 	}
 	case Type::Category::Enum:
 	{
diff --git a/test/libsolidity/semanticTests/getters/mapping_to_struct.sol b/test/libsolidity/semanticTests/getters/mapping_to_struct.sol
new file mode 100644
index 000000000..fed9f6ec5
--- /dev/null
+++ b/test/libsolidity/semanticTests/getters/mapping_to_struct.sol
@@ -0,0 +1,20 @@
+contract C {
+    struct S {
+        uint8 a;
+        uint16 b;
+        uint128 c;
+        uint d;
+    }
+    mapping(uint => mapping(uint => S)) public x;
+    constructor() public {
+        x[1][2].a = 3;
+        x[1][2].b = 4;
+        x[1][2].c = 5;
+        x[1][2].d = 6;
+    }
+}
+// ====
+// compileViaYul: also
+// ----
+// x(uint256,uint256): 1, 2 -> 3, 4, 5, 6
+// x(uint256,uint256): 0, 0 -> 0x00, 0x00, 0x00, 0x00
diff --git a/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol b/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
index e7f43d48d..01460a1c8 100644
--- a/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
+++ b/test/libsolidity/semanticTests/storage/accessors_mapping_for_array.sol
@@ -12,6 +12,6 @@ contract test {
 // compileViaYul: also
 // ----
 // data(uint256,uint256): 2, 2 -> 8
-// data(uint256,uint256): 2, 8 -> FAILURE  # NB: the original code contained a bug here #
+// data(uint256,uint256): 2, 8 -> FAILURE # NB: the original code contained a bug here #
 // dynamicData(uint256,uint256): 2, 2 -> 8
 // dynamicData(uint256,uint256): 2, 8 -> FAILURE
diff --git a/test/libsolidity/semanticTests/storage/struct_accessor.sol b/test/libsolidity/semanticTests/storage/struct_accessor.sol
index 398cf750b..de57d4697 100644
--- a/test/libsolidity/semanticTests/storage/struct_accessor.sol
+++ b/test/libsolidity/semanticTests/storage/struct_accessor.sol
@@ -8,5 +8,7 @@ contract test {
         data[7].d = true;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // data(uint256): 7 -> 1, 2, true

From 5b1426b55e59819df0b7e5ba30c14c0c29050071 Mon Sep 17 00:00:00 2001
From: Djordje Mijovic <djordje.mijovic@gmail.com>
Date: Tue, 2 Jun 2020 15:45:03 +0200
Subject: [PATCH 4/6] Adding fixes for signedness warnings in liblangutil

---
 liblangutil/CharStream.cpp                    |  7 ++--
 liblangutil/CharStream.h                      |  2 +-
 liblangutil/ParserBase.cpp                    |  2 +-
 liblangutil/Scanner.cpp                       | 42 +++++++++----------
 liblangutil/Scanner.h                         |  6 +--
 liblangutil/SemVerHandler.cpp                 | 12 +++---
 liblangutil/SourceLocation.h                  |  8 +++-
 liblangutil/SourceReferenceExtractor.cpp      | 21 +++++++---
 liblangutil/SourceReferenceFormatter.cpp      |  4 +-
 liblangutil/SourceReferenceFormatterHuman.cpp | 20 +++++----
 liblangutil/Token.cpp                         |  2 +-
 11 files changed, 71 insertions(+), 55 deletions(-)

diff --git a/liblangutil/CharStream.cpp b/liblangutil/CharStream.cpp
index 046aca5d3..6f2d47c48 100644
--- a/liblangutil/CharStream.cpp
+++ b/liblangutil/CharStream.cpp
@@ -85,7 +85,7 @@ string CharStream::lineAtPosition(int _position) const
 {
 	// if _position points to \n, it returns the line before the \n
 	using size_type = string::size_type;
-	size_type searchStart = min<size_type>(m_source.size(), _position);
+	size_type searchStart = min<size_type>(m_source.size(), size_type(_position));
 	if (searchStart > 0)
 		searchStart--;
 	size_type lineStart = m_source.rfind('\n', searchStart);
@@ -105,8 +105,9 @@ string CharStream::lineAtPosition(int _position) const
 tuple<int, int> CharStream::translatePositionToLineColumn(int _position) const
 {
 	using size_type = string::size_type;
-	size_type searchPosition = min<size_type>(m_source.size(), _position);
-	int lineNumber = count(m_source.begin(), m_source.begin() + searchPosition, '\n');
+	using diff_type = string::difference_type;
+	size_type searchPosition = min<size_type>(m_source.size(), size_type(_position));
+	int lineNumber = count(m_source.begin(), m_source.begin() + diff_type(searchPosition), '\n');
 	size_type lineStart;
 	if (searchPosition == 0)
 		lineStart = 0;
diff --git a/liblangutil/CharStream.h b/liblangutil/CharStream.h
index 6962864b9..aa8f01af2 100644
--- a/liblangutil/CharStream.h
+++ b/liblangutil/CharStream.h
@@ -72,7 +72,7 @@ public:
 	explicit CharStream(std::string  _source, std::string  name):
 		m_source(std::move(_source)), m_name(std::move(name)) {}
 
-	int position() const { return m_position; }
+	size_t position() const { return m_position; }
 	bool isPastEndOfInput(size_t _charsForward = 0) const { return (m_position + _charsForward) >= m_source.size(); }
 
 	char get(size_t _charsForward = 0) const { return m_source[m_position + _charsForward]; }
diff --git a/liblangutil/ParserBase.cpp b/liblangutil/ParserBase.cpp
index be8ec3eb9..c2162044a 100644
--- a/liblangutil/ParserBase.cpp
+++ b/liblangutil/ParserBase.cpp
@@ -106,7 +106,7 @@ void ParserBase::expectTokenOrConsumeUntil(Token _value, string const& _currentN
 		if (m_scanner->currentToken() == Token::EOS)
 		{
 			// rollback to where the token started, and raise exception to be caught at a higher level.
-			m_scanner->setPosition(startPosition);
+			m_scanner->setPosition(static_cast<size_t>(startPosition));
 			m_inParserRecovery = true;
 			fatalParserError(1957_error, errorLoc, msg);
 		}
diff --git a/liblangutil/Scanner.cpp b/liblangutil/Scanner.cpp
index 6cf319067..e703b5376 100644
--- a/liblangutil/Scanner.cpp
+++ b/liblangutil/Scanner.cpp
@@ -171,7 +171,7 @@ void Scanner::supportPeriodInIdentifier(bool _value)
 bool Scanner::scanHexByte(char& o_scannedByte)
 {
 	char x = 0;
-	for (int i = 0; i < 2; i++)
+	for (size_t i = 0; i < 2; i++)
 	{
 		int d = hexValue(m_char);
 		if (d < 0)
@@ -189,7 +189,7 @@ bool Scanner::scanHexByte(char& o_scannedByte)
 std::optional<unsigned> Scanner::scanUnicode()
 {
 	unsigned x = 0;
-	for (int i = 0; i < 4; i++)
+	for (size_t i = 0; i < 4; i++)
 	{
 		int d = hexValue(m_char);
 		if (d < 0)
@@ -197,7 +197,7 @@ std::optional<unsigned> Scanner::scanUnicode()
 			rollback(i);
 			return {};
 		}
-		x = x * 16 + d;
+		x = x * 16 + static_cast<size_t>(d);
 		advance();
 	}
 	return x;
@@ -207,17 +207,17 @@ std::optional<unsigned> Scanner::scanUnicode()
 void Scanner::addUnicodeAsUTF8(unsigned codepoint)
 {
 	if (codepoint <= 0x7f)
-		addLiteralChar(codepoint);
+		addLiteralChar(char(codepoint));
 	else if (codepoint <= 0x7ff)
 	{
-		addLiteralChar(0xc0 | (codepoint >> 6));
-		addLiteralChar(0x80 | (codepoint & 0x3f));
+		addLiteralChar(char(0xc0u | (codepoint >> 6u)));
+		addLiteralChar(char(0x80u | (codepoint & 0x3fu)));
 	}
 	else
 	{
-		addLiteralChar(0xe0 | (codepoint >> 12));
-		addLiteralChar(0x80 | ((codepoint >> 6) & 0x3f));
-		addLiteralChar(0x80 | (codepoint & 0x3f));
+		addLiteralChar(char(0xe0u | (codepoint >> 12u)));
+		addLiteralChar(char(0x80u | ((codepoint >> 6u) & 0x3fu)));
+		addLiteralChar(char(0x80u | (codepoint & 0x3fu)));
 	}
 }
 
