Merge pull request #6909 from ethereum/yul-delete-operation

[Sol->Yul] Make IRStorageItem work with dynamic offsets

libsolidity/codegen/YulUtilFunctions.cpp

@@ -224,34 +224,45 @@ string YulUtilFunctions::shiftLeftFunction(size_t _numBits)
 	solAssert(_numBits < 256, "");
 
 	string functionName = "shift_left_" + to_string(_numBits);
-	if (m_evmVersion.hasBitwiseShifting())
-	{
-		return m_functionCollector->createFunction(functionName, [&]() {
-			return
-				Whiskers(R"(
-				function <functionName>(value) -> newValue {
-					newValue := shl(<numBits>, value)
-				}
-				)")
-				("functionName", functionName)
-				("numBits", to_string(_numBits))
-				.render();
-		});
-	}
-	else
-	{
-		return m_functionCollector->createFunction(functionName, [&]() {
-			return
-				Whiskers(R"(
-				function <functionName>(value) -> newValue {
-					newValue := mul(value, <multiplier>)
-				}
-				)")
-				("functionName", functionName)
-				("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
-				.render();
-		});
-	}
+	return m_functionCollector->createFunction(functionName, [&]() {
+		return
+			Whiskers(R"(
+			function <functionName>(value) -> newValue {
+				newValue :=
+				<?hasShifts>
+					shl(<numBits>, value)
+				<!hasShifts>
+					mul(value, <multiplier>)
+				</hasShifts>
+			}
+			)")
+			("functionName", functionName)
+			("numBits", to_string(_numBits))
+			("hasShifts", m_evmVersion.hasBitwiseShifting())
+			("multiplier", toCompactHexWithPrefix(u256(1) << _numBits))
+			.render();
+	});
+}
+
+string YulUtilFunctions::dynamicShiftLeftFunction()
+{
+	string functionName = "shift_left";
+	return m_functionCollector->createFunction(functionName, [&]() {
+		return
+			Whiskers(R"(
+			function <functionName>(bits, value) -> newValue {
+				newValue :=
+				<?hasShifts>
+					shl(bits, value)
+				<!hasShifts>
+					mul(value, exp(2, bits))
+				</hasShifts>
+			}
+			)")
+			("functionName", functionName)
+			("hasShifts", m_evmVersion.hasBitwiseShifting())
+			.render();
+	});
 }
 
 string YulUtilFunctions::shiftRightFunction(size_t _numBits)
@@ -261,7 +272,7 @@ string YulUtilFunctions::shiftRightFunction(size_t _numBits)
 	// Note that if this is extended with signed shifts,
 	// the opcodes SAR and SDIV behave differently with regards to rounding!
 
-	string functionName = "shift_right_" + to_string(_numBits) + "_unsigned_" + m_evmVersion.name();
+	string functionName = "shift_right_" + to_string(_numBits) + "_unsigned";
 	return m_functionCollector->createFunction(functionName, [&]() {
 		return
 			Whiskers(R"(
@@ -282,6 +293,30 @@ string YulUtilFunctions::shiftRightFunction(size_t _numBits)
 	});
 }
 
+string YulUtilFunctions::dynamicShiftRightFunction()
+{
+	// Note that if this is extended with signed shifts,
+	// the opcodes SAR and SDIV behave differently with regards to rounding!
+
+	string const functionName = "shift_right_unsigned";
+	return m_functionCollector->createFunction(functionName, [&]() {
+		return
+			Whiskers(R"(
+			function <functionName>(bits, value) -> newValue {
+				newValue :=
+				<?hasShifts>
+					shr(bits, value)
+				<!hasShifts>
+					div(value, exp(2, bits))
+				</hasShifts>
+			}
+			)")
+			("functionName", functionName)
+			("hasShifts", m_evmVersion.hasBitwiseShifting())
+			.render();
+	});
+}
+
 string YulUtilFunctions::updateByteSliceFunction(size_t _numBytes, size_t _shiftBytes)
 {
 	solAssert(_numBytes <= 32, "");
@@ -306,6 +341,29 @@ string YulUtilFunctions::updateByteSliceFunction(size_t _numBytes, size_t _shift
 	});
 }
 
