Long build times can be a significant challenge, especially when working with large legacy codebases. On iOS, using Xcode to build projects that include C and C++ libraries often results in repeated recompilation of unchanged components, which wastes time and resources.
A solution to this problem is
ccache
, a compiler cache tool that optimizes build processes by caching the results of compilations. This approach reduces redundant work and speeds up subsequent builds. Below, we’ll explore how to set upccache
for iOS builds to improve development efficiency.How you can resolve?
There is a library development by a group of people
ccache
is caching your compilers at cache as a build and faster execute entire process.
Here’s the merged and refined version of your article, incorporating the missing details and improvements from my earlier refactored article:
Stage 1: Installation
To get started, install ccache
using Homebrew, a popular package manager for macOS:
brew install ccache
Once installed, verify its location on your system by running:
which ccache
This command will output the installation path of ccache
on your computer.
To confirm the installation was successful and check the version, use:
ccache --version
Stage 2: Linking Libraries
ccache
works by acting as a layer between your compiler and the build process, caching previously compiled results. To enable ccache
for your build tools, you need to create symbolic links to the compiler binaries.
Since this requires administrative privileges, first switch to the root user:
sudo su -
Enter your macOS password when prompted. You now have the necessary permissions to make system-level changes.
Next, run the following commands to create symbolic links:
ln -s $(which ccache) /usr/local/bin/gcc
ln -s $(which ccache) /usr/local/bin/g++
ln -s $(which ccache) /usr/local/bin/cc
ln -s $(which ccache) /usr/local/bin/c++
ln -s $(which ccache) /usr/local/bin/clang
ln -s $(which ccache) /usr/local/bin/clang++
These links ensure that when tools like gcc
, g++
, or clang
are called during the build, ccache
is used first. This allows ccache
to check if a cached object file can be reused, skipping unnecessary recompilation.
Stage 3: Configuring Xcode
By default, Xcode uses fully-specified paths for its compilers, which bypasses ccache
. To ensure ccache
is utilized during builds, modify your Podfile
with a post_install
hook to set Xcode to use relative paths for compilers:
post_install do |installer|
installer.pods_project.targets.each do |target|
target.build_configurations.each do |config|
config.build_settings["CC"] = "clang"
config.build_settings["CXX"] = "clang++"
config.build_settings["LD"] = "clang"
config.build_settings["LDPLUSPLUS"] = "clang++"
end
end
end
After adding this snippet, run:
pod install
This ensures ccache
is integrated into your Xcode build pipeline.
Stage 4: Testing
Once everything is set up, test your build process to ensure ccache
is working as expected. To check cache statistics, run:
ccache -s
This will display statistics about cache hits and misses. On the first build, you will see “misses” since the cache is empty. Subsequent builds should show “hits,” indicating that ccache
is effectively reusing cached objects.
Additional Tips
1. Preserving Cache in CI: For CI environments, the first build will always be slow as the cache is empty. Use your CI provider’s caching mechanism to save and restore the ~/.ccache
directory between builds for faster subsequent builds.
2. Advanced Configuration: To maximize caching for iOS builds, set the following ccache
options either in your shell environment or in the ~/.ccache/ccache.conf
file:
export CCACHE_SLOPPINESS=clang_index_store,file_stat_matches,include_file_ctime,include_file_mtime,ivfsoverlay,pch_defines,modules,system_headers,time_macros
export CCACHE_FILECLONE=true
export CCACHE_DEPEND=true
export CCACHE_INODECACHE=true
Alternatively, in ~/.ccache/ccache.conf
:
sloppiness = clang_index_store,file_stat_matches,include_file_ctime,include_file_mtime,ivfsoverlay,pch_defines,modules,system_headers,time_macros
file_clone = true
depend_mode = true
inode_cache = true
Verify the configuration by running:
ccache -p
3. Troubleshooting: If you notice no improvement in build times or see 0 hits/misses, double-check:
- The symbolic links are correctly pointing to
ccache
. - Xcode is configured to use relative paths for compilers.
ccache
debugging for further insight:
ccache --debug
Conclusion
By using ccache
, you can significantly reduce build times, especially for large projects or in CI environments. While the initial setup takes some effort, the time saved on subsequent builds makes it worthwhile. If you face any issues, don’t hesitate to leave a comment for support.
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