@@ -225,10 +225,10 @@ void Scanner::rescan()
 {
 	size_t rollbackTo = 0;
 	if (m_skippedComments[Current].literal.empty())
-		rollbackTo = m_tokens[Current].location.start;
+		rollbackTo = static_cast<size_t>(m_tokens[Current].location.start);
 	else
-		rollbackTo = m_skippedComments[Current].location.start;
-	m_char = m_source->rollback(size_t(m_source->position()) - rollbackTo);
+		rollbackTo = static_cast<size_t>(m_skippedComments[Current].location.start);
+	m_char = m_source->rollback(m_source->position() - rollbackTo);
 	next();
 	next();
 	next();
@@ -260,7 +260,7 @@ Token Scanner::selectToken(char _next, Token _then, Token _else)
 
 bool Scanner::skipWhitespace()
 {
-	int const startPosition = sourcePos();
+	size_t const startPosition = sourcePos();
 	while (isWhiteSpace(m_char))
 		advance();
 	// Return whether or not we skipped any characters.
@@ -269,7 +269,7 @@ bool Scanner::skipWhitespace()
 
 bool Scanner::skipWhitespaceExceptUnicodeLinebreak()
 {
-	int const startPosition = sourcePos();
+	size_t const startPosition = sourcePos();
 	while (isWhiteSpace(m_char) && !isUnicodeLinebreak())
 		advance();
 	// Return whether or not we skipped any characters.
@@ -309,10 +309,10 @@ bool Scanner::tryScanEndOfLine()
 	return false;
 }
 
-int Scanner::scanSingleLineDocComment()
+size_t Scanner::scanSingleLineDocComment()
 {
 	LiteralScope literal(this, LITERAL_TYPE_COMMENT);
-	int endPosition = m_source->position();
+	size_t endPosition = m_source->position();
 	advance(); //consume the last '/' at ///
 
 	skipWhitespaceExceptUnicodeLinebreak();
@@ -429,7 +429,7 @@ Token Scanner::scanMultiLineDocComment()
 
 Token Scanner::scanSlash()
 {
-	int firstSlashPosition = sourcePos();
+	int firstSlashPosition = static_cast<int>(sourcePos());
 	advance();
 	if (m_char == '/')
 	{
@@ -441,7 +441,7 @@ Token Scanner::scanSlash()
 			m_skippedComments[NextNext].location.start = firstSlashPosition;
 			m_skippedComments[NextNext].location.source = m_source;
 			m_skippedComments[NextNext].token = Token::CommentLiteral;
-			m_skippedComments[NextNext].location.end = scanSingleLineDocComment();
+			m_skippedComments[NextNext].location.end = static_cast<int>(scanSingleLineDocComment());
 			return Token::Whitespace;
 		}
 		else
@@ -467,7 +467,7 @@ Token Scanner::scanSlash()
 			m_skippedComments[NextNext].location.start = firstSlashPosition;
 			m_skippedComments[NextNext].location.source = m_source;
 			comment = scanMultiLineDocComment();
-			m_skippedComments[NextNext].location.end = sourcePos();
+			m_skippedComments[NextNext].location.end = static_cast<int>(sourcePos());
 			m_skippedComments[NextNext].token = comment;
 			if (comment == Token::Illegal)
 				return Token::Illegal; // error already set
@@ -495,7 +495,7 @@ void Scanner::scanToken()
 	do
 	{
 		// Remember the position of the next token
-		m_tokens[NextNext].location.start = sourcePos();
+		m_tokens[NextNext].location.start = static_cast<int>(sourcePos());
 		switch (m_char)
 		{
 		case '"':
@@ -690,7 +690,7 @@ void Scanner::scanToken()
 		// whitespace.
 	}
 	while (token == Token::Whitespace);
-	m_tokens[NextNext].location.end = sourcePos();
+	m_tokens[NextNext].location.end = static_cast<int>(sourcePos());
 	m_tokens[NextNext].location.source = m_source;
 	m_tokens[NextNext].token = token;
 	m_tokens[NextNext].extendedTokenInfo = make_tuple(m, n);
diff --git a/liblangutil/Scanner.h b/liblangutil/Scanner.h
index d54bb7532..5e613cfdf 100644
--- a/liblangutil/Scanner.h
+++ b/liblangutil/Scanner.h
@@ -196,7 +196,7 @@ private:
 	///@}
 
 	bool advance() { m_char = m_source->advanceAndGet(); return !m_source->isPastEndOfInput(); }
-	void rollback(int _amount) { m_char = m_source->rollback(_amount); }
+	void rollback(size_t _amount) { m_char = m_source->rollback(_amount); }
 	/// Rolls back to the start of the current token and re-runs the scanner.
 	void rescan();
 
@@ -231,7 +231,7 @@ private:
 	Token scanString();
 	Token scanHexString();
 	/// Scans a single line comment and returns its corrected end position.
-	int scanSingleLineDocComment();
+	size_t scanSingleLineDocComment();
 	Token scanMultiLineDocComment();
 	/// Scans a slash '/' and depending on the characters returns the appropriate token
 	Token scanSlash();
@@ -245,7 +245,7 @@ private:
 	bool isUnicodeLinebreak();
 
 	/// Return the current source position.
-	int sourcePos() const { return m_source->position(); }
+	size_t sourcePos() const { return m_source->position(); }
 	bool isSourcePastEndOfInput() const { return m_source->isPastEndOfInput(); }
 
 	bool m_supportPeriodInIdentifier = false;
diff --git a/liblangutil/SemVerHandler.cpp b/liblangutil/SemVerHandler.cpp
index 04b81206e..a626c5aa7 100644
--- a/liblangutil/SemVerHandler.cpp
+++ b/liblangutil/SemVerHandler.cpp
@@ -37,7 +37,7 @@ SemVerVersion::SemVerVersion(string const& _versionString)
 	{
 		unsigned v = 0;
 		for (; i != end && '0' <= *i && *i <= '9'; ++i)
-			v = v * 10 + (*i - '0');
+			v = v * 10 + unsigned(*i - '0');
 		numbers[level] = v;
 		if (level < 2)
 		{
@@ -100,10 +100,10 @@ bool SemVerMatchExpression::MatchComponent::matches(SemVerVersion const& _versio
 		int cmp = 0;
 		bool didCompare = false;
 		for (unsigned i = 0; i < levelsPresent && cmp == 0; i++)
-			if (version.numbers[i] != unsigned(-1))
+			if (version.numbers[i] != std::numeric_limits<unsigned>::max())
 			{
 				didCompare = true;
-				cmp = _version.numbers[i] - version.numbers[i];
+				cmp = static_cast<int>(_version.numbers[i] - version.numbers[i]);
 			}
 
 		if (cmp == 0 && !_version.prerelease.empty() && didCompare)
@@ -245,14 +245,14 @@ unsigned SemVerMatchExpressionParser::parseVersionPart()
 		return 0;
 	else if ('1' <= c && c <= '9')
 	{
-		unsigned v = c - '0';
+		unsigned v(c - '0');
 		// If we skip to the next token, the current number is terminated.
 		while (m_pos == startPos && '0' <= currentChar() && currentChar() <= '9')
 		{
 			c = currentChar();
-			if (v * 10 < v || v * 10 + (c - '0') < v * 10)
+			if (v * 10 < v || v * 10 + unsigned(c - '0') < v * 10)
 				throw SemVerError();
-			v = v * 10 + c - '0';
+			v = v * 10 + unsigned(c - '0');
 			nextChar();
 		}
 		return v;
diff --git a/liblangutil/SourceLocation.h b/liblangutil/SourceLocation.h
index e6f97942e..283c8a524 100644
--- a/liblangutil/SourceLocation.h
+++ b/liblangutil/SourceLocation.h
@@ -85,7 +85,7 @@ struct SourceLocation
 		assertThrow(0 <= start, SourceLocationError, "Invalid source location.");
 		assertThrow(start <= end, SourceLocationError, "Invalid source location.");
 		assertThrow(end <= int(source->source().length()), SourceLocationError, "Invalid source location.");
-		return source->source().substr(start, end - start);
+		return source->source().substr(size_t(start), size_t(end - start));
 	}
 
