parser.h

一个纯手工的c++编译器

#ifndef _PARSER_H_
#define _PARSER_H_

#include "scaner.h"

typedef enum { kVarDec, kFunDec, kParam, kStmt, kExp } NodeKind;

typedef enum { kIf, kWhile, kGoto, kBreak, kContinue,
			   kRead, kWrite, kPrintf, kReturn, kLabel, kCall } StmtKind;

typedef enum { kOp, kConst, kID } ExpKind;

// parse-tree node
#define MAX_CHILDREN 3

class CTreeNode
{
public:
	CTreeNode() : father( NULL ), sibling( NULL ), lineno( 0 ), bArray( FALSE )
	{
		for( int i = 0; i < MAX_CHILDREN; i++ ) child[i] = NULL;
	}
	~CTreeNode() 
	{// for convenient self destruction
		for( int i = 0; i < MAX_CHILDREN; i++ ) if( child[i] ) delete child[i];
		if( sibling ) delete sibling;
		/* DO NOT DELETE father */
	}

	CTreeNode* LastSibling()
	{// get last sibling
		CTreeNode* last = this;
		while( last->sibling ) last = last->sibling;
		return last;
	}

public:
	CTreeNode*		child[ MAX_CHILDREN ];	// point to child node
	CTreeNode*		father;					// point to father node
	CTreeNode*		sibling;				// point to sibling node
	int				lineno;
	NodeKind		nodekind;
	union {
		StmtKind	stmt;
		ExpKind		exp;
	} kind;
	enum TokenType	type;
	CString			szName;
	CString			szScope;				// node function scope
	BOOL			bArray;					// is this an array declaration
	int				iArraySize;				// array size
};

// class CParser
class CParser
{
public:
	CParser( CString& str );
	virtual ~CParser();

	CTreeNode*		BuildSyntaxTree();
	void			Trace( LPCTSTR lpszPathName );

// Attributes
public:
	CTreeNode*		m_pProgram;

// Operations
private:
	// help routines
	CTreeNode*		newNode( NodeKind kind, enum TokenType type, CString& ID );
	CTreeNode*		newStmtNode( StmtKind kind, CString& ID );
	CTreeNode*		newExpNode( ExpKind kind, enum TokenType type, CString& ID );

	BOOL			match( enum TokenType type );
	void			ConsumeUntil( enum TokenType type );
	void			ConsumeUntil( enum TokenType type1, enum TokenType type2 );

	// Grammar functions
	CTreeNode*		program();
	CTreeNode*		declaration_list();
	CTreeNode*		declaration();
	CTreeNode*		var_declaration();
	CTreeNode*		fun_declaration();
	CTreeNode*		params();
	CTreeNode*		compound_stmt();
	CTreeNode*		local_declarations();
	CTreeNode*		read_stmt();
	CTreeNode*		write_stmt();
	CTreeNode*		printf_stmt();
	CTreeNode*		expression_stmt();
	CTreeNode*		subcompound_stmt();
	CTreeNode*		if_stmt();
	CTreeNode*		while_stmt();
	CTreeNode*		for_stmt();
	CTreeNode*		goto_stmt();
	CTreeNode*		break_stmt();
	CTreeNode*		continue_stmt();
	CTreeNode*		return_stmt();
	CTreeNode*		expression();
	CTreeNode*		logic1_expression();
	CTreeNode*		logic2_expression();
	CTreeNode*		simple_expression();
	CTreeNode*		additive_expression();
	CTreeNode*		term();
	CTreeNode*		logic3_expression();
	CTreeNode*		factor();
	CTreeNode*		var();
	CTreeNode*		call();
	CTreeNode*		args();

	void			write( char* format, ... );
	void			write( CString& str );
	void			PrintTree( CTreeNode* pNode );

private:
	CScaner*		m_pScaner;
	struct TOKEN	m_token, TypeToken, IDToken;// the latter two are for temporary use
	CString			m_szScope;

	CFile			m_fTraceFile;
	int				indent;// for indent of output to the trace file
};

#endif // _PARSER_H_