Building Gcc From Source

This is a note to self, it contains the build process for gcc for c and c++ frontends. The process is not too different from any project that uses autotools.

Note: This post assumes that we are building gcc on fedora for x86_64 architecture.

Obtain the source code

Clone the repository with

git clone git://gcc.gnu.org/git/gcc.git

dependencies

You will need to install following packages in order to build gcc from source.

• mpfr-devel: Development files for the MPFR library.

  The MPFR library is a C library for multiple-precision floating-point
  computations with correct rounding.
      Source: https://www.mpfr.org/
  

• gmp-devel: Development tools for the GNU MP arbitrary precision library.

  GMP is a free library for arbitrary precision arithmetic, operating on 
  signed integers, rational numbers, and floating-point numbers.
      Source: https://gmplib.org/
  

• libmpc-devel: Headers and shared development libraries for MPC.

  GNU MPC is a C library for the arithmetic of complex numbers with arbitrarily high precision and correct rounding of the result. It extends the principles of the IEEE-754 standard for fixed precision real floating point numbers to complex numbers, providing well-defined semantics for every operation. At the same time, speed of operation at high precision is a major design goal. 
      Source: http://www.multiprecision.org/mpc/
  

• zlib-devel: Header files and libraries for Zlib development.

  A Massively Spiffy Yet Delicately Unobtrusive Compression Library
  (Also Free, Not to Mention Unencumbered by Patents) 
      Source: https://zlib.net/
  

• glibc-devel: Object files for development using standard C libraries.

  The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more. 
      Source: https://www.gnu.org/software/libc/
  

To install these dependencies using dnf

sudo dnf groupinstall "Development tools"
sudo dnf install mpfr-devel gmp-devel libmpc-devel zlib-devel glibc-devel

Or you can use the script contrib/download_prerequisites from the gcc repository itself.

cd gcc
./contrib/download_prerequisites

Build and install gcc

The next process is same as the build process for any other project that uses autotools.

• Create INSTALLDIR env variable for the installation directory path for gcc.
• Create a directory for building the project.
• Run configure scuript for the project from that directory.
• Run make to build.
• Run make install to install.

In this case, - create a directory gcc-build. - run configure script for gcc from that directory with config configure --prefix=$INSTALLDIR --enable-languages=c,c++ --disable-multilib - run make - run make install

export INSTALLDIR=gcc-install
cd ..
mkdir gcc-build
mkdir gcc-install
cd gcc-build
../gcc/configure --prefix=$INSTALLDIR --enable-languages=c,c++ --disable-multilib
make -j$(nproc)
make install

Once this is done, you can add $INSTALLDIR/bin to your $PATH and use gcc that we just built from the source.