RFR: 8237192: Generate stripped/public pdbs on Windows for jdk images
Erik Joelsson
erik.joelsson at oracle.com
Wed Feb 12 22:16:50 UTC 2020
Hello Christoph,
This patch certainly looks better to me, though I agree it's a bit
hackish to have to filter and rename the stripped.pdb files twice, once
for jmods and again for bundles. I think I'm ok with it for now though.
The future improvement I would like to make would be to create two sets
of jdk images, one that contains debug symbols and demos, which we
continue to use for testing, and another which only contains exactly
what we bundle up, including the correctly named top dir. The latter
would be created first and used as input for the former. I think lots of
things would be cleaner then, especially Bundles.gmk.
But, that can wait for later. With your current proposal, my proposed
future change will apply seamlessly in regard to the stripped pdb files
and our distribution bundles.
The clash between launchers and libs is annoying, and we also have it
for java.exe and java.dll already, though the build is explicitly
handling that one somewhere else.
Now to review, there are some details I will nitpick about.
CreateJmods.gmk:
174, 185: Rule declarations should be indented like any other line
inside conditionals. But, I have a problem with these rules as the
target is the directory. This will not work well with incremental
builds. I would recommend doing a SetupCopyFiles construct instead so
you get individual rules for each file. It would look something like this:
rename-stripped-pdb = \
$(patsubst %.stripped.pdb,%.pdb,$1)
$(eval $(call SetupCopyFiles, COPY_STRIPPED_LIBS, \
SRC := $(LIBS_DIR), \
DEST := $(LIBS_DIR_STRIPPED), \
FILES := $(call FindFiles, $(LIBS_DIR)), \
NAME_MACRO := rename-stripped-pdb, \
))
DEPS += $(COPY_STRIPPED_LIBS)
For the corresponding CMD_DIR, the removal of jimage and friends can be
done with $(filter ) around The FindFiles call.
GenerateLinkOptData.gmk:
Please indent inside ifeq block. I would prefer having the TARGETS +=
inside the conditional block. Seems you also left a commented out endif
there.
NativeCompilation.gmk
919: You changed the continuation indent from 4 to 2, please revert.
/Erik
On 2020-02-12 05:26, Langer, Christoph wrote:
>
> Hi Magnus, Erik,
>
> I started off with Matthias’ patch and tried to address your concerns.
> Especially I explored adding the stripped pdbs to the jmods as well.
> Here is what I came up with:
>
> http://cr.openjdk.java.net/~clanger/webrevs/8237192.0/
>
> It’s a bit hacky in that it’ll copy support/modules_libs to
> support/modules_libs_stripped and fix the pdbs to ship in there. The
> same goes for modules_cmds. The problem with that approach is that
> probably not all dependencies are placed correctly and also there’s a
> bit more of duplication of binaries in the build directories. I think,
> it could be repaired eventually by refactoring, e.g. have a
> support/modules_dbgsymbols folder where the real debug symbol files
> get placed and used from there.
>
> There’s also two additional caveats, one is that jimage.pdb and
> jpackage.pdb exist twice. Once for the libs and once for the launchers
> with the same name. This will cause failures when jlinking. I decided
> to keep the pdbs for the libs. And I also had to take care of the
> classlist generation, to have the resulting classlist placed in
> support/modules_libs_stripped as well.
>
> I furthermore updated the naming of options and variables, hopefully
> to your like. And I made the debug output logInfo.
>
> I tested (on Windows), both, with --enable-public-debug-symbols and
> without. Without the option, everything seems as before. With the
> option enabled, the stripped debug symbols will be installed in the
> bundles and also in the jmods. 😊
>
> Please let me know what you think.
