I see that JProfiler comes with libstdc++ and libexpat in the library folder. Also, the standard location libraries will be loaded first since agent(libjprofilerti) is loaded later.
ldd -v says that depend on the libraries which is packaged.
Why are these libraries included?
On some older Linux distributions these libraries are not installed by default, so they are included with the JProfiler agent. On modern Linux distributions it would indeed not be necessary to bundle these libraries.
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I'm looking for a cross compiler to compile for linux under the msys2 environment.
I'm looking for somethink like x86_64-w64-linux-gcc. But I can't find it.
Which package I have to install?
You'll need a VM or a Linux machine to test the resulting binaries, so I'd just compile on one in the first place.
But cross-compilation should be possible too:
Boot up your favorite Linux distribution in a VM.
Install the libraries you want to have. Install g++ to get libstdc++, and possibly other basic libraries.
Copy the root directory / from the VM to the Windows machine.
You only need headers and libraries, not everything. You'll have to experiment to know what directories can or can't be safely removed.
Install Clang on the Windows machine. Installing LLD is also a good idea (it's a separate package in MSYS2; or, if you're using the official Clang binaries, it's bundled with them).
We're using Clang, because it's inherently a cross-compiler, i.e. doesn't require separate binaries to target a different platform, unlike GCC.
Compile with Clang with --target=x86_64-pc-linux-gnu --sysroot=path/to/root/directory.
-fuse-ld=lld is probably a good idea as well.
The string x86_64-pc-linux-gnu was obtained by running clang++ --version on a Linux machine.
You might need a few more flags, but this should be a good starting point.
My developing/producing environments are all CentOS-7.7.
In order to compile my program with gcc-8.3.0, I have installed "devtoolset-8" on my developing env, but it can not be used in the way same as gcc-4.8.5 that was shipped with CentOS7 oringinally.
Every time I need to compile a program, I must use "scl enable devtoolset-8 -- bash" to switch to gcc8 instead of gcc4.8.5.
When the program was deploying onto the producing-env, there is no gcc8, nor libstdc++.so.6.0.25, so it can not run.
I guess libstdc++.so.6.0.25 should be released with gcc8? I can neither install "devtoolset-8" on the producing-env, nor build gcc8 from source on the producing env.
The version of libstdc++ that can be installed from the official yum repo of CentOS, is libstdc++.so.6.0.19, hence my programs can not be loaded at the producing-env.
How to let such programs to run?
Thanks!
Pls forgive my Ugly English.
In order to not have to copy or ship a separate libstdc++.so but rather link statically (as suggested in a comment) against the C++ runtime, one can link C++ programs with -static-libstdc++ (also specifying -static-libgcc will also make sure that the program does not depend on a recent enough version of libgcc_s.so on the system - although that should rarely be a problem).
There can also be the issue of the target system having a version of glibc that is too old (relative to the build system). In that case, one could anyhow compile gcc of no matter how recent of a version on the older system, so that the resulting C++ executables as well as libstdc++ are linked against the older glibc. Linking C++ programs with -static-libstdc++ will again help to not depend on the program having to be able to find libstdc++.so at run-time.
Finally, the C++ program could also be linked with -static not depending on any dynamic libraries at all.
This is similar to this question:
On OS X, how do I find out what architecture a shared lib is compiled for?
Except I want to know if a .dylib will run on 10.5.x or 10.4, for instance.
Run otool -L on the .dylib. That will show you the libraries it depends on and their compatibility versions. Then, run otool -L against the libraries from the OS of interest. That will show you (on the first line) the current version of that library. If the current version is at least the compatibility version, then that library can be used by your .dylib. Repeat for all of the libraries.
There's not much of a shortcut. A .dylib doesn't directly contain any explicit indication of what SDK it was linked against. It only indirectly and implicitly does so via the library dependencies.
If the .dylib links against a central system library, such as /usr/lib/libSystem.B.dylib (which is likely), then you can use compatibility with that one library as a proxy for compatibility with the OS version as a whole.
