教你如何使用gdb调试php！

gdb：启动之后用attach pid 追踪程序
gdb [options] [executable-file [core-file or process-id]]
gdb [options] --args executable-file [inferior-arguments ...]
gdb [options] [--python|-P] script-file [script-arguments ...]

Layout names are:
   src      : Displays source and command windows. 显示源码
   asm      : Displays disassembly    and command windows. 显示汇编指令
   split : Displays source, disassembly    and command windows. 显示源码和汇编指令
   regs     : Displays register window. If    existing layout
              is source/command or    assembly/command, the 
              register window is displayed. If the
              source/assembly/command (split) is displayed, 
              the register    window is displayed with 
              the window that has current logical focus

<?php
echo date('Y-m-d', strtotime("last day of +2month", strtotime('2020-05-31')));

pm = static
pm.max_children = 1

[root@test ~]# ps aux|grep php-fpm
www        1127  0.0  0.1 279352  2816 ?        S    5月12   0:00 php-fpm: pool www
root      12224  0.0  0.0 112736   976 pts/0    S+   17:37   0:00 grep --color=auto php-fpm

[root@test ~]# gdb
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-115.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
(gdb) attach 1127
Attaching to process 1127
Reading symbols from /usr/local/php/sbin/php-fpm...done.
Reading symbols from /usr/lib64/libcrypt.so.1...Reading symbols 
from /usr/lib/debug/usr/lib64/libcrypt-2.17.so.debug...done.
done.

(gdb) b timelib_update_ts
Breakpoint 1 at 0x48ba90: file /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c, line 499.

(gdb) b do_years
`Breakpoint 3 at 0x48bb95: file /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c, line 381.`

[root@test ~]# curl localhost/3.php

(gdb) c
Continuing.

Breakpoint 1, timelib_update_ts (time=time@entry=0x7fc63ec02000, tzi=tzi@entry=0x7fc63ec75000) 
at /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c:499
499    {
(gdb) c
Continuing.

Breakpoint 3, timelib_update_ts (time=time@entry=0x7fc63ec02000, tzi=tzi@entry=0x7fc63ec75000) 
at /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c:505
505        res += do_years(time->y);
(gdb) s
do_years (year=2020) at /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c:381
381        eras = (year - 1970) / 40000;
(gdb) s
timelib_update_ts (time=time@entry=0x7fc63ec02000, tzi=tzi@entry=0x7fc63ec75000) 
at /opt/lnmp1.6/src/php-7.3.11/ext/date/lib/tm2unixtime.c:504
504        do_adjust_special(time);
(gdb) p *time
$1 = {y = 2020, m = 7, d = 31, h = 0, i = 0, s = 0, us = 0, z = 28800, tz_abbr = 0x7fc63ec71018 "CST", 
tz_info = 0x7fc63ec75000, dst = 0, relative = {y = 0, m = 2, 
    d = 0, h = 0, i = 0, s = 0, us = 0, weekday = 0, weekday_behavior = 0, first_last_day_of = 2, invert = 0, 
    days = -99999, special = {type = 0, amount = 0}, 
    have_weekday_relative = 0, have_special_relative = 0}, sse = 0, have_time = 0, have_date = 0, have_zone = 0, 
    have_relative = 1, have_weeknr_day = 0, 
  sse_uptodate = 0, tim_uptodate = 0, is_localtime = 1, zone_type = 3}
(gdb)

static timelib_sll do_years(timelib_sll year)
{
    timelib_sll i;
    timelib_sll res = 0;
    timelib_sll eras;

    eras = (year - 1970) / 40000;
    if (eras != 0) {
        year = year - (eras * 40000);
        res += (SECS_PER_ERA * eras * 100);
    }
    
    if (year >= 1970) {
        for (i = year - 1; i >= 1970; i--) {
            //判断是否是闰年，闰年366天，平年365天
            if (timelib_is_leap(i)) {
                res += (DAYS_PER_LYEAR * SECS_PER_DAY);
            } else {
                res += (DAYS_PER_YEAR * SECS_PER_DAY);
            }
        }
    } else {
        for (i = 1969; i >= year; i--) {
            if (timelib_is_leap(i)) {
                res -= (DAYS_PER_LYEAR * SECS_PER_DAY);
            } else {
                res -= (DAYS_PER_YEAR * SECS_PER_DAY);
            }
        }
    }
    return res;
}

<?php

const YEARLEEP = 366;//闰年366天
const YEAR     = 365;//平年365天

//判断是否是闰年
function is_leap($year)
{
    return ($year % 4 == 0) && ($year % 100 != 0 || $year % 400 == 0);
}

//将年转换成时间戳
function getStime($year)
{
    $res = 0;
    for ($i = $year - 1; $i >= 1970; $i--) {
        if (is_leap($i)) {
            $res += YEARLEEP * 86400;
        } else {
            $res += YEAR * 86400;
        }
    }
    //上海是东八区要减8小时
    $res -= 8 * 3600;
    return $res;
}

echo getStime('2020');