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[CLJ-1604] AOT'ed code that defs a var with clojure.core symbol name causes IllegalStateException Created: 25/Nov/14  Updated: 02/Dec/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.7
Fix Version/s: Release 1.7

Type: Defect Priority: Major
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: aot, compiler

Attachments: Text File 0001-fix-AOT-bug-preventing-overriding-of-clojure.core-fu.patch     Text File 0001-fix-AOT-bug-preventing-overriding-of-clojure.core-fu-v2.patch    
Patch: Code
Approval: Screened

 Description   

AOT'ed code that defs a var that is also a symbol in clojure.core results in an exception at runtime. This problem can be avoided with (:refer-clojure :exclude ...) but this requires a library author to update and release a new version. AOT'ed applications must then wait for all transitive dependencies to update before they can update to a new Clojure version. For some users, this problem prevents them from trying or adopting new releases.

For example, the contrib library data.int-map defines an update function. clojure.core will also have a new update function as of 1.7.0. If this library is AOT'ed, then users of the clojure.data.int-map/update function will see the exception below. This situation can commonly occur when an application uses lein uberjar to compile all of the project+libs. In this case, applications or libraries that use data.int-map (either directly or indirectly) are affected.

java.lang.IllegalStateException: Attempting to call unbound fn: #'clojure.data.int-map/update
 at clojure.lang.Var$Unbound.throwArity (Var.java:43)
    clojure.lang.AFn.invoke (AFn.java:40)
    compiler_update_not_referenced_bug.core$foo.invoke (core.clj:5)

Reproduce with this sample project: https://github.com/yeller/compiler_update_not_referenced_bug

Cause: When AOT compiling a namespace, the def forms are hoisted into the ns__init class (in the example here, clojure.data.int_map__init). The static initializer in this class creates each var in the ns via a call to RT.var(ns, name). For data.int-map the static initializer will properly create the var for clojure.data.int-map/update. But when the ns is loaded (via the clojure.data.int_map.load() method), (refer-clojure) will be called, which will remap clojure.data.int-map/update to point to clojure.core/update.

This problem does not affect non-AOT loading (which doesn't use the ns__init class) and does not affect collisions from any other namespace. Only collisions from clojure.core create this possibility.

Proposed: The proposed patch explicitly refers the Var during ns__init.load() (after Clojure symbols are referred) rather than implicitly during ns__init static {}. This change only happens in the specific case where a core symbol is being shadowed.

Patch: 0001-fix-AOT-bug-preventing-overriding-of-clojure.core-fu-v2.patch

Screened by: Alex Miller



 Comments   
Comment by Andy Fingerhut [ 25/Nov/14 11:28 PM ]

When I try latest Clojure master plus patch CLJ-1604-only-core.patch with the small test project created by Tom Crayford to demonstrate this issue: https://github.com/yeller/compiler_update_not_referenced_bug

In that project, I get the same exception thrown when attempting 'lein do clean, uberjar, test' using this patch, as without it. It is because int-map/update in namespace compiler-update-not-referenced-bug.core is an unbound var.

Comment by Nicola Mometto [ 26/Nov/14 4:25 AM ]

Andy, you're right. For some reason I attached the wrong patch to the ticket, this is the correct one

Comment by Nicola Mometto [ 26/Nov/14 5:21 AM ]

I wasn't able to write a test for this, so here's a repl session using the clojure jar demonstrating this issue:

[˷/test]> ls
classes  clojure.jar  test.clj
[˷/test]> cat test.clj
(in-ns 'test)
(clojure.core/refer 'clojure.core)
(def foo "bar")
(def update "foo")
[˷/test]> java -cp classes:clojure.jar:. clojure.main
Clojure 1.7.0-master-SNAPSHOT
user=> (binding [*compile-files* true] (load "test"))
WARNING: update already refers to: #'clojure.core/update in namespace: test, being replaced by: #'test/update
nil
user=> test/foo
"bar"
user=> test/update
"foo"
user=>
[˷/test]> java -cp classes:clojure.jar:. clojure.main
Clojure 1.7.0-master-SNAPSHOT
user=> (load "test")
nil
user=> test/foo
"bar"
user=> test/update
CompilerException java.lang.RuntimeException: No such var: test/update, compiling: (NO_SOURCE_PATH:0:0)
user=>
Comment by Andy Fingerhut [ 26/Nov/14 10:39 AM ]

Thanks. I have not tried to assess the details of the change, other than to say that patch 0001-fix-AOT-bug-preventing-overriding-of-clojure.core-fu.patch dated 26 Nov 2014, when applied to latest Clojure master as of today, enables both 'lein do clean, test' and 'lein do clean, uberjar, test' to work as expected with Tom Crayford's test project, linked above, whereas 'lein do clean, uberjar, test' fails without this patch, due to a var being unbound that should have a value.

Comment by Andy Fingerhut [ 27/Nov/14 10:53 AM ]

Copying a comment here from CLJ-1591, since it is more appropriate here. It is responding to Tom Crayford's posting of his example project to demonstrate the issue: https://github.com/yeller/compiler_update_not_referenced_bug

Tom, looked at your project. Thanks for that. It appears not to have anything like (def inc inc) in it. It throws exception during test step of 'lein do clean, uberjar, test' consistently for me, too, but compiles with only warnings and passes tests with 'lein do clean, test'. I have more test results showing in which Clojure versions these results change. To summarize, the changes to Clojure that appear to make the biggest difference in the results are below (these should be added to the new ticket you create – you are welcome to do so):

Clojure 1.6.0, 1.7.0-alpha1, and later changes up through the commit with description "CLJ-1378: Allows FnExpr to override its reported class with a type hint": No errors or warnings for either lein command above.

Next commit with description "Add clojure.core/update, like update-in but takes a single key" that adds clojure.core/update: 'lein do clean, test' is fine, but 'lein do clean, uberjar' throws exception during compilation, probably due to CLJ-1241.

Next commit with description "fix CLJ-1241": 'lein do clean, test' and 'lein do clean, uberjar' give warnings about clojure.core/update, but no errors or exceptions. 'lein do clean, uberjar, test' throws exception during test step that is same as the one I see with Clojure 1.7.0-alpha4. Debug prints of values of clojure.core/update and int-map/update (in data.int-map and in Tom's namespace compiler-update-not-referenced-bug.core) show things look fine when printed inside data.int-map, and in Tom's namespace when not doing the uberjar, but when doing the uberjar, test, int-map/update is unbound in Tom's namespace.

In case it makes a difference, my testing was done with Mac OS X 10.9.5, Leiningen 2.5.0 on Java 1.7.0_45 Java HotSpot(TM) 64-Bit Server VM

Comment by Nicola Mometto [ 02/Dec/14 9:04 AM ]

The updated patch only emits the interning bytecode when necessary, avoiding the emission when a clojure.core var with the same name exists but is not mapped to the current namespace





[CLJ-1544] AOT bug involving namespaces loaded before AOT compilation started Created: 01/Oct/14  Updated: 17/Dec/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: Release 1.7

Type: Defect Priority: Critical
Reporter: Allen Rohner Assignee: Unassigned
Resolution: Unresolved Votes: 4
Labels: aot

Attachments: Text File 0001-CLJ-1544-force-reloading-of-namespaces-during-AOT-co.patch     Text File 0001-CLJ-1544-force-reloading-of-namespaces-during-AOT-co-v2.patch    
Patch: Code
Approval: Vetted

 Description   

If namespace "a" that is being AOT compiled requires a namespace "b" that has been loaded but not AOT compiled, the classfile for that namespace will never be emitted on disk, causing errors when compiling uberjars or in other cases.

A minimal reproducible case is described in the following comment: http://dev.clojure.org/jira/browse/CLJ-1544?focusedCommentId=36734&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-36734

Other examples of the bug:
https://github.com/arohner/clj-aot-repro
https://github.com/methylene/class-not-found

A real issue triggered by this bug: https://github.com/cemerick/austin/issues/23

Approach: The approach taken by the attached patch is to force reloading of namespaces during AOT compilation if no matching classfile is found in the compile-path or in the classpath



 Comments   
Comment by Alex Miller [ 04/Dec/14 12:45 PM ]

Possibly related: CLJ-1457

Comment by Nicola Mometto [ 05/Dec/14 4:51 AM ]

Has anyone been able to reproduce this bug from a bare clojure repl? I have been trying to take lein out of the equation for an hour but I don't seem to be able to reproduce it – this makes me think that it's possible that this is a lein/classlojure/nrepl issue rather than a compiler/classloader bug

Comment by Nicola Mometto [ 06/Dec/14 4:20 PM ]

I was actually able to reproduce and understand this bug thanks to a minimal example reduced from a testcase for CLJ-1413.

>cat error.sh
#!/bin/sh

rm -rf target && mkdir target

java -cp src:clojure.jar clojure.main - <<EOF
(require 'myrecord)
(set! *compile-path* "target")
(compile 'core)
EOF

java -cp target:clojure.jar clojure.main -e "(use 'core)"

> cat src/core.clj
(in-ns 'core)
(clojure.core/require 'myrecord)
(clojure.core/import myrecord.somerecord)

>cat src/myrecord.clj
(in-ns 'myrecord)
(clojure.core/defrecord somerecord [])

> ./error.sh
Exception in thread "main" java.lang.ExceptionInInitializerError
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:344)
	at clojure.lang.RT.classForName(RT.java:2113)
	at clojure.lang.RT.classForName(RT.java:2122)
	at clojure.lang.RT.loadClassForName(RT.java:2141)
	at clojure.lang.RT.load(RT.java:430)
	at clojure.lang.RT.load(RT.java:411)
	at clojure.core$load$fn__5403.invoke(core.clj:5808)
	at clojure.core$load.doInvoke(core.clj:5807)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invoke(core.clj:5613)
	at clojure.core$load_lib$fn__5352.invoke(core.clj:5653)
	at clojure.core$load_lib.doInvoke(core.clj:5652)
	at clojure.lang.RestFn.applyTo(RestFn.java:142)
	at clojure.core$apply.invoke(core.clj:628)
	at clojure.core$load_libs.doInvoke(core.clj:5691)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:630)
	at clojure.core$use.doInvoke(core.clj:5785)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at user$eval212.invoke(NO_SOURCE_FILE:1)
	at clojure.lang.Compiler.eval(Compiler.java:6767)
	at clojure.lang.Compiler.eval(Compiler.java:6730)
	at clojure.core$eval.invoke(core.clj:3076)
	at clojure.main$eval_opt.invoke(main.clj:288)
	at clojure.main$initialize.invoke(main.clj:307)
	at clojure.main$null_opt.invoke(main.clj:342)
	at clojure.main$main.doInvoke(main.clj:420)
	at clojure.lang.RestFn.invoke(RestFn.java:421)
	at clojure.lang.Var.invoke(Var.java:383)
	at clojure.lang.AFn.applyToHelper(AFn.java:156)
	at clojure.lang.Var.applyTo(Var.java:700)
	at clojure.main.main(main.java:37)
Caused by: java.io.FileNotFoundException: Could not locate myrecord__init.class or myrecord.clj on classpath.
	at clojure.lang.RT.load(RT.java:443)
	at clojure.lang.RT.load(RT.java:411)
	at clojure.core$load$fn__5403.invoke(core.clj:5808)
	at clojure.core$load.doInvoke(core.clj:5807)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invoke(core.clj:5613)
	at clojure.core$load_lib$fn__5352.invoke(core.clj:5653)
	at clojure.core$load_lib.doInvoke(core.clj:5652)
	at clojure.lang.RestFn.applyTo(RestFn.java:142)
	at clojure.core$apply.invoke(core.clj:628)
	at clojure.core$load_libs.doInvoke(core.clj:5691)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:628)
	at clojure.core$require.doInvoke(core.clj:5774)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at core__init.load(Unknown Source)
	at core__init.<clinit>(Unknown Source)
	... 33 more

This bug also has also affected Austin: https://github.com/cemerick/austin/issues/23

Essentially this bug manifests itself when a namespace defining a protocol or a type/record has been JIT loaded and a namespace that needs the protocol/type/record class is being AOT compiled later. Since the namespace defining the class has already been loaded the class is never emitted on disk.

