RFR: JDK-8036003: Add --with-debug-symbols=[none|internal|external|zipped]

[Omair Majid]

* David Holmes <david.holmes at oracle.com> [2015-11-18 07:01]:
> My main point of contention is that zipping is simply a packaging choice for
> the externally generated symbols - and we already have a configure option to
> control that so I don't see why we would want to double up on that part. (I
> don't think we have a deprecation policy for configure args.)

There's a whole bunch of decisions related to debug information the
build has to make:

1. Should debugging information be generated at all?

Assuming yes:

2. Should the debug information be put in separate debug info flies?

3. Should the debug information be stripped from the original
binaries?

Assuming 2 is "yes":

4. Should the debug info files be zipped?

So, yes, zipping is just one choice.

The current options are not sufficient for us (the distribution
packagers) because they don't cover our desired outcome which is:

1. Yes.
2. No.
3. No.
4. N/A.

Currently, we have to rely on implementation details by calling make
with a set of (implementation defined) flags which are subject to change
within a single release since they are not officially defined at all.

As an example, here's what the build instructions for Fedora look like:

./configure \
  --disable-zip-debug-info 

make \
    DEBUG_BINARIES=true \
    JAVAC_FLAGS=-g \
    STRIP_POLICY=no_strip \
    STRIP="" \
    ALT_OBJCOPY=none \

Just to get what we want.

Returning to your earlier point about zipping being one choice, we could
fix this issue by adding flags for all other choices. However, that
would make the build more complex and it's not clear that all choices
are actually needed. 

So, the proposed patch offers a set of values that basically represent a
set of choices in a more obvious way: they describe the end result and
let the implementation decide how to achieve the result.

Thanks,
Omair

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