# Segmentation fault in eval

**URL:** <https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567>\
**Category:** Development\
**Created:** [October 10, 2008, 12:02am UTC](https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567 "2008-10-10T00:02:45Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/77aa72/32.png) [@Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/u/Kazuhiro_NISHIYAMA)\
**Post date:** [October 10, 2008, 12:02am UTC](https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567/1 "2008-10-10T00:02:45Z")

</div>

e$B@\>;3OB9-$G$9!#e(B

[http://d.hatena.ne.jp/mamamoto/20081007/1223349255](http://d.hatena.ne.jp/mamamoto/20081007/1223349255)  
e$B$N%9%/%j%W%H$r85$K$$$8$C$F$$$?$ie(Bs="n=$\*"e$B$GMn$A$^$7$?!#e(B

e$B:G\>.$^$G$O9J$C$F$$$^$;$s$,!“$”$kDxEY9J$j$3$s$Ge(B  
e$B:F8=%9%/%j%W%H$O0J2\<$N$h$&$K$J$j$^$7$?!#e(B

% cat b.rb  
#/usr/bin/ruby  
def f(s)  
n = 0  
eval(s)  
rescue Exception  
nil  
end

a = %w[= $ \*]

9.times{|i|  
a.permutation(i+1){|b|  
c = %w[n]  
d = b + c  
c.size.step(0, -1){|j|  
d.permutation(d.size-j){|e|  
f(e.join)  
}  
}  
}  
}  
% ruby-trunk b.rb  
(eval):1: warning: variable $= is no longer effective  
(eval):1: warning: variable $= is no longer effective  
(eval):1: warning: variable $= is no longer effective  
(eval):1: warning: variable $= is no longer effective  
(eval):1: warning: variable $= is no longer effective  
(eval):1: warning: variable $= is no longer effective  
(eval):1: [BUG] Segmentation fault  
ruby 1.9.0 (2008-10-09 revision 19722) [i686-linux]

## – control frame ---------- c:0019 p:0004 s:0050 b:0050 l:000041 d:000049 EVAL (eval):1 c:0018 p:---- s:0048 b:0048 l:000047 d:000047 FINISH :=== c:0017 p:---- s:0046 b:0046 l:000045 d:000045 CFUNC :eval c:0016 p:0019 s:0042 b:0042 l:000041 d:000041 METHOD b.rb:4 c:0015 p:0018 s:0037 b:0037 l:000006 d:000036 BLOCK b.rb:16 c:0014 p:---- s:0036 b:0036 l:000035 d:000035 FINISH c:0013 p:---- s:0034 b:0034 l:000033 d:000033 CFUNC :permutation c:0012 p:0024 s:0030 b:0030 l:000006 d:000029 BLOCK b.rb:16 c:0011 p:---- s:0029 b:0029 l:000028 d:000028 FINISH :== c:0010 p:---- s:0027 b:0027 l:000026 d:000026 CFUNC :step c:0009 p:0042 s:0022 b:0022 l:000006 d:000021 BLOCK b.rb:15 c:0008 p:---- s:0019 b:0019 l:000018 d:000018 FINISH :remove\_const c:0007 p:---- s:0017 b:0017 l:000016 d:000016 CFUNC :permutation c:0006 p:0017 s:0013 b:0013 l:000006 d:000012 BLOCK b.rb:12 c:0005 p:---- s:0012 b:0012 l:000011 d:000011 FINISH :class\_eval c:0004 p:---- s:0010 b:0010 l:000009 d:000009 CFUNC :times c:0003 p:0039 s:0007 b:0007 l:000006 d:000006 TOP b.rb:11 c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH :inherited c:0001 p:0000 s:0002 b:0002 l:000001 d:000001 TOP :17

