gcc has been compiled but there is no gcc binary - linux

I have downloaded gcc-4.1.2 from http://gcc.petsads.us/releases/gcc-4.1.2/gcc-4.1.2.tar.bz2 and built with two commands
./configure
make
Now I can see g++ binary. But there is no gcc binary.
$ ls /opt/gcc-4.1.2/host-x86_64-unknown-linux-gnu/gcc/g++
/opt/gcc-4.1.2/host-x86_64-unknown-linux-gnu/gcc/g++
$ ls /opt/gcc-4.1.2/host-x86_64-unknown-linux-gnu/gcc/gcc
ls: cannot access /opt/gcc-4.1.2/host-x86_64-unknown-linux-gnu/gcc/gcc: No such file or directory
What did I miss?

The gcc binary is called xgcc until it is installed.

did you check whether configure and make went without error?
but less probable: did you run also make install which should install all binaries into appropriate directories?

Related

Configure which gcc is called by shell script

I've been struggling with this issue for several weeks now, working it off and on. I've got Ubuntu running on Windows. I also installed OpenFOAM to analyze CFD simulations. My issue is the default the gcc called at the command prompt is the OpenFOAM one.
$ gcc --version
gcc (OpenFOAM) 6.3.0
I needed updated libraries installed for something else I'm working on. I managed to get all the libraries installed, but linux is still looking to the OpenFOAM version of gcc (which doesn't see the libraries) when I run the program at the command prompt. I am calling a shell scrip that in turns calls other programs, so I cannot determine a way to directly call out the full path to the desired gcc version.
I've worked out that the bash gcc command is actually linked to three versions of gcc:
$ type -a gcc
gcc is /opt/OpenFOAM/OpenFOAM-v2012/ThirdParty/platforms/linux64/gcc-6.3.0/bin/gcc
gcc is /usr/bin/gcc
gcc is /bin/gcc
This leads me to believe that the shell scrip is going to the first one and ignoring the next two. How do I get it to go to the second?
i.e. so terminal would return
gcc is /usr/bin/gcc
gcc is /bin/gcc
gcc is /opt/OpenFOAM/OpenFOAM-v2012/ThirdParty/platforms/linux64/gcc-6.3.0/bin/gcc
This should yield the correct version of gcc being called and the installed libraries I need to be referenced at runtime.
$ which gcc
/opt/OpenFOAM/OpenFOAM-v2012/ThirdParty/platforms/linux64/gcc-6.3.0/bin/gcc
I was expecting this to return /usr/bin/gcc instead.
I tried appending the /bin/gcc/ to the front of the path variable:
$ export PATH = /usr/bin/:$PATH
without success. (edited for syntax)
I also researched installing multiple versions of gcc on Ubuntu and worked out there is a command that should permit me to do what I'm trying to, but it doesn't work:
$ sudo update-alternatives --config gcc
update-alternatives: error: no alternatives for gcc
I was expecting to be able to select which version of gcc was called.
Thanks for rici's input:
$ export PATH=/usr/bin:$PATH
prepended '/usr/bin' to the path variable before all the OpenFOAM stuff.
$ type -a $PATH
returned
gcc is /usr/bin/gcc
gcc is /opt/OpenFOAM/OpenFOAM-v2012/ThirdParty/platforms/linux64/gcc-6.3.0/bin/gcc
gcc is /usr/bin/gcc
gcc is /bin/gcc
This should have resolved my issue except for some reason it's still looking for another library in the OpenFOAM directories. As for the original question, the matter is resolved.

What does make install do when compiling GCC from source code?

I am trying to compile GCC from source. After make finishes, I could not find the GCC binary executable. Here is the configure command I used:
../gcc-svn/configure --prefix=/home/user/Documents/mygcc
Here are my questions specifically:
What should I expect make install does?
Is make install going to do more compilation or just moves some files to ~/Documents/mygcc? If it is the latter where the GCC executable resides?
Any other directory in my system also get affected by make install?
Thank you in advance.

Compiler can't find libxml/parser.h

I am on Debian 8 (Jessie), 64 Bit. I installed libxml2-dev, which now sits in /usr/include/libxml2/libxml.
But when I do (just like libxml docs say)
#include <libxml/parser.h>
I only get when compiling (with gcc)
fatal error: libxml/parser.h: no such file or directory
Notes: On another machine, with an old 64 Bit Suse, where libxml2-dev sits in the exact same path and no other environment vars are set compared to the new Debian, it works perfectly fine. Problem occured while migrating from one to another computer using the exact same makefiles. All other -dev libs that I need just worked (with their documented #include <path>) after the migration (they were all installed with apt-get), only libxml2-dev is not found on compilation.
Do I need to do anything else to make libxml2-dev visible?
if you installed it: sudo apt-get install libxml2-dev libxml2-doc go into /usr/include/libxml2 and copy or move all content from that folder on a level below: cp -R libxml/ ../ After this for me it works.
Try to compile with explicite inclusion where the parser.h file is, i.e. smth like this
g++ -I/usr/include/libxml2/
Following environment variables can also be used for lookup of header files
CPATH
C_INCLUDE_PATH
CPLUS_INCLUDE_PATH
OBJC_INCLUDE_PATH
Find more information here
I came across this same problem on a Centos system. I resolved it by doing the following:
yum install libxml2-devel
cd /usr/include
ln -s libxml2/libxml .
That was it. No change to environment variables or compiler switches.
You should use pkg-config to pass parameters to compiler. Like this
g++ `pkg-config --cflags libxml-2.0` example.c -o example.o
and to linker:
g++ `pkg-config --libs libxml-2.0` example.o -o example

