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 157
• The thread terminates execution, and the resources associated with the terminated
thread continues to exist in the application because the thread has not been joined
or detached.
• The thread uses more than the specified percentage of the stack allocated to the
thread.
• The number of threads waiting on any pthread object exceeds the specified thresh-
old number.
14.11.3.1 Pre-requisites for Advanced Thread Debugging
The following pre-requisites apply for advanced thread debugging:
• The advanced thread debugging features are supported only on HP-UX 11i v2 and
later on both PA-RISC and Integrity systems.
• The tracing pthread library is required for advanced thread-debugging. The
pthread tracer library is available by default on systems running on HP-UX 11i
v2 or later. You must install HP WDB 5.5 or later versions of the debugger to
support enhanced thread debugging. The installation scripts for HP WDB 5.5 and
later versions of the debugger automatically add links at /opt/langtools/lib/
to replace the standard libpthread library with libpthread tracer library at
run time.
• The thread debugging feature in HP WDB is dependent on the availability of the
dynamic Linker Version B.11.19.
• HP WDB uses librtc.sl to enable thread debugging support. If the debugger
is installed in a directory other than the default /opt/langtools/bin directory,
you must use the environment variable, LIBRTC_SERVER, to export the path of the
appropriate version of librtc.sl.
• HP WDB does not support debugging of programs that link with the archive ver-
sion of the standard C library libc.a or the core library libcl.a. The programs
must be linked with libc.sl.
• The advanced thread debugging commands work only if set thread-check is set
to on.
• For PA-RISC 32-bit applications, the dynamic library path look-up must be en-
abled for advanced thread debugging. To enable dynamic library path look-up for
advanced thread debugging, enter the following command at HP-UX prompt:
# chatr +s enable <PA32-bitApp>
This command automatically enables dynamic library path look-up. No additional
environmental variables are required to be set.
14.11.3.2 Enabling and Disabling Advanced Thread Debugging
Features
HP WDB 5.6 and later versions of the debugger provide advanced thread debugging
features for debugging multi-threaded applications running on 11i v2, or 11i v3. These
features are available as options to the set thread-check command. The syntax for
the set thread-check command is as follows: