[LLVMdev] possible bug in COFFObjectFile::getSymbolType()

[David Majnemer]

I believe this is fixed in r220952.

On Tue, Aug 26, 2014 at 4:12 PM, Ted Woodward <ted.woodward at codeaurora.org>
wrote:

> The section is .text, so I assume it’s got IMAGE_SCM_CNT_CODE set. The
> problem is the symbol is marked (read & execute), but the test is (read &
> !write), so the symbol gets marked as ST_Data instead of ST_Other.
>
>
>
> *From:* David Majnemer [mailto:david.majnemer at gmail.com]
> *Sent:* Friday, August 22, 2014 5:44 PM
> *To:* Ted Woodward
> *Cc:* LLVM Developers Mailing List
> *Subject:* Re: [LLVMdev] possible bug in COFFObjectFile::getSymbolType()
>
>
>
> COFF sections also contain stuff like IMAGE_SCN_CNT_CODE and
> IMAGE_SCN_CNT_INITIALIZED_DATA.  Are either of those set on the section in
> question?
>
>
>
> It may make more sense to try to key off of those section characteristics
> as well.
>
>
>
> On Fri, Aug 22, 2014 at 9:55 AM, Ted Woodward <ted.woodward at codeaurora.org>
> wrote:
>
> I’m working on adding data detection to llvm-objdump, so it prints out raw
> data for symbols with type SymbolRef::ST_Data instead of disassembling
> them. This causes llvm/test/MC/ARM/Windows/mov32t-range.s to fail, because
> the symbol “truncation” comes back as SymbolRef::ST_Data, and the code gets
> dumped as bytes instead of disassembled.
>
>
>
> I traced the problem back to COFFObjectFile::getSymbolType() in
> llvm/lib/Object/COFFObjectFile.cpp :
>
>     if (Characteristics & COFF::IMAGE_SCN_MEM_READ &&
>
>         ~Characteristics & COFF::IMAGE_SCN_MEM_WRITE) // Read only.
>
>       Result = SymbolRef::ST_Data;
>
>
>
> I think it should also check for ~Characteristics &
> COFF::IMAGE_SCN_MEM_EXECUTE. The symbol, in this case, is READ, EXECUTE,
> !WRITE.
>
>
>
>     if (Characteristics & COFF::IMAGE_SCN_MEM_READ &&
>
>         ~Characteristics & COFF::IMAGE_SCN_MEM_WRITE &&
>
>         ~Characteristics & COFF::IMAGE_SCN_MEM_EXECUTE) // Read only, not
> execute.
>
>       Result = SymbolRef::ST_Data;
>
>
>
> I’m not very familiar with COFF; what ramifications would this change have?
>
>
>
> Ted
>
>
>
>
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>
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