Clojure

Report warnings if *unchecked-math* and boxing happens

Details

  • Type: Enhancement Enhancement
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Completed
  • Affects Version/s: Release 1.6
  • Fix Version/s: Release 1.7
  • Component/s: None
  • Labels:
  • Patch:
    Code and Test
  • Approval:
    Ok

Description

Currently, it is difficult to tell that the compiler is using boxed math unless you look at the generated bytecode. The proposed enhancement here is to emit new warnings if *unchecked-math* is on and boxed math is occurring.

Approach: In the compiler, when compiling a StaticMethodExpr, if *unchecked-math* is true and the class is clojure.lang.Numbers and one of the parameters of static method is of type java.lang.Object or java.lang.Number, then emit a warning at compile-time.

In addition, there is a new WarnBoxedMath Java annotation - a small number of methods on Numbers with Object parameters use this annotation to indicate that warning should not take place. The same annotation can be (but is not currently) used to mark methods on Numbers without Object/Number params that should warn. See boxedmath.txt for a list of methods and categories.

Patch: clj-1325-v3.patch

Screened by:

  1. boxed.diff
    27/Mar/14 11:06 AM
    6 kB
    Alex Miller
  2. boxedmath.txt
    14/May/14 2:29 PM
    9 kB
    Alex Miller
  3. clj-1325.patch
    14/May/14 2:39 PM
    11 kB
    Alex Miller
  4. clj-1325-v2.patch
    16/May/14 11:19 AM
    11 kB
    Alex Miller
  5. clj-1325-v3.patch
    16/May/14 11:51 AM
    11 kB
    Alex Miller

Activity

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Alex Miller added a comment -

Moving to 1.7.

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Alex Miller added a comment - Moving to 1.7.
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Alex Miller added a comment -

List of methods in Numbers and whether they should be considered "boxed math" or not, with some questions.

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Alex Miller added a comment - List of methods in Numbers and whether they should be considered "boxed math" or not, with some questions.
Hide
Alex Miller added a comment -

Ready for screening.

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Alex Miller added a comment - Ready for screening.
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Alex Miller added a comment -

clj-1325-v2.patch is identical to last except for a cleaned up the commit message.

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Alex Miller added a comment - clj-1325-v2.patch is identical to last except for a cleaned up the commit message.
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Alex Miller added a comment -

Added v3 patch that just reworks block/indentation style to match surrounding code better.

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Alex Miller added a comment - Added v3 patch that just reworks block/indentation style to match surrounding code better.
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Stuart Sierra added a comment -

Screened. Comments:

1) There is no way to get both overflow checks and boxed-math warnings at the same time. Maybe this doesn't matter.

2) The error messages aren't ideal, because they refer to clojure.lang.Numbers, but we can assume that anyone savvy enough to be using *unboxed-math* will also be savvy enough to know what clojure.lang.Numbers is.

3) This doesn't protect me from autoboxing in arbitrary Java method calls, but normal reflection warnings should catch most real-world cases, since few Java APIs overload on primitive and Object.

Show
Stuart Sierra added a comment - Screened. Comments: 1) There is no way to get both overflow checks and boxed-math warnings at the same time. Maybe this doesn't matter. 2) The error messages aren't ideal, because they refer to clojure.lang.Numbers, but we can assume that anyone savvy enough to be using *unboxed-math* will also be savvy enough to know what clojure.lang.Numbers is. 3) This doesn't protect me from autoboxing in arbitrary Java method calls, but normal reflection warnings should catch most real-world cases, since few Java APIs overload on primitive and Object.

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Dates

  • Created:
    Updated:
    Resolved: