Decide if we want to generate DivisionByZeroException errors #26

DartBot · 2011-10-10T19:52:43Z

This issue was originally filed by [email protected]

Dart should not report a number divided by zero as infinity. And if infinity is allowed, math using infinity should be correct.

What steps will reproduce the problem?

Use the following code:

main() {
print(1 / 0);
print((1 / 0) / (1 / 0));
}

What is the expected output? What do you see instead?

It should report:

NaN
NaN

Instead it reports:

Infinity
NaN

What version of the product are you using? On what operating system?

Using the following on Oct 10, 2011 15:50 EDT

http://www.dartlang.org/docs/getting-started/

Please provide any additional information below.

DartBot · 2011-10-10T20:26:37Z

This comment was originally written by [email protected]

This is standard IEE 754 behavior: 1/0 = +Infinity, -1/0 = -Infinity, Infinity/Infinity = NaN. Dart isn't doing anything differently here than either Java or JavaScript.

DartBot · 2011-10-10T20:28:25Z

This comment was originally written by [email protected]

(IEE ==> IEEE)

DartBot · 2011-10-10T20:41:23Z

This comment was originally written by [email protected]

You mean just Javascript.

Even though the following does produce Infinity and NaN:

<html>
<body>
<script>
alert(1/0);
alert((1/0)/(1/0));
</script>
</body>
</html>

It is invalid in Java, e.g.:

public class Test {
  public static void main(String args[]) {
    System.out.println( "" + (1/0));
    System.out.println( "" + ((1/0)/(1/0)));
  }
}

results in:

$ java Test
Exception in thread "main" java.lang.ArithmeticException: / by zero
at Test.main(Test.java:3)

Still, Dart is a new language. Couldn't it aspire to get math right instead of being just another Javascript?

Thanks!

DartBot · 2011-10-10T20:47:11Z

This comment was originally written by [email protected]

Your Java example is dividing ints, not (IEEE 754) floats or doubles. Please replace 1 with 1.0 and 0 with 0.0 and give your code another try.

DartBot · 2011-10-10T20:59:09Z

This comment was originally written by [email protected]

IEEE 754 is what hardware implements -- so adopting a different set of semantics for floating-point numbers means relying on software to do the heavy lifting, and puts code at a big disadvantage versus code that is designed to take advantage of what the floating-point hardware can do.

I thing there is a separate issue of how dividing ints should behave in Dart -- note that the / operator produces a num, not an int, even when dividing two ints. For example, 1/2 = 0.5, like JavaScript, not 0 as in Java. There is a ~/ operator that truncates to int. Currently, (1 ~/ 0) also evaluates to Infinity -- this seems like it would be worth taking up with the spec folks.

DartBot · 2011-10-10T21:15:42Z

This comment was originally written by [email protected]

Yes, for Float and Double, but fails again with BigDecimal:

import java.math.BigDecimal;

public class Test {
  public static void main(String args[]) {
    System.out.println( "" + (1F/0F));
    System.out.println( "" + ((1F/0F)/(1F/0F)));
    System.out.println( "" + (1D/0D));
    System.out.println( "" + ((1D/0D)/(1D/0D)));
    System.out.println( "" + (new BigDecimal(1D).divide(new BigDecimal(0D), BigDecimal.ROUND_UNNECESSARY)));
    System.out.println( "" + ((new BigDecimal(1D).divide(new BigDecimal(0D), BigDecimal.ROUND_UNNECESSARY)).divide(new BigDecimal(1D).divide(new BigDecimal(0D), BigDecimal.ROUND_UNNECESSARY), BigDecimal.ROUND_UNNECESSARY)));
  }
}

Produces:

$ java Test
Infinity
NaN
Infinity
NaN
Exception in thread "main" java.lang.ArithmeticException: / by zero
    at java.math.BigDecimal.divide(BigDecimal.java:1327)
    at java.math.BigDecimal.divide(BigDecimal.java:1444)
    at Test.main(Test.java:9)

But it looks like Ruby 1.8.7 still does what you are saying even with BigDecimal:

$ irb

1/0
ZeroDivisionError: divided by 0
from (irb):1:in `/'
from (irb):1
1.0/0.0
=> Infinity
(1.0/0.0)/(1.0/0.0)
=> NaN
require 'bigdecimal'
BigDecimal("1.0") / BigDecimal("0.0")
=> #<BigDecimal:100605f80,'Infinity',4(24)>
(BigDecimal("1.0") / BigDecimal("0.0")) / (BigDecimal("1.0") / BigDecimal("0.0"))
=> #<BigDecimal:1005fbff8,'NaN',4(56)>

Oh, well. It's a shame that we still settle for that. :)

DartBot · 2011-10-10T21:16:29Z

This comment was originally written by [email protected]

You can close this if you want. Sorry to bother about it.

