GCC编译器手册：GNU Compiler Collection使用指南

需积分: 17 63 浏览量更新于2024-07-19 2 收藏 3.26MB PDF 举报

GCC编译手册 GCC（GNU Compiler Collection）是一款功能强大且广泛使用的编译器套件，支持多种编程语言，包括C、C++、Fortran、Java等。GCC编译手册是GCC开发者社区发布的一份详细的编译手册，旨在帮助开发者更好地使用GCC编译器。 **GCC命令** GCC提供了多种命令选项，用于控制编译过程。常用的GCC命令包括： * `gcc`：基本编译命令，用于编译C语言代码 * `g++`：用于编译C++语言代码 * `-c`：仅编译当前文件，不链接对象文件 * `-o`：指定输出文件名 * `-Wall`：启用所有警告选项 * `-g`：生成调试信息 **GCC语法** GCC支持多种语法，包括C语言、C++语言、Fortran语言等。GCC语法与标准C语言语法基本相同，支持所有标准C语言特性。GCC还提供了一些扩展语法，例如： * `__attribute__`：用于指定函数或变量的特性 * `__builtin`：用于访问GCC内置函数 * `asm`：用于嵌入汇编语言代码 **CPU指令** GCC支持多种CPU架构，包括x86、ARM、MIPS、PowerPC等。GCC可以生成针对特定CPU架构的机器代码。GCC还提供了一些特殊的指令，例如： * `asm`：用于嵌入汇编语言代码 * `__builtin_memcpy`：用于复制内存块 * `__builtin_sqrt`：用于计算平方根 **编译过程** GCC编译过程可以分为以下几个阶段： * **预处理**：读取源代码，展开宏定义，包含头文件 * **编译**：将源代码编译成汇编语言代码 * **汇编**：将汇编语言代码编译成机器代码 * **链接**：将多个目标文件链接成一个可执行文件 **GCC开发社区** GCC开发社区是一个活跃的开源社区，旨在推广和发展GCC编译器。GCC开发社区提供了丰富的文档、示例代码和开发资源，帮助开发者更好地使用GCC编译器。 GCC编译手册是一个非常有价值的资源，提供了详细的GCC命令、语法、CPU指令和编译过程信息，帮助开发者更好地使用GCC编译器。

Chapter 2: Language Standards Supported by GCC 5

2 Language Standards Supported by GCC

For each language compiled by GCC for which there is a standard, GCC attempts to follow

one or more versions of that standard, possibly with some exceptions, and possibly with

some extensions.

2.1 C Language

GCC supports three versions of the C standard, although support for the most recent version

is not yet complete.

The original ANSI C standard (X3.159-1989) was ratiﬁed in 1989 and published in 1990.

This standard was ratiﬁed as an ISO standard (ISO/IEC 9899:1990) later in 1990. There

were no technical diﬀerences between these publications, although the sections of the ANSI

standard were renumbered and became clauses in the ISO standard. This standard, in

both its forms, is commonly known as C89, or occasionally as C90, from the dates of

ratiﬁcation. The ANSI standard, but not the ISO standard, also came with a Rationale

document. To select this standard in GCC, use one of the options ‘-ansi’, ‘-std=c90’ or

‘-std=iso9899:1990’; to obtain all the diagnostics required by the standard, you should

also specify ‘-pedantic’ (or ‘-pedantic-errors’ if you want them to be errors rather than

warnings). See Section 3.4 [Options Controlling C Dialect], page 32.

Errors in the 1990 ISO C standard were corrected in two Technical Corrigenda published

in 1994 and 1996. GCC does not support the uncorrected version.

An amendment to the 1990 standard was published in 1995. This amendment added

digraphs and __STDC_VERSION__ to the language, but otherwise concerned the library. This

amendment is commonly known as AMD1; the amended standard is sometimes known as

C94 or C95. To select this standard in GCC, use the option ‘-std=iso9899:199409’ (with,

as for other standard versions, ‘-pedantic’ to receive all required diagnostics).

A new edition of the ISO C standard was published in 1999 as ISO/IEC 9899:1999, and

is commonly known as C99. GCC has substantially complete support for this standard

version; see http://gcc.gnu.org/c99status.html for details. To select this standard,

use ‘-std=c99’ or ‘-std=iso9899:1999’. (While in development, drafts of this standard

version were referred to as C9X.)

Errors in the 1999 ISO C standard were corrected in three Technical Corrigenda published

in 2001, 2004 and 2007. GCC does not support the uncorrected version.