DBG\> : “(eval):1:in `f'" DBG> : "b.rb:4:in `eval’”  
DBG\> : “b.rb:4:in `f'" DBG> : "b.rb:16:in `block (4 levels) in '”  
DBG\> : “b.rb:16:in `permutation'" DBG> : "b.rb:16:in `block (3 levels) in '”  
DBG\> : “b.rb:15:in `step'" DBG> : "b.rb:15:in `block (2 levels) in '”  
DBG\> : “b.rb:12:in `permutation'" DBG> : "b.rb:12:in `block in '”  
DBG\> : “b.rb:11:in `times'" DBG> : "b.rb:11:in `'”  
– backtrace of native function call (Use addr2line) –  
0xb7ed13d7  
0xb7df4053  
0xb7df40c9  
0xb7e7c5d9  
0xb7f30440  
0xb7ec5312  
0xb7ecc1b8  
0xb7ecd595  
0xb7ecdba1  
0xb7ecdcf8  
0xb7ec02d3  
0xb7ecee98  
0xb7ec77bb  
0xb7ecc1b8  
0xb7ecc818  
0xb7eccff5  
0xb7dd1bc7  
0xb7dd1b49  
0xb7dd1b49  
0xb7dd1b49  
0xb7dd68ea  
0xb7ec02d3  
0xb7ecee98  
0xb7ec77bb  
0xb7ecc1b8  
0xb7ecc818  
0xb7eccff5  
0xb7e26fe4  
0xb7ec02d3  
0xb7ecee98  
0xb7ec77bb  
0xb7ecc1b8  
0xb7ecc818  
0xb7eccff5  
0xb7dd1bc7  
0xb7dd1b49  
0xb7dd1b49  
0xb7dd68ea  
0xb7ec02d3  
0xb7ecee98  
0xb7ec77bb  
0xb7ecc1b8  
0xb7ecc818  
0xb7eccff5  
0xb7e225bf  
0xb7ec02be  
0xb7ecee98  
0xb7ec77bb  
0xb7ecc1b8  
0xb7ecc3fd  
0xb7df62af  
0xb7df7d12  
0x8048734  
0xb7c1eea8  
0x8048631

---

<div class="post-metadata">

**Author:** ![Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/77aa72/32.png) [@Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/u/Kazuhiro_NISHIYAMA)\
**Post date:** [October 10, 2008, 11:26am UTC](https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567/2 "2008-10-10T11:26:14Z")

</div>

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

At Fri, 10 Oct 2008 06:59:39 +0900,  
Kazuhiro NISHIYAMA wrote in [ruby-dev:36698]:

> [るびまゴルフ 【第 4 回】といた - mamamotoの日記](http://d.hatena.ne.jp/mamamoto/20081007/1223349255)  
> e$B$N%9%/%j%W%H$r85$K$$$8$C$F$$$?$ie(Bs="n=$\*"e$B$GMn$A$^$7$?!#e(B

$_=0; $_ e$B$,:G\>.$G$9$M!#e(B

argfe$B2s$j$r@0M}$7$?$H$-$K!“e(Brb\_define\_virtual\_variable()e$B$H4V0c$($Fe(B  
rb\_define\_hooked\_variable()e$B$Ne(Bsettere$B$Ke(B0e$B$rEO$9$h$&$K$7$?$?$a$K!”%Ge(B  
e$B%U%)%k%H$Ne(Bsettere$B$,;H$o$l$F$7$^$C$F$$$k$H$$$&%\_%9$G$7$?!#e(B

e$B$7$+$7!“8+D\>$7$F$\_$k$He(Brb\_define\_hooked\_variable()e$B$Ge(Breadonlye$BJQ?te(B  
e$B$r:n$kJ}K!$O$J$$$h$&$G$9!#e(Breadonly\_setter()e$B$J$I$r8x3+$9$k$N$,4Je(B  
e$BC1$J$N$G$9$,!”$I$&$7$?$b$N$G$7$g$&$+!#e(B

e$B$5$i$K$$$&$H!“e(Bmarkere$B$rFH\<+$K;XDj$9$kJ}K!$b$”$j$^$;$s!#e(B

# Index: io.c

— io.c (revision 19741)  
+++ io.c (working copy)  
@@ -8445,9 +8445,9 @@ Init\_IO(void)

```
 rb_define_hooked_variable("$.", &argf, argf_lineno_getter, 

```

argf\_lineno\_setter);

- rb\_define\_hooked\_variable(“$FILENAME”, &argf, argf\_filename\_getter,  
0);

- rb\_define\_hooked\_variable(“$FILENAME”, &argf, argf\_filename\_getter,  
rb\_gvar\_readonly\_setter);  
ARGF.filename = rb\_str\_new2(“-”);

- rb\_define\_hooked\_variable(“$\*”, &argf, argf\_argv\_getter, 0);

