Apple's implementation of precompiled headers

[Stan Shebs]

dewar@gnat.com wrote:
> 
> I am amazed that precompiled headers could make a difference for C, it should
> be easily possible to parse and compile C headers faster than you can read
> them from disk.

You shouldn't be that amazed, I reported the experimental results
last year.  If you want fast compilation of programs with huge
headers (for Macs the round number is 100K lines of header pulled
in per source file), you have to have the set of declarations in
memory and available for random access by name.  Parsing, compiling,
reading from disk, all of them take too long.

Stan