qmake - Precompile

tsschulz

Hi,

I need a precompile step. The reason is that I have a project with DB2 inline sql code. So I have file, i.e. example.sqC. That files needs to be precompiled with db2 first: db2 prep example.sqC bindfile
This will create the example.C file which I can compile normally then.

So what I'll do is:

precompile the .sqC file
compile the generated .C file with the other files of the project
(3. link all together)

I tried it with QMAKE_EXTRA_COMPILERS and QMAKE_EXTRA_TARGETS. With the extra compilers, I got it to pre compile. But then it wasn't compiled with the "normal" tools, and also my INCLUDEPATH was ignored. And it wasn't linked into the .so file.
With extra targets, nothing happend.

Greetings
Torsten

kshegunov

Hi,
Have you added the output from your precompilation step (the object files) to the OBJECTS variable? This'd be required so it's added as a dependency entry in the makefile and linked alongside the other code. I'll try to find you an example, but it'd may take some time.

SGaist

Hi and welcome to devnet,

To add to @kshegunov, can you share your .pro file ? That would give more information about what is happening.

tsschulz

@SGaist said in qmake - Precompile:

Hi and welcome to devnet,

To add to @kshegunov, can you share your .pro file ? That would give more information about what is happening.

Of course. Sorry that I forgot it.

#-------------------------------------------------
#
# Project created by QtCreator 2015-12-11T09:17:05
#
#-------------------------------------------------

QMAKE_CXXFLAGS += -std=c++14 -g -Wno-narrowing
QMAKESPEC = /usr/lib64/qt5/mkspecs/linux-clang-libc++/

QT       -= core gui

TARGET = YpDb
TEMPLATE = lib

DEFINES += YPDB_LIBRARY

SQC.target = ${QMAKE_FILE_BASE}.cpp
SQC.commands = db2 connect to yourpart && db2 PREP ${QMAKE_FILE_NAME} bindfile && mv ${QMAKE_FILE_BASE}.C ${QMAKE_FILE_BASE}.cpp
SQC.depends = FORCE
SQC.input += FAKEINPUTS
PRE_TARGETDEPS += FAKEINPUTS
QMAKE_EXTRA_COMPILER += SQC 

#FAKEINPUTS += dbrights.sqC

SOURCES += db.cpp \
    dbbase.cpp \
    dbgamebase.cpp \
    dbcommunity.cpp \
    dbrights.cpp \
    dbsocial.cpp \

HEADERS += db.h\
        ypdb_global.h \
    dbbase.h \
    dbgamebase.h \
    dbcommunity.h \
    dbrights.h \
    dbsocial.h \

LIBS += -lypconfig \
    -ldb2 \
    -lYpHelper \

unix {
    INCLUDEPATH += /usr/include/qt5
    INCLUDEPATH += /usr/local/include
    INCLUDEPATH += /opt/ibm/db2/V11.1/include
    INSTALLS += target
    QMAKE_CC = g++-7
    QMAKE_CXX = g++-7
    QMAKE_LIBDIR += /opt/ibm/db2/V11.1/lib64
    QMAKE_LIBDIR += /usr/local/lib64
}

target.path = /usr/local/lib64

headers.path = /usr/local/include/Yp
headers.files += $${HEADERS}

INSTALLS += target \
    headers

As you can see, I don't only use more include and lib pathes, I also need another compiler, because the one that is standard at my linux distribution is too old for some libs I use.

