[lld] r188958 - add InputGraph functionality

[Matt Beaumont-Gay]

On Wed, Aug 21, 2013 at 3:57 PM, Shankar Easwaran
<shankare at codeaurora.org> wrote:
> Author: shankare
> Date: Wed Aug 21 17:57:10 2013
> New Revision: 188958
>
> URL: http://llvm.org/viewvc/llvm-project?rev=188958&view=rev
> Log:
> add InputGraph functionality

This is a pretty terse commit message for such a large patch. There
was a great description of what this is all about on the code review
thread, and it would be nice to have some of that context directly
attached to the commit.

Also, I haven't read the whole thing, but I spotted this while
scrolling through:

+/// \brief The inputs to the linker are represented by an InputGraph. The
+/// nodes in the input graph contains Input elements. The InputElements are
+/// either Input Files or Control Options. The Input Files represent each Input
+/// File to the linker and the control option specify what the linker needs
+/// to do when it processes the option. Each InputElement that is part of the
+/// Graph has also an Ordinal value associated with it. The ordinal value is
+/// needed for components to figure out the relative position of the arguments
+/// that appeared in the Command Line. One such example is adding the list of
+/// dynamic dynamic libraries to the DT_NEEDED list with the ELF Flavor. The
+/// InputElements also have a weight function that can be used to determine the
+/// weight of the file, for statistical purposes. The InputGraph also would
+/// contain a set of General options that are processed by the linker, which
+/// control the output

That's not "brief" :)