There is very little documentation on enabling ccache on GNU/Linux. Here is a response from launchpad.net:
At the moment, I think the best way to enable ccache is to add "/usr/lib/ccache" to the front of your path. If you want to enable it for all users by default, change the PATH variable in /etc/environment.
Can someone give me more information on enabling ccache?
After Downloading, Follow the steps as mentioned below:
A) Tar the file using the following command :
$tar -xvf ccache-3.2.4.tar.bz2
Note : I'm using ccache 3.2.4 Version.You can download the latest one.
B) Go inside ccache-3.2.4 folder and run the following commands:
$./configure
$./make
$ sudo make install
C) Go to your .bashrc and insert the following :
export CCACHE_DIR=/home/user_name/.ccache
export CCACHE_TEMPDIR=/home/user_name/.ccache
Note : Fill user_name with your User Name
D) Save your Bashrc and source it
$ source ~/.bashrc
E) To check ccache is working or not type :
ccache -M 10G : To Set the ccache Size to 10GB
F) To check ccache is working or not type :
ccache -s : To check ccache statistics
The ccache manual has a section called Run modes which describes the official ways of activating ccache, so I suggest reading the manual.
Also, as you already noted, Linux distributions often set up a /usr/lib/ccache directory which is designed to be prepended to PATH.
There are at least two methods:
i) Override the CC, CXX, ... flags in a Makefile. Within the R framework, a system and optional user configuration file is read, and I simply set
VER=4.7
CC=ccache gcc-$(VER)
CXX=ccache g++-$(VER)
SHLIB_CXXLD=g++-$(VER)
FC=ccache gfortran
F77=ccache gfortran
which also allows me to switch back and forth between gcc versions. Now all compilations involving R use ccache.
ii) For other uses, I have deployed the fact that /usr/local/bin/ is checked prior to /usr/bin. So one can do
root@max:/usr/local/bin# ls -l gcc
lrwxrwxrwx 1 root root 15 Jan 27 11:04 gcc -> /usr/bin/ccache
root@max:/usr/local/bin# ./gcc --version
gcc (Ubuntu/Linaro 4.7.2-2ubuntu1) 4.7.2
Copyright (C) 2012 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
root@max:/usr/local/bin#
and now gcc is invoked via ccache:
edd@max:/tmp$ cp -vax ~/src/progs/C/benfordsLaw.c .
`/home/edd/src/progs/C/benfordsLaw.c' -> `./benfordsLaw.c'
edd@max:/tmp$ time /usr/local/bin/gcc -c benfordsLaw.c
real 0m0.292s
user 0m0.052s
sys 0m0.012s
edd@max:/tmp$ time /usr/local/bin/gcc -c benfordsLaw.c
real 0m0.026s
user 0m0.004s
sys 0m0.000s
edd@max:/tmp$
Another possibility (instead of export CC=ccache commented by Keltar), if $HOME/bin/ is listed in your $PATH before /usr/bin/, would be to make a symlink
ln -s /usr/bin/ccache $HOME/bin/gcc
Then every execvp(3) of gcc would find that symlink
$ which ccache
/usr/bin/ccache
# ccache
export USE_CCACHE=1
export CCACHE_SLOPPINESS=file_macro,include_file_mtime,time_macros
export CCACHE_UMASK=002
source "~/.bashrc" or "~/.zshrc" 4. The 5 GB disk space set by default for ccache is normally enough. If you are worried about it, you can increase it, ccache -M 30G 5. Confirm successful installation through version
$ ccache --version
ccache version 3.4.1
Copyright (C) 2002-2007 Andrew Tridgell
Copyright (C) 2009-2018 Joel Rosdahl
cache directory /home/username/.ccache
primary config /home/username/.ccache/ccache.conf
secondary config (readonly) /etc/ccache.conf
stats zero time Fri Jul 22 16:15:40 2022
cache hit (direct) 4186
cache hit (preprocessed) 875
cache miss 1069
cache hit rate 82.56 %
called for link 653
cleanups performed 0
files in cache 3209
cache size 159.3 MB
max cache size 30.0 GB
$ git clone https://github.com/zeromq/libzmq.git
Cloning into 'libzmq'...
remote: Enumerating objects: 43791, done.
remote: Counting objects: 100% (36/36), done.
remote: Compressing objects: 100% (28/28), done.
remote: Total 43791 (delta 11), reused 24 (delta 8), pack-reused 43755
Receiving objects: 100% (43791/43791), 21.91 MiB | 1.03 MiB/s, done.
Resolving deltas: 100% (31951/31951), done.
──────┬───────────────────────────────────────────────────────────────────────────────────────
│ File: CMakeLists.txt
───────┼──────────────────────────────────────────────────────────────────────────────────────
1 │ # CMake build script for ZeroMQ
2 │ project(ZeroMQ)
3 │
4 │ if(${CMAKE_SYSTEM_NAME} STREQUAL Darwin)
5 │ cmake_minimum_required(VERSION 3.0.2)
6 │ else()
7 │ cmake_minimum_required(VERSION 2.8.12)
8 │ endif()
9 │
10 + │ find_program(CCACHE_FOUND ccache)
11 + │ if(CCACHE_FOUND)
12 + │ set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
13 + │ set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ccache)
14 + │ message(STATUS "use ccache")
15 + │ endif(CCACHE_FOUND)
16 + │
17 │ include(CheckIncludeFiles)
$ cmake ..
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- use ccache
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Looking for pthread_create
-- Looking for pthread_create - not found
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - found
-- Found Threads: TRUE
...
/usr/bin/time make -j3
result:
48.79user 14.25system 0:21.60elapsed 291%CPU (0avgtext+0avgdata 176036maxresident)k
0inputs+282248outputs (0major+2406923minor)pagefaults 0swaps
/usr/bin/time make -j3
result:
2.78user 2.42system 0:02.15elapsed 241%CPU (0avgtext+0avgdata 23736maxresident)k
0inputs+21744outputs (0major+232849minor)pagefaults 0swaps