>
> Thanks & Best regards
>
> Christoph
>
> *From:*Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com>
> *Sent:* Freitag, 7. Februar 2020 14:09
> *To:* Baesken, Matthias <matthias.baesken at sap.com>; Erik Joelsson
> <erik.joelsson at oracle.com>; Langer, Christoph
> <christoph.langer at sap.com>; David Holmes <david.holmes at oracle.com>;
> 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>;
> 'hotspot-dev at openjdk.java.net' <hotspot-dev at openjdk.java.net>
> *Subject:* Re: RFR: 8237192: Generate stripped/public pdbs on Windows
> for jdk images
>
> On 2020-02-07 09:50, Baesken, Matthias wrote:
>
> Hello, here is a slightly changed new webrev :
>
> http://cr.openjdk.java.net/~mbaesken/webrevs/8237192.4/
>
> In Bundles.gmk, this line:
>
> $(ECHO) found stripped pdb file $$$${f}, we rename it to:
> $$$${f%stripped.pdb}pdb; \
>
> It looks almost like left-over debug output. If you want to keep it,
> please rephrase to something more terse, that fits better with the
> existing style of build messages. Also, it should probably be on the
> LOG=info level, so add a $(LOG_INFO).
>
> In NativeCompilation.gmk:
> Why not just a simple,
> ifeq ($(ENABLE_STRIPPED_PDBS), true)
> $1_EXTRA_LDFLAGS +=
> "-pdbstripped:$$($1_SYMBOLS_DIR)/$$($1_NOSUFFIX).stripped.pdb"
> endif
> ?
> I see no reason to duplicate code.
>
> In jdk-options.m4:
>
> I'm not 100% sure about the name of the new option.
> --enable-stripped-pdb does not fully convey the fact that we do not
> strip the *existing* pdb:s, but instead also add a new type. Maybe
> --enable-bundle-stripped-pdb?
>
> /Magnus
>
> (adjusted $(JRE_STRIPPED_PDB_FILES) in Bundles.gmk, that was in the wrong place ) .
>
> I think it needs to be a separate option as it's all orthogonal to the
>
> main debug symbols file creation.
>
> Yes it is a separate option I agree that’s better . One has to set --enable-stripped-pdbs=yes .
>
> Best regards , Matthias
>
> On 2020-02-06 04:48, Magnus Ihse Bursie wrote:
>
> On 2020-02-06 12:36, Langer, Christoph wrote:
>
> Hi,
>
> let me chime in to this discussion at this point. So, first of all, Matthias,
>
> thanks for your work so far.
>
> Erik, I fully understand your points and I agree that it's probably a good
>
> idea to refactor this whole process of creating these different types of
>
> bundles.
>
> Our idea is to provide functionality in the build system to add "public" or
>
> stripped debug files to the delivery image of the JDK. This would provide
>
> better information in case of crashes and would hence allow for better
>
> supportability. That's something we'd probably want to enable in
>
> SapMachine binary distributions.
>
> I very much support the idea of using these stripped pdb files. It has
>
> been a long standing issue in hotspot on Windows to not have access to
>
> stacktraces.
>
> So, can we get to add a configure option like the one proposed by
>
> Matthias into the current code base?
>
> The option should be turned off by default. If it is switched on, the
>
> images/jdk folder in the build directory will have both, the *stripped.pdb
>
> files and the standard *.pdb files. However, having *stripped.pdb files
>
> around should not matter in terms of functionality (for developers and
>
> testing) as they'd not be used in the presence of the "real" pdb files anyway.
>
> The actual JDK bundle for delivery would then contain the *stripped.pdb
>
> files, renamed to *.pdb. And the debug symbols bundle would have the full
>
> *.pdb files only. Both could then be overlaid as needed.
>
> I think you raised two concerns.
>
> One is that you'd rather like to refactor bundling for several reasons. But I
>
> guess, should you eventually get to your refactoring, it shouldn't be a
>
> problem to take the functionality of this new option along.
>
> The other was regarding JMODs. I believe it's correct, that JMODs have
>
> never carried external debug information. For platforms other than MS
>
> Windows that's actually not a big problem because debug information can be
>
> internalized. And jlink has gotten several additions to set flags for stripping
>
> that data to the right level. I assume if jlinked images on Windows should
>
> ever be enabled to carry debug information, inclusion of external debug files
>
> would have to be added to JMODs and jlink. But that's definitely out of scope
>
> here.
