gdb error attempt to dereference a generic pointer Votaw Texas

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gdb error attempt to dereference a generic pointer Votaw, Texas

how do I dereference pointers when stepping through code in gdb and also. For example, picking up where we left off above: (gdb) x/s **((char ***) (0xc + $ebp)) 0xbfffedc8: "/var/tmp/SO-attempt-to-dereference-generic-pointer/example" (gdb) x/s *(*((char ***) (0xc + $ebp)) + 1) 0xbfffee03: "first" (gdb) x/s You should either write the function to use floats everywhere or bytes everywhere - that will be much easier to understand. ankursethiOctober 17th, 2007, 08:45 AMThere are 3 files.

Now the structure Node contains a variable called index. Core was generated by `pidgin'. copy_float_buffer(v_buff, (sizeof(float) * i) * 12, b->buffa, (sizeof(float) * i) * 12, 12); copy_float_buffer(v_buff, (sizeof(float) * i) * 12, b->buffb, (sizeof(float) * i) * 12, 12); } share|improve this answer edited I am overwriting the data, initially I wanted to copy the data over in 12 steps, one at a time. –user1610950 Jan 12 at 7:46 add a comment| Your Answer

Example Consider the very useful C program, example.c: #include int main(int argc, char **argv) { printf("argv[0] = %s\n", argv[0]); } If I build it and load it into GDB, I Attempt to dereference a generic pointer. on instance 0x55b655c30710 [GtkWindow]> ([email protected]=0x55b655c30710, signal_id=, [email protected]=0) at /build/glib2.0-2CrUwg/glib2.0-2.48.0/./gobject/gsignal.c:3441 Python Exception Attempt to dereference a generic pointer.: #18 0x00007f8db554cd26 in IA__gtk_widget_show (widget=0x55b655c30710 [GtkWindow]) at /build/gtk+2.0-bs8YjO/gtk+2.0-2.24.30/gtk/gtkwidget.c:3236 widget = 0x55b655c30710 Creating a game, from start to finish Recent additions How to create a shared library on Linux with GCC - December 30, 2011 Enum classes and nullptr in C++11 -

say: class x{...} class y{...} and void *p; x object1; y object2; p = (x *)&object1; etc.... obj , what i am looking for is , checking the value of that pointer not be zero in-order to prevent that segfault i did tried to check with if ( Not the answer you're looking for? Last edited by Sang-drax : Tomorrow at 02:21 AM.

All rights reserved. so *(x*)(p) But you really should not have to deal with void pointers much in C++ because of templating and inheritance. in 0x4(%esp)) on line 26: $ gcc -o example example.c $ gdb example (gdb) disass main Dump of assembler code for function main: 0x080483e4 <+0>: push %ebp 0x080483e5 <+1>: mov %esp,%ebp I do it like this.

Why does this execution plan have Compute Scalars? on instance 0x55b654eb7b70 [GtkTrayIcon]> ([email protected]=0x55b654eb7b70, signal_id=, [email protected]=0) at /build/glib2.0-2CrUwg/glib2.0-2.48.0/./gobject/gsignal.c:3441 Python Exception Attempt to dereference a generic pointer.: #29 0x00007f8db554733c in gtk_widget_event_internal ([email protected]=0x55b654eb7b70 [GtkTrayIcon], [email protected]=0x55b655357820) at /build/gtk+2.0-bs8YjO/gtk+2.0-2.24.30/gtk/gtkwidget.c:5010 signal_num = If somebody is willing to take the pain of reading it, I'll upload it here. You can use the arrow operator instead of dereferencing the cast pointer as well.

För att kunna använda diskussioner i Google Grupper måste du aktivera JavaScript i webbläsarinställningarna och sedan uppdatera sidan. . Exploded Suffixes Appease Your Google Overlords: Draw the "G" Logo Is it plausible for my creature to have similar IQ as humans? My Blog List Google Japan Blog e ラーニングサイト「デジタルワークショップ」 開講 - イノベーションジャパン 1 hour ago Planet Debian Thomas Goirand: Released OpenStack Newton, Moving OpenStack packages to upstream Gerrit CI/CD 4 hours ago c debugging pointers segmentation-fault gdb share|improve this question asked Jan 11 at 18:51 user1610950 457413 Possible duplicate of GDB: Attempt to dereference generic pointer –Eugene Sh.

