digitalmars.D - help -- Segmentation fault: std.c.setjmp

digitalmars.D - help -- Segmentation fault: std.c.setjmp - setjmp.d

some where.com (87/87) Apr 30 2004 I'm try to create std.c.setjmp from (on Linux, gcc 3.3.1)

Walter (9/78) Apr 30 2004 sj.d ---------------------

some where.com (23/24) Apr 30 2004 What do you mean?

Walter (4/29) Apr 30 2004 C's setjmp() takes a pointer to a struct, not the struct itself. Just as...

Walter (6/48) Apr 30 2004 Forgot to mention, you'll also need to fix your declaration of setjmp() ...

some where.com (22/30) Apr 30 2004 I also have *thought* that setjmp() should take a pointer. And the call...

Walter (13/45) May 02 2004 You're falling victim to the C rule of implicitly converting arrays to

some where.com writes:

I'm try to create std.c.setjmp from <setjmp.h> (on Linux, gcc 3.3.1)

The following simple program seg faults:

[d] dmd -g sj.d
gcc sj.o -o sj -g -lphobos -lpthread -lm
[d] ./sj
Segmentation fault
------------------------------------------------ sj.d ---------------------
import std.c.setjmp;

jmp_buf env;

void main()
{
if(setjmp(env)) {
printf("0\n");
}
else {
printf("1\n");
}
}
---------------------------------------------------------------------------

Can anybody tell me why? thanks!

Also, if I change "env" to be a local var inside "main()", I cannot link sj:

[d] dmd -g sj.d
gcc sj.o -o sj -g -lphobos -lpthread -lm
sj.o(.gnu.linkonce.t_Dmain+0x8): In function `_Dmain':
: undefined reference to `_init_3std1c6setjmp13__jmp_buf_tag'
collect2: ld returned 1 exit status
--- errorlevel 256
------------------------------------------------ sj.d ---------------------
import std.c.setjmp;

void main()
{
jmp_buf env;

if(setjmp(env)) {
printf("0\n");
}
else {
printf("1\n");
}
}
---------------------------------------------------------------------------

So what's the problem with linking?

Thanks.

The generated setjmp.d is here (also attached):
---------------------------------------------------------- setjmp.d -------
odule std.c.setjmp;

extern (C)
{

alias int __jmp_buf[6];
alias int __sig_atomic_t;

struct __sigset_t
{
uint __val[(1024 / (8 * uint.sizeof))];
}

struct __jmp_buf_tag
{

__jmp_buf __jmpbuf;
int __mask_was_saved;
__sigset_t __saved_mask;
}

alias __jmp_buf_tag jmp_buf;

extern int setjmp (jmp_buf __env) ;

extern int __sigsetjmp  (__jmp_buf_tag __env, int __savemask) ;

extern int _setjmp      (__jmp_buf_tag __env) ;

extern void longjmp     (__jmp_buf_tag __env, int __val) ;

extern void _longjmp    (__jmp_buf_tag __env, int __val) ;

alias __jmp_buf_tag sigjmp_buf;
extern void siglongjmp  (sigjmp_buf __env, int __val) ;

}
---------------------------------------------------------------------------



begin 0644 setjmp.d
M;6]D=6QE('-T9"YC+G-E=&IM<#L*"F5X=&5R;B`H0RD "GL*"F%L:6%S(&EN
M="!?7VIM<%]B=69;-ET["F%L:6%S(&EN="!?7W-I9U]A=&]M:6-?=#L*"G-T
M<G5C="!?7W-I9W-E=%]T"B` >PH ("` =6EN="!?7W9A;%LH,3`R-"`O(" X
M("H =6EN="YS:7IE;V8I*5T["B` ?0H*<W1R=6-T(%]?:FUP7V)U9E]T86<*
M("![" H ("` 7U]J;7!?8G5F(%]?:FUP8G5F.PH ("` :6YT(%]?;6%S:U]W
M87-?<V%V960["B` ("!?7W-I9W-E=%]T(%]?<V%V961?;6%S:SL*("!]" IA
M;&EA<R!?7VIM<%]B=69?=&%G(&IM<%]B=68[" IE>'1E<FX :6YT('-E=&IM
M<"`H:FUP7V)U9B!?7V5N=BD .PH*97AT97)N(&EN="!?7W-I9W-E=&IM<"`)
M*%]?:FUP7V)U9E]T86< 7U]E;G8L(&EN="!?7W-A=F5M87-K*2`[" IE>'1E
M<FX :6YT(%]S971J;7` "2A?7VIM<%]B=69?=&%G(%]?96YV*2`[" IE>'1E
M<FX =F]I9"!L;VYG:FUP(`DH7U]J;7!?8G5F7W1A9R!?7V5N=BP :6YT(%]?
M=F%L*2`[" IE>'1E<FX =F]I9"!?;&]N9VIM<"`)*%]?:FUP7V)U9E]T86< 
M7U]E;G8L(&EN="!?7W9A;"D .PH*86QI87, 7U]J;7!?8G5F7W1A9R!S:6=J
M;7!?8G5F.PIE>'1E<FX =F]I9"!S:6=L;VYG:FUP(`DH<VEG:FUP7V)U9B!?
67V5N=BP :6YT(%]?=F%L*2`[" I]"F=L
`
end

Apr 30 2004

"Walter" <newshound digitalmars.com> writes:

Try &jmp_buf.

