i have trouble with vsc.
#include<stdio.h>
int main ()
{
int a;
printf("Hello World ");
scanf("%d", &a)
printf("%d", a);
return 0;
}
this is my code. & This is Debug Console.
This GDB was configured as "mingw32".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Warning: Debuggee TargetArchitecture not detected, assuming x86_64.
=cmd-param-changed,param="pagination",value="off"
=cmd-param-changed,param="args",value="2>CON 1>CON <CON"
[New Thread 13300.0x59d4]
[New Thread 13300.0x367c]
Loaded 'C:\Windows\SysWOW64\kernel32.dll'. Symbols loaded.
Loaded 'C:\Windows\SysWOW64\KernelBase.dll'. Symbols loaded.
Loaded 'C:\Windows\SysWOW64\msvcrt.dll'. Symbols loaded
When i try to run, it does not start.
I already installed coderunner.
Please help thx.
What exactly do you mean by running it? Your code looks ok, so I'm guessing you are just doing something wrong when you try to run it.
Firstly, you need to compile your code, and then you can run the program that is created after compilation.
The simplest way to compile both c and c++ is to use console and gcc. Try entering this command in the terminal:
gcc -Wall -fsanitize=address,undefined -o yourprogram yourprogram.c
This should create yourprogram file in the directory you are in. To run it, pass this command in the console:
./yourprogram
Related
For example, if we do
mkdir a
mkdir a/b
mkdir a/b/c
mkdir a/b/c/d
ln /bin/ls -s a/b/c/d/myls
ln a -s as
gdb as/b/c/d/myls
...
(gdb) r
Starting program: <mypath>/a/b/c/d/myls
^D
lldb as/b/c/d/myls
(lldb) r
Process 56636 launched: '<mypath>/as/b/c/d/myls' (x86_64)
We can see that gdb debugs on the canonical program, while lldb debugs on the linked program. How can we make gdb debug the linked program w/o getting its absolute path?
We can see that gdb debugs on the canonical program, while lldb debugs on the linked program.
No, we don't see this. We see that GDB performs a realpath to resolve the program, and lldb doesn't, but they both debug the exact same program.
Maybe you can use hard links instead?
This way, gdb will always refer to what you are looking for.
You can also play with with different version of gdb. It seems that version 7.11 provides what you want.
Take a look here:
~/tmp/link] stat hello
File: ‘hello’ -> ‘../hello’
This is what you get for version 7.12
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./link/hello...(no debugging symbols found)...done.
while for older gdb, you get
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from full_path/tmp/hello...(no debugging symbols found)...done.
So, play around with more recent release.
I'm currently running a file manager program that abruptly crashed with a segmentation fault and dumped a core file. So I used gdb to debug the core file as:
gdb /path/to/executable /path/to/core
The program which I was running is written in C++. When I ran GDB and tried to print the source lines using "list", I got the following error:
(gdb) bt
#0 0x0000000000554286 in
MyFSEventManager::AddEvent(wxFileSystemWatcherEvent&) ()
#1 0x00000000005ab2e8 in
MyGenericDirCtrl::OnFileWatcherEvent(wxFileSystemWatcherEvent&) ()
(gdb) f 0
#0 0x0000000000554286 in
MyFSEventManager::AddEvent(wxFileSystemWatcherEvent&) ()
(gdb) l
1 /build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c: No such file or directory.
Why does gdb say this "/build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c: No such file or directory." I do not hit this issue with some other programs that I've debugged using gdb.
The operating system used is Ubuntu 16.04 running on Oracle virtual box. I think may be the gdb symbols were not loaded. I'm not sure why since I compiled the program using the "-g" option. I really need to know the source lines where the code crashes via gdb.
Any suggestions?
EDIT: changes after suggestions from Employed Russian
I was compiling my main using "-g" option and linking it to "existing" object files which were obviously not compiled using "-g" so when the core dumped, I could not see the source for these files. So I went ahead and recompiled those files with "-g" option and reproduced the core dump. It's able to show me the source lines now.
Why does gdb say this "/build/glib2.0-prJhLS/glib2.0-2.48.2/./glib/gmain.c: No such file or directory."
Because you really don't have that file on your system.
I think may be the gdb symbols were not loaded
GDB did load debug symbols for glib, but not for your main executable.
I'm not sure why since I compiled the program using the "-g" option.
Since we don't have your compile and link lines, we can't tell exactly what's wrong, but some of the common issues are:
You have a "stray" -s or -Wl,-s on your link line (this strips debug info from the resulting binary).
You have -g when compiling your main.c, but not when compiling the source in which MyFSEventManager::AddEvent() is defined
P.S.
(gdb) bt
This doesn't seem to be the complete output from bt command. Always try to paste complete outputs as it makes helping easier :)
Before explaining my problem:
My OS is Ubuntu 12.04 LTS 32bits with 4GB RAM.
