背景

静态分析源码，只能知道源码架构流程。
但是，对于不同的输入，程序的跳转走向，动态分析源码方法更加清晰。
本文采用eclipse代替gdb命令行方式，提升动态分析源码的效率。

准备

系统：centos 7.5
软件：
1.Eclipse IDE for C/C++ Developers （需要相应的jdk及gdb版本，自行安装）
2.gdb

源码 ：PostgreSQL 11 Beta 2 Released!

安装pg

为了能够断点调试分析的执行过程，所以采用源码编译安装postgresql，启动debug相关选项。

1.解压

[appusr@postgre ~]$ tar zxvf postgresql-11beta2.tar.gz
[appusr@postgre postgresql-11beta2]$ cd postgresql-11beta2/

2.编译安装 。打开调试选项、关闭编译优化：--enable-debug CFLAGS=-O0

[appusr@postgre postgresql-11beta2]$ ./configure --with-icu --with-perl --with-python --with-tcl --with-gssapi --with-pam --with-ldap --with-openssl --with-pam --without-ldap --with-libxml --with-libxslt --enable-dtrace --enable-depend --enable-cassert --enable-profiling --with-systemd **--enable-debug CFLAGS=-O0** --prefix=/home/appusr/PostgreSQL/11.0.2/ 
[appusr@postgre postgresql-11beta2]$ make -j4
[appusr@postgre postgresql-11beta2]$ make install

注：为了做到全量代码调试，尽量打开更多的编译功能选项

3.设置环境变量：在~/.bashrc 加入以下内容

export PGHOME=/home/appusr/PostgreSQL/11.0.2export
PATH=$PGHOME/bin:/appdev/eclipse:$PATHexport
LD_LIBRARY_PATH=$PGHOME/lib:$LD_LIBRARY_PATH

执行 source ~/.bashrc

4.初始化数据库

[appusr@postgre postgresql-11beta2]$ mkdir /home/appusr/data
[appusr@postgre postgresql-11beta2]$ initdb -D /home/appusr/data

若要网络访问，请自行修改防火墙配置、postgresql.conf、pg_hba.conf

5.启动数据库：

pg_ctl -D /home/appusr/data -l /home/appusr/data/pg.log start

6.初始化数据：

REATE TABLE t_student
(sno char(9) primary key, 
 sname char(20) unique, 
 ssex char(2), 
 sage smallint, 
 sdept char(20) ); 

insert into t_student values('201215121','李勇','男',20,'CS');
insert into t_student values('201215122','刘晨','女',19,'CS');
insert into t_student values('201215123','王敏','女',18,'MA');
insert into t_student values('201215125','张立','男',19,'IS');
insert into t_student values('201215126','李一平','男',18,'IS');
insert into t_student values('201215127','张琴','女',19,'CS');
insert into t_student values('201215128','王方','女',20,'MA');
insert into t_student values('201215129','黄林林','男',21,'IS');

CREATE TABLE t_course 
(cno char(4) primary key, 
 cname char(40), 
 cpno char(4), 
 ccredit smallint);

insert into t_course values('1','数据库','5',4);
insert into t_course values('2','数学',null,2);
insert into t_course values('3','信息系统','1',4);
insert into t_course values('4','操作系统','6',3);
insert into t_course values('5','数据结构','7',4);
insert into t_course values('6','数据处理',null,2);
insert into t_course values('7','C语言','6',4);


CREATE TABLE t_sc 
(sno char(9), 
 cno char(4), 
 grade smallint, 
 primary key (sno,cno));

insert into t_sc values('201215121','1',92);
insert into t_sc values('201215121','2',85);
insert into t_sc values('201215121','3',88); 
insert into t_sc values('201215121','4',98); 
insert into t_sc values('201215121','5',89); 
insert into t_sc values('201215121','6',95); 
insert into t_sc values('201215121','7',93); 
insert into t_sc values('201215122','2',90); 
insert into t_sc values('201215122','3',80); 
insert into t_sc values('201215122','4',85); 
insert into t_sc values('201215122','6',92); 
insert into t_sc values('201215123','1',90); 
insert into t_sc values('201215123','2',84); 
insert into t_sc values('201215123','3',91); 
insert into t_sc values('201215123','4',90); 
insert into t_sc values('201215123','5',80); 
insert into t_sc values('201215123','6',78); 
insert into t_sc values('201215123','7',65); 
insert into t_sc values('201215128','1',78); 
insert into t_sc values('201215128','2',82); 
insert into t_sc values('201215128','3',77);
insert into t_sc values('201215128','4',79);
insert into t_sc values('201215128','5',92);
insert into t_sc values('201215128','6',98); 
insert into t_sc values('201215128','7',50); 
insert into t_sc values('201215125','1',67); 
insert into t_sc values('201215125','2',71); 
insert into t_sc values('201215125','3',90); 
insert into t_sc values('201215126','4',81); 
insert into t_sc values('201215126','5',90); 
insert into t_sc values('201215126','6',56); 
insert into t_sc values('201215126','7',89); 
insert into t_sc values('201215127','1',81); 
insert into t_sc values('201215127','2',72); 
insert into t_sc values('201215127','3',90); 
insert into t_sc values('201215127','4',64); 
insert into t_sc values('201215127','5',79); 
insert into t_sc values('201215127','6',50); 
insert into t_sc values('201215127','7',96);

导入工程

右键 Project Explorer ——》Import
选择 C/C++ ——》Existing Code as Makefile Project

image.png

点击 next， 填入必要信息， 去掉C++勾选，

image.png

代入代码如下

image.png

断点调试

设置Debug，新建一个 C/C++ Attach to Application

image.png

启动调试，输入绑定的pid号，点击 OK。

image.png

连接数据库fork出来的进程号是：14046
可以通过命令查询得到

select * from pg_stat_activity;

设置断点：

image.png

执行SQL命令就能进入到断点位置

select * from pg_stat_activity;

image.png

总结

断点调试postgresql，采用了gdb -p $pid 模式启动调试。
这些断点调试，在gdb中都能实现
采用eclipse 可视化集成环境调试，可以更加快捷方便，分析代码和调试程序效率更加高
不过eclipse集成环境对CPU、内存等资源消耗相对来说也比较高，如果在内存资源很低或没有界面的环境，还是得用gdb