[PATCH] D33496: [LLD][ELF] Move creation of .ARM.exidx sentinel before LinkerScript creation

[Rafael Avila de Espindola via llvm-commits]

LGTM

Thanks.

Peter Smith via Phabricator <reviews at reviews.llvm.org> writes:

> peter.smith updated this revision to Diff 100383.
> peter.smith added a comment.
>
> Updated patch to use Script->getCmd(OS) as suggested.
>
> I removed the comment "This function adds linker-created Out::* sections." as it seemed to be out of date as we don't have Out:: sections any more. I'm happy to put it back in or change it to something more specific like: " // Add any linker dependent sections that are dependent on the OutputSections"
>
>
> https://reviews.llvm.org/D33496
>
> Files:
>   ELF/Writer.cpp
>
>
> Index: ELF/Writer.cpp
> ===================================================================
> --- ELF/Writer.cpp
> +++ ELF/Writer.cpp
> @@ -1189,8 +1189,6 @@
>    if (ErrorCount)
>      return;
>  
> -  // So far we have added sections from input object files.
> -  // This function adds linker-created Out::* sections.
>    addPredefinedSections();
>    removeUnusedSyntheticSections(OutputSections);
>  
> @@ -1258,8 +1256,17 @@
>    // ARM ABI requires .ARM.exidx to be terminated by some piece of data.
>    // We have the terminater synthetic section class. Add that at the end.
>    auto *OS = dyn_cast_or_null<OutputSection>(findSection(".ARM.exidx"));
> -  if (OS && !OS->Sections.empty() && !Config->Relocatable)
> -    OS->addSection(make<ARMExidxSentinelSection>());
> +  if (!OS || OS->Sections.empty() || Config->Relocatable)
> +    return;
> +
> +  auto *Sentinel = make<ARMExidxSentinelSection>();
> +  OS->addSection(Sentinel);
> +  // If there are linker script commands existing at this point then add the
> +  // sentinel to these too.
> +  if (OutputSectionCommand *C = Script->getCmd(OS)) {
> +    auto *ISD = make<InputSectionDescription>("");
> +    ISD->Sections.push_back(Sentinel);
> +  }
>  }
>  
>  // The linker is expected to define SECNAME_start and SECNAME_end
>
>
> Index: ELF/Writer.cpp
> ===================================================================
> --- ELF/Writer.cpp
> +++ ELF/Writer.cpp
> @@ -1189,8 +1189,6 @@
>    if (ErrorCount)
>      return;
>  
> -  // So far we have added sections from input object files.
> -  // This function adds linker-created Out::* sections.
>    addPredefinedSections();
>    removeUnusedSyntheticSections(OutputSections);
>  
> @@ -1258,8 +1256,17 @@
>    // ARM ABI requires .ARM.exidx to be terminated by some piece of data.
>    // We have the terminater synthetic section class. Add that at the end.
>    auto *OS = dyn_cast_or_null<OutputSection>(findSection(".ARM.exidx"));
> -  if (OS && !OS->Sections.empty() && !Config->Relocatable)
> -    OS->addSection(make<ARMExidxSentinelSection>());
> +  if (!OS || OS->Sections.empty() || Config->Relocatable)
> +    return;
> +
> +  auto *Sentinel = make<ARMExidxSentinelSection>();
> +  OS->addSection(Sentinel);
> +  // If there are linker script commands existing at this point then add the
> +  // sentinel to these too.
> +  if (OutputSectionCommand *C = Script->getCmd(OS)) {
> +    auto *ISD = make<InputSectionDescription>("");
> +    ISD->Sections.push_back(Sentinel);
> +  }
>  }
>  
>  // The linker is expected to define SECNAME_start and SECNAME_end