正确的步行方式

here . jar用于生成相应的源文件(并更改了所有 NULL 到 null 在TSqlParser.cpp中,因为冲突)。我在跟踪 doc example (以及网络上的其他示例)演示了如何实现单个规则和侦听器,这些规则和侦听器工作正常。实现多个规则时会出现问题。

#include <iostream>
#include <antlr4-runtime/antlr4-runtime.h>
#include "TSqlParser.h"
#include "TSqlLexer.h"

#include "listener.h"


int main(int argc, const char* argv[])
{
    std::ifstream stream;
    stream.open(argv[1]);

    antlr4::ANTLRInputStream input(stream);
    TSqlLexer lexer(&input);
    antlr4::CommonTokenStream tokens(&lexer);
    TSqlParser parser(&tokens);

    TreeShapeListener listener;

    //antlr4::tree::ParseTree *select_tree = parser.select_statement();
    antlr4::tree::ParseTree *update_tree = parser.update_statement();

    //antlr4::tree::ParseTreeWalker::DEFAULT.walk(&listener, select_tree);
    antlr4::tree::ParseTreeWalker::DEFAULT.walk(&listener, update_tree);

    return 0;
}

侦听器.h:

#include <antlr4-runtime/antlr4-runtime.h>
#include "TSqlParserBaseListener.h"

class TreeShapeListener : public TSqlParserBaseListener
{
public:

    void enterSelect_statement(TSqlParser::Select_statementContext*) override;
    void enterUpdate_statement(TSqlParser::Update_statementContext*) override;
};

#include "listener.h"

void TreeShapeListener::enterSelect_statement(TSqlParser::Select_statementContext *ctx)
{
    std::cout << "Hello Select\n";
}

void TreeShapeListener::enterUpdate_statement(TSqlParser::Update_statementContext *ctx)
{
    std::cout << "Hello Update\n";
}

下面是一个小测试sql文件:

SELECT TOP 1 NAME
FROM MYTABLE
WHERE SEQ = 6

UPDATE MYTABLE
SET NAME = 'Bob'
WHERE SEQ = 5

输出:

line 1:0 mismatched input 'SELECT' expecting {'UPDATE', 'WITH'}
Hello Update

如果我切换SQL语句,我将得到 Hello Update