# X=0;defined?(foo(x)) dumps core

**URL:** <https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995>\
**Category:** Development\
**Created:** [November 22, 2007, 2:06pm UTC](https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995 "2007-11-22T14:06:11Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 22, 2007, 2:06pm UTC](https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995/1 "2007-11-22T14:06:11Z")

</div>

e$B1sF#$H?=$7$^$9!#e(B

defined? e$B$K0z?t$N$"$ke(B NODE\_CALL e$B$rM?$($k$HMn$A$k$h$&$G$9!#e(B

## $ ./ruby -e ‘x=0;defined?(foo(x))’ -e:1: – control frame ---------- c:0003 p:0021 s:0007 b:0006 l:000005 d:000005 TOP -e:1 c:0002 p:---- s:0003 b:0003 l:000002 d:000002 FINISH :inherited c:0001 p:---- s:0001 b:-001 l:000000 d:000000 ------

## – backtrace of native function call (Use addr2line) – 0x80e7f25 0x8105aa3 0x8105b6b 0x80e5fa4 0x80e67f4 0x80e6b2b 0x8059e79 0x805dda0 0x8057b80 0xb7d9fea8 0x8057aa1

[BUG] Stack consistency error (sp: 7, bp: 6)  
ruby 1.9.0 (2007-11-22) [i686-linux]

e$B%"%!\<%H$7$^$7$?e(B

e$BB?J,$3$s$J46$8$G$7$g$&$+!#e(B

# Index: compile.c

— compile.c (revision 13997)  
+++ compile.c (working copy)  
@@ -2295,13 +2295,11 @@  
if (node-\>nd\_args) {  
lfalse = NEW\_LABEL(nd\_line(node));  
defined\_expr(iseq, ret, node-\>nd\_args, lfinish, Qfalse);

- 

```
 ADD_INSNL(ret, nd_line(node), branchunless, lfalse);

```

}  
if (!self) {  
LABEL \*lcont = NEW\_LABEL(nd\_line(node));

- 

```
 if (lfalse) {

```

- ADD\_INSNL(ret, nd\_line(node), branchunless, lfalse);
- 

```
 }
 defined_expr(iseq, ret, node->nd_recv, lfinish, Qfalse);
 ADD_INSNL(ret, nd_line(node), branchif, lcont);
 if (lfalse) {
```

---

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 22, 2007, 2:43pm UTC](https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995/2 "2007-11-22T14:43:09Z")

</div>

e$B1sF#$G$9!#e(B

e$B$5$C$-$N%Q%C%A$OIT40A4$Ge(B def foo;end;x=0;defined?(foo(x)) e$B$Ge(B  
e$BMn$A$k$h$&$K$J$C$F$^$7$?!#$9$\_$^$;$s!#e(B

e$B$b$H$N%3!\<%I$,$I$&$$$&0U?^$G=q$+$l$F$$$?$N$+$h$/$o$+$i$J$$$N$G$9$,!"e(B  
e$B$3$l$,@52r$G$7$g$&$+!#e(B

$ ./ruby -e ‘p defined?(foo)’  
nil  
$ ./ruby -e ‘p defined?(foo(x))’  
nil  
$ ./ruby -e ‘x=0;p defined?(foo(x))’  
nil  
$ ./ruby -e ‘def foo;end;p defined?(foo)’  
“method”  
$ ./ruby -e ‘def foo;end;p defined?(foo(x))’  
nil  
$ ./ruby -e ‘def foo;end;x=0;p defined?(foo(x))’  
“method”

# e$B:G8e$Ne(B jump e$B$H$+MW$i$J$$5$$b$7$^$9!#e(B

# Index: compile.c

— compile.c (revision 13997)  
+++ compile.c (working copy)  
@@ -2295,13 +2295,11 @@  
if (node-\>nd\_args) {  
lfalse = NEW\_LABEL(nd\_line(node));  
defined\_expr(iseq, ret, node-\>nd\_args, lfinish, Qfalse);

- 

```
 ADD_INSNL(ret, nd_line(node), branchunless, lfalse);

