Looking at the libs (:/Qt/5.11.0/5.11.0/gcc_64/lib/) of Qt5.11.0, I was wondering which one was linking openssl. So I ran the following:
for lib in `ls *.so`; do ldd $lib | grep ssl; done
And I got no output, suggesting that none of the libraries are linking against openssl. But I believe that Qt must link against it somehow (e.g. for networking).
How is the linking done? And where does it look for openssl? Do I have a way to know which one Qt found on my system (e.g. given I have multiple ones)?
Qt links some libraries dynamically at runtime. In order to see which libraries are loaded, one can check the diagnostic output of the dynamic linker, as hinted by Matteo:
Say my executable is called QGroundcontrol:
On Linux:
LD_DEBUG=libs ./QGroundcontrol 2>&1 | grep -E "ssl|crypto"
On macOS:
DYLD_PRINT_LIBRARIES=1 ./QGroundcontrol 2>&1 | grep -E "ssl|crypto"
From this I could see that Qt finds openssl on the system.
Now, I still don't know how I can tell Qt to look somewhere else (in case I want to link another openssl), but that's another question.
Related
I am learning to program in Python and Rust. On different versions of Ubuntu these programs compiled and ran perfectly. Now that I have a dedicated Fedora 30 KDE system, every time I try and build a program, I get a warning: Failed to load module "appmenu-gtk-module"
I have tried looking this up and have re/installed anything GTK on my system. The programs otherwise function well, but no menus are drawn. I was also trying things in GNOME and hit the same thing.
I am also using QT. Those programs also build and run fine, but again, no menu.
I'm going bonkers with this. Any help is appreciated.
The appmenu-gtk module is not packaged on Fedora. (GNOME doesn't support them anyway.)
The real questions are:
Why is it configured to load? Did you copy or share GTK config files from an Ubuntu system? You should remove this module from your settings.
Even with improper configs I don't believe this should result in menus not appearing. It should just fail to load and work as normal. How is your application using menus?
I finally got so fed up with getting this error that I went full nerd-diagnosis, and ran this command to find out which file contained the errant reference to the appmenu-gtk (the package that would provide this is not installable on my system either).
(Replace "dolphin" with the command that is giving you the error.)
strace -e openat,access dolphin 2>&1 |grep -v ENOENT |awk '/appmenu-gtk/ {exit} !/appmenu-gtk/ {print}'|cut -d '"' -f2 |sort|uniq|xargs grep appmenu-gtk 2>/dev/null
This will then give you a list of files which contain the line appmenu-gtk, and in my case it was ~/.config/gtk-3.0/settings.ini. From there I just commented it out, and that gets rid of the error message (not sure if this will fix your problem of not having any menus, but you might just be able to edit that line to fix it in another way if commenting it out doesn't work).
I just freshly installed Qt Creator 4.1.0
Based on Qt 5.7.0 (GCC 4.9.1 20140922 (Red Hat 4.9.1-10), 64 bit)
This error drives me crazy after I fixed all kit errors, actually I spent some time on google looking for proper compiler. This could be something with compiler version I think:
/usr/include/c++/5.3.1/cstddef:45: error: stddef.h: No such file or
directory
I saw solutions for windows everywhere but could not find for linux, does anyone has experience how to fix it?
Screenshots
rpm -qa | grep devel | sort
expat-devel-2.1.0-10.fc22.x86_64
fontconfig-devel-2.11.94-4.fc22.x86_64
freetype-devel-2.5.5-2.fc22.x86_64
gdbm-devel-1.11-4.fc22.x86_64
glibc-devel-2.21-13.fc22.i686
glibc-devel-2.21-13.fc22.x86_64
java-1.8.0-openjdk-devel-1.8.0.65-3.b17.fc22.x86_64
kernel-debug-devel-4.2.5-201.fc22.x86_64
kernel-debug-devel-4.2.6-200.fc22.x86_64
kernel-devel-4.2.6-200.fc22.x86_64
libdb-devel-5.3.28-12.fc22.x86_64
libdrm-devel-2.4.61-3.fc22.x86_64
libICE-devel-1.0.9-2.fc22.x86_64
libpng-devel-1.6.16-3.fc22.x86_64
libSM-devel-1.2.2-2.fc22.x86_64
libstdc++-devel-5.3.1-6.fc22.i686
libstdc++-devel-5.3.1-6.fc22.x86_64
libXau-devel-1.0.8-4.fc22.x86_64
libxcb-devel-1.11-8.fc22.x86_64
libXcursor-devel-1.1.14-4.fc22.x86_64
libXdamage-devel-1.1.4-6.fc22.x86_64
libXext-devel-1.3.3-2.fc22.x86_64
libXfixes-devel-5.0.1-4.fc22.x86_64
libXft-devel-2.3.2-2.fc22.x86_64
libXi-devel-1.7.4-2.fc22.x86_64
libXinerama-devel-1.1.3-4.fc22.x86_64
libXrandr-devel-1.4.2-2.fc22.x86_64
libXrender-devel-0.9.9-1.fc22.x86_64
libxshmfence-devel-1.2-1.fc22.x86_64
libXt-devel-1.1.4-10.fc22.x86_64
libXv-devel-1.0.10-2.fc22.x86_64
libXxf86vm-devel-1.1.4-1.fc22.x86_64
libX11-devel-1.6.3-1.fc22.x86_64
mesa-libGL-devel-10.6.9-1.20151008.fc22.x86_64
mesa-libGLU-devel-9.0.0-7.fc22.x86_64
perl-devel-5.20.3-328.fc22.x86_64
python3-devel-3.4.2-6.fc22.x86_64
qt-devel-4.8.7-4.fc22.x86_64
systemtap-devel-2.9-1.fc22.x86_64
systemtap-sdt-devel-2.9-1.fc22.x86_64
xorg-x11-proto-devel-7.7-12.fc21.noarch
zlib-devel-1.2.8-7.fc22.x86_64
I had this problem as well, and for me I had to disable ClangCodeModel plugin. To do this, I went to Help->About Plugins...->Uncheck ClangCodeModel (under C++ category). After restarting QT Creator, everything was working fine. I found this solution on QT Forums
If the compiler works from a terminal, it should work from QtCreator. So first make it work from the terminal.
