-std= 语言标准

2016/5/27 13:13:10

gcc 版本：

cts@SuSe-CTS2:~> gcc --version
gcc (SUSE Linux) 4.3.4 [gcc-4_3-branch revision 152973]
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
cts@SuSe-CTS2:~> man gcc
...(略)

-std=
Determine the language standard. This option is currently only supported when compiling C or C++.

The compiler can accept several base standards, such as c89 or c++98, and GNU dialects（方言；同源语） of those standards, such as gnu89 or gnu++98. By specifing a base standard, the compiler will accept all programs following that standard and those using GNU extensions that do not contradict it. For example, -std=c89 turns off certain features of GCC that are incompatible with ISO C90, such as the “asm” and “typeof” keywords, but not other GNU extensions that do not have a meaning in ISO C90, such as omitting the middle term of a “?:” expression. On the other hand, by specifing a GNU dialect of a standard, all features the compiler support are enabled, even when those features change the meaning of the base standard and some strict-conforming programs may be rejected. The particular standard is used by -pedantic（迂腐的；学究式的） to identify which features are GNU extensions given that version of the standard. For example -std=gnu89 -pedantic would warn about C++ style // comments, while -std=gnu99 -pedantic would not.

A value for this option must be provided; possible values are

c89
iso9899:1990
Support all ISO C90 programs (certain GNU extensions that conflict with ISO C90 are disabled). Same as -ansi for C code.

iso9899:199409
ISO C90 as modified in amendment 1.

c99
c9x
iso9899:1999
iso9899:199x
ISO C99. Note that this standard is not yet fully supported; see http://gcc.gnu.org/gcc-4.3/c99status.html for more information. The names c9x and iso9899:199x are deprecated.

gnu89
GNU dialect of ISO C90 (including some C99 features). This is the default for C code.

gnu99
gnu9x
GNU dialect of ISO C99. When ISO C99 is fully implemented in GCC, this will become the default. The name gnu9x is deprecated.

c++98
The 1998 ISO C++ standard plus amendments. Same as -ansi for C++ code.

gnu++98
GNU dialect of -std=c++98. This is the default for C++ code.

c++0x
The working draft of the upcoming ISO C++0x standard. This option enables experimental features that are likely to be included in C++0x. The working draft is constantly changing, and any feature that is enabled by this flag may be removed from future versions of GCC if it is not part of the C++0x standard.

gnu++0x
GNU dialect of -std=c++0x. This option enables experimental features that may be removed in future versions of GCC.

目前在 gcc 官方上最新版为 gcc 6.1 ，其中：

‘gnu11’
‘gnu1x’
GNU dialect of ISO C11. This is the default for C code. The name ‘gnu1x’ is deprecated.

‘c++98’
‘c++03’
The 1998 ISO C++ standard plus the 2003 technical corrigendum and some additional defect reports. Same as -ansi for C++ code.

‘gnu++98’
‘gnu++03’
GNU dialect of -std=c++98.

‘c++11’
‘c++0x’
The 2011 ISO C++ standard plus amendments. The name ‘c++0x’ is deprecated.

‘gnu++11’
‘gnu++0x’
GNU dialect of -std=c++11. The name ‘gnu++0x’ is deprecated.

‘c++14’
‘c++1y’
The 2014 ISO C++ standard plus amendments. The name ‘c++1y’ is deprecated.

‘gnu++14’
‘gnu++1y’
GNU dialect of -std=c++14. This is the default for C++ code. The name ‘gnu++1y’ is deprecated.