 	/// @returns the smallest SourceLocation that contains both @param _a and @param _b.
@@ -113,7 +113,11 @@ struct SourceLocation
 	std::shared_ptr<CharStream> source;
 };
 
-SourceLocation const parseSourceLocation(std::string const& _input, std::string const& _sourceName, size_t _maxIndex = -1);
+SourceLocation const parseSourceLocation(
+	std::string const& _input,
+	std::string const& _sourceName,
+	size_t _maxIndex = std::numeric_limits<size_t>::max()
+);
 
 /// Stream output for Location (used e.g. in boost exceptions).
 inline std::ostream& operator<<(std::ostream& _out, SourceLocation const& _location)
diff --git a/liblangutil/SourceReferenceExtractor.cpp b/liblangutil/SourceReferenceExtractor.cpp
index 0817e7750..0a6ff0421 100644
--- a/liblangutil/SourceReferenceExtractor.cpp
+++ b/liblangutil/SourceReferenceExtractor.cpp
@@ -58,11 +58,15 @@ SourceReference SourceReferenceExtractor::extract(SourceLocation const* _locatio
 
 	string line = source->lineAtPosition(_location->start);
 
-	int locationLength = isMultiline ? line.length() - start.column : end.column - start.column;
+	int locationLength =
+		isMultiline ?
+			int(line.length()) - start.column :
+			end.column - start.column;
+
 	if (locationLength > 150)
 	{
-		int const lhs = start.column + 35;
-		int const rhs = (isMultiline ? line.length() : end.column) - 35;
+		auto const lhs = static_cast<size_t>(start.column) + 35;
+		string::size_type const rhs = (isMultiline ? line.length() : static_cast<size_t>(end.column)) - 35;
 		line = line.substr(0, lhs) + " ... " + line.substr(rhs);
 		end.column = start.column + 75;
 		locationLength = 75;
@@ -70,8 +74,13 @@ SourceReference SourceReferenceExtractor::extract(SourceLocation const* _locatio
 
 	if (line.length() > 150)
 	{
-		int const len = line.length();
-		line = line.substr(max(0, start.column - 35), min(start.column, 35) + min(locationLength + 35, len - start.column));
+		int const len = static_cast<int>(line.length());
+		line = line.substr(
+			static_cast<size_t>(max(0, start.column - 35)),
+			static_cast<size_t>(min(start.column, 35)) + static_cast<size_t>(
+				min(locationLength + 35,len - start.column)
+			)
+		);
 		if (start.column + locationLength + 35 < len)
 			line += " ...";
 		if (start.column > 35)
@@ -79,7 +88,7 @@ SourceReference SourceReferenceExtractor::extract(SourceLocation const* _locatio
 			line = " ... " + line;
 			start.column = 40;
 		}
-		end.column = start.column + locationLength;
+		end.column = start.column + static_cast<int>(locationLength);
 	}
 
 	return SourceReference{
diff --git a/liblangutil/SourceReferenceFormatter.cpp b/liblangutil/SourceReferenceFormatter.cpp
index 6b1a8286a..965755a10 100644
--- a/liblangutil/SourceReferenceFormatter.cpp
+++ b/liblangutil/SourceReferenceFormatter.cpp
@@ -51,7 +51,7 @@ void SourceReferenceFormatter::printSourceLocation(SourceReference const& _ref)
 		);
 		m_stream << "^";
 		if (_ref.endColumn > _ref.startColumn + 2)
-			m_stream << string(_ref.endColumn - _ref.startColumn - 2, '-');
+			m_stream << string(static_cast<size_t>(_ref.endColumn - _ref.startColumn - 2), '-');
 		if (_ref.endColumn > _ref.startColumn + 1)
 			m_stream << "^";
 		m_stream << endl;
@@ -60,7 +60,7 @@ void SourceReferenceFormatter::printSourceLocation(SourceReference const& _ref)
 		m_stream <<
 			_ref.text <<
 			endl <<
-			string(_ref.startColumn, ' ') <<
+			string(static_cast<size_t>(_ref.startColumn), ' ') <<
 			"^ (Relevant source part starts here and spans across multiple lines)." <<
 			endl;
 }
diff --git a/liblangutil/SourceReferenceFormatterHuman.cpp b/liblangutil/SourceReferenceFormatterHuman.cpp
index b8fdba163..3560955c7 100644
--- a/liblangutil/SourceReferenceFormatterHuman.cpp
+++ b/liblangutil/SourceReferenceFormatterHuman.cpp
@@ -104,7 +104,7 @@ void SourceReferenceFormatterHuman::printSourceLocation(SourceReference const& _
 
 	if (!_ref.multiline)
 	{
-		int const locationLength = _ref.endColumn - _ref.startColumn;
+		auto const locationLength = static_cast<size_t>(_ref.endColumn - _ref.startColumn);
 
 		// line 1:
 		m_stream << leftpad << ' ';
@@ -113,15 +113,17 @@ void SourceReferenceFormatterHuman::printSourceLocation(SourceReference const& _
 
 		// line 2:
 		frameColored() << line << " |";
-		m_stream << ' ' << text.substr(0, _ref.startColumn);
-		highlightColored() << text.substr(_ref.startColumn, locationLength);
-		m_stream << text.substr(_ref.endColumn) << '\n';
+
+		m_stream << ' ' << text.substr(0, static_cast<size_t>(_ref.startColumn));
+		highlightColored() << text.substr(static_cast<size_t>(_ref.startColumn), locationLength);
+		m_stream << text.substr(static_cast<size_t>(_ref.endColumn)) << '\n';
 
 		// line 3:
 		m_stream << leftpad << ' ';
 		frameColored() << '|';
-		m_stream << ' ' << replaceNonTabs(text.substr(0, _ref.startColumn), ' ');
-		diagColored() << replaceNonTabs(text.substr(_ref.startColumn, locationLength), '^');
+
+		m_stream << ' ' << replaceNonTabs(text.substr(0, static_cast<size_t>(_ref.startColumn)), ' ');
+		diagColored() << replaceNonTabs(text.substr(static_cast<size_t>(_ref.startColumn), locationLength), '^');
 		m_stream << '\n';
 	}
 	else
@@ -133,13 +135,13 @@ void SourceReferenceFormatterHuman::printSourceLocation(SourceReference const& _
 
 		// line 2:
 		frameColored() << line << " |";
-		m_stream << ' ' << text.substr(0, _ref.startColumn);
-		highlightColored() << text.substr(_ref.startColumn) << '\n';
+		m_stream << ' ' << text.substr(0, static_cast<size_t>(_ref.startColumn));
+		highlightColored() << text.substr(static_cast<size_t>(_ref.startColumn)) << '\n';
 
 		// line 3:
 		m_stream << leftpad << ' ';
 		frameColored() << '|';
-		m_stream << ' ' << replaceNonTabs(text.substr(0, _ref.startColumn), ' ');
+		m_stream << ' ' << replaceNonTabs(text.substr(0, static_cast<size_t>(_ref.startColumn)), ' ');
 		diagColored() << "^ (Relevant source part starts here and spans across multiple lines).";
 		m_stream << '\n';
 	}
diff --git a/liblangutil/Token.cpp b/liblangutil/Token.cpp
index e051bb552..70b645992 100644
--- a/liblangutil/Token.cpp
+++ b/liblangutil/Token.cpp
@@ -130,7 +130,7 @@ int parseSize(string::const_iterator _begin, string::const_iterator _end)
 {
 	try
 	{
-		unsigned int m = boost::lexical_cast<int>(boost::make_iterator_range(_begin, _end));
+		int m = boost::lexical_cast<int>(boost::make_iterator_range(_begin, _end));
 		return m;
 	}
 	catch(boost::bad_lexical_cast const&)

From e4e3f4984458b17ccd7e9aaf83513b35adfebf48 Mon Sep 17 00:00:00 2001
From: Djordje Mijovic <djordje.mijovic@gmail.com>
Date: Tue, 2 Jun 2020 15:10:14 +0200
Subject: [PATCH 5/6] Fixing signedness conversion warnings in libevmasm