Comment by Nicola Mometto [ 06/Dec/14 6:51 PM ]

I've attached a tentative patch fixing the issue in the only way I found reasonable: forcing the reloading of namespaces during AOT compilation if the compiled classfile is not found in the compile-path or in the classpath

Comment by Nicola Mometto [ 06/Dec/14 7:30 PM ]

Updated patch forces reloading of the namespace even if a classfile exists in the compile-path but the source file is newer, mimicking the logic of clojure.lang.RT/load

Comment by Nicola Mometto [ 06/Dec/14 7:39 PM ]

Further testing demonstrated that this bug is not only scoped to deftypes/defprotocols but can manifest itself in the general case of a namespace "a" requiring a namespace "b" already loaded, and AOT compiling the namespace "a"

Comment by Tassilo Horn [ 08/Dec/14 4:46 AM ]

I'm also affected by this bug. Is there some workaround I can apply in the meantime, e.g., by dictating the order in which namespaces are going to be loaded/compiled in project.clj?

Comment by Nicola Mometto [ 15/Dec/14 10:58 AM ]

Tassilo, if you don't have control over whether or not a namespace that an AOT namespace depends on has already been loaded before compilation starts, requiring those namespaces with :reload-all should be enough to work around this issue

Comment by Tassilo Horn [ 15/Dec/14 11:36 AM ]

Nicola, thanks! But in the meantime I've switched to using clojure.java.api and omit AOT-compilation. That works just fine, too.

Comment by Michael Blume [ 15/Dec/14 5:05 PM ]

Tassilo, that's often a good solution, another is to use a shim clojure class

(ns myproject.main-shim (:gen-class))

(defn -main [& args]
  (require 'myproject.main)
  ((resolve 'myproject.main) args))

then your shim namespace is AOT-compiled but nothing else in your project is.

Comment by Tassilo Horn [ 16/Dec/14 1:07 AM ]

Thanks Michael, that's a very good suggestion. In fact, I've always used AOT only as a means to export some functions to Java-land. Basically, I did as you suggest but required the to-be-exported fn's namespace in the ns-form which then causes AOT-compilation of that namespace and its own deps recursively. So your approach seems to be as convenient from the Java side (no need to clojure.java.require `require` in order to require the namespace with the fn I wanna call ) while still omitting AOT. Awesome!





[CLJ-1392] AOT vs "var already exists warning" results in NPE Created: 26/Mar/14  Updated: 26/Mar/14  Resolved: 26/Mar/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.6
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Aaron Cohen Assignee: Unassigned
Resolution: Duplicate Votes: 0
Labels: aot, compiler


 Description   

I just saw this thread on the cascalog list: https://groups.google.com/forum/#!topic/cascalog-user/Pe5QIpmU0vA

Apparently the "WARNING: some? already refers to: #'clojure.core/some? in namespace: jackknife.seq, being replaced by: #'jackknife.seq/some?" results in a NullPointerException when trying to AOT a namespace that results in the message being output.

Reproducer:

1) lein new aotFail
2) Edit project.clj
;add as appropriate
:aot :all
:dependencies [[org.clojure/clojure "1.6.0"]
[cascalog "2.0.0"]]
2) Add "(:use cascalog.api)" to the ns block of src/aotFail/core.clj
3) lein compile

Output:

Compiling aotFail.core
WARNING: some? already refers to: #'clojure.core/some? in namespace: jackknife.seq, being replaced by: #'jackknife.seq/some?
Exception in thread "main" java.lang.NullPointerException, compiling:(api.clj:1:1)
at clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3558)
at clojure.lang.Compiler.compile1(Compiler.java:7226)
at clojure.lang.Compiler.compile1(Compiler.java:7216)
at clojure.lang.Compiler.compile(Compiler.java:7292)
at clojure.lang.RT.compile(RT.java:398)
at clojure.lang.RT.load(RT.java:438)
at clojure.lang.RT.load(RT.java:411)
at clojure.core$load$fn__5066.invoke(core.clj:5641)
at clojure.core$load.doInvoke(core.clj:5640)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invoke(core.clj:5446)
at clojure.core$load_lib$fn__5015.invoke(core.clj:5486)
at clojure.core$load_lib.doInvoke(core.clj:5485)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invoke(core.clj:626)
at clojure.core$load_libs.doInvoke(core.clj:5528)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invoke(core.clj:628)
at clojure.core$use.doInvoke(core.clj:5618)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at cascalog2.core$loading_4958auto_.invoke(core.clj:1)
at clojure.lang.AFn.applyToHelper(AFn.java:152)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3553)
at clojure.lang.Compiler.compile1(Compiler.java:7226)
at clojure.lang.Compiler.compile1(Compiler.java:7216)
at clojure.lang.Compiler.compile(Compiler.java:7292)
at clojure.lang.RT.compile(RT.java:398)
at clojure.lang.RT.load(RT.java:438)
at clojure.lang.RT.load(RT.java:411)
at clojure.core$load$fn__5066.invoke(core.clj:5641)
at clojure.core$load.doInvoke(core.clj:5640)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invoke(core.clj:5446)
at clojure.core$compile$fn__5071.invoke(core.clj:5652)
at clojure.core$compile.invoke(core.clj:5651)
at user$eval19.invoke(form-init2092370125048380878.clj:1)
at clojure.lang.Compiler.eval(Compiler.java:6703)
at clojure.lang.Compiler.eval(Compiler.java:6693)
at clojure.lang.Compiler.load(Compiler.java:7130)
at clojure.lang.Compiler.loadFile(Compiler.java:7086)
at clojure.main$load_script.invoke(main.clj:274)
at clojure.main$init_opt.invoke(main.clj:279)
at clojure.main$initialize.invoke(main.clj:307)
at clojure.main$null_opt.invoke(main.clj:342)
at clojure.main$main.doInvoke(main.clj:420)
at clojure.lang.RestFn.invoke(RestFn.java:421)
at clojure.lang.Var.invoke(Var.java:383)
at clojure.lang.AFn.applyToHelper(AFn.java:156)
at clojure.lang.Var.applyTo(Var.java:700)
at clojure.main.main(main.java:37)
Caused by: java.lang.NullPointerException
at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4944)
at clojure.lang.Compiler$DefExpr.emit(Compiler.java:437)
at clojure.lang.Compiler.compile1(Compiler.java:7225)
at clojure.lang.Compiler.compile(Compiler.java:7292)
at clojure.lang.RT.compile(RT.java:398)
at clojure.lang.RT.load(RT.java:438)
at clojure.lang.RT.load(RT.java:411)
at clojure.core$load$fn__5066.invoke(core.clj:5641)
at clojure.core$load.doInvoke(core.clj:5640)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at clojure.core$load_one.invoke(core.clj:5446)
at clojure.core$load_lib$fn__5015.invoke(core.clj:5486)
at clojure.core$load_lib.doInvoke(core.clj:5485)
at clojure.lang.RestFn.applyTo(RestFn.java:142)
at clojure.core$apply.invoke(core.clj:626)
at clojure.core$load_libs.doInvoke(core.clj:5524)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.core$apply.invoke(core.clj:628)
at clojure.core$use.doInvoke(core.clj:5618)
at clojure.lang.RestFn.invoke(RestFn.java:408)
at cascalog.api$loading_4958auto_.invoke(api.clj:1)
at clojure.lang.AFn.applyToHelper(AFn.java:152)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.lang.Compiler$InvokeExpr.eval(Compiler.java:3553)



 Comments   
Comment by Nicola Mometto [ 26/Mar/14 12:42 PM ]

Duplicate of http://dev.clojure.org/jira/browse/CLJ-1241





[CLJ-1330] Class name clash between top-level functions and defn'ed ones Created: 22/Jan/14  Updated: 14/Nov/14  Resolved: 14/Nov/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: Release 1.7

Type: Defect Priority: Critical
Reporter: Nicola Mometto Assignee: Unassigned
Resolution: Completed Votes: 8
Labels: aot, compiler

Attachments: Text File 0001-CLJ-1093-v3-no-locals-improv.patch     Text File 0001-CLJ-1093-v3.patch     Text File 0001-CLJ-1330-remove-local-binding-name-enhancement.patch     File demo1.clj    
Patch: Code
Approval: Ok

 Description   

Named anonymous fn's are not guaranteed to have unique class names when AOT-compiled.

For example:

(defn g [])
(def xx (fn g []))

When AOT-compiled both functions will emit user$g.class, the latter overwriting the former.

Impact: this affects apps like Cursive, which has been using a patched version of Clojure to get around this issue for quite a while.

Demonstration script: demo1.clj

Patch: 0001-CLJ-1093-v3.patch (already applied, see below)

Approach: Generate unique class names for named fn's the same way as for unnamed anonymous fn's.
The patch contains an additional enhancement to include the name of the local binding in the class name.

Comparison between pre and post patch naming scheme (N denotes unique number):

code before after note
(defn a []) user$a user$a same
(fn []) user$evalN$fn__N user$evalN$fn__N same
(fn a []) user$evalN$a__N user$evaN$a__N same
(let [a (fn [])] a) user$evalN$a__N user$evalN$a__N same
(let [a (fn x [])] a) user$eval1N$x__N user$evalN$a_x_N IMPROVED - contains local binding name
(def a (fn [])) user$a user$a same
(def a (fn x [])) user$x user$a_x_N FIXED conflict with (defn x [])
(def ^{:foo (fn [])} a) user$fn__N user$fn__N same
(def ^{:foo (fn a [])} a) user$a user$a__N FIXED conflict with (defn a [])
(def a (fn [] (fn []))) user$a$fn__N user$a$fn__N same
(def a (fn [] (fn x []))) user$a$x__N user$a$x__N same

See also: This patch also fixes the issue reported in CLJ-1227.

Screened by: Alex Miller - I am not sure whether the local binding name enhancement is worth doing. It improves debugging of which anonymous class you're talking about but has the downsides of increasing class name (and file name) length.

REOPENED Patch: 0001-CLJ-1093-v3-no-locals-improv.patch
REOPENED UPDATE: The local improvement version of this patch increases class names (and thus .class names) and we've had several reports of exceeding file system limits (~143 chars) - see comments for details. Thus, we should rollback the prior patch (0001-CLJ-1093-v3.patch) and apply the version without this enhancement. The replacement patch (0001-CLJ-1093-v3-no-locals-improv.patch) does not have the same effect on class name length.



 Comments   
Comment by Ambrose Bonnaire-Sergeant [ 22/Jan/14 11:12 AM ]

This seems like the reason why jvm.tools.analyzer cannot analyze clojure.core. On analyzing a definline, there is an "attempted duplicate class definition" error.

This doesn't really matter, but I thought it may or may not be useful information to someone.

Comment by Nicola Mometto [ 22/Jan/14 11:35 AM ]

Attached a fix.

This also fixes AOT compiling of code like:

(def x (fn foo []))
(fn foo [])
Comment by Nicola Mometto [ 22/Jan/14 11:39 AM ]

Cleaned up patch

Comment by Alex Miller [ 22/Jan/14 12:43 PM ]

It looks like the patch changes indentation of some of the code - can you fix that?

Comment by Nicola Mometto [ 22/Jan/14 3:57 PM ]

Updated patch without whitespace changes

Comment by Alex Miller [ 22/Jan/14 4:15 PM ]

Thanks, that's helpful.

Comment by Alex Miller [ 24/Jan/14 10:03 AM ]

There is consensus that this is a problem, however this is an area of the code with broad impacts as it deals with how classes are named. To that end, there is some work that needs to be done in understanding the impacts before we can consider it.

Some questions we would like to answer:

1) According to Rich, naming of (fn x []) function classes used to work in the manner of this patch - with generated names. Some code archaeology needs to be done on why that was changed and whether the change to the current behavior was addressing problems that we are likely to run into.

2) Are there issues with recursive functions? Are there impacts either in AOT or non-AOT use cases? Need some tests.

3) Are there issues with dynamic redefinition of functions? With the static naming scheme, redefinition causes a new class of the same name which can be picked up by reload of classes compiled to the old definition. With the dynamic naming scheme, redefinition will create a differently named class so old classes can never pick up a redefinition. Is this a problem? What are the impacts with and without AOT? Need some tests.

Comment by Nicola Mometto [ 24/Jan/14 11:39 AM ]

Looks like the current behaviour has been such since https://github.com/clojure/clojure/commit/4651e60808bb459355a3a5d0d649c4697c672e28

My guess is that Rich simply forgot to consider the (def y (fn x [] ..)) case.

Regarding 2 and 3, the dynamic naming scheme is no different than what happens for anonymous functions so I don't see how this could cause any issue.

Recursion on the fn arg is simply a call to .invoke on "this", it's classname unaware.

I can add some tests to test that

(def y (fn x [] 1))
and
(fn x [] 2)
compile to different classnames but other than that I don't see what should be tested.

