How to detect core dump by using dbx tool in solaris system . So i would like to share those tips. I hope this may help your debugging.
Advantages/Disadvantages of Using dbx with Core File; Debugging Techniques Using dbx's Help; Summary of dbx Commands. If there is a 'core' file, dbx will trace the variable in the procedure where your program terminated.
Starting dbx. Chapter 1 Starting dbxdbx is an interactive, source- level, command- line debugging tool. You can use it to run a program in a controlled manner and to inspect the state of a stopped program. The simplest way to start a dbx session is to type the dbx command at a shell prompt. To attach dbx to a running process in the Sun Work. Shop Debugging window, choose Debug Attach Process. For more information, see .
Next, dbx searches for the startup file . HOME. If the file is not found, it searches for the startup file .
Debugging a Program With dbx. Debugging Your Program With dbx. Examining a Core File. Chapter 17 Debugging a Java Application With dbx. Using dbx With Java Code. How to Debug Using GDB. We will take you step by step through the debugging process and trace the errors. The core dump generates a file called corewhich can be used for debugging. Chapter 5: Debugging Tutorials. You can also change them explicitly using the file and func com. Debugging a Core File Without the Serviceability Agent, Using JVM and the. C2 Compiled Method Names in a Java Core File Without the Serviceability Agent. A core file or core dump is a dump of the application state. On other systems, you may use a different debugger, such as dbx under Solaris. Problem with DBX debugger. The Problem I am facing is when I start my executable in debugger using dbx <executable name> command gdb prints 'reading symbolic. Core file program (dbx) does not match current.
HOME. Generally, the contents of . In the . dbxinit file, the alias command is defined as dalias and not the normal default, which is kalias, the alias command for the Korn shell. A different startup file may be specified explicitly using the - s command- line option. For more information, see Using the .
File and . A startup file may contain any dbx command, and commonly contains alias, dbxenv, pathmap, and Korn shell function definitions. However, certain commands require that a program has been loaded or a process has been attached to. All startup files are loaded before the program or process is loaded. The startup file may also source other files using the source or .(period) command. You can also use the startup file to set other dbx options. As dbx loads program information, it prints a series of messages, such as Reading filename. Once the program is finished loading, dbx is in a ready state, visiting the .
Typically, you set a breakpoint and then issue a run command, such as stop in main and run for a C program. Setting Startup Properties. You can use the pathmap, dbxenv, and alias commands to set startup properties for your dbx sessions. Mapping With the pathmap Command. By default, dbx looks in the directory in which the program was compiled for the source files associated with the program being debugged. If the source or object files are not there or the machine you are using does not use the same path name, you must inform dbx of their location.
If you move the source or object files, you can add their new location to the search path. The pathmap command creates a mapping from your current view of the file system to the name in the executable image. The mapping is applied to source paths and object file paths.
Add common pathmaps to your . To establish a new mapping from the directory from to the directory to, type. Use - c when you try to correct problems due to the automounter because current working directories are inaccurate on automounted file systems. The mapping of /tmp. You can place dbxenv commands in your . To list variables, type. You can also set dbx environment variables.
See Chapter 2 for more information about the . For more information, see Setting dbx Environment Variables With the dbxenv Command and . For more information, see . The values of stack variables cannot be printed or manipulated in optimized programs because the stack and register locations of these variables are not recorded.
The Analyzing a Program With Sun Work. Shop manual contains more information on compiler optimizations that might be helpful when using the Sun Workshop tools on an optimized program. Compiling a Program for Debugging. You must prepare your program for debugging with dbx by compiling it with the - g or - g. The - g option instructs the compiler to generate debugging information during compilation. For example, to compile using C++, type.
CC - g example. The - g. You cannot debug inline functions with the - g. The - g. 0 option can significantly decrease link time and dbx start- up time (depending on the use of inlined functions by the program). To compile optimized code for use with dbx, compile the source code with both the - O (uppercase letter O) and the - g options. Debugging Optimized Code.
