632344 - autoconf-2.13's AC_CHECK_HEADER is too slow for some headers e.g. atlbase.h

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[[e-mail]]

For some reason, redirecting output to NUL: is painfully slow on Windows. Even on a fast machine I can only get a throughput of 150KB/s while by comparison redirecting to a file or a pipe is 6.5MB/s.

autoconf-2.61 works around this by allowing you to compile the test file rather than merely preprocess it. We can use this instead for nearly all of our checks. There is one file, oleacc.idl, that we check for but isn't really a header.

Comment 1

[[e-mail]]

Attachment: Possible patch

This patch only does boilerplate search/replace to configure.in; there are a number of places where the check is using AC_CHECK_HEADERS for one header or trying to pass a single-element list to AC_CHECK_HEADER or failing to use the optional parameters e.g. AC_CHECK_HEADERS([sdkddkver.h]) could probably become MOZ_CHECK_HEADER(sdkddkver.h, MOZ_WINSDK_MAXVER=0x06000000, MOZ_WINSDK_MAXVER=0x05020000).

Comment 2

[[e-mail]]

Comment on attachment 510561 [details] [diff] [review]
Possible patch

>+    MOZ_CHECK_HEADER(event.h,
>+        [if test ! -f "${LIBEVENT_DIR}/include/event.h"; then
>+            AC_MSG_ERROR([event.h found, but is not in ${LIBEVENT_DIR}/include])
>+        fi],
>+        AC_MSG_ERROR([--with-system-libevent requested but event.h not found]))
Whoops, my reindenting wasn't quite right. Sorry.

Comment 3

[(not currently active) Ted Mielczarek]

Comment on attachment 510561 [details] [diff] [review]
Possible patch

This looks fine. (Not that I feel qualified to review M4 macros!)

Does this impact the speed of the checks on Linux at all? We are caching them, so it's probably not a huge problem, but I'd hate to regress perf there while fixing Windows perf.

Comment 4

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

I'd be willing to trade a little Linux perf for some Windows perf :-P

Comment 5

[[e-mail]]

(In reply to comment #3)
> Does this impact the speed of the checks on Linux at all?
Well, I got the idea from autoconf-2.61, so they must have thought it was OK.

Comment 6

[[e-mail]]

Attachment: Updated for bitrot

Comment 7

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

With: 4min 13sec
Without: 4min 53sec

Can haz for 2.0?

Comment 8

[Mike Shaver (:shaver emeritus)]

No, but you can have right after.

Comment 9

[Mitchell Field [:Mitch]]

http://hg.mozilla.org/projects/build-system/rev/670701b7c645
http://hg.mozilla.org/projects/build-system/rev/16432839ea97

Comment 10

[[e-mail]]

(In reply to comment #9)
> http://hg.mozilla.org/projects/build-system/rev/16432839ea97
It turns out that fcfreetype.h expects you to include fontconfig.h first.

Comment 11

[Kyle Huey (Exited; not receiving bugmail, old account, do not use)]

http://hg.mozilla.org/mozilla-central/rev/670701b7c645
http://hg.mozilla.org/mozilla-central/rev/16432839ea97