Co-authored-by: Harikrishnan Mulackal <webmail.hari@gmail.com>
---
 libevmasm/Assembly.cpp                      | 50 ++++++++++-----------
 libevmasm/AssemblyItem.cpp                  | 38 ++++++++--------
 libevmasm/AssemblyItem.h                    |  6 +--
 libevmasm/BlockDeduplicator.cpp             |  7 +--
 libevmasm/CommonSubexpressionEliminator.cpp | 16 ++++---
 libevmasm/ConstantOptimiser.cpp             |  4 +-
 libevmasm/ControlFlowGraph.h                |  4 +-
 libevmasm/ExpressionClasses.cpp             |  4 +-
 libevmasm/Instruction.cpp                   |  6 +--
 libevmasm/JumpdestRemover.cpp               |  4 +-
 libevmasm/KnownState.cpp                    | 26 +++++------
 libevmasm/LinkerObject.cpp                  |  2 +-
 libevmasm/PeepholeOptimiser.cpp             | 10 ++---
 test/libevmasm/Assembler.cpp                |  4 +-
 test/libevmasm/Optimiser.cpp                | 10 ++---
 15 files changed, 98 insertions(+), 93 deletions(-)

diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp
index 296a330ab..8588832fe 100644
--- a/libevmasm/Assembly.cpp
+++ b/libevmasm/Assembly.cpp
@@ -41,7 +41,7 @@ using namespace solidity::util;
 AssemblyItem const& Assembly::append(AssemblyItem const& _i)
 {
 	assertThrow(m_deposit >= 0, AssemblyException, "Stack underflow.");
-	m_deposit += _i.deposit();
+	m_deposit += static_cast<int>(_i.deposit());
 	m_items.emplace_back(_i);
 	if (!m_items.back().location().isValid() && m_currentSourceLocation.isValid())
 		m_items.back().setLocation(m_currentSourceLocation);
@@ -77,10 +77,10 @@ string locationFromSources(StringMap const& _sourceCodes, SourceLocation const&
 		return "";
 
 	string const& source = it->second;
-	if (size_t(_location.start) >= source.size())
+	if (static_cast<size_t>(_location.start) >= source.size())
 		return "";
 
-	string cut = source.substr(_location.start, _location.end - _location.start);
+	string cut = source.substr(static_cast<size_t>(_location.start), static_cast<size_t>(_location.end - _location.start));
 	auto newLinePos = cut.find_first_of("\n");
 	if (newLinePos != string::npos)
 		cut = cut.substr(0, newLinePos) + "...";
@@ -106,7 +106,7 @@ public:
 		if (!(
 			_item.canBeFunctional() &&
 			_item.returnValues() <= 1 &&
-			_item.arguments() <= int(m_pending.size())
+			_item.arguments() <= m_pending.size()
 		))
 		{
 			flush();
@@ -117,7 +117,7 @@ public:
 		if (_item.arguments() > 0)
 		{
 			expression += "(";
-			for (int i = 0; i < _item.arguments(); ++i)
+			for (size_t i = 0; i < _item.arguments(); ++i)
 			{
 				expression += m_pending.back();
 				m_pending.pop_back();
@@ -225,12 +225,12 @@ Json::Value Assembly::assemblyJSON(map<string, unsigned> const& _sourceIndices)
 	Json::Value& collection = root[".code"] = Json::arrayValue;
 	for (AssemblyItem const& i: m_items)
 	{
-		unsigned sourceIndex = unsigned(-1);
+		int sourceIndex = -1;
 		if (i.location().source)
 		{
 			auto iter = _sourceIndices.find(i.location().source->name());
 			if (iter != _sourceIndices.end())
-				sourceIndex = iter->second;
+				sourceIndex = static_cast<int>(iter->second);
 		}
 
 		switch (i.type())
@@ -340,7 +340,7 @@ AssemblyItem Assembly::namedTag(string const& _name)
 {
 	assertThrow(!_name.empty(), AssemblyException, "Empty named tag.");
 	if (!m_namedTags.count(_name))
-		m_namedTags[_name] = size_t(newTag().data());
+		m_namedTags[_name] = static_cast<size_t>(newTag().data());
 	return AssemblyItem{Tag, m_namedTags.at(_name)};
 }
 
@@ -441,7 +441,7 @@ map<u256, u256> Assembly::optimiseInternal(
 				for (auto const& replacement: deduplicator.replacedTags())
 				{
 					assertThrow(
-						replacement.first <= size_t(-1) && replacement.second <= size_t(-1),
+						replacement.first <= numeric_limits<size_t>::max() && replacement.second <= numeric_limits<size_t>::max(),
 						OptimizerException,
 						"Invalid tag replacement."
 					);
@@ -451,8 +451,8 @@ map<u256, u256> Assembly::optimiseInternal(
 						"Replacement already known."
 					);
 					tagReplacements[replacement.first] = replacement.second;
-					if (_tagsReferencedFromOutside.erase(size_t(replacement.first)))
-						_tagsReferencedFromOutside.insert(size_t(replacement.second));
+					if (_tagsReferencedFromOutside.erase(static_cast<size_t>(replacement.first)))
+						_tagsReferencedFromOutside.insert(static_cast<size_t>(replacement.second));
 				}
 				count++;
 			}
@@ -479,7 +479,7 @@ map<u256, u256> Assembly::optimiseInternal(
 				try
 				{
 					optimisedChunk = eliminator.getOptimizedItems();
-					shouldReplace = (optimisedChunk.size() < size_t(iter - orig));
+					shouldReplace = (optimisedChunk.size() < static_cast<size_t>(iter - orig));
 				}
 				catch (StackTooDeepException const&)
 				{
@@ -544,7 +544,7 @@ LinkerObject const& Assembly::assemble() const
 			immutableReferencesBySub = linkerObject.immutableReferences;
 		}
 		for (size_t tagPos: sub->m_tagPositionsInBytecode)
-			if (tagPos != size_t(-1) && tagPos > subTagSize)
+			if (tagPos != numeric_limits<size_t>::max() && tagPos > subTagSize)
 				subTagSize = tagPos;
 	}
 
@@ -567,7 +567,7 @@ LinkerObject const& Assembly::assemble() const
 		);
 
 	size_t bytesRequiredForCode = bytesRequired(subTagSize);
-	m_tagPositionsInBytecode = vector<size_t>(m_usedTags, -1);
+	m_tagPositionsInBytecode = vector<size_t>(m_usedTags, numeric_limits<size_t>::max());
 	map<size_t, pair<size_t, size_t>> tagRef;
 	multimap<h256, unsigned> dataRef;
 	multimap<size_t, size_t> subRef;
@@ -586,7 +586,7 @@ LinkerObject const& Assembly::assemble() const
 	for (AssemblyItem const& i: m_items)
 	{
 		// store position of the invalid jump destination
-		if (i.type() != Tag && m_tagPositionsInBytecode[0] == size_t(-1))
+		if (i.type() != Tag && m_tagPositionsInBytecode[0] == numeric_limits<size_t>::max())
 			m_tagPositionsInBytecode[0] = ret.bytecode.size();
 
