File reorganisation.

1 files changed, 224 insertions, 0 deletions

diff --git a/libsolidity/codegen/LValue.h b/libsolidity/codegen/LValue.h
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+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	cpp-ethereum is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ * LValues for use in the expresison compiler.
+ */
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include <libevmasm/SourceLocation.h>
+#include <libsolidity/codegen/ArrayUtils.h>
+
+namespace dev
+{
+namespace solidity
+{
+
+class Declaration;
+class Type;
+class TupleType;
+class ArrayType;
+class CompilerContext;
+class VariableDeclaration;
+
+/**
+ * Abstract class used to retrieve, delete and store data in lvalues/variables.
+ */
+class LValue
+{
+protected:
+	explicit LValue(CompilerContext& _compilerContext, Type const* _dataType = nullptr):
+		m_context(_compilerContext), m_dataType(_dataType) {}
+
+public:
+	/// @returns the number of stack slots occupied by the lvalue reference
+	virtual unsigned sizeOnStack() const { return 1; }
+	/// Copies the value of the current lvalue to the top of the stack and, if @a _remove is true,
+	/// also removes the reference from the stack.
+	/// @a _location source location of the current expression, used for error reporting.
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const = 0;
+	/// Moves a value from the stack to the lvalue. Removes the value if @a _move is true.
+	/// @a _location is the source location of the expression that caused this operation.
+	/// Stack pre: value [lvalue_ref]
+	/// Stack post: if !_move: value_of(lvalue_ref)
+	virtual void storeValue(Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(), bool _move = false) const = 0;
+	/// Stores zero in the lvalue. Removes the reference from the stack if @a _removeReference is true.
+	/// @a _location is the source location of the requested operation
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const = 0;
+
+protected:
+	CompilerContext& m_context;
+	Type const* m_dataType;
+};
+
+/**
+ * Local variable that is completely stored on the stack.
+ */
+class StackVariable: public LValue
+{
+public:
+	StackVariable(CompilerContext& _compilerContext, VariableDeclaration const& _declaration);
+
+	virtual unsigned sizeOnStack() const override { return 0; }
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+
+private:
+	/// Base stack offset (@see CompilerContext::baseStackOffsetOfVariable) of the local variable.
+	unsigned m_baseStackOffset;
+	/// Number of stack elements occupied by the value (not the reference).
+	unsigned m_size;
+};
+
+/**
+ * Reference to some item in memory.
+ */
+class MemoryItem: public LValue
+{
+public:
+	MemoryItem(CompilerContext& _compilerContext, Type const& _type, bool _padded = true);
+	virtual unsigned sizeOnStack() const override { return 1; }
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+private:
+	/// Special flag to deal with byte array elements.
+	bool m_padded = false;
+};
+
+/**
+ * Reference to some item in storage. On the stack this is <storage key> <offset_inside_value>,
+ * where 0 <= offset_inside_value < 32 and an offset of i means that the value is multiplied
+ * by 2**i before storing it.
+ */
+class StorageItem: public LValue
+{
+public:
+	/// Constructs the LValue and pushes the location of @a _declaration onto the stack.
+	StorageItem(CompilerContext& _compilerContext, VariableDeclaration const& _declaration);
+	/// Constructs the LValue and assumes that the storage reference is already on the stack.
+	StorageItem(CompilerContext& _compilerContext, Type const& _type);
+	virtual unsigned sizeOnStack() const override { return 2; }
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+};
+
+/**
+ * Reference to a single byte inside a storage byte array.
+ * Stack: <storage_ref> <byte_number>
+ */
+class StorageByteArrayElement: public LValue
+{
+public:
+	/// Constructs the LValue and assumes that the storage reference is already on the stack.
+	StorageByteArrayElement(CompilerContext& _compilerContext);
+	virtual unsigned sizeOnStack() const override { return 2; }
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+};
+
+/**
+ * Reference to the "length" member of a dynamically-sized array. This is an LValue with special
+ * semantics since assignments to it might reduce its length and thus arrays members have to be
+ * deleted.
+ */
+class StorageArrayLength: public LValue
+{
+public:
+	/// Constructs the LValue, assumes that the reference to the array head is already on the stack.
+	StorageArrayLength(CompilerContext& _compilerContext, ArrayType const& _arrayType);
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+
+private:
+	ArrayType const& m_arrayType;
+};
+
+/**
+ * Tuple object that can itself hold several LValues.
+ */
+class TupleObject: public LValue
+{
+public:
+	/// Constructs the LValue assuming that the other LValues are present on the stack.
+	/// Empty unique_ptrs are possible if e.g. some values should be ignored during assignment.
+	TupleObject(CompilerContext& _compilerContext, std::vector<std::unique_ptr<LValue>>&& _lvalues);
+	virtual unsigned sizeOnStack() const;
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(
+		Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(),
+		bool _move = false
+	) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(),
+		bool _removeReference = true
+	) const override;
+
+private:
+	std::vector<std::unique_ptr<LValue>> m_lvalues;
+};
+
+}
+}