使用java语言编写PL/0编译程序的语法分析程序。

以下是使用Java语言编写PL/0编译程序的语法分析程序的示例代码：

import java.util.ArrayList;
import java.util.List;

public class Parser {
    private Lexer lexer;
    private Token currentToken;

    public Parser(Lexer lexer) {
        this.lexer = lexer;
        this.currentToken = lexer.getNextToken();
    }

    public void parse() {
        program();
    }

    private void program() {
        block();
        if (currentToken.getType() != TokenType.PERIOD) {
            throw new RuntimeException("Syntax error: period expected but " + currentToken.getValue() + " found");
        }
    }

    private void block() {
        if (currentToken.getType() == TokenType.CONST) {
            constDeclaration();
        }
        if (currentToken.getType() == TokenType.VAR) {
            varDeclaration();
        }
        while (currentToken.getType() == TokenType.PROCEDURE) {
            procedureDeclaration();
        }
        statement();
    }

    private void constDeclaration() {
        match(TokenType.CONST);
        do {
            String name = currentToken.getValue();
            match(TokenType.IDENTIFIER);
            match(TokenType.EQUAL);
            int value = Integer.parseInt(currentToken.getValue());
            match(TokenType.NUMBER);
            SymbolTable.getInstance().addConstant(name, value);
        } while (currentToken.getType() == TokenType.COMMA);
        match(TokenType.SEMICOLON);
    }

    private void varDeclaration() {
        match(TokenType.VAR);
        do {
            String name = currentToken.getValue();
            match(TokenType.IDENTIFIER);
            SymbolTable.getInstance().addVariable(name);
        } while (currentToken.getType() == TokenType.COMMA);
        match(TokenType.SEMICOLON);
    }

    private void procedureDeclaration() {
        match(TokenType.PROCEDURE);
        String name = currentToken.getValue();
        match(TokenType.IDENTIFIER);
        match(TokenType.SEMICOLON);
        BlockNode blockNode = new BlockNode();
        blockNode.setParentNode(SymbolTable.getInstance().getCurrentScope());
        SymbolTable.getInstance().enterScope(blockNode);
        procedureParams();
        match(TokenType.SEMICOLON);
        block();
        match(TokenType.SEMICOLON);
        SymbolTable.getInstance().exitScope();
        SymbolTable.getInstance().addProcedure(name, blockNode);
    }

    private void procedureParams() {
        if (currentToken.getType() != TokenType.LEFT_PARENTHESIS) {
            return;
        }
        match(TokenType.LEFT_PARENTHESIS);
        List<String> params = new ArrayList<>();
        if (currentToken.getType() == TokenType.IDENTIFIER) {
            params.add(currentToken.getValue());
            match(TokenType.IDENTIFIER);
            while (currentToken.getType() == TokenType.COMMA) {
                match(TokenType.COMMA);
                params.add(currentToken.getValue());
                match(TokenType.IDENTIFIER);
            }
        }
        SymbolTable.getInstance().addProcedureParams(params);
        match(TokenType.RIGHT_PARENTHESIS);
    }

    private void statement() {
        if (currentToken.getType() == TokenType.IDENTIFIER) {
            assignmentStatement();
        } else if (currentToken.getType() == TokenType.CALL) {
            callStatement();
        } else if (currentToken.getType() == TokenType.BEGIN) {
            compoundStatement();
        } else if (currentToken.getType() == TokenType.IF) {
            ifStatement();
        } else if (currentToken.getType() == TokenType.WHILE) {
            whileStatement();
        }
    }

    private void assignmentStatement() {
        String name = currentToken.getValue();
        match(TokenType.IDENTIFIER);
        if (currentToken.getType() == TokenType.LEFT_BRACKET) {
            match(TokenType.LEFT_BRACKET);
            expression();
            match(TokenType.RIGHT_BRACKET);
            SymbolTable.getInstance().setArrayAssignment(true);
        }
        match(TokenType.ASSIGN);
        expression();
        SymbolTable.getInstance().addAssignment(name);
    }