<some where.com> wrote in message news:c6t0e4$1bc8$1 digitaldaemon.com...
 I'm try to create std.c.setjmp from <setjmp.h> (on Linux, gcc 3.3.1)

 The following simple program seg faults:

 [d] dmd -g sj.d
 gcc sj.o -o sj -g -lphobos -lpthread -lm
 [d] ./sj
 Segmentation fault
 ------------------------------------------------ 

sj.d ---------------------
 import std.c.setjmp;

 jmp_buf env;

 void main()
 {
 if(setjmp(env)) {
 printf("0\n");
 }
 else {
 printf("1\n");
 }
 }
 --------------------------------------------------------------------------

-
 Can anybody tell me why? thanks!

 Also, if I change "env" to be a local var inside "main()", I cannot link

sj:
 [d] dmd -g sj.d
 gcc sj.o -o sj -g -lphobos -lpthread -lm
 sj.o(.gnu.linkonce.t_Dmain+0x8): In function `_Dmain':
 : undefined reference to `_init_3std1c6setjmp13__jmp_buf_tag'
 collect2: ld returned 1 exit status
 --- errorlevel 256
 ------------------------------------------------ 

sj.d ---------------------
 import std.c.setjmp;

 void main()
 {
 jmp_buf env;

 if(setjmp(env)) {
 printf("0\n");
 }
 else {
 printf("1\n");
 }
 }
 --------------------------------------------------------------------------

-
 So what's the problem with linking?

 Thanks.

 The generated setjmp.d is here (also attached):
 ---------------------------------------------------------- 

setjmp.d -------
 odule std.c.setjmp;

 extern (C)
 {

 alias int __jmp_buf[6];
 alias int __sig_atomic_t;

 struct __sigset_t
 {
 uint __val[(1024 / (8 * uint.sizeof))];
 }

 struct __jmp_buf_tag
 {

 __jmp_buf __jmpbuf;
 int __mask_was_saved;
 __sigset_t __saved_mask;
 }

 alias __jmp_buf_tag jmp_buf;

 extern int setjmp (jmp_buf __env) ;

 extern int __sigsetjmp  (__jmp_buf_tag __env, int __savemask) ;

 extern int _setjmp      (__jmp_buf_tag __env) ;

 extern void longjmp     (__jmp_buf_tag __env, int __val) ;

 extern void _longjmp    (__jmp_buf_tag __env, int __val) ;

 alias __jmp_buf_tag sigjmp_buf;
 extern void siglongjmp  (sigjmp_buf __env, int __val) ;

 }
 --------------------------------------------------------------------------

-

Apr 30 2004

some where.com writes:

In article <c6tsrh$2r2d$1 digitaldaemon.com>, Walter says...
Try &jmp_buf.

What do you mean?

I tried to put "&" before/after "jmp_buf", the file is not compiling:

[d] dmd sj.d
sj.d(3): no identifier for declarator
sj.d(3): semicolon expected, not '&'
sj.d(3): Declaration expected, not '&'

If I try to put "&" before "env", it says:

[d] dmd sj.d
sj.d(6): function setjmp (__jmp_buf_tag __env) does not match argument types
(__jmp_buf_tag *)


[d] cat sj.d
------------------------------------------------------------------
import std.c.setjmp;

jmp_buf env;
void main()
{
if(setjmp(&env))  { printf("0\n"); }
else              { printf("1\n"); }
}
------------------------------------------------------------------

This is a very tiny example, can you be more verbose in your response?

Thanks.

Apr 30 2004

"Walter" <newshound digitalmars.com> writes:

C's setjmp() takes a pointer to a struct, not the struct itself. Just as you
would in C.

<some where.com> wrote in message news:c6tu09$2t7e$1 digitaldaemon.com...
 In article <c6tsrh$2r2d$1 digitaldaemon.com>, Walter says...
Try &jmp_buf.

 What do you mean?

 I tried to put "&" before/after "jmp_buf", the file is not compiling:

 [d] dmd sj.d
 sj.d(3): no identifier for declarator
 sj.d(3): semicolon expected, not '&'
 sj.d(3): Declaration expected, not '&'

 If I try to put "&" before "env", it says:

 [d] dmd sj.d
 sj.d(6): function setjmp (__jmp_buf_tag __env) does not match argument

types
 (__jmp_buf_tag *)


 [d] cat sj.d
 ------------------------------------------------------------------
 import std.c.setjmp;

 jmp_buf env;
 void main()
 {
 if(setjmp(&env))  { printf("0\n"); }
 else              { printf("1\n"); }
 }
 ------------------------------------------------------------------

 This is a very tiny example, can you be more verbose in your response?