From a terminal, create a file main.cpp with:
#include <cstddef>
int main()
{
return 0;
}
Then type the command:
gcc -H main.cpp -o main
If the compilation works, there must be a problem in your kit definition in QtCreator. Possibly make sure the folder where stddef.h is in the include file list of your kit. But you should not need to do that. Temporarily, you can add the include path to your project (see How to add include path in Qt Creator?) to check this is really the problem. Then you'll need to find a way to fix the kit for good.
If the compilation does not work, fix your environment (possibly using sashoalm's commented link). QtCreator is just and IDE, if you run it with a broken compiler it won't fix it for you. The compilation output will show where files (cstddef and then stddef.h) are picked from (-H option). Try cpp -v to see where included files are searched.
On my machine, compilation output gives me:
. /usr/include/c++/4.8/cstddef ..
/usr/include/x86_64-linux-gnu/c++/4.8/bits/c++config.h ...
/usr/include/x86_64-linux-gnu/c++/4.8/bits/os_defines.h ....
/usr/include/features.h .....
/usr/include/x86_64-linux-gnu/sys/cdefs.h ......
/usr/include/x86_64-linux-gnu/bits/wordsize.h .....
/usr/include/x86_64-linux-gnu/gnu/stubs.h ......
/usr/include/x86_64-linux-gnu/gnu/stubs-64.h ...
/usr/include/x86_64-linux-gnu/c++/4.8/bits/cpu_defines.h ..
/usr/lib/gcc/x86_64-linux-gnu/4.8/include/stddef.h Multiple include
guards may be useful for: /usr/include/c++/4.8/cstddef
/usr/include/x86_64-linux-gnu/bits/wordsize.h
/usr/include/x86_64-linux-gnu/gnu/stubs-64.h
/usr/include/x86_64-linux-gnu/gnu/stubs.h
/usr/lib/gcc/x86_64-linux-gnu/4.8/include/stddef.h
see stddef.h was found in /usr/lib/gcc/x86_64-linux-gnu/4.8/include
And cpp -v gives:
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-linux-gnu/4.8/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
Note: If you created the kit manually, I would recommend that you uninstall QtCreator. Make gcc work from a terminal and then reinstall QtCreator. This one should create the kits automatically and they should then work.
This is a common problem with QT I experience a lot with all versions of Fedora, the problem is that the path to "/usr/lib64/qt5/bin" is missing from the user environment.
To check for the path at a command line what the path is present set to enter the following: echo $PATH
You should see the "/usr/lib64/qt5/bin" listed somewhere in the response if it is not present then edit the .bashrc file in the root of your home directory as follows: -
Add QT5 build environment
if! [[ "$PATH" =~ "/usr/lib64/qt5/bin" ]]
then
PATH="/usr/lib64/qt5/bin:$PATH"
fi
Just above the "export PATH" statement
You will need to log off and on again for the changes to take effect.
When compiling with -fsanitize=memory I get WARNING: Trying to symbolize code, but external symbolizer is not initialized! when running the program. How do I initialize the external symbolizer?
I solved my own problem using MSAN_SYMBOLIZER_PATH=$(which llvm-symbolizer-3.4) ./a.out. The problem is that Ubuntu postfixes the version number but the binary doesn't know that. Of course you need to use MSAN instead of ASAN when using the memory sanitizer.
You are supposed to be able to set the ASAN_FILTER environment variable to point at a symbolizer, but I could not get it to work. However, you can redirect stderr into a symbolizer after the fact. You'll still get the warnings about the uninitialized symbolizer, but the filenames and line numbers will be correct.
