View source for Build Qt 5 PostgreSQL Plugin for iOS

[[Category:Build]]
Hello everyone,

I managed to build the iOS version for the PostgreSQL driver!  Here is how:

First of all, there are two cpu architectures that exist in iOS: armv7 & arm64 so follow the next initially with armv7 and then with arm64.

# ''Initially go to folder with the sources of the PostgreSQL project.  Then go to'' src/interfaces/libpq ''folder.''
# ''Set the $ARCH to armv7 like this:'' ARCH=armv7
# ''Set CC to a path like this:'' CC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
# ''Set CFLAGS to this:'' CFLAGS=-O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument -pthread -pthreads -mthreads  -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS  -DFRONTEND -DUNSAFE_STAT_OK -I. -I../../../src/include  -I../../../src/port -I../../../src/port -DSO_MAJOR_VERSION=5 -arch $ARCH -c
# ''SOURCE files are:'' fe-auth.c fe-connect.c fe-exec.c fe-misc.c fe-print.c fe-lobj.c fe-protocol2.c fe-protocol3.c pqexpbuffer.c fe-secure.c libpq-events.c ../../../src/port/chklocale.c ../../../src/port/inet_net_ntop.c ../../../src/port/noblock.c ../../../src/port/pgstrcasecmp.c ../../../src/port/pqsignal.c ../../../src/port/thread.c ../../../src/backend/libpq/ip.c ../../../src/backend/libpq/md5.c ../../../src/backend/utils/mb/encnames.c ../../../src/backend/utils/mb/wchar.c
# ''We will compile the SOURCE files without linking, so what we need to do for each one of the SOURCE files is:'' $CC $CFLAGS $SOURCEfile -o $OBJECTfile.o '''(eg. for fe-auth.c file this is $CC $CFLAGS fe-auth.c -o fe-auth.o, and for the ../../../src/port/thread.c file this is $CC $CFLAGS ../../../src/port/thread.c -o thread.o).'''
# ''Then run this awk oneliner which is needed for our next step that is the linking step:'' awk '/^[^#]/ {printf "_%s\n",$1}' exports.txt >exports.list
# ''The following will generate the armv7 architecture file that will be used for linking to your projects:'' /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch $ARCH -mios-version-min=9.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/ -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -Wno-unused-command-line-argument -pthread -pthreads -mthreads  -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS  -dynamiclib -install_name '/usr/local/pgsql/lib/libpq.5.dylib' -compatibility_version 5 -current_version 5.6 -exported_symbols_list exports.list -multiply_defined suppress -o libpq.5.6.dylib.$ARCH fe-auth.o fe-connect.o fe-exec.o fe-misc.o fe-print.o fe-lobj.o fe-protocol2.o fe-protocol3.o pqexpbuffer.o fe-secure.o libpq-events.o chklocale.o inet_net_ntop.o noblock.o pgstrcasecmp.o pqsignal.o thread.o  ip.o md5.o encnames.o wchar.o -L../../../src/port -L../../../src/common -headerpad_max_install_names -stdlib=libc++ -single_module -dynamiclib -Wl,-dead_strip_dylibs -lpthread
# ''After that there are two more instructions, one to archive:'' ar crs libpq.a.$ARCH fe-auth.o fe-connect.o fe-exec.o fe-misc.o fe-print.o fe-lobj.o fe-protocol2.o fe-protocol3.o pqexpbuffer.o fe-secure.o libpq-events.o chklocale.o inet_net_ntop.o noblock.o pgstrcasecmp.o pqsignal.o thread.o ip.o md5.o encnames.o wchar.o
# ''And another to generate index to archive:'' ranlib libpq.a.$ARCH
# ''This way you have created the libpq for the armv7 ARCH, now we need to perform the same for the arm64 architecture.''
# ''When we have done both, we need to combine them to one file, which we do with the following command:'' lipo libpq.5.6.dylib.armv7 libpq.5.6.dylib.arm64 -create -output libpq.5.6.dylib
# ''Moving to the final steps, we need to link this file to libpq.5.dylib, with the following command:'' ln -s libpq.5.6.dylib libpq.5.dylib
# ''And to link it to libpq.dylib too, with the following command:'' ln -s libpq.5.6.dylib libpq.dylib
# ''After that we are ready to install it to our system.''

Next step is to build the plugin that will be linked to this library file.  This is done by:
# ''Visiting the'' qtbase ''source folder that contains the driver under'' src/plugins/sqldrivers/psql/.
# ''Then we have to run qmake with some parameters for the library we made, for example:'' qmake "INCLUDEPATH+=/path/to/postgresql/src/interfaces/libpq /path/to/postgresql/src/include" "LIBS+=-L/path/to/postgresql/src/interfaces/libpq/ -lpq"
# ''And in order to compile the driver and install it, we have to run:'' make install

This way, we have both architectures for the iOS environment and we have the driver to access PostgreSQL database servers via our iOS device.

For this page, I would like to thank the author of the PostgreSQL to Android web page ([[https://wiki.qt.io/Build_Qt_5_PostgreSQL_Plugin_for_Android]])