Comment by Stuart Halloway [ 27/Jun/14 2:17 PM ]

incomplete pending the answers to Alex Miller's questions in the comments

Comment by Nicola Mometto [ 27/Jun/14 3:20 PM ]

I believe I already answered his questions, I'll try to be a bit more explicit:
I tracked the relevant commit from Rich which added the dynamic naming behaviour https://github.com/clojure/clojure/commit/4651e60808bb459355a3a5d0d649c4697c672e28#diff-f17f860d14163523f1e1308ece478ddbL3081 which clearly shows that this bug was present since then so.

Regarding redefinitions or recursive functions, both of those operations never take in account the generated fn name so they are unaffected.

Comment by Alex Miller [ 12/Sep/14 4:32 PM ]

Summarizing some cases here from before/after the patch:

1) top-level fn (always has name)
	1.6 - namespace$name
	patch - namespace$name
2) non-top-level fn with name
	1.6 - namespace$name (collides with prior case)
	patch - namespace$topname__x__name  	<-- CHANGED
3) anonymous fn (no name)
	1.6 - namespace$name$fn__x
	patch - namespace$name$fn__x
4) top-level anonymous fn (no name, not at all useful :)
	1.6 - namespace$fn__x
	patch - namespace$fn__x

The key problem is that the first 2 cases produce the identical class name on 1.6. The patch alters the non-top-level named fn so there is no conflict.

Prior to the referenced old commit, I believe cases 1 and 2 would both produce namespace$name__x (where x is unique) so they would not collide. The change was made to prevent the top-level name from changing ("don't append numbers on top-level fn class names"). While the similar change was made on non-top-level fn names, I do not think it needed to be.

I've thought through (and tried) a bunch of the implications of this with the help of Nicola's comments above and I do not see an issue with any of the things I've considered. From a binary compatibility point of view with existing AOT code, old code compiled together should be self-consistent and continue to work. New compiled code will also be consistent. I can't think of a way that new code would expect to know the old name of a non-top-level function such that there could be an issue.

One question - why change the code such that the new class name is namespace$name$topname__x__name instead of namespace$name$topname_name__x (or something else?). And relatedly, while the diff is small, could we refactor a couple more lines to make the intent and cases clearer?

I am 90% ok with this patch but want a little thought into that question before I mark screened.

Comment by Nicola Mometto [ 12/Sep/14 4:47 PM ]

Alex, the attached patch munges into ns$topname__name__x, not into ns$topname__x__name.

Comment by Nicola Mometto [ 12/Sep/14 5:22 PM ]

The attached patch 0001-Fix-CLJ-1330refactored.patch contains the same fix from 0001-FixCLJ-1330-make-top-level-named-functions-classnam.patch but also refactors the code that deals with fn name munging

Comment by Alex Miller [ 12/Sep/14 6:22 PM ]

Hmmm.. I will double-check. That's not why I recall seeing when I did AOT.

Comment by Nicola Mometto [ 12/Sep/14 7:26 PM ]

New patch 0001-CLJ-1093-v2.patch improves the fn naming scheme a lot.
I've threw together a number of test cases that show the improvement + bug fixes:

user=> (fn [])
;; pre:
#<user$eval1$fn__2 user$eval1$fn__2@4e13aa4e>
;; post: (no change)
#<user$eval1$fn__3 user$eval1$fn__3@3c92218c>
user=> (fn a [])
;; pre:
#<user$eval5$a__6 user$eval5$a__6@6946a317>
;; post: (no change)
#<user$eval6$a__8 user$eval6$a__8@6f85c59c>
user=> (let [a (fn [])] a)
;; pre:
#<user$eval9$a__10 user$eval9$a__10@15fdf894>
;; post: (no change)
#<user$eval11$a__13 user$eval11$a__13@4d051922>
user=> (let [a (fn x [])] a)
;; pre: (only contains the name of the fn)
#<user$eval17$x__18 user$eval17$x__18@7f0cd67f>
;; post: (contains the name of the local aswell as the name of the fn
#<user$eval21$a__x__23 user$eval21$a__x__23@528ef256>
user=> (def a (fn [])) a
#'user/a
;; pre:
#<user$a user$a@33e1ccbc>
;; post: (no change)
#<user$a user$a@6bef63f9>
user=> (def a (fn x [])) a
#'user/a
;; pre: (BUG!)
#<user$x user$x@59a04a1b> 
;; post: (bug fixed)
#<user$a__x__28 user$a__x__28@5f0bebef>
user=> (def ^{:foo (fn [])} a) (-> (meta #'a) :foo)
#'user/a
;; pre:
#<user$fn__23 user$fn__23@d9c21c6>
;; post: (no change)
#<user$fn__30 user$fn__30@4cf0f2eb>
user=> (def ^{:foo (fn a [])} a) (-> (meta #'a) :foo)
#'user/a
;; pre: (BUG!)
#<user$a user$a@420dd874>
;; post: (bug fixed)
#<user$a__35 user$a__35@37ff95a9>
user=> (def a (fn [] (fn []))) (a)
#'user/a
;; pre:
#<user$a$fn__30 user$a$fn__30@6f57be76>
;; post: (no change)
#<user$a$fn__41 user$a$fn__41@fd34eac>
user=> (def a (fn [] (fn x []))) (a)
#'user/a
;; pre:
#<user$a$x__35 user$a$x__35@79930089>
;; post: (no change)
#<user$a$x__48 user$a$x__48@6fc334de>
user=> (let [x (fn [])] (def a (fn [] x))) a (a)
#'user/a
;; pre:
#<user$eval40$a__43 user$eval40$a__43@6db1694e>
#<user$eval40$x__41 user$eval40$x__41@20bd16bb>
;; post (no change)
#<user$eval54$a__58 user$eval54$a__58@7c721de>
#<user$eval54$x__56 user$eval54$x__56@43f7b41b>
user=> (let [x (fn a [])] (def a (fn [] x))) (a)
#'user/a
;; pre: (the local binding name doesn't appear in the class name)
#<user$eval48$a__49 user$eval48$a__49@75d6d1d4>
;; post: (the local binding name is included in the class name)
#<user$eval64$x__a__66 user$eval64$x__a__66@460d4>

As you can see, this last patch not only fixes the two bugs, but also improves fn naming in let contexts by preserving the name of the local binding in the class name, this I believe will be a great improvement in the understandability of stacktraces.

Comment by Alex Miller [ 25/Sep/14 7:00 AM ]

The patch should be changed to not create suffix if it's not going to be used. Please update the patch to inline that into each branch name = nm.name + "__" + RT.nextID();.

I am unsure whether the "enhancement" part of this patch goes too far. I think it does provide some improvements in debugging but those seem small to me. I am somewhat concerned about greatly increasing the name of the class for nested locals thus making it harder to read stack traces. There is a large limit to class name size of 16 bits (what you can put in the constant table) but class names also map to file names and there have historically been issues on some older Windows architectures with file size limits - we are increasing the risk of running into problems with this. Small risks. I am ok with passing this on to Rich though and he can decide whether to kick that part back or not.

Comment by Nicola Mometto [ 25/Sep/14 7:08 AM ]

0001-CLJ-1093-v3.patch is identical to 0001-CLJ-1093-v2.patch except it doesn't call RT.nextID() when not necessary, as per Alex's request

Alex, if this is ok please change the "Patch:" field in the description, I won't do that myself since this ticket is now screened

Comment by Nicola Mometto [ 06/Oct/14 11:54 AM ]

Addressing the screening comment by Alex Miller, I've attached an alternative patch "0001-CLJ-1093v3-no-locals-improv.patch" which is identical to "0001CLJ-1093-v3.patch" except it doesn't include the local binding name enhancement, so that it can be picked in case Rich decides that that improvement is out of scope for this ticket.

Comment by Alex Miller [ 28/Oct/14 12:05 PM ]

I've reopened this issue based on early reports of breakage due to long file names.

Two reports:
https://groups.google.com/d/msg/clojure-dev/hnkJb9_il_M/4e5smM6mVlIJ
https://groups.google.com/d/msg/clojure/hnkJb9_il_M/QOaTdCo5wmkJ

Comment by Alex Miller [ 28/Oct/14 12:21 PM ]

Here's an example of a class name that is too long on Ubuntu 12.04 LTS 64bit / Java8 - reported max file size is 143 chars:

https://github.com/ska2342/nested-fn-breaks-clojure-17/blob/master/src/nested_fn_breaks_clojure_17/core.clj

With 1.6.0: (95 chars)
core$this_function_breaks_with_clojure_1_7$my_anonymous_function_18$iter1923$fn24$fn_25

With 1.7.0-alpha3: (144 chars)
core$this_function_breaks_with_clojure_1_7$my_anonymous_function_my_anonymous_function19$iter4951auto__iter2024$fn25$fn_26.class

With the alternate patch here, the name would be: (95 chars)
core$this_function_breaks_with_clojure_1_7$my_anonymous_function_19$iter2024$fn25$fn_26

Comment by Nicola Mometto [ 28/Oct/14 12:26 PM ]

patch "0001-CLJ-1330-remove-local-binding-name-enhancement.patch" has the same effect of reverting f149260c14a75367dc9eba91cbe9b78110113566 and applying "0001-CLJ-1093-v3-no-locals-improv.patch" in case this is preferable

Comment by Stefan Kamphausen [ 29/Oct/14 7:44 AM ]

The tiny and unusual max file size of 143 is standard in the Ubuntu 12.04 crypto container for the home directory. You can get it for any directory with 'getconf NAME_MAX /path/to/dir'.

My initial problem (other than the file to reproduce on github) was triggered by the fns in a for-expression. Don't know if that makes any difference for you.





[CLJ-1315] Don't initialize classes when importing them Created: 28/Dec/13  Updated: 07/Oct/14  Resolved: 07/Oct/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.1, Release 1.2, Release 1.3, Release 1.4, Release 1.5
Fix Version/s: Release 1.7

Type: Enhancement Priority: Critical
Reporter: Aaron Cohen Assignee: Unassigned
Resolution: Completed Votes: 9
Labels: aot, compiler, interop

Attachments: Text File 0001-Don-t-initialize-classes-during-import.patch    
Patch: Code
Approval: Ok

 Description   

Problem: When classes are imported in Clojure, the class is loaded using Class.forName(), which causes its static initialisers to be executed. This differs from Java where compilation does not cause classes to be loaded.

Motivation: In many cases when those classes are normally loaded by Java code during execution of a framework of some kind (IntelliJ in my case, and RoboVM is another culprit mentioned in that thread) the initialiser expects some infrastructure to be in place and will fail when it's not. This means that it's impossible to AOT compile namespaces importing these classes, which is a fairly serious limitation.

Approach: Modify ImportExpr to call RT.classForNameNonLoading() instead of Class.forName(), which will load the class but not initialise it. This change causes the Clojure test suite to fail, since clojure.test-clojure.genclass imports a gen-class'ed class which no longer loads its namespace on initialisation. I'm not sure if this is considered an incorrect use of such a class (IIRC with records it's required to import the class and require its namespace), but given that it's in the Clojure test case it's reasonable to assume that this fix would be a breaking change for more code out there. This test failure is also corrected in the attached patch.

Patch: 0001-Don-t-initialize-classes-during-import.patch

Screened by: Alex Miller - I have tested many open source Clojure projects with this change (particularly seeking out large, complicated, or known users of genclass/deftype/etc) and have found no projects adversely impacted. I know that Cursive has been running with this modification for a long time with no known issues. I am ok with unconditionally enabling this change (re the comment below). The impact is described in more detail in the suggested changelog diff in the comments below.

Alternative: This patch enables the change unconditionally, but depending on the extent of breakage it causes, it might need to be enabled with a configuration flag. I propose we make it unconditional in an early 1.7 beta and monitor the fall-out.

Background: This issue has been discussed in the following threads
https://groups.google.com/d/topic/clojure/tWSEsOk_pM4/discussion
https://groups.google.com/forum/#!topic/clojure-dev/qSSI9Z-Thc0



 Comments   
Comment by Alex Miller [ 29/Dec/13 12:23 PM ]

From original post:

This issue was originally reported by Zach Oakes and Colin Fleming and this patch was also tested by Colin.

I'm duplicating here my suggested release notes for this issue, which includes my current thoughts on potential breakage (it's also in the commit message of the patch):

    "import" no longer causes the imported class to be initialized. This
    change better matches Java's import behavior and allows the importing of
    classes that do significant work at initialization time which may fail.
    This semantics change is not expected to effect most code, but certain
    code may have depended on behavior that is no longer true.