 		switch (i.type())
@@ -629,15 +629,15 @@ LinkerObject const& Assembly::assemble() const
 			ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
 			break;
 		case PushSub:
-			assertThrow(i.data() <= size_t(-1), AssemblyException, "");
+			assertThrow(i.data() <= numeric_limits<size_t>::max(), AssemblyException, "");
 			ret.bytecode.push_back(dataRefPush);
-			subRef.insert(make_pair(size_t(i.data()), ret.bytecode.size()));
+			subRef.insert(make_pair(static_cast<size_t>(i.data()), ret.bytecode.size()));
 			ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
 			break;
 		case PushSubSize:
 		{
-			assertThrow(i.data() <= size_t(-1), AssemblyException, "");
-			auto s = m_subs.at(size_t(i.data()))->assemble().bytecode.size();
+			assertThrow(i.data() <= numeric_limits<size_t>::max(), AssemblyException, "");
+			auto s = m_subs.at(static_cast<size_t>(i.data()))->assemble().bytecode.size();
 			i.setPushedValue(u256(s));
 			uint8_t b = max<unsigned>(1, util::bytesRequired(s));
 			ret.bytecode.push_back((uint8_t)Instruction::PUSH1 - 1 + b);
@@ -683,10 +683,10 @@ LinkerObject const& Assembly::assemble() const
 			break;
 		case Tag:
 			assertThrow(i.data() != 0, AssemblyException, "Invalid tag position.");
-			assertThrow(i.splitForeignPushTag().first == size_t(-1), AssemblyException, "Foreign tag.");
+			assertThrow(i.splitForeignPushTag().first == numeric_limits<size_t>::max(), AssemblyException, "Foreign tag.");
 			assertThrow(ret.bytecode.size() < 0xffffffffL, AssemblyException, "Tag too large.");
-			assertThrow(m_tagPositionsInBytecode[size_t(i.data())] == size_t(-1), AssemblyException, "Duplicate tag position.");
-			m_tagPositionsInBytecode[size_t(i.data())] = ret.bytecode.size();
+			assertThrow(m_tagPositionsInBytecode[static_cast<size_t>(i.data())] == numeric_limits<size_t>::max(), AssemblyException, "Duplicate tag position.");
+			m_tagPositionsInBytecode[static_cast<size_t>(i.data())] = ret.bytecode.size();
 			ret.bytecode.push_back((uint8_t)Instruction::JUMPDEST);
 			break;
 		default:
@@ -722,14 +722,14 @@ LinkerObject const& Assembly::assemble() const
 		size_t subId;
 		size_t tagId;
 		tie(subId, tagId) = i.second;
-		assertThrow(subId == size_t(-1) || subId < m_subs.size(), AssemblyException, "Invalid sub id");
+		assertThrow(subId == numeric_limits<size_t>::max() || subId < m_subs.size(), AssemblyException, "Invalid sub id");
 		std::vector<size_t> const& tagPositions =
-			subId == size_t(-1) ?
+			subId == numeric_limits<size_t>::max() ?
 			m_tagPositionsInBytecode :
 			m_subs[subId]->m_tagPositionsInBytecode;
 		assertThrow(tagId < tagPositions.size(), AssemblyException, "Reference to non-existing tag.");
 		size_t pos = tagPositions[tagId];
-		assertThrow(pos != size_t(-1), AssemblyException, "Reference to tag without position.");
+		assertThrow(pos != numeric_limits<size_t>::max(), AssemblyException, "Reference to tag without position.");
 		assertThrow(util::bytesRequired(pos) <= bytesPerTag, AssemblyException, "Tag too large for reserved space.");
 		bytesRef r(ret.bytecode.data() + i.first, bytesPerTag);
 		toBigEndian(pos, r);
diff --git a/libevmasm/AssemblyItem.cpp b/libevmasm/AssemblyItem.cpp
index 610c6f5dd..c2e9056fe 100644
--- a/libevmasm/AssemblyItem.cpp
+++ b/libevmasm/AssemblyItem.cpp
@@ -34,7 +34,7 @@ AssemblyItem AssemblyItem::toSubAssemblyTag(size_t _subId) const
 {
 	assertThrow(data() < (u256(1) << 64), util::Exception, "Tag already has subassembly set.");
 	assertThrow(m_type == PushTag || m_type == Tag, util::Exception, "");
-	size_t tag = size_t(u256(data()) & 0xffffffffffffffffULL);
+	auto tag = static_cast<size_t>(u256(data()) & 0xffffffffffffffffULL);
 	AssemblyItem r = *this;
 	r.m_type = PushTag;
 	r.setPushTagSubIdAndTag(_subId, tag);
@@ -45,8 +45,8 @@ pair<size_t, size_t> AssemblyItem::splitForeignPushTag() const
 {
 	assertThrow(m_type == PushTag || m_type == Tag, util::Exception, "");
 	u256 combined = u256(data());
-	size_t subId = size_t((combined >> 64) - 1);
-	size_t tag = size_t(combined & 0xffffffffffffffffULL);
+	size_t subId = static_cast<size_t>((combined >> 64) - 1);
+	size_t tag = static_cast<size_t>(combined & 0xffffffffffffffffULL);
 	return make_pair(subId, tag);
 }
 
@@ -54,7 +54,7 @@ void AssemblyItem::setPushTagSubIdAndTag(size_t _subId, size_t _tag)
 {
 	assertThrow(m_type == PushTag || m_type == Tag, util::Exception, "");
 	u256 data = _tag;
-	if (_subId != size_t(-1))
+	if (_subId != numeric_limits<size_t>::max())
 		data |= (u256(_subId) + 1) << 64;
 	setData(data);
 }
@@ -93,22 +93,22 @@ unsigned AssemblyItem::bytesRequired(unsigned _addressLength) const
 	assertThrow(false, InvalidOpcode, "");
 }
 
-int AssemblyItem::arguments() const
+size_t AssemblyItem::arguments() const
 {
 	if (type() == Operation)
-		return instructionInfo(instruction()).args;
+		return static_cast<size_t>(instructionInfo(instruction()).args);
 	else if (type() == AssignImmutable)
 		return 1;
 	else
 		return 0;
 }
 
-int AssemblyItem::returnValues() const
+size_t AssemblyItem::returnValues() const
 {
 	switch (m_type)
 	{
 	case Operation:
-		return instructionInfo(instruction()).ret;
+		return static_cast<size_t>(instructionInfo(instruction()).ret);
 	case Push:
 	case PushString:
 	case PushTag:
@@ -193,7 +193,7 @@ string AssemblyItem::toAssemblyText() const
 		size_t sub{0};
 		size_t tag{0};
 		tie(sub, tag) = splitForeignPushTag();
-		if (sub == size_t(-1))
+		if (sub == numeric_limits<size_t>::max())
 			text = string("tag_") + to_string(tag);
 		else
 			text = string("tag_") + to_string(sub) + "_" + to_string(tag);
@@ -201,16 +201,16 @@ string AssemblyItem::toAssemblyText() const
 	}
 	case Tag:
 		assertThrow(data() < 0x10000, AssemblyException, "Declaration of sub-assembly tag.");
-		text = string("tag_") + to_string(size_t(data())) + ":";
+		text = string("tag_") + to_string(static_cast<size_t>(data())) + ":";
 		break;
 	case PushData:
 		text = string("data_") + util::toHex(data());
 		break;
 	case PushSub:
-		text = string("dataOffset(sub_") + to_string(size_t(data())) + ")";
+		text = string("dataOffset(sub_") + to_string(static_cast<size_t>(data())) + ")";
 		break;
 	case PushSubSize:
-		text = string("dataSize(sub_") + to_string(size_t(data())) + ")";
+		text = string("dataSize(sub_") + to_string(static_cast<size_t>(data())) + ")";
 		break;
 	case PushProgramSize:
 		text = string("bytecodeSize");
@@ -262,7 +262,7 @@ ostream& solidity::evmasm::operator<<(ostream& _out, AssemblyItem const& _item)
 	case PushTag:
 	{
 		size_t subId = _item.splitForeignPushTag().first;
-		if (subId == size_t(-1))
+		if (subId == numeric_limits<size_t>::max())
 			_out << " PushTag " << _item.splitForeignPushTag().second;
 		else
 			_out << " PushTag " << subId << ":" << _item.splitForeignPushTag().second;
@@ -272,13 +272,13 @@ ostream& solidity::evmasm::operator<<(ostream& _out, AssemblyItem const& _item)
 		_out << " Tag " << _item.data();
 		break;
 	case PushData:
-		_out << " PushData " << hex << (unsigned)_item.data() << dec;
+		_out << " PushData " << hex << static_cast<unsigned>(_item.data()) << dec;
 		break;
 	case PushSub:
-		_out << " PushSub " << hex << size_t(_item.data()) << dec;
+		_out << " PushSub " << hex << static_cast<size_t>(_item.data()) << dec;
 		break;
 	case PushSubSize:
-		_out << " PushSubSize " << hex << size_t(_item.data()) << dec;
+		_out << " PushSubSize " << hex << static_cast<size_t>(_item.data()) << dec;
 		break;
 	case PushProgramSize:
 		_out << " PushProgramSize";
@@ -317,7 +317,7 @@ std::string AssemblyItem::computeSourceMapping(
 	int prevStart = -1;
 	int prevLength = -1;
 	int prevSourceIndex = -1;
-	size_t prevModifierDepth = -1;
+	int prevModifierDepth = -1;
 	char prevJump = 0;
 	for (auto const& item: _items)
 	{
@@ -328,14 +328,14 @@ std::string AssemblyItem::computeSourceMapping(
 		int length = location.start != -1 && location.end != -1 ? location.end - location.start : -1;
 		int sourceIndex =
 			location.source && _sourceIndicesMap.count(location.source->name()) ?
-			_sourceIndicesMap.at(location.source->name()) :
+			static_cast<int>(_sourceIndicesMap.at(location.source->name())) :
 			-1;
 		char jump = '-';
 		if (item.getJumpType() == evmasm::AssemblyItem::JumpType::IntoFunction)
 			jump = 'i';
 		else if (item.getJumpType() == evmasm::AssemblyItem::JumpType::OutOfFunction)
 			jump = 'o';
-		size_t modifierDepth = item.m_modifierDepth;
+		int modifierDepth = static_cast<int>(item.m_modifierDepth);
 
 		unsigned components = 5;
 		if (modifierDepth == prevModifierDepth)
diff --git a/libevmasm/AssemblyItem.h b/libevmasm/AssemblyItem.h
index fc8c63c67..6c5e01942 100644
--- a/libevmasm/AssemblyItem.h
+++ b/libevmasm/AssemblyItem.h
@@ -134,9 +134,9 @@ public:
 	/// @returns an upper bound for the number of bytes required by this item, assuming that
 	/// the value of a jump tag takes @a _addressLength bytes.
 	unsigned bytesRequired(unsigned _addressLength) const;
-	int arguments() const;
-	int returnValues() const;
-	int deposit() const { return returnValues() - arguments(); }
+	size_t arguments() const;
+	size_t returnValues() const;
+	size_t deposit() const { return returnValues() - arguments(); }
 
