Thanks! I didn't write out libboost etc just to make sure that at least one
lib is correctly linked, if so, I should see other link errors and I can
just keep passing in required libs. This is exactly what happens when I
pass CGO_LDFLAGS= explicitly in the CLI.
However, when using the directives in the go file, the CGO_LDFLAGS= as far
as I see in the `go build -x` log never includes any the link directives.
Regards,
Chun
On Wednesday, March 1, 2017 at 2:30:12 PM UTC-5, therecipe wrote:
>
> ah okay, I had problems with the ".a" suffix myself, so I though it was
> worth a shot.
>
> I just know that this
> >//#cgo LDFLAGS: $GOPATH/src/kflow/libcolor/lib/libCOLOR
>
> won't work, as the env variables won't be resolved by go afaik.
>
> maybe test it with an absolute path instead
>
> and/or use "go build -n" to see how go would invoke "link"
>
> and maybe you need to link against "libboost_system" and "libxml2" as
> well, if "libCOLOR" really depends on it.
>
>
> Am Mittwoch, 1. März 2017 20:04:50 UTC+1 schrieb Chun Zhang:
>>
>> Yes, I tried quite a few varieties, such as:
>> //#cgo LDFLAGS: $GOPATH/src/kflow/libcolor/lib/libCOLOR with/without .a
>> //#cgo LDFLAGS: ${SRCDIR}kflow/libcolor/lib/libCOLOR with/without .a
>> //#cgo LDFLAGS: -L${SRCDIR}kflow/libcolor/lib -l:libCOLOR with/without .a
>> //#cgo LDFLAGS: -L${SRCDIR}kflow/libcolor/lib -lCOLOR with/without .a
>>
>> None above works for me so far, they are simply ignored during the
>> building process. I even played with the empty spaces at various places,
>> still no luck :(
>>
>> Thanks,
>> Chun
>>
>>
>> On Wednesday, March 1, 2017 at 1:57:15 PM UTC-5, therecipe wrote:
>>>
>>> did you try it without the ".a" suffix in the LDFLAGS?
>>>
>>> Am Dienstag, 28. Februar 2017 20:06:20 UTC+1 schrieb Chun Zhang:
>>>>
>>>> Hi, All,
>>>>
>>>> I have googled quite a bit about this issue, there are some tutorials
>>>> online. But most of them targeted either at older go releases or C instead
>>>> of C++.
>>>>
>>>> Can somebody please help me to figure out how to solve the following
>>>> issues?
>>>>
>>>> I have to use a static library, wrote in C++ in a go project. I have
>>>> the libcolor.a and the COLOR.h header file, the libcolor.a relies on some
>>>> other libraries, such as libboost_system.a, libxml2.a etc to build.
>>>>
>>>> I wrote a libcolor.swigcxx file as follows:
>>>> ---------------------------
>>>> %module libcoror
>>>>
>>>> %{
>>>> #include "include/COLOR.h"
>>>> #include <stddef.h>
>>>> #include <vector>
>>>>
>>>> /* This is where we initialize any global parameters that are not
>>>> search-thread specific */
>>>> extern void COLOR_init_global_config(int argc, char *argv[]); // from
>>>> the COLOR.h file, which is one of the APIs I would like to use
>>>>
>>>> %}
>>>>
>>>> #include "include/COLOR.h"
>>>> extern void COLOR_init_global_config(int argc, char *argv[]);
>>>> ---------------------------
>>>>
>>>> An empty libcolor.go file with the following lines was manually created
>>>>
>>>> ---------------------------
>>>> package libcolor
>>>>
>>>> // #cgo CFLAGS: -I .