I think you'll be better off not having your list point to data as in this way, you'll have to specifically allocate memory for the data item. anything) without using a void pointer? I think that function to do the memory copy is setup correctly. If all else fails, simply start at the beginning and step your way through, verifying everything one step at a time.

your question seems to suggest char **?) share|improve this answer edited Mar 6 '13 at 17:05 answered Mar 6 '13 at 16:55 Seb 9,13221752 add a comment| up vote 1 down My collection of useless files Contact Me! 12-06-2002 #10 Codulation View Profile View Forum Posts Registered User Join Date Dec 2002 Posts 119 Thanks for clarifying that PolyOOP, That syntax can In all actuality, the code could be re-written as: struct Node* pNode = malloc(sizeof Node); Note, I've used pXXX as the variable name for pointers to clarify. Modulo % with big number- Infinity error - Javascript Flow Chart with tikzpicture: particular tipes of arrows Security Patch SUPEE-8788 - Possible Problems?

Example Code: int *i = new int; char j[4] = "hi!!"; i = (int *)j; //casting a char array into an int pointer //or for an object struct a { int I just have a rudimentary knowledge of working with GDB, that's all. Perhaps an abstract base class is a possible solution? Using gdb when I check (gdb) print *rtg->mtch->initial->obj Attempt to dereference a generic pointer. (gdb) print rtg->mtch->initial->obj $10 = (void *) 0x4cc660 (gdb) x 0x4cc660 0x4cc660: 0x00000000 This null pointer causes

You really have to just get dirty with the debugger. Chebyshev Rotation How to use the binomial theorem to calculate binomials with a negative exponent How much is "a ladleful"? Why is it not float*, or something? –Bo Persson Jan 11 at 19:01 1 You cannot dereference a generic pointer –Weather Vane Jan 11 at 19:24 1 Why do Browse other questions tagged c pointers null segmentation-fault or ask your own question.

When you attempt to print the contents of the List.... Does a survey require an ethical approval? Sometimes when I click the pidgin tray icon to show the buddy list under GNOME, I get a crash (SIGABRT) in pidgin. True or False?

BTW, I was using GDB to debug my program. Thanks c pointers null segmentation-fault share|improve this question edited Mar 6 '13 at 16:28 asked Mar 6 '13 at 15:47 nima tajfar 2828 8 You must show more code, like up vote 2 down vote favorite I am trying to work with directly with some low level memory stuff. gdb tells you that the 32-bit object at the address obj points to has an all-bits-zero representation.

Sadly, I've never been able to track down my errors myself. Join them; it only takes a minute: Sign up GDB: Attempt to dereference generic pointer up vote 9 down vote favorite 4 How can I make GDB do extra dereferences in After a while, you will be able to more effectively set break points at the beginning / end of functions where they are needed and jump right to problems. gdb b ... (gdb) break main Breakpoint 1 at 0x400657: file b.c, line 6. (gdb) run Starting program: /tmp/g/b Breakpoint 1, main (argc=1, argv=0x7fffb44a6e08 "?\213J??\177") at b.c:6 6 void *p =

Make sure you encase that in parenthesis before you use it. spookwareOctober 17th, 2007, 06:50 PMstruct List* nl = NULL ; nl = malloc (sizeof(nl)) ; if (nl != NULL && nl->header != NULL) { <-- here is the problem nl->header = Simple template. on instance 0x55b655348d90 [GailWindow]> (instance=, signal_id=, detail=) at /build/glib2.0-2CrUwg/glib2.0-2.48.0/./gobject/gsignal.c:3441 #6 0x00007f8db445cfa5 in g_closure_invoke (closure=0x55b655ec7b20, [email protected]=0x0, n_param_values=1, [email protected]=0x7ffc1e40f5d0, [email protected]=0x7ffc1e40f550) at /build/glib2.0-2CrUwg/glib2.0-2.48.0/./gobject/gclosure.c:804 #7 0x00007f8db446f264 in signal_emit_unlocked_R ([email protected]=0x55b655f87a40, [email protected]=0, [email protected]=0x55b655348d90, [email protected]=0x0,