    1) importing a Class defined via gen-class no longer causes its defining
    namespace to be loaded, loading is now deferred until first reference. If
    immediate loading of the namespace is needed, "require" it directly.
    2) Some code may have depended on import to initialize the class before it
    was used. It may now be necessary to manually call (Class/forName
    "org.example.Class") when initialization is needed. In most cases, this
    should not be necessary because the Class will be initialized
    automatically before first use.
Comment by Greg Chapman [ 13/May/14 6:25 PM ]

I'm not sure if this should also be fixed, but it would be nice if you could emit the code for a proxy of one of these non-initialized classes without forcing initialization. For example, the following raises an exception (I'm using Java 8):

Clojure 1.6.0
user=> (def cname "javafx.scene.control.ListCell")
#'user/cname
user=> (let [cls (Class/forName cname false (clojure.lang.RT/baseLoader))] (.importClass *ns* cls))
javafx.scene.control.ListCell
user=> (defn fails [] (proxy [ListCell] [] (updateItem [item empty] (proxy-super item empty))))
CompilerException java.lang.ExceptionInInitializerError, compiling:(NO_SOURCE_PATH:3:16)

The exception was ultimately caused by "IllegalStateException Toolkit not initialized", which javafx throws if you attempt to initialize a Control class outside of Application.launch.





[CLJ-1244] :prefix is ignored when trying to gen-class with custom methods Created: 14/Aug/13  Updated: 16/Aug/13  Resolved: 16/Aug/13

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Daniel Kwiecinski Assignee: Unassigned
Resolution: Declined Votes: 0
Labels: AOT, gen-class


 Description   

I'm trying to generate several classes defined in one namespace:

(ns aot.core)

(gen-class
:name aot.core.ClassA
:prefix "classA-")

(gen-class
:name aot.core.ClassB
:prefix "classB-")

(defn classA-toString
[this]
"I'm an A.")

(defn classB-toString
[this]
"I'm a B.")

After AOT I can see that

(.toString (ClassA.))

doesn't produce "I'm an A." string but rather uses method from the superclass >> "aot.core.ClassA@33ba4e15"

If on other hand I do:

(ns aot.core)

(gen-class
:name aot.core.ClassA
:prefix "classA-")

(gen-class
:name aot.core.ClassB
:prefix "classB-")

(defn -toString
[this]
"I'm an A.")

(defn -toString
[this]
"I'm a B.")

then both

(.toString (ClassA.))

and

(.toString (ClassB.))

obviously give "I'm a B." as there is only one -toString really defined.

Is it a bug? Am I doing something wrong? How can I make clojure respect :prefix option.



 Comments   
Comment by Daniel Kwiecinski [ 15/Aug/13 5:42 AM ]

Please close the ticket. I have copied an example from a blog post which had wrong keyword.
Instead of :prefix it had :prefix. Notice that fi in :prefix is single character (see: fi fi )

Comment by Alex Miller [ 16/Aug/13 8:59 AM ]

Closed per request





[CLJ-1241] NPE when AOTing overrided clojure.core functions Created: 30/Jul/13  Updated: 29/Aug/14  Resolved: 29/Aug/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5, Release 1.6
Fix Version/s: Release 1.7

Type: Defect Priority: Major
Reporter: Phil Hagelberg Assignee: Unassigned
Resolution: Completed Votes: 2
Labels: aot, compiler

Attachments: Text File 0001-fix-CLJ-1241.patch    
Patch: Code
Approval: Ok

 Description   

When performing AOT compilation on a namespace that overrides a clojure.core function without excluding the original clojure.core function from the ns, you get a NullPointerException.

To reproduce aot compile a namespace like "(ns x) (defn get [])"

For example:

$ lein new aot-get
$ cd aot-get
$ sed -i s/foo/get/
$ lein compile :all
WARNING: get already refers to: #'clojure.core/get in namespace: aot-get.core, being replaced by: #'aot-get.core/get
Exception in thread "main" java.lang.NullPointerException
	at clojure.lang.Compiler$ObjExpr.emitVar(Compiler.java:4858)
	at clojure.lang.Compiler$DefExpr.emit(Compiler.java:428)
	at clojure.lang.Compiler.compile1(Compiler.java:7152)
	at clojure.lang.Compiler.compile(Compiler.java:7219)
	at clojure.lang.RT.compile(RT.java:398)
	at clojure.lang.RT.load(RT.java:438)
	at clojure.lang.RT.load(RT.java:411)

Cause: DefExpr.parse does not call registerVar for vars overridding clojure.core ones, thus when AOT compiling the var is not registered in the constant table.

Proposed: The attached patch makes DefExpr.parse call registerVar for vars overridding clojure.core ones.

Patch: 0001-fix-CLJ-1241.patch

Screened by: Alex Miller



 Comments   
Comment by Nicola Mometto [ 30/Jul/13 7:29 PM ]

DefExpr.parse was not calling registerVar for vars overridding clojure.core ones.

Comment by Alex Miller [ 31/Jul/13 12:25 AM ]

Verified on Clojure 1.5.1.

Comment by Javier Neira Sanchez [ 27/Aug/13 8:34 AM ]

Reproduced with `key` function without `(:refer-clojure :exclude [key])`

Comment by Rich Hickey [ 05/Sep/13 8:32 AM ]

This doesn't meet triage guidelines - i.e. there is this problem, therefore we will fix it by _____ so it then does _____

Comment by Aaron Cohen [ 26/Mar/14 12:52 PM ]

This is still present in the 1.6 release. I think it's mis-classified as low priority.

Comment by Aaron Cohen [ 26/Mar/14 12:52 PM ]

See for instance the cascalog mailing list: https://groups.google.com/forum/#!topic/cascalog-user/Pe5QIpmU0vA

Comment by Andy Fingerhut [ 26/Mar/14 1:07 PM ]

It may help if someone could clarify Rich's comment.

Does it mean that the ticket should include a plan of the form "therefore we will fix it by _____ so it then does _____", but this ticket doesn't have that?

Or perhaps it means that the ticket should not include a plan of that form, but this ticket does? If so, I don't see it, except perhaps the very last sentence of the description. If that is a problem for vetting a ticket, perhaps we could just delete that sentence and proceed from there?

Something else?

Comment by Nicola Mometto [ 26/Mar/14 1:13 PM ]

Andy, I added the two last lines in the description after reading Rich's comment to explain why this bug happens and how the patch I attached works around this.

I don't know if this is what he was asking for though.

Comment by Alex Miller [ 27/Mar/14 11:00 AM ]

I think Rich meant that a ticket should have a plan of that form but does not. My own take on "triaged" is that it should state actual and expected results demonstrating a problem - I don't think it needs to actually describe the solution (as that can happen later in development). It is entirely possible that Rich and I differ in our interpretation of that. I will see if I can rework the description a bit to match what I've been doing elsewhere.

Comment by Andy Fingerhut [ 31/Mar/14 9:34 AM ]

Alex, I have looked through the existing wiki pages on the ticket tracking process, and do not recall seeing anything about this desired aspect of a triaged ticket. Is it already documented somewhere and I missed it? Not that it has to be documented, necessarily, but Rich saying "triage guidelines" makes it sound like a filter he applies that ticket creators and screeners maybe should know about.

Comment by Alex Miller [ 31/Mar/14 11:57 AM ]

To me, Triage (and Vetting) is all about having good problem statements. For a defect, it is most important to demonstrate the problem (what happens now) and what you expect to happen instead. I do not usually expect there to necessarily be "by ____" in the ticket - to me that is part of working through the solution (although it is typical to have this in an enhancement). This ticket, as it stands now, seems to have both a good problem statement and a good cause/solution statement so seems to exceed Triaging standards afaik.

Two places where I have tried to write about these things in the past are http://dev.clojure.org/display/community/Creating+Tickets and in the Triage process on the workflow page http://dev.clojure.org/display/community/JIRA+workflow.





[CLJ-1227] Definline functions do not work as higher-order functions when AOT compiled Created: 27/Jun/13  Updated: 22/Jan/14  Resolved: 21/Jan/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: None

Type: Defect Priority: Blocker
Reporter: Colin Fleming Assignee: Unassigned
Resolution: Declined Votes: 1
Labels: aot
Environment:

OSX 10.8, Linux


Attachments: Text File 0001-CLJ-1227-Fix-definline-in-AOT-scenarios.patch     Zip Archive aot-test.zip    
Patch: Code and Test

 Description   

See discussion on Clojure group: https://groups.google.com/d/topic/clojure/v0ipoiP8X1o/discussion

Functions defined with definline appear to misbehave when AOT compiled and used with higher-order functions - it seems like the macro function is stored instead of the expansion. I've attached a small test project here reproducing the issue. It can be run with:

lein compile
lein uberjar
java -jar target/aot-test-0.1.0-SNAPSHOT-standalone.jar

The relevant part of the test namespace is:

(definline java-list? [element]
  `(instance? List ~element))

(defn -main [& args]
  (println (java-list? 2))
  (println ((var-get #'java-list?) 2))
  (println (filter java-list? [1 2 3]))
  (println (map java-list? [1 2 3])))

The output produced is:

false
(clojure.core/instance? java.util.List 2)
(1 2 3)
((clojure.core/instance? java.util.List 1) (clojure.core/instance? java.util.List 2) (clojure.core/instance? java.util.List 3))


 Comments   
Comment by Tassilo Horn [ 14/Jan/14 9:15 AM ]

I've just fallen into the very same trap. This is definitively a blocker as it means that AOT-compiled code will probably not work correctly if there's a definline in any dependency (transitively).

Comment by Tassilo Horn [ 14/Jan/14 9:57 AM ]

BTW, the problem also applies to the definlines defined in clojure.core such as ints, longs, doubles, etc.

;; This NS is AOT-compiled
(ns aot-test.core
  (:gen-class))

(defn -main [& args]
  (let [ary (make-array Integer/TYPE 5)]
    (println (apply ints [ary]))))

The output is:

% lein uberjar && java -jar target/aot-test-0.1.0-SNAPSHOT-standalone.jar
Compiling aot-test.core
Compiling aot-test.core
Created /home/horn/tmp/aot-test/target/aot-test-0.1.0-SNAPSHOT.jar
Created /home/horn/tmp/aot-test/target/aot-test-0.1.0-SNAPSHOT-standalone.jar
(. clojure.lang.Numbers clojure.core/ints #<int[] [I@39b65439>)
Comment by Tassilo Horn [ 15/Jan/14 3:48 AM ]

I debugged a bit further. What made me wonder is why standard clojure functions with :inline metadata work correctly in AOT-scenarios whereas definlines which expand to normal functions with :inline metadata do not.

The bug can be fixed by adding the :inline metadata immediately in the defn form in the expansion instead of providing it after the defn form using alter-meta!. Here's a demo example:

(ns aot-test.core
  (:gen-class))

;; (definline n? [x]
;;   `(clojure.lang.Util/identical ~x nil))
;;
;; It expands into the following which doesn't work in AOT-scenarios, e.g.,
;; (apply n? [nil]) returns (clojure.lang.Util/identical nil nil) rather than
;; true.
(do
  (clojure.core/defn n? [x] (clojure.lang.Util/identical x nil))
  (clojure.core/alter-meta!
    #'n?
    clojure.core/assoc
    :inline
    (clojure.core/fn n? [x]
      (clojure.core/seq
        (clojure.core/concat
          (clojure.core/list 'clojure.lang.Util/identical)
          (clojure.core/list x)
          (clojure.core/list 'nil)))))
  #'n?)

;; If the expansion would look like this, i.e., the metadata is added directly
;; instead of with alter-meta!, then it works fine in AOT-scenarios.
(do
  (clojure.core/defn nl?
    {:inline (clojure.core/fn fn? [x]
                                 (clojure.core/seq
                                  (clojure.core/concat
                                   (clojure.core/list 'clojure.lang.Util/identical)
                                   (clojure.core/list x)
                                   (clojure.core/list 'nil))))}
    [x] (clojure.lang.Util/identical x nil)))

(defn -main [& args]
  (println "n?")
  (println (meta #'n?))       ;=> {:inline #<core$n_QMARK_ aot_test.core$n_QMARK_@78ffb648>, :ns #<Namespace aot-test.core>, :name n?, :arglists ([x]), :column 3, :line 8, :file aot_test/core.clj}
  (println (apply n? [nil]))  ;=> (clojure.lang.Util/identical nil nil)  BROKEN!!!
  (println (apply n? [1]))    ;=> (clojure.lang.Util/identical 1 nil)    BROKEN!!!
  (println (n? nil))          ;=> true
  (println (n? 1))            ;=> false

  (println "nl?")
  (println (meta #'nl?))      ;=> {:ns #<Namespace aot-test.core>, :name nl?, :file aot_test/core.clj, :column 3, :line 22, :arglists ([x]), :inline #<core$fn_QMARK_ aot_test.core$fn_QMARK_@3b7541a>}
  (println (apply nl? [nil])) ;=> true
  (println (apply nl? [1]))   ;=> false
  (println (nl? nil))         ;=> true
  (println (nl? 1)))          ;=> false
Comment by Tassilo Horn [ 15/Jan/14 4:56 AM ]

Here's a patch fixing the issue by making definline expand only to a defn form where the :inline metadata is added immediately instead of providing it afterwards with alter-meta!.

