---
title: Using build configurations
framework: swift-package-manager
role: article
role_heading: Article
path: swift-package-manager/documentation/packagemanagerdocs/usingbuildconfigurations
---

# Using build configurations

Control the build configuration for your app or package.

## Overview

Overview Package manager supports two general build configurations: Debug (default) and Release. Debug By default, running swift build builds the package using its debug configuration. Alternatively, you can use swift build -c debug. Package manager locates the build artifacts in a directory called debug under the .build folder. When building in the debug configuration, a Swift target uses the following Swift compiler flags: -Onone: Compile without any optimization. -g: Generate debug information. -enable-testing: Enable the Swift compiler’s testability feature. A C language target in the debug configuration uses the following flags: -O0: Compile without any optimization. -g: Generate debug information. Release To build in release mode, type swift build -c release. Package manager locates the build artifacts in a directory called release under the .build folder. When building in the release configuration, a Swift target uses the following Swift compiler flags: -O: Compile with optimizations. -whole-module-optimization: Optimize input files (per module) together instead of individually. A C language target in the release configuration uses the following flags: -O2: Compile with optimizations. Additional Flags You can pass additional flags to the C, C++, or Swift compilers in three different ways: Command-line flags passed to these tools: flags like -Xcc (for the C compiler) or -Xswiftc (for the Swift compiler) pass relevant flags for all targets in the manifest. Target-specific flags in the manifest: use options like cSettings or swiftSettings for fine-grained control of compilation flags for particular targets. A destination JSON file: once you have a set of working command-line flags to apply to all targets, collect them in a JSON file and pass them in through extra-cc-flags and extra-swiftc-flags with --destination example.json. One difference is that C flags passed on the -Xcc command-line or using a manifest’s cSettings are supplied to the Swift compiler tool for convenience, but extra-cc-flags aren’t.

## See Also

### Guides

- [Creating a Swift package](swift-package-manager/documentation/packagemanagerdocs/creatingswiftpackage.md)
- [Setting the Swift tools version](swift-package-manager/documentation/packagemanagerdocs/settingswifttoolsversion.md)
- [Adding dependencies to a Swift package](swift-package-manager/documentation/packagemanagerdocs/addingdependencies.md)
- [Resolving and updating dependencies](swift-package-manager/documentation/packagemanagerdocs/resolvingpackageversions.md)
- [Creating C language targets](swift-package-manager/documentation/packagemanagerdocs/creatingclanguagetargets.md)
- [Packaging based on the version of Swift](swift-package-manager/documentation/packagemanagerdocs/swiftversionspecificpackaging.md)
- [Bundling resources with a Swift package](swift-package-manager/documentation/packagemanagerdocs/bundlingresources.md)
- [Releasing and publishing a Swift package](swift-package-manager/documentation/packagemanagerdocs/releasingpublishingapackage.md)
- [Generating Software Bill of Materials (SBOM)](swift-package-manager/documentation/packagemanagerdocs/generatingsboms.md)
- [Continuous Integration Workflows](swift-package-manager/documentation/packagemanagerdocs/continuousintegration.md)
- [Plugins](swift-package-manager/documentation/packagemanagerdocs/plugins.md)
- [Module Aliasing](swift-package-manager/documentation/packagemanagerdocs/modulealiasing.md)
- [Using a package registry](swift-package-manager/documentation/packagemanagerdocs/usingswiftpackageregistry.md)
- [Package Collections](swift-package-manager/documentation/packagemanagerdocs/packagecollections.md)
- [Using shell completion scripts](swift-package-manager/documentation/packagemanagerdocs/usingshellcompletion.md)