Greetings
Torsten

tsschulz

Hi,

@kshegunov I thought about and and it could help me really - if a) the right compiler would be used and b) the INCLUDEPATH would be used.

kshegunov

Couldn't find my experiments from before, but this should work for you I think (or it should be close at least):

SQC.input = FAKEINPUTS
SQC.output = ${QMAKE_FILE_BASE}.cpp
SQC.commands = db2 connect to yourpart && db2 PREP ${QMAKE_FILE_NAME} bindfile && mv ${QMAKE_FILE_BASE}.C ${QMAKE_FILE_BASE}.cpp
SQC.CONFIG += target_predeps
SQC.variable_out = SOURCES

QMAKE_EXTRA_COMPILER += SQC

By the way you have too much stuff whose place is not in the .pro file, e.g. you force a clang QMAKESPEC for a g++ compilation you specify the debug information and the std version as compiler flags when you should use CONFIG for that.
If you don't want Qt (QT -= core gui), then use CONFIG -= qt. You add system include paths when they are already in the PATH.

tsschulz

Hey, thanks!

With that help I was able to get it running. The block I need is this:

SQC.output = ${QMAKE_FILE_BASE}.cpp
SQC.target = ${QMAKE_FILE_BASE}.cpp
SQC.commands = db2 connect to yourpart && db2 PREP ${QMAKE_FILE_NAME} bindfile && mv ${QMAKE_FILE_BASE}.C ${QMAKE_FILE_BASE}.cpp
SQC.depends = FORCE
SQC.input += FAKEINPUTS
SQC.CONFIG += target_predeps
SQC.variable_out = SOURCES
QMAKE_EXTRA_COMPILERS += SQC 

FAKEINPUTS += db.sqC

(only for if someone search for how to fix this.

What you said too... Well, you're right. The CONFIG -= qt hadn't work in one project, but I think that was an error of code and not by qmake.
The include pathes are historical. I don't know why, but I had to add the system pathes that the self created headers were found.
And also the clang definiton is historical. I was using clang for longer, and I think when everything is working, I'll switch back to it.

One last question:
Can I let the "db2 connect..." be executed as first command? Because I don't need it for every file. I tried

DB2CONN.commands = db2 connect to yourpart
QMAKE_EXTRA_TARGETS += DB2CONN

(and also to add it as another extra_compiler) but it wasn't working :(

kshegunov

@tsschulz said in qmake - Precompile:

DB2CONN.commands = db2 connect to yourpart
QMAKE_EXTRA_TARGETS += DB2CONN

Looks correct, but you ought to also specify that target to be executed in the proper order. Try adding something like this:

# Create a target to be executed before the build
DB2CONN.commands = db2 connect to yourpart
QMAKE_EXTRA_TARGETS += DB2CONN

PRE_TARGETDEPS += DB2CONN

# Add a custom compilation step before the regular build
SQC.output = ${QMAKE_FILE_BASE}.cpp
// ...
SQC.depends = DB2CONN #<< Change here
// ...
QMAKE_EXTRA_COMPILERS += SQC

As for your superfluous lines in the pro:

Remove the QMAKESPEC, that is to be specified in another way:
a) From the command line if you're using qmake that way
b) QtCreator will set it up for you whenever you change the compiler in the UI
Remove QMAKE_CXXFLAGS, use CONFIG += debug (to get -g -Wno-narrowing) and CONFIG += c++14 to get -std=c++14.
Remove QT -= core gui, use CONFIG -= qt to remove Qt dependency
Remove: INCLUDEPATH += /usr/include/qt5 and INCLUDEPATH += /usr/local/include, those are already set up for you.
If you need to change to a newer gcc/g++ version, then there's a better way to do that QMAKE_CC = g++-7 and QMAKE_CXX = g++-7 will work but it's not their place to be in the .pro file.
QMAKE_LIBDIR += /usr/local/lib64 is not needed, remove it.
QMAKE_LIBDIR += /opt/ibm/db2/V11.1/lib64 is wrong. Use LIBS += -L/opt/ibm/db2/V11.1/lib64 -ldb2 when you specify the dependent libraries.

PS. You may also want to read this document about qmake.

tsschulz

@kshegunov

Thanks for your help. Most I did like you said. Only I had to add the -Wno-narrowing, because debug didn't add it. And it is needed for the precompiled files from db2.

The compiler options I didn't change, even that I know that there are other ways. In this case I prefer to set it with the .pro file.

Thank you!