I also added a deftest in test_clojure/macros.clj which checks for the correctness of the expansions.

Although this patch fixes the problem, it should be somehow/somewhere documented why the former approach didn't work in AOT-scenarios.

Comment by Alex Miller [ 21/Jan/14 9:36 AM ]

definline should be considered to be like defmacro in that it is not a function and cannot be used as a HOF. Additionally, definline is considered to be an experimental feature and Rich would like to discourage its use as the hope is to remove it in the future. The desired replacement is something like common lisp compiler macros that could allow the compiler to detect special situations and optimize the result but leave behind a function invocation for the case where no special behavior is available.

I am declining the ticket based on the info above and per Rich's request.

Comment by Colin Fleming [ 21/Jan/14 2:20 PM ]

This is a little disappointing since there's really no alternative right now, and I'm assuming that this sort of advanced optimisation is a ways off. If this is the plan, I'd definitely recommend marking definline as deprecated and making clear in the docstring that it shouldn't be relied on to return a function. Currently it states: "like defmacro, except defines a named function...", and based on this ticket that is clearly people's expectation.

Comment by Alex Miller [ 21/Jan/14 4:20 PM ]

Sorry about that. I will now split some definitional hairs by saying that definline is marked as "experimental" to indicate it may or may not even become a feature whereas "deprecation" indicates that it was a feature which you should no longer use. I think in this case they serve the same functional intent which is to warn you away from relying on it as part of the language.

Comment by Colin Fleming [ 21/Jan/14 5:28 PM ]

Fair enough, although it's been experimental for five major releases now. If we're convinced it's a failed experiment (and if it can't be relied on to create a function, it pretty much is since you might as well use a macro) I'd argue that deprecation is justified and sends a stronger signal that it doesn't actually work as intended. But either way, I'm certainly convinced now

Comment by Tassilo Horn [ 22/Jan/14 2:58 AM ]

Alex, definline's intention is to be considered like defmacro in case of (my-definline x) where it saves one function call, but to be callable as a normal function in higher-order scenarios like (map my-definline [x y z]). Therefore, it expands to a normal defn form with :inline metadata which is a macro that's used by the compiler.

Wether it should be removed in the future is a separate issue. It is there right now, and people use it. The consequence of this bug is that you cannot trust AOT-compiled code, because there might be some dependency that uses definline. Additionally, all clojure.core definlines (booleans, bytes, chars, shorts, floats, ints, doubles, longs) are broken when applied as HOF, because clojure itself is always distributed in AOT-compiled form.

Really, it would be grossly negligent to release Clojure 1.6 knowing of this bug.

I've written a more detailed mail to the clojure-dev list:

https://groups.google.com/d/msg/clojure-dev/UeLNJzp7UiI/UCyVvYLfHWMJ

Comment by Tassilo Horn [ 22/Jan/14 3:35 PM ]

The root cause of this issue is CLJ-1330 as investigated by Nicola Mometto in the thread cited above: http://dev.clojure.org/jira/browse/CLJ-1330
So fixing the latter will fix this one, too.





[CLJ-1129] Invalid ns macro can yield a difficult to trace exception Created: 17/Dec/12  Updated: 19/Dec/12  Resolved: 19/Dec/12

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.4
Fix Version/s: None

Type: Defect Priority: Minor
Reporter: Howard Lewis Ship Assignee: Unassigned
Resolution: Duplicate Votes: 0
Labels: aot, feedback


 Description   

I inadvertently stripped off the namespace part of my ns macro, so that it was (ns (:use .... Clearly a user error, but an easy one. However, the result (from the REPL or the AOT compiler) was not ideal:

Exception in thread "main" java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.Named
	at clojure.core$name.invoke(core.clj:1489)
	at clojure.core$root_resource.invoke(core.clj:5210)
	at clojure.core$load_one.invoke(core.clj:5227)
	at clojure.core$compile$fn__4895.invoke(core.clj:5426)
	at clojure.core$compile.invoke(core.clj:5425)
	at clojuresque.tasks.compile$main$fn__64.invoke(compile.clj:23)
	at clojuresque.cli$with_command_line_STAR_.invoke(cli.clj:92)
	at clojuresque.tasks.compile$main.doInvoke(compile.clj:6)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invoke(core.clj:601)
	at clojure.lang.Var.invoke(Var.java:419)
	at clojuresque.Driver.main(Driver.java:39)

The problem here is that there is no indication of what file was being loaded and compiled at the time of the error. Since I was in the middle of refactoring a big swath of code, I had some work to do to track down which file I had mangled.

I would like to see a little more logging to the System/err to identify what resource file was being read and compiled by the compiler at the time of the exception.



 Comments   
Comment by Andy Fingerhut [ 18/Dec/12 1:12 AM ]

Howard, is this perhaps a duplicate of CLJ-939? Let me know, and I can close this ticket as a duplicate if so.

Comment by Howard Lewis Ship [ 18/Dec/12 11:10 AM ]

Yes, looks like a dupe to me. Sorry about that, I did do a search for existing issue before adding mine, but they can be hard to find.

Comment by Andy Fingerhut [ 19/Dec/12 1:09 AM ]

Closed as duplicate of CLJ-939.





[CLJ-979] Clojure resolves to wrong deftype classes when AOT compiling or reloading Created: 03/May/12  Updated: 17/Dec/14

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.3, Release 1.4, Release 1.5, Release 1.6, Release 1.7
Fix Version/s: Release 1.7

Type: Defect Priority: Critical
Reporter: Edmund Jackson Assignee: Unassigned
Resolution: Unresolved Votes: 13
Labels: aot, classloader, compiler

Attachments: Text File CLJ-979.patch     Text File clj-979-symptoms.patch     Text File CLJ-979-v2.patch     Text File CLJ-979-v3.patch     Text File CLJ-979-v4.patch     Text File CLJ-979-v5.patch     Text File CLJ-979-v6.patch     Text File CLJ-979-v7.patch    
Patch: Code and Test
Approval: Vetted

 Description   

Compiling a class via `deftype` during AOT compilation gives different results for the different constructors. These hashes should be identical.

user=> (binding [*compile-files* true] (eval '(deftype Abc [])))
user.Abc
user=> (hash Abc)
16446700
user=> (hash (class (->Abc)))
31966239 ;; should be 16446700

This also means that whenever there's a stale AOT compiled deftype class in the classpath, that class will be used rather then the JIT compiled one, breaking repl interaction.

Another demonstration of this classloader issue (from CLJ-1495) when reloading deftypes (no AOT) :

user> (defrecord Foo [bar])
user.Foo
user> (= (->Foo 42) #user.Foo{:bar 42}) ;;expect this to evaluate to true
true
user> (defrecord Foo [bar])
user.Foo
user> (= (->Foo 42) #user.Foo{:bar 42}) ;;expect this to evaluate to true also -- but it doesn't!
false
user>

This bug also affects AOT compilation of multimethods that dispatch on a class, this affected core.match for years see http://dev.clojure.org/jira/browse/MATCH-86, http://dev.clojure.org/jira/browse/MATCH-98. David had to work-around this issue by using a bunch of protocols instead of multimethods.

Cause of the bug: currently clojure uses Class.forName to resolve a class from a class name, which ignores the class cache from DynamicClassLoader thus reloading deftypes or mixing AOT compilation at the repl with deftypes breaks, resolving to the wrong class.

Approach: the current patch (CLJ-979-v7.patch) addresses this issue in multiple ways:

  • it makes RT.classForName/classForNameNonLoading look in the class cache before delegating to Class/forName if the current classloader is not a DynamicClassLoader (this incidentally addresses also CLJ-1457)
  • it makes clojure use RT.classForName/classForNameNonLoading instead of Class/forName
  • it overrides Classloader/loadClass so that it's class cache aware – this method is used by the jvm to load classes
  • it changes gen-interface to always emit an in-memory interface along the [optional] in disk interface so that the in-memory class is always updated.


 Comments   
Comment by Scott Lowe [ 12/May/12 9:05 PM ]

I can't reproduce this under Clojure 1.3 or 1.4, and Leiningen 1.7.1 on either Java 1.7.0-jdk7u4-b21 OpenJDK 64-Bit or Java 1.6.0_31 Java HotSpot 64-Bit. OS is Mac OS X 10.7.

Edmund, how are you running this AOT code? I wrapped your code in a main function and built an uberjar from it.

Comment by Edmund Jackson [ 13/May/12 2:20 AM ]

Hi Scott,

Interesting.

I have two use cases
1. AOT compile and call from repl.
My steps: git clone, lein compile, lein repl, (use 'aots.death), (in-ns 'aots.death), (= (class (Dontwork. nil)) (class (map->Dontwork {:a 1}))) => false

2. My original use case, which I've minimised here, is an AOT ns, producing a genclass that is called instantiated from other Java (no main). This produces the same error. I will produce an example of this and post it too.

Comment by Edmund Jackson [ 13/May/12 4:23 AM ]

Hi Scott,

Here is an example of it failing in the interop case: https://github.com/ejackson/aotquestion2
The steps I'm following to compile this all up are

git clone git@github.com:ejackson/aotquestion2.git
cd aotquestion2/cljside/
lein uberjar
lein install
cd ../javaside/
mvn package
java -jar ./target/aotquestion-1.0-SNAPSHOT.jar

and it dies with this:

Exception in thread "main" java.lang.ClassCastException: cljside.core.Dontwork cannot be cast to cljside.core.Dontwork
at cljside.MyClass.makeDontwork(Unknown Source)
at aotquestion.App.main(App.java:8)

The error message is really confusing (to me, anyway), but I think its the same root problem as for the REPL case.

What do you see when you run the above ?

Comment by Scott Lowe [ 13/May/12 8:41 AM ]

Ah, yes, looks like my initial attempt to reproduce was too simplistic. I used your second git repo, and can now confirm that it's failing for me with the same error.

Comment by Scott Lowe [ 13/May/12 10:35 PM ]

I looked into this a little further and the AOT generated code looks correct, in the sense that both code paths appear to be returning the same type.

However, I wonder if this is really a ClassLoader issue, whereby two definitions of the same class are being loaded at different times, because that would cause the x.y.Class cannot be cast to x.y.Class exception that we're seeing here.

Comment by Steve Miner [ 03/Sep/13 9:54 AM ]

This could be related to CLJ-1157 which deals with a ClassLoader issue with AOT compiled code.

Comment by Ambrose Bonnaire-Sergeant [ 29/Mar/14 1:11 PM ]

I've tried this patch attached to CLJ-1157 and it did not solve this issue.

Comment by Ambrose Bonnaire-Sergeant [ 29/Mar/14 2:27 PM ]

This bug seems to be rooted in different behaviour for do/let under compilation. Attached a patch showing these symptoms in the hope it helps people find the cause.

Comment by Peter Taoussanis [ 22/Sep/14 3:12 AM ]

Just a quick note to confirm that this still seems to be around as of Clojure 1.7.0-alpha2. Don't have any useful input on possible solutions, sorry.

Comment by Alex Miller [ 04/Dec/14 1:12 PM ]

Duplicates - CLJ-1495, CLJ-1132

Comment by Nicola Mometto [ 04/Dec/14 1:50 PM ]

The attached patch fixes the classloader issues by routing RT.classForName & variants through the DynamicClassLoader class cache before invoking Class.forName

Comment by Nicola Mometto [ 04/Dec/14 1:59 PM ]

Re-adding triaged status added by Alex Miller that got accidentaly nuked by a race-condition between my edits to the ticket description and Alex's ones

Comment by Nicola Mometto [ 04/Dec/14 2:30 PM ]

0001-CLJ-979-make-clojure-resolve-to-the-correct-Class-in-v2.patch is the same as 0001-CLJ-979-make-clojure-resolve-to-the-correct-Class-in.patch except it unconditionally looks for classes in the class cache of DynamicClassLoader, even if baseLoader() is not a DynamicClassLoader.
This fixes the bug of CLJ-1457 but might just be a workaround

Comment by Michael Blume [ 11/Dec/14 3:29 PM ]

Current patch blows up my Clojure build

https://gist.github.com/MichaelBlume/aa26fc715cbbdf711290

Comment by Nicola Mometto [ 11/Dec/14 3:45 PM ]

Michael: the current patch builds clojure fine for me, I'll try to reproduce. Which jvm version are you using?

