Using the GNU Compiler Collection
For gcc version 4.3.0
(GCC)
Richard M. Stallman and the GC C Developer Community
Published by:
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a division of the General: press@gnu.org
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Last printed October 2003 for GCC 3.3.1.
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Back-Cover Texts being (b) (see below). A copy of the license is included in the section
entitled “GNU Free Documentation License”.
(a) The FSF’s Front-Cover Text is:
A GNU Manual
(b) The FSF’s Back-Cover Text is:
You have freedom to c opy and modify this GNU Manual, like GNU software. Copies
published by the Free Software Foundation raise funds for GNU development.
i
Short Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Programming Languages Supported by GCC . . . . . . . . . . . . . . . 3
2 Language Standards Supported by GCC . . . . . . . . . . . . . . . . . . 5
3 GCC Command Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 C Implementation-defined behavior . . . . . . . . . . . . . . . . . . . . . 237
5 Extensions to the C Language Family . . . . . . . . . . . . . . . . . . . 245
6 Extensions to the C++ Language . . . . . . . . . . . . . . . . . . . . . . 503
7 GNU Objective-C runtime features . . . . . . . . . . . . . . . . . . . . . 515
8 Binary Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
9 gcov—a Test Coverage Program . . . . . . . . . . . . . . . . . . . . . . . 525
10 Known C auses of Trouble with GCC . . . . . . . . . . . . . . . . . . . . 533
11 Reporting Bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551
12 How To Get Help with GCC . . . . . . . . . . . . . . . . . . . . . . . . . . 553
13 Contributing to GCC Development . . . . . . . . . . . . . . . . . . . . . 555
Funding Free Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557
The GNU Project and GNU/Linux. . . . . . . . . . . . . . . . . . . . . . . . . 559
GNU GENERAL PUBLIC LICENSE . . . . . . . . . . . . . . . . . . . . . . . 561
GNU Free Documentation License . . . . . . . . . . . . . . . . . . . . . . . . . 567
Contributors to GCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575
Option I ndex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591
Keyword Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 607
iii
Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Programming Languages Supported by GCC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Language Standards Supported by GCC . . . . . 5
2.1 C language. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 C++ language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Objective-C and Objective-C++ languages . . . . . . . . . . . . . . . . . . . . . 7
2.4 Treelang language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 GCC Command Options . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Option Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Options Controlling the Kind of Output . . . . . . . . . . . . . . . . . . . . . . . 20
3.3 Compiling C++ Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.4 Options Controlling C Dialect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.5 Options Controlling C++ Dialect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.6 Options Controlling Objective-C and Objective-C++ Dialects. . 38
3.7 Options to Control Diagnostic Messages Formatting . . . . . . . . . . . 42
3.8 Options to Request or Suppress Warnings . . . . . . . . . . . . . . . . . . . . . 43
3.9 Options for Debugging Your Program or GCC . . . . . . . . . . . . . . . . . 63
3.10 Options That Control Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . 77
3.11 Options Controlling the Preprocess or. . . . . . . . . . . . . . . . . . . . . . . . 112
3.12 Passing Options to the Assembler . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.13 Options for Linking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
3.14 Options for Directory Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
3.15 Specifying subprocesses and the switches to pass to them . . . . 127
3.16 Specifying Target Machine and Compiler Version . . . . . . . . . . . . 134
3.17 Hardware Models and Configurations . . . . . . . . . . . . . . . . . . . . . . . 135
3.17.1 ARC Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
3.17.2 ARM Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
3.17.3 AVR Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
3.17.4 Blackfin Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
3.17.5 CRIS Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
3.17.6 CRX Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
3.17.7 Darwin Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
3.17.8 DEC Alpha Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
3.17.9 DEC Alpha/VMS Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
3.17.10 FRV Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
3.17.11 GNU/Linux Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
3.17.12 H8/300 Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
3.17.13 HPPA Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
