# A\[\] += 1 $B$G(B SEGV

**URL:** <https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239>\
**Category:** Development\
**Created:** [March 1, 2007, 1:36am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239 "2007-03-01T01:36:52Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 1, 2007, 1:36am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/1 "2007-03-01T01:36:52Z")

</div>

e$BK\5H$H?=$7$^$9!#e(B

e$B0J2\<$N%9%/%j%W%H$,!"e(B  
ruby-1.8.4e$B$G$O@5\>o$KF0$/$N$G$9$,!"e(B  
ruby-1.8.5e$B$G$Oe(BSEGVe$B$7$^$9!#e(B

* * *

class A  
def initialize (v)  
@value = v  
end  
def []  
return @value  
end  
def []= (v)  
@value = v  
end  
end

a = A.new(1)

a[] += 1 ### e$B$3$3$Ge(BSEGVe$B$9$k!#e(B -= e$B$de(B \*=  
e$B$G$bF1MM!#e(B

## p a[] ### =\> 2

Vine Linux 4.0 e$B$G!"\<B9T$9$k$H0J2\<$N$h$&$J=PNO$G$7$?!#e(B

% ruby184 -v test.rb  
ruby 1.8.4 (2005-12-24) [i686-linux]  
2

% ruby -v test.rb  
ruby 1.8.5 (2006-08-25) [i386-linux]  
Segmentation fault

NArraye$B$J$I$G\>e5-$N5-K!$rMQ$$$k$3$H$,$"$j5$$,$D$$$?$N$G$9$,!"e(B  
e$B3’MM$N4D6-$G$b:F8=$7$^$9$G$7$g$&$+!#e(B

e$B0J\>e!"Js9p$^$G!#e(B

e$B$h$m$7$/$\*4j$$$$$?$7$^$9!#e(B

---

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 1, 2007, 1:56am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/2 "2007-03-01T01:56:52Z")

</div>

e$B$I$&$b!":XF#$H?=$7$^$9!#e(B

On Thu, 1 Mar 2007 09:36:20 +0900  
“Hiroki Motoyoshi” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> e$BK\5H$H?=$7$^$9!#e(B
> 
> e$B0J2\<$N%9%/%j%W%H$,!"e(B  
> ruby-1.8.4e$B$G$O@5\>o$KF0$/$N$G$9$,!"e(B  
> ruby-1.8.5e$B$G$Oe(BSEGVe$B$7$^$9!#e(B  
> (snip)  
> e$B3’MM$N4D6-$G$b:F8=$7$^$9$G$7$g$&$+!#e(B

e$B\<+J,$N4D6-$G$b!“e(B1.8.6-preview2e$B$\*$h$Se(Bruby\_1\_8\_6e$B:G?7!”$H$d$C$Q$je(Btrunke$B$G$be(B  
e$B:F8=$7$^$7$?!#e(B

$ ./ruby-1.8.6/bin/ruby-1.8.6 -v segv186.rb  
ruby 1.8.6 (2007-02-28 patchlevel 0) [i686-linux]  
e$B%;%0%a%s%F!\<%7%g%s0cH?$G$9e(B (core dumped)  
$ gdb ./ruby-1.8.6/bin/ruby-1.8.6  
GNU gdb 6.3-debian  
Copyright 2004 Free Software Foundation, Inc.  
GDB is free software, covered by the GNU General Public License, and  
you are welcome to change it and/or distribute copies of it under  
certain conditions. Type “show copying” to see the conditions.  
There is absolutely no warranty for GDB. Type “show warranty” for  
details. This GDB was configured as “i386-linux”…Using host  
libthread\_db library “/lib/tls/i686/cmov/libthread\_db.so.1”.

(gdb) run segv186.rb  
Starting program: /home/tadashi/ruby-1.8.6/bin/ruby-1.8.6 segv186.rb

Program received signal SIGSEGV, Segmentation fault.  
0x4003ec09 in rb\_eval (self=1076521380, n=0x3)  
at …/…/1.8.6/eval.c:2907 2907 switch (nd\_type(node)) {  
(gdb) l  
2902  
2903 again:  
2904 if (!node) RETURN(Qnil);  
2905  
2906 ruby\_current\_node = node;  
2907 switch (nd\_type(node)) {  
2908 case NODE\_BLOCK:  
2909 if (contnode) {  
2910 result = rb\_eval(self, node);  
2911 break;  
(gdb) bt  
#0 0x4003ec09 in rb\_eval (self=1076521380, n=0x3) at  
…/…/1.8.6/eval.c:2907  
#1 0x400401af in rb\_eval (self=1076521380, n=0x3) at  
…/…/1.8.6/eval.c:3563  
#2 0x4003c50c in ruby\_exec\_internal () at …/…/1.8.6/eval.c:1599  
#3 0x4003c564 in ruby\_exec () at …/…/1.8.6/eval.c:1619  
#4 0x4003c5a1 in ruby\_run () at …/…/1.8.6/eval.c:1629  
#5 0x0804874e in main (argc=3, argv=0x3, envp=0xbffff880)  
at …/…/1.8.6/main.c:48  
(gdb)

e$B;~4V$,$J$$$N$G!“$H$j$”$($:Js9p$N$\_$G!#e(B

# e$B$K$7$F$b!"$$$^$^$G%(%i!\<$K$J$i$J$+$C$?$N$OCN$i$J$+$C$?$C$9e(B

---

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 1, 2007, 3:41am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/3 "2007-03-01T03:41:02Z")

