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

[David Spickett via Phabricator via lldb-commits]

DavidSpickett 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) {
----------------
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.


================
Comment at: lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.h:60
+  virtual bool WriteGPR() = 0;
+  virtual bool WriteFPR() = 0;
+};
----------------
seehearfeel wrote:
> DavidSpickett wrote:
> > This doesn't look right, I'd expect `bool ... () override;` here.
> Maybe we should leave it as is, the other archs do the same thing, 
> they will be override in the following file which is not implemented now:
> lldb/source/Plugins/Process/elf-core/RegisterContextPOSIXCore_loongarch64.h/cpp,
> otherwise build failed:
> 
> ```
> In file included from /home/loongson/llvm.git/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.cpp:19:
> /home/loongson/llvm.git/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.h:57:18: error: only virtual member functions can be marked 'override'
>   bool ReadGPR() override;
>                  ^~~~~~~~
> /home/loongson/llvm.git/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.h:58:18: error: only virtual member functions can be marked 'override'
>   bool ReadFPR() override;
>                  ^~~~~~~~
> /home/loongson/llvm.git/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.h:59:19: error: only virtual member functions can be marked 'override'
>   bool WriteGPR() override;
>                   ^~~~~~~~
> /home/loongson/llvm.git/lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_loongarch64.h:60:19: error: only virtual member functions can be marked 'override'
>   bool WriteFPR() override;
>                   ^~~~~~~~
> 4 errors generated.
> ```
Yes I think I was looking at one of the core file versions and didn't realise.


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

https://reviews.llvm.org/D138407