>
> The argument "jmods have never carried external debug information" just
>
> doesn't apply here. Neither has the distribution bundles, for the exact
>
> same reason. You really should not compare these new stripped pdb files
>
> to the existing debug symbol files, they are different files with
>
> different purposes. One is meant to be shipped to customers, the other
>
> is not. You say you want to ship these new stripped pdb files with your
>
> distribution so that customers have them present when they use your
>
> distribution. If you then omit these new files from the jmods, any
>
> customer created jlinked image will not have these new stripped pdb
>
> files, which IMO is a very weird and unexpected behavior from a customer
>
> point of view. Jlinking new images is an integral and promoted way of
>
> using a JDK, so any mismatch between the original JDK distribution and
>
> what you are able to jlink is a serious discrepancy.
>
> So, what do you think? What speaks against adding this option (that is off
>
> by default)?
>
> My main objective is that you introduce further discrepancies between
>
> the original distribution JDK image and what's possible to generate
>
> using jlink from that distribution JDK image. My second objective is
>
> that the already convoluted bundles creation logic becomes even more
>
> convoluted. I believe there is a better possible solution in the build
>
> but it will require a lot more work to figure out.
>
> All that said, if you still wish to continue, I will stop standing in
>
> the way.
>
> While Erik will need to comment on this himself, from my POV this
>
> looks okay. The conditions are:
>
> * This is controlled by a separate option (or perhaps even better as a
>
> new argument to --with-native-debug-symbols), so without this, nothing
>
> will change.
>
> I think it needs to be a separate option as it's all orthogonal to the
>
> main debug symbols file creation.
>
> * The code need to make sure to separate stripped.pdb and normal pdb
>
> files, when enabled.
>
> * And there must not be a heavy penalty in added code complexity.
>
> /Erik
>
> /Magnus
>
> Thanks
>
> Christoph
>
> -----Original Message-----
>
> From: build-dev<build-dev-bounces at openjdk.java.net> <mailto:build-dev-bounces at openjdk.java.net> On Behalf Of
>
> Erik
>
> Joelsson
>
> Sent: Donnerstag, 23. Januar 2020 18:49
>
> To: Baesken, Matthias<matthias.baesken at sap.com> <mailto:matthias.baesken at sap.com>; David Holmes
>
> <david.holmes at oracle.com> <mailto:david.holmes at oracle.com>; 'build-dev at openjdk.java.net <mailto:build-dev at openjdk.java.net>' <build-
>
> dev at openjdk.java.net <mailto:dev at openjdk.java.net>>; 'hotspot-dev at openjdk.java.net <mailto:hotspot-dev at openjdk.java.net>' <hotspot-
>
> dev at openjdk.java.net <mailto:dev at openjdk.java.net>>
>
> Subject: Re: RFR: 8237192: Generate stripped/public pdbs on Windows
>
> for
>
> jdk images
>
> On 2020-01-23 00:03, Baesken, Matthias wrote:
>
> Hi Erik, yes true sorry for answering your comments a bit late .
>
> If a user runs jlink and includes all the jmods we ship with the JDK, the
>
> result
>
> should be essentially equivalent to the original JDK image. The way
>
> the
>
> stripped pdb files are included in the bundles sort of at the last
>
> second of the build here breaks this property.
>
> I think we should address this in a separate bug/CR .
>
> Maybe. I realize that my proposal below is quite a big task. But on the
>
> other hand, I don't think breaking the relationship between the jmods
>
> and the distribution bundles is on the table really.
>
> Looking for example into a Linux build, I see a lot of debuginfo files in
>
> the
>
> jdk image (more or less for every shared lib) .
>
> But when looking into the jmods of that jdk image , no debuginfo files
>
> are
>
> in there ( I checked the java.base jmod).
