>>>>> "Glenn" == Glenn Chambers <[EMAIL PROTECTED]> writes:
Glenn> Akim Demaille <akim at epita dot fr> writes:
>> #ifdef and #ifndef are banished from Autoconf, use only #if and#if
>> !.
Glenn> Interesting trivium: unless I mis-remember, the variant of the
Glenn> C compiler used on Bell Lab's "Plan 9" operating system
Glenn> deprecates '#if' and provides only "#ifdef" and "#ifndef".
you are right:
http://plan9.bell-labs.com/plan9/doc/comp.html
The compilers include an integrated preprocessor that accepts the
familiar #include, #define for macros both with and without
arguments, #undef, #line, #ifdef, #ifndef, and #endif. It
supports neither #if nor ## and honors a single #pragma. The #if
directive was omitted because it greatly complicates the
preprocessor, is never necessary, and is usually
abused. Conditional compilation in general makes code hard to
understand; the Plan 9 source uses it sparingly. Also, because
the compilers remove dead code, regular if statements with
constant conditions are more readable equivalents to many #ifs.
fortunately:
To compile imported code ineluctably fouled by #if there is a
separate command, /bin/cpp, that implements the complete ANSI C
preprocessor specification.
Akim
