RFR: JDK-8072106 Properly handle dependencies for deleted header files

[David Holmes]

Hi Magnus,

On 3/02/2015 1:51 AM, Magnus Ihse Bursie wrote:
> When a header file is deleted, make will complain "No rule to make
> target <old header file>". This often breaks incremental build
> completely unnecessary.

When/why would a header file be deleted?

There's one typo "dependeny" but I can't comment on the rest of the make 
magic.

David

> This can be fixed by adding dummy rules for all header files like this:
> <header file>:
>
> gcc can create such rules by itself by using -MP in the generated make
> dependency files, but that feature is not available for any other
> compiler, so I opted not to use it, in favour of a solution that works
> on all platforms.
>
> This patch also contain a cosmetic fix for printing incremental build
> information that was made somewhat less clear when the vardeps
> functionality was introduced.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8072106
> WebRev:
> http://cr.openjdk.java.net/~ihse/JDK-8072106-make-dependency-targets-generation/webrev.01
>
>
> /Magnus