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
282 Debugging with GDB
^running
(gdb)
*stopped,reason="watchpoint-trigger",wpt=number="2",exp="i",value=old="0",new="7"
,thread-id="1",frame=addr="0x000029c4",func="main",args=[],file="hello.c",line="8"
(gdb)
Setting a watchpoint on a variable local to a function. GDB will stop the program
execution twice: first for the variable changing value, then for the watchpoint going out of
scope.
(gdb)
-break-watch j
^done,wpt=number="2",exp="j"
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-trigger",wpt=number="2",exp="j",value=old="0",new="17",
thread-id="1",frame=addr="0x000029bc",func="call",args=[],file="hello.c",line="10"
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-scope",wpnum="2",thread-id="1",frame=addr="0x000029ec",
func="main",args=[],file="hello.c",line="18"
(gdb)
Listing breakpoints and watchpoints, at different points in the program execution. Note
that once the watchpoint goes out of scope, it is deleted.
-break-watch j
^done,wpt=number="2",exp="j"
(gdb)
-break-list
^done,BreakpointTable=nr_rows="2",nr_cols="6",hdr=[width="3",
alignment="-1",col_name="number",colhdr="Num",width="14",alignment="-1",
col_name="type",colhdr"Type",width="4",alignment="-1",col_name="disp",
colhdr="Disp",width="3",alinment="-1",col_name="enabled",colhdr="Enb",
width="10",alignment="-1",col_name"addr",colhdr="Address",
width="40",alignment="2",col_name="what",colhdr="What],body=[bkpt=number="1",
type="breakpoint",disp="keep",enabled="y",addr="0x00029b4",func="call",
file="hello.c",line="9",times="1",bkpt=number="2",type="wathpoint",disp="keep",
enabled="y",addr="",what="j",times="0"]
(gdb)
-exec-continue
^running
(gdb)
*stopped,reason="watchpoint-trigger",wpt=number="2",exp="j",value=old="0",ne="17",
thread-id="1",frame=addr="0x000029bc",func="call",args=[],file="hello.c,line="10"
(gdb)
-break-list
^done,BreakpointTable=nr_rows="2",nr_cols="6",hdr=[width="3",alignment="-1",
col_name="number",colhdr="Num",width="14",alignment="-1",col_name="type",colhdr"Type",
width="4",alignment="-1",col_name="disp",colhdr="Disp",width="3",alinment="-1",
col_name="enabled",colhdr="Enb",width="10",alignment="-1",col_name"addr",colhdr="Address",
width="40",alignment="2",col_name="what",colhdr="What],body=[bkpt=number="1",
type="breakpoint",disp="keep",enabled="y",addr="0x00029b4",func="call",file="hello.c",
line="9",times="1",bkpt=number="2",type="wathpoint",disp="keep",enabled="y",addr="",
what="j",times="1"]
(gdb)