debug with GDB 2010版

This file documents the gnu debugger gdb.

This is the Ninth Edition, of Debugging with gdb: the gnu Source-Level Debugger for gdb (GDB) Version

7.3.50.20110513.

Copyright © 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,

2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free

Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the

Invariant Sections being “Free Software” and “Free Software Needs Free Documentation”, with the

Front-Cover Texts being “A GNU Manual,” and with the Back-Cover Texts as in (a) below.

Copyright (C) 1988-2010 Free Software Foundation, Inc.

This edition of the GDB manual is dedicated to the memory of Fred Fish. Fred was a long-standing

contributor to GDB and to Free software in general. We will miss him.

Summary: Summary of gdb•

Sample Session: A sample gdb session•

Invocation: Getting in and out of gdb•

Commands: gdb commands•

Running: Running programs under gdb•

Stopping: Stopping and continuing•

Reverse Execution: Running programs backward•

Tracepoints: Debugging remote targets non-intrusively•

Overlays: Debugging programs that use overlays•

Languages: Using gdb with different languages•

Symbols: Examining the symbol table•

Altering: Altering execution•

GDB Files: gdb files•

Targets: Specifying a debugging target•

Remote Debugging: Debugging remote programs•

Debugging with GDB

Debugging with gdb 1

Configurations: Configuration-specific information•

Extending GDB: Extending gdb•

Interpreters: Command Interpreters•

Emacs: Using gdb under gnu Emacs•

GDB/MI: gdb's Machine Interface.•

JIT Interface: Using the JIT debugging interface.•

GDB Bugs: Reporting bugs in gdb•

Command Line Editing: Command Line Editing•

Using History Interactively: Using History Interactively•

Agent Expressions: The GDB Agent Expression Mechanism•

Target Descriptions: How targets can describe themselves to gdb•

Operating System Information: Getting additional information from the operating system•

Trace File Format: GDB trace file format•

Index Section Format: .gdb_index section format•

Copying: GNU General Public License says how you can copy and share GDB•

GNU Free Documentation License: The license for this documentation•

Index: Index•

Table of Contents

Debugging with gdb•

2.1 Invoking gdb

2.1.1 Choosing Files◊

2.1.2 Choosing Modes◊

2.1.3 What gdb Does During Startup◊

♦

2.2 Quitting gdb♦

2.3 Shell Commands♦

2.4 Logging Output♦

3 gdb Commands

3.1 Command Syntax♦

3.2 Command Completion♦

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Debugging with GDB

Table of Contents 2

4.4 Your Program's Environment♦

4.6 Your Program's Input and Output♦

4.7 Debugging an Already-running Process♦

4.9 Debugging Multiple Inferiors and Programs♦

4.10 Debugging Programs with Multiple Threads♦

4.12 Setting a Bookmark to Return to Later

4.12.1 A Non-obvious Benefit of Using Checkpoints◊

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5 Stopping and Continuing

5.1 Breakpoints, Watchpoints, and Catchpoints

5.1.6 Break Conditions◊

5.1.7 Breakpoint Command Lists◊

5.1.8 How to save breakpoints to a file◊

5.1.9 “Cannot insert breakpoints”◊

5.1.10 “Breakpoint address adjusted...”◊

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5.2 Continuing and Stepping♦

5.3 Signals♦

5.4 Stopping and Starting Multi-thread Programs

5.4.2 Non-Stop Mode◊

5.4.3 Background Execution◊

5.4.4 Thread-Specific Breakpoints◊

5.4.5 Interrupted System Calls◊

5.4.6 Observer Mode◊

♦

•

6 Running programs backward•

7 Recording Inferior's Execution and Replaying It•

8 Examining the Stack

8.1 Stack Frames♦

8.2 Backtraces♦

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9.3.1 Choosing your Editor◊

9.4 Searching Source Files♦

9.5 Specifying Source Directories♦

9.6 Source and Machine Code♦

10 Examining Data

10.1 Expressions♦

10.2 Ambiguous Expressions♦

10.3 Program Variables♦

10.4 Artificial Arrays♦

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Debugging with GDB

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10.5 Output Formats♦

10.7 Automatic Display♦

10.8 Print Settings♦

10.9.1 Pretty-Printer Introduction◊

10.9.2 Pretty-Printer Example◊

10.10 Value History♦

10.11 Convenience Variables♦

10.12 Registers♦

10.13 Floating Point Hardware♦

10.16.1.2 Memory Access Size⋅

10.16.1.3 Data Cache⋅

10.16.2 Memory Access Checking◊

10.17 Copy Between Memory and a File♦

10.18 How to Produce a Core File from Your Program♦

10.19 Character Sets♦

10.20 Caching Data of Remote Targets♦

10.21 Search Memory♦

11.1 Inline Functions♦

12 C Preprocessor Macros•

13 Tracepoints

13.1 Commands to Set Tracepoints

13.1.1 Create and Delete Tracepoints◊

13.1.2 Enable and Disable Tracepoints◊

13.1.3 Tracepoint Passcounts◊

13.1.4 Tracepoint Conditions◊

13.1.5 Trace State Variables◊

13.1.6 Tracepoint Action Lists◊

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13.2.2 tdump◊

13.2.3 save tracepoints filename◊

13.3 Convenience Variables for Tracepoints♦

13.4 Using Trace Files♦

•

14 Debugging Programs That Use Overlays

14.1 How Overlays Work♦

14.2 Overlay Commands♦

14.3 Automatic Overlay Debugging♦

14.4 Overlay Sample Program♦

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Debugging with GDB

Table of Contents 4

15 Using gdb with Different Languages

15.1.1 List of Filename Extensions and Languages◊

15.1.2 Setting the Working Language◊

15.2 Displaying the Language♦

15.3 Type and Range Checking

15.3.2 An Overview of Range Checking◊

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15.4 Supported Languages

15.4.1 C and C++

15.4.1.1 C and C++ Operators⋅

15.4.1.7 gdb Features for C++⋅

15.4.1.8 Decimal Floating Point format⋅

◊

15.4.2 D◊

15.4.3 Objective-C

15.4.3.1 Method Names in Commands⋅

15.4.3.2 The Print Command With Objective-C⋅

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15.4.4 OpenCL C

15.4.4.1 OpenCL C Datatypes⋅

15.4.4.3 OpenCL C Operators⋅

◊

15.4.5 Fortran

15.4.5.1 Fortran Operators and Expressions⋅

15.4.5.2 Fortran Defaults⋅

15.4.5.3 Special Fortran Commands⋅

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15.4.6 Pascal◊

15.4.7 Modula-2

15.4.7.1 Operators⋅

15.4.7.2 Built-in Functions and Procedures⋅

15.4.7.3 Constants⋅

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15.4.8 Ada

15.4.8.1 Introduction⋅

15.4.8.2 Omissions from Ada⋅

15.4.8.3 Additions to Ada⋅

15.4.8.4 Stopping at the Very Beginning⋅

15.4.8.5 Extensions for Ada Tasks⋅

15.4.8.6 Tasking Support when Debugging Core Files⋅

15.4.8.7 Tasking Support when using the Ravenscar Profile⋅

15.4.8.8 Known Peculiarities of Ada Mode⋅

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Debugging with GDB

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