- rb\_define\_hooked\_variable(“$\*”, &argf, argf\_argv\_getter,  
rb\_gvar\_readonly\_setter);

# #if defined (\_WIN32) || defined( **CYGWIN** ) Index: variable.c

— variable.c (revision 19741)  
+++ variable.c (working copy)  
@@ -287,9 +287,9 @@ rb\_obj\_classname(VALUE obj)  
}

-struct global\_variable;  
+#define global\_variable rb\_global\_variable

-typedef VALUE gvar\_getter\_t(ID id, void \*data, struct global\_variable  
\*gvar);  
-typedef void gvar\_setter\_t(VALUE val, ID id, void \*data, struct  
global\_variable \*gvar);  
-typedef void gvar\_marker\_t(VALUE \*var);  
+#define gvar\_getter\_t rb\_gvar\_getter\_t  
+#define gvar\_setter\_t rb\_gvar\_setter\_t  
+#define gvar\_marker\_t rb\_gvar\_marker\_t

struct trace\_var {  
@@ -315,15 +315,17 @@ struct global\_entry {  
};

## -static VALUE undef\_getter(ID id, void \*data, struct global\_variable \*gvar); -static void undef\_setter(VALUE val, ID id, void \*data, struct global\_variable \*gvar); -static void undef\_marker(VALUE \*var);

## -static VALUE val\_getter(ID id, void \*data, struct global\_variable \*gvar); -static void val\_setter(VALUE val, ID id, void \*data, struct global\_variable \*gvar); -static void val\_marker(VALUE \*var);

-static VALUE var\_getter(ID id, void \*data, struct global\_variable  
\*gvar);  
-static void var\_setter(VALUE val, ID id, void \*data, struct  
global\_variable \*gvar);  
-static void var\_marker(VALUE \*var);  
+#define undef\_getter rb\_gvar\_undef\_getter  
+#define undef\_setter rb\_gvar\_undef\_setter  
+#define undef\_marker rb\_gvar\_undef\_marker  
+  
+#define val\_getter rb\_gvar\_val\_getter  
+#define val\_setter rb\_gvar\_val\_setter  
+#define val\_marker rb\_gvar\_val\_marker  
+  
+#define var\_getter rb\_gvar\_var\_getter  
+#define var\_setter rb\_gvar\_var\_setter  
+#define var\_marker rb\_gvar\_var\_marker  
+  
+#define readonly\_setter rb\_gvar\_readonly\_setter

struct global\_entry\*  
@@ -355,5 +357,5 @@ rb\_global\_entry(ID id)  
}

-static VALUE  
+VALUE  
undef\_getter(ID id, void \*data, struct global\_variable \*var)  
{  
@@ -363,5 +365,5 @@ undef\_getter(ID id, void \*data, struct g  
}

-static void  
+void  
undef\_setter(VALUE val, ID id, void \*data, struct global\_variable \*var)  
{  
@@ -373,10 +375,10 @@ undef\_setter(VALUE val, ID id, void \*dat  
}

-static void  
+void  
undef\_marker(VALUE \*var)  
{  
}

-static VALUE  
+VALUE  
val\_getter(ID id, void \*data, struct global\_variable \*var)  
{  
@@ -384,5 +386,5 @@ val\_getter(ID id, void \*data, struct glo  
}

-static void  
+void  
val\_setter(VALUE val, ID id, void \*data, struct global\_variable \*var)  
{  
@@ -390,5 +392,5 @@ val\_setter(VALUE val, ID id, void \*data,  
}

-static void  
+void  
val\_marker(VALUE \*var)  
{  
@@ -397,5 +399,5 @@ val\_marker(VALUE \*var)  
}

-static VALUE  
+VALUE  
var\_getter(ID id, void \*data, struct global\_variable \*gvar)  
{  
@@ -405,5 +407,5 @@ var\_getter(ID id, void \*data, struct glo  
}

-static void  
+void  
var\_setter(VALUE val, ID id, void \*data, struct global\_variable \*gvar)  
{  
@@ -411,5 +413,5 @@ var\_setter(VALUE val, ID id, void \*data,  
}

-static void  
+void  
var\_marker(VALUE \*var)  
{  
@@ -417,5 +419,5 @@ var\_marker(VALUE \*var)  
}

