Hello,
With the effort from Luboš Luňák in 2021, building LibreOffice master
with ccache/VS on Windows became possible. But, as discussed in 2021,
and also a few days ago, the conclusion was that it is not helpful. The
recommendation in the TDF Wiki is also not to use ccache:
2021 discussion:
FYI: ccache for MSVC/Windows
https://lists.freedesktop.org/archives/libreoffice/2021-November/088061.html
Building LibreOffice on Windows with Cygwin and MSVC: Tips and Tricks
https://wiki.documentfoundation.org/Development/BuildingOnWindows
Last week, I tried to build again, and this time not using binaries of
the patched ccache for Cygwin, but with the official Windows binaries.
The binary of the patched Cygwin ccache was no longer working with the
latest Cygwin, and I was expecting that the latest binaries should
contain the patches from Luboš.
In addition, I expected that the Windows binary built with MSVC can
possibly perform better, because it is a single binary without reliance
on Cygwin, and without its overhead.
I downloaded ccache from the below link, and put the ccache.exe in
Cygwin binary folder:
cccache 4.8.1 (4.7.5 also work)
Windows x86_64 binary release
https://github.com/ccache/ccache/releases
I also downloaded jom from the below link, and also put it in the Cygwin
binary folder. As you may know, it is a parallel drop-in replacement for
nmake:
jom 1.1.3
https://download.qt.io/official_releases/jom/jom_1_1_3.zip
A small change (adding missing double quotes) is needed to compile
OpenSSL, as it gives error with ccache. This change does not build the
rest of LibreOffice, so a fix is needed. But, the quick and dirty change
works to show the performance difference:
diff --git a/external/openssl/ExternalProject_openssl.mk
b/external/openssl/ExternalProject_openssl.mk
index e44ccf5f3436..dcb49c8d2dc4 100644
--- a/external/openssl/ExternalProject_openssl.mk
+++ b/external/openssl/ExternalProject_openssl.mk
@@ -65,7 +65,7 @@ $(call
gb_ExternalProject_get_state_target,openssl,build):
$(call gb_ExternalProject_run,build,\
CONFIGURE_INSIST=1 $(PERL) Configure $(OPENSSL_PLATFORM)
no-tests no-multilib \
&& export PERL="$(shell cygpath -w $(PERL))" \
- && nmake -f makefile \
+ && jom -f makefile \
$(if $(call
gb_Module__symbols_enabled,openssl),DEBUG_FLAGS_VALUE="$(gb_DEBUGINFO_FLAGS)")
\
)
$(call gb_Trace_EndRange,openssl,EXTERNAL)
diff --git a/solenv/gbuild/platform/com_MSC_class.mk
b/solenv/gbuild/platform/com_MSC_class.mk
index ba42b0ba48df..69f5b00b56c5 100644
--- a/solenv/gbuild/platform/com_MSC_class.mk
+++ b/solenv/gbuild/platform/com_MSC_class.mk
@@ -665,7 +665,7 @@ gb_ExternalProject_INCLUDE := \
$(subst -I,,$(subst $(WHITESPACE),;,$(SOLARINC)))
gb_NMAKE_VARS = \
- CC="$(shell cygpath -w $(filter-out -%,$(CC))) $(filter
-%,$(CC))" \
+ CC="ccache\" \"$(shell cygpath -w $(lastword $(filter-out
-%,$(CC))))" \
INCLUDE="$(gb_ExternalProject_INCLUDE)" \
LIB="$(ILIB)" \
MAKEFLAGS= \
I build with this configuration:
--enable-ccache
--enable-odk
--enable-dbgutil
--without-doxygen
--with-visual-studio=2022
--without-java
Without ccache, my build finishes in 30 minutes:
$ make
...
real 30m8.900s
user 0m0.109s
sys 0m0.078s
To give an overview on build performance difference, I've compared the
time needed to build OpenSSL:
openssl, jom, ccache (warm)
real 0m27.745s
user 0m0.000s
sys 0m0.000s
openssl, nmake, ccache (warm)
real 1m33.791s
user 0m0.000s
sys 0m0.015s
openssl: jom, no ccache
real 2m1.111s
user 0m0.000s
sys 0m0.000s
openssl: nmake, no ccache
real 8m4.923s
user 0m0.000s
sys 0m0.015s
Without ccache, the rest of build (excluding OpenSSL) takes ~25 minutes,
and this will lead to the ~30 minutes time needed to do a full re-build
after 'make clean'.
real 24m40.578s
user 0m0.156s
sys 0m0.109s
On the other hand, full rebuild (make) with jom for OpenSSL and ccache
(warm) finishes in 18 minutes, and that is a considerable improvement!
real 17m57.119s
user 0m0.015s
sys 0m0.031s
Please note that with ccache, the build sleeps for a while while showing
sd, and several MSBuild.exe processes active in the background. The
build finishes anyway, and the built LibreOffice is usable. Fixing the
problem there may save a few more minutes:
[build MOD] sc
There may be possible drawbacks. As OpenSSL in not always built and
tested with jom instead of nmake, there is a chance that it may fail
with some future changes. But anyway, it is a a good optimization.
I think it worth trying ccache + jom on Windows CI. Also, using jom in
every external library that is built with nmake can provide more
performance improvement. One can take a look into:
$ git grep nmake "external/*/*.mk"
Regards,
Hossein
--
Hossein Nourikhah, Ph.D., Developer Community Architect
Tel: +49 30 5557992-65 | Email: hossein@xxxxxxxxxxxxxxx
The Document Foundation, Winterfeldtstraße 52, 10781 Berlin, DE
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