Comment by Michael Blume [ 11/Dec/14 4:26 PM ]

[14:24][michael.blume@tcc-michael-4:~/workspace/clojure((0fc43db...))]$ java -version
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)
[14:24][michael.blume@tcc-michael-4:~/workspace/clojure((0fc43db...))]$ mvn -version
Apache Maven 3.2.3 (33f8c3e1027c3ddde99d3cdebad2656a31e8fdf4; 2014-08-11T13:58:10-07:00)
Maven home: /usr/local/Cellar/maven/3.2.3/libexec
Java version: 1.8.0_25, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.10.1", arch: "x86_64", family: "mac"

build was after I applied the patch to the current master branch of the clojure github repo

Comment by Andy Fingerhut [ 11/Dec/14 5:34 PM ]

I am seeing a similar compilation error as Michael Blume, with both JDK 1.7 and 1.8 on Mac OS X 10.9.5.

By accident I found that if I take latest Clojure master and do 'mvn package', then apply the patch CLJ-979.patch dated Dec 11 2014, then do 'mvn package' again without 'mvn clean', it compiles with no errors. If I do 'mvn clean' then 'mvn package' in a patched tree, I get the error every time I've tried.

Comment by Nicola Mometto [ 12/Dec/14 5:50 AM ]

The updated patch fixes the LinkageError Andy and Michael were getting.

Andy, Michael, can you confirm?

Comment by Nicola Mometto [ 12/Dec/14 9:38 AM ]

Added more testcases to new patch

Comment by Nicola Mometto [ 12/Dec/14 10:09 AM ]

Cleaned up the patch from whitespace changes

Comment by Andy Fingerhut [ 12/Dec/14 12:32 PM ]

I tried latest Clojure master plus patch CLJ-979-v4.patch, dated 12 Dec 2014, with Mac OS X 10.9.5 + JDK7, and Ubuntu Linux 14.04 with JDKs 6 through 9, and 'mvn clean' followed by 'mvn package' built and passed tests successfully with all of them.

I did notice that some files were created in the test directory that were not cleaned up by the end of the test, which you can use 'git status .' to see. Not sure if that is considered a bad thing for Clojure tests.

Comment by Nicola Mometto [ 12/Dec/14 1:07 PM ]

Thanks Andy, I've updated the patch and it now should remove all temporary classes created by the test.
It's probably not the best way to do it but I couldn't figure out how to do it another way.

Comment by Michael Blume [ 12/Dec/14 2:34 PM ]

Yep, looks good to me =)

Comment by Alex Miller [ 15/Dec/14 4:01 PM ]

Thanks first to Nicola for all his work so far on this!

Some feedback:
1) While the ticket itself isn't bad, I would really like to focus the title and description on a crisp statement of the real problem now that we understand it more. I'd like help on making sure we capture that correctly - how is this for a title: "Uses of Class.forName() miss classes in DynamicClassLoader cache?" ?

Similarly, the description should focus on the problem and show some examples. The defrecord one is good. The first example works for me before the patch and fails after?

2) The crux of this whole thing is the change in loading order in DCL.loadClass() - changing this is a big deal. We really need broader testing with things likely to be affected - off the top of my head: Immutant, Pomegranate, Leiningen, or anything else that monkeys with classloader stuff. Maybe something with Eclipse/OSGi if there is something testable out there.

3) DynamicClassLoader comments:
a) loadClass(String name) - I believe this is identical to the super impl, so can be removed.
b) findClass(String name) - now that we are hijacking loadClass(), I'm not sure it's even necessary to implement this or to call super.findClass() - if you get to the super.findClass(), I would expect that to always throw CNFE. Potentially, this method could even be removed (but this might do bad things if there are subclasses of DCL out there in the wild).
c) loadClass(String name, ...) - instead of calling findClass() and using the CNFE for control flow, you could just directly call findInMemoryClass(), then use a returned null as the decision factor. Again, this is possibly bad if there are DCL subclasses, so I'm on the fence about it.

4) Is the change in gen-interface something that should be a separate ticket? Seems like it could be separable.

5) I don't like the test changes with respect to set up and cleanup. The build already supports compiling a subset of test ns'es (like clojure.test-clojure.genclass.examples). I'd prefer to use that existing mechanism if at all possible. Check the build.xml for the hard-coded ns list.

6) What are the performance implications? I'm not expecting they are significant but we just made a bunch of changes for compilation performance and I'd hate to undo them all. Could findInMemoryClass be smarter about avoiding checks that can't succeed (avoiding "java.*" for example?).

Comment by Nicola Mometto [ 15/Dec/14 5:43 PM ]

1) It's not really about Class.forName() specifically, it's about DynamicClassLoader not being class cache aware in the loadClass method. The JVM uses the classloader loadClass method for resolving all kind of class usages,
including but not limited to Class.forName() (i.e. when loading some bytecode containing a "new" instruction, that class reference will be resolved via a call to loadClass)
I'll try to make the documentation a bit more clear, the first example is an exhibit of the bugged behaviour, the two calls should output the same hash.

2,4) So, there are 3 approaches to how DynamicClassLoader could go at it:

  • Prefer in-disk classes over in-memory classes, roughly the current approach (sometimes it will pick the in-memory class over the in-disk one causing weird bugs like Foo. and ->Foo constructing different classes), has the
    negative effect of breaking interaction between AOT compilation and JIT loading, which has created all sorts of troubles with redefinig deftypes/defprotocols in repls while having stale classfiles in disk.
  • Always pick the most-updated class, this has the advangate of being always correct but has several disadvantages that make it inpracticable in my opinion: we'd have to keep track of the timestamp in which a dynamic class
    is defined, and make the loadClass implementation such that if there a class is both in-memory and in-disk, it compares the timestamps and select the most updated one. This would complicate the implementation a lot and we'd
    likely have to pay a substantial performance hit.
  • Prefer in-memory classes over in-disk classes, the approach proposed in the current patches. It has the advantage of being almost always correct, make repl interaction & jit/aot mixing work fine and the implementation is
    mostly straightforward. The downside is that in cases like gen-class where an AOT class can actually be the most updated version, the in-memory version will be used. In clojure all the forms that do bytecode emission either
    only do AOT compilation or do AOT compilation on demand and always load the class in memory, except gen-interface that doesn't load the class in memory if it's being AOT compiled. Changing its semantics to behave like the
    other jit/aot compiling forms (deftype/defrecord/reify) is the only way to make this approach work so I don't think this should go in another ticket.

5) I don't like the previous testing strategy either but couldn't figure out a better way. Thanks for the pointer on the already in-place infrastructure, I'll check it out and update the patch

In the meantime I've uploaded a new patch addressing 3 and 6. Specifically:
3) I removed the unnecessary loadClass(String) arity, I've made loadClass(String, boolean) use findInMemoryClass(String) directly rather than relying on findClass(String) since nowhere in the documentation it guarantess that
findClass will be used by loadClass. However I've left the findClass(String) implementation in place in case there's code out there that relies on this.
6) I haven't done any serious testing but I haven't noticed any significant difference in compile times for any of my tools.* contrib libraries with the current patch. Filtering "java.*" class names before the inMemory check
didn't seem to produce any difference so it's not included in the updated patch. However I'll probably include an alternative patch with that filtering to do more performance testings and see if it can actually help a bit.

All this said, I'm afraid that I won't have time to personally do an in-depth benchmarking & cross project testing of this patch. I've been spending almost all the free time I had in the past weeks working through a bunch of tickets (mostly this one) but now because of school and other commitments I can't promise I will be able to do anything more than maintaining the current patch & answering to any questions about the bug. Any help in moving this ticket further would be appreciated, in particular to address points 2 and 6.

Comment by Alex Miller [ 16/Dec/14 8:33 AM ]

Thanks Nicola. I'll certainly take over sheparding the bug and appeal to the greater community for help in broad testing when I think we're ready for that.

Comment by Nicola Mometto [ 16/Dec/14 12:50 PM ]

Updated patch with better tests, addressing Alex Miller's comments.





[CLJ-956] [java.lang.ClassFormatError: Duplicate method name&signature] when using gen-class Created: 20/Mar/12  Updated: 01/Mar/13  Resolved: 09/Nov/12

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.3
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Daniel Ribeiro Assignee: Unassigned
Resolution: Declined Votes: 0
Labels: AOT
Environment:

$ java -version
java version "1.6.0_29"
Java(TM) SE Runtime Environment (build 1.6.0_29-b11-402-11M3527)
Java HotSpot(TM) 64-Bit Server VM (build 20.4-b02-402, mixed mode)



 Description   

Hi,

When extending a class that defines a method with the signature "public void load();", I get the following load time error:

java.lang.ClassFormatError: Duplicate method name&signature

Looking into javap, I see that in fact gen-class is generating two entries for the load method. Prefix does not help in this case, as the defined load method is generated anyway.

Cheers,

  • Daniel


 Comments   
Comment by Daniel Ribeiro [ 22/Mar/12 5:10 AM ]

Hi,

I've create this small sample project to exemplify the bug ocurring: https://github.com/danielribeiro/ClojureBugReport

Cheers,

  • Daniel
Comment by Daniel Ribeiro [ 24/Mar/12 6:57 PM ]

Note that the name load is not special: it works with any abstract method, no matter the name.

Comment by Daniel Ribeiro [ 24/Mar/12 7:34 PM ]

Not a bug: I was declaring the method load, which was already defined on the abstract class. The docs do mention this:

http://clojuredocs.org/clojure_core/clojure.core/gen-class

Comment by Stuart Sierra [ 09/Nov/12 8:40 AM ]

Closed as not-a-bug.





[CLJ-760] ClassNotFound when AOT compiling a self-referring deftype extended to a protocol Created: 18/Mar/11  Updated: 18/Apr/14  Resolved: 18/Apr/14

Status: Closed
Project: Clojure
Component/s: None
Affects Version/s: Release 1.2
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Ryan Senior Assignee: Unassigned
Resolution: Not Reproducible Votes: 0
Labels: aot
Environment:

Clojure 1.2.0, 1.2.1, 1.3.0-alpha6, JDK 1.6.0_24, Ubuntu 10.10


Attachments: Text File stacktraces.txt    

 Description   

If I create a deftype that refers to itself in a protocol extension like below:

(ns type-test)

(defprotocol Foo
  (isa-foo [x]))

(deftype TypeTest []
  Foo
  (isa-foo [x]
           (instance? TypeTest x)))

And use that code via another namespace:

(ns test-type-user
  (:use [type-test :only (isa-foo)])
  (:import [type-test TypeTest]))

(isa-foo (TypeTest.))

When I try to AOT compile the test-type-user namespace with Clojure 1.2.0, I get java.lang.NoClassDefFoundError: compilestub/type-test/TypeTest (test_type_user.clj:5). Full stack trace attached. Running the same code on 1.2.1 and 1.3.0-alpha6 yielded the same exception with a slightly different error message (stacktrace for 1.2.1 is also in the attached file).

This came up in a test at Revelytix. We worked around this issue by not using instance? and instead comparing based on class name. Another workaround is to define the deftype and the extension separately (using extend-type or something similar). This problem also doesn't occur if the usage of the deftype and the definition of it are in the same namespace (i.e. if type-test and test-type-user were in the same file).



 Comments   
Comment by Alex Miller [ 18/Mar/11 10:27 AM ]

The first case where we saw this was actually in having a deftype implement a Java interface (not a protocol) and in that case you cannot extend the interface outside the deftype (although comparing based on class name of course works).

Comment by Kevin Downey [ 17/Apr/14 10:55 PM ]

I wonder if this could be a problem with the way the compiler does intrinsic magic for "instance?", there have been other bugs and significant changes to that part of the compiler in 2 years.

I am unable to reproduce this issue on clojure 1.6 or 1.5.1

Comment by Kevin Downey [ 17/Apr/14 10:57 PM ]

may be a dup of http://dev.clojure.org/jira/browse/CLJ-698

Comment by Alex Miller [ 18/Apr/14 7:03 AM ]

NR on Clojure 1.6.0.





