[Lldb-commits] [PATCH] Update ObjectFileELF to detect ELF triple based on ELF notes and the ELF header.

[Greg Clayton]

> On Jun 26, 2014, at 3:03 PM, Todd Fiala <tfiala at google.com> wrote:
> 
> Hey Greg,
> 
> On Thu, Jun 26, 2014 at 2:52 PM, Greg Clayton <gclayton at apple.com> wrote:
> A few things with respect to triple comparison:
> 
> The strings really shouldn't be compared, but the arch/vendor/os enums should be. You might also have a "unspecified 'unknown'" or a "specified 'unknown'".
> 
> For example if you type:
> 
> (lldb) file --arch x86_64 ...
> 
> The triple will be:
> 
> arch = x86_64
> vendor = "unspecified 'unknown'"
> os = "unspecified 'unknown'"
> 
> But if you type:
> 
> 
> (lldb) file --arch x86_64-unknown-unknown ...
> 
> The triple will be:
> 
> arch = x86_64
> vendor = "specified 'unknown'"
> os = "specified 'unknown'"
>  
> Is there a way to mark just the vendor portion as "unspecified 'unknown'" without having to use the string form?

Yes

llvm::Triple t;


t.setArchName("x86_64")
t.setVendor(llvm::Triple::Unknown); // Don't set it by string if you want "unspecified 'unknown'
t.setOSName("freebsd9.1)

>  I have a code path where I want to literally clear it meaning "I really don't know what it is, but I know it's not what it is currently set to..."

You might also be able to set to the empty string and it might keep the string value empty (check that "t.getVendorName()" returns the empty string and the "t.getVendor()" returns llvm::Triple::Unknown).


> (I hit that when the arch was defaulting to x86_64-apple-{something} but I was refining the vendor idea of a Linux x86_64 elf file based on note content).  
>  
> 
> 
> 
> -- 
> Todd Fiala |	 Software Engineer |	 tfiala at google.com |	 650-943-3180
>