[Lldb-commits] [PATCH] D140067: Fix an ASAN bug I introduced in debugserver, accessing off the end of an array intentionally

[Adrian Prantl via Phabricator via lldb-commits]

aprantl added inline comments.


================
Comment at: lldb/tools/debugserver/source/MacOSX/arm64/DNBArchImplARM64.cpp:2026-2037
+        if (reg == gpr_pc)
+          value->value.uint64 = clear_pac_bits(
+              reinterpret_cast<uint64_t>(m_state.context.gpr.__opaque_pc));
+        else if (reg == gpr_lr)
+          value->value.uint64 = clear_pac_bits(
+              reinterpret_cast<uint64_t>(m_state.context.gpr.__opaque_lr));
+        else if (reg == gpr_sp)
----------------
jasonmolenda wrote:
> JDevlieghere wrote:
> > `reg` is a uint32_t so you could use a switch here:
> > 
> > ```
> > switch(reg) {
> >   case gpr_pc: 
> >     ...
> > }
> > ```
> I thought about that, but then I'd need a `break;` after each element and it was one extra line.  I don't have a real preference, and this was shorter.
If we are already micro-optimizing, I guess the resulting code would be shorter (and 100% UB-free) if it were
```
uint64_t val = 0;
switch(reg) {
  case gpr_pc: 
      memcpy(&val, m_state.context.gpr.__opaque_pc);
      break;
  ...
}
value->value.uint64 = clear_pac_bits(val);
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140067/new/

https://reviews.llvm.org/D140067