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
142 Debugging with GDB
14.10.5.2 Environment variable setting for Batch mode debugging
Batch mode memory leak detection uses the following environment variables:
• GDBRTC_CONFIG species the location of rtc configuration file. If this option is not
specified, the configuration file is assumed to be in the current location, and has the
filename rtcconfig. If user prefers to set this option, it must include the filename.
• Incorrect usage:
export GDBRTC_CONFIG=./
export GDBRTC_CONFIG=/tmp
• Correct usage:
export GDBRTC_CONFIG=/tmp/yet_another_config
export GDBRTC_CONFIG=/tmp/rtcconfig
• BATCH_RTC enables or disables batch memory leak detection.
• GDB_SERVER is used to override the default path from where the gdb executable is used
to provide the information on memory leak. By default, /opt/langtools/bin/gdb is
used to print the output. This can be overriden by setting GDB_SERVER appropriately.
• RTC_MALLOC_CONFIG is used to override the default config and rtcconfig file settings.
This variable can be set as follows:
export RTC_MALLOC_CONFIG=config_string1[;config_strings].
• The config_strings are separated by ;.
• The following config strings options exist for RTC_MALLOC_CONFIG:
abort_on_bounds=[01]
Aborts execution when heap objects bounds check fail, value is 1,
and the environment variable RTC_NO_ABORT is not set.
abort_on_bad_free=[01]
Aborts execution when free or realloc is trying to free a heap
object which is not valid, value is 1, and environment variable
RTC_NO_ABORT is not set.
abort_on_nomem=[01]
Aborts execution when out of memory if value is 1, and environ-
ment variable RTC_NO_ABORT is not set.
leak_logfile=stderr[+]filename
The log file for batch mode must be specified.
stderr: error message goes to stderr
[+]filename: error message goes to filename, + means output is
appended to the file.
mem_logfile=stderr[+]filename
heap_logfile=stderr[+]filename
• Specify config_strings for +check=malloc on Itanium or WDB memory
check batch mode on Integrity systems.