 Thanks.

Apr 30 2004

"Walter" <newshound digitalmars.com> writes:

Forgot to mention, you'll also need to fix your declaration of setjmp() in
setjmp.d to take a pointer to the struct. Otherwise, you'll get the message
you did in the second example.

"Walter" <newshound digitalmars.com> wrote in message
news:c6uja9$sqg$1 digitaldaemon.com...
 C's setjmp() takes a pointer to a struct, not the struct itself. Just as

you
 would in C.

 <some where.com> wrote in message news:c6tu09$2t7e$1 digitaldaemon.com...
 In article <c6tsrh$2r2d$1 digitaldaemon.com>, Walter says...
Try &jmp_buf.

 What do you mean?

 I tried to put "&" before/after "jmp_buf", the file is not compiling:

 [d] dmd sj.d
 sj.d(3): no identifier for declarator
 sj.d(3): semicolon expected, not '&'
 sj.d(3): Declaration expected, not '&'

 If I try to put "&" before "env", it says:

 [d] dmd sj.d
 sj.d(6): function setjmp (__jmp_buf_tag __env) does not match argument

 types
 (__jmp_buf_tag *)


 [d] cat sj.d
 ------------------------------------------------------------------
 import std.c.setjmp;

 jmp_buf env;
 void main()
 {
 if(setjmp(&env))  { printf("0\n"); }
 else              { printf("1\n"); }
 }
 ------------------------------------------------------------------

 This is a very tiny example, can you be more verbose in your response?

 Thanks.

Apr 30 2004

some where.com writes:

I also have *thought* that setjmp() should take a pointer.  And the calling
function should hold the actual struct.  But ... (Digital Mars Compiler Version
8.38n)

c:\> dmc sj.c
link sj,,,user32+kernel32/noi;

c:\> sj.exe
sizeof(jmp_buf) = 64

----------------------------------------------------------------- sj.c -----
#include <setjmp.h>
#include <stdio.h>

int main()
{
printf("sizeof(jmp_buf) = %d\n", sizeof(jmp_buf));
return 0;
}
----------------------------------------------------------------- sj.c -----

And on Linux:

[d] ./sj
sizeof(jmp_buf) = 156

I'm totally confused.  Can you try my example?  and what's your explanation?

Thanks.


In article <c6uk14$ts0$1 digitaldaemon.com>, Walter says...
Forgot to mention, you'll also need to fix your declaration of setjmp() in
setjmp.d to take a pointer to the struct. Otherwise, you'll get the message
you did in the second example.

"Walter" <newshound digitalmars.com> wrote in message
news:c6uja9$sqg$1 digitaldaemon.com...
 C's setjmp() takes a pointer to a struct, not the struct itself. Just as

you
 would in C.

Apr 30 2004

"Walter" <newshound digitalmars.com> writes:

You're falling victim to the C rule of implicitly converting arrays to
pointers, *EXCEPT* if they are the argument to sizeof. Thus, setjmp(jmp_buf)
passes a pointer to setjmp, but sizeof(jmp_buf) gives the size of the
jmp_buf array, not the size of a pointer.

<some where.com> wrote in message news:c6ull3$104i$1 digitaldaemon.com...
 I also have *thought* that setjmp() should take a pointer.  And the

calling
 function should hold the actual struct.  But ... (Digital Mars Compiler

Version
 8.38n)

 c:\> dmc sj.c
 link sj,,,user32+kernel32/noi;

 c:\> sj.exe
 sizeof(jmp_buf) = 64

 ----------------------------------------------------------------- 

sj.c -----
 #include <setjmp.h>
 #include <stdio.h>

 int main()
 {
 printf("sizeof(jmp_buf) = %d\n", sizeof(jmp_buf));
 return 0;
 }
 ----------------------------------------------------------------- 

sj.c -----
 And on Linux:

 [d] ./sj
 sizeof(jmp_buf) = 156

 I'm totally confused.  Can you try my example?  and what's your

explanation?
 Thanks.


 In article <c6uk14$ts0$1 digitaldaemon.com>, Walter says...
Forgot to mention, you'll also need to fix your declaration of setjmp()


in
setjmp.d to take a pointer to the struct. Otherwise, you'll get the


message
you did in the second example.

"Walter" <newshound digitalmars.com> wrote in message
news:c6uja9$sqg$1 digitaldaemon.com...
 C's setjmp() takes a pointer to a struct, not the struct itself. Just



as
you
 would in C.

May 02 2004

D Programming

C/C++ Programming

Other

digitalmars.D - help -- Segmentation fault: std.c.setjmp - setjmp.d