# -static void +void readonly\_setter(VALUE val, ID id, void \*data, struct global\_variable \*gvar) { Index: include/ruby/ruby.h

— include/ruby/ruby.h (revision 19741)  
+++ include/ruby/ruby.h (working copy)  
@@ -847,4 +847,24 @@ void rb\_include\_module(VALUE,VALUE);  
void rb\_extend\_object(VALUE,VALUE);

+struct rb\_global\_variable;  
+  
+typedef VALUE rb\_gvar\_getter\_t(ID id, void \*data, struct  
rb\_global\_variable \*gvar);  
+typedef void rb\_gvar\_setter\_t(VALUE val, ID id, void \*data, struct  
rb\_global\_variable \*gvar);  
+typedef void rb\_gvar\_marker\_t(VALUE \*var);  
+  
+VALUE rb\_gvar\_undef\_getter(ID id, void \*data, struct rb\_global\_variable  
\*gvar);  
+void rb\_gvar\_undef\_setter(VALUE val, ID id, void \*data, struct  
rb\_global\_variable \*gvar);  
+void rb\_gvar\_undef\_marker(VALUE \*var);  
+  
+VALUE rb\_gvar\_val\_getter(ID id, void \*data, struct rb\_global\_variable  
\*gvar);  
+void rb\_gvar\_val\_setter(VALUE val, ID id, void \*data, struct  
rb\_global\_variable \*gvar);  
+void rb\_gvar\_val\_marker(VALUE \*var);  
+  
+VALUE rb\_gvar\_var\_getter(ID id, void \*data, struct rb\_global\_variable  
\*gvar);  
+void rb\_gvar\_var\_setter(VALUE val, ID id, void _data, struct  
rb\_global\_variable gvar);  
+void rb\_gvar\_var\_marker(VALUE var);  
+  
+void rb\_gvar\_readonly\_setter(VALUE val, ID id, void data, struct  
rb\_global\_variable gvar);  
+  
void rb\_define\_variable(const char,VALUE);  
void rb\_define\_virtual\_variable(const  
char,VALUE()(ANYARGS),void(_)(ANYARGS));

---

<div class="post-metadata">

**Author:** ![Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/77aa72/32.png) [@Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/u/Kazuhiro_NISHIYAMA)\
**Post date:** [October 14, 2008, 2:18pm UTC](https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567/3 "2008-10-14T14:18:54Z")

</div>

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

In message “Re: [ruby-dev:36703] Re: Segmentation fault in eval”  
on Fri, 10 Oct 2008 18:23:30 +0900, Nobuyoshi N.  
[removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes:

|At Fri, 10 Oct 2008 06:59:39 +0900,  
|Kazuhiro NISHIYAMA wrote in [ruby-dev:36698]:  
|\> [るびまゴルフ 【第 4 回】といた - mamamotoの日記](http://d.hatena.ne.jp/mamamoto/20081007/1223349255)  
|\> e$B$N%9%/%j%W%H$r85$K$$$8$C$F$$$?$ie(Bs=“n=$_"e$B$GMn$A$^$7$?!#e(B  
|  
|$_=0; $\* e$B$,:G\>.$G$9$M!#e(B  
|  
|argfe$B2s$j$r@0M}$7$?$H$-$K!“e(Brb\_define\_virtual\_variable()e$B$H4V0c$($Fe(B  
|rb\_define\_hooked\_variable()e$B$Ne(Bsettere$B$Ke(B0e$B$rEO$9$h$&$K$7$?$?$a$K!”%Ge(B  
|e$B%U%)%k%H$Ne(Bsettere$B$,;H$o$l$F$7$^$C$F$$$k$H$$$&%_%9$G$7$?!#e(B  
|  
|e$B$7$+$7!"8+D\>$7$F$_$k$He(Brb\_define\_hooked\_variable()e$B$Ge(Breadonlye$BJQ?te(B  
|e$B$r:n$kJ}K!$O$J$$$h$&$G$9!#e(Breadonly\_setter()e$B$J$I$r8x3+$9$k$N$,4Je(B  
|e$BC1$J$N$G$9$,!”$I$&$7$?$b$N$G$7$g$&$+!#e(B

