Android: Statically link against libstdc++ - c++

my program compiles nicely for Android, however when I try to copy it to the Android emulator, it gives the following error:
knight666#Katja-Linux /media/Data/Shared/Galaxians $ acpy Galaxians.android
Filename: 'Galaxians.android'
819 KB/s (420657 bytes in 0.501s)
link_image[1638]: 825 could not load needed library 'libstdc++.so.6' for '/system/sbin/Galaxians.android' (load_library[984]: Library 'libstdc++.so.6' not found)CANNOT LINK EXECUTABLE
acpy is a small script I wrote that does the following:
#!/bin/sh
FILEPATH=`dirname $1`
FILENAME=`basename $1 .c`
echo "Filename: '$FILENAME'"
adb push $FILEPATH/$FILENAME /system/sbin/$FILENAME
adb shell chmod 777 /system/sbin/$FILENAME
adb shell /system/sbin/$FILENAME
Here is how I build my application:
oem#androiddev /media/YoghurtGum/Tests/Galaxians $ sudo make
arm-none-linux-gnueabi-g++ -static-libgcc -g -Wall -Werror -O2 -w -I ../../YoghurtGum/src/GLES -I ../../YoghurtGum/src -c src/Alien.cpp -o intermediate/Alien.o
arm-none-linux-gnueabi-g++ -static-libgcc -g -Wall -Werror -O2 -w -I ../../YoghurtGum/src/GLES -I ../../YoghurtGum/src -c src/Bullet.cpp -o intermediate/Bullet.o
arm-none-linux-gnueabi-g++ -static-libgcc -g -Wall -Werror -O2 -w -I ../../YoghurtGum/src/GLES -I ../../YoghurtGum/src -c src/Game.cpp -o intermediate/Game.o
arm-none-linux-gnueabi-g++ -static-libgcc -g -Wall -Werror -O2 -w -I ../../YoghurtGum/src/GLES -I ../../YoghurtGum/src -c src/Player.cpp -o intermediate/Player.o
arm-none-linux-gnueabi-gcc
-Wl,--entry=main,
-dynamic-linker=/system/bin/linker,
-rpath-link=/home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib,
-rpath=../../YoghurtGum/lib/Android,
-L/home/oem/android-ndk-r3/build/platforms/android-5/arch-arm/usr/lib
-nostdlib
-lstdc++
intermediate/Alien.o
intermediate/Bullet.o
intermediate/Game.o
intermediate/Player.o
../../YoghurtGum/lib/Android/libstdc++.a
../../YoghurtGum/bin/YoghurtGum.a
-o bin/Galaxians.android
Line breaks are only for clarity, none exist in the actual output.
YoghurtGum is my game library that already statically and dynamically links to libstdc++.
When I remove lstdc++, the program doesn't compile because it can't find the library.
Is there a way to link to stdlibc++ statically or link the application to the correct dynamic library in the emulator?
Thanks in advance.

There is a modification of the ndk with support for exceptions, RTTI and stdlibc++.
http://www.crystax.net/android/ndk-r3.php
The other alternative involves porting just what you need, by hand... eek!

Related

Override -shared option in g++

I was building some Cython extensions, and have to link it against a static library (it has CUDA code in them, so have to be static):
running build_ext
building 'k3lib' extension
gcc -pthread -B /home/kelvin/anaconda3/envs/torch/compiler_compat -Wl,--sysroot=/ -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -I/home/kelvin/repos/tools/include -I/home/kelvin/anaconda3/envs/torch/include/python3.8 -c main.cpp -o build/temp.linux-x86_64-3.8/main.o -O3 -march=native
cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
g++ -pthread -shared -B /home/kelvin/anaconda3/envs/torch/compiler_compat -L/home/kelvin/anaconda3/envs/torch/lib -Wl,-rpath=/home/kelvin/anaconda3/envs/torch/lib -Wl,--no-as-needed -Wl,--sysroot=/ build/temp.linux-x86_64-3.8/main.o /home/kelvin/repos/tools/include/libk2.a -L/home/kelvin/repos/tools/include -lk2 -o build/lib.linux-x86_64-3.8/k3lib.cpython-38-x86_64-linux-gnu.so -static -Wl,-Bstatic -flinker-output=exec
However, Cython's g++ compile command includes the options -shared -fPIC by default. I tried a number of options at the end of the command via this setup file (the static library is at $(LOCAL_INCLUDE)/libk2.a):
includes = [os.getenv("LOCAL_INCLUDE")]
ext_modules = [
Extension("k3lib", sources=["main.pyx"],
libraries=["k2"], include_dirs=includes, library_dirs=includes, language="c++",
extra_compile_args=["-O3", "-march=native"], extra_objects=[f"{includes[0]}/libk2.a"],
extra_link_args=['-static', '-Wl,-Bstatic', '-flinker-output=exec'])
]
#extra_objects=[f"{includes[0]}/libk2.a"]
#extra_link_args=['-static']
setup(name="k3lib", ext_modules=cythonize(ext_modules, language_level="3"))
Still, g++ thinks that I want to build a shared library, and thus the error message. Is there a way to override the -shared option? I'm planning to go into Cython's files and edit them myself, but was wondering is there a simpler way?
Context: I was following this question on SO but can't replicate their success.

