What does "#define _GNU_SOURCE" imply? - Stack Overflow
Defining _GNU_SOURCE has nothing to do with license and everything to do with writing (non-)portable code. If you define _GNU_SOURCE, you will get: access to lots of nonstandard …
c++ - _GNU_SOURCE and __USE_GNU - Stack Overflow
Jul 21, 2012 · _GNU_SOURCE is the only one you should ever define yourself. __USE_GNU is defined internally through a mechanism in features.h (which is included by all other glibc …
Why is _GNU_SOURCE defined by default and how to turn it off?
May 4, 2016 · I'm using g++ and it told me that I defined _GNU_SOURCE on the command line, but I didn't. I now that defining _GNU_SOURCE can be used to enable the gnu extension, but …
Compiler ignores #define _GNU_SOURCE - Stack Overflow
Mar 19, 2015 · _GNU_SOURCE requests everything, including the latest _XOPEN_SOURCE at the time your glibc (or newlib) was released, so it should be sufficient to get a declaration of …
explanation of D_GNU_SOURCE Why to use it and when?
Jan 12, 2012 · _GNU_SOURCE enables GNU extensions to the C and OS standards supported by the GNU C library, such as asprintf. Define it when you're using such non-standard …
c - Why gcc need -D_GNU_SOURCE - Stack Overflow
Nov 29, 2017 · Very straight forward answer: #define _GNU_SOURCE 1 enables GNU extensions supported by the GNU C library. Define it when you're using non-standard …
Defining custom GNU make functions - Stack Overflow
Jun 29, 2011 · You forgot the =: define dep2 = EDIT: Put a semicolon at the end of each line. I've tested this and it works (in GNUMake 3.81). define dep2 $(eval makefile_list_$1 := …
g++ - What are the gcc predefined macros for the compiler's …
Jan 3, 2017 · 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 …
Macros like _GNU_SOURCE, what do they mean? - Stack Overflow
Oct 17, 2014 · Read feature_test_macros (7) man page (and the §1.3.4 Feature Test Macros chapter of GNU libc documentation). You might compile your whole program with some …
How do I show the value of a #define at compile-time?
I know that this is a long time after the original query, but this may still be useful. This can be done in GCC using the stringify operator "#", but it requires two additional stages to be defined first. …