bison

Eliminating grammar ambiguity when a rule covers a subset of another

由 北城余情 提交于 2021-01-28 02:08:27
问题 I am trying to build a small bison grammar, but am having an issue with part of the definition. Functions can be called with any expression legal on the right side (expression_list in the grammar) as arguments. The issue arises because on the left side, functions can be defined by assigning to them (an identifier followed by a list of identifiers - assignment_expression and identifier_list in the grammar) My question is how I can eliminate the ambiguity in my grammar, since the statements

How can flex return multiple terminals at one time

由 故事扮演 提交于 2021-01-27 18:51:22
问题 In order to make my question easy to understand I want to use the following example: The following code is called nonblock do-loop in fortran language DO 20 I=1, N ! line 1 DO 20 J=1, N ! line 2 ! more codes 20 CONTINUE ! line 4 Pay attention that the label 20 at line 4 means the end of both the inner do-loop and the outer do-loop. I want my flex program to parse the feature correctly: when flex reads the label 20 , it will return ENDDO terminal twice. Firstly, because I also use bison, so

Error when attempting to use a type from GNU's GMP library as the yylval type for Bison

由 浪尽此生 提交于 2021-01-27 06:37:19
问题 I'm attempting to use the type mpz_t from the GMP library as the type for yylval by including the following in the Bison file: %define api.value.type {mpz_t} I checked the generated parser and it correctly generates the line typedef mpz_t YYSTYPE , with YYSTYPE later being used to create yylval . mpz_t is typdefed as typedef __mpz_struct mpz_t[1]; in the GMP header file gmp.h . In turn, __mpz_struct is typdefed as typedef struct { // struct members here - don't believe they're important } _

docker-compose1.28.0安装中遇到的问题

由 纵然是瞬间 提交于 2021-01-24 10:16:29
在安装完成docker-compose 1.28.0的时候，执行docker-compose -v可能会报缺少glibc2.28，不需要安装python3，这不是python3的问题. 报错信息：Error loading Python lib '/tmp/_MEIluNF4X/libpython3.9.so.1.0': dlopen: /lib64/libc.so.6: version `GLIBC_2.28' not found (required by /tmp/_MEIluNF4X/libpython3.9.so.1.0) 写在前面： 先看完该文章再照着做 ，至于为什么装个glibc-2.28要升级make和gcc又要装bison呢？ 你可以忽略前两步 并且 第三步不执行sudo yum install -y bison。执行 `sudo ../configure --prefix=/usr --disable-profile --enable-add-ons --with-headers=/usr/include --with-binutils=/usr/bin` 看一下报错结果就知道了。报错信息写在文章结尾 大概就是会提示你make bison compiler太过老旧。 如果你的make本身就是4.2 那就不用升级make，跳过第二步. 本人centOS 7.

Bison one or more occurrences in grammar file

由 Deadly 提交于 2021-01-21 08:00:15
问题 My program that needs to be parsed should be of the form: program : [declaration]+ ; Which should mean: The program consists of one or more declarations. Declaration on its turn is of course defined in a similar way, and so on... Currently, I'm getting an error on the + from the Bison parser. How do I define the one or more condition in a correct way with bison? 回答1: One or more: declarations : declaration | declarations declaration ; Zero or more: declarations : /* empty */ | declarations

yylex errors for simple parser generator

由 橙三吉。 提交于 2021-01-07 01:29:21
问题 I'm just doing a homework assignment where i have to make a simple polynomial parser generator. So it has to accept assignment like: a= 2x2+2 and also evaluation like a[2] will print 10. If a is entered alone it should print 2x2+2. It should work for any polynomial. There is a typedef struct defined in another file which I'm supposed to use: typedef struct Polyn { int sign; int coeff; int exp; struct Polyn *next; } Polyn; lex file: %option noyywrap %{ #include <stdio.h> #include <string.h>