</div>

e$B$J$+$@$G$9!#e(B

At Thu, 1 Mar 2007 09:55:43 +0900,  
Tadashi S. wrote in [ruby-dev:30456]:

> > e$B0J2\<$N%9%/%j%W%H$,!"e(B  
> > ruby-1.8.4e$B$G$O@5\>o$KF0$/$N$G$9$,!"e(B  
> > ruby-1.8.5e$B$G$Oe(BSEGVe$B$7$^$9!#e(B  
> > (snip)  
> > e$B3’MM$N4D6-$G$b:F8=$7$^$9$G$7$g$&$+!#e(B
> 
> e$B\<+J,$N4D6-$G$b!“e(B1.8.6-preview2e$B$\*$h$Se(Bruby\_1\_8\_6e$B:G?7!”$H$d$C$Q$je(Btrunke$B$G$be(B  
> e$B:F8=$7$^$7$?!#e(B

e$B$3$l$G$I$&$G$7$g$&$+!#e(B

# Index: parse.y

— parse.y (revision 11953)  
+++ parse.y (working copy)  
@@ -543,4 +543,5 @@ stmt : kALIAS fitem {lex\_state = EXPR\_F

```
   value_expr($6);

```

- 

```
 if (!$3) $3 = NEW_ZARRAY();
 args = arg_concat($6, $3);
 if ($5 == tOROP) {

```

@@ -1010,4 +1011,5 @@ arg : lhs ‘=’ arg

```
   value_expr($6);

```

- 

```
 if (!$3) $3 = NEW_ZARRAY();
 args = arg_concat($6, $3);
 if ($5 == tOROP) {
```

---

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 1, 2007, 4:31am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/4 "2007-03-01T04:31:10Z")

</div>

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:30459] Re: a[] += 1 e$B$Ge(B SEGV”  
on Thu, 1 Mar 2007 11:40:40 +0900, “Nobuyoshi N.”  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|e$B$3$l$G$I$&$G$7$g$&$+!#e(B  
|  
|  
|Index: parse.y  
|===================================================================  
|— parse.y (revision 11953)  
|+++ parse.y (working copy)

e$B%3%\_%C%H$7$F$/$@$5$$!#e(B

---

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 1, 2007, 4:42am UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/5 "2007-03-01T04:42:10Z")

</div>

At Thu, 1 Mar 2007 12:30:56 +0900,  
matz wrote:

> |— parse.y (revision 11953)  
> |+++ parse.y (working copy)
> 
> e$B%3%\_%C%H$7$F$/$@$5$$!#e(B

e$B!!e(Bruby\_1\_8 e$B$G$b3NG’$7$^$7$?!#%3%\_%C%H$r$\*4j$$$7$^$9!#e(B

–  
/  
/\_\_ \_\_ [Akinori.org](http://Akinori.org) / [MUSHA.org](http://MUSHA.org)  
/ ) ) ) ) / [FreeBSD.org](http://FreeBSD.org) / [Ruby-lang.org](http://Ruby-lang.org)  
Akinori MUSHA aka / (\_ / ( (\_\_( @ [iDaemons.org](http://iDaemons.org) / and.or.jp

“Different eyes see different things,  
Different hearts beat on different strings –  
But there are times for you and me when all such things agree”

---

<div class="post-metadata">

**Author:** ![Hiroki\_Motoyoshi](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/h/4491bb/32.png) [@Hiroki\_Motoyoshi](https://www.ruby-forum.com/u/Hiroki_Motoyoshi)\
**Post date:** [March 2, 2007, 2:08pm UTC](https://www.ruby-forum.com/t/a-1-b-g-b-segv/87239/6 "2007-03-02T14:08:21Z")

</div>

e$BK\5H$H?=$7$^$9!#e(B

e$BCfED$5$s$N%3%_%C%H$N$"$H!"e(Bruby\_1\_8e$B$He(Btrunke$B$GF0:n3NG’$7$Fe(B  
e$B$_$?$H$3$m!"e(Bruby\_1\_8e$B$O4|BTDL$j$NF0:n$r$7$^$7$?$,!"e(B  
trunke$B$OJL$NNc30$,H/@8$7$F$7$^$$$^$9!#e(B

% ./ruby -v test\_segv.rb  
ruby 1.8.6 (2007-03-01 patchlevel 5000) [i686-linux]  
2

% ./ruby -v test\_segv.rb  
ruby 1.9.0 (2007-03-02 patchlevel 0) [i686-linux]  
test\_segv.rb:16:in `’: wrong number of arguments (1 for 0)  
(ArgumentError)

e$B;HMQe(BOSe$B$Oe(BCentOS4.3e$B$G$9!#e(B

e$BJs9p$@$1$G?=$7Lu$"$j$^$;$s$,!"$h$m$7$/$\*4j$$$$$?$7$^$9!#e(B