What macros does gcc define?

4.1 Defining macros The gcc option -D NAME defines a preprocessor macro NAME from the command line. If the program above is compiled with the command-line option -DTEST , the macro TEST will be defined and the resulting executable will print both messages: $ gcc -Wall -DTEST dtest.

Which gcc option Undefine a preprocessor macro?

Which gcc option undefines a preprocessor macro? Explanation: None.

Is gcc macro?

These macros are defined by all GNU compilers that use the C preprocessor: C, C++, Objective-C and Fortran. Their values are the major version, minor version, and patch level of the compiler, as integer constants. For example, GCC version x .

What are the predefined macros?

Standard predefined macros

__cplusplus Defined as an integer literal value when the translation unit is compiled as C++.
__DATE__ The compilation date of the current source file.
__FILE__ The name of the current source file.
__LINE__ Defined as the integer line number in the current source file.

How to define macros in a preprocessor in GCC?

Instead of the normal output, generate a list of `#define’ directives for all the macros defined during the execution of the preprocessor, including predefined macros. This gives you a way of finding out what is predefined in your version of the preprocessor.

Which is implicit in the GCC preprocessor option?

-fpreprocessed is implicit if the input file has one of the extensions ‘ .i ’, ‘ .ii ’ or ‘ .mi ’. These are the extensions that GCC uses for preprocessed files created by -save-temps . When preprocessing, handle directives, but do not expand macros.

What are the macros of the GNU Compiler?

Do you need to predefine macros for GCC compilation?

Do not predefine any system-specific or GCC-specific macros. The standard predefined macros remain defined. Define additional macros required for using the POSIX threads library. You should use this option consistently for both compilation and linking.