[PATCH] D112735: export unique symbol list for xcoff with llvm-objdump new option "--export-unique-symbol"

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: llvm/include/llvm/Object/SymbolicFile.h:122
                                  // (IR only)
+    SF_Protected = 1U << 12,     // Symbol has protected visibility
+    SF_Internal = 1U << 13       // Symbol has internal visibility
----------------
DiggerLin wrote:
> MaskRay wrote:
> > I don't think we need new bits.
> > 
> > If internal visibility has similar behavior with hidden visibility, just reuse it or not set symbol properties at all.
> > 
> > I am mostly concerned with the fact that BFD style describing all binary format's every symbol property simply does not work.
> we need the "protected" visibility in xcoff object file.
> 
> The AIX linker  accepts 4 of such visibility attribute types:
> 
> export: Symbol is exported with the global export attribute.
> hidden: Symbol is not exported.
> protected: Symbol is exported but cannot be rebound (preempted), even if runtime linking is being used.
> internal: Symbol is not exported. The address of the symbol must not be provided to other programs or shared objects, but the linker does not verify this.
> 
>  please  reference 
> 1. [[ https://www.ibm.com/docs/en/aix/7.1?topic=formats-xcoff-object-file-format | xcoff-object-file-format ]] . (search "Symbol visibility" in file". )
> 
> 2. https://developer.ibm.com/articles/au-aix-symbol-visibility/ , search 'STV_PROTECTED"
> 
Thanks for the pointers. But see my comment below: the request is about removing the unneeded `SF_*` abstraction.


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  https://reviews.llvm.org/D112735/new/

https://reviews.llvm.org/D112735