My IDE is Code::Blocks 12.11(I've had the same problem with 10.05)
I'm using the GNU GCC Compiler with the -g flag and the -std=c++0x flag.
When trying to debug this program:
using namespace std;
#include<iostream>
int main(){
int n=10;
for(int i=1;i<=n;i++){
int ax=i;
while(ax) ax--;
cout<<i;
}
return 0;
}
I can't get anything to happen,if I try the "Run to cursor" command or if I try to use breakpoints. They just get skipped and my program finishes running.
This is what I get in the debugger log:
Building to ensure sources are up-to-date
Selecting target:
Release
Adding source dir: /home/classius/CodeBlocks/Dr/
Adding source dir: /home/classius/CodeBlocks/Dr/
Adding file: /home/classius/CodeBlocks/Dr/bin/Release/Dr
Changing directory to: /home/classius/CodeBlocks/Dr/.
Set variable: LD_LIBRARY_PATH=.:
Starting debugger: /usr/bin/gdb -nx -fullname -quiet -args /home/classius/CodeBlocks/Dr/bin/Release/Dr
done
Registered new type: wxString
Registered new type: STL String
Registered new type: STL Vector
Setting breakpoints
Reading symbols from /home/classius/CodeBlocks/Dr/bin/Release/Dr...(no debugging symbols found)...done.
Debugger name and version: GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
No symbol table is loaded. Use the "file" command.
Temporary breakpoint 2 ("/home/classius/CodeBlocks/Dr/main.cpp:10) pending.
[Inferior 1 (process 13381) exited normally]
Debugger finished with status 0
If anyone wants to suggest a solution that implies using the terminal, please do it in the most noob-orieted terms you can find!
PS: How to add breaklines on stack-overflow when asking a question?(Solved-Thanks!)
Reading symbols from /home/classius/CodeBlocks/Dr/bin/Release/Dr...(no
debugging symbols found)...done.
This means you didn't have the -g option during compilation.
UPDATE:
file /home/classius/CodeBlocks/Dr/bin/Release/Dr
/home/classius/CodeBlocks/Dr/bin/Release/Dr: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0x7da8c5cff4af5082d82eecc3ede59a5920b253a0, stripped
So it's 'stripped', which means -g option was not really used. You may recheck your compiler config or try to build the Debug version?
in settings menu choose debugger then gdb-cdb tab and then reset default
I have a file called test. Even after compiling it with -g, when I run it in gdb, it says no debugging symbols found. I have also tried using -ggdb but it too was off no use. Please help.
Output for : gdb test
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/test...(no debugging symbols found)...done.
The issue is that you are attempting to debug the wrong program.
Your program is called test and yet you are debugging /usr/bin/test (a system program that will almost certainly be shipped without symbols; even if it did contain symbols, they wouldn't relate to your source code).
gdb will search $PATH to find the executable. From here:
exec-file [ filename ] Specify that the program to be run (but not the
symbol table) is found in filename. gdb searches the environment
variable PATH if necessary to locate your program. Omitting filename
means to discard information on the executable file.
Try using the command:
$ gdb ./test
Remove a.out and then try again. It worked for me as I was also getting the same error.
rm a.out
gcc -g your_code.c
Check that the executable is not stripped, you can see that with file /usr/bin/test
I've configure all CONFIG_DEBUG_ related options to y,but when I try to debug the kernel,it says no debug symbols found:
gdb /usr/src/linux-2.6.32.9/vmlinux /proc/kcore
Reading symbols from /usr/src/linux-2.6.32.9/vmlinux...(no debugging symbols found)...done.
Why?
Here is my best guess so far: I don't know, and it doesn't matter.
I don't know why GDB is printing the message "(no debugging symbols found)". I've actually seen this when building my own kernels. I configure a kernel to use debug symbols, but GDB still prints this message when it looks at the kernel image. I never bothered to look into it, because my image can still be debugged fine. Despite the message, GDB can still disassemble functions, add breakpoints, look up symbols, and single-step through functions. I never noticed a lack of debugging functionality. I'm guessing that the same thing is happening to you.
Edit: Based on the your comments to the question, it looks like you were searching for the wrong symbol with your debugger. System call handlers start with a prefix of sys_, but you can't tell from looking at the code. The macro SYSCALL_DEFINE4(ptrace, ...) just ends up declaring the function as asmlinkage long sys_ptrace(...), although it does some other crazy stuff if you have ftrace enabled.
make menuconfig->kernel hacking->[]Kernel debugging->[]Compile the kernel with debug info(CONFIG_DEBUG_INFO)
It's also possible when you package your vmlinuz image, the debug symbols were stripped (when using make-kpkg to build deb package for linux kernel). So you have to use the built vmlinux file under your linux source tree to have those debug symbols.
Add -g to the CFLAGS variable in the kernel Makefile
I might be wrong, but I thought you would have to install the debuginfo package for your kernel to get symbols