My OS is centos which has a default gcc in path /usr/bin/gcc
. But it is old, I need a new version of gcc. So I install a new version in a new path /usr/local/bin/gcc
.
But when I run cmake
, it still uses the old version gcc path(/usr/bin/gcc
) . How can I specify the gcc to new path(/usr/local/bin/gcc
).
I have tried to overwrite /usr/bin/gcc
with /usr/local/bin/gcc
, but it not work.
An alternative solution is to configure your project through cmake-gui, starting from a clean build directory. Among the options you have available at the beginning, there's the possibility to choose the exact path to the compilers
This not only works with cmake
, but also with ./configure
and make
:
./configure CC=/usr/local/bin/gcc CXX=/usr/local/bin/g++
Which is resulting in:
checking for gcc... /usr/local/bin/gcc
checking whether the C compiler works... yes
Set CMAKE_C_COMPILER
to your new path.
This question is quite old but still turns up on Google Search. The accepted question wasn't working for me anymore and seems to be aged. The latest information about cmake is written in the cmake FAQ.
There are various ways to change the path of your compiler. One way would be
Set the appropriate
CMAKE_FOO_COMPILER
variable(s) to a valid compiler name or full path on the command-line usingcmake -D
. For example:cmake -G "Your Generator" -D CMAKE_C_COMPILER=gcc-4.2 -D CMAKE_CXX_COMPILER=g++-4.2 path/to/your/source
instead of gcc-4.2
you can write the path/to/your/compiler
like this
cmake -D CMAKE_C_COMPILER=/path/to/gcc/bin/gcc -D CMAKE_CXX_COMPILER=/path/to/gcc/bin/g++ .
Export should be specific about which version of GCC/G++ to use, because if user had multiple compiler version, it would not compile successfully.
export CC=path_of_gcc/gcc-version
export CXX=path_of_g++/g++-version
cmake path_of_project_contain_CMakeList.txt
make
In case project use C++11 this can be handled by using -std=C++-11
flag in CMakeList.txt
CMAKE_<LANG>_COMPILER
path without triggering a reconfigureI wanted to compile with an alternate compiler, but also pass -D options on the command-line which would get wiped out by setting a different compiler. This happens because it triggers a re-configure. The trick is to disable the compiler detection with NONE
, set the paths with FORCE
, then enable_language
.
project( sample_project NONE )
set( COMPILER_BIN /opt/compiler/bin )
set( CMAKE_C_COMPILER ${COMPILER_BIN}/clang CACHE PATH "clang" FORCE )
set( CMAKE_CXX_COMPILER ${COMPILER_BIN}/clang++ CACHE PATH "clang++" FORCE )
enable_language( C CXX )
The more sensible choice is to create a toolchain file.
set( CMAKE_SYSTEM_NAME Darwin )
set( COMPILER_BIN /opt/compiler/bin )
set( CMAKE_C_COMPILER ${COMPILER_BIN}/clang CACHE PATH "clang" )
set( CMAKE_CXX_COMPILER ${COMPILER_BIN}/clang++ CACHE PATH "clang++" )
Then you invoke Cmake with an additional flag
cmake -D CMAKE_TOOLCHAIN_FILE=/path/to/toolchain_file.cmake ...
Source: Stackoverflow.com