Is Compiling UNIX Software on OS X painfully slow compared to on a PC?

xpost

I can't imagine that header files take up that much of the compile time..... I'd imagine that most of the time is spent doing optimizations: reordering, register renaming, optimizing of caller/callee save registers for fxns that don't use some of them, unrolling loops, inlining, etc.

(xpost)

Shouldn't GCC cache the generated header file if the preprocessor symbols used in it are the same as the previous instance of parsing it?

Or I might be totally off my rocker.

I'd have thought GCC would always have had the latest shiny bells and whistles, but it doesn't seem to be the case. I wonder why. MS compilers have used precompiled headers for about a decade.

-- KeefW (m...) (webmail), April 3rd, 2005 5:45 PM. (kmw) (later) (link)

Yes, but what if we care about the start up time of our applications?

Because each recompilation of a library or executable may place functions
at different addresses, a newly installed library or executable's pre-
binding information might not match the libraries already on the disk.
When the dynamic linker determines that prebinding information for a
library could be invalid, it defaults to resolving all the names for that
library, and for all libraries referenced by that library, losing any
advantage of having the prebinding information.

update_prebinding ensures that prebinding information is up-to-date after
new prebound applications or new versions of system libraries are
installed. Given a list of the newly installed files in a package,
update_prebinding finds all the libraries and executables that may dynam-
ically load the changed files. If so, the prebinding information must be
updated, and update_prebinding performs redo_prebinding to update that
file. update_prebinding builds a dependency graph to minimize the files
that must be updated, and applies a few other heuristics to only call
redo_prebinding when necessary.

I think that's roughly what the thing you've just posted says.

that program updates this information to avoid the lookups

Anyway, on another subject have any of you sysadmin types got any experience of Citrix for delivering Windows apps from a server? If so, how has it been?

Solution....

The -I option. Add -I/opt/local/include to the command line.

Some additional environments variables affect the behavior of the pre-
processor.

CPATH
C_INCLUDE_PATH
CPLUS_INCLUDE_PATH
OBJC_INCLUDE_PATH
Each variable's value is a list of directories separated by a spe-
cial character, much like PATH, in which to look for header files.
The special character, "PATH_SEPARATOR", is target-dependent and
determined at GCC build time. For Windows-based targets it is a
semicolon, and for almost all other targets it is a colon.

CPATH specifies a list of directories to be searched as if speci-
fied with -I, but after any paths given with -I options on the
command line. This environment variable is used regardless of
which language is being preprocessed.

The remaining environment variables apply only when preprocessing
the particular language indicated. Each specifies a list of
directories to be searched as if specified with -isystem, but
after any paths given with -isystem options on the command line.

In all these variables, an empty element instructs the compiler to
search its current working directory. Empty elements can appear
at the beginning or end of a path. For instance, if the value of
CPATH is ":/special/include", that has the same effect as
-I. -I/special/include.