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[CLJ-445] Method/Constructor resolution does not factor in widening conversion of primitive args Created: 29/Sep/10  Updated: 20/Feb/12

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

Type: Enhancement Priority: Major
Reporter: Alexander Taggart Assignee: Alexander Taggart
Resolution: Unresolved Votes: 2
Labels: None

Attachments: Text File clj-445-prim-conversion-update-2-patch.txt     Text File prim-conversion.patch     Text File prim-conversion-update-1.patch     Text File reorg-reflector.patch    
Approval: Incomplete

 Description   

Problem:
When making java calls (or inlined functions), if both args and param are primitive, no widening conversion is used to locate the proper overloaded method/constructor.

Examples:

user=> (Integer. (byte 0))
java.lang.IllegalArgumentException: No matching ctor found for class java.lang.Integer (NO_SOURCE_FILE:0)
</code></pre>
The above occurs because there is no Integer(byte) constructor, though it should match on Integer(int).
<pre><code>user=> (bit-shift-left (byte 1) 1)
Reflection warning, NO_SOURCE_PATH:3 - call to shiftLeft can't be resolved.
2

In the above, a call is made via reflection to Numbers.shiftLeft(Object, Object) and its associated auto-boxing, instead of directly to the perfectly adequate Numbers.shiftLeft(long, int).

Workarounds:
Explicitly casting to the formal type.

Ancillary benefits of fixing:
It would also reduce the amount of method overloading, e.g., RT.intCast(char), intCast(byte), intCast(short), could all be removed, since such calls would pass to RT.intCast(int).

 Comments   
Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

Converted from http://www.assembla.com/spaces/clojure/tickets/445
Attachments:
fixbug445.diff - https://www.assembla.com/spaces/clojure/documents/b6gDSUZOur36b9eJe5cbCb/download/b6gDSUZOur36b9eJe5cbCb

Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

ataggart said: [file:b6gDSUZOur36b9eJe5cbCb]

Comment by Assembla Importer [ 23/Oct/10 6:43 PM ]

ataggart said: Also fixes #446.

Comment by Stuart Halloway [ 03/Dec/10 12:50 PM ]

The patch is causing a test failure 

[java] Exception in thread "main" java.lang.IllegalArgumentException: 
     More than one matching method found: equiv, compiling:(clojure/pprint/cl_format.clj:428)

Can you take a look?

Comment by Stuart Halloway [ 28/Jan/11 12:30 PM ]

The failing test happens when trying to find the correct equiv for signature (Number, long). Is the compiler wrong to propose this signature, or is the resolution method wrong in not having an answer? (It thinks two signatures are tied: (Object, long) and (Number, Number).)