```

}  
if (!self) {  
LABEL \*lcont = NEW\_LABEL(nd\_line(node));

- 

```
 if (lfalse) {

```

- ADD\_INSNL(ret, nd\_line(node), branchunless, lfalse);
- 

```
 }
 defined_expr(iseq, ret, node->nd_recv, lfinish, Qfalse);
 ADD_INSNL(ret, nd_line(node), branchif, lcont);
 if (lfalse) {

```

@@ -2319,9 +2317,8 @@  
ADD\_INSN(ret, nd\_line(node), putself);  
ADD\_INSN3(ret, nd\_line(node), defined, INT2FIX(DEFINED\_FUNC),  
ID2SYM(node-\>nd\_mid), needstr);

- 

```
 ADD_INSNL(ret, nd_line(node), jump, lfinish);
 if (lfalse) {

```

- ADD\_INSNL(ret, nd\_line(node), branchif, lfinish);
- ADD\_LABEL(ret, lfalse);  
ADD\_INSN(ret, nd\_line(node), putnil);  
ADD\_INSNL(ret, nd\_line(node), jump, lfinish);

---

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 22, 2007, 4:36pm UTC](https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995/3 "2007-11-22T16:36:25Z")

</div>

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

In message “Re: [ruby-dev:32335] Re: x=0;defined?(foo(x)) dumps core”  
on Thu, 22 Nov 2007 22:42:32 +0900, “Yusuke ENDOH” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)  
writes:

|e$B$5$C$-$N%Q%C%A$OIT40A4$Ge(B def foo;end;x=0;defined?(foo(x)) e$B$Ge(B  
|e$BMn$A$k$h$&$K$J$C$F$^$7$?!#$9$\_$^$;$s!#e(B  
|  
|e$B$b$H$N%3!\<%I$,$I$&$$$&0U?^$G=q$+$l$F$$$?$N$+$h$/$o$+$i$J$$$N$G$9$,!"e(B  
|e$B$3$l$,@52r$G$7$g$&$+!#e(B  
|  
|$ ./ruby -e ‘p defined?(foo)’  
|nil  
|$ ./ruby -e ‘p defined?(foo(x))’  
|nil  
|$ ./ruby -e ‘x=0;p defined?(foo(x))’  
|nil  
|$ ./ruby -e ‘def foo;end;p defined?(foo)’  
|“method”  
|$ ./ruby -e ‘def foo;end;p defined?(foo(x))’  
|nil  
|$ ./ruby -e ‘def foo;end;x=0;p defined?(foo(x))’  
|“method”

e$B$=$&$G$9$M!#%a%=%C%I$,Dj5A$5$l$F$$$F!"$9$Y$F$N0z?t$,e(Bdefined  
e$B$N$H$-$KA4BN$,e(Bdefinede$B$K$J$k$H$$$&;EMM$G$9!#e(B

e$B$5$5$@$/$s!"%3%\_%C%H$7$F$b$h$$$+$7$i!)e(B e$B$=$l$H$b$=$A$i$G3NG’e(B  
e$B$7$^$9$+!)e(B

---

<div class="post-metadata">

**Author:** ![Yusuke\_ENDOH](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/y/c89c15/32.png) [@Yusuke\_ENDOH](https://www.ruby-forum.com/u/Yusuke_ENDOH)\
**Post date:** [November 23, 2007, 12:25am UTC](https://www.ruby-forum.com/t/x-0-defined-foo-x-dumps-core/120995/4 "2007-11-23T00:25:12Z")

</div>

e$B!!$5$5$@$G$9!%e(B

Yukihiro M. wrote:

> e$B$5$5$@$/$s!"%3%\_%C%H$7$F$b$h$$$+$7$i!)e(B e$B$=$l$H$b$=$A$i$G3NG’e(B  
> e$B$7$^$9$+!)e(B

e$B!!%3%\_%C%H$7$F$b$$$$$G$9$,!$$=$N:]$O%F%9%H$rIU$1$F$\*$$$F$/$@$5$$!%e(B