Need reviewers: more predictable binaries

[Tim Bell]

On 09/05/12 21:08, Kelly O'Hair wrote:
> Need a reviewer for this change.
>
>     http://cr.openjdk.java.net/~ohair/openjdk8/jdk8-this-file/webrev/
>
> It does change source, but it's effectively a build change.
>
> The goal here is to try and create more predictable binary files and remove the possibility that
> a full source path (via __FILE__) gets baked into the shared libraries or executables shipped.
>
> So two changes:
>    * sort the .o files during links so they are always provided to the linker in the same order.
>    * replace use of __FILE__ to the macro THIS_FILE with just the basename of the source file being compiled
>
> The __FILE__ issue is that it has an implementation defined string literal value, depending on the compiler
> and the filename supplied on the compile line. By changing to the new THIS_FILE macro, the object files
> will always have a consistent string literal in them, making it easier to compare binaries between builds.
> Something we have never been able to do in the past. Granted it's just the basename for the file, but should be enough.
> The tricky part is that __FILE__ only gets evaluated when it is used. In normal C code, it will appear in
> macros but it only will get evaluated in the source file being compiled. It is rare that macros using
> __FILE__  will get expanded in include files and I detected this not happening in the jdk source at all.
>
> -kto

Looks good ... this is long overdue and it is a pattern we all need to 
use going forward.

Approved.

Tim