[LLVMdev] [lld] Handling a whole bunch of readers

[Shankar Easwaran]

On 10/9/2013 3:09 PM, Nick Kledzik wrote:
> On Oct 9, 2013, at 11:23 AM, Shankar Easwaran <shankare at codeaurora.org> wrote:
>> We have a whole bunch of readers(we would have some more too), and was thinking if we should have a vector of Readers, and have a function isMyFormat in each of them.
>>
>> Any reader that knows to handle, goes ahead and parses the file.
>>
>> On a side note, we currently use .objtxt as an figure out if the file is a YAML file or not. I have added FIXME's in the code, if we could some kind of magic (or) a better way to figure out if the file is YAML ?
> On this topic, we should come up with standard file extension names.  I made up .objtxt for atoms-in-yaml when writing the first test cases.  We will soon need extensions for other kinds of yaml files (such as mach-o in yaml).   With linker scripts we are stuck with there being no magic at the start and no standard file extension.  For new yaml files that we are inventing we should define a standard file extension.
Isnt having a YAML file starting with the below better, so that you dont 
need to go through file extensions.

magic :
arch:

You would also be able to figure out if the yaml file is a valid input 
for the flavor/target too.

> I agree with Rui that we should not be calling identify_magic() in every reader.  Another approach is to just call each reader to try to parse until one succeeds.  The first reader should be the native reader (e.g. ELF or mach-o), so that in the real world there is no time wasted looking at test case formats.
Agree. This is better.

Thanks

Shankar Easwaran