+string YulUtilFunctions::dynamicUpdateByteSliceFunction(size_t _numBytes)
+{
+	solAssert(_numBytes <= 32, "");
+	size_t numBits = _numBytes * 8;
+	string functionName = "update_byte_slice_" + to_string(_numBytes);
+	return m_functionCollector->createFunction(functionName, [&]() {
+		return
+			Whiskers(R"(
+			function <functionName>(value, shiftBytes, toInsert) -> result {
+				let shiftBits := mul(shiftBytes, 8)
+				let mask := <shl>(shiftBits, <mask>)
+				toInsert := <shl>(shiftBits, toInsert)
+				value := and(value, not(mask))
+				result := or(value, and(toInsert, mask))
+			}
+			)")
+			("functionName", functionName)
+			("mask", formatNumber((bigint(1) << numBits) - 1))
+			("shl", dynamicShiftLeftFunction())
+			.render();
+	});
+}
+
 string YulUtilFunctions::roundUpFunction()
 {
 	string functionName = "round_up_to_mul_of_32";
@@ -613,6 +671,89 @@ string YulUtilFunctions::readFromStorage(Type const& _type, size_t _offset, bool
 	});
 }
 
+string YulUtilFunctions::dynamicReadFromStorage(Type const& _type, bool _splitFunctionTypes)
+{
+	solUnimplementedAssert(!_splitFunctionTypes, "");
+	string functionName =
+		"read_from_storage_" +
+		string(_splitFunctionTypes ? "split_" : "") +
+		"_" +
+		_type.identifier();
+	return m_functionCollector->createFunction(functionName, [&] {
+		solAssert(_type.sizeOnStack() == 1, "");
+		return Whiskers(R"(
+			function <functionName>(slot, offset) -> value {
+				value := <extract>(sload(slot), offset)
+			}
+		)")
+		("functionName", functionName)
+		("extract", dynamicExtractFromStorageValue(_type, false))
+		.render();
+	});
+}
+
+string YulUtilFunctions::updateStorageValueFunction(Type const& _type, boost::optional<unsigned> const _offset)
+{
+	string const functionName =
+		"update_storage_value_" +
+		(_offset.is_initialized() ? ("offset_" + to_string(*_offset)) : "") +
+		_type.identifier();
+
+	return m_functionCollector->createFunction(functionName, [&] {
+		if (_type.isValueType())
+		{
+			solAssert(_type.storageBytes() <= 32, "Invalid storage bytes size.");
+			solAssert(_type.storageBytes() > 0, "Invalid storage bytes size.");
+
+			return Whiskers(R"(
+				function <functionName>(slot, <offset>value) {
+					sstore(slot, <update>(sload(slot), <offset><prepare>(value)))
+				}
+
+			)")
+			("functionName", functionName)
+			("update",
+				_offset.is_initialized() ?
+					updateByteSliceFunction(_type.storageBytes(), *_offset) :
+					dynamicUpdateByteSliceFunction(_type.storageBytes())
+			)
+			("offset", _offset.is_initialized() ? "" : "offset, ")
+			("prepare", prepareStoreFunction(_type))
+			.render();
+		}
+		else
+		{
+			if (_type.category() == Type::Category::Array)
+				solUnimplementedAssert(false, "");
+			else if (_type.category() == Type::Category::Struct)
+				solUnimplementedAssert(false, "");
+			else
+				solAssert(false, "Invalid non-value type for assignment.");
+		}
+	});
+}
+
+string YulUtilFunctions::dynamicExtractFromStorageValue(Type const& _type, bool _splitFunctionTypes)
+{
+	solUnimplementedAssert(!_splitFunctionTypes, "");
+
+	string functionName =
+		"extract_from_storage_value_" +
+		string(_splitFunctionTypes ? "split_" : "") +
+		_type.identifier();
+	return m_functionCollector->createFunction(functionName, [&] {
+		return Whiskers(R"(
+			function <functionName>(slot_value, offset) -> value {
+				value := <cleanupStorage>(<shr>(mul(offset, 8), slot_value))
+			}
+		)")
+		("functionName", functionName)
+		("shr", dynamicShiftRightFunction())
+		("cleanupStorage", cleanupFromStorageFunction(_type, false))
+		.render();
+	});
+}
+
 string YulUtilFunctions::extractFromStorageValue(Type const& _type, size_t _offset, bool _splitFunctionTypes)
 {
 	solUnimplementedAssert(!_splitFunctionTypes, "");

libsolidity/codegen/YulUtilFunctions.h

@@ -74,13 +74,18 @@ public:
 	std::string leftAlignFunction(Type const& _type);
 
 	std::string shiftLeftFunction(size_t _numBits);
+	std::string dynamicShiftLeftFunction();
 	std::string shiftRightFunction(size_t _numBits);
+	std::string dynamicShiftRightFunction();
 