[CLJ-322] Enhance AOT compilation process to emit classfiles only for explicitly-specified namespaces Created: 29/Apr/10  Updated: 22/Oct/13

Status: In Progress
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Enhancement Priority: Major
Reporter: Chas Emerick Assignee: Unassigned
Resolution: Unresolved Votes: 15
Labels: aot

Attachments: Text File 0322-limit-aot-resolved.patch     File CLJ-322.diff     Text File compile-interop-1.patch     GZip Archive write-classes-1.diff.gz    
Patch: Code and Test
Approval: Vetted
Waiting On: Chas Emerick

 Description   

Summary: still needs decision on implementation approach.

This was originally/erroneously reported by Howard Lewis Ship in the clojure-contrib assembla:

My build file specifies the namespaces to AOT compile but if I include another namespace
(even from a JAR dependency) that is not AOT compiled, the other namespace will be compiled as well.

In my case, I was using clojure-contrib's clojure.contrib.str-utils2 namespace, and I got a bunch of
clojure/contrib/str_utils2 classes in my output directory.

I think that the AOT compiler should NOT precompile any namespaces that are transitively reached,
only namespaces in the set specified by the command line are appropriate.

As currently coded, you will frequently find unwanted third-party dependencies in your output JARs;
further, if multiple parties depend on the same JARs, this could cause bloating and duplication in the
eventual runtime classpath.

Having the option of shipping either all AOT-compiled classfiles or mixed source/AOT depending upon one's distribution requirements would make that phase of work with a clojure codebase significantly easier and less error-prone. The only question in my mind is what the default should be. We're all used to the current behaviour, but I'd guess that any nontrivial project where the form of the distributable matters (i.e. the source/AOT mix), providing as much control as possible by default makes the most sense. Given the tooling that most people are using, it's trivial (and common practice, IIUC) to provide a comprehensive list of namespaces one wishes to compile, so making that the default shouldn't be a hurdle to anyone. If an escape hatch is desired, a --transitive switch to clojure.lang.Compile could be added.



 Comments   
Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/322
Attachments:
aot-transitivity-option-compat-322.diff - https://www.assembla.com/spaces/clojure/documents/aI7Eu-HeGr35ImeJe5cbLA/download/aI7Eu-HeGr35ImeJe5cbLA
aot-transitivity-option-322.diff - https://www.assembla.com/spaces/clojure/documents/aIWFiWHeGr35ImeJe5cbLA/download/aIWFiWHeGr35ImeJe5cbLA

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

hlship said: I'd like to reinforce this. I've been doing research on Clojure build tools for an upcoming talk and all of them (Maven, Leiningen, Gradle) have the same problem: the AOT compile extends from the desired namespaces (such as one containing a :gen-class) to every reached namespace. This is going to cause a real ugliness when application A uses libraries B and C that both depend on library D (such as clojure-contrib) and B and C are thus both bloated with duplicate, unwanted AOT compiled classes from the library D.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: This behaviour is an implementation detail of Clojure's AOT compilation process, and is orthogonal to any particular build tooling.

I am working on a patch that would provide a mechanism for such tooling to disable this default behaviour.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: A first cut of a change to address this issue is here (caution, work in progress!):

http://github.com/cemerick/clojure/commit/6f14e0790c0d283a7e44056adf1bb3f36bb16e0e

This makes available a new recognized system property, clojure.compiler.transitive, which defaults to true. When set/bound to false (i.e. -Dclojure.compiler.transitive=false when using clojure.lang.Compile), only the first loaded file (either the ns named in the call to compile or each of the namespaces named as arguments to clojure.lang.Compile) will have classfiles written to disk.

This means that this compilation invocation:

java -cp <your classpath> -Dclojure.compiler.transitive=false clojure.lang.Compile com.bar com.baz

will generate classfiles only for com.bar and com.baz, but not for any of the namespaces or other files they load, require, or use.


The only shortcoming of this WIP patch is that classfiles are still generated for proxy and gen-class classes defined outside of the explicitly-named namespaces. What I thought was a solution for this ended up breaking the loading of generated interfaces (as produced by defprotocol, etc).

I'll take a second look at this before the end of the week, but wanted to get this out there so as to get any comments people might have.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

technomancy said: Looks good, but I'm having trouble getting it to work. I tried compiling from master of Chas's fork on github, but I still got the all the .class files generated with -Dclojure.compiler.transitive=false. It could be a quirk of the way I'm using ant to fork off processes though. Is it possible to set it using System/setProperty, or must it be given as a property on the command-line?

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: Bah, that's just bad documentation. :-/

The system property is only provided by clojure.lang.Compile; the value of it drives the binding of clojure.core/transitive-compile, which has a root binding of true.

You should be able to configure the transitivity the same way you configure compile-path (system prop to clojure.lang.Compile or a direct binding when at the REPL, etc).

If not, ping me in irc or elsewhere.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

meikelbrandmeyer said: I think, excluding parts 'load'ed is a little strong. I have some namespaces which load several parts from different files, but which belong to the same namespace. The most prominent example of such a case is clojure.core itself. I'm find with stopping require and use, but load is a bit too much, I'd say.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

technomancy said: Chas: Thanks; will give that a go.

Meikel: Do people actually use load outside of clojure.core? I thought it was only used there because clojure.core is a "special" namespace where you want more vars to be available than can reasonably fit in a single file. Splitting up a namespace into several files is quite unadvisable otherwise.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

technomancy said: I can confirm that this works for me modulo the proxy/gen-class issue that Chas mentioned. I would love to see this in Clojure 1.2; it would really clean up a lot of build-related issues.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

meikelbrandmeyer said: I used it several times and this is the first time, I hear that it is unadvisable to do so. Even with a lower number of Vars in the namespace (c.c is here certainly exceptional) and might be of use to split several "sections" of code which belong to the same namespace but have different functionality. Whether to use a big comment in the source to indicate the section or split things into subfiles is a matter of taste. But it's a perfectly reasonable thing todo.

Another use case, where I use this (and c.c.lazy-xml, IIRC) is to conditionally load code depending on whether a dependency is available or not. Eg. vimclojure uses c.c.pprint and c.c.stacktrace/clj-stacktrace transparently depending on their availability.

There are perfectly legal uses of load. I don't see any "unadvisable" here.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: Thanks, Meikel; I had forgotten about that use case, as I don't use load directly myself at all. I probably wouldn't say it's inadvisable, just mostly unnecessary. In any case, that's a good catch. It complicates things a bit, but we'll see what happens. I'm going to take another whack at resolving the proxy/gen-class case and narrowing the impact of nontransitivity to use and require later tonight.

I agree wholeheartedly that this should be in 1.2, assuming the technical bits work out. This has been an irritant for quite a long time. I actually believe that nontransitivity should be the default – no one wants or expects to have classfiles show up for dependencies show up when a project is AOT-compiled. I think the only negative impact would be whoever still fiddles with compilation at the REPL, and doesn't use maven or lein – and even then, it's just a matter of binding another var.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

meikelbrandmeyer said: Then the var should be added to the default bindings in the clojure.main repl. Then it's set!-able like the other vars ��� warn-on-reflection and friends.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: This is looking pretty good (still WIP):

http://github.com/cemerick/clojure/commit/fedfb022ecef420a932b3d69c182ec7a8e5960a6

Thank you again for mentioning load, Meikel: it was very helpful in resolving the proxy/gen-class issue as well.

Just a single data point: the jar produced by the medium-sized project I've been using for testing the changes has shrunk from 1.8MB to less than 1MB. That's not the only reason this is a good change, but it's certainly a nice side-effect.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: [file:aIWFiWHeGr35ImeJe5cbLA]

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: [file:aI7Eu-HeGr35ImeJe5cbLA]

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: Patched attached. The compat one retains the current default behaviour [*transitive-compile* true], the other changes the default so that transitivity is a non-default option. At least of those I've spoken to about this, the latter is preferred.

The user impact of changing the default would be:

  1. The result of compiling from the REPL will change. Getting back current behaviour would require adding a [*transitive-compile* true] binding to the existing bindings one must set when compiling from the REPL.
  2. The same as #1 goes for those scripting AOT compilation via clojure.lang.Compile as well (whether by shell scripts, ant, etc).
  3. Those using lein, clojure-maven-plugin, gradle, and others will likely have a new option provided by those tools, and perhaps a different default than the language's. I suspect those using such tools would much prefer a change from the default behaviour in any case.
Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

hlship said: Just had a brain-storm:

How about an option to support transitive compilation, but only if the Clojure source file being compiled as a file: URL (i.e., its a local file on the file system, not a file stored in a JAR). That would make it easier to use compilation on the local project without transitively compiling imported libraries, such as clojure-contrib.

So transitive-compile should be a keyword, not a boolean, with values :all (for 1.1 behavior), :none (to compile only the exact specified namespaces) or :local (to compile transitively, but only for local files, not source files from JARs).

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

cemerick said: (Crossposted to the clojure-dev list)

I thought about this some, and I don't think that's a good idea, at least for now. I'm uncomfortable with semantics changing depending upon where code is being loaded from – which, depending upon a tool's implementation, might be undefined. E.g. if the com.foo.bar ns is available in source form in one directory, but as classes from a jar, and classpaths aren't being constructed in a stable fashion, then the results of compilation will change.

If we decide that special treatment depending upon the source of code is warranted in the future, that's a fairly straightforward thing to do w.r.t. the API – we could have :all and :local as you suggest, with nil representing :none.

Comment by Assembla Importer [ 28/Sep/10 12:18 AM ]

stu said: Rich is not comfortable enough with the implementation complexity of this patch (e.g. the guard clause for proxies and gen-class) to slide this in as a minor fix under the wire for 1.2.

Better to live with the pain we know a little longer than ship something we don't have enough experience with to be confident.

Comment by Chas Emerick [ 19/Nov/10 9:28 PM ]

Updated patch to cleanly apply to HEAD and address issues raised by screening done by Cosmin Stejerean. Also includes proper tests.

Note: this patch's tests require the fix for CLJ-432!

Comment by Stuart Halloway [ 29/Nov/10 7:18 AM ]

the "-resolved" patch resolves a conflict in main.clj

Comment by Stuart Halloway [ 29/Nov/10 7:25 AM ]

Several questions:

  1. I am getting an ant build error: "/Users/stuart/repos/clojure/build.xml:137: java.io.FileNotFoundException: Could not locate clojure/test_clojure/aot/nontransitive__init.class or clojure/test_clojure/aot/nontransitive.clj on classpath:"
  2. It feels icky to have a method named writeClassFile that, under some circumstances, does not write a class file, but instead loads it via a dynamic loader. Maybe this is just a naming issue.
  3. Are there any other ways to accomplish the goals of load-level? Or, taking the other side, if we are going to have a load-level, are there other possible consumers who might have different needs?
  4. (Minor) Why the use :only idiom instead of just require?
Comment by Stuart Sierra [ 10/Dec/10 3:34 PM ]

An alternative approach: patch write-classes-1.diff.gz

From my forked branch

What this patch does:

  • Keeps 'compile' and 'compile-files' exactly the same
  • Adds 'compile-write-classes' to write .class files for specifically named classes
  • Minor compiler changes to support this

This approach was prompted by the following observations:

  • Java interop is the dominant reason for needing .class files
  • Things other than namespaces can generate classes for Java interop:
    • deftype/defrecord
    • defprotocol
    • gen-class/gen-interface
  • For library releases, we want to control which .class files are emitted on a per-class basis, not per-namespace
  • Some legitimate uses of AOT compilation will want transitive compilation
    • Pre-compiling an entire application before release
Comment by Chas Emerick [ 10/Dec/10 4:04 PM ]

S. Halloway: My apologies, I didn't know you had commented. I thought that, having assigned this issue to myself, I'd be notified of updates.

FWIW, I aim to review your comments and SS' approach over the weekend.

Comment by Chas Emerick [ 16/Dec/10 7:36 AM ]

S. Halloway:

1. Certainly shouldn't happen. AFAIK, others have screened the patch, presumably with a successful build.
2. Agreed; given the approach, I think it's just a bad name.
3. Yes, I think S. Sierra's is one. See my next comment.
4. Because the :use form was already there. I've actually been using that form of :use more and more; I've found that easier than occasionally having to shuffle around specs between :use and :require. I think I'm aping Chris Houser in that regard.

Comment by Chas Emerick [ 16/Dec/10 9:00 AM ]

I think S. Sierra's approach is fundamentally superior what I offered. I have two suggestions: one slight perspective change (which implies no change in the actual implementation), and an idea for an even simpler approach (at least from a user perspective), in that order.