Build issue with go using SWIG and an external C library

I am trying to create a golang program which will use an external C library.
Before doing complex stuff, I wanted to test the use of SWIG in a small foo example.
I also want to be able to use the "go get" syntax without having to manually run swig. And to take into account that the external C library shall have been built before and can be located anywhere on the machine.
I am using golang 1.12.5 and swig 3.0.12
I have created the following structure:
.
|-- libfoo
| |-- foo.c
| |-- foo.h
| `-- libfoo.so
`-- src
|-- example_test.go
|-- lib.go
`-- libfoo.swig
In the libfoo folder I have a simple shared library. The files contain:
foo.c:
#include "foo.h"
int foo(int c){
return c+1;
};
foo.h
int foo(int c);
That I've compiled it with:
gcc -o ./libfoo.so -fPIC -shared ./foo.c
Then the golang files:
libfoo.swig
%module libfoo
%{
extern int foo(int a);
%}
extern int foo(int a);
lib.go
package libfoo
/*
#cgo LDFLAGS: -L../libfoo -lfoo
*/
import "C"
And finally example_test.go
package libfoo
import (
"testing"
"fmt"
)
func TestFoo(*testing.T) {
i := Foo(1)
fmt.Printf("%v\n",i)
}
When I try to build with "go build -x" It seems that the cgo directives located in the "lib.go" file are not taken into account as I do not see the flag appears in the output. Here is the output
06aa7e308d6:/mnt/data/src# go build -x
WORK=/tmp/go-build551116655
mkdir -p $WORK/b001/
swig -version
cd $WORK
/opt/go/pkg/tool/linux_amd64/compile -o ./b001/_go_.o -trimpath ./b001 -p main -complete -goversion go1.12.5 -D _$WORK -c=4 ./swig_intsize.go
cd /mnt/data/src
swig -go -cgo -intgosize 64 -module libfoo -o $WORK/b001/libfoo_wrap.c -outdir $WORK/b001/ libfoo.swig
CGO_LDFLAGS='"-g" "-O2"' /opt/go/pkg/tool/linux_amd64/cgo -objdir $WORK/b001/ -importpath _/mnt/data/src -- -I $WORK/b001/ -g -O2 ./lib.go $WORK/b001/_libfoo_swig.go
cd $WORK
gcc -fno-caret-diagnostics -c -x c - || true
gcc -Qunused-arguments -c -x c - || true
gcc -fdebug-prefix-map=a=b -c -x c - || true
gcc -gno-record-gcc-switches -c -x c - || true
cd $WORK/b001
TERM='dumb' gcc -I /mnt/data/src -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -I ./ -g -O2 -o ./_x001.o -c _cgo_export.c
TERM='dumb' gcc -I /mnt/data/src -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -I ./ -g -O2 -o ./_x002.o -c lib.cgo2.c
TERM='dumb' gcc -I /mnt/data/src -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -I ./ -g -O2 -o ./_x003.o -c _libfoo_swig.cgo2.c
TERM='dumb' gcc -I /mnt/data/src -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -I ./ -g -O2 -o ./_x004.o -c libfoo_wrap.c
TERM='dumb' gcc -I /mnt/data/src -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -I ./ -g -O2 -o ./_cgo_main.o -c _cgo_main.c
cd /mnt/data/src
TERM='dumb' gcc -I . -fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=$WORK/b001=/tmp/go-build -gno-record-gcc-switches -o $WORK/b001/_cgo_.o $WORK/b001/_cgo_main.o $WORK/b001/_x001.o $WORK/b001/_x002.o $WORK/b001/_x003.o $WORK/b001/_x004.o -g -O2
# _/mnt/data/src
/tmp/go-build551116655/b001/_x004.o: In function `_wrap_foo_libfoo_0f106433f15c8754':
/tmp/go-build/libfoo_wrap.c:255: undefined reference to `foo'
collect2: error: ld returned 1 exit status
If I set the CGO_LDFLAGS using an environment variable, it works. However I want to be able to just use "go get" without having those variables before.
I don't understand why go does not take my #cgo directive into account.
Did I miss something ?
Someone on the golang github repository has solved my issue.
The solution was to remove the newline between the import "C" directive and the comments containing the #cgo directives.

