932737 - Change elfhack such that it doesn't require two injection objects

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Mike Hommey [:glandium]]

The hidden goal is to get rid of this:
    http://hg.mozilla.org/mozilla-central/file/829d7bef8b0a/build/unix/elfhack/inject/Makefile.in#l36

Comment 1

[Mike Hommey [:glandium]]

Attachment: Change elfhack such that it doesn't require two injection objects

The idea here is to have only one injection object, containing both functions, and choosing between functions when we were choosing between files. This changes how the linkage is done, more specifically, this requires choosing which of the code segments are required, which is done by following relocations to defined symbols within the injected object (I hope I'm being clear, here).

https://tbpl.mozilla.org/?tree=Try&rev=567b3ea80e0e

Comment 2

[Nathan Froyd [:froydnj]]

Comment on attachment 824584 [details] [diff] [review]
Change elfhack such that it doesn't require two injection objects

Review of attachment 824584 [details] [diff] [review]:
-----------------------------------------------------------------

::: build/unix/elfhack/elfhack.cpp
@@ +134,5 @@
> +        entry_point = sym->value.getValue();
> +        code.push_back(sym->value.getSection());
> +
> +        // Get all relevant sections from the injected code object.
> +        find_code(code[0]);

Possible small refactoring:

void add_code_section(ElfSection *section)
{
  if (section) {
    code.push_back(section);
    find_code(code.back());
  }
}

then you can call that here...

@@ +226,5 @@
> +            }
> +            if (section) {
> +                code.push_back(section);
> +                find_code(code.back());
> +            }

...and here.

Comment 3

[Mike Hommey [:glandium]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/f9c0cb55b616

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/f9c0cb55b616