Exception in thread "main" java.lang.IllegalArgumentException: More than one matching method found: equiv, compiling:(clojure/pprint/cl_format.clj:428)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6062)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6050)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.access$100(Compiler.java:35)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5492)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2372)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3277)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6057)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2385)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$IfExpr$Parser.parse(Compiler.java:2385)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$LetExpr$Parser.parse(Compiler.java:5527)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:5231)
	at clojure.lang.Compiler$FnMethod.parse(Compiler.java:4667)
	at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3397)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6053)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6043)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.access$100(Compiler.java:35)
	at clojure.lang.Compiler$DefExpr$Parser.parse(Compiler.java:480)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	at clojure.lang.Compiler.analyze(Compiler.java:5866)
	at clojure.lang.Compiler.analyze(Compiler.java:5827)
	at clojure.lang.Compiler.eval(Compiler.java:6114)
	at clojure.lang.Compiler.load(Compiler.java:6545)
	at clojure.lang.RT.loadResourceScript(RT.java:340)
	at clojure.lang.RT.loadResourceScript(RT.java:331)
	at clojure.lang.RT.load(RT.java:409)
	at clojure.lang.RT.load(RT.java:381)
	at clojure.core$load$fn__1427.invoke(core.clj:5308)
	at clojure.core$load.doInvoke(core.clj:5307)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.pprint$eval3969.invoke(pprint.clj:46)
	at clojure.lang.Compiler.eval(Compiler.java:6110)
	at clojure.lang.Compiler.load(Compiler.java:6545)
	at clojure.lang.RT.loadResourceScript(RT.java:340)
	at clojure.lang.RT.loadResourceScript(RT.java:331)
	at clojure.lang.RT.load(RT.java:409)
	at clojure.lang.RT.load(RT.java:381)
	at clojure.core$load$fn__1427.invoke(core.clj:5308)
	at clojure.core$load.doInvoke(core.clj:5307)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.core$load_one.invoke(core.clj:5132)
	at clojure.core$load_lib.doInvoke(core.clj:5169)
	at clojure.lang.RestFn.applyTo(RestFn.java:143)
	at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:77)
	at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28)
	at clojure.core$apply.invoke(core.clj:602)
	at clojure.core$load_libs.doInvoke(core.clj:5203)
	at clojure.lang.RestFn.applyTo(RestFn.java:138)
	at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at clojure.lang.Reflector.invokeMatchingMethod(Reflector.java:77)
	at clojure.lang.Reflector.invokeInstanceMethod(Reflector.java:28)
	at clojure.core$apply.invoke(core.clj:604)
	at clojure.core$use.doInvoke(core.clj:5283)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.main$repl.doInvoke(main.clj:196)
	at clojure.lang.RestFn.invoke(RestFn.java:422)
	at clojure.main$repl_opt.invoke(main.clj:267)
	at clojure.main$main.doInvoke(main.clj:362)
	at clojure.lang.RestFn.invoke(RestFn.java:409)
	at clojure.lang.Var.invoke(Var.java:401)
	at clojure.lang.AFn.applyToHelper(AFn.java:163)
	at clojure.lang.Var.applyTo(Var.java:518)
	at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: More than one matching method found: equiv
	at clojure.lang.Reflector.getMatchingParams(Reflector.java:639)
	at clojure.lang.Reflector.getMatchingParams(Reflector.java:578)
	at clojure.lang.Reflector.getMatchingMethod(Reflector.java:569)
	at clojure.lang.Compiler$StaticMethodExpr.<init>(Compiler.java:1439)
	at clojure.lang.Compiler$HostExpr$Parser.parse(Compiler.java:896)
	at clojure.lang.Compiler.analyzeSeq(Compiler.java:6055)
	... 115 more
Comment by Alexander Taggart [ 08/Feb/11 6:27 PM ]

In working on implementing support for vararg methods, I found a number of flaws with the previous solutions. Please disregard them.

I've attached a single patch (reflector-compiler-numbers.diff) which is a rather substantial overhaul of the Reflector code, with some enhancements to the Compiler and Numbers code.

The patch notes:

  • Moved reflection functionality from Compiler to Reflector.
  • Reflector supports finding overloaded methods by widening conversion, boxing conversion, and casting.
  • During compilation Reflector attempts to find best wildcard match.
  • Reflector refers to *unchecked-math* when reflectively invoking methods and constructors.
  • Both Reflector and Compiler support variable arity java methods and constructor; backwards compatible with passing an array or nil in the vararg slot.
  • Added more informative error messages to Reflector.
  • Added tests to clojure.test-clojure.reflector.
  • Altered overloaded functions of clojure.lang.Numbers to service Object/double/long params; fixes some ambiguity issues and avoids unnecessary boxing in some cases.
  • Patch closes issues 380, 440, 445, 666, and possibly 259 (not enough detail provided).
Comment by Alexander Taggart [ 10/Feb/11 7:35 PM ]

Updated patch to fix a bug where a concrete class with multiple identical Methods (e.g., one from an interface, another from an abstract class) would result in ambiguity. Now resolved by arbitrary selection (this is what the original code did as well albeit not explicitly).

Comment by Alexander Taggart [ 25/Feb/11 9:29 PM ]

Updated patch to work with latest master branch.

