depends: Fix cross build for qt5.7 #9646

theuni commented at 7:01 AM on January 28, 2017: member

The qt build is a mess, but this gets it building for 5.7. Going forward, we need to split it up into smaller parts, where the native tools (qmake/rcc/uic/etc.) are separate from the target libs. That will let us eliminate all of the cross-build hacks.

Includes a temp commit to have Travis build for Windows.

build: find qt's renamed helper libs from 5.7 342eb9618a

depends: add a zlib build

qt5.7 changed the location of some of its symbols, creating a circular
dependency in Qt5Core. Rather than trying to fix that up, build our own zlib
rather than having it built for us.

8efa34fb77

qt: fix build with zlib for target

This contains a few hacks very specific to Qt's buildsystem. These can be
reverted once we split the build between native and target builds.

Qt's build contains a circular dependency when not using a system zlib.
By far the easiest fix is to switch to a system zlib, rather than Qt's own.
However, that confuses Qt's cross build which assumes that when using a system
zlib, it should also find a system (native) zlib for native tools. The build
breaks if that zlib is not present.

To solve this:
1. Always use a system zlib rather than the one provided by qt
2. Set force_bootstrap, which instructs the build tools to be built as though
   we're cross-compiling (build != target)
3. For build tools, use qt's internal zlib so that a native zlib is not
required.

Step 3 means that if any zlib headers are found by the native build, it will
confuse Qt's internal zlib build. So we also need to make sure that the target
headers/libs aren't found. To do so, specify that our
cflags/cxxflags/cppflags/ldflags only apply for non-host builds.

b5f374fef7

fanquake added the label Build system on Jan 28, 2017

fanquake added this to the milestone 0.14.0 on Jan 28, 2017

MarcoFalke commented at 3:19 PM on January 28, 2017: member

Concept ACK.

The travis log mentions, that qt was detected:

Options used to compile and link:
  with wallet   = yes
  with gui / qt = yes
    qt version  = 5
    with qr     = yes
  with zmq      = yes
  with test     = yes
  with bench    = yes
  with upnp     = yes
  debug enabled = no

  target os     = windows
  build os      = 

  CC            = /home/travis/build/bitcoin/bitcoin/depends/x86_64-w64-mingw32/share/../native/bin/ccache x86_64-w64-mingw32-gcc
  CFLAGS        = -pipe -O2 
  CPPFLAGS      = -I/home/travis/build/bitcoin/bitcoin/depends/x86_64-w64-mingw32/share/../include/  -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -D_MT -DWIN32 -D_WINDOWS -DBOOST_THREAD_USE_LIB -D_FILE_OFFSET_BITS=64
  CXX           = /home/travis/build/bitcoin/bitcoin/depends/x86_64-w64-mingw32/share/../native/bin/ccache x86_64-w64-mingw32-g++ -std=c++11
  CXXFLAGS      = -pipe -O2  -fvisibility=hidden
  LDFLAGS       = -L/home/travis/build/bitcoin/bitcoin/depends/x86_64-w64-mingw32/share/../lib

So I guess you are fine to drop the last commit?

theuni force-pushed on Jan 28, 2017

theuni commented at 7:52 PM on January 28, 2017: member

Done

in build-aux/m4/bitcoin_qt.m4:None in b5f374fef7

 472 | @@ -473,8 +473,8 @@ AC_DEFUN([_BITCOIN_QT_FIND_LIBS_WITHOUT_PKGCONFIG],[
 473 |    ])
 474 |  
 475 |    BITCOIN_QT_CHECK(AC_CHECK_LIB([z] ,[main],,AC_MSG_WARN([zlib not found. Assuming qt has it built-in])))
 476 | -  BITCOIN_QT_CHECK(AC_CHECK_LIB([png] ,[main],,AC_MSG_WARN([libpng not found. Assuming qt has it built-in])))
 477 | -  BITCOIN_QT_CHECK(AC_CHECK_LIB([jpeg] ,[main],,AC_MSG_WARN([libjpeg not found. Assuming qt has it built-in])))
 478 | +  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([png_error] ,[qtpng png],,AC_MSG_WARN([libpng not found. Assuming qt has it built-in])))
 479 | +  BITCOIN_QT_CHECK(AC_SEARCH_LIBS([jpeg_create_decompress] ,[qtjpeg jpeg],,AC_MSG_WARN([libjpeg not found. Assuming qt has it built-in])))

MarcoFalke commented at 4:10 PM on January 29, 2017:

We are not using jpeg, so this seems unused.

laanwj commented at 7:43 AM on January 30, 2017: member

Tested ACK b5f374f. I built with gitian and can see that the -qt executables are in the resulting .zip. I have however not tried to test them on windows, but the build works.

fanquake commented at 7:53 AM on January 30, 2017: member

I can't test this at the moment, but the changes look ok. Splitting up the Qt build has been on the cards for a while now.

utACK.

On Mon, 30 Jan 2017 at 07:43, Wladimir J. van der Laan < notifications@github.com> wrote:

Tested ACK b5f374f https://github.com/bitcoin/bitcoin/commit/b5f374fef71ba2ba99e3d9629b66fd1491fd7c90 . I built with gitian and can see that the -qt executables are in the resulting .zip. I have however not tried to test them on windows, but the build works.

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laanwj merged this on Jan 30, 2017

laanwj closed this on Jan 30, 2017

laanwj referenced this in commit 720b579480 on Jan 30, 2017

achow101 commented at 7:34 PM on January 30, 2017: member

Post-merge ACK

Built with gitian and tested on Windows 10

codablock referenced this in commit cdb62e78b1 on Jan 19, 2018

codablock referenced this in commit f10576639d on Jan 20, 2018

codablock referenced this in commit a757261e89 on Jan 21, 2018

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