3a0ed5d25e
Some Qt5 sub-projects as well as 3rd-party apps written on Qt
are failing to compile with gcc 6.x like that:
---------------------------->8-------------------------
In file included from XXX/output/host/usr/arc-buildroot-linux-uclibc/include/c++/6.2.1/bits/stl_algo.h:59:0,
from XXX/output/host/usr/arc-buildroot-linux-uclibc/include/c++/6.2.1/algorithm:62,
from XXX/output/host/usr/arc-buildroot-linux-uclibc/sysroot/usr/include/qt5/QtCore/qglobal.h:88,
from XXX/output/host/usr/arc-buildroot-linux-uclibc/sysroot/usr/include/qt5/QtCore/qpair.h:37,
from qmediametadata.h:37,
from qmediametadata.cpp:28:
XXX/output/host/usr/arc-buildroot-linux-uclibc/include/c++/6.2.1/cstdlib:75:25: fatal error: stdlib.h: No such file or directory
#include_next <stdlib.h>
^
compilation terminated.
---------------------------->8-------------------------
That happens because qmake trying to play smart passes some
include paths in Makefile with "-isystem" prefix.
Which in some cases lead to build failure well described in [1].
A little bit more details below on what really happens:
1. In "configure" script Qt determines default include paths of the
toolchain and stores them in DEFAULT_INCDIRS variable, see [2].
2. On qmake execution when it creates Makefile out of .pro-file
it parses headers in INCLUDEPATH variable and if a path matches
one in DEFAULT_INCDIRS then in CXXFLAGS that path is written
with $QMAKE_CFLAGS_ISYSTEM prefix, otherwise non-matching include
path ends up in CXXFLAGS with normal "-I" prefix.
3. By default for gcc "QMAKE_CFLAGS_ISYSTEM = -isystem", see [3].
4. gcc fails to find stdlib.h, again refer to Jörg's explanation in [1].
What we do here we force set QMAKE_CFLAGS_ISYSTEM to "" and so qmake
won't use "-isystem" any longer instead expected "-I" will be used for
all headers, see [4].
That fixes building of Qt5Webkit on ARM with gcc 6.x and a number of
autobuilder failures for ARC (the an arch that uses gcc 6 by default) like:
http://autobuild.buildroot.net/results/56a/56a6700774af692e7f5a99b452b15e4e8592310f
http://autobuild.buildroot.net/results/697/697412b29bf031bf8f246cc3af97ebcbf6bf6d1b
[1] https://git.buildroot.net/buildroot/commit/?id=e79272fa7ff3d66c18de3514b912cd9d68d121a4
[2] http://code.qt.io/cgit/qt/qtbase.git/tree/configure?h=5.6.1#n3660
[3] http://code.qt.io/cgit/qt/qtbase.git/tree/mkspecs/common/gcc-base.conf?h=5.6.1#n47
[4] http://code.qt.io/cgit/qt/qtbase.git/tree/qmake/generators/unix/unixmake2.cpp?&h=5.6.1#n193
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Seiderer <ps.report@gmx.net>
Cc: Julien Corjon <corjon.j@ecagroup.com>
Cc: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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| linux | ||
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| .gitignore | ||
| CHANGES | ||
| Config.in | ||
| Config.in.legacy | ||
| COPYING | ||
| DEVELOPERS | ||
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| README | ||
Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. The documentation can be found in docs/manual. You can generate a text document with 'make manual-text' and read output/docs/manual/manual.text. Online documentation can be found at http://buildroot.org/docs.html To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the target architecture and the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) find the kernel, bootloader, root filesystem, etc. in output/images You do not need to be root to build or run buildroot. Have fun! Buildroot comes with a basic configuration for a number of boards. Run 'make list-defconfigs' to view the list of provided configurations. Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org You can also find us on #buildroot on Freenode IRC. If you would like to contribute patches, please read https://buildroot.org/manual.html#submitting-patches