 	/// @returns true if the assembly item can be used in a functional context.
 	bool canBeFunctional() const;
diff --git a/libevmasm/BlockDeduplicator.cpp b/libevmasm/BlockDeduplicator.cpp
index decfee650..95aba2a01 100644
--- a/libevmasm/BlockDeduplicator.cpp
+++ b/libevmasm/BlockDeduplicator.cpp
@@ -63,8 +63,9 @@ bool BlockDeduplicator::deduplicate()
 		if (_j < m_items.size() && m_items.at(_j).type() == Tag)
 			pushSecondTag = m_items.at(_j).pushTag();
 
-		BlockIterator first{m_items.begin() + _i, m_items.end(), &pushFirstTag, &pushSelf};
-		BlockIterator second{m_items.begin() + _j, m_items.end(), &pushSecondTag, &pushSelf};
+		using diff_type = BlockIterator::difference_type;
+		BlockIterator first{m_items.begin() + diff_type(_i), m_items.end(), &pushFirstTag, &pushSelf};
+		BlockIterator second{m_items.begin() + diff_type(_j), m_items.end(), &pushSecondTag, &pushSelf};
 		BlockIterator end{m_items.end(), m_items.end()};
 
 		if (first != end && (*first).type() == Tag)
@@ -120,7 +121,7 @@ bool BlockDeduplicator::applyTagReplacement(
 			if (it != _replacements.end())
 			{
 				changed = true;
-				item.setPushTagSubIdAndTag(subId, size_t(it->second));
+				item.setPushTagSubIdAndTag(subId, static_cast<size_t>(it->second));
 			}
 		}
 	return changed;
diff --git a/libevmasm/CommonSubexpressionEliminator.cpp b/libevmasm/CommonSubexpressionEliminator.cpp
index 747f78f24..7fa5c938b 100644
--- a/libevmasm/CommonSubexpressionEliminator.cpp
+++ b/libevmasm/CommonSubexpressionEliminator.cpp
@@ -386,7 +386,11 @@ void CSECodeGenerator::generateClassElement(Id _c, bool _allowSequenced)
 			"Opcodes with more than two arguments not implemented yet."
 		);
 	for (size_t i = 0; i < arguments.size(); ++i)
-		assertThrow(m_stack[m_stackHeight - i] == arguments[i], OptimizerException, "Expected arguments not present." );
+		assertThrow(
+			m_stack[m_stackHeight - static_cast<int>(i)] == arguments[i],
+			OptimizerException,
+			"Expected arguments not present."
+		);
 
 	while (SemanticInformation::isCommutativeOperation(*expr.item) &&
 			!m_generatedItems.empty() &&
@@ -395,8 +399,8 @@ void CSECodeGenerator::generateClassElement(Id _c, bool _allowSequenced)
 		appendOrRemoveSwap(m_stackHeight - 1, itemLocation);
 	for (size_t i = 0; i < arguments.size(); ++i)
 	{
-		m_classPositions[m_stack[m_stackHeight - i]].erase(m_stackHeight - i);
-		m_stack.erase(m_stackHeight - i);
+		m_classPositions[m_stack[m_stackHeight - static_cast<int>(i)]].erase(m_stackHeight - static_cast<int>(i));
+		m_stack.erase(m_stackHeight - static_cast<int>(i));
 	}
 	appendItem(*expr.item);
 	if (expr.item->type() != Operation || instructionInfo(expr.item->instruction()).ret == 1)
@@ -467,7 +471,7 @@ void CSECodeGenerator::appendDup(int _fromPosition, SourceLocation const& _locat
 	int instructionNum = 1 + m_stackHeight - _fromPosition;
 	assertThrow(instructionNum <= 16, StackTooDeepException, "Stack too deep, try removing local variables.");
 	assertThrow(1 <= instructionNum, OptimizerException, "Invalid stack access.");
-	appendItem(AssemblyItem(dupInstruction(instructionNum), _location));
+	appendItem(AssemblyItem(dupInstruction(static_cast<unsigned>(instructionNum)), _location));
 	m_stack[m_stackHeight] = m_stack[_fromPosition];
 	m_classPositions[m_stack[m_stackHeight]].insert(m_stackHeight);
 }
@@ -480,7 +484,7 @@ void CSECodeGenerator::appendOrRemoveSwap(int _fromPosition, SourceLocation cons
 	int instructionNum = m_stackHeight - _fromPosition;
 	assertThrow(instructionNum <= 16, StackTooDeepException, "Stack too deep, try removing local variables.");
 	assertThrow(1 <= instructionNum, OptimizerException, "Invalid stack access.");
-	appendItem(AssemblyItem(swapInstruction(instructionNum), _location));
+	appendItem(AssemblyItem(swapInstruction(static_cast<unsigned>(instructionNum)), _location));
 
 	if (m_stack[m_stackHeight] != m_stack[_fromPosition])
 	{
@@ -502,5 +506,5 @@ void CSECodeGenerator::appendOrRemoveSwap(int _fromPosition, SourceLocation cons
 void CSECodeGenerator::appendItem(AssemblyItem const& _item)
 {
 	m_generatedItems.push_back(_item);
-	m_stackHeight += _item.deposit();
+	m_stackHeight += static_cast<int>(_item.deposit());
 }
diff --git a/libevmasm/ConstantOptimiser.cpp b/libevmasm/ConstantOptimiser.cpp
index 8e6d991a5..018be38ea 100644
--- a/libevmasm/ConstantOptimiser.cpp
+++ b/libevmasm/ConstantOptimiser.cpp
@@ -262,7 +262,7 @@ bool ComputeMethod::checkRepresentation(u256 const& _value, AssemblyItems const&
 		{
 		case Operation:
 		{
-			if (stack.size() < size_t(item.arguments()))
+			if (stack.size() < item.arguments())
 				return false;
 			u256* sp = &stack.back();
 			switch (item.instruction())
@@ -320,7 +320,7 @@ bool ComputeMethod::checkRepresentation(u256 const& _value, AssemblyItems const&
 
 bigint ComputeMethod::gasNeeded(AssemblyItems const& _routine) const
 {
-	size_t numExps = count(_routine.begin(), _routine.end(), Instruction::EXP);
+	auto numExps = static_cast<size_t>(count(_routine.begin(), _routine.end(), Instruction::EXP));
 	return combineGas(
 		simpleRunGas(_routine) + numExps * (GasCosts::expGas + GasCosts::expByteGas(m_params.evmVersion)),
 		// Data gas for routine: Some bytes are zero, but we ignore them.
diff --git a/libevmasm/ControlFlowGraph.h b/libevmasm/ControlFlowGraph.h
index a0c2b9632..5fceb6388 100644
--- a/libevmasm/ControlFlowGraph.h
+++ b/libevmasm/ControlFlowGraph.h
@@ -45,8 +45,8 @@ public:
 	BlockId() { *this = invalid(); }
 	explicit BlockId(unsigned _id): m_id(_id) {}
 	explicit BlockId(u256 const& _id);
-	static BlockId initial() { return BlockId(-2); }
-	static BlockId invalid() { return BlockId(-1); }
+	static BlockId initial() { return BlockId(std::numeric_limits<unsigned>::max() - 1); }
+	static BlockId invalid() { return BlockId(std::numeric_limits<unsigned>::max()); }
 
 	bool operator==(BlockId const& _other) const { return m_id == _other.m_id; }
 	bool operator!=(BlockId const& _other) const { return m_id != _other.m_id; }
diff --git a/libevmasm/ExpressionClasses.cpp b/libevmasm/ExpressionClasses.cpp
index 04686ec94..a208fabe7 100644
--- a/libevmasm/ExpressionClasses.cpp
+++ b/libevmasm/ExpressionClasses.cpp
@@ -190,7 +190,7 @@ ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr)
 		_expr.item->type() != Operation ||
 		!SemanticInformation::isDeterministic(*_expr.item)
 	)
-		return -1;
+		return numeric_limits<unsigned>::max();
 
 	if (auto match = rules.findFirstMatch(_expr, *this))
 	{
@@ -208,7 +208,7 @@ ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr)
 		return rebuildExpression(ExpressionTemplate(match->action(), _expr.item->location()));
 	}
 
