boost_thread not linking on NaCl - boost

I receive this error when linking -lboost_thread into my executable on google Native Client (pepper_19):
nacl_sdk/pepper_19/toolchain/mac_x86_glibc/x86_64-nacl/usr/lib/libboost_thread.a: could not read symbols: Archive has no index; run ranlib to add one
I compiled boost according to the instructions at naclports here: http://code.google.com/p/naclports/wiki/InstallingSDL (except using the boost library directory instead of SDL... I also used this same process to correctly compile NaCl zlib library)
cd naclports/src/libraries/boost_1_47_0
export NACL_PACKAGES_BITSIZE=32; ./nacl-boost_1_47_0.sh
export NACL_PACKAGES_BITSIZE=64; ./nacl-boost_1_47_0.sh
this generates the libboost_thread.a file and puts it them in the /usr/lib directories of my NACL installation. I thought maybe somehow I mistakenly built a wrong type of library for linking with NaCl. Is there a way to check this and/or fix it?
I tried:
cd naclports/src/out/repository-x86_64/boost_1_47_0/bin.v2/libs/thread/build/darwin-4.2.1/release/link-static/threading-multi
nm libboost_thread.a
and this yielded:
libboost_thread.a(thread.o):
0000000000052d08 s EH_frame0
000000000004f50c s GCC_except_table100
000000000004f534 s GCC_except_table101
000000000004f574 s GCC_except_table102
000000000004f5c0 s GCC_except_table103
000000000004f600 s GCC_except_table104
000000000004f64c s GCC_except_table105
000000000004f68c s GCC_except_table106
000000000004f6d8 s GCC_except_table107
.
.
.
.
etc, etc..
However then I ran:
nacl_sdk/pepper_19/toolchain/mac_x86_glibc/bin/x86_64-nacl-nm libboost_thread.a
and got:
__.SYMDEF SORTED: File format not recognized
nacl_sdk/pepper_19/toolchain/mac_x86_glibc/bin/x86_64-nacl-nm: thread.o: File format not recognized
nacl_sdk/pepper_19/toolchain/mac_x86_glibc/bin/x86_64-nacl-nm: once.o: File format not recognized
And finally. I ran:
file pthread/thread.o
pthread/thread.o: Mach-O 64-bit object x86_64
however the same command on a zlib object file results in:
ELF 64-bit LSB relocatable, x86-64, version 1, not stripped
I would appreciate advice on building a correctly cross-compiled NaCl libboost_thread.a
Thank you.

Some libraries in NaCl ports can only be built on linux. So you have to either find why boost decides to use system ar instead of x86_64-nacl-ar or install VM with linux where they are the same.

Related

Cross compiled binary not running on RPI, did I compile it correctly?

I am trying to cross compile a small rust application for the RPI. I am cross compiling because compiling directly on the PI takes way too long and it hits 75C.
I followed various instructions, but what I ended up doing is this:
Install "armv7-unknown-linux-gnueabihf" target with rustup
Download rpi tools from here: https://github.com/raspberrypi/tools
Add the "tools/arm-bcm2708/arm-linux-gnueabihf/bin/" folder to PATH
Add ".cargo/config" file with:
[target.armv7-unknown-linux-gnueabihf]
linker = "arm-linux-gnueabihf-gcc"
run "cargo build --target armv7-unknown-linux-gnueabihf --release"
scp the file to the RPI
chmod +x the_file
do "./the_file"
I get bash: ./the_file: No such file or directory
Yes, I am indeed in the right directory.
So this is the output from "file":
ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically
linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 2.6.32,
with debug_info, not stripped
I'm not experienced enough with this sort of stuff to determine if the binary that I produced is suitable to be run on an RPI3 B.
Did I produce the correct "type" of binary?
P.S. I am running DietPi distro on the PI. It is based on debian if that's of any relevance.
So I solved this by cheating. I found https://github.com/rust-embedded/cross which took about 30 seconds to get going and now I can cross compile to pretty much anything. I highly recommend it!
The error message "No such file or directory" is not about the your executable but about the dynamic libraries linked to it which are missing from the target system.
To find out which libraries your executable needs you have to run the following command.
ldd /usr/bin/lsmem
This will output something like this
linux-vdso.so.1 (0x00007fffc87f1000)
libsmartcols.so.1 => /lib/x86_64-linux-gnu/libsmartcols.so.1 (0x00007fe82fe71000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe82fc7f000)
/lib64/ld-linux-x86-64.so.2 (0x00007fe82fedd000)
Now you have to check that all this libraries are available on your system. rust-cross probably uses the correct linker for your target so that is probably the reason this works with it. To modify the linker see https://stackoverflow.com/a/57817848/5809980

w_scan cross compile issue

I download the w_scan project(a small command line utility used to perform frequency scans for DVB and ATSC transmissions.) from http://wirbel.htpc-forum.de/w_scan/index_en.html. I also install gcc-arm-linux-gnueabi on my Ubuntu x86_64. I use the ./configure --host=arm-linux CC=arm-linux-gnueabi-gcc command to cross-compile, and it generates a binary file. However, I copy that file to my target board and execute that file, it shows sh: ./w_scan: No such file or directory.
I use the file command to see information of that binary file, it shows ELF 32-bit LSB executable, ARM, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.31, BuildID[sha1]=0x9a584b4720fadf5eb5b77034ac85092daeb728c9, not stripped.
I found that error message stands the configuration of cross-compile doesn't correct.(reference http://ubuntuforums.org/showthread.php?t=1141792). How can I fix my configuration and correct cross-compile that project, THANKS!
./configure --host=arm-linux CC=arm-linux-gnueabi-gcc
make CFLAGS=-static
copy that binary file to my target board, it can execute normally and successfully.
And the file w_scan will shows
ELF 32-bit LSB executable, ARM, version 1 (SYSV), statically linked, for GNU/Linux 2.6.31, BuildID[sha1]=0x67b7e9f93015607f891c0b77493d9e47059ef6a1, not stripped.