The dbx tool provides partial debugging support for optimized code. The extent of the support depends largely upon how you compiled the program. When analyzing optimized code, you can: Stop execution at the start of any function (stopinfunction command)Evaluate, display, or modify arguments. Evaluate, display, or modify global or static variables. However, with optimized code, dbx cannot: Single- step from one line to another (next or step command)Evaluate, display, or modify local variables. When programs are compiled with optimization and debugging enabled at the same time (using the - O - g options), dbx operates in a restricted mode. Source line information is available, but the code for one source line might appear in several different places for an optimized program, so stepping through a program by source line results in the .
Type information about structs, unions, C++ classes, and the types and names of locals, globals, and parameters should be available. Complete information about the location of these items in the program is not available for optimized programs. Code Compiled Without the - g Option. While most debugging support requires that a program be compiled with - g, dbx still provides the following level of support for code compiled without - g: Backtrace (dbxwhere command)Calling a function (but without parameter checking)Checking global variables. Note, however, that dbx cannot display source code unless the code was compiled with the - g option.
This restriction also applies to code that has had strip - x applied to it. Shared Libraries Require the - g Option for Full dbx Support. For full support, a shared library must also be compiled with the - g option.
If you build a program with shared library modules that were not compiled with the - g option, you can still debug the program. However, full dbx support is not possible because the information was not generated for those library modules.
Completely Stripped Programs. The dbx tool can debug programs that have been completely stripped. These programs contain some information that can be used to debug your program, but only externally visible functions are available. Runtime checking cannot work on stripped programs or load objects. Quitting Debugging. A dbx session runs from the time you start dbx until you quit dbx; you can debug any number of programs in succession during a dbx session. To quit a dbx session, type quit at the dbx prompt.
However, kill preserves the dbx session itself leaving dbx ready to debug another program. Killing a program is a good way of eliminating the remains of a program you were debugging without exiting dbx.
To kill a program executing in dbx, type. For more information, see . This segment of a debugging session is called a debugging run. The save command saves more than the list of debugging commands issued.
It saves debugging information associated with the state of the program at the start of the run- -breakpoints, display lists, and the like. When you restore a saved run, dbx uses the information in the save- file. You can save part of a debugging run; that is, the whole run minus a specified number of commands from the last one entered.
Example A shows a complete saved run. Example B shows the same run saved, minus the last two steps. If you want to save a debugging run to a file you can restore later, you can specify a file name with the save command.
See Saving a Series of Debugging Runs as Checkpoints. To save an entire debugging run up to the save command, type. To save part of a debugging run, use the savenumber command, where number is the number of commands back from the save command that you do not want saved. Each time you save, dbx overwrites this save- file. However, by giving the save command a filename argument, you can save a debugging run to a file that you can restore later, even if you have saved other debugging runs since the one saved to filename. Saving a series of runs gives you a set of checkpoints, each one starting farther back in the session.
You can restore any one of these saved runs, continue, then reset dbx to the program location and state saved in an earlier run. To save a debugging run to a file other than the default save- file. Restoring a Saved Run. After saving a run, you can restore the run using the restore command.
When you restore a run, dbx first resets the internal state to what it was at the start of the run, then reissues each of the debugging commands in the saved run. Note – The source command also reissues a set of commands stored in a file, but it does not reset the state of dbx; it only reissues the list of commands from the current program location. Prerequisites for an Exact Restoration of a Saved Run. For exact restoration of a saved debugging run, all the inputs to the run must be exactly the same: arguments to a run- type command, manual inputs, and file inputs. Note – If you save a segment and then issue a run, rerun, or debug command before you do a restore, restore uses the arguments to the second, post- save run, rerun, or debug command. If those arguments are different, you might not get an exact restoration. To restore a saved debugging run, type.
To restore a debugging run saved to a file other than the default save- file, type. Saving and Restoring Using replay. The replay command is a combination command, equivalent to issuing a save - 1 followed immediately by a restore. The replay command takes a negative number. By default, the value of - number is - 1, so replay works as an undo command, restoring the last run up until, but not including, the last command issued.
To replay the current debugging run, minus the last debugging command issued, type. To replay the current debugging run and stop the run before a specific command, use the dbxreplay command, where number is the number of commands back from the last debugging command.