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
106 Debugging with GDB
info share
info sharedlibrary
Print the names of the shared libraries which are currently loaded.
sharedlibrary regex
share regex
Load shared object library symbols for files matching a Unix regular expression.
As with files loaded automatically, it only loads shared libraries required by your
program for a core file or after typing run. If regex is omitted all shared libraries
required by your program are loaded.
On HP-UX systems, GDB detects the loading of a shared library and automatically
reads in symbols from the newly loaded library, up to a threshold that is initially set but
that you can modify if you wish.
Beyond that threshold, symbols from shared libraries must be explicitly loaded. To load
these symbols, use the command sharedlibrary filename . The base address of the shared
library is determined automatically by GDB and need not be specified.
To display or set the threshold, use the commands:
set auto-solib-add threshold
Set the autoloading size threshold, in megabytes. If threshold is nonzero, sym-
bols from all shared object libraries will be loaded automatically when the
inferior begins execution or when the dynamic linker informs GDB that a new
library has been loaded, until the symbol table of the program and libraries
exceeds this threshold. Otherwise, symbols must be loaded manually, using the
sharedlibrary command. The default threshold is 100 megabytes.
show auto-solib-add
Display the current autoloading size threshold, in megabytes.
12.2 Specifying shared library locations
On HP-UX, when the shared libraries your program uses are in a different directory than
the path specified in the source or object files, specify the correct files to use with one of
two environment variables.
‘GDB_SHLIB_PATH’
Set this variable to a colon-separated list of directory path names where the
desired shared libraries reside. GDB searches specified list of directories for
shared libraries before searching the default system directories.
‘GDB_SHLIB_ROOT’
Set this variable to point to the root of the library in which the desired libraries
reside.
Note: If you set both the ‘GDB_SHLIB_PATH’ and ‘GDB_SHLIB_ROOT’ environment
variables, the ‘GDB_SHLIB_PATH’ behavior overrides ‘GDB_SHLIB_ROOT’.
These environment variables are useful when you are analyzing core files on a system
other than the one that produced the core file.