问题

在 HashCat 项目中，许多 OpenCL 文件中的内核函数定义如下：
```cpp
KERNEL_FQ void m20600_comp (KERN_ATTR_TMPS (omt_sha256_tmp_t))
{
...
}

参考文件：https://github.com/security-geeks/oclHashcat/blob/c4dfcf48f7f55ee370ca2e6f86f004e4d492da72/OpenCL/m20600-pure.cl#L28

我只见过以 __kernel 定义的 OpenCL 内核函数。KERNEL_FQ 能否有效替代 __kernel？如果不能，它是什么？当我尝试使用 Clang 编译 AMD 内核时，出现以下错误：

kernel-test.cl:138:1: error: unknown type name 'KERNEL_FQ'

我运行的命令是：clang -Dcl_clang_storage_class_specifiers -isystem libclc/generic/include -include clc/clc.h -target polaris11-amdgcn-- -xcl kernel-test.cl -emit-llvm -S -o kernel-test.ll

感谢提供帮助！

<details>
<summary>英文:</summary>

In the HashCat project, a lot of the OpenCL files have kernel functions defined like this:

KERNEL_FQ void m20600_comp (KERN_ATTR_TMPS (omt_sha256_tmp_t))
{
...
}

Reference File: https://github.com/security-geeks/oclHashcat/blob/c4dfcf48f7f55ee370ca2e6f86f004e4d492da72/OpenCL/m20600-pure.cl#L28

I have only seen OpenCL kernel functions defined with `__kernel`. Is KERNEL_FQ a valid replacement for `__kernel`? If not, what is it? When I try to compile the Kernel with Clang for AMD I get:

```kernel-test.cl:138:1: error: unknown type name 'KERNEL_FQ'```

The command I ran was: ```clang -Dcl_clang_storage_class_specifiers -isystem libclc/generic/include -include clc/clc.h -target polaris11-amdgcn-- -xcl kernel-test.cl -emit-llvm -S -o kernel-test.ll```

Any help is appreciated!

</details>


# 答案1
**得分**: 1

KERNEL_FQ 是一个预处理宏，也就是说，在它出现的地方，预处理器会在编译之前用其他文本替换它：https://github.com/security-geeks/oclHashcat/blob/c4dfcf48f7f55ee370ca2e6f86f004e4d492da72/OpenCL/inc_vendor.h#L66

具体来说，它用于在OpenCL和CUDA内核以及其他后端之间进行切换，重用相同的C源代码（大部分兼容），但在两者在语言特定关键字上不同的地方替换关键字。这是一个非常聪明的技巧，可以避免多次冗余实现。

<details>
<summary>英文:</summary>

KERNEL_FQ is a preprocessor macro, i.e. wherever it occurs, the preprocessor replaces it with some other text before compiling: https://github.com/security-geeks/oclHashcat/blob/c4dfcf48f7f55ee370ca2e6f86f004e4d492da72/OpenCL/inc_vendor.h#L66

Specifically it is used to switch between OpenCL and CUDA kernels and other backends, reusing the same C source code (mostly compatible) but replacing the keywords where the two differ to language-specific keywords. A very clever trick to avoid multiple redundant implememtations.

</details>