qmake: Custom code generation that produces both header and cpp files...

[ChrisW67]

How have you defined your extra processing in your PRO file?

This works for me:

fakecompiler.name = Test Compiler
fakecompiler.input = FAKEINPUTS
fakecompiler.commands = fakeit.sh ${QMAKE_FILE_IN}
fakecompiler.output = ${QMAKE_FILE_IN}.cpp
fakecompiler.variable_out = SOURCES
fakecompiler.clean = ${QMAKE_FILE_IN}.cpp ${QMAKE_FILE_IN}.h
 
QMAKE_EXTRA_COMPILERS += fakecompiler
 
TEMPLATE = app
 
SOURCES += main.cpp
FAKEINPUTS += something.fake

fakecompiler.name = Test Compiler
fakecompiler.input = FAKEINPUTS
fakecompiler.commands = fakeit.sh ${QMAKE_FILE_IN}
fakecompiler.output = ${QMAKE_FILE_IN}.cpp
fakecompiler.variable_out = SOURCES
fakecompiler.clean = ${QMAKE_FILE_IN}.cpp ${QMAKE_FILE_IN}.h
                 
QMAKE_EXTRA_COMPILERS += fakecompiler

TEMPLATE = app

SOURCES += main.cpp
FAKEINPUTS += something.fake

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(fakeit.sh generates a do nothing FILE.cpp and FILE.h from the given file name)

First run:

chrisw@newton /tmp/test $ ls
fakeit.sh  main.cpp  something.fake  test.pro
chrisw@newton /tmp/test $ qmake
chrisw@newton /tmp/test $ make
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o main.o main.cpp
make: Circular something.fake <- something.fake.o dependency dropped.
fakeit.sh something.fake
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o something.fake.o something.fake.cpp
g++ -Wl,-O1 -Wl,-rpath,/usr/lib64/qt4 -o test main.o something.fake.o    -L/usr/lib64/qt4 -lQtGui -L/usr/lib64 -L/usr/lib64/qt4 -L/usr/X11R6/lib -lQtCore -lgthread-2.0 -lrt -lglib-2.0 -lpthread

chrisw@newton /tmp/test $ ls
fakeit.sh  main.cpp  something.fake  test.pro
chrisw@newton /tmp/test $ qmake
chrisw@newton /tmp/test $ make
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o main.o main.cpp
make: Circular something.fake <- something.fake.o dependency dropped.
fakeit.sh something.fake
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o something.fake.o something.fake.cpp
g++ -Wl,-O1 -Wl,-rpath,/usr/lib64/qt4 -o test main.o something.fake.o    -L/usr/lib64/qt4 -lQtGui -L/usr/lib64 -L/usr/lib64/qt4 -L/usr/X11R6/lib -lQtCore -lgthread-2.0 -lrt -lglib-2.0 -lpthread

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Second run:

chrisw@newton /tmp/test $ make
make: Circular something.fake <- something.fake.o dependency dropped.
make: Nothing to be done for `first'.

chrisw@newton /tmp/test $ make
make: Circular something.fake <- something.fake.o dependency dropped.
make: Nothing to be done for `first'.

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Third run:

chrisw@newton /tmp/test $ touch something.fake
chrisw@newton /tmp/test $ make
make: Circular something.fake <- something.fake.o dependency dropped.
fakeit.sh something.fake
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o something.fake.o something.fake.cpp
g++ -Wl,-O1 -Wl,-rpath,/usr/lib64/qt4 -o test main.o something.fake.o    -L/usr/lib64/qt4 -lQtGui -L/usr/lib64 -L/usr/lib64/qt4 -L/usr/X11R6/lib -lQtCore -lgthread-2.0 -lrt -lglib-2.0 -lpthread

chrisw@newton /tmp/test $ touch something.fake
chrisw@newton /tmp/test $ make
make: Circular something.fake <- something.fake.o dependency dropped.
fakeit.sh something.fake
g++ -c -pipe -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -o something.fake.o something.fake.cpp
g++ -Wl,-O1 -Wl,-rpath,/usr/lib64/qt4 -o test main.o something.fake.o    -L/usr/lib64/qt4 -lQtGui -L/usr/lib64 -L/usr/lib64/qt4 -L/usr/X11R6/lib -lQtCore -lgthread-2.0 -lrt -lglib-2.0 -lpthread

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I haven't tracked down the circular reference, but it doesn't seem harmful.

[chenz]

That does not work if you try to include something.fake.h

[ChrisW67]

What do you mean?

[chenz]

something.fake.h is not generated as a dependency of main.cpp (because qmake does not know anything about something.fake.h).
For me the files are generated *after* it tries to compile main.cpp.

[ChrisW67]

Yes, I can see that here. So the problem is not that the outputs are not rebuilt when the inputs change, but that the outputs of the custom compiler are a not generated early enough. I don't have time to tinker with it right now. Perhaps someone else will chime in.

[chenz]

Thanks for trying anyway

[ChrisW67]

fake_cpp.name = Compiler to CPP
fake_cpp.input = FAKEINPUTS
fake_cpp.commands = fakeit.sh ${QMAKE_FILE_IN}
fake_cpp.output = ${QMAKE_FILE_IN_BASE}.cpp
fake_cpp.variable_out = SOURCES
fake_cpp.clean = ${QMAKE_FILE_IN_BASE}.cpp
 
fake_h.name = Compiler to H
fake_h.input = FAKEINPUTS
fake_h.commands = @echo Fake making the header for ${QMAKE_FILE_IN}
fake_h.depends = ${QMAKE_FILE_IN_BASE}.cpp
fake_h.output = ${QMAKE_FILE_IN_BASE}.h
fake_h.clean = ${QMAKE_FILE_IN_BASE}.h
 
QMAKE_EXTRA_COMPILERS += fake_cpp 
QMAKE_EXTRA_COMPILERS += fake_h 
 
 
TEMPLATE = app
 
SOURCES += main.cpp
FAKEINPUTS += something.fake

fake_cpp.name = Compiler to CPP
fake_cpp.input = FAKEINPUTS
fake_cpp.commands = fakeit.sh ${QMAKE_FILE_IN}
fake_cpp.output = ${QMAKE_FILE_IN_BASE}.cpp
fake_cpp.variable_out = SOURCES
fake_cpp.clean = ${QMAKE_FILE_IN_BASE}.cpp
                  
fake_h.name = Compiler to H
fake_h.input = FAKEINPUTS
fake_h.commands = @echo Fake making the header for ${QMAKE_FILE_IN}
fake_h.depends = ${QMAKE_FILE_IN_BASE}.cpp
fake_h.output = ${QMAKE_FILE_IN_BASE}.h
fake_h.clean = ${QMAKE_FILE_IN_BASE}.h

QMAKE_EXTRA_COMPILERS += fake_cpp 
QMAKE_EXTRA_COMPILERS += fake_h 


TEMPLATE = app

SOURCES += main.cpp
FAKEINPUTS += something.fake

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Seems to work when main.cpp references "something.h". Line 11 causes a request for "something.h" to build the dependency "something.cpp", which has a side-effect of creating our header also. The command at line 10 must exist but does nothing (use @true on UNIX).

I changed the generated file names a bit to remove the circular dependency problem.