Re: [Mingw-cross-env-list] [call for review UPDATED] Qt 4.7-beta1

[Mark Brand]

 Hi Tony,

> Nice work, it certainly is a much cleaner makefile, and I like the
> out-of-tree build.

The original motivation for building out-of-tree was to be able to use 
the same source tree for both host and target. Only later did I discover 
that the target build now also takes care of the necessary bits for the 
host.

> A small patch is needed to build on OSX and Open Solaris (attached)
> that disables a check for rpath-link. This is only used in the native
> moc build, and I *think* it's more relevant when cross-compiling to
> embedded devices [1]. It doesn't have any affect on Ubuntu.
>
> The only other change is to forcibly disable Cocoa (native OSX gui). I
> think some of the flags (QT_MAC_USE_COCOA) are set early during
> configure and don't check for cross-compile. Later, many "ifdefs" only
> check for this and try to use OSX headers/libs.

My interpretation of your changes is in the updated versions here:
http://www.xs4all.nl/~brandm/mingw-cross-env/

Both changes are in a patch to configure. These will probably be good 
candidates for an upstream merge request. This is the change (for review 
purposes only, since it's in the updated versions):

diff --git a/configure b/configure
index 82f8c7c..0c7c176 100755
--- a/configure
+++ b/configure
@@ -6304,6 +6304,9 @@ if [ "$PLATFORM_MAC" = "yes" ]; then
     fi
 fi

+# but disable Cocoa if cross-building for mingw
+[ "$XPLATFORM" = "win32-g++" ] && CFG_MAC_COCOA="no"
+
 # set the global Mac deployment target. This is overridden on an 
arch-by-arch basis
 # in some cases, see code further down
 case "$PLATFORM,$CFG_MAC_COCOA" in
@@ -7633,7 +7636,7 @@ QMAKE_LIBDIR_QT  = \$\$QT_BUILD_TREE/lib
 EOF

 # Ensure we can link to uninistalled libraries
-if linkerSupportsFlag -rpath-link "$outpath/lib"; then
+if [ "$XPLATFORM" != "win32-g++" ] && linkerSupportsFlag -rpath-link 
"$outpath/lib"; then
     echo "QMAKE_LFLAGS    += -Wl,-rpath-link,\$\$QT_BUILD_TREE/lib" >> 
"$CACHEFILE.tmp"
 fi

I've also done some more work since my original post to make the changes 
more workable for upstream merge requests later on. I hope I didn't 
break anything for you. :)

> The test program and most of the demos work too.

Thanks for checking. Would you mind another round of checking?

> It also looks like webkit is also being successfully cross-compiled in
> places [2], and may be ready for 4.7.

I think [2] is about getting webkit working in Mingw-w64, not in MinGW 
(on which mingw-cross-env is based).  Mingw-w64 is a fork of MinGW.

Anyway, webkit has worked probably since Qt 4.6.0 on mingw-cross-env. 
You just have to enable it with "-webkit -shared" instead of "-no-webkit 
-static". The last time I checked, webkit required shared Qt libraries.

> [1] 
> http://doc.qt.nokia.com/4.7-snapshot/qt-embedded-pointer.html#specifying-a-driver
> [2] http://article.gmane.org/gmane.comp.gnu.mingw.w64.general/927/

One still open issue, albeit not pressing, is that when a 64 bit host is 
detected, the *target* stage of the build fails later on:

{standard input}: Assembler messages:
{standard input}:217: Error: suffix or operands invalid for `cmpxchg

That's why we still use "-host-arch i386" which also works on 64 bit 
systems.

regards,

Mark