OSX qmake support about ycm-generator

[rdnetto]

Have you tried running it with -v?

[IngoMeyer441]

I've tried the following command in a very simple demo project (with macx-clang):

config_gen.py -F ycm -v --qt-version 5 .

and get the following output:

Running qmake in '/var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmpuopyft' with Qt 5...
$ qmake /Users/heimbach/tmp/qt5/src/src.pro
Info: creating stash file /private/var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmpuopyft/.qmake.stash

Running make...
$ make -i -j8
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -c -pipe -g -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -mmacosx-version-min=10.7 -Wall -W -fPIC -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/Users/heimbach/tmp/qt5/src -I. -I/Users/heimbach/tmp/qt5/src -I/usr/local/qt-5.5/lib/QtWidgets.framework/Headers -I/usr/local/qt-5.5/lib/QtGui.framework/Headers -I/usr/local/qt-5.5/lib/QtCore.framework/Headers -I. -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/AGL.framework/Headers -I/usr/local/qt-5.5/mkspecs/macx-clang -F/usr/local/qt-5.5/lib -o main.o /Users/heimbach/tmp/qt5/src/main.cpp
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -headerpad_max_install_names -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -mmacosx-version-min=10.7 -Wl,-rpath,/usr/local/qt-5.5/lib -o src.app/Contents/MacOS/src main.o   -F/usr/local/qt-5.5/lib -framework QtWidgets -framework QtGui -framework QtCore -framework DiskArbitration -framework IOKit -framework OpenGL -framework AGL

Cleaning up...

Build completed in 2.77 sec

Collected 0 relevant entries for C compilation (0 discarded).
Collected 0 relevant entries for C++ compilation (0 discarded).
()
ERROR: No commands were logged to the build logs (C: /var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmpszxdwD, C++: /var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmp4eQNDK).
Your build system may not be compatible.

So, there are enough arguments that could be collected.

[rdnetto]

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++

This indicates that instead of invoking YCM-Gen's toolchain, your build system is invoking the system toolchain. I'm not hugely familiar with qmake, but this typically happens because the build file isn't respecting the CXX variable and has hardcoded the compiler. You should take a look at your .pro file to see if this is the case.

I've also pushed a change to fix OSX Qmake support - please checkout develop and confirm that it works.

[IngoMeyer441]

My .pro file was auto generated with qmake -project and has only the following contents:

TEMPLATE = app
TARGET = src
INCLUDEPATH += .

QT += core
QT += widgets

# Input
SOURCES += main.cpp

Till now, I was not able to figure out why the wrong toolchain is used.
Your commit looks fine (I will test it as soon as my CXX configuration works). On Mac OSX there is an additional -F switch for framework search paths that should be collected like -I. So I think line 333 (on develop)

flags_whitelist = ["-[iID].*", "-W[^,]*", "-std=[a-z0-9+]+", "-(no)?std(lib|inc)", "-m[0-9]+"]

should be altered to

flags_whitelist = ["-[iIDF].*", "-W[^,]*", "-std=[a-z0-9+]+", "-(no)?std(lib|inc)", "-m[0-9]+"]

Is that the only location where new flags must be added?

[IngoMeyer441]

Qmake behavior on OSX is a bit strange. Whatever I set as CXX variable in the qmake project has no effect on the generated Makefile. I always get the following line in the generated output:

CXX           = /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++

Therefore, I wrote a litte helper function that patches the generated Makefile after the qmake run:

    def patch_qmake_makefile_osx(makefile_path):
        compilers = {
            'CC': 'clang',
            'CXX': 'clang++'
        }
        patched_makefile_lines = []
        with open(makefile_path, 'r') as f:
            for line in f:
                line = line.rstrip()
                for variable_name, compiler in compilers.items():
                    if re.match('\s*{}\s*='.format(variable_name), line):
                        line = re.sub('=.*', '= {}'.format(compiler), line)
                        break
                patched_makefile_lines.append(line)
        with open(makefile_path, 'w') as f:
            f.write('\n'.join(patched_makefile_lines))

It's a bit hacky but the collection of flags does work now. However now I get another error:

 Running qmake in '/var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmpBBZ2fG' with Qt 5...
$ qmake /Users/heimbach/tmp/qt5/src/src.pro
Info: creating stash file /private/var/folders/2y/5g7w8vc53mn0xfymbbxg3pxm000lj5/T/tmpBBZ2fG/.qmake.stash

Running make...
$ make -i -j8
clang++ -c -pipe -g -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -mmacosx-version-min=10.7 -Wall -W -fPIC -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I/Users/heimbach/tmp/qt5/src -I. -I/Users/heimbach/tmp/qt5/src -I/usr/local/qt-5.5/lib/QtWidgets.framework/Headers -I/usr/local/qt-5.5/lib/QtGui.framework/Headers -I/usr/local/qt-5.5/lib/QtCore.framework/Headers -I. -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/OpenGL.framework/Headers -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/System/Library/Frameworks/AGL.framework/Headers -I/usr/local/qt-5.5/mkspecs/macx-clang -F/usr/local/qt-5.5/lib -o main.o /Users/heimbach/tmp/qt5/src/main.cpp
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -headerpad_max_install_names -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -mmacosx-version-min=10.7 -Wl,-rpath,/usr/local/qt-5.5/lib -o src.app/Contents/MacOS/src main.o   -F/usr/local/qt-5.5/lib -framework QtWidgets -framework QtGui -framework QtCore -framework DiskArbitration -framework IOKit -framework OpenGL -framework AGL
clang: error: no such file or directory: 'main.o'
make: [src.app/Contents/MacOS/src] Error 1 (ignored)

Cleaning up...

Build completed in 1.14 sec

Collected 0 relevant entries for C compilation (0 discarded).
Collected 1 relevant entries for C++ compilation (0 discarded).
Created YCM config file with 15 C++ flags

Usually, YCM-Generator does not try to do a linking step, does it?

[rdnetto]

YCM-Generator skips the linking step by specifying its own linker (which is just a symlink to the equivalent of /bin/true). This is normally done by appending fake-toolchain/Unix to PATH, so that it takes precedence over the installed compiler/linker.

Take a look at /usr/lib64/qt5/mkspecs/macx-clang/qmake.conf (and the included files) - they might give some hints as to which variables to override. QMAKE_CXX and QMAKE_LINK seem particularly promising, but I'd like to make sure that there aren't any downstream changes to them that might hardcode the compiler.

The reason it's failing is that you haven't replaced all the instances of clang++ - the line immediately before the error is calling the system compiler.

[IngoMeyer441]

Setting QMAKE_CXX and QMAKE_LINK to clang++ directly has no effect unfortunately. The compiler and linker path is always expanded to an absolute path to the executables of the Xcode installation. I browsed through the mkspecs files but could not find any clue yet where the expansion occurs.

[rdnetto]

Hmmm, in that case the simplest solution might be to just modify the generated makefile before invoking it.

[zhongke]

Is there any update about this issue? I have the same issue in my Qt environment. I am eager to know your solution. Thanks.
Brs/Kevin