[PATCH] D32399: [LLD] Order writable executable sections before writable ones

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added inline comments.


================
Comment at: lld/ELF/Writer.cpp:698
     if (AIsExec != BIsExec)
-      return BIsExec;
+      return (A->Flags & SHF_WRITE) ? AIsExec : BIsExec;
   }
----------------
kettenis wrote:
> ruiu wrote:
> > Is there any problem if you just return `AIsExec`?
> Yes.  Then read-only executable sections would be sorted before read-only sections, which is not what we want.  Basically the current ordering is:
> 
> R
> RX
> RW <- contains .bss
> RWX
> 
> I propose we change this to
> 
> R
> RX
> RWX
> RW <- contains .bss
> 
I believe this code is correct, but this function seems a bit puzzling to me. Each decision-making code block is well-commented and clear about what it does, but as a whole it's not easy to predict what this function returns for some two sections. I want to make this as simple as your example

R
RX
RWX
RW.

Do you think you can improve this function? If you don't have a bandwidth to handle it, I'll try to simplify.


https://reviews.llvm.org/D32399