-	return -1;
+	return numeric_limits<unsigned>::max();
 }
 
 ExpressionClasses::Id ExpressionClasses::rebuildExpression(ExpressionTemplate const& _template)
diff --git a/libevmasm/Instruction.cpp b/libevmasm/Instruction.cpp
index 34fef1642..0a61fbea0 100644
--- a/libevmasm/Instruction.cpp
+++ b/libevmasm/Instruction.cpp
@@ -330,8 +330,8 @@ void solidity::evmasm::eachInstruction(
 {
 	for (auto it = _mem.begin(); it < _mem.end(); ++it)
 	{
-		Instruction instr = Instruction(*it);
-		size_t additional = 0;
+		auto instr = Instruction(*it);
+		int additional = 0;
 		if (isValidInstruction(instr))
 			additional = instructionInfo(instr).additional;
 
@@ -357,7 +357,7 @@ string solidity::evmasm::disassemble(bytes const& _mem)
 	stringstream ret;
 	eachInstruction(_mem, [&](Instruction _instr, u256 const& _data) {
 		if (!isValidInstruction(_instr))
-			ret << "0x" << std::uppercase << std::hex << int(_instr) << " ";
+			ret << "0x" << std::uppercase << std::hex << static_cast<int>(_instr) << " ";
 		else
 		{
 			InstructionInfo info = instructionInfo(_instr);
diff --git a/libevmasm/JumpdestRemover.cpp b/libevmasm/JumpdestRemover.cpp
index 6be05b198..cbb498c01 100644
--- a/libevmasm/JumpdestRemover.cpp
+++ b/libevmasm/JumpdestRemover.cpp
@@ -30,7 +30,7 @@ using namespace solidity::evmasm;
 
 bool JumpdestRemover::optimise(set<size_t> const& _tagsReferencedFromOutside)
 {
-	set<size_t> references{referencedTags(m_items, -1)};
+	set<size_t> references{referencedTags(m_items, numeric_limits<size_t>::max())};
 	references.insert(_tagsReferencedFromOutside.begin(), _tagsReferencedFromOutside.end());
 
 	size_t initialSize = m_items.size();
@@ -43,7 +43,7 @@ bool JumpdestRemover::optimise(set<size_t> const& _tagsReferencedFromOutside)
 			if (_item.type() != Tag)
 				return false;
 			auto asmIdAndTag = _item.splitForeignPushTag();
-			assertThrow(asmIdAndTag.first == size_t(-1), OptimizerException, "Sub-assembly tag used as label.");
+			assertThrow(asmIdAndTag.first == numeric_limits<size_t>::max(), OptimizerException, "Sub-assembly tag used as label.");
 			size_t tag = asmIdAndTag.second;
 			return !references.count(tag);
 		}
diff --git a/libevmasm/KnownState.cpp b/libevmasm/KnownState.cpp
index 5f1ca736c..10e4a4f10 100644
--- a/libevmasm/KnownState.cpp
+++ b/libevmasm/KnownState.cpp
@@ -41,7 +41,7 @@ ostream& KnownState::stream(ostream& _out) const
 		if (!expr.item)
 			_out << " no item";
 		else if (expr.item->type() == UndefinedItem)
-			_out << " unknown " << int(expr.item->data());
+			_out << " unknown " << static_cast<int>(expr.item->data());
 		else
 			_out << *expr.item;
 		if (expr.sequenceNumber)
@@ -112,21 +112,21 @@ KnownState::StoreOperation KnownState::feedItem(AssemblyItem const& _item, bool
 			setStackElement(
 				m_stackHeight + 1,
 				stackElement(
-					m_stackHeight - int(instruction) + int(Instruction::DUP1),
+					m_stackHeight - static_cast<int>(instruction) + static_cast<int>(Instruction::DUP1),
 					_item.location()
 				)
 			);
 		else if (SemanticInformation::isSwapInstruction(_item))
 			swapStackElements(
 				m_stackHeight,
-				m_stackHeight - 1 - int(instruction) + int(Instruction::SWAP1),
+				m_stackHeight - 1 - static_cast<int>(instruction) + static_cast<int>(Instruction::SWAP1),
 				_item.location()
 			);
 		else if (instruction != Instruction::POP)
 		{
-			vector<Id> arguments(info.args);
-			for (int i = 0; i < info.args; ++i)
-				arguments[i] = stackElement(m_stackHeight - i, _item.location());
+			vector<Id> arguments(static_cast<size_t>(info.args));
+			for (size_t i = 0; i < static_cast<size_t>(info.args); ++i)
+				arguments[i] = stackElement(m_stackHeight - static_cast<int>(i), _item.location());
 			switch (_item.instruction())
 			{
 			case Instruction::SSTORE:
@@ -134,7 +134,7 @@ KnownState::StoreOperation KnownState::feedItem(AssemblyItem const& _item, bool
 				break;
 			case Instruction::SLOAD:
 				setStackElement(
-					m_stackHeight + _item.deposit(),
+					m_stackHeight + static_cast<int>(_item.deposit()),
 					loadFromStorage(arguments[0], _item.location())
 				);
 				break;
@@ -143,13 +143,13 @@ KnownState::StoreOperation KnownState::feedItem(AssemblyItem const& _item, bool
 				break;
 			case Instruction::MLOAD:
 				setStackElement(
-					m_stackHeight + _item.deposit(),
+					m_stackHeight + static_cast<int>(_item.deposit()),
 					loadFromMemory(arguments[0], _item.location())
 				);
 				break;
 			case Instruction::KECCAK256:
 				setStackElement(
-					m_stackHeight + _item.deposit(),
+					m_stackHeight + static_cast<int>(_item.deposit()),
 					applyKeccak256(arguments.at(0), arguments.at(1), _item.location())
 				);
 				break;
@@ -167,16 +167,16 @@ KnownState::StoreOperation KnownState::feedItem(AssemblyItem const& _item, bool
 				assertThrow(info.ret <= 1, InvalidDeposit, "");
 				if (info.ret == 1)
 					setStackElement(
-						m_stackHeight + _item.deposit(),
+						m_stackHeight + static_cast<int>(_item.deposit()),
 						m_expressionClasses->find(_item, arguments, _copyItem)
 					);
 			}
 		}
 		m_stackElements.erase(
-			m_stackElements.upper_bound(m_stackHeight + _item.deposit()),
+			m_stackElements.upper_bound(m_stackHeight + static_cast<int>(_item.deposit())),
 			m_stackElements.end()
 		);
-		m_stackHeight += _item.deposit();
+		m_stackHeight += static_cast<int>(_item.deposit());
 	}
 	return op;
 }
@@ -388,7 +388,7 @@ KnownState::Id KnownState::applyKeccak256(
 		bytes data;
 		for (Id a: arguments)
 			data += util::toBigEndian(*m_expressionClasses->knownConstant(a));
-		data.resize(size_t(*l));
+		data.resize(static_cast<size_t>(*l));
 		v = m_expressionClasses->find(AssemblyItem(u256(util::keccak256(data)), _location));
 	}
 	else
diff --git a/libevmasm/LinkerObject.cpp b/libevmasm/LinkerObject.cpp
index 21b213101..b7ffaac66 100644
--- a/libevmasm/LinkerObject.cpp
+++ b/libevmasm/LinkerObject.cpp
@@ -40,7 +40,7 @@ void LinkerObject::link(map<string, h160> const& _libraryAddresses)
 	std::map<size_t, std::string> remainingRefs;
 	for (auto const& linkRef: linkReferences)
 		if (h160 const* address = matchLibrary(linkRef.second, _libraryAddresses))
-			copy(address->data(), address->data() + 20, bytecode.begin() + linkRef.first);
+			copy(address->data(), address->data() + 20, bytecode.begin() + vector<uint8_t>::difference_type(linkRef.first));
 		else
 			remainingRefs.insert(linkRef);
 	linkReferences.swap(remainingRefs);
diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp
index e05abd3e4..861cae0f2 100644
--- a/libevmasm/PeepholeOptimiser.cpp
+++ b/libevmasm/PeepholeOptimiser.cpp
@@ -84,7 +84,7 @@ struct SimplePeepholeOptimizerMethod
 	{
 		if (
 			_state.i + WindowSize <= _state.items.size() &&
-			ApplyRule<Method, WindowSize>::applyRule(_state.items.begin() + _state.i, _state.out)
+			ApplyRule<Method, WindowSize>::applyRule(_state.items.begin() + static_cast<ptrdiff_t>(_state.i), _state.out)
 		)
 		{
 			_state.i += WindowSize;
@@ -303,7 +303,7 @@ struct UnreachableCode
 {
 	static bool apply(OptimiserState& _state)
 	{
-		auto it = _state.items.begin() + _state.i;
+		auto it = _state.items.begin() + static_cast<ptrdiff_t>(_state.i);
 		auto end = _state.items.end();
 		if (it == end)
 			return false;
@@ -317,13 +317,13 @@ struct UnreachableCode
 		)
 			return false;
 