    private void callStatement() {
        match(TokenType.CALL);
        String name = currentToken.getValue();
        match(TokenType.IDENTIFIER);
        List<String> params = new ArrayList<>();
        if (currentToken.getType() == TokenType.LEFT_PARENTHESIS) {
            match(TokenType.LEFT_PARENTHESIS);
            if (currentToken.getType() == TokenType.IDENTIFIER) {
                params.add(currentToken.getValue());
                match(TokenType.IDENTIFIER);
                while (currentToken.getType() == TokenType.COMMA) {
                    match(TokenType.COMMA);
                    params.add(currentToken.getValue());
                    match(TokenType.IDENTIFIER);
                }
            }
            SymbolTable.getInstance().checkProcedureParams(name, params);
            match(TokenType.RIGHT_PARENTHESIS);
        }
        SymbolTable.getInstance().addCall(name);
    }

    private void compoundStatement() {
        match(TokenType.BEGIN);
        statement();
        while (currentToken.getType() == TokenType.SEMICOLON) {
            match(TokenType.SEMICOLON);
            statement();
        }
        match(TokenType.END);
    }

    private void ifStatement() {
        match(TokenType.IF);
        condition();
        match(TokenType.THEN);
        statement();
        if (currentToken.getType() == TokenType.ELSE) {
            match(TokenType.ELSE);
            statement();
        }
    }

    private void whileStatement() {
        match(TokenType.WHILE);
        condition();
        match(TokenType.DO);
        statement();
    }

    private void condition() {
        if (currentToken.getType() == TokenType.ODD) {
            match(TokenType.ODD);
            expression();
        } else {
            expression();
            TokenType operator = currentToken.getType();
            if (operator == TokenType.EQUAL || operator == TokenType.NOT_EQUAL ||
                    operator == TokenType.LESS_THAN || operator == TokenType.LESS_THAN_OR_EQUAL ||
                    operator == TokenType.GREATER_THAN || operator == TokenType.GREATER_THAN_OR_EQUAL) {
                match(operator);
                expression();
            } else {
                throw new RuntimeException("Syntax error: invalid operator " + currentToken.getValue());
            }
        }
    }

    private void expression() {
        TokenType operator = null;
        if (currentToken.getType() == TokenType.PLUS || currentToken.getType() == TokenType.MINUS) {
            operator = currentToken.getType();
            match(operator);
        }
        term();
        if (operator != null && operator == TokenType.MINUS) {
            SymbolTable.getInstance().negateLastNumber();
        }
        while (currentToken.getType() == TokenType.PLUS || currentToken.getType() == TokenType.MINUS) {
            operator = currentToken.getType();
            match(operator);
            term();
            SymbolTable.getInstance().addOperator(operator);
        }
    }

    private void term() {
        factor();
        while (currentToken.getType() == TokenType.MULTIPLY || currentToken.getType() == TokenType.DIVIDE) {
            TokenType operator = currentToken.getType();
            match(operator);
            factor();
            SymbolTable.getInstance().addOperator(operator);
        }
    }

    private void factor() {
        if (currentToken.getType() == TokenType.NUMBER) {
            int value = Integer.parseInt(currentToken.getValue());
            match(TokenType.NUMBER);
            SymbolTable.getInstance().addNumber(value);
        } else if (currentToken.getType() == TokenType.IDENTIFIER) {
            String name = currentToken.getValue();
            match(TokenType.IDENTIFIER);
            if (currentToken.getType() == TokenType.LEFT_BRACKET) {
                match(TokenType.LEFT_BRACKET);
                expression();
                match(TokenType.RIGHT_BRACKET);
                SymbolTable.getInstance().addArrayAccess(name);
            } else {
                SymbolTable.getInstance().addIdentifier(name);
            }
        } else if (currentToken.getType() == TokenType.LEFT_PARENTHESIS) {
            match(TokenType.LEFT_PARENTHESIS);
            expression();
            match(TokenType.RIGHT_PARENTHESIS);
        } else {
            throw new RuntimeException("Syntax error: invalid factor " + currentToken.getValue());
        }
    }

    private void match(TokenType expectedType) {
        if (currentToken.getType() == expectedType) {
            currentToken = lexer.getNextToken();
        } else {
            throw new RuntimeException("Syntax error: " + expectedType + " expected but " + currentToken.getValue() + " found");
        }
    }
}

这个示例代码包含了PL/0编译程序的语法分析器，它负责将词法分析器产生的标记序列转换为语法树。它使用递归下降语法分析方法，它对每个语法规则实现了一个相应的方法。每个方法都检查当前标记是否符合该语法规则，如果符合，则继续解析。如果不符合，则抛出一个运行时异常。在解析过程中，符号表也被更新，以便在后面的代码生成阶段使用。