DartBot · 2011-10-10T21:18:34Z

This comment was originally written by [email protected]

Oops, just saw your other comment. Yes, feel free to take up with the spec folks about ints being treated as floating points. Glad I could be of limited assistance.

floitschG · 2011-10-11T00:33:09Z

DartC (the compiler from Dart to JavaScript) is not spec-compliant with regards to numbers. We compile dart numbers to JavaScript numbers (thus losing the distinction between ints and doubles).
dart: x / 0 throws a DivisionByZeroException in correct Dart. In dart->Js code it unfortunately becomes the equivalent of x / 0.0 which becomes infinity/nan.

DartBot · 2011-10-11T15:35:43Z

This comment was originally written by [email protected]

Added Area-Language, Triaged labels.

gbracha · 2011-10-12T20:06:33Z

The spec was carefully thought out and it describes the intended semantics of Dart. We make allowances for dartC, and maybe it is unreasonable to do the right thing and still be performant. But AFIK, this isn't a spec issue unless we want to enshrine special dispensation for dartC in the spec.

Removed Area-Language label.
Added Area-Compiler label.
Changed the title to: "dartC compiles both ints and doubles into Javascript numbers".

DartBot · 2011-10-24T22:14:06Z

This comment was originally written by [email protected]

To me, it seems that JS is correct here. 1/0 is infinity. infinity / infinity is undefined, a.k.a. NaN.

DartBot · 2011-10-25T15:15:00Z

This comment was originally written by [email protected]

As Florian said, the original target for the java-based dartc was to compile dart numbers to JS numbers.

The only thing that we can do here is to decide whether it is worth checking for division by zero in the current dartc or not -- I changed the description accordingly.

Changed the title to: "dartc does not generate DivisionByZeroException errors".

DartBot · 2012-03-28T13:07:18Z

This comment was originally written by [email protected]

Unassigned from area=compiler. This bug is no longer valid for dartc, but I believe is still a general dart to Javsscript translation issue. If not, please close.

Removed Area-Compiler label.
Added New label.

anders-sandholm · 2012-03-28T13:34:33Z

Added Area-Dart2JS, Triaged labels.

kasperl · 2012-04-01T08:53:22Z

Changed the title to: "Make sure dart2js generates DivisionByZeroException errors".

kasperl · 2012-04-01T08:54:39Z

Update summary to reflect that we haven't decided yet.

Changed the title to: "Decide if we want to generate DivisionByZeroException errors".

kasperl · 2012-09-03T11:06:24Z

Added this to the Later milestone.

kasperl · 2012-10-17T10:27:30Z

Removed this from the Later milestone.