boa阅读笔记2

由 拟墨画扇 提交于 2021-01-06 02:03:20
fixup_server_root(); read_config_files(); open_logs(); server_s = create_server_socket(); init_signals(); drop_privs(); create_common_env(); build_needs_escape(); 上次我们讲到了处理命令行选项，接下来要分析一系列初始化函数，先介绍第一个函数。 static void fixup_server_root() { char *dirbuf; if (!server_root) {//如果命令行选项中没有指定server_root，则设置server_root #ifdef SERVER_ROOT //从头文件读取SERVER_ROOT的值 server_root = strdup(SERVER_ROOT); if (!server_root) { perror("strdup (SERVER_ROOT)"); exit(1); } #else //如果没有定义SERVER_ROOT，则报错退出 fputs("boa: don't know where server root is. Please #define " "SERVER_ROOT in boa.h\n" "and recompile, or use the -c

ANTLR VS FLEX&BISON

由 删除回忆录丶 提交于 2020-12-29 15:51:49
1. ANTLR可以一站式的解决词法与语法解析器的生成。 FLEX&BISON需要配合使用，一个实现词法解析器，一个实现语法解析器。 2. ANTLR通过在文法文件中的设置，可以生成多个语言代码。 options {language=Cpp;} options {language=CSharp;} options {language=Java;} options {language=Python3;} FLEX&BISON只能生成C代码。 3. ANTLR可以生成语法解析树的图形化表示，方便开发与测试。 FLEX&BISON没有。 4. ANTLR支持多种IDE的协同开发插件。 FLEX&BISON没有，是纯粹的命令行程序。 5. 语义代码，ANTLR有多种方式支持，可以在文法文件中嵌入代码，也可以使用其它方法（我估计是listener,visitor, channel这些方式，还没搞明白） FLEX&BISON只有一种方式，将用户自己的语义代码嵌入式文法文件中。 来源： oschina 链接： https://my.oschina.net/u/4406457/blog/4868286

postgresql源码安装

由 笑着哭i 提交于 2020-12-26 15:01:27
0. 前言 本文主要记录源码安装postgresql的过程，打开了debug相关内容，方便后续通过gdb进行调试。同时包含了设置postgresql系统服务相关内容，以及配置多个数据库实例的内容。 1. 环境信息 centos 7 2004， postgresql 12.4 2. 编译安装 2.1解压源码 su unzip postgres-master.zip mv postgres-master /usr/local/pgsql 2.2 安装依赖包 yum -y install gcc gcc-c++ automake autoconf libtool make readline-devel zlib-devel readline felx bison 2.3 编译安装 cd /usr/local/pgsql/ ./configure --prefix=/usr/local/pgsql --enable-debug --enable-cassert --enable-depend CFLAGS=-O0 make make install -prefix : 指定安装的目录 --enable-debug : 把所有程序和库以带有调试符号的方式编译，相当于gcc的-g --enable-cassert : 打开服务器中的断言（assertion）检查，它会检查许多”不可能发生

探索synchronized偏向锁与重量锁区别-子路老师

由 荒凉一梦 提交于 2020-12-05 15:52:53
安装CentOS-8.1.1911-x86_64-dvd1.iso（见VirtualBox安装） 下载操作内核glibc库 下载jdk上传到linux 配置环境变量 export JAVA_HOME=/usr/local/software/jdk1.8.0_251 export CLASSPATH=${JAVA_HOME}/lib export PATH=$PATH:${JAVA_HOME}/bin 如果出现 vi /etc/profile修改正确值 输入export PATH=/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin 并进行source /etc/profile 更新 环境变量配置成功 yum -y install gcc 安装c编译环境 任意目录新建build tar -zxvf glibc-2.19.tar.gz -C ./build 解压到build文件夹下 操作系统加锁使用的pthread_mutex_lock()方法，我们再次方法中打印调用的线程Id,只要有线程调用os操作系统加锁都会被打印，找到对应的方法文件 添加打印语句 头部需要添加#include <stdio.h> fprintf(stderr,"tid=%lu\n",pthread_self()); 编译文件到/usr/lib： cd glibc-2.19/
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