>
> So putting the files with debug information into the jmods seems to
>
> be
>
> something that was not done so far cross platform (or is there some
>
> build
>
> switch for it that I did not check?) .
>
> Maybe to keep the jmods as small as possible .
>
> No, we do not put the debuginfo files in the jmods nor the bundles
>
> because those are not intended to be shipped to customers. We are
>
> currently overlaying them into images/jdk in the build output to make
>
> them available for local debugging. (This is convoluted and I would very
>
> much like to get away from this practice at some point so that there is
>
> a 1-1 mapping between images/jdk and bundles/jdk*-bin.tar.gz.) The
>
> stripped pdb files you are proposing are on the contrary intended for
>
> shipping to customers (as I understand your proposal) so comparing
>
> them
>
> with the debuginfo files is not relevant.
>
> Now if MS had been kind enough to define a separate file type for the
>
> stripped pdbs, so that they could live alongside the full pdbs, we
>
> wouldn't have this issue. The heart of the problem is that only one set
>
> of files (either stripped or full) can be present and usable in
>
> images/jdk at a time. We have 2 main uses for images/jdk.
>
> 1. Developer running and debugging locally
>
> 2. Serve as the source for generating the distribution bundles
>
> We currently have one image serving both of these purposes, which is
>
> already creating complicated and convoluted build steps. To properly
>
> solve this I would argue for splitting these two apart into two
>
> different images for the two different purposes. The build procedure
>
> would then be, first build the images for distribution, only containing
>
> what should go into each bundle. Then create the developer jdk image
>
> by
>
> copying files from the distribution images. On Windows, the first image
>
> would contain the stripped pdbs and when building the second, those
>
> would get overwritten with the full pdbs.
>
> Now that I figured out a working model that would solve a bunch of
>
> other
>
> problems as well, I would love to implement it, but I doubt I will have
>
> time in the near future.
>
> /Erik
>
> To properly implement this, care will need to be taken to juggle the
>
> two
>
> sets of pdb files around, making sure each build and test use case has
>
> the correct one in place where and when it's needed. Quite possibly,
>
> we
>
> cannot cover all use cases with one build configuration. Developers
>
> needing the full debug symbols when debugging locally would likely
>
> need
>
> to disable the stripped symbols so they get the full symbols
>
> everywhere.
>
> Possibly this would need to be the default for debug builds and
>
> configurable for release builds.
>
> From my limited experience , the developers do not work with the
>
> bundles (that would contain now after my patch the stripped pds) but
>
> with
>
> a "normal" jdk image that is created my make all.
>
> Best regards, Matthias
>
> This still does not address anything in my objection.
>
> /Erik
>
> On 2020-01-22 07:46, Baesken, Matthias wrote:
>
> Hello, here is an updated version :
>
> http://cr.openjdk.java.net/~mbaesken/webrevs/8237192.3/
>
> this one supports a configure switch "--enable-stripped-pdbs" to
>
> enable
>
> the feature .
>
> Best regards, Matthias
>
> -----Original Message-----
>
> From: Baesken, Matthias
>
> Sent: Dienstag, 21. Januar 2020 11:03
>
> To: 'David Holmes'<david.holmes at oracle.com> <mailto:david.holmes at oracle.com>; 'build-
>
> dev at openjdk.java.net <mailto:dev at openjdk.java.net>'<build-dev at openjdk.java.net> <mailto:build-dev at openjdk.java.net>; 'hotspot-
>
> dev at openjdk.java.net <mailto:dev at openjdk.java.net>'<hotspot-dev at openjdk.java.net> <mailto:hotspot-dev at openjdk.java.net>
>
> Subject: RE: RFR: 8237192: Generate stripped/public pdbs on
>
> Windows
>
> for
>
> jdk images
>
> Hi David , yes I think it makes sense to have a configure option for
>
> this .
>
> Not everyone would like to have a larger JDK (even it is only a bit
>
> larger).
>
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