xmake p参数前面2次plat获取值为空

[evilbinary]

Xmake 版本

xmake v2.8.2+20230909

操作系统版本和架构

Linux evil 6.2.0-32-generic #32~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Aug 18 10:40:13 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

描述问题

带参数p 运行后，plat从get_config 中获取前面2次为nil

evil@evil:~/dev/test-xmake/hello$ xmake f -p linux -v
plat=>	nil
plat=>	nil
plat=>	linux
plat=>	linux
configure
{
    plat = linux
    ndk_stdcxx = true
    buildir = build
    mode = release
    arch = x86_64
    kind = static
    clean = true
    host = linux
    ccache = true
}





### 期待的结果

plat 前面两个不应该为空nil，应该像下面一样：

plat=>	linux
plat=>	linux
plat=>	linux
plat=>	linux

### 工程配置

xmake.lua

```lua
print('plat=>',get_config('plat'))


add_rules("mode.debug", "mode.release")

target("hello")
    set_kind("binary")
    add_files("src/*.cpp")

附加信息和错误日志

evil@evil:~/dev/test-xmake/hello$ xmake f -p linux -vD
plat=>	nil
plat=>	nil
plat=>	linux
plat=>	linux
configure
{
    mode = release
    buildir = build
    plat = linux
    ndk_stdcxx = true
    clean = true
    kind = static
    arch = x86_64
    host = linux
    ccache = true
}
```bash

[Issues-translate-bot]

Bot detected the issue body's language is not English, translate it automatically.

---

Title: xmake The value obtained by plat for the first two times of the p parameter is empty.

Xmake version

xmake v2.8.2+20230909

Operating system version and architecture

Linux evil 6.2.0-32-generic #32~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Fri Aug 18 10:40:13 UTC 2 x86_64 x86_64 x86_64 GNU/Linux

Describe the problem

After running with parameter p, plat obtains nil for the first two times from get_config.

evil@evil:~/dev/test-xmake/hello$ xmake f -p linux -v
plat=>nil
plat=>nil
plat=>linux
plat=>linux
configure
{
    plat=linux
    ndk_stdcxx = true
    buildir = build
    mode=release
    arch = x86_64
    kind = static
    clean = true
    host=linux
    ccache = true
}





### Expected results

The first two of plat should not be empty nil, they should be like the following:

plat=>linux
plat=>linux
plat=>linux
plat=>linux

### Project configuration

xmake.lua

```lua
print('plat=>',get_config('plat'))


add_rules("mode.debug", "mode.release")

target("hello")
    set_kind("binary")
    add_files("src/*.cpp")

Additional information and error logs

evil@evil:~/dev/test-xmake/hello$ xmake f -p linux -vD
plat=>nil
plat=>nil
plat=>linux
plat=>linux
configure
{
    mode=release
    buildir = build
    plat=linux
    ndk_stdcxx = true
    clean=true
    kind = static
    arch = x86_64
    host=linux
    ccache = true
}
```bash  
      

[waruqi]

1. 平台判断用 is_plat
2. 描述域配置会被解析多次，不要去用 print 调试，没意义，每次解析的域不同，可以看下文档，描述域和脚本域的区别，https://xmake.io/#/zh-cn/guide/syntax_description?id=%e9%85%8d%e7%bd%ae%e5%88%86%e7%a6%bb

前两次是有可能会空，最开始两次仅仅是在解析 rule / option 等域，即使为 nil，那个阶段还无法获取到 option config， 对后期 target 的配置行为，也不会产生影响，不影响整体配置编译，正常行为，不用去纠结这个。。如果觉得配置后的构建行为不对，直接提供编译错误以及应该正确构建的流程。

你要想调试各种配置状态，应该在脚本域中去 print

[Issues-translate-bot]

Bot detected the issue body's language is not English, translate it automatically.

---

1. Use is_plat to determine the platform
2. The description domain configuration will be parsed multiple times. Do not use print to debug. It is meaningless. The domain parsed is different each time. You can read the document, https://xmake.io/#/zh-cn/guide/syntax_description? id=%e9%85%8d%e7%bd%ae%e5%88%86%e7%a6%bb

The first two times may be empty. The first two times are only parsing the rule / option and other fields. Even if it is nil, it will not have an impact on the later target configuration behavior, but it will not affect the overall configuration compilation and normal behavior. . If you feel that the configured build behavior is wrong, directly provide the compilation error and the process that should be built correctly.