 	/// @returns the name of a function f(value, toInsert) -> newValue which replaces the
 	/// _numBytes bytes starting at byte position _shiftBytes (counted from the least significant
 	/// byte) by the _numBytes least significant bytes of `toInsert`.
 	std::string updateByteSliceFunction(size_t _numBytes, size_t _shiftBytes);
 
+	/// signature: (value, shiftBytes, toInsert) -> result
+	std::string dynamicUpdateByteSliceFunction(size_t _numBytes);
+
 	/// @returns the name of a function that rounds its input to the next multiple
 	/// of 32 or the input if it is a multiple of 32.
 	std::string roundUpFunction();
@@ -121,6 +126,7 @@ public:
 	/// @param _splitFunctionTypes if false, returns the address and function signature in a
 	/// single variable.
 	std::string readFromStorage(Type const& _type, size_t _offset, bool _splitFunctionTypes);
+	std::string dynamicReadFromStorage(Type const& _type, bool _splitFunctionTypes);
 
 	/// @returns a function that extracts a value type from storage slot that has been
 	/// retrieved already.
@@ -128,6 +134,13 @@ public:
 	/// @param _splitFunctionTypes if false, returns the address and function signature in a
 	/// single variable.
 	std::string extractFromStorageValue(Type const& _type, size_t _offset, bool _splitFunctionTypes);
+	std::string dynamicExtractFromStorageValue(Type const& _type, bool _splitFunctionTypes);
+
+	/// Returns the name of a function will write the given value to
+	/// the specified slot and offset. If offset is not given, it is expected as
+	/// runtime parameter.
+	/// signature: (slot, [offset,] value)
+	std::string updateStorageValueFunction(Type const& _type, boost::optional<unsigned> const _offset = boost::optional<unsigned>());
 
 	/// Performs cleanup after reading from a potentially compressed storage slot.
 	/// The function does not perform any validation, it just masks or sign-extends

libsolidity/codegen/ir/IRLValue.cpp

@@ -54,26 +54,37 @@ string IRLocalVariable::setToZero() const
 IRStorageItem::IRStorageItem(
 	IRGenerationContext& _context,
 	VariableDeclaration const& _varDecl
-):
-	IRLValue(_context, _varDecl.annotation().type)
+)
+:IRStorageItem(
+	_context,
+	*_varDecl.annotation().type,
+	_context.storageLocationOfVariable(_varDecl)
+)
+{ }
+
+IRStorageItem::IRStorageItem(
+	IRGenerationContext& _context,
+	Type const& _type,
+	std::pair<u256, unsigned> slot_offset
+)
+:	IRLValue(_context, &_type),
+	m_slot(toCompactHexWithPrefix(slot_offset.first)),
+	m_offset(slot_offset.second)
 {
-	u256 slot;
-	unsigned offset;
-	std::tie(slot, offset) = _context.storageLocationOfVariable(_varDecl);
-	m_slot = toCompactHexWithPrefix(slot);
-	m_offset = offset;
 }
 
 IRStorageItem::IRStorageItem(
 	IRGenerationContext& _context,
 	string _slot,
-	unsigned _offset,
+	boost::variant<string, unsigned> _offset,
 	Type const& _type
 ):
 	IRLValue(_context, &_type),
 	m_slot(move(_slot)),
-	m_offset(_offset)
+	m_offset(std::move(_offset))
 {
+	solAssert(!m_offset.empty(), "");
+	solAssert(!m_slot.empty(), "");
 }
 
 string IRStorageItem::retrieveValue() const
@@ -81,39 +92,45 @@ string IRStorageItem::retrieveValue() const
 	if (!m_type->isValueType())
 		return m_slot;
 	solUnimplementedAssert(m_type->category() != Type::Category::Function, "");
-	return m_context.utils().readFromStorage(*m_type, m_offset, false) + "(" + m_slot + ")";
+	if (m_offset.type() == typeid(string))
+		return
+			m_context.utils().dynamicReadFromStorage(*m_type, false) +
+			"(" +
+			m_slot +
+			", " +
+			boost::get<string>(m_offset) +
+			")";
+	else if (m_offset.type() == typeid(unsigned))
+		return
+			m_context.utils().readFromStorage(*m_type, boost::get<unsigned>(m_offset), false) +
+			"(" +
+			m_slot +
+			")";
+
+	solAssert(false, "");
 }
 
 string IRStorageItem::storeValue(string const& _value, Type const& _sourceType) const
 {
 	if (m_type->isValueType())
-	{
-		solAssert(m_type->storageBytes() <= 32, "Invalid storage bytes size.");
-		solAssert(m_type->storageBytes() > 0, "Invalid storage bytes size.");
-		solAssert(m_type->storageBytes() + m_offset <= 32, "");
-
 		solAssert(_sourceType == *m_type, "Different type, but might not be an error.");
 
