error 11 runtime NOW [SOLVED]

[bigbass]

this demo worked since 2013
basic-converter.proboards.com/post/12473



'--- typedef struct with pointer
the second example is the same but uses pointers
that is the example that fails in runtime
with

ERROR: signal for SEGMENTATION FAULT received - memory invalid or array out of bounds?
(program exited with code: 11)



11 says Could not resolve hostname

that doesn't give me a clue
it does nothing with the web

any help or workaround would be great


UPDATE I compiled it with debug

and got this

Program received signal SIGSEGV, Segmentation fault.
0x00014338 in main (argc=1, argv=0x7efff3a4) at fails.bac:31
31 stuff->release = (char*)result




I will abandon using struct
and use CLASS



Joe

[Pjot]

Hi bigbass,

If you use pointers in C code, then this means you point to memory where some data is stored. The code must have access to that memory though. This only is possible by allocating the memory.

Declaring a pointer does not automatically allocate memory.

Please refer to this page to see how it works.

So I just tested your demo with BaCon 3.9.3 and it crashes on me also. If you would run your demo in a previous BaCon on a previous platform using Valgrind, then you'll see the same error warnings about unallocated memory.

Sometimes Linux is merciful about memory and does not crash, but that is just a matter of luck...

HTH
Peter

[bigbass]

hello Peter

I appreciate you looking at this and your feedback
and taking the time to debug my example
and the link to the info



well, I guess I got lucky before without a crash ( I wont go that road again)
but luck is not something to bank on or continue
pushing your luck with.
crash and burn is no fun


in theory bacon can compile that and get a result
I see why some GUI tool kits moved to C++ for easy memory
management

and this isn't a fault of bacon
its just more complex I know I could use RECORD with _type also
I did a demo with that before

Joe

if forced to do something like this enclose it
or use RECORD in c style or CLASS in c++




PRAGMA COMPILER gcc
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith  -Wno-deprecated


OPTION PARSE FALSE




USEC
struct point {
  int x;
  int y;
};
struct point my_point = { 3, 7 };
struct point *p = &my_point;  /* p is a pointer to my_point */
//(*p).x = 8;                   /* set the first member of the struct */
p->x = 8;                     /* equivalent method to set the first member of the struct */  

printf("%d\n",p->x );

ENDUSEC



OUT PUT
8

[bigbass]

gave a compile error removed code

[alexfish]

Hi Joe

not sure if something emanating again from this forum , but have looked at the bits : no odd chars

anyway from latest fossil

I get this

Invalid preceding regular expression
Runtime error: function 'REGEX' at line 777 in 'bacon.bac': Illegal regex expression

BR
Alex

[bigbass]

Thanks Alex for testing
I am just going to remove the non USEC example
and let this one go for another time

I usually learn more when something goes wrong
so all is well
Joe

[alexfish]

Hi Joe

I had the same problem so yesterday looked a bit further
basic-converter.proboards.com/thread/1154/bacon-record-reference-pointers
may not be the best since valgrind shows a sligh memloss

no much at its base since it stays the same as per def , creating more makes no difference

that is the only solution at this moment in time ,
one thing there is you have to use the point by ref access at least in that way they appear to be secure

bit like using Gtk Widget, call func ((Widget *) widget)
I think says he.

BR
Alex

[alexfish]

Hi Joe

had a look at gobject methods As in reading further on the typedef struct

HERE

ADDED and found out something I was looking for in my own toolkit done with C++ and ended up with crashes

solved that by mutating & or define array of , to use , code for this does not look pretty, and will bomb at the first misshap

because C++ cannot really create object types at runtime.

BR
Alex

[bigbass]

here is much easier in c++ (baconized)

fighting with forcing the syntax is no fun
I just need it to work and follow some standard format




PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -fpermissive

OPTION PARSE FALSE

'---why c++ is much easier
'---The class does the declaring for you

CLASS point
public:
int x;
int y;

END CLASS


'---pointer to an object declaration (we use a class called point)
DECLARE ptr TYPE point*
'--- correct syntax for class in memory
ptr  = new point()


'--- initialize the x and y in c++
ptr->x = 3
ptr->y = 4


PRINT " x  = ",ptr->x FORMAT "%s%d\n"
PRINT " y  = ", ptr->y FORMAT "%s%d\n"






TERMINAL OUT
x = 3
y = 4

[bigbass]

Ok finally in just BaCon


with the c style Idea
I hope this is stable in memory


that should be enough for struct CLASS and RECORD
when using pointers



'---by bigbass 4-28-2020

RECORD point
LOCAL x TYPE int
LOCAL y TYPE int
END RECORD


'--- dont forget the "magic word" _type as a suffix
DECLARE my_point TYPE point_type

'---easier to do it like this
DECLARE p TYPE point_type*

p = &my_point

'---assign a value to the RECORD
'--- using a pointer to a member
p->x = 9                  

PRINT p->x FORMAT "%d\n"





TERMINAL OUTPUT
9



tested the memory


==6700== HEAP SUMMARY:
==6700== in use at exit: 24 bytes in 5 blocks
==6700== total heap usage: 6 allocs, 1 frees, 1,048 bytes allocated
==6700==
==6700== LEAK SUMMARY:
==6700== definitely lost: 0 bytes in 0 blocks
==6700== indirectly lost: 0 bytes in 0 blocks
==6700== possibly lost: 0 bytes in 0 blocks
==6700== still reachable: 24 bytes in 5 blocks
==6700== suppressed: 0 bytes in 0 blocks

[bigbass]

Well I am going to do a little luck pushing

if it works for you ok if not just forget it
and use RECORD that is the most secure way

