Feature request - a macro defined for GCC

[Jim Wilson]

x z wrote:
> This is somewhat off-topic.  Perhaps the GCC development team should
> consider making this __GNUC__ stuff more clarified in the GCC Manual.

I don't think this is off-topic.  We need to get people to understand 
that __GNUC__ is ambiguous before we can solve the problem.  It means 
two things:
1) This code is written in the GNU C language.
2) This code is meant to be compiled by GCC.
Other compilers that implement the GNU C language are forced to define 
__GNUC__ because of the first issue, even though it then confuses the 
second issue.  If we want to fix this, gcc must change.  And this may 
also require GNU libc changes and linux kernel changes, etc.

The talk about whether __GNUC__ is defined by the preprocessor or the 
compiler proper is irrelevant.  Either way, it is still ambiguous.

You are right that we may also have trouble with other related macros. 
I am not sure if there is a GNU Fortran language, if there is, then we 
may have the same problem with __GFORTRAN__.

We don't need things like __GNUG_MINOR__ as G++ is always distributed in 
lock step with the C compiler, so we only need one set of macros for gcc 
version numbers.

We do however have the problem that the GNU C language changes 
frequently, and people have gotten in the habit of testing 
__GNUC_MINOR__ and other related macros to determine which features are 
present in the version of the GNU C language implemented by this 
compiler.  Hence, this means that other compilers that implement the GNU 
C language may also be forced to define macros like __GNUC_MINOR__ 
through no fault of their own, to correctly describe which version of 
the GNU C language that they implement.

This is a very complicated issue, and until people realize how 
complicated it has gotten, and accept that we need a solution, it is 
unlikely that we will make progress on this issue.

Jim