-		size_t i = 1;
+		ptrdiff_t i = 1;
 		while (it + i != end && it[i].type() != Tag)
 			i++;
 		if (i > 1)
 		{
 			*_state.out = it[0];
-			_state.i += i;
+			_state.i += static_cast<size_t>(i);
 			return true;
 		}
 		else
@@ -345,7 +345,7 @@ void applyMethods(OptimiserState& _state, Method, OtherMethods... _other)
 
 size_t numberOfPops(AssemblyItems const& _items)
 {
-	return std::count(_items.begin(), _items.end(), Instruction::POP);
+	return static_cast<size_t>(std::count(_items.begin(), _items.end(), Instruction::POP));
 }
 
 }
diff --git a/test/libevmasm/Assembler.cpp b/test/libevmasm/Assembler.cpp
index a402101c4..cdb7046be 100644
--- a/test/libevmasm/Assembler.cpp
+++ b/test/libevmasm/Assembler.cpp
@@ -85,7 +85,7 @@ BOOST_AUTO_TEST_CASE(all_assembly_items)
 	// PushSubSize
 	auto sub = _assembly.appendSubroutine(_subAsmPtr);
 	// PushSub
-	_assembly.pushSubroutineOffset(size_t(sub.data()));
+	_assembly.pushSubroutineOffset(static_cast<size_t>(sub.data()));
 	// PushDeployTimeAddress
 	_assembly.append(PushDeployTimeAddress);
 	// AssignImmutable.
@@ -187,7 +187,7 @@ BOOST_AUTO_TEST_CASE(immutable)
 	_assembly.appendImmutableAssignment("someOtherImmutable");
 
 	auto sub = _assembly.appendSubroutine(_subAsmPtr);
-	_assembly.pushSubroutineOffset(size_t(sub.data()));
+	_assembly.pushSubroutineOffset(static_cast<size_t>(sub.data()));
 
 	checkCompilation(_assembly);
 
diff --git a/test/libevmasm/Optimiser.cpp b/test/libevmasm/Optimiser.cpp
index 536eaa951..4690ceddc 100644
--- a/test/libevmasm/Optimiser.cpp
+++ b/test/libevmasm/Optimiser.cpp
@@ -1227,7 +1227,7 @@ BOOST_AUTO_TEST_CASE(jumpdest_removal_subassemblies)
 	sub->append(t4.pushTag());
 	sub->append(Instruction::JUMP);
 
-	size_t subId = size_t(main.appendSubroutine(sub).data());
+	size_t subId = static_cast<size_t>(main.appendSubroutine(sub).data());
 	main.append(t1.toSubAssemblyTag(subId));
 	main.append(t1.toSubAssemblyTag(subId));
 	main.append(u256(8));
@@ -1281,10 +1281,10 @@ BOOST_AUTO_TEST_CASE(cse_remove_redundant_shift_masking)
 	if (!solidity::test::CommonOptions::get().evmVersion().hasBitwiseShifting())
 		return;
 
-	for (int i = 1; i < 256; i++)
+	for (size_t i = 1; i < 256; i++)
 	{
 		checkCSE({
-			u256(boost::multiprecision::pow(u256(2), i)-1),
+			u256(boost::multiprecision::pow(u256(2), i) - 1),
 			Instruction::CALLVALUE,
 			u256(256-i),
 			Instruction::SHR,
@@ -1309,10 +1309,10 @@ BOOST_AUTO_TEST_CASE(cse_remove_redundant_shift_masking)
 	}
 
 	// Check that opt. does NOT trigger
-	for (int i = 1; i < 255; i++)
+	for (size_t i = 1; i < 255; i++)
 	{
 		checkCSE({
-			u256(boost::multiprecision::pow(u256(2), i)-1),
+			u256(boost::multiprecision::pow(u256(2), i) - 1),
 			Instruction::CALLVALUE,
 			u256(255-i),
 			Instruction::SHR,

From 6f8b5fe53b1e28191cbbc17fd8db499890b2abfb Mon Sep 17 00:00:00 2001
From: Mathias Baumann <marenz@supradigital.org>
Date: Wed, 3 Jun 2020 13:53:11 +0200
Subject: [PATCH 6/6] Disallow override with non-public state variables

---
 Changelog.md                                             | 1 +
 libsolidity/analysis/OverrideChecker.cpp                 | 5 +++++
 .../inheritance/override/private_state_variable.sol      | 9 +++++++++
 3 files changed, 15 insertions(+)
 create mode 100644 test/libsolidity/syntaxTests/inheritance/override/private_state_variable.sol

diff --git a/Changelog.md b/Changelog.md
index ec12a214b..a1592946b 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -23,6 +23,7 @@ Bugfixes:
  * Type Checker: Fix internal compiler error when trying to decode too large static arrays.
  * Type Checker: Fix wrong compiler error when referencing an overridden function without calling it.
  * Type Checker: Fix internal compiler error when forward referencing non-literal constants from inline assembly.
+ * Type Checker: Disallow usage of override with non-public state variables.
  * NatSpec: DocString block is terminated when encountering an empty line.
  * Scanner: Fix bug when two empty NatSpec comments lead to scanning past EOL.
  * Code Generator: Trigger proper unimplemented errors on certain array copy operations.
diff --git a/libsolidity/analysis/OverrideChecker.cpp b/libsolidity/analysis/OverrideChecker.cpp
index 4b9a3b7f3..89f9a6637 100644
--- a/libsolidity/analysis/OverrideChecker.cpp
+++ b/libsolidity/analysis/OverrideChecker.cpp
@@ -481,7 +481,12 @@ void OverrideChecker::checkIllegalOverrides(ContractDefinition const& _contract)
 	for (auto const* stateVar: _contract.stateVariables())
 	{
 		if (!stateVar->isPublic())
+		{
+			if (stateVar->overrides())
+				m_errorReporter.typeError(8022_error, stateVar->location(), "Override can only be used with public state variables.");
+
 			continue;
+		}
 
 		if (contains_if(inheritedMods, MatchByName{stateVar->name()}))
 			m_errorReporter.typeError(1456_error, stateVar->location(), "Override changes modifier to public state variable.");
diff --git a/test/libsolidity/syntaxTests/inheritance/override/private_state_variable.sol b/test/libsolidity/syntaxTests/inheritance/override/private_state_variable.sol
new file mode 100644
index 000000000..400da4a8e
--- /dev/null
+++ b/test/libsolidity/syntaxTests/inheritance/override/private_state_variable.sol
@@ -0,0 +1,9 @@
+contract C1 {
+  function f() external pure returns(int) { return 42; }
+}
+
+contract C is C1 {
+   int override f;
+}
+// ----
+// TypeError: (96-110): Override can only be used with public state variables.