Why is my shared library not found?

I'm trying to compile an example program that links to the shared library produced by Sundown. I'm compiling the program like so.
$ gcc -o sd sundown.c -L. -lsundown
Yet, when I run it I get the following error.
./sd: error while loading shared libraries: libsundown.so: cannot open shared object
file: No such file or directory
The output of ls is.
$ ls
libsundown.so libsundown.so.1 sundown.c sd
Why is the shared library not found by ld?
Short solution:
add . (or whatever it is from your -L flag) to your LD_LIBRARY_PATH. When you run sd, it'll look for libraries in the standard places and the LD_LIBRARY_PATH. Note that since you've added ., this will only work if you run sd from the same directory libsundown.so is in.
I plan on distributing the compiled binary. How can I do so that the library can be distributed without forcing people to edit their LD_LIBRARY_PATH?
You should install libsundown.so in one of the standard places, like /usr/lib or /usr/local/lib. You can do that with an installer or a make file, or something as simple as a INSTALL or README that tells the user to stick the libraries there and ensure the permissions are set to something sensible.
On Centos systems with /usr/lib and /usr/lib64, if you install 64-bit libs manually into /usr/lib then at runtime, the library may not be visible even though at build time it is visible (I used autotools and it was able to find my zopfli library from /usr/lib without any problem). When I execute the my_binary that links to /usr/lib/libzopfli.so.1 I got
libzopfli.so.1 => not found
After moving libzopfly.so.1 from /usr/lib to /usr/lib64, then everything works fine.

Linking with libtcmalloc ubuntu

I had installed the package libtcmalloc-minimal0
but when I try to compile my program with flag
-ltcmalloc-minimal0
I am getting error
/usr/bin/ld: cannot find -ltcmalloc_minimal0
I had checked /usr/lib and the library is there
More Info
dpkg gives following o/p
dpkg -L libtcmalloc-minimal0
/.
/usr
/usr/lib
/usr/lib/libtcmalloc_minimal.so.0.0.0
/usr/lib/libtcmalloc_minimal_debug.so.0.0.0
/usr/share
/usr/share/doc
/usr/share/doc/libtcmalloc-minimal0
/usr/share/doc/libtcmalloc-minimal0/TODO
/usr/share/doc/libtcmalloc-minimal0/AUTHORS
/usr/share/doc/libtcmalloc-minimal0/copyright
/usr/share/doc/libtcmalloc-minimal0/changelog.gz
/usr/share/doc/libtcmalloc-minimal0/README.gz
/usr/share/doc/libtcmalloc-minimal0/changelog.Debian.gz
/usr/lib/libtcmalloc_minimal.so.0
/usr/lib/libtcmalloc_minimal_debug.so.0
and I am compiling for 64 bit mode
and library is also 64 bit
file /usr/lib/libtcmalloc_minimal.so.0.0.0
/usr/lib/libtcmalloc_minimal.so.0.0.0: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, stripped
You can't link simply to a file with -l if it doesn't end exactly with .so, since the linker assumes a particular naming convention (lib*.so).
You have several choices:
Install libtcmalloc-minimal0-dev if it exists, which should provide the .so dynamic link.
Create the symlink yourself: cd /usr/lib; ln -s libtcmalloc_minimal.so.0.0.0 libtcmalloc_minimal.so; cd -
Link directly to the library without the symlink by using gcc test.c /usr/lib/libtcmalloc_minimal.so.0.0.0
Link using the -l option using the full name: -l:libtcmalloc_minimal.so.0.0.0
Running dpkg -L libtcmalloc-minimal0 will show you that the library is /usr/lib/libtcmalloc_minimal.so.0 so the correct option should be -ltcmalloc_minimal without any digit

Using gcc libraries with mingw for cross-compiling?

While I am sure that gcc libraries (.a) are incompatible with mingw lubraries (also .a), I want to know. Can I cross-compile a windows executable with mingw using the gcc .a library generated for unix systems?
In code form, keep in mind this is a unix system:
cd mylibrarydirectory/
make #produces mylibrary.a
cd ../myprogramdirectory/
gcc -o UnixExecutable mysrc.c -L../mylibrary.a
#and I get a valid unix executable
i586-mingw32msvc-gcc -o Win32Executable.exe mysrc.c -L../mylibrary.a
#will I get a valid windows executable?
No. You have to recompile the library for Windows.
The second command should give an "incompatible library format" or something error. Or at least undefined references to whatever is linked in.

Resources