[Lldb-commits] [PATCH] D138407: [LLDB] Add LoongArch register definitions and operations

[Tiezhu Yang via Phabricator via lldb-commits]

seehearfeel added inline comments.


================
Comment at: lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_loongarch64.cpp:221
+
+  uint8_t *src = const_cast<uint8_t *>(data_sp->GetBytes());
+  if (src == nullptr) {
----------------
DavidSpickett wrote:
> seehearfeel wrote:
> > DavidSpickett wrote:
> > > Possibly not needed const cast.
> > If no const cast, build failed:
> > 
> > ```
> > /home/loongson/llvm.git/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux_loongarch64.cpp:221:12: error: cannot initialize a variable of type 'uint8_t *' (aka 'unsigned char *') with an rvalue of type 'const uint8_t *' (aka 'const unsigned char *')
> >   uint8_t *src = data_sp->GetBytes();
> >            ^     ~~~~~~~~~~~~~~~~~~~
> > 1 error generated.
> > ```
> Yes, for the way you've written it that makes sense. But I realise I was looking at the wrong thing here. It's fine that the GetBytes() is const because this is a WriteRegister call, that's expected.
> 
> You should be fine using `const uint8_t*` here, because you can still increment that pointer and memcpy from it. Since the pointer itself can change but the data it points to is const.
> 
> https://godbolt.org/z/9M9oqr575 might explain it better.
The correct  code are:

In ReadAllRegisterValues()

```
uint8_t *dst = data_sp->GetBytes();
```

In WriteAllRegisterValues()

```
const uint8_t *src = data_sp->GetBytes();
```

Thank you.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D138407/new/

https://reviews.llvm.org/D138407