Here's a minimal repro that this CL fixes: `ui.dart` ```dart library dart.ui; import 'dart:ffi'; part 'foo.dart'; ``` `foo.dart` ```dart part of dart.ui; @Native<Void Function()>(symbol: 'foo_func', isLeaf: true) external void foo_func(); ``` When compiling with `compile_platform.dart` with `--target=dart2wasm`, the following error appears: ``` Unhandled exception: Verification error: Target=wasm, VerificationStage.afterModularTransformations: Invalid location with target 'wasm' on FunctionNode() (FunctionNode): RangeError (offset): Invalid value: Not in inclusive range 0..56: 91 Context: 'foo_func_$import'. Node: 'FunctionNode()'. #0 VerificationErrorListener.reportError (package:kernel/verifier.dart:81:5) #1 VerifyingVisitor.problem (package:kernel/verifier.dart:222:14) #2 VerifyingVisitor._getLocation (package:kernel/verifier.dart:1361:7) #3 VerifyingVisitor._hasLocation (package:kernel/verifier.dart:1370:26) #4 VerifyingVisitor.getSameLibraryLastSeenTreeNode (package:kernel/verifier.dart:1342:28) #5 VerifyingVisitor.localContext (package:kernel/verifier.dart:1382:24) #6 VerifyingVisitor.defaultDartType (package:kernel/verifier.dart:1491:41) #7 Visitor.visitVoidType (package:kernel/visitor.dart:1309:37) #8 VoidType.accept (package:kernel/ast.dart:11190:42) #9 FunctionNode.visitChildren (package:kernel/ast.dart:3919:16) #10 VerifyingVisitor.visitChildren (package:kernel/verifier.dart:259:10) #11 VerifyingVisitor.visitWithLocalScope (package:kernel/verifier.dart:266:5) #12 VerifyingVisitor.visitFunctionNode (package:kernel/verifier.dart:721:5) #13 FunctionNode.accept (package:kernel/ast.dart:3908:38) #14 VerifyingVisitor.visitProcedure (package:kernel/verifier.dart:620:19) #15 Procedure.accept (package:kernel/ast.dart:3311:40) #16 visitList (package:kernel/ast.dart:14488:14) #17 Library.visitChildren (package:kernel/ast.dart:591:5) #18 VerifyingVisitor.visitChildren (package:kernel/verifier.dart:259:10) #19 VerifyingVisitor.defaultTreeNode (package:kernel/verifier.dart:196:5) #20 TreeVisitor.visitLibrary (package:kernel/visitor.dart:503:35) #21 VerifyingVisitor.visitLibrary (package:kernel/verifier.dart:367:11) #22 Library.accept (package:kernel/ast.dart:577:38) #23 visitList (package:kernel/ast.dart:14488:14) #24 Component.visitChildren (package:kernel/ast.dart:14320:5) #25 VerifyingVisitor.visitChildren (package:kernel/verifier.dart:259:10) #26 VerifyingVisitor.visitComponent (package:kernel/verifier.dart:342:7) #27 Component.accept (package:kernel/ast.dart:14313:38) #28 VerifyingVisitor.check (package:kernel/verifier.dart:171:15) #29 verifyComponent (package:kernel/verifier.dart:69:20) ... ``` The issue seems to be that after doing this native transformation, the node's `fileUri` references the enclosing library (`ui.dart` above), but the `node.location` references the actual source file (`foo.dart` above) indirectly through `node.fileOffset`. This ends up being an issue when compiling the platform dill in Google3, but I didn't look into why `flutter build web --wasm` isn't broken. Internal bug: b/292172146 Change-Id: I2b8d7d215b2c36354860257ce651d50168e9523d Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/315360 Reviewed-by: Ömer Ağacan <[email protected]> Commit-Queue: Jia Hao Goh <[email protected]>

DartBot added Type-Defect area-core-library SDK core library issues (core, async, ...); use area-vm or area-web for platform specific libraries. closed-as-intended Closed as the reported issue is expected behavior labels Oct 17, 2012

DartBot added this to the Later milestone Oct 17, 2012

kodandersson mentioned this issue Jun 23, 2015

VM crash when profiler thread-unsafely accesses stub code entry #23702

Closed

iposva-google mentioned this issue Sep 21, 2015

_methodNameFromUri gets bad Uri #24388

Closed

scheglov mentioned this issue Oct 19, 2015

Exception in completion #24630

Closed

danrubel mentioned this issue Oct 23, 2015

RangeError in local reference contributor #24718

Closed

whesse mentioned this issue Nov 4, 2015

Pub test is failing on dev channel #24825

Closed

zoechi mentioned this issue Nov 21, 2015

Code navigation issue in WebStorm #24910

Closed

AdityaKha mentioned this issue Apr 3, 2023

AngularDart not working dart-lang/build#3481

Closed

ghost mentioned this issue May 11, 2023

the Dart compiler exited unexpectedly. #52348

Closed

Mufaddal1125 mentioned this issue May 13, 2023

Compiler crashed when building flutter app #52382

Closed

FarhanAli-98 mentioned this issue Jun 8, 2023

.dart_tool/flutter_build/82e9e80bd955475dabc6ca394adf8ada/main.dart: Internal Error: The compiler crashed when compiling this element. #52641