Installed OpenMPI library, but cannot use mpicc command in Linux

I am following openmpi install file.
Firstly, I am a normal user in this linux system. I do not have rights to access /usr/local . If I configure with:
./configure --prefix=/usr/local
make will complain about permission.
Therefore, I put the place to install in some other directory (let's call it directory 'A'), and then make install .
I got all the files in the bin and such. I got mpic++, mpicc, etc. in the bin folder and such, in the directory 'A'.
Now, the thing is when I need to compile other programs:
Compiling MPI Applications
==========================
MPI applications should be compiled using the Open MPI "wrapper"
compilers:
C programs: mpicc your-code.c
C++ programs: mpiCC your-code.cc or
mpic++ your-code.cc (for case-insensitive filesystems)
This is from the INSTALL file. The thing is bash complains that mpicc command is not found when I type in "mpicc".
OpenMPI is a dependency for the other programs I am trying to compile, and they invoke OpenMPI by using 'mpicc' command.
What can I do in this case?
Your folder A needs to be on your PATH environment variable. In bash, you would do:
export PATH=/path/to/my/folder/A/bin:$PATH
which will let you just type mpicc. Alternatively, you can use the full path as your command:
/path/to/my/folder/A/bin/mpicc myFile.c
If you don't have write access to the default prefix file tree /usr/local/ you should ./configure with an explicit writable prefix, e.g.
./configure --prefix=$HOME/pub
of course, you could mkdir $HOME/pub then should add $HOME/pub/bin to your PATH

ld cannot find an existing library

I am attempting to link an application with g++ on this Debian lenny system. ld is complaining it cannot find specified libraries. The specific example here is ImageMagick, but I am having similar problems with a few other libraries too.
I am calling the linker with:
g++ -w (..lots of .o files/include directories/etc..) \
-L/usr/lib -lmagic
ld complains:
/usr/bin/ld: cannot find -lmagic
However, libmagic exists:
$ locate libmagic.so
/usr/lib/libmagic.so.1
/usr/lib/libmagic.so.1.0.0
$ ls -all /usr/lib/libmagic.so.1*
lrwxrwxrwx 1 root root 17 2008-12-01 03:52 /usr/lib/libmagic.so.1 -> libmagic.so.1.0.0
-rwxrwxrwx 1 root root 84664 2008-09-09 00:05 /usr/lib/libmagic.so.1.0.0
$ ldd /usr/lib/libmagic.so.1.0.0
linux-gate.so.1 => (0xb7f85000)
libz.so.1 => /usr/lib/libz.so.1 (0xb7f51000)
libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7df6000)
/lib/ld-linux.so.2 (0xb7f86000)
$ sudo ldconfig -v | grep "libmagic"
libmagic.so.1 -> libmagic.so.1.0.0
How do I diagnose this problem further, and what could be wrong? Am I doing something completely stupid?
The problem is the linker is looking for libmagic.so but you only have libmagic.so.1
A quick hack is to symlink libmagic.so.1 to libmagic.so
As just formulated by grepsedawk, the answer lies in the -l option of g++, calling ld. If you look at the man page of this command, you can either do:
g++ -l:libmagic.so.1 [...]
or: g++ -lmagic [...] , if you have a symlink named libmagic.so in your libs path
It is Debian convention to separate shared libraries into their runtime components (libmagic1: /usr/lib/libmagic.so.1 → libmagic.so.1.0.0) and their development components (libmagic-dev: /usr/lib/libmagic.so → …).
Because the library's soname is libmagic.so.1, that's the string that gets embedded into the executable so that's the file that is loaded when the executable is run.
However, because the library is specified as -lmagic to the linker, it looks for libmagic.so, which is why it is needed for development.
See Diego E. Pettenò: Linkers and names for details on how this all works on Linux.
In short, you should apt-get install libmagic-dev. This will not only give you libmagic.so but also other files necessary for compiling like /usr/include/magic.h.
In Ubuntu, you can install libtool which resolves the libraries automatically.
$ sudo apt-get install libtool
This resolved a problem with ltdl for me, which had been installed as libltdl.so.7 and wasn't found as simply -lltdl in the make.
As mentioned above the linker is looking for libmagic.so, but you only have libmagic.so.1.
To solve this problem just perform an update cache.
ldconfig -v
To verify you can run:
$ ldconfig -p | grep libmagic
Unless I'm badly mistaken libmagic or -lmagic is not the same library as ImageMagick. You state that you want ImageMagick.
ImageMagick comes with a utility to supply all appropriate options to the compiler.
Ex:
g++ program.cpp `Magick++-config --cppflags --cxxflags --ldflags --libs` -o "prog"
Installing libgl1-mesa-dev from the Ubuntu repo resolved this problem for me.
I tried all solutions mentioned above but none of them solved my issue but finally I solved it with the following command.
sudo apt-get install libgmp3-dev
This will do the magic.
Another way to solve this problem is to install the -devel package.
If the compiler is looking for libabc.so while you have libabc.so.1, you need to install the -devel package like libabc-devel as libabc.so.1 is a runtime lib but libabc.so is a development lib.

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