A fourth version of the C standard, known as C11, was published in 2011 as ISO/IEC

9899:2011. GCC has substantially complete support for this standard, enabled with

‘-std=c11’ or ‘-std=iso9899:2011’. (While in development, drafts of this standard

version were referred to as C1X.)

By default, GCC provides some extensions to the C language that on rare occasions con-

ﬂict with the C standard. See Chapter 6 [Extensions to the C Language Family], page 369.

Use of the ‘-std’ options listed above will disable these extensions where they conﬂict with

the C standard version selected. You may also select an extended version of the C language

explicitly with ‘-std=gnu90’ (for C90 with GNU extensions), ‘-std=gnu99’ (for C99 with

GNU extensions) or ‘-std=gnu11’ (for C11 with GNU extensions). The default, if no C

language dialect options are given, is ‘-std=gnu11’. Some features that are part of the C99

6 Using the GNU Compiler Collection (GCC)

standard are accepted as extensions in C90 mode, and some features that are part of the

C11 standard are accepted as extensions in C90 and C99 modes.

The ISO C standard deﬁnes (in clause 4) two classes of conforming implementation. A

conforming hosted implementation supports the whole standard including all the library fa-

cilities; a conforming freestanding implementation is only required to provide certain library

facilities: those in <float.h>, <limits.h>, <stdarg.h>, and <stddef.h>; since AMD1,

also those in <iso646.h>; since C99, also those in <stdbool.h> and <stdint.h>; and since

C11, also those in <stdalign.h> and <stdnoreturn.h>. In addition, complex types, added

in C99, are not required for freestanding implementations. The standard also deﬁnes two

environments for programs, a freestanding environment, required of all implementations and

which may not have library facilities beyond those required of freestanding implementations,

where the handling of program startup and termination are implementation-deﬁned, and a

hosted environment, which is not required, in which all the library facilities are provided

and startup is through a function int main (void) or int main (int, char *[]). An OS

kernel would be a freestanding environment; a program using the facilities of an operating

system would normally be in a hosted implementation.

GCC aims towards being usable as a conforming freestanding implementation, or as the

compiler for a conforming hosted implementation. By default, it will act as the compiler for a

hosted implementation, deﬁning __STDC_HOSTED__ as 1 and presuming that when the names

of ISO C functions are used, they have the semantics deﬁned in the standard. To make it act

as a conforming freestanding implementation for a freestanding environment, use the option

‘-ffreestanding’; it will then deﬁne __STDC_HOSTED__ to 0 and not make assumptions

about the meanings of function names from the standard library, with exceptions noted

below. To build an OS kernel, you may well still need to make your own arrangements for

linking and startup. See Section 3.4 [Options Controlling C Dialect], page 32.

GCC does not provide the library facilities required only of hosted implementations, nor

yet all the facilities required by C99 of freestanding implementations on all platforms; to use

the facilities of a hosted environment, you will need to ﬁnd them elsewhere (for example,

in the GNU C library). See Section 13.5 [Standard Libraries], page 702.

Most of the compiler support routines used by GCC are present in ‘libgcc’, but there

are a few exceptions. GCC requires the freestanding environment provide memcpy, memmove,

memset and memcmp. Finally, if __builtin_trap is used, and the target does not implement

the trap pattern, then GCC will emit a call to abort.

For references to Technical Corrigenda, Rationale documents and information concerning

the history of C that is available online, see http://gcc.gnu.org/readings.html

2.2 C++ Language

GCC supports the original ISO C++ standard (1998) and contains experimental support for

the second ISO C++ standard (2011).

The original ISO C++ standard was published as the ISO standard (ISO/IEC 14882:1998)

and amended by a Technical Corrigenda published in 2003 (ISO/IEC 14882:2003). These

standards are referred to as C++98 and C++03, respectively. GCC implements the majority

of C++98 (export is a notable exception) and most of the changes in C++03. To select

this standard in GCC, use one of the options ‘-ansi’, ‘-std=c++98’, or ‘-std=c++03’; to

剩余811页未读，继续阅读

dongoewang

粉丝: 0
资源: 1

GCC编译器手册：GNU Compiler Collection使用指南

linux编译器GCC编译手册

GreenHills 2017.7 编译手册

Jquery编译手册

GCC编译手册 （GNU C Compiler）

GCC编译手册：产品实现与顾客需求

GCC编译手册：资源管理与质量体系评审

GCC编译手册：管理职责与质量体系策划

GCC编译手册：质量管理体系的监视与测量

GCC编译手册：人力资源与基础设施在质量管理体系中的作用

GCC编译手册：监视和测量装置的控制在医疗器械质量管理体系中的应用

最新资源

GCC编译手册（GNU C Compiler）