So I just downloaded mingw-w64-bin_i686-mingw_20110410.zip from here (GCC 4.7 apparently), and discovered it had a very recent version of the GCJ compiler.
I tried using it, but apparently gcj requires ecj1.exe, which is the Eclipse compiler for Java... so, where do I find a compatible version of the binaries of ECJ and the associated Java libraries that are needed (libgcj, etc.)?
Ideally this would be found on the MinGW-w64 project page, but it doesn't seem to exist.
(I've already tried copying them from a slightly older GCC version; it doesn't work.)
The cause for an openSUSE version of the gcc is basically this:
If the configure step of the compilation of gcc did not find the ecj.jar
file, ecj1 will be missing at the time when gcj, which has just been build,
is called.
ecj.jar can be taken from ftp://sourceware.org/pub/java/ecj-4.8.jar
for example.
The two options are:
i) Put ecj.jar in $HOME/share/java/ecj.jar, reconfigure gcc with
./configure .... --with-ecj-jar=$HOME/java/ecj.jar
and recompile gcc. Future compilations with that gcc will not require
ecj1 .
ii) Put ecj.jar in $HOME/share/java/ecj.jar and create ecj1(.exe)
through a compilation like
gcj -o$HOME/bin/ecj1(.exe) --main=org.eclipse.jdt.internal.compiler.batch.GCCMain $HOME/share/java/ecj.jar
assuming that the $HOME/bin is in the PATH for subsequent calls of gcj.
The thing that is actually "broken" here the fact that gcc 4.8.* is not shipped
by default with ecj.jar at some standard place.
That is a very old version of a MinGW-w64 toolchain.
I would suggest downloading one of my builds, I've had reports of gcj working (without libgcj, which does not work on Windows), although I can't seem to find a link to the discussion I had long ago with a user. The user's case had something to do with creating a JNI interface or something, which didn't require libgcj.
My old builds can be found here for 32-bit and here for 64-bit. I checked the 4.8 release build, and it contains the gcj compiler.
Would you be opposed to downloading the source and building it? I looked over the build doc in basic and advanced build docs. I didn't see anything about the GCJ compiler or ECJ, but you'll need gcc 4.5.1 in order to build it.
I have a C++ shared library being called from my Python program. The C++ lib is compiled with HDF5 which I installed using homebrew on OS X, so it resides in /usr/local/lib. Now the problem is that I also have PyTables installed, which includes an older version of libhdf5, installed somewhere in /Library/Frameworks/EPD64.framework/Versions/Current/...
I can compile and link my library just fine, and otool -L indeed points to /usr/local/lib/libhdf5.dylib. However, when I try to run it from Python, there is a version mismatch error. Somehow the runtime linker is loading the older hdf5 library instead.
One workaround is to build hdf5 as a static library instead, but I'd like to find a neater solution - how can I persuade the runtime linker to use the newer library? I already tried setting DYLD_LIBRARY_PATH but that just broke everything else (Python and MacVim wouldn't start).
Can you provide more info? I have a few alternatives (and questions).
If I understood correctly, you have a library that uses lib_ver_a.dyld and pyTables that uses lib_ver_b.dyld. I.e. the same library but different version.
You could either:
Compile your library to use the same version as pyTables (DYLD_LIB... while you compile) and run your program with pyTables library: DYLD_LIBRARY_PATH=/correct/path/lib python myprog.py
Upgrade your xcode (which version you have? also which osx version?). This upgrades your libraries and pyTables (be careful, newest is not necessary the most stable)
You should also check which python you are calling (a custom one or apple one).
There is also a possibility to define a specific dyld while linking (Do you use gcc or ld for linking? I might miss some options here):
gcc /path/lib1.dyld myLib.c -o myLib.o
This way your library is linked to certain version of the library (caution! I don't remember the exact details, but I can dig them out).
I hope this helps.
br,
Juha