Request for Review (XXL): 6989984: Use standard include model for Hotspot

[Volker Simonis]

Hi Stefan and Bengt,

I have some comments/questions regarding your change:

- how did you create the "src/share/vm/precompiled.hpp". I have the
impression that it contains much fewer lines compared to the old,
generated file?
- what is the policy of maintaining "src/share/vm/precompiled.hpp",
i.e. when should a new include statement be added just into the
requiring .cpp file and when will it be appropriate to add it to
precompiled.hpp.
- did you check the build performance with your changes on the various
platforms? Are there any regressions?

And please, please synchronize this change with other changes,
especially the other big ones like Coleens Symtable change to avoid
merges as described here:

http://old.nabble.com/Request-for-review-%28XL%29-6990754%3A-Use-native-memory-and-reference-counting-to-implement-SymbolTable-tt30138063.html#a30138063

Please talk to Coleen who proposed that "..we could arrange that these
symbol changes are pushed to hotspot-rt, run through the nightly tests
and then pushed to hotspot repository before the other baselines.
Maybe it should rate it's own integration slot.  I won't create merge
change sets before pushing."

Your change patch for example already doesn't run with the current
hotspot-rt because change  "6970683: improvements to hs_err output"
which was already pushed 4 weeks ago added a call  to
VMError::fatal_error_in_progress() to parallelScavengeHeap.cpp which
isn't reflected by your change (i.e. VMError isn't visible). So if you
would push your change right now, this would result in a non-empty,
potentially quite large merge set. So please apply one of the
techniques mentioned in the thread referenced above to avoid such
merges.

Thank you and best regards,
Volker

On Wed, Nov 17, 2010 at 4:57 PM, Stefan Karlsson
<stefan.karlsson at oracle.com> wrote:
> We are simplifying the Hotspot build process by standardizing the code and
> reducing the number of required tools. As a first step we are removing the
> use of the MakeDeps tool and the includeDB files.
>
> This will help new developers get up to speed with the code, which will
> benefit both internal developers and the open source community. It will also
> make IDE integration simpler.
>
> MakeDeps provided these services:
> * Includes between source files
> * Platform dispatching
> * Precompiled header management
> * Makefile rules for source file dependencies
> * Source files selection based on compiled target (compiler1, tiered,
> kernel, ...)
> * VisualStudio project creation
> * Circular dependency detection
>
> To replace MakeDeps we updated all source files with explicit include
> statements, include guards and platform dispatching with #ifdefs. We also
> updated the makefiles to provide the rest of the MakeDeps services.
>
> Note: this change will update almost all source files and many makefiles.
> The top-level make commands have not been changed.
>
> Webrev is available here:
> http://cr.openjdk.java.net/~stefank/6989984.2/
>
> Bug:
> 6989984: Use standard include model for Hotspot
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6989984
>
> Thanks,
> Stefan and Bengt
>