Contract compiler and also add ExpressionStatement to AST.

ExpressionStatement functions as glue between Statements and Expressions.

This way it is possible to detect when the border between statements and
expressions is crossed while walking the AST. Note that ExpressionStatement is
not the only border, almost every statement can contains expressions.

1 files changed, 83 insertions, 0 deletions

diff --git a/CompilerUtilities.h b/CompilerUtilities.h
new file mode 100644
index 00000000..90367903
--- /dev/null
+++ b/CompilerUtilities.h
@@ -0,0 +1,83 @@
+/*
+	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 2014
+ * Utilities for the solidity compiler.
+ */
+
+#pragma once
+
+#include <libevmface/Instruction.h>
+#include <liblll/Assembly.h>
+#include <libsolidity/Types.h>
+
+namespace dev {
+namespace solidity {
+
+
+/**
+ * Context to be shared by all units that compile the same contract.
+ * It stores the generated bytecode and the position of identifiers in memory and on the stack.
+ */
+class CompilerContext
+{
+public:
+	CompilerContext() {}
+
+	void startNewFunction() { m_localVariables.clear(); m_asm.setDeposit(0); }
+	void initializeLocalVariables(unsigned _numVariables);
+	void addVariable(VariableDeclaration const& _declaration) { m_localVariables.push_back(&_declaration); }
+	/// Returns the distance of the given local variable from the top of the stack.
+	int getStackPositionOfVariable(Declaration const& _declaration);
+
+	void addFunction(FunctionDefinition const& _function) { m_functionEntryLabels.insert(std::make_pair(&_function, m_asm.newTag())); }
+	eth::AssemblyItem getFunctionEntryLabel(FunctionDefinition const& _function) const;
+
+	void adjustStackOffset(int _adjustment) { m_asm.adjustDeposit(_adjustment); }
+
+	/// Appends a JUMPI instruction to a new tag and @returns the tag
+	eth::AssemblyItem appendConditionalJump() { return m_asm.appendJumpI().tag(); }
+	/// Appends a JUMPI instruction to @a _tag
+	CompilerContext& appendConditionalJumpTo(eth::AssemblyItem const& _tag) { m_asm.appendJumpI(_tag); return *this; }
+	/// Appends a JUMP to a new tag and @returns the tag
+	eth::AssemblyItem appendJump() { return m_asm.appendJump().tag(); }
+	/// Appends a JUMP to a specific tag
+	CompilerContext& appendJumpTo(eth::AssemblyItem const& _tag) { m_asm.appendJump(_tag); return *this; }
+	/// Appends pushing of a new tag and @returns the new tag.
+	eth::AssemblyItem pushNewTag() { return m_asm.append(m_asm.newPushTag()).tag(); }
+	/// @returns a new tag without pushing any opcodes or data
+	eth::AssemblyItem newTag() { return m_asm.newTag(); }
+
+	/// Append elements to the current instruction list and adjust @a m_stackOffset.
+	CompilerContext& operator<<(eth::AssemblyItem const& _item) { m_asm.append(_item); return *this; }
+	CompilerContext& operator<<(eth::Instruction _instruction) { m_asm.append(_instruction); return *this; }
+	CompilerContext& operator<<(u256 const& _value) { m_asm.append(_value); return *this; }
+	CompilerContext& operator<<(bytes const& _data) { m_asm.append(_data); return *this; }
+
+	bytes getAssembledBytecode() { return m_asm.assemble(); }
+private:
+	eth::Assembly m_asm;
+
+	/// Offsets of local variables on the stack.
+	std::vector<Declaration const*> m_localVariables;
+	/// Labels pointing to the entry points of funcitons.
+	std::map<FunctionDefinition const*, eth::AssemblyItem> m_functionEntryLabels;
+};
+
+}
+}