You can use asan_symbolizer.py as the external symbolizer. After downloading it from that link (to /tmp, for example), invoke your program like so (in bash, for this example):
./myprogram 2>&1 | /tmp/asan_symbolize.py | c++filt
On my Ubuntu system, the issue is that LLVM's tools are installed under /usr/bin with version suffixes (like llvm-symbolizer-4.0), and the sanitizer tools are looking for them without version suffixes.
LLVM also installs its binaries to, e.g., /usr/lib/llvm-4.0/bin; the tools under /usr/bin are actually just symlinks. So an easy solution is to add the appropriate /usr/lib/llvm-*/bin directory to your path when working with sanitizers.
I received such warning when I run program debug version (compiled with -fsanitize=address) on Linux machine that didn't contain clang installation. The problem disappeared after I installed clang from devtoolset.
I need to reduce the size of nginx when compiled with openssl on an embedded target.
I am able to compile the nginx with ssl using the steps given in the http://wiki.nginx.org/InstallOptions. It compiles well, but the problem I am facing its size, i.e nginx binary coming to almost 6MB.
Since I have to run the nginx on the embedded target, I tried cross compiling with for arm based board. I am to cross compile and the size is coming to 1.3MB for the target.
If I disable openssl and compile its coming to 400KB, I think nginx is statically linking the openssl .
If so how to dynamically include the openssl to nginx, because my target libs already has the support for crypto and ssl libs. I tried all the option but could not succeeded.
If so how to dynamically include the openssl to nginx
You need to specify OpenSSL with:
--with-http_ssl_module
The above command will effective link against the OpenSSL shared object if available.
ngingx can also build OpenSSL for you with:
--with-openssl
I seem to recall some problems with --with-openssl (but I think they were related to the FIPS Capable OpenSSL Library).
To be certain you link against the shared object, you can run the following script on the nginx sources:
OPENSSL_INSTALL_DIR=/usr/local/ssl
OPENSSL_LIB_DIR="$OPENSSL_INSTALL_DIR/lib"
...
for FILE in "auto/lib/sha1/conf" "auto/lib/md5/conf" "auto/lib/openssl/conf"
do
TFILE=`mktemp /tmp/fix.XXXXXXXXXX`
sed -e "s|-lssl|$OPENSSL_LIB_DIR/libssl.so|g" "$FILE" > "$TFILE"
mv "$TFILE" "$FILE"
TFILE=`mktemp /tmp/fix.XXXXXXXXXX`
sed -e "s|-lcrypto|$OPENSSL_LIB_DIR/libcrypto.so|g" "$FILE" > "$TFILE"
mv "$TFILE" "$FILE"
done
That will ensure the linker links against a specific OpenSSL, and not just the one it finds (I've had a lot of trouble with -L, -l, -static and -shared in the past when cross compiling).
nginx binary coming to almost 6MB.
...
and the size is coming to 1.3MB for the target.
I'm not sure how small the size can get with OpenSSL present. The following may (or may not) reduce it further.
If you compile and link with the static archive, then you also have some compiler and linker options available to you. Specifically, you can discard unused functions with gc-sections:
--with-cc-opt="-ffunction-sections -fdata-sections"
--with-ld-opt="-Wl,--gc-sections"
You also have the strip option. You can run strip -s on the final binary or pass it to the linker though options:
--with-ld-opt="-Wl,-s"
See ld(1) and --strip-debug and --strip-all options.
-Bsymbolic might also help by reducing an ELF section size (I think its either the GOT or PLT, but I don't recall at the moment).
I'm using gcc (GCC) 4.5.4 20120510 for GNAT GPL 2012 (20120509)
and qtada from qtada-gpl-3.2.0-20120708-3871-qt4.8.2-2.exe installer.
I'm trying to compile example from "..\GNAT\2012\examples\qtada\sql\cached_table", but it say "table_editors-moc.ads not found",
The error came from statement :
with Table_Editors.MOC; pragma Warnings (Off, Table_Editors.MOC);
-- Child package MOC must be included in the executable.
Where can i found the "Child package MOC" that contains "table_editors-moc.ads" and another moc file??
I don't know Qt or QtAda, but a quick search indicates that Qt uses a Meta Object Compiler (MOC) to auto-generate source code from macros. Could it be that your Table_Editor.MOC is supposed to be generated?
I'm surprised that QtAda has installed its examples at \GNAT\2012\examples; judging by the way GNAT is set up on this Mac, I'd have expected \GNAT\2012\share\examples.
However .. I suspect that QtAda's file system layout is complicated enough that you'll need to use a "GNAT Project file" to do the build. I hope there's a .gpr file in the same directory as your example code (if not, I can't help); if so, and assuming it's called cached_table.gpr, then in a command window say
gnatmake -p -P cached_table.gpr
or (following the documentation for QtAda 3.1)
gprbuild -p -P cached_table.gpr