[lldb-dev] Loading Linux core files

[Ted Woodward]

I think unknown-unknown is only useful for Hexagon, but in this case the target arch is hexagon-unknown-unknown, so not setting it would be OK.

ProcessElfCore also has this:

ArchSpec
ProcessElfCore::GetArchitecture()
{
    ObjectFileELF *core_file = (ObjectFileELF *)(m_core_module_sp->GetObjectFile());
    ArchSpec arch;
    core_file->GetArchitecture(arch);
    return arch;
}

I think it should be changed to return the target's arch if the OS is unknown. 

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-----Original Message-----
From: Jim Ingham [mailto:jingham at apple.com] 
Sent: Monday, July 13, 2015 6:39 PM
To: Ted Woodward
Cc: lldb-dev at cs.uiuc.edu
Subject: Re: [lldb-dev] Loading Linux core files

Instead of triggering off Linux, can we trigger off the fact that the core module really didn't figure out what the architecture actually is? Would unknown-unknown ever be a correct/useful response for a modules's architecture?

Jim



> On Jul 13, 2015, at 4:22 PM, Ted Woodward <ted.woodward at codeaurora.org> wrote:
> 
> I’m trying to load a core file on Ubuntu 12, but I’m getting an assert in ThreadElfCore::CreateRegisterContextForFrame() because the arch.GetTriple().getOS() returns UnknownOS instead of Linux.
>  
> I’ve stepped through loading my binary, and the target’s OS Is correctly set to Linux. But ProcessElfCore::DoLoadCore() has this code:
>     // Even if the architecture is set in the target, we need to override
>     // it to match the core file which is always single arch.
>     ArchSpec arch (m_core_module_sp->GetArchitecture());
>     if (arch.IsValid())
>         m_target.SetArchitecture(arch);
>  
> The problem is Linux core files don’t have anything in them to indicate that they are Linux. Linux is identified through a note that is added by gcc/clang, but isn’t in the core file. So x86-64-unknown-Linux gets replaced by x86-64-unknown-unknown.
>  
> I’m thinking of changing this to not override the architecture if the target’s OS is Linux. Any thoughts?
>  
> --
> Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>  
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