0004892: 'index out of bound' check too early?

(0005131)
ertai (developer)
2009-10-15 15:12

Why do you expects the arguments of this function to be all evaluated before doing the update.

Array.set could morally be seen as:

let set array index =
...bound...check... array index;
fun v -> ...update...code...

Which have the nice property of checking once the bounds:

let isetter = Array.set array i in
let rec ... k = ... isetter k ...

However the reports is still worthy since the behavior should be the same in bytecode.

(0005132)
frisch (developer)
2009-10-15 16:27

>Why do you expects the arguments of this function to be all evaluated before
>doing the update.

Because, in a call-by-value language, as I said, one expects arguments of a function call to be evaluated before the function is called.

(0005133)
doligez (manager)
2009-10-15 17:39

This bug seems to be a kind of dual to PR#2719...

(0005140)
frisch (developer)
2009-10-20 12:57

The bug is in Cmmgen.transl_prim_3 and the fix is straightforward (always bind "newval" to arg3).

(0007070)
xleroy (administrator)
2012-03-14 10:27

Fixed in 4.00 release branch (r12237) and in trunk (r12238).

Issue History
Date Modified	Username	Field	Change
2009-10-15 00:35	frisch	New Issue
2009-10-15 15:12	ertai	Note Added: 0005131
2009-10-15 16:27	frisch	Note Added: 0005132
2009-10-15 17:38	doligez	Relationship added	related to 0002719
2009-10-15 17:39	doligez	Note Added: 0005133
2009-10-15 17:39	doligez	Reproducibility	have not tried => always
2009-10-15 17:39	doligez	Status	new => acknowledged
2009-10-20 12:57	frisch	Note Added: 0005140
2012-02-14 15:26	gasche	Status	acknowledged => confirmed
2012-03-14 10:27	xleroy	Note Added: 0007070
2012-03-14 10:27	xleroy	Status	confirmed => resolved
2012-03-14 10:27	xleroy	Resolution	open => fixed
2012-03-14 10:27	xleroy	Fixed in Version	=> 4.00.0+dev

Notes
(0005131) ertai (developer) 2009-10-15 15:12	Why do you expects the arguments of this function to be all evaluated before doing the update. Array.set could morally be seen as: let set array index = ...bound...check... array index; fun v -> ...update...code... Which have the nice property of checking once the bounds: let isetter = Array.set array i in let rec ... k = ... isetter k ... However the reports is still worthy since the behavior should be the same in bytecode.

(0005132) frisch (developer) 2009-10-15 16:27	>Why do you expects the arguments of this function to be all evaluated before >doing the update. Because, in a call-by-value language, as I said, one expects arguments of a function call to be evaluated before the function is called.

(0005133) doligez (manager) 2009-10-15 17:39	This bug seems to be a kind of dual to PR#2719...

(0005140) frisch (developer) 2009-10-20 12:57	The bug is in Cmmgen.transl_prim_3 and the fix is straightforward (always bind "newval" to arg3).

(0007070) xleroy (administrator) 2012-03-14 10:27	Fixed in 4.00 release branch (r12237) and in trunk (r12238).