e$B$J$s$+8=\>u$,$h$/$o$+$i$J$$$N$G$9$,!":G\>/$Ge(Bfixe$B$9$k$N$O$I$s$Je(B  
e$B46$8$J$s$G$7$g$&$+!#e(B

readonly\_setter()e$B$J$I$O4JC1$J$b$N$J$N$G!"\<+J,$GDj5A$9$l$P$$e(B  
e$B$$$s$8$c$J$$$+$H!#e(B

|e$B$5$i$K$$$&$H!“e(Bmarkere$B$rFH\<+$K;XDj$9$kJ}K!$b$”$j$^$;$s!#e(B

e$BI,MW$J%1!\<%9$C$F$"$j$^$7$?$C$1!#e(B

hooked  
variablee$B$O$“$s$^$j!V$h$$!We(BAPIe$B$G$O$J$$e(B(Rubye$BE\*$J0UL#$Ge(B)  
e$B$N$G!”$"$s$^$j5!G=6/2=$7$?$/$J$$$s$G$9$,!#e(B

```
                            e$B$^$D$b$He(B e$B$f$-$R$me(B /:|)

```

---

<div class="post-metadata">

**Author:** ![Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/k/77aa72/32.png) [@Kazuhiro\_NISHIYAMA](https://www.ruby-forum.com/u/Kazuhiro_NISHIYAMA)\
**Post date:** [October 14, 2008, 4:28pm UTC](https://www.ruby-forum.com/t/segmentation-fault-in-eval/150567/4 "2008-10-14T16:28:16Z")

</div>

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

At Tue, 14 Oct 2008 21:17:55 +0900,

> |e$B$7$+$7!“8+D\>$7$F$\_$k$He(Brb\_define\_hooked\_variable()e$B$Ge(Breadonlye$BJQ?te(B  
> |e$B$r:n$kJ}K!$O$J$$$h$&$G$9!#e(Breadonly\_setter()e$B$J$I$r8x3+$9$k$N$,4Je(B  
> |e$BC1$J$N$G$9$,!”$I$&$7$?$b$N$G$7$g$&$+!#e(B
> 
> e$B$J$s$+8=\>u$,$h$/$o$+$i$J$$$N$G$9$,!":G\>/$Ge(Bfixe$B$9$k$N$O$I$s$Je(B  
> e$B46$8$J$s$G$7$g$&$+!#e(B

readonly\_setter()e$B$@$1$r8x3+$K$9$k$"$?$j$+$bCN$l$^$;$s!#e(B

> readonly\_setter()e$B$J$I$O4JC1$J$b$N$J$N$G!"\<+J,$GDj5A$9$l$P$$e(B  
> e$B$$$s$8$c$J$$$+$H!#e(B

e$BF1$8$b$N$r:n$k$N$b$P$+$P$+$7$$$7!"5U$KC1=c$@$+$i$3$=B\>$K1F6A$,=Pe(B  
e$B$k$h$&$J$3$H$O$G$-$J$$$N$G$O$J$$$+$H!#e(B

> |e$B$5$i$K$$$&$H!“e(Bmarkere$B$rFH\<+$K;XDj$9$kJ}K!$b$”$j$^$;$s!#e(B
> 
> e$BI,MW$J%1!\<%9$C$F$"$j$^$7$?$C$1!#e(B

e$B$d$O$je(BARGVe$B$G$9$M!#e(B

ARGVe$B$r85$N$h$&$Ke(BARGFe$B$+$iJ,N%$9$k$H$$$&J}K!$b$"$k$N$G$9$,!"%0%m!\<e(B  
e$B%P%kJQ?t$O$G$-$k$3$H$J$ie(B(e$B$H$/$Ke(Bmvme$B2=$r9M$($k$He(B)e$BA}$d$7$?$/$J$$$He(B  
e$B;W$C$F$$$^$9!#e(B

> hooked variablee$B$O$"$s$^$j!V$h$$!We(BAPIe$B$G$O$J$$e(B(Rubye$BE\*$J0UL#$Ge(B)  
> e$B$N$G!"$"$s$^$j5!G=6/2=$7$?$/$J$$$s$G$9$,!#e(B

e$B$&!\<$s!"HyL/$KCfESH\>C\<$J46$8$,$9$k$N$G$9$,!D!#e(B