Closed

heshesh2010 mentioned this issue Aug 12, 2023

bug in the migration tool #53196

Closed

ebraminio mentioned this issue Aug 18, 2023

Compiler crash when destructing and spread operator are used in a for loop #53268

Closed

shubham-jain2 mentioned this issue Aug 24, 2023

type 'Null' is not a subtype of type 'GenericFunctionTypeElement' in type cast at offset <number> #53330

Closed

llfbandit mentioned this issue Sep 10, 2023

Web compiler crash #53479

Closed

Pisey-Nguon mentioned this issue Sep 11, 2023

dart migration failed #53484

Closed

Raj-impetrosys mentioned this issue Sep 15, 2023

Aborting migration due to an exception. This most likely is due to a bug in the migration tool. Please consider filing a bug report at: #53538

Closed

bernardolansing mentioned this issue Sep 27, 2023

Compiler crashes when Future is created and awaited later (during debug) #53637

Closed

manandhar-aarya mentioned this issue Oct 9, 2023

The compiler crashed when compiling an element. #53704

Closed

mboyanna mentioned this issue Dec 7, 2023

BUg in dart migration tool, version 2.19.0 #54261

Closed

cosminbodnariuc mentioned this issue Dec 7, 2023

Unhandled exception: Crash when compiling: Null check operator used on a null value #54267

Closed

mnts mentioned this issue Feb 6, 2024

app crashes once staps on breakpoints #54838

Open

JgomesAT mentioned this issue Feb 28, 2024

Internal Error MapStyler #55039

Closed

adityasaxen mentioned this issue Mar 14, 2024

The analysis server shut down unexpectedly #55193

Closed

upasana-khatiwada mentioned this issue Mar 16, 2024

cannot run any flutter command #55212

Closed

butterbrain mentioned this issue Apr 4, 2024

Crash in Dart Compiler share_plus-8.0.2/lib/src/share_plus_web.dart:316:20 #55379

Closed

abhisiroha mentioned this issue Apr 24, 2024

Compilation Error during web publishing #55563

Closed

eernstg mentioned this issue Jul 1, 2024

The analyzer encounters an unhandled exception during constant verification in a switch statement #56117

Open

Lootwig mentioned this issue Jul 18, 2024

Analyzer exception doesn't specify affected file #56281

Open

ailabs-software mentioned this issue Aug 6, 2024

webdev error after upgrading to Dart 3.5.0 #56382

Closed

thermoworker mentioned this issue Aug 12, 2024

Internal error: Exception while using a AvoidRedundantArgumentValues to visit... #56448

Open

theaquaflower mentioned this issue Aug 15, 2024

Exception from yaml parsing during dart fix #56473

Closed

SwederSchellens mentioned this issue Sep 24, 2024

dart2js crashes in pkg:kernel #56773

Closed

ChaserVasya mentioned this issue Oct 20, 2024

Internal error: Bad state: Expected existing element #56922

Open

MohammadNezarAldalati mentioned this issue Oct 23, 2024

Improve diagnostic reporting on invalid analysis options #56943

Open

This issue was closed.

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Decide if we want to generate DivisionByZeroException errors #26

Decide if we want to generate DivisionByZeroException errors #26

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

floitschG commented Oct 11, 2011

DartBot commented Oct 11, 2011

gbracha commented Oct 12, 2011

DartBot commented Oct 24, 2011

DartBot commented Oct 25, 2011

DartBot commented Mar 28, 2012

anders-sandholm commented Mar 28, 2012

kasperl commented Apr 1, 2012

kasperl commented Apr 1, 2012

kasperl commented Sep 3, 2012

kasperl commented Oct 17, 2012

Decide if we want to generate DivisionByZeroException errors #26

Decide if we want to generate DivisionByZeroException errors #26

Comments

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

DartBot commented Oct 10, 2011

floitschG commented Oct 11, 2011

DartBot commented Oct 11, 2011

gbracha commented Oct 12, 2011

DartBot commented Oct 24, 2011

DartBot commented Oct 25, 2011

DartBot commented Mar 28, 2012

anders-sandholm commented Mar 28, 2012

kasperl commented Apr 1, 2012

kasperl commented Apr 1, 2012

kasperl commented Sep 3, 2012

kasperl commented Oct 17, 2012