(just for the sake of not giving up only )

It allocated memory in c for this one
so it does the same as in c++ but more work

and no USEC to be seen anywhere


PRAGMA INCLUDE <stdio.h>
PRAGMA INCLUDE <stdlib.h>
PRAGMA INCLUDE <string.h>
PRAGMA OPTIONS -Wno-int-conversion

'---use a struct with a pointer!
'---allocate pointer in memory


OPTION PARSE FALSE

struct stock { \
char symbol[5]; \
int quantity; \
float price; \
};
struct stock (*invest)
'--- Create structure in memory
invest=(struct stock * )malloc(sizeof(struct stock))

DECLARE stock TYPE struct

strcpy(invest->symbol,"IBM")
invest->quantity = 100
invest->price = 801.19


PRINT    invest->symbol FORMAT "%s\n"
PRINT invest->quantity FORMAT "%d\n"
PRINT invest->price FORMAT "%.2f\n"
PRINT invest->quantity*invest->price FORMAT "%.2f\n"



TERMINAL OUT
IBM
100
801.19
80119.00

[vovchik]

Dear Joe,

Thanks for that very clear and complete example...

With kind regards,
vovchik

[alexfish]

Hi Joe

looks good but here getting warning pointer without cast : so something simple not working
tried void , did not work ?

anyway it does free

PRAGMA INCLUDE <stdio.h>
PRAGMA INCLUDE <stdlib.h>
PRAGMA INCLUDE <string.h>
PRAGMA OPTIONS -Wno-int-conversion

'---use a struct with a pointer!
'---allocate pointer in memory


OPTION PARSE FALSE

struct stock { \
char symbol[5]; \
int quantity; \
float price; \
};
struct stock (*invest)
'--- Create structure in memory
invest=(struct stock * )malloc(sizeof(struct stock))

DECLARE stock TYPE struct

strcpy(invest->symbol,"IBM")
invest->quantity = 100
invest->price = 801.19


PRINT    invest->symbol FORMAT "%s\n"
PRINT invest->quantity FORMAT "%d\n"
PRINT invest->price FORMAT "%.2f\n"
PRINT invest->quantity*invest->price FORMAT "%.2f\n"

free(invest)
will look further in valgrind

valgrind first results

==15438== HEAP SUMMARY:
==15438==     in use at exit: 26 bytes in 5 blocks
==15438==   total heap usage: 6 allocs, 1 frees, 42 bytes allocated
==15438==
==15438== LEAK SUMMARY:
==15438==    definitely lost: 0 bytes in 0 blocks
==15438==    indirectly lost: 0 bytes in 0 blocks
==15438==      possibly lost: 0 bytes in 0 blocks
==15438==    still reachable: 26 bytes in 5 blocks
==15438==         suppressed: 0 bytes in 0 blocks
==15438== Rerun with --leak-check=full to see details of leaked memory
==15438==
==15438== For counts of detected and suppressed errors, rerun with: -v
==15438== Use --track-origins=yes to see where uninitialised values come from
==15438== ERROR SUMMARY: 6785 errors from 254 contexts (suppressed: 176 from 5)

added
re run --track-origins=yes

==15499== Conditional jump or move depends on uninitialised value(s)
==15499==    at 0x40178D8: calloc (dl-minimal.c:109)
==15499==    by 0x400BBB7: _dl_new_object (dl-object.c:75)
==15499==    by 0x4006067: _dl_map_object_from_fd (dl-load.c:1059)
==15499==    by 0x400939F: _dl_map_object (dl-load.c:2605)
==15499==    by 0x4000FD3: map_doit (rtld.c:719)
==15499==    by 0x401049F: _dl_catch_error (dl-error.c:187)
==15499==    by 0x4000F5B: do_preload (rtld.c:908)
==15499==    by 0x4001CA3: handle_ld_preload (rtld.c:1006)
==15499==    by 0x40039B3: dl_main (rtld.c:1750)
==15499==    by 0x401713B: _dl_sysdep_start (dl-sysdep.c:249)
==15499==    by 0x400137B: _dl_start_final (rtld.c:424)
==15499==    by 0x400160B: _dl_start (rtld.c:652)
==15499==  Uninitialised value was created by a stack allocation
==15499==    at 0x4001BE4: handle_ld_preload (rtld.c:983)


BR
Alex

[bigbass]

ok I removed the warning -Wno-int-conversion we don't need
to quiet the warning its better to fix what causes it when you can

and yes we need the free too thanks Alex for the push

this should do it cleanly now (I hope for everyone)

P.S thanks vovchik hope all is well with you
haven't heard from you for a few days

Joe

PRAGMA INCLUDE <stdio.h>
PRAGMA INCLUDE <stdlib.h>
PRAGMA INCLUDE <string.h>
'PRAGMA OPTIONS -Wno-int-conversion

'---use a struct with a pointer!
'---allocate pointer in memory


OPTION PARSE FALSE

struct stock { \
char symbol[5]; \
int quantity; \
float price; \
};

DECLARE stock TYPE struct
DECLARE invest TYPE struct stock*

struct stock *invest
'--- Create structure in memory
invest = (struct stock* )malloc(sizeof(struct stock))



strcpy(invest->symbol,"IBM")
invest->quantity = 100
invest->price = 801.19


PRINT    invest->symbol FORMAT "%s\n"
PRINT invest->quantity FORMAT "%d\n"
PRINT invest->price FORMAT "%.2f\n"
PRINT invest->quantity * invest->price FORMAT "%.2f\n"

free(invest)



[alexfish]

Brill

looks like systems go or start:

Forgot to mention if have more than 0, 1 of more try calloc and look at the resources

BR
Alex