Debugging with GDB (February 2008)
Table Of Contents
- Summary of GDB
- A Sample GDB Session
- Getting In and Out of GDB
- GDB Commands
- Running Programs Under GDB
- Stopping and Continuing
- Examining the Stack
- Examining Source Files
- Examining Data
- Using GDB with Different Languages
- Examining the Symbol Table
- Altering Execution
- GDB Files
- Specifying a Debugging Target
- HP-UX Configuration-Specific Information
- Summary of HP Enhancements to GDB
- HP-UX dependencies
- Supported Platforms and Modes
- HP-UX targets
- Support for Alternate root
- Specifying object file directories
- Fix and continue debugging
- Inline Support
- Debugging Macros
- Debugging Memory Problems
- When to suspect a memory leak
- Memory debugging restrictions
- Memory Debugging Methodologies
- Debugging Memory in Interactive Mode
- Debugging Memory in Batch Mode
- Debugging Memory Interactively After Attaching to a Running Process
- Configuring memory debugging settings
- Scenarios in memory debugging
- Stop when freeing unallocated or deallocated blocks
- Stop when freeing a block if bad writes occurred outside block boundary
- Stop when a specified block address is allocated or deallocated
- Scramble previous memory contents at malloc/free calls
- Detect dangling pointers and dangling blocks
- Detect in-block corruption of freed blocks
- Specify the amount of guard bytes for every block of allocated memory
- Comparison of Memory Debugging Commands in Interactive Mode and Batch Mode
- Heap Profiling
- Memory Checking Analysis for User Defined Memory Management Routines
- Commands to track the change in data segment value
- Thread Debugging Support
- Debugging MPI Programs
- Debugging multiple processes ( programs with fork and vfork calls)
- Debugging Core Files
- Printing the Execution Path Entries for the Current Frame or Thread
- Invoking GDB Before a Program Aborts
- Aborting a Command Line Call
- Instruction Level Stepping
- Enhanced support for watchpoints and breakpoints
- Debugging support for shared libraries
- Language support
- Enhanced Java Debugging Support
- Commands for Examining Java Virtual Machine(JVM) internals
- Support for stack traces in Java, C, and C++ programs
- Support for 64-bit Java, C, aC++ stack unwinding
- Enhanced support for C++ templates
- Support for __fpreg data type on IPF
- Support for _Complex variables in HP C
- Support for debugging namespaces
- Command for evaluating the address of an expression
- Viewing Wide Character Strings
- Support for output logging
- Getting information from a non-debug executable
- Debugging optimized code
- Visual Interface for WDB
- Starting and stopping Visual Interface for WDB
- Navigating the Visual Interface for WDB display
- Specifying foreground and background colors
- Using the X-window graphical interface
- Using the TUI mode
- Changing the size of the source or debugger pane
- Using commands to browse through source files
- Loading source files
- Editing source files
- Editing the command line and command-line history
- Saving the contents of a debugging session to a file
- Support for ddd
- Support for XDB commands
- GNU GDB Logging Commands
- Support for command line calls in a stripped executable
- Displaying the current block scope information
- Linux support
- The HP-UX Terminal User Interface
- XDB to WDB Transition Guide
- By-function lists of XDB commands and HP WDB equivalents
- Overall breakpoint commands
- XDB data formats and HP WDB equivalents
- XDB location syntax and HP WDB equivalents
- XDB special language operators and HP WDB equivalents
- XDB special variables and HP WDB equivalents
- XDB variable identifiers and HP WDB equivalents
- Alphabetical lists of XDB commands and HP WDB equivalents
- Controlling GDB
- Canned Sequences of Commands
- Using GDB under gnu Emacs
- GDB Annotations
- The gdb/mi Interface
- Function and purpose
- Notation and terminology
- gdb/mi Command Syntax
- gdb/mi compatibility with CLI
- gdb/mi output records
- gdb/mi command description format
- gdb/mi breakpoint table commands
- gdb/mi Data manipulation
- gdb/mi program control
- Miscellaneous GDB commands in gdb/mi
- gdb/mi Stack Manipulation Commands
- gdb/mi Symbol query commands
- gdb/mi Target Manipulation Commands
- gdb/mi thread commands
- gdb/mi tracepoint commands
- gdb/mi variable objects
- Reporting Bugs in GDB
- Installing GDB
- Index
Chapter 14: HP-UX Configuration-Specific Information 181
The debugger recognizes using declarations, using directives, namespace aliases, nested
namespaces, and unqualified lookup within a namespace. It also recognizes using di-
rectives and aliases, and using declarations within namespaces.
When the debugger has a list of possible resolutions for a given symbol, it displays a
menu that shows all names fully qualified whenever namespaces are involved. You can
choose the appropriate symbol from the list.
For example, if you stop the debugger in a function that contains an int i using
directive for a namespace such as:
using namespace A::AB::ABC::ABCD
You can use the command print i and if the only possible resolution for i is
A::AB::ABC::ABCD::i the debugger prints out the name of the symbol and its value.
If, however, a global i exists, the debugger displays a menu from which to choose:
(1) i
(2) A::AB::ABC::ABCD::i
>
Setting breakpoints on functions works in the same way.
The debugger also allows semi-qualified names. For example, if you stop in a function
in namespace B, which is nested in namespace A, and namespace A has an int i, you
can use print B::i to display the value of A::B::i.
To disable namespace support, use the command:
(gdb) set namespaces-enabled off
14.21.9 Command for evaluating the address of an expression
The watch_target command takes an expression as an argument, evaluates it to an
address, and watches the target of that address.
For example:
(gdb) watch_target current_frame
This is equivalent to executing:
(gdb) print current_frame $1 = (struct frame_info *) 0x7fdf78 (gdb) watch
*(struct frame_info *) 0x7fdf78
14.22 Viewing Wide Character Strings
HP WDB print command can print wide characters and wide-character strings of the
type wchar_t. The user must use the /W option of the print command to print wide
characters and wide-character strings.
print /W <wide-char-symbol-name>
14.23 Support for output logging
The Visual Interface for HP WDB terminal user interface (TUI) mode supports the
command, log logfile_name, that saves the content of a session to the specified log
file.