>>>> // #cgo CXXFLAGS: -std=c++11 <--- this does not seem to work
>>>> // #cgo LDFLAGS: -L${SRCDIR}/lib/ -lCOLOR.a -lz <--- this is placed at
>>>> the correct place
>>>> ---------------------------
>>>>
>>>> When I tried to build this using "go build -x" CLI, I hit the following
>>>> error:
>>>>
>>>> WORK=/tmp/go-build797493895
>>>> mkdir -p $WORK/klow/libcolor/_obj/
>>>> mkdir -p $WORK/klow/
>>>> swig -version
>>>> cd $WORK
>>>> /usr/local/go/pkg/tool/linux_amd64/compile -o
>>>> ./klow/libcolor/_obj/_go_.o -trimpath . -p main -complete -buildid
>>>> 73a7f9534f74346db4b3e0f48875da9dbf8bc2fd -D _$WORK ./swig_intsize.go
>>>> cd /home/chzhang/go/src/klow/libcolor
>>>> swig -go -cgo -intgosize 64 -module libcolor -o
>>>> $WORK/klow/libcolor/_obj/libcolor_wrap.cxx -outdir
>>>> $WORK/klow/libcolor/_obj/ -c++ libcolor.swigcxx
>>>> CGO_LDFLAGS="-g" "-O2" /usr/local/go/pkg/tool/linux_amd64/cgo -objdir
>>>> $WORK/klow/libcolor/_obj/ -importpath klow/libcolor -- -I
>>>> $WORK/klow/libcolor/_obj/ $WORK/klow/libcolor/_obj/libcolor.go
>>>> cd $WORK
>>>> gcc -fdebug-prefix-map=a=b -c trivial.c
>>>> gcc -gno-record-gcc-switches -c trivial.c
>>>> cd /home/chzhang/go/src/klow/libcolor
>>>> gcc -I . -fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -I
>>>> $WORK/klow/libcolor/_obj/ -g -O2 -o $WORK/klow/libcolor/_obj/_cgo_main.o
>>>> -c
>>>> $WORK/klow/libcolor/_obj/_cgo_main.c
>>>> gcc -I . -fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -I
>>>> $WORK/klow/libcolor/_obj/ -g -O2 -o $WORK/klow/libcolor/_obj/_cgo_export.o
>>>> -c $WORK/klow/libcolor/_obj/_cgo_export.c
>>>> gcc -I . -fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -I
>>>> $WORK/klow/libcolor/_obj/ -g -O2 -o
>>>> $WORK/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor.cgo2.o
>>>>
>>>> -c
>>>> $WORK/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor.cgo2.c
>>>> g++ -I . -fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -I
>>>> $WORK/klow/libcolor/_obj/ -g -O2 -o
>>>> $WORK/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor_wrap.cxx.o
>>>>
>>>> -c $WORK/klow/libcolor/_obj/libcolor_wrap.cxx
>>>> # klow/libcolor
>>>> In file included from $WORK/klow/libcolor/_obj/libcolor_wrap.cxx:243:0:
>>>> ./include/COLOR.h:13:43: warning: defaulted and deleted functions only
>>>> available with -std=c++11 or -std=gnu++11
>>>> PerSessionData(const PerSessionData &d)=default;
>>>> ^
>>>> ./include/COLOR.h:14:53: warning: defaulted and deleted functions only
>>>> available with -std=c++11 or -std=gnu++11
>>>> PerSessionData& operator=(const PerSessionData&d)=default;
>>>> ^
>>>> g++ -I . -fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=$WORK=/tmp/go-build -gno-record-gcc-switches -o
>>>> $WORK/klow/libcolor/_obj/_cgo_.o $WORK/klow/libcolor/_obj/_cgo_main.o
>>>> $WORK/klow/libcolor/_obj/_cgo_export.o
>>>> $WORK/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor.cgo2.o
>>>>
>>>> $WORK/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor_wrap.cxx.o
>>>>
>>>> -g -O2
>>>> # klow/libcolor
>>>> /tmp/go-build797493895/klow/libcolor/_obj/_tmp_go-build797493895_klow_libcolor__obj_libcolor_wrap.cxx.o:
>>>>
>>>> In function `_wrap_COLOR_init_global_config_libcolor_3cea422eb6211fe0':
>>>> /tmp/go-build/klow/libcolor/_obj/libcolor_wrap.cxx:285: undefined
>>>> reference to `COLOR_init_global_config(int, char**)'
>>>> collect2: error: ld returned 1 exit status
>>>>
>>>>
>>>> Looks like there are two errors:
>>>> 1, the C++11 warning
>>>> 2, the linker can't find the function COLOR_init_global_config in the
>>>> static library. That means the compiler directives I defined in
>>>> libcolor.go
>>>> was not successfully passed to the compiler. From the log, looks like
>>>> another libcolor.go was generated in the $WORK directory by swig. The one
>>>> I
>>>> manually created was not used at all.
>>>>
>>>> Can somebody please help me to figure out what I need to do to get this
>>>> compiled? The tutorial on swig.org does not seem to help. I tried to
>>>> manually build as in
>>>>
>>>> http://zacg.github.io/blog/2013/06/06/calling-c-plus-plus-code-from-go-with-swig/
>>>> But the 6c etc go tools does not exist anymore.
>>>>
>>>>
>>>> Thanks,
>>>> Chun
>>>>
>>>> --------------------------------
>>>>
>>>> This is my setup
>>>> go version go1.7.1 linux/amd64
>>>> GOARCH="amd64"
>>>> GOBIN=""
>>>> GOEXE=""
>>>> GOHOSTARCH="amd64"
>>>> GOHOSTOS="linux"
>>>> GOOS="linux"
>>>> GOPATH="/home/chzhang/go"
>>>> GORACE=""
>>>> GOROOT="/usr/local/go"
>>>> GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
>>>> CC="gcc"
>>>> GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0
>>>> -fdebug-prefix-map=/tmp/go-build155119108=/tmp/go-build
>>>> -gno-record-gcc-switches"
>>>> CXX="g++"
>>>> CGO_ENABLED="1"
>>>>
>>>>
>>>>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