Is there an option for gcc which discards -g flag?

I'm building a package which provides many makefiles, each makefile has hard coded in side something like
CFLAGS = -g -O2 -Wall ...
CXXFLAGS = -g -O2 -Wall ...
I want to discard -g option but I don't want to edit all makefiles (even not automatically with sed or something similar). The configure script which comes with the package doesn't have enable/disable debug option but I can pass it CFLAGS and CXXFLAGS variables and it concatenates their values to the CFLAGS and CXXFLAGS variables respectively which include the -g option.
Is there an option which will discard -g in case it is specified? Something like
gcc -option-im-looking-for -g file.c -o file
Will build the binary file without debug symbols. I don't want to strip the binary, I want it to be created stripped.
You could negate the effect of -g by adding -g0. Saying
gcc -g -g0 foo.c -o file.o
would produce a binary identical to one obtained by saying
gcc foo.c -o foo.o
Quoting man gcc:
-glevel
...
Level 0 produces no debug information at all. Thus, -g0 negates
-g.
You don't need to edit makefiles. Just override the variables on the command line:
$ cat Makefile
CFLAGS = -g -Wall
all:
echo $(CFLAGS)
$ make
echo -g -Wall
-g -Wall
$ make CFLAGS=-Wall
echo -Wall
-Wall

How to build Qt 5.1 for QNX target (arm)

