What is an XCFILELIST file? An XCFILELIST file is a file list used by Apple Xcode, Apple’s integrated development environment ( IDE ) for macOS, to specify input and output files for build scripts or custom build rules. It is a plain-text file containing a list of file paths that Xcode build scripts reference to define dependencies. This capability helps Xcode track changes efficiently and ensures scripts run only when necessary.

More Information XCFILELIST file open in Apple Xcode 16.2 Apple introduced the XCFILELIST format in Xcode 9 (2017) as part of its efforts to optimize build performance in large projects. Xcode developers building iOS, macOS, watchOS, and tvOS apps are the most likely to encounter XCFILELIST files. In Xcode, build scripts and custom build rules are tools that let developers customize and extend the build process of their app or framework projects. For example, build scripts are shell scripts (usually written in Bash , Zsh, or another scripting language) that run at specific points in the Xcode build process to automate tasks, such as generating code or assets before compilation or validating files or configurations. Developers often add build scripts to a target’s build phases in Xcode using a Run Script phase ( Build Phases → Run Script ). When they add a Run Script build phase to a target, they can specify input file lists and output file lists (saved as XCFILELIST files). Xcode then references the XCFILELIST files to understand the files a script depends on or produces, which helps it avoid unnecessary rebuilds by tracking file changes more precisely. Notable features of XCFILELIST files Each line in an XCFILELIST file represents a path to a file or directory. Paths can be absolute (full path) or relative (relative to the project directory). Developers can add comments using the # symbol.