While interop is the driving requirement behind AOT, I absolutely do not want to have to keep an updated enumeration of all of the classes resulting from each and every defrecord et al. usages in my pom.xml/project.clj (and I wouldn't wish the task of ferreting those usages and their resulting classnames on any build tool author).

Right now, *compile-write-classes* is documented to be a set of classname strings, but could just as easily be any other function. *compile-write-classes* should be documented to accept any predicate function (renamed to e.g. *compile-write-class?*?). There's no reason why it shouldn't be bound to, e.g. #(re-matches #"foo\.bar\.[\w_]+$" %) if I know that all my records are defined in the foo.bar namespace.

To go along with that, I think some package/classname-globbing utilities along with corresponding options to clojure.lang.Compile would be most welcome. Classname munging rules are not exactly obvious, and it'd be good to make things a little easier for users in this regard.


Another alternative

If there's a closed set of forms that generate classes that one might reasonably be interested in having in a build result (outside of use cases for pervasive AOT), then why not have a simple option that only those forms utilize? gen-class and gen-interface already do this, but reusing the all-or-nothing *compile-files* binding; if they keyed off of a binding that implied a diminished scope (e.g. *compile-interop-forms* – which would be true if *compile-files* were true), then they'd do exactly what we wanted. Extending this approach to deftype (and therefore defrecord) should be straightforward.

An implementation of this would probably be somewhat more complicated than S. Sierra's patch, though not as complex as my original stab at the problem (i.e. no *load-level*). On the plus side:

1. No additional configuration for users or implementation work for build tool authors, aside from the addition of the boolean diminished-scope AOT option
2. Class file generation would remain opaque from a build process standpoint
3. Future/other class-generating forms (there are a few people futzing with ASM independently, etc) can make local decisions about whether or not to participate in interop-centric classfile generation. This might be particularly helpful if a given form emits multiple classes, making the determination of a classname-based filter fn less straightforward.

I can see wanting to further restrict AOT to specific classnames in certain circumstances, in which case the above and S. Sierra's patch might be complimentary.

Comment by Stuart Sierra [ 16/Dec/10 11:49 AM ]

I like the idea of *compile-interop-forms*. But is it always possible to determine what an "interop form" is? I think it is, I'm just not sure.

Comment by Allen Rohner [ 09/Oct/11 12:50 PM ]

I'm also in favor of compile-interop-forms. As far as determining, how about sticking metadata on the var?

(defmacro ^{:interop-form true} deftype ...)

Comment by Stuart Sierra [ 21/Oct/11 8:38 AM ]

Summary and design discussion on wiki at http://dev.clojure.org/display/design/Transitive+AOT+Compilation

Comment by Stuart Sierra [ 29/Nov/11 6:54 PM ]

New attachment compile-interop-1.patch has new approach: Add a third possible value for *compile-files*. True and false keep their original meanings, but :interop causes only interop-related forms to be written out as .class files. "Interop forms" are gen-class, gen-interface, deftype, defrecord, defprotocol, and definterface.

Pros:

  • doesn't change existing behavior
  • handles common case for non-transitive AOT (interop)
  • minimal changes to the compiler

Cons:

  • not flexible
Comment by Stuart Sierra [ 02/Dec/11 8:12 AM ]

Just realized my patch doesn't solve the transitive compilation problem. If library A loads library B, then compiling interop forms in A will also emit interop .class files in B.

Comment by Paudi Moriarty [ 01/Jan/13 3:55 AM ]

It's disappointing to see an important issue like this still unresolved after 2.5 years. This is a real pain for us. We have a large closed source project where shipping source is not an option. This forces us to manage the AOT'ing of dependencies due to the hard dependency on protocol interfaces introduced by transitive AOT compilation (see https://groups.google.com/forum/?fromgroups=#!topic/clojure-dev/r3A1JOIiwVU).

Comment by Andy Fingerhut [ 01/Jan/13 4:27 PM ]

Paul, do you have a suggestion for which of the approaches described in comments here, or on the wiki page http://dev.clojure.org/display/design/Transitive+AOT+Compilation would be preferable solution for you? Or perhaps even a patch that implements your preferred approach?

Comment by Howard Lewis Ship [ 04/Jan/13 4:18 PM ]

Andy,

I'm now consulting with Paudi's organization, so I think I can speak for him (I'm now the default buildmeister).

I like Stuart's :interop idea, but that is somewhat orthogonal to our needs.

I return to what I would like; compilation would compile specific namespaces; dependencies of those namespaces would not be compiled.

To be honest, I'm still a little hung up on the interop forms: especially defprotocol and friends; from a cursory glance, it appears that todays AOT compilation will compile the protocol into a Java class, then compile the namespace that references the protocol with the assumption that the protocol's Java class is available. When we use build rules to only package our namespace's class files into the output JAR, the code fails with a NoClassDefFoundError because the protocol really needs to be recompiled, at runtime compilation, into an in-memory Java class.

Obviously, supporting this correctly will be a challenge; the compiled bytecode for our namespace would ideally:
1) check to see if the Java class already exists and use it if so
2) load the necessary namespaces so as to force the creation of the Java class

I can imagine any number of ways to juggle things to make this work, so I won't suggest a specific implementation.

In the meantime, our workaround is to create a "stub" module as part of our build; it simply requires in the necessary namespaces (for example, org.clojure:core.cache); this forces an AOT compile of the dependencies and we have a special rule to package such dependencies in the stub module's output JAR. This may not be a scalable problem, and it is expensive to identify what 3rd party dependencies require this treatment.

Comment by Stuart Halloway [ 24/May/13 1:25 PM ]

I am marking this incomplete because there does not yet seem to be plurality, much less consensus or unanimity, on approach.

Personally I am in favor of a solution based on a predicate that gets handed the class name and compiled bits, and then can choose whether to write the class. Pretty close to Stuart Sierra's compile-write-classes. Might be possible to flow more information than classname to the predicate.

Comment by Alex Miller [ 21/Oct/13 2:35 PM ]

Removed the 1.6 release from this and added to Release.Next list to make this a priority for the next release.

Comment by Kevin Downey [ 21/Oct/13 3:42 PM ]

Howard,

I don't exactly understand your write up, I am reading the compiler, the emit-protocol macro, and emit-method-builder to try and understand it.

You might check to see if you have a situation similar to the following:

(ns a.b)

(defprotocol P1
  (pm [a]))

then either

(ns a.c
  (:import (a.b P1))

(defrecord R []
  P1
  (pm [x] x))

or

(ns a.c)

(defrecord R []
  a.b.P1
  (pm [x] x))

in both examples defrecord is actually getting the class behind the protocol instead of the protocol, the correct thing to do is

(ns a.c
  (:require [a.b :refer [P1]]))

(defrecord R []
  P1
  (pm [x] x))

This is an extremely common mistake people make when using protocols, unfortunately the flexibility of using interfaces directly in defrecord forms, and protocols being backed by interfaces means it is very easy to unwittingly make such a mistake. Both of the mistake examples could result in missing classes/namespace problems.





[CLJ-130] Namespace metadata lost in AOT compile Created: 19/Jun/09  Updated: 06/Dec/14

Status: In Progress
Project: Clojure
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Stuart Sierra Assignee: Unassigned
Resolution: Unresolved Votes: 4
Labels: aot, metadata

Attachments: Text File 0001-CLJ-130-preserve-metadata-for-AOT-compiled-namespace.patch     File aot-drops-metadata-demo.sh    
Patch: Code
Approval: Triaged

 Description   

AOT-compilation drops namespace metadata.

This also affects all of the namespaces packaged with Clojure, except clojure.core, for which metadata is explicitly added in core.clj.

Cause of the bug:

  • a namespace inherits the metadata of the symbol used to create that namespace the first time
  • the namespace is created in the load() method, that is invoked after the __init() method
  • the __init0() method creates all the Vars of the namespace
  • interning a Var in a namespace that doesn't exist forces that namespace to be created

This means that the namespace will have been already created (with nil metadata) by the time the load() method gets invoked and thus the call to in-ns will be a no-op and the metadata will be lost.

Approach: The attached patch fixes this issue by explicitely attaching the metadata to the namespace after its creation (via ns) using a .resetMeta call



 Comments   
Comment by Assembla Importer [ 24/Aug/10 6:45 AM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/130

Comment by Assembla Importer [ 24/Aug/10 6:45 AM ]

richhickey said: Updating tickets (#127, #128, #129, #130)

Comment by Assembla Importer [ 24/Aug/10 6:45 AM ]

juergenhoetzel said: This is still a issue on

Clojure 1.2.0-master-SNAPSHOT

Any progress, hints? I prefer interactive documentiation via slime/repl

Comment by Howard Lewis Ship [ 09/Sep/14 9:44 AM ]

This is of great concern to me, as the Rook web services framework we're building depends on availability of namespace metadata at runtime.

Comment by Howard Lewis Ship [ 09/Sep/14 9:53 AM ]

BTW, I verified that this still exists in 1.6.0.

Comment by Howard Lewis Ship [ 09/Sep/14 10:11 AM ]

For me personally, I would raise the priority of this issue. And I think in general, anything that works differently with AOT vs. non-AOT should be major, if not blocker, priority.

Comment by Howard Lewis Ship [ 09/Sep/14 10:25 AM ]

Alex Miller:

@hlship I think the question is where it would go. note no one has suggested a solution in last 5 yrs.

Alas, I have not delved into the AOT compilation code (since, you know, I value my sanity). But it seems to me like the __init class for the namespace could construct the map and update the Namespace object.

Comment by Howard Lewis Ship [ 09/Sep/14 4:27 PM ]

Just playing with javap, I can see that the meta data is being assembled in some way, so it's a question of why it is not accessible ...

  public static void __init0();
    Code:
       0: ldc           #108                // String clojure.core
       2: ldc           #110                // String in-ns
       4: invokestatic  #116                // Method clojure/lang/RT.var:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Var;
       7: checkcast     #12                 // class clojure/lang/Var
      10: putstatic     #10                 // Field const__0:Lclojure/lang/Var;
      13: aconst_null
      14: ldc           #118                // String fan.auth
      16: invokestatic  #122                // Method clojure/lang/Symbol.intern:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Symbol;
      19: checkcast     #124                // class clojure/lang/IObj
      22: iconst_4
      23: anewarray     #4                  // class java/lang/Object
      26: dup
      27: iconst_0
      28: aconst_null
      29: ldc           #126                // String meta-foo
      31: invokestatic  #130                // Method clojure/lang/RT.keyword:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Keyword;
      34: aastore
      35: dup
      36: iconst_1
      37: aconst_null
      38: ldc           #132                // String meta-bar
      40: invokestatic  #130                // Method clojure/lang/RT.keyword:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Keyword;
      43: aastore
      44: dup
      45: iconst_2
      46: aconst_null
      47: ldc           #134                // String doc
      49: invokestatic  #130                // Method clojure/lang/RT.keyword:(Ljava/lang/String;Ljava/lang/String;)Lclojure/lang/Keyword;
      52: aastore
      53: dup
      54: iconst_3
      55: ldc           #136                // String Defines the resources for the authentication service.
      57: aastore
      58: invokestatic  #140                // Method clojure/lang/RT.map:([Ljava/lang/Object;)Lclojure/lang/IPersistentMap;
      61: checkcast     #64                 // class clojure/lang/IPersistentMap
      64: invokeinterface #144,  2          // InterfaceMethod clojure/lang/IObj.withMeta:(Lclojure/lang/IPersistentMap;)Lclojure/lang/IObj;

If I'm reading the code correctly, a Symbol named after the namespace is interned, and the meta-data for the namespace is applied to the symbol, so it's just a question of commuting that meta data to the Namespace object. I must be missing something.

Comment by Nicola Mometto [ 30/Sep/14 6:45 PM ]

Attached patch fixes this issue by explicitely attaching the metadata to the namespace after its creation using a .resetMeta call.

Comment by Nicola Mometto [ 30/Sep/14 7:46 PM ]

Here's an explaination of why this bug happens:

  • a namespace inherits the metadata of the symbol used to create that namespace the first time
  • the namespace is created in the load() method, that is invoked after the __init() method
  • the __init0() method creates all the Vars of the namespace
  • interning a Var in a namespace that doesn't exist forces that namespace to be created

This means that the namespace will have been already created (with nil metadata) by the time the load() method gets invoked and thus the call to in-ns will be a no-op and the metadata will be lost.





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