[PATCH] D18055: ELF: Implement --build-id.

[Ed Maste via llvm-commits]

On 11 March 2016 at 13:32, Rui Ueyama <ruiu at google.com> wrote:
> I sent out http://reviews.llvm.org/D18091 for review. It implements FNV1
> hash.

Great! I've applied it locally and am testing it out.

>> One other item to consider, some tools make expectations about the
>> size of the build-id data. For example, "file" uses the size to report
>> the putative algorithm used. It reports "sha1" for a 20-byte build-id
>> and "md5/uuid" for a 16-byte build-id.
>> [...]
>>
> The build-id note section has the size field for the build-id so that any
> tools that reads an ID is able to know the size of it. In our case, because
> it is 64-bit FNV1, it's set to 8 (byte.)

Right, I just mean that some tools aren't prepared to handle a
build-id note that is not either 16 or 20 bytes. For example, with an
8-byte build ID file doesn't report anything. This is arguably a file
bug, but I wouldn't be surprised if some other tools behave the same
way.