Re: GCC Support of Function/Variable Attributes

[Marc Glisse <marc dot glisse at inria dot fr>]

On Thu, 28 Feb 2013, Jeffrey Walton wrote:

> I'm having trouble compiling sources adorned with the aligned
> attribute under Clang 3.1. Clang claims its GCC 4.2.1 compatible:
>
> $ clang -dM -E -x c /dev/null | grep -i gnuc
> #define __GNUC_MINOR__ 2
> #define __GNUC_PATCHLEVEL__ 1
> #define __GNUC_STDC_INLINE__ 1
> #define __GNUC__ 4
>
> When did GCC add support for function and variable attributes?
> Specifically, __attribute__(aligned) for x86/x64? Did the aligned
> attribute come into being after GCC 4.2?

That wouldn't be the only place where clang is not perfectly compatible 
with gcc...

> http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
> http://gcc.gnu.org/onlinedocs/gcc/Variable-Attributes.html

When you click on "Manual" on gcc's webpage, you are sent to a list of 
manuals per version:
http://gcc.gnu.org/onlinedocs/

Seems easy to check the oldest one:
http://gcc.gnu.org/onlinedocs/gcc-2.95.3/gcc_4.html#SEC90

(and if it hadn't been supported then, you could have used a dichotomy)

--
Marc Glisse