-		return Whiskers("sstore(<slot>, <update>(sload(<slot>), <prepare>(<value>)))\n")
-			("slot", m_slot)
-			("update", m_context.utils().updateByteSliceFunction(m_type->storageBytes(), m_offset))
-			("prepare", m_context.utils().prepareStoreFunction(*m_type))
-			("value", _value)
-			.render();
-	}
-	else
-	{
-		solAssert(
-			_sourceType.category() == m_type->category(),
-			"Wrong type conversation for assignment."
-		);
-		if (m_type->category() == Type::Category::Array)
-			solUnimplementedAssert(false, "");
-		else if (m_type->category() == Type::Category::Struct)
-			solUnimplementedAssert(false, "");
-		else
-			solAssert(false, "Invalid non-value type for assignment.");
-	}
+	boost::optional<unsigned> offset;
+
+	if (m_offset.type() == typeid(unsigned))
+		offset = get<unsigned>(m_offset);
+
+	return
+		m_context.utils().updateStorageValueFunction(*m_type, offset) +
+		"(" +
+		m_slot +
+		(m_offset.type() == typeid(string) ?
+			(", " + get<string>(m_offset)) :
+			""
+		) +
+		", " +
+		_value +
+		")\n";
 }
 
 string IRStorageItem::setToZero() const

libsolidity/codegen/ir/IRLValue.h

@@ -20,8 +20,11 @@
 
 #pragma once
 
+#include <libdevcore/Common.h>
+
 #include <string>
 #include <ostream>
+#include <boost/variant.hpp>
 
 namespace dev
 {
@@ -83,7 +86,7 @@ public:
 	IRStorageItem(
 		IRGenerationContext& _context,
 		std::string _slot,
-		unsigned _offset,
+		boost::variant<std::string, unsigned> _offset,
 		Type const& _type
 	);
 	std::string retrieveValue() const override;
@@ -91,8 +94,14 @@ public:
 
 	std::string setToZero() const override;
 private:
-	std::string m_slot;
-	unsigned m_offset;
+	IRStorageItem(
+		IRGenerationContext& _context,
+		Type const& _type,
+		std::pair<u256, unsigned> slot_offset
+	);
+
+	std::string const m_slot;
+	boost::variant<std::string, unsigned> const m_offset;
 };
 
 

test/libsolidity/semanticTests/asmForLoop/for_loop_break.sol

@@ -9,5 +9,7 @@ contract C {
         }
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f() -> 6

test/libsolidity/semanticTests/asmForLoop/for_loop_continue.sol

@@ -9,5 +9,7 @@ contract C {
         }
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f() -> 5

test/libsolidity/semanticTests/asmForLoop/for_loop_nested.sol

@@ -13,6 +13,8 @@ contract C {
         }
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f(uint256): 0 -> 2
 // f(uint256): 1 -> 18

test/libsolidity/semanticTests/functionCall/named_args_overload.sol

@@ -24,6 +24,8 @@ contract C {
         return 500;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // call(uint256): 0 -> 0
 // call(uint256): 1 -> 1

test/libsolidity/semanticTests/shifts.sol

@@ -4,6 +4,7 @@ contract C {
     }
 }
 // ====
+// compileViaYul: also
 // EVMVersion: >=constantinople
 // ----
 // f(uint256): 7 -> 28

test/libsolidity/semanticTests/smoke_test_multiline.sol

@@ -3,6 +3,8 @@ contract C {
         return a + b + c + d + e;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f(uint256,uint256,uint256,uint256,uint256): 1, 1, 1, 1, 1
 // -> 5

test/libsolidity/semanticTests/smoke_test_multiline_comments.sol

@@ -3,6 +3,8 @@ contract C {
         return a + b + c + d + e;
     }
 }
+// ====
+// compileViaYul: also
 // ----
 // f(uint256,uint256,uint256,uint256,uint256): 1, 1, 1, 1, 1
 // # A comment on the function parameters. #