Comment by Stuart Halloway [ 06/Mar/11 1:54 PM ]

patch appears to be missing test file clojure/test_clojure/reflector.clj.

Comment by Alexander Taggart [ 06/Mar/11 2:39 PM ]

Bit by git.

Patch corrected to contain clojure.test-clojure.reflector.

Comment by Stuart Halloway [ 11/Mar/11 10:30 AM ]

Rich: I verified that the patch applied but reviewed only briefly, knowing you will want to go over this one closely.

Comment by Stuart Halloway [ 11/Mar/11 10:55 AM ]

After applying this patch, I am getting method missing errors:

java.lang.NoSuchMethodError: clojure.lang.Numbers.lt(JLjava/lang/Object;)

but only when using compiled code, e.g. the same code works in the REPL and then fails after compilation. Haven't been able to isolate an example that I can share here yet, but hoping this will cause someone to have an "a, hah" moment...

Comment by Alexander Taggart [ 02/Apr/11 12:55 PM ]

The patch now contains only the minimal changes needed to support widening conversion. Cleanup of Numbers overloads, etc., can wait until this patch gets applied. The vararg support is in a separate patch on CLJ-440.

Comment by Christopher Redinger [ 15/Apr/11 12:50 PM ]

Please test patch

Comment by Christopher Redinger [ 21/Apr/11 11:02 AM ]

FYI: Patch applies cleanly on master and all tests pass as of 4/21 (2011)

Comment by Christopher Redinger [ 22/Apr/11 9:57 AM ]

This work is too big to take into the 1.3 beta right now. We'll revisit for a future release.

Comment by Alexander Taggart [ 28/Apr/11 1:19 PM ]

To better facilitate understanding of the changes, I've broken them up into two patches, each with a number of isolable, incremental commits:

reorg-reflector.patch: Moves the reflection/invocation code from Compiler to Reflector, and eliminates redundant code. The result is a single code base for resolving methods/constructors, which will allow for altering that mechanism without excess external coordination. This contains no behaviour changes.

prim-conversion.patch: Depends on the above. Alters the method/constructor resolution process:

  • more consistent with java resolution, especially when calling pre-1.5 APIs
  • adds support for widening conversion of primitive numerics of the same category (this is more strict than java, and more clojuresque)
  • adds support for wildcard matches at compile-time (i.e., you don't need to type-hint every arg to avoid reflection).

This also provides a base to add further features, e.g., CLJ-666.

Comment by Alexander Taggart [ 29/Apr/11 3:01 PM ]

It's documented in situ, but here are the conversion rules that the reflector uses to find methods:

  1. By Type:
    • object to ancestor type
    • primitive to a wider primitive of the same numeric category (new)
  2. Boxing:
    • boxed number to its primitive
    • boxed number to a wider primitive of the same numeric category (new for Short and Byte args)
    • primitive to its boxed value
    • primitive to Number or Object (new)
  3. Casting:
    • long to int
    • double to float
Comment by Alexander Taggart [ 10/May/11 3:13 PM ]

prim-conversion-update-1.patch applies to current master.

Comment by Alexander Taggart [ 11/May/11 2:15 PM ]

Created CLJ-792 for the reflector reorg.

Comment by Stuart Sierra [ 17/Feb/12 2:29 PM ]

prim-conversion-update-1.patch does not apply as of f5bcf64.

Is CLJ-792 now a prerequisite of this ticket?

Comment by Alexander Taggart [ 17/Feb/12 3:15 PM ]

Yes, after the original patch was deemed "too big".

After this much time with no action from TPTB, feel free to kill both tickets.

Comment by Andy Fingerhut [ 20/Feb/12 2:04 PM ]

Again, not sure if this is any help, but I've tested starting from Clojure head as of Feb 20, 2012, applying clj-792-reorg-reflector-patch2.txt attached to CLJ-792, and then applying clj-445-prim-conversion-update-2-patch.txt attached to this ticket, and the result compiles and passes all but 2 tests. I don't know whether those failures are easy to fix or not, or whether issues may have been introduced with these patches.

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