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 183
14.23.2 Support for Fortran array slices
HP WDB prints Fortran array slices if you specify a range of elements by the Fortran
90 array section syntax. For instance, for an array X declared by REAL, DIMENSION(-
1:1, 2:10) :: X, you could print all five even-numbered elements of the row with the
first dimension equal to 0 by typing the WDB command print X(0,2:10:2).
14.23.3 Displaying enumerators
You can display the union of several enumeration elements by specifying a value if the
elements of the enumeration type are the powers of 2 and the given value is a sum of
any given combination of the enumeration elements.
For example, assume you have an enumerated type named color in the program, with
these elements: RED=0, ORANGE=1, YELLOW=2, GREEN=8, and BLUE=16. If you use the
command printf 3, the debugger displays ORANGE|YELLOW, the elements corresponding
to 1 and 2. If you print 5, you will get the value, 5, because it does not form the
sum of any combination in the set. However, if you wanted to print 25, you will get
Orange|Green|Blue.
Values that do not form the sum of any combination of the elements will be displayed
as integers while the values that form the sum of any combination of the elements will
be printed as unions.
14.23.4 Support for debugging typedefs
When you have a typedef class as a template parameter, you can set a breakpoint on
a member function by using the command:
break Class<typedef_classB>::memfunc
14.23.5 Support for steplast command for C and C++
Typically, if a function call has arguments that make further function calls, executing
a simple step command in GDB steps into the argument evaluation call. HP WDB
includes the steplast command, which helps to step into a function, and not into the
calls for evaluating the arguments. However, the steplast command is not available
on Integrity systems. The following example illustrates how GDB behaves when you
execute the steplast command:
(gdb) 16 foo (bar ()); ---> bar() will return 10 (gdb) steplast foo (x=10) at
foo.c:4 4 int k = 10;
If the steplast command is not meaningful for the current line, GDB displays the
following error message:
"Steplast is not meaningful for the current line."
For example,
(gdb) 4 int k = 10; (gdb) sl ---> alias to "steplast" command error: Steplast
is not meaningful for the current line