new update
I think I should edit the title now.
To make sure I got a clean environment, I
download qt5.1.1 src code from qt-prject.
export QNX_TARGET, QNX_HOST, AND add QNX_HOST into PATH.
then Run the script
./configure -opensource -confirm-license -xplatform qnx-armv7le-qcc -v
so in here, -opensource -confirm-license just avoid the Q&A -v is to show full message.
a lot of error message.
Creating qmake...
make: Nothing to be done for `first'.
Running configuration tests...
Determining architecture... ()
qcc -Vgcc_ntoarmv7le -c -Wno-psabi -lang-c++ -g -Wall -W -fPIE -DQT_NO_CLIPBOARD -I../../mkspecs/qnx-armv7le-qcc -I. -I/opt/qnx650/target/qnx6/usr/include -I/opt/qnx650/target/qnx6/usr/include/freetype2 -o arch.o arch.cpp
Unable to determine architecture!
Could not determine the target architecture!
Turn on verbose messaging (-v) to see the final report.
Determining architecture... ()
g++ -c -pipe -g -Wall -W -fPIE -I../../mkspecs/linux-g++ -I. -o arch.o arch.cpp
g++ -o arch arch.o { test -n "" && DESTDIR="" || DESTDIR=.; } && test $(gdb --version | sed -e 's,[^0-9]\+\([0-9]\)\.\([0-9]\).*,\1\2,;q') -gt 72 && gdb --nx --batch --quiet -ex 'set confirm off' -ex "save gdb-index $DESTDIR" -ex quit 'arch' && test -f arch.gdb-index && objcopy --add-section '.gdb_index=arch.gdb-index' --set-section-flags '.gdb_index=readonly' 'arch' 'arch' && rm -f arch.gdb-index || true
Found architecture in binary
CFG_HOST_ARCH="x86_64"
CFG_HOST_CPUFEATURES=" mmx sse sse2"
System architecture: 'unknown'
Host architecture: 'x86_64'
C++11 auto-detection... ()
qcc -Vgcc_ntoarmv7le -c -Wno-psabi -lang-c++ -O2 -Wc,-std=gnu++0x -Wall -W -fPIE-DQT_NO_CLIPBOARD -I../../../mkspecs/qnx-armv7le-qcc -I. -I/opt/qnx650/target/qnx6/usr/include -I/opt/qnx650/target/qnx6/usr/include/freetype2 -o c++11.o c++11.cpp
C++11 disabled.
floatmath auto-detection... ()
qcc -Vgcc_ntoarmv7le -c -Wno-psabi -lang-c++ -O2 -Wall -W -fPIE -DQT_NO_CLIPBOARD-I../../../mkspecs/qnx-armv7le-qcc -I. -I/opt/qnx650/target/qnx6/usr/include -I/opt/qnx650/target/qnx6/usr/include/freetype2 -o floatmath.o floatmath.cpp
qcc -Vgcc_ntoarmv7le -c -Wno-psabi -lang-c++ -O2 -Wall -W -fPIE -DQT_NO_CLIPBOARD -I../../../mkspecs/qnx-armv7le-qcc -I. -I/opt/qnx650/target/qnx6/usr/include -I/opt/qnx650/target/qnx6/usr/include/freetype2 -o freetype.o freetype.cpp
FreeType disabled.
STL auto-detection... ()
qcc -Vgcc_ntoarmv7le -c -Wno-psabi -lang-c++ -O2 -Wall -W -fPIE -DQT_NO_CLIPBOARD -I../../../mkspecs/qnx-armv7le-qcc -I. -I/opt/qnx650/target/qnx6/usr/include -I/opt/qnx650/target/qnx6/usr/include/freetype2 -o stltest.o stltest.cpp
STL disabled.
STL functionality check failed! Cannot build Qt with this STL library.
Turn on verbose messaging (-v) to /home/pasadeveloper/qt-everywhere-opensourcesrc-5.1.1/qtbase/configure to see the final report.
UPDATE:
I am working on QNX for ARM, target is an arm platform device.
Thing is getting weird. in Env Var, I put
$QNX_CONFIGURATION=/etc/qnx
$QNX_JAVAHOME=/opt/qnx650/_jvm
$QNX_TARGET=/opt/qnx650/target/qnx6
$QNX_HOST=/opt/qnx650/host/linux/x86
but when I do qmake qmake.conf mkspecs/qnx-armv7le-qcc folder
it returns an error message Project ERROR: QNX_TARGET environment variable not set
Have no clue what is going on now.
not just qmake qmake.conf
I try to build qt 5.1.2 at another host, ubuntu 12.04-64bit.
also get the same error message. Project ERROR: QNX_TARGET environment variable not set
I was working at Qt development under linux(FYI Ubuntu 12.04 -64bits), but I need to compile this program to binary for QNX.
I install QNX MOmentics IDE which provide QNX-gcc for me.
but I can't find the qmake-qnx.
Under the QT/gcc_64/mkspecs/qnx-armv7le-qcc, there is a file call qmake.conf. I guess this is where I can generate my qmake-qnx. after I run qmake -o Makefile qmake.conf, there is a Makefile generated.
However, when I run make, error occured.
qcc -Vgcc_ntoarmv7le -lang-c++ -Wl,-rpath-link,/opt/qnx650/target/qnx6/armle-v7/lib -Wl,-rpath-link,/opt/qnx650/target/qnx6/armle-v7/usr/lib -Wl,-O1 -Wl,-O1 -Wl,-rpath,/home/pasadeveloper/Qt5.1.0/5.1.0/gcc_64 -Wl,-rpath,/home/pasadeveloper/Qt5.1.0/5.1.0/gcc_64/lib -o qmake -L/opt/qnx650/target/qnx6/armle-v7/lib -L/opt/qnx650/target/qnx6/armle-v7/usr/lib -lm -L/home/pasadeveloper/Qt5.1.0//5.1.0/gcc_64/lib -lQt5Gui -lQt5Core -lGL -lpthread
cc: no files to process
make: *** [qmake] Error 1
pasadeveloper#ubuntu:~/Qt5.1.0/5.1.0/gcc_64/mkspecs/qnx-armv7le-qcc$
You do not "generate" your qmake-qnx like that. You are supposed to use the native qmake for generating proper makefiles for your target to aid the cross-compilation. Also, running qmake qmake.conf in the relevant mkspecs folder is wrong because that is not a project file as you may think.
When building Qt itself for instance, you should be using the proper mkspecs files for the target in which case, it is the one you also mentioned above if it is built for that particular arm qnx variant, called qnx-armv7le-qcc.
Here is the exact command you need to run after downloading the relevant Qt sources, like 5.1.1:
./configure -opensource -confirm-license -xplatform qnx-armv7le-qcc -v
For this QNX version, the bottom line is, if you do not have SP1 and libscreen, it will not work. The QPA plugin would link against it. This library provides the API to the graphics server on newer QNX variants. You need to talk to your QNX representatives.
Here you can find further information about the topic.
$QNX_TARGET=/opt/qnx650/target/qnx6
is probably not doing what you want. In shell scripts, you don't put a "$" in front of a variable when you are defining the variable, only when you access the variable:
X=hello
echo $X

How to compile LD_PRELOAD for most systems

I Have a LD_PRELOAD file. On what OS and conditions i should compile this preload to work on most systems (Unix/Linux). The most wanted are FreeBSD, Ubuntu, CenstOS, Solaris.
Thanks!
You need to compile it into a shared library. Here's how I typically compile mine:
libt.so: t.lo
g++ -fPIC -O3 -W -Wall -shared -Wl,-export-dynamic -o $# $^ -lc
t.lo: t.cc
g++ -c -fPIC -O3 -W -Wall $^ -o $#
Then to use it, you add the library to the LD_PRELOAD environment variable before launching that file. If you do it this way from the bash command line:
LD_PRELOAD=libt.so executable_name -and args
then, it will only set it for that command line run, and not affect any other programs you launch afterwards.