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, 24 insertions, 117 deletions

diff --git a/Compiler.h b/Compiler.h
index 1c5523e0..2ffaaa8d 100644
--- a/Compiler.h
+++ b/Compiler.h
@@ -20,133 +20,40 @@
  * Solidity AST to EVM bytecode compiler.
  */
 
-#include <libevmface/Instruction.h>
 #include <libsolidity/ASTVisitor.h>
-#include <libsolidity/Types.h>
-#include <libsolidity/Token.h>
+#include <libsolidity/CompilerUtilities.h>
 
 namespace dev {
 namespace solidity {
 
-/// A single item of compiled code that can be assembled to a single byte value in the final
-/// bytecode. Its main purpose is to inject jump labels and label references into the opcode stream,
-/// which can be resolved in the final step.
-class AssemblyItem
+class Compiler: private ASTVisitor
 {
 public:
-	enum class Type
-	{
-		CODE,    //< m_data is opcode, m_label is empty.
-		DATA,    //< m_data is actual data, m_label is empty
-		LABEL,   //< m_data is JUMPDEST opcode, m_label is id of label
-		LABELREF //< m_data is empty, m_label is id of label
-	};
-
-	explicit AssemblyItem(eth::Instruction _instruction) : m_type(Type::CODE), m_data(byte(_instruction)) {}
-	explicit AssemblyItem(byte _data): m_type(Type::DATA), m_data(_data) {}
-
-	/// Factory functions
-	static AssemblyItem labelRef(uint32_t _label) { return AssemblyItem(Type::LABELREF, 0, _label); }
-	static AssemblyItem label(uint32_t _label) { return AssemblyItem(Type::LABEL, byte(eth::Instruction::JUMPDEST), _label); }
-
-	Type getType() const { return m_type; }
-	byte getData() const { return m_data; }
-	uint32_t getLabel() const { return m_label; }
+	/// Compile the given contract and return the EVM bytecode.
+	static bytes compile(ContractDefinition& _contract);
 
 private:
-	AssemblyItem(Type _type, byte _data, uint32_t _label): m_type(_type), m_data(_data), m_label(_label) {}
-
-	Type m_type;
-	byte m_data; //< data to be written to the bytecode stream (or filled by a label if this is a LABELREF)
-	uint32_t m_label; //< the id of a label either referenced or defined by this item
+	Compiler(): m_returnTag(m_context.newTag()) {}
+
+	void compileContract(ContractDefinition& _contract);
+	void appendFunctionSelector(const std::vector<ASTPointer<FunctionDefinition> >& _functions);
+
+	virtual bool visit(FunctionDefinition& _function) override;
+	virtual bool visit(IfStatement& _ifStatement) override;
+	virtual bool visit(WhileStatement& _whileStatement) override;
+	virtual bool visit(Continue& _continue) override;
+	virtual bool visit(Break& _break) override;
+	virtual bool visit(Return& _return) override;
+	virtual bool visit(VariableDefinition& _variableDefinition) override;
+	virtual bool visit(ExpressionStatement& _expressionStatement) override;
+
+	bytes getAssembledBytecode() { return m_context.getAssembledBytecode(); }
+
+	CompilerContext m_context;
+	std::vector<eth::AssemblyItem> m_breakTags; ///< tag to jump to for a "break" statement
+	std::vector<eth::AssemblyItem> m_continueTags; ///< tag to jump to for a "continue" statement
+	eth::AssemblyItem m_returnTag; ///< tag to jump to for a "return" statement
 };
 
-using AssemblyItems = std::vector<AssemblyItem>;
-
-
-/// Context to be shared by all units that compile the same contract. Its current usage only
-/// concerns dispensing unique jump label IDs and storing their actual positions in the bytecode
-/// stream.
-class CompilerContext
-{
-public:
-	CompilerContext(): m_nextLabel(0) {}
-	uint32_t dispenseNewLabel() { return m_nextLabel++; }
-	void setLabelPosition(uint32_t _label, uint32_t _position);
-	uint32_t getLabelPosition(uint32_t _label) const;
-
-private:
-	uint32_t m_nextLabel;
-
-	std::map<uint32_t, uint32_t> m_labelPositions;
-};
-
-/// Compiler for expressions, i.e. converts an AST tree whose root is an Expression into a stream
-/// of EVM instructions. It needs a compiler context that is the same for the whole compilation
-/// unit.
-class ExpressionCompiler: public ASTVisitor
-{
-public:
-	ExpressionCompiler(CompilerContext& _compilerContext): m_currentLValue(nullptr), m_context(_compilerContext) {}
-
-	/// Compile the given expression and (re-)populate the assembly item list.
-	void compile(Expression& _expression);
-	AssemblyItems const& getAssemblyItems() const { return m_assemblyItems; }
-	bytes getAssembledBytecode() const;
-
-	/// Compile the given expression and return the assembly items right away.
-	static AssemblyItems compileExpression(CompilerContext& _context, Expression& _expression);
-
-private:
-	virtual bool visit(Assignment& _assignment) override;
-	virtual void endVisit(UnaryOperation& _unaryOperation) override;
-	virtual bool visit(BinaryOperation& _binaryOperation) override;
-	virtual void endVisit(FunctionCall& _functionCall) override;
-	virtual void endVisit(MemberAccess& _memberAccess) override;
-	virtual void endVisit(IndexAccess& _indexAccess) override;
-	virtual void endVisit(Identifier& _identifier) override;
-	virtual void endVisit(Literal& _literal) override;
-
-	/// Appends code to remove dirty higher order bits in case of an implicit promotion to a wider type.
-	void cleanHigherOrderBitsIfNeeded(Type const& _typeOnStack, Type const& _targetType);
-
-	///@{
-	///@name Append code for various operator types
-	void appendAndOrOperatorCode(BinaryOperation& _binaryOperation);
-	void appendCompareOperatorCode(Token::Value _operator, Type const& _type);
-	void appendOrdinaryBinaryOperatorCode(Token::Value _operator, Type const& _type);
-
-	void appendArithmeticOperatorCode(Token::Value _operator, Type const& _type);
-	void appendBitOperatorCode(Token::Value _operator);
-	void appendShiftOperatorCode(Token::Value _operator);
-	/// @}
-
-	/// Appends a JUMPI instruction to a new label and returns the label
-	uint32_t appendConditionalJump();
-	void appendPush(unsigned _number);
-	void appendDup(unsigned _number);
-	void appendSwap(unsigned _number);
-
-	/// Append elements to the current instruction list.
-	void append(eth::Instruction const& _instruction) { m_assemblyItems.push_back(AssemblyItem(_instruction)); }
-	void append(byte _value) { m_assemblyItems.push_back(AssemblyItem(_value)); }
-	void append(bytes const& _data);
-	void appendLabelref(byte _label) { m_assemblyItems.push_back(AssemblyItem::labelRef(_label)); }
-	void appendLabel(byte _label) { m_assemblyItems.push_back(AssemblyItem::label(_label)); }
-
-	/// Stores the value on top of the stack in the current lvalue and copies that value to the
-	/// top of the stack again
-	void storeInLValue(Expression const& _expression);
-	/// The same as storeInLValue but do not again retrieve the value to the top of the stack.
-	void moveToLValue(Expression const& _expression);
-	/// Returns the position of @a m_currentLValue in the stack, where 0 is the top of the stack.
-	unsigned stackPositionOfLValue() const;
-
-	Declaration* m_currentLValue;
-	AssemblyItems m_assemblyItems;
-	CompilerContext& m_context;
-};
-
-
 }
 }