Is there any way of use asan in gcc 4.7 - gcc

According to the address-sanitizer home page it comes only with the gcc 4.8 or above. Isn't there anyway of using it with gcc 4.7?

No, there is no reliable way (to get ASAN before GCC 4.8). ASAN requires compiler support and is very intimately connected to your particular compiler (and version, and host and target systems, and specific configuration, etc...)
In other words, try to compile a recent GCC (that is, GCC 5.2 in july 2015; use that since ASAN did progress since 4.8 and you'll get more -fsanitize= options in recent versions of GCC) from its downloaded source code. See hints here & there. You should try some recent Linux distribution.
(on Linux or other POSIX systems, you don't need root privileges to configure, compile, and install gcc-mine-5 in $HOME/soft/; you need appropriate ../gcc-5.2/configure options, notably --prefix=$HOME/soft --program-suffix=-mine-5, then add $HOME/soft/bin/ in your PATH then run with CC=gcc-mine-5 e.g. for make)

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Is it possible to use a different gcc version inside a Conda environment?

I have to install a package (spatial-correlation-sampler) which calls for gcc: >=5.3. On my system (Linux, remote server), gcc version is 4.8.5, and a Conda virtual environment uses the same version. Is it possible to use a different version within the virtual environment?
Is it possible to use a different gcc version inside a Conda environment?
Probably yes, except if you (or your Conda environment) needs or uses some GCC plugin. These plugins are specific to a particular version of GCC: a plugin coded for GCC 4.8 (such as my old GCC MELT) won't work with GCC 6. But see also this draft report on Bismon (which might become a successor to GCC MELT).
On Linux/x86-64, a C code compiled with GCC 4.8 would be compatible with the same code compiled with GCC 10, since both follow the same ABI and calling conventions.
For C++ code compiled with GCC, there could be subtle ABI or calling conventions incompatibilities (related to name mangling and exceptions).
Be also aware that Python 2 and Python 3 have different foreign function interfaces. Read chapters related to extending and embedding the Python interpreter.
See also the Program Library HowTo, Advanced Linux Programming and C++ dlopen mini-HowTo and Linux Assembly HowTo and of course Linux From Scratch.
On my system (Linux, remote server), gcc version is 4.8.5
GCC is Free Software.
You are allowed to compile and install a more recent GCC from its source code on your system. An installed GCC 4.8 can be use to build e.g. a GCC 8 from its source code (then installed into /usr/local/bin/gcc, then you just configure wisely your $PATH variable). You could even do that with the unsupported GCC 5.
On recent Debian or Ubuntu you would install dependencies with something like sudo aptitude build-dep g++ and you might also want to use Docker. You may need to download several gigabytes.
Some companies or freelancers are able (for a fee) to compile a GCC tailored for your system. I know AdaCore, but there are many others corporations or freelancers selling support on GCC. Contact me by email for more.
PS. On a powerful AMD Threadripper 2970WX desktop, I just built GCC 10.1 with make -j8 and g++ 9.3 on Debian/Sid in 10:21.38 elapsed time, requiring less than 7 Gbytes of disk space (for both GCC source code and object files). Of course, I disabled the compiler bootstrap. You could do the same thru ssh to your system (it could take an hour or two of elapsed time, because a Linux VPS has less cores so you might need to just make -j2).

Run a program built with gcc8 on a producing environment without gcc8

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.

one binary for several Linux distros, one compiler for all

First Question: What is the best way to support various 'standard' Linux platforms with a single C++11 binary?
This binary uses a handful of third party libraries including boost, zlib, xml2, openssl (all of which
I can build statically).
The binary must run on a variety of Linux platforms for x86_64: Ubuntu 16.04 and 14.04, Centos 7.2 and Debian.
Soon it must run on Darwin x86_64 and Ubuntu 16.04 on a Beagle Bone Black.
The default versions of compilers, libstdc++ and libc runtimes vary quite a bit on these platforms.
I have had some Linux success building on Ubuntu 14.04 with an upgraded (toolchain r-test) g++ 5.3 compiler
using these compiler options (note not using the "-static" switch):
-static-libstdc++ -static-libgcc -D_GLIBCXX_USE_CXX11_ABI=0
However, this requires installing the upgraded 5.3 compiler on the host (default is 4.9 IIRC) and
some runtime libs on the target platforms which is not preferred and risks issues with libc.so.
If it should be determined that this sort of solution is best, then I would prefer to build on
16.04 with the newest g++ or clang with switches so the binary runs on older platforms with
minimal changes to defaults. Yes, I know I am perhaps asking for the moon :)
Second question: instead of one binary, maybe one compiler and libc for all platforms including Darwin and Windows?
I was also considering an attempt to use musl to create a 'more consistently behaved binary. I could consider using clang instead of g++.
Anyone with experience/recommendations? I would very much like to avoid maintaining
separate compilations and combinations of third-party libs and compilers and settings and upgrades for each platform (especially for Linux targets but pretty typical for different operating systems).
Using the same version of the same compiler and possibly the same version of a libc would be best
but may not be possible: clang with musl?
Thanks

custom built gcc 4.6.0 on ubuntu 11.04 links wrong libstdc++

my custom built gcc 4.6.0, installed in my home directory, on ubuntu 10.04, links the system libstdc++ instead of the custom built one, most of the time (as evidenced by ldd). to be more puzzling, using this newly built gcc, custom compiled openmpi libraries are linked correctly, and this is the only software i have compiled that behaves ok. does anybody have any explanation for this, or a workaround?
thanks
Isn't there an option to statically link the libstdc into the gcc when you configure it? --disable-shared if I understand how it works correctly. Worst case make another compile of gcc with that switch and see if you run into the issue.
I don't know why this isn't detailed more clearly on the GCC website for end-users. The GCC FAQ clearly states this is a common problem wrt libstdc++. Environment variables are troublesome. Wrapping the linker, nobody knows how to do that. Editing /etc/ld.so.conf isn't an option. Adding -Wl,-rpath everywhere, come on. The easiest solution is the specs file. For a typical 64-bit x86 Linux system, go into your custom gcc installation, in dirname `g++ -print-libgcc-file-name`and then run g++ -dumpspecs > specs. Edit that file, find the *link_command: section. After %(link_libgcc) add -rpath /home/user/bin/gcc-9/lib64 (of course use your own path). Or add the same rpath to end of *link: section. Alternatively, configure gcc with --with-specs='%{!static:%x{-rpath=/home/user/bin/gcc9/lib64} %x{-enable-new-dtags}}' . Enjoy your own C++ compiler that generates binaries that just work.
See also:
GCC specs file: how to get the installation path
Linking g++ 4.8 to libstdc++
How to configure libstdc++ with GCC 4.8?

Does gcc work when the wrapper is a different version than the platform-specific binary?

The way I understand gcc, /usr/bin/gcc (and other bits related to gcc, like ld) is a small wrapper that delegates to a platform-specific binary somewhere else on the system.
So does compilation still work correctly if you have a cross compiler that is a couple of versions behind /usr/bin/gcc?
Yes, the whole Idea is to allow gcc to be installed in different versions and for different target platforms (in any combination) to be installed in parallel.
/usr/bin/gcc just uses fork+exec to call the actual compiler. The command line arguments given to gcc are just passed to the actual compiler with two exceptions: -V and -b. The latter selects the target platform the former the version of the compiler.
You won't use /usr/bin/gcc to cross-compile. Instead you'll install another compiler in another prefix. For instance if you're on debian/ubuntu you can install a ming (win32) cross-compiler by doing:
apt-get install mingw32
Which will work perfectly fine side by side with the normal gcc.

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