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
180 Debugging with GDB
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14.21.6 Support for __fpreg data type on IPF
WDB internally converts __fpreg data type to long double data type to evaluate an
expression or to print the value of the expression. Since long double data type has only
15 bit exponent as opposed to 17 bit exponent of __fpreg, some precision is lost when
the exponent is larger than that can fit in 15 bits.
14.21.7 Support for Complex variables in HP C
HP C on Itanium systems supports a _Complex data type built from any of the floating
point types.
A _Complex number holds a pair of floating point numbers; the first is the "real part"
and the second is the " imaginary part".
Here are examples of declarations and initializations using _Complex numbers:
float _Complex glob_float_complex;
double _Complex glob_double_complex = 6;
long double _Complex glob_long_double_complex = _Imaginary_I;
__float80 _Complex glob_float80_complex = 8 + 9 * _Imaginary_I;
_Imaginary_I is a keyword which represents the square root of -1.
The debugger has limited support for _Complex variables. No arithmetic operations
are allowed with _Complex numbers. A _Complex number may be cast or assigned to
any numeric data type and vice versa.
A _Complex variable can be initialized with an expression of the form:
A + B * _Imaginary_I
Where A and B are ordinary numeric expressions, perhaps in parentheses.
This is also the format in which the debugger displays a Complex value.
Imaginary values cannot be assigned to variables because there is no imaginary data
type. You can take a normal number and multiply it by an imaginary number and get
another imaginary number. You can take a normal number and add it to an imaginary
number to get a complex number.
Complex numbers cannot be used in arithmetic expressions in the debugger.
For more information of _Complex type, refer to the HP C/ANSI C documentation.
14.21.8 Support for debugging namespaces
This release of HP WDB provides full support for debugging namespaces.
You do not need to use fully qualified names to access symbols within a namespace.
The debugger can compile a list of namespaces active in the scope that you are in and,
when possible, choose an appropriate symbol.