3.4. Options Controlling C Dialect
3.4 Options Controlling C Dialect
The following options control the dialect of C (or languages derived from C, such as C++, Objective-C and Objective-C++) that the compiler accepts:
-ansi
-
In C mode, this is equivalent to
-std=c90
. In C++ mode, it is equivalent to-std=c++98
.This turns off certain features of GCC that are incompatible with ISO C90 (when compiling C code), or of standard C++ (when compiling C++ code), such as the
asm
andtypeof
keywords, and predefined macros such asunix
andvax
that identify the type of system you are using. It also enables the undesirable and rarely used ISO trigraph feature. For the C compiler, it disables recognition of C++ style ‘//
’ comments as well as theinline
keyword.The alternate keywords
__asm__
,__extension__
,